US2645190A - Control means for buttonholing apparatus - Google Patents

Description

July 14, 1953 W. T. LEONAR D CONTROL MEANS FOR BUTTONHOLING APPARATUS 2 Sheets-Sheet 1 Filed Nov. 3, 1951 M'lliam 2 11; $55 2 QM A'ITORNEY July 14, 1953 w. 'r. LEONARD CONTROL MEANS FOR BUTTONHOLING APPARATUS 2 Sheets-Sheet 2 Filed NOV. 3, 1951 ATToR'N Y Patented July 14, 1953 CONTROL MEANS FOR BUTTONHOLING APPARATUS William '1. Leonard, Rcading la., assignor to Textile Trimming & Boarding Machine 00., Inc., Reading, Pa.,' a corporation of Pennsyl- Vania Application November 3, 1951, Serial No. 254,745

6 Claims; Cl. 112- 68) 1 The present invention relates to control means for buttonholing apparatus, such, for example, as a buttonhole stitching and cutting machine, and, more particularly, to a strand or thread continuity operated arrangement for controlling the cutting instrumentality of buttonholing apparatus.

Machines for automatically stitching button holes are available which perform a complete stitching operation following which the button hole is out. When the thread in the machine breaks, a special repair job on the workpiece is necessary due to the fact that the buttonhole is out before it is fully or properly stitched. The present invention provides a strand or thread continunity operated device which prevents the buttonhole cutting operation if the thread breaks or otherwise loses proper operating tension. Solely by way of example, the thread continuity operated arrangement of the present invention is shown in the setting of a buttonhole sewing machine of a well known type. selected for illustrative purposes is the Singer sewing machine No. 71-101 manufactured by'the Singer Manufacturing Company. A similar machine is the Singer sewing machine No. 71-107.

Parts of these machines which are to be controlled in accordance with the present invention are de provision of a unitary control device of novel form which can be installed in an existing ma chine without, or substantially without, modification thereof.. The invention also resides in the novel cooperation of the device provided by this invention with the mechanism with which it is associated.

The primary object of the present invention is to provide a novel strand or thread cantinuity operated arrangement for controlling operation of a sewing machine.

Another and related object of the invention is to provide novel means for preventing the cutting of a buttonhole in the process of being finished upon breakage of the buttonhole stitching thread. i 1

In the disclosure of The machine 7 2 A'further object of the invention is to provide a unitary device which can be readily installed in an existing buttonhole machine whereby to prevent operation of a part or parts of the existing machine in the event of thread breakage. Other objects and advantages of the invention will, of course, become apparent and immediately suggest themselves to those skilled in the art to which the, invention is directed from a reading of the following specification in connection with the accompanying drawing in which: A

Fig. l is a fragmentary perspective view of a buttonhole stitching and cutting machine including a deviceconstructed in accordance with the present invention;

Fig. 2 is a fragmentary 'view in plan of the machine of Fig. 1 including only parts thereof which are referred to in describing the functioning of the present invention;

Fig. 3 is a fragmentary view inside elevation of the parts of Fig. 2 and;

Fig. 4 is a view in perspective of the device of. I this invention which is to be installed in an.

existing machine.

Referring to the drawing, and for the-present to Fig. l thereof, there is shown a portion of a machine H) for making buttonholes in a work piece such as a shirt. The machine I0 is of standard make, as stated above, and therefore only. the parts of the machine actuated or. controlled in accordance with the present invention will be described in detail. The forwardly extending arm l2 of the machine is provided with a head I 4 which houses the needle bar 16 and its driving mechanism (not shown). The top rear, portion l8 of the arm [4 houses the needle vibrating mechanism and part of a stitch control mechanism not essential to an understand ing of the present invention for controlling certain steps in the stitching process known as barring whereby the ends of the buttonhole are finished with a bar stitch. I

The course of the stitching thread i9 is shown in Fig.1 1 of the drawing. The thread is stored in an unwinder rack (not shown) or any convenient reel and it passes downwardly'through a hole 2| in the top of a thread leader post 22. The thread emerges through a hole 24 and passes to a tension device 26 provided with the usual discs. The tension device 26 is controlled by a rod 28, the purpose of which is not directly concerned with the present invention. From the tension device, the thread goes to a thread guide3l and from there to a tensioning device 33. From the tensioning device 33, the thread I9 goes to a spring takeup 34. A tension thread guide 36 guides the thread (in the absence of the device 38 of the present invention) through a hole in the end of a thread take-up lever 4| and from there into a slot 43 in the face plate of the head I4. From the slot, the thread goes into the eye of the needle 46.

