US2374043A - Sewing machine - Google Patents

Description

April 17., 1945. E. SIMMONS ET AL SEWING MACHINE 5 Sheets-Sheet 1 Fil ed Feb. 18, 1942 WII.

April 11, 1945. E. N. SIMMONS ETAL 2,374,043

SEWING MACHINE Filed Feb. l8, 1942 5Sheets-Sheet 2 wa t ZVMM M April 17, 1945. E. N. SIM'MIONS ET AL SEWING MACHINE 5 Sheets-Sheet 3 Filed Feb. 18, 1942 April 1945. E. N. SIMMONS ET AL 2,374,043

SEWING MACHINE Filed Feb. 18,. 1942 5 Sheets-Sheet 4 Y 4 "um. I A I 06m l4 W April 17, 1945. E. N. SIMMONS ET AL SEWING MACHINE 5 Sheets-Sheet 5 Filed Feb. 18, 1942 relatively simple construction is the Patented Apr. 17, 1945 SEWING MACHINE Edward N.

Chicago, 111.; said Simmons Simmons and Donagh F. Dwyer,

Dwyer minor to said Application February 18, 1942, Serial No. 481,386

Claims.

This application is a continuation our copending application Serial No. 380,220, filed February 24, 1941.

The invention relates to sewing machines andv particularly to sewing machines of the hand operated type adapted for the performance of tacking and like operations.

Sewing machines adapted for the performance of tacking and like operations have in the 'past been comparatively complicated in structureso that the cost of such machines has been excessive, and, moreover, such machines have not been constructed so as to attain maximum ease and efficiency of operation, and to attain such ease and efficiency of operation in a machine of a primary object of the present invention.

Sewing machines of the aforesaid character are in the nature of general utility machines in that they must be adapted for the performance of a fairly wide variety of different types of operations, as for example it may be desirable to use a single machine for tacking the cloth or material of a garment in a predetermined relation as a preliminary to the final sewing or seaming of the garment, while in other instances it may be desirable to secure to such a garment a suitable work tag or label, and while these difierent operations may utilize the same manner of stitching or tacking, the conditions under which the operations are performed may-vary quite widely.-

Accordingly it is a further objector this invention to enable a single tacking machine to perform various classes of work with ease and facility. I

Further objects of this invention are to so arrange and dispose the operative parts or elements of the machine as to facilitate and promote rapid and efficient operation of the machine; to coordinate and simplify the manual operations to be performed by an operator in a series of tacking operations; and to enable ad- Justment of the width of the tacking stitch to be readily accomplished.

In many types of sewing machines provision has been made through the medium of a stopmotion mechanism to limit the number of stitches made by the machine in aparticular operation thereof, and in such prior machines the stopmotion mechanism has been of a relatively complicated character and the arrangement thereof has been such that the release means for the stop-motion mechanism was not coordinated with the other elements of the machine.- As a result in part 01' machine.

tion of such prior machines has not been possible in all-instances, and a further object of this invention is to enable the stop-motion mechanism in such a machine to be released in such a manner as to promote rapid and effective use of the A further object of the present invention is to enable the number of stitches made in a particular operation of the machine to be predetermined by a novel stop-motion mechanism, and to attain this end in such a manner,

' once the machine has been automatically stopped at the end of a cycle'of operation, that another cycle of operation may be instituted and also to enable the stitches in such a succeeding cycle of operation to be continuations of and joined to the stitches produced in the preceding cycle of operation of the machine. An object related to the foregoing is to stop the operation of a machine of the aforesaid character in such a manner that operation may thereafter be resumed to form tacking stitches which are continuations of the previously formed stitches, and to arrange the machine so that the needle-thread is severed from the last needle-thread loop only as an incident to the unclamping of the work. A further object related to the foregoing is to enable the needlethread loop to be severed in such a manner as to insure that the thread will remain in the needle as the work is removed from the machine.

In certain instances it is desirable to perform a tacking operation so that the'threads are concealed, or in other words to tack pieces of material together by means of one or more blind stitches, and to enable this to be done by a machine of a simple character is still a further object of this invention. Another object related to the foregoing is to enable such a blind stitching operation to be performed through the use of a it has been found that rapid and eflicient operaas novel work-clamping mechanism which will also function to clamp the work for the performance of what might be termed ordinary tacking operatime.

