GB2172824A - Rail bender - Google Patents

Abstract

The bender, e.g. rail straightener, has a clamp with closing cams 8 actuated by hydraulic rams 6 in such a manner as relieve these rams of adverse loading yet at the same time keep the overall width of the clamping device narrow enough to work in confined spaces. Such a work condition would be found between a running rail and an adjacent conductor rail as found in some electrified railway systems. The clamp is central between two actuator operated bending heads. Deflection measurements are continually monitored. <IMAGE>

Description

SPECIFICATION Apparatus for bending material This invention relates to a device for bending material (usually in bar or formed section).

Bending machines are well known and often comprise one or more material clamping sections, and one or more force applying sections. Some are portable and others mounted within a framework or carrying system. Most are too cumbersome and of too large proportions to carry out a specific task, as for example, straightening a railway rail whilst in situ, with additional restrictions often imposed by the proximity of high tension conductor rails, as found in the Southern region of British Rail and the London Underground system. Often the clamping sections are not positive in their action and allow partial slip.

According to the present invention there is provided a bending machine having slip free clamps, facility for mounting into, and working from a transporting carriage, a facility for operation and control by and in association with a micro processor control system. Since the control system can sense extremely small increments of deflection and translate this into the elastic/plastic section of the load versus deflection graph of the material being bent, it follows that control of bending can be absolutely precise, providing no slip of the clamping sections is permitted. This is particularly true if electronic load cells are used (to measure force applied) in conjunction with displacement transducers (to measure deflection) in the micro processor control system. It follows that such a device can be used for precise control of rail straightening.

A specific embodiment of the invention will now be described by way of examples with reference to the accompanying drawings.

Figure 1 shows a side view of the complete bending machine mounted upon a standard rail.

Figure 2 shows a section upon A-A of the side view (Figure 1).

Figure 3 shows a section similar to Figure 2 with clamping jaws closed over the rail head in the condition to commence bending.

Figure 4 shows a section similar to Figure 2 but with the clamping jaws open (for retraction away from the bending position) or prior to projection into that position.

Referring to the drawings Figure 1 the slip free clamp 5 is mounted upon the main beam 1 which is equipped with two bending power sources 2 (in the case shown, hydraulic rams), which are anchored to the main beam via load cells or other load indicating device 20 positioned one at each end of the beam 3. A central pair of side extensions 4 carry the slip free clamp 5 and supports its actuating mechanism 6. In the case illustrated the side extensions also act as bearings 7 for the rotating locking cam 8 the actuator 6 for the cam and pivot systems for the clamp 10 (not shown in this view).

In order that the deflection detection portion of this device 11 shall be free from the influences of the load application and frame deflection the deflection detection device is mounted within the main beam on a separate and independent wheeled trolley 9.

In operation the open jawed clamping device is lowered over the rail head to the correct position, as shown in Figure 2. The jaws are closed by means to be defined later and bending (straightening) commences. When satisfactory deflection of the rail or bar has been achieved the jaws are opened and the device retracted away from the working position.

In order that the clamps be kept narrow and that locking forces should not be translated into adverse loading on the actuating means (in this case, hydraulic rams) 6 the jaws are closed by means of a novel cam device.

Referring to Figure 2 the circular cams (with flat actuating faces) are bearinged (as described above) in the central side extensions passing through slots 12 in the clamp jaw side plates 13 in a manner to allow the cams to rotate and the clamp jaws to move in an arcuate manner within the slots, rotation to the cams being imparted by the actuator 6 extension allowing the flat face (which with jaws open is in "flat to flat" mutual contact with the central web 14 of the jaws) to be repiaced progressively by the full circular section 15 of the cam acting against the central web 14 of the jaws, in order to close them. To increase the mechanical advantages the cams are fitted with arms 16 into which the actuator pivot 17 is connected.From Figure 2 it can be seen that no jaw opening forces, as for example generated by the sloping underhead surface of the rail, can be transmitted into bending of the actuator extension rods 18 since such forces are resisted by the cams and their bearings, and that the line of action of these forces passes through the cam centre line and into the cam pivots and not to the actuator rod.

Conversely, as the actuator causes the cam to rotate back to the "flat to flat" contact stage (in this case by cam retaction) the jaws are permitted to open being aided to do so by jaw release springs 19 set in the body of the main beam. In this condition the bending machine can be retracted away from the material being bent and prepared for the next operation.

1. A novel clamping device having a system of clamping such as to prevent slipping movement in the direction of applied bending forces, a facility to enable it to be incorporated into an apparatus for bending material (which apparatus may be controlled manually or automatically by micro processor), and an ability to prevent the forces bending to open the clamping jaws from having an adverse effect upon the action of the jaw closing actuators.

