US2515753A - Barring mechanism for buttonhole sewing machines - Google Patents

Description

July is, 1950 A. R. WOOD 2,515,753

BARRING MECHANISM FOR BUTTONHOLE SEWING MACHINES Filed June 22, 1948 6 Sheets-Sheet 1 IN V EN TOR.

ykfllfiecl ll/00d v WITNESS ATTORNEY July I8, 1950 A. R. WOOD 2,515,753

BARRING MECHANISM FOR BUTTONHOLE SEWING MACHINES Filed June 22, 1948 6 Sheets-Sheet 2 IN V EN TOR.

flzfied j 700001 BY WITNESS? ATTORNEY July 18, 1950 M A. R. OOD 2,515,753

EARRING MECHANISM FOR BUTTONHOLE SEWING MACHINES Filed June 22, 1948 6 Sheets-Sheet 3 INVENTOR.

Byu l/i'ed Wood a? WITNESS:

ATTORNEY July 18, 1950 A. R. WOOD BARRING MECHANISM FOR BUTTONHOLE SEWING MACHINES Filed June 22, 1948 6 Sheets-Sheet 4 a INVENTOR. vqfleol ll/0005 ATTORNEY July 18, 1950 A. R. WOOD 2,515,753

EARRING MECHANISM FOR BUTTONHOLE SEWING MACHINES- Filed June 22, 1948 s Sheets-Sheet s zwsurox.

lflzfiwz Q. "1110001 WITNESS ATIDRNEY July 18, 1950 A. R. WOOD BARRING MECHANISM FOR BUTTONHOLE SEWING MACHINES Filed June 22, 1948 6 Sheets-Sheet 6 INVENTOR. L/I Zfi'ed W000i ATTORNEY Patented July 18, 1950 UNITED STATES PATENT OFFICE EARRING MECHANISM FOR BUTTONHOLE SEWING MACHINES Alfred R. Wood, Bridgeport, Conn, assignorto The Singer Manufacturing Company, Elizabeth, N. J., a corporation .of New Jersey Application June 22, 1948, Serial No. 34,374

4 Claims.

1 This invention relates to Sewing machines and more particularly to sewing machines of the buttonhole type having mechanism whereby the length of the stitches is automatically increased at the end or ends of the buttonhole upon cessation of the feeding movements of the work-clamp for the purpose of producin barrin stitches.

The present invention is an improvement over the barring mechanism disclosed in my prior Patent No. 2,411,493, issued Nov. 19,1946, and it has for its primary object to provide a barring mechanism in which the components thereof remain mutually operatively connected throughout the entire cycle of operation.

In the mechanism disclosed in my prior patent there is a complete separation of certain of the members in the mechanism during the time the said members are being shifted to effect a change in the amplitude of vibration of the needle. The separation of the parts renders the mechanism susceptible of faulty operation particularly during the reconnecting of the parts. This results from the fact that the parts or members to be mutually connected may not be in proper reg-' ister relative to each other and, obviously, when this occurs the instantaneous recoupling of the members is impossible. The fact that the members of the present barring mechanism are notseparated at any time during themachine'cycle renders the same more positive in its action, without any chance of defective operation incident to the interruption of the operative rela: tionship of the parts comprising the mechanism. With my improved barring mechanism, change in the amplitude of vibration of the needle is instantaneous and positive, regardless of whenthe mechanism is actuated in the stitching cycle.

Further advantages and beneficial results in operation will be apparent from the following description of an illustrative embodiment of my invention taken in connection with the accompanying drawings, in which: i

Fig. 1 is a right side elevational view of a portion of a buttonhole sewing machine embodying the present invention, the head of the .machine being sectioned to disclose the needle-bar vibratory frame.

Fig. 2 is a top planview of the bracket-ar of the sewing machine.

Fig. 3 is an enlarged top plan view of the needle-bar vibrating mechanism and the barstitch counting device, showing the relative positions of the component parts thereof when'the machine is producing the side stitches oi'the buttonhole.

Fig. 4 is a view similar to Fig. 3, but with the bar-stitch counting mechanism removed to show more distinctly the details of the needle-bar vibrating mechanism.

