| 摘要 |
1513431 Mechanical switches WALTER PREH GmbH 2 May 1975 [7 May 1974] 18578/75 Heading H1N In an electric switch assembly two printed circuits 18, 22 Fig. 6 gave an intermediate insulating layer 20 and are interconnected at apertures 21 in the layer 20 by mechanical switching connections to both circuits simultaneously. The upper printed circuit 22 is covered by a further insulating layer 23 with apertures 24 providing access to the switch contact point locations 19 only. Mechanical switching is provided by contact tongues 27 Fig 4 of a contact plate 28 separated from the printed assembly by an insulating layer 25 having apertures 26 over which the tongues 27 extend to positions above the contact locations 19 The assembly is covered by a protective film 29 and push buttons 5 Fig. 8 having a pair of projections 30 at diagonally opposite corners are arranged to operate selected pairs of tongues 27. The switch assembly may be used in an ultrasonic control device for a television receiver. |
