US3099974A

US3099974A - Feed mechanism for sewing machines

Info

Publication number: US3099974A
Application number: US94120A
Authority: US
Inventors: Chudner Joseph
Original assignee: Individual
Current assignee: Individual
Priority date: 1961-03-06
Filing date: 1961-03-06
Publication date: 1963-08-06
Anticipated expiration: 1980-08-06

Description

Aug. 6, 1963 Filed March 6, 1961 FIG. 1

J. CHUDNER 3,099,974

FEED MECHANISM FOR SEWING MACHINES z Sheets-Sheet 1 INVENTOR.

JOSEPH CHUDNER MARCH AND CURTISS ATTORNEYS Aug. 6, 1963 J. CHUDNER 3,099,974

FEED MECHANISM FOR SEWING MACHINES Filed March 6, 1961 3 Sheets-Sheet 2 IN VEN TOR. JOSEPH CHUDNER MARCH AND CuRns's ATTORNEYS Aug- 6, 1963 J. CHUDNER 3,099,974

FEED MECHANISM FOR SEWING MACHINES Filed March 6, 1961 s Sheets-Sheet 3 7 INVENTOR.

JOSEPH CHUDNER MARCH AND CURT\$S ATTORNEYS Unite States 3,099,974 FEED MECHANISM FOR SEWING MAC Joseph Chudner, 2907 Brighton Beach 8 St., Brooklyn, NY. Filed Mar. 6, 1961, Ser. No. 94,120 11 Claims. (Cl. 112-207) This invention relates to sewing machines, and more particularly to a feed device for transporting work material from the front of a sewing machine through the stitching area thereof and toward the rear of the machine.

The work material usually comprises two separate pieces of fabric or the like in overlapped relation, and ordinarily it is transported by a feed-dog located in a throat passage which opens through a fiat topped work support. The feed-dog is operated by mechanism which effects a four-motion action of the feed-dog to produce a feed-advance-and-return movement thereof. Being located below the work support and operating through the throat passage, the feed-dog engages the under surface of the work material only. Thus the feed-dog may by its operation induce slippage between the two work pieces or it may be ineifective to prevent slippage, particularly as between two pieces of difierent material where one of them is smooth and slippery like silk or a material made of synthetic fibers.

The primary object of the present invention is to obviate the foregoing and other objectionable features of the ordinary form of material transport in a sewing machine and provide a device to insure the positive transport of both the lower and the overlying pieces of the work material.

To this end, the present invention contemplates means cooperatnig with and synchronized with the usual feeddog of a sewing machine to operate in unison therewith for transporting the work material from the front of the machine through the stitching area thereof and toward the rear of the machine.

More specifically, the invention provides an overhead or secondary feed-dog arranged to overlie the work material above the regular feed-dog, whereby the work material is engaged by and clamped between the two feeddogs, and means for actuating the overhead feed-dog in unison with the movement of the regular feed-dog to transport the work material. Also contemplated is means for effecting the synchronization of the two feed-dogs and for adjusting the overhead feed-dog for operation in the production of a stitch which is either longer or shorter than a stitch of normal length. Furthermore, the invention provides an attachment for existing sewing machines which is positive in its action and is operated in timed relation to the operation of the machine.

Other objects and features of the invention will occur to those skilled in the art from a study of a preferred embodiment of the invention show-n in the drawings and the detailed description thereof which follows.

In the accompanying drawings, the invention has been shown merely by way of example and in preferred form and obviously many modifications and variations thereof may be made which will still be comprised within its spirit. It is to be understood, therefore, that the invention is not limited to any particular form or embodiment, or in its application, except insofar as such limitations may be set forth in the appended claims.

Referring to the drawings:

FIG. 1 is a rear elevation of the work material support and bracket arm of a sewing machine;

FIG. 2 is an elevation of the right-hand end of the parts shown in FIG. 1;

FIG. 3 is an enlarged end view of the lower portion of the parts shown in FIG. 2;

FIG. 4 is a view similar to FIG. 3, showing the parts in a different position;

FIG. 5 is a sectional elevation, taken on the line 5-5 of FIG. 3, looking in the direction of the arrows;

"FIG. 6 is a top plan view, taken on the line 6-6 of FIG. 3, looking in the direction of the arrows; and

FIG. 7 is a vertical section, taken on the line 7-7 of FIG. 3, looking in the direction of the arrows.

