US2128353A - Sewing machine feeding mechanism - Google Patents

Description

Aug. 30, 1938. c. w. DOWD SEWING MACHINE FEEDING MECHANISM Filed March 25. 1936 This invention relates to sewing machine feeding mechanism and particularly to such a mechanism having a positively driven top feed roller.

The principal object of the invention is to provide means to assist the feed roller in passing over extraordinary thicknesses of work, such as cross seams in very heavy fabrics, which may. be

passed through the stitch-forming mechanism.

Another object is to actuate said means by n movement of the presser-foot and particularly by tilting movement of the foot caused by the passage of the heavy thickness of work under said foot.

The aforesaid and other objects, which will be apparent from the detailed description and drawing, are realized by the present invention, the now preferred embodiment of which is illustrated in the accompanying drawing, wherein- Figure 1 is a perspective view of a complete ma- 2'9 chine having the present invention applied there- Figure 2 is a front elevation of a portion of the machine at the free end of the feed-oif-thearm work arm and showing a very heavy thick- 95 ness of work or cross-seam entering beneath the forward end of the presser-foot and tilting the same upward at said end;

Figure 3 is a similar view with the heavy thickness advanced to about the middle of the foot so that the same is approximately horizontal; and

Figure 4 is a similar view with the heavy thickness still further advanced until it is about to pass from beneath the rear end of the foot.

In the accompanying drawing, the invention is 35 illustrated in conjunction with a feeding mechanism such as set forth in Merritt Patent No. 1,837,468, dated December 22, 1931.

As shown, the machine has a framework comprising two hollow standards and ii connected 4Q by a hollow bridge i2 (corresponding to parts 36, di and 32 respectively of said patent). A hollow work-arm extends forward from the upper end of standard Ill in a horizontal part l3 from the outer end of which a part I depends vertically. At its upper end the hollow standard ll curves or bends forward to form the hollow overhanging head portion l! of the machine frame or casing. The standard II and its head portion i5, bridge i2, standard ill, and parts i3, IQ of the work-arm are all preferably integrally formed in one casting. A lower horizontal work-supporting part it of the arm extends toward the left and rearward from the lower end of the vertically depending part i4, terminating at its free end (which con- 55 stltutes the free end 01- 1 11? 9 4%? awe-a m 391 PATENT oFncF.

SEWING Ii'EEUlNG DIECHANISM Charles w. Dowd, Highland Park, N. 1., asslgnor to Willcox a Gibbs Sewing Machine Company, New York, N. Y., a corporation of New York Application March 25, 1938, Serial No. 70,871

Backward from its horizontal pivotal axis, the 55 the end oil! which the work is fed) beneath the overhanging head portion I! of the machine frame and casing. Part I of the work-arm is preferably a trough-like casting and is rigidly but detachably secured to the lower end of part I4. 5 At the free end of said part l6 there is a U-shaped cloth-plate frame it properly positioned and removably secured in place. I8 is the throat plate, or cloth plate, which is applied over the frame I! and properly positioned and secured in place 10 thereon. The cloth plate l8 has needle slots (not shown) and longitudinally extending slots l9 (Fig. l) to accommodate the rows of teeth on the lower feed dog. 20 is a removable top cover for the part 88 of the work-arm. Other removable caps or covers are also provided to facilitate assembling and access to parts enclosed within the hollow frame-work or casing, the same including a cap it at the top of standard ii; an upright cover 22 at the front of the head of the machine; a cover 23 at the left-hand end of the machine. 24 is a folder, shown in dotted outline in Fig. 1, and which may be of any well known suitable construction for interfolding edges of fabric in making felled seams and which is mounted on the 25 work-supporting part it of the work-arm. Preferably, for certain classes of work, the folder 24 is movably mounted .on the cover plate 20 in the manner set forth in Lewis Patent 1,796,111, dated March 10, 1931.

25 is the needle bar carrying two thread-carrying needles 2t, 21, shown in Fig. 2 with their lower ends broken away. Other parts of the stitchforming mechanism are not shown. 28 is a fourmotion feed dog of the lower or bottom feed, having rows of teeth which work upwardly through the slots it in the cloth plate B8 in engaging and feeding the work.

30 is the presser-foot bar vertically movable in bearings (not shown) in the head 15 of the machine. M is the shank of the presser-foot having a split hub which embraces the lower end of bar 30 and is clamped thereto by tightening screw 82. Shank 3i extends forwardly and downwardly in two spaced fork-like legs 83 and 34', each formed 5 at its lower end to constitute a partly cylindrical cross-head or pivot knob 35, the cylindrical surfaces of both knobs being on a common axis and of the same diameter. Forward of its horizontal pivots or pivotal axis, the presser-foot is solid and includes a normally horizontal portion 38 having therethrough elongated needle openings or, slots 31 for the needles 26, 21, respectively, and an upwardly inclined forward end or toe portion 38.

presser-foot includes two parallel rearwardly extending side bars 40 and 4|, between which the top feed roller is positioned and works, as presently described. The pivot knobs 35, 35 at the lower ends of the legs 33, 34, are engaged in their corresponding pivot sockets in the presser-foot by slight relative sidewise movement. Plate 42 (Fig. l) at its upper end embraces and is secured by a screw 43 to leg 33 and at its lower end overlies the end of pivot knob 35. There is a similar plate 42, not shown, associated with leg 34, so that the two plates thus prevent disengagement of the pivot knobs from their sockets.

