US1344748A - Buttonhole-sewing machine - Google Patents

Description

3 SHEETS-SHEET l.

Patented June 29, 1920.

E. BLALLEN.

BuUoNHoLE SEWING MACHINE.

APPLICATION FILED JULY 26| 1915.

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E. B. ALLEN.

BuTToNHoLE SEWING MACHINE.

APPLICATION FILED JULY 26| 1915.

Patented June 29, 1920.

3 SHEETS-SHEET 2.

` W/ TNESSES:

E. B. ALLEN.

BUTTONHOLE SEWINGMACHINE.

APPLICATION FILED JULY 26, |915.

1,344,748., 4 PawndJune29,192o.

3 SHEETS-SHEET 3.

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By i

UNITED STATES PATENT OFFICE.

EDWARD R. ALLEN, or BRIDGEPCRT, CONNECTICUT, AssIcNoR To THE SINGER MANUFACTURING COMPANY, A CORPORATION or NRW JERSEY,

BUTTONHOLE-SEWING MACHINE.

Application lerd July 26,

are spread laterally for stretching it after the slit is out and preparatory to the stitching upon completion of which the clamp is iinspread and opened for release of the work preparatory to the succeeding buttonhole-producing operation. It has for its particular object the provision of simple and effective means to insure the prompt opening and unspreading of the workholder at the completion ofthe stitching operation.

The present invention is preferably einbodied in a machine of the type represented in my pending application Serial No. $72,333, filed Novemberl, 1914, and coniprising a. cutter-actuating shaft driven independently of the actuating means for the stitcli-foi'ining mechanism through periodical connection with and disconnection from an actuating belt-wheel which is continuously driven. According to said application, the slit-cutting elements are carried by cutter-levers mounted upon atraveling ful.- criim and derive their operative movements from suitable cams upon the cutter-shaft.

The work holder comprises traveling clamp-plates mounted for slight movement toward and from each other and sustaining upper clamping levers carrying clamping feet adapted to coperate with them in gripping the work, the clamping levers beingdepressed by cam projections upon connected sections of a camshaft one of which carries a tappet-arm adapted for engagement by a clamp-closing rook-lever actuated by a cam upon the cutter-shaft. As in my Patent No. 1,240,642, of Sept. 18,

Specification of Letters Patent.

Patented J une 29, 1920.

1915. Serial. NO. 41,884. I

1917, thespreadin'g of' the separable pairs of clamping members of the work-holder is preferably effected by the movement of the traveling support for the cutter-lever fulcrum-pinl In the preferred embodiment of the present invention, one section of the cam-shaft of the work-holder carries a second tappetarm .adapted for engagement to effect the opening .of the work-holder by a tripping pin carried by a sliding support which is connected with a reciprocating bar carrying a spring-pressed angular coupling lever. O ne arm of the coupling lever is formed with a notch adapted to embrace a pin upon an arm of a vibrating angle-lever having a second arm carrying a roller-stud which enters a oam-groove in the actuating beltwheel to which the cam-shaft is adapted to be connected in operating the cutting device. The other arm of the coupling lever is adapted for engagement by a detent-lever having a portion lying in the range of movementl of a reciprocatoiy plunger of the stopmotion which controls the period of action of the stitch-forming mechanism. l

The tripping pin support is normally inactive, and derives an operative reciprocatory movement through the coupling of the connected bar with the constantly 'vibrating lever; and this is effected through the tripping of the detent-lever by the rise of the stop-motion plunger in stopping the stitch-forming mechanism which causes the bar, and with it the coupling lever, to move forwardly, and on return of the coupling lever the engagement of the latter with the detent-lever for effecting the uncoupling of the temporarily connected parts. As shown and described in my said Patent No. 1,240,642, the clamp-spreading device is maintained in spreading position by means of a latch-lever whichaccording to the present improvement is adapted for engagement and retraction by the sliding support for the tripping pin before referred tos for eHecting the unspreading of the work-holder through the action of a suitable spring. The unspreading of the Workliolder is effected by the same means which effects the opening of the Work-holder, both tion in the head 4.

of these actions being produced by an element of the slit-cutting mechanism under control ofthe stop-motion, but independently of the stitch-forming and vfeeding mechanisms.