Other and further objects of the present invention will be apparent from the following description and claims and will be understoodby reference to the accompanying drawings which, by way of illustration, show preferred embodiments and the principle thereof and what we now vconsider to be the best mode in which we have contemplated applying that principle. Other emor equivalent principle may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention and the purview of the appended claims. In the drawings:

Fig. 1 is a side elevational view of a hand opererated sewing or tacking machine embodying the features of our invention;

'Fig. 2 is a iragmental plan section taken along the line 2--2 of Fig. 1 and illustrating the thread severing means;

Fig. 3 is a side elevational view of the side of the machine opposite that shown in Fig. 1, the cover of a gear case appearing therein having been removed;

Fig. 4 is a rear elevational view of the machine with the handle of the actuating mechanism shown in section;

Fig. 5 is a perspective view illustrating the stop plate employed in the present machine as a part of the stop-motion mechanism;

Fig. 6 is a fragmental perspective view illustrating the relationship of the needle, the looper and the thread severing means;

Fig. 7 is a plan sectional view taken substantially along the line 1-1 in Fig. l and illustrating a portion of the work holder;

Fig. 8 is a view similar to Fig. '7 and showing the parts in a different relative position;

Fig. 9 is a fragmental vertical sectional view taken substantially along the line 9-9 in Fig. 4;

Fig. 10 is a fragmental vertical sectional view taken along the line iii-I in Fig. 9;

Fig. 11 is a fragmental side elevational view generally similar to Fig. 1 and illustrating another embodiment of our invention;

Fig. 12 is a fragmental plan sectional view taken along the line 12- in Fig. 11;

Fig. 13 is a fragmental perspective view of the machine shown in Figs. 11 and 12 ;'and

Fig. 14 is a fragmental vertical sectional view illustrating the manner in which the work is associated with the work holder for the performance of blind stitching operations.

In the form disclosed in Figs. 1 to 10 inclusive of the drawings the invention is embodied in the hand operated sewing or tacking machine having a bed ll supported on a base [4. The bed II is relatively long and narrow and has a standard l2 upstanding from the rear end of the bed H so as to support an overhanging bracket arm 13 which projects forwardly from the standard l2 over the bed ll. At the forward end of the arm l3 a vertically extending head 18' is provided in which a needle bar BI is mounted for vertical reciprocation. At its lower end the needle bar i carries an eye-pointed needle M which in the vertical reciprocation of the needle bar is moved toward and away from a rotary chain-stitch looper 42. The looper 42 is adjustably mounted by a set screw 43 on the forward end of a looper shaft 38, and the looper shaft 38 is rotatably mounted in a horizontal position in the bed H. The bed H is formed with an internal vertical clearance opening ll immediately forwardly of the lower end of the standard [2, and the shaft 38 extends rearwardly through the bed so that its rear end projects into a recess 40 formed in the rear end of the bed. The looper shaft 88 is maintained in predetermined longitudinal position in the bed by a collar 39' secured on the shaft within the recess ll'- and a. relatively large crank disk 39 secured as by a set screw 4| to the rear end of the looper shaft within the recess 40. The crank disk 39 is utilized in obtaining vertical reciprocatory movement of the needle bar Si in timed relation to the rotative movement of the Figs. 1, '7 and looper 42 and to this end a generally horizontal rock shaft 48 is mounted in a, horizontal position in a recess 41 in one side of the bracket arm l3. At it rear end the rock shaft 46 has an arm 48 fixed thereto and a connecting link 44 has its upper end secured to the arm 48 by a pivot stud 50 mounted in the arm 48 and embraced by a bearing 48 secured on the link 44. The lower end of the link 44 is connected eccentrically by a bearing stud 45 to the crank disk 39. Thus in each revolution of the looper shaft 38 the link 44 is reciprocated and a rocking movement is imparted to the rock shaft 48. At its other or forward end the rock shaft 46 has an arm 52 secured thereto and a link 53 located within the head l3 forms an operative driving connection between the arm 52 and the needle bar Bl. Hence the needle bar 5! is operated through a reciprocatory stroke each time the looper shaft 38 is rotated through a complete revolution, and through the adjusting screw 43 the looper 42 is adjusted both longitudinally and in a rotative sense so as to cooperate with the needle 8| in forming a chain-stitch.

The thread is supplied from a spool 55 mounted on a stud 54 at the top of the standard 12, the thread in the present instance being indicated' at 56. The thread 58 is led from the spool 55 to a spring tensionlng device 51 and thence to a guide 58 located at the top of, the head 13'. Intermediate the vertical extent of the head l3 a guide pulley 59 may be provided and the thread is led downwardly from the guide 68 beneath the guide pulley 59 and is then lead reversely or upwardly through a thread takeup arm 60 carried by the needle bar 5|. The thread 56 is then led downwardly and through the eye of the needle 6|.

