US3108557A

US3108557A - Thread cutting attachment for sewing machines

Info

Publication number: US3108557A
Application number: US157700A
Authority: US
Inventors: George M Lober
Original assignee: H ROSENSTOCK AND SONS Inc
Current assignee: H ROSENSTOCK AND SONS Inc
Priority date: 1961-12-07
Filing date: 1961-12-07
Publication date: 1963-10-29
Anticipated expiration: 1980-10-29

Description

Oct. 29, 1963 GM. LOBER 3,108,557

THREAD CUTTINQATTACHMENT FOR SEWING MACHINES Filed Dec. 7, 1961 2 Sheets-Sheet l INVENTOR Georg e M. L obm' BY KID-MM ATTORNEYS THREAD CUTTING ATTACHMENT FOR SEWING MACHINES Filed Dec. '7, 1961 G; M. LOBER Oct. 29, 1963 2 Sheets-Sheet 2 8 INVENTOR H George M-LOIDQT'.

BY ATTORNEYS l 9 0 WW ,7 7 4 3 9 J I v M (W 8 Jwmw J a i A 9 United States Patent 3,108,557 THREAh @UTTENG ATTACHMENT FGR SEWENG MAQHINES George M. Fischer, Saiishury, Nail, assignor to H. Rosenstocl; & Sons, Hno, Ellenviile, NSEL, a corporation of New York Filed Dec. 7, 1961, Ser- No. 157,760 8 Claims. (ill. 1l2-252) This invention relates to the art of sewing, and more particularly to a thread cutting attachment which may be applied to existing sewing machines without alteration thereof, or supplied as standard equipment on newly manufactured sewing machines.

Heretofore, numerous types of thread-cutting attachments have been provided on sewing machines, but many of these required modification of the sewing machine to accommodate such attachment, and furthermore, in many cases, the cutting edge was unprotected, and thereby subject to damage or dulling, and in the main these attachments merely provided a means for severing the thread, and provided no means for retaining the cut ends of the thread until such time as these ends were manually removed preparatory to a further sewing operation. In view of the usual exposed location of the thread cutting attachments formerly used on sewing machines, in many instances the cutting edges provided were relatively blunt or dull in order to protect the operator from injury, with the consequence that the thread-severing operation was relatively difiicult, and often resulted in an undue pulling or strain being applied to the thread or material which had been previously sewed.

It is accordingly an object of the invention to provide a thread-cutting attachment for sewing machines which may be conveniently and economically manufactured from readily available materials, and applied to existing sewing machines without requiring any modification, or which may be supplied as an attachment for newly manufactured sewing machines.

A further object of the invention is the provision of a thread-cutting attachment for sewing machines, including a cutting blade having a keen cutting edge, and in which the cutting edge is completely protected from damage, and also in which the operator is completely protected against injury.

A still further object of the invention is the provision of a thread-cutting attachment for sewing machines incorporating a relatively small, keen-edged, cutting blade, and in which the cutting blade may be conveniently replaced when the same becomes dull, without the necessity of utilizing tools, or requiring any particulm manual dexterity.

Another object of the invention is the provision of a thread-cutting attachment for sewing machines, which may be releasably secured to the sewing machine by utilizing the conventional clamp screw, which serves to secure the conventional presser foot to the presser foot bar of the sewing machine, and without in any way interfering with the use or substitution of different types of presser feet.

A further object of the invention is the provision of a thread-cutting attachment for sewing machines which provides for rapid and convenient severing of the thread in that a throat is provided for guiding the thread into engagement with the edge of the cutting blade, thereby eliminating the necessity for accurate positioning of the thread for the cutting operation.

A still further object of the invention is the provision of a thread-cutting attachment for sewing machines, in which means is provided for resiliently and releasably retaining the severed ends of the thread subsequent to amass? Patented et. 29, 1963 2 the cutting operation, and until such ends are manually removed from the device.

