US618372A - Thread-controlling mechanism for sewing-machines - Google Patents

Description

Patented m. 2 4, 399.

J. E. BERTRAND. G MECHANISM'FOR SEWWG- MACHINES.

plicat'xon file'd. June 8, 1.898.!

THREAD GONTROLLIN (No Modem Y NITED STATES ATENT nrron.

JOSEPH ELI BERTRAND, OF BOSTON, MASSACHUSETTS.

SPECIFICATION forming part of Letters Patent No. 618,372, dated January 24, 1899.

Application filed June 8, 1898. Serial No. 682,927. (No model.)

To all whom, it may concern.-

Be it known that I, JOSEPH ELI BERTRAND, of Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in ThreadMeasuring and Looking Devices for Sewing-Machines, of which the following, taken in connection with the accompanying drawings, is a specification.

My invention relates to thread measuring and locking devices for sewing machines; and it consists in certain novel features of construction, arrangement, and combination of parts, which will be readily understood by reference to the description of the accompanying drawings and to the claims hereto appended and in which my invention is clearly is a sectional plan showing the novel features of my invention. Figs. 3 and 4 are respectively a plan and an elevation of the adj ustable thread-guiding sheave, its locking-pawl, and a portion of its carrying-arm; and Fig. 5 is an elevation of the thread-measuring finger. Figs. 3, 4:, and 5 are drawn to an enlarged scale.

In the drawings, A is a portion of the column upon which the machine-head is mounted, and B the base of the head-frame.

O is the cam-shaft, mounted in suitable bearings in columns carried plate, but not shown.

D is a stand secured upon the base-plate B at the rear of the cam-shaft and cams, and having set therein the stud E,upon which are mounted upon opposite sides of said stand D the levers F and G, only a portion of the former being shown.

II is a lever fulcrumed at a and having secured thereto the work support'or table 5 and provided at its lower end with a lug c, which engages the slotted front end of the sliding bar I and has mounted upon a stud set therein a roll d, as shown, and a is the presser-foot.

J is .a hand-lever fulcrumed at e and arranged to act upon the roll d on the lever H to move said lever H around its fulcrum and move the sliding bar I to the rear and proby said basevided with the lifter-toe f to act upon the short arm of the locking-lever K to lift its heel g from contact with the plate h and un* lock the bar I against the tension of the spring L, mounted upon the upper end of the rod 12 between the tension-adjusting nut at the upper end of said rods, and the bearing of said rodin the hub of the stand D, the lower end of said rod being connected to the rear end of said lever K, said heel g also being raised once in each revolution of the shaft 0 by the cam g acting upon a truck mounted upon the lever K between said rod 19 and the heel g of said lever, as shown in dotted lines in Fig. 1.

M is a portion of a bracket for supporting the wax-pot, (not shown,) and M is a smaller bracket carrying at its rear end a spindle 2', upon which is mounted the tension-wheel j, the friction-disk j, the spring and the tension-adjusting nut 7' all of well-known con struction.

The levers H, J, andK are fulcrumed upon studs set ina standard N, projecting upward lfrom the base-plate B, the outline of a portion of which is shown in dotted lines in Fig. 1 and in full lines in Fig. 2.

The sliding bar I has formed in one piece therewith or secured thereto the rearward extension I, having set therein near its rear end a fixed stud is, upon which is mounted the thread guiding sheave Z, upon one side of the groove in whichis formed a series of ratchet reeth, with which the stop pawl engages to prevent a backward rotation of said shield, said pawl being pressed into engagement with said-teeth by the spring m, and n is a wire guard secured to the stud 70 by the screw 11 to prevent displacement of the thread on said sheave.

The needle-thread m in passing from the wax-pot orthe source of supply to the work on the work-support passes once around the tension-Wheel j, thence to and once around the sheave Z, and thence in any well-known manner to the work.

The lever G has secured to its rear end the brake-shoe 0, which when the rear end of said lever is depressed bears upon the thread on the tension-wheel and clamps it thereto, so

as to prevent said thread being drawn from said wheel or the source of supply when the needle is pulling the loop through the work, when the shuttle is passing through and expanding said loop, or when the stitch is being set. The forward end of said lever G carries a cam-truck, which is acted upon by the cam 0 to move said lever in one direction, it being moved in the opposite direction by the tension of the spring 1), said cam O and spring 1) being shown only in dotted lines in Fig. 1.

The lever F is vibrated by the action of the cam-path q upon a cam -truck 7", carried by said lever, and indicated by a dotted circle in Fig. 1. The forward end of said lever (which is omitted from the drawings) is connected to and imparts motion to the awl-segment (not shown) in a well-known manner, and said lever has a rearwardly projecting arm, in which is set the pendent fingers, the lower end of which is forked, as shown in Fig. 5, to engage the thread as, between the tension-wheel j and the sheave Z, when the rear end of the lever B is moved downward, and depress it, thereby drawing from said tension-wheel and the source of supply the necessary amount of thread to form a stitch. said downward movement of the finger s takin g place when the brake-shoe 0 is raised from contact with the thread on the tension-wheel.

The remaining parts of the sewing-machine to which the parts herein described appertain and with which they cooperate are shown and described in an otherapplication of mine, filed June 8, 1898, Serial No. 682,928, and the parts herein described and claimed are shown and described, but not claimed, except in special combinations, in said other application.

