| 摘要 |
1,128,236. Dentists instrument trays. W. A. McMASTER. 30 March, 1967 [30 March, 1966], No. 14110/66. Addition to 919,673. Heading A4H. [Also in Division A5] The cantilever shelf 3 of the dental unit of the parent Specification 919,673 or the cantilever shelf 3 and the part of the dental unit to which it is attached is movable vertically. The movement may be effected by a fluid ram 44 or by a reversible electric motor (48, 57, 69) driving a threaded rod (49, 56, 68) or by an expansible air bag. The electric motor is controlled by trip switches (53, 54) and the fluid ram by limit valves. |
