US1885927A

US1885927A - Lockstitch sewing machine

Info

Publication number: US1885927A
Application number: US169203A
Authority: US
Inventors: Bernard T Leveque
Original assignee: United Shoe Machinery Corp
Current assignee: United Shoe Machinery Corp
Priority date: 1927-02-18
Filing date: 1927-02-18
Publication date: 1932-11-01
Anticipated expiration: 1949-11-01
Also published as: DE492188C; FR651689A; GB285487A

Description

Nov. 1, 1932.

B. T. LEVEQUE LOCKSTITCH SEWING MACHINE 19 27 10 Sheets-Sheet l Filed Feb. 18

Nov. 1, 1932 B. T. LEVEQUE 1,885,927

LOCKSTITCH SEWING MACHINE Filed Feb. 18, 1.927 10 Sheets-Sheet 2 Nov. 1, 1932. B. T. LEVEQUE LOCKSTITCH SEWING MACHINE 1927 10 Sheets-Sheet 3 Filed Feb. 18

m1& Z4953 29am fi Nov. 1, 1932. B. T. LEVEQ'UE LOCKSTITCH SEWING MACHINE 10 Sheets-Sheet 4 Filed Feb. 18, 1927 Nov. 1, 1932. B. T. LEVE UE 1,885,927

LOCKSTITCH SEWING MACHINE Filed Feb. 18. 1927 10 Sheets-Sheet 5 Nov. 1, 1932. B. T. LEVEQUE LOCKSTITCH SEWING MACHINE Filed Feb. 18, 1927 10 Sheets-Sheet 6 Nov. 1, 1932. B. T. LEVEQUE LOCKSTITCH SEWING MACHINE 1o Sheets-Sheet 7 Filed Feb. 18 1927 v ix 7 v Nov. 1, 1932. B. T. LEVEQUE 1,885,927

LOCKSTITCH SEWING MACHINE Filed Feb. 18, 1927 10 Sheets-Sheet 8 1, 1932 B T. LEV EQU'E LOCKSTITCH SEWING MACHINE Newa Filed Feb. 18, 1927 1Q Sheets-Sheet 9 Nov. 1, 1932. B. T. LEVEQUE 1,885,927

LOCKSTITCH SEWING MACHINE Filed Feb. 18, 1927 10 Sheets-Sheet 1O Patented Nov. 1, 1932 UNITED stares smear oFFIcE BERNARD T. LEVEQUE, OF WENHAM, MASSACHUSETTS, ASSIGNOR TO UNITED SHOE MAQHENERY COHPORA'EIGN, OF PATEESQH, NEX JERSEY, CORPORATION OF NEW JnnsnY LOCKSTITGH SEXVING FZAGHINE Application filed February 18, 1927. Serial No. 169,293.

The present invention relates to lockstitch sewing machines and more particularly to machines which employ a hooked needle to draw loops of needle thread through the work and a loop taker in the form of a shuttle or hook to pass a locking thread through the loops of needle thread, which loop taker is necessarily located on the same side of the work as the needle. The invention is herein shown as embodied in a sole sewing machine of the so called McKay type, the hook needle of which is straight and the work support of which consists of a rotatable horn arranged to extend within the shoe and provided at its tip with a needle threading device or whirl for laying the thread in the hook of the needle.

One object of the invention is toproduce a lockstitch machine of the McKay type which may be operated smoothly and quietly at high speeds and which can be stopped even when operating at its highest speed without injurious shock or jar, and which is simple and durable in construction and reliable in operation.

A further object of the invention is to provide in a machine of this type means whereby the machine may bev stopped automatically with the parts in position with the needle thread appearing above the work so that the threads may be cut from above the work preparatory to removing the work from the machine.

Other objects of the invention are to simplify and improve the construction and operation of various mechanisms of shoe sewing machines.

Vdllll these objects in view the invention onsists in the devices, combinations and arangement of parts hereinafter described and iaimed, certain of which while peculiarly dapted for use in sole sewing machines of ..e McKay type, are also capable of use in other types of sewing machines. I

The severa features of the present invention and the advantages attained thereby will be readily understood by those skilled in the art from the following description taken in connection with the accompanying drawings which illustrate the several features of the invention as embodied in a lockstitch McKay sewing machine.

