Combustion-powered placing tool and method for operating such a placing tool

Patent metadata

Field	Value
Publication number	US-10898996-B2
Application number	US-201616062351-A
Country	US
Kind code	B2
Filing date	Dec 20, 2016
Priority date	Dec 22, 2015
Publication date	Jan 26, 2021
Grant date	Jan 26, 2021

Abstract

A combustion-powered placing tool for driving fastening elements into a subsurface comprises a main combustion chamber for a compressible fuel, a driving piston, which in a starting position is retracted, and which can be driven from the main combustion chamber in the placing direction via expandable gases, a prechamber to which an ignition device is assigned, and in which a pressure acting upon the main combustion chamber can be build up prior to ignition of a fuel-air mixture in the main combustion chamber, wherein an additional ignition device is assigned to the main combustion chamber. In order to improve the effectiveness and/or the functionality during driving-in of a fastener, the placing tool comprises a selector device, allowing a selection between a reduced energy operation having an ignition in the main combustion chamber and a high-energy operation having an ignition in the prechamber.

First claim

The invention claimed is:

1. A combustion-powered setting tool for driving fastening elements into a substrate, the tool comprising at least one main combustion chamber for a fuel; a driving piston that is completely retracted in an initial position and can be driven by expandable gases out of the at least one main combustion chamber in a setting direction in a low-power mode and a high-power mode; a prechamber; an ignition device, wherein the ignition device is associated with the prechamber and in the prechamber, prior to the ignition of a fuel/air mixture in the at least one main combustion chamber, a pressure acting on the at least one main combustion chamber is built up in the high power mode; an additional ignition device, wherein the additional ignition device is associated with the at least one main combustion chamber, and in the at least one main combustion chamber, a fuel/air mixture is ignited without prior ignition in the prechamber in the low power mode; and a selector device by which a selection is made between the low-power mode and the high-power mode.

2. The combustion-powered setting tool as set forth in claim 1 , wherein the setting tool comprises a control device that is connected to at least one sensor device for detecting the pressure, temperature, and/or position in or near the prechamber and/or connected to at least one sensor device in or near the at least one main combustion chamber.

3. The combustion-powered setting tool as set forth in claim 1 , wherein the setting tool comprises a reset device that is connected for control to the ignition device of the at least one main combustion chamber and/or the prechamber in order to effect a resetting of the driving piston into the initial position of the driving piston in the event of a piston fault as a result of an ignition in the at least one main combustion chamber and/or the prechamber.

4. The combustion-powered setting tool as set forth in claim 1 , wherein the setting tool comprises an actuator with which a target value of a pressure, temperature, position, and/or time control can be set or adjusted manually.

5. The combustion-powered setting tool as set forth in claim 1 , wherein, in addition to the low-power mode and the high-power mode, the setting tool has at least one other operating mode in which a piston fault is detected and/or eliminated.

6. The combustion-powered setting tool as set forth in claim 1 , wherein, in addition to the low-power mode and the high-power mode, the setting tool has at least one other operating mode in which a gas mixture is first ignited by the ignition device of the prechamber, and then the gas mixture is ignited in the at least one main combustion chamber by the additional ignition device based on time, pressure, position, and/or temperature control.

7. The combustion-powered setting tool as set forth in claim 2 , wherein the setting tool comprises a reset device that is connected for control to the ignition device of the at least one main combustion chamber and/or the prechamber in order to effect a resetting of the driving piston into the initial position of the driving piston in the event of a piston fault as a result of an ignition in the at least one main combustion chamber and/or the prechamber.

8. The combustion-powered setting tool as set forth in claim 2 , wherein the setting tool comprises an actuator with which a target value of a pressure, temperature, position, and/or time control can be set or adjusted manually.

9. The combustion-powered setting tool as set forth in claim 3 , wherein the setting tool comprises an actuator with which a target value of a pressure, temperature, position, and/or time control can be set or adjusted manually.

10. The combustion-powered setting tool as set forth in claim 2 , wherein, in addition to the low-power mode and the high-power mode, the setting tool has at least one other operating mode in which a piston fault is detected and/or eliminated.

11. The combustion-powered setting tool as set forth in claim 3 , wherein, in addition to the low-power mode and the high-power mode, the setting tool has at least one other operating mode in which a piston fault is detected and/or eliminated.

12. The combustion-powered setting tool as set forth in claim 4 , wherein, in addition to the low-power mode and the high-power mode, the setting tool has at least one other operating mode in which a piston fault is detected and/or eliminated.

13. The combustion-powered setting tool as set forth in claim 2 , wherein, in addition to the low-power mode and the high-power mode, the setting tool has at least one other operating mode in which a gas mixture is first ignited by the ignition device of the prechamber, and then the gas mixture is ignited in the at least one main combustion chamber by the additional ignition device based on time, pressure, position, and/or temperature control.

14. The combustion-powered setting tool as set forth in claim 3 , wherein, in addition to the low-power mode and the high-power mode, the setting tool has at least one other operating mode in which a gas mixture is first ignited by the ignition device of the prechamber, and then the gas mixture is ignited in the at least one main combustion chamber by the additional ignition device based on time, pressure, position, and/or temperature control.

15. A combustion-powered setting tool for driving fastening elements into a substrate, the combustion-powered setting tool comprising at least one main combustion chamber for a fuel; a driving piston that is completely retracted in an initial position and can be driven by expandable gases out of the at least one main combustion chamber in a setting direction; a prechamber; an ignition device, wherein the ignition device is associated with the prechamber and in the prechamber, prior to the ignition of a fuel/air mixture in the at least one main combustion chamber, a pressure acting on the at least one main combustion chamber can be built up; an additional ignition device, wherein the additional ignition device is associated with the at least one main combustion chamber; and an air bleed valve device associated with the at least one main combustion chamber, wherein the air bleed valve device is capable of equalizing pressure with a surrounding of the setting tool if there is a piston fault during a secondary ignition in the at least one main combustion chamber.

16. A method for operating a combustion-powered setting tool for driving fastening elements into a substrate, the combustion-powered setting tool comprising at least one main combustion chamber for a fuel; a driving piston that is completely retracted in an initial position; a prechamber; an ignition device associated with the prechamber; an additional ignition device associated with the at least one main combustion chamber;
the method comprising driving the driving piston by expandable gases out of the at least one main combustion chamber in a setting direction; selecting between a low-power mode and a high power mode; and, if the high-power mode is selected, building up a pressure in the prechamber, prior to the ignition of a fuel/air mixture in the at least one main combustion chamber, acting on the at least one main combustion chamber; and, if the low-power mode is selected, igniting a fuel/air mixture in the at least one main combustion chamber without prior ignition in the prechamber.

17. The method as set forth in claim 16 , wherein a piston fault is detected automatically, and an ignition is initiated in the prechamber or in the at least one main combustion chamber to return the driving p

Assignees

• Hilti Ag

Inventors

• Heeb Norbert
• Bruggmueller Peter
• Schmidt Dominik
• Dittrich Tilo

Classifications

• F02B63/02

  for hand-held tools · CPC title

• B25D9/10

  comprising a built-in internal-combustion engine · CPC title

• F02B1/04

  with fuel-air mixture admission into cylinder · CPC title

• B25C1/08 Primary

  operated by combustion pressure · CPC title

• B25C5/15

  operated by electric power · CPC title