Intermediate the needle BI and the looper 42 a work-supporting plate 62 shown in detail in 8 is secured in stationary relation upon the top of the bed H, the plate 62 being arranged to project forwardly from the bed and over the looper 42. Thus the forward end of the plate 62 forms a part of a housing for the looper 42, there being a shiftable housing member 63 secured as by a hinge to the lower face of the bed I l. The housing 63 may be tipped downwardly to the open position shown in Fig. 3, or upwardly to its closed position shown in Fig. 1. In the downward movement of the needle bar iii the needle 6| passes through an opening 82' formed in the work-supporting plate 62, as shown in Fig. 9, so as to advance the thread 56 into cooperating relation with respect to the looper 42.

Work-supporting and shifting means is provided on the work-supporting plate 62 and as herein shown this means comprises a slide bar 64 longitudinally slotted as at 65 so that retaining and guiding studs 66 may project downwardly therethrough and into the work-supporting plate 62. The studs 66 are so disposed that the slide bar 64 may be shifted along a limited stroke toward and away from the needle opening 82', and

means is provided on the slide bar 84 for clamping and holding the work such as one or more pieces of cloth in a position over the needle opening 62'. In the present instance this workclamping means includes a lower clamping jaw 61 formed from a relatively thin strip of spring steel and fixedly secured to the forward end of the slide bar 64 so as to extend forwardly therefrom and over the needle opening 62'. The work-clamping means also includes a shiftabie upper work-clamping member 10 in the form of end bya screw H on the upper end of a post which is in turn mounted on the rear end. of the slide bar 84. The upper work clamp II slopes. I

so as to slope downwardly at a steep angle and then forwardly in a relation substantially par-- allel to the lower work clamp 81. The lower work clamp 81 has an elongated slot 68 iormed therein through which the needle 8i may pro- Ject, and a similar elongated.slot I2 is formed in the upper work clamp Ill. Thus when the work clamp 10 is actuated soas to elevate its forward end to the dotted line position shown in Fig. l a piece of work such as folded textile fabric or a piece of fabric and a label or tag may be inserted beneath the arm 10 so as to be clamped between the upper clamp 70 and the lower clamp 57 when the clamp 10 is released. Means is-provided for attaining such operation of the work clamp 70 and in the present instance this means comprises a bell crank lever 81 pivoted by a stud 82 on one side of the overhanging bracket arm it. One arm of the bell crank 8| extends downwardly and has a laterally projecting finger 84 formed thereon which proiects beneath the work clamp 10. A coiled torsion spring 83 surrounds an elongated spring strip anchored at its rear lever ll extends through a clearance opening 15 in the work-support! plate 82 and is connected by a link 18 to the upstanding post 69 of the work holder, and pivot mean is provided intermediate the ends of the lever 14 whereby actuation of the lower end of the lever 14 by the cam 13 acts to impart reciprocation to the work holde'r. I

The length oi. the stroke whichis thus imparted to the work holder governs the width of the stitch which is made by the stitch-forming mechanism, and in order that the present machine may have a wide range or utility, the pivot means which provides theintermediate pivot for the lever 14 is arranged for adjustment. As

' shown in Figs. 9 and 10, this pivot means comprises a bearing pivot 11 adjustably secured in a vertically extending slot in the side wall or the bed II. The adjustable mounting of the pivot I1 is attained through oppositely threaded telescoping nuts 18 and 80 which may be clamped into engagement with the. bordering portions of the bed around the slot 18, the bearing pivot 11 being extended through and supported by the adthe mounting stud 82 and acts upon the bell crank 8! to urge the same to the inactive relation shown in full lines in Fig. l. The other arm or the bell crank extends in a rearward direction and forms an operating handle 85 whereby an operator may actuate the bell crank B! to the position shown in dotted outline in'Fig. 1, thereby to release the work clamp 10. Operation-oi the work clamp 70 may be facilitated through the provision of a depending flexible member such as a chain 85', Fig. l,' connected to the rear end of the handle 85 of the lever 8i and extending downwardly for operation by the foot of the operator.

In order that the stitches or successive penetrations of the needle 8! through the work may be Justable mounting which is thus provided. Thus the vertical adjustment of the bearing pivot Tl governs the length of the effective arm of the lever 14 beneath the pivot 11 and correspondingly varies the length of the stroke of the work holder.

