| 摘要 |
1,150,597. Machinery guards. E. R. N. JACKSON. 27 Oct., 1967 [18 Nov., 1966], No. 51717/66. Heading F2J. [Also in Division H3] Safety means for a sheet-metal press comprise a gate formed by end members 1 and contact-sensitive electrical conductive wires 2 insulated from the press frame and connected in-an electrical control circuit by which operation of the press is controlled. The gate is mounted so as to be slidable vertically and is attached to a lever 9 mounted on a pivot 10. The lever 9 carries a horizontal screw 16 which is adapted to be engaged by a vertically adjustable screw 15 carried by the ram 12 of the press, so that as the ram 12 descends the gate is lifted. A projection 26 at the rear end of lever 9 is adapted to actuate a micro-switch 25 connected between the gate and earth, the switch being open-circuited when the gate is lowered. A suitable control circuit is shown which remains inoperative when the selected resistance of the wire 2 is in circuit. If the resistance is modified by contact of an operator's hand, the control circuit is activated to operate a relay for stopping the press, cutting off power supply and/or actuating a warning or alarm. A further micro-switch may be included in the control circuit and adapted to be opencircuited by a cam on the crank-shaft of the press to render the gate control circuit operative only during the period of downward movement of the beam. |
