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. 13, 1990
Filed:
Mar. 15, 1989
Harald Breisch, Kressbronn, DE;
Abstract
A ball drain valve (2), for the piston space (33) of a rotary clutch disc (3) for releasing the clutch disc piston (32) from pressure generated by rotation of pressurized oil remaining in the piston space when it is bled, including an opening (220), at least two ball spaces (25, 26) and a ball valve (23) actuated by rotation and control pressure. The ball drain valve (2) has two stages coordinated with the engaged and the disengaged positions of the clutch and the two ball spaces (25, 26) have outer diameters (D1, D2) of different sizes so that the ball valve (23), when the multi-disc clutch (3) is engaged, is in ball space (25) of large diameter (D1) and, when the clutch is disengaged, the ball valve is in ball space (26) of small diameter (D2). This arrangement achieves a quick drainage of the piston space (33) past a large gap (250) when the clutch is disengaged and prevents very little pressurized oil from escaping past a small gap (260) when the clutch (3) is engaged.