US2000929A - Work supporting means for sewing machines - Google Patents

Description

May 14,- 1935. c. A. DEARBORN WORK SUPPORTING MEANS FOR SEWING MACHINES Filed Dec. 7, 1935 4 Sheets-Sheet 1 May 14, 1935. c. A. DEARBORN WORK SUPPORTING MEANS FOR SEWING MACHINES Filed Dec. '7, 1933 4 Sheets-Sheet 2 INVENTOR May 14, 1935. c. A. DEARBORN WORK SUPPORTING MEANS FOR SEWING MACHINES 4 Sheets-Sheet 3 Filed Dec. 7, 1933 INVENTOR M 1. Mn.

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May 14, 1935. c. A. DEARBO RN WORK SUPPORTING MEANS FOR SEWING MACHINES Filed Dec. 7, i933 4 Sheets-Sheet 4 INVENTOR and 4. M

Patented May 14, 1935 2,000,929

UNITED STATES PATENT OFFICE woa r svrroar iigi ill vs ron. snwmo Charles A. Dearborn, New York, N. Y., assignor to American Blind Stitch Machine Company, New York, N. Y., a corporation of New York Application December 7, 1933, Serial No. 701,297 11 Claims. (Cl. 112-177) The present invention relates to improvements Figure l is a side elevation of the improved main overseaming blind stitch sewing machines of chine embodying the present invention; the power driven type illustrated for example in Figure 2 is a plan view of the same, parts being the machine of my Patent No. 1,025,082 granted broken away for the sake-of clearness; April 30, 1912. v Figure 3 is a vertical longitudinal sectional In the years of the development of this t pe f View taken on h l -4 Of Fi r 2 machine I have produced a machine for blind Figure 4 is a view similar to Figure 3 showing stitching which operates at a speed of 1500 to. the parts in a slightly c n e b i n; 2000 revolutions a minute, such rapidity of opera- Figures 5 and 6 are detail vertical transverse tion requiring substantial strength in the design Se tional V w k n respectively 1 the Section of the machine and great refinement and acculines 55 of Figure 3 and 8-8 of Figure racy in the various parts to enable it to satisfac- Figure 7 is a detail horizontal sectional view torily perform a great quantity and. fine quality taken on the line l'! of Figure 3; of the desired work. Figure 8 is a view similar to Figure 1 showing Improvements in the present development of parts in section with the automatic operating the machine relate to the adjustable work supmechanism for the work supporting table thrown porting means and the automatic operating out of action; mechanism therefor by means of which the depth Fi s 11 n 12 are detail views illusof the work presented in the path of the needle trating different phases of the work performed is periodically changed or adjusted for effecting by the improved machine.

a succession of deep stitches and intermediate The main frame of the machine of the type to shallow stitches. The deep stitches pass through which the pres nt mpr v m nts a e part ular y the several layers of material, such, for instance, app a is f rm d .01 a s ngl h avy cast n as the base material and the folded over portion having integral strengthenin ri s n D B- v of a hem that is being sewed, while the hall w ing essentially a rigid central base i, centrally stitches pass through the inner edge of th folded perforated for rigid bolting to a work bench,- the over layers only and skip the base mat i l. upwardly extending main arm 2 at the rear ter- Machines for performing this general opera-'- minating in the shaft bearing sleeve 3 from the tion have long been known in the art, but the t o w ch projects the fo w rdly ex end n an improvements of the present application a of arm 5 having horizontal bearings l for the needle simple and effective construction to apply t th rock-shaft i5. This forward machine arm 5 particular power driven type of blind stitch sewa o supp s t e low and f ed a n t ing machine referred to above. Th number of manner hereinafter referred to.

shallow or skip stitches between the more widely Extending forwardly and upwardly from the spaced deep stitches depends upon the gear ratio front base is the integral arm 9 terminal?- of the operating mechanism which controls the in the sleeve 1 in which is secured h front variable position of the work supporting table, it horizontal hearing shall; l 8 p n w ch s being possible with suitable gearing to provide pivoted the Work pport l0, present y to e 1, 2, 3 or more shallo stitches between s ced scribed- 40 deep stitches, pa ill is the main driving shaft of the machine A further improvement in the mechanism f journalled in the sleeve bearing I of the rear arm the present application is in the provision of means, by which the automatic mechanism for driving pulley H and fly'wheel The forwardly extending needle rock-shaft i5 effecting the perlodic changes in the depth of 4 journalled in bearings 4 has rigidly mounted upon stitches in the work can be thrown out of operait t d nd th n e e d1 8 ca mg mcba the machine adjusted to perform uni- 8 Omar e e 4 nu and it in which is mounted the usual curved needle 01m blind sutch sewing such as is perfumed by H. The machine is provided with the usual the weu'knwn, blind stitch sewing machines thread guides and tension devices which form no nowm part of the present invention and are therefore In order that the invention may be fully undert referred t m detail.

