US2984264A - Dobbies - Google Patents

Description

May 16, 1961 E. HOENiG ETAL DOBBIES Filed Nov. 4, 1958 United States Patent C) DOBBIES Ernst Hoenig and Walter Wicker, Obern'eden, Switzerland, assignors to Gebr. Staubli & Co., Horgen, Switzerland, a Swiss company Filed Nov. 4, 1958, Ser. No. 771,771

Claims priority, application Switzerland Feb. 21, 1958 2 Claims. (Cl. 139-71) This application is an improvement on Staubli copending application, Serial Number 711,076, filed January 24, 1958.

Our co-pending patent application Serial Number 711,076 describes a dobby with a pattern card, at least one draw knife and draw hooks associated with the knife and controlled in the association by the card pattern. All draw hooks attached to this draw knife are separated therefrom by a movement of the knife, initiated in accordance with the pattern control of the hooks.

The present invention relates to an improvement in a dobby of this kind. According to the invention, a draw knife which is about a pivot axis extending in the longitudinal plane of the knife has a projection that fits into recesses in the draw hooks in such a manner that the draw hooks can be driven by the projection in both its directions of oscillation.

An embodiment of the invention chosen by way of example is particularly described hereunder with reference to the accompanying drawing in which:

Figure 1 is a diagrammatic sketch of a portion of a dobby in which the invention is installed.

A part of a double-lift open-shed positive dobby is shown in section in the drawing. Two knives 1 and 2 are driven oppositely to one another in a known manner and each can alternately occupy an upper or basic lower position. The knife 1 in the upper position, is engaged with the hook 3 of one of the two baulk-levers 4 shown in the drawing and mounted to pivot about a pivot. By these means the associated baulk lever 4 has been oscillated upward and as viewed in the drawing the associated heald shaft has been drawn into the upper shed by means of a rod 5. A movable stop bar 6 capable of reciproeating movement in unison with the knife 1 engages the top end of the baulk lever to ensure that the hook 3 moves without play. When the baulk lever 4 is rotated to its right position as viewed in the drawing the knife 1 is in its basic position. The upper hook 7 is supported by a support needle 8 beyond engagement with the knife 1. A shoulder 9 on the hook 7 extends behind a stationary rail 10, to hold the top end of the associated baulk lever against a stationary stop bar 11. The support needles 8 are actuated by pressure needles 12 and a presser rail 13, in the manner illustrated and described hereafter with reference to support needles 15 associated with lower hooks 14 mounted to oscillate about the pivot axis of baulk levers 4.

The lower knife 2 is in the basic position and released from engagement in the recess of hook 14, so that the associated hooks 14 can be controlled as hereinafter described. While the knife 2 is in this basic position, it first of all pivots in the clockwise direction. A mechanism for pivoting the knife is described for instance in US. Patent No. 2,815,044 and does not form part of the subject matter of the present invention. The draw knives 1 and 2 are specially shaped in such a way that the attachment surfaces A for the draw hooks 3 and 14 Patented Mary 16, 1961 respectively to have the shape of a tooth of a gear wheel. The hooks are shaped accordingly; that is the attachment surfaces of the hooks are recesses 16 into which fits the tooth-formed attachment surfaces of the associated knives. When the knives are pivotally oscillated as described in US. Patent No. 2,815,044 and as the attachment surfaces of the knives are a certain distance from the pivoting axes of the knives they lift the hooks, or in other words, they make the hooks pivot a certain amount around their axis of the attachment with the baulks. It is quite clear, that after a certain amount of oscillation of the knives they get out of gear as shown by the relative positions of knife 2 and hook 14. The oscillation of the knives are limited to such a degree, that the hooks are lifted to a position, wherefrom the knives can rotate in anticlockwise direction without meshing with the recess of the book if the hooks have been supported by the supporting needle according to the pattern card. If on the contrary, according to the pattern card, a hook according to the pattern has to be engaged by the knife, the supporting needle has been pushed away by its pushing needle thus freeing the hooks to fall. .As soon as the hook has fallen a small amount, the attachment surface A of the knife will mesh with the recess of the hook and bring it to full attachment. When the hooks are lifted by the knives, the shoulders 9 and 17 of the respective hooks are behind respective stationary rails 10 and 18. While the hooks 14 are in this disengaged position, the support needles 15 associated with the hooks are con trolled according to the pattern. When a reading needle 19 engages a hole in a pattern card 20, the associated presser needle 21 is moved to the right by a presser rail 22, so that the support needle 15 is moved to the right. The top ends of the support needles 15 are clamped firmly in a stationary transverse member 23, and these needles tend, owing to their own resiliency, to bear against a transverse member 24. In this position the bent lower ends of the support needles 15 are under projections 25 on the hooks 14, so that these hooks are held by the projections 25 from moving downward, when the knife rotates in the counter-clockwise direction, before the knife is engaged in recess 16. The hooks 14 supported by the support needles 15 in accordance with the pattern are not touched by the knife pivoting in the counter-clockwise direction, and the knife cannot enter the recesses 16 in the supported hooks. But the hooks 14 which have the support needles moved to the right are biased downward around the pivot axis by plate springs 26 fixed to the transverse member 13 and by their own weight, and are engaged by the projection Zn on the knife 2 as it pivots in a counterclockwise direction enters the recesses 16 of the associated hooks 14 immediately after the downward pivotal movement of the knife begins, and positively engages these hooks with the knife 2. The downward pivotal movement of the projection 2a on the knife 2 at the same time completely removes the play in the recesses 16, so that the attached draw hooks 14 are moved without play by the knife 2 and the movable stop bar 27 associated with the knife. The position of the knife 2 and of an associated hook 14, immediately after the downward pivoting of the projection on the knife 2 is shown in dot-dash lines in the drawing.

