US2902133A - Typewriter carriage return and indexing mechanism - Google Patents

Description

Sept. 1, 1959 N. D. WALTON ETAL TYPEWRITER CARRIAGE RETURN AND INDEXING MECHANISM Filed Dec. 30, 1957 3 Sheets-Sheet l IN VENTORS NEIL D. WALTON HENRY R. KRUSPE ATTORNEY Sept. 1, 1959 N. D. WALTON ETAL 2,902,133

' TYPEWRITER' CARRIAGE RETURN AND mnzxmc MECHANISM Filed bee. so, 1957 s Sheets-Sheet 2 Sept'. 1, 1959 N. D. WALTON ETIAL 2,902,133

TYPEWRITER CARRIAGE RETURN AND INDEXING MECHANISM Filed Dec. 30, 1957 3 Sheets-Sheet 3 United States Patent TYPEWRITER CARRIAGE RETURN AND HVDEXING MECHANISM Neil D. Walton and Henry R. Kruspe, Lexington, Ky.,

assignors to International Business Machines Corporation, New York, N .Y., a corporation'of- New York Application December 30, I957, SerialNo. 705,978

4 Claims. (Cl.. 19766) This invention relates to typewriters, and more particularly to mechanisms for controlling the movement of a typewriter carriage during typing operations.

All typewriters are provided with a carriage which is movable on a stationary frame to obtain a positioning of type elements. and a sheet of paper such that printing takes place on the paper at the desired location. Most of the typewriters in use today have a carriage carrying a platen about which the sheet of paper is wrapped. The carriage is moved to position the paper relative to a point at which type elements may be engaged selectively with the paper.

In a patent application by L. E. Palmer, Serial Number 653,806, filed April 19, 1957, there is shown a typewriter having a carriage on which a type head ismounted. The carriage is moved to position the type head for printing on a sheet of paper wrapped about a stationary platen.

Regardless of what form the typewriter takes, the carriage is moved at a comparatively high speed from a position where typing takes place at the end of one line to a position at the beginning of the next line. It is desirable that the carriage be stopped without excessive shock when the beginning of a new line is reached, and it is essential that the'carriage always be brought to rest in the same position so that the typing for each line is started from the same point. As the carriage is moved to a position for typing another line, means should operate automatically to index the platen for positioning the sheet of paper to'receive print a desired distance below the line already typed. The indexing; means should be associated with the carriage return mechanism in such a Way that an indexing of the platen without carriage return can be obtained, if desired.

An object of this invention is to provide an improved mechanism for moving the carriage of a typewriter from any point in one line to a position for typing at the beginning of another line.

Another object of this invention is to provide an improved mechanism for moving a typewriter carriage with a minimum of shock and noise from any point in a line to a position for typing at the beginning of the line.

Still another object is to provide an improvedplaten indexing means associated with ya carriage moving means in such a way that an indexing of the platen is obtained simultaneously with movement of the carriage. by the moving means, or an indexing of the platen may be obtainedwhile the moving means is held inoperative.

Other objects of the invention will be. pointed out in the following description and claims and illustrated in the accompanying drawings, which disclose, by way of example, the principle of the invention and the best mode, which has been contemplated, ofapplying that principle.

'Inthe drawings:

Fig. 1 isa. perspective view of the improved mechanism for moving a typewriter carriage from a typing position in one line to a typing position at the beginning of an- V other line.

Fig. 2 is an enlarged sectional view of the clutch mechanism controlling the drive of the carriage.

Fig; 3 is an elevational view taken from the right hand sideof Fig. 1.

Fig. 4 is a perspective view of mechanism for operating the escapement pawl of Fig. 1 during letter spacing.

Referring to the drawings it will be noted that there is shown in Fig. 1 a mechanism for moving a carriage 2 like the carriage in the Palmer application referred to above. This carriage is adapted to carry a print head, as shown in the Palmer application, which can be engaged with a sheet of paper on a platen 3 to effect printing. Since the print head and the mechanism for actuating it form no part of the present invention, it will not be shown or described herein.