A preferred embodiment of the invention is shown in the drawings as an attachment adapted for use with sewing machines of well-known construction and, therefore, the sewing machine parts are illustrated fragmentarily-as a means of orientation for those familiar with the art. The illustrated parts and mechanism of the sewing machine include a work support 10 mounting a bracket 11, which comprises a vertical leg 12 and horizontal arm 13 extending lengthwise of the support 10 in spaced relation thereto. The support 10 is *apertured to provide a throat passage (not shown) which is partially covered by a slotted throat plate 14 (FIG. 3) through which a feed-dog 15 operates to transport work material resting on the support 10. The mechanism for operating the feed-dog 15 is located below the support 10 and actuated in the usual manner through suitable connections to effect the feedadvance-and-return movements of the feed-dog, which is a cyclic four-motion movement well known in the art that causes the feed-dog 15 to rise and present its serrated top surface 15a above the top surface of the support 10, then move linearly toward the rear of the machine while engaging the underside of the work material, thereafter to drop out of engagement with the work material and return in a linear path to its starting position.

Other parts of the sewing machine shown in the drawings include a vertically reciprocating needle-bar 16 and a spring biased presser-bar 17 mounted in the end of the bracket arm 13, the needle-bar being operated by suitable connections (not shown) located within the bracket 11 and leading from the needle bar 16 to a fly wheel 18 at the opposite end of the bracket which is connected to and powered by suitable driving mechanism such as an electric motor (not shown).

The present invention comprises an attachment 20 mounted on the machine as by means of a bracket 21 secured by cap screws 22 to the bracket arm 13. The attachment 20 comprises a pulley drive wheel 23, a drive shaft 24 and a driven shaft 25 for actuating an overhead feed-dog 26 arranged to overlie the feed-dog 15 and adapted to have imparted to it a four-motion movement similar to that of the feed-dog 15 (but reversed as to the rise and fall movements), whereby it grips the top of the work material to move in unison with the feed-dog 15 in the transport of the work material.

In general, the overhead feed-dog 26 and its actuating mechanism is supported in a bifurcated bracket 30 whose horizontal lower 31 is fastened to the resser-bar 17 by a screw 32, the end of the resser-bar 17 being cut away as at 33 to provide a flat surface against which the end of the arm 31 abuts. A vertical arm 34 of the bracket 30 is provided near its free end with a screw 35 which serves as an anchor for the lower end of a tension sp'nng 36 which has its opposite end connected to the bracket 21 as by a hooked portion 37 thereof passing through an aperture 38 in the bracket. The tension of the spring 36 yieldingly holds the bracket 30 in the proper relation to the machine to present the overhead feed-dog 26 in a working position substantially parallel with the top surface of the feed-dog 15.

A joined bell-crank 40 is arranged between the arms of the bifurcated bracket 30 and comprises a horizontal arm 41 pivoted as at 42 to the lower end of a vertical arm 43. The upper end of the arm 43 is formed with a circular aperture 44- formed to receive an eccentric 45 formed on the drive shaft disposed at a right angle to the arm 43-. The free end of the horizontal arm 41 of the bell-crank is formed with a depending front or nose portion 47 provided with a vertically elongate aperture 48 to accommodate the shank of a screw 49 threaded into an opening 50 in the shank 51 of the overhead feeddog 26. The feed-dog 26 is accurately positioned and secured to the nose portion 47 by the seating of a tongue 52 on a shank portion 51 thereof in a groove 53 formed in the nose 47. Thus the overhead feed-dog 26 is adjustable vertically within the limits of the aperture 48.

