US3582748A

US3582748A - Electric sewing machine with remote hand operated control

Info

Publication number: US3582748A
Application number: US703475A
Authority: US
Inventors: Kenzi Kato
Original assignee: Janome Sewing Machine Co Ltd
Current assignee: Janome Corp
Priority date: 1967-02-07
Filing date: 1968-02-06
Publication date: 1971-06-01
Anticipated expiration: 1988-06-01
Also published as: GB1190482A; DE1660886B2; DE1660886A1; DE1660886C3

Abstract

A variable resistor device for controlling the speed of an electric motor is installed in a case small enough to be put into the operator''s palm and a sliding element slidable on a variable resistor can be moved and set to any position as desired by a proper fingering operation of a pair of pushbuttons on said case.

Description

United States Patent Inventor KenziKato [56] ReferencesCited Tokyo, J p UNITED STATES PATENTS I 2, 31 1,660,979 2/1928 Thayer gf ml 3,457,538 7/1969 Rannalli Assignee .lanome Sewing Machine Co. Ltd. 2337066 12/1943 schmlitet Tokyohpan 3,165,688 [/1965 Gutzwlller iggg "319673837, 3:33:23? @1132? 321132.83;:::.......::i:: Ja an 3,364,452 1/1968 Thompsonetal. p 3,374,758 3/1968 Mais 42/4281331, 42/4218606 and 42/429731 ELECTRIC SEWING MACHINE WITH REMOTE Primary Examiner0ris L. Rader Assistant Examiner-Thomas Langer Att0rneyLinton and Linton HAND OPERATED CONTROL 3 Claims, 13 Drawing Figs.

US. Cl 318/551, ABSTRACT: A variable resistor device for controlling the 338/184 speed of an electric motor is installed in a case small enough to Int. Cl H02p 5/16, be put into the operators palm and a sliding element slidable l-IOlh 3/12 on a variable resistor can be moved and set to any position as Field of Search 318/ 17, desired by a proper fingering operation of a pair of pushbuttons on said case.

PATENTEDJUNHSTI I 3582148 SHEET1UF6 INV KENZ/ KDTO ENTOR ATTORNEYS PATENIED JUN nan 3,582,748

SHEET 2 OF 6 ENTOR INV KENZI K T BY /0 K? ATTORNEYS ATENTED Jun 1 l97| SHEET 3 [IF 6 INVENT OR KE/VZ/ KA T0 ATTORNEY 3 PATENTED JUN 1 I97! 3,582,748

SHEEI s 0F 6 INVENTOR KENZ/ K1: T0

ATTORNEYS PATENTEDVJUN Hen 3,582,748

SHEET 5 BF 6 ENTOR KENZ/ KATO ATTORNEYS PATENTEU JUN I I9?! sum 6 BF 6 INVENTOR KENZ! KATO ATTORNEYS ELECTRIC SEWING MACHINE WITH REMOTE HAND OPERATED CONTROL DESCRIPTION OF THE INVENTION This invention relates to an electric-sewing machine, and more particularly to an electric-sewing machine which is capable of performing embroidery and other handicraft stitching work smoothly as well as accurately.

Now the electric-sewing machine is widely used and it enables the operator to perform a sewing operation far more easily than the conventional pedal-driven or hand-driven sewing machine. However generally with this kind of sewing machine the operator has to appropriately control the machine motor to conform the driving speed of the sewing machine to each stitching operation she wants. The speed control of the electric-sewing machine has been conducted usually by adjusting the resistance which is connected in series with the sewing machine motor. Such a conventional speed control has been accompanied by such a drawback as to bring about a power consumption of about 30 watts at the resistance even in a domestic small sewing machine, and accordingly the temperature rise in such a speed control device becomes relatively great. So in reference to the conventional electric-sewing machine it becomes unavoidable to make the speed control device a relatively big one, and moreover it becomes extremely inconvenient in case such a control device is to be installed in the sewing machine. Of course such a big control device would not be not preferable from a view point of manufacture.

The main object of this invention is to eliminate the abovementioned drawbacks and to provide an electric-sewing machine which is capable of performing any kinds of stitching work including an embroidery stitching work more smoothly as well as more accurately. For this purpose the speed control device in this invention is constituted with a small numbers of small electron parts, and therefore this control device is much smallerthan the conventional one. Moreover electric loss in the whole apparatus is at least 1 watt with almost no temperature rise in this device. This speed control device may be operated in the palm of the operators hand or it may be installed in the sewing machine bed, depending on the stitching works.

