Trocar needle grinding machine

Abstract

To provide a fixture for a workpiece and an improved system and method for performing a machining operation by using the fixture.SOLUTION: Each holder is configured to receive and secure one workpiece 200. Each holder is rotationally coupled to a frame. An actuator is operatively coupled to the plurality of holders in order to drive rotation of the holders with respect to the frame. A bracket 104 allows for mounting the frame to a manipulator configured to move a fixture 100. This method includes the steps of: loading the workpiece 200 to the holder of the fixture 100; moving and / or rotating the workpiece 200 by the actuator in order to perform one or more auxiliary operations on the workpiece 200; and moving and / or rotating the workpiece by the actuator in order to grind the workpiece 200 against a grinding surface.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention generally relates to fixtures for workpieces and systems for performing machining operations, and more particularly to fixtures for holding and operating workpieces and systems for performing machining operations using such fixtures.

[0002] This application claims the benefit of the filing date of U.S. Provisional Patent Application No. 62 / 970,888, filed on February 6, 2020, the disclosure of which is incorporated herein by reference.

Background Art

[0003] Needles are manufactured, inter alia, by grinding the needle tip against a grinding surface. The needle is loaded into a cartridge or fixture and positioned relative to the grinding surface. The needle must be rotated one or more times during the grinding process to achieve the desired needle tip profile. For example, a trocar needle is made by rotating the needle at least twice to produce the three flat bevels required for a trocar needle. Grinding can be performed using various grinding methods, including electropolishing.

[0004] In addition to the grinding operation, various other operations are required to complete the manufacture of the needle. For example, various pre-processing operations are required to prepare the needle for grinding, and various post-processing operations are required to prepare the ground needle for use. During these various operations, one or more needles are moved from one workstation to another, securely held in place, and must be moved and rotated at each workstation to complete the machining steps at each workstation.

Summary of the Invention

Problems to be Solved by the Invention

[0005] The various steps involved in needle manufacturing require significant time and effort to move the needle through each of the workstations and manipulate the needle at each manufacturing step. Accordingly, an improved needle manufacturing system and method are desired.

Means for Solving the Problem

[0006] In some embodiments, the present disclosure generally relates to fixtures for workpieces. In other embodiments, the present disclosure relates to a system for performing machining operations using the fixture. In still other embodiments, the present disclosure relates to a method for performing machining operations using the fixture.

[0007] In one aspect of the present disclosure, a fixture for holding a plurality of workpieces is presented. According to this aspect, the fixture includes a frame, a plurality of holders, an actuator, and a bracket. Each holder is configured to receive and secure a workpiece. Each holder is rotatably coupled to the frame. The actuator is operably coupled to the plurality of holders to drive the rotation of the plurality of holders relative to the frame. The bracket enables the frame to be attached to a manipulator configured to move the fixture.

[0008] According to this aspect, each holder may be a collet configured to removably secure a workpiece.

[0009] According to this aspect, each holder may be coupled to a holder gear. The actuator may include a shaft having a shaft gear. The shaft gear may be operably coupled to the holder gear to drive the rotation of the holder relative to the frame.

[0010] According to this aspect, the fixture may include a support structure disposed away from the holder to minimize or eliminate deflection of the workpiece during the machining operation. The shaft gear may be operably connected to the holder gear by a connecting gear. In one aspect, the connecting gear may be a linear actuator. The linear actuator may include a rack gear driven by a pinion constituted by the shaft gear. The actuator may be constituted by an electric motor for driving the rotation of the shaft. In another aspect, the connecting gear may be a first helical gear. The first helical gear may extend along the shaft. The first helical gear may be substantially parallel to the shaft. The rotation axis of the first helical gear may be parallel to the shaft. The first helical gear may be operably connected to the shaft gear by a pulley drive. The pulley drive may include a belt connecting the shaft gear to the first helical gear.

[0011] According to this aspect, the fixture may include a support structure disposed away from the holder to minimize or eliminate deflection of the workpiece during the machining operation.

[0012] According to this aspect, the manipulator may be a robot. The robot may include an arm having a distal end with a rotary actuator. The fixture may be configured to be connected to the distal end of the arm such that the actuator of the fixture is operably connected to the rotary actuator of the robot.

