×

Low pressure responsive downhole tool with floating shoe retarding means

  • US 4,515,219 A
  • Filed: 09/19/1983
  • Issued: 05/07/1985
  • Est. Priority Date: 09/19/1983
  • Status: Expired due to Term
First Claim
Patent Images

1. An annulus pressure responsive downhole tool apparatus, comprising:

  • a tool housing;

    a power piston slidably disposed in said housing;

    a first pressure conducting passage means for communicating a well annulus with a first side of said power piston;

    a second pressure conducting passage means for communicating said well annulus with a second side of said power piston;

    said tool housing including inner and outer concentric tubular members defining an annular cavity therebetween, said second pressure conducting passage means being at least partially defined by said annular cavity;

    retarding means, disposed in said second pressure conducting passage means, for delaying communication of a sufficient portion of an increase in well annulus pressure to said second side of said power piston for a sufficient time to allow a pressure differential from said first side to said second side of said power piston to move said power piston from a first position to a second position relative to said housing, said retarding means including an annular floating shoe closely received in said annular cavity, said floating shoe including resilient friction means snugly engaging both said inner and outer tubular members of said tool housing; and

    pressure relief means, communicated with a first portion of said second pressure conducting passage means between said second side of said piston and said retarding means, for relieving from said first portion of said second pressure conducting passage means a volume of fluid sufficient to permit said power piston to travel to its said second position.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×