US 7,344,569 B2
Closed position maintainable selector valve, knee torque device using the valve, and artificial leg
Toyohiko Imakita, Kobe (Japan); Aritomo Fukui, Kobe (Japan); Masahiko Okuda, Kobe (Japan); and Yoshiaki Nakaya, Kobe (Japan)
Assigned to Nabtesco Corporation, Tokyo (Japan)
Appl. No. 10/589,295
PCT Filed Sep. 09, 2004, PCT No. PCT/JP2004/013157
§ 371(c)(1), (2), (4) Date Aug. 14, 2006,
PCT Pub. No. WO2005/093305, PCT Pub. Date Oct. 06, 2005.
Claims priority of application No. 2004-097145 (JP), filed on Mar. 29, 2004.
Prior Publication US 2007/0173953 A1, Jul. 26, 2007
Int. Cl. A61F 2/64 (2006.01); A61F 2/68 (2006.01); F16K 31/12 (2006.01)
U.S. Cl. 623—43  [251/50; 251/52; 251/323] 9 Claims
OG exemplary drawing
 
1. A selector valve comprising:
a housing having a cylinder hole;
a valve element capable of entering said cylinder hole of said housing and moving in an axial direction of said cylinder hole, a first end of said valve element entered in said cylinder hole being seated on/unseated from a valve seat on said housing side, said valve element receiving such an operating force in a second end on an opening side of said cylinder hole opposite to said first end as making said first end seat on said valve seat;
a valve spring for exerting a returning force for returning said valve element in an opposite direction of said operating force;
a first port located at the depth of said cylinder hole; and
a second port located near the opening of said cylinder hole from said first port,
said valve being opened and closed by making said first end of said valve element seat on/unseat from said valve seat according to the presence or absence of said operating force received in said second end of said valve element,
said selector valve capable of maintaining a closed position further including the following features,
(A) said valve element is formed in a stepped structure, and receives a force based on a difference in pressure receiving area by said stepped structure which results from the pressure of hydraulic fluid flowing through said first and second ports, and
(B) a seating state of said valve element seated on said valve seat is maintainable by force based on a difference in pressure receiving area by said stepped structure of said valve element when said first end of said valve element is seated on said valve seat on said housing side.