CA1171016A - Printer - Google Patents
PrinterInfo
- Publication number
- CA1171016A CA1171016A CA000422476A CA422476A CA1171016A CA 1171016 A CA1171016 A CA 1171016A CA 000422476 A CA000422476 A CA 000422476A CA 422476 A CA422476 A CA 422476A CA 1171016 A CA1171016 A CA 1171016A
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- Canada
- Prior art keywords
- carriage
- shaft
- gear
- arm
- motor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Abstract
ABSTRACT OF THE DISCLOSURE
A printer having clutches for selectively transmitting the driving power from a motor to a rotary shaft for rotating type wheels and to a hammer drive shaft for driving a hammer, the clutches being under the control of a same controlling member so that the typing operation is accomplished by the power furnished by a motor having a shaft which rotates conti-nuously only in one direction.
A printer having clutches for selectively transmitting the driving power from a motor to a rotary shaft for rotating type wheels and to a hammer drive shaft for driving a hammer, the clutches being under the control of a same controlling member so that the typing operation is accomplished by the power furnished by a motor having a shaft which rotates conti-nuously only in one direction.
Description
g ~ 6 The present invention relates to a typing mechanism for a serial printer suitable for use in the display of desk-top calculators, measuring instruments and so for-th.
This is a division of copending Canadian Application Serial No~ 355,666, filed July 8, 1980.
Many desk--top calculators, measuring instruments and so forth proposed heretofore employ displays using liquid crystals or the like for producing a digital display. Recently, however, there have been proposed desk~top calculators and measuring instruments having a small serial printer for printing and recording on recording paper the result of calculations or measurements. The serlal printers of the type described preferably have as small a size as possible because of limited space. It is often quite difficult to realize the small size desired because the serial printer has various complicated mechanisms, such as the mechanism Eor rotatably driving the type wheel, the mechanism for shifting the carriage, and the mechanism for driving the typing hammer~ paper feed mechanism and so on.
Current desk-top calculators have various operation functions, and it is required that the calculators be able, in addition to printing the numerals 0 to 9, to print various data on the operation function, and the number oE these operation functions may well correspond to that of the numeral data. If the numerals and function symbols are carried by a single type wheel, the size of the type wheel must be increased - to an impractical size so that the size of the printer would be increased inconveniently to make the printer unsuitable for use in portable type desk-top calculators or the like.
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In order to obviate this problem, a new serial printer has been proposed in which the type wheel for the function syr~ol and the type wheel for numerals are constructed separately from each other and only the type wheel having the numerals is shi.fted to provide the different columns of characters. As can be seen from Japanese Patent Laid-open Publication No. 46930/1977, this type of serial printer has two hammers whic`h are associ.ated with two type wheels and . operate independently of each other. This arrangement requires a complicated mechanism for selectively actuating the two hammers by a single actuating mechanism.
Also a serial printer has been proposed in which the mechanism for selectively actuating the two hammers is eliminated and two type wheels are associated with a single cornmon hammer so as to be selectively operated by the latter.
Such a serial printer is shown in Japanese Patent Laid-open Publication No. 56514/1978.
The serial printers shown in Japanese Patent Laid-open Nos. 46930/1977 and 56514/1978 are suitable for use in desk-top calculators or the like, because they have sufficiently reduced size and weight~ However, the cost of parts of the driving power source and the space occupied by the latter tend to become large, because a pulse motor is used for rotatively driving the type wheels, a solenoid plunger of a comparatively large size is used for column shift of the type wheel and driving of the hammer, and another solenoid plunger of a comparatively large size is used for feeding the paper and releasing the carriage.
On the other hand, Japanese Patent Laid open No.
This is a division of copending Canadian Application Serial No~ 355,666, filed July 8, 1980.
Many desk--top calculators, measuring instruments and so forth proposed heretofore employ displays using liquid crystals or the like for producing a digital display. Recently, however, there have been proposed desk~top calculators and measuring instruments having a small serial printer for printing and recording on recording paper the result of calculations or measurements. The serlal printers of the type described preferably have as small a size as possible because of limited space. It is often quite difficult to realize the small size desired because the serial printer has various complicated mechanisms, such as the mechanism Eor rotatably driving the type wheel, the mechanism for shifting the carriage, and the mechanism for driving the typing hammer~ paper feed mechanism and so on.
Current desk-top calculators have various operation functions, and it is required that the calculators be able, in addition to printing the numerals 0 to 9, to print various data on the operation function, and the number oE these operation functions may well correspond to that of the numeral data. If the numerals and function symbols are carried by a single type wheel, the size of the type wheel must be increased - to an impractical size so that the size of the printer would be increased inconveniently to make the printer unsuitable for use in portable type desk-top calculators or the like.
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In order to obviate this problem, a new serial printer has been proposed in which the type wheel for the function syr~ol and the type wheel for numerals are constructed separately from each other and only the type wheel having the numerals is shi.fted to provide the different columns of characters. As can be seen from Japanese Patent Laid-open Publication No. 46930/1977, this type of serial printer has two hammers whic`h are associ.ated with two type wheels and . operate independently of each other. This arrangement requires a complicated mechanism for selectively actuating the two hammers by a single actuating mechanism.
Also a serial printer has been proposed in which the mechanism for selectively actuating the two hammers is eliminated and two type wheels are associated with a single cornmon hammer so as to be selectively operated by the latter.
Such a serial printer is shown in Japanese Patent Laid-open Publication No. 56514/1978.
The serial printers shown in Japanese Patent Laid-open Nos. 46930/1977 and 56514/1978 are suitable for use in desk-top calculators or the like, because they have sufficiently reduced size and weight~ However, the cost of parts of the driving power source and the space occupied by the latter tend to become large, because a pulse motor is used for rotatively driving the type wheels, a solenoid plunger of a comparatively large size is used for column shift of the type wheel and driving of the hammer, and another solenoid plunger of a comparatively large size is used for feeding the paper and releasing the carriage.
On the other hand, Japanese Patent Laid open No.
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68325/1~79 proposes a serial printer in which a single motor performs various actions such as selection of type, prin-ting, column shift, paper feed and so forth. In this printer, however, there is a practical limit in increasing the typing speed, because the motor has to be reversible. For the same reason, the motor is comparatively expensive and requires a complicated control. In addition, a complicated mechanism is required for selecting and retaining the two type wheels independently.
According to the present invention there is provided a printer having a motor, a rotary shaft adapted to be rotated unitarily with type wheels and adapted to be driven rotatably by the motor with a first clutch means for selectively transmitting the rotation of the mo~or to the rotary shaft.
A hammer member is adapted to be moved into and out of contact ! with the type wheels, and a hammer drive shaft is adapted to be driven by the motor and carries a cam member for actuating the hammer member. A second clutch means is adapted for selectively transmitting the rotation of the motor to the hammer drive shaft. Control means is provided for controlling the first and second clutch means simultaneously to engage one of the clutch means while disengaging the other. A
carriage carries the type wheels and is slidable in a direction parallel to the rotary shaft. A spring member is connected to one end of the carriage and is adapted to urge the carriage toward the initial position, a thread member being connected to the other end of the carriage with means adapted to gather the thread means to overcome the force of the spring member, the gathering means being ac-tua-ted by rotation of -the harnmer 'pc/,,~
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drive shaft when the ]atter is driven through the second clutch means.
According to another aspect of the presen-t invention there is provided a printer having a motor adapted to rotate a motor shaft in one direction only with a carriage being movable slidably along a line to be printed and a spring member connected to the carriage for con-tinuously biasing the carriage toward the initial position on the line. A thread member is - connected to the carriage and adapted to pull the carriage toward the last position on the line, and a rotary drum is provided for winding-up the thread member by overcoming the biasing force of the spring member. A feed mechanism includes clutch means for selectively transmitting the rotation of the motor shaft to the rotary drum to rotate the ro-tary drum and draw the carriage towards the last position. An arm engages the gear of the rotary drum and is adapted to prevent the rotary drum from being rotated by the force of the spring.
A releasing means is adapted to keep the arm in the state separate from the gear of the rotary drum when the carriage is returned to the initial position. Means is provided for maintaining the arm separated ~rom the gear over a predetermined period of time when the carriage has been returned to the initial position by means of the releasing means.
It is an ob~ec-t of the present invention to provide a serial printer of reduced size and weight to overcome the above-described problems.
It is another object of the present invention to provide a serial printer suitable for use in a desk-top calculator of small size and weight, by reducing as much as ' pc/~
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possible the number of driving or actuating sources and, hence, the space occupied by such driving or actuating sources.
It is a further object of the invention to provide a serial printer of a size which is reduced as much as possible through decreasing the number of rotary shafts.
It is a still further object of the invention to simplify the construction of the serial printer and to reduce the size of the same by attaching various parts to a rotary shaft to make efficient use of the shaft.
BRIEF DESCRIPTION OE' TH.E DR~WINGS
Fig. 1 is a plan view of a printer according to the pc/~
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¦ present invention;
~ig. 2 is an exploded perspective ~iew of a rotary shaft ¦ ~echanism ~first clutch) in the printer of Fig. l; .
Fig. 3 is an e~ploded perspective view of a hamme~ driv . ¦ ing mechanism ~secona clutch) in the printer of Pig. l;
Fig~ 4 is an exploded perspec~ive.- view of a paper feed . mechanism (third clutch) in the printex of Fig. l; .
. Fig. 5 is an exploded perspective view showing the rota ry shaft mechanism, hammer driving mechanims and a controllin~
meohanism for driving both mechanisms; . . . ..
~ig. 6 is a right-side elevational view of he pxinter ~s seen from the right side thereof with a part of the printer being shown schematically, .
Fig. 7 is an exploaed perspective view of the printer of Pi~ 1 as seen from the left side thereof;
. Fig. 8 is a left-side elevational view of the printer of Fig. 1 with a part thereof sho~m schematically;
Fiy. 9a and 9b are sectional plan views of the printer : of ~ig. 1 for explaining the operation ~f the printer;
Figs. 10 and 11 are exploded p~rspective views for e~-plaining the operation of the clutch of the paper feed mechanism;
and Fig. 12 ~s an exploded perspective ~iew of a windi~g-up . mechanism of the printar in accordance with ~he invention -DESCRIPTION OF THE PE~EFERRED El~lBODI~IENTS
. A prePexred embodiment of the present invention will be described hereinunder with re~erence to the accompanying drawing .
Fi~. 1 is a plan vie~ of a serial printer embodying the pxesent invention. A reference numeral 1 denotes a frame plate ~f iron or the like to which are attached upright side plates la and lb. The side plates la and lb face one another Prom opposit , 11 , . s 1.