Another object of the invention is the provision of a thread-cutting attachment for sewing machines, such attachment comprising only four parts, including a spring clip for releasably holding the parts in assembled relationship.

Further objects and advantages of the invention will be apparent from the following description taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is an elevational view showing a thread-cutting attachment constructed in accordance with this invention, and installed on the presser foot bar of a sewing machine, and also showing the thread-cutting operation;

FIG. 2 is a top plan view, with parts in section for greater clarity, and showing the thread-cutting attachment secured to a presser foot bar, and the relationship of the attachment to the conventional presser foot;

FIG. 3, a side elevational view of the thread-cutting attachment removed from the sewing machine;

FIG. 4, a sectional view taken substantially on the line 4-4 of FIG. 3;

FIG. 5, a sectional view taken on the line 5--5 of FIG. 3;

FIG. 6, an elevational View showing one of the threadguiding and gripping plates, together with the means provided thereon for securing the attachment to a sewing machine;

FIG. 7 is a side elevational view showing the other thread-guiding and gripping plate which cooperates with the plate shown in FIG. 6;

FIG. 8, a fragmentary sectional view taken substantially on :the line 8-8 of FIG. 9, and showing the manner in which the cut ends of thread are retained in the device after the cutting operation;

FIG. 9, a sectional view taken substantially on the line 9-9 of FIG. 8, and further showing the operation of the plates to grip the cut ends of the thread subsequent to the cutting operation; and,

FIG. 10, a view in perspective, showing the resilient clip member utilized for retaining the parts of the attachment in assembled relationship.

With continued reference to the drawings, and particularly FIG. 1, there is shown a vertically disposed presser foot bar lit and a needle 11 of a standard sewing machine, and the presser foot bar lit is provided at the lower end thereof with a fiat portion 12 for engaging the bracket portion of a presser foot 13 in a manner well known in the sewing machine art, and the presser foot 13 is releasably or removably held in position by a clamping screw 14 threadedly received in the lower end portion of the presser foot bar 10. Also shown in FIG. 1 is an upper supporting surface 15 for supporting work during the sewing operation, and a conventional feed dog 16 which operates to feed the work beneath the presser foot 13 during the sewing operation. The upper thread 17 passes through the eye of the needle 11, and the lower thread 18 is supplied from a shuttle below the supporting surface =15, and feeds upwardly through an aperture in alignment with the needle 11. This is all conventional sewing machine construction, and is merely described for the purpose of facilitating the description of the structure and operation of the thread-cutting attachment of this invention.

As best shown in FIGS. 2, 3, 5, 6 and 7, the thread-cutting attachment of this invention may well comprise a pair of elongated, generally rectangular opposed thread-guiding and

gripping plates

19 and 20, a cutting blade 21, and a generally U-shaped, resilient clip member 22 partially embracing the

plates

19 and 20 and the cutting blade 21 for holding all of the elements in assembled relationship.

With particular reference to FIGS. 5 and 6, the threadgripping and guiding plate 19 may well comprise an elongated, generally rectangular body portion 23 terminating at the forward end in an outwardly diverging portion 24, and being provided at the rear end with a transverse notch 25. Intermediate the ends of the plate 19 is a transverse, elongated opening 26, and it is to be noted that the

end walls

27 and 28 of the opening 26 are V-Shaped. A transverse aperture 29 is provided in the plate 19 between the opening 26, and the outwardly diverging forward end 24. inwardly of the notch 25, and adjacent the rear end of the plate 19 there is provided an inwardly opening recess 'or aperture 30 in the inner surface, and projecting upwardly from the rear end of the plate 19 is an ear 31 having an open ended elongated slot 32 therein for receiving the clamping screw 14 to secure the plate 19 in position on the lower end of the presser foot bar 10, and as best shown in FIG. 4, if desired, the car 31 may be offset, as shown at 33, in order to provide adequate clearance between the plate 19 of the thread-cutting attachment and the presser foot 13, which is also attached to the presser foot bar 10, as described above.

