Safety device for a peck drill
AssigneeLockheed Martin Corporation
InventorsWilliam B. Carr, William L. Jenkins
Life of this patent
Estimating the term…
Abstract
A pneumatic feed drill has a control unit that repeatedly advances and retracts the drill bit in peck cycles while drilling the hole. The drill has a hydraulic damper cylinder with a damper rod protruding from it that limits the speed of advancement of the drill bit. A retainer device is mounted to the damper rod and prevents the damper rod from resetting to its initial position during the peck cycles. The retainer device releases the damper rod to reset when the drill bit has reached total depth. A safety device is pivotally mounted to the housing and has a closure tab that blocks access to the start button of the drill unless the damper rod is in its initial position.
Claims20
In a peck drill having a start button for actuating a motor to rotate and a piston to advance a drill bit, a hydraulic damper assembly including a hydraulic cylinder and a damper rod for limiting the speed of advancement of the drill bit, the hydraulic damper assembly including a retainer device that prevents the damper rod from resetting to an initial position when the piston retracts the drill bit during a peck cycle, and the retainer device releasing the damper rod to reset when the drill bit is at total depth, the improvement comprising:
- a housing enclosing the damper rod and the start button, the housing having an aperture that provides manual access to the start button;
- and
- a safety device pivotally mounted to the housing and in cooperative engagement with the hydraulic damper assembly, the safety device having a closed position that blocks the aperture and access to the start button when the damper rod has moved from the initial position, and an open position that opens the aperture to provide access to the start button when the damper rod is in the initial position.
A pneumatic peck drill, comprising:
- a pneumatic motor and a pneumatic piston for rotating and advancing a drill bit;
- a hydraulic cylinder having a damper rod protruding therefrom for limiting the speed of advancement of the drill bit;
- a retainer device in engagement with the damper rod for movement therewith, the retainer device preventing the damper rod from resetting to an initial position while the piston retracts the drill bit during a peck cycle, and the retainer device releasing the damper rod to reset when the drill bit is at total depth;
- a housing enclosing the damper rod and the start button, the housing having an aperture that provides manual access to the start button;
- a safety device pivotally mounted to the housing, the safety device having a closure tab that has a closed position, blocking the aperture in the housing when the damper rod is not substantially in the initial position;
- a contact member mounted to the retainer device for movement therewith, the contact member engaging the safety device to move the closure tab to the open position while the damper rod is in the initial position;
- and
- a spring mounted between the safety device and the housing to urge the closure tab to the closed position.
A safety assembly for a pneumatic peck drill having a start button for actuating a pneumatic motor to rotate and a pneumatic piston to advance a drill bit, a hydraulic damper assembly including a hydraulic cylinder and a damper rod for limiting the speed of advancement of the drill bit, the hydraulic damper assembly including a retainer device that prevents the damper rod from resetting to an initial position when the piston retracts the drill bit during a peck cycle, and releases the damper rod to reset when the drill bit is at total depth, the safety device comprising:
- a housing for mounting to the drill and enclosing the damper rod and the start button, the housing having an aperture for providing manual access to the start button;
- and
- a safety device pivotally mounted to the housing for cooperative engagement with the hydraulic damper assembly, the safety device having a closed position that blocks the aperture when the damper rod is not in the initial position, and an open position that opens the aperture to provide access to the start button when the damper rod is substantially in the initial position.
Dependencies are inferred from the claim text.