Patent GB-191409035-A (GB)
Title: Improvements in or relating to Electric Switches.
Inventor: TUCKER JOHN HENRY
IPC: H01H21/02
Filed: 1914-04-09
Granted: 1915-04-09
Abstract: 9035. Tucker, J. H., and Crabtree, J. A. April 9. [Cognate Application, 18,942/14.] Switches, quick-break.-Relates to enclosed switches comprising two or more pivoted contact-members, and a coaxially pivoted operating-bar extending from one contactmember to another and disposed out of the axis of movement. According to the invention the operating-member passes through the casing co-axially or substantially coaxially with the pivots of the contact-members, and the essential bearing-means for the operating-member are independent of the casing. As shown in Fig. 2, the operating-bar g has lugs g by means of which it is pivoted to the axially-alined spindles e upon which the contact-members f are pivoted, the spindles being carried by brackets secured to the base. The bar g carries a bracket g<1> having a part g<2> co-axial with the spindles e, the part g<2> passing through the wall of the casing and carrying an operating-handle g<3>. The bar g engages the contact-members f on one side or the other of their pivots e for opening and closing the circuit. The closing movement takes place against the action of springs coiled round the spindles e and the switch is held closed by the clipping action of the contacts. Upon a reverse movement of the bar g, a quick-break movement ensues. An operating handle may be provided at each end of the bar g or a #-shaped member may pass externally around the box and be provided with a single central handle. The operating-member g may have an additional bearing in the side of the casing in the form of a plate having a circular hole and adjustably secured to the casing. If the part g<2> passes through the division between the case and the cover, the additional bearing comprisestwo plates, with semicircular holes, adjustably secured to the case and cover respectively. These additional bearings may be in electrical contact with the part g<2> and thus serve to earth the handle part. If additional bearings in the side of the casing are not employed, the handle g<3> is earthed by a spring k secured within the casing and always bearing upon a part integral with or electrically connected with the handle, such as g<2>, which may be covered with a metal stamping j to secure effective electrical contact. The portion g<2>, in such cases, has an internal enlargement g<*> to shield the unoccupied portion of the recess in the side of the casing. If the portion of the operating- member that passes through the casing is not precisely in alinement with the axis about which the operating-member moves, the case and cover are provided with shaped openings a<2>, b<2>, Fig. 7, which are covered at all times by plates j<1> upon the operating-member adjacent to the inner surface of the casing. Earthing-springs k<1> engage the plates j<1>, which may have cam-formations j<2> in order to ensure a light spring retention of the operating-member in its ' on ' and ' off ' positions. Switch mechanism interlocking with lids.- When the handle is in the form of a #-shaped strap which bestrides the cover, the switch cannot be closed unless the cover is first closed, and the cover cannot be opened unless the switch is off.' In the form shown in Figs. 2 and 3, projections g<6>, g<5> on the handle engage projections b<4>, b<3> on the cover, and prevent the cover from being raised when the switch is ' on.' When the cover is open, the projection b<4> comes in the path of the handle, and in consequence the cover must be closed before the switch can be closed.