As best shown in FIGS. 5 and 7, the thread-guiding and gripping plate may well comprise an elongated, generally rectangular body portion 34 terminating at the forward end in an outwardly diverging portion 35, and being provided at the rear end with a notch 36, which is of the same general size and configuration as the notch in the rear end of the plate 19. Intermediate the ends of the plate 20, there is provided an elongated opening 37, and the end walls 38 and 39 of the opening 37 are V-shaped, and this opening 37 as well as the end walls thereof are of the same size and configuration as the opening 26, and

end walls

27 and 28 thereof in the plate 19. Also provided in the plate 20 between the opening 37 and the diverging end is an aperture 40 of the same size as the aperture 29 in the plate 19, and inwardly of the notch 36 adjacent the rear end of the plate 20, there is provided a dimple 'or projection 41 of a size tobe received in the recess 30 in the inner surface of the plate 19.

The thread-guiding and

gripping plates

19 and 20 are assembled in abutting side-to-side relationship, as shown in FIGS. 2, 3 and 5, and disposed in the

openings

26 and 37 in the

plates

19 and 20 is the cutting blade 21 having a cutting edge 43 facing toward the

diverging ends

24 and 35 of the

plates

19 and 20, and as best shown in FIGS. 3 and 8, the cutting edge 43 of the blade 21 engages the apexes of the V-shaped end walls as the forward ends of the

openings

26 and 37, while the rear end 44 of the cutting blade 21 engages the apexes of the V-shaped rear end walls of the

openings

26 and 37. This arrangement serves to maintain the cut-ting blade 21 fixed in a substantially horizontal position parallel to the major axes of the

plates

19 and 20, and prevents inadvertent displacement of the cutting blade 21. If desired, however, the V-shaped end walls of the

openings

26 and 37 could be omitted, and the cutting blade 42 positioned loosely therein, or the

openings

26 and 37 provided with dimensions suitable to snugly receive the cutting blade 21. It will be noted that as shown in FIGS. 5 and 9, the cutting blade 21 is of somewhat greater length than the combined thickness of the

plates

19 and 20.

The

plates

19 and 20, as well as the cutting blade 21 are held in assembled relationship by the resilient spring clip 22, which, as best shown in FIG, 10, is generally U-shaped, being provided with a closed end 45 connecting the

legs

46 and 47 thereof, and the leg 46 is provided at the free end thereof with an inturned tab 48, while the leg 47 is provided at the free end with an inturned tab 48 in alignment with the tab 48. With reference to FIGS. 9 and 10, it will be seen that the

legs

46 and 47 are provided with outwardly pro- 4 jecting,

elongated dimples

50 and 51, Which serve to provide inwardly opening

elongated recesses

52 and 53, the purpose of which will be presently described.

As best shown in FIGS. 3 and 5, the resilient clip member 22 partially embraces the

plates

19 and 20, with the closed end 45 of the clip member 22 received in the aligned

notches

25 and 36, the

legs

46 and 47 extending forwardly in engagement with the outer surfaces of the plates 19 and 21), and with the inturned

tabs

48 and 49 received in the

apertures

40 and 29, respectively, to prevent inadvertent displacement of the clip 22. The engagement of the dimple or projection 41 on the inner surface of the plate 20 in the recess or aperture 30 in the inner surface of the plate 19 serves to align the rear ends of the

plates

19 and 20 with the

notches

25 and 36 in alignment, and also with the

openings

26 and 37 in alignment. The dimple 41 and re cess or aperture 30 may, if desired, be omitted or other suitable means for maintaining the

plates

19 and 20 in alignment may be utilized. The engagement of the

tabs

48 and 49 in the

apertures

40 and 29 serve to retain the forward ends of the

plates

19 and 35 in substantial alignment. Since the

leg

46 and 47 of the clip member 22 cover the outer ends of the

openings

37 and 26, respectively, the cutting blade 21 is retained therein with the projecting ends of the blade 21 received in the

recesses

52 and 53, as shown in FIG. 9, and inadvertent displacement or removal thereof is prevented. If, however, it is desired to remove or renew the cutting blade 21, it is only necessary to remove the resilient clip member 22, which serves to expose the

openings

26 and 37, to permit convenient removal of the blade 21, and replacement thereof by a new or sharpened blade.

