Improvements in Electric Switches.
Year: 1896

page_text: Date of Application, 23rd Mar., 1896
Complete Specification Left, 23rd Dec., 1896-Accepted, 23rd Apr., 1897
IONAL ST
Improvements in Electric Switches.
We WILLIAM HENRY DINGUE of 204 Vauxhall Bridge Road, Westminster
Electrical Engineer, and JOHN MACKENZIE URQUHART of 23 Bucklersbury
Mansion House, London, E.C. Electrical Engineer do hereby declare the nature
of this invention to be as follows:-
A base of earthenware slate vulcanite or other suitable nonconducting material.
and preferably of circular form fitted with a stamped or cast top or cover attached
thereto by any of the well known means such as screw bayonet joint etc. A
stamped or cast brass frame carries the top plate through which two holes convey
"make" and "break" pushes. Pivotally attached to the end of the frame is a
contact lever bar made preferably of an insulating material such as vulcanized
fibre. Impinging on this contact bar is the lower end of a T shaped lever which
lever is pinned in its centre to the middle support of the frame. It is also attached.
at its upper or horizontal limb one end to the "make" push and the other end to
the "break" push as beforementioned. When the "break" push is depressed the
circuit is opened and the lower limb of the T lever falls into a slot formed in the
centre of the contact.bar allowing the bar to rise and causing a corresponding 'rise
of the other end of the horizontal top bar of the said T lever and of the push piece
attached thereto. The beforementioned slot has a sloping wall. down which the
To make contact
said lower limb of the T lever falls when breaking contact.
between the contact bar and the small contact. pieces on base which form the,
connection from one of the wires it is necessary to press down the "make" push
which in turn depresses one end of the top bar of the T lever and gives the said
lever a quadrantal movement and so forces the lower limb of the T lever up the.
sloping wall of the beforementioned slot and out and upon top of the said. contact
lever bar thus pressing the said contact bar into a rubbing contact with the
connecting contact pieces on ibase as aforesaid. A spring is placed under the contact
lever bar in such a position. that when the lower end of the T lever moves on to
the top edge of the slope it is suddenly and forcibly driven into the slot by the
upward movement of the said contact bar and the contact immediately broken
between the bar and the connections. on base. We adopt the usual means of
attaching the base to the wall etc..
Dated this 12th day of March 1996
WILLIAM HENRY DINGLE.
JOHN MACKENZIE URQUHART.
Improvements in Electric Switches.
We WILLIAM HENRY DINGLE of 204 Vauxhall Bridge Road Westminster
Electrical Engineer and JOHN MACKENZIE URQUHART of 23 Bucklersbury
Mansion House London E.C. 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:-
A base of earthenware slate vulcanite or any other suitable. non-conducting

page_text: material fitted with a cover attached thereto by a screw, bayonet joint or other
means. A metal frame is attached to the said base by screws or otherwise which
frame carries at its upper portion a quadrantal lever preferably of the shape known
as a lever. In the smaller forms of switches Figs. 1. 2. 3 & 4 we have a
"make" and a "break" push or button attached pivottally to the ends of the
horizontal limb of the said T lever. The lower end of the beforementioned
Tlever impinges on a horizontal contact bar also pivotted at one part to the frame
of the switch. When the "make" push is pressed a quadrantal movement is given
to the said horizontal limb of the T lever and also to the vertical limb of the same,
with the result that the end of the vertical limb depresses and forces into contact
with two fixed contact pieces on the base, the beforementioned horizontal
contact bar.
When the "break" press is pushed down the quadrantal or T lever swings in
the opposite direction, with the effect of dropping the end of the vertical
limb of the T lever into or partly through a slot or recess in the said horizontal
contact bar.
A small spring under the contact bar tends to raise it suddenly, immediately the
pressure of the vertical limb is removed from the upper part of the said contact
bar. The recess or slot in the contact bar may have a sloping wall in either
direction as in Figure 1 where the slope is backward and upward or Figure 3
where the wall slopes forward and upward.
Connections are made in the regular way through the base and up to the contact
pieces where a screw forms a clamp and fastens the wires.to. the pieces aforesaid.
We vary the form for heavy currents as for main switches by substituting a lever
handle K Figs. 5 & 6 for a "make" and "break" push, where the raising
of the said handle moves the quadrantal lever into the recess of the contact bar F,
and allows of it rising out of the contact pieces H and so breaks the connection.
The reverse motion, that of depressing the lever presses on the arm of the
quadrantal lever and forces the vertical arm on top of the contact bar and into
contact with the contact pieces before described.
Where we employ the switches for main currents as in Figures 5 & 6 we
modify the form of the quadrantal lever and instead of the horizontal part of the
same being at right angles to the lower limb we make the upper limb with two
horns (M in Figures 5 & 6). Working on the same pin to which the said quadrantal
lever is pivotally attached is a lever with a handle at its free end K. Upon one
part of the last mentioned lever is a fixed pin or stop S fixed in such position that
upon raising the said handle the pin S presses on the upper horn (M) and forces
the quadrantal lever lower limb into the recess of the contact bar and breaks
contact. Upon lowering the handle the pin presses on the lower horn and forces
the quadrantal lever lower limb on top of the contact bar thus closing the circuit.
We modify our designs still keeping to the main feature of a quadrantal lever
depressing a contact bar.

page_text: S Stop to raise or lower quadrantal lever.
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
1. In electric switches the combination of a T lever or its equivalent with push
pieces, contact lever bar and fixed terminal contacts substantially as herein
described and set forth.
2. The combination of a pivotted lever having a vertical arm swinging
quadrantally which arm presses on and depresses a contact bar into a rubbing.
connection between fixed terminal contacts."
3. In electrical switches the combination of a lever, having a quadrantal
movement and actuated by pushes, with a horizontal, pivotted contact lever for
the purpose and used in the manner herein described.
4. In an electrical switch a T lever or its equivalent in combination with a.
pivotted lever bar recessed in such manner that when the T lever is given a
quadrantal movement, portion of the lower arm falls suddenly into such recess and
the lever is allowed to rise and break the circuit substantially as herein described
and set forth.
Dated this 23rd day of December 1896.
WILLIAM HENRY DINGLE.
JOHN MACKENZIE URQUHART.