GB2078447A

GB2078447A - Conveyor systems

Info

Publication number: GB2078447A
Application number: GB8118843A
Authority: GB
Original assignee: HUWOOD ARDEE Ltd
Current assignee: HUWOOD ARDEE Ltd
Priority date: 1980-06-18
Filing date: 1981-06-18
Publication date: 1982-01-06

Abstract

In a conveyor system control of the conveyor can be effected from any point along its length by means which includes a plurality of switch boxes 1 spaced along the length of the conveyor. Each switch box 1 contains a double armed switch actuating lever 14, each arm of which is connected to an arm of the adjacent switch box 1 by a cable (not shown) and rod 2. By pulling on any of the cables, the switch in one of the boxes that is connected to the cable will be operated, and operation of the switch will have a controlling effect on the conveyor. The switches all have the same effect. <IMAGE>

Description

SPECIFICATION Improvements in or relating to conveyor systems This invention relates to conveyor systems, such as belt conveyor systems. It may be desirable to be able to exercise a control on the system, such as being able to bring the system to a halt, at any point along the length of the system and the present invention is concerned to facilitate this.

According to the present invention there is provided in a conveyor system, a plurality of switch units spaced apart lengthwise of the system and each containing a double armed lever that can be swung between a rest position and an active position in which it has operated a control switch of which the effect of the operation is the same as that of the operation of the control switch associated with any other switch unit, of any three adjacent switch units, one arm of the central switch unit is connected to an arm of the switch unit lying to one side of the central unit, the other arm of the central switch unit is connected to an arm of the switch unit lying to the other side of the central switch unit, each connection is effected by a cable, and the arms to which the cable is connected are such that an increase in the tension in the cable, with the levers to which it is connected in their rest position, will act in the sense that moves the levers to their active position. The units may be spaced at 100 metre intervals, and by pulling on any cable, the control switch associated with one of the switch units between which the cable is connected may be operated.

By way of example, an embodiment of the invention will now be described with the reference to the accompanying drawing which shows, with the cover removed, the box of a switch unit included in the control means of a conveyor. The switch units are distributed along the length of the conveyor at intervals of, say, 100 metres.

Each switch unit includes a box 1 mounted with its back-plate vertical. Two similar, and similarly disposed, composite, axially reciprocable, operating rods 2 project from the sides of the box, one of the rods 2 projecting to the right and from the upper part of the box 1 and the other of the rods 2 projecting to the left and from the lower part of the box 1.

Each rod 2 is supported by a bush 4 fixed to the inner face of a side wall of the box 1 and a slide 5 mounted on the back-place of the box. The slide 5 acts as a guide for the enlarged head 6 of the rod 2 during the reciprocation of the arm. A spring 8 acts between the bush 4 and a nut 9 screwed on to the rod 2 to urge the rod 2 to a retracted position in which it lies as far as possible within the box 1.

A ring 11 provided at the outer end of the rod 2 forms an anchor by which a cable (not shown) can be connected to the non-corresponding rod of the next adjacent box, i.e. so that the upper rod of the box shown can be connected to the lower rod of the box next to the right and the lower rod of the box shown can be connected to the upper rod of the box next to the left. The springs 8 are effective to keep the cables under slight tension.

Within the box 1, a double-armed lever 14 is mounted on a horizontal spindle 1 5. The upper of the rods 2 passes through an opening in the upper arm of the lever 1 4 and the lower of the rods 2 passes through an opening in the lower arm of the lever 1 4. After each rod 1 has moved a short distance from the position to which it is urged by the spring 8, the end of the enlarged head 6 makes contact with the lever 14, so that further movement of the rod 2 in that direction will turn the lever 1 4. A helical spring (not shown) encircling the spindle 1 5 behind the lever 1 4 tends to urge the lever 1 4 towards the position in which it is shown in the drawing.

The lever 14 comprises a laterally projecting striker arm 1 4a that co-operates with the indicator denoted generally by 1 6. The indicator 1 6 includes a disc 1 7 that, when the cover of the box 1 is in position, lies within a circular opening in the cover. The disc 1 7 turns on a horizontal spindle mounted on the back plate of the box 1 and a roller 1 8 extends rearwardly from the striker arm 1 4a.

Rotation of the lever 14 in a clockwise direction, which results from outward movement of either of the rods 2, will turn the indicator 1 6, by acting on the roller 1 8 to a position in which it will rest unless manually restored. For the purpose, a handle 2, in the form of a ridge, is formed on the disc. Reflector plates are fixed to what is normally the top and bottom 20a of the handle 20; when they are in the positions shown, they will not be visible by looking along the row of boxes but when the box with which they are associated has been operated, they will be noticable to a person looking along the row of boxes and this will give an indication at a distance which box has been operated.

A switch (not shown), by operation of which the conveyor is immobilized, is disposed to be operated by rotation of the lever 1 4 and indicator 1 6 from the position in which it is shown. The switch remains in its operated condition unless positively restored and does not revert by restoration of the lever to the condition in which it is shown in the drawing.

The operation of any switch unit will render the conveyor inoperative.

Other switches may be included in the switch unit. For instance, one may be included in a circuit to give an indication by a lamp, remotely or at the switch unit, that the lever of the switch unit has been turned. Such switches may be mounted on the cover of the box so as to be readily accessible for servicing.

With the apparatus that has been described, a conveyor may be rendered inoperative at any point along its length. An indication of this point is given and whilst a pull on a cable may operate the switch box at either of the extremities of the cable, movement will not be transmitted across a lever in a sense that actuates the other cable associated with that lever.

A device may also be included so that, if a cable loses its tension by a fault, the conveyor will be rendered inoperative and an indication of the fault produced.

Claims

1. In a conveyor system, a plurality of switch units spaced apart lengthwise of the system and each containing a double-armed lever that can be swung between a rest position and an active position in which it has operated a control switch of which the effect of the operation is the same as that of the operation of the control switch associated with any other switch unit, of any three adjacent switch units, one arm of the central switch unit is connected to an arm of the switch unit lying to one side of the central unit, the other arm of the central switch unit is connected to an arm of the switch unit lying to the other side of the central switch unit, each connection is effected by a cable, and the arms to which the cable is connected are such that an increase in the tension in the cable, with the levers to which it is connected in their rest positions, will act in the sense that moves the levers to their active positions.

2. Apparatus as claimed in claim 1 in which the switch units are all similar, and similarly orientated relatively, to each other, and each cable is connected between an arm on one unit and the non-corresponding arm on the other unit.

3. Apparatus as claimed in either of the preceding claims in which the lever of each switch unit is resiliently biassed towards its rest position.

4. Apparatus as claimed in any of the preceding claims in which the control switch associated with any switch unit is such that, once operated by movement of the lever to its active position, movement of the lever to its rest position does not restore the control switch to its unoperated condition.

5. Apparatus as claimed in any of the preceding claims in which the lever acts on the control switch through a member that is moved from one orientation to another by movement of the lever from its rest to its active position, movement of the lever to its rest position does not restore the member of the position from which it was moved by movement of the lever from its rest to its active position, and the orientation of the member is visually apparent.

6. Apparatus as claimed in claim 5 in which the member is mounted to rotate about a horizontal axis, and reflector means carried by the member is vertical when the member has the orientation to which it is moved by movement of the lever to its active position, the reflector means then being visible from each side of the switch unit.

7. Apparatus as claimed in any of the preceding claims in which the effect of the operation of any of the control switches is to render the conveyor inoperative.

8. In a conveyor system, apparatus substantially as described with reference to, and as illustrated by, the accompanying drawing.