The jointed bell-crank 40 is adapted for movement relative to the fixed bifurcated bracket 30 and to this end the width of the bifurcation is determined by spacing elements slightly greater width than the thickness of the bell-crank 40. Thus, the horizontal arms of the bracket 30 are held in spaced relation by a spacer 85 clamped between them as by a screw 86 passing through one arm and a drill hole in the spacer 85 and being secured in a threaded aperture in the other arm of the bracket. In the region of the upper end of the vertical arm 34- of the bracket 30, a circular spacer 90 is secured between the arms as by set screws 91. It will be noted that the spacer 90 is interrupted to provide an opening 92 in the lower part thereof which is adapted to leave a space for a rocking movement of the bell-crank arm 43, the purpose of which will be described hereinafte In order that the bellcrank 40 will be free to move, and to guide it in its movement, the spacer 85 is formed to have a sliding fit within an elongate aperture 55 formed in the horizontal arm 41, whereby the spacer 85 provides upper and

lower bearing surfaces

56 and 57, respectively, in sliding engagement with the contiguous walls of the aperture 55. The vertical arm 43 of the bell-crank 40 is similarly formed with an elongated aperture 58' within which a guiding spacer 59 is located, the spacer 59 being clamped by two thumb nuts 60 on a screw 61 threaded at its opposite ends and passing through apertures 62 in the arms of the bracket 30 and a drill hole in the spacer 59. It will be noted that the apertures 62 are in the form of elongate slots whose longitudinal axes are coincident with the longitudinal axis of the arm 43, and the purpose of this arrangement will be set forth presently.

Referring now to FIGS. 1 and 5, the shaft 25 carrying the eccentric 45 is joined by a pinand slot connection 63 to a sleeve 64 fastened as by a set screw 65 to the drive shaft 24. The opposite end of the shaft 24 is joined by a similar pin and slot connection 66 to the recessed end of a shaft 67 journeled in a bearing 68 secured as by set screws 69 to the bracket 21. The opposite end of the shaft 67 projects beyond the end of the leg 12 of the machine bracket 11 and has the drive wheel 23 fixedly mounted thereon. A fly wheel 70 is mounted on the shaft 67 between the bearing 68 and the wheel 23' to balance the action of the drive shaft 24.

'Ilhe drive wheel 23 is in alignment with a primary pulley drive Wheel 71 fixed to a stud 72 projecting axially beyond the fly wheel 18, the stud 72 being an extension of a drive shaft mounting the fly wheel which transmits the motive power for operating the feed-dog 15 and the needle-bar 16. The belt channels of the

wheels

23 and 71 are toothed or notched (not shown) and connected by a timing belt 75 provided on its inner surface with lugs or teeth 76 which are formed to seat in the said notches and thus effect a positive, timed belt drive.

In the operation of the machine, as already stated, the overhead feed-dog 26 is located to overlie the feed-dog 15 and both the feed-dog 15 and the overhead feed-dog 26 are intended to operate in unison and, therefore, their movements must be synchronized. Accordingly, by loosening the set screw 65 the sleeve 64 can be slid axially along the shaft 24 to the left, as viewed in FIG. 1, to disengage the pin and slot connection 63' and thus free the overhead feed-dog actuating mechanism from its 4 drive shaft 24. With the overhead feed-dog mechanism thus disconnected from the machine by rotation of the fly wheel 18 the machine parts may be set in the position shown in FIG. 3, for example, with the needle-bar 16 in its uppermost position and the feed-dog 15 in its lifted position ready to partake of a rearward, linear movement. The vertical arm 43 of the bell-crank 40 is rocked by the eccentric 45 and by manually turning the shaft 25 the crank arm 43 may be brought into a position which moves the other crank arm 41 forward and locates the overhead feed-dog 26 in its forward position ready to partake of a rear-ward linear movement. The sleeve 64 may then be rotated relative to the shaft 24 to align the pin and slot connection 63 and then slid toward the end of the shaft 24 to effect the connection, whereupon the set screw 65 may be tightened against the shaft 24 to prevent relative rotation. Thus, the parts may be set in position so that when the machine commences its operation the movements of the feed-dog 15 and overhead feed-dog 26 will be synchronized and a uniform pull will be exerted thereby on both the upper and lower surfaces of the work material.

