US2848966A - Thread tension releasing devices - Google Patents

Description

Aug. 26, 1958 H. RITTER ETAL THREAD TENSION RELEASING DEVICES Filed Nov. 14, 1956 IN VEN TORS Herman R/ffer Adam P Steiner BY 74 241/ @w I XTTORNEY Fig.l

WITNESS United States THREAD TENSION RELEASING DEVICES Herman Ritter, Cranford, and Adam P. Steiner, Linden, N. J assignors to The Singer Manufacturing Company, Elizabeth, N. .L, a corporation of New Jersey Application November 14, 1956,-'Serial No. 622,061 Claims. Cl. 112-433 This invention relates to sewing machines and more particularly to a means for releasing'the tension of the sewing thread of the sewing ,machine each vtime the Presser-bar is raised, and the invention has as its'primary object to provide an improved device of thisjcharacter.

Another object of the invention is to provide an improved adjustable thread tension releasing device, by use of which the time of initiation of thread tension release can be adjusted at will.

A further object of the invention is to provide an improved means by the useof which the time of initiation of thread tension release can be adjusted without also changing the setting of the slack-thread regulator.

A still further object of the invention is to provide an adjustable thread tension release which is inexpensive to manufacture and which has facilities for easy adjustment.

With the above-and otherobjects 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 preferred 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.

In the single sheet of drawings, which forms a part of this specification:

Fig. 1 is an elevational end view of a sewing machine embodying the present invention,

Fig. 2 is an elevational fragmentary sectional view taken on the line 2-2 of Fig. 1, and

Fig. 3 is a perspective view of certain parts of the mechanism shown in Figs. 1 and 2.

The sewing machine illustrated has a work-support or bed 16, from one end of which rises a hollow standard 17 of a bracket-arm having a head 18 from which a face-plate (not shown) has'been removed. The head 18, in a well known manner, carries a vertically reciproeating needle-bar 19 and a stationary presser-bar bushing 20 which receives a movable presser-bar 21. The lower end of the presser-bar 21 carries a presser-foot 22 and the upper end of the presser-bar 21 is hollow, thereby accommodating a helical spring 23 and the lower end of a rod 24. The upper end of the rod 24 is held in place by an adjusting screw 26. A bracket 27, which is secured to the presser-bar 21 by means of a split collar and a screw 28, is provided with a second screw 29 and a horizontally extending hole 31. The hole 31 receives one end of a slack-thread regulator bar 32, which is held in the hole 31 by the screw 29. At its other end 33, the slack-thread regulator bar 32 passes through an aperture 34 in the head 18 and is bent downwardly, thereby functioning to control the sewing thread (not shown), which thread also passes between a pair of tension disks 36-37, forming part of a thread tension device 38 of a type somewhat similar to that shown in U. S. Patent No. 2,462,812. An L-shaped link 39 has a lower circular end 41 loosely wrapped around the resser-bar 21 at a 2,848,966 Patented Aug. 26, 1958 location directly below the bracket 27. The upper end of the link 39 surrounds a lifting stud 42 carried by one end of an arm 43. Lifting the arm 43, in a known manner by means of a foot-pedal (not shown) or by means ofa hand lever 44, lifts the bracket 27, the presser-bar '21, and the slack-thread regulator bar 3233. Adjust member 53, and a clamp screw 54. The body member 52 is supported in the head 18 of the sewing machine by means of a pivot-pin 56 which enters a hole 57 formed at a central location in the member 52. An arm 58 of the member 52, which extends to one side of the hole 57, has a projection 59 which engages the small end of a beehive spring 61, of which the large end engages an inner surface of the head 18. Beyond the projection 59, the arm 58 is bent at right angles to form a finger 60 adapted to engage the inner end of a tension-releasing pin 62 formed as part of the thread tension device 38. The other end of the pin 62, in a well known manner,

releases the grip of the disks 3637 on the thread (not the clamp screw, 54. The segmental member'53, in addition to having a pair of guides 6768 which engage the sides of the arm 63, thereby maintaining the segmental member 53 upright and in line with the end of the arm 63, also has a hooked end 69 adapted to overlie and be engaged by an end 72 formed on the end of the screw 28 which is carried by and extends beyond the bracket 27. Reference to Fig. 1 shows that the slotted head of the screw 54 faces toward the open end of the head 18 and thus is easily accessible for loosening and tightening of the said screw 54.

