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. 21, 1989
Filed:
Jun. 15, 1987
Kousuke Matsubara, Yokohama, JP;
Takeo Fukumura, Yokohama, JP;
NHK Spring Co., Ltd., Tokyo, JP;
Abstract
A cylinder piston apparatus according to the present invention comprises a cylinder housing having an oil chamber therein, and a rod fitted in the cylinder housing. A piston-shaped partition member is arranged in the cylinder assembly. The oil chamber is divided into first and second oil chambers by the partition member. The partition member is provided with a valve housing, which has an outside circulation hole capable of communicating with the second oil chamber. A rotary valve is fitted in the valve housing. The valve has an inside circulation hole, which is situated at a position corresponding to the outside circulation hole, and can communicate with the first oil chamber. A stepping motor for driving the rotary valve is housed in a motor-holding chamber which is defined inside the cylinder assembly. The motor-holding chamber is filled with oil, so that the motor is immersed in the oil.