US1731080A

US1731080A - moffatt

Info

Publication number: US1731080A
Authority: US
Publication date: 1929-10-08
Anticipated expiration: 1946-10-08

Description

I Oct. 8, 1929.

J. R. MOFFATT REVERSIBLE FEED FOR SEWING MACHINES Original Fild Sept. 8. 1922 2 Sheets-Sheet 1 Oct. 8, 1929. J. R. MOFFATT 1,731,080

REVERSIBLE FEED FOR SEWING MACHINES Original Filed Sept. 8. 1922 2 Sheets-Sheet 2 Patented Get. 8, 1929 UNITED STATES PATENT QFFICrEZ JAMES R.'MOFFATT, OF CHICAGO, ILLINOIS, ASSIGNOR TO UNION SPECIAL MACHINE COMPANY, 015' CHICAGO, ILLINOIS, A GGRPORATION OF ILLINOIS .BEVERSIBLE FEED FOR SEVING MACHINES Original application filed September 8, 1922, Serial No. 586,897.

16, less.

The invention relates to new and useful improvements in a reversible feeding mechanism for sewing machines, and more particularly to a reversible feeding mechanism for a flat bed sewing machine.

An object of the invention is to provide a feeding mechanism for a flat bed sewing machine wherein the feed dog is moved back and forth and raised and lowered by mechanism located at the same end of the machine as the feed bar, and wherein parts of said mechanism may be quickly shifted so as to bring about a movement of the feed dog in the op-' posite direction so as to change the direction of feed of the material during the stitching thereof.

A further object of the invention is to provide a reversible feeding mechanism of the abovetype, wherein thelength of feed in one direction may be varied from what it is in the opposite direction.

A still further object of the invention is to provide a reversible feeding mechanism of the above type, wherein the shifting of the parts for reversing the feed is under control of a treadle adapted to be actuated by the operator.

In the drawings Figure 1 is a vertical sectional view through a machine embodying the improved reversible feeding mechanism, with the parts set for feeding in one direction;

Fig. 2 is a similar view but with the parts shifted so as to feed in the opposite direction;

Fig. 3 is a view partly in plan and partly in section of the parts beneath the work support, and i Fig. 4 is a sectional view on the line 4-4; of Fig. 3.

In my prior application Serial No. 586,897, filed September 8, 1922, I have shown and described a sewing machine for forming chain stitches wherein the feeding mechanism is capable of being reversed so as to feed the material in the opposite direction to the needle, when desired. This machine of the prior application is also provided with a thread carrying looper moving in a direction at right angles to the feed when entering and leaving the needle thread loop, and a device Divided and this application filed June Serial No. 57,479.

is associated with the thread carrying looper for aiding in the forming of the thread triangle for the needle to enter when the feed of the fabric is reversed, so as to feed toward the front of the machine. When the feed is toward the rear of the machine, then the movement of the fabric will aid in the opening of the thread triangle for the needle, and when the feed is toward the front of the machine, the thread retainer just referred to cooperates with the looper in holding the thread triangle open for the needle to enter. This application is a division of my prior application, and is limited to the feeding mechanism contained therein. While the present feeding mechanism is especially adapted for use in conjunction with a chain stitch sewing mechanism having a device associated with the looper for insuring proper stitch formation when the fabric is fed toward the front of the machine, it may be used in connection with other types of stitching mechanisms where the stitches will be properly formed and secured regardless of the direction of feed without any assisting elements.

The machine includes a bed plate 1 on which is mounted a work support 2. At the front end of the machine, there is a bracket 3. A main shaft 4 extends lengthwise of the machine and is journaled in this bracket 3. A feed dog 5 is mounted on the feed bar 6, and this feed bar is raised and lowered by means of an eccentric 6 on the main shaft 4. The feed bar 6 is pivotally secured to a feed rocker 7 at the rear of the machine. Said feed bar is preferably rigidly connected to a pin 8 which is journaled in this feed rocker 7 (see Fig. 3). The feed rocker 7 is mounted so as to oscillate about an axis 9, and said feed rocker is oscillated by means of link and lever connections with the crank pin 10 mounted for radial adjustment in the disk 11 carried by the end of the main shaft 4. Said disk has a slot formed therein, and the crank pin 10 is shiftable in the slot. This crank pin for oscillating the feed bar is of common construction in the sewing machine art. An auxiliary bracket 12 is securedto the bed plate 1 by means of screws 1313. Journaled in the upper end of this bracket 12 is a short stub shaft 1 1. Rigidly secured to the outer end of the stub shaft 14 is a plate 15. This plate 15 has a forwardly projecting arm 16 which is pivoted at 17 to the upper end of a link 18, which link in turn is journaled on the crank pin 10. As this crank pin rotates, it will oscillate the plate and the stub shaft on which it is mounted. There is also a late 19 which is formed as a part of theplate 15, but which is spaced from said plate 15 as clearly shown in the plan view thereof in Fig. 3. This plate 19 oscillates with the plate 15 and about the center of the stub shaft 14. The plate 19 is formed with a slot 20.

