US2724354A - Feeding mechanisms for sewing machines - Google Patents

Description

Nov. 22, 1955 A. J. MATUZAS FEEDING MECHANISMS FOR SEWING MACHINES Filed Jan. 15, 1954 IN VEN TOR. Anfh ony J. Moruzos A TTORNEY 2,724,354 Patented Nov. 22, 1955 United States Patent Ofifice 2,724,354 FEEDING MECHANISMS FOR SEWING MACHINES Anthony J. Matuzas, Union, N. 1., assignor to The Singer Manufacturing Company, Elizabeth, N. J., a corporation of New Jersey Application January 15, 1954, Serial No. 404,300

7 Claims. (Cl. 112-210) :This invention relates to sewing machines and more particularly to improvements in feed-dog throw-out devices especially adapted foruse with family-type sewing machines. Feed-dog throw-out devices are designed to inactivate the work-feeding mechanism of sewing machlnes when it is desired to use the machine for darning,

embroider-ing and other similar operations, and to reactivate the feeding mechanism when the machine is to be used for ordinary sewing operations.

The present invention is applicable to the feed-dog throw-out device which is described in the prior patent applications Serial No. 222,616, filed April 24, 1951, now Patent No. 2,682,242, and Serial No. 301,644, filed July 30, 1952, now Patent No. 2,682,243, and the present invention has for its primaryobject the provision of an improved feed-dog throw-out device.

Another object of the invention is to provide an improved feed-dog throw-out device which is quicker and easier to operate and more positive in its action than similar devices heretofore used.

With the above and other objects in view, as will hereinafter appear, the invention comprises the devices, combinations, and arrangements of parts hereinafter set forth and illustrated in the accompanying drawings of a pre' ferred embodiment of the invention, from which the several features of the invention and the advantages attained thereby will be readily understood by those skilled in the art. i

In the accompanying drawings: s

Fig. 1 is a vertical sectional view of a portion of a sewing machine with a feed-dog throw-out device embodying the present invention,

Fig. 2 is a bottom plan view of the portion of the sewing machine shown in Fig. 1, and

i Fig. 3 is an exploded perspective view of certain of the elements illustrated in Figs. 1 and 2.

In the embodiment of this invention selected for illustration, numeral 11 indicates a substantially rectangular bed-plate or base of a sewing machine, providing on its upper side a work-carrying plate 12 formed on its under side with depending front and rear walls 14 and 16, and end walls 17 and 18, forming a box-like enclosure, of which the downwardly facing opening is normally closed by a bottom cover-plate 19 held by a nut (not shown). 7 An upstanding hollow standard 21 rises from the bed 11 and at its upper end the standard carries an overhanging upper arm (not shown) in the free end of which are arranged the usual reciprocatory needle-bar 24 and the resser-bar 25.

Journaled in the upper arm (not shown) is a main driveshaft (not shown), which operates the needle-bar 24, in a known manner, and this same drive-shaft in a manner shown and described in Patent No. 2,617,375 drives a loop-taker shaft 27, which in turn drives a looptaker 28 arranged to cooperate with a thread-carrying needle 29 in the formation of stitches. Since the stitchforming mechanism forms no part of the present invention, further illustration and description thereof is deemed unnecessary.

The work-carrying plate 12 is provided with a throatplate 31 having feed-slots 32 through which operates a serrated feed-dog 34 secured by screws 37 on one end of a long feed-bar 36. At its rearward end, the feed-bar 36 is pivotally connected, at 38, to the upper end of a pair of feed-advance rockers 39 extending upwardly from a feed-advance rock-shaft 41 journaled on pintles of which one is shown at 42. Also a feed-lift rock-shaft 44 is journaled on pintles, of which one is shown at 43. Oscillatory movements are given to the feed-advance rockshaft 41 and the feed-lift rock-shaft 44 by any known means such, for example, as described :in Patent No. 2,617,375.

