US1990616A

US1990616A - Feeding mechanism for sewing machines

Info

Publication number: US1990616A
Application number: US532934A
Authority: US
Inventors: Charles F Rubel
Original assignee: Union Special Machine Co
Current assignee: Union Special Machine Co
Priority date: 1931-04-25
Filing date: 1931-04-25
Publication date: 1935-02-12
Anticipated expiration: 1952-02-12
Also published as: DE579871C

Description

Feb; 12, 1935.

Filed April 25, 1931 5 Sheets-Sheet 1 Feb. 12, 1935. c. F. RUBEL FEEDING MECHANISM FOR SEWING MACHINES 5 Sheets-Sheet 2 Filed April 25, 1951 Feb; 12, 1935. c. F. RUBEL 1,990,616

FEEDING MECHANISM FOR SEWING MACHINES Filed April 25, 1931 5 Sheets-Sheet 5 tor Feb. 12, 1935. c, F, RUBEL FEEDING MECHANISM FOR SEWING MACHINES Filed April 25, 1931 5 Sheets-Sheet 4 gmn'ntot Feb. 12, 1935. I c. RUBEL 1,990,616

FEEDING MECHANISM FOR SEWING MACHINES Filed April 25, 1951 5 Sheets-Sheet 5 7 UNITED STATES PATENT OFFICE FEEDING MECHANISM FOR SEWING MACHINES Charles F. Rubel, Chicago, llll., assignor to Union Special Machine Company, Chicago, 111., a corporation of Illinois Application April 25, 1931, Serial No. 532,934

15 Claims.

The invention relates to new and useful im-' provements in a feeding mechanism for sewing machines, which not only includes means for moving the fabric, but also for holding the fabric during the stitching thereof.

An object of the invention is to provide a sewing machine of the above character having av presser foot and a feed roller operating on the fabric in rear of the presser foot, with common means for supporting said presser foot and feed roller, whereby said feed roller is forced against the material with a greater pressure than the presser foot.

A further object of the invention is to provide a feeding mechanism of the above character wherein the feed'roller and the presser foot are mounted on a pivoted rock frame and so disposedrelative to the pivot thereof that yielding pressure on the support for the rock frame will force both the feed roller and the foot into engagement with the fabric.

A further object of the invention is to provide a feeding mechanism of the .above character wherein there is an additional yielding pressure on the rock frame which increases the pressure of the feed roller against the fabric and decreases the pressure of the foot against the fabric.

A- still further object of the invention is to provide a presser foot of the above character wherein the feed roller is intermittently and positively rotated.

A still further object of the invention is to provide a machine of the above character wherein the feed roller is positively rotated by a shaft disposed vertically fiid formed in sections so as to rotate together and have a sliding movement one on the other whereby the feed roller is free to move up and down.

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

In the drawings which show by way of illustration one embodiment of the invention- Figure 1 is a view from the end of the machine showing partly in section and partly in elevation one embodiment of the invention;

Fig. 2 is a view from the front side of the machine;

Fig. 3 is a top plan view of the same;

Fig. 4 is a front view of the presser foot and the parts immediately associated therewith;

Fig. 5 is a plan view on the line 55 of Fig. 4;

Fig. 6 is a view partly in section and partly in plan showing the rock frame, the feed roller and the presser foot;

Fig. 7 is a view showing diagrammatically the presser bar, the rock frame, the feed roller, the presser foot and the yielding devices operating on the rock frame and on the presser bar;

Fig. 8 is a view in part like Fig. '7, but showing the presser foot as passing on to a cross seam;

Fig. 9 is a view similar to Fig. 8, but showing the presser foot as passing off from the cross seam, and 1 Fig. 10 is a view similar to Fig. 8, but showing the presser foot as having completely passed off the cross seam which is passing underneath the feed roller.

The invention is directed to a feeding mechanism for sewing machines. This feeding mechanism includes a feed dog operating on the material beneath the work support, which is of the usual character. Cooperating with this feed dog above the work support is a presser foot and a feed roller. The invention has to do particularly with the'means for mounting the presser foot and feed roller and for imparting positive, intermittent rotations to said feed roller. The feed roller is located in rear of the presser foot, and both are mounted on a frame which is pivoted at a point intermediate the feed roller and the foot to the presser bar of the sewing machine. The presser bar is yieldingly forced downward. There is a rearwardly projecting part on this rock frame, and a yielding means operates there on and adds to the pressure of the spring on the presser bar in forcing the feed roller toward the material. This spring operates in the other direction upon the presser foot so as to decrease the pressure thereof on the material. The presser foot'is pivoted to the rock frame, and the pivot thereof is substantially in a line intersecting the stitching point. The feed roller is intermittently rotated by a vertical shaft formed in sections, and connected by bevel gears to the shaft which supports the feed roller; The lower section of the shaft is mounted on the rock frame and can move up and down therewith. The upper section of the shaft is fixed to the needle head. This permits the upper section of the shaft to impart positive rotations to the feed roller, and at the same time, permits the feed roller to have a limited up and down movement relative to the upper section of the shaft. There is also preferably embodied in the shaft a flexible section which permits of a slight angular movement of the lower portion of the shaft. This shaft is rotated by a clutch drum at the upper end thereof.

