GB2136961A - Chain length measuring and sorting apparatus - Google Patents

Abstract

A chain length measuring and sorting apparatus includes means for mounting a chain to be measured between a fixed and a movable peg 16, 18, pneumatic means 22 for moving the movable peg 18 away from the fixed peg 16 until a predetermined tension is applied to the chain, and measuring 24 means 26 for measuring the chain length when the predetermined tension has been reached. Additional means 40 are provided for rotating the apparatus such that a chain of a predetermined measured length is automatically positioned above a receiving station (42, fig 2) for chains of that length, and a means 46 is provided for removing the chain from the pegs such that it is deposited at that station. The apparatus may include a plurality of measurement assemblies, each capable of measuring a different range of chain lengths (fig 2). <IMAGE>

Description

SPECIFICATION Improvements in or relating to chain handling arrangements The present invention concerns a chain handling arrangement, especially but not exclusively a chain length measurement and sorting arrangement.

In certain items of equipment, for example coal mining equipment, conveyor systems therein utilise several relatively short sections of chain.

For example, in a scraper conveyor the flight bars are inter-connected at their ends by sections of chain. It will be appreciated that if the flight bars have to be parallel to each other and perpendicular to the direction of movement it is important that the section of chain connected to the flight bar at one side of the conveyor corresponds in length to the section of chain at the other side.

The method of manufacturing chains is such that it cannot be guaranteed that two sections of chains with equal numbers of links have exactly the same length. Furthermore if the equipment is being refurbished and the chains are being re-used it cannot be guaranteed that one section of chain of a pair of sections to be re-used corresponds in length to the other section.

The problem of differing lengths has been encountered in the past and has been overcome by manually comparing the length of one chain section with others. Obviously this is a time consuming and laborious task as the chains are relatively heavy.

It is an object of the present invention to obviate or mitigate these disadvantages.

According to the present invention there is provided a chain handling arrangement comprising a first peg on which one end of the chain can be mounted, a second peg adapted to receive the other end of the chain, means for moving said second peg relative to the first peg, means for measuring the tension in the chain and length measuring means for determining the position of the second peg when a predetermined tension is measured.

Preferably said moving means is a piston and cylinder device.

Preferably said length measuring means comprises a plurality of devices contactable by said second peg or an extension therefrom and actuable dependent upon the position of said second peg relative to the first peg. Preferably four devices are provided and each comprises a pneumatic valve and mechanical actuating means therefor.

Preferably the first peg is arranged above the second peg on a framework and means are provided for pushing the end of the chain off the first peg after measurement has taken place.

Preferably the framework is rotatably mounted on a base such that prior to ejecting a chain therefrom it can be rotated into position above a bin adapted to receive chains of a particular measured length.

Preferably the pneumatic valves are connected to a device for rotating the structure, the device being so connected to the valves that it automatically selects the position at which the chain has to be ejected and thus the bin in which it is to be received.

Preferably said tension measuring means includes pressure switch incorporated in said piston and cylinder device.

Preferably the framework mounts a plurality of chain length measurment assemblies such that a range of chain lengths can be measured on the same arrangement.

Preferably means are provided for disengaging said structure rotating device whereby any one of said measurement assemblies can be positioned at a station for loading chains.

An embodiment of the present invention will now be described by way of example only with reference to the accompanying diagrammatic drawings in which: Fig. 1 is a partial sectional elevation of a chain length measurement and sorting arrangement and Fig. 2 is a plan thereof.

A chain length mesurement and sorting arrangement comprises a base 10 on which is rotatably mounted a framework 12 which is hexagonal in plan, having six similar sides 14 only one of which will be discussed with reference to Fig. 1.

Side 14 is arranged vertically and has a first chain peg 1 6 rigidly fixed adjacent its upper end. A second chain peg 1 8 projecting through a slot in the side 14 and is rigidly fixed to an extension 20 from the piston of a pneumatic piston and cylinder device 22. A pressure sensor is supplied in the air line 24 to the piston and cylinder device 22 to cut off further supply of air to the cylinder when a predetermined pressure has been sensed such that a predetermined tension is applied to a chain supported between the first and second pegs, the second peg being moved away from the first peg by means of the piston and cylinder device 22 to apply said tension.

