COMPOSITIONS AND PROCESSES FOR DOWNHOLE CEMENTING OPERATIONS

摘要

A rotary actuator for use in surgical instruments is provided, including a plurality of engine elements placed symmetrically around a rotation axis; a disk in contact with the engine elements, centered on the rotation axis, the engine elements providing a first rotation to the disk; an input shaft coupled to the disk to rotate with the first rotation; and a coupling mechanism to provide a second rotation to an output shaft from the first rotation of the input shaft. A surgical manipulator is also provided, including a base to provide stability and support; a first rotary actuator as above coupled to the base; and a first arm coupled to the rotary actuator.

主权项

1. A suspension comprising:
(1) from about 15 to about 25 weight percent based on the total weight of the suspension of a first component selected from the group consisting of calcium carbonate, talc, silica, and mixtures thereof wherein the first component has an average particle size distribution of from about 0.5 microns to about 100 microns based on laser scattering; (2) from about 30 to about 70 weight percent based on the total weight of the suspension of a second component selected from the group consisting of crushed rock, gravel, sand and mixtures thereof wherein the second component has an average particle size distribution of from about 50 microns to about 600 microns based on laser scattering; (3) from about 25 to about 45 weight percent based on the total weight of the suspension of a thermosetting resin selected from a polyester resin, a vinyl ester resin, and mixtures thereof; and (4) a catalyst capable of causing the suspension to gel and cure and wherein said gel time is from about 2 to about 10 hours; wherein the uncured suspension has a pumpability of from about 10 to about 120 Bearden units and wherein the cured composition is characterized by a ratio of tensile strength to compressive strength of at least about 10% wherein the tensile strength is measured according to ASTM C1273 with a 0.01 inch/min of cross-head speed at ambient 25 C at 50% humidity and the compression strength is measured according to ASTM 873 with a 0.01 inch/min of cross-head speed at ambient 25 C at 50% humidity.