Rotary valve actuator

Abstract

A rotary actuator for a valve includes a cam mechanism for transmitting opening force to a movable valve member to move the valve member off a valve seat, against the bias of a closing spring. The cam mechanism does not transmit spring force to the valve member when the valve member is being moved to the closed position or is in the closed position. Also, the parts of the cam mechanism have a large surface area of contact when the valve is in the open position, to minimize unit loading of the cam surfaces. The movable cam is movable axially relative to the actuator handle. The movable valve member is blocked from rotation relative to the valve body. The cam mechanism does not transmit spring force to the movable valve member when the valve member is in the closed position.

1 - 30 . (canceled)  
   
   
       31 . A valve actuator comprising: 
 a biasing element;    an actuator member adapted to move a movable valve member between an open position and a closed position;    a first cam; and    a second cam engageable with said first cam and rotatable to effect movement of said actuator member from a closed position toward an open position against the bias of said biasing element;    said biasing element acting on said actuator member to move said actuator member from the open position toward the closed position other than by transmission of bias force through said second cam.    
   
   
       32 . A valve actuator as set forth in  claim 31  wherein said second cam is movable axially relative to said actuator member.  
   
   
       33 . A valve actuator as set forth in  claim 31  wherein each one of said first and second cams has a cam surface defining a circumferentially extending cam profile engageable with the cam profile on the other one of said fist and second cams.  
   
   
       34 . A valve actuator as set forth in  claim 31  further comprising a handle for receiving actuating force for rotating said second cam, said second cam being movable axially relative to said handle.  
   
   
       35 . A valve actuator as set forth in  claim 31  wherein said actuator member is adapted to move the movable valve member axially without rotation.  
   
   
       36 . A valve actuator comprising: 
 a biasing element;    an actuator member adapted to move a movable valve member between an open position and a closed position;    a first cam; and    a second cam engageable with said first cam and rotatable about an axis to effect movement of said actuator member from a closed position toward an open position against the bias of said biasing element;    said second cam being movable axially relative to said actuator member.    
   
   
       37 . A valve actuator as set forth in  claim 36  wherein said biasing element acts on said actuator member to move said actuator member from the open position toward the closed position without transmission of bias force through said second cam.  
   
   
       38 . A valve actuator as set forth in clam  36  wherein each one of said first and second cams has a cam surface defining a circumferentially extending cam profile engageable with the cam profile on the other one of said first and second cams.  
   
   
       39 . A valve actuator as set forth in  claim 36  further comprising a handle for receiving actuating force for rotating said second cam, said second cam being movable axially relative to said handle.  
   
   
       40 . A valve actuator as set forth in  claim 36  wherein said actuator member is adapted to move the movable valve member axially without rotation.  
   
   
       41 . A method of actuating a valve having a movable valve member, said method comprising the steps of: 
 engaging a first cam with a second cam;    rotating the second cam against the first cam about an axis to effect axial movement of the second cam;    transmitting axially directed force from the second cam to an actuator member to move the actuator member against the bias of a biasing element; the actuator member being adapted to move the movable valve member from a closed position toward an open position against the bias of the biasing element; and    transmitting bias force from the biasing element to the actuator member other than by passing through the second cam to move the movable valve member from the open position toward the closed position.    
   
   
       42 . A method as set forth in  claim 41  wherein said second cam is movable axially relative to said actuator member when in the closed position.  
   
   
       43 . A method as set forth in  claim 41  wherein said step of rotating the second cam against the first cam about an axis to effect axial movement of the second cam comprises applying actuating at force to the second cam with a handle relative to which the second cam is movable axially.  
   
   
       44 . A method as set forth in  claim 41  wherein said step of engaging a first cam with a second cam comprises engaging a first cam having a cam surface defining a circumferentially extending cam profile with a second cam having a cam surface defining a circumferentially extending cam profile.  
   
   
       45 . A method as set forth in  claim 41  wherein said step of transmitting bias force from the biasing element to the actuator member without passing through the second cam to move the movable valve member from the open position toward the closed position results in axial movement of the movable valve member without rotational movement of the movable valve member.  
   
   
       46 - 47 . (canceled)  
   
   
       48 . A method of actuating a valve having a movable valve member, said method comprising the steps of: 
 rotating a handle about an axis to effect rotational movement of a cam and axial movement of the cam relative to said handle;    transmitting axially directed force from the cam to an actuator member adapted to move the movable valve member from a first position toward a second position,    wherein the movable valve member moves only in an axial direction relative to said cam.    
   