Referring'more in detail to the drawings, the invention is shown as applied to a sewing machine of the type illustrated in the patent granted Norman V. Christensen and Harold J. LeVesconte, December 24, 1929, No. 1,741,095. This machine is of the suspended work arm type in which the material as it is stitched is fed off from the end of the arm. The machine includes a standard 1 having an overhanging bracket portion 2 on which is mounted the upper frame member 3. At one end of this upper frame member is a laterally projecting portion 4 carrying a needle head 5.

Mounted for reciprocation in the needle head is a needle bar 6 carrying preferably three needles, two of which are indicated at '7 and 8 in Fig. 2 of the drawings. Also carried by this upper frame member 3 is a suspended work arm 9 in which is located the complemental stitch forming mechanism which may be of any desired character. Also mounted in this work arm is a feeding mechanism which includes a feed dog 10 operated in the usual way for engaging the under face of the fabric and feeding the same in a direction so that the stitched fabric passes off from the end of the work arm.

The present invention is directed particularly to the parts of the feeding mechanism which are above the work support. On the end of the work arm is a throat plate 11 against which the fabric is pressed by the presser foot 12 and a feed roller 13. Both the presser foot and the feed roller are mounted on a rock frame 14. This rock frame 14 is pivoted at 15 to a shank portion 16 which in turn is secured to the presser bar 1'7 of the machine. The presser bar 17 is mounted in the needle head and is yieldingly pressed downwardly by the leaf spring 18 shown diagrammatically in Fig. '7. This leaf spring and the manner in which it is mounted and bears on the presser bar is all shown in the Christensen and LeVesconte patent, and further detail showing and description thereof is not thought necessary.

The rock frame 14 projects in front of the pivotal support 15 therefor, and forms two spaced

arms

19, 19. Located between these arms is the presser foot 12. It is secured to the outer ends of the arms by

pivot bolts

20, 20. The presser foot as shown is provided with three needle openings -21, 22 and 23, and has the usual upturned front portion. The

pivot bolts

20, 20 are located in a line which intersects the middle needle hole which is substantially the center of the stitch forming devices. When the foot rocks, due to the passing of cross seams, the portion of the foot in the region of the needle openings will remain in contact with the fabric.

The rock frame projects in rear of the pivotal support 15 therefor, and is in the form of a yoke indicated at 24 in the drawings. The feed roller 13 is located between the arms of the yoke and is mounted on a shaft 25 which is journaled in bearings in the rock frame 14. A sleeve 26 bears on the rear end of the yoke member 24 of the rock frame 14. The lower end of this sleeve is rounded and engages a recess 2'7 in the end of the yoke member. Extending into the sleeve is a rod, and surrounding the rod is a compression spring 28. This compression spring bears against a shoulder on the threaded portion 29 of the rod which telescopes within the sleeve 26. This threaded portion is supported by an arm 30 which is fixed to a collar on the presser bar, and extends outwardly between two

guide bars

31 and 32 secured to the needle head. This arm 30 serves to prevent the presser bar from oscillating about its axis, as well as a support for the threaded portion 29. The spring forces the sleeve downwardly into contact with the rock frame at a point well in rear of the support for the feed roller, and also well in rear of the pivotal support for the rock frame. This spring, therefore, exerts a pressure on the rock frame which results in adding to the pressure of the leaf spring on the presser bar, which forces the feed roller downwardly, and also decreases the pressure exerted by the leaf spring on the presser foot. The tension on this spring 28 is, of course, less than the tension of the leaf spring bearing on the presser bar, so that the presser foot is forced against the fabric with a comparatively light pressure, while the feed roller is forced against the fabric with a much stronger pressure.