stood it will first be described with reference to Secured to the rear end of the needle rock- 2 and having secured at one end the combined th ac mi iying drawings and the novelty shaft I5 is a rock-arm 25 having universal joint afterwards pointed out in the annexed claims. connection with link 21 which encircles a spheroi In said drawings dal eccentric (not shown) mounted upon the shaft GI which carries the main powershaft I0 just inside crank disk I0. This needle operating mechanism is the same as in my former patents.

40 is the work supporting frameformed with the spaced bearing sleeves H which are freely journalled upon the oppositely projecting ends of the rod or shaft 8 carried in sleeve I in the upper end of frame arm 6. These bearing sleeves 4| rest snugly against the finished vertical side faces of the sleeve 1 which they embrace. Projecting downwardly from one of the bearings M is an integral rock-arm 42 engaged at its lower end by a heavy coil spring 43 which extends rearwardly from said arm 42 to one arm of a stout horizontal bell crank lever 44 which is pivoted at 45 to the base I. The other arm engaged by an adjustable screw stop 46 threaded through a rib Ia of the base frame, the described arrangement giving to the pivoted cloth supporting frame 40 a strong spring support to hold it in its normal horizontal working position, which is determined roughly by the adjustable screw stop 41 threaded through a bracket arm 6a of front machine arm 6 and presented in the vertical plane of the rock-arm 42 by which it is engaged. See Figures 1, 3 and 4 of the drawings. This work supporting frame is operated through mechanism hereinafter described for automatically and periodically shifting its position to vary the depth of material presented by its ridge forming member in the path of'the needle as hereinafter explained.

The depression of the frame for placing the work upon the frame horn beneath the presser foot is accomplished by the usual treadle 15 connected by a chain or wire lid with a link 40a hooked to the rear edge of frame 40.

The work supporting frame 40 is extended to the left to form a work supporting horn as is usual with this type of machine. Journalled in the work supporting frame 40 upon the usual conical axial bearing screws 55 is the oscillating fulling in ridge forming rib or disk 60 of .the usual construction. The usual independently yielding work supporting plates or platens l0 are mounted upon opposite sides of the ridge forming disk 60, each plate I0 being pivoted'upon an arm or lever I2 pivoted at. 10 upon frame 40 and provided with a spring 120.

I00 is the rigidly mounted presser foot projecting forwardly from the under face of machine arm 5 to a position above the ridge forming disk 60 and the work supporting platens I0. The presser foot is formed with the usual longitudinal slot into which a ridge of the work is pressed by the disk 60 for the action of the stitch forming mechanism.

The shaft 6| has adjustably secured to it a downwardly presented crank arm 02 to which is pivotally connected at 63, a link 64 in turn pivoted at 65 to one arm of a bell crank lever 61 pivotaliy mounted upon a screw bolt 68 secured to machine frame. The other arm of the bell crank lever 01 is pivoted'to the lower end of an eccentric link 69 having a yoke at its upper end encircling the eccentric I4 which is secured upon the shaft l0 alongside of the pulley II.

It will be observed that the work supporting frame 40 projects rearwardly from the machine arm 0, which is just the reverse of the arrangement of the work supporting frame that has heretofore been employed in this type of machine.

By the eccentric link connection between the power shaft and the shaft 0| of the ridge forming of bell crank 44 is the desired adjusted position disk it will be observed that theforward stroke of the disk is effected by an upward thrust upon the rock arm 02. This upward thrust in actively moving the ridge forming disk is exerted in the same direction as the spring induced upward pressure of the work supporting frame which is important in that it cooperates with and does not conflict with the normal spring support of the work supporting frame.

