US2269253A - Piece-end stitching machine - Google Patents

Description

H. coRRALL Erm. 2,269,253

Filed Nov. 13, 1939 5 Sheets-Sheet l Jan. 6, 1942.

l PIECE-END STITCHING MACHINE wfe: 0%

Jan. 6, 1942. H. coRRALL Erm.

PIECE-END STITCHING MACHINEV 5 snets-sneet s4 Filed Nov. 13, 1939 :fumes J/fjyie Jan. 6, 1942. H. coRRALLE-rAL PIECE-END STITCHING MACHINE Filed Nov. 13, 1939 5 Sheets-Sheet 4 and James' JjyI/'e Jan. 6, 1942. H. coRRALL ET Al. 2,269,253

PIECE-END STITCHING MACHINE Filed Nov. 15, 1939 f5 Sheets-Sheet 5 alla? James .yyz'e Patented Jan. 6, 1942\ PIECE-END STITCHING MACHINE Herbert Corrall, St. Alban,V Helensbu1-gh, `and James Begg-ie, Clydebank, Scotland, assignors to The Singer Manufacturing Company,` Elizabeth, N. J., a corporation of-New Jersey Application November 13, 1939, serial No.y 393,996

In Great Britain November14, 1938 11 Claims.

element of a driven gear-train mounted upon thel carriage.

The object of the present invention is to provide a machine of thistype with an automatically operable device whereby the travelling speed of the carriage upon the rails and the work-feeding movements of the feed-dog of the sewing machine are automatically and synchronously retarded for a predetermined period at the start and at the finish of a seam whereby the stitches at the start and ,finish are more closely spaced than those intermediate thereof and the seam consequently reenforced at Athose portions.

With the above and other objects in view, as will hereinafter appear, the invention comprises combinations and arrangements of parts hereinafter set forth, and illustrated in the accompanying drawings of a` preferred embodiment of the invention, from which the several features of the invention and the advantages attainedthereby will be readily understood by those skilled in the art. y

In the accompanying drawings, Fig. 1 is a side elevation of a piece-end stitching machine embodying the invention, inclusivev of the railway upon which travels the carriage supporting the sewingmachine; Fig. 2 is a topplan view of the machine. Fig. 3 is an enlarged detail view of the mechanism for changing the work-feeding movements of the feed-dog and synchronizing the travelling movements of the carriage therewith. Fig. 4 is a disassembled view of certain of the parts shown in Fig. 3. Fig. 5 is a detailed View of the forked escapement lever and escapement wheel. Fig. 6 is a sectional elevation of the change-speed gear, Figs. 'l and 8 represent details thereof and Fig. 9 is a detain view of thebeitshipper and its holdinglatch.

In the preferred embodiment of the invention, as illustrated, I are spaced, horizontal rails of Lecross scetion secured upon the channel crossmembers 2, `one of which is partially shown in` eachfoi Figs. 1 and `2. yThe cross-members 2 Vare supported by leg-members, onegof which is shownin Fig.1.'Ihe rails I aremaintained in spaced relation by tie-rods 4 yone of which is partially shown in Fig. 2. Y

Adapted to freelyr run forward and backward upon the spaced rails I constituting a railway, is a carriage 5 fitted with grooved wheels 6 which rest upon the rails. Mounted upon the carriage 5 is a sewing machine A, preferably of the well known 'Singer Class 81-24 single-thread overedge stitchingL type, more fully illustrated in the U. S. Patent to `I. F. lWebb, No. 1,983,258., of Dec. 4, 1934. This machine is provided with the usual cloth-plate l and amain shaft 8 upon which are mounted thejtight pulley 9 and loose pulley II).

VAn electricmotor M, `for driving the sewing machine A, and for propelling the carriage along the railway is alsown'lounted upon the carriage 5 and has itsgdriving'pulley II connected with the pulleys 9 and I0 of the sewingmachine by means of the belt I2.

As describedpin,our'earlier patent above referred to, B is a, blower suitably mounted upon the carriagey 5 and driven by a belt I3 fromthe motor M. The blower is provided with a tubey I4 which terminates above an inclined chute I5.

The blower ldirectsga blast of air against the f trimmer chute and clears it of trimmings severed fromv Ythe piece-,ends being joined and prevents such trimmings from clogging the stitch-forming and feeding mechanisms of the sewing machine.

