US768144A - Shedding mechanism for looms. - Google Patents

Description

No. 768,144.v 1 PATENI'BD AUG. 213, 1904.-

4 C. F.' PERHAM.

sHinnlwz-MEGHANISM PuR Looms.

APPLIOTION FIL-ED JUNE 14, 1900.

N'o MODEL.

No. I768,144.

.UNITED STATES Patented August 23, 1904 i CHARLES F. PERHAM, OF LOWELL, MASSACHUSETTS, ASSIGNOR TO PERHAM-STICKNEY COMPANY, OF TEVVKSBURY, MASSACHUSETTS,

A CORPORATION or MAINE.

SHEDDlNG MEoHANlpsM FoR Looms.

SPECIFICATION forming part of Letters Patent No. 768,144, dated August 23, 1904.

Application iilcd June 14, 1900. Serial No.v 20,307. (No model.)

To @ZZ whom it may con/067%:

Be it known that I, CHARLEsFosTER PER- HAM, of Lowell, in the county of Middlesex and State ofMassachusetts, have invented certain new and useful Improvements in Shedding Mechanism for Looms, of which the following is a specification.

This invention has` relation to looms, and more particularly to mechanism employed for actuating the dobby by means of which the various harnesses are changedvin weaving a pattern in cloth.

The object of the present invention is to provide a loom in which the dobby may be actuated. directly from the crank-shaft, by means vof which shaft power is imparted to the lay to reciprocate vthe same.

Referring to the drawings, which represent one embodiment of the invention,/Figure l represents, in end elevation, a portion of the loom with v.the dobby mechanism thereon.

Fig. 2 `represents a partial front elevation ofl the same. Fig. 3 represents a diagram of the cam, by means of which the dobby mechanism is actuated.

On the drawings, ct indicates one of the side standards of the loom which is provided with bearings for the crank-shaft b, said shaft being provided with the cranks b', which are connected'with the flay. (Not shown.) The dobby comprises the frame c, which is secured to the bracket d1, projecting upwardly from the side standard a. The frame consists of two sides c c', suitably connected together, and on a shaft c2, extending between the sides, are pivoted a plurality of upwardly-projecting levers d d, cach of which h as a notched upper end connected by-a cord d with a harness-frame, (not shown,) said cords d passing over pulleys 022, journaled on a shaft d3 in the Each leverv d has a projecting arm di, on the end of which is centrally fulcrumed a lever c. When the levers d are in an inoperative position, the rear edges of the end of the levers e f rest against fulcrum-rods c2 c3, which extend through the frame c. Pivoted tothe ends of the levers e are drop-wiresff,

having hooked ends, the drop-wires f being longer than those at f and being located in a lower plane. They are all held raised and in an inoperative position by tracker rods g, `whose lower ends rest upon tilting levers e, fulcrumed upon la shaft t, extending from 'side to side of the frame c. l a' indicates a pattern-chain, which is below the tilting levers /t and by means of which the rear ends of said levers are depressed to permitthe dropping ofl the' tracker-rods g and the consequent dropping of the drop-wires into operative position. The pattern-chain is of the ordinary construction, and it receives a step-by-step movement from a pawl-andratchet mechanism, which I shall describe.

The sides c of the frame c are slotted, as

at c4 c5, to receive slides 7' j", respectively, said; slides having knife-edges adapted to engage the hooked ends of the drop-wires ff. The ends of the slides project through the slots'c4 c, and they are connected by rods f2 f3 with two-armed levers placed upon a shaft 7n, eX- tending through the sides of the frame c. The said two-armed levers are provided with the'arms it" 7a2, to the ends of which the rods f2 ,7'3 are connected, and one of themis provided with a long arm 7c3, the end of which is connected by a link 7c4 with the long armvm of an elbow-lever fulcrumed on a stud m', supported by the frame t of the machine. The shorter arm m2 of the elbow-lever is provided witha cam-piece m3, extendinginto the groove in a cam a, keyed upon the crank- .shaft The groove in vthe cam is shown in diagram in Fig. 3. It is in the form of a figure 8, so that at each double rotation of the cam the elbow-lever is moved first in on direction and then in the other.Y

Pivotally connectedl to the arm k2-o`f one of the two-armed levers, which, as stated, are secured to the shaft 7n, is an elongated pawl 0, which engages a ratchet-tooth o on a shaft 02, carrying the roller by which the pattern-chain is advanced, so that when the two-armed lever is rocked the ratchet is rotated with a stepby-step movement to feed the chain. A deadnarily the case.

pawl fr engages a toothed wheel p on the shaft o2 to position the chain after each movement thereof.

The operation of the mechanism is as follows: Assuming that the pattern-chain has moved forward one step and certain of the tilting levers have been raised to lower the tracker-rods c, and thereby permit the drop- .to permit the lower slide y" to engage and move the drop-wires f and actuate the proper lever ld, the lever e then swinging about the crossbar 02 as a fulcrum.

The cam n, in which the cam-groove 11/ is formed, as previously described, is mounted directly upon the crank-shaft b, so that the dobby is operated without the employment or' a supplemental or auxiliary shaft, as is ordi- The cam-groove a intersects itself at if and forms two angles n3 a", which g l I have termed, respectively, the angle oi aph ltl lf Tl p1 oac anc ie ang e o recession. ie

angle of approach is considerably greater or more abrupt than the angle ot' recession, where? by the shed is closed very rapidly, but is opened slowly. It is desirable that the opening motion should be comparatively slow and gradual, so as not to strain or injure the warp, while the l closing` motion should bc rapid, especially as the strain upon the warp decreases therewith. The opening motion is several times in dura* tion greater than the closing motion, thereby preventing` the dancing of the heddle-irames and enabling` the shed to be opened to the proper extent to permit the shuttle to be sent through it without requiring the excessive opening of the shed, as where an eccentric is employed.

Having thus explained the nature ot' the inn vention and explained a way of constructing and using the same, although without attemptingto set forth all ofthe forms in which it may be made and all or' the modes of its use, 1 declare that what I claim is l. In a loom, a dobby, a dobby-actuating lever fulcrumed on the loom, and a cam on the lay-operating crank-shaft for moving said lever, said cam having an endless intersecting groove, the said groove having at its intersection an angle of convergence greater than the angle of di\f*ergence.

2. ln a loom, a dobby, actuating mechanism therefor including a rock-shaft, an elbow-lever fulcrumed on the loom and having one arm operatively connected to the said shaft, and a path-cam on the lay-operating crank-shaft for actuating the said elbow-lever, said cam having the portion which controls the shed-closing movement more abrupt than the portion which controls the shed-opening movement.

In testimony whereof l have aiiixcd my sig nature in presence of two witnesses.

CHARLES F. PERI-IAM.

Titnessesz M. B. MAY, P. W. PEZZETTI.

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