Torque thrust and surface sensing device

• US 4,944,643 A
• Filed: 05/08/1989
• Issued: 07/31/1990
• Est. Priority Date: 05/08/1989
• Status: Expired due to Fees

• Current Assignee: Robert A. Lehmkuhl
• Original Assignee: Robert A. Lehmkuhl
• Inventors: Lehmkuhl, Robert A.
• Primary Examiner(s): Bishop, Steven C.
• Application Number:
  US07/348,772
• Time in Patent Office: 449 Days
• Field of Search: 408/3, 408/6, 408/10, 408/11, 408/12, 408/13, 408/14, 409/80, 409/127, 409/187, 409/193, 409/194, 409/196, 409/218, 279/1 A, 279/1 ME, 33/556, 33/558, 33/559, 33/561
• US Class Current: 409/80
• CPC Class Codes: B23B 31/006 Conical shanks of tools
• CPC Class Codes: B23Q 11/04 Arrangements preventing overload of tools, e.g. restricting load
• CPC Class Codes: B23Q 17/0961 by measuring power, current or torque of a motor
• CPC Class Codes: Y10T 279/3418 for particular tool or workpiece
• CPC Class Codes: Y10T 408/08 with means to regulate operation by use of templet, tape, card, or other replaceable information supply
• CPC Class Codes: Y10T 408/14 Responsive to condition of Tool or tool-drive
• CPC Class Codes: Y10T 408/172 Responsive to Tool
• CPC Class Codes: Y10T 409/300896 with sensing of numerical information and regulation without mechanical connection between sensing means and regulated means [i.e., numerical control]
• CPC Class Codes: Y10T 409/306888 In response to cutter condition
• CPC Class Codes: Y10T 409/30728 In response to cutter condition

Abstract

A tooling device for numerically controlled machining centers having programmable torque, thrust and surface sensing utilizing a telescopic tool holder comprising an adapter to be retained in the taper of the machine spindle and a control rod in the spindle attached to an actuating rod having electronic coupling means to control the axis feed rate of the computer numerical control for controlling deceleration of the spindle and a transducer for producing a signal to feed the spindle to a programmable depth and to measure the tool thrust and torque and to sense the location of work surfaces with random length tools and also be able to control feed rate of tool proportional to tool thrust or torque.

Claims

1. A tooling device for computer numerically controlled machining centers having a spindle, a control rod passing through said spindle, a sliding element, said control rod connected to said sliding element, means connected to said sliding element to control position, a spring loaded telescoping tool holder, an actuating rod in said tool holder adapted to engage said control rod, said actuating rod displacing said control rod to displace said sliding element and electronic coupling means to the axis feed rate of the computer numerical control for controlling spindle deceleration from rapid traverse to zero traverse, a means for producing a signal to transmit work surface location to the computer numerical control to feed the spindle to a programmed depth at a programmed feed rate, said telescoping tool holder having a presetable spring loaded thrust unit arranged to permit further telescoping of said tool holder if tool cutting thrust exceeds preset amount further displacing said actuating rod, before programmed depth is reached signalling said computer numerical control that excessive thrust has been reached.

2. A programmable torque sensing device for computer numerically controlled machining center having a spindle, a control rod passing through said spindle, a sliding element, said control rod connected to said sliding element, an electronic coupling means to said computer numerical control connected to said sliding element to control the position and force of said sliding element, said torque sensing device mounted in said spindle comprising an adapter body, a bearing mounted spindle having a collet mounted in said adapter body, a torque transmitting coupling connecting said spindle to said adapter, a tool actuating rod connected to said torque transmitting coupling to engage said control rod, the amount of torque that can be transmitted by said torque transmitting coupling is a function of the programmed force on said sliding element, when a tool in said spindle collet requires a greater level of torque than determined by the programmed force, then said torque transmitting coupling will cause said tool actuating rod to force said control to displace said sliding element thereby signalling computer numerical control that excessive torque has been reached.

