US3307510A - Motor drive and needle positioning mechanism for sewing machines - Google Patents

Description

March 7, 1967 K. HEDEGAARD ETAL 3,307,510 MOTOR DRIVE AND NEEDLE POSITIONING MECHANISM FOR SEWING MACHINES F i led "Aug. 15, 1964 4 Sheets-Sheet l Fig. 1

/N VE N TOPS. KRIS TEN HEDEGAA R0 By ALBERT MA/ER HEINZ VOGEL March 7, 1967" K. HEDEGAARD ETAL ,5

MOTOR DRIVE AND NEEDLE POSITIONING MECHANISM FOR SEWING MACHINES Filed Aug 13, 1964 4 Sheets-Sheet 2 Fig. 5

INVENTORS KRISTEN HEDEGAARD y- ALBERT MA/ER HE/NZ VOGEL March 7, 1967 K. HEDEGAARD ETAL 7,5

MOTOR DRIVE AND NEEDLE POSITIONING MECHANISM FOR SEWING MACHINES Filed Aug. 13, 1964 4 Sheets-Sheet 5 Fig. 6 4

Fig. 10 W INVENTORS.

KRISTEN HEDEGAARD. BY ALBERT MAIER HE INZ VOGEL March 7, 1967 K. HEDEGAARD ETAL 3,307,510

MOTOR DRIVE AND NEEDLE POSITIONING MECHANISM FOR SEWING MACHINES Filed Aug. 13, 1964 v 4 Sheets-Sheet 4.

ER EL INVENTORS KRISTEN HEDEGAARD y ALBERT MAI HE/NZ voe United States Patent 11 Claims. in. 112 219 The present invention relates to motor drive and needle stoppage or positioning mechanisms for sewing machines of the type comprising a continuously running drive motor and main and auxiliary coupling means operably connecting said machine with said motor, said auxiliary drive means including speed reduction means and becoming operative upon the stoppage of the machine or disconnection of the main drive means upon completion of a sewing operation, whereby to rotate the machine at reduced operating speed for the final stoppage thereof, by the aid of an electrical contact device operably connected with the drive shaft of the machine, at one of a plurality of predetermined angular positions of said shaft, such, for instance, in the UP or DOWN position of the needle.

More particularly, the invention is concerned with automatic needle positioning means for sewing machines of the type including a foot pedal or the like operating organ selectively operable from a zero or rest position in one direction, such as by a downward deflection of said pedal, for the starting and control of the speed of the machine, as well as in the opposite direction, such as by an upward deflection of said pedal, for effecting the selective stoppage of the machine with the needle in either the UP or DOWN position, respectively.

The contact device is advantageously connected in series with a main control switch in the circuit of a solenoid or the like for the starting and stopping of the auxiliary drive and a changeover switch, to select the needle stopping positions.

In the known arrangements of this type, it is necessary for the seamstress, in order to control the sewing speed and to effect the stoppage of the machine at a desired needle position, to actuate, aside from the operation of the foot pedal or the like, a further operating organ, if it is desired to selectively stop the machine in more than one predetermined needle position. This additional operating organ may be in the form of a further foot pedal,or in the form of a knee-controlled lever or the like control device. The alternate operation of the main foot pedal for effecting the control of the sewing speed and of the auxiliary pedal or the like to control the needle stopping position not only imposes an added burden on the seamstress by requiring her constant attention or concentration, to ensure a proper operation of both control organs at the proper time and in a correct manner or sequence, but will result in early or premature fatigue. Besides, the operation of such a control requires an extended training period or special skill on the part of the operator.

Accordingly, an important object of the present invention is the provision of improved motor drive and needle positioning mechanism of the referred to type by which a separate control or operating step, to select a desired needle stopping position is substantially eliminated, whereby to allow of the full attention or concentration of the seamstress to be devote-d to the guidance of the work and the sewing operation at hand.

In other words, the invention purports to simplify the needle positioning control to an extent as to require. little 3,3015 10- Patented Mar. 7, 1967 or no pre-training, or special skill on the part of the operator.

Among the other objects of the invention is the provision of improved needle positioning mechanism of the type referred to which is both simple in design and construction; which is practically foolproof in operation, and which can be readily structurally embodied in conventional motor drive and needle stopping devices or systerm.

The invention, both as to the foregoing and ancillary objects, as well as novel aspects thereof, will be better understood from the following detailed description, taken in conjunction With the accompanying drawings forming part of this specification and in which:

FIG. 1 is a longitudinal cross-section through a motor drive and needle stopping or positioning mechanism for sewing machines, being constructed in accordance with the principles of the invention;

FIG. 2 is a partial view taken on line lIII of FIG. 1;

FIG. 3 is a sectional view taken on line 'IIIIII of FIG. 1;

FIG. 4 is a perspective detail view of the motor brake locking and release mechanism forming part of FIG. 1;

FIG. 5 is a circuit diagram showing the electrical connections of the needle positioning system according to the preceding figures;

FIG. 6 is a fragmentary perspective view of the needle positioning control of the preceding figures, shown with parts thereof in extended or exploded position;

FIG. 7 is a fragmentary view of FIG. 1, showing a modification of the needle stoppage and positioning mechanism according to the invention;

FIG. 8 is an enlarged sectional view taken on line VIII-VIII of FIG. 7;

FIG. 9 is an enlarged partial view of FIG. 7, and

FIG. 10 is a circuit diagram illustrating an alternative needle stoppage control device according to the invention.

Like reference numerals denote like parts throughout the different views of the drawings.

