GB1049505A - Improvements in or relating to mounting assemblies for electrical apparatus - Google Patents

Abstract

1,049,505. Circuit assemblies. DEVRY TECHNICAL INSTITUTE Inc. Feb. 26, 1964, No. 8033/64. Heading H1R. [Also in Division H2] In a circuit assembly, components are mounted on and interconnected by contact units secured to a chassis. The invention is described with reference to a photo-cell switching circuit, Fig. 4 (not shown). Contact units. Figs. 2, 3 (not shown).-Each contact unit comprises a hollow rectangular block 14 of resilient plastics material, e.g. polyethylene, having cylindrical pegs 46 protruding from its base 22 to engage perforations in a pegboard chassis 10. The interior cavity of the block accommodates a resilient contact member 12, e.g. of copper-coated spring steel, comprising a base 28 and straight portions 30, 38, 40, 42. The base 28 is continuous, but the other portions are divided along their lengths into a plurality of spring contacts adapted to receive conductive members inserted through registering apertures 26 in the top 24 of the block 14. Modifications. The pegs 46 may be replaced by pointed metal pins for insertion in a fibreboard chassis, Figs. 11, 12 (not shown), or by a bar magnet, located in a recess in base 28, to enable the unit to be held on a ferromagnetic, e.g. sheet steel, chassis, Figs. 13, 14 (not shown). The plastics block may be made in two identical halves, Fig. 9 (not shown), each comprising semi-cylindrical half-pegs 136, mutually complementary apertures 152, 156, and flanged protrusions 154, 158, also a circular hole 162 and a cylindrical peg 160. Transverse apertures 178A . . . 178D and end recesses 180 are dimensioned to receive the pegs of further contact units. Adapter boards.-To enable components such as a transistor 56 to be mounted on a plurality of contact units 52A, 52G, the transistor is placed on a thin insulating adapter board 94; the transistor terminals 90 pass through apertures 92 in the board to contact conductive strips 98 which make connection with pins 96 adapted to plug into the apertures 26 in the contact units. Circuit assembly, Fig. 1.-Contact units 52A . . . 52L are mounted as shown on a pegboard chassis 10, and transistors 54, 56, relay 62, and photo-cell 78 are mounted between relevant contact units via adapter boards 57, 57A, 57B. Resistors 84, 86, 87, lamp 68, and diode 80 are mounted on contact units by their leads. Necessary interconnections between contact units are effected by conductors 100A . . . 100E and 100G. Preferably the chassis is covered with an electrostatic screen 102 e.g. of silver or copper, which is earthed via a clip 104 and conductor 100H to the negative pole of battery 66. A circuit diagram 122 may be placed over the screen 102 to facilitate assembly; if the chassis is transparent the diagram 122 may be located underneath the chassis and a metal plate may both hold the diagram in position and form a screen. Modification, Fig. 6 (not shown). A threedimensional chassis is formed from pegboards 182A . . . 182F, each having on opposite sides complementary dovetail protrusions 190 and recesses 184 to enable boards to be joined in a plane, as 182A and 182E. Boards 182B, 182C, 182D and 182F are disposed normal to boards 182A and 182E, being held in position by rods 200A, 200B, 200D, 200E, 200F, placed parallel to the latter boards, and passing through transverse apertures in contact units 130A, 130B &c. Further rods normal to boards 182A and 182E may engage perforations in the latter boards and apertures on contact units mounted on boards 182B, 182C, 182D, 182F. Reference has been directed by the Comptroller to Specification 963,190.