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:
Dec. 11, 1990
Filed:
Nov. 20, 1989
Mark A Beran, Niwot, CO (US);
Allan J Evans, Boulder, CO (US);
BC Research and Development, Inc., Niwot, CO (US);
Abstract
A speed control apparatus for controlling the rate of motion of a door is disclosed which includes a shaft connected with the door by a gear train for causing rotation of the shaft at a preselected relative rate of rotation related to the rate of motion of the door by a preselected ratio, a braking assembly including a brake drum spaced from the shaft and first and second brake shoes pivotably connected at one end thereof with a carrying member attached to the shaft and having a single biasing spring adjustably connected between the other ends thereof, the brake shoes having a contact surface made of a non-asbestos friction material for contacting the brake drum when a selected rate of rotation of the shaft is exceeded, and an improved housing which is more efficiently sealable against invasion of moisture into the housing and the escape of lubricants from the housing.