With the foregoing objects in view, the invention involves generally the provision of improved needle positioning control mechanism of the referred to type, wherein the main control switch and the change-over switch of said mechanism are so arranged relative to or coupled with the foot pedal or the like operating organ, or a linkage or the like member operably connected therewith, said pedal serving for the starting of and control of the operating speed of the drive motor through the main coupling means, as to control both said switches by the deflection of said pedal in either direction from its rest or normal position, respectively.

According to a prefer-red embodiment, the pedal in the depressed position, or deflection in one direction from its normal or rest position for the carrying out of a sewing operation, causes the main switch to be opened and the change-over switch to be in a position for effecting the stoppage in the DOWN position of the needle, while in the normal or rest position of the pedal the main switch becomes closed and the changeover switch remains in the position for stopping the needle in the DOWN position, and finally, in the position of deflection of the pedal in the opposite (upward) direction beyond the zero position, the change-over switch is operated to a position for stopping the needle in the UP position.

In other words, the main switch controlling the operation of the needle positioning mechanism is disconnected during depression of the pedal or the carrying out of a sewing operation and is automatically closed at the instant of stoppage of the machine upon completion of the sewing operation, whereby to automatically position the needle in the lower or DOWN position upon release or return of the pedal to its normal or rest position. On the other hand, in order to arrest the needle in the UP position, all that is necessary on the part of the seamstress is to operate the pedal in the opposite, that is, the upward direction from the normal or'rest position. The normal stoppage of the needle in the DOWN position and the upward deflection of the pedal for affecting the stoppage of the needle in the UP position inherently serve as a mental assist to the operator in carrying out the respective controls or needle stopping operations.

According to a preferred embodiment of the invention, the needle positioning mechanism may include locking means becoming operative in the upward or raised position of the foot pedal and serving to maintain the switching position of the change-over switch upon release and return of the pedal to the rest position, as well as to release said locking means upon the subsequent depression or deflection of the pedal in the downward direction for the commencement of a new sewing operation. As a consequence, the needle, even with the pedal being prematurely returned from its upward position, will remain in the UP position, whereby to make it unnecessary for the seamstress to hold the pedal in the raised position during the entire period of the needle stopping or positioning operation. In other words, a brief upward fling of the pedal is all that is needed to initiate the stopping and positioning operation.

In order to adapt the commercially available coupling motors for use in connection with needle positioning mechanism according to the invention, there may be linked, according to a further aspect of the invention, to a coupling member rotatably mounted upon an axially shiftable motor coupling sleeve, an operating lever, on the one hand, and an oscillating lever having a pivot coaxial with the pivot of the operating lever, on the other hand, whereby the compression spring normally provided to urge the coupling sleeve to a position of engagement of the motor coupling disk with its braking disk, engages both said operating and oscillating levers.

An especially advantageous arrangement of the main control and change-over switches of the needle position control mechanism is obtained by the mounting of both I said switches upon said coupling member with the cam or the like actuating member of the main control switch projecting into the path of a switching member secured to the coupling sleeve, and with the actuating member of the change-over switch arranged to control a swivelling arm rotatively mounted upon and being in frictional engagement with said coupling member, said arm having a slot providing an adequate lateral play and engaging a pin extending from the switching member. Aside from enabling a simple mounting as well as operation of said switches, such an arrangement has the further advantage of eliminating extended connecting leads between the switches and other electrical parts of the system as will become further apparent from the description in reference to the drawings.

According to a further feature of the invention, the coupling motor may be adapted for use in connection with needle positioning mechanism according to the invention by arranging the spring, which serves to displace the motor coupling sleeve to a position of engagement of the motor coupling disk with its braking disk, between said sleeve and a further sleeve or hub secured to or forming part of the motor housing, and by providing an operating lever engaging, through a spring or the like, a follower of the coupling sleeve and fitted with means for the actuation of the control and change-over switches.

In the latter case, the main switch and the change-over switch are advantageously rigidly connected with the motor casing, in such a manner that the actuating means of the switches project into the path of control levers adjustably mounted upon said operating lever.

The blocking and release of the change-over switch may be achieved with a minimum of parts by the provision of a pawl rotatively mounted upon an extension of the motor casing and adapted, in the operative position of the change-over switch, or raised position of the foot pedal, to lock with a flat spring and to be released upon depression of said pedal to start a new sewing operation.

Alternatively, an'electrical blocking and release device may be provided, whereby the change-over switch is replaced by a simple operating switch for a relay connected in series with said switch in which case the contacts of the relay assume the function of the change-over switch and a holding contact of the relay serves to maintain the needle in the UP position upon release of the foot pedal, in the manner as will become further apparent from the following description of the drawing.

Referring more particularly to FIG. 1, the drive motor of the sewing machine is mounted within a casing 1 being composed of three cylindrical parts or sections 2, 3, 4 and a cover or closure 5. Mounted within section 3 of the casing 1 is a stator 6 carrying a stator winding 7. Both sections 3 and 4 have a separating wall 8 and 9, respectively, in which is journalled a hollow motor drive shaft 11 carrying a rotor 10 cooperating with the stator 6. Secured, by means of a key 13, to the end of the drive shaft 11 projecting into the casing part or section 2 is a driving member or flywheel 12 of the main motor drive, while the opposite end of said shaft projecting into section 4 carries a sleeve 14 being fitted at one end with a gear 15 and having its opposite end acting as a bearing for a freely rotatable coupling disk 17 of the auxiliary motor drive. Meshing with the gear 15 is a gear 18, FIG. 2, which, together with a gear 19 fixedly connected therewith is rotatively supported upon an axis 20 mounted in the wall 9. Meshing with the gear 19 is a gear 21 supported by an axis 22 which is in turn supported by a carrier 23 secured to the axis 20. Meshing with the gear 21 is a further gear 24 which, together with a gear 25 rigidly connected therewith is rotatively supported by an axis 26 secured in the wall 9. Finally, gear 25 meshes with a peripheral gear ring 27 of the coupling disk 17.

