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. 10, 1990
Filed:
Jun. 10, 1988
Baxter R Watkins, Foster City, CA (US);
Quest Technologies Corp., Sunnyvale, CA (US);
Abstract
A latch for each of a pair of cushioning arms, respectively, of a stair-climbing wheelchiar. The latch for each arm includes a first member coupled to the arm and a second member coupled to a fixed support of the wheelchair, with the second member being coupled to the armature of a solenoid which is energized to unlatch the arm from latched relationship with the support when it is desired to use the arm for cushioning purposes. An ultrasonic transducer coupled to the wheelchair adjacent to each latch, respectively, provides signals to energize the respecting latch solenoid when the arm is to be unlatched. To latch each arm, the adjacent edge margins of the two members are bevelled so that, during upward movement of the arm, such as by movement of the wheelchair from an inclined position to a horizontal position, the members are spread apart and a first spring biases the two members back together in coupled relationship to each other. When the latch solenoid is energized, the second member is moved away from the first member to allow a second spring to pull the arm down and into an unlatched position. A limit switch senses when each arm is latched.