The sleeve 64 and the recessed end of the shaft 67 each is formed with four slots 80, shown in FIG. 1 as being in axial alignment. However, any degree of staggered axial alignment may be obtained according to the position in which the sleeve 64 is fastened on the shaft 24 by the set screw 65. It is possible, therefore, to pre-set the sleeve 64 so that without manipulating the screw 65 the proper synchronized adjustment and length of stitch adjustment may be made by merely disengaging the pin and slot connection of the sleeve 64 and shaft 25 and bringing the desired slot into alignment with the pin. The disengagement is readily effected by virtue of the fact that the spring 36 supporting the upper end of the overhead feed device permits sufficient sidewise movement of the device for that purpose.

There are times when it is desirable to have the feeddog 15 and the overhead feed-dog 26 operate in unison but to have the overhead feed-dog 26 move linearly faster, i.e., to a greater or lesser extent, as the case may be, .than the feed-dog 15. For example, in sewing a smooth material such as a silk lining to a material such as velvet, it may be desirable to effect a slippage of the lining relative to the velvet material, and this can be accomplished by increasing or speeding up the feeding stroke of the overhead feed-dog 26. Hence, provision is made to change the stroke of the bell-crank arm 41.

To this end, it will :be noted that along the sides of the elongate slots 62 formed in the arms of the bifurcated bracket 30 there is provided a graduation to serve as a guide in shifting the spacer 59, and when the pivot screw 61 is moved upward or downward it varies the point about which the vertical arm 43 pivots. When the spacer 59 is located so that the axis of the screw 61 is coincident with the transverse axis of the arm 43, the portions of the arm on either side of the pivot point are equal or in a 1 to 1 ratio. To increase the stroke of the overhead feed-dog 26 the thumb nuts 60 may be loosened and the spacer 59 shifted upwardly and then the thumb nuts tightened to clamp the spacer in its shifted position. This will decrease the length of the arm 43 above the pivot point and increase the length of the arm 43 below the pivot point whereby the throw of the eccentric 45 will effect a longer and, hence, a faster movement of the horizontal arm 41. Contrariwise, if the pivot screw 61 is moved downwardly below the transverse axis of the vertical arm 43 so as to make the lower part of the arm shorter than the upper part, the throw of the eccentric 45 will produce a shorter and, hence, a slower movement of the horizontal arm 41.

The foregoing adjustment of the stroke of the overhead feed-dog 26 is utilized also to adapt the mechanism to be synchronized with the feed dog '15 when the latter is set for making a stitch which is longer or shorter than the normal stitch of the machine and there is no prob lem of or desire for slippage involved.

As stated before, a preferred embodiment of the invention has been shown and described merely by way of example and modifications and variations thereof may be made without departing from the spirit of the invention. For example, the sleeve 64 could be made and mounted on the shaft 24 in the form of the well-known spring biased sleeve which can be retracted axially of the shaft against the compression of its spring to disengage the pin and slot connection. Also, the overhead feed device need not be in the form of an attachment but could be built into the machine to effect the same result, although possibly a different form of actuating means might be employed. Further, the support for the overhead feed-dog 26 need not be attached to the presser-bar 17, since it could be connected to a separate mounting, it having been shown herein as attached to the presser-bar as the more convenient and expedient manner of bringing it into play simultaneously with the dropping of the presser-bar to hold the work material against the throat plate 14. Therefore, to repeat, the invention is not limited to the embodiment shown herein and the language of the claims should not be construed as being limited except to the extent that express limitations are recited therein.

Having thus described my invention, what I claim is:

l. A sewing machine adapted for feeding and sewing together at least two overlapping pieces of fabric comprising a work support, a movable feed dog operating through said work support, means for effecting a four motion feeding movement of said feed dog for transporting the fabric from front to the rear of the machine, said feed dog engaging from below the lowermost piece of said fabric, and a secondary feed attachment connected to said machine, said attachment including a secondary feed means mounted to overlie said feed dog and to engage the upper piece of said overlying piece of fabric from above, said secondary feed means including a bracket having angularly disposed leg portions, a pair of angularly disposed pivotally jointed lever arms, each of said pivotally jointed arms having an elongated slot formed intermediate the ends thereof, guide means receivable in the respective slots of said arms for slidably connecting each of said pivotally jointed arms to a respective leg portion of said bracket, an overlying feed dog mounted to the free end of one of said pivotally jointed arms, and an eccentric journaled in an opening in the free end of the other of said pivotally jointed arms and means for rotating said eccentric whereby the rotation thereof efiects a four-way motion of said overlying feed dog for exerting uniform pull on both the upper and lower overlying pieces of fabric.