The invention will be understood by reference to the accompanying (ilrawings, in which Figure 1 is a front side elevation of a buttonhole sewing machine embodying the invention, and Fig. 2 a plan of the same with the bracket-arm removed to expose the parts beneath. Fig. 3 is a bottom view of the main slide-plate ofthe work-holder and a portion of the clamp-spreading means, and Fig. 4 is a detail sectional Velevation of the same. Fig. is a side elevation and Fig, G a rear end elevation of the clamp-opening mechanism. Fig. 7 is a detail elevation of the coupling lever. Fig. 8 is a transverse section showing onepair of the work-holder spreading elements,

As represented in the drawings, the frame of the machine comprises the hollow rectangular base 1 sustaining the bracket-arm comprising the hollow standard 2 and lateral arm 3 terminating in the hollow head 4. Journaled within the base is the main shaft formed with the cranks (3 which are connected by the pitmen 7 with similar cranks 8 of the upper sha-ft 9 ournaled in the arm 8.

The stitch-forming mechanism is constructed substantially in accordance with my Patent No. 1,030,046, of June 18. '1912,the needle mechanism being that of my Patent No. 1,161,277, of November 23, 1915. The needle 10 is carried by the laterally jogging needle-clamp 11 sustained upon the lower end of the vertically reciprocating needle bar 12 which is in practice journaled for rota- T he needle-bar has fixed thereon the collar 18 carrying the lateral stud 14 which is embraced by one end of the pitman 15 whose opposite end embraces the crank-pin 16 upon the crank-disk 17 carried by the actuating shaft 18. This shaft is driven by the shaft 9 through a trammel connection comprising the disks 19 and 20 mounted upon the respective shafts and provided with the usual pin and cross-groove connection through which the shaft 1S derives two rotations for each rotation of the shaft 9b The needle 10 is adapted to c0- operate with the usual looper mechanism located below the work and operatively connected with the mainshaft 5, as shown and described in my said Patent No. 1,030,040.

As shown and described more fully in my reissued Patent No, 14,529, of October 8, 1918, the main-shaft has a driving connection, including the intermeshing bevel pinions 21 and 22 and the intermittently moving gear-'wheel 23 with the feed-wheel 24 which has usual or suitable connections with Ahe longitudinally moving slide-plate 25 and the cross slide-plate 26 mounted thereon.

Upon the cross slide-plate are pivotally mounted by means of studs 27 the usual clamp-plates 27 provided with the lower work-supporting plates 28 upon which the work is clamped by the feet 29 pivotally secured upon the forward ends of the clamparms 30 which are fulcrumed at their opposite ends within the brackets 31 secured upon the clamp-plates 27. The clamp-plates are drawn together by means of the springs 32 having their opposite ends connected respectively with the studs 33 sustained by the clamp-plates and the studs 34 upon projecting lugs of the cross slide-plates; and the clamp-arms 30 are pressed normally upward by means of springs 35 interposed between them and the clamp-plates 27.

Journaled in the bearing blocks 31 are the alined sections 36 of the clamp-operating rock-shaft, each section being provided upon the lower side with the cam projection 37 adapted for engagement with the wearing plate 88 of its respective clamp-arm 30. The rock-shaft sections are provided upon their adjacent ends with the interlocking crankarms and 40, and that at the front side of the machine has in addition the angularly disposed tappet-arms 41 and 42 and the linger-lever 43 by means of which the rockshaft may be turned to depress and release the clamp arms.

Suita-bly journaled at the rear of and above the top of the base 1 is the transverse cutter-shaft 44 carrying upon its forward end the continuously driven belt-wheel 45 embraced by the driving belt 46. Asset forth more fully in my Patent No. 1,048,786, of lloc. 31, 1912, the belt-wheel 45 has the annular rib 47 provided with notches 48 adapted to be entered by the coupling lug 49 upon the slide-,block 50 which is litted within a suitable radial guideway of the disk 51 having its hub 52 secured upon the cutter-shaft, the slide-block being normally pressed outwardly by a spring and maintained in inner inoperative position byengagement of a stud 53 thereon with a cam element 54 upon the controlling lever 55 fulcruinedat 56 upon the bed 1. This coupling device is so constructed that the cutter-shaft is uncoupled from the belt-wheel 45 at the completion of a rotation of the latter.

The connection, therefore, between the cutter operating and clamp closing shaft 44 and the continuously ruiming actuator or belt-wheel 45 is of a one-to-one nature; that is` the shaft 44 is driven through one complete revolution or cycle of motion during' the time the actuator 45 performs one coniplete revolution or cycle of motion. This is an important advantage from the standpoint of high speed operation and is superior to worm and wheel or other speed reducing connections requiring the actuator to perform a plurality of revolutions in order to drive the cutter mechanism through a cycle of operations.