In the performance oi a tacking operation-it is desirable that the machine be operated through a plurality of stitch-forming cycles, and that the number of such stitches be limited in each op- 1 eration oi! the machine to thereby. assure unilocated at spaced points, to thereby form proper stitches, means is provided for imparting a reciprocating stroke to the slide baz- 64 and hence to the work holder. The means for imparting means of the stitch-forming mechanism, is

mounted transversely of the bed ii within the recess I i. A helical gear 36 is'fixed on the shaft 35 so as to mesh with a complemental helical gear secured on the looper shaft 38. The ratio or the gears 38-41 is such that the looper shaft 38 is driven through two revolutions each timethe transmission shaft 35 is driven through a single revolution. With this particular ratio in the gearing 3631 the desired reciprocation oi the work holder in timed relation to the operation of the stitch-forming mechanism may be attained by. actuating means carried on the shaft '35. To this end the shaft 35 has a single lobe cam 13 thereon, this can; in the present case bein formed on one or the hubs or the gear at, and the cam 73 is disposed between the bifurcations 15' of a lever 14. The upper end oi the i'ormity in the work produced. This end is usually attained by stop-motion mechanism which is of a relatively complicated charactenbut in acso as to facilitate rapid operation of the ma-,

chine. To accomplish these purposes the present machine embodies a main actuating shaft l5 located transversely of the bed H immediately beneath the column i2, or in other words near the rear end oi the bed. A hand wheel i8 is fixed on one ofthe ends of the shaft I5, and as herein shown the hand wheel is located on the righthand end as. respects an operator stationed in front of themachine. The hand wheel is preferably formed to afiord a flywheel and has an operating crank handle i7 ,mounted thereon.

The crank handle I! is preferabl mounted on.

' a sleeve l8 that is freely rotatable upon a cylindrical shell is threaded as at 20 into the hand wheel l6 adjacent the rim thereof. The handle I1 is utilized, in accordance with the present invention not only to impart rotation to the hand wheel l6, but also to control the stop-motion mechanism which determines the number 01 stitches to be made by the machine in a particular operation thereof. To this end the shell 19 has a plunger 2i mounted therein which is urged toward the machine frame, that is away from the handle H, by a spring 24 mounted within the shell 19 and acting between the flanged end 25 thereof and a shoulder on the plunger 2|. The reduced end 23 of the plunger 2| is connected as by a nut 28 to the sleeve l8 so that the spring 24 urges the handle I? as well as the plunger 2| in a right-hand direction as viewed in Fig. 4.

As hereinbefore pointed out, the present machine is constructed and arranged so that the requisite number of stitches are made in but a single revolution of the operating or actuating shaft l5, and a stop or abutment means is therefore provided on the bed H for engagement by the plunger 2 I In the present instance this abutment means comprises thesegmental plate 22 having an opening 21 therein which surrounds the shaft H5. The plate 22 extends in radial direction from the axis of the shaft l and may be clamped in various positions of circumferential adjustment by a clamping screw 29 which extends through an arcuate slot 28 in the plate 22 and is threaded into the bed Hi. In the form herein shown the plate 22 has an arcuate slot 30 formed therein by a U-shaped rib 3|, Fig. 5, the slot 30 being positioned so that in a clockwise rotation of the hand wheel as viewed in Fig. 1 the plunger 2| will engage the sloped end of the slot 30 to thereby compress the spring 24. This tends to cushion the stopping action, although the movement will continue until the plunger 2| strikes the abutment formed by the closed end of this slot, at which point the plunger will be pressed by its spring 24 into a bore or recess 32 formed in the slot 30. By suitable adjustment of the stop plate 22, the machine operation is terminated at such a point that the needle bar 5| is located at the upper end-of its stroke, thereby to insure that a sufllcient length of thread ex tends beyond the eye of the needle 8| so that upon severance of the thread the end thereof will remain threaded through the needle. When an operator wishes to initiate a further operation of the machine, the handle I! is withdrawn in an axial direction until the plunger has been disengaged from the slot 80, after which the operator may impart rotative movement to the hand wheel through a complete revolution. It will be understood that the spring 24 exerts a substantial endwise force on the handle H tending to return the handle and the stop plunger 2| to their normal positions of Fig. 4. Hence, unless the operator purposely overcomes this force of the spring 24, the plunger 2| will resume its active position as the hand wheel is rotated and at the end of a complete revolution the rotation of the hand wheel IE will be terminated with a cushioned action through the operation of the stop-motion mechanism provided by the plunger 2| and the abutment plate 22.

It has been pointed out that the single revolution of the hand wheel |6 and the actuating shaft I5 causes operation of the stitch-forming mechanism through the desired number of stitches, and this end is attained by interconnection of the shaft l5 with the intermediate transmission shaft 35 inthe proper driving ratio. In the present instance the machine is arranged to produce six needle penetrations or stitches during the one-revolution cycle of the actuating shaft l5, and in accomplishing this result the shaft I5 has a gear 33 fixed thereon which is meshed with a gear 34 fixed on the intermediate transmission shaft 35. These gears are preferably located within a housing 33' disposed on the side of the bed l| opposite from the hand wheel it. By utilizing a gear ratio of 3 to 1 between the gears 33 and 24 the desired number of stitches is attained in each operation of the machine.

