Abstract: One embodiment of the invention provides a joining element for joining a tube with a port. The joining element comprises a seal having a bore for accepting the tube, a nut and a ferrule. The ferrule has a bore for accepting the seal and the tube, a retaining member which retains the tube with the ferrule by engaging the tube, and a positive stop which limits engagement of the retaining member and the tube. The nut has a bore for accepting the ferrule and the tube and a bearing surface which engages the positive stop on the ferrule to positively limit engagement of the retaining member and the tube. Still other embodiments provide methods for forming a connection between a tube and a port. One such method comprises inserting the tube into a first member and a second member. The first member is moved with respect to the second member such that the second member is positioned partially within the first member. The first member, the second member and the tube are placed in the port.

Abstract: One embodiment of the invention provides a joining element for joining a tube with a port. The joining element comprises a seal having a bore for accepting the tube, a nut and a ferrule. The ferrule has a bore for accepting the seal and the tube, a retaining member which retains the tube with the ferrule by engaging the tube, and a positive stop which limits engagement of the retaining member and the tube. The nut has a bore for accepting the ferrule and the tube and a bearing surface which engages the positive stop on the ferrule to positively limit engagement of the retaining member and the tube. Still other embodiments provide methods for forming a connection between a tube and a port. One such method comprises inserting the tube into a first member and a second member. The first member is moved with respect to the second member such that the second member is positioned partially within the first member. The first member, the second member and the tube are placed in the port.

Abstract: A gripper assembly for a robotic arm includes two opposing elements displaced by means of a worm gear arrangement for grasping an object positioned therebetween. The worm gear is driven by a rotary drive motor with a torsion spring coupling the drive motor shaft to the worm. First and second shaft encoders are respectively mounted to the drive motor shaft and the worm shaft. First and second pairs of optical sensors respectively coupled to the first and second shaft encoders detect the angular speed and displacement of the drive motor shaft and the worm. With the torsion constant of the spring known, the force applied by the gripper assembly which is proportional to the angular displacement of the worm may be accurately determined and controlled. In addition, the size of the object grasped by the gripper assembly may be determined. By comparing these operating parameters with selected values, the gripper assembly may be precisely controlled such as by means of a microcomputer.