Combustion-engined tool

• US 20010006045A1
• Filed: 12/19/2000
• Published: 07/05/2001
• Est. Priority Date: 12/23/1999
• Status: Active Grant

• Current Assignee: Hilti Aktiengesellschaft (Hilti Martin Family Trust)
• Original Assignee: Hilti Aktiengesellschaft (Hilti Martin Family Trust)
• Inventors: Wolf, Iwan, Towfighi, Kaveh, Thieleke, Joachim
• Granted Patent: US 6,460,507 B2
• Time in Patent Office: Days
• US Class Current: 123/46R
• CPC Class Codes: B25C 1/08 operated by combustion pressure
• CPC Class Codes: F02B 71/04 Adaptations of such engines for special use; Combinations of such engines with apparatus driven thereby

Abstract

A portable, combustion-engined tool including a collapsible combustion chamber (1) having a movable separation plate (18) for dividing the combustion chamber (1), in an expanded position of the combustion chamber, in a forechamber section (21) and at least one further chamber section (22), a movable combustion chamber wall (14) arranged parallel to the separation plate (18) for limiting, together with the separation plate (18), the forechamber section, an ignition device (52) located in the forechamber section (21), and a collapse control device (19, 20, 33) for controlling movement of the separation plate (18) and the movable wall (14) after the combustion of the gas mixture in the combustion chamber.

Claims

1. A portable, combustion-engined tool, comprising a collapsible combustion chamber (1);

a movable separation plate (18) located in the combustion chamber (1) for dividing the combustion chamber (1), in an expanded position of the combustion chamber, in a forechamber section (21) and at least one further chamber section (22), the separation plate (18) having a plurality of through-openings (38) for communicating the forechamber section (21) with the at least one further chamber section (22);

a movable combustion chamber wall (14) arranged parallel to the separation plate (18) for limiting, together with the separation plate (18), the forechamber section;

an ignition device (52) located in the forechamber (21); and

collapse control means (19, 20, 33) for controlling movement of the separation plate (18) and the movable wall (14), after combustion of the gas mixture in the combustion chamber (1), so that first, the forechamber section (21) collapses and then, the at least one further chamber section (22) collapses.

2. A tool according to

claim 1

, wherein the collapse control means (19, 20, 33) comprises means for preloading the movable wall (14) and the separation plate (18) relative to each other.

3. A tool according to

claim 2

, wherein the collapse control means (19, 20, 33) comprises a lug (19) secured on the separation plate (18) and extending through the movable wall (14), and wherein the preloading means comprises a compression spring (33) arranged between a free end of the lug (19) and the movable wall (14).

4. A tool according to

claim 1

, wherein the collapse control means provide for adjusting friction between the movable wall and the separation plate and another wall (2) of the combustion chamber (1).

5. A tool according to

claim 1

, wherein the collapse control means comprises pneumatic means.

6. A tool according to

claim 1

, wherein the through-openings (38) of the separation plate (18) are formed as check valves providing for gas flow only from the forechamber section (21) into the further chamber section (22).

7. A tool according to

claim 6

, wherein the movable wall (14) is provided with at least one check valve (36) for enabling flow into the forechamber section (21).