[0013] In a further aspect of the present disclosure, a robotic end effector for holding a plurality of workpieces is presented. The robotic end effector according to this aspect includes a plurality of holders, a shaft, a first connecting gear, and a second connecting gear. Each holder is configured to receive and fix a workpiece. Each holder is connected to each holder gear. The shaft includes a shaft gear. The shaft is configured to rotate the shaft, move, and position the robotic end effector relative to a polishing abrasive. The first connecting gear is connected to the shaft gear. The second connecting gear is connected to the first connecting gear and the holder gear. Rotation of the shaft by the robot is adapted to simultaneously rotate each of the plurality of workpieces about each workpiece axis via each holder gear, the first connecting gear, and the second connecting gear.

[0014] In a further aspect of the present disclosure, a polishing system is presented. The polishing system according to this embodiment includes a polishing surface, an end effector, and a robot. The end effector includes a frame having a plurality of holders. Each holder is configured to receive and fix one workpiece. Each holder is rotatably connected to the frame. An actuator is operably connected to the plurality of holders to drive rotation of the plurality of holders relative to the frame. The robot is connected to the actuator of the end effector. The robot is configured to rotate the actuator and move and position the end effector relative to the polishing surface such that the workpiece contacts the polishing surface at a first position of the end effector and does not contact the polishing surface at a second position of the end effector for polishing the workpiece at the first position of the end effector. Rotation of the actuator is adapted to simultaneously rotate each of the plurality of workpieces about each workpiece axis.

[0015] According to this aspect, each of the holders may be connected to each holder gear. The actuator may include a shaft having a shaft gear. The shaft gear may be operably connected to the holder gear to drive the rotation of the holder relative to the frame. The shaft gear may be connected to the holder gear via a connecting gear. The shaft gear may be connected to a first connecting gear and a second connecting gear. The second connecting gear may be connected to the holder gear.

[0016] According to this aspect, the rotation of the actuator by the robot may be performed to polish a portion that does not contact the polishing surface at the second position.

[0017] According to this aspect, the holder may be configured to receive and fix the trochcar needle.

[0018] According to this aspect, the polishing system may be an electrolytic polishing system.

[0019] In a further aspect of the present disclosure, a method for polishing a workpiece is presented. The method according to this embodiment includes: (i) loading the workpiece into a holder of an end effector; (ii) performing at least one of movement and rotation of the workpiece by an actuator to perform one or more auxiliary operations on the workpiece; and (iii) performing at least one of movement and rotation of the workpiece by an actuator to polish the workpiece on a polishing surface. The holder is rotatably connected to the frame. An actuator is operably connected to the holder to drive the rotation of the holder relative to the frame.

[0020] According to this aspect, the auxiliary operation may include either a pre-polishing operation or a post-polishing operation. The pre-polishing operation may include either taking in the material or cutting the material. The post-polishing operation may include any one of deburring the workpiece, grit blasting, inspection, and electrolytic polishing.

[0021] According to this aspect, the processed product may be a trocar needle.

[0022] According to this aspect, the actuator may be a robot. This method may further include the step of attaching the robot to the end effector.

[0023] According to this aspect, the commands for performing steps (i)-(iii) may be transmitted via a human-machine interface.

[0024] The subject matter of the present disclosure and its various advantages will be more fully understood by reference to the following detailed description based on the accompanying drawings below.

Brief Description of the Drawings

[0025]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5A

Figure 5B

Figure 5C

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Figure 19

Figure 20

DETAILED DESCRIPTION OF THE INVENTION

[0026] Hereinafter, various embodiments of the present disclosure shown in the accompanying drawings will be described in detail. In order to describe the same or similar features, the same or similar reference numerals are used throughout the drawings as much as possible. Note that the drawings are simplified and not drawn to an exact scale. In addition, the article "a" used in this specification means "at least one".

[0027] As used herein, the terms "needle" and "workpiece" are used interchangeably, and unless otherwise specified, if either term is explicitly used, the other term shall also be considered to be explicitly used. Similarly, the terms "fixture", "end effector", and "robotic end effector" are used interchangeably, and unless otherwise specified, if any of these terms is explicitly used, the other terms shall also be considered to be explicitly used.

