US2313063A - Shoe sewing machine - Google Patents

Description

March' 9,1943. A ,RHAAS' A 2,313,063`

SHOE SEWING MACHIN'E Filed Nov. 23, 1940 Patented Mar. 9, 1943 SHOE SEWING MACHINE Otto B. Haas, North Beverly, Mass., assignor to United Shoe Machinery Corporation, Flemington, N. J., a corporation of New Jersey Application November 23, 1940, Serial No. 366,896

8 Claims.

The present invention relates to shoe sewing machines, and more particularly to improvements in presser foot and work grooving mechanism especially adapted for use on sewing machines employed in shoe repair work.

An object of the invention is to provide an improved construction and arrangement of presser foot and sole grooving knife wherein the various adjustments of knife and presser foot relative to one another and to the sewing point may be quickly and accurately effected.

Another object of the invention is to provide a presser foot shaped to clamp the work eiectively, yet which enables the grooving knife to operate in close proximity to the needle and likewise permits the loop spreader and needle guide to operate without interference in close relationship to the work.

Still another object is to provide a simple and compact arrangement of presser foot and grooving knife which will'permit sewing into close proximity with the heel of ashoe, a particular advantage in the case of repair work.

In accordance with these and other objects, a feature of the invention involves the provision of a presser foot, a supporting arm, and a work grooving knife, wherein the grooving knife is adjustably mounted in the presser foot in a direction to vary the depth of the groove, the presser foot and the grooving knife being bodily adjustable as a unit relative to the supporting arm in the direction of the seam line.

Another feature of the invention involves the provision of a presser foot and grooving knife wherein but a single clamping means serves both to secure the presser foot to its support and to clamp the knife in the presser foot in adjusted relation thereto.

Another feature of the invention involves the provision of screw-threaded means for raising and lowering the grooving knife in the presser foot to permit accurate adjustment of groove depth, while nevertheless permitting the knife to be readily withdrawn upwardly from its holding means.

A further feature of the invention involves the provision of a presser foot having a work grooving knife carried thereby, the presser foot being so constructed that it extends but a short distance in advance of the sewing point in the direction of the seam line, as compared with constructions heretofore available.

In the drawing illustrating the invention in its preferred embodiment, Fig. 1 is a view in righthand side elevation of the portion of a shoe sew..

ing machine adjacent the sewing point, showing the presser foot of the invention in operative engagement with work of extreme thickness, and likewise showing the inter-relation of Y needle guide and loop spreader with the presser foot; Fig. 2is a plan view on an enlarged scale of the presser foot and grooving knife and certain other parts shown in Fig. l; Fig. 3 is a viewin left side elevation on an enlarged scale of the presser foot and grooving knife; Fig. 4 is a front view of the parts shown in Fig. 3; Fig. 5 is a view in left side elevation, partly in section, and on a still further enlarged scale, of the lower portion of the presser foot and knife; and Fig. 6 is a view on the same enlarged scale of the parts, taken endwise of the grooving knife and adjusting screw.

The presser foot of the invention is of two-part construction comprising a work engaging portion 8 constituting the presser foot proper, and a supporting arm l0 on which the presser foot 8 is mounted. The arm is secured at its rear end to the presser foot bar I4, being received within a channel I6 for forward and back adjustment transversely of the seam line. A stud vI8 passing through slot 20 clamps the arm l0 to the presser foot bar in adjusted position.

From its rear portion l2, the presser foot arm Ill extends downwardly and to the left (see Figs. 1, 2, and 3) to its forward end 22, the outer face of which lies parallel to the direction of work feed. Said outerv face of the end 22 is formed with an outwardly extending lower, portion to provide a shoulder 24 lying longitudinally across the end.

The presser foot proper is of one piece con-v struction and is shaped to engage the end 22 of the presser foot arm and likewise to extend rearwardly thereunder so as to provide an unbroken work clamping surfacefree of a junction or seam line likely to mark the work. The rearward eX- tension 26 of the presser foot beneath the end portion 22 likewise enables the clamping pressure to be directly transferred from arm to presser foot, thereby substantially reducing the strain on clamping stud 28 by which the presser foot is secured to the arm.