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sides of the frame plate 1 and are supported at their upper ends by a transverse supporting plate lc. ~ rail 2 extends between the side plates la and lb. A reference numeral 3 denotes a ~ar-riage which can be moved along the rail 2 to the right and left, i.e. in the direction of a line to be printea Reference numeral ;
4 and 5 denote, respectivelyp a type wheel for printing function symhols and a type wheel for printing numerals, and these type wheels are carried by the carriage 3. The type wheels 4 and 5 are penetrated by a rotary shaft 6 so as to be driven rotatably by the latter. ~hese type wheels are not allowed to rotate rela-tive to the rotary sha~t 6 ~t can move indepenaently o~ each other in the axial direction therealong within ~espective prede-termined distances.
Although not ~ully shown in the drawings, a tension spring 7 is ~ixed at its one end to the side plate la while the other end extends through the side plate lb and is fixed to ~he ~uter right side wall of the carriage 3 to urge the carri~ge 3 to its initial p~5ition, i.e~ to the position shown in Fig. 1. A
reference numeral 8 denotes a wire or threaa for effecting a col-umn shift of the car~iage 3 by pulling it in the direction of the arrowO Numerals 9 and 10 denote guide members for guiding the tension spring 7 and the col~mn shift wire 8 which are at-tached to the side plates la and lb, respectively. A reerence n~meral 11 denotes a typing hammer provided at its right end with a notch lla ~or preventing typing, as will be set forth more ful-ly below. The typing hammer 11 is adapted to be actuated by a non-circular hammer c~m 12 which is attached to a drive sha~t 13.
A re~erence numeral 14 denotes a recording paper interp3sed ba-tween the typing hammer 11 and the type wheels 4 and 5 Numer-als 3b ~nd 15 desi~nate, respectively, an ink roller and a stop-per disk . . .
Before turning to the detailed aescription of the driv~
iny mechanism, a description will be made as to the printiny ope-. . .
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¦ ration.
¦ As the rotary shaft 6 is rotated to bring the desir~d I function symbol to the typing position~ the drive shaft 13 is ro-: ¦ tated to make the ha~ner cam 12 press the typing ha~ner 11, so that the latter presses the recording paper onto the type wheel ¦ 4 thereby to print the function symbol. In this state, no typing ¦ of the numeral is effected because the type wheel 5 is positioned within the notched part lla of the hammer 11 and thus is not ~ contactea by the hamçner.
¦ ~fter the completion of the typing o the first column ox place on a line to be printed, the coIumn shift wire 8 is pull-ed in the direction of the arrow to shift the carriage 3 to the left by one coluçnn. Meanwhile, the type wheel 5 carried by the carriage arm 3a is shifted to the second column. On the other hand, the type ~Jheel 4 does not follow the mo~ement of the car-riage 3 although it is shifted to the left by the action of spri 14', and is stopped at a position opposite the notched part lla of the typing ham.-ner 11. The type wheel 4 remains at this posi-~ion until the carria~e is returned after completion of the t~pin of one line. Although ~ot shown, the type wheel 4 abuts a step formed on the sha~t 6 so as to be retained by the step in a posi-tion opposite the notched part lla.
The typing operat~on mentiQned above for the firs~ col-u~n is repeated to e~fect the typi~g of the secona column after the c~rraige 3 is shifted to the second column and the desired numeral is brought to the typing position.
After the typing of all the characters for one line is oompleted, the shift wire a is freed. In consequence, the car-ri~ge 3 is returned to the initial position shown in Fig. 1 hy the action of the tens~on spring 7, and the paper feed is advance .
Th~ typing mechanism will be described in detail here-inund r.
The ~yping mechanism of the serial printer of the in-vention has three shaft rne~han;sms: 11) rotary sh~ft mechanism '.. i . ' ., , t ,.
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-' ~ ~ 7 :~ ~3 ~ ~i for rotatably driving the type wheels 4 and 5, ~2) shaft mecha-nism for rotatably dri-ring a hammer cam 12 for driving a typing hammer and ~3~ a paper feed shaft mechanism for feeding recording pap~r. These mechanisms are coupled in an inter-related manner through a gear mechanism and clutches to effect the various se-:
quence of operations.
The driving mechanism for xotatably driving the type wheels 4 and 5 is illustrated in Fig. 2, wherein reference numeral 16 denotes a stationary bearing received within a semicircular bore lb-l formed in the side plate lb so as not to be able to ro-tate with respect to the latter. The bearing 16 has a central 'oore 16a for receiving the rokary shaft 6. An anti-r~versing ring 17 is rigialy fitted to the rotary shaft 6 so as to rota-te unitari ly with the latter. An anti-reversing coiled spring 18 is coiled such that it is unwound as the rotary shaft 6 is rotated in the proper direction. The stationary ~earing 16 and the anti-reversin ~ing 17 a~e proYided with drum portions 16b and 17a of an e~ual diameter a~d kept in close contact with each other at their side surfaces, The coiled spring 18 i5 wound around these drums. The inside diameter o~ the coiled spring 18 is slightly smaller than the outside diameter of each dl~lm~ The coiled spring 18 is u~woun a~ the rotary shaft 6 rotates in the proper airection, so th~t the drums 16b and 17a are disengaged from the spring and thus ~ach othe .
Elowever, if th~ rotary shaft 6 is rota-ted in the wrong direction even by a small angle, the coiled spring 18 tightens against the dxums 16b and 17a to connect them to each other thereby to prevent the reversing of the rotary shaft 6. ' .
The drawings also show a clutch assembly 21A with a l ortion thereof being omitted. A gear 19 loosely fitted to the ro-tary shaft 6 has a drum 19a. A holding sleeve 20 has at its one side a bore 20a penetrated by the drum 19a, and pro~ided at its ¦ eripheral 5urface with a groove 20b. A cylinder 21 is provided a~
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710 t 6 its one side with a drum 21a and at its peripheral surface with a ¦ ~roove 21b. Although not fully illustrated; a coiled spring 22 ¦ has its respective ends 22a and 22b bent as shown. A ratchet gear ¦ 23 is proYided at its one side with a bo-~s 23a and has an internal ¦ cavity for recei~ing parts of the aforementionea clutch assembly ¦ 21A. .
¦ Por assembling the clutch assembly 21A, at first one end 22b of the coiled spring 22 is inserted into the groove 21b of the cylinder 21 and almost half of the coiled spring Z2 is fit-ted around the drum 21a of the cylinder 21. (Thè inside diameter of the coiled spring 22 is slightly smaller than the common out-side diameter of the drums 19A and 21a)~ Then, the drum l9a o~
the gear 19 is loosely inserted through the bore 20a o~ the holdin sleeve 20 to pro~ect from the latter and the remainder part of the . . coiled spring 22 i5 press-fitted onto the drum l9a~ At the same time, the other end 22a of the c~iled spring is insertea into the groove 20b of the holding sleave 20. In consequence, the members I9 and 20 are coupled to each other through the coiled spring 22 so as to be rotated unitarily in a predetermined direction, i.e.
20 in the direction for tightening the coiled spring. During assembly the holding slee~e 20 is xotated sligh~ly with respect to a xatche gear 23 which will be explained later, so as to-absorb the fluctu-ation o the angular distance between both ends 22a and 22b of the coiled spring 22 which inevitably takes place during manufacturing of the sprin~.
Then, the cylinder 21 is press-fitted into the rotary sha~t 6 and then the ~atchet gear 23 is fittea arou~a the cylinder 21, such that a sector projection 21d on the outer circumfereAtial surface of dxum 21_ of the cylinder 21 aligns with a sector bore 23c communicating with the central bore 23b of the end of the rat-chet gear 23. The holding sleeve 20 is adjusted and rotated while engaging the sector projection 21d and sector bore 23c to eEfect the alignment of the attachin~ positionO A certain margin is pr~-~' ,: . .
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served for mutual eng?gement between the sector projection 21d and the sector bore 23c so as to smooth the movement o the coile spring in the tightening and loosening directions during the .
operation of the clutch which will be described later.
TAe aforementioned coiled springs 18 and 22 are set in the opposite winding directions with respect to one another. In this way, the rotation of the ~ear 19 caused by a later-mentioned motor is transmitted to the rotary s~laft ~ via the cylinder 21 through the connection of the coiled spring 22 wound tightly on the drives l9a and 21a. On the other hand~ as the rotation of the ratchet gear 23 is checked by a checking me~ber to be aescrib~ d below, the cylinder 21 is also stopped so that the coiled spring 22 is slacked without delay to interrupt the connection between the.gear 19 and the cylinder 21, i.e. the ro~ary shaft 6. If he rotary shaft 6 tends to rotate in the direction reve~se to the direction caused by the motor, the aforementioned coiled spxing 18 is tightened without delay to rigidly connect the sta-tionary bearing 16 and the anti-reversing ring 17, thereby to .-pre~ent reverse`rotation Df the rotor shaft 6~
The shaft mechanism for rotata~ly driving the hammer ~am 12 for the typinghammer is shown in Fig. 3, and includas a stationary bearin~ 24 received within a semicirc~lar ~ore lb-2 formed in the side plate lb so as not to, be able ~o rotate xela-tive to the latter, and has a central bore 24 a ~eceiving the drive shaft 13. An anti-reversing ring 25 .is rigidly fitted to the drive shaft 13 so asto be rotated unitarily with the latter. .
A~ anti-re~ersing coilded spring 26 is wouna in such a direction to be unwound as it is twisted rn the proper direction of r~-tation of the dirve shaft 13. The stationary bearing 24 ana the anti-reversing ring 25 are provided with respective drums 24~ and 25a of an equ~l diameter which are kept in close ~ontact with eac~
. other at their facing sides. The aforementioned coiled spring 26 is wound round . these drums. The coiled spring 26 has an in-side diameter slightly smaller than .
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the outside diameter of these drums. As the d~ e shaft 13 i5 rotated in the direction of -the arrow, the coiled spring 26 is driven in the unwinding direction so that the drums 24b and 25a are disconnected from each other. ~owe~er, if the drive shaft I3 is reversed even by a small angle of rotation, the coiled spring 26 tightens against the drums 2~b and 25a to connect these drums thereby to prevent the rotation of the drive shaft 13 in th0 re-verse direction. Although not fully illustra~ed, a gear 27 loose ~ ly carried by the dri~e shaft 13 is provided at its one side with a ratchet gear 27a formed unitarily therewith or fixed the~eto.
