An Electric Switch.
Year: 1891

page_text: Date of Application, 7th May, 1891
Complete Specification Left, 8th Feb., 1892-Accepted, 12th Mar., 1892
PROVISIONAL SPECIFICATION.
An Electric Switch.
I, GEORGE SYLVESTER GRIMSTON, of Claremont, Glenluce Road, Westcombe
Park, in the County of Kent, Electrical Engineer, do hereby declare the nature of
this invention to be as follows:-
According to this invention a central spindle has fitted loosely on it a handle and
also a pair of contact bars, the one bar above the other, each bar consisting of a
number of metal plates which are bent down at each end so as to make contact with
metal plates fixed on the insulating base from which the central spindle projects.
The handle is connected to the pair of contact bars by a helical spring which is
strained when the handle is moved in the one direction or the other, tending to
pull the contact bars round in the same direction. These, however, are held at
either extreme of their stroke by the one or the other of a pair of spring pawls
engaging in a notch of the boss to which the contact bars are fixed. The handle
has projecting down from it two arms the one or the other of which when the
handle is moved over against a stop, disengages the pawl that is then holding the
contact bars, and thereupon they, being under strain of the spring connecting them to
the handle, make a rapid stroke till they are arrested by a spring buffer, thus either
making or breaking contact, or reversing, as the case may be.
Dated this 7th day of May 1891.
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE
SPECIFICATION.
An Electric Switch.
I, GEORGE SYLVESTER GRIMSTON of Claremont, Glenluce Road, Westcombe
Park, in the County of 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:-
This invention relates to an electric switch constructed and operating as I shall
describe referring to the accompanying drawings.
Figure 1 is a plan, Figure 2 is a central longitudinal section, and Figure 3 is an
end view, partly in transverse section, of a double or reversing switch according to
my invention. A central spindle A working freely in a stationary sleeve C standing
up from a base B of insulating material has fixed on it a handle D having an
arm E and two arms F1 F2 bent down in form of an inverted U. Free to turn on
the sleeve C is an arm G connected to the arm E by a helical spring G¹. Attached
to the arm G and moving with it, but insulated from it from each other, and from
the sleeve C, are two cross conducting bars H1 H2, the one above the other and
each consisting of a number of metal plates bent down at each end to make contact
respectively with metal plates 1' 12, 131, 15 1 which are fixed on the base B and
are connected as shewn in Figure 1 with the posts J' J2 J3 J4 to which the circuit
wires are connected. Attached to the arm G and conducting bars H₁ H² but
insulated from the latter is a cross bar K having a notch k at one end. On a
pin L are pivotted two pawls L' L² drawn by helical springs towards the centre A,
so that when, on turning K, the notch k presents itself to either of these pawls it
snaps into the notch and prevents K from being turned backwards. The operation
of the switch is as follows: In the position of the parts shewn in Figure 1, post J1
is connected through plate I¹ conducting bars H¹, and plate 13 to post J³, whilst

page_text: post J is connected through plate 12, conducting bars H2 and plate 15 to J. On
turning the handle D in the direction of the arrow, the limb F2 acts on the
pawl moving it out of the notch A, and the spring G' being strained, immediately
causes the arm G and with it the conducting bars H₁ H2 and bar K to move
rapidly round until K encounters a fixed stop k². The bars H1 H2 are now in such
position that post J' is connected through plate I, conducting bars H¹ and plate 1*
to post J, whilst post J is connected through plate I², conducting bars H² and
plate I with post J³. The pawl L' being now engaged in the notch k prevents the
bars from being turned back, until, by the reverse movement of the handle D, the
limb F moves the pawl L out of k and thereupon the conducting bars move
rapidly back to the position shewn in Figure 1, the bar K being stopped against
the fixed stop k
Although I have described and shewn a double or reversing switch, it is obvious
that by suppressing one set of the conducting bars such as H2 a pair of the posts
and the plates connected to them, the apparatus can be operated as a simple switch.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
An electric switch wherein conducting bars fitted to revolve on a central pin are
held in either of two positions by a spring pawl until by partly turning a handle
the pawl is disengaged and the conducting bars are turned rapidly against a stop by
the recoil of a spring strained by the movement of the handle, substantially as
described.
Dated this 8th day of February 1892.
ABEL & IMRAY,
Agents for the Applicant.