US3500782A

US3500782A - Needle guard for sewing machines

Info

Publication number: US3500782A
Application number: US729351A
Authority: US
Inventors: Kenneth M Smith
Original assignee: KENNETH M SMITH
Current assignee: KENNETH M SMITH
Priority date: 1968-05-15
Filing date: 1968-05-15
Publication date: 1970-03-17
Anticipated expiration: 1987-03-17

Description

March 17, 1970 K. SMlTH 3,500,782

NEEDLE GUARD FOR SEWING MACHINES Filed May 15, 1968 INVENTOR. KENNE-TH M. SM/V'H United States Patent O 3,500,782 NEEDLE GUARD FOR SEWING MACHINES Kenneth M. Smith, P.O. Box 55, Weatherford, Okla. 73096 Filed May 15, 1968, Ser. No. 729,351 Int. Cl. Db 83/00 U.S. Cl. 112-261 8 Claims ABSTRACT OF THE DISCLOSURE A needle guard for attachmentto a sewing machine and including an inner sleeve, an outer sleeve concentrically and rotatably mounted on the inner sleeve, a lug projecting radially outwardly from the outer sleeve, an elongated guard shaft slidably extending through the lug, and an arcuate guard element secured to one end of the guard shaft. Securing elements are included in the structure for adjustably interlocking the inner and outer sleeves in predetermined positions of rotation relative to each other, for securing the inner sleeve at a predetermined position along a suitable supporting shaft of the sewing machine, and for adjusting the position of the guard shaft relative to the lug.

BACKGROUND OF THE INVENTION Brief description of the prior art In textile sewing machines of the relatively small, portable type used by housewives, there is some danger in usage that the operator may inadvertently interpose some foreign object in the path of the vertically reciprocating needle with the result that the needle or the object or both may be damaged. A more serious danger is that the seamstress may, through carelessness, permit a finger or hand to be positioned in the path of travel of the needle, resulting in a painful, incapacitating injury.

It has heretofore been proposed that rigid guard structures be attached at some point to the sewing machine and project into a position adjacent the path of the needle to block access to this path by the fingers of the operator and other foreign objects. Frequently, these guard structures have been relatively immovable or diflicult to move to an out-of-the-way inoperative position, so that the seamstress has difiiculty in attaining access to the point of the needle for purposes of threading, or for other operations. This has too frequently resulted in the guard structure being removed from the machine, or not installed, with the result that injuries continued to occur. Another disadvantage which has been characteristic of many of the needle guard structures heretofore proposed is that they can be mounted on only one or a few makes or models of sewing machines, and this has limited their usefulness, and their attractiveness to purchasers.

BRIEF DESCRIPTION OF THE PRESENT INVENTION The present invention provides a needle guard structure for sewing machines, which structure can be moved in several directions or in several planes while mounted on a sewing machine, and can be very quickly and easily shifted between a guarding and an out-of-the-way, inoperative position. The guard structure is also susceptible to mounting on many different makes and models of sewing machines.

Broadly described, the present invention comprises an inner sleeve adapted for securement around a vertically extending shaft .or rod of the sewing machine, an outer sleeve concentrically and rotatably mounted on the inner sleeve, a lug or stud projecting radially outwardly from the outer sleeve, and an elongated guard shaft slidably extending through the lug. An arcuate guard element is secured to one end of the guard shaft. Securing elements are included in the structure for adjustably interlocking the inner and outer sleeves in at least two predetermined positions of rotation relative to each other, for securing the inner sleeve at a predetermined position along a supporting shaft of the sewing machine, and for iidjusting the position of the guard shaft relative to the The described structure permits the achievement of the important objects of (a) quick and easy movement to and from a guarding position of the guard structure, and (b) mounting of the guard structure on many different types of sewing machines.

A marked advantage of the needle guard of the invention is its simplicity of structure, mechanical durability, and sturdiness in use.

In addition to the described objects and advantages of the invention, additional objects and advantages will become apparent as the following detailed description of the invention is read-in conjunction with the accompanying drawings which illustrate the invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a view in elevation of the needle guard of the invention as it appears when mounted on a sewing machine.

FIGURE 2 is a view in elevation of the needle guard of the invention as it appears when viewed from a different angle than that in which it is shown in FIGURE 1.

FIGURE 3 is a plan view of the needle guard of the invention.

