US1074670A - Dobby. - Google Patents

Description

B.. F. WATGHORN.

DOBBY.

APPLIouIoN FILED D20. s, 1912.

1,074,670. Patented oeuf/,1913.

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APPLICATION FILED DEO. 5, 1912.

Patented 0G13. 7, 1913.

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DOBBY.

APPLIGATION FILED 1130.5., 1912.

Patented 00L?, 1913.

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ROBERT F. WTCHORN, OF MILLBURY, MIASSACHUSETTS.

DOBBY.

T 0 all whom t may concern Be it known that T, RoBERT F. WATCH- oRN, a citizen of the United States, residing at Millbury, in the county of Worcester and State of Massachusetts, have invented anew and useful Dobby, of which the following is a specification.

This invention relates to a dobby capable of general application, and in which the harness jacks are moved positively in one direction only, the return movement of the harnesses being accomplished by means of spring connections.

A dobby constructed in accordance with my invention comprises important advantages when used upon any form of work ordinarily produced by a. dobby loom,A but is particularly adapted tothe production of that class of fancy goods which are termed full-turn lenos. The production of this type of fancy weave upon a dobby of ordinary form, such for instance as that shown in the patent to Crompton, No. 771,462, of Oct. 4, 1904, involves a rearrangement of parts and an addition of auxiliary mechanism. Leno weaving of this description is usually four harness work, the harnesses taken in order from front to back being designated as the doup harness, the front standard harness, the crossover harness, and the back standard harness. The operation of the first and last mentioned of these harnesses presents no difficulties, as the harnesses have the usual full-up or full-down motion, and the order in which these motions take place may be readily controlled by the usual pattern chain. The so-called front-standard and cross-over harnesses however, have a peculiar motion for the production of which the ordinary dobby is not well adapted. The front-standard harness is maintained in the upper shed at each pick, but must be brought to half-way down or to middle position between each two successive picks. To accomplish this on the ordinary dobby, it is necessary to use two jacks for each harness, and to insert temporary attaching means between the second or auxiliary jack and the harness. With this arrangement, one jack allows the-harness to descend under the influence of the usual retracting spring, until it reaches mid-position when the second jack traveling in the opposite direction picks up the harness and raises it again to the upper shed.

Speccation of Letters Patent.

Application filed December 5, 1912.

Patented Oct. 7, 1913.

Serial No. 735,018.

The connections necessary to permit two jacks to operate upon a single harness are of more or less delicate construction, and much diiiiculty is experienced in their operation. The movement of the cross-over harness presents still more serious difficulties. This harness is normally maintained in the lower shed at each pick, but must be raised to mid-position between each two successive picks. This movement cannot be performed by the ordinary harness jacks, as there is no method by which a jack .when once started in the upward direction can be stopped until it has performed its full stroke. TvVith the usual dobby, therefore, it is necessary to disconnect the cross-over harness entirely from the usual jack operating mechanism and to provide some form of independent auxiliary mechanism commonly known as a jumper to operate the cross-over harness.

It is one of the objects of my invention to produce a dobby1 in which the peculiar motions of the front standard and crossover harnesses may be secured merely by the proper pinning of the pattern chain, and without the use of auxiliary mechanism or rearrangementof parts.

Another object of my invention is to provide improved means for operating the pattern chain and hook-lifting mechanism.

Further objects of my invention will ap pear in the following specification.

Reference is tobe had to the accompanying drawings in which- Figure l is an end elevation of a leno dobby constructed in accordance with this invention; Fig. 2 is a front elevationthereof, and Fig. 3 is a vertical sectional view on the line 3 3 of Fig. l.

The invention is shown as applied to a dobby provided with jacks 4. The jacks are pivoted on a transverse rod 5 and removably supported thereon. Each one is pro-vided with a curved slot 6 through which slots passes a rod 7 supported in stationary position on the frame to limit their motion for the purpose of lifting the harnesses in the usual way. The means for operating the jacks will now be described.