[0028] Figures 1 and 2 show front and rear perspective views of a fixture 100 according to an embodiment of the present disclosure. The fixture 100 includes a frame that holds a plurality of collets 102 for receiving and securing one or more workpieces 200. The collets 102 can receive workpieces of different thicknesses and lengths, as described in more detail below. Each workpiece 200 is loaded into and firmly secured within a collet 102. A shaft 110 connects the collets 102 to a manipulator, such as a robot (not shown), via a connection structure 144 and a set of mounting arms 112. The shaft 110 is surrounded by a bracket 104 that includes a mounting end 118 for attachment to the robot. As best shown in Figure 1, one or more connections 130 for providing control and / or power to the fixture are provided on the shaft 110. For example, the connection 130 is configured to control a motor 156 that drives rotation of the shaft 110. The motor 156 is shown disposed within the bracket 104 and can be an electric motor, such as a stepper motor or a servo motor.

[0029] The fixture 100 includes a support structure 116 for minimizing or eliminating the deflection of the workpiece 200 during a machining process such as grinding. The workpiece 200 extends beyond the support structure 116 to enable the workpiece 200 to contact a grinding surface (not shown). When the workpiece is pressed against the grinding surface for grinding, the support structure 116 acts as a back support to minimize or eliminate the deflection of the workpiece during grinding.

[0030] The fixture 100 includes a plurality of mounting structures 132 that enable the fixture 100 to be tethered or attached to another structure such as a machining bed or other tool. As described in more detail below, a plurality of ports 134 are provided in the base 152 to actuate the piston 150 such that the collet 102 opens and closes. The mounting end 118 includes a recess 136 that receives a corresponding head (not shown) of a robot. The mounting end 118 includes a plurality of fixtures 138 and dowel pins 122 configured to engage the distal end of the robot to securely attach the fixture 100 to the robot. A (not shown) refrigerant port may be provided in the fixture 100 to enable refrigerant to flow across the fixture to maintain the operating temperature of the fixture at a desired level.

[0031] Referring now to FIG. 3, a front perspective view of the actuator mechanism of the fixture 100 is shown. The shaft 110 includes a shaft gear 128 coupled to the upper gear rack 106. The shaft gear 128 and the upper gear rack 106 form a rack and pinion mechanism in which rotation R2 of the shaft gear 128 produces linear movement L1 of the rack 106. Rotation of the shaft gear 128 is effected by rotating the shaft 110 about a shaft central axis A2 as shown in FIG. 3.

[0032] The upper gear rack 106 is attached to the lower gear rack 108 such that these upper and lower gear racks move together. As shown in FIG. 3, the linear movement L1 of the upper gear rack 106 causes a similar linear movement L2 of the lower gear rack 108. Each collet 102 is connected to a collet gear 126. The collet gear 126 is connected to the lower gear rack 108, thereby forming a second rack and pinion mechanism in which the linear movement L2 of the lower gear rack causes a rotation R1 about the central axis A1 of the workpiece. Accordingly, the rotation of the shaft 110 causes the rotation of each workpiece 200. The rotation of each workpiece with respect to the rotation of the shaft 110 can be controlled as desired by adjusting the gear ratio. For example, an increase in the gear ratio of the rack and pinion makes the rotation of the workpiece more accurate, while a decrease in the gear ratio of the rack and pinion makes the rotation of the workpiece faster. Although two rack and pinion mechanisms are shown with two sets of gear racks in this embodiment, in other embodiments, only one rack and pinion mechanism for converting the rotation R2 of the shaft 110 into the rotation R1 of each workpiece may be provided. In this embodiment, a rotation-linear motion conversion by a rack and pinion mechanism is used to convert the rotation R2 of the shaft 110 into the rotation R1 of each workpiece 200, but in other embodiments, other gear mechanisms such as a helical gear, bevel gear, worm gear, internal gear, etc. may be used to convert the rotation R2 of the shaft 110 into the rotation R1 of each workpiece 200. For example, a chain or belt drive may be used to connect the shaft 110 and the collet 102 to each other, and in this case, each of the shaft gear 128 and the collet gear 126 can be in the form of a sprocket connected to a loop of a roller chain, for example. In other embodiments, a rotation-linear motion conversion of the shaft 110 may be used to rotate each workpiece 200.