The cutter-shaft is provided with the cutter-actuating` cams 57 and 58 adapted for engagement with the rearward ends of the upper and lower cutter-levers 59 and 60', respectively, carrying the buttonhole cutting elements 61 and 62. The cutter-levers are mounted intermediate their ends upon the itulcrum-pin 68 which is sustained by the slide-block or support 64 pivotally attached by means of the stud-pin 65 with the connecting rod 66 carrying the roller-stud 67 entering the cam-groove 68 oi? the cam-wheel 69 lixed upon the cutter-shaft 44. By the means just described, in the rotation of the cutter-shaft the cutting elements are advanced into register with the needle-opening of the work-holder and closed upon the work.

and then returned into retratted position in a manner well known.

.The cutter-shaft carries a clamp-closing cam 70 adapted for engagement with the rearwardly extending arm of the rock-lever 71 having its hub 72 fulcrumed upon the fixed stud 73 and provided with a forwardly extending arm adapted for engagement with the tappet-arm 41 of the clamp-operating rock-shaft 36. The rock-lever 71 is normally maintained in operative contact with the cam 70 by means of the spring 74. The lateral tappet-arm 41 is in its upper position when the clamp is open preparatory to a buttonhole producing operation, and the tilting of the rock-lever 71 just prior to the closing of the buttonhole cutting elements under the action of the cutter-shaft effects the depression of such tappet-arm to turn the rockshaft 36 and depress the clamp arms,

Vhen the clamp is closed, as represented in Fig. 1, the upwardly extending tappetarm 42 is in backwardly inclined position within the range of movement of the extremity of the trip-rod 75 having its threaded rearward portion adjustably secured by means of the clamp-nuts 76 within the apertured boss 77 of the post 78 with its foot 79 secured upon the slide-bar 80 which is in practice fitted within a suitable guideway formed in the top of the base 1, as shown in my said application Serial No. 87 2,333. The post 78 has upon its rearward edge the lug 81 carrying the screw-stud 82 which is embraced by the apertured lateral boss 83 at one end of a reciprocatory bar 84 which is provided near its other end with the longitudinal slot 85 entered by the fixed supporting stud-pin 86 projecting from the frame-standard 2. The bar 84 is normally drawn backward by a spring 84X.

Pivotally mounted upon the rearward end of the bar 84 by means of the stud-screw 87 is an angular coupling lever formed with the forwardlyextending arm 88 and the depending arm 89. The arm 88 is formed with a wedge-shaped forward end portion adjacent which is the notch or recess 90 in the lower edge. The arm 88 has upon one of its side faces the stud-screw 91 entering and resting upon the bottom of a notch 92 in the upper edge of the bar 84 upon which it is normally pressed by the forwardly extending arm of a spring 93 secured upon said bar by the fastening screw 94.

The notch 90 of the coupling lever arm 88 is adapted to embrace a roller-stud 95 upon the upright arm 96 having its hub 97 fixed upon the rock-shaft 98 which is journaled in the front side wall of the base 1. The rockshaft 98 has fixed upon its outer end the hub 99 of a lateral arm 100 carrying a rollerstud 101 which enters an oval cam-groove 102 formed in the inner face of the beltwheel 45. The arms 96' and 100 with the supporting rock-shaft 98 constitute a constantly vibrating angle-lever adapted to impart to the bar 84, land hence to the trip-rod 75, to--and-iro movements Vwhen the notched lateral arm of the coupling lever is in engagement with the roller-stud 95. It will be noted that the connection between the clamp-opening and unspreading bar 84 and the actuator 45 is of a one-to-one nature, resulting in the performance of one complete cycle of motion by the bar 84 during one revolution of the actuator 45, with advantages similar to those described in connection with the buttonhole cutting and clampclosing mechanisms.

The rearwardly notched lower extremity of the coupling lever arm 89 is adapted to normally engage the forward face of the upright-arm 103 of an angular detent-lever tulcru'med upon the stud-screw 104 tapped into the base 1 and provided with a lateral arm 105 extending beneath the stud-screw 106 andnormally pressed downwardly under the action of the spring 107 having one extremity' engaging the arm 105 of the detentlever and the other extremity attached to the screw 106.