Coupling disk 17, FIG. 1, is fitted with a friction layer or lining 28 arranged to engage an auxiliary coupling disk 29 which is secured, by means of a cross pin 30 or the like, to an auxiliary drive shaft 31 axially displaceably mounted within the main drive shaft 11.

Provided in the end wall of the casing section 2 is a hub 32 in which is mounted an axially displaceable shifting or coupling sleeve 33. Hub 32 is fitted with a depending arm 34 upon which are rotatably mounted, by means of a common bolt 35, an actuating lever 36, FIG. 6, and symmetrically thereto an oscillating lever 37. The oscillating lever 37 carries a limiting member 38 fitted with a pair of oppositely disposed stops 39 and 40 which project on both sides across the actuating lever 36. The upper ends of both levers 36 and 37 are each fitted with coupling pins 41 having a spherical end, said pins each arranged to engage a slot 42 of a coupling or switchactuating member 43. The coupling member 43 is rotatively mounted upon the shifting sleeve 33 by means of a pivot screw or bolt 44, said bolt extending through a longitudinal slot 45 provided in the hub 32 in the direction parallel to the motor axis. Secured to one end of the coupling member 43 is an electrical switch 46, preferably in the form of microswitch, serving for the ON and OFF control of the positioning device, and secured to the opposite end of tthe member 43 is a change-over switch 47 for the control of the UP and DOWN positions of the needle. Rotatively connected to the coupling member 43, by means of a pin 48, is a swivelling arm 50 which has a bore 49 engaged by said pin. The swivelling arm 50 has a conical recess 51 through which is passed the screw 44, and a longitudinal slot 52. Projecting into the slot 52 is a pin 53 which is secured to a switching member 54 disposed above the arm 50 and whose diameter is somewhat less than the width of the slot 52. The switching member 54 having a bore 55 passing the screw 44 is extended beyond the end of the swivelling arm 50 and carries upon its underside a projection or cam 56 which during deflection of the coupling member 43 actuates the switch 46. Secured to the underside of the swivelling arm 50 is a further projection or cam 57 which serves to actuate the change-over switch 47 in dependence upon the position of the swivelling arm 50 and the coupling mem- A bolt or pin 58 being in line with the slot 45 in the hub 32 and passing through the recess 51 of the swivelling arm 50 engages the guide slot or recess 59 of the switching member 54, whereby to secure the latter against rotation and to allow of displacement thereof in the longitudinal direction only together with and during displacement of the sleeve 33. The swivelling arm 50 consists of spring steel and is slightly vaulted in the center in such a manner as to engage the central portion of the member 43 under light pressure.

A compression spring 60 engaging the arm 34, on the one hand, and engaging both the angular extension 61 of the operating lever 36 as well as the angular extension 62 of the oscillating lever 37, serves to normally displace the coupling member 43 towards the right, as viewed in FIG. 1, and at the same time causes said member to assume a normal position at right angle to the motor axis.

Rotatively mounted within the sleeve 33, FIG. 1, is the driven or output shaft 63 to the end of which projecting outwardly from the casing 1 is secured a pulley 64. Further secured, by means of a key 65, to the driven shaft 63 and Within the casing part 2 is a main coupling disk 66 being provided on the side facing the flywheel 12 with a first friction layer or lining 67 and being provided on its opposite face with a further friction layer or lining 68 arranged to operatively engage a braking disk 70 which is rotatively mounted upon a reduced portion or shoulder of the hub 32.

The braking disk 70 has a cylindrical shoulder 71 upon its rear surface which serves to support a braking ring 73 disposed between the disk 70 and a further supporting ring 72 mounted upon the shoulder 69. The braking ring 73 has a depending radial extension 74, FIG. 3, provided with a slot 75 which is engaged by a pin 76 of an adjusting bolt 77 mounted in the casing part 2. Braking ring 73 is further provided with a radial nose 78 diametrically opposite to the extension 74 and a pair of axially extending glide pins 79 disposed below said nose symmetrically to or at equal distances from a line connecting the center of said ring with the extension 74. The glide pins 79 project into the circular groove 80 of the braking disk 70, the distance between the walls of said groove slightly exceeding the diameter of said pins.

The nose 78 projects through a slot 81, FIG. 4 of an oscillating lever 82 which is rotatively supported upon the casing part 2 by a bolt or pin 83. The end 85 of the oscillating lever 82 which projects through a slot 84 in the casing 2 is deflected by one end of a torsion spring 87 secured to the casing 2 by a screw 86. The opposite end of the spring 87 engages a stop or pin 88 also secured in the casing part 2. Both ends 89 of the spring 87 are bent to enable the spring to be compressed for removal and remounting to engage the end 85 of the lever 82 and a further stop or pin 90, to adapt the device to different directions of rotation of the motor, as will become further apparent from the description of the operation of the invention. The opposite end of the oscillating lever 82 is fitted with a pair of inwardly tapering lugs or plates 91, 92.

The output shaft 63, FIG. 1, has a hollow portion disposed within the casing part 2 wherein is mounted a compression spring 93 engaging the end of the auxiliary drive shaft 31 which projects into the shaft 63. A cross pin 94 secured in the shaft 31 and passing through a slot in the shaft 63 serves to couple both the shafts 31 and 63.

A lever 96 pivotally mounted upon the cover 5 has an extension 97 which engages the opposite end of the drive shaft 31, projecting through a bore 98 in the cover 5, and is provided at its free end with a first link 99 of an actuating rod 100 and a second link 101 of a pull rod 102 of an electromagnet on solenoid 103 mounted within the casing part 4 and upon the wall 9. The actuating rod 100 extends through the casing sections 4, 3 and 2 and has its cone-shaped end 104 disposed between the lugs 91 and 92 of the oscillating lever 82.

