Improvements in Electric Switches.
Year: 1893

page_text: Date of Application, 27th Mar., 1893
Complete Specification Left; 22nd Dec., 1893-Accepted, 27th Jan., 1894
PROVISIONAL SPECIFICATION.
Improvements in Electric Switches.
We, THOMAS EDMUND MARSH of 42 Reighton Road, Upper Clapton,
Middlesex, Engineer and THOMAS GEORGE POOLE of 4 Whitbread Road,
Brockley, Kent, Electrical Engineer, do hereby declare the nature of this
invention to be as follows:-
Our invention relates to an improvement in that class of electric switches,
known as "Tumler" switches, and consists of an arrangement by which the switch
arm or bar is automatically locked and the throw off springs can only be released by
the movement of the handle, with the additional advantage, that supposing the said
springs fail to act from any cause, the movement of the handle effects a positive
action on the contact bar and releases it.
To carry this action into effect, on a base of any suitable insulating material,
we mount a framework on which a lever is pivotted at its centre, one end serving
for the handle and on the other end is fixed a crosshead which engages in suitable
slots on the contact arm. The contact arm is likewise a lever, but pivotted at one
of its ends either on a separate bracket or on the aforesaid mentioned framework,
the crosshead engages in suitable slots along the contact bar, causing it to be
depressed or raised according to the direction in which the handle is moved, the
other end of the contact bar engages when depressed between suitable contact
blocks fitted with terminals mounted on the base. We may make use of a spring or
springs to ensure a quick break action.
The handle and framework may be insulated from the contact bar by bushing
with a suitable nonconducting material where necessary.
Dated this 27th day of March 1893.
THOS. E. MARSH.
THOS. G. POOLE.
COMPLETE SPECIFICATION.
Improvements in Electric Switches.
We, THOMAS EDMUND MARSH of 42 Reighton Road, Upper Clapton,
Middlesex, Engineer, and THOMAS GEORGE POOLE of 4 Whitbread Road,
Brockley, Kent, 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:-
Our invention relates to an improvement in that class of electric switches,
known as
"Tumler" switches, and consists of an arrangement by which the switch
arm or bar is automatically locked and the throw off springs can only be released
by the movement of the handle, with the additional advantage, that supposing the
said springs fail to act from any cause, the movement of the handle effects a positive
action on the contact bar and releases it.
To carry this action into effect, and having reference to the accompanying
drawings, on the base A, which is made of any suitable insulating material, we
mount a frame-work B, on which a lever C, shown in detail in Figure 3, pivotted
at its centre, one end D serving for the handle, and the other end E is fixed a
cross-head F which engages in suitable slots G on the contact arm H, Fig. 1.
Contact arm H is likewise a lever bar pivotted at one of its ends J on the afore
Din 077

page_text: mentioned frame-work B. The crosshead F engages in suitable slots G along the
contact bar H, causing it to be depressed or raised according to the direction in
which the handle is moved. The other end of the contact bar H engages when
depressed between suitable contact blocks K and K', Figs. 1 and 2, fitted with
terminals mounted on the base A. We may make use of a spring L to ensure a
quick break action. The handle and frame-work are insulated from the contact
bar by means of the insulating brushes M.
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,―
A lever with cross-head working directly in a slot in a contact bar, substantially
as described in the accompanying drawings.
Dated this 22nd day of December 1893.
T. E. MARSH.
THOS. G. POOLE.