US2646824A

US2646824A - Boss for dobby jacks

Info

Publication number: US2646824A
Application number: US237344A
Authority: US
Inventors: Emil C Johnson
Original assignee: H F LIVERMORE CORP
Current assignee: H F LIVERMORE CORP
Priority date: 1951-07-18
Filing date: 1951-07-18
Publication date: 1953-07-28
Anticipated expiration: 1970-07-28

Description

y 28, 1953 E. c. JOHNSON 2,

' soss'm DOBBY JACKS Filed July 18, 1951 Patented July 28, 1953 BOSS FOR- DOBBY JACKS Emil Johnson, Manchesten. Conn assignortov H. F. Liverm'ore Corp0ratio n,. Allston, Mass a.

corporation of Delaware Applicatiomluly 1 8, 1951, Serial N 0., 2313,44;

9 Claims. (Cl. 139-74) 1 This invention relates to dobby; motions in looms, and more particularly to dobby jacks.

In a common form of dobby motion the hooks. controlled by the pattern chai-ntransmit the moticn imparted to them by the knives to the dobby jacks through jack-backs which. are pivotally connected to the jacks by bosses formed, integrally on the jacks. These bosses project into the center bearings of the jack-backs and are made-of length or. s iah-thumbin he; ckness of the jack-backs, sothat the jacks; canbe positioned close together side by side for com paetness inthe dobby head; reliance being placed solely on the next adjacent jack to hold; the inte vening jack-hack in placev on its pivot. Since sufficient clearance must be given to. allow the individual jacks to move freely with respect to other in response to the demands of the pattern, the jfiCkr-bEtCKSLBJBJ able to. deviate way from their proper jacks Qutw-ardly onthebosses;v forming their pivots, with the result; that the, bosses: wear most. rapidly toward their outward ends. departing fromv their desired cylindrical form andr-ounding, off their outer; edges onwhich the. wear concentrates; in. an oblique manner which results in lost motion depriving the jack of itsintended scope of movement, and; also camming the jack-back sidewise into. interference andv jamming contact, with. the; adjacent jack, impairing, the latters freedom: of movement. Since thesebosses are conventionally an integral portion of they castin comprising the jaclgg. this wear; of the bosses ordinarily compels discarding replacing. of the entirejack. A repair-'- has. been proposed consisting oi; machining andzd'rill'r. ing the boss to make possible the. installation ofv a stud-like boss; usually made of bronze, rigidly and: non-rctatably riveted to the jack, which at: bestisonly aqteniporary. expedient, asitgis subject to-the same wealmessesoi; rapid wear andLjammingiof'the adjacent jacks, particularly on heavy loads of harnesses, where it sometimes wears. out in a weeks use. 7

In both these. cases, addition-ally; Wear of the center bearing of the jack-back which rides on the boss occurs becauseef the relative rotation of the boss surface within such bearing, evenwally-requiring replacement of the jack-back also. 1 r 1.

An. important object: of the. invention therefore is toienable; a jack. which hasabeen/rendered un. usable through wear ofthe integral boss initially. r ed; er-nontoe p r d. and: ont ued. in

'use; by removing the bossthereon.

2 I a. replacement boss. of simple and compact propprtionswhichembodies few partsand yet.is -.c n.-. structed so; that wear throughengagement with he jack-each is not, concentrated, ononeportion of, theouter rim to round off its. edges or to diminish its working diameter, but is distributed uniformly around the boss.

Another object of the invention is to provide a boss capable of supporting greater load than heretofore and at thev same time to; increase the life-of. the jack.

A further I object is toprovide a. boss which; will largely eliminate or reduce to a. negligible. degree thewear of the center bearing of; the jack-back incident to its. pivotalmounting on; the jack.

To thesevends; I have; devised a novel replaces of the jack-back and placed on; the stud androll; being distributed evenly around" the entire surface-of the roll. Whentheroll finally rou h. ens. 5 ar ow to: n mp ner size fit itcan easily bereplaced by an ideni a s thou h n c s ty of; discard naand replacing, the jaelnwhich itself-is a source of 'l i ii illustrative; embodiment of. the, device is shown: in the accompanying drawings; in which. 1; is-an elevation: of a portion-ofa (lobby jack Showing the roll. and mountingstud com.- prisi-ng the nevelhoss: fixed. thereon.

