Search

EP-4735209-A1 - THERMAL CONTROL FOR COMBUSTION-POWERED TOOLS

EP4735209A1EP 4735209 A1EP4735209 A1EP 4735209A1EP-4735209-A1

Abstract

The invention relates to a combustion-powered tool (100, 200, 300) comprising an engine (101, 201, 301), a fuel cartridge (102, 202, 302) and heat transfer means (103, 203, 303) for selectively transferring heat from the engine to the fuel cartridge.

Inventors

  • BAUDRAND, Olivier

Assignees

  • Illinois Tool Works, Inc.

Dates

Publication Date
20260506
Application Date
20240621

Claims (11)

  1. 1. A combustion-powered tool (100, 200, 300) comprising a heat source, a fuel cartridge (102, 202, 302) and heat transfer means (103, 203, 303) for selectively transferring heat from the heat source to the fuel cartridge.
  2. 2. The combustion-powered tool (100, 200, 300) according to claim 1 , in which the heat source comprises an engine (101 , 201 , 301 ) configured to receive fuel from the fuel cartridge (102, 202, 302).
  3. 3. The combustion-powered tool (100, 200, 300) according to claim 2, in which the heat transfer means (103, 203, 303) comprise a thermal bridge to provide a conductive path between the engine (101 , 201 , 301 ) and the fuel cartridge (102, 202, 302).
  4. 4. The combustion-powered tool (100, 200, 300) according to claim 3, in which the heat transfer means (103, 203, 303) comprises an actuator which moves the thermal bridge between a connected position, in which a conductive path is provided between the engine (101 , 201 , 301 ) and the fuel cartridge (102, 202, 302), and a disconnected position, in which the conductive path is shut off.
  5. 5. The combustion-powered tool (100, 200, 300) according to claim 4, in which the actuator comprises a thermal actuator configured to move the thermal bridge to the disconnected position when the temperature of the fuel cartridge (102, 202, 302) reaches a preset maximum threshold and/or to move the thermal bridge to the connected position when the temperature of the fuel cartridge (102, 202, 302) reaches a preset minimum threshold.
  6. 6. The combustion-powered tool (100, 200, 300) according to claim 3, in which the thermal bridge comprises a bimetallic thermal switch configured to move the thermal bridge to the disconnected position when the temperature of the fuel cartridge (102, 202, 302) reaches a preset maximum threshold and/or to move the thermal bridge to the connected position when the temperature of the fuel cartridge (102, 202, 302) reaches a preset minimum threshold.
  7. 7. The combustion-powered tool (100, 200, 300) according to claim 4, in which the actuator comprises an engine, an electromagnet or a solenoid.
  8. 8. The combustion-powered tool (100, 200, 300) according to claim 7, in which the heat transfer means (103, 203, 303) comprises a thermal circuit breaker configured to connect the engine (101 , 201 , 301), electromagnet or solenoid to a power source when the temperature of the fuel cartridge reaches a preset minimum threshold and/or to disconnect the engine, electromagnet or solenoid from the power source when the temperature of the fuel cartridge (102, 202, 302) reaches a preset maximum threshold.
  9. 9. The combustion-powered tool (100, 200, 300) according to claim 2, in which the heat transfer means (103, 203, 303) comprises air circulation means for directing a flow of engine-warmed air towards the fuel cartridge (102, 202, 302).
  10. 10. The combustion-powered tool (100, 200, 300) according to claim 9, in which the air circulation means comprises a fan for inducing a flow of air around and/or through the engine (101 , 201 , 301 ) and a valve downstream of the engine for selectively allowing air to flow towards the fuel cartridge (102, 202, 302).
  11. 11. The combustion-powered tool (100, 200, 300) according to any of the preceding claims, in which the tool comprises a nail gun or a stapler.

Description

THERMAL CONTROL FOR COMBUSTION-POWERED TOOLS PRIORITY CLAIM This application claims priority to and the benefit of French Application No. 2306810, which was filed on June 28, 2023, the entire contents of which is incorporated herein by reference. Technical field of the invention The present invention generally relates to the thermal control of one or more components of a combustion-powered tool. More specifically, although not exclusively, the present invention relates to the thermal control of a fuel cartridge of a combustion- powered tool. Technical background Combustion-powered nail and staple driving tools are known and normally comprise a housing enclosing an internal combustion engine. The engine is powered by a pressurized fuel gas canister, also known as a fuel cartridge. Summary of the invention The present invention aims to provide a more reliable combustion-powered tool. The invention relates to a combustion-powered tool comprising a fuel cartridge and a control means for controlling the temperature of the fuel cartridge when in use. When fuel is drawn from the fuel cartridge when in use, part of the remaining fuel evaporates, which reduces the temperature of the fuel in the fuel cartridge. One of the consequences of the reduced temperature in the cartridge is an ensuing drop in the pressure of the cartridge and of the fuel it contains. The inventors found that this reduced pressure can affect the injection system and, in extreme cases, cause the tool to fail, if the combustion-powered tool is used continuously for long periods. The invention therefore provides a more reliable combustion-powered tool, by controlling the temperature of the fuel cartridge. The control means can comprise a heat transfer means. The heat transfer means can be used to selectively transfer heat from a heat source to the fuel cartridge. The invention also relates to a combustion-powered tool comprising a heat source, a fuel cartridge and a heat transfer means for selectively transferring heat from the heat source to the fuel cartridge. The heat source can comprise an engine. The engine can be configured to receive fuel from the fuel cartridge. More specifically, the heat source can comprise an engine configured to receive fuel from the fuel cartridge. The control means or heat transfer means can comprise a control mechanism, for example to control the heat transfer between the heat source and the fuel cartridge. The control means, heat transfer means or control mechanism can comprise or can operate in a first, connected, state in which heat can be transferred from the heat source to the fuel cartridge. The control means, heat transfer means or control mechanism can comprise or can operate in a second, disconnected state, in which heat transfer is inhibited between the heat source and the fuel cartridge. The control means or heat transfer means can comprise a thermal bridge, for example to provide a conductive path between the engine and the fuel cartridge. More specifically, the heat transfer means can comprise a thermal bridge to provide a conductive path between the engine and the fuel cartridge. The control means, heat transfer means or control mechanism can comprise an actuator. The actuator can be used to selectively close and open the thermal bridge. The actuator can cause the thermal bridge to move into and out of thermal contact with the fuel cartridge or the engine. The actuator can move the thermal bridge, for example, between a connected and a disconnected position. A conductive path can be provided between the engine and the fuel cartridge, for example in the connected position. The conductive path can be shut off, for example in the disconnected position. More specifically, the heat transfer means can comprise an actuator that moves the thermal bridge between a connected position, in which a conductive path is provided between the engine and the fuel cartridge, and a disconnected position, in which the conductive path is shut off. The actuator can comprise a thermal actuator. The thermal actuator can comprise a material that expands and contracts in response to the temperature of the mechanism. For example, the material can be a liquid, a gas, wax or a wax-like substance. The thermal actuator can comprise a thermal actuator made of wax. The thermal actuator can be configured to move the thermal bridge to the disconnected position when the fuel cartridge temperature reaches a preset minimum threshold. The thermal actuator can be configured to move the thermal bridge to the connected position when the fuel cartridge temperature reaches a preset maximum threshold. More specifically, the actuator can comprise a thermal actuator configured to move the thermal bridge to the disconnected position when the fuel cartridge temperature reaches a preset minimum threshold and/or to move the thermal bridge to the connected position when the fuel cartridge temperature reaches a preset maximum threshold. The thermal b