US2056551A - Needle guard for sewing machines - Google Patents

Description

at, 6 1936. H. L. WILLIS NEEDLE GUARD FOR SEWING MACHINES Filed June 4, 1954 2 Sheets-Sheet 1 Patented Oct. 6, 1936 UNITED STATES PATENT OFFICE NEEDLE GUARD FOR SEWING MACHINES Application June 4, 1934, Serial No. 728,981

12 Claims.

The present invention relates to new and useful improvements in needle guards, and more particularly to an improved needle guard which is mounted on the feed bar and movable there- 5 with.

An object of the invention is to provide means for supporting a needle guard on the feed bar whereby it may be adjusted toward and away from the path of reciprocation of the needle and for shifting said needle guard to different set positions.

A further object of the invention is to' provide supporting means for the needle guard, of the above type; wherein said needle guard may be raised and lowered on the feed bar without disturbing the means for shifting the same to different set positions and without disturbing the feed dog.

A still further object of the invention is to provide a supporting device for the needle guard wherein the clamping screw which holds the feed dog in a set position on the feed bar may also be used for clamping the needle guard and its support in a set position.

These and other objects of the invention will in part be obvious and will be hereinafter more fully pointed out.

In the drawings:

Figure 1 is a sideview of a sewing machine with the improvements embodied therein.

30 Fig. 2 is a plan view showing the mechanism below the work support.

Fig. 3 is a plan view in section showing the details of the needle guard and the means by which it is supported on the feed bar.

Fig. 4 is a side view of Fig. 3 showing the various details of construction.

For purposes of illustration only; the needle guard is shown applied to the feed bar assembly of a sewing machine which is similar to that shown in the patent granted to Norman V. Christensen and Frederick F. Zeier on March 25, 1930, Number 1,751,508. It is to be clearly understood, however, that the needle guard may be used with any type of sewing machine.

In the particular type of machine illustrated in the accompanying drawings, there is provideda supporting bed plate l having the usual brackets on which the work support H is mounted. Mounted on the bed plate and located at one side of the work support is a standard which extends above the work support and which is provided with suitable bearings for the main actuating shaft l2, which, in turn, is driven by a belt wheel [3. A needle bar l4 carrying a needle I5 reciprocates in a needle head It which is carried by the standard. This needle bar is driven from the main shaft by suitable mechanism which forms no part of the present invention. Cooperating with the needle l5 below the work support is a looper I! which is oscillated into and out of the needle thread loop by an eccentric l8 on the main shaft l2 which is connected to the looper through suitable mechanism. The looper I1 is given a needle avoiding movement through an eccentric l9 on the main shaft and through a suitable system of connecting mechanism.

The material is fed across the work support H toward the rear of the machine by a feed dog 20 which operates in the usual slot formed in the throat plate which is carried by the work support. The particular mechanism for operating the feed dog is shown and described in the application of Norman V. Christensen, Serial Number 621,460, filed July 8, 1932. In this particular type of machine, the feed bar 2! is mounted on a pin 22 carried by a feed rocker 23 which is carried by a bar 24 mounted in the bed plate I!) of the sewing machine. The feed rocker is provided with an arm 25 havinga slot 26. An eccentric strap 21 is connected to a ball stud 28 which is adjustably mounted in the slot 26 by a screw 29. The eccentric strap cooperates with an eccentric 30 on the main shaft l2 and in this manner the feed bar is given a back and forth movement. A pin 3| is secured to the forward end of the feed bar by a screw 32 and this pin is provided with a ball end 33. An arm 34 is mounted on the pin 3! and therear end of said arm is slotted, as indicated at 35, in order to permit an adjustment thereof 'by loosening the screw 36. An eccentric strap 3'! is connected to the ball end of the pin 3| and cooperates with an eccentric 38 on the mainshaft l2 to raise and lower the feed bar.

This invention relates particularly to the mounting of a needle guard 39 on the arm-34. The shank 20 of the feed dog 20 is mounted in a grooved portion of the arm 34. The rear end of the feed dog 20 rests upon an adjusting screw 4|. The shank 20 of the feed dog is provided with a vertical slot 42 through which a clamping screw 43 passes into the arm 34. A block 44 which is provided with edge portions 45 snugly fitting the sides of the shank of the feed dog is adapted to be shifted vertically relative to the feed. dog. The needle guard 39 is provided with a shank portion 31') which has a horizontalslot 46 therein. The portion 39 ofrthe needle guard fits in a horizontal groove in the block 44 and may be shifted in a direction at right angles to the shank of the feed dog. The block 44 is prevented from turning about the screw 43 by the edge portions 45 and the needle guard is likewise restrained from making any angular movement by the groove in the block 44. The clamping screw 43 passes through the slot 46 in the needle guard, the block 44 and the slot 42 in the feed dog shank, and finally into the arm 34. A metal washer 4'! extends over the slot 46 in the needle guard and thus the entire assembly is firmly held when the screw 43 is tightened. A screw 48 is threaded into the lower end of the block 44 and is provided with an annular portion 49 which extends into a slot 50 in the portion 39 of the needle guard. Thus, when the clamping screw 43 is.

loosened, the needle guard may be positively shifted horizontally by turning the screw 48. Likewise, theblock 44 may be shifted vertically when the clamping screw is loosened so that it is thus possible to obtaina complete adjustment of the needle guard without disturbing the setting of the feed dog.