A clutch 35 is formed by a clutc~ disk 28 fixed to the drive shaft 13 so as to rotate unitarily with the latter. ~he clutch disk 28 is provided in its periphery with two diame~ricall opposing notches 28a and-28d and, at its one side~ with a hole 28 far ~ixiny the end 29a of a p~n 29. The clutch disc 28 is urthe prov~ded at its one side ~ith 2 ~r'~. 28c for receiving a coiled spring 30, both ends 30a and 30b of which ar~ bent out~ardly as shown. A checking plate 31 is provided in its periphery with two diamet~ically opposing notches 31a and 31b an~ has a central bore 31c for receiving the drive shaft 13. The checking plate 31 is further provided with a circumferentially elon~ated hole 31d and a radially elongated bole 31e. A reference numeral 32 den~tes a ratchet pawl at both ends of which are foxmea respective bores 32a and 32b. Also, a pawl 32c i5 foxmed at the center. Reference numeral ~4 d~notês a ~plit washer~
Por assem~ling tile clutch 35~ the end 29a of the pin 29 is inserted into the bore 28b of the clutch disk 28 so as to be fixea b~ the latter, while the reduced-diameter portion 33a of a pi~ 33 i5 inserted into the elongated bore 31e of the checking plate 31. Thereafter, the reduced diameter portion 33a of the p~n 33 is fitted and fixed to the hole 32b of the ratchet pawl 32.
~hen, the ~oiled spring 30 is fitted round the body por-tion 28c of the clutch disk 28 and the end 30a o th~: 6pring is retained . ' .
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by the pin 29. Subsequently, the circular bore 31c of the check-ing plate 31 is fitted to the body portion 28c. In this state, the pin 29 is introduced into the hole 32a of the ratchet pawl 32 through the elon~ate~ bore 31d in the checking plate 31, and the end 30b of the coiled spring 30 is retained by the reduced I diameter por-tion 33a of the pin 33. Finally, the washer 34 iæ
¦ fitted to the end of the pin 29.
A drive shaft 13 is inserted into the center of the l clutch 35 thus assembled, and the clutch disk 28 and the drive ¦ shaft 13 are coupled to each other. ~t the same time, the ratche gear 27a and the pawl 32c are made to e~gage with each other.
As tha gear 27 is rotated from this state in the airec-tion of the arrow, the ratchet gear 27a engages and pulls the pawl 32 so that the clutch disk 28 is also rotated to drive the rive shaf~ 13. In the course of rotation, the notch 28a and the notch 31a may be cngaged by claws not shown, and the rotation of the ~lutch disk 28 and the checking plate 31 is stopped so that the ratchet gear 27a of the 27 comes to push the ratchet pawl ~Z
since tne gear 27 is rotated continously by the motor. In conse- .
¦ quence, the r~tchet pawl 32 is movea o-ltwardl~ as the respective ¦ pins slide within the elongated bores 31d a~d 31e so tha~ the ratchet gear 27 is disengaged from the rat~het pawl 32. The con~
ne~tion between the gaar 2? (i.e. the motor~ ana the ~lytch disk 28 Si.e. the drive shaft 13) is thereby broken. Movem~nt of the rive shaft i3in the reverse direction is prevented by the anti-reversing mechanism contituted b~ the aforementioned coiled spring 26. ~ - :
¦ The mechanism for ~eeding the recording paper is shown ¦ in Fig. 4, wherein a stationary bearing 36 is fitted to a semi-¦ circular bore lb-3 formed in the siae plate lb so as not to be ¦ a~le to rotate with respect to the latter, and has a central bore 36a for receiving a paper feed shat 37. A reference numeral 38 ¦ denotes an anti-reversin~ ring which is fitted to the paper feed ~ ;
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shaft 37 so as to be rotated unitaxily with the latter. An anti-reversing coiled spring 39 is wound in such a direction as to be unwound as it is twis-ted in the'direction of rotation oE the shaft 37. The stationary beariny 36 and the anti-reversing ring 38 are pro~ided with respective drums 36b and 38a which are closely;con-tactea by each other at their facing ends. The a orementioned coiled spring 39 is wound on *hese drums~ The inside diameter of the spriny 39 is slightly srnaller than the outside diameters o~
these drums. The arrangement is such'that the coiled spring 39 is driven in slackin~ or unwinding direction when the paper feed s~aft 37 rotates in the proper direction, so that the co~nection between the drums 36b and 38a is broken. Hbwever, if the paper feed shaft 37 is r~tatea in the reverse or wrong direction even by a small angle, the coile~ 5-~ 39 tightens against the drums 36b and 38a so that'these drums are operatively connec~ed to each other to preventreverse rotation of the paper feed shaft 37.
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Although not fully illustrated, a clutch 48 is formed by a gear 40 loosely mounted on the paper ~eed shaft 37~ The gear 40 is provided with a ratchet gear 4-0a fixed to one side :
thereof~ ~ clutch disk 41 has a hole 41a for fixedly receiving a reduced diameter portion 42a of the pin 42,'and a hub portion ~lb at one side thereof for receiving a coiled spring 43 there-around. The ends 43a and 43b of the coiled spring 43 are bent outwardl~ as shown. A checking plate 44 ig provided with 5 (five~
teeth 44a formed on the ollter periphery thereof, and has a central circ~lar bore 44b ~xough which the paper ~eed shaft 37 passes.
The checking plate 44 is further provided with a circumferentially elongated bore 44c and a radially elongated bore 44d. A reference numeral 45 denote5 a ratchet pawl at both ends of which are formed respective hole~ 4Sa and 45b. Also, a pawl 45c is formed at the ' ' ,~ -' ' ' ,, .
central portion of the xatchet pawl 45. Refexence numerals 46 ~nd 47 denote, respectively, a pin and a washer.
For assembliny the clutch 48, the end 42a of the pin 42 i5 fitted and fixed in the hole 41a o~ the clutch disk 41 and the reduced diameter portion 4fia of the pin 46 is fitted and fixed in the hole 45b o~ the ratchet pawl 45, through the elongat ed bore 44d of the checking plate 44. Then, the coiled spring 43 is wound ~ound the hub portion 41b of the clutch disk 41, ana one end 43a thereoE i5 retained ~y the pin 42. Subsequen-tly, the hub portion 41b is fitted in the circular bore 44b of the checking plate 44. In this state, the pin 42 is inserted into the hole 45a o~ the ratchet pawl 45 through the elongated bore 44c of the . checking plate 44, and the end 43b of the coiled spring 43 is retained by the reduced diame-ter portion of the pin 46. Finally, the washer 47 is fitted to the end of the pin 42.
The paper feed shaft 37 is inserted into the center of the clutch 48 thus assembled, and the clutch disk 41 is rigidly fitted to the paper feed shzft 37. i~t the same time, the ratchet gear 40a and the pawl 45c are made t~ engage with each other. Th claw 50a providea at one end of an arm 50 fixed to a paper-feed instruction sha~t 49 supported by th~ side plate lb may be brought into engagement with the teeth 44_ of the checking plate 40 to check therotation o~ the latter, as will be set forth more fully below. A reference ~umeral Sl denotes a pinion ~ttached to the motor shaft o~ a drivincJ motor which is not shown, whereas a reference numeral 52 denotes an intermediate gear ~not shown full carried hy a shaft 53 which in turn is at~ached to the side plate lb. ~he qear portion 52a o the gear 52 meshes with the pinion 5 while the gear portion 52b meshes with the gear 40.
As the gear 40 is rotated in this state, the ratchet gear 40a engages and pulls the ratchet pawl 45, and the clutch disk 41 is chec~ed by the mu-tual engagement between the claw SOa and the checking plate 44, althou~h it tends to rotate.
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As a further orce is applied to cause the rotation, the ratchet paw7 45 slides outwardly as the pins 42 and 46 move within the bores 44c ana 44d of the checking plate 44, so that the pawl 45c is moved out of engagement with the ratchet gear ~Oa. In this . 5tate, the gear 40 idles without being accompanied by the rotation of the shaft 37. As the arm 50 is rotated'in response to a paper feed instruction to temporarily disengage the claw 50a from the teeth 44a of the checking plate 44, the ratchet pawl 45 is moved to again bring the pawl 45c into engageme~t of the ratchet gear 40a and the paper feed shaft 37'is ro-tated by the gear 40 and, after the completion of the feed of paper ~when the checking ~
plate 4-3 ha~ made a 1/5 rotation), the claw 50a is brought again into engagement with the teeth 44a by the forc~ of a spring, so that the rotation of the gear 40 is interruptea hy the clutch 48 to stop the paper feed shaft ~7.
Three maj~r rotary sha-.s of the serial'printer of the inv~ntion have been described. In the assembled state of these three shafts, the gea~ 40 carriea by the paper feed shaft 37 en-gages the gear 27 carried by the drive shaft 13, and the gear 27 in turn is engaged by the'gear 19 carried by the rotary shaft 6, so that the rotation o~ ~he gear 51 is finally transmitted to ~he gear 19 ~o make these gears rotate simultaneously.
A ~hange-over mechanism for changing o~er the clutches on the rotary shaft 6 and the drive shaft l3 is provided on the side plate lb. In Fig. 5, a reference numeral 53 denotes a change-over pla'te o~ this mechanism. Also, reference numerals 54 and 55 designate a driving magnet and a tension spring incorporated in this mechanism. The change-over plate 53 is provided at its both end portions with oversized bores 53_ and 53b as shown, ana has a ' retaining tab 53_ formed centrally. Further, a slit 53d is formed at the lower part of the elongated bore 53a. The change-ove;r plat 53 i5 carried by the rotary shat 6 and the drive shaft 13 receive~
within the elongated bores 53a and S3b, respectively. The chanye-- 16 - ' ' ," . ,. . , ~ . .
over plate 53, however, is free to move laterally between the shaf-t 6 and 13. The arrangement i.s such that, when the change-over plate 53 is located at one end of its stroke, the engaging tab 53c en~ages the ratchet gear 23, whereas, when the change-over plate is located at the other end, the engaging tab 53c en-. gages the notch 31a of the checking plate 31 and the notch 28a of the clutch disc 28, The driYing ma4net 54 carries the arm 54a which is attracted by the solenoid coil 54b overcoming the force of the spring 55 as the solenoia coil 54b is energiæed.
As will be seen rom Fig. 6 which shows the side ele-vation of the typing mechanism as v;ewed rom the same side ~s the side plate lb, with parts thereof being omitted, the driving .
magnet 54 is fixed to the side plate by means of screws 56 with ..
the end portion 54a' of the arm 54a fitting within the slit 53d .
of the change-over plate 53, while the tension spring 55 is st~ecthed between the 2rm 54a a~d a post 57 provided on the side . plate lb,. When the magnet 54 is not energized, the-spring keeps .
the engaging tab 53c in engagemen' with the clutch dicc 28 and the checking plate 31. .
