US2317185A - Sewing machine needle guard - Google Patents

Description

April 20, 1943- M. N. DUNLAP Erm. 2,317,185

' SEWING MACHINE NEEDLE GUARD Filed April 10, 1940 lll 2 mnu! Patented Apr. 20, 1943 UNITED SEWING MACHINE NEEDLE GUARD Marshall N. Dunlap and Grant Fortney, Chicago, Ill.

Application April 10, 1940, Serial No. 328,820

6` Claims.

This invention relates to linger guard attachments for sewing machines designed to protect the ngers of the operator from possible injury while operating the machine. It is obvious that while the sewing machine needle bar and needle are unguarded there is danger that a careless operator, while feeding material under the presser foot of the machine, may allow his fingers to come into the path of movement of the needle and become severely injured.

The need for safeguards against such accidents has heretofore been recognized, and numerous forms of needle guards have been proposed. Many of them are cut and bent to shape from sheet metal, and such guards, of course, present numerous raw and sharp edges which scratch and even cut the ngers of the operator, aside from being somewhat expensive to manufacture. Others are so shaped as to interfere with a clear vision of the needle, as well as with the threading of the latter. Still others interfere more or less with the manual feeding of the material beneath the presser foot, rendering the proper manual guiding of the material difcult. For these and other reasons, the use of such needle guards on sewing machines has heretofore been very limited, since many operators consider that their disadvantages and drawbacks outweigh their advantages.

Among the objects of our present invention have been; to provide an improved needle guard of such simple structure and extremely low cost of manufacture that its cost is no deterrent to its acquisition and use; to provide a guard that will not interfere either with the operators vision of the needle and presser foot or with the facile threading of the needle; to provide a guard that may be attached by the same clamp screw that attaches the shank of the presser foot to the presser foot bar; to provide a guard that may easily be adjusted both forwardly and rearwardly of the needle and presser foot, as well as upwardly and downwardly, to provide a guard that will present no rough or raw edges to catch in the material or scratch or cut the fingers of the operator; to provide a guard for use on machines equipped with a pivoted or walking presser foot that can be swung upward and backward clear or" the needle when not in use and will be yieldably locked in both working and idle posit-ions; and, generally, to provide a simpler, better, cheaper and more enicient sewing machine needle guard than the art has heretofore produced.

Our invention in one form has been designed for use on machines having a plain or xed presser foot, and in another slightly different form for use on machines equipped with a pivoted or walking presser foot; and in the accompanying drawing we have illustrated practical and approved embodiments of both forms.

Referring to the drawing- Fig. 1 is a perspective View of a portion of the working parts of a sewing machine, showing the needle bar and needle, the presser bar and a pivoted or walking presser foot, and one form of our improved needle guard pivotally mounted on the presser foot and pivotally connecting the latter to the detachable presser foot shank.

Fig. 2' is a perspective view of the presser foot, presser foot shank, and guard of Fig. 1, showing the latter raised and yieldably locked in raised position.

Fig. 3 is a plan section on the line 3-3 of Fig. 1.

Fig. 4 is a vertical section on the line d-=l of Fig. 1.

Fig. 5 is an isolated perspective viewof the guard appearingin Figs. 1 to 4.

Fig. 6 is a vertical longitudinal section through the parts appearing in Fig. 2.

Fig. 7 is a side elevation of a modication, showing a cam on the forward ends of the twin lugs of the presser foot for snapping the guard into, and yieldably holding it in, both fully raised and fully lowered positions.

Fig. 8 is a plan section on the line S- of Fig. 7

Fig. 9 is a vertical section through the guard pivot on the line 9-9 of Fig. 8.

Figs. 10 to 13, inclusive, illustrate a form of needle guard embodying the structural principle of the invention, but more particularly designed and adapted for use on sewing machines equipped with a presser foot that is fixed or rigid relatively to the presser bar; Fig. 10 being a perspective view, Fig. 11 being a plan section on the line II-I I` of Fig. 10, Fig. 12 being a side elevation viewed on the line I2-I2 of Fig. l1, and Fig. 13 being an isolated perspective of the guard.