Extending beneath the arm 105 is a triparm 108 rigidly secured by means of the screw 109 upon the block 110 which is slidingly sustained by the stop-motion lever 111 and provided with the lateral tooth 112.

`The stop-lever 111 is fixed upon the rockshaft 113 and is provided with a lateral projection 114 between which and the standard 2 isinterposed the spring 115 by means of which the lever is thrown into a stopping position wherein the tooth 112 is caused to rest upon the eccentric periphery of the disk 116 oi the clutch i'or coupling the main-shaft with the constantly running belt-wheel 117 driven by the belt 118. The stop-motion is constructed and operated substantially as described in my Patent No. 1,024,490, of April 30, 1912. f

At the completion ot a lnittonholeproducing cycle oi" operation of the machine, the bar 34 is in extreme retracted position, the coupling lever-arm S9 being` in engagement with the detent-lever arm 103, and the coupling lever arm 33 being raised out oft operative relation with the constantly re eiprocating roller-stud 95 ot the vibratory lever 96. Upon the rise ot the block 110 under the action of the cam portion o1 the ring 116 upon the tooth 112, the trip-arm rises and tilts the detent-lever 'for disengagement of its arm 103 trom the coupling lever which latter descends under the action ot its spring and engages the roller-stud 95 at the end of its next reciprocation. As thus coupled with the vibratory lever 96, the bar 84 moves forward and carries the trip-rod 75 into operative engagement with the tappet-arm 42 whereby the clamp is opened.

The trip-arm 10S having descended with the tooth 112 when, entering the peripheral notch of the clutch-disk 116 to stop the stitch-forming mechanism, and the detentlever he Ting thus been permitted to return to initial operative position under the action of its spring` 107, the return movement ot the bar 84 causes the rengagement of the coupling lever-arm 89 with the detent leverarm 103 whereby the coupling lever-arm 83 is raised into retracted position and the bar S4 thereby uncoupled from the vibratory lever 96 at the completion of a single operative reciprocation. In the accompanying drawings, the machine is represented at the completion of a stitching period, the stopmotion having operated to arrest the mainshaft 5 and the coupling lever having .immediately assumed operative relation with the vibratory lever 96 in readiness for its operative or clamp-opening movement.

The cross slide-plate 26 has formed in its upper tace a U-shaped slideivay extending toward the front end in which is fitted a correspondingly shaped slide-plate 119 carrying upon the upper face of each ot its lateral members a cam-block 120. The outer cam-edge or each of the blocks 120 is adapted to engage the depending stud 121 upon a block 122 which is adjustably secured by means of screws 123 upon a suitable transverse seat ot each clampplate 27. The cross-member ofi the slide-plate 119 has at its inner edge a substantially circular recess within which is fitted the correspondingly shaped end et a link 124 Whose similar opposite end is litted Within a correspondingly shaped recess in a crank-arm 125 upon the upper end oit' a rocking pin 1.26. The rocking of the pin 126. through the described connections, causes the to-andfro movement of the slide-plate 119 and the consequent operative engagement of the studs 121 with the camsblocks 120 to cause the reciprocal recession and approach of the clamp-plates 27 in opposition to and under the action ot their respective springs 32.

The mechanism for rocking the pin 126 to spread. and unspread the ivorlcclainping clemcuts is similar in general constri'iction to that shown and described in my said Patent No. 1,240,642. The pin 126, which is journaled in an aperture ot the cross slide-plate 26, has liXed upon its lower end the hub l2? of the lateral arm 123 attached to one end of the spring 129 Whose opposite end is attached to a stud 130 upon the plate 26. The hub 12'? is provi-:led also with the oppositely extending rigid arms 131 and 132 disposed at substantially right angles with the arm 128.

The outer extremity of the arm 131 lies Within the range of movement ot' the reciprocating cam-block 133 pivotally mounted by means of the stud-screw 134 upon the head 135 of a rack-bar 136 meshing With the pinion 137 which is mounted upon the fixed stud 13S and meshes in turn with a series of rack-teeth 139 upon the adjacent edge of the traveling tulcrum-block 64 of the slit-cutting mechanism. The body of the cam-block 133 has its upper tace formed at the outer extremity ith a bevel. and a lateral extension 133X thereorn has an abrupt shoulder adapted vfor engagement With the edge of' the arm 131, the cam-block being maintained yieldingly Within the plane ot .movement of the arm 131 by means of the spring 140.

lournaled upon the stud-screw 141 upon the under tace et the slide-plate 26 is a plural-armed latch-lever comprising an arm 142 notched in its outer end to form a detaining shoulder tor the arm 132, a second annularly arranged arm 143 having a lateral finger 144 With beveled extremity for engagement with the beveled face of the cam-block 133, a third arm 145 projecting Within the range of movement of the end of the slide-bar 80, and a fourth arm 1.46 having connected therewith one end ot a spring 14'? whose other end is attached to a stud 143 depending from the slide-plate 26. The clamp-spreading motion of the lever 123, 132, under the influence of the spring 129, is arrested by the stop-pin 149.