Fig. 2 is a section online-Q-Zof Fig-1.

Figs. Sandi-a showthe stud in section, illustrating, successive: stages: in; the; manufacture of the stud.

steel roll having a central; aperture 2 which fits rotatahly aboutthe cylindrical'surface I4 of the head 4. of a stud; ifixed the'jack; lever 8. Roll; I is retained in place on the head ei the; stud reasonofan inwardly extendingannular flange Ii which fits about a neck portion ti-of the head i oi the stud which is of reduced diameter intervening between the full diameter head; 4 andsthe, shank]. 0fthe,stud. Thisboss is applied towthe j ack lever at thesamelocation as that.

5.5.01 the origi al in e ral oss. te med. thereon...

For this purpose, the center of the original boss is spotted and a hole Iii drilled through the jack concentric therewith, of the proper size to receive the shank 1 of stud 5, and countersunk at its extremity remote from the boss, and thereafter the remainder of the old boss is ground off flush with the adjacent surface of the jack.

The stud is most securely fixed to the jack 8 by being riveted thereto, and for this purpose the shank I is made soft enough for heading over and also provided with a conical recess l2 faciliating the expansion of the end of the shank into the countersunk extremity of hole In as indicated in Fig. 2, while avoiding the formation of a protruding head at this surface of the jack lever. The roll I is made to fit closely within the hub or bearing provided at midlength of the jack-back (not shown) for its connection to the jack lever. But in accordance with the invention and contrary to the practice with the integral boss, this roll is not intended to have relative movement within the hub or hearing of the jackback; instead, all or most of the relative motion is intended to occur at the bearing surfaces comprised by the interior surface of aperture 2 of the roll and the opposing cylindrical surface M of the stud 5.

To attain a long life of the boss, provision must be made for preparing these bearing surfaces to endure their mutual contact, and because the boss is in novel manner made in two parts, it becomes simple in accordance with the invention to prepare these surfaces to receive such wear, by the step of hardening them. Thus, the entire roll I is hardened as a unit wholly apart and away from the stud, by any suitable or desired known hardening process. The stud presents a different problem, since its shank 1 must be left soft and malleable to provide for being riveted in place in jack 8. However, by coating the entire surface of a stud made of low carbon steel with a layer I6 of resist, as shown in Fig. 3, which for one example is effected sim ply by copper-plating the stud, and then grinding off such resist from the cylindrical surface of the head t of the stud to leave the underlying component steel of the surface it! exposed, as indicated in Fig. 4, which is easily done in a centerless grinder, hardening of the surface I4 alone can be easily accomplished by a cyanide treatmentin well known manner. Thus the bearing surfaces of the roll interior and the head of the stud are made capable of enduring long wear without rounding oif or wearing obliquely, a suitable lubricant being occasionally supplied, and wear of the jack-back by the boss is eliminated entirely or largely reduced, while the replacement boss is capable of being applied to and fixed in the jack lever in a very strong and secure manner by riveting it thereto.

The location of the bearing surface provided on the stud for the support of roll I is important in reducing the work and cost of making the novel boss to practical levels. By making the retaining flange on the roll I instead of on the stud, and making the part of the stud which has the greatest diameter serve as the bearing surface, the stripping of this surface :4 in most economical manner by the precise and nearly automatic action of a centerless grinder is made possible.

The neck portion 6 of stud 5 which intervenes between the head and the shank serves as a spacer permitting the stud to be drawn down against the surface of jack 8 to seat the interd vening radial shoulder 18 with the requisite tightness against the face of jack 8, while leaving the flange 3 of roll I loose and free. That is, portion 6 of the stud has greater axial extent than flange 3 of the roll.

By making the annular retaining flange 3 on the roll very narrow, a wide bearing surface M can be provided on the stud and thereby render the roll capable of supporting a heavier load through preventing the concentration of wear on the outer rim or any one portion of the roll.