With each jack is pivotally connected a hook 9 and to it is pivoted a second hook 10. Thus these hooks reciprocate in pairs. The mechanism illustrated herein is intended to be run by a crank or eccentric on the crank-shaft (not shown) of the loom.

This crank is Connected with a link 11 which is adjustably connected with an arm 12 having a slot therein for the connection. This arm is fixed on a rock shaft 13 supported by the frame and is thus given a complete up and down reciprocation for each revolution of the crank shaft, and hence for each pick of the shuttle. On the shaft 18 are a pair of arms 14 extending in opposite directions and connected with links 15 and 16, respectively, which are in turn connected with reciprocating knives 17 and 18. Thus the two knives reciprocate alternately and each performs a complete reciprocation/f for each pick of the shuttle. The knife 17 operates under the set of hooks 9 and the knife 18 operates under the hooks 10. The links 16, as shown in F ig. 2, are pivoted to the arms 14 at a greater distance from the axis than the links 15, and hence the knife 18 receives a greater travel than the knife 17. Each knife has also a certain amount of idle travel or lost motion at the left extreme of its travel, as shown at 18 in Fig. 2, and at 17 Yin Fig. 3, this idle travel being beyond the limit of travel of the hooks 9 and 10 toward the left. The arms 14 are so proportioned that the effective travel of the knife 17 is substantially one half that of the knife 18. 1n other words, the knife 17 which engages all of the jack hooks 9 at each pick raises them only half way, thus bringing the warp threads controlled thereby to substantially horizontal position, while the knife 18 which engages certain of the hooks 10 as determined by the pattern chain moves those hooks to the extreme righthand position in Fig. 2, thus raising the Warp threads cont-rolled thereby to the extreme upward position. This arrangement possesses certain peculiar advantages in the production of lenos which will be hereinafter explained, but it also possesses distinct advantages when applied to any weave in which one or more of the harnesses remains in the lower shed for a succession of two or more picks. On the rock shaft 18 is another arm 2O with which is connected a link 21 operating to oscillate an arm 22 on a short shaft 28 which is provided with a spring-pressed roll 24 adapted to cooperate with a cam wheel 25 on the chain cylinder shaft 26. This shaft is supported on another arm 27 extending from the shaft 28 and the oscillation of the arm 20 causes the chain cylinder 28 to rise and fall at regular intervals. At each reciprocation of the cylinder and while the pins are substantially out of contact with the tumblers, the cylinder is turned one step by any suitable means, such as a ratchet 25, (see Fig. 2) coperating with a hooked pawl mounted upon a stud fixed to the frame of the dobby. The pattern cylinder is thus advanced one step for each vertical reciprocation thereof or hooks 10. lVhen the cylinder rises the wires 32 corresponding to the pins then at the top ofthe cylinder drop and thus allow the hooks 10 to drop.

This construction is designed to overcome certain objections to the use of the rigidly mounted attern cylinder heretofore coinmon and cisclosed in the patent to Crompton mentioned, in which the pins have a sliding motion relative to the tumblers. Vhen metal pins are used this constant sliding motion results in excessive wear of the tumblers, and when it is sought to avoid this wear by the use of wooden pins, the 'pins frequently break and cause imperfections in the cloth which continue until the broken pin is detected. In my arrangement the pattern cylinder is turned when the pins are substantially out of contact with the tumblers, and are then moved toward the tumblers in a direct lineal motion so v'that theV wear due to the sliding contact is eliminated.A

The operation of my device in the roduction of full-turn lenos will now be explained For the operation of the front standard harness which, as before stated, is normally in the upper shed and is brought half down and returned to upper positionV between each two successive picks, it is merely necessary to arrange the pattern chain so that the hook 10 connected with said harness shall remain substantially in lowered or operative posi-V tion. Assuming that the harness is up and the knife 18 is about-'to commence its travel toward the left in Fig. 3, it will be seen that the harness will be lowered until the hook 9 contacts with the knife 17, which is at this time moving toward the right in Fig.