Mounted on the shaft 25 which carries the feed roller is a bracket 33. Said bracket has depending' spaced arms engaging the shaft outside of the arms of the yoke member 24 (see Fig. 1). This bracket has a laterally projecting arm 34 carrying a sleeve 35 in which is journaled a vertical shaft 36. On the lower end of the shaft is a bevel gear 38 which meshes with a bevel gear 37 on the end of the shaft 25 carrying the feed roller 13. The bracket 33 is provided with a rearwardly projecting lug 39 which extends between the lower ends of the guide bars 31 and 32. This serves to steady the rock frame and prevents turning movements of the presser bar, but which permits the rock frame to freely oscillate on its pivotal support 15 when the feed roller and presser foot are in engagement with the fabric. There is a U-shaped wire 39 secured to the

bars

31 and 32 which underlies this lug 39 and limits the downward movement thereof when the feed roller and presser foot are lifted from the work support for the purpose of inserting or removing the material.

The shaft 36 is formed in two sections. The lower section 36 thereof extends into a sleeve section 36 This sleeve section 36 has a slot 41 therein, and the section 36 carries a block 42 which extends into the slot and is free to slide up and down in the slot. This provides a connection between the shaft sections which causes the upper section to impart rotations to the lower section, and at the same time, permits the lower section to freely move up and down relative to the upper section. The lower section is journaled in the rock frame, and the rock frame in turn is pivotally supported on the presser bar. The presser bar necessarily is moved up and down, and this sectional construction of the vertical shaft permits the free movement of the presser bar up and down, while at the same time, the feeding movements are imparted to the feed roller from this vertical shaft. Attached to the upper end of the section 36 of the vertical shaft is a flexible shaft 43. The upper end of the flexible shaft is connected to a shaft 44 mounted in a bracket 45 secured to the needle head. At the upper end of this shaft 44 is a clutch feed of the usual construction. This clutch feed includes a member 46 which oscillates about the axis of the shaft and which is provided with clutch rollers for clutching the member to the shaft when moved in one direction, and which releases the shaft when moved in the opposite direction. Attached, to the bracket 45 is a clutch member which prevents retrograde movement of the shaft 44. The member 46 is oscillated by means of a link 4'7 which is connected to a ball stud 48 attached to the member 46 and also to a ball stud 49 attached to a lever 50. The ball stud 49 is adjustable in a slot 51 in the lever an.

The lever 50 is pivoted at 52 and carries a ball stud 53 at its lower end with which an eccentric strap 54 cooperates. This eccentric strap in turn cooperates with an eccentric 55 on a shaft 56. As the shaft 56 rotates, it will, through this clutch mechanism, impart intermittent positive step rotations to the vertical shaft, which in turn imparts similar motions to the feed roller. The flexible shaft section 43 permits the rock frame to swing on its pivot without any cramping of the operating parts, While the sectional shaft 36 permits the up and down movements of the rock frame with the up and down movements of the presser foot. Through this construction, the feed roller is positively rotated, and is free at alltimes to move up and down with varying thicknesses of fabric, maintaining its firm gripping feed thereon, and is also permitted to be lifted from the fabric whenever desired, without disturbing the actuating mechanism therefor. The feed roller 13 has a toothed or knurled surface for engaging the fabric.

A cover plate 57 is attached to the needle head and covers the greater portion of the vertical shaft.

Referring to the diagrammatic Figures '7 to 10, inclusive, of the drawings, the operation of the feeding mechanism above the material will be made clear. The presser bar 17 is continuously forced in a downward direction by the leaf spring 18. This causes the feed roller 13 to be pressed against the material, and also the presser foot 12 to be pressed against the material. The rock frame 14 is also pressed downwardly at its rear end by the spring 28, which, of course, moves up and down as a unit with the presser bar 17 as it bears at the upper end against the arm as an abutment. The pressure of the spring 23 on the rear end of the rock frame 14 tends to force the feed roller 13 in a downward direction and the foot 12 in an upward direction. The resulting f action is that the pressure of the spring 28 is added to the pressure of the leaf spring in creating a strong downward pressure of the feed roller against the material, while the pressure of the spring 28 is subtracted from the pressure of the leaf spring .18 in its resulting action on the foot l2, and therefore, the foot 12 is moved downward with a lighter pressure. The feed dog cooperates with both the presser foot 12 andthe feed roller 13. The presser foot 12, however is mainly for the purpose of holding the fabric sections lightly against the work support andfori stripping the fabric from the needles as they rise;

It does function to direct the fabric to the needles during the stitching operation and into gripping engagement with the feed roller 13, and then the feedroller gripping the fabric as it is stitched, pulls and feeds the fabric to the stitching mechanism and ofi from the end v of the Work support. When a cross seam approaches thepresser foot 12 it will pass underneath the upturned toe there- I of, tilting the presser foot as shown-in Fig. 8. The

rock frame 14 will turn about the shaft 25 as a center, moving the presser barupward against the spring tension thereon, andthus the foot is yieldingly held against the fabric as it rides up .on* to the-cross seam.' .During this time, the

feed roller is just as firmly gripping the fabric and feeding-the same. In other words, the riding 'of the foot on to the cross seam ,does not change, in any way, the pressure of the feed roller on the fabric section. As the seam .ap-

