US1443634A - Feeding mechanism for sewing machines - Google Patents

Description

Jan. 30, 1923. 1,443,634 J. R. MOFFATT ET AL.

FEEDING MECHANISM FOR SEWING MACHINES.

FILED SEPT. 26. I917 4 SHEETS'SHEET I (O 4 I I fizal. gi

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FEEDING MECHANISM FOR Sawms MACHINES.

Fl LED SEPT. 26 I 917. 4 SHEETS'SHEET 2 cmv Jan. 30, 1923. 1,443,634

J. R. MOFFATT ET AL.

FEEDING MECHANISM FOR SEWING MACHINES.

FILED SEPT. 26, 1917. 4 SHEETS-SHEET 3 V i WWW Jan. 30, 1923. 1,443,634

J, R. MOFFATT ET AL. FEEDING MECHANISM FOR SEWING MACHINES,

FILED SEPT. 26, 1917. 4 SHEETS'SHEET 4 Patented Jan. 30, 1923.

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hiddfidd JAMES R. MOFFAT'I AND RALPH S. KELSO, OF CHICAGO, ILLINOIS, ASSIGNORS T0- UNION SPECIAL MACHINE COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

FEEDING MECHANISM FOR SEWING MACHINES.

Application filed September 28, 1917. Serial No. 193,363.

To all ill/107M it may concern:

Be it known that we, JAMES R. MorrA'r'r, and RALPH S. KELso, citizens of the United States, residing at Chicago, in the county of Cook, State of Illinois, have invented certain new and useful Improvements in Feeding Mechanism for Sewing Machines, of

which the following is a description, reference being had to the accompanying drawing and to the figures of reference marked thereon.

This invention relates to new and useful improvements in feeding mechanism for sewing machines, and more particularly to a feeding mechanism having a lower feed dog engaging the under face of the fabric and an upper feed dog which cooperates therewith and engages the upper face of the fabric.

This invention embodies specific improvements on our copending application 131,223 filed November 14, 1916, for feeding mechanism for sewing machines.

In the above mentioned application a top feed dog was positively moved up and down and back and forth in a substantially four-motion path of travel, and by reason.

of the positive driving connections for said feed dog, the latter necessarily pounded to a considerable extent on the lower feed dog when partaking of its downward movement.

The principal object of this invention is therefore to provide a mechanism for imparting a four-motion path of travel of the upper feed dog, and including in the driving connections therefor, a cushioning arrangement which will greatly reduce the pounding of said upper feed dog as above noted.

These and other objects will in part be obvious and will in part be more fully disclosed.

In the drawings which showby way of illustration-one embodiment of the inven- .t1on

Figure 1 is a view partly in end elevation and partly in vertical section showing a sewing machine embodying our improvements, the upper and lower feed dogs bein shown engaging the fabric;

Figure 2 is a similar View showing the feed dogs respectively raised and lowered for their return movements, the presser foot clamping the fabric to the work support;

Figure 3 is a rear elevation of the sewing machine;

Figure l is an enlarged perspective view showing the mechanism for imparting the four motion path of travel to the upper feed dog, said mechanism including the cushionmg device; and

Figure 5 is a detail vertical sectional view through the cushioning device for the upper feed dog.

In carrying out our invention, we have provided a lower feeding mechanism which includes a main or lower feed dog which is given the usual four-motion path of travel. Cooperating with this lower feed dog is an upper feed dog or feeding foot and also a presser foot. its backward and forward movement through a train of mechanisms connected with the The upper feed dog is given mechanism for giving the lower feed dog its backand forward movements, so. that said upper and lower feed dogs are timed together in their backward and forward movements. The up and down movements to the upper feed dog are obtained through a train of mechanism from an eccentric on the main shaft'of the machine, and the connection with this eccentric is adjustable to permit of the timing the up and down movements of said upper feed dog to be varied. This last mentioned train of mechanism includes a rocking lever, and a connection between one arm of said lever and the bar which supports the upper feed dog so that upon rocking'movement of said lever the upper feed dog will be given its up and down movements. This connection between the rocking lever and said feed bar includes a loose and yieldable device whereby when the foot is moved downwardly to engage the fabric said yieldable device will yield under the'positive action of the rocking lever and thereby greatly lessen the pounding of said upper feed dog on the under feed Referring more in detail to the drawings We have shown our improvements as applied to a sewing machine having a supporting bed 1 carrying an overhanging arm 2 in which a needle bar 3 reciprocates. Said needle bar is provided, as shown, with needles 4-4. This needle bar is reciprocated in the usual way. Cooperating with the .tion.

A work support 6 is carried by the supporting bed 1 and is provided with a feed said pin 18.

v up and down and back and forth at this- -'cl0sed end of the upper tube 33. This slot 7 through which the main or lower feed dog 8 operates. The material is held on the work support between feeding movements by a presser foot 9, and this foot is carried by a presser bar 10 mounted to move vertirally only in the overhanging arm 2.

Cooperating with the main or lower dog 8 is an upper feed dog 11. The lower feed dog is carried by a feed bar 12 and this bar is reciprocated by a feed rocker '13 to impart the backward and forward movements to said feed dog. -The feed rocker is reciprocated in the usual manner from the main shaft 14. The feed bar 12 is raised and lowered by an eccentric fixed to the main shaft 14. i

The upper feed dog 11 is clamped to the lower end of a vertically disposed feed bar 16. The upper end of this bar is provided with a slot 17 which has sliding engagement with a fulcrum pin 18 fixed to the overhanging arm '2. This permits the bar to recip rocate vertically and also to swing. about The feed bar 16 is also provided with an opening 19; and a bearing plate 20, larger than the opening, spans the same, and is secured to the overhanging arm 2 by a screw 21. This opening 19 is of sulficient size to permit the feed bar 16 to move point.