Referring to the wiring diagram, FIG. 5, the sewing machine 105 is connected with the drive mechanism described by way of a belt 106 connecting the pulley 64 with the arm shaft 107. Starting and stopping of the machine and control of the operating or sewing speed is effected in known manner by means of a foot pedal 108 connected with the operating lever 36 through a pull rod 109.

The drive motor is energized from a three-phase power circuit or network R, S, T, M through a main control or master switch 110. Upon closing of the switch 110, a rectifier 111 is simultaneously energized to provide direct current operating voltage at the rectifier terminals 112, 113. The direct current supplied by the rectifier passes, with the switch 46 in the normal or closed position, from the rectifier terminal 111 to the change-over switch 47 whose contacts 114 and 115 are connected with either of a pair of brushes 116 and 117 arranged diametrically to one another and cooperating with a contact disk 118 of a contact device 119 secured to and rotating together with the arm shaft 107 of the sewing machine 105. The disk 118 includes an insulating segment being engaged in succession by the brushes 116 and 117 during rotation of the shaft 107 and is, in turn, connected by way of a brush and slip ring 121 with one pole of the electromagnet or the like electrical actuating device 103 having its opposite pole connected to the remaining rectifier output terminal 113.

The motor drive and needle positioning mechanism described in the foregoing corresponds substantially, except for the improvements according to the present invention, to the construction shown and described by the co-pending patent application Serial No. 374,950, entitled Motor Drive and Coupling Mechanism for Sewing and the Like Machines, filed June 15, 1964, now Patent No. 3,224,543, dated December 21, 1965, and assigned to the same assignee as the instant application, said prior application being incorporated, for further details, in the instant application by reference.

In the following will be described the operation of needle positioning mechanism according to FIGS. l-6 of the drawings.

Upon closing of the main switch 110, FIG. 5, the rotor 10, FIG. 1, of the drive motor is started to rotate and in turn drives the flywheel 12 by way of the main drive shaft 11. At the same time, the shaft 11 drives, by way of gears 15, 18, 19, 21, 24, 25 and gear ring 27, FIG. 2, the coupling disk 17 of the auxiliary drive at a reduced speed determined by the transmission ratio of the gear train 15-27.

Depression of the foot pedal 108 by the seamstress at first causes the pull rod 109 to deflect the operating lever 36 in the downward direction against the action of the spring 60, urging said lever and the oscillating lever 37 to a normal or mean position, whereby the coupling pin 41 of lever 36 acts to rotate the coupling member 43 in clockwise direction, as viewed from above, about the screw 44, to in turn result in the projection 56 of the switching member 54, not taking any part in this rotation, to actuate the switch 46 and to interrupt the circuit of the electromagnet 103. During rotation of the coupling member 43 the swivelling arm 50 is carried along by the pin 48 with the pin 53 of the switching member acting as a pivot.

The relative rotation of the actuating lever 36 and of the oscillating lever 37, as a result of the lost motion connection between the members 36, 38-40, continues to a point only where the actuating lever 36 engages the stop 40 of the oscillating lever 37. Upon continued depression of the foot pedal 108, the actuating lever 36 causes a displacement of the coupling member 43 which carries with it the coupling sleeve 33 and, in turn, the main coupling disk 66, the latter being displaced in a direction towards the left until the friction layer 67 engages the flywheel 12. As a consequence, the arm shaft 107 of the sewing machine 105 is set in motion by way of the main coupling disk 66, output shaft 63, pulley 64 and belt 106, the sewing speed of the machine depending upon the pressure between the disk 66 and the flywheel 12, or pressure applied to the pedal 108.

Upon release of the foot pedal 108, the latter is returned to its zero or rest position by the action of the spring 60. During this operation, the coupling member 43 is at first displaced towards the right, resulting in the main coupling disk 66 being disengaged from the flywheel 12 by the action of spring 60 and in the engagement of its friction lining 68 with the braking disk 70, to be arrested thereby. The braking disk 70 is locked or arrested in the rotating direction of the disk 66 by the wedging action of the glide pins 79 which engage the walls of the groove 80 by the action of the ring 73 rotating about pin 76. The torsion spring 87 causes rotation of the ring 73 by acting, by way of the oscillating lever 82 upon the nose 78 of the ring 73. Depending upon the sense of rotation of the motor, the spring 87 is disposed between the end 85 of the lever 82, on the one hand, and either of the pins 88 and 90, respectively, to arrest or lock the braking disk upon stopping of the main drive in the manner described.

At the end of afore-described displacement of the coupling member 43, the latter together with the oscillating lever 50 is returned to its norm-a1 position at right angle to the motor axis under the influence of the compression spring 60.

As a result of the last-mentioned rotation, the projection 56 of the switching member 54 releases the switch 46 the contacts of which are thus returned to the closed position. As a consequence, there is established a direct current flow from the terminal 112 of the rectifier 111 by way of the switch 46, the change-over switch 47, contact 114 of the latter, brush 116, contact disk 118 of the contact device 119, brush 121, electromagnet 103, and back to the remaining terminal 113 of the rectifier 111. As a result, the electromagnet 103 is energized, causing a deflection of lever 96 towards the right by way of the pull rod 102, FIG. 1. Lever 96 further acts to operate rod 100 towards the right, whereby to cause its conical end 104 to engage the lug 91 of the oscillating lever 82 and to rotate the latter about its mean position by the action of spring 87. The oscillating lever 82 in turn causes rotation of the braking ring 73 about its mean position and by way of its nose 78, whereby to release the two glide pins 79 from the walls of the groove 80 of the braking disk 70. The proper adjustment of the position of the braking ring 73 actuated by the rod 100 may be effected by rotation and setting of the bolt 77.

