Pulsating Jarring Tool

Abstract

A rotary device imposes torque in a first direction for a first period of time causing a screw to exert force in a compression direction, causing a spring to compress. The rotary device does not impose torque for a second period of time, causing the spring to decompress at the beginning of the second period of time, causing the screw to move in a decompression direction opposite the compression direction. The rotary device imposes torque in a second direction opposite the first direction for a third period of time causing the screw to exert force in the decompression direction.

1 . An apparatus comprising:
 a rotary device having an output that can have a compression state in which it outputs compression torque, a jarring state in which it does not output torque, and an initializing state in which it outputs decompression torque in the opposite direction of the compression torque;   a transmission device coupled to the rotary device;   a screw coupled to the transmission device,   a spring coupled to the screw, wherein the spring compresses when the screw moves in a compression direction;   wherein the transmission device:
 converts compression state torque to linear motion of the screw in the compression direction, 
 prevents the screw from moving in a decompression direction opposite the compression direction when the rotary device is in the compression state, and 
 allows the screw to move in the decompression direction when the rotary device is in the jarring state. 
   
     
     
         2 . The apparatus of  claim 1  wherein the transmission device further converts decompression torque into linear motion of the screw in the decompression direction. 
     
     
         3 . The apparatus of  claim 1  wherein the spring is a Bellville washer. 
     
     
         4 . The apparatus of  claim 1  wherein the decompression direction is not aligned with a direction of gravity. 
     
     
         5 . The apparatus of  claim 1  wherein the transmission device allows the screw to move in the decompression direction when the rotary device is in the jarring state in the absence of gravity. 
     
     
         6 . The apparatus of  claim 1  wherein the spring comprises a wire coil and a jarring force provided by the apparatus is adjusted by selecting a spring constant factor selected from the group consisting of a wire material, the diameter of the wire, the diameter of the coil, the length of the spring, and the number of coils in the spring. 
     
     
         7 . An apparatus comprising:
 a housing;   a rotary device control logic having an output that is commandable to provide an electrical output of a first polarity, an electrical output of a second polarity, and no electrical output;   a rotary device comprising:
 an electrical input coupled to the rotary device control logic output, 
 a mechanical output that:
 provides torque in a first direction when the electrical input receives power of the first polarity, 
 provides torque in a second direction when electrical input receives power of the second polarity, and 
 provides no torque when the electrical input receives no power; 
 
   a transmission device comprising:
 a rotary input coupled to the mechanical output of the rotary device, and 
 a screw coupled to the rotary input by friction caused by resistance of the screw to torque provided by the rotary input, 
 wherein the screw moves in a compression direction away from the rotary input in response to rotation of the rotary input in the first direction, and 
 wherein the screw moves in a decompression direction toward the rotary input in response to rotation of the rotary input in the second direction; 
   a spring that is compressed when the screw moves in the compression direction, the spring urging the screw in the decompression direction;   wherein, when the rotary device provides no torque, a previously-compressed spring causes the screw to move in the decompression direction.   
     
     
         8 . The apparatus of  claim 7  wherein an amplitude of the electrical output of the rotary device control logic is commandable. 
     
     
         9 . The apparatus of  claim 7  wherein the rotary device comprises a direct current motor. 
     
     
         10 . The apparatus of  claim 7  wherein the screw moves in the decompression direction toward the rotary input in response to rotation of the rotary input in the second direction in the absence of gravity. 
     
     
         11 . The apparatus of  claim 7  wherein the spring comprises a wire coil and a jarring force provided by the apparatus is adjusted by selecting a spring constant factor selected from the group consisting of a wire material, the diameter of the wire, the diameter of the coil, the length of the spring, and the number of coils in the spring. 
     
     
         12 - 16 . (canceled) 
     
     
         17 . A method comprising:
 a rotary device imposing torque in a first direction for a first period of time causing a screw to exert force in a compression direction, causing a spring to compress;   the rotary device not imposing torque for a second period of time, causing the spring to decompress at the beginning of the second period of time, causing the screw to move in a decompression direction opposite the compression direction; and   the rotary device imposing torque in a second direction opposite the first direction for a third period of time causing the screw to exert force in the decompression direction.   
     
     
         18 . The method of  claim 17  further comprising repeating the rotary device imposing rotary device imposing torque in the first direction for the first period of time, the rotary device not imposing torque for the second period of time, and the rotary device imposing torque in the second direction opposite the first direction for the third period of time. 
     
     
         19 . The method of  claim 18  wherein an amplitude of the torque imposed for the first period of time is different from an amplitude of the torque imposed for the repetition of the first period of time. 
     
     
         20 . The method of  claim 17  wherein the rotary device imposing torque in the second direction opposite the first direction for the third period of time causes the screw to exert force in the decompression direction in the absence of gravity. 
     
     
         21 . The method of  claim 17  wherein the spring comprises a wire coil, further comprising adjusting a jarring force provided by the screw by selecting a spring constant factor selected from the group consisting of a wire material, the diameter of the wire, the diameter of the coil, the length of the spring, and the number of coils in the spring. 
     
     
         22 . The method of  claim 17  wherein the first period of time, the second period of time, and the third period of time are not all the same. 
     
     
         23 . The method of  claim 17  wherein the force exerted by the screw in the decompression direction comprises an impulse of force. 
     
     
         24 . The method of  claim 17  wherein the force exerted by the screw in the compression direction comprises a tensile force.