The feed-bar 36 is provided with a depending lug 47, of which the lower end carries a horizontally extending pin 48 that pivotally mounts the lower end of an upwardly extending link 49. The upper end of the link 49is pivotally connected by a pin 51 to one arm 52 of a horizontally extending lever 53 having a central hub 54 freely journaled on the feed-lift rock-shaft 44. The hub 54 is provided with an annular recess 56 coaxial with the shaft 44. The recess 56 accommodates a. helical spring 57 one end of which is anchored in a hole 58 formed in the lever 53 and the other end is anchored in a hole 59 provided in a flange 61 integral with the feed-lift rockshaft 44. The lever 53 is held from movement in the other direction longitudinally of the shaft 44 by a spring wire clip 62 seated in a groove in the shaft 44. Another arm 63 of the horizontally extending two-armed lever 53 is apertured by a horizontally extending funnel-shaped hole or clearance aperture having a cylindrical portion 64 and having, at its end nearest the wall 17 and thus remote from the crank-arm 68 hereinafter mentioned, a concave frusto-conical countersink or seat portion 66for seating a convex frusto-conical self-centering member 221, presently to be described.

. It will be noted that the two arms 52 and 63 of the lever 53 extend horizontally on opposite sides of the feedlift rock-shaft 44, the arm 52 extending toward the loop: taker shaft 27 in the front of the sewing machine bed, and the arm 63 extending toward the feed-advance rock-shaft 41 in the rear of the bed. It will also be noted that the lever 53 is of uniform thickness as measured in the direction of the axis of the feed-lift rock-shaft 44. Also the seating members 66 and 221 are both of symmetrical, frusto-conical form, and the cylindrical portion 64 and the frusto-conical portion 66 are coaxial.

The hereinbefore mentioned feed-lift rock-shaft 44 carries a horizontally extending crank-arm 68 adjacent to and integral with the flange 61. In order to limit the downward movement of the feed-dog 34,. there is provided a bracket 83, which is held by a screw 82 to a boss formed on the base 11. The bracket 83 has a threaded hole and thereby carries an adjustable stop screw 86 of which the upper end (not shown) may be engaged by the lower surface of the arm 52. The previously described mechanism is substantially the same as the mechanism which formed the subject of patent application Serial No. 222,616 supra.

The present invention is concerned primarily with improved means for selectively connecting and disconnecting the integrally formed flange 61 and the crank-arm 68 with the arm 63 which is apertured by the hole 6466 of which, as stated, one portion 64 is cylindrical and the other portion 66 is frusto-conical. This connecting means comprises a cylindrical stem or screw 201. of which one end is threaded as at 202, the thread end 202 of the stem,

201 being screwed into a threaded hole 203formed in the arm 68, and a nut 204 locks the end 202 of the stem 201 to the arm 68 which arm is formed integral with the feed-lift rock-shaft 44. The unthreaded or free end of the tem Wines an nlar gnt r a y in a h ad 205 having a hole 206 that carries a radially disposed cam-pin 207 and turnably mounted on the head 205 is a hollow cylindrical sleeve 208, equipped with an operating handle 209 which extends radially from the outer end of the sleeve208. The cylindrical wall 211 of the hollow sleeve 208 .is provided with a spiral cam-slot 212 one end of which terminates in an enlarged notch or positioning recess 213. When the parts are assembled, the pin 207 enters the cam slot 212 or the recess 213 and operates in a manner-later to be described. As best seen in Fig. 2, a comparatively strong helical compression spring 214 surrounds the stem 201, one end of the spring 214 engaging one end of the hollow sleeve 208 and the other end ofithe spring 214 engaging the smaller end of a hollow sleeve-member 216 having an enlarged end or head 217 and a cylindrical stem 218 provided with an unthreaded concentric bore 219 extending the full length of the stem 21,8 and the head 217. The enlarged end 217 has an outfacing convex frusto-conical member or centering surface 221 having the same conicity as the concave frustoconical countersink 66 hereinbefore described. The convergent endof the member 221 engages one end of a relatively weak helical compression spring 222 and the other end .of the weaker spring 222 is seated in a recess 22,3 coaxially formed with respect to the threaded hole 203 ,inthe flanged crank arm 68.

In operation, the device functions in the following manner. If it'is assumed that the feed-dog 34 is raised so that the sewing machine may perform ordinary straightaway stitching operations, the handle 209 will be turned to the position shown by solid lines in Fig. 1, and the .pin 207 .will be positioned in the recess 213. This causes the sleeve 208 .to compress the spring 214 which moves the sleeve member 216 along the stem 201 until the frustoconical centering surface 221 is pressed firmly against the inner surface of the countersink 66. Since the spring 222 is relatively weaker than the spring 214, the weaker spring 222 will be compressed fully and thus will allow the" surface 221 to seat in the countersink 66.