In the drawings, Fig. 1 is a View in side elevation of the complete machine; Fig. '2 is a view in front elevation of the head of the machine with a portion of the horn and the work being operated upon shown in section; Fig. 3 is a view similar to Fig. 2 with the work withdrawn showing. the parts in stopped position; Fig. 4 is a view in front elevation illustrating particularly the mechanism for actuating the shuttle and the work feeding and the presser foot lifting mechanisms; Fig. 5'is a sectional plan view taken on the line 5-5 of Fig. l; Fig. 6 is a view 6 in side elevation of the head of the machine looking from the right; Fig. 7 is a view in site elevation of the head of the machine looking from the left; Figs. 8 and 9 are realand side detail views of a portion of the mechanism for automat-icaily lifting the presser foot upon stopping the machine; Fig. 10 is a detail sectional view taken on the line l0l0 of Fig. 8; Fig. 11 is a view in front elevation showing the take-up mechanism and thread clamp for the needle thread; Fi 12 a view in side elevation, partly in section,'on the line -12l2 of Fig. 11 0f the takeup mechanism and thread clamp; Figs. 13 and let are detail figures illustrating parts of the mechanism for actuating the thread clamp; Fig. 15 is a view in side elevation looking from the right, of the parts shown in Fig. 11; Figs. 16, 17, and 18 are detail views showing the relative movement of the take-up mechanism and the mechanism for actuating the thread clamp; Fig. 19 is a View in front elevation of the shuttle mechanism in connection with the needle and a portion'of the work with the machine parts and the needle and shuttle threads in the positions they assume when the needle is at the limit of its loop drawing stroke; Fig. 2G is a view inside elevation of the mechanism illustrated in Fig. 19; Figs. 21 and 22 are views illustrating somewhat diagrammatically the positions which the threads, shuttle and needle assume at diiferent stages in the stitch forming cycle of the machine; Fig. 23 is a central sectional view of the shuttle and bobbin case, and Fig. 24 is a view similar to Fig. 23 with the bobbin case broken away to show the thread tension plate on the inside wall of the shuttle. In producing the lockstitch shoe sewing machine illustrated in the drawings many of the parts and mechanisms of the chain stitch shoe sewing machine disclosed in applicants Fatent No. 1,738,778, dated December 10, 1929, have been utilized. Thus the shoe supporting horn with its needle threading whirl, the driving mechanism for the cam shaft, and the treadle and connections for connecting and disconnecting the driving mechanism and cam shaft, are the same as in said chain atitchlmachine. Also, the mechanism for lifting the presser foot during each stitch forming cycle is substantially the same as thatof the chain stitch machine. The needle actuating mechanism is somewhat similar to that of the chain stitch machine, but is simpler in construction, and also connecions from the needle actuating mechanism to the feed point of the work feeding mechanism are utilized for actuating the feed point, said connections having the same general mode of operation as in the chain stitch machine, but having their parts somewhat difierently constructed and arranged. Substantially all of the parts common to the two machines are illustrated in the drawings accompanying this application, but inasmuch as are fully illustrated and described in applioant s patent hereinbefore referred to the will be only briefly referred to in the folfiawing description.

The horn comprises an upper portion 26 arranged to extend within and support the shoe during the sewing operation and a downwardly extending cylindrical portion 28 rotatgbly mounted in a forward extension of machine column. The needle threading whirl is indicated at 30 and is driven from a vertical shaft 32 extending through and journaled concentrically with the cylindrical porticst28 of the horn.

The machine is driven from an electric motor 34 through a clutch mechanism indicated in Fig. 1 in dotted lines. This clutch mechanism is controlled from a foot treadle indicated at 36 mounted on a treadle lever 38 which is normally held in raised position bymeans of a spring 40. The clutch mechanism acts to connect and disconnect the motor with a shaft 42 and sleeve 44 in the base of the machine from which motion is transmitted to the sewing cam shaft 46 in the head of the machine through the vertical shaft 48. Motion is transmitted to the shaft and to the whirl from the vertical shaft fithreugh a horizontal shaft 50.

, he presser foot indicated at is adjustahl secured in a groove in the lower face of a 54 secured to the lower end of the vggtigally movable presser foot bar 56.

The presser foot is forced downwardly against the work by means of a spring 58 surrounding the presser foot bar, and also by a spring 60 which surrounds a shaft 62, and is secured at one end to a collar fast on the shaft and at the other end to .a collar 64 mounted in the machine frame. An arm (36 is secured to the shaft 62 and is connected to the block 54 on the lower end of the presser foot bar by means of a link 68.

The presser foot is raised slightly during each cycle of operations to permit the feed ing of the work by mechanism which comprises a block secured to the presser foot bar. On the block 70 is pivotally mounted a block 72 in the lower face of which a V- shaped groove is formed to cooperate with a correspondingly V-shaped edge of a lifting lever 74. This lever extends beneath the block 72 and is pivotally connected directly above the block to an arm 76 projecting from a rock shaft 78. This rock shaft is provided with another arm 80 which is connected by a link 82 to a cam actuated lever 84. The lever 84 extends across the cam shaft 46 and is mounted upon a fixed pivot stud 86. In order that the lifting movement imparted to the presser foot may be constant, regardless of variations in the thickness of the work, means are provided for swinging the lever 74: about its pivotal connection with the arm 76 as the work varies in thickness. This means comprises a lever 88 pivoted at 90 on the machine frame and equipped at its lower end with a cam groove 92 adapted to receive a roll 94 which is mounted on the block 54 at the lower end of the presser foot bar. The upper end of the lever 88 has an eye 96 through which extends a rod 98 secured at one end to the lever 7i.

The eye 96 is held yieldingly in engagement with a nut 100 on the rod by means of a spring 102 coiled about the rod between the eye and a nut 104.

' As the presser foot is depressed into contact with the work the roll 94 running in its cam groove causes the upperend of the lever 88 to swing to the left as viewed in Fig. 4 so that the lever 74 is swung positively to the left by the engagement of the eye 96 with the nut 100 in proportion to the distance the presser foot is depressed. The arrangement of the parts is such that an adjustment of the lever 74 in the manner described as the work varies in thickness, causes the block 72 to be engaged by the lever always at the same point in the upward movement of the arm 76 so that the upward movement imparted to the presser foot is always the same. As the presser foot rises the lever 88 will be swung back to the 1 right without, however, disturbing the ad justment of the presser foot lifting lever 74 due to the yielding connection afforded by the spr" 102.

The straight hook needle of the machine is nesaea'r indicated at 106 and the needle bar to the lower end of which the needle is clamped is oscillate w th the le "err 118 the shaft 116 the sleeve 120 to which the levers are secured. are connected by a coiled spring latch 126 is mounted on the lever 1 arranged to engage a pin 128 on the lever 110.

