GB2215421A

GB2215421A - Safety device

Info

Publication number: GB2215421A
Application number: GB8805002A
Authority: GB
Inventors: John Eamon Gourley
Original assignee: Individual
Current assignee: Individual
Priority date: 1988-03-02
Filing date: 1988-03-02
Publication date: 1989-09-20
Anticipated expiration: 2008-03-02
Also published as: GB8805002D0; GB2215421B

Abstract

A device for controlling a machine comprises a monitor means operative to monitor the position of a person relative to the machine. The monitor means comprises a controller 3 and a marker 7, the controller being associated with the machine and controlling the switching on and off of the machine. The marker is associated with the person operating the machine and interacts with the controller whereby, in use, the position of the marker is monitored by the controller which results in the machine being switched on or off depending on the position of the marker relative to the machine. In use, the marker 7 may be attached to protective equipment, such as goggles 8, so that the controller is induced to switch the power on to the machine when a beam from the marker impinges on it, thereby ensuring that the safety equipment is always worn by the person.

Description

SAFETY DEVICES This invention relates to devices which are designed to reduce the risk of injury to an operator of a machine, such as a grinding tool, by making the operator wear protective clothing such as goggles or by switching the machine off if the operator is likely to be endangered by it.

Goggles, or other protective devices for the eyes, should be worn when operating many machines, for example grinders, to protect the eyes of the operator from sparks and debris thrown from the machines. Operators frequently do not wear such eye protectors because they find them uncomfortable, restrictive or because they forget to wear them.

Existing devices are known which are designed to ensure that the operator wears protective eye equipment whilst using machines such as grinders. One such device is disclosed in French Patent Application No 2354506A which provides for a box attached to the machine. The box contains a pair of goggles which bear on a microswitch in the box. The electricity to the machine is automatically cut whilst the goggles are in contact with the microswitch. When the goggles are removed the microswitch is released allowing the machine to operate. In a further embodiment a wire connects the goggles and the microswitch. A signal is sent down the wire to the microswitch activating it and allowing the machine to work, when the arms of the goggles are opened. The microswitch is deactivated, thus switching off the machine, when the arms of the goggles are closed.

Other known devices include infra-red beams and the like which are connected to the machine and are set to scan across the space near a machine and when interrupted, by a person for example, will cut the electricity supply to the machine thus stopping it. Such devices are essentially safety devices to stop persons getting caught in moving machines and are not adapted to ensure that the machine operator wears protective equipment for example goggles.

Accordingly the present invention provides a device for controlling a machine comprising monitor means operative to monitor the position of a person or part of a person relative to the machine, said monitor means comprising a controller and a marker, said controller controlling the switching on and off of the machine and said marker interacts with said controller whereby in use the position of said marker on said person or part of said person is monitored by said controller which results in the machine being switched on and off as the postion of the marker is changed.

Suitable controllers include for example a light source, an infra-red light source or any source of radiating energy.

Suitable controllers will also incorporate a unit capable of registering and or responding to the irradiation for example light emitted from the controller when it is reflected back from the marker on the person.

Preferably the controller will be situated on the machine and more preferably near the working area of that machine.

Preferably the controller is directly or indireclty connected with the power supply, for example electricity, to the machine so that the controller can switch the power supply on and off thus stopping and starting the machine.

The marker is preferably attached to the person operating the machine. For example, the marker could be attached tq the arms, head or chest of the person operating the machine or to protective clothing and equipment used to protect any part of the person.

Suitably the marker is adapted to reflect the irradiation from the controller back to the controller. The marker can be made from any suitable reflective material, for example, glass, plastic or metal.

In a preferred embodiment the marker is attached to the front of the goggles worn by the person operating the machine. The light from the controller strikes the marker and is reflected back to the controller, which permits power to flow to the machine thus allowing it to operate, when the person operating the machine, who is wearing the goggles with a marker, is looking at the controller. When the person looks away no light is reflected from the marker to the controller, the flow of power is stopped, and the machine ceases to operate. Thus the machine will only operate when the person operating the machine is wearing his goggles with their marker and is looking at the machine and can therefore see what he is doing and can thus reduce the risk of any injury. The machine stops working as soon as the person operating the machine looks away and cannot therefore see what he is doing.

Thus the advantages of the devices of the present invention are that they ensure that the person operating the machine wears protective equipment such as goggles and that the machine can only operate when the person is looking at the machine.

Previous safety devices described herein before were of such a design that the machine could be operated with the goggles removed from the machine but without the person operating the machine necessarily having to wear the goggles.

In other embodiments the marker can be fitted to other pieces of safety equipment such as face masks and gloves and the controller arranged appropriately.

In a further embodiment the controller is adapted to switch the power on to the machine when it receives the first reflection from the marker and will not then respond to any further reflections or absence of reflections from the detector.

In yet a further embodiment the controller- can be for example a passive device for example radio receiver or photo electric cell which is activated by the marker on the person where the marker is an active device for example a radio emitter or a light. In this embodiment the controller would be induced to switch the power on to the machine when the beam from the marker impinged on it and switch off the power to the machine when the beam from the marker was not impinging on the controller.

One particular embodiment is shown in figure 1 in which the machine 1 is a grinding machine with a grinding wheel 2 at either end. The controller 3 is mounted on the front of the machine andintis tis embodiment comprises a light source 4 which shines to the front of the machine and a photo electric cell 5. The controller is connected to the on/off switch 6 for the machine so that the on/off switch is on when light is reflected back from the marker 7 and is off when no light is reflected back from the marker.

The photo electric cell can be shaded (not shown) so that it is not affectd by the ambient light. The goggles 8 on the operator (not shown) have a marker 7 on them which reflects the light from the light source.

Claims

1. A device for controlling a machine comprising a monitor means operative to monitor the position of a person or part of a person relative to the machine, in use, said monitor means comprising a controller associated with the machine and a marker associated with the person or part of the person, said controller controlling the switching on and off of the machine and said marker interacting with the controller whereby, in use, the orientation of the marker associated with the person or part of the person is monitored by the controller which results in the machine being switched on or off depending on the orientation of the marker relative to the controller.

2. A device as claimed in claim 1 including a controller comprised of a light source, an infra-red light source or any source of radiating energy.

3. A device as claimed in claims 1 or 2 whereby the controller includes a unit capable of registering and/or responding to the irradiation of light emitted from the controller when it is reflected back from the marker associated with the person or part of the person.

4. A device as claimed in any preceding claim whereby the controller is situated on the machine near the working area of that machine.

5. A device as claimed in any preceding claim whereby the controller is directly or indirectly connected to the power supply of the machine such that the controller can switch the power supply to the machine on and off.

6. A device as claimed in any preceding claim whereby the marker is attached to the person operating the machine or to protective clothing or equipment used to protect the person or any part of the person.

7. A device as claimed in any preceding claim whereby the marker is made from any suitably reflective material Such as, glass, plastic or metal.

8. A device as claimed in claim 6 whereby the marker is attached to the front of goggles to be worn by the person operating the machine.

9. A device as claimed in claim 1 whereby the controller is a passive device such as a radio receiver or photo electric cell, which is to be activated by the machine associated with the person or part of the person, in use, and where the marker is an active device such as a radio emitter or light source.

10. A device as claimed in claim 9 whereby the controller is induced to switch the power on to the machine when a beam from the marker impinges upon it and to switch off the power to the machine when the beam from the marker is not impinging on it, in use.

11. A device for controlling a machine substantially as hereinbefore described with reference to the accompanying drawing.