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. 21, 2009
Filed:
Oct. 22, 2007
Shin-ichi Hayase, Itabashi-ku, JP;
Yasuhito Haijima, Itabashi-ku, JP;
Shin-ichi Hayase, Itabashi-ku, JP;
Yasuhito Haijima, Itabashi-ku, JP;
Kabushiki Kaisha TOPCON, Tokyo-to, JP;
Abstract
A laser surveying instrument, comprising a rotating unit for projecting a laser beam by rotary irradiation, a main unit for rotatably supporting the rotating unit, and a sealing means for sealing between the rotating unit and the main unit, wherein the sealing means comprises annular ridges formed on the main unit concentrically to the rotation center of the rotating unit, and annular grooves formed on the rotating unit so that the annular ridges are engaged in the annular grooves and gaps are formed between the annular ridges and the annular grooves, the annular ridges and the annular grooves being arranged concentrically to each other and disposed in double arrangement, and wherein the sealing means further comprises a route bent and crooked in a radial direction by the gaps, and a cavity disposed at least at one point along the route and having larger volume than the volume of the gap.