Year: 1888

page_text: I, FREDERICK THOMAS SCHMIDT, of Hustlergate, Bradford, in the County of York,
Electrical Engineer, 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 relates to certain improvements in electrical switches, and has for
its object, the construction of the same in such a manner that, an electrical circuit
may be rapidly opened or closed in a simple and efficient manner by the operation of
a disc so arranged that, each time it is turned the necessary distance, the electrical
circuit is completed or broken as the case may be ; and consists in mounting a disc
on a suitable base of insulating material to which are attached terminals, and arranging
the said disc with metallic surface plates, which, when the disc is turned to complete
the electrical circuit, the same are pressed tight and rub against the terminal flanges,
thereby preventing corrosion of the metallic surfaces in contact, effectually completing
the circuit and reducing the possibility of sparkling; the circuit being broken by again
turning the disc the necessary distance, the metallic surface plates being connected
by suitable fusible material.
In describing my invention more in detail, reference is made to the accompanying
sheet of drawings, on which Fig. 1 represents a front view of a switch constructed
according to my invention; Fig. 2 a plan of the same; Fig. 3 a side view; Fig. 4 a
section through line a. b. in Fig. 1; and Fig. 5 a view of the underside of the disc
showing one way in which the disc may be held in position.
The base A may be formed of any insulating material, and secured thereto, are
two terminals B and B', both of which have flanges F projecting for some distance
over the disc D, which is composed of insulating material and mounted on a pin P in
the centre thereof. In the centre of the disc around the said pin is formed an annular
groove, in which is placed a spiral spring C, the same being compressed between the
collar P¹ on pin P, and the disc at the top of the before mentioned annular groove;
thus when the switch is out of circuit keeping the disc tight against the collar R¹.
At the back of the said disc I secure a retainer D', against which the arm E is
pressed by a spiral spring S or other well known form of spring, mounted or attached
in any suitable manner, so that the arm is in contact with the retainer, and allows the
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page_text: disc to be turned whenever required. On the opposite side of the said disc, I secure
two metallic surface plates G and G', both of which are reduced in thickness at one
end as at H; the other ends may be reduced in the same manner, but I prefer to leave
them the full thickness, and place a piece of insulating material J at the end of each,
and to form a double metallic connection between the surface plates G and G¹ by
metallic fusible wires R. R. attached to the said surface plates in any well known or
convenient manner.
Each projecting flange F of the terminals, I prefer to reduce in thickness at one end
only as at F1, the other ends being left the full thickness, so that on turning the disc D
in the direction of the arrow by the handle K, the reduced portions of the metallic
surface plates come in contact with the reduced portions of the projecting flanges, and
the spring C yielding, allows the disc D to move nearer to the base A, and the
metallic surface plates G and G₁ to slide under, and in contact with the said flanges;
thus completing the circuit and preventing corrosion of the metallic surfaces by the
rubbing contact; the circuit being broken on again turning the disc in the same
direction until the next flat of the retainer is in contact with the arm E.
When the metallic surfaces are out of circuit and arranged as shown and described, it
is impossible to move the disc in an opposite direction to that denoted by the arrow,
in consequence of the spring C raising the disc such a height that, when moved in an
opposite direction, the vertical ends of the insulating material J, come in contact with
the vertical ends of the flanges for some distance above the under surface of the said
flanges, thus forming a stop or preventative against the disc being moved in both
directions.
Although I have shown and described the disc as capable of being moved in one
direction only, yet it will be easily understood, that by reducing both ends of the
metallic surface plates and flanges, sufficient to allow the reduced surfaces to come in
contact, on turning the disc in either direction, the spring C will yield and allow the
surfaces G and G to slide under the flanges F as before described, the disc being
held in position by the pressure of the arm E on one of the flat sides of the retainer.
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 :
1. An electrical switch in which are combined a disc with metallic surface plates
for making and breaking contact by the operation of the disc in the same or opposite
directions, the same being constructed and operated substantially in the manner as
shown and described.
2. An electrical switch in which a disc having metallic surface plates thereon,
combined with a spring C substantially in the manner and for the purpose described.
3. An electrical switch having a disc with metallic surface plates thereon, reduced
at one or both ends combined with flanges also reduced at one or both ends and
constructed substantially in the manner and for the purpose as shown and described.
Dated this 1st day of March 1888.
JOHN WAUGH,
Agent.