GB489326A - Improvements in crank shafts built up from hollow metal parts - Google Patents

Abstract

489,326. Making crank shafts. HIRTH, H. Nov. 30, 1937, No. 32993. Convention date, Nov. 30, 1936. [Classes 83 (ii) and 83 (iv)] [Also in Group XXIV] Uniting by fusion.-Crank shafts are formed by assembling hollow sheet metal members or thin drop forgings, the hollow crank pins or shaft elements 2, 1, Fig. 1, extending through the hollow crank webs 4, 4, and being secured by welds 5, 6, 8, 9 to both walls of each web. The tubular members 1, 2 are formed by bending up and welding sheet metal strips or from drawn steel tubing. Corrugations 3 engage recesses in the webs which comprise dished members 4 secured by welds 7. A crank shaft which may be dismantled and re-assembled comprises pins 11, 12, Fig. 3, having on their end faces teeth which engage similar teeth on the portions 10 which extend through and are welded to the webs 4, 4. The parts are held in engagement by members 13 having differential screw-threads at their ends. The portions 10 may have corrugations only on their inner ends, their outer ends being of reduced diameter or of conical form, Fig. 5. In a further modification, Fig. 1, corrugations are not employed, but the teeth on the member 10 engaging those on the pin 12 are continued into the annular flange on the web 4 and the weld 5. Specification 160,751, [Class 80 (ii)], is referred to. The Specification as open to inspection under Sect. 91 states that the portions 10 may be made from solid bars. Further, the parts may be connected together by flanging the rims one upon the other over the whole or part of their periphery or by means of interengaging toothed connections or by tongue-and-slot connections, instead of by welding. The crank shafts are stated to be used for high-speed multi-cylinder light engines. This subject-matter does not appear in the Specification as accepted.