While inmost instances the limitation of the number of stitches to be used in tacking material or the like together is desirable, there are many instances where in the Judgment of the operator it may be desirable to continue the tacking operation so as to form a greater number of stitches. The utilization of the machine to attain such operation is facilitated in accordance with the present invention through the provision of a threadsevering means which is operated only when the work is to be removed from the work holder, and thus, even though the operation of the machine vis automatically stopped by the stop-motion mechanism at the end of a predetermined number of stitches, it is possible for the operator to form additional stitches when required by initiating another cycle of machine operation so as to form such additional stitches as a continuation of the previously formed stitching.

Thus, instead of automatically severing the thread at the end of the predetermined number of stitches, the present machine embodies a manually operable thread-severing means which is operated only after the user has decided that the tacking operation is to be concluded. To this end the present 'machine has a threadsevering lever 88 pivoted at 89 intermediate its ends on the bed II and beneath the work-supporting plate 62. One end of the lever 88 is extended laterally as shown at 8| in Fig. 2 so that a thread-severing or shearing end 92 thereof may be shifted from the full line position to the dotted line position of Fig. 2'. This movement is coordinated with the final or stopped position of the looper 42 as determined by the stop-motion mechanism so that the needle-thread limb 56b of the last needle-thread loop is out of the path of the cutting edge 92, but the other or work limb 56a of the last needle-thread loop is located in the path of the cutting edge 92 as indicated in Figs. 2 and 6. Thus the thread is severed close to the work and the balance of the last needlethread loop is of such a length that the thread remains threaded through the eye of the needle 6| during the work changing operation as well as during the initiation of the "nexttacking operation.

The cutting lever 88 is normally biased by spring means 88', Fig, 2, to its inactive full line position of Fig. 2, and is actuated in timed relation with the work releasing lever 8|. This end is attained through a link 88 connected to the arm of the lever 8| and extending downwardly into a slot 88' in the bed II. The lower portion of the link 88 has a sloping cam face 81 thereon which engages with the bottom of the notch 90 formed in the lever 88, and when the lever 8| is operated to release the work clamp I0, the lever 8% is operated to sever the thread. Upon completion of the thread severing operation the work is withdrawn from the work clamp and the lever 8| is permitted to return to its normal position, thereby to permit return of the thread-severing lever 88 by the spring means 88'; and return of the work clamp ill to its full line position of Fig. 1.

In the form herein illustrated in Figs. 1 to 10 the invention is embodied in a relatively small or portable machine adapted for mountingas by legs No on a suitable stand or work bench. when the machine is thus mounted it is located relatively close to the front of the work bench, and the actuating chain 85' is extended downwardly through the work bench for connection with a suitable foot-operated treadle or the like. When the machine is thus mounted the operator may easily and conveniently insert the work into position beneath the work clamp 10, and the actuvenient position for operation through the desired machinecycla, It will beiobserved that the operator with the present machine may release the stop-motion mechanism by the use of the same handle which'is to be thereafter used to drive the machine; and through this arrangement the use of the machine is materially. simplified and the production :rate oi a worker is materially increased.

In Figs. 11 to 14 of the-drawings there is illustrated another embodiment of the invention which in many respects is similar to the embodiment shown in Figs. l t'o '10, but the machine shown in Figs. '11 to 14 is adapted for the performance, of blind-stitching operations in addition to the work which may be performed by the embodiment shown in Figs. 1' to 10. Thusit'will be noted in Fig, 11 that this embodiment of the invention includes a similar-.bed II with an up standing column or standard at the rear end thereof. Means such as an overhanging bracket arm serves to support a head I 9' over the forward end of the bed II and a needle bar 5| reciprocably mounted in the head I9 carries an eyepointed needle 6| for cooperation with a looper 42 rotatably supported in the bed II in substantially the same manner as in the first embodiment. A similar worksupporting plate 62 is provided beneath which a thread-severing lever 88 is disposed for operation in the same manner as in the other embodiment.

A similar slide bar 64 is reciprocable on the I work-supporting plate 62 and at its forward end the slide bar 64 has a relatively wide lower clamp 91' which projects forwardly and beneath the needle BI. The lower clamp 61' is slotted in.a manner substantially similar to that employed with the clamp 61 oi! Fig. 7. At the rear end of the slide bar 04 a post 69 similar to the post 69 of Fig. l is provided, and an upper work clamp I0 substantially similar to the work clamp I0 is secured to the .top of the post 69 by a screw II. The work clamp I0; however, extends forwardly of the machine and upwardly at a slight angle to a point adjacent to the needle 6| at which Point it is bent down asat 10". At the lower end of the section 10" the work clamp I0 is bent forwardly so as to be substantially parallel to the lower clamp 61', and this portion of the work clamp is slotted as at I2 for passage of the needle 6| therethrough'.