Since the thread-guiding and gripping

plates

19 and 26 are assembled in face-to-face abutting relationship, the outwardly

diverging ends

24 and 35 thereof will pro-' vide a thread receiving and guiding throat 54 between these diverging ends, and in the use of the thread-cutting attachment of this invention, it is assumed that as shown in FIG. 1, a garment or other workpiece has been provided with a seam or other line of sewing in a conventional manner, and the garment or workpiece 55 with a chain of stitching 56 attached thereto and leading from the upper and lower threads 17 and 18 is pulled outwardly a sufiicient distance to permit reception of the chain 56 or the threads 17 and 18 into the throat 54 between the

plates

19 and 20, and rearward movement of the thread between the

plates

19 and 29 will result in slightly spreading the same against the action of the resilient clip member 22, as clearly shown in FIGS. 1, 8 and 9, until the thread engages the cutting edge 43 of the cutting blade 21, which will result in severing the thread at this point. The chain 56, or portions of the threads attached to the garment 55 may then be manually removed from between the

plates

19 and 20, and the ends of the threads 17 and 18 still received between the

plates

19 and 20 will be releasably held in this position until removed by the operator, or until the com mencement of the succeeding sewing operation. This retaining action of the

plates

19 and 20 prevents inadvertent removal of the upper thread 17 from the eye of the needle 11, or inadvertent loss of the lower thread 18 through the opening in the supporting surface 15 to the underside of the machine. Furthermore, by reason of the excess length of the blade 21 over the com bined thickness of the

plates

19 and 20, these plates may spread a sufiicient distance to accommodate any commonly used size or gauge of thread, and at the same: time provide adequate support for the blade 21.

it will be seen that by the above described invention, there has been provided an extremely simple, yet highly effective threadcutting attachment for sewing machines which may be conveniently attached to a sewing machine, or removed therefrom merely by manipulation of the presser foot clamping screw 14, and without requiring any modification of the sewing machine, or in any way interfering with the normal attachments applied thereto or the operation thereof.

The device comprises only four parts which are releasably held in assembled relationship by the resilient clip member 22, and the cutting blade 21 may be conveniently replaced when dull or otherwise inoperative, and it is further to be noted that the cutting blade 21 is completely protected from inadvertent damage, and is also positioned in such a manner as to preclude injury to the operator. The construction and design of the thread-cutting attachment of this invention permits manufacture and sale thereof for attachment to existing sewing machines without any modification whatsoever, or the device may be applied to new sewing machines as standard equipment thereon.

It will be obvious to those skilled in the art that various changes may be made in the invention without departing from the spirit and scope thereof, and therefore the invention is not limited by that which is shown in the drawings, and described in the specification, but only as indicated in the appended claims.

What is claimed is:

1. A thread-cutting attachment for sewing machines, said attachment comprising a pair of elongated, generally rectangular opposed thread guiding and gripping plates, said plates diverging at one end to provide a thread-guiding throat, said plates having aligned elongated openings disposed lengthwise thereof, a cutting blade disposed in said openings with the cutting edge facing toward said diverging ends, the length of said blade being greater than the combined thickness of said plates, the opposite ends of said plates aligned transverse notches, said plates having aligned transverse apertures therein between said openings and said diverging ends, a clip for yieldably holding said plates in opposed face-to-face relationship and for retaining said blade in said openings, said clip comprising a generally U-shaped resilient member having legs embracing a portion of said plates with the closed end of said member received in said notches and inturned tabs on the free ends of said legs received in said apertures to prevent inadvertent displacement of said member, inwardly opening recesses in said legs for receiving the projecting ends of said blade, and means on one of said plates for removably mounting the same on the presser foot bar of a sewing machine, said last-named means comprising an ear projecting from said one plate, said ear having a slot for receiving a clamping screw, whereby upon pulling a thread into said throat between said plates and into engagement with said blade, said thread will be severed, the ends of the cut thread being releasably retained between said plates.