Simultaneously with the actuation of the rod 100, the lever 96, by way of its projection 97, causes the coupling shaft 31 to be displaced towards the right, whereby to effect engagement of the coupling disks 17 and 29 of the auxiliary drive and to drive shaft 31 at the speed of the disk 17 and, in turn, to drive the output shaft 63 by way of the coupling pin 94 in such a way as to re-start the arm shaft 107 of the machine 105 at reduced. operating speed.

. The arm shaft 107 continues to rotate only until the insulating segment 120 of the contact device 119 is engaged by the brush 116, whereby to interrupt the circuit of the electromagnet 103. As .a result of the deenergization of the electromagnet 103, the spring 93 acts to displace the coupling shaft 31 towards the left, whereby to disengage the coupling disk 29 from the coupling disk 17 and to simultaneously release the lever 82 by way of the lever 96 and rod As a consequence, the torsion spring 87 acts to return the lever 82 to a position of engagement of the glide pins 79 with the walls of the groove 80. Further rotation of the braking disk 70 and of the main coupling disk 66 is thus prevented.

The sewing machine is thus automatically arrested, at the completion of a sewing operation, in a position determined by the position of the insulating segment 120 of the contact device 119, that is, corresponding to the DOWN position of the needle in accordance with the present invention.

In order to arrest the needle in the UP position, it is necessary to deflect the pedal 108 in the reverse or upward direction beyond its zero or rest position. As a consequence, the pull rod 109 operates the actuating lever 36 in an upward direction, whereby its coupling pin 41 rotates the coupling member 43 in anticlockwise direction about the screw 44, as viewed from above, until the stop 39 of the oscillating lever prevents further rotation by engagement with the lever 36. During the rotation of the coupling member 43, the swivelling arm 50 is carried along by the pin 48, whereby the pin 53 of the switching member 54 acts as a pivot. The turning radius (distance between the pins 48 and 53) of the swivelling arm 50 is less than the turning radius (distance between the pin 48 and the screw 44) of the coupling member 43, whereby the projection 57 of the swivelling arm 50 performs a greater rotary displacement than the change-over switch 57 mounted upon the coupling member 47 and actuates the change-over switch 43 at the end of the rotating movement. As 'a result, the electric current passes from the terminal 112 of the rectifier 111 by way of the closed switch 46, contact 115 of the change-over switch 47, brush 117, contact disk 118 of the contact device 119, brush 121, electromagnet 103 and back to the terminal 113 of the rectifier 111. The electromagnet 103 is again energized, whereby to release the braking disk 70 by way of the lever 96 in the manner described and to simultaneously cause engagement of the coupling disks 17 and 29 of the auxiliary drive. The arm shaft 107 is now rotated at reduced speed through an angle of 180 until the insulating segment of the contact device 119 is engaged by the brush 117, whereby to interrupt the circuit of the electromagnet 103 and to release the coupling disks 17 and 29, as well as the braking disk 70, in the manner described herein-before. The needle of the sewing machine 105 is accordingly arrested in the UP position, whereby to enable the seamstress to remove or position the work or to carry out any other operations that may be required.

Upon release of the foot pedal 108, the latter is returned to the normal or rest position by the action of the spring 60. At the same time, the coupling member 43 is rotated to its normal position at right angle to the motor axis. Due to the play between the slot 52 and the pin 53 as well as the friction with the coupling member 43, the swivelling arm 50 together with its projection 57 remains above the change-over switch 47, whereby to retain the latter in a position corresponding to the UP position of the needle.

Upon subsequent depression of the foot pedal 108 for the commencement of a new sewing operation, the coupling member 43 is again rotated in clockwise direction, whereby to rotate the swivelling arm 50 by the pin 48 about the pin 53 and to adjust the latter to a position for effecting stoppage of the needle in the DOWN position. At the same time, rotation of the coupling member 43 in the manner described results in disconnection of the switch 46, to interrupt the current through the contact device 119 and electromagnet 103 during the sewmg operations.

The embodiment shown by FIGS. 7-9 is a modification of the embodiment according to FIGS. l-6 to which it corresponds principally. Accordingly, the parts com- 9 mon to both embodiments will no longer be referred to in the description of FIGS. 7-9.

In contrast to the embodiment of FIGS. 1-7, the end wall of the casing part 2 is fitted with a hub 132 in which is mounted a sleeve 133. Sleeve 133 has an offset bore 134, the resulting bore sections being separated by an annular surface 135. Mounted in axially displaceable manner within the sleeve 133 is a coupling or shifting sleeve 136 whose outer diameter is offset corresponding to the offset of the bore 134 of the sleeve 133, to result in a further annnular surface 137. Mounted within the DOWN position.

space bounded by the sleeve 133 and the coupling sleeve 136 is a compression spring 138 having its ends engaging the annular surfaces 135 and 137, respectively.

Extending from the sleeve 133 is a depending arm or extension 139 in which is rotatively mounted, by means of a bolt or axis 140, 'a fork-shaped actuating lever 141, the fork-shaped ends 142 of which are each provided with a slot 143. Projecting into the slots 143 are a pair of pins 145 secured to the coupling sleeve 136 and passing through longitudinal slots 144 of the sleeve 133.

The distance between the lateral walls 146 and 147 of the slots 143 is inexcess of the diameter of the pins 145, to afford displacement of the actuating lever 141 independently of the movement of the pins 145.

