Piston-activated valve and methods and apparatus for restraining free play in a device

Abstract

Apparatus and methods for fitting mechanical parts to minimize prevent free play are described. An apparatus having a piston is designed so as to restrain the piston before actuation, and so as to allow the piston to gain momentum before striking an object. The described apparatus are applicable to devices involving shearable elements. An embodiment of the invention relates to a pyrotechnically activated valve incorporating such features to minimize free play in conjunction with such features so as to restrain the piston and also allow the piston to gain momentum.

1 . An apparatus, comprising: 
 a first part including a bore;    an eccentric sleeve mounted in said bore of said first part, said eccentric sleeve including outer surface corresponding to the bore of said first part, and said eccentric sleeve including a bore which is parallel to and not coaxial with the outer surface of the eccentric sleeve; and    a second part comprising a pin corresponding to the bore in said eccentric sleeve, said pin for insertion in the bore in said eccentric sleeve.    
   
   
       2 . The apparatus of  claim 1 , further comprising: 
 a scuring means passing through said first part, the securing means for contacting the outer surface of said eccentric sleeve.    
   
   
       3 . The apparatus of  claim 2 , further comprised of said securing means comprising a set screw passing through said first part.  
   
   
       4 . The apparatus of  claim 2 , further comprised of said securing means comprising: 
 a ball member for contacting the outer surface of said eccentric sleeve; and    a set screw passing through said first part, with an end of said set screw contacting said ball member.    
   
   
       5 . The apparatus is claimed in  claim 2 , further comprised of said first part comprising a piston, and said second part further comprising a seal tube, with an end of said pin for insertion in said seal tube.  
   
   
       6 . The apparatus of  claim 1 , further comprised of said first part comprising a piston, and said second part further comprising a seal tube, with an end of said pin for insertion in said seal tube.  
   
   
       7 . An apparatus, comprising: 
 a first part including a bore;    a sleeve mounted in said bore of said first part, said sleeve including an outer surface corresponding to the bore of said first part, and said sleeve including a bore; and    a second part comprising a pin corresponding to the bore in said sleeve, said pin for insertion in the bore in said sleeve.    
   
   
       8 . The apparatus of  claim 7 , further comprising: 
 a securing means passing through said first part, said securing means for contacting the outer surface of said sleeve.    
   
   
       9 . The apparatus of  claim 8 , further comprised of said securing means comprising a set screw passing through said first part.  
   
   
       10 . The apparatus of  claim 8 , further comprised of said securing means comprising: 
 a ball member for contacting the outer surface of said sleeve; and    a set screw passing through said first part, with an end of said set screw contacting said ball member.    
   
   
       11 . The apparatus of  claim 8 , further comprised of said first part comprising a piston, and said second part further comprising a seal tube, with an end of said pin for insertion in said seal tube.  
   
   
       12 . The apparatus of  claim 7 , further comprised of said first part comprising a piston, and said second part further comprising a seal tube, with an end of said pin for insertion in said seal tube.  
   
   
       13 - 29 . (canceled)  
   
   
       30 . A pyrovalve, comprising: 
 a housing including a bore;    a pyrotechnic initiator mounted in an upper portion of said housing;    a seal tube mounted in and extending out from said housing, with an axis of the seal tube being positioned perpendicular to an axis of the bore of said housing, said seal tube further comprising a shearable cap on an end of said seal tube located inside the housing;    a piston located inside in the bore of said housing so as to define a direction of motion for the piston, said piston comprising:    a hollow formed in a side of the piston, said hollow for receiving said shearable cap, said hollow being larger in cross-section than the shearable cap so as to define a gap between an overhang of the piston and said shearable cap; and    a shear pin connecting said shearable cap to said piston through a sleeve, for restraining play in said piston.    
   
   
       31 . The pyrovalve of  claim 30 , further comprising: 
 a first portion of said shear pin for insertion into an aperture in said shearable cap;    said piston including a bore for surrounding said sleeve including a second portion of the shear pin not located in said aperture of the shearable cap;    said sleeve for insertion into the bore of said piston, said sleeve including an outer surface corresponding to said bore of said piston, and said sleeve including a bore corresponding to the second portion of the shear pin and oriented parallel to and not coaxial with the outer surface of the sleeve; and    said second portion of said shear pin for insertion into said bore of said sleeve.    
   
   
       32 . A pyrovalve, comprising: 
 a housing including a bore;    a pyrotechnic initiator mounted in an upper portion of said housing;    a seal tube mounted in and extending out from said housing, with an axis of the seal tube being positioned perpendicular to an axis of the bore of said housing, said seal tube further comprising a shearable cap on an end of said seal tube located inside the housing;    a piston located inside in the bore of said housing so as to define a direction of motion for the piston, said piston comprising:    a hollow formed in a side of the piston, said hollow for receiving said shearable cap, said hollow being larger in cross-section than the shearable cap so as to define a gap between an overhang of the piston and said shearable cap; and    a shear pin press fit in an aperture of said shearable cap and for being coupled to said piston, for restraining play in said piston.    
   
   
       33 . The pyrovalve of  claim 32 , further comprising: 
 a first portion of said shear pin for insertion into an aperture in said shearable cap;    said piston including a bore for surrounding a second portion of the shear pin not located in said aperture of the shearable cap;    a sleeve for insertion into the bore of said piston, said sleeve including an outer surface corresponding to said bore of said piston, and said sleeve including a bore corresponding to the second portion of the shear pin and oriented parallel to and not coaxial with the outer surface of the sleeve; and    said second portion of said shear pin for insertion into said bore of said sleeve.    
   
   
       34 . The pyrovalve of  claim 32 , further comprising: 
 a first portion of said shear pin for insertion into an aperture in said shearable cap;    said piston including a bore for surrounding a second portion of the shear pin not located in said aperture of the shearable cap;    a sleeve for insertion into the bore of said piston, and said sleeve including a bore corresponding to the second portion of the shear pin; and    said second portion of said shear pin for insertion into said bore of said sleeve.    
   
   
       35 . A method for restraining free play in an apparatus, comprising the steps of: 
 providing a first part including a bore;    mounting a sleeve in said bore of said first part, said sleeve including an outer surface corresponding to said bore of said first part, and said sleeve including a bore;    inserting a pin into the bore in said sleeve.    
   
   
       36 . The method of  claim 35 , further comprising the steps of: 
 passing a securing means through said first part; and    contacting an outer surface of said sleeve by said securing means to restrain free play in said first part.    
   
   
       37 . The method of  claim 37 , further comprising the steps of: 
 providing a second part; and    inserting an end of said pin into said second part, to restrain free play in said first part.    
   
   
       38 . The method of  claim 35 , further comprising the steps of: 
 providing a second part; and    inserting an end of said pin into said second part, to restrain free play in said first part.    
   
   
       39 . The method of  claim 38 , further comprising the step of: 
 press fitting into a bore of said second part an end of said pin, and a coupling said second part to said first part through said pin.    
   
   
       40 . The method of  claim 35 , further comprised said bore of said sleeve being parallel to and not coaxial with the outer surface of said sleeve.  
   
   
       41 . A method for restraining free play, comprising the steps of: 
 providing a first part including a bore;    providing a second part including a bore;    press fitting a pin into said bore of said second part; and    coupling said first part to said second part through said pin.    
   
   
       42 - 50 . (canceled)