Patent ID: 6516510
Filing Date: 2003-02-11
Classification: B21J,F16B,Y10T

Abstract:
A tool for securing a plurality of workpieces with a multi-piece swage type fastener which includes a pin adapted to extend through aligned openings in the workpieces and a tubular collar adapted to be located on the pin and swaged into locking grooves on the pin with the pin having a pull portion with helical pull grooves, said tool comprising:a swage section, a rotary drive section and a sensor section operatively connected together, said swage section including a rotary nut member threadable onto the pull portion of the pin and being rotatably supported from a substantially fixed axial position, said swage section further including an annular swage anvil having a swage cavity with an inner diameter less than the outer diameter of the collar, said rotary nut member located radially inwardly in said swage cavity of said swage anvil and adapted to rotate relative to said swage anvil and with said swage anvil being supported for axial movement relative to said nut member in said fixed axial position, said rotary drive section including rotary means operable for rotating said nut member for threaded engagement onto and disengagement from the pull portion of the pin, said swage section including annular fluid piston-cylinder means comprising a fluid cylinder having a central axis and a piston supported in said cylinder for axially reciprocating movement along said central axis in response to fluid pressure in said cylinder for applying a relative axial force between said swage anvil and said nut member and for applying such axial force of a first magnitude after said nut member has been threaded to a first predetermined position onto the pull portion of the pin whereby said swage anvil is moved axially forwardly and outwardly relative to said nut member to radially overengage the collar to swage the collar into the locking grooves on the pin, said sensor section including first sensor means operatively connected with said nut member for detecting the amount of threaded engagement of said nut member with the pull portion of the pin and second sensor means detecting the completion of swage of the collar, control means operatively connected with said rotary means and responsive to a signal from said first sensor means indicating the location of said nut member at said first predetermined position on the pull portion of the pin for halting rotary motion of said nut member by said rotary means and actuating the application of fluid swage pressure to said piston for applying the axial force of said first magnitude for swaging, said control means responsive to a signal from said second sensor means for actuating the application of ejection pressure to said piston for ejecting said swage anvil from the collar after swage, said piston including a piston head slidably supported in said cylinder and a piston rod extending axially forwardly from the outer end of said piston head and having an end section connected to said swage anvil for axially reciprocating movement of said swage anvil forwardly for swage and rearwardly for ejection whereby the overall axial length of said cylinder and hence overall effective length of said swage section can be minimized for use of the tool in limited clearance applications, fluid pressure means connected to said cylinder and responsive to said control means for applying the swage pressure into said cylinder on the inner end of said piston head and the ejection pressure to said cylinder on the outer end of said piston head with said piston rod and with said piston head thereby providing a larger effective pressure responsive area to achieve the magnitude of relative axial force required for swage which is substantially greater than the relative axial force required for ejection after swage by fluid pressure applied to said cylinder at the outer or piston rod end of said piston head whereby the diameter of said piston head and hence effective diameter of said cylinder can be minimized for use of the tool in limited clearance applications.