LU84822A1 - JAWS FOR TRACTION AND LIFTING APPARATUS WITH METAL CABLE - Google Patents

Description

- 2 - Jaws for wire rope pulling and lifting device The invention relates to jaws for wire rope pulling and lifting device as described in patent N ° 260,697.

In a device of this kind, the cable passes between the jaws of two identical clamping devices which, during the operation of the device, move towards and away alternately from each other, one sliding along the cable and the other tightening it.

Trunnions of semi-circular section integral with the jaws are pivoted in rods which ensure the spacing and the bringing together of the jaws.

The usual jaws for this type of traction and cable lifting apparatus are produced in the following manner: - forging of a part intended to supply two upper jaws, - forging of a part intended to supply two lower jaws, - turning four pins on each of the two forgings, - longitudinal sawing of the two forgings, thereby obtaining two upper jaws and two lower jaws, - milling the cable passage channel for each jaw, - breaking the angles and deburring, - heat treatment, - assembly of an upper jaw and a lower jaw to make a clamp.

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Such a manufacturing method has various drawbacks, among which a high cost price, but above all it involves a risk of malfunction due to the dispersion of manufacturing tolerances, since the operations are numerous and require two forging tools.

Trunnion centers can vary not only on the upper jaws, but also on the lower jaws.

As the upper and lower jaws work in association and as the functional dimensions relate to this association, the risk of scrap or incorrect operation is very high, a bad carrying for example which can compromise the tightening functions and cause a discontinuity in the progression of the cable in the device (pumping phenomenon).

In order to remedy the drawbacks of the usual jaws, the jaws according to the invention are characterized in that they are identical and constitute, when they are arranged opposite one another, after pivoting 180 ° relative to one another. to the other around their transverse axis, a clamp having a longitudinal offset compatible with the cutting of clamping rods intended to grip together a pin of each of the two jaws.

The attached drawing schematically illustrates the invention.

Figure 1 is an elevational view of two conventional jaws superimposed to form a collet.

Figure 2 is an elevational view of a jaw according to the invention.

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Figure 3 is a view similar to Figure 1 showing c two jaws according to Figure 2 superimposed and associated with rods.

In Figure 1 there is shown an upper jaw 1 and a lower jaw 2 conventional, which are associated for the production of a clamp. The lateral pins of the upper jaw are shown in 3 and in k those of the lower jaw. These jaws are manufactured separately, each requiring a special forging tool.

The body 5 of the jaw shown in FIG. 2, has on each face lateral pins 6, 7 with semi-circular section, the respective distances of which at the end closest to the jaw (distance a ^ for the pin 6 and distance b for the pin 7) are calculated so that, as shown in FIG. 3, by associating with the jaw 5 an identical jaw 5 'initially placed opposite it with the pins 6, 6' and 7, 7 'facing exactly the same as the cable passage channels 8, 8' then having undergone a rotation of 180 ° around the transverse axis YY 'perpendicular to the plane of the edges of its cable passage channel 8 ', the longitudi- shift. nal (of ab value) created between the facing pins 6, 7 'on the one hand and 7, 6' on the other hand is exactly compatible with the central cutout 9 presented by the tightening link 10 (shown in phantom) intended to cooperate with each pair of pins 6, 7 '; 7, 6 'to control the tightening and loosening of the clamp thus created.

It is thus understood that the embodiment of a jaw according to FIG. 2 allows, for the production of a collet, to use a single type of jaw to serve either as upper jaw or lower jaw, thereby providing significant advantages by reducing production costs and eliminating the risks of malfunctioning hitherto due to the dispersion of is; »I N.

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i! '' Thus, using two identical jaws placed exactly face to face so that the cable passage channels and the side pins are arranged opposite, then by rotating one of the jaws 180 ° around its perpendicular transverse axis in the plane of the edges of its cable passage channel, a clamp is produced, the journals of its lower element and of its upper element having between them exactly the longitudinal offset compatible with the cutout presented by each clamping rod and intended; to enclose together a pin of each of the two jaws, without the two jaws having between them the longitudinal offset i „which would be detrimental to the effectiveness of clamping the clamp.

The advantages obtained apart from a lower cost are the following: | a) Due to the fact that only one part model is used, only one forging tool is required for its manufacture, so that the jaws are absolutely similar, b) the machining operations are eliminated, there is no therefore more risk of disparity between the pins, whether in diameter or in alignment, c) if there were, if necessary, a drift in tolerances, it would concern identical parts and the pair of jaws would remain made up of absolutely compatible parts between them.

Claims (1)

1. Jaws for traction and lifting apparatus with metal cable, characterized in that they are identical and constitute when they are arranged facing one another, after pivoting 180 ° relative to one another to the other around their transverse axis, a clamp having a longitudinal offset compatible with the cutting of clamping rods intended to grip together a pin of each of the two jaws. UAAiJü