Fig. 5 is a view similar to Fig. 3, with the components of the needle-bar vibrating mechanism intheir relative positions at the end of the sidestitching operation and just before the parts are shifted into their barring position.

Fig. 6 represents an enlarged vertical sectional view taken substantially along the line 66, Fig.

2, but with the parts located in the position" shown in Fig. 5.

Fig. 7, is a top plan view similar to Fig. 3, but

with the needle-bar vibrating mechanism in pa; sition to produce the relatively long barringstitches and. the bar-stitchcounting device opf; crating to determine the number of stitches coinprising the bar. I I

Fig. 8 represents an enlargedvertical sectional view taken substantially along the line 8- 8',

Fig. 2.

Fig. 9 is a view similar to Fig. 7, but with the bar-stitch counting device advanced to a posi-;' tion in which it is about to release theneedle-f bar vibrating mechanism from its barring p0 sition, so that said vibrating mechanism can be spring-returned to its side-stitching position.

Fig. 10 represents an enlarged horizontal sec tional view taken substantially along the use l0-!0, Fig. 1, showing in elevation the cam foreffecting an interruption in the feed of the workclamp and forshifting the needle-bar vibrating mechanism for S de-stitching to bar-stitchin' position. v Fig. 11' represents a horizontal sectional view-f taken substantially along the line ll-I I, Fig. 1.: Fig. 12' represents an enlarged sectional V ew" taken substantially along the line l2-l2, Fig. 5.

Fig. 13 represents a sectional View taken sub 7 stantially along the line [3-43, Fig. 3.

Fig. 14 represents a sectional view taken sub;

stantially along the line '|4 |4; Fig. '1.

by spur-gears l5, (5, H and 18, Fig. 2, to a countershaft l9 driven by a belt adapted to run upon a nest of pulleys 25 carried by the countershaft :9. For a detailed description of the mainshaft drive, reference may be made to my U. S. Patent No. 2,338,611, issued Jan. 4, 1944.

