Improvements in Electrical Switches.
Year: 1893

page_text: Date of Application, 1st Dec., 1893
Complete Specification Left, 1st Oct., 1894-Accepted, 3rd Nov., 1894
Improvements in Electrical Switches.
I, WILLIAM PAUL THEERMANN 11 Great Ducie Street, Strangeways,
Manchester in the County of Lancashire, Engineer, do hereby declare the nature
of this invention to be as follows:-
These improvements relate to electrical switches, which are fitted within the
holder or socket of incandescent lamps, but can also be applied to brackets,
electroliers &c.
In switches at present in use, which are fitted within the lamp holders or sockets,
have generally a knob or handle, which, by being partly rotated, turns the current
on or off, and to effect this, both hands are required when the lamps are suspended
by flexible wire cords; one hand to steady the lamp and the other to turn the
knob or handle.
The object of my invention is to make such a switch simple in construction,
reliable in its action and to be able to switch the current on or off by the use of
two fingers only and to effect these improvements, I make the switch and holder of
the following novel design:
I employ an insolating block of any suitable non conducting material enclosed
in a case of metal or other suitable material and preferably cylindrical in shape.
Attached to the block are two electrodes, one forming a double ended lever which
is fitted into a cross opening of the said block and the ends projecting through
both sides of the metal case.
The said lever is provided with a small central pin by which it is supported and
allowed freely to oscillate.
A small hollow, wedge shaped stud, fitted into the said insolating block, is
provided with a suitable spring, to press the said stud against a A shaped projection
of the double ended lever and thus securely locking the said lever in either one
position or the other.
At a suitable distance below the said lever is a small metal bar or strip, secured
to the said insolating block and which forms the second electrode.
The under side of the said bar and the two projecting ends of the said lever are
insolated with suitable material and are so arranged that when the ends of the said
bar and lever on one side of the holder are pressed together the circuit is open.
The lower part of the said metal case is so shaped, as to receive the lamp, fitted
either with brass collar, screw, bottom loops, or any other suitable arrangement.
A modification of my invention is by fitting the said double ended lever longi-
tudinal into the said insolating block and metal case, and only a short piece of
metal or screw is required to form the second electrode, and the said lever is
provided with a strip of non conducting material on the outer side, which projects
through the metal case.
Dated this First day of December 1893.
W. P. THEERMANN,
Applicant.

page_text: improvements in Electrical Switcnes.
I WILLIAM PAUL THEERMANN of 11 Great Ducie Street Strangeways,
Manchester, 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:-
My said invention relates to an improved construction of electric switch or
device for making and breaking the circuit for electric lamps and may be applied
either to the sockets of incandescent lamps or to brackets electroliers and the like
and has for its object to provide a switch of simple construction which may be
operated by two fingers of one hand.
In order that my said invention may be more clearly understood I will describe
it with reference to the accompanying drawings which are sectional elevations.
In a suitable block a of insulating or non-conducting material (held in a casing b
of preferably cylindrical shape) are fixed two terminals one of which is formed
as a double armed lever c working in a transverse recess in the block a and
projecting through opposite openings in the casing b. The said lever is capable of
being turned about a central pin or stud.
The
A stop e having a suitable spring e' is so placed as to bear against the lever cand
to retain it in either of its two positions while capable of yielding when the position
of the lever is reversed by the exercise of slight pressure. Under one end of the
said lever is another metal terminal secured in the insulating block a.
projecting arms of the lever e are made of non-conducting material, while the central
part forms a conductor from the stud e (to which one of the wires of the circuit is
connected) to a metal plate or block c' on the underside of the lever. When the
lever is in the position shown in Figure 1 the said block or plate e¹ is not in contact
with the terminalf. When however the position of the lever is reversed the two
terminals are in contact and the circuit is closed.
Projecting from opposite sides of the casing are lugs b. To throw over the
lever from one position to the other it is only necessary to squeeze one of the
projecting arms of the lever c against its corresponding lug by means of a slight
pressure of the fingers and thus the current can be easily and conveniently turned
on to the lamp.
In Figure 2 is shown a modification of my said invention in which the lever c
works in a longitudinal recess in the block a. The function and mode of operation
of the parts is precisely as described with reference to Figure 1 as will be well
understood.
The upper part of the casing is constructed to receive wires and the lower part
may be constructed either to receive wires or as a lamp socket.
Having now particularly described and ascertained the nature of my said
invention and in what mauner the same is to be performed I declare that what
I claim is.
1. The combination of a two armed contact making and breaking lever turning
about a fixed centre a yielding spring in electrical contact therewith for retaining
the same in position and a fixed terminal the whole comprising an electrical switch
substantially as described and shown in the accompanying drawings.
2. In an electrical switch a double armed lever capable of turning about a fixed

page_text: centre for the purpose of making and breaking contact in combination with a
spring for retaining the said lever in either of its alternate positions substantially
as set forth.
Dated 29th day of September 1894.
E. T. WHITELOW, A.M. Inst. C.E.,
70, Deansgate, Manchester, Agent for the Applicant.