If it is desired to use the sewing machine for darning or'embroidering, in which case the feed-dog must be lowered to an ineffective position below the top surface of the throat-plate, the handle 209 will be turned counterclockwise to the dotted position shown in Fig. 1. Turning the handle 209 and thus the sleeve 208 first causes the pin 207 to become disengaged from the recess 213 and then to move along the slot 212to the end 212. When this happens the strong spring 214 is relaxed sufficiently so that the weak spring moves the member 216 to the left in Fig. 2, thereby disengaging the surface 221 from the seat 66 with the result that the coil-spring 57 turns the double armed lever 53 clockwise (Fig. 1) about the shaft 44 to" lower the feed-dog 34 in a manner similar to that described in patent applications Serial Nos. 222,616 and 301,644, supra. When it is desired to return the feed-dog to its proper elevated work-feeding position, it is only necessary to turn the handle 209 in a clockwise direction, asviewed in Fig. 1. This causes the sleeve member 208 to move endwise inwardly of the stem 201, thereby compressing the strong spring 214 which forces the member 216 with its frusto-conical centering surface 221 toward and into the aperture 66 of the arm 63. When the member 216 is fully seated in the aperture 66 the feeddog is elevated to its proper height for work-feeding operation. h i

Having thus set forth the nature of the invention, what I claim herein is: V

1. A'feeding mechanism for sewing machines comprising a feed-dog, a feed-advance rock-shaft'connectedto said feed-dog for impartingfeed-advance motion thereto, a.fed-liftfrok-shaft, and disengageable connecting means interposed between said feed-lift rock-shaft and said feeddogysaid disengageabl'e connecting means comprising a first member operated by said feed-lift rock-shaft, a second m m e onne d o ai f ed-d e a o b d ice carried by one of said members and movable into engagement with said other member, a spring engaging one end of said movable device, and means for compressing said spring thereby moving said movable device and connecting said movable device with said other member.

2. A feeding mechanism for sewing machines comprising a feed-dog, a feed-advance rock-shaft connected to said feed-dog for imparting feed-advance motion thereto, a feed-lift rock-shaft, and disengageable connecting means interposed between said feed-lift rockshaft and said feed-dog; said disengageableconnecting means comprising a first member operated by said feedlift rock-shaft, a second member-connected to said feeddog, a movable device carried by one'of said members and movable into engagement with said other member, a comparatively weak spring located between one of said members and one end of said movable device, a comparatiyely strong spring engaging the other end of said movable device, and means for compressing said strong spring thereby moving said movable device, compressing said weak spring, and connecting said movable device with said other member.

'3. A feed-dog throw-out mechanism for sewing machines including in combination, a rock-shaft, a crankarm secured to said rock-shaft and said crank-arm being provided with a hole, a lever pivoted on said rock-shaft and provided with a hole, one of said holes being frusto conical, a feed -dog, means connecting said lever with said feed-dog, a releasable connection selectively connecting and disconnecting said lever and said crank-arm, said releasable connection comprising, a stern member freely passing through said frusto-conical hole and entering said other hole, means for locking said stem member into said other hole, a hollow cylindrical sleeve memberturnably monnted on said stem member, one of said members being provided with a spiral cam groove and the other of said members being provided with a cam-pin cooperating with said cam groove, and a sleeve member slidably mounted on said stern and having a frusto-conical end adapted to enter said frnsto-conical hole.

4. A feed-dog throw-out mechanism for sewing machines including in combination, a rock-shaft, a crankarrn secured to said rock-shaft and said crank-arm being provided with a hole, a lever pivoted on said rock-shaft and provided with a hole, one of said holes being threaded and the other of said holes being frusto-conical, a feeddog, means connecting said lever with said feed-dog, a'releasable connection selectively connecting and disconnecting said lever and said crank-arm, said releasable connection comprising, a stem freely passing through said frusto-conical hole and screwed into said threaded hole, means for locking said stem into said threaded hole, an unthreaded cylindrical head on the free end of said stem, a cam-pin protruding from said head, a hollow cylindrical sleeve turnably mounted on the head of said stem and said hollow sleeve being provided with a spiral cam slot c0- operatingwith said cam-pin, and a sleeve member slidahly mounted on said stem and having a frusto-conical end adapted to enter said frusto-conical hole.