DisposedV longitudinally ,of and between` the rails I is an endless chain I6,;a portion of which isishown in Fig, 1. `As vmore fully described in our said patent previously referred to, this chain constitutes an element of an auxiliary feeding mechanism for positively moving the carriage 5 upon the `rails during the stitching operation and for returning the carriage to starting position on said rails after completion ofa stitching 'opera tion. Y

Also pivotally secured upon the carriage vis a manually operable belt-'shipper I'I which is spring-biased rto normally retain the driving belt I2 on the loose pulley I0. A latch-lever I8 retains the belt-'shipper when manually shifted in running position to start the sewing machine. There is also adjustably secured upon one of the rails'a `slotted block I9 having a stop-pin 20 and a tripper-armZl `the rounded upper end of which is in the path of travelling movement of the tail of the latch-lever rISA-to lift it at they end of a sewing operation for release of the belt-shipper Il which shiftsgthe motor-belt I2 from the'tight pulley 9 to the loose pulley I9, thereby stopping the sewing machine. The stop-pin engages the spring-pressed plunger 22 at the lower end of an arm depending from the belt-shipper l1 and prevents overrunning or coasting of the carriage 5 beyond seam-finishing position. A similar stop-block (not shown) is adjustably clamped upon the same rail, near the end from which the sewing starts, having a similar stop-pin in thev path of movement of the spring-pressed plunger 22 which retains the carriage in starting position preparatory to a sewing operation.

The machine is further provided with a feeding mechanism whereby the initial and finishing stitches of a seam may be shortened. As described in our prior patent, previously referred to, the feeding mechanism comprises a Yfeed-dog 23 secured upon the free end of the feed-bar 24 pivotally mounted at 25 upon the feed-rocker 26. The feed-bar is connected by a short pitman 21 with a feed-lift eccentric 28 on the sewing machine main shaft 8. The feed-advance eccentric 29 is connected by a pitman 30 with the bell-crank lever 3|, 32 fulcrumed at 33 on the machine frame. The arm 32 of the ball-crank lever is provided with a curved undercut slot or guideway 34 for the slide-block 35 connected t0 the lower end of a link 36 the upper end of which is connected at 31 to an arm 38 of the feed-rocker 26. As in the device of our prior patent, the slide-block is connected by a link 39 with the lower end of a manually operable plural-armed lever 49 pivotally mounted upon the screw-stud 4| entering the xed arm 42 rising from the sew-ing -machine bed. The plural-armed lever is providedl with an arm 43 terminating in a button 44 for convenient actuation by the operator.

As thus far described the present machine is made substantially in accordance with the disclosure of our prior U. S. Patent No. 2,163,304 previously referred to.

The present machine differs from the machine of our earlier patent in the provision of an mproved construction wherein the stitching speed of the carriage along the railway and the workfeeding movements of the feed-dog of the sewing machine are automatically and synchronously retarded for a predetermined period, without stopping the stitch-forming mechanism, at the start and at the finish of a seam, whereby to form closely spaced or typing stitches at these parts of the seam and to prevent distortion of the joined fabric pieces.

Rising from the carriage 5 (Fig. 6) is a split upright bearing standard 45 in which is journaled a stud-shaft 46 retained in its bearing at one end by a collar 41 secured by a set-screw 48. Secured upon the other end of the studshaft by a pin 49 is a gear 50 upon the hub 5| of which is frictionally mounted al sprocketwheel 52 retained upon said hub by a collar 53 and spring-washer 54 secured upon the reduced threaded end of the stud-shaft 48 by nuts 55. The teeth of the sprocket-wheel 53 are in permanent mesh with the upper flight of the normally stationary chain or feeding element I6 disposed between the rails An idler sprocketwheel 55 (Fig. 1) journaled upon a screw stud 51 xed in an arm 58 extending laterally from the bearing standard 45, maintains the chain IB in mesh with lthe sprocket-wheel 52.