The feed rocker 7 is mounted on the supporting shaft 21 at the lower end thereof, and the axis 9 referred to above is the axis of this shaft. Ri 'idly secured to this shaft 21 is a forwardly projecting lever arm 22. This lever arm 22 at its outer end is pivotally connected to a link 23. The upper end of this link 23 is forked as at 2 1 and straddles the plate 19. A pin 25 passing through the forked upper end of the link 23 also passes through the slot in said plate 19. When the pin is at the right-hand end of the slot 20 as viewed in Fig. 1, the oscillations of the plate 19 through this link 23 will move the arm 22 and thus oscillate the rock shaft to which the feed bar is connected. When this pin 25 is moved to the other end of the sleeve 20 as viewed in Fig. 2, then the link will be raised and lowered and will oscillate the feed rocker, but the oscillations will be reversed from what they were when the pin was at the forward end of this slot. In other words, when the pin 25 is at the forward end of the slot 20, the feed is operating in a normal way so as to feed the material from the front side of the machine toward the rear side thereof, that is, the feed dog moves from front to rear when the teeth thereof extend above the plane of the wor; support. When, however, this link 23 is shifted so as to bring the pin 25 to the rear end of the slot 20, then the feed dog will be moved from the rear of the machine toward the front thereof when the feed teeth are above the plane of the work support. The bracket 12 carryingthe stub shaft 14 is capable of vertical adjustment. When the bracket is raised, it will raise the stub shaft, and this will lift the arm 22 to a new oscillating position. The lifting of the arm 22 will change the working position of the feed rocker and the feed dog. By this adjustment of the bracket up or down, the working position of the feed dog may be shifted either to-the rear or to the front, and thus the feed dog properly positioned in the slot in the throat plate for the most efficient operation.

'Mounted in the rear end of the plate 19 is a stop screw 26 which is adapted to limit the movements of the link 23 toward the rear end of the slot. This link 23 is shifted by means of a rock lever 27 which is connected by a suitable flexible connect-ion 28 with a treadle. This rock lever swings about the cen r 9 above referred to. Said rock lever has an upwardly extending arm 29 and a link 30 is pivoted to the upper end of t is arm 29. This link is also pivoted at its other md to the link 23 intermediate the ends thereof. When the treadle is dopressed, the rock lever will be oscillated so as to pull upon the link 30, and thus shift the link 23 so that the parts are positioned as shown in 2. When the treadlc is released, a spring 31 hearing on the eXtension 32 of the rock lever will swing the rock lever in a clockwise direction, so that the link 30 will push on the link 23 and move tl e upper end ther of to the other end of the slot 20, that is, to the position shown in 1. The length of the feed stroke will, of course, be determined upon the extent of the up and down movement of the link and this in turn depends upon the distance of the pin 25 from the center of the stub shaft 1 1. By properly adjusting the stop 26, it will readily be seen that the feed in one direction may be made longer or shorter than the feed in the other direction.

It is to be noted that the machine is of the flat bed type. The stitching mechanism has not been illustrated except to show the needle 33 carried by the needle bar 3 1, the lc-oper carrier 35 in which the thread carrying looper is adapted to be mounted, and the cooperating thread retaining finger 36. These parts are fully shown and described in my copending application of which this application is a division, and further description thereof is not thought necessary. The material is held on the work support 2 by means of a presser foot 37, as shown in Figures 1 and 2. The presser foot is shown in these figures as raised to inoperative position for the insertion or removal of the material to be stitched and for the sake of clearness. The material to be stitched is placed beneath the presser foot and the machine operated in the usual way. If the treadle is released which controls the rock lever 27, then the feed of the fabric will be from the front of the machine toward the rear thereof, between successive punctures of the material by the needle. Vhen it is desired to feed the material in the opposite direction for tacking or for any other purpose, a depressing of the treadle will shift the parts to the position shown in Fig. 2, and this will cause the feed of the material in the opposite direction, that is, from the rear toward the front of the machine between successive punctures of the material by the needle.

