US1883746A

US1883746A - Thread cutter for sewing machines or the like

Info

Publication number: US1883746A
Application number: US482552A
Authority: US
Inventors: Doubler Charles W H
Original assignee: Individual
Current assignee: Individual
Priority date: 1930-09-17
Filing date: 1930-09-17
Publication date: 1932-10-18
Anticipated expiration: 1949-10-18

Description

Oct. 18, 1932. 0. w. HDOUBLER" THREAD CUTTER FOR SEWING MACHINES OR THE LIKE Filed Sept. 17. 1950 l-I /8 1 ml!!!" I J I I c Patented Oct. 18, 1932 CHARLES nnouBLER, or SPRINGFIELD, ivrrssounr THREAD CUTTER FOR SEWINGMACHINES OR THE LIKE Application filed; September 17, 1930. Serial No. 482,552.

The present invention relates to new and useful improvements in thread cutters for sewing machines or the like. i I

Thread cutters, such as have heretofore been used in connection with sewing machines, are customarily supported on the presser bar or the head block of the machine and, being exposed,'are a menace to the operators fingers if possessed of a suf'iciently keen edge to cut the thread effectively. The prior thread cutters are, therefore, usually provided with edges that are so blunt that instead of cutting they break the thread pulled over them. Then too, after the threads have been cut or broken to release the sewed material from the machine, the two ends of the thread supply are .left loose and must be caught up and adjusted below the presser foot before a new seam is begun.

It is one of the objects of the present invention to overcome these objectionable features of prior devices of this character. rAnother object of the invention is to provide a thread cutter for sewing machines or the like, which has a keen thread cutting portion so formed and positioned that the sharp cutting edge thereof cannot come in contact with the oper- A further object of the invention is to pro? vide a thread cutter for sewing machinesor the like, which is formed and positioned in such manner, that when the thread of a fin ished seam has been severed from the material or goods, the two ends of the unused thread may be yieldingly retained under the cutter bar in proper and convenient position for the beginning of a new seam.

Still another object of the invention is to provide a thread cutter which is simple and compact in construction, and which is moreover highly efficientin operation. With the above and other objects in view my invention consists of the improved thread cutter for sewing machines or the like, set forth in the specifications and in the claims annexed to and forming part of this specification.

. In the accompanying drawing, also forming part of this specification, I have illustrated two slightly varying: examples of actual embodiments of my invention, constructed according to modes which I have thus far devised for the practical application of the principles thereof, and in which: Fig. 1 is a front elevation of a special type of sewing machine equipped with the improved thread cutter; ,7

Fig. 2 is a top view of the front end of the same sewing machine showing'the improved thread cutter in plate portion;

Fig. 3 isyan enlarged side view of the improved thread cutter detached from the sewing machine; and. j

Fig. 4 is an enlarged top view of a slightly modified form of the invention showing the same mounted upon a fragment of the bed plate of a different type of sewing machine from that shown in Figs. 1 and 2. 7

Referring to the drawing, the numeral 5 indicates the bed plate of a sewing machine. Rising from the bed plate 5 at the rear end thereof is the usual tubular arm 6, which terminates at the front in an integral head 7. The head 7 has mounted therein for reciprocation, a needle bar 8 of usual formation and a presser bar 9. The needle bar 8 carries a needle 10 and the presser bar 9 has a presser foot 11. The needle bar is reciproc'able'by theusual mechanism (not shown) mounted, within the arm whereby stitches are formed in the material being sewed by the needle 10, and a thread 12 cooperates during sewing with a lower thread 13 supported in the bobbin member of a complemental loop taker (notshownlmounted below the sewing plate, to form the stitches.

To permit convenient access to the loop taker, a throat plate 14' covering ,a usual access opening,'is provided, this plate being pivoted to the bed plate 5 by a screw 15.

The bed plate 5 is formed flush with the top of the throat plate at the one side there of but is machined on the opposite side, as at 16,to provide clearance for'swinging the throat plate on its pivot screw 15. In providing such clearance a shoulder 17 is formed running in a straight line from the back edge of the throat plate to the adjacent edge of the bed plate 5. There is also a narrow position on the bed slot 19 provided in the bed plate, running transversely to and intersecting the shoulder 17, this slot being cut to the same depth as the shoulder. The thread cutter 18 is formed with a downwardly directed hook portion 18 and with a curved cutting portion 21 near its outer end, and also has a lip C at the inner end thereof which is slightly long-er than the depth of the slot 19 in which it is seated so that the front end of the medial portion of said thread cutter will, when positioned, stand somewhat above the surface of the bed plate to provide means, coacting with the screw 20, for properly adjusting the frictional tension on the threads which will lie between the bed plate and the flat, resilient rear end portion of the cutter bar adjacent the cutting edge thereof.

The thread cutter 18 is secured to the bed plate 5 and made adjustable thereto by the aforementioned screw 20. It is positioned upon said bed plate with the lip C seated in the slot19 and the inside edge of the medial portion thereof in direct line with the needle when viewed from the operative side of the machine; and when so positioned, and properly adjusted as to tension, the cutting edge of said cutter will rest closely against the bed plate to protect said cutting edge and the operators fingers from accidental injury.

The thread cutter is preferably formed of carbonized steel and is suitably tempered, first, to provide resiliency for the body portion thereof, and second, to insure an effective and keen cutting edge on the curved cutting portion 21 when chamfered inwardly as shown at a to position the cutting edge as close as possible to the bed plate.