The feeding mechanism of the mac comprises a feed point indicated at 130 which is secured in a holder 132 pivotally mounted upon the forward end of a feed point carrier 134. A spring 136 tends to swing the feed point holder in a direction to bring it into contact with the forward end of the feed point carrier 134:. lhe feed point carrier is mounted upon the block 54 the lower end of the presser bar by means of pins 138 which project from the block through slot formed in the feed point carrier. This slot is horizontal throughout ti o greater part of its length and has at its left hand end viewing the machine from the front a dew e wardly extending inclined portion. As a result of this construction, the carrier moves back and forth throughout the greater part of its movement in the line of feed, the left hand end only being elevated, as the carrier is fully retracted, to withdraw the fees point from the work.

The feed point carrier is actuated from the mechanism for reciprocating the needle through connections which include a lever 142, a link 1 .4, a lever 146 and a link 1 18 fastened at one end to the feed point carrier and at the other end to the lower end of the lever 1 16. The upper end of the lever 1&2 is pro vided with a cam slot 150 which is engaged by a roll 152 mounted on the lever 114: at the pivot of the latch 126. The lever 1 12 is acted upon by a spring which moves the lever in a direction to hold the left hand side of the cam slot 150 in engagement with the roll 152.

During the sewing operation the roll 152 travels up and down in the slot 150 against the left hand side of the slot and thus vibrates the lever 142. The spring which acts on the lever 142 is indicated at 154:. This spring surrounds a shaft 156 on which a lever 158 is loosely mounted, one end of the spring being connected to the hub of the lever 158 and the other to a collar secured to the shaft. The

lever 158 is connected by means of a link 160 to an arm 162 projecting from a pivot shaft 164 to which the lever 1 12 is secured.

he so far described the machine does not difier materially from the chain stitch in.- chine disclosed in applicants prior application above referred to. To adapt the machine for the production of a lOCliStltCh seam a locking thread mechanism is provided and also a take-up and a thread lock to cooperate with the needle and locking thread mechanism to form the lockstitch. The locking thread mechanism comprises a loop taker in the form of a shuttle for interlocking the needle and locking threads, and as affording a simple and efficient construction for actuating the shuttle, connections are provided through which the shuttle is driven from the needle actuating mechanism. This manner driving the shuttle also facilitates the stopping of the machine without injurious shock or even when operated at much higher speeds than have heretofore been pos sible with this type ofmachine. in the illustrated machine the stopping is effected by disconnecting the sewing cam sh -ft driving mechanism and for rendering inoperative the actuating connections between the sewing shaft and the needle and shuttle so that in stopping the machine the momentum of the needle and shuttle mechanisms only have to be overcome. driving the shuttle from the needle actuating mechanism, a single means can be utilized for rendering both the needle and shuttle actuating mechanisms inoperative. 1n the machine illustrated, the means which are utilized to accomplish this result are substantially the same as those utilized in the machine of applicants patent hereinbefore referred to to render inoperative th operating connections between the s wing shaft and the needle of that machine. The connections between the sewing shaft and the needle and shuttle are preferably rendered inoperative when the needle is at the limit of its loop drawing :troke and before the shuttle has entered the needle loop. At tl is time both the needle and the shuttle are stationary so that they can be retained in stopped position without any shock or jar. Also, the needle loop is still in the hook of the needle and is held in a position to permit the thread to be severed readily by the operator so as not to interfere with the removal of the work.

As has been stated, the several features of the invention are illustrated as embodied in a lockstitch machine of the McKay type. In these machines, it is impracticable to provide a thread finger or an equivalent thread measuring mechanism in the horn to provide thread on the work side of the needle during its retracting stroke. Accordingly, in this type of machine it has been proposed to employ a take up which pulls the needle loop from the shuttle part way only down to rom its 'r'lw'n'rds the work in order to leave a loop above the work sufficient in length to provide the needle with thread for one side of its loop during its next retracting stroke. Inthe illustrated machine a take-up acting in this manner is provided and in order to enable the take-up to be actuated smoothly and evenly at a high rate of speed the take-up is arranged to be actuated from a continuously m rotatingcrank. Also, in order that the length of loop left standing above the work may be adjusted for different thicknesses of stockso. that an excessive amount of thread 'maynot be drawn around the work from this loop by the action of the needle and shuttle .sthetake-up mechanism has provision for ad- 23 jmtment.

;...p In the machine illustrated in the drawings,

stitch forming devices and the work hold- .i rireig and feeding devices are actuated and tively timed so as to operate smoothly and to the best advanta e during each stitch forming and Work feeding cycle of the machine. During the up or retracting stroke g; of. the needle the shuttle is making its reverse stroke and the work is being fed, the wnpcrfiser foot during the feeding of the work in raised position. During the down I or a vancin stroke of the needle the shuttle a oes throug the needle loop which it takes 0111 the needle and as the loop is carried over the shuttle the preceding stitch is 'wt'by' the shuttle against'the needle thread :rtension. and thread for the next stitch an is pulled from the supply. After the COlI..-'-

. pletion of'the feeding movement, however, :and just before a stitch setting strain is placed on the thread the presser footis forced downwardly and thus the work is compressed Kai 40: against the horn while the stitch is being set.

.2 After the loop of needle thread passes over the top of the shuttle the take-up comes int0- 'actioaand pulls the loop part way down towards the work. The needle loop, however, does not leave the shuttle until the point of the needle has nearly reached the work and thus there is no danger that this loop will beimpaled or caught by the needle. By giving the feeding devices, the needle, the shuttle and the take-up the movements above described each part is permitted to operate for a sufficient length of time during each work feeding and stitch forming cycle to insure a smooth, regular and efficient operation ofthe parts at extremely high speeds.

In addition to the features above referred to, the illustrated machine is also provided with means whereby the feeding device is thrown out of operation upon stopping the machine simultaneously with the stopping of the needle and shuttle.

' The machine is also provided with athread 'clamp which cooperates with the take-up 5 tle down towards the work during the operation of the machine in sewing a seam and which is held in released position at the conclusion of the sewing operation after the movement of the needle and shuttle is stopped, in order to prevent the breaking of the thread during the continued operation of thetake-up.