[0033] Figure 4 shows a top view of the actuator mechanism of the fixture 100. The distance D1 between the distal end 202 of the workpiece 200 and the support 116 defines the protruding amount of the workpiece 200 beyond the support 116. The distance D2 between the distal surface of the collet 102 in the workpiece 200 and the support 116 defines the distance between the fixed end (collet 102) and the free end (the workpiece 200 above the support 116). Accordingly, the portion of the workpiece 200 defined by the distance D2 functions as a cantilever beam when the workpiece 200 does not contact the support 116. The distances D1 and D2 are adjustable by moving the support 116. For example, by using the linear slots 158 and one or more locking bolts 160, the support 116 can be slid to different positions and locked in place. Such an adjustment function is preferably utilized when polishing a workpiece 200 made of a brittle material and / or a thin material. For example, in order to reduce the curvature of such a workpiece 200 during polishing, the distance D1 should be minimized. By performing the adjustment of the support 116 for changing the distances D1 and D2 by a manipulator such as a robot, the desired adjustment can be automated. Thereby, the robot can adjust these distances based on the input from the operator. The pneumatic or hydraulic control of the support 116 is enabled by the pneumatic or hydraulic ports 166 as shown in FIG. 2. For example, by lowering the support 116 by pneumatic or hydraulic control, the workpiece 200 can be loaded onto the collet 102, and by lifting the support 116 by pneumatic or hydraulic control during polishing, deflection support for the workpiece can be provided.

[0034] As best shown in FIG. 4, the linear rail 140 is connected to the collet 102 and attached to the shaft 110 via the attachment portion. As best shown in FIG. 2, the base 152 includes a piston 150 connected to the U-arm 148. As shown in FIG. 1, the end cap 114 fixes the piston 150 to the base 152.

[0035] FIG. 5A shows an exploded view of the workpiece 200, the collet 102, and the collet gear 126. The workpiece 200 includes a distal end 202 and a proximal end 204. In this embodiment, the workpiece 200 is a trocar needle having three bevel surfaces at the distal end 202. In other embodiments, other needle tip types are possible, such as, but not limited to, diamond tips, crown saws, back bevels, Meningi, scalpel blades, and the like. The fixture 100 of the present disclosure may be used with any polishing system, such as an electropolishing system. The diameter of the collet opening 154 is expandable and contractible to receive and fix the proximal end 204 of the workpiece 200. Specifically, by the relative translational movement between the bush 146 and the collet 102 along the axis A1, the tapered end 162 of the collet 102 is gradually tightened within the bush 146, thereby reducing the size of the opening 154 and gripping the workpiece 200. Also, the workpiece 200 can be loaded through a rear opening (not shown) of the collet 102.

[0036] Figures 5B and 5C show perspective views of the actuating mechanism for opening and closing the collet 102. Each piston 150 is connected to port 134. As best shown in Figure 5C, port 134 is used as a fluid pressure or pneumatic port, whereby a linear movement L3 can be imparted to piston 150 by fluid pressure or pneumatic means. The extension of piston 150 away from end cap 114 pushes U-arm 148 and pivots U-arm 148 about pivot 164, whereby collet gear 126 pulls collet 102 into bushing 146, resulting in the closing of opening 154. When piston 150 moves towards end cap 114, collet gear 126 pushes collet 102 out of bushing 146, resulting in the opening of collet 102. In other embodiments, a rigid link connected to the piston can be used to move collet 102 directly in and out of the bushing. In this way, the linear movement L3 of the piston causes U-arm 148 to move relatively between collet 102 and bushing 146, fixing or releasing workpiece 200. The linear movement L3 may be performed by a manipulator such as a robot, thereby enabling the complete automation of the loading / unloading and adjustment of the workpiece with respect to collet 102.

[0037] Fixture 100 has been generally described herein in relation to grinding operations, but fixture 100 may be used to receive, hold, manipulate, and remove workpieces in any other machining operation. Fixture 100 has been generally described herein as being used with a robot, but in other embodiments, any operating means from manual to fully automated may be used. The rotation of shaft 110 has been generally described as being performed by a manipulator such as a robot, but in other embodiments, motor 156 may be adapted to rotate shaft 110 alone without the need for a manipulator. In other embodiments, motor 156 may be used in conjunction with a manipulator such as a robot that rotates the shaft.

[0038] Referring to FIG. 6, a perspective view of a machining system according to another embodiment of the present disclosure is shown. In this embodiment, a polishing system 300 is shown as an example, but in other embodiments, other machining systems such as a cutting system, a welding system, a drilling system, etc. may be used. The polishing system 300 includes a fixture 100 connected to a robot 400. The polishing system includes a polishing wheel 302 for polishing a workpiece and a coolant tank 304 for supplying coolant to the polishing process. As shown in FIG. 6, a machine base 306 having a machine bed 308 is also provided. The control panel 310 is used for operator control input and includes a display for monitoring the polishing process. The operator can monitor and control the polishing process via the control panel 310.