The stitch-forming mechanism of the machine includes an eye-pointed threadsca-rrying needle 2!, Fig. 1, carried. in the lower end of a needle-- bar 22 journaled for endwise reciprocatory move? ments in spaced bearings formed in a vibratory needle-bar-gate 23 supported upon pintles 24 within the head 3. The needle-bar 22 may derive its reciprocatory movements from the mainr shaft M by means of any usual or suitable connections therewith. Cooperating with the needle in the formation of stitches is any suitable form of lolo' p-taker (not shown) located beneath the bed The work to be buttonholed is adapted to be held in a work-clamp, Fig. 1, comprising the sual lower workrplate 25 and the upper clampfoot 25, {The work-clamp is slowly moved in step-by-step fashion under the endwise reciproatery and la erall vibratory needle 2!, first away from the machine-frame standard (to the left Fig. 1) and then towards the standard to ause the and seco d rows of side zigz stitches to be laid side by side in the work. The Werk el mp d riv s i s step-by step mov m n rom t usua --feed-e r not sh wn) carried n the we e ot a vertical ed-S af 27 journaled in the machine-frame. The OOImectieh between the work clamp and the fe m and the manner n wh h he f -cam interm t en y ro ate s f ly illust a ed a sc bed in my bo e m t n d prior Pa en o, .4111 93. nclud d n th mechanism f r intermittently rotating the feed-cam is a one- Wey elut Automa ically con r lled means ar pr id d for e de in he one-wa c utch ineifective during certain periods in the button.- holt s cy le s ha th stee-bv-step mo em nt f: the rk-c amp e ati e o th latera y vi aliv needle n be su pended o a short ime in order that a suitable number of barring tit h s. m y be ma e a t e e ds of e b nhe e The riod of he su pensi n f the ne way clu ch is d rm n by the mar ban-stitch counting mechanism later to be dec ed- The automatically controlled means for rendering the one-way clutch ineffective cornprises a spline 28 preferably extending the en.- tire length of the feed-shaft 21 and operatively connected at its lower end to the clutch so that the raising of the spline will shift the clutching elements of the clutch into an ineffective position. The spline is shifted up and down relative to the feed-shaft 2'! by means of a collar 29 (Figs. 6 and 8) slidably mounted on the feed-shaft and secured preferably by screws 30 to the spline 28. Formed in the collar 29 is an annular recess 3| enteredby a roller 32 carried on the inner end of a lifting lever 33 freely pivoted on a fulcrumestud 34 journaled in spaced bearing lugs 35 (Fig. l) integral with the Wall of the bracket-arm I2. The lifting lever 33 is adapted to be actuated in a clockwise direction (Fig. 8) to raise the spline 28 and thereby render the One-Way clutch ineffective, by a vertically disposed rocker 3.6 fixed on the fulcrum-stud 34. The lower end of the vertically disposed rocker is in peripheral contact with a eedam lea c uat n ment i the orm of a two-lobe cam 31 (Fig. 10) which is fast upon the feed-shaft 21. Each lobe of the cam 3'! is cut with a gradual rise 38 terminating in a drop-off 39 so that, as the feed-shaft 2'! is turned, the lower end of the rocker 36 is gradually swung outwardly in opposition to a coil spring 40 (Figs. 1 and 6), which is anchored at one end to an arm M on the bracket-arm l2 and connected at its other end to the lower end of a lever-arm 42 pinned to the fulcrum-stud 34, As the outwardly swinging motion of the rocker .36 is continued, a pawl-lever 43 (Figs. 1, 5, 6 and 8) pivotally carried on the rocker 36 is raised relative to the lifting lever 33 until a step or shoulder 44 formed on the pawl-lever 43 moves above the level of the upper edge of the lifting lever 33 when, under the action of the spring-wire 45, the pawl-lever 43 snaps into a substantially vertical position, i. e. from the position shown in Fig. 3 to that shown in Fig. 5, thereby connecting the lifting lever 33 with the rocker 36. As the feed-shaft v2'1 continues to turn and. th d op-e of e m 3 pa s s by the lower end of the rocker 36, the rocker snaps inwardly under the influence of the coil spring 40 and into a position determined by an adjustable stop 46 carried by the rocker 36. This rapid inward motion of the rocker 36, through the pawl-lever 43 and the lifting lever 33, raises the spline 28 and this forces the clutchelements of the one-way clutch into ineffective position, As explained in my above mentioned Patent No. 2,411,493, when the clutch-elements are in their ineffective position, the feed-shaft is not intermittently rotated, but remains stationary. Thus the work-clamp is not shifted relatively to the laterally vibratory needle.

It will be understood that during the step-bystep movements of the work-clamp the needle 2! is vibrated transversely of the line of movement of the work-clamp, To provide for this, the needle-bar 22 is endwise journaled in the needle-bar-gate 23 supported for vibratory movements on the pintl-es 24. Connected to the upper end of the needle bar-gate 2 3 is one end of an endwise extensible link 46 adjustably connected at its other end to a vibratory lever 47 fulcrumed on a pivot-stud 48 threaded into the bracket-arm l2. The vibratory lever 41 is connected by a link 49 to one end of an actuating rock-lever 50 supported in the slotted upper portion of a fulcrumedisk 5| seated for free turning movement in a socket 52 formed in one end of a fulcrum-carrying slide 53 slidable in .A a guideway 54 formed in the bracket-arm I 2. 'A plate 55 retains the actuating rock-lever 50 and the fulcrum-disk 5! in proper assembled relation in the fulcrum-carrying slide 53. The other end of the actuating rock-lever 50 is connected by a link 56 to one end of an oscillatory actuator-lever 51 (Fig. 4) fulcrurned on a stud 58 threaded intothe bracket-arm I2. 59 connecting the link 56 to the oscillatory actuator-lever 51 is extended at its lower end and has journaled thereon a roller 60 (Fig. 8), which tracks a cam-groove 61 formed in an operating driving element or cam 62 fast upon the countershaft IS; the speed of rotation of which is onehalf that of the arm-shaft l4 during the normal buttonholing cycle. The stud 50' (Figs. 7 and 8) is provided with a roller at its lower end, which roller tracks a guide-slot 5| formed in a angle-bracket 52 secured to the side of the bracket-arm I2. It will be understood from the above description that rotation of the cam A stud lobe.

where one of its drop-offs 39 passes by the 62 will cause the actuator-lever 51 to oscillate of the end of the link 46 on the vibratory-lever 41 permits regulation of the amplitude of vibration of the needle bar-gate 23 and hence the length of the stitches forming the buttonhole.

