Combustion-engined setting tool

• US 20030218042A1
• Filed: 05/08/2003
• Published: 11/27/2003
• Est. Priority Date: 05/21/2002
• Status: Active Grant

• Current Assignee: Hilti Aktiengesellschaft (Hilti Martin Family Trust)
• Original Assignee: Hilti Aktiengesellschaft (Hilti Martin Family Trust)
• Inventors: Odoni, Walter, Schiestl, Ulrich, Gschwend, Hans, Rosenbaum, Ulrich
• Granted Patent: US 6,722,548 B2
• Time in Patent Office: Days
• US Class Current: 227/10
• CPC Class Codes: B25C 1/08 operated by combustion pressure

Abstract

A combustion-engined setting tool for driving fastening elements in a constructional components includes at least one mechanically controlled valve (14) arranged in a feeding conduit (12) that connects a reservoir (11) with an oxidation agent or fuel with the tool combustion chamber (13), a switch element (15) for time-delayed opening of the mechanically controlled valve (14) upon being actuated, and at least one normally open, electronically controlled valve (24) likewise arranged in the feeding conduit.

Claims

1. A combustion-engined setting tool for driving fastening elements in a constructional component, comprising a reservoir (11) for storing one of fuel and oxidation agent;

a combustion chamber (13);

a feeding conduit connecting the reservoir (11) with the combustion chamber (13);

at least one mechanically controlled valve (14) arranged in the feeding conduit (12) for controlling flow of the one of fuel and oxidation agent therethrough;

switch means (15) for time-delayed opening of the mechanically controlled valve (14) in response to actuation of the switch means (15); and

at least one normally open, electronically controlled valve (24) likewise arranged in the feeding conduct (12) for controlling the flow of the one of oxidation agent and fuel.

2. A setting tool according to claim 1, further comprising an electronic control circuit (20) that insures closing of the electronically controlled valve (24) during an operational cycle before the mechanically controlled valve (14) closes.

3. A setting tool according to claim 2, where the reservoir (11) stores fuel, and wherein the setting tool comprises a flow meter (21) for measuring an amount of fuel flowing into the combustion chamber (13) and communicating with the control circuit (20), and wherein the control circuit (20) closes the electronically controlled valve (24) when the amount of fuel measured by the flow meter (21) reaches, during the operational cycle, a set value.

4. A setting tool according to claim 3, further comprising sensor means (22) for determining operational status parameters of the setting tool (10) and environmental condition parameters and communicating with the control circuit (20), the control circuit (20) predetermining, for each operational cycle, a set amount of fuel to be fed into the combustion chamber (13) in accordance with the determined parameters of operational status of the setting tool (10) and of an environmental condition.

5. A setting tool according to claim 4, where in the sensor means (22) comprises sensors for determining air pressure, temperature, and humidity of surrounding air.

6. A setting tool according to claim 1, wherein the electronically controlled valve (24) is actuated by a priezo element.

7. A setting tool according to claim 4, wherein the control circuit (20) comprises a parameter processing unit.

8. A setting tool according to claim 7, wherein the processing unit comprises a microprocessor.

9. A setting tool according to claim 1, wherein the at least one electronically controlled valve (24) is arranged, in a flow direction (26) of the one of oxidation agent and fuel, downstream of the at least one mechanically controlled valve (14).