Dynamic bushing for medical device tubing
View Patent ↗A dynamic bushing and/or gripper mechanism comprises an apparatus for retaining a tubular member in a position during processing so that the tube does not move transverse to the longitudinal axis of the bushing, but wherein the tube may be rotated within the confines of the bushing and/or in the case of the gripper mechanism the tube may be moved longitudinally within the confines of the gripper.
1. A dynamic bushing assembly for preventing a tubular member from moving transverse to a longitudinal axis defined thereby but permitting the tube to be rotated about the longitudinal axis, the assembly comprising:
a tube retention area, the tube retention area being defined at least partially defined by a crown member, the crown member defining an apex, the apex having at least one top guide member extending therefrom into the tube retention area, the tube retention area being further defined by a surface of a piston, the piston being moveable toward and away from the apex, the surface of the piston having at least two bottom guide members extending therefrom into the tube retention area, wherein at least one of the guide members comprises a roller ball.
2. The assembly of claim 1 further comprising a piston housing, the piston being moveably engaged to the piston housing and being moveable therethrough, the crown member being fixedly engaged to the piston housing.
3. The assembly of claim 2 further comprising a cradle, the cradle being supportively engaged to a portion of the piston housing.
4. The assembly of claim 3 further comprising an elevator mechanism, the elevator mechanism being engaged to at least a portion of the cradle, the elevator mechanism constructed and arranged to move the cradle in a vertically up and down direction.
5. The assembly of claim 1 wherein the at least one top guide comprises:
a guide housing, at a first end of the guide housing the guide housing being engaged to the apex of the crown member, at a second end of the guide housing a roller ball is frictionally engaged to the guide housing, the roller ball being rotatable relative to the guide housing, the guide housing containing a biasing mechanism therein, the biasing mechanism exerting a predetermined biasing force on the roller ball in a direction toward the tube retaining area.
6. The assembly of claim 5 wherein the at least two bottom guides each comprise:
a guide housing, at a first end of the guide housing, the guide housing being engaged to the surface of the piston, at a second end of the guide housing a roller ball is frictionally engaged to the guide housing, the roller ball being rotatable relative to the guide housing, the guide housing containing a biasing mechanism therein, the biasing mechanism, exerting a predetermined biasing force on the roller ball in a direction toward the tube retaining area.
7. The assembly of claim 6 wherein the biasing mechanism of the at least one top guide exerts a predetermined biasing force that is greater than the predetermined biasing force exerted by the biasing mechanism of each of the at least two bottom guides.
8. The assembly of claim 6 wherein the tube retaining area has a predetermined size, the size of the tube retaining area being reduced when the piston is moved toward the apex of the crown, the size of the tube retaining area being expanded when the piston is moved away from the apex of the crown.
9. The assembly of claim 8 further comprising a tubular member, the tubular member defining an external surface, the tubular member being positioned in the tube retaining area so that the roller ball of the at least one top guide contacts a point on the external surface of the tubular member and the roller ball of each of the at least two bottom guides contact a point on the external surface of the tubular member.
10. The assembly of claim 6 wherein each roller ball is at least partially constructed from a wear resistant material.
11. The assembly of claim 10 wherein the wear resistant material is selected from at least one member of the group consisting of: ceramic, crucible powder metal, tungsten carbide and any combination thereof.
12. The assembly of claim 6 wherein each biasing mechanism is selected from at least one member of the group consisting of: a spring, a pressurized fluid column, a hydraulic mechanism, and any combination thereof.
13. The assembly of claim 1 wherein the at least one top guide is moveably engaged to the crown.
14. The assembly of claim 1 wherein each of the at least two bottom guides are moveably engaged to the piston.
15. The assembly of claim 1 wherein the longitudinal axis has a substantially horizontal orientation.