Other novel features of the machine comprise aguard to hold the thread in the hook of the needle during the first portion of 1ts downward stroke and until the loop istaken from the needle by the shuttle, a tension device for the locking thread which maintains a constant tension on the locking thread as it passes from the shuttle and an improved and simplified mechanism for lifting the presser foot and holding it in raised position at the end of the sewing operation.

The shuttle of the'machine is indicated at 166, seeFigs. 19 to 24 inclusive. This shuttle is discoidal in shape and is mounted in a raceway formed in a segmental holding ring '168- removably secured by screws to a correspondingly shaped extension on a bracket 172 forming a portion of the machine frame. The shuttle is arranged to reciprocate back and forth about its axis which extends rearwardly substantially at right angles to the direction of feedland at an angle to the horizontal, as best shown in Fig. 20. The shuttle is provided with a removable beak 174 and the arrangement of the shuttle is such that during the rotation of the shuttle the beak intersects'the path of movement of .the needle and is adapted to enter the loop of needle thread held by the needle while the needle is near the upper limit of its stroke. During each forward or counter-clockwise rcciproeation of the shuttle the needle loop is taken from-the needle andpassed over the shuttle, as indicated in Figs. 19, 21 and 22, thereby interlocking the needle loop with the locking thread which is supplied from a bobbin-176 mounted in abobbin case 178 with which the shuttle is provided. The connections between theneedle actuating mechanism and the shuttle for actuating the shuttle in clude ashuttle driving shaft 180 mounted in the bracket 172. At its forward end this shaft is provided with a shuttle driver 182 and at its rear end is provided with a pinion 184 which is engaged by a segmental rack formed on the lower end of a lever 186. The upper end of the lever 186 is connected by means of a link 188 to the lower end of an it:

arm 190 which forms a downward extension from the hub of the needle actuating lever 114. The shuttle is thus reciprocated simultaneously with the needle, reaching the limit of its backward or clockwise stroke as the u needle reaches the limit of its upward or retracting stroke, and reaching the limit of its 1 forward or loop taking stroke as the needle awhile pulling the needle loop from the shut-1 reaches the. limit of its downward or advancing stroke.

The guard which holds the thread in the hook of the needle during the first portion of the downward stroke of the needle is indicated at 192. This guard acts to cover the needle hook at the upper end of the needle stroke and thus prevents the escape of the loop as the needle begins its down stroke prior to the taking of the loop by the shuttle. The guard consists of a finger mounted on the lower end of a lever 194 pivoted at 196 on the machine frame. This lever is ctuated to swing the guard into and out of engagement with the needle in timed relation to the movements of the needle bar, as indicated in Fi s. 19, 21 and 22. For this purpose, a cam roll 198 is mounted on the needle bar and is arranged to engage a cam slot 200 formed in the upper end of the lever 194.

The take-up mechanism of the machine is conveniently located directly beneath the horn and is actuated from the horizontal shaft 50 through which the whirl is driven by means of a crank pin 202 mounted on a cam disk 204 which is secured to the end of the shaft 50. The crank pin 202 is connected by a link 206 to the central ivot 208 of toggle levers 210 and 212 which are connected respectively to the fixed pivot 214 and to one end of the take-up lever 216 which has a fixed pivot 218. In order to regulate the throw of the take-up lever 216 the pivot 214 of the toggle lever 210 and the pivot 218 of the take-up lever are mounted on a bracket 220 which is pivotally mounted on a stud 222 fixed in the machine frame and is secured to the stud by a binding bolt 224. An arm eX- tending upwardly from the hub of the bracket and provided with a slot through which a set screw 226 extends into the frame affords an additional means by which the bracket may be adjusted and retained in position to give the desired amount of throw to the takeup lever.

To further facilitate the handling of the needle thread an auxiliary take-up is provided consisting of a lever 228 mounted on the take-up lever 216 and provided with an eye 230 through which the thread is passed. A. spring 232 stretched between the auxiliary take-up lever and a pointon the take-up lever 216 tends to turn the auxiliary take-up lever about its pivot to take up slack thread. The movement of the lever in the opposite direction is limited by the engagement of a flange 234 formed on the lower end of the lever with the under side of the take-up lever 216.

The thread clamp consists of two disks indicated at 236 loosely mounted on a shaft 238 and interposed between an abutment 240 on the machine frame and the hub of a cam lever secured to one end of the shaft. To the other end of the shaft is secured a cam faced block 244 which is held in engagement with an opposing stationary cam faced lock 246 by means of a spring 248 coiled about the shaft between the cam block 244 and the machine frame. The cam lever 242 carries on its outer end a cam roll 250 which engages the surface of the cam disk-204 secured to the horizontal shaft 50. When the cam roll 250 rides onto the high portion of the cam 204 the shaft 238 will be rocked and moved axiallv against the pressure of the spring 248 through the inter action of the cam faced

blocks

244 and 246 to release the thread clamp as illustrated in Figs. 11 and 15. When the cam roll reaches the low portion of the cam the pressure of the spring 248 will cause the shaft 238 to be rocked in the opposite direction by the contact of the cam blocks and the shaft to be moved axially to close the thread clamp.