It has now been made apparent that when a seam has been completed the operator need only draw the two threads 12 and 13, which connect the finished seam with the sewing machine, around and under the outside end of the thread cutter from the rear side thereof. By giving a slight pull the threads will be readily severed and the two unused ends thereof will be yieldingly retained under the resilient body of the cutter bar in correct posi tion for beginning a new seam without further attention and, furthermore, said thread ends will be long enough to tie or sew in when the seam has been finished. Moreover the thread ends are so retained, that when the new seam has been sewed a suflicient distance, the two yieldingly retained thread ends will be automatically drawn free from the thread cutter.

' It is to be understood that the gist of the present invention does not reside in any exact shape of the thread cutter but rather in its mode of operation and its disposition relative to the machine. The means by which the two thread ends are yieldingly retained after the threads have been cutloose from the material being sewed, is also an important feature of the present improvement.

Nor is the application of the present invention to be restricted to the type of sewing machine illustrated and described. I have, therefore, illustrated in Fig. 4 a slightly modified form of the invention wherein the thread cutter is mounted upon a fragment of the bed plate 5 of a sewing machine which is not necessarily provided with a shoulder adapted to be utilized in connection with the thread cutter previously described.

The improved thread cutter as illustrated in Fig. 4c is similar to the one already described, excepting that the hook portion 18 is eliminated, and a slight difference is introduced in the chamfer, shown at b. This chamfer is, however, still formed to position the cutting edge at the bottom of the curved cutting portion of the thread cutter, close to the bed plate. 1

In this modification, as in the first described device the thread cutter 18 is mounted flat upon the bed plate by the screw 20, the lip C resting in the slot 19, and the back edge of the thread cutter lying in approximate alignment with the needle 10 when viewed from the operating side of the sewing machine.

From the foregoing description, it will be noted that the invention provides a thread cutter especially adapted for use in connection with sewing machines or the like, which is simple and compact in construction and which is moreover highly efficient in operation. The improved device not only insures maintenance of a keen cutting edge without danger to inquiring individuals handling the machine, but also maintains the cut ends of threads in most effective condition for subsequent operation of the machine. The thread cutter is moreover out of the way of fabric being worked upon, and may be manufactured and applied to machines at but slight cost.

It should be understood that it is not desired to limit the invention to the exact details of construction herein shown and described, for various modifications within the scope of the claims may occur to persons skilled in the art.

What I claim as my invention is:

1. In combination with a thread utilizing machine having a presser foot, a thread cutter comprising a fiat resilient member secured to the frame of said machine entirely to the rear of the presser foot and having a cutting edge disposed on the outer side edge of said member closely adjacent to said frame. I

2. In combination with a sewing machine having a presser foot, a thread cutter for the needle and bobbin threads of said machine comprising a resilient member adjustably secured to the frame of said machine-entirely to the rear of the presser foot and having a cutting edge disposed on the outer side edge of said member closely adjacent to and ap cutter comprising a resilient member adjustably secured to the frame of said machine entirely to the rear of said presser foot and having a cutting edge disposed on the outer side edge of said member closely adjacent to said frame, said member being formed to hold the end of a cut thread in proper position for subsequent operation of said machine.

4. In combination with a sewing machine having a presser foot, a thread cutter for the needle and bobbin threads of said machine comprising a fiat resilient member secured to the frame of said machine entirely to the rear of the presser foot of the machine and having a cutting edge disposed on the outer side edge of said member approximately parallel and closely adjacent to said frame, said member being formed to hold the end of a cut thread in proper position for subsequent operation of said machine.

5. In combination with a sewing machine having a presser foot, a thread cutter for the needle and bobbinthreads of said machine comprising a member secured to the work supporting surface of said machine substantially in the plane of travel of the material operated upon by said machine and entirely to the rear of the presser foot of said machine, said member having a cuting edge disposed on the outer side edge thereof approximatelyparallel and closely adjacent to said surface.

6. In combination with a thread utilizing machine having a presser foot and a frame provided with a slot, a thread cutter positioned to the rear of the presser foot and comprising a member having a down turned front end portion coacting with said slot and having a medial portion secured to said frame, the opposite rear end portion of said member being provided with a cutting edge disposed on the side edge of said member closely adjacent tosaid frame.

7. In combination with a thread utiliz-' ing machine having a presser foot andv a frame provided with a slot, a thread cutter positioned to the rear of the presser foot and comprising a member having a down turned front end portion coacting with said slot and having a medial portion secured to said frame, the opposite rear end portion of said member being resiliently biased toward said frame and having a cutting edge disposed on the side edge thereof directly adjacent and approximately parallel to said frame.

8. In combination with a sewing machine having a presser vfoot and a frame provided with a slot extending transversely of the direction of travel of material past the needle thereof, a thread cutter positioned to the rear of the presser foot and comprising a member having a down turned front end-portion coacting with said slot and having a resilient opposite rear end portion extending away from said slot and from the needle of said machine, said resilient rear end portion of said member being provided with a cutting side edge disposed closely adjacent and approximately parallel to said frame.

9. In combination with a sewing machine having a presser foot and a work supporting surface provided with a slot, a thread cutter positioned to the rear of the presser foot and comprising a member having a down turned front end portion coacting with said slot and having an opposite resilient rear end portion extending away from said slot and from the needle of said machine, said mem berextending away from said needle in the direction of travel of material past said needle and having a cutting edge at its rear outer side edge closely adjacent to said surface.

' 10. In combination with a sewing machine having a presser foot and a work supporting surface between the needle and the bobbin thereof, a thread cutter for the needle and bobbin threads of said machine positioned on the worksupporting surface entirely to the rear of the presser foot and comprising a member having a resilient rear end portion adapted to receive saidthreads