Lockout for fastener-driving tool

Patent metadata

Field	Value
Publication number	US-9486906-B2
Application number	US-201213469795-A
Country	US
Kind code	B2
Filing date	May 11, 2012
Priority date	May 11, 2012
Publication date	Nov 8, 2016
Grant date	Nov 8, 2016

Abstract

A combustion-powered fastener-driving tool includes a combustion-powered power source having a combustion chamber, a reciprocating piston and driver blade, and a valve sleeve reciprocable relative to the power source between a rest position and a firing position. The valve sleeve partially defines the combustion chamber. A lockout device is in fluid communication with the combustion power source and includes a reciprocating gas piston connected to a latch in operational proximity to the valve sleeve. The lockout device is configured such that upon combustion in the combustion chamber, gas from the combustion engages the gas piston and moves the latch to an engaged position in which the valve sleeve is prevented from moving to the rest position.

First claim

The invention claimed is:

1. A fastener-driving tool, comprising:
a combustion-powered power source having a housing, a combustion chamber, and a reciprocating piston and driver blade that each move along a main axis;
a valve sleeve reciprocable relative to said power source between a rest position and a firing position and partially defining said combustion chamber; and
a lockout device in fluid communication with said power source and including a reciprocating gas piston connected to a latch in operational proximity to said valve sleeve, said latch being pivotably connected to said housing and configured such that upon combustion in said combustion chamber, gas from said combustion engages said gas piston and moves said latch to an engaged position in which said valve sleeve is prevented from moving to said rest position.

2. The tool of claim 1 further including a tool control system, and an electromagnet connected to said control system and located in operational proximity to said gas piston for holding said gas piston so that said latch is retained in said engaged position for a period determined by said control system.

3. The tool of claim 1 wherein said gas piston has a piston rod and reciprocates within a gas cylinder between an extended position and a retracted position, said cylinder being provided with a return spring for biasing said gas piston to said extended position.

4. The tool of claim 3 further including an electromagnet associated with said gas cylinder and constructed and arranged for retaining said gas piston in said retracted position under control of a tool control system.

5. The tool of claim 4 wherein said return spring is compressed when said gas piston is in said retracted position.

6. The tool of claim 3 wherein said return spring is located in said gas cylinder between said gas piston and said electromagnet.

7. The tool of claim 3 wherein said electromagnet is located at an end of said gas cylinder opposite said gas piston rod.

8. The tool of claim 1 wherein said latch pivots about a pivot axis extending transverse to said main axis and includes a first portion connected to said gas piston, and a second portion configured for engaging said valve sleeve.

9. The tool of claim 8 wherein said first portion of said latch is pivotally connected to a rod of said gas piston.

10. The tool of claim 1 , wherein said reciprocating piston moves between a pre-firing position and a driving position, and a tool control system configured for causing said latch to remain in said engaged position after a combustion until said reciprocating piston reaches the pre-firing position.

11. A fastener-driving tool, comprising:
a combustion-powered power source having a combustion chamber, and a main piston and driver blade reciprocating along a main tool axis between a pre-firing position and a fastener driving position;
a valve sleeve reciprocating along said main tool axis relative to said power source between a rest position and a firing position and partially defining said combustion chamber; and
a lockout device in fluid communication with said combustion power source and including a reciprocating gas piston moving between an extended position and a retracted position, and a latch pivotably connected to said gas piston and in operational proximity to said valve sleeve and moving between a disengaged position in which said valve sleeve moves between said firing position and said rest position, and an engaged position in which said valve sleeve is prevented from moving from said firing position to said rest position;
a tool control system connected to an electromagnet associated with said gas cylinder and configured for energizing said electromagnet for a preset period of time; and
said tool configured such that upon combustion in said combustion chamber, gas from said combustion forces said gas piston to said retracted position, moving said latch to said engaged position in which said valve sleeve is prevented from moving to said rest position, and said control system energizes said electromagnet for retaining said gas piston in said retracted position until said main piston returns to said pre-firing position.

Assignees

• Zhao Hanxin
• Porth Christopher H
• Moore Stephen P
• Illinois Tool Works

Inventors

• Zhao Hanxin
• Porth Christopher H
• Moore Stephen P

Classifications

• B25C1/08 Primary

  operated by combustion pressure · CPC title

• B25C1/008 Primary

  Safety devices · CPC title