The take-up mechanism and the mechaism for actuating the thread clamp are so timed that the thread clamp is closed and holds the thread locked during the action of the take-up in pulling the needle thread from the shuttle part way down towards the work and is open while the needle is retracting through the work with the loop of thread a and while the shuttle is passing through the loop. The relative timing of the take-up and thread clamp is clearly indicated in Figs. 16, 17 and 18, in which Fig. 16 shows the position of the take-up and clamp actuating cam when the take-up is at the limit of its upward sroke and While the loop of needle thread is passing over the top of theshuttle. At this time, it will be noted that the high portion of the cam is active so that the thread clamp is in its open position with the thread released. In Fig. 17 the take-up is still at the top of its-stroke, but is about to start down while the thread clamp has just been closed. In Fig. 18 the take-up is at the limit of its downward stroke and the thread clamp has been opened.

In stopping the machine as hereinbefore described the needle and shuttle are brought to rest while the needle is at the limit of its loop drawing stroke and before the shuttle has entered the needle loop. The take-up, however, may continue in operation for an appreciable interval. At this time the needle thread is held in the hook of the needle and in order to prevent breaking of the thread as the take-up completes a downward stroke after the needle has come to rest means are provided for holding the thread clamp open at this time. As the needle comes to rest at the limit of its upward stroke in stopping the machine, the presser foot is automatically lifted as will be hereinafter described, and this presser foot lifting mechanism is utilized in the illustrated machine to open the thread clamp so that during the continued operation of the take-up thread can be drawn from the supply through the thread lock and an excessive strain on the thread leading from the take-up to the needle lib prevented. In lifting the presser foot, as above described, the shaft 62 is rocked in a counter-clockwise direction, as viewed in F 2, 3 and 4, and this rocking movement is Lmparted to the shaft 238 of the thread clamp mechanism through an arm 252 projecting from the shaft 62, a link 254 connecting the arm 252 with the rear end of a lever 256 and a horizontal arm 258 projecting from the hub of the lever 242 beneath which the forward end of the lever 256 extends. The thread clamp is opened before the takeup makes its downward stroke and during this downward stroke the take-up pulls in and sets the preceding needle loop and then draws any further thread which may be required through the open clamp from the "i ie tension device for the locking thread comprises a yielding spring plate 260 arr d to press the thread against a coopcrating thread support formed by the inner surface of the cylindrical wall of the shuttle. This thread supporting surface is concentric with and, therefore, parallel to the axis of the shuttle. The plate 260 is held in the shuttle by means of holding screws 262 and by an. adjusting screw 264 by means of which the tension exerted on the thread may be initially adjusted. The bobbin is supported on a stud 266 projecting from the rear wall of the shuttle and bobbin case centrally of the bobbin case and the bobbin thread leads from the bobbin through an opening 268 in the bobbin case to a guiding notch in the free end of the tension plate 260. The bobbin thread then passes between the tension plate and the thread supporting wall of the shuttle to a second guiding notch 27 0 formed inthe forward edge of the tension spring. The thread then passes inwardly towards the center of the shuttle and emerges through an openigl lzg 272 formed in the bobbin retaining 4. From the opening 272 the bobbin thread leads to the work. With this arrangement of the tension plate, cooperating thread support and thread guides it will be seen that a pull exerted on the thread leading from the tension plate to the opening 272 and to the work will tend to swing the tension plate260 inwardly away from the thread supporting surface and thereby decrease the fnctional. resistance offered by the tension piste to the passage of the thread. The reof .this arrangement is that the tension on the thread leading from the tension plate to the work is maintained constant regardless of an variations in the resistance offeted by t e thread leading from the bobbin tothe tension plate.

' To render imperative the actuating con neetions between the sewing cam shaft and the needle and shuttle, the illustrated machln'o'ispro'vided with connections from the skating and stopping treadle through which the latch 126 may be actuated to disconnect the needle bar as the needle bar reaches the top of its stroke. These connections are substantially the same as those utilized in the chain stitch sewing machine disclosed in up plicants patent hereinbefore referred to. These connections, see Fi s. 1, 2, 3, 7 and 8, comprise an arm 276 fast to the shaft 156, a rod 278 connecting this arm to the starting treadle, a lug projecting laterally from the arm 276 beneath a rearward extension of the lever 158 and a heavy spring, not shown in the drawings, surrounding the shaft 156 and tending to turn the shaft in a clockwise direction, as viewed in Fig. 1. With this construction, when the starting treadle is permitted to rise the lug on the lever 276 en gages the lever 158 and the heavy spring above referred to, acting through the shaft 156 and arm 276, exerts a pressure on the lever 142 which holds the right hand side of the slot 150, as viewed in Figs. 2 and 3, against the roll 152 on the needle actuating lever 114. With the lever 142 thus yieldingly pressed towards the left, as viewed in Figs. 2 and 3, the upper end of the lever will be moved to the left as soon as the roll reaches the upper portion of the slot 150 and the roll will enter the notch formed by the horizontal extension of the slot. During this movement of the lever 142 a pin 280 at the upper end of the lever engages an upward projection from the latch 126 and moves the latch out of engagement with the pin 128 on the lever 118. The needle is thus stopped at the limit of its upward movement and retained in this position, and since all of the parts of the needle actuating mechanism are stationary at the instant the latchv 126 is disconnected from the pin 128 the needle mechanism is stopped. and retained in position without shock or ar regardless of the speed at which the machine is run. Likewise, since the shuttle is actuated through connections from the needle actuating lever 114 the shuttle and its actuating mechanism are also stopped and retained accurately in position without the necessity of overcoming the momentum of any moving parts. The act of disconnecting the needle actuating lever 114 from its connection with the sewing cam shaft also simultaneously disconnects the feeding mechanism from the sewing cam shaft and brings it to rest without shock or jar since the feeding mechanism, as has been hereinbefore described, is actuated from the needle actuating lever 114 through the slotted lever 14.2. As in the chain stitch machine of applicants pending application, the movement of the lever 142 in disconnecting the latch 126 from the pin 128 also moves the feed point 130 away from the needle so that the feed point will not interfere with the removal and insertion of work.