2. A thread-cutting attachment for sewing machines as defined in claim 1, in which one of said plates is provided with a recess in the inner surface adjacent the notched end, the other plate having a projection on the inner surface adjacent the notched end, said projection being received in said recess to maintain said plates in alignment.

3. A thread-cutting attachment for sewing machines as defined in claim 1, in which the end walls of said openings are V-shaped to engage and retain said blade substantially parallel to the major axis of said plates.

4. A thread-cutting attachment for sewing machines, said attachment comprising a pair of elongated generally rectangular opposed thread-guiding .and gripping plates, said plates diverging at one end to provide a threadguiding throat, said plates having aligned elongated openings disposed lengthwise thereof, a cutting blade disposed in said openings with the cutting edge facing toward said diverging ends, the length of said blade being greater than the combined thickness of said plates, the opposite ends of said plates having aligned transverse notches, said plates having aligned transverse apertures 6 therein between said openings and said diverging ends, a clip for yieldably holding said plates in opposed faceto-face relationship and [for retaining said blade in said openings, said clip comprising a generally U-shaped resilient member having legs embracing a portion of said plates with the closed end of said member received in said notches and inturned tabs on the free ends of said legs received in said apertures to prevent inadvertent displacement of said member, inwardly opening recesses in said legs for receiving the projecting ends of said blade and means on one of said plates for removably mounting the same on the presser toot bar of a sewing machine, whereby upon pulling a thread into said throat between said plates and into engagement with said blade, said thread will be severed, the ends of the cut thread being releasably retained between said plates.

5. A thread-cutting attachment for sewing machines, said attachment comprising a pair of elongated generally rectangular opposed thread-guiding and gripping plates, said plates diverging at one end to provide a thread-guiding throat, said plates having aligned elongated openings disposed lengthwise thereof, a cutting blade disposed in said openings with the cutting edge facing toward said diverging end-s, said plates having aligned transverse apertures therein between said openings and said diverging ends, a clip for yieldably holding said plates in opposed face-toface relationship and for retaining said blade in said openings, said clip comprising a generally U-shaped resilient member embracing a portion of said plates with the closed end of said member disposed opposite said diverging ends and inturned tabs on the free ends of said member received in said apertures to prevent inadvertent displacement of said member and means on one of said plates for removably mounting the same on the presser foot bar of a sewing machine, whereby upon pulling a thread into said throat between said plates and into engagement with said blade, said thread will be severed, the ends of the out thread being releasably retained between said plates.

6. A thread-cutting attachment for sewing machines, said attachment comprising a pair of elongated generally rectangular opposed thread-guiding and gripping plates, said plates diverging at one end to provide a threadguiding throat, said plates having aligned elongated openings disposed lengthwise thereof, a cutting blade disposed in said openings with the cutting edge facing toward said diverging ends, a clip for yieldably holding said plates in opposed .face-to-face relationship, and for retaining said blade in said openings, said clip comprising a generally U-shaped resilient member embracing a portion of said plates with opposed end of said member disposed opposite said diverging ends, means to prevent inadvertent displacement of said member and means on one of said plates for removably mounting the same on the presser foot bar of a sewing machine, whereby upon pulling a thread into said throat between said plates and into engagement with said blade, said thread will be severed, the ends of the cut thread being releasably retained between said plates.