The looper mechanism of the machine is not involved in the present improvement and is not specifically shown, but it will be understood that the same form of looper is employed as has been used in the past in this type of machine, the looper being indicated at I0 carried on the forward end of the looper rod 11 carrying on its rear end a yoke pivoted upon a sleeve which is freely journalled upon the crank pin mounted in the angularly offset arm 00 of the crank disk I0. This looper and its operating mechanism will be clearly understood from my Patent No. 1,467,570 dated September 11, 1923.

The feed mechanism may be of the general type shown in my Patent No. 814,026 datedMarchB, 1906, the specific structure of the same being immaterial to the present invention.

I25 is the longitudinally movable rocking feed bar actuated at its rear end by the usual eccentric (not shown) upon main shaft I0.

The arm 42 of the work supporting frame 40 has secured to it a bracket block 420 through which is threaded an adjustable tappet screw 40 which carries upon its outer end a milled head 40 having a crown wheel collar 50 on which is marked an index scale 5|. The crown wheel collar 50 operates in peripheral engagement with a small spring plunger 52, which latter is slidingly mounted in a socket of the block 420. with its conical outer end in latching engagement with the serrated edge of the collar 50 for the purpose of retaining the screw 40 in the desired adjusted position.

The inner end of the screw 40 engages the vertical tappet face of the short arm IOI of the work controlling bell crank lever which is pivoted upona set screw I02 threaded into a vertical face of the base frame rib la. The other or long arm I03 of said bell crank projects rearwardly from its pivot I02 and is formed in its rear end with a horizontal elongated slot I04 (Figure 7) through which projects a bolt I05. A short rock-shaft I00 extends transversely of the machine below and parallel with the main shaft I0. This rock-shaft I06 is freely journalled in a suitable bearing I01 formed in the frame arm 2 just above the frame base I. The inner end of said rock-shaft I00 carries a forwardly projecting rock-arm I00 which overlaps the rear end of arm I00. The forward end of rock-arm I00 has an elongated slot I00 (Figure 1) in which is adjustably fixed the threaded end of the pin I05 which forms a jointed connection between parts I00 and I00. As shown in Figure '7 of the drawings the pin I05 is formed with an enlarged head which engages the bell crank arm I00 and upon which is freely journalled a hand-operated cam lever H0 in the recessed face of which rests a washer III engaged by a set screw II2 by which the member III is rotatably confined upon the head of pin I05. The pin I05 has .a sliding fit in the slot I04 and is formed with a threaded reduced end which snugly fits and passes through the slot I00 to receive the retaining nut H0 which is screwed upon said threaded end and firmly clamps the pin I00 in upon rock-arm I00,

The hand lever H0 is formed with a cam peripheral surface, shown particularly at la in Figure 8 of the drawings, said periphery being designed to operate upon the upper face of the base frame I to shift the position of the interengaging arms I II! and III. into inactive position and lock them in that position as will presently be described.

The rock shaft I06 carries at its outer end an arm 5 having an anti-friction roller I I which operates in peripheral engagement with a controlling cam II1 mounted upon and rotating with a gear H8 freely journalled upon a stub shaft II! carried in the machine arm 2 beneath the main shaft III. This gear I I8 meshes with and is driven by a smaller gear I20 keyed to the shaft it alongside of the eccentric link 69. The intermeshing gears Ill and I20 may have any desired ratio such as 2:1, 3:1, etc., depending upon the number of impulses it is desired to impart to the system of levers which control the periodic movement of the work support.

It will be observed that the engagement of antiiriction roller H5 of lever I II with the high portion of cam II'I rocks the long arm III of the work controlling bell crank to press upon the tappet screw 48 and slightly lower the ridge forming member 60 by which the work. is supported in the path of the needle. This position of the parts is illustrated in Figures '3 and 5. the needle in the stitching operation taking a shallow bite in the work which, when operating upon a hem, will pass through the edge of the hem and skip the lower layer or base material. When the roller of rock-arm II! is in engagement with the low portion of cam II! the work support is in position to present the ridge forming member 60 in a slightly higher elevation as shown in Figures 4 and 6, in which position the needle passes through a deeper bite of the material passing through the base material as well as the edge of the turned over layers. 7

Figures 9 and 10 represent opposite faces of a stitched hem performed on the machine equipped with the improved mechanism. In Figure 9 the inner face and the hem is shown which appears as of-ordinary stitching, but, infact, also has shallow or skip stitches between the deep anchoring stitches. In Figure 10 the right side of the work is shown in which the spaced deep stitches show through.

