Title:
CRUSHER FOR CONCRETE STRUCTURE
Document Type and Number:
WIPO Patent Application WO/1993/015291
Kind Code:
A1
Abstract:
A crusher for crushing a column or beam of a concrete structure by holding a column or beam by means of press breaking blades provided at the leading end of an arm and opening and closing the arm. A hydraulic cylinder (1) for opening and closing the arm comprises a second cylinder in which the bottoms of two cylinders (3' and 3") are connected to each other, and a first cylinder in which the cylinder bottoms fitted into the respective cylinders (3' and 3") serve as pistons (9). When a hydraulic fluid is introduced via a fifth oil port (18) that is provided on the cylinder bottom side of the second cylinder, the first cylinder (2) is caused to move forward, and when the first cylinder (2) reaches the stroke end, the piston of the first cylinder is caused to move forward, this forward movement of the piston causing the arm to be closed to thereby press break a concrete structure. When the hydraulic fluid is introduced via a fourth oil port (16), the hydraulic fluid so introduced causes a piston (5) to move backward through a second oil port (10) and an oil passage (11), and when the piston (5) reaches the stroke end, the pressure of the hydraulic fluid is caused to act on the cylinder bottom of the first cylinder through a gap (between 24 and 25) having a set fluid resistance for establishing a communication between the second oil port (10) and a piston rod side fluid chamber (14) of the second cylinder to thereby cause the first cylinder (2) to move backward, this backward movement serving to open the arm. Supply of the hydraulic fluid to the hydraulic cylinder (1) is effected only via the fourth oil port (16) and fifth oil port (18), this resulting in easy control.
Inventors:
TAGAWA ITUO (JP)
KOZAKI TAKAHARU (JP)
KOZAKI TAKAHARU (JP)
Application Number:
PCT/JP1992/000100
Publication Date:
August 05, 1993
Filing Date:
February 03, 1992
Export Citation:
Assignee:
TAGAWAKOUGYOU CO LTD (JP)
International Classes:
E04G23/08; (IPC1-7): E04G23/08
Foreign References:
| JPS6340061A | 1988-02-20 | |||
| JPH06340061A | 1994-12-13 |
Other References:
See also references of EP 0578820A4
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