GB2153784A

GB2153784A - Article handling equipment

Info

Publication number: GB2153784A
Application number: GB08500585A
Authority: GB
Inventors: Michael Keddy
Original assignee: Northern Engineering Industries PLC
Current assignee: Rolls Royce Power Engineering PLC
Priority date: 1984-02-01
Filing date: 1985-01-10
Publication date: 1985-08-29
Also published as: GB8402591D0; GB2153784B; GB8500585D0

Abstract

Article handling equipment, for example for handling railway rails, has a support structure on which is mounted a gripper 26 for movement relative thereto. The gripper 26 has gripper members 28 pivotally mounted intermediate their ends on a crosshead 30, the upper ends of the members 28 being interconnected by toggle links 32. The members 28 are openable and closeable by a piston-and-cylinder arrangement 34. The arrangement 34 has a piston 56, 58 the rod 58 being connected to the crosshead 30; a cylinder 60 in which the piston 56, 58 is relatively reciprocable; and a cylinder 64 in which a piston formation 62 on the cylinder 60 is relatively reciprocable. The toggle links 32 are connected to the cylinder 64 via a crosshead 52. As the piston 56, 58 and the cylinders 60, 64 float relatively to one another, any tendency of the gripper 26 prematurely to lift the article or to impose strains on the mounting means is reduced or obviated. <IMAGE>

Description

SPECIFICATION Article handling equipment The invention relates to article handling equipment.

According to the invention, article handling equipment comprises a support structure and an article gripper mounted on the structure, the gripper comprising at least two gripper members pivotally mounted on a support member so that the lower ends of the gripper members are locatable on either side of an article, actuator means associated with the gripper members and a piston-andcylinder arrangement having a piston relatively reciprocable in a first cylinder and a piston formation of the first cylinder relatively reciprocable in a second cylinder, the support structure, the support member and the actuator means being secured to a respective one of the piston and the cylinders whereby the support members and the actuator means are movable relatively to one another by the piston-and-cylinder arrangement to open or close the gripper members.

According to the invention also, a gripper as defined in the preceding paragraph.

Preferably, the equipment comprises means for mounting the gripper on the structure for movement relative thereto.

Preferably, the gripper members are mounted on the support member intermediate their ends, the actuator means being associated with the upper ends of the gripper members.

Preferably, the support structure is secured to the second cylinder, the actuator means is secured to the first cylinder and the support member is secured to the piston.

Preferably, the actuator means comprises a toggle having two links each pivotally attached at one end to the respective one of the piston and cylinders and at the other end to the upper end of a respective one of the gripper members.

Preferably, the support member and the actuator means can swivel relatively to the piston-and-cylinder arrangement whereby the support member and the actuator means are rotatable to align the gripper members with an article to be handled.

Rail handling equipment will now be described to illustrate the invention by way of example only with reference to the accompanying drawings, in which: Figure 1 is a schematic side view of a train having rail handling equipment in the form of a machine running on a track laid on the waggons forming the train; Figure 2 is a schematic side view, half in vertical section on line 11 - II in Figure 3, of the rail gripper forming part of the equipment shown in Figure 1, the gripper being in its closed, unloaded condition; Figure 3 is a schematic end view, half in vertical section on line Ill - Ill in Figure 2, of the gripper shown in Figure 2, the gripper being in its open, unloaded condition and being located over a rail; and Figure 4 is a view similar to Figure 3 but with the gripper in its closed, loaded condition having gripped the rail.

The train 10 (see Figure 1) has an engine (not shown) for moving the waggons, 12, 14 relative to a railway track 16. The train 10 is adapted to lay rails down or lift rails from the track 16. The rails can be laid down or lifted from the inside or the outside of the track 16. Typically, the rails are in lengths of approximately 180 metres. The rails are stored on waggons 12 which are provided with sets of roller assemblies 18. The waggons 14 are provided with chutes and rollers (not shown) to assist in guiding the rails as they are lifted up or laid down.

A track (not shown) is provided on the waggons 12, 14 for a rail handling machine 20. The machine 20 has operator cabs, drive equipment for propelling it along the track on the waggons 12, 14 and other ancillary gear. A pair of booms 22 are mounted on one end of the machine 20 for both slewing and luffing movement. The booms 22 are each provided with a fixed or movable end arm 24 on the outer end of which is fixed a rail gripper 26 (see Figures 2 to 4).

One of the chute waggons 14 may be provided with a turntable to turn the machine 20 around thereby making the train double-ended.

The machine 20 can handle rails either singly or in pairs.

The grippers 26 (see Figures 2 to 4) each have two pairs of gripper members 28 pivotally mounted intermediate their ends on a support member in the form of a crosshead 30; actuator means in the form of toggle links 32; and a pistonand-cylinder arrangement 34.

