Tool driving or impacting – Impacting devices – Hammer head constitutes piston of drive motor
Reexamination Certificate
2005-08-24
2008-08-12
Smith, Scott A. (Department: 3721)
Tool driving or impacting
Impacting devices
Hammer head constitutes piston of drive motor
C173S090000, C173S128000, C173S135000, C173S206000, C091S300000, C091S321000
Reexamination Certificate
active
07410010
ABSTRACT:
A hydraulic impact mechanism includes a housing with a cylinder bore, a forward working chamber and a rear working chamber, a hydraulic fluid supply passage connected to the forward working chamber and a drain passage connected to the rear working chamber, a hammer piston reciprocally guided in the cylinder bore for delivering blows to a working implement attached to the housing, a pressure accumulator pre-loaded to a certain pressure level, and a distribution valve for alternatingly connecting the rear working chamber to the supply passage and the drain passage to thereby reciprocate the hammer piston, wherein a sequence valve is provided in the drain passage to keep up the pressure in the rear working chamber so that the resulting forward directed force prevents the piston from being moved backwards in the cylinder bore at pressure levels in the supply passage below the pre-load pressure level of the accumulator.
REFERENCES:
patent: 3774502 (1973-11-01), Arndt
patent: 4460051 (1984-07-01), Widmer
patent: 4474248 (1984-10-01), Musso
patent: 4479551 (1984-10-01), Justus
patent: 4676323 (1987-06-01), Henriksson
patent: 4784228 (1988-11-01), Ito
patent: 4817737 (1989-04-01), Hamada et al.
patent: 4899836 (1990-02-01), Vernot
patent: 5064005 (1991-11-01), Krone
patent: 5174387 (1992-12-01), Arndt et al.
patent: 5653295 (1997-08-01), Juvonen et al.
patent: 5718297 (1998-02-01), Weber
patent: 5890548 (1999-04-01), Juvonen
Henriksson Roland Stig
Lundgren Anders Wilhelm
Atlas Copco Construction Tools AB
Frishauf Holtz Goodman & Chick P.C.
Smith Scott A.
LandOfFree
Hydraulic impact mechanism does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Hydraulic impact mechanism, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hydraulic impact mechanism will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3999106