The carriage 2 is slidably mounted on a shaft 4 so as to present the type head for printing at any point along a line on the sheet of paper carried by the platen. Fixed to the carriage is a tape or wire 5 extending about pulleys 6 and 7 to a pulley 8 to which it is attached by any suitable means. The pulleys 6 and 7 are rotatably supported by fixed shafts 1 0 and ll, respectively, and pulley 8 is fixed to a rotatable shaft 12. Another tape or wire 14 is fixed to the carriage and extends around pulleys 15 and 16 to a pulley 17 to which it is connected by any suitable means. Pulley 15' is rotatably supported by a stationary shaft 19 while pulley 16 is rotatably supported by the shaft 11 and pulley 17 is fixed to the rotatable shaft 12. The arrangement is such that a rotation of the shaft 12 in a clockwise direction causes the tape 5 to be wound onto the pulley 8 and effect movement of the carriage to the left. During this time, the tape 14 is unwound from the pulley 17. When the shaft 12 is rotated in a counterclockwise direction, the tape 14 is wound onto the pulley 17 to cause movement of the carriage to the right.

For rotating the shaft 12 in a clockwise direction, there is provided a toothed belt 20v driven at a constant speed by a power means, not shown. The belt 20 engages a toothe Whe 1'21, g. fi ed o a h f 2- E di from tllQ'Wheel is a hub 23 which is carried by a bearing 24 mounted within an opening in a frame plate 25. Freely mounted on the shaft 22 adjacent the hub 23 is a sleeve shaped member 26 having an outside diameter at its left end equal to the outside diameter of a reduced portion 28 on the hub. Surrounding the reduced portion 28 and an adjacent portion of the sleeve member is a coiled spring 30 which is wound in a clockwise direction looking from left to right in Fig. 2. Fixed to the hub 23 by a screw 31 is a bracket having a finger portion 32 extending over the spring 30 parallel to the shaft 22, and another finger portion 34 acting against the left hand end of the spring 30 to clamp it to the hub. The spring 30 is wound so as to have frictional contact with the surface of the sleeve member 26, and the right hand end of the spring 30 is pulled by a spring 36 in a direction to in crease its frictional engagement with the sleeve member.

Freely mounted upon the shaft 22 adjacent the sleeve member 26 is a bevel gear 38 having a hub portion 39 slightly smaller in outside diameter than a reduced portion 40 on the sleeve member. Surrounding the reduced portion 40 and part of the hub 39' is a clutch spring 41 which is wound in a direction opposite to the direction of rotation of the shaft 22. A clamp 42 holds the left hand end of the spring for rotation with the sleeve member 26, and a slight clearance between the spring and the hub 39 permits the gear 38 to rotate normally free of the shaft 22 and the member 26. Arranged adjacent the right end of the spring 41 is a roller 44 which may be moved by mechanism to be described later, against the spring 41 for forcing it into engagement with the hub .of the gear 38. The friction between the hub and the spring causes the latter to wind tightly against the hub and effect a driving of the gear 38.

Fixed to the shaft 12 is a bevel gear 46 meshing with the bevel gear 38. When the gear 38 is driven by engagement of the spring 41 with its hub, the shaft 12 is also driven in a clockwise direction. Surrounding the shaft 12, as shown in Fig. 2, is a helically wound spring 47 which is connected at one end to the shaft and is connected at its other end to a stationary part of the typewriter frame. This spring is wound in such a direction that it tends to rotate the shaft 12 in a counter-clockwise direction. Fixed to the shaft 12 is a ratchet wheel 48 which is normally engaged by a pawl 49 for holding the shaft against rotation by the spring 47. This pawl is pivotally supported by a pin 50 and is urged by a spring 51 into engagement with the ratchet wheel. Engaging a slot 53 in an upwardly projecting arm of the pawl is a link 54 which is connected to a bellcrank 55 pivotally supported on a rod 56.

The roller 44 controlling the clutch spring 41 is carried by an arm 58 pivotally supported at 59 and urged by a spring 60 in a direction to disengage the roller from the clutch spring. A bellcrank 61 is operable to actuate the arm 58 for engaging the roller 44 with the clutch spring 41, and a link 62 connects the bellcrank 61 to a bellcrank 63 pivotally supported on the rod 56. The bellcranks 55 and 63 are provided with arm portions 65 and 66 extending parallel to each other, and formed integral with the arm portion 66 is a bridge portion 67 extending over the arm portion 65 and having a projecting portion 68 engageable at its upper edge by a latch 70. Arranged adjacent the ends of the arm portions 65 and 66 are latches 71 and 72 pivotally supported on a shaft 73 and urged toward each other by a spring 74. When the bellcranks 55 and 63 are in the positions shown in Fig. 1, the pawl 49 is permitted to engage the ratchet wheel 48 while the roller 44 is held out of engagement with the clutch spring 41, and the arm portions 65, 66 of the bellcranks are raised so that their upper edges are above the latches 71 and 72. Pivotally mounted on the end of shaft 73, as shown in Figs. 1 and 3, is a member 75 carrying an eccentric 76 which acts against the left edge of the latch 71. Projecting from this member, as shown in Fig. 3, is a finger 77 in a position to engage the right edge of the latch 72 when the member 75 is rocked in a counter clockwise direction. The member 75 is normally rocked by a spring 79 in a clockwise direction about the shaft 73, engaging the eccentric with the latch 71 and forcing the latter away from the arm portion 65 of the bellcrank 55. Spring 74 connecting the latches operates at this time to hold the latch 72 against the side of the arm portion 66 on the bellcrank 63. As shown in Fig. 3, a slight clearance exists between the latch 72 and the finger 77 on the member 75.

