Impact pinner apparatus

Claim 1

Machine apparatus for pinning plural metallic pins to a cured substrate of ceramic particles, said pins being located in respective pre-formed openings of said substrate prior to being pinned thereto, said apparatus comprising: tube-like chamber means, piston means slidably operable in said chamber means in first and second opposite direction, a magnetizable member affixed to said piston means, pneumatic first means for driving said piston means in said first direction within said chamber means and away from a predetermined first position, said piston means simultaneously impacting said plural pins at a predetermined second position when being driven in said first direction, pneumatic second means for returning said piston means in said second direction within said chamber means away from said second position and to said first position, selective valve means for selectively interconnecting said first and second pneumatic member means to said chamber means, air bearing means for laterally supporting said piston means relative to said chamber means at least during the movement of said piston means within said chamber means between said first and second positions, said piston means impacting said pins with a predetermined impact force that places said pins in a temporary viscoelastic fluid state causing each of said pins to flow between said particles of said substrate in the region surrounding the particular hole in which each said pin is located, said fluid flow forming an integral extension in each of said pins in interlocking engaged relationship with the ceramic particles of said substrate region surrounding the particular hole in which each said pin is located upon return of each said pin and said fluid flow to its undisturbed solid state, and delay means for delaying release of said piston means from said first position to said second position until said air pressure from said pneumatic first means becomes stabilized in said chamber means and in said air bearing means, said delay means further comprising: a permanent magnet maintaining said piston means in said first position by a magnetic force of attraction of said magnetizable member thereto, and release means for interrupting said magnetic force of attraction when said air pressure from said pneumatic first means becomes stabilized in said chamber means.