AN IMPROVED CONSTRUCTION OR ARRANGEMENT OF ELECTRIC SWITCH OR APPARATUS FOR MAKING AND BREAKING CONTACTS
Year: 1883

page_text: LETTERS PATENT to John Lea of 43 Clarence Gardens Regents Park in the
county of Middlesex Telegraph Engineer for an Invention of AN IMPROVED
CONSTRUCTION OR ARRANGEMENT OF ELECTRIC SWITCH OR APPARATUS FOR
MAKING AND BREAKING CONTACTS
PROVISIONAL SPECIFICATION left by the said John Lea at the Office of
the Commissioners of Patents on the 11th August 1883.
JOHN LEA of 43 Clarence Gardens Regents Park in the county of Middlesex
Telegraph Engineer AN IMPROVED CONSTRUCTION OR ARRANGEMENT OF ELECTRIC
SWITCH OR APPARATUS FOR MAKING AND BREAKING CONTACTS
This invention relates to improvements in electric switches or contact breakers
for making and breaking the circuit of electric currents whereby a perfect contact
and break are ensured as well as greater cleanliness of the various parts. The
wearing parts of the switch are made removable to ensure greater durability than
in the case in other switch in use.
The switch is also constructed so that the electric spark which takes place on
breaking the circuit is divided into several small sparks by which means the
destruction of the various parts by oxidization is reduced to a minimum.
For the purposes of my invention two terminals are connected by a cross piece
which is moved or actuated by a handle to make and break the contact
This cross piece is kept up against the underside of the terminal plate when
breaking the contact by ineans of a spring underneath said cross piece so that the
lower portion of the terminal plates is always kept clean or free from oxidization
caused by the sparks which is an important feature of the invention.
I provide the cross piece with movable parts studs or scrows at each end so that
when the sparks take place the parts on the cross piece as well as on the terminal
plates which are affected by the sparks can be renewed at any time and the switch
be as good as ever which is another feature of the invention.
Instead of one cross piece for making and breaking the contact I use several cross
pieces by which means I divide the sparks into several small sparks thereby
reducing the wear by oxidization considerably. In such case I also provido as
many intermediate contact plates as there are broak ends in the cross pieces in
addition to the two terminal breaks.
A spring is employed to ensure a sudden and complete break of the current when
the handle is operated upon for the purpose

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Lea in the Patent Office on the 11th February 1884.
JOHN LEA of 43 Clarence Gardens Regents Park in the county of Middlesex
Telegraph Engineer "AN IMPROVED CONSTRUCTION OR ARRANGEMENT OF ELECTRIC
SWITCH OR APPARATUS FOR MAKING AND BREAKING CONTACTS
"
This invention relates to improvements in electric switches or contact breakers
for making and breaking the circuit of electric currents whereby a perfect contact
and break are ensured as well as greater cleanliness of the various parts. The
wearing parts of the switch are made removable to ensure greater durability than
is the case in other switches in usc.
The switch is also constructed so that the electric spark which takes place on
breaking the circuit. .is. divided into several small sparks by which means the
destruction of the various parts by oxidization is reduced to a minimum.
-For the purpose of my invention of which Figure 1 is a plan with the handle
removed and Figure 2 a sectional-elevation two_terminals are connected by a cross
piece which is moved or actuated by a handle to make and break-the-contact.
This cross piece a is kept up against the underside of the terminal plate wlien
breaking the contact by means of a spring b underneath said cross piece so that the
lower portion of the terminal plates is always kept clean-or free from oxidization
caused by the sparks which is an important feature of the invention
I provide the cross piece with movable parts, studs or screws co at each end so
that when the sparks take place the parts on the cross piece as well as on the
terminal plates which are affected by the sparks can be renewed at any time and
the switch be as good as ever which is another feature of the invention.
Instead of one cross piece for making and breaking the contact I use several cross
pieces by which means I divide the sparks into several small_sparks thereby
reducing the wear by oxidization considerably. In such cases I also provide as
many intermediate contact plates as there are break ends in the cross pieces in
addition to the two terminal breaks.
A spring d is employed to ensuro a sudden and complete break of the current
when the handle is operated upon for the purpose.
My invention consists of the improvements in what is known as switches or cut
outs hereinafter described so that electric currents of large electro motive force may
be cut off or switched into other circuits of greater resistance without materially
damaging the switch or cut out by sparking or arcing.
I
I will describe my invention as applied to a large current say 1000 volts
where the current is to be cut off by broak of the circuit. For this purpose
employ an instrument of about forty four breaks thus dividing the arcing or
sparking into forty four parts which divisions will cause the sparks to be so small
as to do no harm to the instrument by burning. I do not depend upon the forty
four breaks or broken contacts to convey the current all the time it is in use there-
fore I provide cach cut out or switch with a short circuiting piece as shown in
Figure 3 at D and at Figure 4 where it is shown in plan with its two spring pieces
attached for making rubbing contact with terminal pieces b¹ b³
In Figure 3 PP are connections from the terminal b' to the first contact S
which is one of another row similar to those marked down each side B¹ C¹ of which
there are cleven on each of the four sides of the instrument. Supposing the terminal
on the right side be positive then the current will pass down its connection P
to the first contact piece B¹ which is a single one, then through the cross piece B to
the contact piece C₁ on the left side; this contact piece being a double one.
Its