Fig. 7 is an exploded .perspective view of mechanisms located at the same side as ~he siae plate la, in which a refer-~nce numeral 58 denotes a retainer arm carried by the rotaxy shaf 6 for free rotation regardless of the rotation of the rotary shaft 6. A coiled spring 59 normally biases the arm 58 rotativel in the direction of the arrow. The retainer arm 58 is provided at its end with a pawl 58a, and a projection 58b extends outwardl ~rom an intermediate portion thereof. A reference numeral 70 de-notes a rotary encoder disc fixea to the rotary shaft 6 A feed pawl 60 fixed to the dri~e shaft 13 has two claws 60a and 60b and kick claws 60c and 60d, diametrically opposed. A pentagonal cam 61 ~s fixed to the paper feed shaft 37 for rotation unitarily with the latter, while a wind-up ~ear 62 (gear portion being ill~ _ . ¦¦ tF~ted only tially) is carFied also by the paper eed sha~t 37 ¦
. 17 -~ 3 ~ G
b~t is allowed to rotate independently of the latter.
ThE wind~up gear 62.is providad with a year portion 62a and a ratchet gear 62b. The teeth of the gear portion 62a are eliminated over a certain circumferential length to form a teeth-lacking portion 62c.
A drum62d is formea between the ratchet gear 62b and the gear portion 62a, arourld which drum.is wound the column shift wire ~ox thread~ 8 connected to the carriage 3. A reference numeral 63 . denotes a releasing arm rotatably carried by a shaft 6~ providea on the side plate la. The releasing arm 63 is provided with two ~am valleys 63a and 63b and one cam ridge 63c f as well as a projec tion 63d formed heneath the latter.. An engaging arm 65 fixed to a paper-feed instruction shaft 49 is provided at its end with a slit : 65a. A reference numeral 66 aenotes a guide post fo~ned on the : side plate la, the end or which is f tted to a siit (not shown~
formed in the back side or the win~-up ge~r 62 to act as a stopper Tnember for determining the initial position of the winding-up gear - In the assem~led state of the parts located at the same.
. side as the side plate la, when the carriage 3 is at the initial position, the projection 58b of the retaining arm.58 fits within the c~m valley 63a o~ the releasi~g arm 63 50 that the pawl 58a o~
the latter is kept away from the ratchet gear 62b~ and the windi~g : up gear 62 is thus in a free stateO Also, the projection 63d of . the releasing ar~ 63 is kept in contact with a flat surface of the cam body 61. ..
; Fig. a shows the typing mechanism in side elevation as viewed from the same side as the side plate la, with parts thereof heing omitted for simplicity~ As will be seen from this Figure, . the slit 65a of the engaging arm 6S loosely receives the end 67b o~ the actuating arm 67a of solenoid 67 which is adapted to be energi~ed when an instruction is given to advance the record paper A reference numeral 68 denotes a terminal plate having contact pieces 69 or contacting the rotary encoder disc 70~
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: ~ 1 0 1 6 A series of typing operati~s performed by the serial printcr of the inventi~n will be described hereinafter.
As the motor starts to rotate in response to a typing instruction, from the state in which the carriage 3 is at the rigthmost position, i.e. at the initial position as shown in Fig.
l, all of the gears l9, 27 and ~0 provided on the th~ee shaft mechanisms star-t to rotate. Since the clutch 21A associated with the gear 19 is in the connected state, the ratchet ~ear 23 and the rotary shaft 6 are rotated so that the rotary encoder disc 70, as well as the type wheels 4 and 5 are rotated.
Then,as the desired f~mction type is brought ~o the typing position, the driving magnet 54 ~See Fig. 6) is energi~ea to move the change-o~er plate 53 to the left as ~iewed in FigO 6.
In consequence r the engaging tab 53c of the change-over plate 53 engages the ratchet gear 23 to stop the latter. Figs. 9a and 9b sh~w ~bestates of the mechanism before and after the movemen~ of t~e change-over plate 53, respectively. As mentioned before, as the ratchet gear 23 is stopped, the clutch 21A on the rotary shaft 6 is turned into its disengaged sta~e, so that the rotary s~aft 6 stops to ro~a~e, allowing the gear l9 to rotate idly.
On the other hand, the movement of the change-o~er plate 53 causes the engaging tab 53c of the latter to be aisengaged from the notches 28a and 31a of the clutch 35 (See Fig. 3), so that the clutch 35 is turned into its connecting condition to cause the drive shaft 13 to rotate. Then, at the initial period of the xota-tion, the hammer cam 12 presses the typing hammer ll ~See ~ig. 1 to effect the typing to the ~unction symbol.
As the dri~e shaft li rotates further, referxing to Fig.
7, the feed pawl 6G is rotated in the direction of arrow so that a kick claw 60c (or 60d) drive5 the end 63_ of the releas;ng arm 63 downwardl~ thexeby to rotate the latter to place the pxojection 58b of the retaining arm sa in the cam valley 63b. Consequently, the xetainin~ arm 58 is rotated in the direction of ~rrow to bring ., - 19 - . , ,_...... , , ~ .
r :1~ 1371015 . I
¦ the claw 58a into engagement with the ratchet gear 6~b to check l the rotation of the wind-up year 62. Thereafter, the kick claws ¦ 60c and 60d cannot contact ~he releasing arm 63 until the carriage
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o ~ ~
68325/1~79 proposes a serial printer in which a single motor performs various actions such as selection of type, prin-ting, column shift, paper feed and so forth. In this printer, however, there is a practical limit in increasing the typing speed, because the motor has to be reversible. For the same reason, the motor is comparatively expensive and requires a complicated control. In addition, a complicated mechanism is required for selecting and retaining the two type wheels independently.
According to the present invention there is provided a printer having a motor, a rotary shaft adapted to be rotated unitarily with type wheels and adapted to be driven rotatably by the motor with a first clutch means for selectively transmitting the rotation of the mo~or to the rotary shaft.
A hammer member is adapted to be moved into and out of contact ! with the type wheels, and a hammer drive shaft is adapted to be driven by the motor and carries a cam member for actuating the hammer member. A second clutch means is adapted for selectively transmitting the rotation of the motor to the hammer drive shaft. Control means is provided for controlling the first and second clutch means simultaneously to engage one of the clutch means while disengaging the other. A
carriage carries the type wheels and is slidable in a direction parallel to the rotary shaft. A spring member is connected to one end of the carriage and is adapted to urge the carriage toward the initial position, a thread member being connected to the other end of the carriage with means adapted to gather the thread means to overcome the force of the spring member, the gathering means being ac-tua-ted by rotation of -the harnmer 'pc/,,~
~ ~7~0~
drive shaft when the ]atter is driven through the second clutch means.
According to another aspect of the presen-t invention there is provided a printer having a motor adapted to rotate a motor shaft in one direction only with a carriage being movable slidably along a line to be printed and a spring member connected to the carriage for con-tinuously biasing the carriage toward the initial position on the line. A thread member is - connected to the carriage and adapted to pull the carriage toward the last position on the line, and a rotary drum is provided for winding-up the thread member by overcoming the biasing force of the spring member. A feed mechanism includes clutch means for selectively transmitting the rotation of the motor shaft to the rotary drum to rotate the ro-tary drum and draw the carriage towards the last position. An arm engages the gear of the rotary drum and is adapted to prevent the rotary drum from being rotated by the force of the spring.
A releasing means is adapted to keep the arm in the state separate from the gear of the rotary drum when the carriage is returned to the initial position. Means is provided for maintaining the arm separated ~rom the gear over a predetermined period of time when the carriage has been returned to the initial position by means of the releasing means.
It is an ob~ec-t of the present invention to provide a serial printer of reduced size and weight to overcome the above-described problems.
It is another object of the present invention to provide a serial printer suitable for use in a desk-top calculator of small size and weight, by reducing as much as ' pc/~
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possible the number of driving or actuating sources and, hence, the space occupied by such driving or actuating sources.
It is a further object of the invention to provide a serial printer of a size which is reduced as much as possible through decreasing the number of rotary shafts.
It is a still further object of the invention to simplify the construction of the serial printer and to reduce the size of the same by attaching various parts to a rotary shaft to make efficient use of the shaft.
BRIEF DESCRIPTION OE' TH.E DR~WINGS
Fig. 1 is a plan view of a printer according to the pc/~
1~ 011~ I
¦ present invention;
~ig. 2 is an exploded perspective ~iew of a rotary shaft ¦ ~echanism ~first clutch) in the printer of Fig. l; .
Fig. 3 is an e~ploded perspective view of a hamme~ driv . ¦ ing mechanism ~secona clutch) in the printer of Pig. l;
Fig~ 4 is an exploded perspec~ive.- view of a paper feed . mechanism (third clutch) in the printex of Fig. l; .
. Fig. 5 is an exploded perspective view showing the rota ry shaft mechanism, hammer driving mechanims and a controllin~
meohanism for driving both mechanisms; . . . ..
~ig. 6 is a right-side elevational view of he pxinter ~s seen from the right side thereof with a part of the printer being shown schematically, .
Fig. 7 is an exploaed perspective view of the printer of Pi~ 1 as seen from the left side thereof;
. Fig. 8 is a left-side elevational view of the printer of Fig. 1 with a part thereof sho~m schematically;
Fiy. 9a and 9b are sectional plan views of the printer : of ~ig. 1 for explaining the operation ~f the printer;
Figs. 10 and 11 are exploded p~rspective views for e~-plaining the operation of the clutch of the paper feed mechanism;
and Fig. 12 ~s an exploded perspective ~iew of a windi~g-up . mechanism of the printar in accordance with ~he invention -DESCRIPTION OF THE PE~EFERRED El~lBODI~IENTS
. A prePexred embodiment of the present invention will be described hereinunder with re~erence to the accompanying drawing .
Fi~. 1 is a plan vie~ of a serial printer embodying the pxesent invention. A reference numeral 1 denotes a frame plate ~f iron or the like to which are attached upright side plates la and lb. The side plates la and lb face one another Prom opposit , 11 , . s 1.
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``\ ll .
1 ~ o ~ ~ .
sides of the frame plate 1 and are supported at their upper ends by a transverse supporting plate lc. ~ rail 2 extends between the side plates la and lb. A reference numeral 3 denotes a ~ar-riage which can be moved along the rail 2 to the right and left, i.e. in the direction of a line to be printea Reference numeral ;
4 and 5 denote, respectivelyp a type wheel for printing function symhols and a type wheel for printing numerals, and these type wheels are carried by the carriage 3. The type wheels 4 and 5 are penetrated by a rotary shaft 6 so as to be driven rotatably by the latter. ~hese type wheels are not allowed to rotate rela-tive to the rotary sha~t 6 ~t can move indepenaently o~ each other in the axial direction therealong within ~espective prede-termined distances.