' proaches the feed roller and passes-beneath the same, the foot passes ofi, rocking onits pivotal support so as to engage the fabric section following the seam. This holds the fabric well down against the work support, stripping it from the needles as they rise, and prevents the drum heading of the fabric. The feed roller holds the fabric under complete control, rolling up on to the cross seam as shown in Fig. 10. The foot is moved off from the cross seam and is controlling the fabric section which is following the crossseam. The feed roller will then pass 01f from the cross seam and on to the fabric section, and during the entire passing of the cross seam beneath the presser foot and the feed roller, the feed roller has a firm gripping engagement with the material in advance of the cross seam, on top of the cross seam, and in rear of the cross seam, cooperating at all times with the feed dog in the feeding of the material. At the same time, the presser foot during the passing of the cross seam, is in contact with the fabric during the approach of the cross seam, while on top of the cross seam, and after the cross seam has passed the same, even though the feed roller is raised on top of the cross seam. This insures that the fabric will be held well against the cloth plate and stripped from the needles during the entire stitching operation.

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

Having thus described the invention, what I claim as new and desire to secure by Letters Patent, is I 1. In a sewing machine, a work support, stitch forming mechanism including a needle, a presser foot and a feed roller above the work support, said feed roller being located in rear of the presser foot, common means for supporting the feed roller and presser foot, devices associated with said supporting means and operating to force the feed roller into contact with the fabric with a greater pressure than the presser foot,

.means for intermittently and positively rotating -presser foot, a presser bar, means for yieldingly moving said presser bar downwardly, means carried by the presser bar and supporting said feed roller and said presser foot, yielding means hear-- ing on said supporting means and disposed relative to the presser bar so as to create a pressure of the feed rolleron the fabric greater than the pressure of the presser foot on the fabric, means for positively and intermittently rotating the feed roller, and a feeding mechanism beneath the work support including a feed dog extending from a point adjacent thefront end of the presser foot to a point in rear of the needle.

3. In a sewing machine, a work support, a stitch forming mechanism including a needle, and a feeding mechanism including a feed dog beneath the work support, a presser bar, a spring normally moving said presser bar downwardly, a rock frame pivoted to the presser bar intermediate the ends of the frame, a presser foot supported at the forward end of said rock frame, a feed roller mounted for rotation in said rock frame in rear of the pivotal support therefor, a spring yieldingly forcing the rear end of the rock frame downwardly, and means for positively and intermittently rotating said feed roller.

4. In a sewing machine, a work support, a stitch forming mechanism including a needle, and a feeding mechanism including a feed dog beneath the work support, a presser bar, a rock frame pivoted to said presser bar intermediate the ends of said frame, a presser foot pivotally supported at the forward end of said rock frame and a feed roller mounted in said rock frame in rear of the pivotal support therefor, a spring yieldingly forcing said presser bar downwardly, a spring for yieldingly forcing the rear end of said rock frame downwardly, and means for positively and intermittently rotating said feed roller.

5. In a sewing machine, a work support, stitch forming mechanism including a needle, a feeding mechanism including a feed dog beneath the work support, a presser bar, a rocker pivoted to the lower end of said presser bar, a presser foot supported at the forward end of said rocker, a presser roller pivotally mounted in rear of the presser foot and at the rear end of said rocker, and spring means bearing on said presser bar and rocker and operating to force the presser roller into contact with the material with a greater pressure than the presser foot.

6. In a sewing machine, a work support, stitch forming mechanism including a needle, a feeding mechanism including a feed dog .beneath the work support, a presser bar, a rocker pivoted to the lower end of said presser bar, a presser foot supported at the forward end of said rocker, a presser roller pivotally mounted in rear of the presser foot and at the rear end of said rocker, spring means bearing on said presser bar and rocker and operating to force the presser roller into contact with the material with a greater pressure than the presser foot, and means for positively and intermittently rotating said presser roller to aid in the feeding of the material.

'7. In a sewing machine, a work support, stitch forming mechanism including a needle, a feedingmechanism including a feed dog beneath the work support, a presser bar, a rocker pivoted to the lower end of said presser bar, a presser foot.

supported at the forward end of said rocker, a presser roller pivotally mounted in rear of the presser foot and at the rear end of said rocker, a spring bearing on said presser bar for yieldingly forcing the same downward, and a spring bearing on the rocker and against an abutment on the presser bar and operating to force the presser roller into contact with the material with a greater pressure than the presser foot.