Clamped in the upright standard 45 by the bolts 59 is a stationary bearing-bushing G for the shaft 56, on one end of which shaft is se- (ill cured by set-screw 8| the pinion 62 which meshes with the gear 59 secured upon the shaft 46. Disposed on the other end of the bushing are two spaced ball bearings 63 upon which rotates a planetary pinion carrier or housing 64 of a change-speed gear, e. g., a two-speed gear drive preferably constituted as an epicyclic gear provided with two pairs of planetary pinions. Secured to the housing by screws 65 is a beltwheel 65 connected by a belt 66 with the tight pulley 9 on the sewing machine main shaft 8.

The housing end of the bearing-bushing $9 is formed as a pinion 61 which meshes with a second pinion 68 journaled upon a headed bearing stud 69 entering a threaded aperture in the pinion carrier or housing 64. Journaled for endwise movement upon a bearing 1|), afforded by the hub of the pinion 68, is a third pinion 1I of slightly smaller pitch diameter than that of pinion 63. Pinion 5B is provided with a circular series of apertures 12 adapted to be entered by a coupling-pin 13 fixed in the pinion 1|. Secured upon the exposed face of the pinion 1| by fastening screws 14, one of which is shown in Fig. 6, is a disk 15 freely rotatable upon a necked stud 19 which is pivotally connected to one end of a rock-lever 11, journaled upon a pin 18 passing through ears 19 of the bracket 89 which is fastened upon the inner face of the housing cover 8| by screws 82. Also secured upon the inner face of the housing cover, by screws 83, is a` U-shaped wire spring 84 which urges and maintains the pinion 1| in driving relation with the pinion 53 by means of the coupling-pin 13 entering one of the apertures 12. Pivotally secured upon the other end of the lever 11 is a plunger-stud 85, with a rounded outer end, passing through a bearing lug 85 formed in the housing cover 8|.

Pinions 68 and 1| constitute one of the two pairs of pinions supported on the carrier or housing 64 und maintained in driving relation by the coupling-pin 13. These pinions are adapted to be uncoupled by a selector hereinafter to be described.

Journaled upon a bearing stud 81 entering the rear wall of the .pinion carrier or housing 64 and disposed diametrically opposite the bearing stud 69 of the pinion 68 is another pinion 88 which also meshes with the pinion 61 of the ilxed bearing bushing 60. Journaled upon the hub 89 of the pinion 88 is another pinion 90. Pinions 99 and 1| mesh with the pinion 9| upon the end of the shaft 56. Pinions 38 and 99 constitute the second pair of planetary pinions supported upon the carrier or housing 64. Pinion 90 has formed on the face thereof, remote from the pinion 83, a series of ratchet teeth-92 adapted to be engaged by similarshaped teeth formed on the adjacent face of clutch collar 93. This clutch collar is maintained in driving `relation with pinion 90 by means of circularly disposed coupling pins 94 entering apertures 95 provided by grooves, respectively, in the collar and in the hub 89 of the pinion 88. Entering a central aperture 96 in the stud 89 is the pin 91 of a spring-urged collar 98 provided with a reduced portion 99 having a di'a'metrical slot |00 entered by the crossmember of a U shaped wire spring |9| secured to the inner wall of the-pinion carrier or housing 64 by fastening screws |92. The spring-urged collar 98 with its ratchet teeth constitutes a slipping clutch between the one pair of pinions I88 `and 90 when the other pair of pin-ions, 68 and l1| are. in coupled relation.

By. way of example, the stationary pinion 61 and the pinions 68 and 88, which mesh therewith, may have 28 teeth each. Pinion 90, which is slightly smaller than pinion 88 in pitch-diameter, also has 28 teeth, while pinion 1|, which is smaller than pinion 68 in pitch-diameter, has 27 teeth. Pinion 9| has 29 teeth. Pinions 88 and 90 are, by the spring-pressed ratchet teeth 92, permanently coupled together in one-way driving relationship. Pinions 68 and 1| are coupled together or vuncoupled by the action of the pivoted lever 11 and plunger stud 85.

When the pinions 68 and 1| are uncoupled, th shaft 56 is positively driven at a certain slow speed by the operation of the differential gearing 61, 88, 90, 9| the power being transmitted against the coacting ratchet teeth 92 so that there is no slippage between them. When the coupling pin 13 is thrown in to couple the pinions 68 and 1| together, they take over from pinions 88 and 90 the drive of the shaft 56 and drive the latter at another slow speed which is somewhat faster than the speed of drive through pinions 88 and 90. This overdrive through pinions 68 and 1| simply causes the ratchet-coupled pinions 88 and 90 to slip relatively to one-another in a direction opposite their torque-transmitting direction of axial rotation.