To accommodate feeding strokes of different lengths and to assist in positioning the hereinafter describedwork grooving knife in relation to the needle 30 of the machine, the presser foot is adjustable relative to its supporting'arml in the direction of the seam line, the shoulder 24 on the arm and the correspondingly shaped channel in the presser foot serving as a guideway to vkeep the presser foot in alignment while the adjustment is being carried out. The presser foot has an enlarged bore at 32 to afford a passage for the clamping stud 28.

To provide a groove for the seam, there is combined with the presser foot a work grooving knife so positioned and arranged as to operate in eX- ceptionally close proximity to the needle, enabling the groove to be accurately located with respect to the seam line even while the Work is being turned, as in sewing Iaround the tce portion of a shoe. The knife, indicated at 36, consists of a rod of hardened steel ground at its lower end to a triangular shape to provide a sharp wedge-shaped point 38. The knife is received in a passage 4B in the presser foot, said passage being inclined in the direction of the seam line downwardly toward the sewing point. The lower end of the knife has a face 42 ground at an angle so as to lie in a vertical plane, not only to provide a point of increased sharpness, but also to permit the needle to operate vas close to the point of the knife as possible.

The knife is raised or lowered in the presser foot to adjust the depthof the groove by means of a thumb screw 44 the shank of which is received in a threaded face parallel to and spaced from the knife. The outer portion Iof the head 46 of the adjusting screw passes through a slot 48 formed in the upper end of the kni-fe, so that rotation of the screw accurately and positively moves the knife upwardly or downwardly in relation to the presser foot. Such arrangement permits the knife to be removed for re-sharpening or the like Without disassembling the presser foot, since the thumb screw may be entirely unscrewed from the presser foot, permitting the knife to be drawn upwardly out of its guideway.

To clamp the knife rigidly in its adjusted position so as not to chatter or vibrate during operation and to insure against rotation of the knife during adjustment, the passage or bore 40 is so positioned in the presser foot that it intersects the channel which receives the shoulder 24 on the presser foot arm, while the knife has a fiattened face II) which is exposed at said channel to engage the shoulder.24. When the clamping stud 28 is loosened, the knife may be raised or loweredin its passage by rotating thumb screw 44, the flattened face 50 preventing the knife from rotating. After the proper projection of the knife below the surface` of the presser foot is obtained, the stud is tightened, thereby not only securing the knife firmly in the presser foot but also clamping the presser foot rigidly to the presser foot arm.

In order that the work may be firmly clamped between the presser foot 8 and the work support 52 while leaving unobstructed the space between the grooving knife and the needle, the presser foot is shaped so that its principal work lclamping portions extend along the seam line on each side thereof. The rear portion 54 is of generally triangular section, as shown in Fig. 5, and terminates approximately opposite the needle 30 at an angle, as at 56. The front portion 58 on the other hand, extends past the needle and then turns inwardly to provide a toe portion 60 which lies at an angle across the line of stitches to turn down or compress the lip of leather raised by the grooving knife just before the seam was laid therein. To provide better visibility for inspection of the operation of the grooving tool and its relation to the needle, the inner face 62 of the portion 58 is shaped to slant outwardly from bottom to top.

The obliquely directed passage or space between the toe 6U and the face 56 of the two arms of the presser foot permits the needle guide 64 to move into close proximity with the work, so as to support the needle effectively, especially where work of unusual thickness is encountered, as illustrated in Fig. l. The needle guide is formed with its needle engaging portion 66 oifset toward the presser foot arm withrespect to the rear portion 68 of the guide by which the guide is secured to its actuating segment 10. This offset permits the hook end 12 of the loop spreader to operate directly behind the needle and close to the rear portion 54 of the presser foot (see Fig. 1), while the arm 'I4 of the loop spreader passes between the end of the needle guide and the presser foot.

The described construction and arrangement of presser foot and supporting arm permits sewing of the seam closer to the heel 76 (see Fig. 2) of a shoe in repair work than does the conventional form of presser foot. This results from the relatively small dimension of the assembly in the direction of the seam line, the face 18 lying but a short distance in advance of the actual sewing points.