It is obvious that minor changes in the details of construction and arrangement of the parts may be made without departing from the spirit of the invent-ion as set forth in the appended claims.

Having thus described the invention, what I claim as new and desire to secure by Letter Patent, is

1. A reversible feed for sewing machines including in combination a work support, a main shaft located beneath the work support and extending lengthwise thereof, a feed bar, a feed dog carried thereby, a feed rocker at the rear of the work support to which said feed bar is pivoted, means carried by said shaft for raising and lowering said feed bar, a rotating crank mounted on the outer end of said main shaft, devices actuated by said crank for oscillating said rock shaft for moving the feed dog back and forth, said devices including a shiftable member for controlling the direction of the feed, means under the con trol of the operator for moving said shiftable member for reversing the direction of feed, a spring for moving said controlling means in one direction, and an adjustable stop for limiting the movement of said control means.

2. A reversible feed for sewing machines including in combination a bed plate, a work support, a main shaft located beneath the work support, a feed bar, afeed dog carried thereby, a feed rocker at the rear of the work support to which the feed bar is pivoted, a rotating crank on the end of the main shaft, a bracket mounted on said bed plate, a shaft journaled in said bracket. a substantially horizontal rocker arm carried by said shaft and having a slot therein, a substantially vertical link having a shiftable connection with said slot, an arm attached to the feed rocker and to the lower end of said link, a link connecting said rocker arm with the crank on the nain shaft, manually controlled means for shifting the link in said slot for reversing the feed, and an adjustable stop for limiting the movement of said shiftable link.

3. A reversible feed for sewing machines including in combination a bed plate, a work support, a main shaft located beneath the work support. a feed bar, a feed dog carried thereby, a feed rocker at the rear of the work support to which said feed bar is pivoted, an eccentric member on said shaft for raising and lowering the feed dog, an eccentric member on the end of said shaft, a bracket mounted on"said bed in rear of said shaft, a shaft j ournaled in the bracket, a substantially hori- Zontal rocker arm carried by said shaft and having a slot therein, means for oscillating said rocker arm from said eccentric member on the end of the shaft, a link having a shiftable connection with the slot in the rocker arm, and an arm disposed substantially horizontal and connected to the feed rocker to which arm said link is attached.

4. A feeding mechanism for sewing machines including in combination a throat plate having a feed slot therein, a feed dog operating in said slot, a feed bar on which said feed dog is mounted, means for raising and lowering the feed bar, a feed rocker to which the feed bar is pivoted, an oscillating member, means for oscillating said member, a supporting bracket for said oscillating member, a link connecting said oscillating member to said feed rocker, and means for raising and lowering said bracket supporting said oscillating member for shifting the working position of the feed dog in the slot in the throat plate.

5. A feeding mechanism for sewing machines including in combination throat plate having a feed slot therein, a feed dog operating in said slot, a feed bar on which said feed dog is mounted, means for raising and lowering the feed bar, a feed rocker to which the feed bar is pivoted, an oscillating member, means for oscillating said member, a supporting bracket for said oscillating member, a link connecting said oscillating member to said feed rocker, and means for raising and lowering said bracket supporting said oscillating member for shifting the working position of the feed dog in the slot in the throat plate, said link being disposed in the same general direction as the adjustment of the bracket.

6. A feeding mechanism for sewing machines including in combination a throat plate having a feed slot therein, a feed dog operating in said slot, a feed bar on which said feed dog is mounted, means for raising and lowering the feed bar, a feed rocker to which the feed bar is pivoted, an oscillating member, means for oscillating said member, a supporting bracket for said oscillating member, a link connecting said oscillating member to said feed rocker, and means for raising and lowering said bracket supporting said oscillating member for shifting the working position of the feed dog in the slot in the throat plate, said link being shiftable from one side of the axis of the oscillating member to the other for reversing the feed.

In testimony whereof, I aliix my signature.

JAMES R. MOFFATT.