[0039] FIG. 7 shows details of the polishing wheel 302 of the polishing system 300. The polishing wheel 302 includes a polishing surface 320. The polishing wheel guard 312 protects the operator and those around during the polishing process. The motor 314 and various other accessories are disposed above the polishing surface 320. The polishing bed 318 is disposed below the polishing surface 320. A second fixture 100' pre-loaded with the workpiece is disposed on a shelf 316 close to the polishing surface 320 and the robot 400.

[0040] Referring to FIGS. 8 - 10, various views of a method of performing polishing using a polishing system 300 according to another embodiment of the present disclosure are shown. The workpiece 200 is loaded within the collet 102 of the fixture 100. As shown in FIG. 9, a robot 400 coupled to the fixture 100 positions the fixture 100 such that the distal end 202 of the workpiece 200 contacts the polishing surface 320. A coolant is supplied across the width of the polishing surface 320 via a plurality of injection hoses 322 to reduce heat damage and remove abrasive debris from the workpiece. After polishing the first bevel surface of the distal end 202 of the workpiece 200, the robot 400 moves the fixture 100 away from the polishing surface 320 and rotates the workpiece by rotating the shaft 110 of the fixture 100, as described in more detail below. This process is repeated until the polishing of the workpiece is complete and the desired shape is achieved, depending on the type of the workpiece, i.e., trocar, diamond tip, etc. The robot 400 then disengages from the fixture 100 having the polished workpiece, picks up the fixture 100' pre - loaded with a new workpiece, and performs polishing on the new workpiece.

[0041] Referring to FIG. 11, an example of a robot 400 used together with the fixture 100 in the polishing system 300 is shown. The robot 400 includes a head 402 configured to be received within the recess 136 of the fixture 100. The fixture 138 and the dowel pin 122 are used to fix the robot 400 to the fixture 100 via the head 402. The head 402 can include an actuator configured to rotate about the axis A2 of the shaft 110. The robot 400 includes joints 404, 406, 408. Each of these joints is configured to rotate about its respective axis. The joint 404 rotates about the axis A3, generating a rotation R3. Similarly, as best shown in FIG. 11, the joints 406, 408 rotate about the axes A4, A5, respectively, generating rotations R4, R5. Further, the base 410 of the robot 400 attached to the polishing system 300 rotates about the axis A6, generating a rotation R6. Thus, in addition to the rotation of the shaft 110 about the shaft axis A2, the robot 400 positions the head 402 with various degrees of freedom provided by the joints, enabling a 360° arrangement of the fixture 100. It should be noted that for performing polishing, the fixture 100 of the present disclosure can be used together with a two-degree-of-freedom, three-degree-of-freedom, or four-degree-of-freedom robot.

[0042] FIG. 12 shows a schematic diagram of a machining system 500 using a fixture 100 and a robot 400 according to another embodiment of the present disclosure. Although the machining system 500 shows a fully automated needle manufacturing system, the machining systems disclosed herein may be used for machining any other product. The needle manufacturing system 500 is a fully automated or semi-automated needle manufacturing system, and all or most of the manufacturing steps are performed by operating a workpiece loaded in the fixture 100 by a robot. The needle manufacturing system 500 includes a pre-polishing operation 502, a polishing process 504, and a post-polishing operation 506. The workpiece 200 may be manually pre-loaded into the fixture 100 while the fixture 100 is connected to the robot 400, or the workpiece 200 may be manually pre-loaded into the fixture 100 while the fixture 100 is not connected to the robot 400, and then the fixture 100 may be connected to the robot 400. As another alternative, while the fixture 100 is attached to the robot 400, the robot 400 can automatically load the workpiece 200 into the fixture 100.

[0043] When the fixture 100 including the workpiece 200 is connected to the robot 400, the robot 400 can move the workpiece for various pre-polishing operations 502. Also, in any pre-polishing operation 502, the robot 400 can operate the workpiece by, for example, moving the fixture 100 to change its position and orientation and rotating the workpiece through the shaft 110. Examples of pre-polishing operations include, but are not limited to, operations of cutting the workpiece to a desired length by electrolysis or abrasive cutting, pre-polishing cleaning, pre-polishing testing, and the like. The robot 400 is configured to adjust the length of the workpiece passing through the collet 102 by opening the collet and pressing the workpiece against the back stopper to achieve the desired length.