'In'the machine shown in Figs. 11 to 14 an in- I tacking may be produced. In the attainment of this result the foot portion 96 oi the clamp 95 has a forward posit oning edge 9'! which bears a particular relation to the path of the needle SI, as will be hereinafter described. Thus, as-

showrl in'detail in Fig. 14, a double thickness of textile fabric may be reversely bent as at 98 to form the cuff of a pair of mens trousers, and

it may bedesirable to stitch the cuff which is thus formed to the leg of the trouser bymeans of a blind stitch. that is a stitch which does not engage the outer thickness of the material of the cuil. Thus the reversely bent portion '98 is in- 'l i, 9 a

, I apnoea I 5 ating handle'l l is' located in anunusually con- 1 serted beneathrthe' lower suriace oi the intermediate clamp-95 and the tree edge of the cuiiis reverselybent in arearward direction sov as to project rearwardly between the upper surface of theinterm'ediatewlamp and the lower surface oi! the uppersclamp. The positioning edge 91 is so located that when two thicknesses .oimaterial are bent around this edge as shown in Fig. 14

the thickness of material which is directly ad iacent the edge 91 is located out or the path of I the needle 9|. Thus when the work holder is in its forward position the needle 0| will penetrate but one thickness of the cloth 0! the cuff, as inposition indicated at-09in Fig. 14, and it will be evident that when this is done the stitches which have been formed are entirely concealed.

' The release of the two clamps I0 and 95 is attained in this embodiment of the invention by a lever 8| similar to that shown in Fig. 1, there being a laterally projecting finger 82 on the lever 9| disposed beneath the work clamp 10'. The

releasing force is thereby exerted upon the clamp I0 and after the clamp I0 has been released, further movement oi! the lever 8| is efi'ective to impart releasing movement to 'the clamp 95.

, This end is attained through a lost motion conmotion formed by a screw and nut device I00 which extends through the clamp I0 and the clamp 95. As shown in Figs. 11 to 13 this screw and nut device comprises the headed bolt IOI extending upwardly through a slot I02 in the clamp. 95, and through a suitable bore in the clamp I0 so that a nut I09 may be threaded onto the bolt above the clamp I0. By adjustment of the screw and nut device the degree of lost motion between the two clamps may be varied as desired.

It will be evident that the work-clamping means of the embodiment shown in Figs. 11 to 14 may also'be used for ordinary tacking operations, in addition to its use in producing blindstitching or tacking, arid to enable the full range of adjustment oi the stroke of the work holder to be attained in such instances the foot portion 99 of the intermediate clamp is preferably slotted in a rearward direction as at 96' at least to a pointibelow the rear end of the slot- I2 of the upper clamp.

It will be evident from the foregoing description that the present invention limits the number of stitches in a novel manner such that an operator may, where desired, continue a tacking operation after automatic termination of the previous cycle of machine operation, and the tacking stitches are continuations of those formed in the previous cycle. The machine of the present invention is such that the thread is severed from the last needle-thread loop only as an incident .to the unclamping of the work, and since the needle is stopped in its uppermost position and the thread is severed on the work limb of the needle-thread loop, the present machine assures that the beginning end of the thread will in every instance be sufliciently' long to insure proper operation of the machine.

It will also be apparent that the present invention enables tacking and like operations to be performed with greater facility and ease. than with prior machines, and, moreover, the present invention'enables wide variety of tacking operations to be performed withbut a sinslemachine. 'I'he'machine of the'present inventio'nis unusually simple in construction andoperation and the novel drivemechanism materially simplifleaand improves not only the construction but alsovthe operation of the stop-motion mechanism,

While we haveillustrated and described soiected embodiments of ourinvention, it is to be "understood that these are'capable of variation and modification and we therefore do not wish to be limited to the precise details set forth but desire to avail ourselves of such changes and alterations as fall within thepurview of the following claims.