8. In a sewing machine, a work support, stitch forming mechanism including a needle, a feeding mechanism including a feed dog beneath the work support, a presser bar, a rocker pivoted to the lower end of said presser bar, a presser foot supported at the forward end of said rocker, a presser roller pivotally mounted in rear of the presser foot and at the rear end of said rocker, a spring bearing on said presser bar for yieldingly forcing the same downward, a spring hearing on the rocker and against an abutment on the presser bar and operating to force the presser roller into contact with the material with a greater pressure than the presser foot, and means for positively and intermittently rotating the feed roller for aiding in the feeding of the material.

9. In a sewing machine, a work support, a

stitch forming mechanism including a needle, a feeding mechanism including a feed dog beneath the work support, a presser foot and a feed roller above the work support, said feed roller being located in rear of the presser foot, means for supporting said feed roller and presser foot and for forcing the feed roller into contact with the material with a greater pressure than the presser foot, and a vertically arranged shaft connected to said feed roller for positively and intermit tently rotating the same, said shaft being formed in telescoping sections so as to permit said feed roller to move up and down freely.

10. In a sewing machine, a work support, a stitch forming mechanism including a needle, a feeding mechanism including a feed dog beneath the work support, a presser foot and a feed roller above the work support, said feed roller being located in rear of the presser foot, means for supporting said feed roller and presser foot and for forcing the feed roller into contact with the material with a greater pressure than the presser foot, and a vertically arranged shaft connected to said feed roller for positively and intermittently rotating the same, said shaft being formed in telescoping sections so as to permit said feed roller to move up and down freely, said shaft also having a flexible section.

11. In a sewing machine, a work support, stitch forming mechanism including a needle, a feeding mechanism including a feed dog beneath the work support, a feed roller above the material, means for yieldingly supporting said feed roller whereby it may be moved up and down, a shaft on which said feed roller is mounted, a vertical shaft, gears for connecting the vertical shaft with the shaft supporting the feed roller, and means for intermittently rotating said vertical shaft, said vertical shaft having telescoping sections permitting said feed roller to freely move up and down.

12. In a sewing machine, a work support, a

stitch forming mechanism including a needle, a-

feeding mechanism including a feed dog beneath the work support, a presser bar, means for yieldingly moving said presser bar downward, a rocker pivotally supported at the lower end of the presser bar, a spring bearing on the rear end of said rocker and against an abutment on the presser bar, a presser foot pivoted to the front end of said rocker, a feed roller pivotally supported by the rocker in rear of said presser foot, a vertically arranged shaft having a gear connection to said feed roller, and means for intermittently and positively rotating said shaft, said shaft having telescoping sections and a flexible section permitting said rocker to freely oscillate on and move up and down with the presser foot.

13. In a sewing machine, a work support, stitch forming mechanism including a needle, a feeding mechanism including a feed dog beneath the work support, a presser bar, means for yieldingly moving said presser bar downward, a rocker pivoted to said presser bar, a spring bearing on an abutment carried by the presser bar and against the rear end of said rocker, means for varying the tension of said spring, a presser foot pivoted to the forward end of said rocker, and a presser roller pivotally supported by said rocker in rear of the presser foot.

14. In a sewing machine, a work support, stitch forming mechanism including a needle, a. feeding mechanism including a feed dog beneath the work support, a presser bar, means for yieldingly moving said presser bar downward, a rocker pivoted to said presser bar, a spring bearing on an abutment carried by the presser bar and against the rear end of said rocker, means for varying the tension of said spring, a presser foot pivoted to the forward end of said rocker, a

presser roller pivotally supported by said rocker in rear of the presser foot, and means for positively and intermittently rotating said feed roller.

15. In a sewing machine, a work support, stitch forming mechanism including a needle, a feeding mechanism including a feed dog beneath the work support, a presser bar, means for yeldingly moving said presser bar downward, a rocker pivoted to said presser bar, a spring bearing on an abutment carried by the presser bar and against the rear end of said rocker, means for varying the tension of said spring, a presser foot pivoted to the forward end of said rocker, a presser roller pivotally supported by said rocker in rear of the presser foot, a vertically arranged shaft geared to said presser roller for rotating the same to aid .in the feeding of the material, said shaft having telescoping sections and a flexible section for permitting said rocker to oscillate and move up and downwith the presser bar, and means for intermittently rotating said vertical shaft.

CHARLES F. RUBEL.