IMPROVEMENTS IN FITTINGS FOR ELECTRIC LIGHTING, APPLICABLE ALSO TO OTHER PURPOSES "
Year: 1883

page_text: LETTERS PATENT to John Holmes Sheldrake of Stockwell in the County of
Surrey for an Invention of "IMPROVEMENTS IN FITTINGS FOR ELECTRIC
LIGHTING, APPLICABLE ALSO TO OTHER PURPOSES
"
PROVISIONAL SPECIFICATION left by the said John Holmes Sheldrake at
the Office of the Commissioners of Patents on the 18th September 1883.
JOHN HOLMES SHELDRAKE of Stockwell in the County of Surrey IMPROVE-
MENTS IN FITTINGS FOR ELECTRIC LIGHTING APPLICABLE ALSO TO OTHER
PURPOSES
This invention relates more particularly to electric lighting but it is also
applicable to telegraphic, telephonic, and other electrical purposes and consists
chiefly in a novel construction of contact maker and breaker The invention also
consists in a novel arrangement of means for carrying the contact maker and for
securing the same to the walls of apartments.
The contact maker consists of a quick threaded screw of some insulating
material which carries on its upper end a metal disc This disc is intended to
form the connection between two binding screws carried by a block of insulating
material suitably arranged above the screw. As it is essential that to ensure
proper contact the rubbing surfaces should be perfectly clean I form the screw
with a square end which fits into a corresponding hole in the disc, the disc will
thus be caused to turn with the screw and as it comes into contact with the
binding screws a slight rubbing or scraping action will take place which will serve
to keep not only the disc but the screw heads clean.
The block of insulating material is secured in any convenient manner in a
cylindrical metal casting which is open at one end and is provided at opposite
sides with hollow arms or extensions.
One of these extension is provided with a union joint by which it is connected
to a socket on a fixing or wall plate, a suitably shaped rose being first screwed
onto the socket to hide the wall plate. The other extension is, in the case of an
electric lamp, connected by a pendent or other arm to the lamp The wires will
pass from the wall through the socket to the contact maker

page_text: The open end of the cylindrical casting is closed by a screw cap through which
the quick threaded screw is passed.
In the upper side of the block of insulating material I form a groove in which I
lay the insulated return wire, the leading wires being secured to the block by the
binding screws before mentioned.
By the above construction of contact maker and breaker it will be seen that the
contact can be made or broken with great facility and rapidity and that the risk
of danger from sparks will be reduced to a minimum
I may here remark that the means for carrying the contact maker may be
varied according to the use for which the contact maker is to be applied but the
above described means will be found readily adaptable for all electrical purposes.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent and of
an Order of the Lord Chancellor filed by the said John Holmes Sheldrake in
the Patent Office on the 20th March 1884.
JOHN HOLMES SHELDRAKE of 44 Stockwell Park Road, Stockwell, in the
County of Surrey-IMPROVEMENTS IN FITTINGS FOR ELECTRIC LIGHTING
APPLICABLE ALSO FOR OTHER PURPOSES
This invention relates more particularly to Electric Lighting but it is also
applicable to Telegraphic and Telephonic and other electric purposes and consists
chiefly in a novel construction of contact maker and breaker
The invention also consists in a novel arrangement of means for carrying the
contact maker and for securing the same to the walls of apartments
The contact maker consists of a quick threaded screw of some insulating
material which carries on one end a metal disc, this disc is intended to form the
connection between two binding screws carried by a block of insulating material
suitably arranged at the end of the screw, as it is essential that to ensure proper
contact the rubbing surfaces should be perfectly clean
I form the screw with a square end which fits into a corresponding hole in the
disc, The disc will thus be caused to turn with the screw and as it comes into
contact with the binding screws a slight rubbing or scraping action takes place
which serves to keep not only the disc but the screw heads clean
The block of insulating material is secured in any convenient manner in a
cylindrical metal casting which is open at one end and is provided at opposite
sides with hollow arms or extensions
One of the extensions is provided with a union joint by which it is connected to
a socket on a fixing or wall plate, a suitably shaped rose being first secured on to
the socket to hide the wall plate, the other extension is in the case of an Electric
Lamp connected by a pendant or other arm to the Lamp
The wires will pass from the wall through the socket to the contact maker
The open end of the cylindrical casting is closed by a screw cap through which
the quick acting screw is passed
In the upper side of the block of insulating material I form a grove in which I
lay the insulating return wire, the leading wires being secured to the block by
binding screws as before mentioned
On the other or outer end of the quick acting screw I fix a metal lever or arm
weighted at the end, this is for the purpose of opening or closing the contact by
moving it from right to left-By being thus weighted the contact is certain to be
open or closed-When used on Pendants or Electroliers where it cannot be reached
by hand it is easily acted upon by the use of a long stick or rod so as to open or
close the contact as required In the application of this invention for Telegraphic
or Telephonic purposes I use a round milled head to the screw in place of the
lever arm
By the above construction of contact maker and breaker it will be seen that
the contact can be made or broken with great facility and rapidity and that the
risk of danger from sparks is reduced to a minimum
I may here remark that the means for carrying the contact maker may be
varied according to the use for which the contact maker is to be applied, but the
above described means will be found readily adaptable for all electrical purposes
In order that the foregoing may be more easily understood, Drawings are
attached to this specification of which the following is a description
Fig 1 is a section of my invention as applied to Telegraphic or Telephonic
purposes A is the screw made of wood or any insulating material B is a block

page_text: of insulating material to which are attached the two binding screws S. S which
are connected with the electric wires n. n. e. is a metal disc worked by the action
of the screw A so as to form a contact between the two binding screws S S. O is
the screwed cup in which the screw A works and p. is the metal case for attaching
to wood block D or to the wall
Fig 2 is a plan of the above.
Fig 3 is an elevation of my contact maker, as applied to a Bracket, the action
or direction of movement of the lever is shown by dotted lines
Fig 4 is a section of the above-H is the wall plate K the rose to cover same
which is screwed on to the wall plate H-m. is a cap or union for attaching the
arm to the wall plate to facilitate the electric wires being passed through-B is a
block of insulating material and f. f. are the binding screws
Fig 5 is a section of Fig 3. on the lines a b-A is the screw B the block G the
lever O a screw cap in which the screw works e. is the disc. n. n. are the electric
wires
Fig 6 is a section on the line c. d. and shows the grove in block B for the return
wire n.
Fig 7 & 8 represent a front and side elevation as I propose to adapt my
Invention to pendants and electroliers
Having thus described the nature of my Invention and in what manner the
same is to be performed I. claim
First The application of a screw to form a contact maker and breaker for
electrical purposes
Second The application of a metal disc with a rotary movement so as to form
a clean metallic contact with the binding screws in connection with the wires
conveying the electric current
Third The screw having a weighted lever the contact must either be perfect
or completely broken, it cannot be left partly formed, so as to cause a spark to
pass between the binding screws and disc, which would cause damage to the
insulating material
Fourth The contact maker and breaker being cased in metal and away from the
wall or ceiling where it may be fixed, there is no risk from fire as is the case with
the ordinary switches usually fixed in walls
Fifth An economical and simple method of conveying the electrical wires
through wall brackets or electroliers
In witness whereof I the said John Holmes Sheldrake have hereunto set my
hand and seal this nineteenth day of March in the year of our Lord oue thousand
eight hundred and eighty four
JOHN HOLMES COTTADAT
JOHN HO
HN HOLMES SHEDAKT (L.B.)