Improvements in Electrical Switches.
Year: 1890

page_text: Improvements in Electrical Switches.
We, CARL GEORG DAHLGREN, Mechanic, and JOHN HUGO SVENSSON,
Engineer, both of Göteborg, in the Kingdom of Sweden, 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 and consists in a switch of improved
construction adapted both to make and break contact instantaneously.
Reference being made to the accompanying drawings,
Fig. 1 is a central vertical section through the improved switch.
Fig. 2 is a horizontal section thereof on line 1. 2. of Fig. 1 showing the parts
with contact made.
Fig. 3 is a similar section showing the parts in the position they occupy when
the contact is broken.
Fig. 4 is a side elevation and plan of the moving contact plate of the switch.
Fig. 5 is a vertical section, side elevation and cross section on line 3. 4. of the
turn button and parts connected therewith.
Fig. 6 is a plan and side elevation of the fixed contact plate of the switch and
Fig. 7 is a plan and side elevation of the metallic conductor on the base of the
switch.
According to this invention, the moving contact plate adapted to be brought
into contact with, or out of contact with the fixed contact plate by means of a
spring which, normally not in a state of tension, is tensioned in the one or other
direction by the turning of the turn button the shaft of which also serves as a
temporary detent for holding the said moving contact plate in its respective first
position until sufficient tension has been given to the spring by turning the button
to cause it when released by the turning of the button, to leap from its position of
contact to its position of disconnection or vice-versa and thus suddenly interrupt or
make contact with the fixed contact plate.
The drawing illustrates the construction. a is the insulating base of the switch.
the fixed contact plate, which may be forked as in Fig. 6 to make contact above
and below the moving contact plate. is the binding and fixing screw thereof.
c is the metallic plate fastened to the base by the binding and fixing screw c¹ and
carrying a socket let into a pit in the base to receive the spindle of the turn
button. is the moving contact plate which is pivoted at / on the metallic plate c
and is in electrical connection therewith through its metallic pivot screw.
the shaft of the turn button, e the turn button and the spring carried by the
sleeve surrounding the upper part of the shaft d. kis the cover plate.
d is
The shaft d is cut away at opposite sides at d (Figs. 2 and 3) at the part where
it passes through the plate i. The latter is made with two circular holes i¹² of
equal diameter the same as the longer measurement of the part di so that the
latter can turn within either of the holes the first of which corresponds to the
position of contact, the second to the position of disconnection. The two holes ¹²
are connected by the passage the breadth of which is but slightly larger than
the smaller measurement of the part d'. The end of the plate i is provided with
the lug to receive the end of the spiral spring 9 the other end of which is
connected to the turn button.
The parts being in the position of Fig. 2 by turning the button e to the right
the spring g is brought into tension in the direction of the arrow Fig. 2. After
the turning of the button has been continued sufficiently to enable the plate d' to
pass through the passage the tension of the spring g will throw the plate into
the position shown in Fig. 3 and the part d' will now be located in the hole.
The reverse movement of the button e will make contact in a similar manner.
го

page_text: The point m on the lower flange of the sleeve and the lugs on the sides of
the plate are to prevent the button being turned too far by which the spring g
might be broken or injured.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is
1. An electrical switch having a fixed contact plate, a moving contact plate, a
turn button or equivalent and a spring so constructed that the turning or move-
ment of the button or equivalent in the one or other direction brings said spring
into tension for operating said moving contact plate to make or break contact
respectively said button or equivalent acting also as a detent to temporarily
restrain the movement of the contact plate until the tension of the spring is
sufficient.
2. An electrical switch having a fixed contact plate, a moving contact plate a
turn button and a spring, the turn button having on its shaft the locking device d'
and the moving contact plate having two holes connected by the passage the
parts being arranged to operate in the manner described.
Dated this 12th day of December 1890.
.
HERBERT & Co.,
18, Buckingham Street, Strand, London, W.C., Agents to Applicants.