2,. A sewing machine adapted for feeding and sewing together at least two overlapping pieces of fabric comprising a work supoprt, a movable feed dog operating through said work support, means for effecting a four motion feeding movement of said feed dog for transporting the fabric from front to the rear of said machine, said feed dog engaging from below the lowermost piece of said fabric, and a secondary feed attachment connected to said machine, said attachment including a secondary feed means mounted to overlie said feed dog and to engage the upper piece of said overlying piece of fabric from above, said secondary feed means including a bracket having angularly disposed leg portions, a pair of angularly disposed pivotally jointed lever arms, each of said pivotally jointed arms having an elongated slot formed intermediate the ends thereof, guide means receivable in the respective slots of said arms for slidably connecting each of said pivotally jointed arms to a respective leg portion of said bracket, an overlying feed dog mounted to the free end of one of said pivotally jointed arms, and an eccentric journaled in an opening in the free end of the other of said pivotally jointed arm, means for rotating said eccentric whereby the rotation thereof effects a four-way motion of said overlying feed dog, and means for synchronizing the movement of the respective feed dogs to exert a uniform pull on both the upper and lower overlying pieces of fabric during a sewing operation.

3. A sewing machine adapted for feeding and sewing together at least two overlapping pieces of fabric comprising -a work support, a movable feed dog operating through said work support, means for efiecting a four motion feeding movement of said feed dog for transporting the fabric from front to rear of said machine, said feed dog engaging from below the lowermost piece of said fabric, and a second feed attachment connected to said machine, said attachment including a secondary feed means mounted to said machine to overlie said feed dog and to engage the upper piece of said overlying piece of fabric from above, said secondary feed means including an L-shaped bracket having angularly disposed leg portions, a pair of angularly disposed pivotally jointed lever arms, each of said pivotally jointed arms having n elongated slot formed intermediate the ends thereof, guide means receivable in the respective slots of said arms for slidably connecting each of said pivotally jointed arm to the respective leg portions of said L-shaped bracket, an overlying feed dog mounted to the free end of one of said pivotally jointed arms, and an eccentric journaled in an opening in the free end of the other pivotally said jointed arms, means for rotating said eccentric whereby the rotation thereof affects a four-way motion of said overlying feed dog, means for adjusting the stroke of the overlying feed means with respect to said feed dog, and means for synchronizing the movement of the respective feed dogs to exert a uniform pull on both the upper and lower overlying pieces of fabric.

4. A secondary feed attachment for use on a sewing machine in sewing double-ply fabric comprising secondary feed means adapted to overlie a feed dog of a sewing machine and adapted to engage the upper piece of said double-ply fabric from above, said secondary feed means including a bracket having angularly disposed leg portion, a pair of angularly disposed pivotally jointed lever arms, each of said pivotally jointed arms having an elongated slot formed intermediate the ends thereof, guide means receivable in the respective slots of said arms for slidably connecting each of said pivotally jointed arm to the respective leg portions of said bracket, an overlying feed dog mounted to the free end of one of said pivotally jointed arms, and an eccentric journaled in an opening in the free end of the other of said pivotally jointed arm, and means for rotating said eccentric whereby the rotation thereof effects a four-way motion of said overlying feed dog, and means for adjusting the stroke of the overlying feed means.

5. The invention as defined in claim 4 wherein said adjusting means including a slot formed in the leg portion of said bracket, for adjusting the position of said guide means therein, and means for maintaining said guide means in adjusted position relative to said bracket arm slot.

6. In combination with a sewing machine having a work support and a movable feed dog operating with a four way feed motion through the work support to engage from below the material being stitched and advance the same from front to rear of the sewing machine, the apparatus comprising, a movable auxiliary feed dog carr-ied by supporting means detachably fixedly secured to and shiftable with the presser foot bar of the sewing machine, said auxiliary feed dog being positioned to overlie the sewing machine feed dog in upwardly spaced relation thereof for engaging from above the material being stitched, drive means coupling said auxiliary feed dog to the sewing machine drive to operate the auxiliary feed dog with a four way feed motion to advance the material being stitched from front to rear of the sewing machine, said drive means including adjustable means for synchronizing the four way feed motion of the auxiliary feed dog with the four way feed motion of the sewing 7 machine feed dog to cause both said feed dogs to move the material being stitched in the same direction and substantially simultaneously when such material is engaged thereby.