2. A device substantially as described in Claim 1 whose construction is such as to limit its over all width and thus enable the device to be operated in confined spaces.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Apparatus for bending material This invention relates to a device for bending material (usually in bar or formed section). Bending machines are well known and often comprise one or more material clamping sections, and one or more force applying sections. Some are portable and others mounted within a framework or carrying system. Most are too cumbersome and of too large proportions to carry out a specific task, as for example, straightening a railway rail whilst in situ, with additional restrictions often imposed by the proximity of high tension conductor rails, as found in the Southern region of British Rail and the London Underground system. Often the clamping sections are not positive in their action and allow partial slip. According to the present invention there is provided a bending machine having slip free clamps, facility for mounting into, and working from a transporting carriage, a facility for operation and control by and in association with a micro processor control system. Since the control system can sense extremely small increments of deflection and translate this into the elastic/plastic section of the load versus deflection graph of the material being bent, it follows that control of bending can be absolutely precise, providing no slip of the clamping sections is permitted. This is particularly true if electronic load cells are used (to measure force applied) in conjunction with displacement transducers (to measure deflection) in the micro processor control system. It follows that such a device can be used for precise control of rail straightening. A specific embodiment of the invention will now be described by way of examples with reference to the accompanying drawings. Figure 1 shows a side view of the complete bending machine mounted upon a standard rail. Figure 2 shows a section upon A-A of the side view (Figure 1). Figure 3 shows a section similar to Figure 2 with clamping jaws closed over the rail head in the condition to commence bending. Figure 4 shows a section similar to Figure 2 but with the clamping jaws open (for retraction away from the bending position) or prior to projection into that position. Referring to the drawings Figure 1 the slip free clamp 5 is mounted upon the main beam 1 which is equipped with two bending power sources 2 (in the case shown, hydraulic rams), which are anchored to the main beam via load cells or other load indicating device 20 positioned one at each end of the beam 3. A central pair of side extensions 4 carry the slip free clamp 5 and supports its actuating mechanism 6. In the case illustrated the side extensions also act as bearings 7 for the rotating locking cam 8 the actuator 6 for the cam and pivot systems for the clamp 10 (not shown in this view). In order that the deflection detection portion of this device 11 shall be free from the influences of the load application and frame deflection the deflection detection device is mounted within the main beam on a separate and independent wheeled trolley 9. In operation the open jawed clamping device is lowered over the rail head to the correct position, as shown in Figure 2. The jaws are closed by means to be defined later and bending (straightening) commences. When satisfactory deflection of the rail or bar has been achieved the jaws are opened and the device retracted away from the working position. In order that the clamps be kept narrow and that locking forces should not be translated into adverse loading on the actuating means (in this case, hydraulic rams) 6 the jaws are closed by means of a novel cam device. Referring to Figure 2 the circular cams (with flat actuating faces) are bearinged (as described above) in the central side extensions passing through slots 12 in the clamp jaw side plates 13 in a manner to allow the cams to rotate and the clamp jaws to move in an arcuate manner within the slots, rotation to the cams being imparted by the actuator 6 extension allowing the flat face (which with jaws open is in "flat to flat" mutual contact with the central web 14 of the jaws) to be repiaced progressively by the full circular section 15 of the cam acting against the central web 14 of the jaws, in order to close them. To increase the mechanical advantages the cams are fitted with arms 16 into which the actuator pivot 17 is connected.From Figure 2 it can be seen that no jaw opening forces, as for example generated by the sloping underhead surface of the rail, can be transmitted into bending of the actuator extension rods 18 since such forces are resisted by the cams and their bearings, and that the line of action of these forces passes through the cam centre line and into the cam pivots and not to the actuator rod. Conversely, as the actuator causes the cam to rotate back to the "flat to flat" contact stage (in this case by cam retaction) the jaws are permitted to open being aided to do so by jaw release springs 19 set in the body of the main beam. In this condition the bending machine can be retracted away from the material being bent and prepared for the next operation. CLAIMS

1. A novel clamping device having a system of clamping such as to prevent slipping movement in the direction of applied bending forces, a facility to enable it to be incorporated into an apparatus for bending material (which apparatus may be controlled manually or automatically by micro processor), and an ability to prevent the forces bending to open the clamping jaws from having an adverse effect upon the action of the jaw closing actuators.

2. A device substantially as described in Claim 1 whose construction is such as to limit its over all width and thus enable the device to be operated in confined spaces.

3. A material bending apparatus fitted with a slip free clamping device such as described in Claims 1 and 2.

4. A clamping device substantially as described in Claims 1 and 2 capable of being actuated by hydraulic rams and by nature of the novelty of this invention such rams will not suffer adverse loadings (as for example, bending at their piston rods) due to the closing forces or other forces generated in a direction tending to open the jaws of said clamping device.

5. A clamping device as described in Claims 1 to 4 which by virture of the novel embodiment of cams in slots closing technique permits the jaw closing cams to apply forces perpendicular to the jaw opening forces, thus relieving the closing actuators (in this case hydraulic rams) of any adverse effect of these opening forces.

5. A material bending apparatus fitted with a slip free clamping device such as to enable accurate deflection measurements to be continuously monitored and thus enable the apparatus to be operated manually or automatically either directly or remotely and for the results obtained to be continuously recorded.

New claims or amendments to claims filed on 20 June, 1985 Superseded claims 5 New or amended claims: