Fluid Pressure Actuator

Abstract

A method and apparatus including a fluid pressure actuator that includes a diaphragm that has a top and a bottom surface. In an exemplary embodiment, the fluid pressure actuator also has plunger coupled to the diaphragm and that extends from the bottom surface of the diaphragm in a first direction. The fluid pressure actuator also includes a bellow sensor that is coupled to the bottom surface of the diaphragm and that has an interior surface. In an exemplary embodiment, a height of the interior surface of the bellow sensor prevents the movement of the plunger in the first direction.

What is claimed is: 
     
         1 . A fluid pressure actuator, comprising:
 a diaphragm having a top surface and a bottom surface;   a plunger coupled to the diaphragm and extending away from the bottom surface of the diaphragm in a first direction; and   a bellow sensor that extends away from the bottom surface of the diaphragm in the first direction, the bellow sensor comprising:
 a first plate coupled to the diaphragm, the first plate comprising:
 an interior surface of the first plate that is concentrically disposed about an exterior surface of the plunger; 
 an opposing exterior surface of the first plate; and 
 a first circumferentially extending cavity extending from the exterior surface of the first plate towards the first interior surface of the first plate. 
 
   
     
     
         2 . The fluid pressure actuator of  claim 1 ,
 wherein a top surface of the first plate forms a first circumferentially extending protrusion; and   wherein the first protrusion of the top surface of the first plate is coupled to the bottom surface of the diaphragm to form a first annular chamber that extends from the interior surface of the first plate towards the exterior surface of the first plate and that is at least partially defined by the bottom surface of the diaphragm and the top surface of the first plate.   
     
     
         3 . The fluid pressure actuator of  claim 2 , wherein the first protrusion of the top surface of the first plate is coupled to a circumferentially extending protrusion formed on the bottom surface of the diaphragm to form the first annular chamber. 
     
     
         4 . The fluid pressure actuator of  claim 1 , wherein the bellow sensor further comprises:
 a second circular plate coupled to the first plate, the second plate comprising:
 an interior surface of the second plate that is concentrically disposed about the exterior surface of the plunger; 
 an opposing exterior surface of the second plate; and 
 a second radially extending cavity extending from the exterior surface of the second plate towards the interior surface of the second plate. 
   
     
     
         5 . The fluid pressure actuator of  claim 4 ,
 wherein a top surface of the second plate forms a second circumferentially extending protrusion; and   wherein the second protrusion of the top surface of the second plate is coupled to a bottom surface of the first plate to form a second annular chamber that extends from the second interior surface of the second plate towards the second exterior surface of the second plate and that is at least partially defined by the bottom surface of the first plate and the top surface of the second plate.   
     
     
         6 . The fluid pressure actuator of  claim 5 , wherein the second protrusion of the top surface of the second plate is coupled to a third circumferentially extending protrusion formed on the bottom surface of the first plate to form the second annular chamber. 
     
     
         7 . The fluid pressure actuator of  claim 1 , wherein the plunger extends beyond the bellow sensor in the first direction by a first distance. 
     
     
         8 . The fluid pressure actuator of  claim 4 , wherein a bottom surface of the second plate forms a circular channel. 
     
     
         9 . The fluid pressure actuator of  claim 8 , further comprising an elastomeric seal accommodated within the circular channel. 
     
     
         10 . The fluid pressure actuator of  claim 1 , wherein the interior surface of the first plate has a height measured along the first direction that is sized to limit movement of the plunger in the first direction. 
     
     
         11 . The fluid pressure actuator of  claim 5 , wherein movement of the plunger in the first direction is based on a height of the second annular chamber that is measured along the first direction. 
     
     
         12 . A method for actuating a downhole tool, the method comprising:
 introducing a pressurized fluid into a pressure chamber of the downhole tool;   utilizing the pressurized fluid to elastically compress a diaphragm into a chamber formed between the diaphragm and a first plate;   elastically compressing the first plate into a chamber formed between the first plate and a second plate; and   utilizing the diaphragm to urge a plunger into engagement with an actuator when the plates are elastically compressed.   
     
     
         13 . The method of  claim 12 ,
 wherein each of the first plate and the second plate is a u-shaped plate, each having opposing arms and forming a cavity therebetween with an outwardly extending protrusion at the end of each arm; and   wherein the first plate and the second plate are positioned adjacent one another such that the protrusion of the first plate abuts the protrusion of the second plate to form the chamber formed between the first plate and the second plate.   
     
