US2730055A - Spiral stitch attachment for sewing machines - Google Patents

Description

Jan. 10, 1956 s. DESPERAK ETAL SPIRAL STITCH ATTACHMENT FOR SEWING MACHINES Filed June 5, 1953 2 Sheets-Sheet 1 FIG. I.

l NVE N T O R S.

SAM DESPERAK JOSEPH ROSCHKO GERARD DESMOND THEIR ATTO NEY.

Jan. 10, 1956 s. DESPERAK ET AL SPIRAL STITCH ATTACHMENT FOR SEWING MACHINES Filed June 5, 1953 2 Sheets-Sheet 2 FIG. 3.

INVENTORS.

BY 5 Q THEIR ATTORNEY.

United States Patent SPIRAL STITCH ATTACHMENT FOR SEWING MACHINES Sam Desperak and Joseph Roschko,

Desmond, Franklin Square, Spiral Machine Company,

Brooklyn, and Gerard N. Y., assignors to Advance Inc., New York, N. Y.

This invention relates to a for sewing machines.

Spiral stitchingattachments are'known to the prior art, but no practical attachment of this type has heretofore been devised. The attachments of the prior art are much too complicated both in structure and in operation. The mechanism itself is involved and complex and thedrive mechanism which connects it to the sewing machine motor is no less so. Furthermore, no prior art attachment of this general nature is provided with a suitable clutch mechanism by which it may quickly and readily be disengaged from the drive mechanism and equally as quickly and readily re-engaged therewith.

The principal object of this invention is the provision of a spiral stitching attachment of the character described which has a relatively simple mechanism and which is exceedingly easy to operate. Its basic component is a cam mechanism which moves the work laterally relative to the sewing machine needle. The lateral movement of the work is uniform and the spacing between adjacent rows or convolutions of stitching is similarly uniform throughout. This is true of the innermost convolutions as well as of the outermost convolutions and all of the intermediate convolutions.

An important feature of the present invention is the clutch mechanism by which the attachment may very quickly and readily be engaged with or disengaged from the drive mechanism. The clutch mechanism also makes it possible to reverse the direction of movement of the work and to retrace the convolutions to any selected point including, most importantly the starting position of the attachment, as at the conclusion of one sewing operation and the beginning breaks and the machine continues to operate aconsiderable distance before stopping. It then becomes necessary to return the work to the place where the thread became severed and to resume the stitching operation from that point on. The clutch mechanism herein provided, coupled with the cam mechanism above mentioned makes it possible to disengage the spiralattachment from the drive mechanism and to return it to that position which it occupied at the precise moment of severance of the thread. Continuous, uninterrupted and perfectly uniform spiral stitching results despite any interruption in the stitching operation such as occurs upon the breaking of the sewing machine thread.

Another important feature of the present invention is its simple drive mechanism whereby it may be connected to and driven by the drive mechanism which operatesthe sewing machine itself. The present attachment may be attached to any conventional sewing machine without modifying the construction of said sewing machine in any way whatsoever. The present attachment need not be built into the sewing machine mechanism although this may be done, if desired.

Still another important feature of this invention is the spiral stitching attachment of another. Also the thread sometimes I button and curved surface 26a is sufiicient work holding elementto which the work may very quickly andeasily be attached and from which it may very quickly and easily be removed.

A preferred form of this invention is shown accompanying drawing in which:

Fig. 1 is a plan view of a spiral sewing attachment made in accordance with this invention.

F ig. 2 is a side view thereof.

Fig. 3 is a sectional view on the line Sit-3 of Fig. 2.

Fig. 4 is another sectional view on the line 4-4 of Fig. 1.

Fig. 5 is a plan view of a piece of work stitched spirally by means of the attachment herein claimed.

The dotted lines 10 represent a conventional sewing machine head having a needle 12. The entire attachment herein claimed is mounted on a horizontal plate 14 which may or may not be rectangular in shape as shown in the drawing. This plate may be described as the base plate of the present invention and it'may be mounted on the sewing machine table (not shown). It will be seen that slidably mounted on base plate 14 is a work-supporting arm 16 which has an upwardly pointing pin 18 on which the work 2t) may be impaled. It may be found necessary to hold the work down upon arm 16 mechanically and this may be done by means of an arm 22 which is of inverted U-shape. One end of arm 22 is provided with an axial hole 24 to receive pin 18. See Fig. 4. The opposite end is secured to a bracket 26 which is pivotally mounted by means of bolt 28 on a second bracket 30. This second bracket is secured by means of screws 32 to an arm 34 to which reference will hereafter again be made. Arms 34 and 16 constitute the work support of the attachment herein claimed.