To effect the production of the barrin stitches during the time that the step-by-step movements of the work-clamp are suspended, the amplitude of the lateral vibrations of the needle is customarily increased preferably to substantially twice that of the lateral vibrations of the needle during the formation of the side stitches. The improvedmeans by which the amplitude ofthe vibration of the needle can be increased operates to effect a shift of the fulcrum-disk 5! lengthwise of the guideway 54; the result being to shift the fulcrum-axis of the actuating rock-lever 5!! and thereby change the effective lengths of the respective lever-arm of the rocklever 50. To this end, the rocker 36 is provided with an extension 63 (Figs. 3, 5, 7 and 9) having pivoted to its free end a latch 64 formed with a vertical shoulder 65 (Figs. 13 and 14); the latch fit being biased downwardly by a coilspring 66 into cooperative relation with one end of a slide-shifting lever 6'! fulcrumed intermediate its ends on a pivot-stud 68. The other end of the slide-shifting lever 61 is forked to engage a roller 69 journaled on a pin ll! extending upwardly from the fulcrum-carrying slide 53. As shown in Fig. 8, the fulcrum-carrying slide 53 is provided with a second roller 'H engaged by the forked upper end of a lever 12 pivoted on the fulcrum-stud 34 and having connected to its lower end the coil-spring it. The coil-spring I3 is provided to yieldingly maintain the fulcrum-carrying slide 53 in its side-- stitching position, shown for example in Fig. 8. From the above, it will be understood that as the feed-shaft is intermittently rotated to impart step-by-step movements to the work-clamp, the cam 3! likewise turns and causes the rocker 36 to turn on its supporting fulcrum-stud 34 (counterclockwise in Fig. 8). As the rocker 36 continues to turn, the rocker-extension 63 moves inwardly, carrying with it the latch M, which latch slides across one end of the slide-shifting lever 5'! (Fig. 3) until its shoulder 65 moves beyond the edge of the lever 6'3. The spring 66 then pulls the latch 54 downwardly so that the slide-shifting lever 6'l becomes latched to the rocker 35, as shown in Fig. 5. The latching together of the lever El and the rocker 36 occurs just before the cam 3'! travels to the point where the lower end of the rocker 35 is in engagement with the high point of the cam- When the cam 31 rotates to the point lower end of the rocker 35, the latter snaps inwardly under the influence of the coil-spring 4!) into a position determined by the adjustable stop 45. During this rapid movement of the rocker 36 the fulcrum-carrying slide is quickly shifted from its side-stitching position (Fig. 3) to its bar-stitching position (Fig. 7). As previously explained, the rapid drop-off of the rocker 36 from the high point on the cam 31 also er fects a shift of the clutch-releasing spline 28; into a position such that the feed-clutch is rendered ineffective and the step-by-step movements of the work-clamp are terminated. It

will be appreciated that the termination of the feeding movements of the work-clamp and the increase in the amplitude of needle-vibration is effected simultaneously, without any hesitation or interruption on the part of either mechanism. This is desirable for the reason that the barring stitches are formed in a neatly stacked arrangement at the end of the buttonhole and are not dispersed in any form of a spread pat-- tern. It will be understood that the shifting from side-stitching position to bar-stitching position can be accomplished with facility in any position of the parts for the reason that the actuating rock-lever 5G is continuously in engagement with its fulcrum-disk 5| and that,

in changing from side-stitching position to barstitching position, the fulcrum disk 5| is merely shifted longitudinally of the guideway 54 by the rapid movement of the rocker 36.

The number of stitches included in each bar is determined by a suitable bar-stitch counting mechanism substantially the same in design as that disclosed in my previously mentioned Patent No. 2,411A93. The present bar-stitch counting mechanism comprises a ratchet-wheel 14 mounted for limited turning movement on the upper end of the fulcrum-stud 58 (Figs. 4 and 9). Interposed between the head of a screw 15 threaded into the end of the fulcrum-stud 58 and the top of the fulcrum-stud 58 is a disk 16 resting upon a coil-spring 'l'l having one of its ends anchored in a hole 18 formed in the stop 79 depending from a cover-plate 8i) and adapted to be clamped in desired set position by a thumb-nut 8i. That portion of the ratchet-wheel it which is normally biased into contact with the adjustable stop '19 comprises an arcuate plate-member 82 (Fig. 9) clamped for circular adjustment by screws 83 in an annular recess 84 formed in the upper face of the ratchet-wheel 'M.