The lower ends of the gripper members 28 are shaped so as to have upper and lower abutment surfaces 36 and 38, respectively, which in the closed position of the gripper 26 (see Figure 4) engage corresponding lower and upper abutment surfaces 40 and 42, respectively, on the head 46 and the flange 48 of a rail 44. The provision of two abutment surfaces 36, 38 on the gripper members 28 enhances the frictional grip of the members 28 on the rail 44 and also tends to resist twisting of the rail during the lifting or laying operation.

The upper ends of the gripper members 28 are forked to receive one end of one of the toggle links 32 which is pivotally attached to the respective member 28. The other ends of the toggle links 32 relating to each pair of members 28 are received in, and pivotally attached to, the forked end of a respective suspension link 50 integral with and depending from an upper crosshead 52. The length of the toggle links 32 is selected such that, in the closed, loaded condition of the gripper 26 (see Figure 4), the pivot axes of the ends of the toggle links 32 on the suspension links 50 are below the pivot axes of the ends of the toggle links 32 on the members 28. With that arrangement, any increase in load during lifting of the rail 44 causes the grip of the members 28 on the rail 44 to increase.

The piston-and-cylinder arrangement 34 has piston having a piston head 56 from which extends a piston rod 58; a first cylinder 60 in which the pis ton head 56 is relatively reciprocable; and a second cylinder 64 in which a piston formation 62 of the first cylinder 60 is relatively reciprocable.

The lower crosshead 30 is secured to the lower end of the piston rod 58 through a bearing 66. The upper cross head 52 is secured to the upper end of the first cylinder 60 through a bearing 68. The two crossheads 30 and 52 are interlinked by vertical guidebars 70 which extend upwardly from the lower crosshead 30 to pass through apertures in lateral guide members 72 extending from the upper crosshead 52. The guidebars 70, and the suspension links 50, also pass through respective apertures in further lateral guide members 74 extending from a support ring 76 on the second cylinder 64. The ring 76 is rotatable on the cylinder 64 and is retained thereon by a collar 78. Thus, the gripper members 28 can swivel about the central vertical axis 80 of the gripper 26 relatively to the piston-and-cylinder arrangement 34.

The second cylinder 64 has trunnions 82 by which the gripper 26 is pivotally mounted on its respective arm 24.

The first cylinder 60 has an upper port 84 above the piston head 56 of the piston and a lower port 86 below the piston head 56. Flow of hydraulic fluid through the upper port 84 is controlled by a lock valve (not shown) whereby hydraulic pressure can be maintained in the first cylinder 60 above the piston head 56. The lower port 86 opens into the second cylinder 64 which has a port 88.

The operation of the rail handling machine will now be described.

To lift two rails 44 from the track 16, the train 10 is positioned with the "front" waggon 14 adjacent the rail ends. The grippers 26 are in their closed, unloaded condition (see Figure 2).

The operation of each of the grippers 26 is substantially the same. Consequently, the following description refers to only one of the grippers 26.

Hydraulic fluid is introduced into the first cylinder 60 through the ports 88 and 86 to move the piston 56, 58 upwardly in the first cylinder 60. The lock valve is open to allow hydraulic fluid to exhaust from the first cylinder 60 through the port 64. The crosshead 30 moves with the piston 56, 58 relatively to the suspension links 50. During such movement, the toggle links 32 cause the gripper members 28 to pivot on the crosshead 30 so that their lower ends move outwardly (see Figure 3).

The boom 22 is lowered and slewed as necessary to place the lower ends of the gripper member 28 on either side of the rail 44 (see Figure 3).

If the two pairs of gripper members 28 and the rail 44 are only slightly out of alignment, the lowering operation will cause the gripper members 28 and crosshead 30 and 52 to swivel relatively to the piston-and-cylinder arrangement 34 to bring them into alignment.

If a greater mis-alignment is present, the gripper 26 is positioned alongside the rail 44 and the boom 22 is slewed to cause relative swivelling of the gripper parts to correct the alignment by abutment of the gripper 26 with the rail 44. The boom 22 is then moved to place the gripper members 28 on either side of the rail.

The gripper 26 is then closed onto the rail 44 by introducing hydraulic fluid into the first cylinder 60 through the port 84 and releasing hydraulic fluid from the first and second cylinders 60 and 64 through the ports 86 and 88. As a consequence, the first cylinder 60 and the suspension links 50 move upwardly relatively to the piston 56, 58 and the second cylinder 64. During such movement, the toggle links 32 cause the gripper members 28 to pivot on the crosshead 30 so that their lower ends move inwardly to grip the rail 44 (see Figure 4). The lock valve is then closed to maintain the hydraulic pressure in the first cylinder 60.

As the gripper members 28 close onto the rail 44, a cam action between the abutting surfaces 38 and 42 slightly raises the crosshead 30 relative to the rail 44. As a result, in the closed position of the gripper 26, the lower surfaces of the crosshead 30 are not in contact with the upper surface of the rail head 46.

Because the piston 56, 58 and the first cylinder 60 can float relatively to the second cylinder 64, any tendency of the gripper 26 to lift the rail 44 or for deflection to occur in the boom 22 or the arm 24 during the closing operation is reduced or obviated.

