| 摘要 |
556,869. Drilling-machines. SOC. GENEVOISE D'INSTRUMENTS DE PHYSIQUE. May 12, 1942, No. 6436. Convention date, June 18, 1941. [Class 83 (iii)] [Also in Group XXIV] Consists in means for eliminating the effects of temperature variations on the position of a tool, optical instrument or the like used in precision machines and instruments. An upright 4 of a machine tool carries a casting 20 in which is accurately and slidably fitted a housing 11a to one end of which is bolted a tool-holder head 12, the other end carrying an electric motor 13 driving the tool through transmission 14, 16, 17, 18. The head 12 is connected to the casting 20 by one or more links 19 of non-expansible metal, e.g. an iron alloy with 36 per cent nickel. Thus the axes 1, 2 are maintained at a constant distance apart despite movements of the housing 11a. In a modification, Fig. 3, the links 19 are connected by pins 27 to the housing 11 a, fit accurately in bores in the housing and extend somewhat beyond the end 29 thereof to be secured to the toolholder head 12. |
