Patent GB-191516395-A (GB)
Title: Improvements in, or relating to, Electrical Switches.
Inventor: WYNNE ALBERT COURTNEY
IPC: H01H19/24
Filed: 1915-11-20
Abstract: 16,395. Wynne, A. C. Nov. 20. Switches, quick-action.-A quick-action switch movement applicable to different types of switches comprises a rotary handle e' which operates a spindle e carrying an operating-cam g, a stationary cam a', a<2>, and a contact cam h loosely mounted on the spindle e and connected with the contact-carrying member i. Each cam is of double formation, the fixed cam consisting of similar upper and lower plates a', a', Fig. 6, each shaped as shown in Fig. 5. This cam is enclosed within the operating-cam g, which is of cylindrical box-formation, the top and bottom plates being similar and formed with camslots g', g<3> shaped as shown in Fig. 8. The cam g is, in turn, enclosed within the box-shaped contact cam h having cam-slots h', h<2>, shaped as shown in Fig. 9. When the parts are assembled, the surface of the fixed cam and the cam-slots in the other two cams overlie one another, and two pins f<1>, f<2> pass through the coincident slots and bear against the fixed cam under the influence of the quick-action spring c, which passes round the fixed cam and round the pin f<2> and has its ends connected to the pin f<1>, as shown, so as to tend to draw the pins together. In action, starting from the "on" position, in which the superimposed cams are in the positions shown in Fig. 13 (I), and the cams g, h are locked by the engagement of the pins f<1>, f<2> with recesses h<3>, h<4> of the cam h, with the recess of the cam-slot g' and with two recesses a<3> of the fixed cam, on rotating the handle in the clockwise direction, during the first part of the movement the cam-edge g<5> disengages the pin f<1> from the locking-recesses a<3>, h<3>, Fig. 13 II, thereby commencing the distention of the spring, the contact cam meanwhile remaining locked by the engagement of the pin f<2> with the recesses h<4>, since, by reason of the concentric formation of the part g' of the operating-cam, the initial movement has no action on the pin f<2>. By continuing the rotation, the inner edges of the slot g<3> disengage the pin f<2> from its locking-recess a<3>, and the two pins f<1>, f<2> are driven along two faces of the fixed cam without, however, having any action on the contactcarrying cam, since the outer edges of the slots h<1>, h<2> follow the same curvature as the fixed cam. When the spindle has been turned through nearly 90 degrees (see Fig. 13 (III), the pins f<1>, f<2> arrive at two extreme points of the fixed cam, and the spring tension is at a maximum. At the completion of the 90-degrees movement, the pins are forced over the cam-points and are then drawn together by the reaction of the spring and travel down the opposite sides of the cam-points, at the same time wiping along the cam-slots h<1>, h' and imparting to the contact cam a rapid movement through 90 degrees into the " off " position, Fig. 13 (IV). To close the switch again, the movement of the spindle may be reversed through 90 degrees or continued through 90 degrees, each movement producing a rapid " on " or "off" switch movement, as the case may be. If the spring fails, the switch may still be operated by rotating the spindle through a sufficient angle. The contact cam is connected to the body part of the contact-carrying member i, Fig. 1, which is adapted to receive any desired number of flat or cranked contact-arms of standardized construction, which, in conjunction with standardized fixed contacts of different heights, enable switches of various types to be assembled, for example, single-pole, double-pole, "intermediate," and series-parallel switches. The contact-carrying member consists of two superimposed plates j, j<1>, Fig. 1, either or both formed with equidistant radially-disposed keeper-channels to receive the inner ends of the flat or cranked contact-arms, which may have projections engaging holes in one or other of the plates. When the desired selection of contact plates are in position, the plates j, j' are secured together by metal straps n, Fig. 1. The fixed contacts consist of angle posts o, Fig. 12, of different heights, to. which the clip contacts m<1> are secured, as shown. The operating- handle may be interlocked with the switch cover by means of wards, so that it is only possible to remove the cover when the switch is in the " off " position.