US 4,784,308 A · Fastener driving tool

Abstract

A pneumatic fastener driving tool includes a return system for efficiently and rapidly returning a drive piston to the static position and effecting a fastener feeding operation. A housing defines a pressure fluid reservoir connected by a pneumatic control system to a first side of a drive piston to move a driver blade through a drive track in a drive stroke. A pressure fluid actuated fastener feed assembly advances fasteners along a feed path to the drive track. Following a drive stroke, the return system connects the reservoir to the second side of the drive piston for moving the drive piston and driver blade in a return stroke. The return system also connects the reservoir to the fastener feeding assembly for feeding of a fastener. The return system includes two separate return valves operable at different flow capacities and fluid pressures for drive piston return and for fastener feeding.

Claims17

Dependent claims

A fastener driving tool comprising a pressure fluid reservoir, a drive piston, a fastener feed piston, valve means to connect the reservoir to the drive piston to effect a fastener drive stroke, and a pressure fluid return system for returning the drive piston and operating the feed piston at the end of a drive stroke, said return system comprising in combination:

a drive piston return valve having an inlet connected to the reservoir and an outlet connected to the drive piston;
and
a feed piston return valve having an inlet connected to the reservoir and an outlet connected to the fastener feed piston.

A pneumatic fastener driving tool comprising in combination:

a housing defining a pressure fluid reservoir, a fastener drive track and a fastener feed path;
a pressure fluid actuated fastener feed assembly for advancing fasteners along said fastener feed path to said drive track;
a driver blade movable in said drive track for driving fasteners into a workpiece;
a cylinder in said housing;
a drive piston connected to said driver blade and movable in said cylinder from a static position in a fastener drive stroke and movable back to said static position in a return stroke;
a pneumatic control system for connecting a first side of said drive piston to said reservoir during a drive stroke and for venting said first side of said drive piston during a return stroke;
a return system for connecting said reservoir to the second side of said drive piston to effect a return stroke and for connecting said reservoir to said fastener feed assembly to effect feeding of a fastener;
and
the improvement in accordance with which the return system includes;
a drive piston return valve having an outlet connected to the second side of said drive piston;
a fastener feed return valve having an outlet connected to said fastener feed assembly;
inlets of both said return valves connected to said reservoir;
and
a return valve control system for opening both said return valves following a drive stroke and for closing both said return valves in the static position of said drive piston.

11 more elements

Dependencies are inferred from the claim text.

Fastener driving tool

Life of this patent

Fastener driving tool

Life of this patent

Abstract

Claims17