The operation of myinvention is as follows: The needle-thread 00 being drawn from the source of supply through the wax-pot (not shown) to and once around the tension-wheel j, thence to and once around the sheave Z,

and thence to the work in any well-known manner, as hereinbefore described, and the machine being in operation sewing Work placed between the presser-foot and the worksupport, at the proper time in each revolution of the shaft (1 in the direction indicated by the arrow on Fig. 1 the brake-shoe 0 is raised from contact with the thread on the tension-wheel, and at the proper time after said brake-shoe has been raised the measuring-finger s is moved downward by the action of the cam-path (1 upon the lever F and engages the thread 00 between the tension-wheel and the sheave Z and depresses it to a sufficient distance to draw from said tension-wheel and the source of supply an amount of thread sufficient for the formation of a stitch, the sheave Z being locked against-rearward revolution by the .pawl is engaging the ratchetteeth on the sheave, and thus preventing any thread being drawn from in front of said sheave. Later in the revolution of the shaft 0 and while the needle is drawing the loop of thread through the work the brake-shoe 0 descends upon the thread in the groove of the tension-wheel and locks the thread against being drawn from said tensionwheel and source of supply while the shuttle is passing through said loop and while the stitch is being set, as fully described in said before-cited other application.

The work-support I) being secured to the pivoted lever H, one arm of which is connected to the bar I, which is pressed toward the front by the spring t, and the arm I, which carries the sheave Z,being formed in one piece with or secured to and movable with the bar I, it follows that if the work being sewed varies in thickness the feeding of the work from a position with a thin portion thereof between the work-support and presser-foot to a position with a thicker portion between said parts will cause a depression of the worksupport 1), thereby moving the bar I I and the sheave Z toward the rear, the heel g of the locking-lever K being raised by the action of the cam g upon said lever to release said bar and permit said rearward movement. The rearward movement of the sheave Z, which shortens the distance between said sheave and the tension-wheel j, causes the downward movement of the measuring-finger s to draw an increased quantity of thread from the tension-wheel and the source of supply by virtue of the facts that the distance between the sheave Z and the tension-wheel is lessened, while the downward movement of the measuring-finger is the same, and that the sheave Z is locked against rearward revolution, and the thread being wound entirely around said sheave must cross on the top of the sheave,

and when the finger s descends and presses upon said thread it is drawn closely into the angle of the groove of said sheave, causing the crossing portions of the thread tobind each other firmly against slipping, and as the brake at this time is removed from the tension-wheel the necessary thread is drawn from said tension-wheel and the source of supply.

If the work is fed from a thick to a thin portion, the reverse action takes place and a less length of thread is drawn from the tension-wheel and the source of supply, the forward movement of the bar I Iand the sheave Z being effected by the reaction of the spring t, connected at one end to the barI and at its other end to a fixed part of the machine.

What I claim as new, and desire to secure by Letters Patent of the United States, is-

1. In a thread-measuring device for sewingmachines the combination with a frictional tension-wheel, of a thread-guiding sheave in near proximity to said tension-wheel; means for locking said sheave against backward revolution a thread-en gagin g fin ger arranged above a line tangent to the tops of said sheave and tension-wheel, and having its lower end forked or notched to engage the thread between said sheave and tension-wheel in near proximity to said tension-wheel; and means for reciprocating said finger and causing it to IIO engage and depress said thread below a line tangent to said tension-wheel and sheave and thus draw thread from said tension-wheel and the source of supply.

2. In a thread measuring and locking de vice for sewing-machines the combination with a frictional tension-wheel, and a worksupport and presser-foot cooperating to clamp the work, of a thread-guiding sheave in near proximity to said tension-wheel but between it and said work-support freely revoluble in a forward direction; means for locking said sheave against backward revolution; a thread-measuring finger arranged to engage the thread between said tension-wheel and sheave; means for reciprocating said finger and causing it to depress said thread to draw thread from the tension-wheel and the source of supply; and mechanism between the axis of said sheave and the work support constructed and arranged to cause the downward and upward movements, respectively, of the work-support, due to varying thicknesses of the work, to move the axis of said sheave toward and from said tension-wheel, and thus cause the amount of thread drawn from said tension-wheel to correspond with the amount required to form a stitch.

3. The combination of the tension-wheelj; the pivoted lever G provided with a camtruck; a cam constructed and arranged to act upon said truck to move said lever in one direction; the spring 19 arranged to move said lever in the opposite direction; the brakeshoe 0 carried by said lever and arranged to engage and clamp the thread on said tensionwheel; the reciprocating bar I the sheave Z provided with ratchet teeth and mounted upon a stud set in said bar 1; the pawl it for locking said sheave against backward movement, and pivoted to said bar I the leverF provided with the cam-truck r; the measuring-finger 8 carried by said lever F and having its lower end forked or notched as set forth; and the cam-path q to act upon and vibrate said lever, all substantially as described.

4. The combination of the pivoted worksupport b H; the sliding bar I and extension I; the locking-lever K; the cam g for operating said locking-lever; the sheave Z provided with ratchet-teeth; the pawl 7;; the tension-wheelj; the leverF; the measuringfinger 8 carried by said lever; and the campath q for operating said lever and'finger.

vJune, A. D. 1898.

JOSEPH ELI BERTRANlI Witnesses:

N. O. LOMBARD, E. H. TANSEY.

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