     
         14 . The method of  claim 13 , further comprising limiting the compression of the diaphragm using the arms of the first plate. 
     
     
         15 . The method of  claim 14 , wherein a height of the chamber formed between the diaphragm and a first plate and a height of the chamber formed between the first plate and the second plate limits the compression of the diaphragm to discourage the plastic deformation of the diaphragm. 
     
     
         16 . A method for actuating a downhole tool, the method comprising:
 providing a fluid pressure actuator within a chamber that is formed within a working string, the fluid pressure actuator comprising:
 a diaphragm having a top surface and a bottom surface; 
 a plunger coupled to the diaphragm and extending away from the bottom surface of the diaphragm in a first direction; and 
 a bellow sensor that extends away from the bottom surface of the diaphragm in the first direction, the bellow sensor comprising:
 a first circular plate coupled to the diaphragm, the first plate comprising:
 an interior surface of the first plate that is concentrically disposed about an exterior surface of the plunger; 
 an opposing exterior surface of the first plate; and 
 a first circumferentially extending cavity extending from the exterior surface of the first plate towards the first interior surface of the first plate; 
 
 
   accommodating a portion of the plunger within an opening formed in a floor of the chamber;   allowing a pressurized fluid to enter the chamber;   moving the plunger in the first direction due to the pressurized fluid applying a force against one or more surfaces of the fluid pressure actuator that are exposed to the pressurized fluid in the first direction; and   depressing an actuator located below the floor of the chamber, using the plunger, to activate the subterranean system controlled by the actuator.   
     
     
         17 . The method of  claim 16 ,
 wherein a top surface of the first plate forms a first circumferentially extending protrusion; and   wherein the first protrusion of the top surface of the first plate is coupled to the bottom surface of the diaphragm to form a first annular chamber that extends from the interior surface of the first plate towards the exterior surface of the first plate and that is at least partially defined by the bottom surface of the diaphragm and the top surface of the first plate.   
     
     
         18 . The method of  claim 17 , wherein the first protrusion of the top surface of the first plate is coupled to a circumferentially extending protrusion formed on the bottom surface of the diaphragm to form the first annular chamber. 
     
     
         19 . The method of  claim 16 , wherein the bellow sensor further comprises:
 a second circular plate coupled to the first plate, the second plate comprising:
 an interior surface of the second plate that is concentrically disposed about the exterior surface of the plunger; 
 an opposing exterior surface of the second plate; and 
 a second radially extending cavity extending from the exterior surface of the second plate towards the interior surface of the second plate. 
   
     
     
         20 . The method of  claim 19 ,
 wherein a top surface of the second plate forms a second circumferentially extending protrusion; and   wherein the second protrusion of the top surface of the second plate is coupled to a bottom surface of the first plate to form a second annular chamber that extends from the second interior surface of the second plate towards the second exterior surface of the second plate and that is at least partially defined by the bottom surface of the first plate and the top surface of the second plate.   
     
     
         21 . The method of  claim 20 , wherein the second protrusion of the top surface of the second plate is coupled to a third circumferentially extending protrusion formed on the bottom surface of the first plate to form the second annular chamber 
     
     
         22 . The method of  claim 16 , wherein the plunger extends beyond the bellow sensor in the first direction by a first distance. 
     
     
         23 . The method of  claim 19 , wherein an elastomeric seal is accommodated within a radial channel formed within a bottom surface of the second plate to fluidically isolate the actuator from the chamber. 
     
     
         24 . The method of  claim 21 , further comprising sizing a height of the first protrusion along the first direction and a height of the second protrusion along the first direction to limit the movement of the plunger in the first direction. 
     
     
         25 . The method of  claim 16 , wherein moving the plunger in the first direction due to the pressurized fluid applying a force against one or more surfaces of the fluid pressure actuator that are exposed to the pressurized fluid in the first direction comprises deforming the bellow sensor to reduce a height of the first annular chamber. 
     
     
         26 . The method of  claim 20 , wherein moving the plunger in the first direction due to the pressurized fluid applying a force against one or more surfaces of the fluid pressure actuator that are exposed to the pressurized fluid in the first direction comprises deforming the bellow sensor to reduce a height of the second annular chamber.