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:
Jun. 13, 1989
Filed:
Oct. 13, 1987
Tom T Hashimoto, Conroe, TX (US);
Branham Industries, Inc., Conroe, TX (US);
Abstract
A folding telescoped drill rig mast having wheel assemblies which travel along the power swivel guide rail to guide the telescoped upper mast as it retracts or extends within the lower mast. The fully extended upper mast locks into a transfer frame which moves laterally relative to the lower mast between a first position with the upper guide rail offset from the lower guide rail to a second position with the upper guide rail in longitudinal alignment with the lower guide rail. This lateral movement aligning the upper and lower masts enables pinning the upper and lower masts together to transfer the upper mast loading to the support members of the lower mast. The mast includes a base structure, a lower mast with a guide rail, and an upper mast held within the lower mast. The upper mast includes a guide rail for the power swivel. A dolly wheel assembly mounts to the upper mast and engages the lower guide rail to guide the upper mast as it travels between a first position within the lower mast to a second extended position. A transfer frame at the free end of the lower mast connects rigidly to the upper mast. The transfer frame and the upper mast are moved laterally relative to the lower mast to align the upper and lower masts and the upper and lower power swivel guide rails.