US2836295A - Cable press with stationary press-head - Google Patents

Description

May 27, .1958 E. MULLER ET AL 2,336,295

CABLE PRESS WITH STATIONARY PRESS-HEAD 'Filed Nov. 18, 1952 [VVf/VTOZS ASE/V57 M04452 Aueusr GEOHMANN 7 7740170 1, n ul-ldmo plg THE/z Ame/vex;

.United States Patent- CABLE PRESS WITH STATIONARY PRESS-HEAD Ernst Miiller and August Grohmann, Duisburg, Germany, assignors to Hydraulik G. in. b. H., Duisburg, Germany, a German company Application November 18, 1952, Serial No. 321,244

1 Claim. (Cl. 207-22) The invention relates to a sheathing press in which a sheathing is provided for cables and the like, and which is particularly intended to press light metals and light metal alloys. Such a press is operated with a stationary press-head and two dies moved in opposite directions, which force equal quantities of the pressed material into the press-head.

In such known presses, one of the difliculties is the problem of moving the rams in opposite directions in such manner that they force out equal volumes at equal periods.

The known devices, by which this reverse motion is ensured, are heavy, bulky and expensive, and necessitate complicated control devices.

The invention is based on the discovery that in practice any resistance differences that do occur between the two pressed materials do not exceed a certain magnitude, so that balancing may be effected by means of devices which transmit only limited pressures, which in any case may be readily controlled constructionally and operationally.

According to the invention the oppositely directed rams are connected by means of a hydraulic power line which efiects the balancing When the pressure resistances are diflerent. This hydraulic power line entails at least one of the rams being provided with a larger diameter than the other and with a secondary cylinder, said cylinder being connected to a secondary cylinder of the opposite ram by means of a fluid-pipe. One secondary piston displaces as much fluid as is released by the other secondary piston, with exactly oppositely directed rams. If, due to a resistance difference, one ram remains stationary it will be supplied with energy by the secondary cylinder through the power line hereinbefore described, so that pressure is applied to effect the reverse motion.

The power line includes one secondary piston for each ram, and a third secondary piston on which the smaller ram acts.

When the diameter of one ram exceeds that of the other, a ramming pressure is constantly transmitted from one ram to the other through the hydraulic power line. Instead of having the diameter of one ram larger, it is also possible to provide additional cylinders, which serve the same purpose and render it possible to transmit to one side more energy than to the other and to transmit this excess energy through the hydraulic power line to the opposite side in spite of the diameters of the rams being the same.

The addition of the secondary cylinders, and if necessary or desired, of the additional cylinders, need not imply a substantial complication of the press, as most of these cylinders may be designed as return stroke cylinders which are required in any case. The control is provided accordingly.

The figure shows a diagram of the press with two pairs of hydraulic power lines between the rams. The two receivers 2 and 3 into which the pressed material indicated at 4 is forced by the rams 5 and 6 are provided 2,836,295 Patented May 1958 ICC on the stationary press-head 1. The rams are mounted on the cross-heads 7 and 8, which are operated by the rams 9 and 10a in the cylinders 11 and 120. Ram 10a and cylinder 12a are larger in diameter than ram 9 and cylinder 11.

To the cross-head 7 are connected the secondary pistons 39, the co-operating cylinders 31 of which are provided on the support 15 for the receivers, that is to say, they are stationary. When the ram 5 moves downwardly, the pistons 30 are also moved downwardly. The fluid displaced thereby in the cylinders 31 is fed through the pipes 16 to the hydraulic main.

As the force on the ram 6 is greater, the ram is inclined to lead the ram 5, but, additional ramming pres sure is fed thereto through the piston 20 and the pipe 22 as well as the cylinders 23 and the pistons 24, so that an exactly equal oppositely directed motion is obtained automatically.

The control devices 25 render it possible to release the hydraulic coupling between the cylinders 21 and 23 in that the line 22 can be opened against atmosphere so that the occurrence of pressure therein is avoided. In this manner it is possible to move the cross-heads 7 and 8 independently of each other towards the pressure head. By means of the control means 25 it is also possible to introduce pressure fluid from the outside into the cylinder 21 in order to be able to move the cross-head 8 independently. The independent retraction of the crosshead 7 by the piston 30 can be efiected by introducing water under pressure at 16 when the control means 25 allows the liquid to flow ofi from the cylinders 23. When, however, the control means 25 are so adjusted that the connecting lines 22are closed upon themselves, then the hydraulic linkage between the cylinders 23 and 21 is also effective during the retraction movement of the cross-heads 7 and 8 inasmuch as it is only necessary to introduce water under pressure through the line into the cylinders 31.

The control members 25 are used for effecting operation of the hydraulic power line by controlling the direction of the flow of fluid through the lines.

The secondary pistons 20 may be used for the return movement of the piston 10a. Special additional pistons 30 with corresponding cylinders 31 are provided for the piston 9.

These secondary pistons may be used to pass a greater flow of energy to one side of the press, even when the diameters of the rams 9 and 10a are equal. In this case, the cylinders 31 are connected to the hydraulic main of the pressure cylinders also during the pressure stroke, so that the piston 30 counteracts the piston 9, the result being the same as if the piston 9 had a smaller diameter than the piston 10a. The fact that the piston 30 is used for this purpose does not exclude the possibility of its being also used as a return-stroke piston.

We claim:

A press for the sheathing of cables and the like, particularly for pressing light metal and metal alloys, comprising a frame, a stationary press-head to hold the metal to be pressed, oppositely acting rams mounted on movable cross-heads to press the metal in the press-head from two sides, main cylinders mounted on the frame, one of said cylinders having a diameter larger than the other, pressure fluid actuated pistons of different diameter in the main cyinders secured to the ram cross-heads to move the rams in a metal-pressing direction, secondary cylinders mounted on opposite sides of the press-head, pressure fluid actuated pistons in the secondary cylinders secured to opposite sides of each ram cross-head for retracting said rams and said cross-heads, further secondary cylinders mounted on the frame, pressure fluid actuated pistons therein secured to one of said ram crossg-retracting the other ram cmgs head whi ch is actuated 5 by said 1 nain pistotx fgreater diameter, thus balancing heads; which .is :actuated by'sziid main piston of smallety pressure fluid-1t0 or between the secondary cylinder: to 7 diameter, "to move in metal-pressing direction, conneccause the pistons to alternately balance or move the ram tioti means' between said last secondary cylinders and p y- H v V said secondarycyhnders'mounted on the press-head for 7 References Cited inthg file of this patent UNITED STATES PATENTS the press head on the ramicross-head pf the smaller Re. 13,562 Summey;v 5 May 13, 1913 main piston', and va1ve-means for'selectively valving the 1,109,555 Summey Sept. 1, 1914 V

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