US2858785A - Clamp-washers for hand wheel clutches of sewing machines - Google Patents

Description

Nov. 4, 1958 L. J. KUHAR 2,858,785

CLAMP-WASHERS FOR HAND WHEEL CLUTCHES OF SEWING MACHINES Filed Dec. 2. 1954 IN VENTOR I Ludwig J. Kuhar WITNESS ATTO NE Y United States Patent CLAlVlP-WASHERS FOR HAND WHEEL CLUTCHES F SEWING MACHINES Ludwig J. Kuhar, Clark Township, N. J., assignol' to The Singer Manufacturing Company, Elizabeth, N. J., a corporation of New Jersey Application December 2, 1954, Serial No. 472,583

4 Claims. (Cl. 112--220) This invention relates to sewing machines and more particularly to an improved clamp-washer used as part of the hand wheel clutch of a sewing machine.

For many years sewing machines have been equipped with hand wheel clutches by means of which the main shaft of the sewing machine may be connected to or disconnected from the hand wheel. When the clutch is disengaged, the hand Wheel may be driven without driving the main shaft of the sewing machine. Because of this a bobbin winder can be driven from the hand wheel or the hand wheel driving belt while other parts of the sewing machine remain stationary. One form of a hand wheel clutch is shown in United States Patent No. 1,934,- 373, issued November 7, 1933.

While hand wheel clutches have, for the most part, proved satisfactory, it has been found that the clampwashers heretofore used have, in some instances, caused difficulty when the clutch parts were engaged or disengaged. Therefore, one of the primary objects of the present invention is to provide an improved clamp-washer especially adapted for use with the hand wheel clutch of a sewing machine.

Another object of the invention is to provide an improved clamp-washer which will flex whenever the hand wheel clutch of the sewing machine is engaged.

Another object of the invention is to provide an improved clamp-washer which may be used on any of the individual sewing machines of a particular class, thereby eliminating the need for selecting a clamp-washer that will work best with a particular sewing machine.

With these and other objects in view as will hereinafter appear, the invention consists in the devices, combinations and arrangements of parts hereinafter described in connection with the accompanying drawings, which illustrate a preferred embodiment of the invention and in which:

Fig. 1 is a vertical sectional view showing a portion of a sewing machine and specifically illustrating a hand wheel clutch using an improved clamp-washer which embodies the present invention;

Fig. 2 is an exploded perspective View further illustrating parts shown in Fig. 1;

Fig. 3 is a side elevational view of the clamp-washer shown in Figs. 1 and 2;

Fig. 4 is a view similar to Fig. 1 but showing another type of hand wheel clutch and clamp-washer embodying the present invention;

Fig. 5 is an exploded perspective view further illustrating parts shown in Fig. 4; and

Fig. 6 is a side elevational view of the clamp-washer shown in Figs. 4 and 5.

Many different types of sewing machines may be equipped with a hand wheel clutch having a clampwasher of the type herein described, however, the invention illustrated in Figs. 1, 2 and 3 is shown applied to a self-contained motor-driven sewing machine of the type shown in U. S.-Patent No. 1,934,373, supra. The sewing machine illustrated comprises a number ofelements fully set forth in Patent No. 1,934,373, and includes a gooseneck or bracket-arm 16 formed with a cylindrical bearing boss 17 adapted rotatably to support a main shaft 18, the bearing boss 17 being surrounded by a flat annular surface 19 formed on the bracket-arm 16. Other elements of the sewing machine include a cupshaped motor frame casting 21, a worm 22, a motor shaft 23 carrying the worm 22, a sleeve 24, a hand wheel 26, a gear 27, a circular spring 28, a thin metal washer 29 and a collar 30. It will be understood that the motor shaft 23 drives the worm 22 which in turn drives the gear 27. The gear 27 is, by means of the washer 29 and the spring 28, arranged to drive the hand wheel 26, and by means, presently to be described, the hand wheel 26 selectively drives or is disconnected from the sleeve 24, which in turn drives the main shaft 18. The sleeve 24, which is secured tothe main shaft 18 by means of a tapered pin 31, is provided at one end with a flange 32, one annular shoulder or surface of which is designated by the numeral 33. The other end of the sleeve 24 has an end surface 34 and an internally threaded bore 36, the surface 34 being interrupted by a pair of diametricallyrecess 47 having an annular clutch surface or seat 48,

the recess 47 being adapted to receive a clutch member or clamp-washer 49 presently to be described. A clutch screw 51, having an externally threaded shank 52 and a boss 53 with an internally facing annular clutch surface 54, is screwed into the internally threaded bore 36 of the sleeve 24. The screw 51 also has a removable stop pin 56 and in order to provide for easy manipulation, the rim 57 of the screw 51 is knurled. In order to cause the clampwasher 49, which is annular in form, to rotate with the sleeve 24, the clamp Washer 49 is provided with a pair of diametrically opposite inwardly extending keying tongues 58-58 which enter the keying notches 37-37 of the sleeve 24. The front or outer face 59 of the clamp-washer 49 has three outwardly struck lugs 6161-61, each lug having an outwardly facing sur- 7 face 62 designed to engage the clutch surface 54 of the screw 51. Also protruding from the outer surface 59 of the clamp-washer 49 are three equidistantly spaced stop-pins 63-6363, these pins in certain circumstances being engaged in a known manner by the stop-pin 56.