With the device 38 of this invention installed in the machine I0, the thread I9 is led from the thread guide 36 under a hook 5| at the end of the downwardly extending rod 53 of the device 38. The functioning of the device 38 will be described more in detail hereinafter. From the preceding descri tion it will be seen that when the tension of the thread is maintained, the rod 53 will be biased upwardly as viewed on Fig. 1 of the drawmg.

The needle 48 cooperates with a work piece which is moved by a work piece clamping device 56. The latter executes a path which is suitable for stitching the sides and ends of a buttonhole. Since the specific form of work piece clamping device and its function is not directly a part of the present invention, its functioning and control will not be further described.

Cutting of the buttonhole is accomplished by a knife 58 clamped in a knife holder 59. The latter is mounted at the end of a knife bar 63. A downward thrust, for cutting purposes, is imparted to the bares by a knife bar driving lever 65 which is pivoted on a knife bar driving lever hinge screw 68 which is. received in a tapped hole in the arm I2. A knife bar connecting link (not shown) couples the lever 66 to the bar 63. A knife bar driving lever spring H anchored by a knife bar driving spring screw I3, biases the lever 66 and the bar 63 upwardly.

A driving stroke for the knife bar driving lever is imparted by an intermediate knife bar driving lever I6 through an intermediate knife bar driving lever connecting link I8. The latter is provided with a slot 8I which receives a screw stud 83 secured to the lever 66. Pivotal connection for the link I8 is provided by a hinge screw 84. The slot BI and the screw 83 in conjunction with a knife bar disengaging lever 86 provides a controlled lost motion connection. The lever 86 is pivoted, to the link. 18 b means of a hinge screw 88. The lever 76 is pivoted to the machine body (fragmentarily shown) by means of a cap screw.

80. An intermediate knife bar driving lever roller 92, secured to a part of the stop mechanism (not shown), operates the knife driving lever system described above.

The knife bar disengaging lever 86 is provided with a shoulder 94 which can engage the screwv stud 83 to cause the lever 50 to be rocked when the right hand end of the lever '16 rises. This drives the knife 53 downwardly to cut the buttonhole. An arm 55 extending from the knife bar disengaging lever S6 rests on a tongue 96 which extends upwardly from a knife bar disengaging lever catch !0 I. The catch IOI is pivotally mounted at the endof a fixed bracket I93 by means of a hinge screw I06 and a nut I118. The catch IUI, as shown in Fig. 2, is angularly shaped, being composed of two arms III and IIZ. The arm III, as described above, is pivoted on the bracket I03 by means of the hinge screw I05.

The arm I I 2 is provided with a roller [I4 which is periodically engaged by a disengaging lever catch tripping point H6. The latter is carried by a collar H8 mounted on. a shaft I2I which is driven by a feed driving gear I24. The gear I24 meshes with a gear I25 connected to the cycling mechanism of the machine I0. A spring I26 anchored to the bracket I03 serves to bias the knife bar disengaging lever to the left as viewed in Fig. 1. A spring I28 biases the knife bar disengaging lever catch in a clockwise direction as viewed in Fig. 2. A stop I23 for the catch IN is schematically shown.

The parts thus far described are part of the sewing machine for sewing and cutting buttonholes. As pointed out above, the showing of these parts is modified for the sake of convenience of illustration. The unitary control device 33 of novel form, which can be installed in the machine so far described by way of a setting for the present invention, will now be described together with the manner of its functioning in cooperation with the sewing machine parts. Fig. 4 of the drawing will be referred to for the present in describing the device 38. A plate member I is notched as indicated at I43 so that it will fit around the supporting pin for the tension device 26 previously described or any other convenient part of a sewing machine. A hole I46 receives a screw I41 of the machine I0 which supports a thread guide. A downwardly extending bracket I 49 provides pivotal support for a pair of arms I5I and I52. These arms are rigidly connected and are pivoted to the bracket I49 by means of a pintle or hinge screw I54. The arm I5I carries the previously described rod 53 which is provided with the hook 5I.

The arm I52 has an arm I56 pivoted thereon by means of a hinge screw I58. The arm I 56 has laterally extending tongue I59 and a tongue IN. The unitarily joined arms I5I and I52 have a rod 104 connected thereto upon which a counterweight IBS is adiustably slidable. A set screw I63 can be used to fix the position of the counterweight I66.

In operation of the machine I0 with the device 38 installed therein, so long as the thread I! is intact, the arm I5I is raised and the tongue I59 does not interfere with operation of the knife bar disengaging lever 86. With the thread unbroken, when the point I I5 trips the knife bar disengaging lever catch IOI, the tongue 98 is withdrawn which permits the shoulder 94 on the lever 86 to engage the screw stud 83 and effect a buttonhole cutting operation.

When the thread I9 breaks, the arm I5I drops by gravity and the laterally extending tongue I59 moves to the left as viewed in Fig. l to lie over the hinge screw I06. When the disengaging lever catch tripping point H5 moves the catch IOI to shift the tongue 99, the knife bar disengaging lever 86 is prevented from moving under the influence of the spring I26 by engagement of an inturned extension HI with the laterally extending tongue I59 which rests on the hinge screw I06 at this time. The shoulder 84 cannot engage the screw stud 83 so that the lever 66 is not moved to drive the knife bar 63.

The invention claimed is:

l. A device for application to a buttonhole sewing machine having a workpiece cutter to prevent operation of the cutter in the event of sewing thread failure, said device comprising a bracket, means on said bracket to facilitate connection thereof to an existing stationary part of the sewing machine, a pair of rigidly joined arms pivoted to said bracket, said arms being angularly disposed with respect to each other, the first of said arms having a rod secured thereon to extend from said first arm substmtially at a right angle, a hook at the end of said rod for engagement with a tensioned sewing thread whereby to be supported by said thread, a member pivoted to the second of said arms adjacent its free end, said member having an extension substantially aligned with the body of said member, and a tongue extending laterally from said member.

2. A device for application to a buttonhole sewing machine having a workpiece cutter to prevent operation of the cutter in the event of sewing thread failure, said device comprising a bracket, means on said bracket to facilitate connection thereof to an existing stationary part of the sewing. machine, a pair of rigidly joined arms pivoted to said bracket, said arms being angularly disposed with respect to each other, adjustable biasing means associated with said arms, the first of said arms having a rod secured thereon to extend from said first arm substantially at a right angle, a hook at the end of said rod for engagement with a tensioned sewing thread whereby to b supported by said thread, a member pivoted to the second of said arms adjacent its free end, said member having an extension substantially aligned with the body of said member, and a tongue extending laterally from said member.

3. A device for application to a buttonhole sewing machine having a workpiece cutter to prevent operation of the cutter in the event of sewing thread failure, said device comprising a bracket, means on said bracket to facilitate connection thereof to an existing stationary part of the sewing machine, a pair of rigidly joined arms pivoted to said bracket, said arms being angularly disposed with respect to each other, an adjustable counter weight secured to said arms, the first of said arms having a rod secured thereon to extend from said first arm substantially at a right angle, a hook at the end of said rod for engagement with a tensioned sewing thread whereby to be supported by said thread, a member pivoted to the second of said arms adjacent its free end, said member having an extension substantially aligned '"with the body of said member, and a tongue extending laterally from said member.

4. In a buttonhole sewing machine having means to perform a cutting operation on a workpiece, a knife, a first lever for driving said knife, a second lever, means to impart a driving stroke to said second lever, a link pivoted to said second lever, a lost motion connection between said link and said first lever, a member pivoted to said link for locking said lost motion connecton, biasing means for said member, a trip for said memher, a pivotal support for said trip, a tongue on said member, and movable means controlled by thread tension for engagement between said tongue and said pivotal sup-port, means whereby said movable means is prevented from engaging said pivotal support by tension existing in a sewing thread, said movable means having means associated therewith to bias it for engagement with said pivotal support upon thread failure.

5. In a buttonhole sewing machine having means to perform a cutting operation on a workpiece, a knife, a first lever for driving said knife, a second lever, means to impart a driving stroke to said second lever, a link pivoted to said second lever, a slot in said link, a projection from said first lever movable in said slot to. provide a lost motion connection between said link and said first lever, a member pivoted to said link for locking said lost motion connection, a trip for said member, a pivotal support for said trip, a tongue on said member, and movable means controlled by thread tension for engagement between said tongue and said pivotal support, means whereby said movable means is prevented from engaging said pivotal support by tension existing in a sewing thread, said movable means having means associated therewith to bias it for engagement with said pivotal support upon thread failure.

6. In a buttonhole sewing machine having means to perform a cutting operation on a workpiece, a knife, a first lever for driving saiu knife, a second lever, means to impart a driving stroke to said second lever, a link pivoted to said second lever, a lost motion connection between said link and said first lever, a member pivoted to said link for locking said lost motion connection, a trip for said member, a pivotal support for said trip, a tongue on said member, a second member controlled by thread tension and being movable for engagement between said tongue and said pivotal support, means whereby said second member is prevented from engaging said pivotal support by tension existing in a sewing thread, said second member having means associated therewith to bias it for engagement with said pivotal support upon thread failure.

WILLIAM T. LEONARD.

References Cited in the file of this patent IbbOtt Oct. 24, 1944

Images