Rotary pivot unit

Abstract

A positioning apparatus includes a housing having a chamber. The vane is rotatably movable within the chamber. An arm is coupled to the vane.

What is claimed is:  
     
         1 . A positioning apparatus comprising: 
 a housing having a chamber;    a vane rotatably movable within said chamber;    an arm coupled to said vane; and    a workpiece coupled to said arm, wherein said arm and said workpiece rotate in response to rotation of said vane.    
     
     
         2 . The positioning apparatus of  claim 1  further comprising at least one fluid port in communication with said chamber, said port allowing entry of fluid into said chamber to rotate said vane relative to said member.  
     
     
         3 . The positioning apparatus of  claim 2  wherein said vane includes a portion directly in contact with said fluid.  
     
     
         4 . The positioning apparatus of  claim 3  wherein said fluid is air.  
     
     
         5 . The positioning apparatus of  claim 3  wherein said arm has a mass center and wherein said vane has a mass center and an axis of rotation, wherein said arm mass center is positioned substantially opposite said vane mass center across said axis of rotation.  
     
     
         6 . The positioning apparatus of  claim 5  wherein said axis of rotation extends through said chamber.  
     
     
         7 . The positioning apparatus of  claim 1  further including a second arm and a mount block, said mount block interconnecting said arm and said second arm wherein said arm and said second arm are positioned substantially parallel to each other in an offset relationship.  
     
     
         8 . The positioning apparatus of  claim 1  further comprising a shock absorber, wherein rotation of said arm is limited by said shock absorber.  
     
     
         9 . The positioning apparatus of  claim 1  wherein said vane provides a substantially constant torque output throughout a range of rotation of said arm.  
     
     
         10 . The positioning apparatus of  claim 9  wherein said range of rotation of said arm is substantially equal to 105 degrees.  
     
     
         11 . A positioning apparatus comprising: 
 a rotary actuator; and    an arm drivingly coupled to said rotary actuator, wherein said arm at least partially surrounds said rotary actuator.    
     
     
         12 . The positioning apparatus of  claim 11  wherein said arm is a generally “U” shaped member having substantially parallel side plate portions interconnected by a mount block, wherein at least a portion of said rotary actuator is positioned between said parallel side plate portions.  
     
     
         13 . The positioning apparatus of  claim 12  wherein said arm and said actuator are drivingly coupled with a drive pin.  
     
     
         14 . The positioning apparatus of  claim 11  further comprising an industrial work piece coupled to said arm.  
     
     
         15 . The positioning apparatus of  claim 11  wherein said rotary actuator includes a vane rotatably positioned within a chamber and at least one fluid port in communication with said chamber, said port operably allowing entry of fluid into said chamber to rotate said vane relative to said chamber.  
     
     
         16 . A positioning apparatus comprising: 
 a rotary fluid actuator having a plurality of pin apertures extending therethrough;    an arm drivingly engaged with said rotary actuator; and    a pin selectively disposed within one of said pin apertures to define a range of rotary travel of said arm by the presence of said pin in one of said pin apertures.    
     
     
         17 . The positioning apparatus of  claim 16  wherein said arm includes a stop portion selectively engagable with said pin to limit said range of rotary travel of said arm.  
     
     
         18 . The positioning apparatus of  claim 17  further including a second pin positioned within one of said pin apertures, said stop portion being positioned between said pin and said second pin, said stop portion being engagable with said second pin to further limit said range of rotary travel.  
     
     
         19 . The positioning apparatus of  claim 17  further including a shock absorber coupled to said stop portion.  
     
     
         20 . The positioning apparatus of  claim 19  wherein said shock absorber contacts said pin before said stop portion contacts said pin.  
     
     
         21 . The positioning apparatus of  claim 18  further including a shock absorber coupled to said rotary fluid actuator, said shock absorber contacting said stop portion of said arm prior to said stop portion contacting said second pin.  
     
     
         22 . A method of operating a rotary pivot unit having a rotary fluid actuator, an arm and a pin, the method comprising: 
 (a) inserting the pin in one of a plurality of apertures extending through the actuator, the aperture positions corresponding to a desired range of rotational travel;    (b) supplying fluid to the rotary actuator;    (c) rotating a portion of the actuator by direct contact with the fluid;    (d) rotating the arm in response to movement of the portion of the actuator; and    (e) limiting the rotation of the arm by engaging the arm with the pin.    
     
     
         23 . The method of  claim 22  further including inserting a second pin in another of said plurality of apertures to further limit the range of rotational travel of the arm to positions between the pin and the second pin.  
     
     
         24 . The method of  claim 23  further including outputting a signal indicating the position of the arm.  
     
     
         25 . The method of  claim 22  further including mounting an industrial tool to the arm thereby causing the industrial tool to rotate in response to rotation of the arm.