3. A presetable torque sensing device for computer numerically controlled machining centers having a spindle, a control rod passing through said spindle, a sliding element, said control rod connected to said sliding element, an electronic coupling means to said computer numerical control connected to said sliding element to control the position and force of said sliding element, said torque sensing device mounted in said spindle comprising an adapter body, a bearing supported spindle having a collet mounted in said adapter body, a torque transmitting coupling connecting said spindle to said adapter body, a tool actuating rod connected to said torque transmitting coupling adapted to engage said control rod, a settable pressure torque control spring whereby the amount of torque that can be transmitted by said torque transmitting coupling is a function of the pressure of the torque control spring, when a tool in said spindle collet requires a greater level of torque than determined by torque control spring pressure then said torque transmitting coupling, causing said actuating rod to force said control rod to displace said sliding element and thereby signalling said computer numerical control that excessive torque has been produced.

4. A presetable torque sensing and thrust sensing device for computer numerically controlled machining centers having a spindle, a control rod passing through said spindle, a sliding element, an electronic coupling means connected to said sliding element to control the position and force of said sliding element, a torque sensing and thrust sensing device mounted in said spindle comprising an adapter body, a bearing supported spindle having a tool collet, said bearing supported spindle mounted in a sleeve which sleeve is slideably mounted in said adapter body, a torque transmitting coupling connecting said spindle to said adapter body through said spindle sleeve, a tool actuating rod connected to said torque transmitting coupling to engage said control rod, a torque control spring, when a tool in said spindle collet required a greater level of torque then determined by the torque control spring pressure, said torque transmitting coupling will cause said actuating rod to force said control rod to displace said sliding element, thereby signalling said computer numerical control that excessive torque has been reached, and a presetable spring loaded thrust unit arranged to permit said sliding spindle sleeve to telescope into said adapter body when tool cutting thrust exceeds the preset amount thereby causing said actuating rod to force said control rod to displace said sliding element and means for signalling said computer numerical control that excessive thrust has been reached.

5. A presetable torque and surface sensing device for a computer numerically controlled machining center having a machine spindle, a control rod passing through said machine spindle, a sliding element, said control rod connected to said sliding element, electronic coupling means to said computer numerical control, connected to said sliding element to control the position and force of said sliding element, said torque sensing and surface sensing device mounted in said machine spindle comprising an adapter body, a bearing supported spindle having a tool collet mounted in a spindle sleeve which is spring loaded and slideably mounted in said adapter body, a torque transmitting coupling connecting said bearing supported spindle to said adapter body by said spindle sleeve, a tool actuating rod connected to said torque transmitting coupling adapted to engage said control rod, a torque control spring, whereby the amount of torque transmitted by said torque transmitting coupling is a function of the pressure torque control spring, when a tool in said collet requires a greater level of torque then determined by the torque control spring pressure, then said torque transmitting coupling will cause said actuating rod to move said sliding element thereby signalling said computer numerical control that excessive torque has been reached, when the tool in said collet contacts the work surface during the movement of the machine spindle the control rod, actuating rod and sliding element are moved, signalling numerical control for controlling machine spindle deceleration from rapid traverse to zero traverse as the spindle sleeve telescopes into said adapter body, producing a signal to transmit work surface location to the computer numerical control to feed the spindle to a programmed feed rate.

6. A presetable torque sensing, thrust sensing and surface sensing device for computer numerically controlled machining centers, a spindle, a machine head for carrying said spindle, a sliding element in said machine head, a support for said sliding element connected to said machine head, said control rod rotatably connected to said sliding element, an electronic coupling connected to said sliding element to control the position and force of said sliding element, said torque sensing, thrust sensing and surface sensing device mounted in said spindle, and comprising an adapter body, a bearing supported spindle having a tool collet and mounted in a spring loaded spindle sleeve slideably mounted to permit telescoping in said adapter body, a torque coupling connected to said bearing mounted spindle, a tool actuating rod connected to said torque coupling adapted to engage said control rod, a torque control springs when a tool in said spindle collet requires a greater level of torque determined by the torque control spring pressure, then said torque transmitting coupling will cause said actuating rod to force said control rod to displace said sliding element thereby signalling said computer numerical control that excessive torque has been reached, a presetable spring loaded thrust unit arranged to permit said sliding spindle sleeve to telescope into said adapter body, to cause said actuating rod to move, said sliding element to signal the numerical control excessive thrust has been reached, when the tool in said collet contacts the work surface during the movement of the machine spindle the control rod, actuating rod and sliding element are moved, signalling numerical control for controlling machine spindle deceleration from rapid traverse to zero traverse as the spindle sleeve telescopes into said adapter body, producing a signal to transmit work surface location to the computer numerical control to feed the spindle to a programmed feed rate.