The mechanism for automatically lifting .3 her a retaining a. .3 S 1 p the presser foot as the machine is stopped at the end of the sewing operation comprises a presser foot lifting member which is driven continuously from the sewing shaft and which is inoperative while the machine is sewing a seam, but is rendered operative to lift the presser foot when the sewing cam shaft is disconnected from its driving means. The presser foot lifting member is indicated at 282, see Figs. 4, 8, 9 and 10. This member is supported from the sewing cam shaft l and hangs vertically from the shaft, its upper end being formed as an eccentric strap surrounding an eccentric 284 on the shaft from which a constant vertical reciprocation is imparted to the member. At its lower end the presser foot lifting member is provided with a projection 286 which is adapted to engage beneath a lug 288 projecting laterally from an arm 290 fast on the rock shaft 62. While the machine is in operation the presses foot lifting member 282 is held in a position in which the lug 288 is out of the path of movement of the projection286, as indicated in Fig. 4:. During the stopping of the machine, however, the presser foot lifting member is moved into the position indicated in Fig. 8 and during its upward movement acts to rock the shaft 62 by the engagement of the projection 286 with the lug 288 and lift the presser foot. The reciprocating movements of the presser foot lifting member are so timed that the presser foot is not lifted until the needle is substantially at the limit of its upward stroke at which time the needle is brought to rest, as hereinbefore described. Any interference with the proper operation of thread handling devices in forming the last stitchis, therefore, avoided.

l? After the presser-footis raised, the sewing cam shaft continues to rotate through one or more revolutions and in order to retain the presser foot in the position to which it has been raised by the presser foot li ting memmember is provided in the form of a latch arranged to engage lug pr jecting laterally from the arm 290 in the opposite direction from the lug 288. This ining member is indicated at 294 and is ported in a vertical position from the sewing cam shaft 46 at the side of the presser foot lifti f member 282. Thelower end of retai member is provided with a projection 296 similar to the projection 286 on the press-er foot lifting member, which proiection 296 constitutes ii latch which can engage the lug 292 and retain the arm 290 and consequent y the presser foot n the position to which it has been elevated by the presser foot lifting member. The retaining member has no vertical movement, but

it is arranged to swing about the shaft 46 as p st to move the-projection 296 into and out of a position to engage the lug 292.

1 While the machine is in operation, the retain ing member is held in an inoperative position in the same manner as the presser foot lifting member and d ring the stopping of the machine is allowed to move with the presser foot lifting member into operative position.

The means for holding the presser foot lifting member and retaining member in inoperative position while the machine is in operation comprises an arm 298 fast on the shaft 156 and arranged to engage an inclined surface on the upper portion of the retaining member 29%. The shaft 156 is rocked Jhrough connections from the starting and stopping treadle, as has heretofore been described, and the arm 298 is so placed that the movement of the shaft 156 as the treadle rises in stopping the machine moves the arm downwardly and permits the retaining memher to be moved into operative position. A laterally extending arm 800, see particularly Fig. 10, projects from the lower portion of the retaining member into a position to engage the presser foot lifting member so that the presser foot lifting member is caused to swing into and out of operative position with the retaining member. The movement of the presser foot lifting member and the retaining member to operative position is insured by compression springs 302- and 804 coiled respectively about rods 806 and 308 pivotally connected at one end to thelower ends of the presser foot lifting and retaining members and at their other ends sliding through a cross pin 310 mounted in a downward projection from the hub of the arm 290. To enable the height to which the presser foot is lifted to be adjusted as may be desired, each of the presser foot lifting and retaining members is made in two parts, the lower part being cylindrical at its upper end and being adjustably held by a retaining screw 312 in a socket formed in the lower end of the upper portion of the member.

The presser foot may be raised manually by the operator by means of ahand lever 814 pivoted at 316 on the machine frame. The hand lever is normally held out of operation with the lower end resting against an abutment on the machine frame by a spring coiled about its pivot. lVhen the hand lever is depressed by the operator the lower end of the lever is brought into contact with a roll 318 mounted on the block secured to the press.

or foot bar and as the lever is depressed still further the nresser foot is lifted.

In the illustrated machine, the locking thread mechanism comprises a loop taker which has been termed a shuttle. This shuttle containsthe thread case for the bobbin thread and passes bodily through the needle loop together with the bobbin threads in interlocking the bobbin and needle threads.

In the following claims the term shuttle is also used, but it is to be understood that eX- as, i

cept'os otherwise expressly limited this term is babe construed as includin a hook or other loop taking device by which the bobbin thread is interlocked with the needle thread,

- 5-, The operation of the machine has been indicated in connection with the description of itsrvarious parts and mechanism, and accordingly a separatedescription of the operation is believed to be unnecessary. The take-up meohanism and the thread case with its tensiondevices for the locking thread herein disclosed form the subject-matter respectively of applicants pending application Serial No. 265,541 filed March 29, 1928 and applicants Patent No. 1,778.081 dated October 14, 1930.

The nature and scope of the invention haviIngbeen-indicated and a machine embodying the several features of the invention having been specifically described, what is claimed "1. A lockstitch sewing machine having, in combination, stitch forming devices including'fm straight hook needle, a shuttle, a shoe supporting horn arranged to extend within the shoe, needle threading mechanism located Within the born, a sewing shaft and suitable connections for actuating the stitch forming devices, means for driving the sewing shaft, and'means for disconnecting the sewing shaft from its driving means and for rendering inoperative the actuating connections between theshaft and the needle and shuttle while. the needle is at the limit of a loop drawing stroke and before the shuttle has taken the 86 40 p from the needle.

