Improvements in Electric Switches.
Year: 1891

page_text: Date of Application, 11th Dec., 1891
Complete Specification Left, 11th Oct., 1892-Accepted, 12th Nov., 1892
PROVISIONAL SPECIFICATION.
Improvements in Electric Switches.
I, ALEXANDER MARR of 9 Repton Street, Chorlton on Medlock, Manchester in
the County of Lancaster, Electrical Engineer, do hereby declare the nature of this
invention to be as follows:-
This invention relates to electrical switches by means of which the direction of
an electric current may be deviated or one circuit be substituted for another.
According to these improvements, the switch is constructed with two pairs or a
pair and a set of contacts of which it is arranged that the contacts of one pair or of
one set only can complete the circuit at the same time, the other set or pair being
open. The first pair of contact pieces may for example oppose each other on
suitable springs on normal open circuit, and the second pair or set may have one of
the contact pieces or set of pieces on a spring connected with the first spring, and
the opposed piece or pieces on a fixed bracket or brackets. The second pair is
normally closed, but its spring being connected with the spring of the first pair, the
motion of closing that pair causes also the opening of the second pair or set.
The motion may be conveyed to the spring by means of a lever, button, slide, or
other device of a suitable nature.
The contact pieces are preferred to be formed in such a manner that opposed
contacts may be secured within an indiarubber tube or other flexible impervious
enclosure for the purpose of excluding the dust and preventing atmospheric action
or oxidation.
Dated this 10th day of December A.D. 1891
WILLIAM E. HEYS,
Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Electric Switches.
I, ALEXANDER MARR, of 9 Repton Street Chorlton on Medlock, Manchester, in
the County of Lancaster, 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 electrical switches in and by means of which the
direction of an electric current may be deviated, or one current be substituted for
another and in which one circuit or set of circuits is temporarily kept open or
closed.
According to these improvements, the switch is constructed with two pairs or a
pair and a set of pairs of contacts of which it is arranged that the contacts of one pair
or of one set of pairs only can complete the circuit at the same time, the other
pair or set being open. The first pair of contact pieces may, for example, oppose
each other on suitable springs on normal open circuit, and the second pair or set of
pairs may have one contact or set of contacts on one of the springs, and the other
contact or set of contacts completing the pair or pairs, on a fixed bracket or brackets.
The second pair or set of pairs is or are normally closed, but its spring being
mechanically but not electrically connected with the spring of the first pair, the
motion of closing that pair causes also the opening of the second pair or set.
In such switches, some. of the contacts are always open, and are liable to become
To avoid this
coated with dust and dirt or to be oxidised or corroded in some cases.

page_text: result I construct and arrange the contact pieces in such a manner that opposed
contacts may be secured within an indiarubber tube or other flexible impervious
enclosure which will exclude the dust and the external air.
I have illustrated my invention by the accompanying drawings and will now
proceed to more particularly describe it with reference thereto.
Figure 1 represents in front view, and Figure 2 in side view, the switch as con-
structed for use in combination with electric telephonic apparatus.
Figures 3 and 4 are details the brackets being reversed to make the drawings
clearer.
As represented by the drawings, the apparatus is supposed to be in use, the
receiver being off the hook. The speaking circuits are consequently closed, and the
ringing circuit is open. The contacts 1, 1°, through and by means of which
the ringing or signalling circuit is opened and closed are mounted opposite to each
other on the springs A and B. The contact 1 is firmly secured upon its spring,
whilst 1 is formed upon the end of a light screwed stud F the lower end of which
passes through a hole in B, and the upper end of which is secured in an insulating
bush G in the spring C. Good contact between 1 and B is secured by the spiral
spring H which presses B into close contact with 1. The spring C is arranged
parallel with the spring A, but is insulated therefrom. If the spring A is forced
towards the spring C, contact 1° will be pressed into contact with 1, thus closing
the signalling circuit, and if the pressure be continued, the spring C will also be
moved in the same direction as spring A.
The spring C has three tongues, C, C2, C, which carry the contacts 2b, 3b, and 4b,
of which the two outer ones are in electrical connection with the spring, and 3b, is
insulated therefrom by an insulating bush D, as shewn by Figure 3.
Three
brackets E¹, E', E³, are fixed upon the bottom of the telephone box with their
upper ends opposed to the ends of the tongues on the spring C, and carry the
contacts 2, 3, and 4*. When the apparatus is in use,
the contacts on the spring C,
are in electric connection with those on the brackets, the contacts 1°, and 1 being
as already described, open.
The insulated contact 3b, is electrically connected with the spring J, and the
terminal K.
Lis the back, M the bottom, and N one side, of the telephone or switch box.
O is the hook on which the receiver is hung when the apparatus is out of use, and
which when the receiver is removed therefrom is pulled into the position shewn in
Figure 1 by the spring P.
+
The receiver being removed from the hook, the contacts 10, and 1b, are separated,
and the ringing or signalling circuit is open, whilst the contacts on the spring Care
pressed against those on the brackets E¹, E', and E³, thus closing the circuits of
which they form part. The first of these circuits takes the course E¹, 2°, 2b, C¹, C;
C, 4, 4, and E, the circuits which are joined to the brackets E and E being
thus electrically connected. The second circuit takes the course E³, 3, 3, and J,
thus putting the middle bracket into connection with the terminal K.
When the instrument is out of use, the weight of the receiver upon the hook
pulls up its inner end against the spring A, presses the contacts 1" and 1 together;
and forces the spring C to the right, thus opening the circuits having their contacts
on the tongues C¹, C³, and C³.
It will be evident that the arrangements of the circuits: may be considerably
modified to suit especial circumstances and for different uses.
The means which I adopt for preventing the 'access of dust to the contacts, and
for preventing possible corrosion from the moisture or acids contained in the air are
illustrated by Figure 4 which otherwise corresponds with Figure 3, save that the
spring J and its connections are omitted.
Short lengths of indiarubber tube R R are slipped over the contacts as shown:
When there are no abutments for the ends of the tubes, they may be bound round
the necks of the contacts which are then grooved for the purpose as shown. In
the figure, the tube to the right is shewn in elevation, the contacts being open. The

page_text: other two tubes are shewn in vertical section, the middle contacts being closed and
that to the left open.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
1. An electrical switch, constructed arranged and operated substantially as and
for the purpose hereinbefore described and as illustrated by the accompanying
drawings.
2. In an electrical switch in which contacts are vertically moved into and out of
contact with each other, the combination with the contacts of a surrounding tube of
indiarubber or other impervious flexible material, substantially as and for the
purpose hereinbefore described and as illustrated by Figure 4 of the accompanying
drawings.
Dated this 28th day of September A.D. 1892.
WILLIAM E. HEYS,
Agent for the Applicant.