FIGURE 4 is a vertical sectional view taken through the center of the needle guard of the invention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION In FIGURE 1 of the drawings, the needle guard 10 of the invention is illustrated as it appears when mounted on the presser bar shaft 12 of a sewing machine 14. The machine 14 carriesfthe usual reciprocating needle 15. The needle guard 10 includes an inner sleeve 16 which is .of reduced diameter over a portion of its length to provide an external shoulder 18. Extending radially through the relatively large diameter portion of the inner sleeve 16 are a pair of threaded

holes

20 and 21 which accommodate set

screws

22 and 23. At its end of reduced diameter, the inner, sleeve 16 is provided with an annular snap ring groove 24. Between the groove 24 and the shoulder 18 are a pair of circumferentially spaced

recesses

26 and 28 which are positioned about from each other around the small diameter portion of the sleeve 16. A bore 30 extends axially through the sleeve 16. The inner sleeve 16 is positioned concentrically within an outer sleeve 32 whichis provided with an internal shoulder 34 which mates with the shoulder 18 on the inner sleeve. It will also be noted that the outer sleeve 32 carries a groove 36 in an'end face. A snap ring 38 seats in the groove 36 and extends into the groove 24 in the inner sleeve 16 to retain the inner sleeve within the outer sleeve 32 while permitting rotation of the sleeves relative to each other.

The outer sleeve 32 has a threaded, radial bore 42 extending therethrough at a location which permits this bore, through a small communicating counter-bore 43, to register with the

recesses

26 and 28 in the inner sleeve 16 as the outer sleeve is rotated upon the inner sleeve. Threaded into the threaded bore 42 in the outer sleeve 32, and projecting radially therefrom is a locking assem bly designated generally by reference numeral 50. The

locking assembly 50 includes a locking pin housing 52 which is a cylindrical member having an open end threaded into the threaded, radial bore 42 in the outer sleeve 32, and having a closed end 54 opposite its threaded inner end. The closed end 54 has a relatively small locking pin aperture 56 therethrough to accommodate the shank 58 60 intermediate its length and has an inner end portion 62 which projects through .the outer sleeve 32 and bears against the inner sleeve 16. It will be noted that the inner end portion 62 of the locking pin is positioned for engagement with the circumferentially spaced

recesses

26 and 28 provided in the inner sleeve 16. The outer end portion 62 of the locking pin is threaded into an actuator cap 70 which has an enlarged gripping portion 72 and a collar portion 74 which extends concentrically around the outer end of the locking pin housing 52. Positioned within the locking pin housing 52 concentrically around the shank 58 of the locking pin, and bearing against the closed end 54 of the locking pin housing 52 and against the annular flange 60 of the locking pin is a compression spring 76. It will be noted that the compression spring 76 continuously biases the locking pin inwardly within the locking pin housing 52 and, in so doing, also biases the actuator cap 70 inwardly.

At a point spaced circumferentially around the outer sleeve 32 about 90 from the locking assembly 50, a stud or lug 77 is secured in any suitable manner to the outer periphery of the outer sleeve 32, and projects radially outwardly therefrom. The stud 77 has a shaft bore extending diametrically therethrough for slidingly accommodating an elongated guard shaft 78. Extending inwardly in an axial direction from the free outer end of the stud 77 is a threaded set screw hole 80. An Allen head set screw 82 is extended into the threaded hole 80 and bears at its inner end against the guard shaft 78 so that the guard shaft may be fixed in its position relative to the stud 77.

It will be noted that the guard shaft 78- extends in a direction such that its longitudinal axis is generally pa allel to the axis of the bores through the inner and outer sleeves, 16 and 32, respectively. Intermediate its length, however, the guard shaft 78 is provided with an offsetting bend therein which interconnects the parallel end portions of the guard shaft. At its end portion opposite the end portion which extends through the stud 77, the guard shaft 78 is secured to an arcuate guard element 84. In a preferred embodiment of the invention, the arcuate guard element 84 is of semicircular configuration, and is formed of a pair of parallel

spring metal wires

84a and 84b which are interconnected through rounded bight portions at their ends.

OPERATION In utilizing the needle guard of the invention, the needle guard is first mounted upon the presser bar shaft 12 so that the inner sleeve 16 concentrically surrounds the presser bar shaft and is slidable in a vertical direction thereon. The vertical location of the needle guard upon the presser bar shaft 12 is set at the desired point by the use of the

set screws

22 and 23 which extend through the holes and 21. The inner end of the set screws bear against the presser bar shaft.

With the needle guard 10 slidably mounted on the presser bar shaft 12, the outer sleeve 32 is swiveled or pivoted about the inner sleeve by pulling outwardly on the actuating cap 70. As the actuating cap 70 is pulled outwardly with respect to the locking pin housing 52 on which it is slidably mounted, it withdraws the locking pin with it. The locking pin can slide within the locking pin housing 52 and, in moving outwardly with the actuating cap 70, compresses the compression spring 76 between the end 54 of the locking pin housing and the annular flange 60 of the locking pin. Pulling outwardly on the enlarged gripping portion 72 of the actuating cap 70 retracts the inner end 62 of the locking pin from one of the

recesses

26 or 28 formed in the inner sleeve 16 of the needle guard 10. When the locking pin is withdrawn from the

recesses

26 and 28, the outer sleeve 32 is free to rotate concentrically on the inner sleeve 16. Axial movement of the outer sleeve with respect to the inner sleeve is prevented, however, by the cooperation of the shoulder 18 with the shoulder 34, and by the snap ring 38 which snaps into the groove 24 formed in the upper end of the inner sleeve 16.

-It will be apparent that by the rotational movement of the outer sleeve 32 on the inner sleeve 16, the stud 77 can be swiveled about the axis of the presser bar shaft 12 to adjust the relationship of the guard shaft 78 and the arcuate guide element 84 which is carried thereby with respect to the needle 15 carried at the lower end of the vertically reciprocating needle shaft. Adjustment of the position of the arcuate guard element 84 with respect to the needle 15 can also be obtained by sliding the guard shaft 78 upwardly and downwardly in the stud 76 after the set screw. 82 has been loosened. This is a valuable characteristic of the invention, for it permits the inner sleeeve 16 to be limited in the position which it may occupy on the presser bar shaft 12. The ability to slide the guard shaft 78 upwardly in the stud 77 permits the arcuate guard element 84 to be brought to the proper position for providing a guarding barrier around the needle 15 to prevent the seamstress from endangering fingers and hands during sewing with the machine.

At such time as it may be desired to move the arcuate guard element 84 out of the way so that the needle may be threaded or the pressure foot lifted or the like, the seamstress need only pull outwardly on the enlarged gripping portion 72 of the actuating cap 70 to retract the locking pin within the locking pin housing 52 and disengage the inner end portion 62 of the locking pin from one of the

recesses

26 and 28. The outer sleeve 32 can then be pivoted or swiveled about the axis of the sleeve until the inner end portion 62 of the locking pin snaps into the

alternate recess

26 or 28 formed in the inner sleeve 18. At this time, the inner sleeve 16 will be locked or engaged with the outer sleeve, and the arcuate guard element 84 will be moved out of the guarding position to a position permitting access to the needle or the presser foot. It will thus be noted that one of the important advantages of the needle guard of the present invention is the ability to shift the guard shaft 78 and the arcuate guard element 84 in several directions or in several planes so that the arcuate guard element may be properly mounted for guarding the needle on different makes and models of sewing machines, and so that the seamstress can quite easily and quickly pivot the guard shaft and arcuate guard element to an out-ofthe-way position in which they do not interfere in any way with the operations necessary for all types of sewing with the machine.

Although a preferred embodiment of the invention has been hereindescribed, the specific structure depicted in the drawings and referred to in the written description may be altered in many respects without departure from the basic principles underlying the invention. Changes and modifications of this type which do not depart from these basic principles are deemed to be circumscribed by the spirit and scope of the invention except as the same may be necessarily limited by the appended claims.

What is claimed is:

1. A needle guard device for a sewing machine comprising:

an inner sleeve;

an outer sleeve concentrically surrounding the inner sleeve and rotatable thereabout;

means for selectively securing said outer sleeve at one of a plurality of positions around said inner sleeve; an elongated guard shaft slidably supported on said outer sleeve and movable thereon in a direction parallel to the axis of rotation of the outer sleeve; and

a needle guard element secured to one end of said elongated guard shaft.

2. A needle guard device as defined in claim 1 and further characterized to include a stud projecting radially outwardly from said outer sleeve and slidably journaling an end portion of said guard shaft opposite the end secured to said needle guard element; and means for releasably and adjustably securing said guard shaft against sliding movement in said stud.

3. A needle guard device as defined in claim 2 and further characterized to include means for securing said inner sleeve to a presser bar shaft of a sewing machine.

4. A needle guard device as defined in claim 1 wherein said means for selectively securing said outer sleeve comprises:

a locking pin projecting through said outer sleeve and bearing against said inner sleeve;

a spring mounted on said outer sleeve for biasing said locking pin radially inwardly against said inner sleeve; and

means for retracting said locking pin away from said inner sleeve against the bias of said spring.

5. A needle guard device as defined in claim 4 and trically around the radially outer portion of said locking pin housing.

6. A needle guard device as defined in claim 5 and further characterized to include a stud projecting radially outwardly from said outer sleeve and slidably journaling an end portion of said guard shaft opposite the end secured to said needle guard element; and means for releasably and adjustably securing said guard shaft against sliding movement in said stud.

7. A needle guard device as defined in claim 6 and further characterized to include means for detachably securing said inner sleeve to a presser bar shaft of a sewing machine.

8. A needle guard device as defined in claim 7 wherein said inner and outer sleeves have cooperating shoulders extending radially inwardly and outwardly, respectively, and wherein said inner sleeve has a circumferential groove therearound adjacent one of its ends and adjacent said outer sleeve; and said guard device is further characterized in including a snap ring positioned partially in said groove and bearing against said outer sleeve, said snap ring cooperating with said shoulders to prevent said inner and outer sleeves from moving axially relative to each other.

References Cited UNITED STATES PATENTS 1,394,396 10/1921 Beattie 112-261 1,407,114 2/1922 Bailey 112261 1,939,620 12/ 1933 Ciravolo 11226l FOREIGN PATENTS 2,072 1913 Great Britain.

ALFRED R. GUEST, Primary Examiner mud r h 17, 1970 Patent No. 3, 500, 782

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