A pair of torsion springs 148 mounted upon the bolt 140 and engaging the actuating lever 141, on the one hand, and engaging the pins 145, on the other hand, serve to maintain said pins in resilient engagement with the wall 146 of the slots 143 located opposite from the motor, or to urge said pins away from the wall 147.

The arm 139 has an extension 149 upon which is mounted the switch 46 being closed in the normal position, in such a manner that the actuating member 150 of said switch projects into the path of an actuating arm 151 which is adjustably mounted upon the actuating lever 141 in the direction towards and away from the member 150. The adjustment or position of the arm 151 is such that, immediately after the deflection of the actuating lever 141 by depression of the foot pedal 108 from the zero position, the switch 46 is opened by the arm 151.

Further mounted upon the extension 149 is the changeover switch 47 whose actuating member 152 projects into the path of an actuating arm or lever 153 also adjustably mounted upon lever 141 in the direction towards and away from the member 152. Disposed between the actuating member 152 and the actuating arm 153 is a leaf spring 154 being secured to the arm 149 and resiliently engaging the arm 153.

Cooperating with the leaf spring 154 is a pawl 155 which is rota-tively mounted upon the arm 149. The nose 156 of the pawl 155 is so arranged as to engage 'and lock with the spring 154 upon rotation of the actuating lever 141 from its rest position in the clockwise direction. A torsion spring 157 engaging the pawl 155, on the one hand, and engaging the arm 149, on the other hand, serves to maintain the pawl 155 in engagement with an abutment pin 158 also being secured to the arm 149. A release pin 159 secured to the actuating lever 141 cooperates with a slanting abutment 160 of the pawl 155.

In the following will be described the operation of the embodiment shown by FIGS. 7-9.

Upon depression of the foot pedal 108 by the seamstress, the actuating lever 141 is operated in the downward direction by way of the pull rod 109, whereby said lever, aside from displacing the main coupling disk 66 towards the flywheel 12 operates the switch 46 by way of the actuating lever 151 and actuating member 150, whereby to interrupt the circuit connecting the rectifier 111 with the electromagnet 103.

Upon release of the foot pedal 108, at the end of a sewing operation, the pedal returns to its normal or rest position as a result of the disengagement of the lever 151 from the member 150.

In order to arrest the needle in the UP position, the foot pedal 108 is operated in the upward direction beyond its rest position, whereby to rotate or deflect the actuating lever 141 by way of the pull rod 109 in clockwise direction until the pins 145 engage the walls 147 of the slots 143, to thereby urge the actuating lever 153 of the leaf spring 154 against the actuating member 152 of the change-over switch 47. The latter is thus operated to open the contact 114 and to re-close contact 115 whereby to operate and adjust the needle to the UP position by the auxiliary drive in the manner described by engagement of the insulating segment by the brush 117.

Simultaneously with the actuation of the member 152 by the leaf spring 154, the latter acts to deflect the pawl 155 against the action of spring 157 by engaging the nose 156 until thespring 154 becomes locked with said nose.

During the return movement of the actuating lever 141 to the rest position, the actuating levers 151 and 153 are subject to the same return movement. The actuating member of the switch 46 is not yet engaged While the actuating member 152 of the change-over switch 47 maintains contact 115 in the closed position and maintains contact 114 in the open position by the spring 154 being retained by the pawl 155. As a consequence, the needle will be retained in the UP position during the return of the pedal 108 to its rest position. Only after renewed depression of the foot pedal 108 for the commencement of a new sewing operation, will the pawl 155 be lifted by the release pin 159 engaging the abutment 160, whereby the nose 156 releases the spring 154 which, in turn, releases the actuating member 152. As a consequence, the con-tact 115 of the change-over switch 47 will be opened and contact 114 will be closed. Simultaneously with the actuation of the change-over switch 47, switch 46 is operated, whereby to interrupt the circuit of the electromagnet 103 in the manner described.

In place of the mechanical locking device shown an electrical locking circuit may be provided as shown by FIG. 10. According to this modification, the change-over switch 47 is replaced by a simple switch 47 controlling a relay 161 and cooperating with the actuating arm 153 only of the actuating lever 141. Parts 154, 155, 157 and 159 are dispensed with in this embodiment of the invention. The function of the latter parts is assumed by the relay 161 being fitted with holding con-tact 162 and having a pair of switch-over contacts 114 and 115.

More particularly, during the upward deflection of the foot pedal 108, switch 47 is closed to energize the relay 161. Actuation of the relay 161, in turn, results in the closing of the holding contact 162 and of the operating contact 115, while the contact 114 remains in open position. As a consequence, the needle will be operated to and arrested in the UP position, in the same manner as described hereinbefore.

During return of the foot pedal 108 to its rest position, switch 47 is opened, while the relay 161 remains in energized condition by way of the holding contact 162, whereby to maintain the position of the relay contacts 114 and 115 and to retain the needle in the UP position. Only after renewed depression of the foot pedal 108, to start a new sewing operation will the switch 46 be operated in the described manner, to open its contacts and to de-energize the electromagnet 103 and the relay 161. Besides, the holding contact 162 and operating contact 115 are now opened, while the contact 114 remains in closed position, whereby to cause the needle to be arrested in II the DOWN position upon the return of the pedal to its rest position at the end of the sewing operation.

In the foregoing the invention has been described in reference to a specific illustrative device. It will be evident, however, that variations and modifications, as well as the substitution of equivalent parts or elements for those shown herein for illustration, may be made without departing from the broader scope and spirit of the invention as set forth in the appended claims. The specification and drawings are accordingly to be regarded in an illustrative rather than in a restrictive sense.