1n the advance ot the cutting device, comlirising the cutter-levers with their cutting elements and the traveling fulcrum, into cutting position, the rack-bar 136 recedes from advance position and the cam-block 133 is depressed by engagement of the beveled faces of the extension 133X and the arm 131; and in the retraction ofthe cutting device after a cutting operation, the rack-bar 136 advances and effects the en-A gagement of the abrupt shoulders 133x and 131, thereby turning the pin 126 and through its crank-and-link connection with maintains during the succeeding stitching` operation.

In the advance of the slide-bar 80 with its tripping pin 75 to open the work-clamp, Aits forward extremity engages the arm 145 of the ylatch-lever and turns the latter to disengage the latch-arm 142 from the arm 132. itt the same time the wedge-shaped extremity of the iinger 144 thrusts the cam-block 133 .downwardly to permit the arm 131 to assume normal unspreading position under the action of the spring 129, the turning of the crank-arm 125 thus causing the return shift of the plate 119 to interrupt the forcible engagement of the cam-blocks 120 with the studs 121 so as to permit the separable clamping members to-come together under the action of their respective springs 32.

The actuator for the buttonhole-cutting and clamp-operating devices consists, in the present embodiment of the invention, of the constantly running wheel 45 which performs repeated excursions from any given position during each buttonhole producing cycle; but it is evident that the specific natureof this element is not material to the present invention in certain of its aspects,

so long as it performs its necessary funetion in connection with the movement of the parts which depend upon it for their operation.

It will be observed that in the machine represented in the drawings, the opening, closing, spreading and unspreading of the work-holder are effected by connections with the slit-cutting mechanism which is driven independently of the stitch-forming and feedingmechanisms, and that the closing and opening of the work-holder are effected through one-toone operating connections with the actuating means for the cutting device, these connections being respectively with the constantly driven belt-pulley or driving member 45 and the cam upon the cutter-shaft ordriven member 44 of the actuating means. As set forth in my said Patent No. 1,240,642, a connection is provided between the cam-wheel G9 and the stop-lever 111 for tilting the latter to inaugurate the stitching operation succeeding a slit-cutting operation, the tripping of the stop-motion being effected by a suitable connection ywith the feed-wheel 24.

This machine is of the type designed for working upon firmk material such as leather in which it is customary to cut the buttonhole slit preparatory to the edge stitching operation; but it is obvious that the present improvement is equally adapted to machines designed especially for operation upon cloth wherein the slit-cutting operation usually succeeds the stitching operation. In either case the reciprocating'parts connected with the cutting mechanism are employed to per form initial and {inal actuations of the clamp-operating and spreading devices; and the timing of operation of the cutting device in relation to that of thestiteh-forming and feeding mechanisms will determine the manner of connecting these reciprocating actuating parts with the parts which they are required to actuate.

It is evident that the present improvement is susceptible of considerable modification within the scope of the present invention and that certain of its features are capable of use separately from others.

Having thus set forth the nature of the invention, iwhat I claim herein is t- 1. In a buttonhole sewing machine, in combination, stitch-forming and feeding mechanisms, a work-clamp, clampfopening means, a slit cutting device, an actuator operative independently of the stitch-forming and feeding mechanismsand independently acting means for establishing a one-to-one operative connection of the clamp-opening means and the cutting device respectively with said actuator.

In 'a buttonhole sewing machine, in combination, stitch forming mechanism, actuating means therefor, a work-clamp, clamp-opening means, a continuously rotating actuator performing repeated idle excursions for each. buttonhole producing cycle and operative independently of the stitch-forming mechanism and its actuating means, means for establishing operative connection between said actuator and the clamp-opening means, and means for interrupting said operative 'connections at the completion of the first working cycle of motion of said actuator. f

3. In a buttonhole sewing machine, in combination, stitch-forming mechanism, a shaft for actuating the same, a stop-motion for controlling its period of action, a workclamp, clamp-opening means, an actuator operable independently of said shaft during stitching periods, and means controlled by the stop-motion for establishing operative connection between said actuator and the clamp-opening means substantially at the time thestitch-forming mechanism is being stopped.