Although not ~ully shown in the drawings, a tension spring 7 is ~ixed at its one end to the side plate la while the other end extends through the side plate lb and is fixed to ~he ~uter right side wall of the carriage 3 to urge the carri~ge 3 to its initial p~5ition, i.e~ to the position shown in Fig. 1. A
reference numeral 8 denotes a wire or threaa for effecting a col-umn shift of the car~iage 3 by pulling it in the direction of the arrowO Numerals 9 and 10 denote guide members for guiding the tension spring 7 and the col~mn shift wire 8 which are at-tached to the side plates la and lb, respectively. A reerence n~meral 11 denotes a typing hammer provided at its right end with a notch lla ~or preventing typing, as will be set forth more ful-ly below. The typing hammer 11 is adapted to be actuated by a non-circular hammer c~m 12 which is attached to a drive sha~t 13.
A re~erence numeral 14 denotes a recording paper interp3sed ba-tween the typing hammer 11 and the type wheels 4 and 5 Numer-als 3b ~nd 15 desi~nate, respectively, an ink roller and a stop-per disk . . .
Before turning to the detailed aescription of the driv~
iny mechanism, a description will be made as to the printiny ope-. . .
. .. ~ . ..
1~ 7:103LG
¦ ration.
¦ As the rotary shaft 6 is rotated to bring the desir~d I function symbol to the typing position~ the drive shaft 13 is ro-: ¦ tated to make the ha~ner cam 12 press the typing ha~ner 11, so that the latter presses the recording paper onto the type wheel ¦ 4 thereby to print the function symbol. In this state, no typing ¦ of the numeral is effected because the type wheel 5 is positioned within the notched part lla of the hammer 11 and thus is not ~ contactea by the hamçner.
¦ ~fter the completion of the typing o the first column ox place on a line to be printed, the coIumn shift wire 8 is pull-ed in the direction of the arrow to shift the carriage 3 to the left by one coluçnn. Meanwhile, the type wheel 5 carried by the carriage arm 3a is shifted to the second column. On the other hand, the type ~Jheel 4 does not follow the mo~ement of the car-riage 3 although it is shifted to the left by the action of spri 14', and is stopped at a position opposite the notched part lla of the typing ham.-ner 11. The type wheel 4 remains at this posi-~ion until the carria~e is returned after completion of the t~pin of one line. Although ~ot shown, the type wheel 4 abuts a step formed on the sha~t 6 so as to be retained by the step in a posi-tion opposite the notched part lla.
The typing operat~on mentiQned above for the firs~ col-u~n is repeated to e~fect the typi~g of the secona column after the c~rraige 3 is shifted to the second column and the desired numeral is brought to the typing position.
After the typing of all the characters for one line is oompleted, the shift wire a is freed. In consequence, the car-ri~ge 3 is returned to the initial position shown in Fig. 1 hy the action of the tens~on spring 7, and the paper feed is advance .
Th~ typing mechanism will be described in detail here-inund r.
The ~yping mechanism of the serial printer of the in-vention has three shaft rne~han;sms: 11) rotary sh~ft mechanism '.. i . ' ., , t ,.
...
-' ~ ~ 7 :~ ~3 ~ ~i for rotatably driving the type wheels 4 and 5, ~2) shaft mecha-nism for rotatably dri-ring a hammer cam 12 for driving a typing hammer and ~3~ a paper feed shaft mechanism for feeding recording pap~r. These mechanisms are coupled in an inter-related manner through a gear mechanism and clutches to effect the various se-:
quence of operations.
The driving mechanism for xotatably driving the type wheels 4 and 5 is illustrated in Fig. 2, wherein reference numeral 16 denotes a stationary bearing received within a semicircular bore lb-l formed in the side plate lb so as not to be able to ro-tate with respect to the latter. The bearing 16 has a central 'oore 16a for receiving the rokary shaft 6. An anti-r~versing ring 17 is rigialy fitted to the rotary shaft 6 so as to rota-te unitari ly with the latter. An anti-reversing coiled spring 18 is coiled such that it is unwound as the rotary shaft 6 is rotated in the proper direction. The stationary ~earing 16 and the anti-reversin ~ing 17 a~e proYided with drum portions 16b and 17a of an e~ual diameter a~d kept in close contact with each other at their side surfaces, The coiled spring 18 i5 wound around these drums. The inside diameter o~ the coiled spring 18 is slightly smaller than the outside diameter of each dl~lm~ The coiled spring 18 is u~woun a~ the rotary shaft 6 rotates in the proper airection, so th~t the drums 16b and 17a are disengaged from the spring and thus ~ach othe .
Elowever, if th~ rotary shaft 6 is rota-ted in the wrong direction even by a small angle, the coiled spring 18 tightens against the dxums 16b and 17a to connect them to each other thereby to prevent the reversing of the rotary shaft 6. ' .
The drawings also show a clutch assembly 21A with a l ortion thereof being omitted. A gear 19 loosely fitted to the ro-tary shaft 6 has a drum 19a. A holding sleeve 20 has at its one side a bore 20a penetrated by the drum 19a, and pro~ided at its ¦ eripheral 5urface with a groove 20b. A cylinder 21 is provided a~
. _~_ :,: ,, , . ~' '' ..
710 t 6 its one side with a drum 21a and at its peripheral surface with a ¦ ~roove 21b. Although not fully illustrated; a coiled spring 22 ¦ has its respective ends 22a and 22b bent as shown. A ratchet gear ¦ 23 is proYided at its one side with a bo-~s 23a and has an internal ¦ cavity for recei~ing parts of the aforementionea clutch assembly ¦ 21A. .
¦ Por assembling the clutch assembly 21A, at first one end 22b of the coiled spring 22 is inserted into the groove 21b of the cylinder 21 and almost half of the coiled spring Z2 is fit-ted around the drum 21a of the cylinder 21. (Thè inside diameter of the coiled spring 22 is slightly smaller than the common out-side diameter of the drums 19A and 21a)~ Then, the drum l9a o~
the gear 19 is loosely inserted through the bore 20a o~ the holdin sleeve 20 to pro~ect from the latter and the remainder part of the . . coiled spring 22 i5 press-fitted onto the drum l9a~ At the same time, the other end 22a of the c~iled spring is insertea into the groove 20b of the holding sleave 20. In consequence, the members I9 and 20 are coupled to each other through the coiled spring 22 so as to be rotated unitarily in a predetermined direction, i.e.
20 in the direction for tightening the coiled spring. During assembly the holding slee~e 20 is xotated sligh~ly with respect to a xatche gear 23 which will be explained later, so as to-absorb the fluctu-ation o the angular distance between both ends 22a and 22b of the coiled spring 22 which inevitably takes place during manufacturing of the sprin~.
Then, the cylinder 21 is press-fitted into the rotary sha~t 6 and then the ~atchet gear 23 is fittea arou~a the cylinder 21, such that a sector projection 21d on the outer circumfereAtial surface of dxum 21_ of the cylinder 21 aligns with a sector bore 23c communicating with the central bore 23b of the end of the rat-chet gear 23. The holding sleeve 20 is adjusted and rotated while engaging the sector projection 21d and sector bore 23c to eEfect the alignment of the attachin~ positionO A certain margin is pr~-~' ,: . .
... _.. _ ........ , _ .. . . ~.
, .
7, ~
1~ . . .
served for mutual eng?gement between the sector projection 21d and the sector bore 23c so as to smooth the movement o the coile spring in the tightening and loosening directions during the .
operation of the clutch which will be described later.
TAe aforementioned coiled springs 18 and 22 are set in the opposite winding directions with respect to one another. In this way, the rotation of the ~ear 19 caused by a later-mentioned motor is transmitted to the rotary s~laft ~ via the cylinder 21 through the connection of the coiled spring 22 wound tightly on the drives l9a and 21a. On the other hand~ as the rotation of the ratchet gear 23 is checked by a checking me~ber to be aescrib~ d below, the cylinder 21 is also stopped so that the coiled spring 22 is slacked without delay to interrupt the connection between the.gear 19 and the cylinder 21, i.e. the ro~ary shaft 6. If he rotary shaft 6 tends to rotate in the direction reve~se to the direction caused by the motor, the aforementioned coiled spxing 18 is tightened without delay to rigidly connect the sta-tionary bearing 16 and the anti-reversing ring 17, thereby to .-pre~ent reverse`rotation Df the rotor shaft 6~
The shaft mechanism for rotata~ly driving the hammer ~am 12 for the typinghammer is shown in Fig. 3, and includas a stationary bearin~ 24 received within a semicirc~lar ~ore lb-2 formed in the side plate lb so as not to, be able ~o rotate xela-tive to the latter, and has a central bore 24 a ~eceiving the drive shaft 13. An anti-reversing ring 25 .is rigidly fitted to the drive shaft 13 so asto be rotated unitarily with the latter. .
A~ anti-re~ersing coilded spring 26 is wouna in such a direction to be unwound as it is twisted rn the proper direction of r~-tation of the dirve shaft 13. The stationary bearing 24 ana the anti-reversing ring 25 are provided with respective drums 24~ and 25a of an equ~l diameter which are kept in close ~ontact with eac~
. other at their facing sides. The aforementioned coiled spring 26 is wound round . these drums. The coiled spring 26 has an in-side diameter slightly smaller than .
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`\. I ~ i 7 ~
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the outside diameter of these drums. As the d~ e shaft 13 i5 rotated in the direction of -the arrow, the coiled spring 26 is driven in the unwinding direction so that the drums 24b and 25a are disconnected from each other. ~owe~er, if the drive shaft I3 is reversed even by a small angle of rotation, the coiled spring 26 tightens against the drums 2~b and 25a to connect these drums thereby to prevent the rotation of the drive shaft 13 in th0 re-verse direction. Although not fully illustra~ed, a gear 27 loose ~ ly carried by the dri~e shaft 13 is provided at its one side with a ratchet gear 27a formed unitarily therewith or fixed the~eto.