7. A presentable torque sensing and thrust sensing device for computer numerically controlled machining centers having a spindle, a control rod passing through said spindle, a sliding element, a linear motor and transducer connected to said sliding element, a torque sensing and thrust sensing device mounted in said spindle comprising an adapter body, a bearing supported spindle having a tool collet, said bearing supported spindle mounted in a sleeve which sleeve is slideably mounted in said adapter body, a torque transmitting coupling compressing a spindle cam ring, actuating rod cam ring and cam balls connecting said spindle to said adapter body through said spindle sleeve, a tool actuating rod connected to said torque transmitting coupling to engage said control rod, a torque control spring, when a tool in said spindle collet requires a greater level of torque than determined by the torque control spring pressure, said torque transmitting coupling will cause said actuating rod to force said control rod to displace said sliding element and said transducer, a presetable spring loaded thrust unit arranged to permit said sliding spindle sleeve to telescope into said adapter body when tool cutting thrust exceeds the preset amount thereby causing said actuating rod to force said control rod to displace said sliding element and said transducer signalling said computer numerical control that the preset torque or preset thrust has been reached allowing computer numerical control to monitor the amount of spring deflection which determines actual torque or thrust and to control feed rate and machining cycle durations.

8. A telescoping tool adapted for computer numerically controlled machining centers having a spindle, a control rod passing through said spindle, a sliding element, said control rod passing through said spindle, said control rod connected to said sliding element, a linear motor and transducer connected to said sliding element to control the position and force of said sliding element, a spring loaded telescoping tool holder, an actuating rod in said tool holder adapted to engage said control rod, said actuating rod displacing said control rod to displace said sliding element to displace said transducer, said transducer having electronic coupling means to the axis feed rate of the computer numerical control for controlling spindle deceleration from rapid traverse to zero traverse, said transducer producing a signal to transmit work surface location to the computer numerical control to feed the spindle to a programmed depth at a programmed feed rate, said telescoping tool adapter having a presetable spring loaded thrust unit comprising a spring guide body, a thrust nut, a spring, inner thrust collar, outer thrust collar, and snap ring arranged to permit further telescoping of said tool holder if tool cutting thrust exceeds preset amount further displacing said actuating rod, and said transducer before programmed depth is reached signalling said computer numerical control that preset thrust has been reached allowing computer numerical control to monitor amount of spring deflection which determines actual thrust load and to control feed rate or machining cycle duration.

9. A programmable torque sensing device for computer numerically controlled machining centers having a spindle, a control rod passing through said spindle, a sliding element, said control rod connected to said sliding element, a linear motor and transducer having electronic coupling means to said computer numerical control connected to said sliding element, to control the position and force of said sliding element, said torque sensing device mounted in said spindle comprising an adapter body, a bearing mounted spindle having a collet mounted in said adapter body, a torque transmitting coupling comprising a spindle cam ring, actuating rod cam ring and cam balls, connecting said spindle to said adapter, a tool actuating rod connected to said torque transmitting coupling to engage said control rod, whereby the position of said sliding element is set to zero and positioning loop is closed when said spindle control rod is engaged with said tool actuating rod at that the amount of torque being transmitted by the torque coupling during a machining cycle is being monitored by the computer numerical control by means of the level of current necessary to maintain zero set position as the cutting load changes.