Bracket 26 has a hole 36 formed therein to receive in verted U-shaped member 22. Set screws 33 are provided in said bracket 26 to adjustably secure said arm 22 thereto. It is by this means that arm 22 may be raised or lowered in said bracket until it is properly set therein. When arm 22 is swung in clockwise direction as viewed in Fig. 4 until it reaches its solid line position therein, it receives pin 18 in its hole 24 and thereby performs two important functions: In the first place, it covers the pin to avoid injury to the operator of the machine. In the second place, it bears down upon the work to prevent dislodgment thereof from its supporting arm 16.

A compression spring element 40 is provided to assist arm 22 in its two functions above described. Spring 40 is mounted in bracket 30 and it may be provided with a ball or button at its upper end for engagement with said curved surface 26a. Compression spring 40 bears upwardly directly or indirectly against curved surface 26a of bracket 26. The friction between said spring 40 or said ball or to hold arm 22 and its supporting brackets 26 in any selected angular position. Thus, the solid line representation of arm 22 and bracket 26 shows said arm and said bracket in operative position relative to the work. The dotted lines 42 indicate the inoperative position of said arm 22 and said bracket 26, said operative and inoperative positions being separated by an angle of approximately degrees. See Fig. 4.

A second spring element is provided for guiding the work to the presser foot of the machine. This element is a wire spring 44 which is secured at one end by means of screw 46 to the head 10 of the sewing ma chine. The opposite end of wire 44 is provided with a shoe 48 which is engageable with the work to smooth and guide it to the presser foot. An arcuate plate 50 is secured to arm 22 above hole 24. Plate 50 engages the work on the far side from the sewing machine needle to prevent it from folding over upon itself.

Arm 34 above mentioned is pivotally secured to base plate 14 by means of screw 52. It is movable on a horizontal plane parallel to the plane of said base plate.

in the mam . 13' An expansion or extensionspring 54 is connected at onev end to a screw 56 which is secured to base plate 14 and is connected at its opposite end to a screw 58 which is secured to said arm 34. The action of said spring is to cause arm.34 to move in clockwise direction about the axis-of screw 52 as viewed in Fig. 1. Arm 34 is'movablc against the action of spring 54 toitsdotted line position shown in Fig. l as well as to any intermediate position. A stop pin 60 is secured to base plate 14 to limit 7 the counter-clockwise movement of arm 34.

A wire arm 62-is adjustably secured'to arm 34 by means of a pair of screws 64 and 66 respectively. Arm

62 is provided with a transversely bent end piece 68 which serves as a contact member relative to switch arm 70 of micro-switch 72. This micro-switch is mounted on base plate 14 and it is connected to the circuit which controls the motor that operates the machine. When end piece 68 of'arm 62 engages switch arm 70, the microswitch opens and'breaks' the circuit to the motor, thereby stopping the machine. It will be understood that arm 62 may be set in any desired position on arm 34 to control the time or moment when the circuit is broken.

An arm 74aispivotally-secured to base plate '14 by means of pivot 76. One. end of arm 74 projects over arm 34. A rollcr 78 is provided on said over-lying end of arm 74- and it will be noted thatit engages arm 34. The opposite end of arm 74 isprovided with a second roller-80 which constitutes'a cam follower relative to cam 82. Cam 82 is pivotally mounted on shaft 84 and when said shaft is made to turn in counter-clockwise direction as viewed in Fig. 1 by the means which Willhereinafter be described, arm 74 will becaused toswing in clockwise direction, thereby causing arm 34 to turn about pivot 52 in counter-clockwise direction. The spiral stitching starts at the center of the work and continues in outward direction from said center. his the counterclockwise movement of arm 34 which moves the work laterally relative to the sewing machine needle so as to guide the work away from the needle while the feed mechanism of'thc machine causes the work to rotate about pin 18.

