US3834425A

US3834425A - Double hooks for double-lift open-shed jacquard

Info

Publication number: US3834425A
Application number: US00340905A
Authority: US
Inventors: R Neyraud
Original assignee: Verdol SA
Current assignee: Staeubli Verdol SA
Priority date: 1972-03-27
Filing date: 1973-03-13
Publication date: 1974-09-10
Anticipated expiration: 1991-09-10
Also published as: FR2177565B1; DE2314603A1; FR2177565A1; JPS496246A; DE2314603C3; JPS5723010B2; DE2314603B2

Abstract

In a double hook for a double-lift open-shed jacquard, of the kind formed of a steel wire bent to U-shape to determine two parallel branches each carrying one of the main beaks of the hook while one branch has an open-shed catch welded thereto, this catch is welded to the branch along at least one of the two lateral generatrices thereof in order that the weld or welds may be situated substantially in the neutral plane of the branch with respect to the deflections to which it is submitted in operation. This avoids wire breakages due to the fatigue of the steel resulting from the repeated stresses which tend to concentrate around the weld when same is effected along a generatrix situated in the longitudinal plane of the hook, i.e. in the plane of flexion thereof.

Description

United States Patent 1 Neyraud Sept. 10, 1974 DOUBLE HOOKS FOR DOUBLE-LIFT 1,517,985 2/1968 France 139/65 E S JACQUARD 44,204 6/1908 Switzerland 139/63 [75] Inventor: Rene Neyraud, OTHER PUBLICATIONS Saint-Cyr-Au-Mont-DOr, France 1,909,333, 10-10-1970, Ger. Application (Kenk). [73] Assigneez Verdol S.A., Lyon, France Primary Examiner JameS Kee Chi [22] Flled: Mar. 13, 1973 Attorney, Agent, or FirmAlexander & Dowell [21 A 1. No.: 340 905 1 Pp [57] ABSTRACT In a double hook for a double-lift open-shed jacquard, [30] Foreign Apphcamn Prmmy Data of the kind formed of a steel wire bent to U-shape to Mar. 27, France l determine two parallel branches each carrying one of the main beaks of the hook while one branch has an [52] U.S. Cl. 139/65 open shed Catch Welded thereto, this catch is welded [51] Int. Cl. D03c 3/08 the branch along at least one f the two lateral [58] Field of Search 139/59-65 eratrices th f in Order that the weld or welds may be situated substantially in the neutral plane of the [56] References Clted branch with respect to the deflections to which it is UNITED STATES PATENTS submitted in operation. This avoids wire breakages 838,279 12/1906 Senn 139/63 due to the-fatigue 0f the Steel resulting from the 900,948 10/1908 Perrin 139/63 peated stresses which tend to concentrate around the 2,701,585 2/ 1955 Dalle 139/65 X weld when same is effected along a generatrix situated 3,480,044 11/1969 Servillat 139/65 X in the longitudinal plane of the hook, Le, in the plane FOREIGN PATENTS OR APPLICATIONS Of flexlon thereof 460,658 9/1968 Switzerland 139 59 6 Claims, 6 Drawing Figures H 4 I l, F- 1 1 9 ,1

DOUBLE HOOKS FOR DOUBLE-LIFT OPEN-SHED J ACQUARD The present invention relates to hooks for the jacquards associated with looms.

Modern jacquards generally comprise two movable knife frames or griffes which are reciprocated vertically in opposed directions and each hook is realized under double form with two branches by means of a steel wire folded at 180,the free end of each branch being bent in the form of a downwardly directed beak for cooperation with one of the movable griffes. One of the branches has a catch which is located above a stationary open-shed griffe when the hook is at the raised position. If the hook is to remain raised at the next weft stroke this catch is retained by the stationary griffe. But if on the contrary the hook should be lowered, it is pushed back by the corresponding needle in order that the catch may escape the stationary griffe. Since the upper beak of one of the branches is retained by a bar of the descending griffe, this branch should flex. Jacquards hooks are thus submitted to repeated resilient deflections at a rate which may reach five times per second with high speed looms. The periodic stresses thus generated are at a maximum where the needle acts on the hook.

The catches are generally welded to one branch of each hook along one of the two generatrices of the wire which are located in the mean longitudinal plane thereof, i.e. in the plane of flexion of the branch. Moreover the stationary open-shed griffe is usually situated just below the needles and therefore each catch is welded to the corresponding branch near the point thereof where the bending stresses are at a maximum. This results in a relatively rapid fatigue of the steel in the zone of the weld. The wire becomes brittle and sometimes breaks during operation of the jacquard.

It has been attempted to use wires made of special steels and/or to heat-treat the books after the welding of the catches, but these expensive methods have not eliminated hook breakages.

It is an object of the present invention to avoid these drawbacks in a simple and inexpensive manner.

In accordance with the present invention the openshed catch is disposed substantially laterally against the corresponding branch of the hook and it is welded thereto substantially along a generatrix situated in a radial plane perpendicular to the plane of flexion of the said branch, i.e. in the neutral plane of the branch with respect to the deflections thereof.

In the annexed drawings:

FIG. 1 is a side view of a double hook according to the present invention in a double-lift open-shed jacquard of which only the movable bars and the stationary bar which correspond to this hook are illustrated in cross-section.