The booms 22 are then raised and slewed as necessary to position the rail ends relatively to the respective chutes and rollers on the waggon 14.

The machine 20 and the train 10 are then moved in reverse and forwardly respectively at the same speed so that the machine 20 remains stationary relative to the ground. Thus, the rails 44 are pulled up through the chutes and onto the roller assemblies 18 on the waggons 12.

When the ends of the rails 44 are reached, the train 10 is stopped but the machine 20 continues to move on the train 10 to correctly position the rails 44 on the assemblies 18, i.e. clear of the waggon 14.

The booms 22 are then lowered and the rail ends are released from the grippers 26. The grippers 26 are opened in the same way as is described above.

The machine 20 is then free to travel to the front of the train 10 for the cycle to be repeated if required.

To lay rails 44 down onto the track 16, the machine 20 is used to pull the rails into position relative to the chutes and rollers of one of the waggons 14 with the ends of the rails 44 on the track 16. The machine 20 is then moved to a position intermediate the ends of the train 10 and the rails 44 are gripped again. The machine 20 and the train 10 are moved forward and reversed, respectively, to push the rails 44 off the train 10. Once the machine 20 has reached the waggon 14, the rails 44 are released. Continued reverse movement of the train 10 causes the rails 44 to be pulled off the remaining waggons 12 and 14. The grippers 26 are operated as previously described.

The machine 20 can be used to handle single rails 44 instead of pairs of rails 44 if required.

It will be appreciated that the machine 20 is intended to exemplify the invention only and article handling equipment in accordance with the invention may take many forms including other types of rail maintenance vehicles or rail handling cranes, for example, as well as equipment for handling other types of articles, particularly elongate articles. In other applications, the equipment could be a machine tool, for example, the gripper or grippers holding a workpiece during a machining operation. In that instance, the gripper or grippers could be either fixed or movable relative to the support structure.

Other modifications (not shown) are possible within the scope of the invention. For example, in the machine 20, the booms 22 can be replaced by rams or members reciprocable in slideways. Alternatively, several grippers 26 may be mounted on a beam of a rail handling crane in a rail assembly shop. In a further alternative, the or each gripper may be mounted on an articulated arm. The toggle links 32 can be replaced by interengaging cam surfaces on the ends of the piston rod 58 and the gripper member 28. The gripper members 28 can be pivotally mounted on the crosshead 30 at their upper ends, the actuator means being positioned intermediate their ends. It will be appreciated also that the relationship between the piston-and-cylinder of the arrangement 34 and the crossheads 30 and 52 and booms 22, for example, can be varied.

Claims

1. Article handling equipment comprising a support structure and an article gripper mounted on the structure, the gripper comprising at least two gripper members pivotally mounted on a support member so that the lower ends of the gripper members are locatable on either side of an article, actuator means associated with the gripper members and a piston-and-cylinder arrangement having a piston relatively reciprocable in a first cylinder and a piston formation of the first cylinder relatively reciprocable in a second cylinder, the support structure, the support member and the actuator means being secured to a respective one of the piston and the cylinders whereby the support member and the actuator means are movable relatively to one another by the piston-and-cylinder arrangement to open or close the gripper members.

2. Article handling equipment according to claim 1, the equipment comprising means for mounting the gripper on the structure for movement relative thereto.

3. Article handling equipment according to claim 1 or claim 2, in which the gripper members are mounted on the support member intermediate their ends, the actuator means being associated with the upper ends of the gripper members.

4. Article handling equipment according to any preceding claim, in which the support structure is secured to the second cylinder, the actuator means is secured to the first cylinder and the support member is secured to the piston.

5. Article handling equipment according to any preceding claim, in which the actuator means is arranged such that any increase in load during handling of an article causes the grip of the gripper members on the article to increase.

6. Article handling equipment according to any preceding claim, in which the actuator means comprises a toggle having two links each pivotally attached at one end to the respective one of the piston and cylinders and at the other end to the upper end of a respective one of the gripper members.

7. Article handling equipment according to any preceding claim, in which the support member and the actuator means can swivel relatively to the piston-and-cylinder arrangement whereby the support member and the actuator means are rotatable to align the gripper members with an article to be handled.

8. Article handling equipment according to any preceding claim, in which the gripper members have abutment surfaces for engaging corresponding abutment surfaces on an article.

9. Article handling apparatus according to any preceding claim, in which the gripper is adapted to grip a rail.

10. Article handling equipment according to claim 9 when dependent on claim 8, in which the gripper members have upper and lower abutment surfaces for engaging corresponding lower and upper abutment surfaces, respectively, on the head and flange of a rail.

11. Article handling equipment according to claim 1 substantially as hereinbefore described with reference to the accompanying drawings.

12. Rail handling equipment according to claim 9 when dependent on claim 1 substantially as hereinbefore described with reference to the accompanying drawings.

13. A gripper as claimed in any preceding claim.