In the past, adjustment of the time of initiation of thread tension release in the type of machine herein shown has been accomplished by loosening a screw (equivalent to the screw 28) and moving the position of a bracket (equivalent to the bracket 27). In previous machines, this has not only adjusted the time of initiation of thread tension but also moved the slack-thread regulator bar (equivalent to bar 32) and thus it was impossible to adjust the time of initiation of thread tension release without also adjusting the slack-thread regulator. With the present arrangement the time of initiation of thread tension release can be adjusted by loosening the screw 54 and adjusting the segmental member 53 with respect to the end 72 of the screw 28. If it is desirable to adjust the slack-thread regulator 32 without also changing the time of initiation of the thread tension release, both screws 28 and 54 are loosened. Then the segmental member 53 is adjusted to compensate for any change made in the location of the bracket 27.

From the above it is evident that there has been provided an improved tension release lever 51 having an easily accessible adjusting screw 54 by use of which the time of initiation of thread tension release advantageously can be adjusted without changing the setting of the slackthread regulator bar 32 and by the use of which adjustment of the slack-thread regulator bar 32 can be effected while the time of initiation of thread tension release is maintained at its original setting.

Having thus set forth the nature of this invention, whatwe claim is:

1. In combination, a sewing machine comprising a head, a presser-bar movably supported in said head, a bracket adjustably held to said presser-bar, means for raising said resser-bar, a tension release lever pivotally supported in said sewing machine head, said tension release lever comprising a body member and asegmental member, means adjustably securing said segmental member to said body member, and means carried by said bracket for engaging said segmental member and thereby moving said tension release lever when said presser-bar is raised.

2. In combination, a sewing machine comprising a head, a resser-bar movably supported in said head, a bracket adjustably held to said presser-bar, means for raising said resser-bar, a tension release lever pivotally supported in said sewing machine head, said tension release lever comprising a body member and a segmental member, said body member having a threaded hole formed adjacent to the free end thereof, and a screw carried in said threaded hole, the said segmental member having an elongated hole through which passes said screw, and means carried by said bracket for engaging said segmental member and thereby moving said tension release lever when said presser-bar is raised.

3. In combination, a sewing machine comprising a head, a presser-bar movably supported in said head, a bracket adjustably held to said resser-bar, means for raising said bracket and thereby raising said resser-bar, a tension release lever pivotally supported in said sewing machine head, said tension release lever comprising a body member and a segmental member, said body member having a threaded hole formed adjacent to the free end thereof, and a screw carried in said threaded hole, the said segmental member having an elongated hole through which passes said screw, a pair of guides engaging the end of said body member, and means carried by said bracket for engaging said segmental member and thereby moving said tension release lever when said presser-bar is raised.

- '4. In combination, a sewing machine comprising a head, a presser-bar movably supported in said head, a bracket having a split collar by which it is adjustably held to said Presser-bar, a screw arranged to tighten said split collar and having an end extending beyond the said bracket, a slack-thread regulator bar carried by said bracket, means for raising said bracket and thereby raising said resser-bar and said slack-thread regulator bar, a beehive spring of which one end engages the inner surface of said head, and a tension release lever pivotally supported in said sewing machine head, said tension release lever comprising a body member and a segmental member, said body member comprising two arms, a projection carried by a first of said arms and engaging one end of said beehive spring, a finger formed as part of said first arm, said second arm having a threaded hole formed adjacent to the free end thereof, and a screw carried in said thread hole, the said segmental member having an elongated hole through which passes said screw, a pair of guides engaging the end of said second arm, and a hooked end, the hooked end overlying the end of the screw which is carried by said bracket.

5. A tension releasing mechanism for a sewing machine having a needle thread tension device and a presserfoot and means for raising said presser-foot, comprising a pivot adapted to be supported on said sewing machine, a body member pivotally supported on said pivot so that one of its ends is disposed to engage said tension device, a segmental member adapted to be disposed to be engaged by said means for raising said presser-foot, and means securing said body member and said segmental member together and providing for regulating the time of initiation of the tension release.

References Cited in the file of this patent UNITED STATES PATENTS 954,858 Free Apr. 12, 1910

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