45 is a power-driven intermittently rotated top feed wheel or roller adapted by engagement with the upper surface of the fabric or work to intermittently feed or advance the same the length of one stitch at a time, each feed movement being timed to take place, as usual, while the needle or needles are clear of the work. In the embodiment illustrated herein, the peripheral surface of the feed roller is formed to constitute teeth for gripping the fabric or work to be fed and also to constitute gear teeth through which the roller is rotated by a spiral gear 46 meshing therewith. 41 is a top feed presser-bar of rectangular cross-section having vertical sliding movement, parallel to the presser-foot bar 36, in a suitable slideway in the head I 5 of the machine.

' At its lower end, bar 41 has a right-angle extension branching into two downwardly curved spaced arms 48 between which the roller 45 is journaled on a stud 49. As thus supported the feed-roller 45 is also positioned to engage the top surface of the fabric or work in the space between the side arms 40 and 4| of the presserfoot close to the rear beveled edge of the horizontal solid bottom portion 36 of the presser-foot and thus close to the point where the needles penetrate the work.

The top feed roller 45 is yieldingly pressed downward into gripping engagement with the work by a spring 6| presently described, and may yieldingly move up and down, not only to accommodate itself to variations of thickness of work passing thereunder, but in response to up and down movements of the lower feed dog 26,

thereby enabling said roller to continuously maintain its feeding grip upon the work. The roller 45 is power driven and intermittently rotated to feed the work through driving connections from the main shaft (not shown) of the machine, said connections including a vertical rotatable shaft 50, shown in dotted lines in Figs. 3 and 4, extending longitudinally within and movable up and down with the bar 41, and the previously mentioned spiral gear 46 which is secured to the lower end of said shaft.

Means for lifting the top feed roller and presser-foot, both by hand and by foot, and for holding them in elevated position, during introduction of or manipulation of, work and for other purposes, are shown at the left-hand end of Fig. 1. is a short tubular rock-shaft or sleeve rotatable on a stud 52 rigidly projecting from the head l5 of the machine frame or casing. A rock-arm 53, preferably cast integral with the said tubular shaft, extends toward the rear side of the machine where it is engaged by rod 54 depending to a suitable treadle or knee actuated device (not shown), whereby the rod and arm 53 may be pulled downward to the limit of a stop pin 55 against the tension of a coiled spring 56 surrounding the rod and normally tending to hold the arm 53 up to the position in which it is connecting bar 1| toward the left.

shown in Fig. 1 in contact with a part which sur rounds pivot stud 51. An arm 58, also preferably cast integral with the tubular shaft 5|, extends toward the front side of the machine and carries at its outer end a block 59 adapted to engage the underside of a stud 60 projecting from the lower end of the feed roller bar 41. The free end of a flat spring 66 engages and yieldingly presses downward upon said stud 60, said spring at its other end being pivoted on said pivot stud 51 secured to the standard ll of the machine. An adjusting bolt 63, engaging the top side of the flat spring 6|, between its pivot 51 and its engagement with stud 60, serves to increase or decrease the tension of the spring as desired.

As will be readily understood downward pull upon rod 54 by the action of a treadle or knee actuated device (not shown) will lift the top feed roller against the tension of spring 6|.

In addition to such means for lifting the top feed roller from a treadle or knee-actuating device, the following means are provided for hand actuation. A bent link 64 pivoted at its lower end to the rock arm 53 by a screw pivot 65 is pivotally connected at its upper end to the outer end of an arm 66 secured to the end of a shaft 61 projecting from and journalled in the wall of the standard H of the machine frame, said shaft carrying within said standard means (which need not be herein illustrated or described) which prevent lifting of the presser foot except when the needles are elevated above the cloth plate. 68 is a hand lever fulcrumed to the head of the machine by a screw pivot 69, and carrying a screw .stud the shank of which works in a slot in the upper end of a connecting bar 1| which latter at its lower end pivots on the screw pivot 65 beneath the link 64. 12 is a buffer spring secured in a groove along the underside of the hand lever 66 and adapted to contact with a stop stud 13. A spring 14 coiled about the shank of the screw screwed into the connecting bar 1|, has one end anchored in an opening in said rod and at its other end bears in a short groove along the upper edge of rock-arm 53. In the normal position of the parts, the pressure of spring 56 on the treadle rod 54 constantly tends to move the parts to their normal position shown in Fig. 1, where the rock-arm 53 contacts with the screw stop 51 and the connecting rod H is elevated tilting the hand lever 66 forward with its buffer spring 12 against stop screw 13. In this position of the parts the axis of the pivot screw 10 lies 'to the left of an imaginary straight line connecting the axes of the pivot screws 65 and 69. To elevate the presser-foot by operation of the hand lever 68 the latter is swung upward.