The ratchet-wheel i4 is adapted to be advanced in acounterclockwise direction, as viewed in Figs. 4 and 9 by an actuating pawl 85 pivotally mounted on an extension 86 of the oscillatory actuatorlever 51; the actuating pawl 85- being biased into engagement with the teeth on the ratchet-wheel M by a leaf-spring bl. Cooperating with the actuating pawl 85 in advancing the ratchet-wheel M is a detent-pawl 88 which functions to preclude retrograde turning of the ratchet-wheel. It will be understood that as the actuator-lever 5"; is oscillated about its fulcrum-stud 58 by the cam 62, the actuating pawl 35 is operated in such; a manner as to engage and advance the ratchet- I wheel tooth-by-tooth and that the detent-pawl 88 maintains the ratchet-wheel in its various steps of advancement. After the number of barring stitches to which the adjustable stop lQ'is set has been produced, during which time the ratchetwheel M is being advanced by the actuator-pawl 85, a trip-plate 89 adjustably secured in the recess 84 formed in the ratchet-wheel M is brought into engagement with a pin 99 depending from a crosslever 9| which is pivoted intermediate its ends on a stud 92 threaded into the cover-plate 80.

the action of the actuating pawl 85, swings the cross-lever 9i about its pivot 92 in the direction indicated by the arrow in Fig, 5, thus moving its free end into contact with the upstanding tail portion of the pawl-lever 43. Continued swinging movement of the cross-lever 9| turns the pawl-lever 43, against the action of the spring 45, thereby moving its shoulder id from its position vertically above the lifting lever 33 to the position indicated in dotted lines in Fig. 12. Depending from the cross-lever 91 is a release-pin 93 to which is pivoted, adjacent the cross-lever 9|, a tripfinger 94 slidable between two guide pins 95 and formed at its free end with a wedge or inclined face 98 disposed to slide beneath the latch 64. After the cross-lever 9! has moved the pawl-lever 43 out of operative relation with the lifting lever 33, continued movement of the cross-lever will move the trip-finger 94 in a direction to cause its wedge-shaped end to slide beneath the latch 64 and raise it about its pivot to release the slide" shifting lever El, permitting the coil-spring 3 to rapidly return the fulcrum-carrying slide 53 to its side-stitching position. During the release of the latch 64, the lower end of the release pin 93 is adapted to move into contact with the limb SI of a pawl 98 (Fig. 9) journaled on a ball-stud 99 threaded into the upper end of the rocker 36. Further turning of the cross-lever ill, in response to the step-by-step advance of the ratchet-wheel l4, swings the pawl 98 about the ball-stud 99 causing the limb I of the pawl 98 to release a projection lBl on a reclutching lever Hi2 pivoted at I03 on the bracket-arm l2. When the projection liii is released, the reclutching lever I02, under the influence of a coil-spring Illa, snaps from bar-stitching position (Fig. 9) to side-stitching position (Fig. 3) In moving from bar-stitching position to side-stitching position, a cam-projection its on the reclutching lever H32 engages a tail-member H36 on the ratchet-wheel actuating pawl 85 and shifts the actuating pawl, in opposition to the leaf-spring 81, from its effective position shown in Fig. 9 to its inefiective position shown in Figs. 3 and 5. As shown in Fig. 5, this shifting of the actuating pawl 85 causes it to move into engagement with the detent-pawl 88 and shift the latter against its spring I01 out of engagement with the teeth on the ratchet-wheel Hi. When the ratchet-wheel is thus released from the detent-pawl, the spring I! biases the ratchetwheel in a clockwise direction (Fig. 9) and against the stop 19., whereby the bar-stitch counting mechanism is reset for the subsequent barring operation.