[0044] As will be described in further detail below, after completing the pre-polishing operation 502, the robot 400 positions and operates the fixture 100 such that the workpiece 200 is disposed opposite the polishing surface and the distal end of the needle assumes a desired shape.

[0045] Once the needle has been polished to the desired shape, the robot 400 moves the fixture 100 for one or more post-polishing operations 504. Similar to the pre-polishing operation, the robot 400 can operate the workpiece in each of the post-polishing operations 504 by, for example, moving the fixture 100 to change its position and orientation, and rotating the workpiece via the shaft 110. Examples of post-polishing operations include, but are not limited to, grit blasting, inspection (and additional polishing to compensate for insufficient polishing if necessary), electropolishing, packaging, and the like.

[0046] With the machining system 500, an operator can control the operation of the system using a human-machine interface (HMI) such as the control panel 310 shown in FIG. 6. However, it is preferable that the HMI itself is configured to be able to program and reprogram the robot 400, rather than using another "teach box" or "teach pendant" connected to the control device for the robot. Further, due to the design of the fixture of the present disclosure enabling sufficient operability of the workpiece, i.e., all rotations and positions of the workpiece, the operator can easily program the robot 400 (e.g., via the HMI) to perform a number of different machining operations. As a result, the machining system of the present disclosure can provide a fully automated robotic machining process that can be easily programmed to manufacture various different components, such as various needle types for trocars or cannulas (e.g., via polishing and pre / post-polishing processes). In contrast, conventional automated machine tending processes utilize robots mainly to perform one or more specific operations (e.g., loading and unloading functions) in machining operations set to manufacture specific components, so a great deal of effort is required to design and implement different sequences of machining operations necessary to manufacture different components.

[0047] Referring to FIG. 13, a front perspective view of a fixture 600 according to another embodiment of the present disclosure is shown. The fixture 600 is similar to the fixture 100, and similar elements shall be denoted by similar numbers in the 600 series. For example, the fixture 600 includes a collet 602 for fixing the workpiece 200, a support structure 616 for minimizing or eliminating the deflection of the workpiece 200 during a machining process such as polishing, and one or more connectors 630 for providing at least one of control and power to the fixture. However, as best shown in FIG. 14, the shaft 610 and the motor 656 of the fixture 600 are oriented along the fixture 600 in a direction orthogonal to the orientation shown in FIG. 1. That is, the shaft 610 and the motor 656 are preferably oriented at a right angle to the direction defined between the robot head 402 and the end of the workpiece 200. As shown in FIG. 14, this orientation shortens the distance between the robot head 402 configured to be connected to the recess 636 of the fixture 600 (shown in FIG. 11) and the collet 602 holding the workpiece 200. As a result, the moment load applied to the robot 400 during a machining operation using the fixture 600 is reduced.

[0048] As shown in FIG. 13, the fixture 600 includes a coolant nozzle 613 individually disposed above the collet 602. The coolant nozzle 613 disposed directly above the workpiece provides improved cooling, and as a result, improves the machining operation. For example, the abrasive debris generated during polishing is removed, i.e., washed away, by an individual coolant supply directed to each workpiece by each nozzle 613. A fluid path is provided through the fixture 600 to easily connect a coolant source supplying coolant to the nozzle 613. Since the fluid path is disposed within the fixture 600, the coolant supply to the workpiece 200 can be suitably maintained and controlled through various machining operations.

