Gas-operated setting tool

• US 20030230620A1
• Filed: 06/16/2003
• Published: 12/18/2003
• Est. Priority Date: 06/17/2002
• Status: Active Grant

• Current Assignee: Hilti Aktiengesellschaft (Hilti Martin Family Trust)
• Original Assignee: Hilti Aktiengesellschaft (Hilti Martin Family Trust)
• Inventors: Fielitz, Harald
• Granted Patent: US 6,755,335 B2
• Time in Patent Office: Days
• US Class Current: 227/10
• CPC Class Codes: B25C 1/08 operated by combustion pressure

Abstract

A gas-operated setting tool for in fastening elements includes a combustion chamber (20), a piston displaceable in the tool guide cylinder under pressure generated as a result of the combustion of the air-fuel mixture in the combustion chamber (20), a scavenging chamber (30) adapted to be filled with scavenging air and pneumatically connected with the combustion chamber, and at least one slide member (31) for discharging the scavenging air from the scavenging chamber toward the combustion chamber.

Claims

1. A gas-operated setting tool for driving fastening elements in a constructional component, comprising:

a combustion chamber (20) in which combustion of an air-fuel mixture takes place;

a guide cylinder (12) adjoining the combustion chamber (20);

a piston (11) displaceable in the guide cylinder (12) under pressure generated as a result of the combustion of the air-fuel mixture in the combustion chamber (20); and

means for forming a scavenging chamber (30) adapted to be filled with scavenging air and pneumatically connected with the combustion chamber, the forming means including at least one slide member (31) for discharging the scavenging air from the scavenging chamber toward the combustion chamber (20).

2. A setting tool according to claim 1, comprising at least one separation element for dividing the combustion chamber (20) into two chamber sections (21, 22),

wherein a volume of the combustion chamber (20) is reduced at least in one of the chamber sections (21,22) after completion of the combustion process, and

wherein the scavenging chamber (30) expands with reduction of the volume of the combustion chamber (20), the scavenging chamber (30) being limited, at its end (36) facing in a direction opposite an expansion direction (35) thereof by the slide member (31) and at its end (37) facing in the expansion direction, by the at least one separation element.

3. A setting tool according to claim 1, wherein the slide member (31) is axially displaceably arranged in the setting tool.

4. A setting tool according to claim 2, wherein the slide member (31) is formed as a plate extending parallel to the at least one separation element.

5. A setting tool according to claim 2, wherein in a section (25) of the combustion chamber (20) facing in a setting direction (15) of the setting tool, at least one channel (26) is formed in a combustion chamber wall (27) and which in a setting direction-side, end position (28) of the at least one separation element (23), is opened, on one hand, toward the scavenging chamber (30) and on another hand, toward an intermediate chamber (21′

, 22′

) between the at least one separation element and a bottom (29) of the combustion chamber (20).

6. A setting tool according to claim 2, comprising a spring (32) for biasing the at least one slide member (31) in an operational position (38) in the expansion direction (35′

) of the scavenging chamber (30); and

means for releasably retaining the at least one slide member (31) in the operational position (38) thereof.

7. A setting tool according to claim 6, wherein the retaining means (40) comprises at least one locking element (42) engaging a complementary element (41) provided on the at least one slide member (31) in the operational position (38) of the at least one slide member (31).

8. A setting tool according to claim 3, wherein the locking element (42) is formed as a pivotal hook member.

9. A setting tool according to claim 7, wherein the retaining means (40) comprises releasing means (43) that displaces the locking element (42) in a release position (44) dependent on a position of the at least one separation element.

10. A setting tool according to claim 1, wherein a maximum inner volume of the scavenging chamber (30) is greater than a maximum inner volume of the combustion chamber (20).