By providing for adjustment of the presser foot in the direction of the seam line in conjunction with the adjustability of the grooving knife along a path inclined in the direction of the seam line, the point of operation of the knife may be caused to lie as close to the sewing point as the length of the feed stroke will permit, since variations in the amount of projection of the knife for different depths of grooves may be compensated for by an appropriate shift of the presser foot to one side cr the other on its arm. While only a single clamping stud is employed to secure the presser foot to the presser foot arm in adjusted relation thereto, and to clamp the grooving knife rigidly in the presser foot, nevertheless the adjustments are readily effected independently of one another. For example, during adjustment of the presser foot and grooving knife toward or from the sewing point, the knife is maintained in position by its adjusting screw 44, while raising or lowering of the knife in the presser foot has no tendency to displace the presser foot relative to its supporting arm. The only other adjustment that of positioning the knife transversely of the seam line, is effected by sliding the presser foot arm itself forward or back in its channel in the presser Ifoot bar, stud i3 being loosened slightly for this purpose.

The nature and scope of the present invention having been 1ndicated, and a specific embodiment hav1ng been described, what is claimed is:

1. A presser foot and grooving attachment for shoe sewing machines comprising a presser foot a supporting arm therefor adapted to be secured to the machine for mounting the attachment thereon, a guideway in the presser foot and a grooving knife adjustable in said guideway to vary the depth of the groove, the presser foot and grooving knife being bodily adjustable relative to the supporting arm in a direction corresponding, when the attachment is mounted on rthe machine, to the direction of the seam line.

2. A presser foot and grooving attachment for shoe sewmg machines comprising a presser foot a support for the presser foot, a grooving knife carried by the presser foot, means for adjusting the knife relative to the depth of the groove, and for securing the presser presser foot to vary the unitary clamping means foot to its support and for clamping the knife in the presser foot in adjusted position,

3. A presser foot and grooving attachment for shoe sewing machines comprising a presser foot, an arm for supporting the presser foot adapted to be secured to the machine for mounting the attachmentl thereon, a grooving knife carried by the presser foot and having a vertical component of adjustment with relation thereto to vary the depth of the groove, fthe presse-r foot and knife being adjustable as a unit relative to the supporting arm in a direction corresponding, when the attachment is mounted on the machine, to the direction of the seam line, and unitary means for securing the presser foot to the arm in adjusted position and for clamping the knife in the presser foot.

4. A presser foot and grooving attachment for shoe sewing machines comprising a presser foot, an arm for sup-porting fthe presser foot adapted to be secured to the machine for mounting the attachment thereon, said arm and presser foot having cooperating clamping surfaces arranged to permit relative sliding movement for adjustment of the presser foot in a direction corresponding, when the attachment is mounted on the machine, to the direction of the seam line, a grooving knife carried by the presser foot and having an exposed surface adapted to be engaged by a clamping surface of the presser foot supporting arm, and means for securing the presser foot to the arm and for clamping the knife in the presser foot.

5. A presser foot and grooving attachment for shoe sewing machines comprising a presser foot having a passage therein, a grooving knife slidable in said passage to vary the depth of the groove, a transverse slot in the knife, and means for adjusting said knife comprising a headed screw received within a threaded passage in the presser foot parallel to and spaced from the knife, the head of the screw engaging the slot in the grooving knife.

6. A presser foot and grooving attachment for shoe sewing machines comprising a rod-like grooving knife sharpened at one end, separable presser foot members having cooperating shoulder and guideway surfaces extending in a direction corresponding, when the attachment is mounted on the machines, to the direction of the seam line in the work, one of the members having a passage to receive the grooving knife with its sharpened end engaging the work, and a single clamping stud operative when tightened to secure the knife in thepassage and simultaneously to clamp the presser foot members together.

7. A presser foot and grooving attachment for shoe sewing machines comprising a rod-like grooving knife sharpened at one end, separable presser foot members having cooperating shoulder and guideway surfaces to permit relative adjustment of the members in a direction corresponding, when the attachment is mounted on the machine, to the direction of the seam line in the work, one of said members engaging the work and formed with a passage disposed at an angle to the shoulder and gudeway surfaces of said members to receive and support the grooving knife with its sharpened end engaging the work, said knife supporting member having an enlarged bore extending therethrough, and a single clamping stud passing -through said bore into the other presser foot member and operative when tightened to secure the knife in its supporting member and simultaneously to clamp said knife supporting member to the other presser foot member.

8. A presser foot and grooving attachment for shoe sewing machines comprising a presser foot, a grooving knife, supporting means for the knife and presser foot adapted to be secured to the machine to mount the attachment thereon, a knife holder adjustable relative to the supporting means in a direction corresponding, when the attachment is mounted on the machine, to

the direction of the seam line, the knife holder

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