The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 30, 1999
Filed:
May. 19, 1998
Berndt Ekwall, Saltsjobaden, SE;
Uniroc AB, Fagersta, SE;
Abstract
Down-the-hole drilling machine comprising a housing (1) with a hammer piston (5) movable to-and-fro and intended to exert a drill bit (3) to impacts. The hammer piston is formed with two piston heads (6,7) and a waist (9) between them. An intermediate wall (10) is arranged around the waist (9) so that two chambers (11,12) are formed on either side of the intermediate wall. The chamber (11) between the intermediate wall and the forward piston head (6) is continuously pressurized via a first channel (13) in the intermediate wall. The chamber (12) is via a second channel (15) in the intermediate wall connected to a space (16) in front of the hammer piston (5). Through this double drive areas are obtained during the working stroke of the hammer piston.