Describing first that form of the invention designed for use on machines having a pivoted or walking presser foot, and referring to Figs. 1 to 6, inclusive, I5 designates the lower portion of the machine head, I6 the needle bar, il the needle, I8 the presser bar, and I9 the walking presser foot. In the usual construction the presser foot is pivotally connected to the presser bar by means of a presser foot shank comprising an upper channel portion 20 partially embracing the lower squared end of the presser bar I8 and secured thereto by a clamp screw 2l and a lower downwardly and forwardly extending portion 22, the lower end of which lies between twin lugs 23 on the upper side of the presser foot and is connected to said lugs by a horizontal pivot pin passed through registering holes in the lugs and the shank member 22.

The guard member is made from a single length of round pliable wire, bent to the shape shown in the drawing. This structural shape includes a pair of relatively long and short skeleton sides respectively disposed on opposite sides of the path of the needle. The longer side member comprises upper and lower longitudinal ` limbs 24 and 25 connected at their forward ends by a slightly rounded substantially 'vertical vlimb 26, and the shorter side member comprises upper and lower and longitudinal limbs 21fand-23 conf nected at their forward ends by a slightly rounded substantially vertical limb 29. The inner or rear ends of the lower - limbs 25 and 28 are connected by a transverse limb 36. The inner or rear ends of the upper limbs 24 and `2l Vhave downward substantially vertical extensions 3| and 32, continuous with the lower ends of which are inward horizontal extensions 33 and 34 that meet in a joint 35, as best shown in Figs. 3, 4 and 5. The forward portion of the longer side limb is preferably bent to incline toward the other or vshorter side limb, as best shown in Fig. 3, so as to sufficiently narrow the space between the forward ends of the side limbs to prevent the thumb or fingers of the operator from approaching dangerously close to the pathof the needle.

In applying this guard to the walking presser s foot, the usual pivot pin is withdrawn, and the rear parts of the `sides of the guard are expanded sufficiently to enter the terminal limbs 33 and 34 into the pivot holes, as shownin Figs. 3 and 4, so that the transverse member of the guard represented by the meeting ends 33 and 3G constitutes the pivot for connecting the presser foot I9 to the lower shank portion 22. This construction v enables the guard to be 'readily applied to a standard walking presser -foot 'by the simple substitution of an element oi the Yguard for `the usual pivot pin. When the-guard -is\applied, the transverse limb slidably engages over the rounded forward end of the lower member y22 of the Vpresser foot shank, andthe guard can be readily swung upwardly to the vertical position shown in Figs. 2 and 6 so asto beentirely out of the way when threadingthe needle. However, since the two sides of thelguard are of skeleton form, by suitably lowering-the needle, the latter can be threaded with the guard in `its lowered position. If desired,a shallow -notch indicated at 36 in Figs. l and 6 may be iiled'in-the top edge of the member 22 into which the limb f3!! will automatically set itself when the-guard is Afully raised so as to yieldingly hold the guard in raised position. l

In Figs. '7, 8 and 9 we illustrate va somewhat modified form of the device as previously described, which we deem somewhat preferable;

although embodying Vslight structural changes of the presser foot lugs and shank, which ordinarily may require these parts Ytobe especially made to cooperate with the guard as a unitary combination. The change inthe guard itself yconsists-in "omitting one of the meeting terminalportions Y33 and V34 which together form'the pvot, and making the other, such as 33 (Figs. 8 and 9) of sufficient length to alone serve as thepivot, the

free end being swaged over as shownat 31'form-,=

a straight outer portion 39 directly overlying and substantially parallel with the big toe of the presser foot; while the shorter side of the guard may consist of a relatively small curl or eye 40. A transverse limb 30' connects the lower limbs of the two sides of the guard. This limb 30' does not bear on the upper forward edge of the shank member 22, as does the limb 30 in the Vstructure illustrated in Fig. 1 to 6, inclusive, but on lthe forward ends of the presser foot lugs 23 are formed rounded cams 4l that are engaged by the transverse limb 30. The radii of these cams are longest at their centers and shorten toward each'end, so =that,when the guard is raised from the lowered position shown by full lines in Fig. 7 to thefully raised position shown by dotted lines, the guard is first stretched slightly until it reaches the peak of the cam, `and then, Yby the elasticity of the wire, it contracts and snaps automatically into the `fully raised position `as it descends the other side of the cam. These same operations take `place in the inverse-order when loweringthe guard from fully raised position to fully lowered position. As will `be Yseen by reference to Fig. 8, the -forward end ofthe shank member 22 terminates behind the cams 4l, so that the transverse limb Y3D of the guard is not engaged with or influenced by the member 22 of the presser foot shank. With this construction, all the operator has to do is to push `the guard half-way 4to final position in either direction, and the cams, `cooperating with the Y VZontal U-shaped loop 42 open Vat vits rear Iend and adapted to straddle thestem of theclamp screw 2l, in a manner clearly shown in Figs.