causing the pivot screw 10 to act against the lower end of the wall of the slot in connecting bar 1| thereby imparting a longitudinal downward and swinging movement to said rod and moving it and the rock-arm 53, the arm 66 and link 64, to positions in which the end of hand lever 68 contacts a pin 16 projecting from the end wall of the machine head and in which position the axis of the screw 16 will occupy a position slightly to the right of an imaginary straight line connecting the axes of the pivot screws 65 and 69. In this relationship of parts the upward pressure exerted by spring 56 tends to hold the end of lever 68 tightly in engagement with the pin 16 notwithstanding the weaker pressure of the spring 14 tending to swing the upper end of the The parts 9,188,858 .are thus temporarily locked in position to hold a the feed roller elevated and will so remain until released by a slight forward and downward movement of ie hand lewr il 01' asllght-down ward movement of the treadle connections, whereupon the parts will quickly snap back to the position in which they are illustrated in F18. 1.

The lifting of the feed roller, either by actuation of a treadle or knee device (not shown). or

by actuation of the hand lever I, also lifts the presser foot by means which will now be' described. A second arm 11 (similar to arm 58) extends toward ,the front of the machine from the tubular rock-shaft BI and carries a block (similar to block 59) which engages under a lug (similar to lug I28 of Fig. 2 of the aforesaid Merritt Patent 1,837,468) or overhanging shoulder on the shank 3| of the presser-foot. Preferably the parts are so positioned or related that the arm 11 begins to lift the presser-foot just after the arm 88 begins to lift the feed roller; but this may be changed as desired.

The construction as hereinbefore set forth in the detailed description is substantially the same as that shown in the aforesaid Merritt patent, except as to certain minor features which will be apparent, and its operation is entirely satisfactory for all ordinary conditions.

But extraordinary conditions, particularly as to thickness of fabric or work passing under the presser-foot, have been encountered in which it has been found desirable to assist the operation of the feed roller by slightly lifting the same in addition to its own capabilityof elevating itself in passing over humps or extra thicknesses of fabric or work. For example, where a felled cross seam passes through the felling folder 24 (Fig. 1) and under the presser-foot and the fabric isof average thickness, the feed roller will ride up over said cross seam, or'elevate itself, without assistance. But if the fabric is very thick, as sometimes occurs, it has been found dimcult for the feed roller, by its own action, to ride up over the hump formed by the cross-seam. In other words, under such conditions it is desirable to provide means to assist in lifting or elevating the feed roller over the cross-seam and one embodiment of such means will now be described.

is a horizontal arm having an enlarged end grooved transversely to fit about the lower end of the presser-bar 41 for the feed roller, as clearly shown in Fig. 1. A set screw 8i, passing through a vertical slot in the enlarged end of arm 80 and into bar M, rigidly securesv the arm to said bar in any desired position of adjustment within the limits of the length of the vertical slot. When the fabric being sewed or operated upon is of average thickness, the arm is secured to the bar 41 with screw 8! passing through the lower end of vertical slot, in which position of the parts the arm does not function or is out of action. But when the thickness of the fabric exceeds the average, or the fabric is very thick, the arm is secured to the bar 41 in a relatively lower position, such as shown in the drawing, so that the arm does function. At its other end or outer end, the arm 80 overlies a shoulder or offset 82 on the shank 3| of the presser-foot.

Figures 2, 3 and 4 showtwo sections of very heavy or thick fabric being joined by a felled seam, and with a felled cross-seam passing under the presser-foot and feed roller. The fabric is shown in vertical longitudinal section down the middle of the seam, so that there are sixteen thicknesses of fabric at the cross-seam and four thicknesses at imately shown, the side edge of the cross-seam rises almost vertically from the main body of the fabric and presents aahump over which it would be difficult for the feed roller to. lift itself, with the result that it would rotate in the corner or space immediately in front of the cross-seam without feeding the work and would thus mar or tear the surface of the fabric at this point. But with the assistance of the liftin means of the present invention, the feed-roller is assisted over such cross-:seams and also performs its feeding function at normal feed speed.

