Mechanical lockout for a pneumatic tool

A pneumatic tool comprising:

• a motor in the form of a piston movably contained within a cylinder and including means for directing pressurized air to opposite ends of said piston to thereby cause the piston to travel upwardly or downwardly within said cylinder;
• a handle operatively attached to a first end of the cylinder;
• an air inlet leading from an exterior source of pressurized air to the motor;
• a control valve in the air inlet for controlling a flow of pressurized air to the motor;
• an implement retainer connected to a second end of the cylinder and movable therewith in a manner wherein during normal operation of the tool, said implement retainer remains fixed to the cylinder and is stationary relative to the cylinder, said implement retainer having a thru-bore and an implement retaining means, and wherein when an implement adapted for contacting a workpiece is placed within the thru-bore of the retainer and the retainer is connected to the housing, the implement retaining means functions to retain said implement to the cylinder while allowing said implement to move within the thru-bore of the retainer, and wherein the retainer will normally be in a locking first position in which it fully secures the implement to the tool so that when the piston moves to a position at a bottom portion of the cylinder, it imparts a downward force on the implement, and wherein the retainer can be moved to a non-locking second position in which the implement is not fully secured to the tool and wherein when the retainer is located in its lock position, it is proximate a bottom end of the cylinder and wherein when the retainer is moved to its non-locking position, the distance between it and the cylinder is increased;
• and
• a safety shut-off means that is functionally dependent on the position of the implement retainer and includes a detecting means that senses the position of the retainer and wherein the safety shut-off means includes a stop means that prevents pressurized air from causing downward movement of the piston when the retainer is not in its lock position.

A power tool comprising:

• an elongated housing having a user graspable handle proximate a first end;
• a removable member connected by fastening means to a second end of said housing, said removable member having a thru-bore and an implement retaining means, wherein when an implement adapted for contacting a workpiece is placed within the thru-bore of the removable member and the removable member is connected to the housing, the implement retaining means functions to releasably retain said implement to said housing while allowing said implement to move within the thru-bore of the removably member and wherein during normal operation of the tool, said removable member remains fixed to the housing and is stationary relative to the housing and wherein the removable member will normally be in a locking first position in which it fully secures the implement to the tool, and wherein the removable member can be moved to a non-locking second position in which the implement is not fully secured to the tool;
• a motor means located within said housing between the housing's first and second ends, said motor means functioning to transform inputed power to a movement that is imparted to the implement;
• and
• a safety shut-off means that is functionally dependent on the position of the removable member and includes a detecting means that senses the position of the removable member and wherein the safety shut-off means includes a stop means that prevents power from being imparted to the implement when the removable member is not in its lock position.