The inner or rear surface 69 of the washer 49 has three struck lugs 71--7171, each providing an iufacing surface 72 arranged to engage the annular clutch seat '48 of the recess 47. Reference to Fig. 2 shows that each lug 71 is spaced equidistantly between a pair of lugs 61-61,- and that each lug 61 is spaced equidistantly between a pair of lugs 71-71'. In other words, the

lugs 61 and 71 are alternately arranged or circumferentially spaced around the washer 49 so that lugs 61 are spaced sixty degrees (60) from lugs 71 and so that g each lug 61 is spaced one hundred-twenty degrees from each of the other lugs 61, also so that each lug 71 is spaced one hundred-twenty degrees (120") from It will also be noted (Fig. 2)

51 is tightened in the threaded bore 36 of the sleeve 24,

the clutch surface 54 of said screw engages the three equally spaced surfaces 62-62-62 on one side of the clamp-washer 49, while the three surfaces 72-72-72 onthe opposite side of the clamp-washer engage the annular clutch seat 48 on the hand wheel 26. Since the surfaces 62-62-62 are circumferentially spaced about the clamp-washer relatively to the surfaces 72-72-72, the washer flexes slightly as the clamp screw 51 is tightened. The flexing of the clamp-washer permits the clutch screw 51 to be readily tightened effectively to lock the hand wheel to the arm-shaft and at the same timeit permits the clutch screw to be loosened with the application of only a small amount of effort on the part of the operator. It will be further appreciated that the surfaces 62-62-62 and 72-72-72 provide in effect three-point contact between the clutch face on the hand wheel and the clutch. face on the clamp screw with the obvious advantage that, regardless of the looseness of fit between the threaded shank 52 and the threaded bore- 36, the clamp screw will seat square with the clutch face 48 on the hand wheel and consequently will run true with the hand wheel.

Figs. 4, and 6 disclose a modified form of the invention as applied to a belt driven sewing machine having among other elements a bracket arm 116 provided with a bearing bushing 117 adapted rotatably to support a main shaft 118. Other elements of the sewing machine include a belt 125 for driving a hand wheel 126. A cylindrical sleeve 124, which is secured to the main shaft 118 by means of a screw headed pin 131, is provided at one end with a flange 132, one annular surface of which is designated by the numeral 133. The other endof thesleeve 124 has an end surface 134 and an internally threaded bore 136, the surface 134 being interrupted by a pair of diametrically opposed keying notches 137-137. The hand wheel 126 is formed with an annular end face 146, which abuts the aforementioned annular surface 133. The outer face of the hand wheel 126 is provided with a collar 147 having an annular clutch face 148, the face 148 being adapted to be contacted by portions of a clamp-washer 149, presently to be described. A clutch screw 151, having an externally threaded shank 152 and an internally facing annular clutch surface 154 is screwed into the threaded bore 136. The screw 151 has a removable stop pin 156 and a knurled rim 157 of known construction.

In order to cause the washer 149 to rotate with the sleeve 124, the clamp-washer 149 is provided with a pair of diametrically opposed inwardly extending bent key tongues 158-158, which enter the notches 137-137, one of the key tongues being bent toward the front face of. the clutch member and the other key tongue being bent toward the rear face of the clutch member, as shown. in Fig. 5, so that the clutch member can be placed on the shaft with either face being considered the front face. The outer rimof the washer 149 is substantially annular in form except for the fact that this rim has three outwardly extending lugs 163-163-163 which, in certain circumstances, are engaged in a known manner by the stop-pin 156. The front or outer face 159 of the clamp-washer 149 has three outwardly struck lugs 161-161-161, each lug having an outwardly facing surface 162 designed to engage the clutch surface 154. The inner surface 169' of the Washer 149 has three struck. lugs 171-171-171 each providing an infacing surface 172 arranged to engage the annular clutch face 148. This arrangement of lugs provides a washer 149 which could be said to be corrugated. The lugs 161 and 171 are spaced around the washer 149 ,in the same manner as the lugs 61 and 71 are spaced around the washer 49-, the only difference being that the lugs 161 and 171 both extend from the inner circumference tothe' outer circumference of the washer 149. The clampwasher 149 functions. in. the same manner as that previously described for the washer 49.

