Fail-safe fluid control valve

• US 4,057,004 A
• Filed: 07/22/1976
• Issued: 11/08/1977
• Est. Priority Date: 07/25/1975
• Status: Expired due to Term

• Current Assignee: Teijin Seiki Co., Ltd. (Nabtesco Corporation)
• Original Assignee: Teijin Seiki Co., Ltd. (Nabtesco Corporation)
• Inventors: Kamimura, Toshio
• Primary Examiner(s): Cohan, Alan
• Assistant Examiner(s): Michalsky, Gerald A.
• Application Number:
  US05/707,762
• Time in Patent Office: 474 Days
• Field of Search: 91/30, 91/31, 91/448, 137/596, 251/232
• US Class Current: 91/30
• CPC Class Codes: F15B 20/008 Valve failure
• CPC Class Codes: Y10T 137/87169 Supply and exhaust

Abstract

A fail-safe fluid control valve including a first sleeve accommodated in and fixed to a valve housing, a second valve also accommodated in and fixed to the valve housing in parallel relation with the first sleeve, a first valve spool slidably accommodated in the first sleeve, and a second valve spool slidably accommodated in the second sleeve. The first and second sleeves are properly formed with grooves and ports while the first and second valve spools are properly formed with large diameter portions spaced. When there occurs such an abnormal condition that the first valve spool and the first sleeve are jammed or stuck to each other, the second valve spool is adapted to be moved for actuating the fail-safe control valve under entirely the same condition as a normal condition.

Claims

1. A fail-safe fluid control valve comprising:

a valve housing having first and second concave portions formed therein parallel relation with each other,

a first sleeve positioned within and fixed to said first concave portion of said valve housing, said first sleeve including first, second and third port groups located at a predetermined interval along its axial direction and each having one or more radial ports circumferentially equi-angularly formed in said first sleeve, a first orifice group located between said first and second port groups and having one or more radial orifices circumferentially equi-angularly formed in said first sleeve, a second orifice group located between said second and third port groups and having one or more radial orifices circumferentially equi-angularly formed in said first sleeve, a first annular groove formed on the outer periphery of said first sleeve in fluid communication with said ports of said first port group, a second annular groove formed on the outer periphery of said first sleeve in fluid communication with said orifices of said first orifice group, a third annular groove formed on the outer periphery of said first sleeve in fluid communication with said ports of said second port group, a fourth annular groove formed on the outer periphery of said first sleeve in fluid communication with said orifices of said second orifice group, a fifth annular groove formed on the outer periphery of said first sleeve in fluid communication with said ports of said third port group;

a first valve spool reciprocably accommodated in said first sleeve and having first, second, third and fourth large diameter portions integrally formed on the outer periphery of said first valve spool, the interval between said second and third large diameter portions being substantially equal to the interval between said first and second orifice groups, the axial length of each of said second and third large diameter portions being substantially equal to the axial length of each of said orifices of said first and second orifice groups, and said first and fourth large diameter portions being located at all times axially outwardly of said first and third port groups;

a second sleeve positioned within and fixed to said second concave portion of said valve housing, said second sleeve including fourth, fifth, sixth and seventh port groups located at a predetermined interval along its axial direction and each having one or more radial ports circumferentially equi-angularly formed in said second valve spool, a third orifice group located between said fourth and fifth port groups and having one or more radial orifices circumferentially equi-angularly formed in said second sleeve, a sixth orifice group located between said sixth and seventh port groups and having one or more radial orifices circumferentially equi-angularly formed in said second sleeve, fourth and fifth orifice groups positioned in side-by-side relation between said fifth and sixth port groups and each having one or more radial orifices circumferentially equi-angularly formed in said second sleeve, seventh and eighth orifice groups positioned in side-by-side relation axially outwardly of said seventh port group and each having one or more radial orifices circumferentially equi-angularly formed in said second sleeve, a sixth annular groove formed on the outer periphery of said second sleeve in fluidal communication with said ports of said fourth port group, a seventh annular groove formed on the outer periphery of said second sleeve in fluidal communication with said orifices of said third orifice group, and eighth annular groove formed on the outer periphery of said second sleeve in fluidal communication with said ports of said fifth port group, a ninth annular groove formed on the outer periphery of said second sleeve in fluidal communication with said orifices of said fourth orifice group, an eleventh annular groove formed on the outer periphery of said second sleeve in fluidal communication with said orifices of said sixth orifice group, a thirteenth annular groove formed on the outer periphery of said second sleeve in fluidal communication with said orifices of said eighth orifice group, a tenth annular groove formed on the outer periphery of said second sleeve in fluidal communication with said orifices of said fifth orifice group and said ports of said sixth port group, and a twelveth annular groove formed on the outer periphery of said second sleeve in fluidal communication with said ports of said seventh port group and said orifices of said seventh orifice group;