A clutch 35 is formed by a clutc~ disk 28 fixed to the drive shaft 13 so as to rotate unitarily with the latter. ~he clutch disk 28 is provided in its periphery with two diame~ricall opposing notches 28a and-28d and, at its one side~ with a hole 28 far ~ixiny the end 29a of a p~n 29. The clutch disc 28 is urthe prov~ded at its one side ~ith 2 ~r'~. 28c for receiving a coiled spring 30, both ends 30a and 30b of which ar~ bent out~ardly as shown. A checking plate 31 is provided in its periphery with two diamet~ically opposing notches 31a and 31b an~ has a central bore 31c for receiving the drive shaft 13. The checking plate 31 is further provided with a circumferentially elon~ated hole 31d and a radially elongated bole 31e. A reference numeral 32 den~tes a ratchet pawl at both ends of which are foxmea respective bores 32a and 32b. Also, a pawl 32c i5 foxmed at the center. Reference numeral ~4 d~notês a ~plit washer~
Por assem~ling tile clutch 35~ the end 29a of the pin 29 is inserted into the bore 28b of the clutch disk 28 so as to be fixea b~ the latter, while the reduced-diameter portion 33a of a pi~ 33 i5 inserted into the elongated bore 31e of the checking plate 31. Thereafter, the reduced diameter portion 33a of the p~n 33 is fitted and fixed to the hole 32b of the ratchet pawl 32.
~hen, the ~oiled spring 30 is fitted round the body por-tion 28c of the clutch disk 28 and the end 30a o th~: 6pring is retained . ' .
1 ~371016 . I
by the pin 29. Subsequently, the circular bore 31c of the check-ing plate 31 is fitted to the body portion 28c. In this state, the pin 29 is introduced into the hole 32a of the ratchet pawl 32 through the elon~ate~ bore 31d in the checking plate 31, and the end 30b of the coiled spring 30 is retained by the reduced I diameter por-tion 33a of the pin 33. Finally, the washer 34 iæ
¦ fitted to the end of the pin 29.
A drive shaft 13 is inserted into the center of the l clutch 35 thus assembled, and the clutch disk 28 and the drive ¦ shaft 13 are coupled to each other. ~t the same time, the ratche gear 27a and the pawl 32c are made to e~gage with each other.
As tha gear 27 is rotated from this state in the airec-tion of the arrow, the ratchet gear 27a engages and pulls the pawl 32 so that the clutch disk 28 is also rotated to drive the rive shaf~ 13. In the course of rotation, the notch 28a and the notch 31a may be cngaged by claws not shown, and the rotation of the ~lutch disk 28 and the checking plate 31 is stopped so that the ratchet gear 27a of the 27 comes to push the ratchet pawl ~Z
since tne gear 27 is rotated continously by the motor. In conse- .
¦ quence, the r~tchet pawl 32 is movea o-ltwardl~ as the respective ¦ pins slide within the elongated bores 31d a~d 31e so tha~ the ratchet gear 27 is disengaged from the rat~het pawl 32. The con~
ne~tion between the gaar 2? (i.e. the motor~ ana the ~lytch disk 28 Si.e. the drive shaft 13) is thereby broken. Movem~nt of the rive shaft i3in the reverse direction is prevented by the anti-reversing mechanism contituted b~ the aforementioned coiled spring 26. ~ - :
¦ The mechanism for ~eeding the recording paper is shown ¦ in Fig. 4, wherein a stationary bearing 36 is fitted to a semi-¦ circular bore lb-3 formed in the siae plate lb so as not to be ¦ a~le to rotate with respect to the latter, and has a central bore 36a for receiving a paper feed shat 37. A reference numeral 38 ¦ denotes an anti-reversin~ ring which is fitted to the paper feed ~ ;
0 ~ ~ -.'.'. . .
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shaft 37 so as to be rotated unitaxily with the latter. An anti-reversing coiled spring 39 is wound in such a direction as to be unwound as it is twis-ted in the'direction of rotation oE the shaft 37. The stationary beariny 36 and the anti-reversing ring 38 are pro~ided with respective drums 36b and 38a which are closely;con-tactea by each other at their facing ends. The a orementioned coiled spring 39 is wound on *hese drums~ The inside diameter of the spriny 39 is slightly srnaller than the outside diameters o~
these drums. The arrangement is such'that the coiled spring 39 is driven in slackin~ or unwinding direction when the paper feed s~aft 37 rotates in the proper direction, so that the co~nection between the drums 36b and 38a is broken. Hbwever, if the paper feed shaft 37 is r~tatea in the reverse or wrong direction even by a small angle, the coile~ 5-~ 39 tightens against the drums 36b and 38a so that'these drums are operatively connec~ed to each other to preventreverse rotation of the paper feed shaft 37.
.
Although not fully illustrated, a clutch 48 is formed by a gear 40 loosely mounted on the paper ~eed shaft 37~ The gear 40 is provided with a ratchet gear 4-0a fixed to one side :
thereof~ ~ clutch disk 41 has a hole 41a for fixedly receiving a reduced diameter portion 42a of the pin 42,'and a hub portion ~lb at one side thereof for receiving a coiled spring 43 there-around. The ends 43a and 43b of the coiled spring 43 are bent outwardl~ as shown. A checking plate 44 ig provided with 5 (five~
teeth 44a formed on the ollter periphery thereof, and has a central circ~lar bore 44b ~xough which the paper ~eed shaft 37 passes.
The checking plate 44 is further provided with a circumferentially elongated bore 44c and a radially elongated bore 44d. A reference numeral 45 denote5 a ratchet pawl at both ends of which are formed respective hole~ 4Sa and 45b. Also, a pawl 45c is formed at the ' ' ,~ -' ' ' ,, .
central portion of the xatchet pawl 45. Refexence numerals 46 ~nd 47 denote, respectively, a pin and a washer.
For assembliny the clutch 48, the end 42a of the pin 42 i5 fitted and fixed in the hole 41a o~ the clutch disk 41 and the reduced diameter portion 4fia of the pin 46 is fitted and fixed in the hole 45b o~ the ratchet pawl 45, through the elongat ed bore 44d of the checking plate 44. Then, the coiled spring 43 is wound ~ound the hub portion 41b of the clutch disk 41, ana one end 43a thereoE i5 retained ~y the pin 42. Subsequen-tly, the hub portion 41b is fitted in the circular bore 44b of the checking plate 44. In this state, the pin 42 is inserted into the hole 45a o~ the ratchet pawl 45 through the elongated bore 44c of the . checking plate 44, and the end 43b of the coiled spring 43 is retained by the reduced diame-ter portion of the pin 46. Finally, the washer 47 is fitted to the end of the pin 42.
The paper feed shaft 37 is inserted into the center of the clutch 48 thus assembled, and the clutch disk 41 is rigidly fitted to the paper feed shzft 37. i~t the same time, the ratchet gear 40a and the pawl 45c are made t~ engage with each other. Th claw 50a providea at one end of an arm 50 fixed to a paper-feed instruction sha~t 49 supported by th~ side plate lb may be brought into engagement with the teeth 44_ of the checking plate 40 to check therotation o~ the latter, as will be set forth more fully below. A reference ~umeral Sl denotes a pinion ~ttached to the motor shaft o~ a drivincJ motor which is not shown, whereas a reference numeral 52 denotes an intermediate gear ~not shown full carried hy a shaft 53 which in turn is at~ached to the side plate lb. ~he qear portion 52a o the gear 52 meshes with the pinion 5 while the gear portion 52b meshes with the gear 40.
As the gear 40 is rotated in this state, the ratchet gear 40a engages and pulls the ratchet pawl 45, and the clutch disk 41 is chec~ed by the mu-tual engagement between the claw SOa and the checking plate 44, althou~h it tends to rotate.
.., ' . ...
As a further orce is applied to cause the rotation, the ratchet paw7 45 slides outwardly as the pins 42 and 46 move within the bores 44c ana 44d of the checking plate 44, so that the pawl 45c is moved out of engagement with the ratchet gear ~Oa. In this . 5tate, the gear 40 idles without being accompanied by the rotation of the shaft 37. As the arm 50 is rotated'in response to a paper feed instruction to temporarily disengage the claw 50a from the teeth 44a of the checking plate 44, the ratchet pawl 45 is moved to again bring the pawl 45c into engageme~t of the ratchet gear 40a and the paper feed shaft 37'is ro-tated by the gear 40 and, after the completion of the feed of paper ~when the checking ~
plate 4-3 ha~ made a 1/5 rotation), the claw 50a is brought again into engagement with the teeth 44a by the forc~ of a spring, so that the rotation of the gear 40 is interruptea hy the clutch 48 to stop the paper feed shaft ~7.
Three maj~r rotary sha-.s of the serial'printer of the inv~ntion have been described. In the assembled state of these three shafts, the gea~ 40 carriea by the paper feed shaft 37 en-gages the gear 27 carried by the drive shaft 13, and the gear 27 in turn is engaged by the'gear 19 carried by the rotary shaft 6, so that the rotation o~ ~he gear 51 is finally transmitted to ~he gear 19 ~o make these gears rotate simultaneously.
A ~hange-over mechanism for changing o~er the clutches on the rotary shaft 6 and the drive shaft l3 is provided on the side plate lb. In Fig. 5, a reference numeral 53 denotes a change-over pla'te o~ this mechanism. Also, reference numerals 54 and 55 designate a driving magnet and a tension spring incorporated in this mechanism. The change-over plate 53 is provided at its both end portions with oversized bores 53_ and 53b as shown, ana has a ' retaining tab 53_ formed centrally. Further, a slit 53d is formed at the lower part of the elongated bore 53a. The change-ove;r plat 53 i5 carried by the rotary shat 6 and the drive shaft 13 receive~
within the elongated bores 53a and S3b, respectively. The chanye-- 16 - ' ' ," . ,. . , ~ . .
over plate 53, however, is free to move laterally between the shaf-t 6 and 13. The arrangement i.s such that, when the change-over plate 53 is located at one end of its stroke, the engaging tab 53c en~ages the ratchet gear 23, whereas, when the change-over plate is located at the other end, the engaging tab 53c en-. gages the notch 31a of the checking plate 31 and the notch 28a of the clutch disc 28, The driYing ma4net 54 carries the arm 54a which is attracted by the solenoid coil 54b overcoming the force of the spring 55 as the solenoia coil 54b is energiæed.
As will be seen rom Fig. 6 which shows the side ele-vation of the typing mechanism as v;ewed rom the same side ~s the side plate lb, with parts thereof being omitted, the driving .
magnet 54 is fixed to the side plate by means of screws 56 with ..
the end portion 54a' of the arm 54a fitting within the slit 53d .
of the change-over plate 53, while the tension spring 55 is st~ecthed between the 2rm 54a a~d a post 57 provided on the side . plate lb,. When the magnet 54 is not energized, the-spring keeps .
the engaging tab 53c in engagemen' with the clutch dicc 28 and the checking plate 31. .