Generally the sewing machine operator could control the sewing machine with her elbow or foot, but the operators fingers would be best for minute and delicate control of the sewing machine. Therefore the speed control device for the electric-sewing machine of this invention is made to enable the operator to deal with the cloth or other stitching materials with both hands while she controls the driving speed of the sewing machine, gripping this control device in her palm or fingering the same installed in the machine bed. In this manner the operator could pay all her attention to her stitching work.

Therefore another object of the present invention is to provide an electric-sewing machine with a speed control device which maintains a predetermined driving speed of the sewing machine without requiring any special operation, and requires quite an easy operation only when the driving speed of the sewing machine is desired to be changed to conform to a given stitching operation. Accordingly the electric-sewing machine of the present invention is made to allow the operator to put the speed control device in her palm while she devotes both hands to her stitching work.

Still another object of the present invention is to provide an electric-sewing machine with a speed control device which may be installed in the sewing machine bed, Especially when the operator stitches a cloth or other materials of relatively large size, with this control device being installed in the machine bed she could make a more stabilized stitching operation than she could with the same put in her palm. Moreover when the operator performs a relatively monotonous and easy stitching she will need not put the control device in her palm. According to this invention since the speed control device is made so small as to be put in the operators palm the opening to be formed in the machine bed or in the machine table to receive the control device may be as well so small as never to harm the smoothness of the machine bed surface, and moreover when the control device is positioned in the opening, only the button parts of the control device are protruded a little above the surface of the machine bed or machine table, and accordingly there will never be any danger for smooth handling of the stitching material during a stitching operation.

Other features and advantages of this invention will be well understood from the following description made in reference to the attached drawings; in which FIG. I is a perspective view of the whole electric-sewing machine of this invention with some portions of the table and others being omitted.

FIG. 2 is a front elevational view of the electric-sewing machine incorporating the embodiment of this invention with some parts in section and with some parts omitted.

FIG. 3 is a bottom partial view of the electric-sewing machine with the embodiment of the present invention being incorporated therein.

FIG. 4 is a speed control device of the present invention illustrated in a longitudinal side section.

FIG. 5 is a top plane sectional view of the control device of the present invention taken along the line V-V of FIG. 4.

FIG. 6 is a partial sectional view of the embodiment of the present invention taken along the line V1Vl of FIG. 5.

FIG. 7 is a perspective view of the speed control device and a portion of the machine bed to receive the former.

FIG. 8 is a sectional viewof Vlllembodiment of the present invention taken along the line VIII-V111 of FIG. 7. 7.

FIG. 9 is a supporting member and the set screws of the present invention.

FIG. 10 is a diagrammatic view of the connection system of the electric parts according to the present invention.

FIG. 11 is a diagrammatic view showing one example of the electric circuit of the present invention.

FIG. 12 is a diagrammatic representation of control property according to the present invention.

FIG. 13 is a diagrammatic view of the output waveform according to the present invention.

To explain the embodiment of the present invention in reference to the drawings, the machine frame 1 is as shown in FIG. 1 provided on the machine bed 2, and within said frame 1 is incorporated a stitch-generating mechanism such as well known in the art. In the forward end portion of the frame 1 the needle bar 101 is mounted in such a manner that it may make a longitudinal reciprocation movement to and from the needle plate 29 arranged on the machine bed, and also at the lower end of the presser bar 102 is attached the presser foot 103 for pressing the stitching material on the machine bed, all ready for stitching as in the well known manner.

The machine bed 2 supporting the machine frame 1 thereon is hinged on the machine table 6 by means of a pair of

hinge members

51, 61 and carried on the table 6 by means of the support block 62 as shown in FIG. 1, and the machine bed and the frame may be wholly received into the underside of said machine table 6 as becomes necessary. When they are put into the underside of the machine table the auxiliary table 64, connected to said table 6 by means of the hinge member 63, is turned to be laid on said table 6, thus the auxiliary table 64 closes the opening in the table 6 in which said machine bed 2 took its place. As shown in FIGS. 2 and 3, on the underside of the machine bed 2 a machine motor 3 is fixedly mounted on a mounting seat 31 by means ofa pair of bolts 31 Adjacent the electric machine motor 3, a control box 5 is fixedly mounted on the underside wall portion of the machine bed 2 by means of screws 26, which box encloses therein a control circuit portion A of FIG. 11 which is made very small by using electron part members as will be explained hereinafter. To one end of the rotary shaft of the electric-machine motor 3 is fixedly mounted a pulley 33, which is fitted with a portion of a V section belt 7 suspended at another portion around the drive shaft (not illustrated) which is to be horizontally journaled in the machine frame 1, and thus the driving force generated by the electric motor 3 is transmitted to the drive shaft as in a well known manner. As shown in FIG. 3 a portion of a timing belt 28 is fitted on one end of the undershaft 27 which is connected at the other end to the shuttle mechanism (not illustrated), and said timing belt is suspended at another portion to the drive shaft, and thus the rotary movement of the drive shaft is transmitted to the shuttle mechanism. On the other hand the feed shaft 8 is provided in parallel to said undershaft 27 on the underside of the machine bed 2 and is actuated by the feed actuating rod 81 which is connected at the upper end to the drive shaft and at the lower end to the feed shaft 8, and thus the feeding motion, predetermined at the feeding pitch adjust ing device (not illustrated) by the adjusting member 82 provided outside of the machine frame 1, is transmitted to the feed dog (not illustrated) which is provided also on the underside of the machine bed 2, and therefore the stitching cloth or other materials are fed by the feed dog on the machine bed 2 during a stitching operation, which are all well known in the art.