10. A presetable torque sensing device for computer numerically controlled machining centers having a spindle, a control rod passing through said spindle, a sliding element, said control rod connected to said sliding element, a linear motor and transducer having electronic coupling means to said computer numerical control connected to said sliding element to control the position and force of said sliding element, said torque sensing device mounted in said spindle comprising an adapter body, a bearing supported spindle having a collet mounted in said adapter body, a torque transmitting coupling comprising a spindle cam ring, actuating rod cam ring and cam balls, connecting said spindle to said adapter body, a tool actuating rod connected to said torque transmitting coupling adapted to engage said control rod, a settable pressure torque control spring whereby the amount of torque that can be transmitted by said torque transmitting coupling is a function of the pressure of the torque control spring when a tool in said spindle collet requires a greater level of torque than determined by torque control spring pressure than said torque transmitting coupling, causing said actuating rod to force said control rod to displace said sliding element and said transducer thereby signalling said computer numerical control when the preset torque has been reached allowing computer numerical control to monitor the amount of deflection of said spring which determines actual torque and to control feed rate and machining cycle duration.

11. A presetable torque and surface sensing device for a computer numerically controlled machining center having a machine spindle, a control rod passing through said machine spindle, a sliding element, a linear motor and transducer having electronic coupling means to said computer numerical control, connected to said sliding element to control the position and force of said sliding element, said torque sensing and surface sensing device mounted in said machine spindle comprising an adapter body, a bearing supported spindle having a tool collet, mounted in a spindle sleeve which is spring loaded by a spring and slideably mounted in said adapter body, a torque transmitting coupling comprising a spindle cam ring, an actuating rod cam ring and cam balls, connecting said bearing supported spindle to said adapter body by said spindle sleeve, a tool actuating rod connected to said torque transmitting coupling adapted to engage said control rod, a torque control spring, whereby the amount of torque transmitted by said torque transmitting coupling is a function of the torque control spring pressure when the tool in said collet contacts the work surface during the movement of the machine spindle, said transducer, control rod, actuating rod and sliding element are displaced signalling numerical control for controlling machine spindle deceleration from rapid traverse to zero traverse as the spindle sleeve telescopes into said adapter body, said transducer producing a signal to transmit work surface location to the computer numerical control to feed the spindle to a programmed depth when preset torque has been reached, torque transmitting coupling will deflect said torque control spring causing said actuating rod to move said sliding element and said transducer thereby signaling said computer numerical control that preset torque has been reached allowing said computer numerical control to monitor amount of spring deflection which determines actual torque and to control the feed rate and machining cycle duration.

12. A presetable torque sensing, thrust sensing and surface sensing device for a computer numerically controlled machining center having a machine spindle, a control rod passing through said machine spindle, a sliding element, said control rod connected to said sliding element, a linear motor and transducer having electronic coupling means to said computer numerical control, said motor and transducer connected to to said sliding element to control the position and force of said sliding element, said torque sensing, thrust sensing and surface sensing device mounted in said machine spindle comprising an adapter body, a bearing supported spindle, a spindle sleeve in which said spindle is mounted, a tool collet mounted in said spindle, said spindle sleeve spring loaded and slideably mounted in said adapter body, a torque transmitting coupling comprising a spindle cam ring, an actuating rod cam ring and cam balls, connecting said bearing supported spindle to said adapter body by said spindle sleeve, a tool actuating rod connected to said torque transmitting coupling adapted to engage said control rod, a torque control spring, whereby the amount of torque transmitted by said torque transmitting coupling is a function of the torque control spring pressure, a presetable spring load thrust unit comprising a thrust spring body, a sliding thrust collar, a calibrated thrust spring, a fitting collar and snap ring, arranged to permit said sliding spindle sleeve to telescope into said adapter body, the amount of thrust transmitted is a function of said thrust control spring, when the tool in said collet contacts the work surface during the movement of the machine spindle, the transducer, control rod, actuating rod and sliding element are displaced signalling computer numerical control to control axis feed rate for controlling machine spindle deceleration from rapid traverse to zero traverse as said spindle sleeve telescopes into said adapter body until said spindle load thrust unit is seated in said adapter body, said transducer, producing a signal to transmit work surface location to the computer numerical control to feed the spindle to programmed depths, when either preset torque or thrust is exceeded, either said torque control spring or said thrust control spring will deflect causing said tool actuating rod to move said sliding element and said transducer, thereby signalling said computer numerical control to monitor the amount of spring deflection which determines actual torque or actual thrust and to correct feed rate and machining cycle duration.