While I have illustrated and described a certain form in which the invention may be embodied, I am aware that many modifications may be made therein by any person skilled in the art, without departing from the scope of the invention as expressed in the claims. Therefore, I

. do not wish to be limited to the particular form shown, or to the details of construction thereof, but what I do claim is:

1. Areplacement boss for a part of the dobby motion of a loom comprising in combination a relatively hard metallic roll having an annular flange at one end, and a metallic stud for rotatably supporting the roll on the dobby part and retaining the roll by means of the rolls annular flange, the stud having a relatively soft metallic shank for riveting to the said part of the dobby motion.

2. A replacement boss for a dobby jack comprising in combination a headed metallic stud having a relatively soft metallic shank integral therewith for attaching the stud to the jack and a relatively hard bearing surface, and a relatively hard metallic roll rotatably mounted on the stud having an annular flange integral therewith retaining the roll on the stud by engagement under the latters head.

3. A replacement boss for a dobby jack having in combination a metallic roll having an annular flange at one end integral therewith, and a metallic stud provided with a head and a neck, the latter acting as a spacer spacing the head from the jack, such stud rotatably supporting the roll and retaining the latter by means of the annular flange.

4. A replacement boss for a dobby jack, having in combination, a relatively hard metallic roll having an annular flange integral therewith, and a metallic stud having an enlarged head and a reduced portion fitting within the flange and seating against a surface on the dobby jack, such stud rotatably supporting the roll and retaining the latter by means of the rolls annular flange, and having a relatively soft metallic shank for attaching the stud to the jack.

5. A replacement boss for a dobby jack, having in combination, a relatively hard metallic roll having an annular flange integral therewith, a metallic stud having an enlarged head relatively hard at its periphery and a reduced portion fitting within the flange-and seating against a surface on the dobby jack, such stud rotatably supporting the roll and retaining the latter by means of the rolls annular flange, and having a relatively soft metallic shank for attaching the stud to the jack.

6. A replacement boss for a dobby jack, having in combination, a relatively hard metallic roll having an annular flange integral therewith, a metallic stud having an enlarged head relatively hard at its periphery and engaged by the roll, and having a reduced portion fitting Within the flange and seating against a surface on the dobby jack, such stud rotatably supporting the roll and retaining the latter by means of the rolls annular flange, and having a relatively soft metallic shank for attaching the stud to the jack.

7. A replacement boss for a dobby jack, having in combination, a relatively hard metallic roll having an annular flange at one end of the roll integral therewith, and a metallic stud having an enlarged head and a reduced portion fitting within the flange and seating against a surface on the dobby jack, the head of such stud having a relatively hard peripheral surface rotatably supporting the roll and retaining the latter by means of the rolls annular flange, and having a relatively soft metallic shank for attaching the stud to the jack. 7

8. A replacement boss for a dobby jack, having in combination, a relatively hard metallic roll having an annular flange integral therewith, and a metallic stud having an enlarged head with a hardened peripheral surface rotatably supporting the roll and retaining the latter by means of the rolls annular flange, the stud having a soft metallic shank for attaching the stud to the jack.

9. A replacement boss for a dobby jack, having in combination, a relatively hard metallic roll having an annular flange integral therewith, and a metallic stud having an enlarged head and a reduced portion fitting within the flange and extending therethrough seating against a surface on the dobby jack, the head of such stud having a relatively hard peripheral surface in rotational engagement with the roll and retaining the latter by means of the rolls annular flange, and having a relatively soft metallic shank with a conical recess in its extremity for attaching the stud to the jack.

EMIL C. JOHNSON.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,568,943 Amsden Jan. 5, 1926 1,841,923 Waters Jan. 19, 1932 2,368,007 Delahan et al Jan. 23, 1945 2,497,224 Laure Feb. 14, 1950 2,540,319 Bitzer Feb. 6, 1951 FOREIGN PATENTS Number Country Date 536,704 Great Britain May 23, 1941 597,797 Great Britain Feb. 3, 1948