Pneumatic actuator for impact engraving tool
OwnerChristian DeCamillisinventor
Life of this patent
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Abstract
A pneumatic actuator for use in pneumatic impact tools of the type used to engrave jewelry, and an impact tool adapted for the pneumatic actuator. The actuator includes a cylinder body with a pneumatic chamber housing a piston assembly reciprocating in response to pulses of pressurized air. The piston assembly includes a piston base and a striker pin in the pneumatic chamber, an outer end of the striker pin extending through and residing outside a forward end of the chamber. The outer end of the striker pin has an enlarged striker head of greater mass than the striker pin and/or the piston base in the chamber. A pneumatic impact tool is also disclosed, and includes a forward stylus section having a guide bore for the striker head and holding a graver assembly in spaced relationship to the striker head.
Claims14
A pneumatic impact tool comprising a pneumatic actuator including a pneumatic cylinder comprising a pneumatic chamber including an air supply inlet, and a piston assembly including a piston base movably mounted in the pneumatic chamber to be driven forward from a home position in the pneumatic chamber to an impact position in the pneumatic chamber in response to pressure delivered via the air supply inlet, the piston assembly further including a striker head operatively connected to and spaced from the piston base and located forward of and outside the pneumatic chamber, the pneumatic impact tool further comprising a non-pneumatic guide bore containing the striker head, the non-pneumatic guide bore located forward of the pneumatic chamber and pneumatically separate from the pneumatic chamber such that the non-pneumatic guide bore remains at a pressure essentially equal to atmosphere outside the pneumatic impact tool, the non-pneumatic guide bore terminating in a graver assembly, the striker head movably positioned in the non-pneumatic guide bore and movable with the piston base toward and away from the graver assembly sufficient to strike the graver assembly at the forward end of a drive stroke, wherein:
- the piston base has a first diameter and rides in and approximates the diameter of the pneumatic chamber, and a striker pin having a second diameter smaller than the first diameter extends forwardly from the piston base through a forward end of the pneumatic cylinder body and includes an outer end residing outside the pneumatic chamber in the non-pneumatic guide bore, the striker head secured to the outer end of the striker pin in the non-pneumatic guide bore, the striker head having a diameter and mass greater than the diameter and mass of the striker pin and/or a mass greater than the mass of the piston base inside the pneumatic chamber;
- and,
- a spring return means in the pneumatic chamber is in operative engagement with the piston base for returning the piston assembly from the impact position to the home position.
Dependencies are inferred from the claim text.