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:
Apr. 13, 2010
Filed:
Sep. 17, 2003
Applicant:
John L. White, Kent, WA (US);
Inventor:
John L. White, Kent, WA (US);
Assignee:
American Piledriving Equipment, Inc., Kent, WA (US);
Primary Examiner:
Int. Cl.
CPC ...
B25D 9/00 (2006.01);
U.S. Cl.
CPC ...
Abstract
A drop hammer for driving piles. The drop hammer of the present invention comprises a housing member and a ram member. The housing member defines a housing chamber. The ram member is supported within the housing chamber for movement relative to the housing member between an upper position and a lower position. When the ram member moves into the lower position, the impact of the ram member drives the pile. When the ram member falls below a preload position between the lower and upper positions, fluid within a preload chamber portion of the housing chamber compresses as the ram member moves into the lower position.