Improvements in Electric Switches.
Year: 1890

page_text: Date of Application, 2nd Sept., 1890-Accepted, 25th Oct.,
1890
COMPLETE SPECIFICATION.
Improvements in Electric Switches.
I, CHARLES WILLIAM HUNTINGTON of The Times Building, in the City and State of
New York, United States of America, Manufacturer, do hereby declare the nature
of this invention, and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :—
This invention has reference to electric switches and cut-outs, and its object is to
provide a switch which shall be cheap of manufacture, efficient in operation, and not
liable to become deranged from use.
In general terms, the switch constructed according to these improvements consists
of a base of insulating material, in the face of which a circular groove or channel is
formed, the bottom of the channel being formed of an even number of inclined planes,
the opposite ends of each of which are respectively in two parallel planes. The
surfaces of alternate planes are armed with metallic plates and the others are left bare.
The number of the inclined planes should not be loss than four and this is the number
it is preferred to empl v. A centrally pivoted circuit controlling arm is pivoted with
contact brushes at its opposite ends which, when the arm is turned in one direction,
drag over the inclined surfaces and make or break the electric circuit. A spring is
suitably arranged in connection with the circuit controlling arms to hold the brushes
in contact with the inclined surface.
Referring to the accompanying drawings―
Figure 1 represents a perspective view of the switch with the cover removed;
Figure 2 a plan of the same; and
Figure 3 a central section through the base.
A represents the base. This may be of wood, porcelain, fibre, or any similar and
suitable insulating material. Its upper surface is flat and is provided with a circular
groove B, concentric with the base. This groove may or may not be provided with
raised edges b for the purpose of deepening the groove and preventing foreign matter
from falling into it. On the bottom of this groove are formed (preferably) four
inclined planes or teeth 1 which make a form of flat ratchet on the bottom of the
groove. Two of these teeth which stand opposite each other, are faced with metal
and form the switch terminals of an electric circuit. The other two teeth are left bare
or are made of any suitable insulating material. In the centre of the base piece, a post C
is pivoted. Its lower end is fitted with a nut or cross-head c which plays in and out of a
chamber a in the base. Between the cross-head and the inner extremity of the
chamber a spiral spring is placed, the tendency of which is to force the cross-head and
the centre post downward or outward from the base. Above the face of the block the
post has fitted to it a circuit controlling arm C¹ which is adapted to turn with
the post through a plane substantially parallel to the face of the base of the switch.
The extremities of this arm are at diametrically opposite points above the groove B
and the said extremities have attached to them trailing contact pieces c¹ of spring
metal which extend down into the groove and bear with a yielding pressure upon the
bottom thereof. The central post is fitted with a key D of insulating material by
means of which the arm may be turned round to operate the switch.
The object of the groove is to retain the contact brushes c¹ squarely upon the bottom
or contact plates of the switch, so as to secure good electric connection. Furthermore,
if there should be any sparking between the contacts, the same would be confined
within the walls of the groove and would not do injury to other parts of the switch.
In operating, the key is turned in a single direction, movement in the opposite
direction being prevented by the contact of the trailing brushes with vertical walls
between the teeth or inclines. The spring in the chamber a tends continually to hold
the brushes to their work, thus insuring good contact.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is―
In an electric switch, a Imse of insulating material having a circular groove formed
in its face, the bottom of which is in the form of a series of inclined planes, every
alternate plane being metallic and the other planes being of insulating material, in
combination with a circuit controlling element working in the groove adapted to
make and break contact with the metallic surfaces, substantially as hereinbefore
described and as illustrated by the accompanying drawings.
Dated this 1st day of Soutambur AD 1800
WILLIAM E. HEYS,
Agent for the Applicant.