[0049] Figures 15 - 17 show the actuator mechanism of the fixture 600. This actuator mechanism includes a main helical gear 609 that extends across the fixture 600. Each collet 602 has a collet helical gear 611 connected to the main helical gear 609, as best shown in FIGS. 16 and 17. As shown in FIG. 17, the rotation of the main helical gear 609 about the rotation axis A10 simultaneously rotates all the collet helical gears 611 about the axis A11. The rotation axis A10 is parallel or substantially parallel to the shaft 610. Thus, by rotating the main helical gear 609, all the workpieces 200 can be rotated simultaneously. A driven gear 615 disposed at one end of the main helical gear 609 is connected to a driving gear in the form of a shaft gear 613 via a belt, a chain, an intermediate gear, or a similar driving connector. The gears 609, 615 can be precision ground spur gears. These precision ground spur gears reduce backlash and accurately rotate the workpiece, while also providing continuous and non-interfering rotation of the workpiece. However, other types of gears (e.g., helical gears) may be used alternatively. The shaft gear 613 is controlled by the rotation of the shaft 610. Thus, the rotation of the shaft 610 controls the simultaneous rotation of each workpiece 200. As shown in FIG. 16, the pulley cover 607 houses the driven gear 615 and the shaft gear 613. The advantage of using the helical gear mechanism shown in FIGS. 16 - 17 instead of the rack and pinion mechanism shown in FIG. 3 is that the helical gear mechanism has no limit on the amount of rotation in any rotation direction of the collet 602. The helical gear mechanism is advantageous in that, in addition to the ease of programming the system for manufacturing various different components (as described above), it can be more flexible in accommodating the types of components to be manufactured. For example, since the amount of rotation is not limited in any rotation direction, the conical tip of the workpiece 200 can be easily polished.

[0050] Referring to FIG. 18, a fixture 700 having a tool changer 800 according to another embodiment of the present disclosure is shown. The fixture 700 is similar to the fixture 600, and similar elements shall be denoted by similar numbers in the 700s. For example, the fixture 700 includes a collet 702 for fixing the workpiece 200, a support structure 716 for minimizing or eliminating the deflection of the workpiece 200 during machining operations such as polishing, and one or more connectors 730 that provide at least one of control and power to the fixture 700. The tool changer 800 connected to the fixture 700 enables quick and easy connection to the robot 400.

[0051] The tool changer 800 includes a fixture attachment end 804 and a robot attachment portion 802, as best shown in FIGS. 19 and 20 respectively. The fixture attachment end 804 is attached to the bracket 604 of the fixture 600 (see FIG. 15). The robot attachment portion 802 includes a quick-change interface that can be easily attached to the robot. Various electrical connectors such as modules 806, 810 having male / female pin devices 808 are connected to the tool changer 800 to provide an electrical interface between the fixture 700 and the robot 400 via the tool changer 800. A number of through ports 812 in the tool changer 800 enable a fluid path between the fixture 700 and an external source via the tool changer 800. For example, a refrigerant container may be connected to the tool changer 800 to supply refrigerant to the workpiece 200 via the fixture 700 (e.g., via the refrigerant nozzle 713) during various machining operations. The robot 400 may be programmed to automatically select a desired fixture by being connected via an interface to a tool changer connected to the fixture.

[0052] Although trocar needles have been generally described as an example of needles in various embodiments of the present disclosure, the above embodiments are not limiting, and for example, can be used in any needle form such as back bevel tip needles, biased polished needles, diamond tip needles, Menghini needles, probe tip needles, razor blade needles, stylets, trifacet lancets, etc.

[0053] Furthermore, although the invention disclosed herein has been described with reference to specific features, it should be understood that these features are merely illustrative of the principles and applications of the invention. Accordingly, it should be understood that many modifications, including changes in the size of the various features described herein, can be made to the exemplary embodiments, and that other configurations can be devised without departing from the spirit and scope of the invention. In this regard, the invention includes many additional features in addition to the specific features described in the following paragraphs. Furthermore, the foregoing disclosure should be regarded as being made for purposes of illustration rather than limitation of the invention, since the invention is defined in the numbered paragraphs that describe the features set forth in the following claims according to various embodiments of the invention.

Claims

1. A fixture for holding a plurality of workpieces, comprising: a frame; a plurality of holders, each holder being configured to receive and fix one workpiece and being rotatably connected to the frame; an actuator operably connected to the plurality of holders for driving the rotation of the plurality of holders relative to the frame; a bracket for attaching the frame to a manipulator configured to move the fixture; and comprising: each of the holders is connected to a holder gear, the actuator comprises a shaft having a shaft gear, and the shaft gear is operably connected to the holder gear for driving the rotation of each holder relative to the frame; The shaft gear is operably connected to the holder gear by a first helical gear. A fixture.

2. The fixture according to claim 1, wherein each of the holders is a collet configured to removably fix the workpiece.

3. The fixture according to claim 1, wherein the shaft gear is operably connected to the holder gear by a linear actuator.

4. The fixture according to claim 3, wherein the linear actuator comprises a rack gear driven by a pinion composed of the shaft gear.

5. The fixture according to claim 1, wherein the actuator is composed of an electric motor for driving the rotation of the shaft.