It will be noted that cam 82 is provided with a laterally extending arm 86. This arm is engageable with cam follower 80 to limit the movement of the cam in clockwise direction relative to arm 74 and it serves as a stop member to limit the backward or return movement of the mechanism precisely as stop pin 60 serves as a stop commodates 1089i disc 102.v When lockin arm 11.; is in one angular position about screw 114, its groove 118 is concentric with rim 108 and there is no interengagement or clutching engagement between said arm 112 and said rim 108. When arm 112 is swung to another angular position about screw 114, groove 118 is eccentric relative to rim 108 and the wallsof said groove engage or clutch said rim 108 to prevent relative movement between st id arm 112. an said dis 1.0.2 a

Spring 116 urges mm 112 to the latter of its said positions so as to prevent relative movement between arm 112'and disc 102. Consequently, when the machine is in operation and disc 102 iscaused to rotate by the drive means shown in Fig. 2 com 32 will becaused to turn with said disc 102 since arm 112 is locked to rim 108 and said arm 112 is secured to said cam. When it is desired to stop the angular movement of cam 82 without stopping the. operation of the machine, all that need be done is to move locking arm 112 in counter-clockwise direction as viewed in Fig. 3 against the action of spring 116. Since locking arm 112 is inaccessibly located with re spect to the operator of the machine, it is necessary to provide handicr means for actuating the locking arm.

It will be noted that two vertically extending rods 120 and lllrcspcctively are provided, rod 120 being securedto. cam 82. and rod 122 being secured to an actuating arm 124. Actuating arm 124 is pivotally mounted on member to prevent movement of the mechanism beyond a predetermined point in the opposite or forward direction.

Shaft 84 is connected through a clutch mechanism to shaft 88. "It will be noted that a bevel gear 90 is secured to the lower end of shaft 88 and that said bevel gear engages a second bevel gear 92 on shaft 94. Shaft 94 is supported in horizontal position by means of suitable bearings 96. A pulley 98 is secured to' shaft 94 and a drive belt 100 engages said pulley. Said drive belt is connected to the drive mechanism of the sewing machine so that. when the sewing machine is in operation, shaft 94 will rotate and with it gears 92 and 90, shaft 88,v the clutch mechanism hereinafter described, shaft 84 and cam 82.

Shaft 84 and shaft 88 may be connected to each other or integral with each other, as desired. It will be, noted that a disc 102 having a hub 104 is secured to shaft 88 by means of set" screws 106. Disc 102has an enlarged and thickened rim or peripheral edge 108. Cam 82 is provided with a plurality of downwardly extending pins 110 which bear against rim 1080f disc 102. A locking arm 112 is pivotally secured at oneend to cam 82 by means of screw 114'. A tension spring 116 engages the opposite end of locking arm 112 and it will be noted'that said spring is secured to one of the pins 110. An arcuate groove 118is formed in locking arm1'12, transversely thereof, and it will be seen that said arcuate groove ac-i shaft 84' for movement in either clockwise or counterclockwise direction on a horizontal plane. When the two rods 120 and 122 are grasped manually and pushed together, the initial movement will be that of rod 122 rather than of rod 120. Consequently, actuating arm 124 will be moved in clockwise direction as viewed in Fig. l and rod 120 will remain relatively stationary. its move- 16 1 Will be limited to the angular movement of cam 82 while said cam is connected to the drive mechanism.

It willbe noted that a pin 126 projects upwardly from lockingarm 112 through a slot 128 in cam 82. This pin 126 is Qngagcd by a recessed or notched portion 130 of actuating. arm 124. When said actuating arm 124 is moved in clockwise direction as viewed in Fig. 1, it will push pin 126 andlocking arm 112 in the same direction, thereby disengaging the walls of its arcuate groove 113 from ring 108 of disc 102. Cam 82 will now be free tomove relative to disc 102 and while said disc continues to turn under the influence of the drive mechanism, cam 82 may be moved in the opposite direction, either to its. starting position or to any other selected position. When the two rods 120 and 122 are released, spring 116 will once again'move the locking arm 112 into engagement'with rim 108 and the actuating arm 124 will similarlybe thrust back to its original inoperative position. The limit of movement of actuating arm 124 is determined by scrcw'132 secured to cam 82 and projecting through slot: 134 in said actuating arm 124. V

It will be understood from the foregoing that the angular position of .cam 82 will determine the angular positions of arms 34 and 74 and consequently the relationship of the work to the needle of the machine. Whenver cam 82 is turned in either direction, and reaches a given angu lar position, the angular positions of arms 34 and 74 will thereby be precisely determined and there will be no variation as long as. the parts show nosigns of wear.

