Low Pressure Shut Off for a Pneumatic Tool

Patent metadata

Field	Value
Publication number	US-2016003370-A1
Application number	US-201414770046-A
Country	US
Kind code	A1
Filing date	Feb 24, 2014
Priority date	Feb 26, 2013
Publication date	Jan 7, 2016
Grant date	—

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.

First claim

What is claimed is:

1 . 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; 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.

2 . The low pressure shut off according to claim 1 , wherein the air path includes a neck positioned between the main inlet and the outlet, the neck and the first piston including a common sectional shape and size such that the first piston blocks the air path at the neck in the first position.

3 . The low pressure shut off according to claim 2 , further comprising a flexible gasket mounted at a periphery of the first piston such that the gasket contacts against the neck in the first position.

4 . The low pressure shut off according to claim 1 , further comprising a second bore with sidewalls and a bottom, the second piston positioned in the second bore in the first position and having a common sectional shape and size as the second bore.

5 . The low pressure shut off according to claim 4 , wherein the second bore is positioned away from the air path that extends between the main inlet and the outlet.

6 . The low pressure shut off according to claim 1 , further comprising a first bore positioned away from the air path that extends between the main inlet and the outlet, the first bore including a sectional shape and size that matches the first piston, the first piston being positioned in the first bore in the second position and away from the first bore in the first position.

7 . The low pressure shut off according to claim 1 , wherein the biasing member is positioned away from the air path that extends between the main inlet and the outlet.

8 . The low pressure shut off according to claim 1 , further comprising a shut-off button at an end of the shaft, the shut-off button extending outward from a housing that extends around the low pressure shut off a greater amount in the second position than in the first position.

9 . 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; 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.

10 . The method of claim 9 , further comprising biasing the first piston towards the first position.

11 . The method of claim 10 , wherein a biasing force that biases the first piston towards the first position is less than the second force that maintains the first piston in the second position when the air pressure is above the preset level.

12 . The method according to claim 9 , further comprising moving each of the first and second pistons an equal amount between the first and second positions as the first and second pistons are each connected to a shaft.

13 . The method according to claim 9 , further comprising sealing the first piston in a bore in the second position and preventing air from the air path from acting on an opposing side of the first piston that faces away from the air path.

14 . The method according to claim 9 , further comprising moving air through a secondary inlet and applying air against the second piston to create the first force, the secondary inlet being positioned away from the air path that extends from the air inlet to the air outlet.

15 . The method according to claim 9 , further comprising moving a manual shut-off button outward relative to an outer housing when moving the first piston from the first position to the second position.

Assignees

• Apex Brands Inc

Inventors

• Da Palma Edouard
• Bourcier Pascal

Classifications

• B23Q5/263

  with means to control the feed rate by controlling the fluid flow · CPC title

• B25B21/00

  Portable power-driven screw or nut setting or loosening tools; (details or components, e.g. casings, bodies, of portable power-driven tools not particularly related to the operation performed B25F5/00; {for mounting or dismounting wheels B60B29/006}); Attachments for drilling apparatus serving the same purpose (machines B23P19/06) · CPC title

• B25F3/00

  Associations of tools for different working operations with one portable power-drive means; Adapters therefor · CPC title

• B25F5/00

  Details or components of portable power-driven tools not particularly related to the operations performed and not otherwise provided for · CPC title

• F16K31/1225 Primary

  with a plurality of pistons · CPC title