5. A feed-dog throw-out mechanism for sewing machines including in combination, a rock-shaft, a crankarm secured to said rock-shaft and said crank-arm being provided with a hole, a lever pivoted on said rock-shaft and provided with a hole, one of said holes being threaded and the other of said holes being frusto-conical, a feeddog, means connecting said lever with said feed-dog, a releasable connection selectively connecting and disconnecting said lever and said crank-arm, said releasable connection comprising, a stem freely passing through said frns to-conica'l hole and screwed into said threaded hole, a nut locking said stem into said threaded hole arm, an unthreaded cylindrical head on the free end of said stein 5 and saidhead having a radial hole, acam-pin protruding from said radial hole, a hollow cylindrical sleeve turnably mounted on the head of said stem and said hollow sleeve being provided with a spiral cam slot cooperating with said cam-pin and said cam slot having an enlarged positioning notch at one end thereof, a sleeve member slidably mounted on said stem and having a frusto-conical end adapted to enter said frusto-conical hole.

6. A feed-dog throw-out mechanism for sewing machines including in combination, a rock-shaft, a crankarm secured to said rock-shaft and said crank-arm being provided with a threaded hole, a lever pivoted on said rock-shaft and prOvided with a hole, one of said holes being threaded and the other hole being frusto-conical, a feed-dog, means connecting said lever with said feeddog, a releasable connection selectively connecting and disconnecting said lever and said crank-arm, said releasable connection comprising, a stem freely passing through said frusto-conical hole and screwed into said threaded hole of said crank-arm, a nut locking said stem into said threaded hole, an unthreaded cylindrical head on the free end of said stem and said head having a radial hole, a cam-pin protruding from said radial hole, a hollow cylindrical sleeve turnably mounted on the head of said stem and said hollow sleeve being provided with a spiral cam slot cooperating with said cam-pin and said cam slot having an enlarged positioning notch at one end thereof, a sleeve member slidably mounted on said stem and having a frusto-conical end adapted to enter said frusto-conical hole, a comparatively heavy helical spring surrounding said stern and positioned between the head of said stem and said sleeve member, and a comparatively weak spring surrounding said stem and positioned between said sleeve member and said crank-arm, said weak spring being of such size as to pass freely through said frusto-conical hole.

7. A feed-dog throw-out mechanism for sewing machines including in combination, a rock-shaft, a crankarm formed integral with said rock-shaft and said crankarm being provided with a threaded hole and a spring receiving hole coaxial therewith, a lever pivoted on said rock-shaft and provided with a funnel-shaped hole having a cylindrical portion and a frusto-conical portion coaxial with said cylindrical portion, a feed-dog, means connecting said lever with said feed-dog, a releasable connection selectively connecting and disconnecting said lever and said crank-arm, said releasable connection comprising, a stem freely passing through said funnel-shaped hole and screwed into said threaded hole of said crank-arm, a nut locking said stem to said crank-arm, an unthreaded cylindrical head on the free end of said stem and said head having a radial hole, a cam-pin protruding from said radial hole, a hollow cylindrical sleeve turnably mounted on the head of said stem and said hollow sleeve being provided with a spiral cam slot cooperating with said cam-pin and said cam slot having an enlarged positioning notch at one end thereof, a sleeve member slidably mounted on said stem and having a frusto-conical end adapted to enter said frusto-conical portion of said funnel-shaped hole, a comparatively heavy helical spring surrounding said stem and positioned between the head of said stem and said sleeve member, and a comparatively weak spring surrounding said stern and positioned between said sleeve member and said crank-arm, said weak spring being of such size as to pass freely through the cylindrical portion of said funnel-shaped hole and to enter the spring receiving hole in said crank-arm.

References Cited in the file of this patent UNITED STATES PATENTS 2,440,031 Wainwright Apr. 20, 1948 2,643,625 Reimer June 30, 1953 2,682,243 Matuzas June 29, 1954

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