Year: 1886

page_text: Date of Application, 6th Apr., 1886.
Complete Left, 6th Jan., 1887.
Complete Accepted, 8th Feb., 1887.
We, ROBERT CORNTHWAITE of 30 Belle Vue Terrace, Skipton in the County of
York, Mill Manager, and ROBERT INGHAM of 58 Otley Street, Skipton, aforesaid,
Mechanic, do hereby declare the nature of this invention to be as follows:-
Our invention relates to apparatus for making or breaking an Electric circuit. In
the case of circuits conveying considerable currents such as are used in Electric
Lighting, it is important that the circuit should be broken very suddenly, so as to
prevent an are being established at the point of rupture: also the points at which the
current is broken should be easily replaced when they become worn by the
sparking.
It is also important that the contact should be over as large a surface as possible
with sufficient pressure on the surfaces in contact.
To secure these points a switch is constructed according to our invention with a
bow spring which bridges across the two terminals. The bow spring is carried on a
crosshead attached to a rod sliding through holes cut in two lugs fastened to the base
of the switch, or the bow spring may be placed below the spiral sping.
Between the lugs, and thrusting at one end against one of them, a spiral spring
is coiled round the rod and attached to it at the other end. The spiral spring
thus acts to withdraw the bow spring before mentioned from contact with the
terminals.
On a spindle attached to the lug nearest the cross head a cam can be rotated by any
suitable handle. The cam bears against the crosshead and brings the bow spring
into contact with the terminals against the action of the spiral spring.
In order to secure sudden break of contact, we make the cant and that portion of
the crosshead against which it bears of such a shape that when the bow spring is
on the point of breaking contact a very small motion of the handle of the switch
releases the crosshead which is then brought back instantaneously by the spiral
spring.

page_text: COMPLETE SPECIFICATION.
Improvements in Switches for Making or Breaking Electric
Circuits.
We, ROBERT CORNTHWAITE, of Belle Vue Terrace, Skipton, in the County of
York, Mill Manager, and ROBERT INGHAM of 58 Otley Street, Skipton, aforesaid,
Mechanic, 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:―
Our invention relates to apparatus for making or breaking an electric circuit. In
the case of circuits conveying considerable currents, such as are used in electric
lighting, it is important that the circuit should be broken very suddenly so as to
prevent an are being established at the point of rupture, also the points at which
the circuit is broken should be easily replaced when they become worn by sparkling.
It is also important that the contact should be over as large a surface as possible,
with considerable pressure on the surfaces in contact, and in describing our apparatus
we make reference to the accompanying drawings shewing three ways in which we
may accomplish our object; Fig. 1 representing the front elevation of one arrangement,
Fig. 2 the plan of the same, and Fig. 3 a side elevation.
To secure the above objects, we connect the two terminals with a bow spring, and
operate the latter by a tappet or cam and spiral spring. In the figures before
mentioned the switch base is indicated by the letter A, and secured thereto is a
bracket B in which is mounted a sliding bar C having an enlargement or
cross head at one end, to which is secured and insulated the how spring D.
The sliding bar Cis prepared with a projecting pin P near to one end between
which and a portion of the bracket B, is compressed a spiral spring E. Projecting
from the bracket B is a circular stud S upon which is mounted the tappet or cam F,
which is operated by the handle G. The before-mentioned tappet or cam bears
against the enlargement or cross head C¹ of the sliding bar C, and when operated
or turned by the handle. G, so that the full portion of the tappet or cam is in contact
with the cross-head C¹, the bar C is raised bringing the bow spring D into contact,
thus closing the circuit between the terminals Hand H', and at the same time
compressing to a greater degree the spiral spring E.
In order to secure a sudden breakage of contact, the full portion of the tappet or
cam F is narrow, so that when the bow spring D is on the point of breaking contact,
a very little motion of the handle G releases the bar C which is then brought back
instantaneously by the compressed spiral spring E, thus suddenly breaking the electric
circuit.
The cam of the apparatus shewn in plan and side view Figs. 4 and 5 respectively,
is mounted in a different manner to that before described; according to this arrange-
ment, the bow spring D is insulated and secured to a tube placed on a centre bar J,
projecting at right angles and fixed to the switch base A. At the end of the tube

page_text: is formed or secured a collar or enlargement K, hollowed out for the cam F,
which is mounted so as to be turned or operated by the handle G on the centre
bar J.
When the cam F is in the position shewn by the last mentioned figures, the bow
spring D is not in contact with the terminals H and H³, but by turning the handle
and cam F one fourth of a revolution, the contact with the terminals is made, the
spiral spring E being compressed at the same time, so that on the cam being turned
to its original position, the said spring causes the bow spring to leave the terminals
instantly, and thus suddenly break the electrical circuit.
The cam F may be mounted on a pin passing through two side bars I, L, as shewn
by Figs. 6 and 7, the latter being a side elevation with a portion of one of the side
bars removed. The cam F is shewn in the position when the bow spring D is
out of contact with the terminals H and H¹ on moving the cam lever F¹ in line
with the side bars L L at right angles to the position shewn, the spiral spring E is
compressed and the bow spring D brought into contact with the terminals H and H¹,
thus completing the circuit; the bow spring D being insulated from the metallic
connections by any well known material, is suddenly withdrawn from the terminals by
the action of the spiral spring E on the movement of the lever and cam F to their
original position.
Having now particularly described and ascertained the nature of our said invention
and in what manner the same is to be performed, we declare that what we claim is:
An apparatus for the making and breaking of electrical circuits by operating a
bow spring D by a tappet or cam combined with a spiral spring all arranged
substantially in the manner shewn and described.
JOHN WAUGH,
Agent.