The feed bar 16 is oscillated about the pin 18 by a train of mechanism which includes a reciprocatory lever 22, a link 23 pivotally connecting said lever with said feed 'bar, and suitable driving connections between the lever. and the feed rocker 13 said parts being arranged whereby the back and forth movements of the upper feed dog will be timed with the back andfo'rth movements of .the lower feed dog.

Fixedly secured to the presser bar 10 is a guide arm 24, and this guide armis in turn fixedly connected to a guide bar 25 which is movable vertically in suitable bearings in the overhanging arm. The guide arm 24 serves to prevent oscillations of the presser bar 10 and also causes the guide bar- 25 to be moved vertically with said presser bar.

The upper feed bar 16 is reciprocated in a vertical plane through a train of mechanism which includes a reciprocatory lever 26 which is in turn actuated from an eccentric on the main'shaft 14. The lever 26 is connected by a link 27 to the lower end of the vertical arm 28 of a rocking lever 29. This rocking lever is pwoted at its fulcru for a limited distance.

as at 30, to a block 31 which is rigidly clamped to the, presser guide bar 25. One end of this block 31 has sliding engagement with the presser bar 10 to maintain said block against oscillatory movement about said guide bar 25. The horizontal arm 32 of said rocking lever is connected to the upper feed bar 16 by a connection which will impart up and down movements to the upper foot 11 upon oscillatory movements of said rocking lever 29. This connection is a two-part connection and includes a loose connection between the parts, and also a yielding device disposed between said parts to cushion the downward movement of the upper feed dog. This connection includes upper and lower tubes 33 and 34 respec tively which are arranged in telescopic relation, the lower tube being disposed within the upper tube. The upper end of the upper tube is closed and is pivotally connected by a pin 35 to the outer endcof the horizontal arm 32 of said rocking lever 29. The lower end of the lower tube 34 is closed and is pivotally connected-by a pin 36 to the upper feed bar 16. A vertically disposed slot' 37 is located in the upper tube 33 and a stop screw 38 is arranged within this opening and threaded into the lower tube 34. The slot 37 is'of a length sufiicient to permit the screw to have vertical movements This connection between tlie upper and lower tubes forms a loose but positive connection therebetween. Disposed within the lower tube 34 is a coiled spring 39 which normally extends above the upper edge thereof and bears against the spring normally acts to urge the upper and lower tubes. apart. but the movement is of course limited by the screw 38 engaging the wallof the slot 37.

From the foregoing it will be noted that the oscillations of the lever 26 will through the link 27 impart oscillatory movements to the rocking lever 29. As the horizontal arm 32 of said rocking lever moves downwardlyto lower the top feed dog 11 onto the fabric, said downward movement of the arm 32 will be cushioned by the spring 39 as soon as the foot 11 engages the fabric, and thereby practically eliminate any pounding of the top feed dog against the under feed dog. Upon continued movement of the arm 32 of said rocking lever the pivot thereof is changed from the fulcrum 30 to the pivot pin 35, and as a result the presser foot 9 through the rigid connections between the presser bar 10, fulcrum .30 and block 31 will cause the presser foot to be elevated. Be-

v fore the feed dogs begin their return movenients the foot is caused to move downwardly to engage and clamp the fabric against the work support, and immediately following said clamping action, the two feed we claim as new, and desire to secure by Let-" ters Patent, is:

l. A feeding mechanism for sewing machines including an upper feed dog, a feed bar, a feed dog rigidly connected to the lower end of said feed bar, means for moving the lower end of the feed bar back and forth for imparting feeding movements to i the feed dog, and means for moving the feed bar up and down including a pivoted openng connection with said feed bar whereby said bar may move freely back and forth.

2. A feeding mechanism for sewing machines including an upper feed dog, a'feed bar for supporting said dog, means for moving said dog back and orth, and means for moving said dog up and down including a rocking lever and a yieldable connection between said lever and said feed dog support, said connection being independent of the support and including two parts telescopically arranged, a pin and slot connection between said parts for limiting their relative movements, and a spring interposed be tween said parts.

8. A feeding mechanism for sewing machines including an upper feed dog, a vertically disposed feed bar carrying said feed dog, means for supporting the upper end of said feed bar whereby it may be oscillated and bodily raised and lowered, means for positively swinging said feed bar for moving the feed dog backand forth, a rock lever having a vertically disposed arm and a horizontally disposed arm, means con nected to said vertically disposed arm for oscillatin said rock lever, a link for connecting t e horizontally disposed arm to said feed bar, said link including two telescoping parts, a pin and slot connection between said parts for limiting their relative movements, and a spring interposed between said parts.

4. A sewin machine including in combination, a wor support, a feed dog disposed vbeneath said work support, means for moving said feed-dog back and forth and for raising and lowering the same, the upper feed dog constituting the sole feeding member for engaging the upper face of the fabric, a vertically disposed feed bar to which said feed dog is rigidly connected, means for supporting the upper end of said feed bar whereby it may be swung for impartin feeding movements to the feed dog and whereby it may be raised and lowered, means for positively swinging the feed bar, a rock lever, said rock lever having a horizontally disposed arm, a link pivotally connecting the horizontally disposed arm with the feed bar for raising and lowering the same, means adjacent the lower end of the feed bar for guiding the same in its back and forth and up and down movements, said link including a yielding means having a positive limitation whereby the feed bar may be positively raised from engagement with the fabric and yieldingly forced against the fabric when lowered.

In testimony whereof, we affix our signatures, in the presence of two witnesses.

JAMES MOFFATT. RALPH S. KELSO,

Witnesses R. H. SIMMONS, JNO. KENNEDY,

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