We claim:

1. Motor drive and needle positioning mechanism for a sewing machine comprising in combination:

(1) a drive shaft and a driven shaft of said machine,

(2) a driving motor,

(3) main transmission means between said motor and said driven shaft including main coupling means having a main driving member connected to said motor and a main driven member operable into and out of engagement with said driving member,

(4) an operating member for said main coupling means operable from a rest position in a first direction, to start and stopsaid machine for the carrying out of a sewing operation, and being operable in a second opposite direction beyond said rest position,

(5) auxiliary transmission means operably connected between said motor and said driven shaft including auxiliary coupling means having an auxiliary driving member and an auxiliary driven member operable into and out of engagement with said auxiliary driving member,

(6) reduction gearing means connecting said motor with said auxiliary driving member, to rotate the latter at a reduced speed compared with the speed of said main driving member, I

(7) an electrical actuating device for said auxiliary driven member,

(8) an electrical control circuit including a current source, said actuating device, a normally closed control switch, a two-position change-over switch having a first and a second change-over contact, and a contact device,

(9) said contact device including -a rotary contact having an insulating segment and driven by said shaft, and a pair of stationary contacts cooperating with said rotary contact and connected each to one of said change-over contacts, whereby to interrupt said circuit by said insulating segment and to stop said machine at predetermined first and second needle positions determined by the positions of said stationary contacts, and

(10) actuating means to actuate said control and change-over switches operated by said operating member, to open said control switch and to close said first change-over contact during operation of said operating member in said first direction, to close both said control switch and said first change-over contact in the rest position of said opera-ting member, and to close both said control switch and said second change-over contact upon operation of said member in said second direction, whereby to re-start and stop said machine by said auxiliary transmission means at said first predetermined needle position upon return of said operating member to its rest position at the end of a sewing operation, and to re-start and stop said machine at said second predetermined needle position upon operation of said operating member in said second direction beyond said rest position, respectively.

2. In motor drive and needle positioning mechanism for sewing machines as claimed in claim 1, said operating member being comprised of a foot pedal operable from a rest position in a downward direction for the starting and control of the speed of said machine during the carrying 12 out of a sewing operation, and said contact device stopping the machine with the needle in the DOWN position upon return of said pedal to said rest position at the end of a sewing operation and stopping the machine with the needle in the UP position by operation of said pedal in an upward direction beyond said rest position.

3. In motor drive and needle positioning mechanism for sewing machines as claimed in claim 1, said main coupling means including a driven friction coupling disk comprising said main driven member and a displaceable coupling sleeve controlled by said operating member, and said actuating means comprising a double-arm actuating member pivotally mounted upon said sleeve and carrying both said control and said change-over switch at its opposite ends, control means cooperating with both said switches and carried by said sleeve, and means to pivot said actuating member from a normal position by the initial shifting movement of said sleeve to effect coupling connection between said main driving member and said disk, and to return said actuating member to said normal position upon de-coupling of said main driving member and said disk by said sleeve.

4. In motor drive and needle positioning mechanism as claimed in claim 3, said last means including said double arm actuating member which comprises a pair of spaced and spring-urged levers having a common pivot axis and arranged with one end of their lever arms each engaging a slot of said actuating member and having the other ends of the lever arms coupled in lost-motion connection, with said operating member, whereby to first pivot said actuating member and to subsequently displace said sleeve for effecting coupling connection between said disks, and to first displace said sleeve and to subsequently pivot said actuating member during de-coupling of said disks by said sleeve.

5. In motor drive and needle positioning mechanism as claimed in claim 1, said main coupling means and said actuating means including a spring-urged operating lever controlled by said operating member, a pair of switchactuating elements carried by said lever and adapted to cooperate, respectively, with said control and change-over switch disposed in relative stationary relation to said lever.

6. In motor drive and needle positioning mechanism as claimed in claim 1, including locking means for said change-over switch to maintain the needle in said second position upon return of said member to its rest position, and further means to release said locking means upon subsequent operation of said member in said first direction to start a new sewing operation.

7. In motor drive and needle positioning mechanism as claimed in claim 6, said locking means being comprised of a pawl and ratchet mechanism operably connected to said actuating means.

8. In motor drive and needle positioning mechanism as claimed in claim 6, said change-over switch including a double-contact relay controlling said actuating and contact devices and having a holding contact to maintain said relay in energized condition independently of the return of said member to its rest position.

9. In motor drive and needle positioning mechanism as claimed in claim 1, including a normally locked rotatable braking member engaged by said main driven member when disengaged from said main driving member, and means controlled by said actuating means to unlock said braking member in the coupled position of said auxiliary coupling means.

10. Motor drive and needle positioning mechanism for i a sewing machine comprising in combination:

(1) a drive shaft and a driven shaft of said machine, (2) a driving motor, (3) main transmission means between said motor and said driven shaft including main coupling means having a main driving member connected to said motor and a main driven member operable into and out of engagement with said driving member,

(4) a foot pedal to control said main coupling means operable from a rest position in the downward direction, to start and stop said machine for the carrying out of a sewing operation, said pedal being further operable in the upward direction beyond said rest position,

(5) auxiliary transmission means between said motor and saiad driven shaft including auxiliary coupling means having an auxiliary driving member and an auxiliary driven member operable into and out of engagement with said auxiliary driving member.

