| 摘要 |
665,190. Piezo-electric crystals. BRUSH DEVELOPMENT CO. Oct. 22, 1947 [June 2, 1944[, No. 19865/50. Divided out of 665,100 under which a Specification was laid open to inspection under Sect. 91 of the Acts, May 31, 1948. Drawings to Specification. Class 40 (viii). A piezo-electric instrument is made by connecting a plurality of crystal elements to a flatbase such that in operation they expand in a direction normal to the base, working the free ends of the crystals until all are in a single plane parallel to the base and then enclosing the crystals in a housing having a vibration-transmitting portion. The constructional features of the instrument described are described in Specification 600,853, [Group XL (c)]. Specification 665,189 also is referred to. |