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

1. A sewing machine comprising a main shaft; a sleeve carried by said shaft and thereby forming a shaft-sleeve combination, one end of said shaft-sleeve combination being provided with a threaded portion and a keying notch; a hand wheel mounted on said shaft-sleeve combination, said hand wheel having on a front portion thereof a surface located in a plane normal to the axis of said shaft; means for driving said hand wheel; a threaded clamp means engaging the threaded portion of said shaft-sleeve combination and having an annular surface located in a plane normal to the axis of said shaft on said threaded clamp means; a stop lug carried by said threaded clamp means; and an annular clamp washer adapted to be interposed between the surface on the front portion of said hand wheel and-the annular surface on said threaded clamp means, said clamp washer comprising a front face, a rear face, an inner circumferential surface, a keying tongue extending radially inwardly from said inner circumferential surface and engaging said keying notch, three lugs protruding axially from the rear face of said clamp washer and having infacing surfaces adapted to engage the surface on the front portion of said hand wheel, three lugs protruding axially from the front face of said clamp Washer and having outfacing surfaces adapted to be engaged by the annular surface on said threaded clamp means, said last named three lugs extending radially from this innercircumferential surface to a maximum radial distance defined by a circle concentric with said inner circumferential surface, and a plurality of stop-members carried by said clamp-washer and adapted to contact said stop-lug on said threaded clamp means, said stop-member being located radially outside of said last defined circle. 7

2. A sewing machine including a frame, a shaft journaled in-said frame and having fixed thereto a first member providing an annular shoulder normal to the axis of said shaft, a hand-wheel supported by said shaft to turn about the axis of said shaft and having an: inner hub face arranged to bear against the annular shoulder of said first member, said hand-wheel having an outer hub face located in a plane normal to the axis of said shaft; a clamp member threadedly supported by said shaft and having an annular surface located in a plane normal to the axis of said shaft, and an annular bodied clutch member apertured to receive said shaft and interposed between the outer hub face on said hand-wheel and the annular surface on said clamp member, said clutch member having a front face and a rear face, three lugs protruding axially from the rear face of said clutch member and having intacing surfaces adapted to engage the outer hub face of the hand-wheel, and three lugs protruding axially from the front face of said clutch member and having outfacing surfaces adapted to be engaged by the annular surface on said clamp member.

3. A clutch member adapted to be used with a sewing machine having a rotary shaft driven by a driving wheel arranged through said clutch member to be clutched to and declutched from said shaft; said clutch member com prising an integral annular body apertured to engage the shaft of the sewing machine and having front and rear faces, three lugs substantially equally spaced around the said clutch member protrudins axially from the rear face of said clutch member and having infacing surfaces defining a plane, and three lugs substantially equally spaced around the said clutch member pro ruding axially from the front face of said clutch member, and alternately disposedcircumferentially with respect to the lugs on the rear face and having outfacing. surfaces defining a plane parallel to that defined by the infacing of said other three lugs, each of said lugs having a portion located adjacent to the surface defining the aperture of said clutch member.

4; A clutch member adapted to be used with a sewing machine having a rotary shaft provided with a keying notch and driven by a driving wheel arranged through said clutch member to be clutched to and declutched from said shaft by means of a thumb nut member threadedly supported by said shaft; said clutch member comprising an annular body having front and rear faces and an inner circumferential surface defining a centrally located shaft receiving aperture, three lugs protruding axially from the rear face of said clutch member and having infacing surfaces defining a plane, three lugs protruding axially from the front face of said clutch member and having outfacing surfaces defining a plane parallel to that defined by the infacing surfaces of said other three lugs, each of said lugs having a portion located adjacent to said inner cir cumferential surface of said clutch member, a pair of diametrically located keying tongues extending radially inwardly from said inner circumferential surface and adapted to enter the keying notch in said rotary shaft, one of said keying tongues being bent toward the front face of said'clutch member and the otherof said keying tongues being bent toward said rear face of said clutch member, and stop means provided on said clutch member and adapted to limit the turning of said thumb nut member.

References Cited in the file of this patent UNITED STATES PATENTS 1,934,373 Peets Nov. 7, 1933 2,012,032 Zinnbauer Aug. 20, 1935 2,069,402 -Cow1in Feb. 2, 1937 2,097,710 Whitelaw et a1. Nov. 2, 1937 FOREIGN PATENTS 308,309 Italy June 1, 1933 314,425 Italy June 26, 1934 578,289 Great Britain June 21, 1946 691,317 Great Britain May 13, 1953

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