10, ll and 12; it lbeing ,necessary only :toback the screw off suiic'iently 1to-insert the loop between it and the upper shank member 2D, and then retighten the screw. The loop `l2 lis y'long enough to 'permit Vboth 'a limited fiore and 'aft and up 'and down adjustment of the guard; butpreferably the adjustment will be such that the transverse limb 30 will lie in vcontact 'with the neck 22 of the shank, so as to securely support the guard against upor down displacement when in use.

:It lwill nalso be observed dthat vin lallforms'of the invention illust-ratedgthe `two side Vmembers of the guard are spaced adistancegreater than,

the width of the shank member l2li, so `that the 4latter'dces -not interfere with the'elevationlof the-guard to its fully raised position.

The making of theguardallrinone pieceand regard as an important'improvement in needle surfaces to catch in the-fabric orscratch or-cut the fingers of the operator, it is very easily Vbent to the desired or required shape, as, Vfor instance, where the clamp screw may be on the rear or the opposite side of the presser bar, the attaching stem of the guard illustrated in Figs. to 13 may be correspondingly bent to cooperate with such clamp screw, and the device can be manufactured and sold so cheaply that its cost is practically negligible, even to users who have to count their pennies. And iinally, due to its skeleton form and particularly to its capacity for being shifted fully to one side of the needle, it presents no hindrance to the threading of the needle or the insertion of new needles in the holder of the needle bar.

While we have shown and described what we believe to be the best and most practical mechanical embodiments of the principle of the invention, we reserve all such variations and modifications in the structural details` as fall within the spirit and purview of the claims.

We claim:

1. A needle guard for sewing machines of the type having a pivoted presser foot, made from a single length of wire bent to form skeleton side members disposed respectively on opposite sides of the needle, a transverse limb connecting the lower portions of said side members, and a transverse pivot extending between said side members in rear of said transverse limb and adapted to replace the pivot pin of the presser foot.

2. The combination with a presser foot shank and a presser foot, of a needle guard formed with a transverse limb constituting a pivot connection of said presser foot to said shank, and cooperating means on said guard and shank yieldably locking said guard in raised position.v

3. The combination with a presser bar and a presser foot, of a needle guard of pliable spring wire formed with skeleton side members disposed respectively on opposite sides of the neele, a transverse limb constituting a pivot connection of said presser foot to said presser bar, and a transverse member connecting said side members in front of said pivot connection, and a cam on the upper side of said presser foot cooperating with said transverse member to snap said guard into, and yieldably hold it in, both fully raised and fully lowered positions.

4. The combination with a presser foot having on its upper side a lug, and a presser foot shank pivotally connected to said lug, of a needle guard of pliable spring wire formed with skeleton side members disposed respectively on opposite sides of the needle, said guard being pivoted on said lug to swing in a'vertical plane and having a transverse member connecting said side members in advance of the guard pivot, and a cam on the forward end of said lug over which said transverse member of the guard rides when the latter is raised and lowered, the operative surface of said cam being so shaped as to snap said guard into, and yieldably hold it in, both fully raised and fully lowered positions.

5. The combination with a presser foot having on its upper side twin laterally spaced lugs, and a presser foot shank having' its lower end portion lying between said lugs, of a needle guard of pliable spring wire formed with skeleton side members disposed respectively on opposite sides of the needle, a transverse limb continuous with one of said side members extending through and pivotally connecting said lugs and shank, and a transverse member connecting said side members in front of said transverse limb, and twin cams on the forward ends of said lugs extending beyond the lower end portion of said shank over which said transverse member of the guard rides when the latter is raised and lowered, the operative surfaces of said cams being so shaped as to snap said guard into, and yieldably hold it in, both fully raised and fully lowered positions.

6. A needle guard for sewing machines of the type having a pivoted presser foot, the guard embodying skeleton side members disposed respectively on opposite sides ofthe needle, a transverse limb connecting the lower portions of said side members, and a transverse pivot extending between said side members in the rear of said transverse limb and adapted to replace the pivot pin of the presser foot.

IVIARSHALL N. DUNLAP. GRANT FORTNEY.

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