In Figure 11 a perspective view illustrates the work in which the spaced deep stitches indicated at a pass through the base layer b and the twoply folded over layers 0, 0', while the shallow or skip stitches d are shown passing only through the folded over layers 0, c.

The work shown in Figure12 is the ordinary work of the blind stitch sewing machine with the stitch skipping attachment locked out of operation. The work in this figure is of the ordinary blind stitch type in which the stitches pass entirely through the folded over layers of the hem and engage only the inner surface of the base layer to produce a blind stitch or one that will not show on the right side of the work.

continuous run of normal By suitable adjustment of the tappet screw It the elevations of the ridgeforming member 6| can be controlled to a nicety for both the deep and the shallow stitches. when it is desired to use the machine for its ordinary work with a stitches the work controlling bell crank III, Ill, is locked against movement in its inoperative position by throwing over the cam lever IIO causingit to engage the face of the machine base I and liftthe rear end of long arm I" as well as ing rock-arm I" 'which places the anti-friction roller I I8 on rock-arm III just outside the path of the high portion of cam III. The work support, when the .stitch skipping m is locked out of operation, is in its Iowpodtion for making shallow stitches so that to perform the ordinary continuous line of deep stitching through the several layers of'the work including ment arranged between said work support and said lever.

3. The combination, in a sewing machine, with a driving shaft, a pivotally mounted yielding 10 the forwardly proiectwork support carrying a ridge forming member,

and suitable work feeding and stitch forming mechanisms, of a pivotally mounted work controlling lever, operating mechanism between said shaft and said lever,

operating mechanism ing said lever against movement.

4. The combination, in a sewing machine, with a driving shaft, a pivotally mounted yielding work support carrying a ridge forming member, and suitable work feeding and stitch forming mechanisms, of a pivotally mounted work controlling lever, operating mechanism between said shaft and said lever, and an adjustable screw tappet arranged between said worksupport and said adjustable means of en- I 6. The combination, in a sewing machine, with a yielding work support carrying a ridge forming member, and suitable work feeding and stitch forming mechanisms, of a pair of interengaging pivoted levers, driving mechanism operating one of said levers, and engaging means between said work support and the other of said levers.

7. The combination, in a sewing machine, with a yielding work support carrying a ridge forming member, and suitable work feeding and stitch forming mechanisms, of a power driven rock-arm, a rearwardly extending pivoted lever overlapping said rock-arm, pin and slot engagement between the overlapping portions of said rock-arm and said lever, and engaging means between said work support and said lever.

B. The combination, in a sewing machine, with a yielding work support carrying a ridge forming member, and suitable work feeding and stitch forming mechanisms, of a power driven rock-arm, a rearwardly extending pivoted lever overlapping said rock-arm, pin and slot engagement between the overlapping portions of said rock-arm and lever, engaging means port and said lever and a manually adjustable cam lock iournalied upon said pin in position to engage the machine nected rock-arm and lever in inactive position. 9.,The combination, in a sewing machine, with ayielding work support carrying a ridge forming member, and suitable work feeding and stitch frame and hold said conforming mechanisms, a. driving shaft, reducing gears operated by said shaft, a cam actuated by said reducing gears, a rock-shaft carrying a rockarm presented in operative relation to said cam,

a second rock-arm mounted upon said rockshaft, 9. pivoted bell crank lever having one arm overlapping said second rock-arm, pin and slot engagement between said overlapping rock-arm and bell crank lever, adjustable means of engagement between said bell crank lever and said work support, and manually operable means for moving said connected rock-arm and bell c'rank lever to shift the-arm out of the path of said cam.

10. The combination, in a sewing machine, with a yielding work support carrying a ridge forming member, and suitable work feeding and stitch forming mechanisms, of a power driven rock-arm, a rearwardly extending pivoted lever engaging said work support and overlapping said rockarm, and a member adjustably mounted upon said rock-arm operatively engaging said lever. 11. The combination, in a sewing machine, with a yielding work support carrying a ridge forming member, and suitable work feedingand stitch forming mechanisms, of a power driven rock-arm,

a pivotally mounted slotted lever engaging said work support and overlapping said rock-arm, and

a pin adjustably mounted upon said rock-arm and operatively engaging the slot of said lever. CHARLES A, DEARBORN.

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