To said control box is connected a speed control device 9 of the present invention by means ofa flexible cord 10 extending from said speed control device 9 at a three lead jack 11 provided on said control box 5 as illustrated in FIGS. 2 and 10. Thus according to this invention said speed control device 9 is either operatively gripped in the operator's palm or installed in an opening 19 formed on the machine bed 2 or on the machine table 6, or in some case installed on the conventional pedal-type machine controller, so as to enable the operator to perform an easy control operation of the sewing machine while she devotes her attention to her stitching operation. In reference to FIG. 2 numeral 16 indicates a plug receiver to receive a plug provided at one end of a power source cord 14, at the other end of which is provided with another plug 13 to be connected to the power source.

As shown in FIGS. 4--6 said speed control device 9 is oblong in appearance, and on the upper side of said speed control device 9 are provided a pair of

pushbuttons

91, 92. The outer frame of said speed control device 9 consists of an enclosing frame 9' and a cover frame 9". In said enclosing frame 9' an actuating lever 93 is pivoted at one end by a pivot 94 to one end portion of said enclosing frame 9' and at the other free end is provided with a pair of sliding elements 95, 95'. A variable resistor plate 96 and a conductor plate 97 are oppositely provided on the other end portion of said enclosing frame 9'. Each sliding element is in a contact relation with the corresponding one of said variable resistor plate 96 and conductor plate 97. The upper and lower ends of said variable resistor plate 96 are connected to two of the three leads introduced by said flexible cord 10, one to the upper and the other to the lower end thereof, and the remaining lead is connected to one end of said conductor plate 97, and further to said variable resistor plate 96 is connected a resistor R by means of two leads, one of which is connected at one end to one end of said variable resistor plate 96 and at the other end to the upper end of the resistor R and the other of which being connected at one end to the lower end of the resistor R and the other end to the middle portion of the variable resistor 96. A rod 910 of said pushbutton 91 is at the lower end fixed on said actuating lever 93 at a position near to said pivot 94, and between said pushbutton 91 and said cover frame 9" is inserted a spring member 91b which usually serves to push said pushbutton 9] upward. When said pushbutton 91 is pushed down against the urging force of said spring member 9112 said actuating lever 93 is moved downward around said pivot 94, and accordingly said pair of sliding

elements

95, 95 are moved downward each in a sliding contact respectively with the corresponding variable resistor plate 96 and conductor plate 97. Towards one side of said actuating lever 93 is extend ing the end portion of a detaining piece 99, base portion of which being pivoted by a pivot 99 to said enclosing frame 9'. Said detaining piece 99 is usually subjected to the urging force ofa coil spring 98 or some other elastic material to engage one side of said actuating lever 93, said coil spring 98 or some other elastic material being fixedly mounted on said enclosing frame 9 and of stronger elasticity than said spring member 91b, and accordingly said actuating lever 93 is detained at any given position during its downward or upward movement with said sliding elements 95, 95' being in contact with said variable resistor plate 96 and conductor plate 97 respectively as aforementioned.

Further opposite to said detaining piece 99 another rod 92a of said pushbutton 92 is provided, said rod 92a being formed with a sloping face 92c at the intermediate portion thereof for engagement with said detaining piece 99 and at the lower end thereof guided in a guide hole 92d formed on the bottom of said enclosing frame 9', and as is in the former case another spring member 92!; is inserted between said pushbutton 92 and said cover frame 9". When said pushbutton 92 is pressed down against the urging force of said spring member 92b said sloping face 920 of said rod 92b pushes said detaining piece 99 around said pivot 99 in the direction away from said actuating lever 93 against the urging force of said coil spring 98 or other elastic material, and thereby releases said actuating lever 93 from the detaining force of said detaining piece 99, and then said actuating lever 93 is subjected to the upward urging force of said spring member 91!; and moved upward. In such a manner said actuating lever 93 may be detained at any given position during its upward and downward movement.

