Patent GB-464488-A (GB)
Title: Improvements in electrical switchgear
IPC: H02B1/00
Filed: 1935-10-23
Abstract: 464,488. Switchgear structures; heavy-current switches. WHITEHEAD, G. E., and WHITEHEAD'S ELECTRICAL INVENTIONS, Ltd. Oct. 23, 1935, No. 29303. [Class 38 (v)] Covers ; contacts.-A switchgear unit comprises a longitudinal framework divided into three compartments, an end one of which contains busbars and circuit-breaker terminals connected therewith, the remote compartment containing breaker terminals which may be connected such as with cable ends, whilst the middle compartment contains pairs of aligned fixed breaker contacts and moving bridge contacts carried by a spider or rotor which is rotatable on a longitudinal axis. The vertical framework shown comprises four angle members as 1, secured to rectangular end members, as 3, which may be die castings. The framework is divided by barriers 8, 9 into compartments 5 .. 7 and is normally closed by sheet iron or, where it forms one of a number, asbestos board may close the sides of compartments 6, 7. Barriers 8, 9 carry shrouded terminals 10, 11 connected respectively with a cable end and busbars 12. Current transformers and fuses may be housed in compartment 7. The operating handle 15 is adapted to rotate the operating shaft 16 through 60‹, and the shaft 16 carries a spider 22 on which are insulatingly mounted by means of clamps 24 a set of vertical bars 25, the upper ends of which engage jaw contacts 18 clamped at 20 to terminals 10. Similar jaw contacts 19 are carried on terminals 11, with which co-operate the lower ends of bars 27 insulatingly clamped at 29 to the lower, isolating, spider 23 loose on the shaft 16. The upper ends of bars 27 carry jaw contacts 21, which are similar to 18, 19 and with which the lower ends of bars 25 co-operate, the arrangement being that, after the spider 22 has been rotated to open circuit, spider 23 can be rotated through a smaller angle in the same direction to isolate the gear from the busbars 12. In the arrangement shown, opening of the isolating contacts is effected, subject to a suitable interlock, by means of an inspection door 32 having a fastening screw 35 and handle 34. The door is pivoted at 33 and has a lug 31 to which the spider 23 is linked at 30. An insulating plate 57 on the spider 23 shuts off the live contacts 19, and interphase barriers, as 55, may be mounted on spider 22. Each contact, Fig. 2, comprises a laminated copper or brass member 36 which is secured at 37 to the D-shaped stub member 38 extending from the clamp 20. Stiff steel backing springs 39 and D-shaped contact jaws proper 40 may be fitted. The opening spring of the circuit-breaker may be coiled round the base 16a of shaft 16, and the Specification refers also to an oil-filled centre compartment 6. Automatic circuit-breakers.-The handleshaft 41 carries two arms 43, 44, of which 43 is engageable with a gravity-latch 46, and 44 has pivoted to it at 52 a lever 51 carrying a roller 53 which is engageable with an arm 54 which is fixed to a bevel wheel 42. In closing, rotation of shaft 41 drives the wheel 42, and hence wheel 42a and shaft 16 also, by means of the arm 44 and connection 53, 54, until the pin 45 engages latch 46. Manual tripping is effected by means of button 17, and arm 51 can be lifted by the core of a solenoid 49 to break the connection 53, 54.