7. In combination with a sewing machine having a work support and a movable feed dog operating with a four way feed motion through the work support to engage from below the material being stitched and advance the same from front to rear of the sewing machine, the apparatus comprising, a movable auxiliary feed dog carried by support means detachably fixedly secured to and shiftable with the presser foot bar of the sewing machine, said auxiliary feed dog being positioned to overlie the sewing feed dog in upwardly spaced relation thereto for engaging from above the material being stitched, drive means coupling said auxiliary feed dog to the sewing machine drive to operate the auxiliary feed dog with a four way feed motion to advance the material being stitched from front to rear of the sewing machine, said drive means including adjustable means for synchronizing the four way feed motion of the auxiliary feed dog with the four way feed motion of the sewing machine feed dog to cause both said feed dogs to move the material being stitched in the same direction and substantially simultaneously when such material is engaged thereby, and means coupled to said auxiliary feed dog effective to vary the rate of feed of said auixiliary feed dog independently of the rate of feed of the sewing machine feed dog.

8. In combination with a work support and a movable feed dog operating with a four way feed motion through the work support to engage from below the material being stitched and advance the same from front to rear of the sewing machine, the apparatus comprising, a movable auxiliary feed dog carried by support means detachably fixedly secured to and shiftable with the presser foot bar of the sewing machine, said auxiliary feed dog being positioned to overlie the sewing machine feed dog in upwardly spaced relation thereto for engaging from above the material being stitched, drive means coupling said auxiliary feed dog to the sewing machine drive to operate the auxiliary feed dog with a four way feed motion to advance the material being stitched from front to rear of the sewing machine, said drive means including adjustable means for synchronizing the four way feed motion of the auxiliary feed dog with the four way feed motion of the sewing machine feed dog to cause both said feed dogs to move thematerial being stitched in the same direotion and substantially simultaneously when such material is engaged thereby, and means carried by said auxiliary feed dog support means and coupled to said auxiliry feed dog effective to selectively vary the rate of feed of said auxiliary feed dog independently of the rate of feed of the sewing machine feed dog.

9. In combination with a sewing machine having a work support and a movable feed dog operating with a four way feed motion through the work support to engage from below the material being stitched and advance the same from front to rear of the sewing machine, the apparatus comprising, a movable auxiliary feed dog carried by support means detachably fixedly secured to and shiftable with the presser foot bar of the sewing machine, said auxiliary feed dog being positioned to overlie the sewing machine feed dog in upwlardly spaced relation thereto for engaging from above the material being stitched, drive means coupling said auxiliary feed dog to the sewing machine drive to operate the auxiliary feed dog with a four way feed motion to advance the material being stitched from front to rear of the sewing machine, said drive means including adjustable means for synchro izing the sewing machine having a four way feed motion of the auxiliary feed dog with the four Way feed motion of the sewing machine feed dog to cause both said feed dogs to move the material being stitched in the same direction and substantially simultaneously when such material is engaged thereby, and means carried by said auxiliary feed dog support means and coupled to said auxiliary feed dog elfective to selectively vary the length of feed stroke of said auxiliary feed dog independently of the length of feed stroke of the sewing machine feed dog.

10. For external attachment to and use with a sewing machine of the type having a work support and a movable feed dog operating with a four way feed motion through the work support to engage from below the material being stitched and advance the same from front to rear of the sewing machine, an attachable and detachable auxiliary feed device comprising in combination, a movable auxiliary feed dog positioned to overlie the sewing machine feed dog in upwardly spaced relation thereto for engaging from above the material being stitched, support means carrying said auxiliary feed dog and detachably coupled to and shiftable with the presser foot bar of the sewing machine, auxiliary drive means detachably secured to said sewing machine and coupling said auxiliary feed dog to the sewing machine power drive effective to operate the auxiliary feed dog with a four way feed motion to advance the material being stitched from front to rear of the sewing machine, said auxiliary drive means including adjustable means for synchronizing the four way feed motion of the auxiliary feed dog with the four way feed motion of the sewing machine feed dog to cause both said feed dogs to move the material being stitched in the same direction and substantially simultaneously when such material is engaged thereby. 5 l