The gear ratios are such that when the pinions 61, 68, 1| and 9| drive the shaft 56', the carriage with the sewing machine A travels twice as fast, and results in stitches twice as long, intermediate the ends of the seam, as when the pinions 61, 88, 90 and 9| drive the shaft 56', producing relatively short stitches at both ends of the seam.

We will now describe the mechanism for automatically operating the selector to synchronize the retarded feed of the carriage 5 with corresponding retarded work-advancing movements of the feed-dog 23 in order to more closely space the stitches.

Secured upon the top of the upright standard 45, for the stud-shaft 56', by the fastening bolts 59, is the seat of a bearing bracket |03 (Fig. 4)

having spaced inclined arms |04, |05 apertured to receive a rook-shaft |06. Secured upon one end of the rock-shaft |06 is an arm |01 whose free end is apertured to receive a pulland pushrod |08 and pivotally connected at one end with the downwardly extending arm 43' of the manually operable plural-armed feed-adjusting lever 43. The connection between the rod |08 and the arm |01 of the rock-shaft 06, is cushioned by two buffer springs |09 retained by collars ||0.

Secured upon the rock-shaft |06 is a depending forked escapement-lever which cooperates with an escapement wheel ||2 unitary with a ratchet wheel 3 mounted upon a bearing stud ||4 entering the depending arm |05 of the bearing bracket |03. Also journaled upon said bearing stud ||4 is an actuator ||5 having a springpressed actuating pawl |6 journaled upon the screw-stud ||1 near the top thereof. A springpressed holding pawl ||8 is mounted upon a screw-stud near the lower portion of the arm |05. Pivotally mounted upon a bearing stud ||9 entering the lateral arm of the actuator ||5 is the upper end of a depending lever or follower |2| whose lower end carries a roller |22 engageable by a tripping device or cam |23 carried by the block |24 adjustably clamped upon the rail by the set screw |25. A coil-wire spring |26 secured at one end to the arm |20 `and its other endto rthe lever |,2I' urges said lever against a stop-block |21 embraced between a guide-plate |28 and an angular extension |29 of the arm |05 and secured to the latter by screws |30. Another coil-wire spring |3| secured at its upper end to the arm |20 and its lower end to the extension |29 urges the lever |2| downwardly so that its roller |22 is normally in the path of the tripping device or cam |23, which is secured upon the block |24 adjustably mounted upon the rail by the screw |25 near the end at which the carriage starts at the beginning of a sewing period. It will be observed that the lever |2|, pivotally mounted upon the bearing stud ||9 is normally maintained, by the action of the coil-wire spring |26, against the stop-block |21 when the carriage 5 travels in the direction indicated by the arrow y rshown in Fig. 1 but that it is free to swing away from said block suiiiciently high for the roller |22 to pass over the high point ofthe cam |23 when the carriage travels in the opposite'direction or that indicated by the arrow z. An ear |28 extending from the plate |28 forms an abutment for the adjustable stop screw ||5 threaded into an ear H5" extending from the actuator |l5.

Also adjustably secured upon the rail (Fig. l) near the end where the carriage stops at the completion of a sewing period, is another slotted block |36 maintained in fixed spaced relation with the slotted block |9 by a bar |31 secured to the blocks by fastening screws |38. Block |36 is fitted with a tripping device or cam |40 similar to the cam |23 also'secured to the rail In the operation of stitching two piece-ends together, these are secured in a customary Inanner upon impaling pins (not shown) in overlapping relation, with the free ends of the fabric pieces disposed between the presser-foot |4| and the cloth plate 1 of the sewing machine A. The electric motor M is then started by a conventional toggle-switch S mounted upon the carriage 5 and, as the driving belt I2 from the motor to the sewing machine is on the loose pulley I0, the carriage 5 with the sewing machine will'remain stationary. When it is desired to begin stitching, the belt |2 is shifted from, the loose pulley l0 to the tight pulley-9 by manual actuation of the shipper |1 which is retained in running position by the latch-lever |8.

