Downhole trigger apparatus

Abstract

A selectively operable timing device is in operable communication with a force reducing mechanism. The timing device restrains an effect of an external force on a tool member through the force reducing mechanism.

1 . A selectively operable timing device in operable communication with a force reducing mechanism, the timing device restraining an effect of an external force on a tool member through the force reducing mechanism. 
   
   
       2 . The selectively operable timing device in operable communication with a force reducing mechanism of  claim 1 , wherein the effect is movement. 
   
   
       3 . The selectively operable timing device in operable communication with a force reducing mechanism of  claim 1 , wherein the tool member is a piston. 
   
   
       4 . The selectively operable timing device in operable communication with a force reducing mechanism of  claim 1 , wherein the external force is due to pressure acting on the tool member. 
   
   
       5 . The selectively operable timing device in operable communication with a force reducing mechanism of  claim 1 , wherein the external force is supplied by a biasing member. 
   
   
       6 . The selectively operable timing device in operable communication with a force reducing mechanism of  claim 5 , wherein the biasing member is a spring. 
   
   
       7 . The selectively operable timing device in operable communication with a force reducing mechanism of  claim 1 , wherein the force reducing mechanism includes a series of levers. 
   
   
       8 . The selectively operable timing device in operable communication with a force reducing mechanism of  claim 7 , wherein the series of levers is in a form of a rolling lever. 
   
   
       9 . The selectively operable timing device in operable communication with a force reducing mechanism of  claim 1 , wherein the selectively operable timing device is a clock. 
   
   
       10 . The selectively operable timing device in operable communication with a force reducing mechanism of  claim 9 , wherein the clock is a wind up clock. 
   
   
       11 . The selectively operable timing device in operable communication with a force reducing mechanism of  claim 1 , wherein the selectively operable timing device is activated in response to a change in environment. 
   
   
       12 . The selectively operable timing device in operable communication with a force reducing mechanism of  claim 11 , wherein the change in environment is a change in pressure. 
   
   
       13 . The selectively operable timing device in operable communication with a force reducing mechanism of  claim 1 , wherein a torque coupling device operably connects the selectively operable timing device to the force reducing mechanism. 
   
   
       14 . The selectively operable timing device in operable communication with a force reducing mechanism of  claim 1 , wherein the selectively operable timing device is an electronic timer.