The latch 70 is pivotally connected at its lower end to a cam lever 81, and is urged by a spring 82 in a direction to engage the projecting portion 68 on the bellcrank 63. Formed upon the forward end of the cam lever is a projecting portion 84 carrying a cam 85 which is adapted to rotate into engagement with a power roll 86 fixed to the rotating shaft 22. A spring actuated arm 87 acts against a stud 88 on the cam for urging the latter in a clockwise direction to engage the power roll. At the opposite side of the cam is a stud 90, see Fig. 3, normally engaging a latch 91 which holds the cam free of the power roll. The latch 91 is urged by a spring 92 about a pivot point 93 on the cam lever to a position in which the end of the latch lies in the path of the stud 90. A clevis 94 engages a slot in an arm 95 of the latch and is connected by links 97 and 98 to key levers 99 and 100, as shown. Upon actuation of either one of these keylevers, the latch 91 is rocked to release the cam 85 so that the arm 87 forces it into engagement with the power roll. As the cam is rotated by the power roll, the cam lever 81 is caused to rotate about a pivot point 102 in a clockwisedirection.

Arranged below the cam lever adjacent its rear end is a member 104 pivotally mounted in a bracket 105 and having an arm 106 engageable with the lower end of the latch 70 for holding the latter free of the portion 68 on the bellcrank 63. Formed in the member 104 is an L-shaped slot 197 receiving a pin 108 of a clevis 109 which is connected by a link 110 to an arm 111 integral with the key lever 99. The link 110 is normally held by a spring 112 in such a position that the pin 108 lies in the vertical portion of the L-shaped slot 107, as shown in Fig. 3. The member 104 is urged upwardly by a spring 114 against an abutment 115 to position the arm 186 for engagement with the lower end of the latch 70.

As the key lever 99 is depressed, the link 110 is first actuated to swing the member 104 so that the arm 106 is removed from the latch 70. This latch is then moved by the spring 82 to a position for engaging the portion 68 of the bellcrank 63. Depression of the key lever 99 also actuates the link 97 to rook the latch 91 out of the path of the stud 90 on the cam 85. The spring arm 87 then rocks the cam against the power roll which drives the cam to effect a rocking of the cam lever 81 in a clockwise direction about its pivot 102. As the cam lever rocks, the latch 70 is pulled downwardly and causes the bellcrank 63 to rock in a clockwise direction. Since the bridge portion 67 on the bellcrank 63 overlies the bellcrank 55, the latter bellcrank is also caused to rock in a clockwise direction. These bellcranks are rocked to a position where the latch 72 engages the upper edge of the arm portion 66 on the bellcrank 63 and causes both bellcranks to be held in their rocked positions. The rocking of the bellcrank 63 causes the arm 58 to be actuated for engaging the roller 44 with the clutch spring 41 and causing the gear 38 to be driven for rotating the shaft 12. Rocking of the bellcrank 55 causes the pawl 49 to be disengaged from the ratchet wheel 48.

During the swinging of the cam lever 81 about its pivot, a projection 116 on the lower end of the latch 70 is engaged with the link 110 to force the latter downwardly until the clevis pin 108 is moved into the horizontal portion of the L-shaped slot 107. This permits the member 104 to be swung upwardly by the spring 114 until the arm portion 106 engages a surface 117 on the lower end of the latch 70. At the forward side of the latch 70 is a member 118 engageable by a cam surface 119 on the latch for forcing the latter away from the portion 68 of the bellcrank 63 when the arm portion 66 is in position to be engaged by the latch 72. As the latch 70 is cammed away from the portion 68, the arm 106 of the member 104 moves from the surface 117 to a. position in back of the latch 70 for holding the latter in its released position.