When the motor belt is shifted on the tight pulley 9, stitching will begin and, by means of g the driving belt 66 between the tight pulley 9 and the belt-wheel 65 secured to the planetary pinion carrier or housing B4, the speed-reducing gearing will be set in motion and, through the sprocket wheel 52 meshing with the normally stationary chain or feeding element I6, the carriage 5 with the sewing machine A, will be propelled along the rails Under normal conditions, while the carriage and sewing machine are at rest, the slide-block 35 of the `feeding mechanism is so positioned in its guideway 34 (dotted lines in Fig. 3) in the arm 32 of the bell-crank lever 3|, 32 that, when the sewing machine is started, the feed-dog 23 will execute relatively short strokes, Aresulting in closely spaced stitches. The cam |01" holds the plunger-stud pushed in to hold uncoupled the pinions 68, 1| for the slowest or short stitch drive through the pinions 88, 90. As the follower or link |2|, with its roller |22, contacts the tripping device or cam |23, it rides up the incline on said cam thereby turning the actuatorv ||5 until its pawl |I6 drops into a depression formed between successive ratchet-teeth. In the continued travel of the carriage 5, the follower or link |2| will ride and drop off the cam |23 and, due to the forceable depression of the link or follower |2| by the action of the spring |3I, the actuator ||5 (coupled with the ratchet II3 by the pawl H6) will perform a partial rotation and, in so doing, one of the teeth of the escapenient-wheel I I2 will engage one of the arms I|I of the escapementlever carried by the rock-shaft I B6 and thereby impart to the latter a slight rotary movement, which, through the arm IQI will impart an endwise pull to the pushand pull-rod |68 connected to the feed-adjusting lever 43. The slide-block 35 is thus shifted in that portion of the guideway 34 in the feed bell-crank lever 3|, 32 (full lines Fig. 3) to cause the feed-dog 23 to execute relatively long strokes of normal stitch-length. During the slight rotation of the rock-shaft |06, the arm |01 will, with its cam Ill, be shifted to the position shown in Figs. 1 and 6 and thus permit the plunger 85 and lever 'I7 to react under the inuence of the spring 84 and effect the coupling of the pinion 1| to pinion 68 to effect a faster travel of the carriage 5 in the production of relatively long stitches.

As the carriage 5 approaches the end of its range of travel, the depending lever or follower I2I will ride up another tripping device or cam |40, which will again operate the actuator II5 and trip the mechanism to produce relatively short stitches during the completion of the seam.

When the carriage 5 arrives at the end of its range of travel, the latch-lever I8 will be released by engagement of the rounded upper end of the tripper-arm 2| whereby the belt-shipper will be moved to ofi position wherein the belt I2 will be shifted from the tight pulley 9 to the loose pulley IIl to cause the sewing machine to come to rest.

The carriage 5 with the sewing machine A is then returned to its starting position by manual actuation of the chain I6, as fully disclosed in our earlier patent previously referred to.

In the return travel of the carriage to starting position the roller |22 of the lever or follower |2I contacts, respectively, the vertical end walls of the stationary cams Idil and |23 against which it rolls upwardly, in the continued return travel :'.f

of the carriage, until the roller |22 clears, respectively, the high points of said cams when the lever with its roller is returned to vertical position against the block |21 by the coil-wire spring |26.

Having thus set forth the nature of the invention, what we claim herein is:

1. In a travelling sewing machine outfit, a railway, a wheeled carriage on said railway, a sewing machine mounted on said carriage and including stitch-forming mechanism and variable stitch-length work-feeding mechanism, variable speed driving means independent of said variable work-feeding mechanism to propel said carriage along said railway at different speeds, and interconnected governing devices to concomitantly and commensurately vary the work-feeding speed of the sewing machine work-feeding mechanism and the speed at which said carriage is propelled along said railway independently of said work-feeding mechanism.

2. In a machine of the class described the combination with a railway and a wheeled carriage mounted thereon, of a sewing machine mounted on said carriage and including stitch-forming mechanism and variable stitch-length workfeeding mechanism, an electric motor mounted on said carriage for driving said sewing machine and variable speed driving connections between said motor and carriage for propelling said carriage on said railway, and interconnected governing devices for automatically and synchronously changing the rate of travel of said carriage and the work-feeding movements of the feeding mechanism without stopping the stitchforming mechanism.

