DE1040886B - Device, in particular straightening machine for bars, with two coaxially spaced heads - Google Patents

Description

A device with two coaxially spaced heads is known, which exert a tension or pressure on a workpiece and their holder on a parallel to the direction of force arranged carrier seated by bending forces by one on the opposite side of the carrier arranged strut engaging the holders and a compensating force on the strut exerting hydraulic piston is relieved. The invention also relates to such Device and in particular a straightening machine for bars.

In the known device, which serves as a press, the carrier is standing in the same or in arranged smaller parallel distance from the strut than from the axis of the heads. In contrast to this is according to the invention, the carrier in the floor parallel to this at a greater parallel distance from the underneath strut lying on it than arranged from the axis of the heads. That leads to a decrease in the Buckling and tensile loads on the girder, because these are due to the sum of the forces acting on the workpiece and the force exerted on the strut by the hydraulic piston. The one exercised on the strut However, the greater the distance between the strut and the support, the smaller the force. As a result of the lesser Buckling or tensile load on the carrier reduce its dimensions so much that the carrier can easily be accommodated in the floor. But this has the advantage that you can use the Operation of the device can comfortably approach the workpiece in order to monitor the work process and to be able to clamp and unclamp the workpiece.

In a preferred embodiment of the invention, the holder is on the carrier and the strut Can be moved and locked in the longitudinal direction. This has the advantage that the device of Can easily adjust the length of the workpiece to be treated.

The horizontal arrangement of straightening machines for bars is not new in itself. At acquaintances Machines of this type, however, were not supported in the floor, but arranged above it and impaired hence the accessibility of the workpiece.

In the drawing in which the invention is applied is shown on a hydraulic stretching machine for metallic workpieces, shows 1 shows a side view of the machine, FIG. 2 shows a section along line 2-2 of FIG. 1. Fig. 3 is a section along the line 3-3 of FIG. 2. The machine shown in the drawings for Stretching metallic workpieces contains a first device,

in particular stretch straightening machine

for poles, with two in distance

coaxially arranged from one another

Minds

Applicant:

The Loewy Engineering Company Limited, London

Representative:

Dipl.-Ing. M. Licht, Berlin-Steglitz, Borstellstr. 51, and Dr. R. Schmidt, Oppenau (Renchtal), patent attorneys

Claimed priority:

Great Britain 22 February 1955 20

Frank Sidney Salter, Parkstone, Darset (UK), ag has been named as the inventor

Gripper head 10, which is attached to a hydraulic piston 11. This is in a cylinder bore 12 a holder 19 displaceable. The piston 11 and the cylinder 12 together form the hydraulic one Main drive 13. Opposite the first gripper head 10 there is a second one formed by a holder 20 Gripper head 14. This can by a (not shown) drive in the direction of the first gripper head 10 and moved away from it. Both gripper heads have tongs 15, into which the workpiece to be stretched, e.g. B. a rod / ?, can be firmly clamped.

The frame of the machine contains horizontal, arranged in the floor parallel to this, in the The longitudinal direction of the machine extending carrier 16, which are attached to the holder 19 and a sliding

4-5 tracks for moving the second holder 20 form. The carriers 16 are provided with recesses 17 at points spaced apart from one another, in which a cross rail 18 can be inserted. If that happens. The holder 20 is thereby counteracted Shift in the direction of the holder 19 locked. The holder 20 can also be on a slide be arranged, which runs with wheels on the upper supports 16 and is provided with hooks. those in notches the carrier 16 can occur.