   
       49 . A method as set forth in  claim 48  wherein the rotational and axial movement of the cam are coaxial with the handle.  
   
   
       50 . A method as set forth in  claim 48  wherein said cam includes a cam surface defining a circumferentially extending cam profile.  
   
   
       51 . A method as set forth in  claim 48  further comprising the step of transmitting a bias force from a biasing element to the actuator member to move the movable valve member from the second position toward the first position, wherein the bias force is not transmitted through the cam.  
   
   
       52 . A method as set forth in  claim 51  wherein the bias force transmitted from the biasing element to the cam is zero when the movable valve member is in the first position.  
   
   
       53 . A valve actuator for a rotary valve that has a valve seat and a movable valve member movable relative to the valve seat between a first position and a second position, said valve actuator comprising: 
 a handle rotatable about an axis; and    a cam rotatable in response to rotation of said handle, said cam being movable axially relative to said handle to effect movement of the movable valve member from the first position toward the second position,    wherein the movable valve member moves only in an axial direction relative to the valve seat.    
   
   
       54 . A valve actuator as set forth in  claim 53  wherein the rotational and axial movement of the cam are coaxial with the handle.  
   
   
       55 . A valve actuator as set forth in  claim 53  wherein said first position is a closed position and said second position is an open position.  
   
   
       56 . A valve actuator as set forth in  claim 53  wherein the movable cam includes a cam surface defining a circumferentially extending cam profile.  
   
   
       57 . A valve actuator as set forth in  claim 53  further comprising a biasing element acting on the valve member to move the valve member from the second position toward the first position other than by transmitting bias force to the valve member through said cam.  
   
   
       58 . A valve actuator comprising: 
 an actuator member adapted to move between a first position and a second position;    a first cam;    a second cam engageable with said first cam and rotatable to effect movement of said actuator member between the first position and the second position; and    a biasing element adapted to exert a bias force that when transmitted between said first and second cams produces a surface pressure between said first and second cams that varies in amount depending on the relative rotational position of said first and second cams;    said surface pressure reaches a peak during movement of the actuator member between the fist position and the second position, and    said surface pressure between the first and second cams being no more than about 5%-10% of the peak surface pressure throughout the majority of travel of the actuator member between the first position and second position.    
   
   
       59 . A valve actuator as set forth in  claim 58  wherein said surface pressure between the first and second cams arising from the bias force when the valve member is in the first position being no more than about 5% to 10% of the peak surface pressure.  
   
   
       60 . A valve actuator comprising: 
 a handle for receiving an actuating force;    a valve member movable between an open position and a closed position;    a biasing element for transmitting a bias force to the movable valve member to move said valve member from the open position to the closed position;    a means for transmitting the actuating force to the movable valve member other than by transmitting bias force to the movable valve member through said means when the movable valve member moves from the open position to the closed position.    
   
   
       61 . A valve actuator as set forth in  claim 60  wherein the bias force is not transmitted to said movable valve member through said means when said valve member is in the closed position.  
   
   
       62 . A valve actuator for a rotary valve that has a valve seat and a movable valve member movable relative to the valve seat between all open position and a closed position, said valve actuator comprising: 
 a first valve part fixed in position relative to the valve seat; and    a second valve part rotatable relative to the first valve part, the second valve part in contact with the first valve past to effect axial movement of the second valve part relative to the valve seat,    wherein the axial movement of the second valve part move the moveable valve member from a closed position to an open position,    wherein the contact between the first valve part and second valve part defines a contact surface area that varies in amount depending on the relative rotational position of said first and second valve parts;    the contact surface area reaching a minimum amount at a position other than the open position or the closed position.    
   
   
       63 . A valve actuator as set forth in  claim 62  wherein each one of said first and second valve parts includes a cam surface defining a circumferentially extending cam profile.  
   
   
       64 . A valve actuator as set forth in  claim 62  further including a biasing element exerting a bias force that when transmitted between said first and second valve parts produces a surface pressure between said first and second valve parts that varies in amount depending on the relative rotational position of said first and second valve parts.  
   
   
       65 . A valve actuator as set forth in  claim 64  wherein the surface pressure reaches a peak during movement of the actuator member from the closed position toward the open position, and 
 the surface pressure between the first and second cams arising from the bias force being no more man about 5%/10% of the peak surface pressure throughout the majority of actuator travel.    
   
   
       66 . A valve actuator as set forth in  claim 64  wherein the surface pressure reaches a peak during movement of the actuator member from the closed position toward the open position, and 
 the surface pressure between the first and second cams arising from the bias force when the valve member is in the first position being no more than about 5% to 10% of the peak surface pressure.