a second valve spool reciprocably accommodated in said second sleeve and having fifth, sixth, seventh, eighth, ninth, tenth and eleventh large diameter portions, the interval between said sixth and ninth large diameter being substantially equal to the interval between said third and sixth orifice groups, the axial length of each of said sixth and ninth large diameter portions being substantially equal to the axial length of each of said orifices of said third and sixth orifice groups, the end face of said eighth large diameter portion facing said seventh large diameter portion being brought into substantial alignment with the inner face of each of said orifices of said fifth orifice group adjacent to said sixth port group and the end face of said tenth large diameter portion facing said eleventh large diameter portion being brought into substantial alignment with the inner face of each of said orifices of said seventh orifice group adjacent to said seventh port group when said orifices of said third and sixth orifice groups come to be in opposing relation with and closed by said sixth and ninth large diameter portions, respectively, the end face of said seventh large diameter portion facing said eighth large diameter portion being brought into substantial alignment with the inner face of each of said orifices of said fourth orifice group adjacent to said fifth port group when said orifices of said third and sixth orifice groups come to be in opposing relation with and closed by said sixth and ninth large diameter portions, respectively, the axial length of said seventh large diameter portion being substantially equal to the axial length of each of said orifices of said fourth orifice group, the end face of said eleventh diameter portion facing said tenth large diameter portion being brought into substantial alignment with the axially outermost inner face of each of said eighth orifice group when said orifices of said third and sixth orifice groups come to be in opposing relation with and closed by said sixth and ninth large diameter portions, respectively, the axial length of said eleventh large diameter portion being larger than the axial length of each of said orifices of said eighth orifice group, and said fifth large diameter portion being at all times positioned axially outwardly of said fourth port group,

a first passage formed in said valve housing to communicate said second and seventh annular grooves;

a second passage formed in said valve housing to communicate said third and ninth annular grooves;

a third passage formed in said valve housing to communicate said fourth and eleventh annular grooves;

a fourth passage formed in said valve housing to communicate said first, fifth and thirteenth annular grooves;

a fifth passage formed in said valve housing to communicate said sixth and twelveth annular grooves;

a valve cylinder having a pair of cylinder conduits communicated with said second and fourth annular grooves, respectively;

an inlet conduit communicated with said eighth and tenth annular grooves;

an outlet conduit communicated with said twelveth annular groove; and

a reciprocating input mechanism disposed in the vicinity of and operably connected to said first and second valve spools so that only said first valve spool is reciprocated with said second valve spool held stationary to reciprocate any one of said valve housing and a piston rod of said valve cylinder in a normal condition while said second valve spool is reciprocated for imparting a reciprocating motion to any one of said valve housing and said piston rod of said valve cylinder in an abnormal condition where said first valve spool is stuck to said first sleeve to prevent said first valve spool from being reciprocated in said first sleeve.

2. A fail-safe fluid control valve comprising:

a valve housing having first and second concave portions formed therein in parallel relation with each other, a first sleeve positioned within and fixed to said first concave portion of said valve housing, a second sleeve positioned within and fixed to said second concave portion of said valve housing, a first valve spool reciprocably accommodated in said first sleeve, a second valve spool reciprocably accommodated in said second sleeve, a valve cylinder operatively connected to said valve housing and having a reciprocable piston rod, whereby said first valve spool is reciprocated in said first sleeve for reciprocation motion of any one of said valve housing and said piston rod of said valve cylinder in a normal condition while said second valve spool is reciprocated in said second sleeve for reciprocation motion of any one of said valve housing and said piston rod of said valve cylinder in an abnormal condition where said first valve spool is stuck to said first sleeve and thus unable to be reciprocated in said first sleeve;

the improvement comprising in combination;

a first lever provided adjacent the end portions of said first and second valve spools;

a second lever having an upper end pivotally connected to the end portion of said second valve spool and a lower end pivotally connected to the end portion of said first valve spool;

a rockable rod provided adjacent said second valve spool and securely connected to said first lever in perpendicular relation with said first lever and said second valve spool for imparting a rocking motion to said first lever;

a pivotal pin pivotally connecting the intermediate portion of said first and second levers for allowing said first and second lever to be pivotable;

a projection integrally connected to the end of said first valve spool through an annular ledge interposed therebetween and extending in axial alignment with said first valve spool;

a movable annular collar axially slidably retained on said projection;

a fixed annular collar securely retained on the free end of said projection;

a first compression coil spring positioned between said movable annular collar and said fixed annular collar to surround said projection;

a cylindrical member pivotally connected to the lower end of said first lever and retained in slidable relation with the first valve spool to surround said projection;

a fixed annular member securely retained on the inner periphery of the free end of said cylindrical member; and

a second compression coil spring positioned between said movable annular collar and said fixed annular member to surround said first compression coil spring.

3. A fail-safe fluid control valve as defined in claim 2, in which the pivotal center point of the end of the second valve spool and the upper end of the second lever is separated by a small length from the pivotal point of the first lever and the rockable rod.