Means 26 are provided to measure the piston of the second peg 18 relative to the first peg when said chain is subjected to the predetermined tension. A valve block includes a valve 28 whose actuating member takes the form of a resilient needle 30 which projects towards the wall 14. A plate 32 is fixed to the lower end of the piston rod 20 and carries a needle contact member 34 having a downwardly directed V-notch therein, the member 34 being adjustably mounted on the plate 32 by a bolt 36. It will be realised that as the plate 30 moved downwardly with the needle 30 accommodated in the notch in the plate 32 the top of the notch will contact the needle 30 and causes the valve 28 to be actuated, further downwards movement deforming the needle 30.

Actuation of the valve 28 cause a pneumatic signal to be given thus signalling that the chain under measurement between the pegs 1 6 and 1 8 is at least of a particular predetermined length.

Four similar arrangements of valves 28, needles 30 and members 34 are arranged in side-by-side relationship with the members 34 being positioned progressively lower so that the arrangement can measure four different lengths of chain.

In operation when the predetermined tension has been applied to a length of chain the pressure sensor in the air line to the piston and cylinder device 22 indicates that measurement has been concluded and depending upon which or how many valves 28 have been actuated the length of the chain included in the range of four possible lengths is known and a corresponding signal is given to an hydraulic motor 40 which rotates the framework until the side carrying the chain overlies a storage bin 42 (Fig. 2) which is intended to receive only chains of one length. At this point a signal is given to an hydraulic ram 44 positioned below the fixed peg 16, the piston 46 of which advances to push the end of the chain off the peg 16 so that it falls into the bin 42.

It will be realised that similar arrangements can be provided on each of the six sides of the structure and it is convenient that each side is intended to give four incremental measurements of a length of chain lying within a particular range, the range varying from side to side. Means (not shown) are provided to disengage the motor 40 so that the framework can be rotated such that the side 14 suitable for the particular chain length to be measured can be brought to the loading station. The motor can taken be re-engaged and the device will function as described above. To economise on relatively expensive pneumatic circuitry and control gear only one control unit need be supplied as the actions carried out by each side of the device are the same.As a result the pneumatic connections from the valves 28, piston and cylinder devices 22 and 44, sensors etc. are led to a socket assembly 48 on the top of the device, one socket being provided for each side 14. A flexible multi-channel lead extends from the control consul and terminates in a plug which is connectible to the socket 48 for the side 1 4 which is in operation at the time.

Various modifications can be made without departing from the scope of the invention, for example more or less than four length measuring cylinders etc. can be provided for each side. In a further modification an hydraulic ram could be replaced by a pneumatic ram or by a mechanical ram. The structure need not have six sides but could have any number of sides upwards of one.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to whether or not particular emphasis has been placed thereon.

Claims (12)

1. A chain handling arrangement comprising a first peg on which one end of the chain can be mounted, a second peg adapted to receive the other end of the chain, means for moving said second peg relative to the first peg, means for measuring the tension in the chain and length measuring means for determining the position of the second peg when a predtermined tension is measured.

2. An arrangement as claimed in claim 1, in which said moving means is a piston and cylinder device.

3. An arrangement as claimed in claim 1 or claim 2, in which said length measuring means comprises a plurality of devices contactable by said second peg or an extension therefrom and actuable dependent upon the position of said second peg relative to the first peg.

4. An arrangement as claimed in claim 3, in which four devices are provided and each comprises a pneumatic valve and mechanical actuating means therefor.

5. An arrangement as claimed in any one of the preceding claims, in which the first peg is arranged above the second peg on a framework and means are provided for pushing the end of the chain off the first peg after measurement has taken place.

6. An arrangement as claimed in claim 5, in which the framework is rotatably mounted on a base such that prior to ejecting a chain therefrom it can be rotated into position above a bin adapted to receive chains of a particular measured length.

7. An arrangement as claimed in claim 6, in which the pneumatic valves are connected to a device for rotating the framework, the device being so connected to the valves that it automatically seiects the position at which the chain has to be ejected and thus the bin in which it is to be received.

8. An arrangement as claimed in any one ofthe preceding claims, in which said tension measuring means includes a pressure switch incorporated in said piston and cylinder device.

9. An arrangement as claimed in any one of the preceding claims, including a plurality of chain length measurement assemblies such that a range of chain lengths can be measured on the same arrangement.

10. An arrangement as claimed in any one of claims 6 to 9, in which means are provided for disengaging said framework rotating device whereby any one of said measurement assemblies can be positioned at a station for loading chains.

11. A chain handling arrangement substantially as hereinbefore described with reference to the accompanying drawings.

12. Any novel subject matter or combination including novel subject matter herein disclosed, whether or not within the scope of or relating to the same invention as any of the preceding claims.