Improvements in Electrical Switches.
Year: 1896

page_text: Improvements in Electrical Switches.
I, JOHN HENRY TUCKER, of 16, Oozells Street, in the City of Birmingham,
Electrical Engineer, do hereby declare the nature of this Invention to be as
follows:-
This Invention has reference more particularly to that class of electrical switches
in which a rocking handle operates a rocking double contact arm, that is a contact
arm which has a contact piece at each end and arranged to rock so that when either
end of the contact arm is raised and "off," the contact piece at the other end of the
arm is depressed and "on." My Invention is also applicable to those electrical
switches which have a single ended contact arm.
This Invention consists in arranging the said double or single contact arm to
rock backwards and forward's about two fulcra at a short distance apart in
combination with a spring and the rocking handle so that the said spring and the
peculiar arrangement of the centres and connections and the two fulcra cause the
contact arm to make and break contact quickly and a considerable amount of
leverage by the rocking handle is obtained.
I will first describe how my Invention is applied to a switch which has a double
ended contact arm. I make the contact arm to turn about two fulcra arranged at
short distance apart one on either side of about the centre of the contact arm
which has (or may have) two notches underneath to rest upon two cross bars
fixed on the base of the switch and forming the two fulcra as aforesaid so that
when the contact arm is turned in either direction it turns on one fulcrum bar and
lifts up off the other fulcrum bar. The rocking movement of the contact lever is
obtained by a rocking handle which is jointed to a stand on the base of the switch
at some little distance above the contact lever and about mid-way between the two
fulcra. The lower end of the rocking handle projects below the fulcrum of the
same and is jointed or otherwise connected to or engages with an upwardly
projecting part of the contact lever so that by rocking the handle about its fulcrum
the contact lever will be rocked on one or other of its fulcra as aforesaid. A
spiral or other spring arranged about centrally between the contact lever and the
base of the switch acts upon the contact lever and raises the same and maintains
either end of the same raised according to on which of the two fulcra the contact
ever is turned.
Instead of the lower end of the rocking lever being jointed to the upwardly
projecting part of the contact lever as aforesaid the rocking lever may be arranged
work in a notch in the contact lever and move the same backwards and
forwards as aforesaid.
In another arrangement of this Invention one fulcrum of the contact lever is
connected to the other fulcrum by means of a link or links and under the first
amed fulcrum the spiral spring is arranged. By this arrangement the contact
ever is permanently connected to one of its fulcra and is thus more effectually
revented from getting out of position.

page_text: My Invention is similarly applied to those electrical switches which have one
armed single ended contact levers the two fulcra being located towards one end of
the lever.
Dated this 11th day of September 1896.
CHARLES BOSWORTH KETLEY,
Agent for the Applicant.
improvements
I, JOHN HENRY TUCKER, of 16, Oozells Street, in the City of Birmingham,
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 has reference more particularly to that class of electrical switches
in which a rocking handle operates a rocking double contact arm, that is a contact
arm which has a contact piece at each end and is arranged to rock so that when
either end of the contact arm is raised and "off" the contact piece at the other
end of the arm is depressed and "on." My Invention is also applicable to those
electrical switches which have a single ended contact arm.
This Invention consists in arranging the said double or single contact arm to
rock backwards and forwards about two fulcra at a short distance apart in com-
bination with a spring and the rocking handle so that the said spring and the
peculiar arrangement of the centres and connections and the two fulcra cause the
contact arm to make and break contact quickly and a considerable amount of
leverage by the rocking handle is obtained.
In the accompanying drawings Fig. 1 is a sectional elevation of an electrical
switch constructed according to my Invention; Fig. 2 is an end elevation of the
same; Fig. 3 is a sectional elevation of the same shewing the same parts as Fig. 1
but with the switch thrown over in the opposite direction; Fig. 4 is a general
view of the contact arm separately; Fig. 5 shews separately a link forming part
of the said switch and Fig. 6 is a separate view of the bracket part of the said
switch which is used in connection with the said link; Fig. 7 is a sectional
clevation of a modified form of the switch constructed according to my Invention;
Fig 8 is a sectional elevation of a further, modification of the same and Fig. 9 is
an end elevation of the same.
The same letters of reference indicate the same or corresponding parts, in all
the Figures of the drawings.
Referring firstly more particularly to Figs. 1 to 6 both inclusive which illustrate
my Invention applied to a switch made with a double ended contact arm, I make
the contact arm A to turn about two fulcra marked respectively bb arranged at
a short distance apart one on either side of the centre line XX of the contact arm.
The fulcrum b is connected to the fulcrum 62 by means of the link C which is
made with a notch c to engage with the fulcrum b (which is formed on the cross
bar B) and is jointed to the contact lever A by a più passing through the hole
in the link C and through a hole 62 in the lever A. The contact lever A is slotted
vertically at to admit the link C. The spiral spring D (or instead of a spiral
spring any other kind of spring may be used) is provided in a hole el.in the base E
and presses upwardly against the underside of the link C so as to also press up the
contact lever A and raise the same and maintain either the end a² or a³ of the
same raised according to on which of the two fulcra bor b2 the contact lever is
turned. The rocking movement of the contact lever A is obtained by the rocking

