IMPROVEMENTS IN OR RELATING TO SWITCHES OR ELECTRICAL CURRENT CHANGERS
Year: 1885

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I JAMES MACKENZIE of 48 Osnaburgh Street, London in the county of
Middlesex Gas Engineer do hereby declare the nature of my invention for
"IMPROVEMENTS IN OR RELATING TO SWITCHES OR ELECTRICAL CURRENT CHANGERS
and in what manner the same is to be performed to be particularly described
and ascertained in and by the following statement :-
This invention relates to certain improvements in or relating to switches or
electrical current changers. The object of the improvements is to provide a
durable effective and cheap instrument, combining very simple mechanism, which
shall be applicable to any electric circuits for the purpose of establishing good
electric contacts, between any one conductor and any other conductor or conductors,
or for shunting an electric current from one circuit to any other circuit or circuits
connected with the switch, and to change the contact instantaneously when
required from one to another. I will now fully describe my invention by aid
of the accompanying drawings, in which Figure 1, is a plan; Figure 2, a side view
of a multiple switch; and Figure 3, a plan of a single way switch having my
improvements applied thereto. In all these Figures like letters indicate like
parts.
A, is a swith board of wood or other suitable nonconducting material, to which
is attached, by a boss and stud connection the handle B, capable of being freely
turned on the stud.
The current enters and passes along the metal bar C, which is formed in the
shape of a half dovetail, having its top narrower than its base. The metallic
contact piece D, which is of a dovetail shape in section, is attached to the shank
of the handle B, by a slotted stud arrangement E, and is capable of being slid
along in contact with the bar C, by the movement of the handle B. The wires or
cables for completing the circuits are connected with the binding screws F, J, H,
respectively, the permant metallic connection between K, and H, Figure 1, being
made by a strip of copper or suitable material beneath the switch board A, as
shown dotted in Figure 1.
In Figure 3, the binding screw and block F, are connected to the contact
block K, by a safety fusible connection L. In the single way switch shown in

page_text: Figure 3, the circuit is closed when the handle B, and contact piece D, are in the
position shown in the drawing, and the circuit is open when the handle is placed
at the other side.
In the multiple switch, shown in Figures 1, and 2, the circuits C J. C, K, H. and
C F. are closed respectively, according as the contact piece D, makes connection
with J, K, or F, when the handle B, is to the right, centre, or left, of the switch
board. By this invention the current passes direct from block to block, through
the sliding contact D, and not through the shank and boss of the handle B, as is
usually the case in switches of this nature.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
A switch by which contact is made for the purpose of closing opening or
changing any circuit for electrical currents by means of a sliding piece D, capable
of movement in contact with a terminal bar C, and making contact with any 1
other terminal as F, K, J. as desired substantially as hereinbefore described and
illustrated by the accompanying drawings.