We claim:

1. In asewing machine for performing tacking and like operations, a machine frame, stitchforming mechanism comprising a rotary chainstitch looper having a looper shaft upon which said looper is rotatably supported in said machine frame and a reciprocatory needle bar havshaft, meansincluding a cam on said transmission shaft operable to reciprocate said work 7 holder in one direction when said looper shaft operates through a first revolution and in the frame and having a stop-motion mechanism associated therewitli to limit said actuating shaft to a single revolution, speed change, gearing connected between saidfactuating' shaft and said transmission shaft 'operable'in a single revolution of said actuating'shaft' to drive said transmission shaft through a plurality of revolutions equal to one-half the number of stitches desired to be formed in a backing operation of the machine, and a manual operating crank handle on said actuating shaft located at one side of shaft operable to reciprocate said work holder in one direction when said looper shaft operates through a first revolution and in the other direction when said looper shaft operates through a second revolution, an operative connection between said looper shaft and said needle bar for operating'said needle bar in timed relation to said looper shaft, and an actuating shaft having a stop-motion mechanism. associated therewith to limit said actuating shaft to asingle revolution, and speed change gearing connected between said actuating shaft and said transmission shaft and operable in a single revolution of said actuating shaft to drive said transmission shaft through a plurality of revolutions equaLto one-half the number of stitches desired to be formed in a tacking operation of the machine.

2. In a sewing'miachine for performing tacking and like operations, a machine frame having front and rear ends, stitch-forming mechanism comprising a rotary chain-stitch looper located near the front of the machine frame and having a looper shaft extending in a direction from front to rear of the frame and upon which said looper is rotatably supported in said machine frame, and a-reciprocatory needle bar mounted in said frame adjacent the front end thereof and having an eye-pointed needle therein for cooperation with said looper, thread supply means on said frame, a reciprocatory work holder mounted on said frame and adapted to support the work between said needle bar and said looper, an

. actuating means for said needle bar, said looper and said work holder comprising a transmission shaft extending transversely of and mounted in said frame and geared to said looper shaft to drive said looper shaft through two revolutions for each single revolution of said transmission Yil frame. a

3. In a sewing machine for performing tacking said machine frame for operation by an operator stationed in front of the forward end of said and like operations, a bed having a standard, an overhanging bracket arm, a head on said arm, stitch-forming mechanism comprising a recipro cable needle bar mounted in said head and having an eye-pointed needle mounted therein, thread supply means' for said needle, a rotary chain-stitch looper mounted in said bed for cooperation with said needle, a shiftable work holder including a clamp having clamped and unclamped positions, actuating means for said needle bar, said looper and said work holder, thread-severing means including a first lever mounted on a vertical pivot axis on said bed and operable to cut the work-limb of the last needlethread loop, and a common means for unclamping the clamp of said work holder and operating the lever of said thread-severing means through a cutting operation, said common means comprising a second lever mounted on a horizontal pivot axis on said bracket arm and operativeiy engageable with said clamp to release the same, and a link connected to said second lever' for actuation thereby and having a cam surface engagement with said first lever to operate the same through a severing operation when said second lever is operated to release said clamp.

"i. In a sewing machine for performing tacking and like operations, a bed having a work-supporting surface, stitch-forming mechanism comprising a reciprocable' needle bar supported over said bed and having an eye-pointed needle mounted therein, thread-supply means for said needle, a rotary chain-stitch looper mounted on said bed beneath said work-supporting surface for cooperation with said needle, a shiftable work holder, coordinated actuating means for said needle bar, said looper and said work holder,

said work holder comprising a lower clamp member, an opposed upper clamp member movable between clamped and unclamped positions and an intermediate clamp member located between said lower and upper clamp members. and having a work-locating edge disposed in predetermined relation to the path of shifting moveand having an eye-pointed needle mounted therein, thread-supply means for said needle, a rotary chain-stitch looper mounted on said bed beneath said work-supporting surface for cooperation with said needle, a shiftable work holder mounted on saidbed within said throat, and coordinated actuating means for said needle bar, said looper and said work holder. said work holder comprising a lower clamp member, an opposed upper clamp member movable between clamped and unclamped positions and an intermediate clamp member located between said lower and upper clamp members and having a work-locating edge disposed in predetermined relation to the path of shifting movement of said work holder and about which the bight of a folded piece of material may be located for thefcrmation of a blind stitch therethrough by said stitchforming mechanism.

