Patent ID: 6316763
Filing Date: 2001-11-13
Classification: B21D,F16P

Abstract:
A safety apparatus for a machine having a working member provided with a working end and a work-piece supporting member, whereby one of the members is controlled to selectively move convergingly towards the other member of the machine, the safety apparatus including:corresponding light emitting means and light receiving means for mounting in fixed relationship with the working end of the working member, so as to define a protected region fixedly spaced therefrom;said light emitting means being adapted for emitting a beam of light and the corresponding light receiving means being adapted for receiving the beam of light so that normally the beam may be emitted and received by said corresponding light emitting means and light receiving means along an uninterrupted path fixedly spaced from the working end of the working member;control means to activate said light emitting means to emit the light beam and said light receiving means to sense receipt of the emitted light beam during a range of prescribed movement of the moving member, said range of prescribed movement being completed at a mute point and the moving member being capable of continuing to move through a further range of prescribed movement past said mute point; andhalting means for halting advancing movement of the moving member in response to some contingency as detected or sensed by said control means, said halting means being disabled from halting advancing movement of the moving member for certain contingencies during said further range of prescribed movement;wherein said control means includes position processing means to continuously track the movement of the moving member and check that said movement is in accordance with said prescribed movement; and wherein said halting means halts advancing movement of the moving member in response to said position processing means determining that said advancing movement is not in accordance with said prescribed movement.