GB833989A - Improvements in burnishing machines - Google Patents

Abstract

833,989. Sizing bores of tubes. WEATHERLEY OILGEAR Ltd. Aug. 24, 1956 [Aug. 31, 1955], No. 25038/55. Class 83 (4). A machine for burnishing the bores of metal tubes 15 comprises a tube-holding fixture 2 and a reciprocating slide 1 which on each stroke forces a burnishing tool 6 through a tube. The tubes are fed in threes through holes 3a, Fig. 2, in a fixed upper plate 4 and into aligned bores 3 in the fixture which is rotatable stepwise. The fixture is adjustable by a hand wheel 21 for accommodating different lengths of tubes. Three parallel burnishing tools 6 are retained in bores in upper or lower stationary plates 4, 5 by spring detents 18. On the downstroke of the slide 1, which is actuated by an hydraulic motor fed by a variable speed pump, a double cam 9 on the slide first actuates a rack 8, meshing with a pinion 7 which, through a ratchet mechanism, indexes the fixture 2 through 90 degrees, thus bringing three unburnished tubes into alignment with the tools 6. Three push-rods 16 then engage the tools and press them through the bores and into the lower plate 5 and a cam 11 then withdraws the rack 8. On the upstroke the double cam 9 first indexes the fixture to bring three further tubes into alignment with the tools 6 which are pressed upwardly through the tubes by push-rods 17. A cam 12 subsequently withdraws the rack. The fixture is locked in the burnishing position by a plunger actuated through a push-rod 23 by cams 24 on the slide. A safety device is connected to the machine operating lever 22 for preventing operation if the tubes project above the fixture 2. Subsequently the burnished tubes fall by gravity down a discharge shoot 25. The tubes are for use as cylinders of shock absorbers.