Positioning apparatus and method of use

Abstract

A positioning system having a base, a manually movable end effector and a first joint interposed between the base and the end effector is disclosed. The first joint may comprise a proximal portion and a distal portion coupled together by magnetic attraction and configured to be intermittently separated by a pressurized gas cushion. The first joint may be configured to be changeable between a movable state and a fixed state. In the movable state, the proximal and distal portions are separated by the pressurized gas cushion and are movable relative to each other. In the fixed state, the proximal and distal portions contact each other and relative movement is thereby impeded. Methods of precisely positioning an end effector may include providing a device having a base, a first joint located distally from the base, and an end effector located distally from the first joint. The first joint may have two portions separated by a gas cushion, the first joint allowing the end effector to be movable with respect to the base. The method may further comprise manually positioning the end effector, and removing the gas cushion to cause the two joint portions to contact each other, thereby locking the end effector in the precise location in which it was positioned.

What is claimed is: 
     
         1 . A positioning system comprising:
 a plurality of lockable spheres, each of the plurality of lockable spheres comprising a base portion and a spherical member coupled together by magnetic attraction and configured to be intermittently separated by a pressurized gas cushion, each of the plurality of lockable spheres configured to be changeable between a movable state in which the base portion and spherical member are separated by the pressurized gas cushion and rotatable relative to each other in three degrees of rotational freedom, and a fixed state in which the base portion and spherical member contact each other and relative movement is thereby impeded.   
     
     
         2 . The system of  claim 1 , wherein each of the plurality of lockable spheres shares a common base portion. 
     
     
         3 . The system of  claim 2 , wherein at least two of the plurality of lockable spheres have an interruptible pressurized gas cushion that is separate from the other of the two. 
     
     
         4 . The system of  claim 1 , wherein at least one of the spherical members and or base portions has a surface that has been roughened to increase a holding force between the spherical member and a mating surface of the base portion when the associated lockable sphere is in the fixed state. 
     
     
         5 . The system of  claim 4 , wherein the surface of the at least one spherical member and or base portion has been roughened by coating the surface. 
     
     
         6 . The system of  claim 4 , wherein the surface of the at least one spherical member and or base portion has been roughened by sand blasting. 
     
     
         7 . The system of  claim 4 , wherein the surface of the at least one spherical member and or base portion has been roughened by the use of a porous surface material. 
     
     
         8 . The system of  claim 1 , wherein at least one of the plurality of lockable spheres comprises an electromagnet that can be energized to lock the lockable sphere. 
     
     
         9 . The system of  claim 8 , wherein the electromagnet can be energized to lock the lockable sphere without interrupting an air flow that creates the pressurized gas cushion in the lockable sphere. 
     
     
         10 . The system of  claim 8 , wherein the electromagnet can be energized in conjunction with interrupting an air flow that creates the pressurized gas cushion in the lockable sphere to lock the lockable sphere. 
     
     
         11 . The system of  claim 1 , wherein at least one of the plurality of lockable spheres comprises a permanent magnet configured to lock the lockable sphere in the fixed state once the pressurized gas cushion is removed. 
     
     
         12 . The system of  claim 11 , wherein the permanent magnet is located in the base portion of the at least one lockable sphere. 
     
     
         13 . The system of  claim 12 , wherein the base portion further comprises a ferromagnetic liner located coaxially with the permanent magnet. 
     
     
         14 . A method of positioning an object, the method comprising:
 providing a positioning system having a plurality of lockable spheres, each of the plurality of lockable spheres comprising a base portion and a spherical member coupled together by magnetic attraction and configured to be intermittently separated by a pressurized gas cushion, each of the plurality of lockable spheres configured to be changeable between a movable state in which the base portion and spherical member are separated by the pressurized gas cushion and rotatable relative to each other in three degrees of rotational freedom, and a fixed state in which the base portion and spherical member contact each other and relative movement is thereby impeded;   providing a pressurized gas supply to create a pressurized gas cushion in at least one of the plurality of lockable spheres, thereby putting the at least one lockable sphere in the movable state and allowing movement of the object; and   removing the pressurized gas supply from the at least one lockable sphere, thereby putting the at least one lockable sphere in the fixed state and inhibiting movement of the object.   
     
     
         15 . The method of  claim 14 , comprising putting at least one of the lockable spheres in the fixed state and putting at least another one of the lockable spheres in the movable state to inhibit full movement of the object while allowing partial movement of the object. 
     
     
         16 . The method of  claim 14 , comprising putting each of the plurality of the lockable spheres in the fixed state to fully constrain the object from movement. 
     
     
         17 . The method of  claim 14 , wherein at least one of the spherical members and or base portions has a surface that has been roughened to increase a holding force between the spherical member and a mating surface of the base portion when the associated lockable sphere is in the fixed state. 
     
     
         18 . The method of  claim 14 , wherein the base portion of at least one of the lockable spheres comprises a permanent magnet and a ferromagnetic liner located coaxially with the permanent magnet.