Fig. 7 is an exploded .perspective view of mechanisms located at the same side as ~he siae plate la, in which a refer-~nce numeral 58 denotes a retainer arm carried by the rotaxy shaf 6 for free rotation regardless of the rotation of the rotary shaft 6. A coiled spring 59 normally biases the arm 58 rotativel in the direction of the arrow. The retainer arm 58 is provided at its end with a pawl 58a, and a projection 58b extends outwardl ~rom an intermediate portion thereof. A reference numeral 70 de-notes a rotary encoder disc fixea to the rotary shaft 6 A feed pawl 60 fixed to the dri~e shaft 13 has two claws 60a and 60b and kick claws 60c and 60d, diametrically opposed. A pentagonal cam 61 ~s fixed to the paper feed shaft 37 for rotation unitarily with the latter, while a wind-up ~ear 62 (gear portion being ill~ _ . ¦¦ tF~ted only tially) is carFied also by the paper eed sha~t 37 ¦
. 17 -~ 3 ~ G
b~t is allowed to rotate independently of the latter.
ThE wind~up gear 62.is providad with a year portion 62a and a ratchet gear 62b. The teeth of the gear portion 62a are eliminated over a certain circumferential length to form a teeth-lacking portion 62c.
A drum62d is formea between the ratchet gear 62b and the gear portion 62a, arourld which drum.is wound the column shift wire ~ox thread~ 8 connected to the carriage 3. A reference numeral 63 . denotes a releasing arm rotatably carried by a shaft 6~ providea on the side plate la. The releasing arm 63 is provided with two ~am valleys 63a and 63b and one cam ridge 63c f as well as a projec tion 63d formed heneath the latter.. An engaging arm 65 fixed to a paper-feed instruction shaft 49 is provided at its end with a slit : 65a. A reference numeral 66 aenotes a guide post fo~ned on the : side plate la, the end or which is f tted to a siit (not shown~
formed in the back side or the win~-up ge~r 62 to act as a stopper Tnember for determining the initial position of the winding-up gear - In the assem~led state of the parts located at the same.
. side as the side plate la, when the carriage 3 is at the initial position, the projection 58b of the retaining arm.58 fits within the c~m valley 63a o~ the releasi~g arm 63 50 that the pawl 58a o~
the latter is kept away from the ratchet gear 62b~ and the windi~g : up gear 62 is thus in a free stateO Also, the projection 63d of . the releasing ar~ 63 is kept in contact with a flat surface of the cam body 61. ..
; Fig. a shows the typing mechanism in side elevation as viewed from the same side as the side plate la, with parts thereof heing omitted for simplicity~ As will be seen from this Figure, . the slit 65a of the engaging arm 6S loosely receives the end 67b o~ the actuating arm 67a of solenoid 67 which is adapted to be energi~ed when an instruction is given to advance the record paper A reference numeral 68 denotes a terminal plate having contact pieces 69 or contacting the rotary encoder disc 70~
.: I - 18 - ..
.. _ =7- - . ~ . .
: ~ 1 0 1 6 A series of typing operati~s performed by the serial printcr of the inventi~n will be described hereinafter.
As the motor starts to rotate in response to a typing instruction, from the state in which the carriage 3 is at the rigthmost position, i.e. at the initial position as shown in Fig.
l, all of the gears l9, 27 and ~0 provided on the th~ee shaft mechanisms star-t to rotate. Since the clutch 21A associated with the gear 19 is in the connected state, the ratchet ~ear 23 and the rotary shaft 6 are rotated so that the rotary encoder disc 70, as well as the type wheels 4 and 5 are rotated.
Then,as the desired f~mction type is brought ~o the typing position, the driving magnet 54 ~See Fig. 6) is energi~ea to move the change-o~er plate 53 to the left as ~iewed in FigO 6.
In consequence r the engaging tab 53c of the change-over plate 53 engages the ratchet gear 23 to stop the latter. Figs. 9a and 9b sh~w ~bestates of the mechanism before and after the movemen~ of t~e change-over plate 53, respectively. As mentioned before, as the ratchet gear 23 is stopped, the clutch 21A on the rotary shaft 6 is turned into its disengaged sta~e, so that the rotary s~aft 6 stops to ro~a~e, allowing the gear l9 to rotate idly.
On the other hand, the movement of the change-o~er plate 53 causes the engaging tab 53c of the latter to be aisengaged from the notches 28a and 31a of the clutch 35 (See Fig. 3), so that the clutch 35 is turned into its connecting condition to cause the drive shaft 13 to rotate. Then, at the initial period of the xota-tion, the hammer cam 12 presses the typing hammer ll ~See ~ig. 1 to effect the typing to the ~unction symbol.
As the dri~e shaft li rotates further, referxing to Fig.
7, the feed pawl 6G is rotated in the direction of arrow so that a kick claw 60c (or 60d) drive5 the end 63_ of the releas;ng arm 63 downwardl~ thexeby to rotate the latter to place the pxojection 58b of the retaining arm sa in the cam valley 63b. Consequently, the xetainin~ arm 58 is rotated in the direction of ~rrow to bring ., - 19 - . , ,_...... , , ~ .
r :1~ 1371015 . I
¦ the claw 58a into engagement with the ratchet gear 6~b to check l the rotation of the wind-up year 62. Thereafter, the kick claws ¦ 60c and 60d cannot contact ~he releasing arm 63 until the carriage
3 is returned. As the feed pawl 60 is further rotated, another claw 60a of 60b, which has a phase difference from the kick claw, is bxought into engagement with the gear portion 62a to cause the wind-up gear 62 to rotate through a small arc of one pitch. The rotation of the wind-up gear 62 in turn causes the column shift wire 8 to be taken-up by the drum portion 62d so *hat the carriage 0 i5 subjectea to a column shift. The above-explained series of operatio~sis performea during a half rotation of the dri~e shaft 13~ Meanwhile, the driving magnet 54 is de-energized so that the.
change-over plate 53 is pulled ana xeturned to the right as viewed in Fig. 6 by the force of the tension spring 55. After the hal rotation of the drive shaft 13, the engaging tab 53c comes into engagement with the notches ~8d 2nd 31_ ~or 28a and 31a~ of ~he clutch 35 and is thus disengaged fro~ the ratchet gear ~3. In consequence, the clutch 21A and the clutch 35 are turnea into con~ecting and disconnecting states, respectively, so that the rotary shaft 6 rotates to cause the rotation o~ ~he type wheels and S, while the rotation of the drive shaft 13 is suspended.
. ~s the numeral whiCh iS to be typed i~ the second colun is brought to the typing position, the driving magnet 54 is ener-gi~ed again to move the change-over plate 53 t~ move to the left as viewed in Fig. 6, so that the engaging tab 53c of the change-over plate 53 come~ to mesh with the ratchet ~ear 23 to stop the latter, which in turn causes the clutch 21A on the rotary sha~t 6 to be turned into disco~ecting state so that the rotary shaft 6 is stopped allowing the gear l9 to idle.
On the other hand, as the change-over plate 53 is moved the engaging tab 53c of the latter is disengaged from the notches 28b and 31d of the clutch 35 so that the clutch 35 is turned into conn~ctin te t~ drive the drive ~ha't 13 thereby to m~te the 101~ I
hamrner cam 12 press the typing hammer 11 to type -the aforesaid numeral.
~eferring again to ~ig. 7, as the drive sha~t 13 is ro-tatea, the feed pawl 60 is rotated in the direction of the arr~ b~
bring the claw 60a (or 60b7 into engagement with the teeth as ex-plained before. This in turn causes the drum 62 to wind-up the column shift wire 8 so that the carriage 3 is shifted by a further Dne column overcoming the force of the tensio~ spring 7. As the feed pawl 60 makes a half rotation, the claw 60a and the gear 62a lU are disengaged ~rom each other to complete the column shift opera-tion by one column. Meanwhile, the driving magnet 54 is de-ener-gi~ed to permit the change-ov0r plate 53 to be shite~ to the right as viewed in Fig. 6 by the force of the tension spring 55 and, after a half rotation of the drive shaft 1~, the latter comes into engagement with the notcr-s 28~ and 31a ~or 28d and 31b) of the ~lutch 35 and is disengase~ -~02 _he ratchQt gear 23~ ~n conse-quence, the clutch 21A ænd the clutch 35 are turned into connectin ~nd disconne~ting states, respective:Ly, so that the rotary shaft 6 ;~ is rotated to cause rotation of the type wheels 4 and 5, while the drive shaft 13 is stopped to complete the typing of the numeral in the second column.
This typing operation is repeated to ef~ect the typing o~ the de9ired number of columns. As the typiny is f inished with one line, the solenoid 67 ~See Fig. 8) is energized to causè a clockwise rotation o~ the actuatin~ arm 67a, so that the engaging arm 65 is kicked up to rotate in the counter-clockwise direction overcoming the force of the spring 71, thereby to cause a rotation of the paper-feed instruction sha~t 49.
In consequence, the arm 50 looated at ~he same side as the plate lb, adapted to rotate unitarily with the shat 49, is rotated so that the claw 50a which has been engaged by the teeth 44a of the retaininy plate 44 ~s shown in Fig. 10 is temporarily moved out o~ engagement with the teeth 44a to turn the clutch 4 . .
..... , ..... ... , . ; ...
` 1~ 137~016 in~o connecting state. In conseguence, the paper feed shaft 37 starts to xotate to feed thc recording paper 14 by one pitch.
As the paper feed shaft 37 starts to rotate, cam body 61 (See ~ig. 7) unitary with the latter is rotated to push up the projection 63d of the releasing axm 63 as shown in Pig~ 12. This motio~ in turn ca~ses the projection 58b of the retaining arm 58 tD moved from the cam valley 63b to the cam valley 63a thereby to dise~gage the claw 58a and the ratchet gear 62b from each other to free the wind-up gear 62. In the state where the projection 53b o~ 'he retaining arm 58 engages the valley 63a of the releasin arm 63, both membexs 58 and 63 are in the dynamically balanced ~tate which is maintained until the releasing arm 63 is depressea by the kick claws ~Oc and 60d of the aforementionea feed pawl 60, thereby to ensure the correct returning operation of the car-r;age. As the gear 62 is freed, the carriage 3 is normally pulled by the tension spring 7 towzr2 'he initial position, so that the Garriage returns to the initial position without delay, pulling the column shift Wire 8 which in turn rotates the wind-up gear 62 to reset the latter to the starting position.