2. A lockstitch sewing machine having, in combination, stitch forming devices including a hook needle, and a shuttle, a sewing shaft and suitable connections for actuating the stitch forming devices, means for driving the sewing shaft and means for disconnecting the sewing shaft from its 'driving means and for rendering inoperative the actuating connections between the sh aft and the needle and shuttle while the needle is at the limit of a loop drawing stroke and before the shuttle'has taken the loop thus drawn from the needlei "3. A lockstitch sewing machine having, in

combination, stitch forming devices including a hook needle and a shuttle, a sewing shaft and suitable connections for actuating the stitch forming devices, means for driving. the sewing shaft, a treadle, means for disconnecting the shaft from its driving ing a hook needle, a shuttle, a work feeding device, mechanism for actuating the stitchforming devices including a sewing cam shaft and connections actuated thereby for actuating the needle, and mechanism actuated from said connections for actuating the shuttle and the feeding device.

5. A lockstitch sewing machine having, in combination, stitch'forming devices including a hook needle, a shuttle, mechanism for actuating the stitch-forming devices inclu" ing a sewingcam shaft and connections actuated thereby for actuating'the needle, and mechanism actuated from said connection for actuating the shuttle.

6. A lockstitch sewing machine having, in combination, stitch forming "devices including a hook needle and a shuttle, 'a sewing shaft and suitable connections for actuating the stitch forming devices, and means for rendering inoperative the operating connections between the shaft and needle and shuttle while leaving operative the operating connections between the shaft and other of the stitch-forming devices and for stopping the needle and shuttle in a predetermined position.

7. A lockstitch sewing machine having, in combination, stitch forming devices including a hook needle and a shuttle, a sewing shaft and suitable connections for actuating the stitch-forming devices, and means for rendering inoperative the operating connections between the shaft and needle and shuttle while leaving operative the operating connections between the shaft and other of the stitch-forming devices and for stopping the needle and shuttlewith the needle at the limit of a loop drawing stroke and before the shuttle has taken the loop from the needle. 7

8. A lockstitch sewing machine having, in combination, a straight hook needle, an oscillatoryshuttle, a shoe supporting horn, a lever for oscillating the shuttle, a needle lever and connections for actuating the'needle and connections between said levers for actuating the shuttle oscillating lever from the needle lever.

7 9. A lockstitch sewing machine having, in combination, stitch forming devices including a hook needle and a shuttle, a needle actuating mechanism including a vibrating lever, a pin on the lever, connections between the lever and the shuttle for actuating the shuttle from the needle actuating mechanism, and a treadle controlled member provided with a notch to engage said pin and lock said lever with the needle at the limit of its stroke and before the shuttle has taken theloop from the needle.

10. A lockstitch sewing machine having, in combination, stitch forming devices including a needle and a shuttle, a sewing shaft and suitable connections for actuating the stitch forming devices, means for driving the sewing shaft, means for disengaging the sewing shaft from its driving means, and means for rendering inoperative simultaneously the actuating connections between the sewing shaft and the needle and shuttle.

11. A lockstitch sewing machine having, in combination, stitch forming devices including a needle, a shuttle, mechanism for actuating the stitch-forming devices includlng a sewing cam shaft and connections actuated thereby for actuating the needle, mechanism actuated by said connections for actuating the shuttle, means for driving the sewing shaft, and means for disconnecting the sewing shaft from its driving means and for rendering inoperative the actuating con nections between the needle and the sewing shaft and thereby rendering inoperative the connections for actuating the shuttle while leaving operative the connections between the shaft and other of the stitch-forming devices.

12. A lockstitch sewing machine having, in combination, stitch forming devices comprising a needle, a shuttle, a take-up and a thread clamp, a sewing shaft and suitable connections for actuating the stitch forming devices, driving means for the sewing shaft, and means acting upon stopping the machine to retain the needle and shuttle in a predetermined position during the continued rotation of the sewing shaft and the actuation therefrom of other of the stitch-forming devices and to release the thread clamp.

18. A lockstitch sewing machine having, in combinationfstitchforming devices including a hook needle and a shuttle, means for actuating the needle and shuttle, and means for feeding the work during each stitch forming cycle after the needle has withdrawn from the work with a loop of needle thread and before the shuttle enters said loop.

let. A lockstitch sewing machine having, in combination, stitch forming devices including a hook needle and a shuttle, means for actuating the needle and shuttle timed to cause the shuttle to pass through the loop of needle thread during the advancing stroke of the needle, and means for feeding the work during each stitch forming'cycle after the needle has withdrawn from the work with a loop of needle thread and before the shuttle enters said loop.

15. A lockstitch sewing machine having, in combination, stitch forming devices including a hook needle acting during its retracting stroke to draw thread from the pre ceding needle loop and a shuttle acting to set the stitch, a presser toot having a rising and a depressing movement during each stitch forming cycle to permit the-work to be fed, and means for feeding the work while the presser-foot is raised and after the needle has withdrawn from the work with a loop of needle thread, and means for depressing the presser foot on the work before the stitch is set.

16. A lockstitch sewing machine having, in combination, stitch forming and setting devices including a hook needle acting during its retracting'stroke to draw thread from the preceding needle loop, a shuttle, means for actuating the needle and shuttle, a presser foot having a rising and a depressing movement during each stitch forming cycle to permit the work to be fed, means for feeding the work during the retracting stroke of the needle, and means for depressing the presser toot upon the work before the stitch is set.

17. A lockstitch sewing machine having, in combination, stitch forming and setting devices including a hook needle acting during its retracting stroke to draw thread from the preceding needle loop, a shuttle, means for actuating the needle and shuttle, a presser foot having a rising and a depressing movement during each stitch forming cycle to permit the work to be fed, means for feeding the work while the presser-foot is raised and after the needle has withdrawn from the work with a loop at needle thread, and means for depressing the presser foot on the work before the stitch is set.