7. A thread-cutting attachment for sewing machines, said attachment comprising a pair of elongated generally rectangular opposed thread-guiding and gripping plates, said plates diverging at one end to provide a threadguidin-g throat, said plates having aligned elongated openings disposed lengthwise thereof, a cutting blade disposed in said openings with the cutting edge facing toward said diverging ends, a clip for yieldably holding said plates in opposed face-to-face relationship and for retaining said blade in said openings, said clip comprising a generally U-shaped resilient member embracing a portion of said plates with the closed end of said end of said member disposed opposite said diverging ends, means to prevent inadvertent displacement of said member and mounting means for said attachment, whereby upon pulling a thread into said throat between said plates and into engagement with said blade, said thread will be severed, the ends of the cut thread being releasably retained between said plates.

8. A thread-cutting attachment for sewing machines, said attachment comprising a pair of elongated generally rectangular opposed thread-guiding and gripping plates, said plates diverging at one end to provide a threadguiding throat, said plates having aligned elongated openings disposed lengthwise thereof, a cutting blade removably disposed in said openings with the cutting edge facing toward said diverging ends and detachable biasing means for yieldably holding said plates in opposed facetoface relationship and for retaining said blade in said References Cited in the file of this patent UNITED STATES PATENTS Silver-man July 12, 1949 Klapper Jan. 6, 1959 OTHER REFERENCES IBM Technical Disclosure Bulletin, Vol. 2, No. 1, June 1959, page 8. (Copy available in Div. 11.)

Claims

1. A THREAD-CUTTING ATTACHMENT FOR SEWING MACHINES, SAID ATTACHMENT COMPRISING A PAIR OF ELONGATED, GENERALLY RECTANGULAR OPPOSED THREAD GUIDING AND GRIPPING PLATES, SAID PLATES DIVERGING AT ONE END TO PROVIDE A THREAD-GUIDING THROAT, SAID PLATES HAVING ALIGNED ELONGATED OPENINGS DISPOSED LENGTHWISE THEREOF, A CUTTING BLADE DISPOSED IN SAID OPENINGS WITH THE CUTTING EDGE FACING TOWARD SAID DIVERGING ENDS, THE LENGTH OF SAID BLADE BEING GREATER THAN THE COMBINATED THICKNESS OF SAID PLATES, THE OPPOSITE ENDS OF SAID PLATES ALIGNED TRANSVERSE NOTCHES, SAID PLATES HAVING ALIGNED TRANSVERSE APERTURES THEREIN BETWEEN SAID OPENINGS AND SAID DIVERGING ENDS, A CLIP FOR YIELDABLY HOLDING SAID PLATES IN OPPOSED FACE-TO-FACE RELATIONSHIP AND FOR RETAINING SAID BLADE IN SAID OPENINGS, SAID CLIP COMPRISING A GENERALLY U-SHAPED RESILIENT MEMBER HAVING LEGS EMBRACING A PORTION OF SAID PLATES WITH THE CLOSED END OF SAID MEMBER RECEIVED IN SAID NOTCHES AND INTURNED TABS ON THE FREE ENDS OF SAID LEGS RECEIVED IN SAID APERTURES TO PREVENT INADVERTENT DISPLACEMENT OF SAID MEMBER, INWARDLY OPENING RECESSES IN SAID LEGS FOR RECEIVING THE PROJECTING ENDS OF SAID BLADE, AND MEANS ON ONE OF SAID PLATES FOR REMOVABLY MOUNTING THE SAME ON THE PRESSER FOOT BAR OF A SEWING MACHINE SAID LAST-NAMED MEANS COMPRISING AN EAR PROJECTING FROM SAID ONE PLATE, SAID EAR HAVING A SLOT FOR RECEIVING A CLAMPING SCREW, WHEREBY UPON PULLING A THREAD INTO SAID THROAT BETWEEN SAID PLATES AND INTO ENGAGEMENT WITH SAID BLADE, SAID THREAD WILL BE SERVED, THE ENDS OF THE CUT THREAD BEING RELEASABLY RETAINED BETWEEN SAID PLATES.