6. In a sewing machine for performing tacking and like operations, an elongated bed having a work-supporting surface adjacent one end thereof, an upwardly projecting standard at the other end of said bed, an overhanging arm projecting fromsaid standard in spaced relation to said bed and over said work-supporting surface to thereby define a throat beneath said arm, a head supported on said arm over said worksupporting surface, stitch-forming mechanism comprising a reciprocable needle bar supported oversaid bed and having an eye-pointed neede mounted therein, thread-supply means for said needle, a rotary chain-stitch looper mounted on said bed beneath said work-supporting surface for cooperation with said needle, a'shiftable work holder mounted on said bed within said throat. and coordinated actuat'ng means for said needle bar, said looper and said work holder, said work holder comprising a lower clamp member, an opposed upper clamp member movable between clamped and unclamped positions and an intermediate clamp member located between said lower and upper clamp members and'having a work- 7 tion with said needle, a work holder shiftable over said work-supporting surface, and coordinated actuating means for said needle bar, said looper and said work holder, said work holder comprising a lower clamp member, an opposed upper clamp member movable between clamped and 'unclamped positions and an intermediate clamp member located between said lower and upper clamp memberg and having a work-locating edge disposed in a predetermined relat.on to the path ofshifting movement of said work holder and about which the bight of a folded piece of material may be located for the formation of a a blind stitch therethrough by said stitch-forming mechanism.

8. In a sewingmachine, a frame having a bed affording a work supporting surface having 'a clearance opening therein, a standard having a bracket in overhanging and spaced relation to said surface and cooperating therewith to define a work receiving throat, stitch-forming means comprising a reciprocable needle bar carrying an eye-pointed needle for movement across said throat and through said clearance opening and thread-manipulating means disposed beneath said clearance opening forstitch-forming cooperation with said needle, a main shaft operatively connected to said needle bar and said thread-manipulating meansto operate the same in timed relation through stitch-forming cycles in whichsaid needle bar reciprocates through a complete stroke each time said main shaft is rotated through one revolution, a reciprocatory' work holder mounted on said bed and adapted to sup associated therewith to limit said actuating shaft' to a single revolution, and speed change gearing connected between said actuating shaft and said transmission shaft and operable in a single revolution of said actuating shaft to drive said transmission shaft through a plurality of revolutions equal to one-half the number of stitches desired locating edge disposed in predetermined relation to the path of shifting movement of sad work such that when two thicknesses of textile fabric clamped between said intermediate clamp and said lower clamp are bent about said work-locating edge the then exposed thickness of fabric is so located that said needle in at least ce tain of its reciprocatory movement will penetrate said then exposed thickness of fabric to form a stitch independent of the other of said thickne s d of fabric.

to be formed in an operation of the machine.

9. In a sewing machine, a frame having a bed affording a work supporting surface having a clearance opening therein, a standard having a bracket in overhanging and spaced relation to said surface and cooperating therewith to..,define a work receiving throat, stitch-forming means comprising a reciprocable needle bar. carrying an eye-pointed needle for movement across said throat and through said clearance opening and thread-manipulating means d sposed beneath said clearance opening for stitch-forming cooperation with said needle. a. main shaft operatively connected to said needle bar and said threadmanipulating means to operate the same in timed relation through stitch-forming cycles, and aci tuating'means for said main shaft comprising an actuating shaft. gearing between said shafts'operable to actuate said main shaft and the associated stitch-forming means through a plurality handle mounted on said hand wheel for imparting rotation thereto and for longitudinal shifting movement relative to said hand wheel, a springpressed stop plunger mounted on said hand wheel, an abutment on said bed in position for engagement by said plunger to terminate rotation of said hand wheel at a particular point after a complete revolution thereof, and means connectiIlg said handle to said plunger to release said lunger from said abutment when said handle is moved longitudinally with respect to said hand wheel to thereby release said hand wheel for rotative movement.

10. In a sewing machine, a frame having a bed affording a work supporting surface having a clearance opening therein, a standard having a bracket in overhanging and spaced relation to said surface and cooperating therewith to define a work receiving, throat, stitch-forming means comprising a reciprocable needle bar carrying an eye-pointed needle for movement across said throat and through said clearance opening and thread-manipulating means disposed beneath said clearance opening for stitch-forming cooperation with said needle, a main shaft operatively connected to said needle bar and said threadaera e-is manipulating means to operate the same in timed relation through stitch-forming cycles, and actuating means for said main shaft comprising an actuating shaft, gearing between said shafts operable to actuate said main shaft and the associated stitch-forming means through a plurality oi stitch-forming cycle in each complete revolution of said actuating shaft, crank means fixed on said actuating shaft for rotating the same, a handle forming part of said crank means and adapted for manual engagement to impart rotative movement to said actuating shaft, said handle being mounted for limited longitudinal shifting movement, a spring pressed plunger mounted on said crank means, an abutment on said bed for engagement by said plunger to terminate rotation of said crank means at a particular point after a complete revolution of said crank means, and means connecting said handle to said plunger to release said plunger from said abutment when said handle is moved in one longitudinal direction to thereby release said crank means for rotative movement.

EDWARD N. SIMMONS.

DONAGH F. DWYER.

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