Apparatus and method for testing an edge of a workpiece for sharpness

Abstract

An apparatus for testing an edge of a workpiece for sharpness includes a body, a probe extending outwardly and pivotably mounted from the body, the probe is biased in a direction for placement against an edge of a workpiece with a predetermined force, a test head on a distal end of the probe for mounting test tape for physical contact with an edge as a test medium, a test point for mounting to the workpiece, and a continuity circuit mounted to the body in electrical communication with the test head and the test point for providing a predetermined electrical current between the test head and the test point through the workpiece when the test tape is cut sufficiently by the workpiece to allow the test head to touch the workpiece to form a complete circuit.

What is claimed is:  
     
       1. An apparatus for testing an edge of a workpiece for sharpness comprising:
 a body;  
 a probe extending outwardly from the body and pivotably mounted thereto, the probe being biased by biasing means in a direction for placement against an edge of a workpiece with a predetermined force;  
 a test head disposed on a distal end of the probe for mounting test tape for physical contact with an edge as a test medium;  
 a test point for mounting to the workpiece; and  
 a continuity circuit mounted to the body in electrical communication with the test head and the test point for providing a predetermined electrical current between the test head and the test point through the workpiece when the test tape is cut sufficiently by the workpiece to allow the test head to touch the workpiece to form a complete circuit and thereby use electrical continuity as an indication of an excess of edge sharpness.  
 
     
     
       2. An apparatus for testing an edge of a workpiece for sharpness according to  claim 1  and further comprising a continuity indicator to provide an indication that electrical continuity has been achieved during a test, thereby indicating excess edge sharpness. 
     
     
       3. An apparatus for testing an edge of a workpiece for sharpness according to  claim 1  wherein the continuity circuit is configured such that a current of 5 mA is considered continuity for the purposes of an indication of excess sharpness of the edge. 
     
     
       4. An apparatus for testing an edge of a workpiece for sharpness according to  claim 2  wherein the continuity circuit is configured such that a continuous current of 5 mA activates the indicator for the purposes of an indication of excess sharpness of the edge. 
     
     
       5. An apparatus for testing an edge of a workpiece for sharpness according to  claim 1  and further comprising a continuity indicator to provide an indication that electrical continuity has been achieved during a test, thereby indicating excess edge sharpness, the indicator remaining active until reset and a reset switch disposed in the continuity circuit for interrupting current flow within the continuity circuit including current to the indicator and maintaining such interruption until continuity is achieved during a sharpness test, thereby preparing the continuity circuit for testing. 
     
     
       6. An apparatus for testing an edge of a workpiece for sharpness according to  claim 5  and further comprising a continuity indicator to provide an indication that electrical continuity has been achieved during a test, thereby indicating excess edge sharpness, the indicator remaining active until reset and a reset switch disposed in the continuity circuit for interrupting current flow within the continuity circuit including current to the indicator and maintaining such interruption until continuity is achieved during a sharpness test, thereby preparing the continuity circuit for testing; and a second indicator providing an indication that the continuity circuit has been reset and is ready for use in testing an edge of a workpiece for sharpness. 
     
     
       7. An apparatus for testing an edge of a workpiece for sharpness according to  claim 1  wherein the continuity circuit includes a main power switch for electrically disabling the apparatus when not being used for testing an edge of a workpiece for sharpness. 
     
     
       8. An apparatus for testing an edge of a workpiece for sharpness according to  claim 1  wherein the probe is electrically conductive and in electrical communication with both the test head and the continuity circuit. 
     
     
       9. An apparatus for testing an edge of a workpiece for sharpness according to  claim 1  wherein the test head is wired to the continuity circuit. 
     
     
       10. A method for testing an edge of a workpiece for sharpness comprising the steps of:
 providing an apparatus for testing the edge of a workpiece for sharpness including: 
 a body;  
 a probe extending outwardly from the body and pivotably mounted thereto, the probe being biased by biasing means in a direction for placement against an edge of a workpiece with a predetermined force;  
 a test head disposed on a distal end of the probe for mounting test tape for physical contact with an edge as a test medium;  
 a test point for connecting to the workpiece; and  
 a continuity circuit mounted to the body in electrical communication with the test head and the test point for providing a predetermined electrical current between the test head and the test point through the workpiece when the test tape is cut sufficiently by the workpiece to allow the test head to touch the workpiece to form a complete circuit and thereby use electrical continuity as an indication of an excess edge sharpness;  
 
 applying a plurality of tape members in a layered configuration on the test head in a predetermined manner;  
 connecting the test point to the workpiece;  
 applying the tape members on the test head to the edge to be tested in by applying a predetermined force using the body, the probe and the biasing means and drawing a stroke of predetermined length across the edge under test;  
 inspecting the apparatus for an indication that continuity had been achieved wherein the tape was cut by the edge under test sufficiently to make electrical contact between the test head and the workpiece, thereby allowing electrical communication between the test head and the test point via the continuity circuit and the workpiece, and thereby indicating to the user that the edge tested had excess sharpness.  
 