& 09 657/263

Claims (2)

The holders 19 and 20 have downwardly directed tail pieces which carry a strut 21 at their lower ends. A piston 23 which is displaceable in a cylinder bore 22 of the holder 19 and is fastened to the strut 21 exerts a compensating force on the latter. The inner surfaces of the cylinders 12 and 22 are connected to one another by a channel 24 which is provided in the holder 19 and which is in turn connected by a channel 25 to a pump or another source of pressure medium. The other end of the strut 21 is slidably mounted in the holder 20 and provided with a series of notches 26 which correspond to the recesses 17 and serve the purpose of receiving an approximately U-shaped bolt 27, which is then attached to that side of the Holder 20 applies, which faces away from holder 19. In this way, the strut 21 can be locked against displacement in the holder 20. When the machine is in operation, the workpiece in the form of the rod B is first introduced into the space between the gripper heads and clamped into the tongs 15. Before this, the gripper head 14 must be brought to a distance from the gripper head 10 corresponding to the workpiece length and then locked with the aid of the parts 18 and 27. Then the hydraulic pressure medium is switched on. As a result, the main hydraulic drive 13 generates a force by which the workpiece B is stretched. This force seeks to pull the gripper head 10 away from the gripper head 14. The tensile stress on the rod B corresponds to a counterforce which is absorbed by the upper frame girders 16 as a compressive force. Since these frame girders lie below the horizontal plane which absorbs the axis of the operating force, the frame girders 16 would be subject to bending due to a lack of special precautions. L * m to relieve the carrier 16 of these bending forces and to cancel the bending moments, the compensation device in the form of the strut 21 and the hydraulic auxiliary drive, which is formed by the cylinder 22 and the piston 23, is provided. The cylinder 22 is charged with the pressure fluid through the common channels 24 and 25 at the same time as the cylinder 12. As a result, a force acts on the piston 23 which tries to pull the strut 21 away from the holder 20. The force acting in the strut 21 therefore has the same direction as the operating force acting on the rod B. This compensating force also generates a bending moment acting on the upper frame girder 16, which, however, has the opposite direction as the bending moments generated by the operating force. The ratio of the balancing force to the operating force is now measured inversely relative to the ratio in which the distances between the rod B and the strut 21 from the frame girders 16 are. Then the two bending moments turn out to be the same, but act in opposite directions, so that they cancel each other out and therefore the upper frame girders 16 are not subjected to bending stress and therefore do not experience any deflection. Of course, the size of the hydraulic cylinder 22 and the piston 23 depends on the distance. in which the strut 21 of the upper frame girders 16 is arranged. The greater this distance, the smaller the size of the hydraulic auxiliary drive. This distance is therefore as large as possible, in any case greater than the distance between the carriers 16 and the axis of the heads 10 and 14. Since the frame girders 16 are only subjected to pressure, but not to bending, they can be relatively weakly dimensioned, as the drawings show. The space between the gripper heads 10 and 14, which picks up the workpiece, is not blocked laterally by any parts of the machine, as FIGS. 2 and 3 show. This is a very important advantage of the invention. In another embodiment of the invention, the entire frame can run on wheels in the horizontal direction on the foundation of the machine and be bound by springs. This absorbs the impact that occurs if the workpiece breaks, for example. Since the machine has a relatively low weight, the invention has the advantage that the intermittent stresses exerted by the machine frame on the springs when the workpiece breaks are reduced. It is true that the invention has been described above in application to a hydraulic machine for stretching workpieces. However, it is just as suitable for use on other machines where it is important to exert a force on a non-displaceably clamped workpiece. An example of this are machines for testing or expanding pipes. Patent. * NSPB? * CHE: 1. Device, in particular a straightening machine for bars, with two spaced apart coaxially arranged heads that exert a train or pressure on a workpiece and whose holders sit on a carrier that is arranged parallel to the direction of force and that of bending forces by one arranged on the opposite side of the carrier and engaging the holders Strut and by a hydraulic piston exerting a balancing force on the strut is relieved, characterized in that the carrier (16) in the floor parallel to this in greater parallel distance from the strut (21) below it than from the axis of the heads (10 and 14) is arranged. 2. Device according to claim 1, characterized in that that one of the holders on the carrier (16) and the strut (21) in the longitudinal direction \ -schieb- and is detectable. Considered publications:
German Patent No. 545 082;
U.S. Patent Nos. 2,580,078, 2,296,051. 1 sheet of drawings © 809 657/263 9.