Low pressure shut off for a pneumatic tool
AssigneeApex Brands, Inc.
InventorsEdouard Da Palma, Pascal Bourcier
Life of this patent
Estimating the term…
Abstract
A low pressure shut off for a pneumatic tool. The tool may include an air path for input air. A shaft may be positioned along the air path and movable relative to the air path between a first position and a second position. First and second pistons may be spaced axially apart along the shaft and each may extend radially outward beyond the shaft. In the first position, the first piston may extend across the air path to block the air path. In the second position, the second piston may be positioned to be acted on by air from a secondary inlet to apply a force to the second piston that overcomes a biasing force and positions the first piston to allow air to flow along the air path.
Claims17
A low pressure shut off for a pneumatic tool comprising:
- an air path comprising a main inlet, an outlet, and a secondary inlet;
- a shaft positioned along the air path between the main inlet and the outlet, the shaft being movable relative to the air path between a first position and a second position;
- first and second pistons spaced axially apart along the shaft and each extending radially outward beyond the shaft;
- and
- a biasing member acting on the shaft to bias the shaft towards the first position;
- a first bore positioned away from the air path and including a sectional shape and size that matches the first piston;
- a seal on the first piston that contacts and seals against walls of the first bore when the first piston is in the second position;
- in the first position, the first piston extends across the air path between the main inlet and the outlet to block the air path;
- in the first position, the second piston is positioned to be acted on by air from the secondary inlet to apply a force to the second piston that overcomes the force of the biasing member and position the shaft at the second position with the first piston away from the air path to allow air to flow along the air path between the main inlet and the outlet;
- the first piston being positioned in the first bore in the second position such that a force acting on the first piston that is supplied through the air flowing along the air path maintains the first piston in the second position in the first bore after the force acting on the second piston that is supplied from the air from the secondary inlet is removed from the second piston.
A method of operating a valve for a pneumatic tool, the method comprising:
- positioning a first piston in a first position at a neck in an air path and blocking air from flowing along the air path from an air inlet to an air outlet;
- applying a first force to a second piston and moving the first piston to a second position out of the neck and allowing the air to flow along the air path from the air inlet to the air outlet;
- applying a second force to the first piston through the air flowing along the air path and maintaining the first piston in the second position after the first force is removed from the second piston;
- sealing the first piston at the second position and preventing the air from the air path from moving past the first piston;
- and
- when air pressure of the air flowing along the air path falls below a preset level, moving the first piston to the first position and blocking air from flowing along the air path from the air inlet to the air outlet.
Dependencies are inferred from the claim text.