4. In a buttonhole sewing machine, in combination, stitch-forming mechanism, a stop-motion for controlling its period of action, a work-clamp, clamp-opening means,

an actuator, means controlled by the stopmotion for establishing operative connection between said actuator and the clampopening means as the stitch-'forming mechanism is being stopped, and means acting in` dependently of the stop-motion for interrupting said connection.

5. In a buttonhole sewing machine, in combination, stitch-forming and feeding mechanisms, a work-clamp, clamp-opening and closing means, a slit-cutting device, operating means therefor independent oiI the stitch-forming and feeding mechanisms, and operative connections between said operating means and the clamp-opening and closing means, respectively; the operative connections Jfor the clamp-closing means including a normally stationary element of the slit-cutting device.

6. In a buttonhole sewing machine, in combination, stitch-forming and feeding mechanisms, a stop-motion for determining their period of cooperative action, a workrlamp, clamp-opening and closing means, slit-cutting mechanism, an operative connection between the clamp-closing means and the slit-cutting mechanism Jfor closing the clamp during the action of the slit-cutting mechanism, and means controlled by the stop-motion for establishing` operative connection between the clamp opening means and the cutting mechanism.

7. In a buttonhole sewing machine, in combination, a work-clamp, clamp-opening means, a slit-cutting device, an actuator from which the clamp-opening means and cutting device are normally disconnected, and means for establishing a one-to-one operative connection of the slit-cutting device and the clamp-opening means with said actuator.

8a In a buttonhole sewing machine, in combination, a work-clamp, normally inactive clamp-closing means, an element performing repeated reciprocations during a buttonhole producing cycle, means for coupling the clamp-opening means with said reciprocating element, and means for ei'fecting the uncoupling of said means and element at the completion of the iirst working reciprocation of said element.

9. In a buttonhole sewing machine, in combination, stitch-forming mechanism,` a stop-motion for controlling its period of action, a work-clamp, normally inactive clamp-opening means, a 'reciprocating element operative while the stitch-forming mechanism is at rest, and means controlled by said stop-motion for coupling the clamp- .opening means with said reciprocating element.

l0. In a buttonhole sewing machine, in combination, stitch-forming mechanism, a stop-motion for controlling` its period ot ac-A tion, a work-clamp, normally inactive clamp-opening means, a reciprocating element, means controlled by said stop-motion for coupling the clamp-opening means with said reciprocating element, and means for uncoupling said parts.

ll. In a buttonhole sewing machine, in combination, a work-clamp, normally inactive clamp-opening means, a reciprocating element performing repeated excursions during a buttonhole-producing cycle, a rotary elementirom which the latter derives at regular intervals its reciprocatory movements, and means for coupling the clampopening meanswith said reciprocating element.

l2. In a buttonhole sewing machine, in

combination, stitch-forming mechanism, a work-clamp, normally inactive clamp-open ing means, a slit-cutting device, a continuously driven cam-wheel operative independently oi the stitch-forming mechanism, a vibratory lever deriving from said camwheel uniformly recurring operative movements, means whereby the cutting device is connected with and disconnected from said cam-wheel, and means whereby the clampopening means is coupled to and uncoupled from said vibratory lever.

13. In a buttonhole sewing machine, in combination, a work-clamp, normally inactive clampeopening means including a reciprocatory bar, a continuously driven camwheel, a reciprocating element deriving from said cam-wheel uniformly recurring operative movements, a normally retracted coupling element mounted upon said reciprocatory har, and means for effecting the operative connection of the coupling element with said reciprocating element.

la. In a buttonhole sewing machine, in combination, stitch-forming mechanism, a stop-motion therefor, a work-clamp, normally inactive clamp-opening means including a reciprocatory bar, a continuously driven camwheel, a reciprocating element deriving from said cam-wheel uniformly recurring operative movements, a normally retracted coupling element mounted upon said reciprocatory bar, and means controlled by said stop-motion for effecting the operative connection of the coupling element with said reciprocating element.

l5. In a buttonhole sewing machine, in combination, stitch-forming mechanism, a stop-motion therefor, a work-clamp comprising upper clamp-levers and a cam-shaft provided with a tappet-arm and having an operativek connection with said clamp-levers, a tripping element adapted for engagement with said tappet-arm, a movable support therefor, an endwise movable bar connected with said support, a spring-pressed coupling lever mounted thereon, a continuously driven cam-wheel operative independently ot the stitch-forming mechanism, a vibratory lever deriving from said cam-wheel uniformly recurring operative movements, and means controlled by said stop-motion for effecting the engagement of the coupling lever with said vibratory lever.