The foregoing is illustrative of a preferrediorm of this invention and it will b un rstood that h s ri'ef rre form. may be mo ified and other f rm may be pr i e within the broad spirit of the invention and the broad scope of the claims.

We claim:

1. A spiral stitching attachment for sewing machines, comprising a work support which is mounted for movemen toward and away from he s wing m chin nee a rotatabl'y mounted cam c nn ed o id work s pp rt to move it relative to sa'id'needle, a rotary drive mechanism, and a disengageable clutch between said rotary drive mechanism and said cam, whereby the drive mechanism actuates the cam and causes the work support to move relative to the sewing machine needle when the clutch is engaged and whereby the cam is released from the drive mechanism to stop movement of the work support relative to the sewing machine needle when the clutch is disengaged, said work support including an arm which is pivotally mounted for movement toward and away from the sewing machine needle, a spring connected to said arm and urging it to move in one direction relative to said needle, a second arm which is also pivotally mounted for movement relative to said needle, a roller at one end of said second arm engaging the first arm, and a second roller at the opposite end of the second arm engaging the cam, whereby actuation of the cam by the drive mechanism when the clutch is engaged causes the second arm to pivot in engagement with the first arm, thereby causing the first arm to pivot relative to the sewing machine needle in the opposite direction from the direction in which it is urged to move by said spring, said clutch comprising a rotably mounted disc which is directly connected to the rotary drive mechanism, and a locking arm which is pivotally connected to the cam, said disc having a pronounced rim and said locking arm having a slot which accommodates said rim, the side walls of said slot being engageable with said rim to lock the locking arm and the disc against relative movement when the locking arm is in one position relative to the rim, said side walls of the slot being disengageable from said rim to free the locking arm and the disc for relative movement when the locking arm is moved to another position relative to said rim.

2. A spiral stitching attachment for sewing machines, comprising a work support which is pivotally mounted for movement toward and away from the sewing machine needle, a rotatably mounted cam, an arm pivotally mounted intermediate its ends between said work support and said cam, a cam follower on one end of said arm engaging said cam and a second cam follower on the opsite end of said arm engaging said work support, whereby rotary movement of the cam causes pivotal movement of the arm and pivotal movement of the work support relative to said needle, a rotary drive mechanism, and a disengageable clutch between said rotary drive mechanism and said cam, whereby the drive mechanism actuates the cam and causes the work support to move relative to the sewing machine needle when the clutch is engaged and whereby the cam is released from the drive mechanism to stop movement of the work support relative to the sewing machine needle when the clutch is disengaged, said clutch comprising a rotatably mounted disc which is directly connected to the rotary drive mechanism, and a locking arm which is pivotally connected to the cam, said disc having a pronounced rim and said locking arm having a slot which accommodates said rim, the side walls of said slot being engageable with said rim to lock the locking arm and the disc against relative movement when the locking arm is in one position relative to the rim, said side walls of the slot being disengageable from said rim to free the locking arm and the disc for relative movement when the locking arm is moved to another position relative to said rim.

3. In a spiral stitching attachment for sewing machines in which a work support is mounted for movement toward and away from the sewing machine needle and a rotary cam driven by a rotary drive mechanism is operatively connected to said work support to cause it to engage in such movement, the improvement comprising a clutch which is adapted to be connected between the cam and the rotary drive mechanism, said clutch comprising a rotatably mounted disc which is adapted to be connected to the rotary drive mechanism and a locking arm which is adapted to be pivotally connected to the cam, said disc having a pronounced rim and said locking arm having a slot which accommodates said rim, the side walls of said slot being engageable with said rim to lock the locking arm and the disc against relative movement when the locking arm is in one position relative to the rim, said side walls of the slot being disengageable from said rim to free the locking arm and the disc for relative movement when the locking arm is moved to another position relative to said rim.

References Cited in the file of this patent UNITED STATES PATENTS 1,462,168 Denemark July 17, 1923 2,437,624 Sutker Mar. 9, 1948 2,521,085 Ogden Sept. 5, 1950 2,674,963 Guide Apr. 13, 1954 2,674,964 Guide II Apr. 13, 1954

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