Formed on the rear end of the cam lever is a cam surface 120 which is engageable with a roller 122 carried by a bellcrank 123 for rocking the latter about a pivot point 124. A link 125 is connected at one end to the bellcrank 123 and is connected at its other end to another bellcrank 126 which has mounted on it a dog 127 engageable with a ratchet wheel 128 fixed to the platen 3. On each rocking motion of the cam lever 81, the bellcrank 123 is operated to actuate the dog 127 for indexing the platen.

-It will be noted that a depression of the key lever 99 results in a releasing of the cam 85 to engage the power roll for rocking the cam lever, and the member 104 is also actuated to release the latch 70 so that it can effect an engagement of the clutch spring 41 to drive the shaft 12 and also disengage the pawl 49 from the ratchet wheel '48. A depression of the key lever 100, however, results only in a release of the cam 85 to engage the power roll for rocking the cam lever 81. During this time, the member 104 remains in the position shown to hold the latch 76 out of engagement with the portion 68 on the bellcrank 63. The rocking of the cam lever results in an indexing of the platen but, since the bellcrank 63 is not actuated, the cairiage 'r'etiiainsstationary. .As mentioned above, a depression of. the key lever 99 results in a release ofthe pawl 49 from the ratchet wheel 48 and an operation of the'clutch spring 41 to effect a driving of the shaft 12in a clockwise direction for moving the carriage Z to the left. Fixed to the carriage is a lproiecting member 130 which is engageable with a stop 131 adjustably: mounted on a rack I32 extending trans -verseIy of the typewriter parallel to the sh'aft14. The rack is slidably supported at its left end, as shown in Fig. 1, by a frame portion 134, and a spring 135 acts between. the frame and the rack for urging the latter to Ithe right. Similar supporting means is provided for the :right hand end of the rack. Formed upon the rack at tits right end is a portion 136 extending beyond the frame :support and carrying a pm 137 engaging a bellcrank 138 whichis connected by a link 139, as shown in Fig. 3, to the member 75. The pull on the member 75 by the :spring 79 operates through the link 139 to hold the bellcrank 138 against the pin 137.

The stop 131 is positioned on the rack 132 so that :it is first engaged by the member 130 when the carriage .2 is in.a position for typing at the beginning of a line. .As the carriage is driven to the left, the member 130 engages the stop 131 and causes the rack 132 to move :against the action of the spring 135. This movement of the rack causes the bellcrank 138 to swing about its pivot 1-40 and rock the member 75 in a counter clockwise direction in Fig. 3. During the first part of the rocking :motion by member 75, the latch 71 is permitted to move ninder the action of the spring 74 to a position for latching the arm portion 65 of the bellcrank 55. The finger 77 on the member 75 then engages the latch 72 and moves the latter out of contact with the arm portion 66 of the bellcrank 63. As soon as the bellcrank 63 is nnlatched, the roller 44 is moved out of engagement with the clutch spring 41 by a swinging of the arm 58 under the action of the spring 60. This results in release of the drive connections to the carriage but the latter may continue to move to the left under its inertia against the action of the spring 47 tending to rotate the shaft 12 in a counter clockwise direction. The spring 135 acting on the rack 132 will also operate to oppose movement of the carriage after the drive clutch has been disengaged. When the inertia of the carriage has been overcome by the springs 47 and 135, the carriage is moved to the right and the rack 132 moves with it. Movement of the rack permits the member 75 to rock clockwise about its pivot under the action of the spring 79. As the carriage approaches the position for typing at the beginning of a line, the eccentric 76 on the member 75 moves the latch 71 out of engagement with the arm portion 65 of the bellcrank 55. This results in an operation of the pawl 49 by the spring 51 to engage the ratchet wheel 48 when the carriage reaches the beginning of the line and causes it to be held against further movement by the spring 47.

Movement of the carriage to the right from the beginning of a line of type takes place under the action of the spring 47 as the pawl 49 is operated upon actuation of type keys, a space bar, or a tabulation key, not shown. As shown and described in the Palmer application referred to above, a shaft 133, Fig. 4, is caused to rotate 180 upon each actuation of a type key. Mounted upon the shaft 133 is a cam 142 which actuates a bellcrank 143 once upon each turning of the shaft through 180. A link 144 connects the bell crank 143 to a bellcra-nk 145 which actuates the pawl 49 to permit a rotation of the wheel 48 one tooth space for effecting escapement of the carriage. Tabulation may be obtained by holding the pawl free of the ratchet wheel 48 through any suitable means, not shown, until the carriage engages a tabulation stop.

