Press brake safety device
AssigneeRoyston Manufacturing Corporation
InventorsRichard P. Adams, Charles Christian
Life of this patent
Estimating the term…
Abstract
In a mechanical press brake, a photoelectric sensor causes extension of an air cylinder in the linkage between the operating pedal and the clutch lever, thereby disabling the pedal whenever the operator's hand or arm is in dangerous proximity to the machine's ram. The piston of the air cylinder is connected to the pedal through a lost-motion, and the pedal is continuously urged toward its rest position by a spring. The lost-motion and spring prevent repeated extension and retraction of the cylinder from causing dangerous and annoying operation of the pedal during preparation for a forming operation.
Claims12
In a mechanical press brake having a bed, a ram cooperable with the bed, ram control means operable to effect movement of the ram toward the bed to effect a forming operation, a foot-operable pedal movable from a rest position to an operating position, linkage means, connected between the pedal and the ram control means, for effecting movement of the ram toward the bed upon movement of the pedal to its operating position, and sensing means associated with the bed for sensing the presence of the operator's hands and arms in dangerous proximity to the ram, the improvement comprising means operatively connected to and responsive to the sensing means for disabling the linkage means when the sensing means senses the presence of an operator's hand or arm in dangerous proximity to the ram at least within a preestablished range of ram positions, and the improvement being characterized by:
- means connected to the pedal and arranged to urge the pedal toward its rest position;
- lost motion means constituting part of the linkage and normally transmitting motion from the pedal to the ram control means, said lost motion means being movable between a first position in which movement of the pedal effects movement of the ram toward the bed and a second position in which movement of the pedal does not effect movement of the ram;
- and
- an actuator operatively connected to the lost motion means and responsive to the sensing means for moving the lost motion means from its first position to its second position whenever the sensing means senses the presence of an operator's hand or arm in dangerous proximity to the ram;
- whereby the operative connection between the pedal and the ram control means is disabled without movement of the pedal whenever the operator's hand or arm is in dangerous proximity to the ram.
In a mechanical press brake having a bed, a ram cooperable with the bed, a flywheel, and clutch means, connected between said flywheel and said ram and operable to effect movement of the ram toward the bed to effect a forming operation, clutch-actuating means movable to effect engagement and disengagement of the clutch means, a foot-operable pedal movable from a rest position to an operating position, linkage means, connected between the pedal and the clutch-actuating means for effecting operating movement of the clutch-actuating means upon movement of the pedal to its operating position, and sensing means associated with the bed for sensing the presence of the operator's hands and arms in dangerous proximity to the ram, the improvement comprising means operatively connected to and responsive to the sensing means for disabling the linkage means when the sensing means senses the presence of an operator's hand or arm in dangerous proximity to the ram at least within a preestablished range of ram positions, and the improvement being characterized by:
- means connected to the pedal and arranged to urge the pedal toward its rest position,
- lost motion means constituting part of the linkage and normally transmitting motion from the pedal to the clutch actuating means, said lost motion means being movable between a first position in which movement of the pedal effects engagement of the clutch means and a second position in which movement of the pedal does not effect engagement of the clutch means;
- and
- an actuator operatively connected to the lost motion means and responsive to the sensing means for moving the lost motion means from its first position to its second position whenever the sensing means senses the presence of an operator's hand or arm in dangerous proximity to the ram;
- whereby the operative connection between the clutch means and the pedal is disabled without movement of the pedal whenever the operator's hand or arm is in dangerous proximity to the ram.
Dependencies are inferred from the claim text.