| 摘要 |
1424477 Toothed gearing BERTIN & CIE 27 Feb 1973 [3 March 1972 21 Sept 1972] 9573/73 Heading F2Q A rack comprises teeth 4 mounted on a rigid base 11 by means of an intermediate resilient element 3 comprising a band or strip of natural or synthetic rubber. The teeth 4 may be integral with one another, as shown in the left-hand part of Fig. 6, or the teeth 4 can be separated from one another by small gaps 31. A toothed pinion 2 comprises a resilient ring 5 interposed between a hub 7 and a tooth-bearing rim 10. In a modification, shown in Fig. 7, a rack comprises a resilient element 3 of substantially constant thickness which covers a toothed blank 36 and is adopted to contact a pinion 2 which preferably is made of nylon. Fig. 8, shows a modification in which the thickness of a resilient element 3 varies and is a minimum value in the region N of the pitch circle. In another modification, rack teeth are formed by a metal sheet 44, Fig. 9, secured to a base 40 and covered by a resilient element 3 to which a protective covering 45 of hard rubber or plastics material is applied. The gaps between the members 40 and 44 are filled with a substance 28 such as sand, concrete, fibres or polyurethane, Fig. 10 shows an embodiment in which a resilient element 3 fills the space between sheet members 50 and 55. The rack teeth may be coated with a substance having a low coefficient of friction such as molybdenum disulphide or polyethylene. |