When the carriage is released for movement to the right a substantial distance under the action of the spring 47, the carriage speed may become. eiicessive unless som regulating means is provided. To control the. speed. of the carriage, there is provided a bevel gear 147 freely mounted on the shaft. 22 and meshing with the. gear 46* As the spring 47 rotates the shaft 12. tov move the Carriage to the right, the gear 46 drives. the gear'1 47 in the same direction as the shaft 22 rotates. Fixed to the. shaft 22, as shown in Fig. 2', is a sleeve member 148. Coiled about the member 148-and'. a hub1l4 9' of the gear 147 is a spring 150. This springiis. coiled'abo'ut the member 148 and the hub 149 in the same direction as the shaft rotation looking fromleft to right and has frictional engagement therewith. It will be seen that. a-IQ- tation of the gear 147 at a speed below that of the shaft results in an expanding of the spring. 150 so that. it. does not affect the turning of the gear. If thefg ear 147 tends to rotate, however, atv a speed greater than that of the shaft, the spring 150 grips the member 148 and the hub 149 and places such a load on the gear 147 that it can be driven only at the speed of the shaft.

While there have been shown and described and pointed out the fundamental novel features of the invention as applied to a preferred embodiment, it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention. It is the intention therefore, to be limited only as indicated by the scope of the following claims.

What is claimed is:

1. A mechanism for moving a typewriter carriage from any typing position in a line to a position for typing at the beginning of the line comprising, in combination, power means, meansadapted to be actuated by said power means for moving said carriage toward a position at which typing may take place at the beginning of the line, a clutch mechanism for controlling the connection of said power actuated means to said power means, means for yieldingly urging said carriage in a direction opposite to the movement by said power actuated means, means normally holding said carriage against movement by said yielding means, means including a pair of members movable against the action of yieldable means to a control position, one member operating on movement to such position for engaging said clutch mechanism and the second member operating to release said holding means, manually controlled power means for moving said members to said control position, a first latch operable to hold said pair of members in said control position when moved thereto, a second latch engageable with said second member when in said control position, means operating on movement of said carriage to said position at the beginning of the line for releasing said first latch from said pair of members and engaging said second latch with said second member, said carriage moving by inertia beyond said position at the beginning of the line against the action of said yielding means, and means operating on return of said carriage to said position for disengaging said second latch from said second member.

2. The mechanism of claim 1 in which said manually controlled power means includes. a cam lever, a continuously driven power roll, a cam on said lever engageable with said power roll, a key lever operable manually for effecting engagement of said cam with said power roll, a latch pivoted on said cam lever and engageable with said pair of members, means yieldingly urging said latch toward said pair of members, and means operating upon predetermined movement of said cam lever for moving said latch out of engagement with said pair of members.

3. A mechanism for moving a typewriter carriage from any typing position in a line to a position for typing at the beginning of another line comprising, in combination, power means, means adapted to be actuated by said power means for moving said carriage toward the beginning of a line, a clutch mechanism for controlling the connection of said power actuated means to said power means, means yieldingly urging said carriage in the opposite direction, a ratchet and pawl normally holding said carriage against movement by said yielding means, means including a pair of bellcranks movable to a control position, one operating to apply said clutch and the second operating to release said holding means, a first latch operable to hold said bellcranks in their control position, a second latch operable to hold said second bellcrank in its control position, a cam lever, a third latch pivoted on said cam lever and engageable with said bellcranks for moving them to said control position, a

cam mounted on said cam lever, a continuously rotating 15 power roll, means including a key lever operable to engage said cam with said power roll for effecting a rocking of'said cam lever, indexing means operable by said cam lever, means operating on movement of said carriage to said typing position at the beginning of a line to disengage said first latch from said bellcranks and to engage said second latch with said second bellcrank, and means operating on return of said carriage to said position for disengaging said second latch from said second bellcrank.

4. The mechanism of claim 3 including a member engageable with said third latch for holding it free from said bellcranks, and means operable by said key lever for disengaging said holding member from said third latch.

References Cited in the file of this patent UNITED STATES PATENTS 2,258,116 Khalil Oct. 7, 1941 2,797,789 Yaeger July 2, 1957 2,831,558 Toggenburger Apr. 22, 1958.

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