page_text: handle F which is jointed at f' to the stand G fixed on the hase 1 of the switch
the fulcra f' being at some little distance above the contact lever and about midway
between the two fulera . The lower end of the rocking handle F projects
below the fulcrum fi and is jointed or otherwise connected thereto and engages
at a with an upwardly projecting part as of the contact lever S so that by rocking
the handle about its fulcrum f the contact lever A will be rocked on one or
other of its fulcra 2 as aforesaid. This will be clear by an examination of
Figs. 1 and 3, where in Fig. 1 the handle 1' has been moved to the left hand side
throwing over its jointed end a and turning the contact lever A about its
fulcrum raising the end a" of the contact arm and lowering the other end a
between the two contacts on the base. It will be seen that the parts are effectually
maintained in this position by the spiral spring 1) as the centre a' has been thrown
over beyond a line joining the fulcra f' and When the lever handle F is turned
in the opposite direction the lever A is thereby first turned about its fulcrum
and then the lever A and the link C are turned about the fulcrum & so that the
end a is lowered between the contacts, and the other end a of the contact arm is
raised.
Instead of the lower end of the rocking lever F being jointed to the upwardly
projecting part at of the contact lever A as aforesaid, the lower end of the rocking
lever F may be arranged to work in a notch in the contact lever A to move the
same backwards and forwards as aforesaid as will readily be understood.
In the arrangement of my Invention shown by Fig. 7 the two fulcra b¹ ª about
which the contact lever A turns, are the two upper edges of the two cross
bars B1 B2 which are fixed to the base E and take into two notches as a which are
formed in the underside of the lever A so that when the contact arm A is turned
in one direction it turns on one of the fulcrum bars say B' and lifts off the other
fulcrum bar B2 and when turned in the opposite direction the contact lever turns
on the fulcrum bar B2 and lifts up off the other fulcrum bar B
In the arrangement of my Invention shown by Figs. 8 and 9 the two fulcra of
the contact lever A are formed by the two pins b6 62 which pass through the contact
arm A and through slots in the two upright plates H H between which the
contact arm A passes and works, so that when the rocking lever F is turned in one
or the other direction the contact arm A will turn about one or other of its fulcrum
pins 6 62 which will work in the slots h and the action will be the same as
above described with reference to the arrangement shewn in Figs. 1, 2, 3, 4, 5
and 6.
My Invention as above described and illustrated by Figs. 7, 8 and 9 is similarly
applied to those electrical switches which have one armed single ended contact
arms, that is to say, one or other of the ends a² a³ of the contact arm A will be
cut off or wanting, as will readily be understood.
Having now particularly described and ascertained the nature of my said In-
vention and in what manner the same is to be performed, I declare that what
I claim is:
1. In an electrical switch of the kind herein referred to in which a rocking
handle operates a rocking double contact arm, mounting the said contact arm to
rock about two fulcra arranged at a short distance apart at each side of the fulcrum
of the rocking handle in combination with a spring which presses the contact arm
and tends to turn the rocking handle the parts being so arranged that when the
rocking handle is thrown over in the one or the other direction the contact arm
is thereby rocked about one or other of its two fulcra so that one end of the contact
arm is raised out of contact whilst the other end is forced into contact, all
substantially as set forth.
2. In an electrical switch of the kind herein referred to and in combination with
the rocking handle F of the same, the double ended contact arm A jointed about
centrally to the rocking handle and mounted on the two fulera &, the link C
connecting the two fulcra b' together and the spring D adapted to press the link C

page_text: upwardly and turn the rocking handle so that when the rocking handle F is
thrown over in the one or the other direction, the contact arm A is thereby rocked
about one or other of its two fulcra b' 62 and one end of the contact arm is raised
out of contact whilst the other end is forced into contact, all substantially as herein-
before described with reference to Figs. 1, 2, 3, 4, 5 and 6 of the accompanying
drawings.
3. In an electrical switch of the kind herein referred to and in combination with the
rocking handle 1', the double or single ended contact arm A jointed to the rocking
handle and mounted on the two fulcrum pins 61 62, the upright side plates H H
forming guides for the contact arm and for the fulcrum pins b1 62 and the spring 1)
adapted to press the contact arm upwardly and turn the rocking handle so that
when the rocking handle is thrown over in the one or the other direction the
contact arm A is thereby rocked about one or other of its two fulcra b' be for the
purpose and substantially as herein before described with reference to Figs. 8 and 9
of the accompanying drawings.
4. In an electrical switch of the kind herein referred to and in combination
with the rocking handle F, the double or single contact arm A jointed to the
rocking handle and mounted on the two fulcrum bars b 63 which engage in
notches a6 a7 in the contact arm A and the spring D adapted to press the contact
arm upwardly and turn the rocking handle so that when the rocking handle F
is thrown over in the one or the other direction the contact arm A is thereby rocked
about one or other of its two fulcra 61 62 for the purpose and substantially as
herein before described with reference to Fig. 7 of the accompanying drawings.
Dated this 4th day of June 1897.
CHARLES BOSWORTH KETLEY.
Agent for the Applicant.