JPS63165553A - Improvement in negative dobby of system having revolving lever - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a passive dobby of the type with a swinging lever, intended for controlling the belt frame of a loom.

In the following, the present invention will be explained in detail in relation to the prior art.

It is known that in this type of dobby each belt frame is acted upon against the action of a spring or other elastic means which tends to return the frame to a predetermined position. As shown schematically in FIG. 1 of the drawings, each frame C is connected by a cable and/or a tension arm 1 to a suspension lever 2 which is pivoted at 3 to the frame 4 of the dobby. A connecting rod 5 supports each lever 2 and a lever 6 supporting a lever element.
, and the lever assembly 6 is pivotally supported on a common pivot shaft 7. The free end of this lever 6 is provided with a lever element 8 which is biased by periodic rotation about a pivot shaft 9. The fitted nasal element IO can cooperate with the rotating retaining hook 11.

The two hooks 11 are controlled by a common reading device 12 in the form of a peg or paperboard, which device contains a weaving program for producing the planned fabric.

In order to cyclically actuate the assembly of lever elements 8 of the dobby, a common mechanism is provided, comprising two pushers or crosspieces 13, which rotate on fixed pivots in the frame 4. It is carried by two side plates 14. At least one of these two plates 14 is, for example, an arm 1 whose hub L5a is eccentrically attached to the drive shaft 16.
It is energized by rotating with the help of 5.

This conventional structure is well known in practice and neither its arrangement nor its operation need be described in detail.

In conventional dobbies, the crosspiece 13 is constituted by a large, heavy rod of square or rectangular cross section (see FIG. 2), which, at the rear of the pivot 8a, is connected to a flat bead on each nose element 10. abutting a free surface, thereby ensuring that each of these nasal elements 10 on its lever 8 is pivotally fixed.

Regarding the upper cross member 13, this large and heavy characteristic is
The same does not apply to the opposing crosspieces, which requires making wide and deep notches 6a in each lever 6, although this is not a drawback since there is sufficient space.

This opposing crosspiece, whose C-shaped side profile already promotes deformation, clearly reduces the strength of the lever 60, while this crosspiece is present in the region where the associated lever is subject to very high forces.

Designers are therefore faced with two contradictory demands.

In order to reduce the bulk of the cross-pieces 13, their thickness is slightly reduced, these cross-pieces become centers of untimely bending, which leads to unfavorable vibrations and the nose piece 10
The working gap provided between the end of the reading hook 11 and the reading hook 11 is reduced, leading to reading errors. In order to avoid this drawback, if the thickness of the crosspiece 13 is increased, the depth of the cutout 6a of the lever 6 must be increased and the resistance to deformation will be reduced.

Therefore, a compromise must be made that clearly does not fully satisfy one or the other of the two requirements.

The object of the invention is to remedy at least the above-mentioned defects by providing a cross member 13 present at the level of the lever 6, which has an L-shaped cross section as shown in FIGS. 1 and 3. .

To see the benefits of the solution proposed in FIG. 3 with respect to the solution shown in FIG. 2, it is sufficient to compare the former with the latter.

Due to its L-shaped cross-section, the part or branch of the crosspiece 13 in FIG. 3 that is supported on the flat rear surface of the bead of the nasal element 10 has a much greater thickness and bulk than the crosspiece 13 in FIG. In addition, the bending strength is provided by the lateral parts or branches which, due to their orientation, have a high bending moment of inertia and therefore a very high stiffness.

Under these conditions, the depth of the notch 6a made in the lever 6 for the swinging of the crosspiece 13 in FIG. 3 can be reduced without reducing the strength of said crosspiece. , it is therefore possible to give said lever a much greater width than 1 in FIG.

A passive dobby of a batter's sleigh, of the type shown in FIG. It must be mentioned that the present invention can be advantageously applied to. These towing hooks 24 are rods actuated by the reading device 22 so that they are brought into position in the passage of a rotary traction member 250 which is biased by reciprocating motion at the moment of folding as a function of the weave of the fabric to be made. 21 and the gripped hook is then driven to actuate the corresponding pivot lever 8. The operation is therefore substantially similar to that previously described with respect to FIG. 1, the difference being that the movement begins at the level of the member 25 and no longer at the level of the crosspiece.

As can be easily seen, the L-shape of the lower cross member 13 provides the same benefits as in FIG. This is because it is possible to avoid the need to make the notches 6a of each lever 6 of the dobby too deep.

The invention also provides that at the end of each pivoting lever there is provided a nose piece similar to the nose piece referenced 10 in FIG. 1, which nose piece carries member 25 of FIG. It is also applicable to batter's sleigh dobies in cooperation with a tow hook carried by a similar pivot plate. In that case as well, it is advantageous to form the fixed lower supporting crosspiece from a piece with an L-shaped cross-section so that it has a reduced diameter and high resistance.

Furthermore, the above description is given by way of example only and in no way limits the scope of the invention, which cannot be exceeded by any other equivalents, even by substituting implementation details described. must be understood.

[Brief explanation of the drawing]

FIG. 1 is a schematic partial sectional view of a passive dobby with improved equipment according to the invention; FIG. 2 is an enlarged partial sectional view of a dobby with a conventional crosspiece; and FIG. 1 is a partially enlarged view, and FIG. 4 is a schematic partial sectional view of a hunter slade bee to which the present invention is applied. 6... Rotating lever 6a... Notch 10... Nose element 12... Reading device 13... Cross member

Claims (1)

[Claims] (1) Rotation of the type in which each of the pivot levers cooperates with two common cross members adapted to be supported on the bead of the nose element or pivot hook as a function of the control carried out by the reading device. In a passive dobby of the type incorporating a moving lever, at least the cross member disposed at the level of the lever supporting the pivot lever having a notch made to accommodate said cross member has a bending strength of A negative dobby characterized in that it has an L-shaped cross section, adapted to reduce its bulk while increasing its bulk.