(6) reduction gearing means connecting said motor with said auxiliary driving member, to rotate the latter at a reduced speed compared with the speed of said main driving member,

(7) an electrical actuating device for said auxiliary driven member,

(8) an electrical control circuit including a current source, said device, a normally closed control switch, a change-over switch having first and second changeover contacts and a contact device operably connected withsaid drive shaft and designed to interrupt said circuit in the UP and DOWN" needle positions by closing of said first and second change-over contacts, respectively, and i (9) actuating means to operate said control switch and change-over switch operated by said foot pedal, to open said control switch and to close said first change-over contact during operation of said pedal in the downward direction, to close both said control switch and said first change-over contact in the rest position of said pedal, and to close both said control switch and said second change-over contact upon operation of said pedal in the upward direction beyond said rest position, whereby to re-start and stop said machine by said auxiliary coupling means in the DOWN position of the needle upon return of said pedal to its rest position at the end of a sewing operation, and to re-start and stop said machine in the UP position of the needle upon operation of said pedal in the upward direction beyond said rest position.

11. In motor drive and needle positioning mechanism as claimed in claim 10, including locking means for said change-over switch to maintain the needle in the UP position upon return of said pedal to its rest position, and further means to release said locking means upon subsequent operation of said pedal in the downward direction to start a new sewing operation.

References Cited by the Examiner UNITED STATES PATENTS 2,838,019 6/1958 Winz 112-219 2,961,591 11/1960 Frankel et al. 112-219 X 3,026,834 3/1962 Frentzel 112-219 3,114,340 12/1963 Hedegaard 112-219 3,170,424 2/1965 Fuge 112219 lORDAN FRANKLIN, Primary Examiner.

H. H. HUNTER, Assistant Examiner.

Claims (1)

1. MOTOR DRIVE AND NEEDLE POSITIONING MECHANISM FOR A SEWING MACHINE COMPRISING IN COMBINATION: (1) A DRIVE SHAFT AND A DRIVEN SHAFT OF SAID MACHINE, (2) A DRIVING MOTOR, (3) MAIN TRANSMISSION MEANS BETWEEN SAID MOTOR AND SAID DRIVEN SHAFT INCLUDING MAIN COUPLING MEANS HAVING A MAIN DRIVING MEMBER CONNECTED TO SAID MOTOR AND A MAIN DRIVEN MEMBER OPERABLE INTO AND OUT OF ENGAGEMENT WITH SAID DRIVING MEMBER, (4) AN OPERATING MEMBER FOR SAID MAIN COUPLING MEANS OPERABLE FROM A REST POSITION IN A FIRST DIRECTION, TO START AND STOP SAID MACHINE FOR THE CARRYING OUT OF A SEWING OPERATION, AND BEING OPERABLE IN A SECOND OPPOSITE DIRECTION BEYOND SAID REST POSITION, (5) AUXILIARY TRANSMISSION MEANS OPERABLY CONNECTED BETWEEN SAID MOTOR AND SAID DRIVEN SHAFT INCLUDING AUXILIARY COUPLING MEANS HAVING AN AUXILIARY DRIVING MEMBER AND AN AUXILIARY DRIVEN MEMBER OPERABLE INTO AND OUT OF ENGAGEMENT WITH SAID AUXILIARY DRIVING MEMBER, (6) REDUCTION GEARING MEANS CONNECTING SAID MOTOR WITH SAID AUXILIARY DRIVING MEMBER, TO ROTATE THE LATTER AT A REDUCED SPEED COMPARED WITH THE SPEED OF SAID MAIN DRIVING MEMBER, (7) AN ELECTRICAL ACTUATING DEVICE FOR SAID AUXILIARY DRIVEN MEMBER, (8) AN ELECTRICAL CONTROL CIRCUIT INCLUDING A CURRENT SOURCE, SAID ACTUATING DEVICE, A NORMALLY CLOSED CONTROL SWITCH, A TWO-POSITION CHANGE-OVER SWITCH HAVING A FIRST AND A SECOND CHANGE-OVER CONTACT, AND A CONTACT DEVICE, (9) SAID CONTACT DEVICE INCLUDING A ROTARY CONTACT HAVING AN INSULATING SEGMENT AND DRIVEN BY SAID SHAFT, AND A PAIR OF STATIONARY CONTACTS COOPERATING WITH SAID ROTARY CONTACT AND CONNECTED EACH TO ONE OF SAID CHANGE-OVER CONTACTS, WHEREBY TO INTERRUPT SAID CIRCUIT BY SAID INSULATING SEGMENT AND TO STOP SAID MACHINE AT PREDETERMINED FIRST AND SECOND NEEDLE POSITIONS DETERMINED BY THE POSITIONS OF SAID STATIONARY CONTACTS, AND (10) ACTUATING MEANS TO ACTUATE SAID CONTROL AND CHANGE-OVER SWITCHES OPERATED BY SAID OPERATING MEMBER, TO OPEN SAID CONTROL SWITCH AND TO CLOSE SAID FIRST CHANGE-OVER CONTACT DURING OPERATION OF SAID OPERATING MEMBER IN SAID FIRST DIRECTION, TO CLOSE BOTH SAID CONTROL SWITCH AND SAID FIRST CHANGE-OVER CONTACT IN THE REST POSITION OF SAID OPERATING MEMBER, AND TO CLOSE BOTH SAID CONTROL SWITCH AND SAID SECOND CHANGE-OVER CONTACT UPON OPERATION OF SAID MEMBER IN SAID SECOND DIRECTION, WHEREBY TO RE-START AND STOP SAID MACHINE BY SAID AUXILIARY TRANSMISSION MEANS AT SAID FIRST PREDETERMINED NEEDLE POSITION UPON RETURN OF SAID OPERATING MEMBER TO ITS REST POSITION AT THE END OF A SEWING OPERATION, AND TO RE-START AND STOP SAID MACHINE AT SAID SECOND PREDETERMINED NEEDLE POSITION UPON OPERATION OF SAID OPERATING MEMBER IN SAID SECOND DIRECTION BEYOND SAID REST POSITION, RESPECTIVELY.

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