2tl ¦ As has been described, in the typing mechanism of the in~2ntion, the rotary driving mechanism for driving the type whee and the driving shaft mechanims for driving the typing hammer are brought into *he sequential operation by the actions of various clutches. This arrangement offers various advantages. For in-~tancç,the number of the driving sources i5 reduced. In addition it is possible to obtain a serial printer of reduced size and weight and having a high typing speed, because it is possible to ~aintain a constant direction of rota~ of the motor shaft. In addition, the mechanism is very simple and operates at a high re-liability, because the change-over of the clutches is performed b~
~he member selecting the s~nbols or numerals of the type wheels. ' .' ' .
change-over plate 53 is pulled ana xeturned to the right as viewed in Fig. 6 by the force of the tension spring 55. After the hal rotation of the drive shaft 13, the engaging tab 53c comes into engagement with the notches ~8d 2nd 31_ ~or 28a and 31a~ of ~he clutch 35 and is thus disengaged fro~ the ratchet gear ~3. In consequence, the clutch 21A and the clutch 35 are turnea into con~ecting and disconnecting states, respectively, so that the rotary shaft 6 rotates to cause the rotation o~ ~he type wheels and S, while the rotation of the drive shaft 13 is suspended.
. ~s the numeral whiCh iS to be typed i~ the second colun is brought to the typing position, the driving magnet 54 is ener-gi~ed again to move the change-over plate 53 t~ move to the left as viewed in Fig. 6, so that the engaging tab 53c of the change-over plate 53 come~ to mesh with the ratchet ~ear 23 to stop the latter, which in turn causes the clutch 21A on the rotary sha~t 6 to be turned into disco~ecting state so that the rotary shaft 6 is stopped allowing the gear l9 to idle.
On the other hand, as the change-over plate 53 is moved the engaging tab 53c of the latter is disengaged from the notches 28b and 31d of the clutch 35 so that the clutch 35 is turned into conn~ctin te t~ drive the drive ~ha't 13 thereby to m~te the 101~ I
hamrner cam 12 press the typing hammer 11 to type -the aforesaid numeral.
~eferring again to ~ig. 7, as the drive sha~t 13 is ro-tatea, the feed pawl 60 is rotated in the direction of the arr~ b~
bring the claw 60a (or 60b7 into engagement with the teeth as ex-plained before. This in turn causes the drum 62 to wind-up the column shift wire 8 so that the carriage 3 is shifted by a further Dne column overcoming the force of the tensio~ spring 7. As the feed pawl 60 makes a half rotation, the claw 60a and the gear 62a lU are disengaged ~rom each other to complete the column shift opera-tion by one column. Meanwhile, the driving magnet 54 is de-ener-gi~ed to permit the change-ov0r plate 53 to be shite~ to the right as viewed in Fig. 6 by the force of the tension spring 55 and, after a half rotation of the drive shaft 1~, the latter comes into engagement with the notcr-s 28~ and 31a ~or 28d and 31b) of the ~lutch 35 and is disengase~ -~02 _he ratchQt gear 23~ ~n conse-quence, the clutch 21A ænd the clutch 35 are turned into connectin ~nd disconne~ting states, respective:Ly, so that the rotary shaft 6 ;~ is rotated to cause rotation of the type wheels 4 and 5, while the drive shaft 13 is stopped to complete the typing of the numeral in the second column.
This typing operation is repeated to ef~ect the typing o~ the de9ired number of columns. As the typiny is f inished with one line, the solenoid 67 ~See Fig. 8) is energized to causè a clockwise rotation o~ the actuatin~ arm 67a, so that the engaging arm 65 is kicked up to rotate in the counter-clockwise direction overcoming the force of the spring 71, thereby to cause a rotation of the paper-feed instruction sha~t 49.
In consequence, the arm 50 looated at ~he same side as the plate lb, adapted to rotate unitarily with the shat 49, is rotated so that the claw 50a which has been engaged by the teeth 44a of the retaininy plate 44 ~s shown in Fig. 10 is temporarily moved out o~ engagement with the teeth 44a to turn the clutch 4 . .
..... , ..... ... , . ; ...
` 1~ 137~016 in~o connecting state. In conseguence, the paper feed shaft 37 starts to xotate to feed thc recording paper 14 by one pitch.
As the paper feed shaft 37 starts to rotate, cam body 61 (See ~ig. 7) unitary with the latter is rotated to push up the projection 63d of the releasing axm 63 as shown in Pig~ 12. This motio~ in turn ca~ses the projection 58b of the retaining arm 58 tD moved from the cam valley 63b to the cam valley 63a thereby to dise~gage the claw 58a and the ratchet gear 62b from each other to free the wind-up gear 62. In the state where the projection 53b o~ 'he retaining arm 58 engages the valley 63a of the releasin arm 63, both membexs 58 and 63 are in the dynamically balanced ~tate which is maintained until the releasing arm 63 is depressea by the kick claws ~Oc and 60d of the aforementionea feed pawl 60, thereby to ensure the correct returning operation of the car-r;age. As the gear 62 is freed, the carriage 3 is normally pulled by the tension spring 7 towzr2 'he initial position, so that the Garriage returns to the initial position without delay, pulling the column shift Wire 8 which in turn rotates the wind-up gear 62 to reset the latter to the starting position.
2tl ¦ As has been described, in the typing mechanism of the in~2ntion, the rotary driving mechanism for driving the type whee and the driving shaft mechanims for driving the typing hammer are brought into *he sequential operation by the actions of various clutches. This arrangement offers various advantages. For in-~tancç,the number of the driving sources i5 reduced. In addition it is possible to obtain a serial printer of reduced size and weight and having a high typing speed, because it is possible to ~aintain a constant direction of rota~ of the motor shaft. In addition, the mechanism is very simple and operates at a high re-liability, because the change-over of the clutches is performed b~
~he member selecting the s~nbols or numerals of the type wheels. ' .' ' .
Claims (6)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A printer comprising:
a motor;
a rotary shaft adapted to be rotated unitarily with type wheels and adapted to be driven rotatably by said motor;
first clutch means for selectively transmitting the rotation of said motor to said rotary shaft;
a hammer member adapted to be moved into and out of contact with said type wheels;
a hammer drive shaft adapted to be driven by said motor and carrying a cam member for actuating said hammer member;
second clutch means adapted for selectively transmitting the rotation or said motor to said hammer drive shaft;
control means for controlling said first and second clutch means simultaneously to engage one of said clutch means while disengaging the other;
a carriage carrying said type wheels and slidable in a direction parallel to said rotary shaft;
a spring member connected to one end of said carriage and adapted to urge said carriage toward the initial position;
a thread member connected to the other end of said carriage; and means adapted to gather said thread means to overcome the force of said spring member, said gathering means being actuated by rotation of said hammer drive shaft when the latter is driven through said second clutch means.
a motor;
a rotary shaft adapted to be rotated unitarily with type wheels and adapted to be driven rotatably by said motor;
first clutch means for selectively transmitting the rotation of said motor to said rotary shaft;
a hammer member adapted to be moved into and out of contact with said type wheels;
a hammer drive shaft adapted to be driven by said motor and carrying a cam member for actuating said hammer member;
second clutch means adapted for selectively transmitting the rotation or said motor to said hammer drive shaft;
control means for controlling said first and second clutch means simultaneously to engage one of said clutch means while disengaging the other;
a carriage carrying said type wheels and slidable in a direction parallel to said rotary shaft;
a spring member connected to one end of said carriage and adapted to urge said carriage toward the initial position;
a thread member connected to the other end of said carriage; and means adapted to gather said thread means to overcome the force of said spring member, said gathering means being actuated by rotation of said hammer drive shaft when the latter is driven through said second clutch means.
2. A printer as claimed in claim 1, wherein said gathering means include a drum for winding-up said thread member, said drum being engaged by a gear fixed to said hammer drive gear.
3. A printer as claimed in claim 1, wherein said first and second clutch means have respective ratchets adapted to be engaged by said control means.
4. A printer as claimed in claim 3, wherein said control means includes a solenoid and means including a lever adapted to be actuated by said solenoid for selectively engaging said ratchets of first and second clutch means.
5. A printer comprising:
a motor adapted to rotate a motor shaft in one direction only;
a carriage movable slidably along a line to be printed;
a spring member connected to said carriage for continuously biasing said carriage toward the initial position on said line;
a thread member connected to said carriage and adapted to pull said carriage toward the last position on said line;
a rotary drum for winding-up said thread member by overcoming the biasing force of said spring member;
a feed mechanism including clutch means for selectively transmitting the rotation of said motor shaft to said rotary drum to rotate said rotary drum and draw said carriage towards said last position;
an arm engaging said gear of said rotary drum and adapted to prevent said rotary drum from being rotated by the force of said spring;
a releasing means adapted to keep said arm in the state separated from said gear of said rotary drum when said carriage is returned to said initial position; and means for maintaining said arm separated from said gear over a predetermined period of time when said carriage has been returned to said initial position by means of said releasing means.
a motor adapted to rotate a motor shaft in one direction only;
a carriage movable slidably along a line to be printed;
a spring member connected to said carriage for continuously biasing said carriage toward the initial position on said line;
a thread member connected to said carriage and adapted to pull said carriage toward the last position on said line;
a rotary drum for winding-up said thread member by overcoming the biasing force of said spring member;
a feed mechanism including clutch means for selectively transmitting the rotation of said motor shaft to said rotary drum to rotate said rotary drum and draw said carriage towards said last position;
an arm engaging said gear of said rotary drum and adapted to prevent said rotary drum from being rotated by the force of said spring;
a releasing means adapted to keep said arm in the state separated from said gear of said rotary drum when said carriage is returned to said initial position; and means for maintaining said arm separated from said gear over a predetermined period of time when said carriage has been returned to said initial position by means of said releasing means.
6. A printer as claimed in claim 5, wherein said means for maintaining said arm separated from said gear over a predetermined period of time includes: a releasing arm engaging said arm and movable between a first position and a second position; a cam member adapted to move said releasing arm from said first position to said second position in response to the rotation of paper feed shaft; and a member for driving said releasing arm from said second position to said first position in response to the operation of said feed mechanism.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000422476A CA1171016A (en) | 1979-07-09 | 1983-02-25 | Printer |
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP54086756A JPS5910916B2 (en) | 1979-07-09 | 1979-07-09 | printing device |
| JP86756/79 | 1979-07-09 | ||
| CA000355666A CA1153977A (en) | 1979-07-09 | 1980-07-08 | Printer |
| CA000422476A CA1171016A (en) | 1979-07-09 | 1983-02-25 | Printer |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000355666A Division CA1153977A (en) | 1979-07-09 | 1980-07-08 | Printer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1171016A true CA1171016A (en) | 1984-07-17 |
Family
ID=27166740
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000422476A Expired CA1171016A (en) | 1979-07-09 | 1983-02-25 | Printer |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1171016A (en) |
-
1983
- 1983-02-25 CA CA000422476A patent/CA1171016A/en not_active Expired
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |