US2358878A - Sewing machine - Google Patents

Description

4 Sheets-Sheet l 20S ./...fl Y .,IIIIIUHHJLU l A Sept. 26, 1944.

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Sept. 26, 1944. J. H.P|KUL 'SEWING MACHINE Filed July 11, 1941 4 Sheets-Sheet 2 INvfN-l'nf MGM,

Sept. 26, 1944. J. H. PIKUI.

SEWING MACHINE Filed July 11, 1941 4 Sheets-Sheet 5 L. .MS

INVENIVUR J. H. PIKUL SEWING MACHINE Filed July 1l, 1941 Sept. 26, 1944.

4 Sheets-Sheet 4 Suv mk Patented Sept. 26, 1944 UNITED A PATENT OFFICE l @2,358,878 y 'I SEWING amounts;` y y Joseph H.-i West Newton, Mass. Application JulyV 11, 1941, serial No. 401,932 Y fel-claims. (ci.112;252) l This invention relates to sewing machines, and.'

especially, although not exclusively, to button hole'.

sewing machines of the type known as straight hole machines, described, for examplein`.1?at` ents Nos. 714,284, November V25, 1'902`;j.749',776',v

January 19, 1904;v 1,088,652, February2'4, 19,14; 1,402,073, January', 1922,. and 1,483,307', February 12, 1924. Y

The invention relates particularly tothrea/dV cutting or trimming mechanisms forv machines fof. this and other types, and has for one object yto provide simple means, operable upon the comple,-

tion of the stitching operation, llrst to settheand the stopping of the machine. In many suchv machines the button hole cutter and theA thread trimmingV cutter arecbliged to operate in intersecting orv closely adjacent paths. Normallyth'e button hole cutter completes its operation and is retracted or raised just priorY to the operation of, the thread cutter, but should the buttonhole cutter be inadvertently jammed in the Vwork andjfail to rise promptly, there is a possibility of its being struck by the thread cutter with resulting damage to `one'or both cutters. The present invention has for another object toprovide button hole and thread cutting mechanism of such character that operation of the thread. cutter is renderedautomatically contingent upon the retraction' of the button hole cutter.

The foregoing and other objects of the invention, together with means whereby the latter may be carried' into ele'ct, will best be'understood from the following description of a preferred embodiment thereofV shown inthe accompanying drawings, this', however, having been 'chosen for purposes of exemplication merely,`since the inven. tion, as defined by the claims hereuntoappended, may be otherwise embodied without departure from the spirit and scope thereof. l In said-drawings: V "f v Fig. 1 is a side elevation, partly broken away, of a machine embodying'the invention,Y certain partswhose particular construction and arrangement are not essential to theunderstanding of the present invention, and which may be substantially as more fully shown-and'described in thel patents above referred to, bein-g omitted for the sakeof simplicity of illustration.

Fig. -2 is a plan view of the machine as shown in Fig. 1.

-Figy 3 is an end elevation, partly broken away, as vviewed' from the left in Figs. 1 and 2.

Fig. 4'is'an end elevation as viewed from the right in Figs. "l and 2.

Fig. 5 is a `fragmentary View of certain parts shown in Fig. 4, showing said parts ina different position,

Figs. 6 and 7 are diagrammatic perspectiveviews illustrating the operation of the combined stitch setter and thread trimmer. l

The machine shownv in the drawings, which, as above stated, may, as to its general organization, be similar to those described in the patents above referred to, comprises a bed I5 from which rises a standard I6 carryingV an overhanging arm I7 spaced above the bed. The work W is carried by a workclamp or holderjcomprisingra clamp "plate land cooperating clamping arms- I9', said needle 20 is carried by a needle bar 23 which is longitudinally and vertically reciprocated, .by means generally indicated at 24, in a needle b-ar guide- 25, means, not shown, being provided` for oscillating said needle bar guide alternately in opposite directions transversely to the direction of lfeed of the Work clamp between successive strokes of the needle to position the depth stitches. The thread t from a suitable source passes, through a take-up 26 and suitable tension devices 27 and 28, to the needle eye, whence it passes through the work and throat plate to the loopers 2l. A main shaft 2 9 journalled in suitable bearings in the Vbed has power-applied thereto by a belt`30 alternatively engageable with fast land'loose pulleys V3| 'and 32 under the control of a belt shifter 33; The

belt shifter 33 constitutes an extension of a stop member or'arm- 34 carried byA an oscillating and longitudinally Vmovablel rock shaft 35,- mounted 1forfkoscillatio'n andA a'limited longitudinal movement in' the V-bed :15. vSlidably mounted in theV stop arm 34 is a stop element or bolt 4| normally urged toward the right in Figs. 4 and 5 by a spring 42. At its end the bolt 4| is formed with a nose 43 which, when the shaft 35 is in the longitudinal position to cause the belt shifter 33 to engage the belt 30 with the loose pulley 32, is in the path of movement of a cam 44 fast on the shaft 29, said cam having a concentric portion a, a rise b, a notch c and a stop shoulder d, arranged to engage the nose 43 in the order. named when the shaft is rotated in the direction of the arrow in Figs. 4 and 5. The nose y43, when in the path of movement of the cam 44, is held in a spring-pressed plunger 45 carried by the upright i6 and engaging the stop arm 34, said plunger tending to turn said arm and the rock shaft 35 in a clockwise direction, as shownin. Figs. 4 and 5, and thereby press the nose 43 against the periphery of the cam 44.

The button hole cutter 50 is carried by a lever journalled on a short stud shaftr 52 supported in the bed, said lever Vhaving an arm 53 carrying at its end a sleeve 54 in which is journalled a stud 55 having at one end a sleeve portion 56 which receives a stud 51 extending inwardly from the stop arm 34. 1

The construction, arrangement and Amode of operation of the parts above referredvto, and certain associated parts, are, or may be, substantially as morer fully described in the above mentioned patents. Associated with the sliding rock shaft 35 is a spring 65 (Fig. 2) surrounding said shaft and interposed between a collar GB'thereof and. one of the bearing b-rackets or ears 61 in which" the fast pulley 3| and moving-'the nose 43 out of the path of movement of the cam 44, said shaft 35 being retained in this position by engagement of a detent 69 with a recess 10 therein. The detent 69 is controlled by mechanism (not shown) associated with the feeding means for the work clamp and adjustable in accordance with the length of the button hole to be sewn, the arrangement being such that just before the conclusion of the sewing cycle, and at about the beginning of the last stitch-forming cycle, the detent 69 is withdrawn from the notch 10, whereupon the spring 65 causes the shaft 35 to be restored to its normal position, thereby shifting the belt 30 from the fast pulley 3| to the loose pulley 32 and bringing the nose 43 into the path of movement of thev cut the button hole slit. Thereafter the nose,43

drops off of the rise b of the cam 44and, under the influence of the spring-pressed-plunger 45,`

enters the notch c, as shown in Fig. 4this movetracted or raised to its original normal position. The nose 43 is thereupon immediately engaged by the stop shoulder d, thereby positively stopping the machine at the completion of the final stitch, the stopping impact being cushioned by a yielding of the bolt 4| toward the left in Fig. 4 against the tension of the spring 42.

In accordance with the present invention, a combined stitch-setting and thread-trimming element is guided in ways in the bed I5 immediately below they throat plate 22 and between the latter and the loopers 2|'. At the completion of the last Stitch-forming cycle, and substantially engagement with the periphery of the latter by' "(Concidentauy With the Stopping 0f the machine said lelement is moved, by means hereinafter den scribed, from its normal retracted position, shown in Fig. 2, into engagement with the thread loop Z which, at this time, is held by one of the loopers 2| and extends from the work about said looper to-the needle 2U, as shown in Fig. 6. The element 15 is formed with a blunt or rounded forward edge e which is intersected by an Vinclined cutting edge f. As Asaid Y element 15 is moved across the throat plate from the normal position shown `in Fig. 2 through the position shown in Fig. 6 into the position shown in Fig. '7, the blunt edge e thereof first engages the leg Z1 of the loop Z leading from the needle, deecting the same, and thereby drawing the other leg l2 leading from the work about the looper 2 I, tensioning lsaid leg l2 and acting to set the last stitch. Thereafter,

as the element 15 moves into the position shown in Fig. 7, the cutting edge f engages the tensioned leg l2 and severs the latter. f

The trimming element or thread engaging member 15 is provided with an opening to receive a stud 16 carried by an arm 11 fast on one end of a rock shaft 18 journalled insuitable bearings in the bed l5 and having secured to its opposite end an arm 19. Pivotally connected to the arm 18 is a link 80 guided on the outer side of the bed on4 a screw 8| projecting from said bed and received ina slot 82 in said link. At its end opposite its connection with the arm 19 the link 8,0 is formed with a notch 83 adapted f tofbe entered by a nose 84 on a collar 85 secured tothest0pbolt4l. l When the nose 43 of the stop bolt,4,l"enters the notch c in the cam .44 under the'inuence of the spring-pressed plunger 45, as above explained, and asA shown in Fig. 4, the nose. 84 enters the notch 83. Thereafter, when the stop Vbolt 4| yields under the impactA of the shoulder d on the nose 43, the link 80 is` moved toward the left in Fig. 4, thereby turning'the shaft 18 and operating the trimming element 15 as above described.

ment causing the buttonhole cutter 5,0 tog-be rel-f1 Should the button hole cutter 50 be jammed in the work, or otherwise fail to rise promptly under the influence of the spring-pressed plunger 45, its connection with the stop arm 34 will prevent the nose 43 from entering the notch c and hold said stop arm in the position shown in Fig. 5. The nose 84 is thereby prevented from entering the notch 83, so that the subsequent yielding of the stop bolt 4| under the impact on the nose 43V of the stop shoulder d (which stop shoulder is of sufficient length to engage said nose 43 even when the stop arm 34 is in the .position shown in Fig. 5) will not produce any movement of the link 80, the trimmer element'15 will not be actuated, and all danger of interference thereof with the jammed button hole cutter is prevented.

Vl. I n a buttonhole sewing machine, a driving sha ftstoplmechanism therefor including a stop l arm movable in one direction into and out of stopping position, said shaft having a stop shoulder and said stop arm having a yielding stop element engageable thereby when in stopping position, means operable when said stop arm is in stopping position, and prior to the engagement of said stop shoulder with said stop element for moving said stop arm in another direction, a buttonhole cutter connected with said stop arm and actuated by the movement thereof in said last named direction, a thread cutter, and means actuated by the yielding movement of said stop element for operating said thread cutter, said last named means including a connection rendered operative or inoperative by the buttonhole cutter actuating movement of said stop arm.

2. In a buttonhole sewing machine, a driving shaft, means for controlling the application of power to and for stopping said shaft including a stop arm having a yielding stop bolt, a cam on said shaft having a stop shoulder, said stop arm being movable out of and into the path of movement of said cam and simultaneously to apply or discontinue the application of power to said shaft, a buttonhole cutter connected with said stop arm and moved therethrough by said cam into projected or cutting position, spring means for retracting said cutter and arm when permitted by said cam, a thread cutter, and means for operating said thread cutter by the yielding movement of said stop bolt when engaged by said stop shoulder, said last named means inoluding an element operatively engageable with a portion of said stop bolt when said stop arm is in a position corresponding to a retracted position of said buttonhole cutter.

JOSEPH H. PIKUL.

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