3. In a travelling sewing machine outfit, a railway, a wheeled carriage on said railway, a sewing machine mounted on said carriage and including stitch-forming mechanism and variable stitch-length work-feeding mechanism, variable speed means independent of said Work-feeding mechanism to propel said carriage along said railway, and automatically governed interconnected devices to concomitantly and commensurately change the length of feed of the sewing machine work-feeding mechanism and the speed of travel of said carriage, at one or more predetermined stations of the latter along said railway.

4. In a machine of the class described the combination with a railway and a wheeled carriage mounted thereon, of a sewing machine mounted on said carriage comprising stitchforming mechanism and variable stitch-length work feeding mechanism including a feed-dog for advancing the work, an electric motor mounted on said carriage for driving said sewing machine, variable speed driving connections with said motor for propelling said carriage on said railway, and interconnected governing means for automatically and synchronously changing the rate of travel of said carriage and the amplitude of the work-advancing movements of said feeddog without stopping said stitch-forming mechanism.

5. In a travelling sewing machine outfit, a railway, a wheeled carriage on said railway, a sewing machine on said carriage, said sewing machine having stitch-forming and work-feeding mechanisms, carriage-propelling mechanism independent of said work-feeding mechanism, means to drive said sewing machine and said carriage propelling mechanism, a tripping device adjustable on and lengthwise of said railway, and means governed by said tripping device to concomitantly and commensurately vary the rate of feed of the sewing machine work-feeding mechanism and the rate of travel of said carriage.

6. In a travelling sewing machine outt, a railway, a wheeled carriage on said railway, a sewing machine mounted on said carriage and including stitch-forming mechanism, work-feeding mechanism and feed-regulating means, variable speed driving mechanism independent of said work-feeding mechanism to propel said carriage along said railway, governing means for said variable speed driving mechanism to vary the rate of travel of Said carriage, and a connection between said last mentioned means and said feed-regulating means whereby they are caused to function concomitantly.

7. A travelling lsewing machine having stitchforming mechanism, a feed-dog, feeding mechanism to cause the feed-dog to intermittently engage the work and feed it a stitch-length, feed-regulating means, a railway, variable speed driving means independent of said ,feeding means to propel said sewing machine along said railway, governing means for said variable speed driving means to change the rate ofy travel of the -sewing machine, and a connection between said last mentioned means and said feed-regulating means to effect a change in stitch-length commensurate with the change in the lrate of travel of the sewing machine. i

8. In a travelling sewing machine, a railway, a wheeled carriage thereon, a sewing machine on said carriage, a motor to drive said sewing machine, and carriage propelling means driven by said motor and including a rgear-train having two pairs of differential epicycloidal gears for driving said carriage at diierent speeds, the slower driving pair of which gears are connected to slip relatively to each other in one direction only, and means to uncouple the faster driving pair of gears.

9. In a travelling sewing machine, a railway, a wheeled carriage thereon, a sewing machine on said carriage, a means driven by said motor and including a gear-trainhaving two pairs of dif*- ferential epicycloidal gears for driving said carriage at different speeds, the slower driving pair of which gears are connected to slip relatively to each other in one direction only, and means governed by a device on said railway to uncouple the faster driving pair of gears.

10. A travelling sewing machine outt having,

in combination, a railway, a sewing machine mounted to travel along said railway and including stitch-forming and work-feeding mechanisms, feed-regulating means, a one-way slow speed drive to propel said sewing machine along said railway at a slow speed, a higher speed drive to propel the -sewing machine along said railway at a higher speed without throwing out the slow speed drive, means to throw in and throw out the higher speed drive, and a feed-regulating connection between said last mentioned means and said feed-regulating means. l

l1. In a machine of the class described the combination with a railway and a 'wheeled carriage mounted thereon, of a sewing machine mounted on said carriage and including stitchforming and work-feeding mechanisms, said work-feeding mechanism including a feed-regulator, an electric motor mounted on said carriage for driving said sewing machine, variable speed mechanism driven by said motor for propelling said carriage on said railway, a rockshaft, an actuator mounted thereon, means mounted on said railway for engaging said actuator and operative connections between said rock-shaft, said feed-regulator and variable speed mechanism. .Y

' HERBERT CORRALL.

JAMES I-IEGGIE.

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