In Fig. 2 a cross-seam formed in very heavy fabric is shown as entering beneath the forward upturned end of the presser-foot and hastilted the foot upward at said end withv the rear endv of the foot resting on the main body'of the work.

has moved closer to the underside of the arm 80. 1

Further feeding'movement of the cross-seam under the presser-foot engages the shoulder 82 with arm 80 and thereby lifts said arm and with.

it the bar 41 and feed roller 45 until saidroiler bears upon the top of the cross-seam as shown in Fig; 3. As the feeding of the work and crossseam continues, the presser-foot tilts downward at its forward endyas shown in Fig. 4, and the reverse of the aforesaid movements beginand continue until the, cross-seam passes from beneath the rear end of the presser-foot.

When the fabric is of a thickness which does not require such lifting of the feed roller .by the action of the presser-foot, the arm 80 is set on the bar 41 to an inactive position. by loosening set-screw-8l, sliding the arm 80 upward on bar.

d'l until the bottom of the slotin the enlarged end of the bar contacts the shank of said screw and the screw then tightened to secure arm 80 to bar 41 in said inactive position.

What is claimed is:

1. A sewing machine including in combination, a work support; a feed member downwardly and yieldingly engaging work on said work support; means for imparting feed movement to said feed member; and means for lifting said feed member in passing over thicknesses in the work such as cross-seams.

2. A sewing machine including in combination, a work support; a rotary feed member downwardly and yieldingly engaging work on said work support; means for imparting feed movement to said feed member; and means for lifting said feed member in passing over thicknesses in the work such as cross-seams.

3. A sewing machine including in combination, a work support; a rotary feed member downwardly and yieldingly engaging work on said work support; means for imparting feed movement to said feed member; an upright bar movable up and down in a portion of the machine above said work support and carrying said feed member; and means for lifting said bar and with it the feed member as the latter passes over thicknesses in the worksuch as cross-seams.

4. A sewing machine including in combination, a work support; a feed member downwardly and yieldingly engaging work on said work-support;

a presser foot downwardly and yieldingly engaging said work on said work-support in advance and downwardly at its forward end; means imeach side thereof. As approx- 1 means actuated by the rocking or tilting of the presser foot to lift the feed member in passing over thicknesses in the work such as cross-seams.

5. A sewing machine including in combination, a work support; a feed member downwardly and yieldingly engaging work on said work support; a presser-foot downwardly and yieldingly engaging said work on said work-support in advance of its engagement by said feed member; driving means imparting feed movement to said feed member; and means actuated by movement of the presser foot in passing over thicknesses in the work such as cross-seams to lift said feed member in passing over said thicknesses.

6. A sewing machine including in combination, a work support; a rotary feed member downwardly and yieldingly engaging work on said work support; a presser-foot downwardly and yieldingly engaging said work on said work-support in advance of its engagement by said feed member; driving means imparting feed movement to said feed member; and means actuated by movement of the presser foot in passing over thicknesses in the work such as cross-seams to lift said feed member in passing over said thicknesses.

7. A sewing machine including in combination, a work arm having a free end off which work is adapted to be fed; stitch-forming mechanism positioned to operate on work advancing along said arm toward the free end thereof; a top feed member engaging work on and feeding the same along said arm toward the free .end thereof; driving connections for imparting feed movement to said feed member in a direction to feed the work along said arm toward the free end thereof; and means actuated by thicknesses in the work such as cross-seams to lift the feed member in passing over said thicknesses in the work.

8. A sewing machine including in combination, a work arm having a free end on which work is adapted to be fed; stitch-forming mechanism positioned to operate on work advancing along said arm toward the free end thereof; a rotary top feed member engaging work on and feeding the same along said arm toward the free end thereof; driving connections for imparting feed movement to said feed member in a direction to feed the work along said arm toward the free end thereof; and means actuated by thicknesses in the work such as cross-seams to lift the feed member in passing over said thicknesses in the work.

9. A sewing machine including in combination, a work arm having a free end on which work is adapted to be fed; stitch-forming mechanism positioned to operateon work advancing along said arm toward the free end thereof; a top feed roller engaging work on and feeding the same along said arm toward the free end thereof; driving connections for imparting feed movement to said feed roller in a direction to feed the work along said arm toward the free end thereof; and means actuated by thicknesses in the work such as cross-seams to lift the feed roller in passing over said thicknesses in the work.

10. A sewing machine-including in combination, a work support; a top feed member downwardly engaging and feeding the work along said work support; a bottom feed member upwardly engaging and feeding the work along said work support; means for imparting feed movement to said top and bottom feed members; and means for lifting said top feed member in passing over thicknesses in the work such as cross-seams.

11. A sewing machine including in combination, a work support; a rotary top feed member downwardly engaging and feeding the work along said work support; a bottom feed member upwardly engaging and feeding the work along said work support; means for imparting feed movement to said top and bottom feed members; and means for lifting said top feed member in passing over thicknesses in the work such as cross-seams.

CHARLES W. DOWD.

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