18. A lockstitch sewing machine having, in combination, stitch forming devices including a hook needle, a shuttle acting to set the stitch, means for actuating the needle and shuttle timed to cause the shuttle to pass through the needle loop and set the stitch during the advancing stroke of the needle, a presser foot having a rising and a depressing movement during each stitch forming cycle to permit the work to be fed, means for feeding the work during the retract-ing stroke of the needle, and means for depressing the presser foot on the work before the stitch is set.

19. A lockstitch sewing machine having, in combination, stitch torming devices including a hook needle, a shuttle and a take-up acting to pull the loop of needle thread from the shuttle part way down to the work, means for actuating the needle, shuttle and take-up and means for stopping the needle and shuttle with a loop of thread in the hook of the needle, and continuing the operation of the take-up to set the preceding needle loop.

20. A lockstitch sewing machine having, in combination, stitch forming devices including a needle and a shuttle, means for actuating the stitch-forming devices, and means for disconnecting the shuttle from its actuating mechanism and arresting it in a predetermined positicn while other of the stitchtorming devices continue in operation.

21. A lockstitch sewing machine having, in combination, stitch forming devices'including a needle and a reciprocating shuttle, mechanism for actuating the needle and dmwle, and means for disconnecting the shuttle from its actuating mechanism at the of its movement in one direction.

:22. A lockstitch sewing machine having, in

ation, stitch forming devices includilgl hook needle, a shuttle acting to set the stitch, a take-up acting to pull the thread from thedautfle part way down to the work, a thmad .leck acting to lock the thread during the taking up action of the take-up, mechanism for actuating the needle, shuttle, takeup and thread lock, means for disconnecting the needle and shuttle from their actuating m with the needle out of the work and with a loop of needle thread in its book 'liiie leaving other of the stitch-forming deviceaeonnected to their actuating mechanism, and means for holding the thread lock open lbl'ingthe continued action of the take-up.

23. A lockstitch sewing machine having, in

stitch forming devices includiuga hook needle, a shuttle acting to set the stitch, a take-up acting to pull the thread a from the shuttle part way down to the work,

and: thread lock acting to lock the thread dating the taking up action of the take-up, mechanism for actuating the needle, shuttle, takeup and thread lock, a presser foot, means for disconnecting the needle and shuttle from their actuating mechanism with the needle out of the work and with a loop of needle thread in its hook while leaving other of the stitch-forming devices connected to their actuating mechanism, mechanism for raising the presser footie the needle and shuttle are diacmmcted from their actuating mechamin, and connections between the presser foot lifting mechanism and the thread clamp for opening the clamp.

A sewing machine having, in combination, stitch formin devices, a presser foot, a sewing shaft an suitable connections for actuating the stitch forming devices, means for driving the sewing shaft, a reciprocating member actuated continuously by the sewing shaft, means for disconnecting the sewing shaft from its driving means and for causin said member to lift the presser foot, an means for holding the presser foot raised during the continued rotation of the sewing shaft.

25. A sewing machine having, in combination, stitch forming devices, a presser foot, a sewing shaft and suitable connections for the stitch forming devices, means for driving the sewing shaft, :1 presser foot lifting mechanism including a rock shaft, an arm on said rock shaft, a reciprocating presser foot lifting device driven continuously by the sewing shaft, a treadle, suitable connections controlled from the treadle for disconnecting the sewing shaft from its driving means and for moving the presser foot lifting device into engagement with said arm to lift the presser foot, and a latch arranged to engage said arm and hold the prcsscr foot in raised position during the continued rotation of the sewing shaft.

26. A sewing machine having, in combination, stitch forming devices, a presser foot, a sewing shaft and suitable connections for actuating the stitch forming devices, means for driving the sewing shaft, a presser foot lifting mechanism including a rock shaft, an arm on said rock shaft, a reciprocating presscr foot lifting device driven continuously by the sewing shaft, means for disconnecting the sewing shaft from its driving means and for moving the lifting device into engagement with said arm to raise the presser foot, and means for holding the presser foot raised during the continued rotation of the sewing shaft.

27. A. sewing machine having, in combination, stitch forming devices, a presser foot, a sewing shaft and suitable connections for actuating the stitch forming devices, means for driving the sewing shaft, a presser foot lifting device driven continuously by the sewing shaft, 1 member and suitable connections acting when engaged by the presser foot lifting device to lift the presser foot, a latch arranged to engage said member and hold the presser foot raised during the continued rotation of the sewing shaft, a starting and stopping treadle, means actuated by the treadle for connecting the sewing shaft with its driving means and for disconnecting it therefrom, and connections to the treadle for moving said presser foot lifting device and retaining latch into and out of operative position.

28. A sewing machine having, in combination, stitch forming devices, a presser foot, a sewing shaft and suitable connections for actuating the stitch forming devices, means for driving the sewing shaft, a reciprocating member actuated continuously b the sewing shaft, connections through whic the presser foot can be lifted by said member, a treadle, means controlled by the treadle for disconnecting the sewing shaft from its driving means and for causing an engagement of said member and connections to lift the presser foot, and means for holding the presser foot raised during the continued rotation of the sewing shaft.

29, A lockstitch sewing machine having, in combination, stitch forming devices including a hook needle and a shuttle, means for actuating the needle and shuttle timed to cause the shuttle to enter the needle loop during the advancing stroke of the needle, and a guard for holding the loop in the hook of the needle until taken by the shuttle.

30. A lockstitch sewing machine having, in combination, a hook needle and. a shuttle, means for actuating the needle and shuttle timed to cause the shuttle to enter the needle