GB2114949A

GB2114949A - Detector means for conveyor belts

Info

Publication number: GB2114949A
Application number: GB08204516A
Authority: GB
Inventors: Maurice Bryan Herbert
Original assignee: STATUS ENGINEERING Ltd
Current assignee: STATUS ENGINEERING Ltd
Priority date: 1982-02-16
Filing date: 1982-02-16
Publication date: 1983-09-01
Also published as: GB2114949B

Abstract

A detector for use in association with a conveyor belt comprises a roller 14 adapted to run on one face of the belt 26. The roller is rotatably mounted with respect to a support 11 about an axis which extends transverse to the run of the belt, and is urged towards the belt by resilient means 18. A pair of axially extending studs 30 are fixed to the end of the roller. The proximity of the studs to a sensing element causes a signal, which can be transmitted to a control unit, to be produced. <IMAGE>

Description

SPECIFICATION Detector means for conveyor belts This invention relates to detector means for conveyor belts.

It is known to employ automatic control switches which can detect the movement of a conveyor belt. These switches usually employ a cantilever arm having a roller at one end which is held into contact with the underside of the a belt by lever action. Such switches do not produce an electrical signal. They operate mechanical levers which can be adjusted to close or open electrical contacts in relation to varying belt speeds.

Moreover, they operate on one side of the belt only and are driven by the underneath side of the top belt or the underneath side of the bottom belt.

They are completely self-contained with no associated control equipment.

These switches do not usually produce a warning signal when the belt stops or when the belt breaks.

Unfortunately, such control switches are not completely satisfactory and it is an object of the present invention to provide an improved detector means for a conveyor belt.

According to the present invention we provide detector means for use in association with a conveyor belt comprising a detector roller adapted to run on one face of the belt, said detector roller being rotatably mounted with respect to support means therefor about an axis which extends transverse to the run of the belt, the roller being urged towards the belt by resilient means and sensor-actuating means associated with said roller which in association with a sensor enables the rotation of the roller to be detected.

Preferably, the detector roller runs on the upper side of the return run of a belt and is disposed above, or closely adjacent to, a support roller which rotates about a parallel axis and is in contact with the underside of the return run of the belt.

Conveniently the resilient means comprises a coil spring.

Preferably, the tension in the coil spring is adjustable and conveniently this is effected by means of a compression screw.

Conveniently the sensor-actuating means comprises one or more studs which extend axially from one end of the detector roller and are off-set from the axis thereof whereby the studs can actuate a suitable sensor such as a magnetic sensor.

In one form of the invention, two diammetrically opposed studs are used for this purpose.

Reference is now made to the accompanying drawings, in which: Figure 1 is a scrap front view of an assembly incorporating detection means according to the invention with a part broken away to show internal detail; Figure 2 is a side view of the device shown in Figure 1; and Figure 3 is a schematic perspective view showing the operation of detection.

The assembly comprises a stand 10, which may be mounted on the floor, the stand supporting a pair of vertical pillars, only one of which is shown in Figures 1 and 2.

The pillars 11 are of square tubular crosssection and at the upper end a slidable carriage 12 is disposed within the support pillars 11, the carriage 1 2 carrying an axle 1 3 for a detector roller 14.

The axle 13 extends through a slot 1 5 in the wall of the support pillars 11. In addition, an arm 1 6 which is welded to the carriage 12 also extends through the slot 1 5 and at its other end carries a sensor casing 1 7.

Details of the sensor within the casing 1 7 are conventional and it will be apparent to a person skilled in the art that any one of a number of different types of sensor can be employed for this purpose.

The carriage 1 2 is biassed downwardly by means of a coil spring 1 8 which abuts against a plate 1 9. An adjusting screw 20 can be screwed into a top plate 21 to adjust the compression of the spring 1 8.

A similar arrangement is provided at the other side of the belt with the exception that the arm 1 6 and sensor casing 1 7 is not required.

When the assembly is arranged on a conveyor belt the detector roller 1 4 is disposed closely adjacent to a support roller 22 for the return run of the conveyor belt 26. The roller 22 is a conventional bottom roller which has an axle 27 which can be disposed in one of a series of slots 28 in a support plate 29.

When the assembly is in position on a belt, as shown in Figures 1 and 2, it can be seen that the roller 14 is urged towards the roller 22 by means of the springs 1 8 and thus, the belt 26 passes through the nip between the rollers and a very positive drive to the roller 14 is achieved.

Variations in thickness of the belt, eg where the belt is joined or where dirt is adhered to the belt are accommodated by means of the resilience of the spring 18.

In order to detect rotation of the detector roller 14, a pair of metal studs 30 extend axially from the end of the detector roller in diametrically opposed relationship. The proximity of the studs 30 to the second element 31 on the sensor casing 1 7 is sensed by the sensor to produce a signal which can then be transmitted to a suitable control in the conventional manner.

The assembly described above is adapted for floor mounting for use in association with a floor mounted conveyor structure. It will be evident however that where a suspended conveyor structure is employed the assembly could be modified to incorporate brackets to enable it to be secured to the suspended conveyor structure.

It will be appreciated that the assembly of the present invention provides an improved detection means in that a very positive drive is achieved to the detector roller which thus gives a faithful indication of the movement of the conveyor belt.

This is not the case with prior devices where the drive is not so positive and the rollers may make only intermittent contact with the belt thereby giving a false indication of belt movement.

Claims

1. Detector means for use in association with a conveyor belt comprising a detector roller adapted to run on one face of the belt, said detector roller being rotatably mounted with respect to support means therefor about an axis which extends transverse to the run of the belt, the roller being urged towards the belt by resilient means and sensor-actuating means associated with said roller which in association with a sensor enables the rotation of the roller to be detected.

2. Detector means according to Claim 1 in which the detector roller runs on the upper side of the return run of a belt and is disposed above, or closely adjacent to, a support roller which rotates about a parallel axis and is in contact with the underside of the return run of the belt.

3. Detector means according to Claim 1 or 2 in which the resilient means comprises a coil spring.

4. Detector means according to Claim 3 in which the tension in the coil spring is adjustable.

5. Detector means according to Claim 4 in which the tension is adjustable by means of a compression screw.

6. Detector means according to Claims 1 to 5 in which the sensor actuating means comprises one or more studs which extend axially from one end of the detector roller and are off-set from the axis thereof whereby the studs can actuate a suitable sensor such as a magnetic sensor.

7. Detector means substantially as herein described with reference to and as shown in the accompanying drawings.