It will be noted that the needle guard may be shifted in a substantially horizontal direction relative, to the block 44 and that the block and the needle guard may be shifted vertically on the shank of the feed dog so that a Very Wide range of adjustment may be obtained. It will also be appreciatedthat vertical adjustment of the block 44 may be accomplished without in any way disturbing the horizontal adjustment of the needle guard because the annular portion 49 of the screw 48 holds the needle guard in position at all times. It will be further noted that the several parts are all secured to the arm 34 by the one screw 43 so that an extremely simple and inexpensive construction is thus afforded. It

, is to be noted also that, by means of the present construction, the feed, dog may be adjusted without disturbing the set position of the needle guard. This fact is of extreme importance considering the very fine adjustment which is necessary.

The present invention, therefore, provides a novel needle guard assembly which moves with the feed dog and operates to prevent the needle from being deflected into the path of the looper. It is obvious that the needle guard may be employed on any type of sewing machine and that minor changes in the arrangement of parts and details of construction may be made without departing from the scope of the invention as set forth in the appended claims.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In 'a sewing machine, a needle, a feed dog, a feed bar carrying said feed dog, a needle guard mounted on said feed bar for adjustment longitudinally thereof, and means for positivelyshifting said needle guard on the feed bar to different set positions.

2. In a sewing machine, a needle, a feed dog, a feed bar carrying said feed dog, a needle guard mounted on said feed bar for movement longitudinally thereof, and means including an adjusting screw having anannular portion engaging said needle guard for shifting the same to different set positions.

3. In a sewing machine, a needle, a feed dog, a feed bar carrying said feed dog, a member mounted on said feed bar for vertical adjustment, a needle guard mounted on said member for horizontal adjustment, and clamping means for securing said needle guard and said member in a set position on the feed bar.

4. In a sewing machine, a needle, 2. feed dog, a feed bar carrying said feed dog, amembermounted on said feed bar for vertical adjustment, a needle guard mounted on said member for adjustment longitudinally of the feed bar, clamping means for securing said member and said needle guard in a set position on said feed bar, and means for positively shifting said needle guard to different set positions on said member when said clamping means is released.

5. In a sewing machine, a needle, a feed dog, a feed bar carrying said feed dog, a member sup ported by said feed bar for vertical adjustment, a needle guard mounted on said member for adjustment longitudinally of said feed bar, clamping means for securing said member and said needle guard in a set position on said feed bar, and an adjusting screw threaded into said member and having an annular portion engaging said needle guard whereby to positively shift said needle guard to different set positions on said member when said clamping means is released.

6. In a sewing machine, a needle, a feed dog, a feed bar, means for mounting said feed dog on said feed bar to prevent angular movement there of relative to the feed'bar, a member mounted on the shank of said feed dog andhaving means to prevent angular movement thereof relative to said feed dog, said member being movable vet} tically relative to said feed dog, a needle guard, means for mounting said needle guard on said member to prevent angular movement thereof relative to the member, and a single clamping device for securing the feed dog, the member and the needle guard to said feed bar in a set position.

7. In a sewing machine, a needle, a feed dog, a feed bar, means for mounting said feed dog on said feed bar to prevent angular movement thereof relative to the feed bar, a member mounted on the shank of said feed dog and having means to prevent angular movement thereof relative to said feed dog, said member being movable vertically relative to said feed dog, a needle guard, means for mounting said needle guard on said member to prevent angular movement thereof relative to the'inember, a single clamping device forsecuring the feed dog, the member and the needle guard to said feed'bar in a set position, and means for positively shifting said needle guard'relati've to said member when the clamping device is released;

8. In a sewing machine, a needle, a feed dog having a shank portion, a feed bar having a grooved portion to receive said shank, a member having a vertical grooved portion adapted to fit over said shank whereby to prevent angular movement of said member, a needle guard, means for mounting said needle guard on said member to prevent angular movement thereof relative to saidm'ember, and a single clamping screw for securing the feed dog, the needle guard and said member in a set position on said feed bar, said shank having a vertical slot through which said clamping screw passes to permit vertical adjustmentof said membensaid needle guard having a horizontal slot through which said clamping screw passes to permit horizontal adjustment of said needle guard.

9. In a' sewing machine; a needle, a feed dog having a shank portion, a feed bar having 'a grooved portion to receive said shank whereby to prevent angular movement of said feed dog, a member having a vertical grooved portion adapted to fit over said shank whereby to prevent angular movement of said member, a needle guard, means for mounting said needle guard on said member to prevent angular movement thereof relative to said member, a single clamping screw for securing the feed dog, the needle guard and said member in a set position on said feed bar, said shank having a vertical slot through which said clamping screw passes to permit vertical adjustment of said member, said needle guard having a horizontal slot through which said clamping screw passes to permit horizontal adjustment of said needle guard, and means for positively shifting said needle guard longitudinally of said feed bar when said clamping screw is released.

10. In a sewing machine, a needle, a feed bar, a feed dog carried by said feed bar, a needle guard carried by said feed bar, and means including a single securing device for simultaneously clamping said feed dog and said needle guard to said feed bar.

11. In a sewing machine, a needle, a feed bar, a feed dog mounted on said feed bar, a needle guard mounted on said feed bar, and means including a single securing device for permitting the adjustment of said feed dog and said needle guard on said feed bar and for simultaneously clamping said feed dog and said needle guard in their adjusted positions.

12. In a sewing machine, a needle, a feed bar, a feed dog carried by said feed bar, a needle guard carried by said feed bar, means including a single securing device for simultaneously clamping said feed dog and said needle guard to said feed bar, said means permitting horizontal adjustment of said needle guard when released, and means for maintaining said feed dog in a set position vertically when said securing means is released for permitting said needle guard to be adjusted horizontally without disturbing the set position of the feed dog.

HARRY L. WILLIS.

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