11. For external attachment to and use with a sewing machine of the type having a work support and a movable feed dog openating with afour way feed motion through the work support to engage from below the material being stitched and advance the same from front to rear of the sewing machine, an attachable and detachable auxiliary feed device comprising in combination, a movable auxiliary feed dog positioned to overlie the sewing machine feed dog in upwardly spaced relation thereto for engaging from above the material being stitched, support means carrying said auxiliary feed dog and detachably coupled to and shiftable with the presser foot bar of the sewing machine, auxiliary drive means detachably secured to said sewing machine and coupling said auxiliary feed dog to the sewing machine power drive effective to operate the auxiliary feed dog with a four way feed motion to advance the material being stitched from front to rear of the sewing machine, said auxiliary drive means including adjustable means for synchronizing the four way feed motion of the auxiliary feed dog with the four way feed motion of the sewing machine feed dog to cause both said feed dogs to move the material being stitched in the same direction and substantially simultaneously when such material is engaged thereby, and means carried by said auxiliary feed dog support means and coupled to said auxiliary feed dog effective to selectively vary the rate of feed of said auxiliary feed dog independently of the rate of feed of the sewing machine feed dog.

References Cited in the file of this patent UNITED STATES PATENTS 447,401 Gardner Mar. 3, 1891 466,273 Dimond Dec. 29, 1891 1,809,148 Schrago June 9, 1931 1,984,593 Mueller Dec. 18, 1934 2,967,498 Russell et al V Jan. 10, 1961

Claims

1. A SEWING MACHINE ADAPTED FOR FEEDING AND SEWING TOGETHER AT LEAST TWO OVERLAPPING PIECES OF FABRIC COMPRISING A WORK SUPPORT, A MOVABLE FEED DOG OPERATING THROUGH SAID WORK SUPPORT, MEANS FOR EFFECTING A FOUR MOTION FEEDING MOVEMENT OF SAID FEED DOG FOR TRANSPORTING THE FABRIC FROM FRONT TO THE REAR OF THE MACHINE, SAID FEED DOG ENGAGING FROM BELOW THE LOWERMOST PIECE OF SAID FABRIC, AND A SECONDARY FEED ATTACHMENT CONNECTED TO SAID MACHINE, SAID ATTACHMENT INCLUDING A SECONDARY FEED MEANS MOUNTED TO OVERLIE SAID FEED DOG AND TO ENGAGE THE UPPER PIECE OF SAID OVERLYING PIECE OF FABRIC FROM ABOVE, SAID SECONDARY FEED MEANS INCLUDING A BRACKET HAVING ANGULARLY DISPOSED LEG PORTIONS, A PAIR OF ANGULARLY DISPOSED PIVOTALLY JOINTED LEVER ARMS, EACH OF SAID PIVOTALLY JOINTED ARMS HAVING AN ELONGATED SLOT FORMED INTERMEDIATE THE ENDS THEREOF, GUIDE MEANS RECEIVABLE IN THE RESPECTIVE SLOTS OF SAID ARMS FOR SLIDABLY CONNECTING EACH OF SAID PIVOTALLY JOINTED ARMS TO A RESPECTIVE LEG PORTION OF SAID BRACKET, AN OVERLYING FEED DOG MOUNTED TO THE FREE END OF ONE OF SAID PIVOTALLY JOINTED ARMS, AND AN ECCENTRIC JOURNALED IN AN OPENING IN THE FREE END OF THE OTHER OF SAID PIVOTALLY JOINTED ARMS AND MEANS FOR ROTATING SAID ECCENTRIC WHEREBY THE ROTATION THEREOF EFFECTS A FOUR-WAY MOTION OF SAID OVERLYING FEED DOG FOR EXERTING UNIFORM PULL ON BOTH THE UPPER AND LOWER OVERLYING PIECES OF FABRIC.