For each draw hook 14 there is a spring 26 which tends to bias the draw hook, supported by the associated support needle 15 or 8, downwards.

It is clear that the control operation for the upper knife 1 and the upper draw hooks 3 proceeds similarly to that described with reference to the lower knife 2 and the lower draw hooks 14.

The advantage of the construction described is that the attachment of the hooks to the knives: and their detachment therefrom is positively effected by the projection on each knife, and that particularly the engagement of the selected hooks with the projection on the knife takes place very smoothly. Moreover, the construction described is not only applicable to positive dobbies but can also be used equally well in (lobbies with resilient return of the heald shafts. It will also be clear that theretention of those hooks which are not to be attached to the knives need not necessarily be eifected by means of the support needles 8 and 15, and that it is also possible to use for instance a construction as described in our co-pending patent application Serial Number 711,074.

What we claim is:

1. A dobby having pattern card means for pattern control and comprising; a plurality of elongated draw hooks, each having a longitudinal axis and a pivot end and a free end, said draw hooks being pivo-tally mounted with their longitudinal axes parallel for oscillation about a common axis normal to said longitudinal axes, each said free end defining a recess shaped similarly to recesses defined between the adjacent teeth of gear wheels, said recesses being positioned at an acute angle to said longitudinal axes of said draw hooks; at least one draw knife having a longitudinal axis mounted adjacent said recesses of the draw hooks for pivotal oscillation about said longitudinal axis parallel to said common axis of oscillation of said draw hooks, said draw knife having a radial projection extending for the length of said knife and shaped similarly to a tooth of a gear wheel and complementary to the acutely angled recesses of said draw hooks for engaging in said recesses; means for biasing said plurality of draw hooks toward said knife for engagement therewith; means for pivotally oscillating said knife about its longitudinal axis to engage said radial projection in said acutely angled recesses when said knife moves in one direction in its oscillation to lock said draw hooks to said knife, and for disengaging said radial projection from said acutely angled recesses when said knife moves in the other direction in its oscillation to free said draw hooks from engagement with said knife; and means for moving said draw hooks into and out of engaging juxtaposition with said knife in accordance with said pattern control means as said knife is oscillated.

2. A dobby as described in claim 1 characterized in that means for biasing said plurality of draw hooks toward said draw knife comprises blade spring clips mounted stationary and adjacent said hooks, and having free ends turned back to form sliding contacts with respective knives, and said knives being shaped to engage in sliding cooperation with said blade spring clips.

References Cited in the file of this patent UNITED STATES PATENTS 1,674,862 Gordon June 26, 1928 2,431,597 Wiget Nov. 25, 1947 2,644,488 Pfarrwaller July 7, 1953 2,815,044 Staubli Dec. 3, 1957

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