In order to resume the side-stitching operation at the completion of the bar-stitching operation, it is required that the clutch-releasing spline 28 be lowered to permit the clutch-members to assume their wedging relation between the clutchdrum and the live clutch spider, in the manner disclosed in my previously mentioned Patent No. 2,411,493. In the present case, the reclutching lever W2 is fitted with a depending adjustable abutment-screw Hi8, and this screw is adapted to strike the upper end of a spline-depressing bellcrank lever I09 (Fig. 6) when the reclutching lever is released from the pawl 95 at the completion of the barring operation. As the bell-crank lever E09 turns under the blow of the abutmentscrew 108, the horizontal limb of the bell-crank lever (Fig. 6) moves downwardly and a roller I I0 carried at the free end of the horizontal limb of the lever I09 and disposed in the annular recess 3| of the collar 29 slides the collar downwardly on the feed-shaft 21. The collar, through the spline 8 I 28, renders the clutch again effective to turn the feed-cam.

From the above description, it will be understood that I have invented an improved barring mechanism in which a change in the amplitude of vibration of the sewing machine needle is efiected by merely shifting the fulcrum axis about which one of the members or the mechanism is oscillated. The fulcrum for said member is carried on a slide which is automatically moved in one direction and spring returned after the requisite number of barring stitches is made. It .will be appreciated that by supporting the rock-lever 50 in a fulcrum disk 5! such that the rock-lever is never separated from the fulcrum disk, the mechanism to change the amplitude of vibration of the needle can be operated anytime in the buttonholing cycle. Its action in changing the amplitude of needle vibration is instantaneous, it can be performed without a clashing of the parts and with the expenditure of a minimum of effort.

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

l. A buttonhole sewing machine having stitchforming mechanism including a reciprocatory and laterally vibratory needle and barring mechanism for changing the amplitude of vibration of the needle to sew barring stitches at an end of the buttonhole, said barring mechanism comprising, an operating driving element, an actuating rocklever operatively connected to said driving element and to said needle, a shiftable fulcrumsupport for said actuating rock-lever having a side-stitching position and a bar-stitching -position, a fulcrum-carrying slide to which said fulcrum-support is attached, a spring for biasing said fulcrum-carrying slide into one of its positions, releasable connections for moving said slide and thereby said fulcrum-support to the other of its positions against the action of said spring, and trip means for. separating said releasable connections and permitting said spring to return said slide to its other position.

2. A buttonhole sewing machine having stitchiorming mechanism including areciprocatory and laterally vibratory needle and barring mechanism for changing the amplitude of vibration of the needle to sew barring stitches at an end of the buttonhole, said barring mechanism. comprising, an operating driving element, an actuating rocklever operatively connected to said driving element and to said needle, a shiftable fulcrumsupport for said actuating rock-lever having a side-stitching position and a bar-stitching position, a fulcrum-carrying slide to which said fulcrum-support is attached, a spring for biasing said fulcrum-carrying slide in a direction to move said fulcrum-support into its side-stitching position, cam-controlled releasable connections for moving said slide and thereby said fulcrum support to bar-stitching position against the action of said spring, a bar-stitch counting device for controlling the number of stitches in the bar, and trip means associated with said bar-stitch counting device for separating said releasable connections and permitting said spring to return said fulcrum-support to its side-stitching position.

3. A buttonhole sewing machine having stitchforming mechanism including a reciprocatory and laterally vibratory needle and barring mechanism for changing the amplitude of vibration of the needle to sew barring stitches at an end of the buttonhole, said barring mechanism comprising, an operating driving element, an actuating rocklever operatively connected to said driving element and to said needle, :3, support for said actuating rock-lever including a fulcrum-disk slotted for slidingly engaging said actuating rock-lever,

a supporting slide on which said fulcrum-disk is to said needle, a fulcrum-carrying slide supported 5 for end'wise movement and having a socket formed therein, a fulcrum-disk rotatably seated in said socket and formed with a slot to slidingly engage said actuating rock-lever, a spring for biasing said fulcrum-carrying slide in one direction, and operative connections for shifting said fulcrumcarrying slide in the opposite direction.

ALFRED R. WOOD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 694,150 Hogan Feb. 25, 1902 1,459,374 Leveque June 19, 1923

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