1G. In a buttonhole sewing machine, in combination, stitch-forming mechanism, a stop-motion therefor, a work-clamp comprising upper clamp-levers and a cam-shaft provided with a tappet-arm and having an operative connection with said clamp-levers, a tripping element adapted for engagement with. said tappet-arm, a movable support therefor, an endwise movable bar connected with said support, a spring-pressed coupling lever mounted thereon, a continuously driven cam-wheel operative independently of the stitch-forming mechanism, a vibratory lever deriving from said cam-wheel uniformly recurring operative movements, means controlled by said stop-motion for effecting the engagement of the coupling lever with said vibratory lever, and means for insuring the retraction of the coupling lever in the same rotation of said cam-wheel.

li'. In a buttonhole sewing machine, in combination, stitch-forming mechanism, a stop-motion including a cam-wheel and a reciprocating plunger operatively connected therewith, a work-clamp, normally inactive elan'ip-opening means including a movable element, a normally retracted coupling element supported thereby, a reciprocatory element with means for imparting to it uniformly recurring operative movements, and a detent-lever engaging and normally maintaining the coupling element in retracted position and having an arm extending within the range of movement of the reciprocating plunger of said stop-motion.

18. In a buttonhole sewing machine, in combination, a work-clamp, clamp-opening and closing means, a slit-cutting device, a rotary cam-shaft with which the same is operatively connected, a continuously driven actuating wheel, coupling means whereby said cam-shaft is connected with and disconnected from said wheel in a single rotation of the latter, an operative connection between said cam-shaft and the clamp-closing means, and means for establishing operative connection between the clamp-opening means and said rotary actuating wheel.

V19. In a buttonhole sewing machine, in combination, a work-clamp, spreading means therefor, slit-cutting mechanism, a continuously rotating actuator, coupling means for connectingthe cutting mechanism with said actuator, a connection between the cutting mechanism and said spreading means for effecting the spreading of the clamp, and means for connecting the spreading means with. said actuator for unspreading the clamp.

20. In a buttonhole sewing machine, in

combination, a work-clamp, spreading means therefor, slit-cutting mechanism, an actuator therefor, a coupling for temporarily connecting the cutting mechanism with said actuator, and means adapted for operative connection with said actuator respectively through and independently of said cutting mechanism whereby the spreading means are reciprocally operated to effect the spreading and unspreading of the clamp.

21. In a buttonhole sewing machine, in combination, a work-clamp, opening and closing and spreading means therefor, slitcutting mechanism, a continuously ruiming actuator for said slit-cutting mechanism, operative connections between the slitcutting mechanism and the closing and spreading means for effecting closing and spreading of the work-clamp, and operative connections between said actuator and the clamp opening and spreading means for effecting the opening and unspreading of the worlr-claml 22. In a buttonhole sewing machine, in combination, a work-clamp, opening and closing and spreading means therefor, slitcutting mechanism, a constantly running actuator therefor, an automatic throw-out clutch between said slit-cutting mechanism and said actuator, operative connections between a driven element of the slit-cutting mechanism and the clamp-closing and spreading means for effecting the closing and spreading of the clamp, and operative connections between said actuator and the clamp-opening and spreading means for effecting the opening and unspreading of the clamp.

23. In a buttonhole sewing machine, in combination, a work-clamp, spreading means therefor, slit-cutting mechanism, and independent operative connections between the slit-cutting mechanism and the spreading means whereby the clamp is successively spread and unspread.

24. In a buttonhole sewing machine, in combination, a work-clamp, spreading means therefor, a slit-cutting device, actuating means therefor including driving and driven elements with a coupling for establishing and interrupting operative relation` between them, an operative connection between said driven element and the spreadingk means for effecting the spreading of the work-clamp, and a connection between said driving element and the spreading means for effecting the unspreading of the workclamp.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

EDWARD B. ALLEN.

Witnesses STANLEY N. SMITH, HERBERT M. BURN.

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