FIG. 2 is an enlarged fragmental perspective view showing the open-shed catch laterally secured to one of downwardly to form beaks, respectively 2a, 3a. The lower portion 4 of the hook which connects branches 2 and 3 with each other is directed obliquely and it supports a cord 5 of the loom harness.

Reference numerals

6 and 7 designate the bars of the vertically movable griffes which correspond to hook I. At the position illustrated hook I has been raised by bar 7 acting on beak 3a.

An open-shed catch 8 is secured to branch 3 in the central portion thereof. At the raised position of book 1 this catch is situated just above a bar 9 of a stationary open-shed griffe. At the beginning of the descending stroke of bar 7 catch 8 is retained by bar 9 if hook I is to remain raised for the next weft of the loom. If on the contrary hook 1 is to be lowered, the corresponding needle (not illustrated) deflects branch 3 as indicated at F to such an extent as to bring same to the position shown in dash and dot lines, for which catch 8 may pass freely in front of bar 9 without hindering the descending motion of hook I.

This deflection of branch 3, which occurs in the mean longitudinal plane of the hook, determines in the wire a bending moment or in other words tensile stresses in the convex side of the branch (left-hand side in FIG. 1) and compressive stresses in its concave side (right-hand side). In the conventional construction the open-shed catch 8 is directly welded by its rear edge to the concave side, or in other words along a generatrix situated in the mean longitudinal plane of the hook, i.e. in the plane of flexion. The weld tends to concentrate the stresses and theresulting fatigue may cause breakage of the wire in the vicinity of the catch.

In the embodiment of the invention illustrated in FIGS. 2 and 3 the catch 8 if formed of a planar flat member having approximately the shape of a rightangled trapezium with its parallel sides perpendicular to the axis of branch 3. The vertical side is centrally notched to define two

lugs

8a, 8b. The lower side which is slightly inclined downwardly starting from the notched vertical side, forms the resting surface adapted to rest on the open-shed bar 9 while the oblique side 8d imparts to the catch the ratchet tooth profile desired. Catch 8 is disposed laterally against branch 3 in a plane parallel to the mean longitudinal plane of the hook and

lugs

8a, 8b are point-welded to the said branch at 11 and 12 along a generatrix situated in a plane radial to the branch and perpendicular to the general longitudinal plane of the hook i.e. to the plane of flexion of branch 3.

Points

11 and 12 are therefore situated in the neutral plane of the branch, i.e. in the zone unaffected by the bending stresses and they cannot cause any fatigue in the metal of the branch.

In the embodiment of FIG. 4 the catch 18 is more or less S-shaped in horizontal section in order that the portion of its lower edge adapted to bear on bar 9 may be situated in the mean longitudinal plane of the hook. A somewhat similar result may be obtained by disposing catch 28 and its oblique side 28d at a small angle with respect to the said mean longitudinal plane as illustrated in FIG. 5. In such an

embodiment points

11 and 12 nevertheless remain close to the neutral plane of the branch.

In the embodiment shown in FIG. 6 the catch 38 is U-shaped in horizontal section and the two straight portions l3, 14 thus formed, each of which may be similar to the catch of FIG. 2, is laterally point-welded to branch 3.

I claim:

1. In a double hook for a double-lift open-shed jacquard, comprising two resilient branches one of which has an open-shed catch welded thereto, said catch having a protruding nose adapted to rest on an open-shed branch, with said one branch being submitted during operation of the jacquard to deflections which determine a neutral plane in said one branch, said neutral plane including two generatrices of said one branch, the improvement which consists in said catch being welded laterally to said one branch substantially along at least one of said two generatrices.

2. In a hook as claimed in Claim 1, said hook having a mean longitudinal plane and said catch being in the form of a substantially flat planar member disposed laterally of said hook against said one branch and extending in a plane spaced from but substantially parallel to the mean longitudinal plane of said hook.

3. In a hook as claimed in claim 2, said member having a central recessed edge defining two separate lugs with said lugs being point-welded to said one branch.

4. In a hook as claimed in claim 1, said hook having a mean longitudinal plane and said catch being in the form of a substantially flat member folded twice to S- shape in a plane perpendicular to said one branch to determine a first portion disposed laterally of siad hook against said one branch and a second portion extending substantially in the mean longitudinal plane of said hook to form said protruding nose.

5. In a hook as claimed in claim 1, said hook having a mean longitudinal plane and said catch being in the form of a substantially flat planar member disposed against said one branch at an angle to the mean longitudinal plane of said hook.

6. In a hook as claimed in claim 1, said catch being in the form of a substantially flat member folded to U- shape in a plane perpendicular to said one branch to form two parallel portions disposed each side of said branch and each welded to said one branch along one of said generatrices.

Claims

4. In a hook as claimed in claim 1, said hook having a mean longitudinal plane and said catch being in the form of a substantially flat member folded twice to S-shape in a plane perpendicular to said one branch to determine a first portion disposed laterally of siad hook against said one branch and a second portion extending substantially in the mean longitudinal plane of said hook to form said protruding nose.

6. In a hook as claimed in claim 1, said catch being in the form of a substantially flat member folded to U-shape in a plane perpendicular to said one branch to form two parallel portions disposed each side of said branch and each welded to said one branch along one of said generatrices.