Safety apparatus and protection method for machines

A method for protecting an object entering into the path of a moving member of a machine, the moving member being either a working member provided with a working end, or a work-piece supporting member, whereby one of the members is controlled to selectively move convergingly towards the other member of the machine, the method including:

• emitting a light beam at a fixedly spaced distance along a normally uninterrupted path in advance of the working end of the working member whilst the moving member moves through a range of prescribed movement, 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;
• continuously sensing for the receipt of said light beam after it has traversed in advance of the working end;
• halting the advancing movement of the moving member in response to any failure to receive and sense the emitted light beam at any time during said range of prescribed movement or in response to some contingency;
• preventing the moving member from being halted for certain contingencies during said further range of prescribed movement;
• and
• pulsing said light beam in a prescribed manner and halting the advancing movement of the moving member in response to failing to receive and sense the emitted light beam as pulsed in said prescribed manner.

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;
• and
• halting 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 vibration sensing means to analyse signals in response to said light receiving means sensing receipt of the light beam and distinguish between normal vibration of the light beam and abnormal interruption of the light beam;
• and wherein said halting means halts advancing movement of the moving member in response to said vibration sensing means sensing said abnormal interruption of the light beam during said range of prescribed movement.

A method for protecting an object entering into the path of a moving member of a machine, the moving member being either a working member provided with a working end, or a work-piece supporting member, whereby one of the members is controlled to selectively move convergingly towards the other member of the machine, the method including:

• emitting a light beam at a fixedly spaced distance along a normally uninterrupted path in advance of the working end of the working member whilst the moving member moves through a range of prescribed movement, 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;
• continuously sensing for the receipt of said light beam after it has traversed in advance of the working end;
• halting the advancing movement of the moving member in response to any failure to receive and sense the emitted light beam at any time during said range of prescribed movement or in response to some contingency;
• preventing the moving member from being halted for certain contingencies during said further range of prescribed movement;
• and
• analysing the received light beam to discriminate between normal vibration and abnormal interruption of the light beam and halting advancing movement of the moving member in response to sensing said abnormal interruption during said range of prescribed movement.

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 continuously monitor for 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;
• and
• halting 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 a plurality of said corresponding light emitting means and light receiving means are provided so that said light emitting means are integrally mounted in substantially parallel relationship adjacent to each other as a discrete unit relative to the working member and said light receiving means are integrally mounted in substantially similar parallel relationship adjacent to each other as a separate discrete unit relative to both the working member and said discrete unit, but in substantial alignment with said corresponding light emitting means to receive the respective emitted light beams therefrom.