A mechanism effecting play-free sinker movements in a shedding motion

Abstract

 The invention relates to a mechanism in a shedding motion, including a large number of preferably pneumatically or electromagnetically controlled selection members connectible with sinkers or the like.
The novelty resides in the feature that the selection members are arranged on reciprocally mobile carrying means (1, 2) which are actuable by operating means (3, 5,6, 9, 10; 4, 7, 8, 11, 12) imparting a preferably positive movement to the carrying means and being set so that relative motion between sinkers (29) and selection members (25, 26) will be eliminated at the selection moment.

Description

[0001] The present invention relates to a mechanism in a shedding motion, including a large number of preferably pneumatically or electromagnetically controlled selection members connectible with sinkers or like means.

[0002] In conventional jacquard machines the so-called knives must carry out a certain upward movement before the sinker hooks (suspension hooks) engage with their respective knives and, inversely, the knives must carry out a longer downward movement than the upper and bottom shed positions of the sinkers to permit the knives to be unhooked from their respective sinkers.

[0003] These over-riding or idle movements between knives and sinker hooks or between sinker studs and suspension studs or latch studs cause momentaneous accelerations or retardations in the sinkers with adherent harness threads and heald. This results in jerks causing inconvenient oscillations and vibrations in sinkers and harnesses.

[0004] The novel feature achieved by this invention is that the selection members are arranged on reciprocally mobile carrying means which are actuable by operating means imparting a preferably positive movement to the carrying means and being set so that relative motion between sinkers and selection members will be eliminated at the selection moment.

[0005] The invention will be described more fully hereinafter with reference to the accompanying drawings, in which:

Fig. 1 schematically shows an assembly according to the invention including sinker operating means or the like carried by mobile beams;

Figs. 2 and 3 are respectively a frontal and a sectional view showing examples of selection and hooking means fit for use in accordance with the invention; and

Figs. 4, 5, 6 and 7 graphically illustrate the relative movements in connection with various movements of the selection mechanisms.

[0006] A number of pneumatically or electronically operated guide and selection means 25 and 26 are mounted, in close and parallel relationship, on a pair of reciprocally movable beams 1 and 2, respectively. The beams are adapted to be actuated by a pair of cam disc means 3, 4 which are connected to the beams 1 and 2 via runners 5, 6, 7 and 8 and lifting levers 9, 10, 11 and 12.

[0007] To eliminate the jerk strains in a jacquard machine or the like, which includes a number of pneumatically or electromagnetically controlled guide and selection members 25, 26 for selection, hooking and release of sinkers in the diametrically opposite turning positions of the latter, i.e. top and bottom shed position, a small reciprocal collective movement is given to the sinkers during those time intervals of a shedding cycle when the sinker operating means or the locking mechanisms can stand still, i.e. in the top and bottom shed position, for instance through 75° of a revolution.

[0008] The selection members or selection bars 25, 26 are placed in parallel and close relationship and fixed on the two reciprocally movable beams 1 and 2, as shown in Fig. 1. The beams 1 and 2 are given their preferably positive movements by the cam disc system 3, 4 via the runners 5, 6, 7 and 8 and the lifting levers 9, 10, 11 and 12. Instead of the sinkers 39 being carried along with their curved sections and profiles, as shown in Figs. 4 and 5, in their turning positions, in movements relative to the studs 42 and 51 of the latch rockers ₃₇ and ₃8, respectively, the turning bearings 56, 56₁ of all the latch rockers 37, 38, in Figs. 2, 3, 4 and 5, in the selection system 25 and 26 move collectively towards and away from each other, so that the studs 42, 51 of the latch rockers will be given the same movements relative to the curved sections and profiles of the sinkers. However, the release and/or hooking of the sinkers takes place while the sinkers stand still. The selection members according to Figs. 2 and 3 are of the type shown in Swedish Patent 396,098.

[0009] Fig. 4 is a movement pattern showing the movements of the sinker operating mechanisms indicated by full curve lines. Broken curve lines, drawn within these curves, show how the turning bearings 56, 56₁ of the latch rockers 37, 38 move in relation to the movements of the sinker operating means. It is clearly shown here how the bearings 56, 56₁ of the latch rockers move a small distance S and S₁, respectively, during the same period, corresponding to e.g. 75° of the revolution, as the sinker operating mechanisms and consequently the sinkers 39 in Figs. 2 - 3 stand still in their diametrically opposite turning positions, i.e. in the top and bottom sheds.

[0010] Fig. 5 shows by full lines only the movements of the oscillation bearings.

[0011] Fig. 6 shows the reduced shed height h which can be obtained through a long period of rest in an open shed as compared to the much greater shed height H which would be necessary if the sinker operating means move according to a sine curve with the same ingoing and outgoing times for the weft introduction means, i.e. shuttles, spears and the like.

[0012] Fig. 7 shows different movement courses shedding courses for four different sinkers illustrated by the symbols: .... X X X -. -. -. 0 0 0 0.

[0013] From this it is clearly apparent how certain sinkers stand quite still during several weaving cycles in top and bottom shed.

[0014] This gives the following advantages:

1. that the sinkers need not carry out any over-riding movement, dead lift; the sinkers do not stop dead after a movement have started; hence considerably reduced vibrations in sinkers and harnesses; and

2. that hooking up of the sinkers on the hook studs 37₁, 38₁ of the latch rockers takes place when the bearings 56, 56₁ of the latch rockers, and consequently said latch rockers themselves, have taken their highest or lowest positions, while the speed between the latch studs 37₁ and 38₁, respectively, and the sinker studs 49 and 57, respectively, is nihil or almost nihil, whereby the wear on latch studs, sinker studs and the bearings of the latch rockers is considerably reduced. Jerks between latch studs and sinker studs can be entirely eliminated.

Claims

1. A mechanism in a shedding motion, including a large number of preferably pneumatically or electromagnetically controlled selection members connectible with sinkers or like means, characterized in that the selection-members are arranged on reciprocally mobile carrying means (1, 2) which are actuable by operating means (3, 5, 6, 9, 10; 4, 7, 8, 11, 12) imparting to the carrying means a preferably positive movement and being set so that relative motion between sinkers (29) and selection members (25, 26) will be eliminated at the selection moment.

2. A mechanism as claimed in claim 1, characterized in that suspension or latch means or latch rockers (34, 38) pneumatically or electromagnetically servo-operated on the selection members, including latch or suspension studs (37₁, 38₁), are carried along, via pairwise, collectively and reciprocally mobile bearing means (56, 56₁) for said hook means, in such a motion relative to sinker hooks or studs that the velocity approches zero at the moment when the sinkers (29) are hooked for standing still in top or bottom shed.

3. A mechanism as claimed in claim 2, characterized in that the suspension or latch means (37, 38) are carried along via their bearing means (56, 56_.) in collectively reciprocal movements relative to protruding or curved sections of sinkers standing still during the same time interval and that the bearing means (56, 56_.) are attached or mounted on bars, frames or like means, common to said bearing means, constituting the carrying means (1, 2).

Drawing