8 and which will prevent the retracting Y springs from depressing therharness below the horizontal position of the warp threads controlled thereby. As the knife 18 performs a complete reciprocation and returns to the extreme right position between each two successivev picks, it will be evident that if the hook 10 is allowed to remain in lowered position, the knife 18 will again assume control of said hook upon its return travel toward the right and will return the harness to extreme upper position.v

The operation of the so-called cross-over harness which is normally in the lower shed and is raised to mid-position between each two picks is accomplished by simply maintaining the hook 10 connected therewith in raised position, so that the harness is operated entirely by the knife 17 through the hook 9. This knife, as before stated, raises all of the harnesses to mid-position between each two picks of the loom, and therefore, communicates precisely the desired motion to the cross-over harness. It will be evident that the raising of all of the harnesses to mid-position will relieve the warp threads inv the lower shed of the excessive strain in beating up, which is experienced when certain of the harnesses are maintained in lowered position during the forward beat of the lay.

Although I have illustrated and described one form in which the invention may be made, I am aware of the fact that modications can be made therein without departing from the scope of the invention as expressed in the claims. Therefore, I do not wish to be limited to the details of construction herein shown and described, but

I/Vhat I do claim is Y 1. A dobby comprising a set of jacks, a pair of hooks connected to each jack, and a reciprocatingknife for moving each hook, each of said knives making a complete reciprocation during each pick of the loom, and one of said knives having an eective travel substantially twice that of the other knife.

2. A dobby comprising a set of jacks, means to move all of sai-d jacks to mid-positio-n at each beat of the lay, and selective means to move certain of said jacks to extreme upper position.

3. A loom having in combination harnesses, jacks connected to said harnesses, hooks mounted on said jacks, and a second set of hooks pivotally mounted on said first mentioned hooks, means for moving said rst mentioned hooks to raise all of the harnesses to mid-position at each beat of the lay, means for moving the harnesses connected to certain of said second mentioned hooks to eXtreme upper position, and pat tern means for selecting said last mentioned harnesses.

4. In a dobby, a jack, a pair of hooks connected to said jack, and means operable upon said hooks to raise said jack to eXtreme upper position for successive picks and to permit said jack to be moved to mid-position between such successive picks.

5. In a dobby, a jack, a pair of hooks connected to said jack, and means operable upon said hooks to raise said ]ack from eX- treme lower to mid-position and to permit said jack to return to eXtreme lower position between two successive picks of the loom.

6. In a dobby, a pair vof reciprocating knives, a pattern cylinder, an oscillating shaft, means on said shaft to reciprocate said knives simultaneously in opposite directions, additional means on said shaft to raise and lower said cylinder, an operating arm on said shaft, and a link directly connecting the arm to the crank shaft of `the loom,.whereby the knives and cylinder each perform a complete cycle of movements at each revolution of the crank shaft.

7 In a dobby, a pattern cylinder, pattern pins mounted thereon, a set of tumblers,

and means for both raising and lowering said cylinder between each two successive picks of the loom, said cylinder being rotated step by step when said pins are substantially out of contact with sai-d tumblers.

8. In a dobby for looms, the combination with a set of jacks, of hooks connected with the jacks, additional hooks connected with the first named hooks and movable therewith, two knives, one adapted to coperate with each vset of hooks, and means for simultaneously reciprocating said knives in opposite directions and for returning them to their original po-sitions during each complete beat of the lay.

9. In a loom, a crank shaft in combination with a set of jacks, hooks connected with the jacks, additional hooks connected with the first named hooks and movable therewith, two knives, one adapted to coperate with each set of hooks, an oscillating shaft having arms projecting therefrom in opposite directions, a link from each arm to one of said knives for operating it, and an additional arm on sai-d oscillating shaft connected by a link to the crank shaft, whereby each knife is given a complete reciprocation for each beat of the lay.

In testimony whereof I have hereunto set my hand, in the presence of two subscribing witnesses.

ROBERT F. WATCHORN. IVitnesses:

Rosa WATCHORN, C. FoRRnsT Wasson.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, D. C.

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