According to this invention said speed control device 9 is, as understood from the foregoing description, made to be a small one of no more than 5 cm. long, one so small as to be put into the operators palm. As especially shown in FIG. 2 this device 9 could very well be operated in the operator's palm by pushing or releasing said

pushbuttons

91, 92 with any fingers other than the thumb and fore finger, and therefor the operators thumb and fore finger could serve to deal with the stitching cloth or other material on the machine bed 2 in cooperation with the other hand while she grips this device 9 in her palm. On the other hand said speed control device 9 may be installed on the machine bed 2 as shown in FIGS. I and 7. For this purpose an opening 19 with a slot 19' extending from one end of said opening 19 is formed on the machine bed 2 or on the machine table 6, the opening receiving therein said speed control device 9 and the latter receiving therein a portion of said flexible cord 10 which extends from said speed control device 9. Below said opening 19 a supporting member 22 is arranged and fixedly mounted by a pair of setscrews 23 on the underside wall of said machine bed 2. Said supporting member 22 is all integrally consisted of a pair of elastic-holding pieces 22a formed at the free end of said supporting member 22 and a supporting seat 25 formed in the middle portion of said sup porting member 22, said supporting seat 25 being adapted to support said speed control device 9 in a stabilized condition while said holding pieces 22a adapted to elastically hold the same in cooperation with said supporting seat 25. In such a manner said speed control device 9 is fittedly positioned in said opening 19 with said

pushbuttons

91, 92 thereof protruded a little above said machine bed 2. Of course such an opening 19 may be formed on the machine table 6 when necessary as shown in FIG. 1. In any case in consideration of the size of said device 9, it will never deform the whole appearance of the sewing machine or hinder the operator from freely dealing with the stitching cloth or other material on the machine bed 2.

FIG. 10 represents an electric connection for this electricsewing machine, and FIG. 11 is a diagrammatic electric circuit, i.e. one example for the electric connection of FIG. 10. In FIG. I0 the portion encircled by the two-dot chain line is an electric connection system incorporated within the machine frame 1 and bed 2, and there are condensers C and C resistors R and R pulse transformer P.T., symmetrical semiconductor elements SSSM and SSST and diode D, all arranged on a printed base board 30 and connected to a dielectric piece 34 which is printed on said base board 30, so as to constitute an electric circuit, and then received in said control box 5 on the underside of the machine bed 2. F is a cooling fan for said symmetrical semiconductor element SSSM which is attached to said fan by means of an attaching member (3 and connected to said printed base board 30 by means of a con ductor 35. M is laminated armatures of said electric motor and LM is a field winding thereof, and L is a sewing machine lamp. So said power source plug 13, plug receiver plug 16, lamp L, said electric motor 3, and said leads 18, which extending from said printed base board 30, are connected in such a system as shown in FlG. 10. Accordingly said variable resistor device V.R, actually consisted of said variable resistor plate 96 and conductor plate 97, is taken out of the machine frame 1 and enclosed in said speed control device 9, and also said speed control device may be separated at connecting jack 11 from this electric-sewing machine as it becomes necessary.

According to the present electric circuit the speed control of the motor is performed by changing the continuity angle of the semiconductor element SSSM for main circuit. This circuit is relatively simple in structure and also extremely sensitive to the speed change of motor which is brought about by the fluctuation of the load. Moreover this circuit achieves a simple and accurate control by making the voltage applied to the element SSST for ignition positively and negatively asymmetrical and also by utilizing the electromotive force of the motor generated by the magnetic residue which is brought about by the continuity electric current to the motor. The speed control according to the present circuit may be performed through wave omission control and phase control. Namely the present circuit improves the low speed starting property as well as the low speed control of the sewing machine much more than the conventional one, and at the same time assures the high speed workability of the sewing machine. In this circuit the voltage applied to the motor is controlled in such a manner as shown in FIG. 13 (a)(/), in which dotted lines indicate the voltage wave of alternating current source and the portions defined by solid lines show that the motor is supplied with electric current. As shown in FIG. 13 the voltage waves at (a) to the ones at (d) are not all subjected to phase control, but they are subjected to so called wave omission control, and the waves at (d) to (e) are sub jected to phase control, and the waves at (f) are all subjected to control. In the present circuit such various controls are realized to increase the workability of the sewing machine.