6. The fixture according to claim 1, wherein the first helical gear is parallel to the shaft.

7. The fixture according to claim 6, wherein the first helical gear is operably connected to the shaft gear by a pulley drive.

8. The fixture according to claim 7, wherein the pulley drive comprises a continuous loop connecting the shaft gear to the first helical gear.

9. The fixture according to claim 1, further comprising a support structure disposed away from the holders for minimizing or eliminating deflection of the workpiece during a machining operation.

10. The fixture according to claim 1, wherein the manipulator is a robot. **Claim 11**: The fixture according to claim 10, wherein the robot comprises an arm having a distal end with a rotational actuator, and the fixture is configured to be coupled to the distal end of the arm such that the actuator of the fixture is operably coupled to the rotational actuator of the robot. **Claim 12**: A robot end effector for holding a plurality of workpieces, a plurality of holders, each holder being configured to receive and fix one workpiece and being coupled to a holder gear, a shaft having a shaft gear, the shaft being attached to the robot and configured to rotate the shaft and move and position the robot end effector relative to a grinding wheel, a first connecting gear coupled to the shaft gear, a second connecting gear coupled to the first connecting gear and the holder gear, comprising a robot end effector, wherein rotation of the shaft by the robot causes each of the plurality of workpieces to rotate simultaneously about its respective workpiece axis via each of the holder gears, the first connecting gear, and the second connecting gear. **Claim 13**: A grinding system, a grinding surface, an end effector comprising a frame having a plurality of holders, each holder being configured to receive and fix a workpiece, each holder being rotatably coupled to the frame, and an actuator being operably coupled to the plurality of holders to drive rotation of the plurality of holders relative to the frame, a robot coupled to the actuator of the end effector, the robot being configured to rotate the actuator and move and position the end effector relative to the grinding surface such that the workpiece contacts the grinding surface at a first position of the end effector and does not contact the grinding surface at a second position of the end effector for grinding the workpiece at the first position of the end effector, comprising a grinding system, wherein rotation of the actuator causes the plurality of workpieces to rotate simultaneously about their respective workpiece axes. **Claim 14**: The polishing system according to claim 13, wherein each of the holders is connected to a holder gear, the actuator includes a shaft having a shaft gear, and the shaft gear is operably connected to the holder gear to drive the rotation of each holder relative to the frame. **Claim 15**: The polishing system according to claim 14, wherein the shaft gear is connected to the holder gear via a connecting gear. **Claim 16**: The polishing system according to claim 15, wherein the shaft gear is connected to a first connecting gear and a second connecting gear, and the second connecting gear is connected to the holder gear. **Claim 17**: The polishing system according to claim 13, wherein the rotation of the actuator by the robot is performed to polish a portion that does not contact the polishing surface at the second position. **Claim 18**: The polishing system according to claim 13, wherein each of the holders is configured to receive and fix a trochlear needle. **Claim 19**: The polishing system according to claim 13, wherein the polishing system is an electrolytic polishing system. **Claim 20**: A method for polishing a workpiece, comprising: (i) loading the workpiece into an opening of the holder of an end effector having a plurality of holders, the opening defining a variable diameter configured to be expandable and contractible to receive and fix the workpiece, the holder being rotatably connected to a frame, and a shaft gear provided on a shaft that outputs rotation from an actuator being operably connected to a holder gear provided on the holder to drive the rotation of the holder relative to the frame; (ii) performing at least one of movement and rotation of the workpiece by the actuator to perform one or more auxiliary operations on the workpiece; (iii) performing at least one of movement and rotation of the workpiece by the actuator to polish the workpiece on a polishing surface. A method comprising the above steps. **Claim 21**: The method according to claim 20, wherein the auxiliary operation includes either a pre-polishing operation or a post-polishing operation. **Claim 22**: The method according to claim 21, wherein the pre-polishing operation includes either taking in a material or cutting the material.

23. The method according to claim 21, wherein the post-grinding operation includes any one of deburring, grit blasting, inspection, and electropolishing of the processed product.

24. The method according to claim 21, wherein the processed product is a trocar needle.

25. The method according to claim 21, wherein the actuator is a robot.

26. The method according to claim 25, further comprising the step of attaching the robot to the end effector.

27. The method according to claim 21, wherein the commands for performing the steps (i)-(iii) are transmitted via a human-machine interface.

Images