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:
Mar. 29, 1994
Filed:
Jun. 23, 1993
Rolf A Jacobsson, Saltsjo-Boo, SE;
Atlas Copco Tools AB, Nacka, SE;
Abstract
An overspeed safety device for a pneumatic rotation motor comprises a housing (10, 18) and a valve element (28) which is located in a bore (27) in the housing (10, 18) and which by a trip device (29, 31) is locked in a normally open position and arranged to block at least the main part of the air supply to the motor when shifted to a closed position, and an activating device (37, 38) coupled to a rotating part (14) of the motor and arranged to be shifted by inertia forces from a normal rest position to an active position at a predetermined motor speed level. The trip device (29, 31) comprises an open spring wire lock ring (29) pretensioned toward a closed condition and located in a groove (30) in the valve element (28), and a holding device (31) normally located between the ends of the lock ring (29) to maintain the lock ring (29) in an expanded condition in which its outer diameter exceeds the inner diameter of a shoulder (32) in the bore (27). At overspeed, the activating device (37, 38) moves the holding device (31) out of its lock ring (29) expanding position, thereby enabling the latter to contract and release the valve element (28) for movement toward a closed position.