page_text: other projection is in connection with cross piece N° 2 through which it passes by
the contact piece on the right, returning again by cross piece N° 3 and so on, until
t passes by No 11 through the bottom contact piece at R Figure 3 returning
brough the other eleven cross pieces E placed at right angles to the cross piece B
and contact pieces to the top of the instrument at S and thus to terminal negative
on the left.
The cross pieces E are similar to the cross piece B in construction and mako
circuit by similar contact pieces.
By turning the handle h it will be seen that bb will break off from b¹ 6ª but as
the block D is placed in such a position that it breaks off before the 22 cross pieces
no spark occurs at b and b' b because the current instead of passing by that way
passes by the 22 cross pieces and contact pieces until they break, when the spark
that would have been very large if it had taken place at b 6' is now divided into 44
small sparks.
T is a spring to keep all the contacts together and when the handle is turned in
the other direction these contacts make connection on the 22 cross pieces and raise
the whole of them causing the spring to be pressed. N is a nut to keep the
spring in position. M is a bush piece or bottoin bearing for the spindle carrying
the cross pieces, between each cross piece is an insulation which may be of any
known material marked C; the bottom of the centre spindle has a nut to bind tho
bottom one of these insulation washers to cross piece N° 11 where it will be seen
that a sufficient amount of play is allowed to enable the spring T to work.
Figure 5 represents another mode of carrying out my Invention; a round block
of wood A or other insulating material is recessed at the bottom to allow a spring
to act upon an eccentric or pin to prevent the break being left half way; this
block of wood is also recessed at the top to allow of another smallor round block A¹
to turn in. Upon the first named block is placed at proper distances a number of
contact pieces ee with a hole or holes made through each in which pieces of copper
ff or other wire or small rods of copper or other metal of low resistance are placed
and fixed by a side screw, upon the small block is placed a corresponding number
of projecting arins g g on the ends of which are fixed contact holders kk, theso
take the place of the cross piece shown in Figure 3. In these contact holders are
placed copper wire or rods or pins the same as in the above named pieces, with set
screws. There is also fixed upon this block a short circuiting piece m or make
piece, this make piece is fixed to the spindle carrying the handle and eccentric, the
short circuiting piece rides on one or two blocks of motal upon which are the
terininals n n. The small block of wood has a pin p fixed into it which works in
a slot q or hole in the make piece so that the make picce is turned with the spindlo
by the handle until it breaks off one of the above named blocks or terminals and
as soon as this takes place the pin being at the end of the slot turns the small block
with its arms and contact pieces and disconnects the wires or rods or pins which
are attached thereto from the wires or pins that are fixed by the adjusting screws
in the lower contact pieces on the larger block or base of the instrument; theso
wires or contact pins are made adjustable and removable and divide the destructive
effects of the spark amongst them leaving the make piece perfectly clean and free
from oxidization.
Figure 6 is another form of carrying out my invention or improvement in
switches, or cut-outs, or breaks. B is a box or caso upon the bottom of which is
placed a number of contact pieces C over which is placod a block of wood or other
non-conductor W upon which is fixed a number of springs S carrying on their ends
a metal piece C¹ fixed thereto, these pieces C to make contacts between the pieces
CC. In the centre of the spring block is a short spindle in which is fixed a
carrying pin P, over this is placed upon a ledge in the box another block of wood
or other insulating material upon which are arranged make piece and contact
pieces and terminals, under this said block is fixed the eccentric arrangement spring
as previously described. A spindle is placed to carry the make piece or cross piece
eccentric pin and handle; the eccentric pin is acted upon by a spring to prevent

page_text: the cross piece being left half way. At the bottom of this spindle is attached a
short tube slotted to take hold of the carrying pin P fixed in the spring block W,
this slot allows the cross piece attached to the handle to be off the contacts before
the contacts are broken C and thereby throwing the spark entirely upon the
break parts C and C¹ and so dividing the spark amongst them and keeping the
make piece perfectly clean.
The examples shown on the annexed sheet of drawings are only exemplifications
of the shape or arrangement preferred, it will therefore be understood that the
make pieces or switch may be in other forms or shapes than here shown.
Having now described the nature of my said Invention and in what manner the
same is to be performed, I wish it to be understood that I do not confine myself to
any particular form, shape, or arrangement of switch, cut-out, or break, but what I
claim is ;-
The construction of a switch, cut-out, or break so that the make piece shall be
free from the destructive effects of sparking by throwing the sparks upon a
number of contacts or breaks to divide the spark amongst then, which contacts
can be easily adjusted and replaced or renewed in the manner described and
substantially as shown in the annexed drawings.
In witness whereof I the said John Lea have hereunto set my hand and scal
this Ninth day of February in the year of our-Lord, One-thousand.eight hundred
and eighty four.