     
     
       11. A method for testing an edge of a workpiece for sharpness according to  claim 10  wherein the step of providing an apparatus includes providing such an apparatus with a continuity indicator to provide an indication that electrical continuity has been achieved during a test, thereby indicating excess edge sharpness; and the step of inspecting the apparatus includes inspecting the indicator. 
     
     
       12. A method for testing an edge of a workpiece for sharpness according to  claim 10  wherein the step of providing an apparatus includes providing a continuity indicator to provide an indication that electrical continuity has been achieved during a test, thereby indicating excess sharpness, the indicator remaining active until reset and a reset switch disposed in the continuity circuit for interrupting current flow to the continuity circuit including current to the indicator and maintaining such interruption until continuity is achieved during a sharpness test, thereby preparing the continuity circuit for testing and; the step of inspecting the apparatus includes inspecting the indicator and resetting the continuity circuit using the reset switch in preparation for further use. 
     
     
       13. A method for testing an edge of a workpiece for sharpness according to  claim 10  wherein the step of providing an apparatus includes providing a continuity indicator to provide an indication that electrical continuity has been achieved during a test, thereby indicating excess edge sharpness the indicator remaining active until reset, a reset switch disposed in the continuity circuit for interrupting current flow to the to the continuity circuit including current to the indicator and maintaining such interruption until continuity is achieved during a sharpness test, thereby preparing the continuity circuit for testing, and a second indicator providing an indication that the continuity circuit has been reset and is ready for use in testing an edge of a workpiece for sharpness; and the step of inspecting the apparatus includes inspecting the indicator and resetting the continuity circuit using the reset switch in preparation for further use; and wherein the method further comprises the step of inspecting the second indicator for an indication that the continuity circuit has been reset and is ready for use in testing an edge of a workpiece for sharpness. 
     
     
       14. A method for testing an edge of a workpiece for sharpness according to  claim 10  wherein the step of providing an apparatus includes providing such an apparatus with an electrically conductive probe in electrical communication with both the continuity circuit and the test head. 
     
     
       15. A method for testing an edge of a workpiece for sharpness according to  claim 10  wherein the step of providing an apparatus includes providing such an apparatus with a test head wired to the continuity circuit. 
     
     
       16. An apparatus for testing an edge of a workpiece for sharpness, the apparatus comprising:
 a carrier;  
 a trip component mounted on the carrier, the trip component being deployable against an edge of a workpiece and the trip component being disposable between a trip condition that occurs when the trip component is deployed against an edge of a workpiece, the edge of the workpiece has a predetermined sharpness characteristic, and the predetermined sharpness characteristic of the edge of the workpiece effects a change in the trip component and a non-trip condition that occurs when the trip component is not deployed for testing against an edge of a workpiece and the edge of the workpiece has a predetermined sharpness characteristic; and  
 a signal generating element, the signal generating element being operatively connected to the trip component, the signal generating element providing an electrical current that, when the trip component is in its trip condition, flows through the signal generating component and the trip component in a complete electrical circuit and the signal generating element operating to generate a signal in response to the flow of electrical current therethrough in a complete electrical circuit.  
 
     
     
       17. An apparatus for testing an edge of a workpiece for sharpness according to  claim 16 , wherein, during a test of an edge of a workpiece, the trip component is in electrical communication with the signal generating element and the signal generating element is in electrical communication with the workpiece such that a complete circuit is formed through the trip component, the signal generating element, and the workpiece when the trip component is in its trip condition. 
     
     
       18. An apparatus for testing an edge of a workpiece for sharpness according to  claim 17 , wherein the trip component includes an electrically conductive test head for supporting a test tape for physical contact with an edge of a workpiece as a test medium. 
     
     
       19. An apparatus for testing an edge of a workpiece for sharpness according to  claim 10  and further comprising an indicator light operative responsive to a signal generated by the signal generating element. 
     
     
       20. An apparatus for testing an edge of a workpiece for sharpness according to  claim 10  and further comprising a reset switch in electrical communication with the indicator light, signal generating element and the trip component operable to effect a change in the trip component from a trip condition to a non-trip condition after the trip component has been used for testing against an edge of a workpiece, and to effect a change in the signal generating element from a signal generating condition to a non-signal generating condition after the signal generating element has been used during an edge sharpness test.