Trocar Needle Grinder

Abstract

Disclosed herein is a fixture for a workpiece, a system and a method for performing a machining operation using the fixture. The fixture may include a frame, a plurality of holders, an actuator and a bracket. Each holder may be configured to receive and secure a workpiece. Each holder may be rotationally coupled to the frame. The actuator may be operatively coupled to the plurality of holders to drive rotation of the holders with respect to the frame. The bracket may allow for mounting the frame to a manipulator configured to move the fixture. The method may include the steps of loading a workpiece to the holder of the fixture, moving and/or rotating the workpiece by the actuator to perform one or more ancillary operations on the workpiece, and moving/and or rotating the workpiece by the actuator to grind the workpiece against a grinding surface.

1 . A method for grinding a workpiece comprising the steps of:
 (i) loading a workpiece to a holder of an end effector, the holder being rotationally coupled to a frame, an actuator operatively coupled to the holder to drive rotation of the holder with respect to the frame,   (ii) moving and/or rotating the workpiece by the actuator to perform one or more ancillary operations on the workpiece; and   (iii) moving/and or rotating the workpiece by the actuator to grind the workpiece against a grinding surface.   
     
     
         2 . The method of  claim 1 , wherein the ancillary operations include any of a pre-grinding operation and a post-grinding operation. 
     
     
         3 . The method of  claim 2 , wherein the pre-grinding operations include any of retrieving feedstock and cutting feedstock. 
     
     
         4 . The method of  claim 2 , wherein the post-grinding operations include any of deburring, grit blasting, inspection and electropolishing of the workpiece. 
     
     
         5 . The method of  claim 2 , wherein the workpiece is a trocar. 
     
     
         6 . The method of  claim 2 , wherein the actuator is a robot. 
     
     
         7 . The method of  claim 6 , including a step of attaching the robot to the end effector. 
     
     
         8 . The method of  claim 2 , wherein instructions to perform steps (i) to (iii) are communicated via a human-machine interface. 
     
     
         9 . The method of  claim 1 , wherein the holder has a substantially circular opening defining a variable diameter. 
     
     
         10 . The method of  claim 9 , wherein the step of loading the workpiece to the holder includes varying the variable diameter to receive and secure the workpiece. 
     
     
         11 . The method of  claim 1 , wherein the holder is couple to a holder gear, the actuator including a shaft having a shaft gear, the shaft gear being operatively coupled to the holder gear to drive rotation of the holder with respect to the frame. 
     
     
         12 . A method for grinding comprising the steps of:
 (i) loading a plurality of workpieces to respective holders of an end effector, each holder being rotationally coupled to a frame, an actuator operatively coupled to the holders to drive simultaneous rotation of the holders with respect to the frame;   (ii) manipulating the plurality of workpieces by the actuator to perform one or more ancillary operations simultaneously on the workpieces; and   (iii) grinding the plurality of workpieces against a grinding surface while simultaneously rotating the workpieces using the actuator.   
     
     
         13 . The method of  claim 12 , wherein the actuator includes a shaft having a shaft gear operatively coupled to a plurality of holder gears, and wherein simultaneous rotation of the workpieces is achieved by driving the shaft gear with a motor. 
     
     
         14 . The method of  claim 12 , wherein the ancillary operations include loading the workpieces to collets configured to releasably secure the workpieces, the collets being adjusted to accommodate varying workpiece dimensions. 
     
     
         15 . A method for grinding a trocar comprising the steps of:
 (i) rotating a trocar within a holder of an end effector, the holder being coupled to a gear system to enable rotation;   (ii) grinding the trocar against a grinding surface to form a beveled tip; and   (iii) adjusting a position of the holder to create additional beveled surfaces at predefined angles.   
     
     
         16 . The method of  claim 15 , further comprising the step of applying coolant to the grinding surface and the trocar during grinding to reduce thermal damage and debris accumulation. 
     
     
         17 . The method of  claim 15 , wherein the predefined angles for the additional beveled surfaces are selected based on a desired trocar tip geometry. 
     
     
         18 . The method of  claim 15 , further comprising a step of dynamically adjusting the rotation speed of the trocar to based on material properties of the trocar. 
     
     
         19 . The method of  claim 15 , wherein the holder includes a support structure configured to minimize deflection of the trocar during grinding. 
     
     
         20 . The method of  claim 15 , wherein the grinding surface is an electrochemical grinding surface.