ln reference to FIG. 11 SSSM is a symmetrical semiconductor element for main circuit; P.T. is a pulse transformer; and M is a single phase series winding commutator motor; they constitute a series circuit with the alternating power source AC as illustrated, and in parallel with said alternating power source AC is connected a series circuit of variable resistor V.R and resistor R3, said variable resistor V.R being used as a potentiometer in this circuit. To said variable resistor V.R is connected the condenser C in parallel; between the connecting point of said V.R and R and a desired point of the V.R is connected resistor R between the aforementioned sliding elements 95, 95' of the variable resistor V.R and one terminal Y of motor M is connected \a series circuit of condenser C diode D and resistor R and to said condenser C is connected in parallel a series circuit of symmetrical semiconductor element SSST for ignition and the primary winding of pulse transformer P.T. ln thus constituted electric circuit when said slid ing elements 95, are progressively shifted from point P to point 0 the voltage applied to the motor is gradually con trolled just as illustrated in FIG. 13 (a)-(f). Especially in this circuit to make possible a delicate control of the sewing machine resistor R is employed as illustrated which serves to produce the controlled voltage waves such as illustrated in FIG. 13, (a)(d), and thereby the voltage distribution over the variable resistor V.R is made of nonstraight line as illustrated in FIG. 12. Accordingly as said sliding elements 95, 95' slide over such a voltage distribution the rotation of the sewing machine gains a mild variation property at low speed operation and a swift variation property at high speed operation, and therefore a very preferable machine property.

I claim:

1. In an electric-sewing machine having a machine bed and a machine frame supported thereon, a single-phase series winding commutator motor for driving said sewing machine and a control circuit adapted to control the rotational speed of said motor, said circuit consisting of a speed control circuit portion incorporating a plurality of semiconductor control elements and a resistor adjusting portion incorporating as the main constituents a variable resistor and a plurality of sliding elements, said speed control circuit portion and said resistoradjusting portion being spaced-apart, a case containing said speed control circuit portion and mounted in said machine frame or on the underside of said machine bed, a second case small enough to be put in the operators palm and containing said adjusting portion, a flexible cord connecting said portions, a plurality of operating members mounted on said second case, said motor and said speed control circuit portion adapted to be connected to a power source enabling the operator to perform general stitching operations on the sewing machine with one hand while performing a speed control operation of said sewing machine, said operating members being two pushbuttons slideably arranged on one side of said second case, an actuating lever attached to said sliding element and pivotally mounted in said case and to one of said pushbuttons for being actuated by said one of said pushbuttons to adjust the contacting position of said sliding elements on said variable resistor, a detaining member and an elastic member provided in said second case in such a manner that said elastic member tends to urge said detaining member into engagement with said actuating lever and thereby detain said sliding elements at a given position on said resistor and the second of said pushbuttons being positioned to engage said detaining member and capable of releasing said lever from the detaining force of said detaining member.

2. In an electric-sewing machine as set forth in claim 1, wherein an opening is provided in said machine bed to receive said second case accommodating said resistor-adjusting portion and a support member is arranged in said opening to support said case in said opening.

3. In an electric-sewing machine as set forth in claim 1, wherein said machine table has an opening for receiving said case and a support is provided on said machine table to support said case when in said opening.

Claims

1. In an electric-sewing machine having a machine bed and a machine frame supported thereon, a single-phase series winding commutator motor for driving said sewing machine and a control circuit adapted to control the rotational speed of said motor, said circuit consisting of a speed control circuit portion incorporating a plurality of semiconductor control elements and a resistor adjusting portion incorporating as the main constituents a variable resistor and a plurality of sliding elements, said speed control circuit portion and said resistor-adjusting portion being spaced-apart, a case containing said speed control circuit portion and mounted in said machine frame or on the underside of said machine bed, a second case small enough to be put in the operator''s palm and containing said adjusting portion, a flexible cord connecting said portions, a plurality of operating members mounted on said second case, said motor and said speed control circuit portion adapted to be connected to a power source enabling the operator to perform general stitching operations on the sewing machine with one hand while performing a speed control operation of said sewing machine, said operating members being two pushbuttons slideably arranged on one side of said second case, an actuating lever attached to said sliding element and pivotally mounted in said case and to one of said pushbuttons for being actuated by said one of said pushbuttons to adjust the contacting position of said sliding elements on said variable resistor, a detaining member and an elastic member provided in said second case in such a manner that said elastic member tends to urge said detaining member into engagement with said actuating lever and thereby detain said sliding elements at a given position on said resistor and the second of said pushbuttons being positioned to engage said detaining member and capable of releasing said lever from the detaining force of said detaining member.