Improvements in Fittings and Switches for Incandescent Electric Lamps.
Year: 1888

page_text: Date of Application, 21st Nov., 1888.
Complete Specification Left, 21st Aug., 1889-Accepted, 16th Nov., 1889
PROVISIONAL SPECIFICATION.
Improvements in Fittings and Switches for Incandescent Electric
Lamps.
I JAMES YATE JOHNSON of 47 Lincolns Inn Fields in the County of Middlesex
Gentleman do hereby declare the nature of this invention which has been commu-
nicated to me from abroad by Theodore Mace of Montclair, Essex County, New
Jersey in the United States of America, Merchant, to be as follows:-
This Invention relates to the fittings by which the bulbs of incandescent electric
lamps are detachably connected to the chandelier bracket or the like with which they
It relates mainly to those fittings in which vitrite or other insulating
material is used in combination with metal.
are used.
In order to give a positive support to the bulb and shade especially where a com-
paratively brittle substance such as vitrite is used the screwed metal socket by which
the connection with the chandelier bracket or the like is made is provided with wing
or supporting pieces preferably embedded in the vitrite or the like and having at their
ends means whereby the holding tube which carries the bulb or bulb and shade is
connected thereto.
Such means consist for instance of screws constituting projections which engage
with bayonet joint slots in the holding tube. These screws can be tightened
up to pinch and firmly secure the said holding tube. Or the connection may be
made by bending over the ends of the said wings or supports so as to form projections
which pass into recesses in the said holding tube and in a ring screwed thereon so that
when this ring is screwed up the recesses therein are brought out of coincidence with
the recesses in the holding tube and the ring presses on the said projections of the
wings or supports and holds the parts firmly together. The screw on the holding
tube also serves for the attachment of the shade. The use of coiled springs upon nuts
which screw upon screws and constitute pinching nuts or binding screws for the
attachment of the lead wires passing through a slot in the screw on which the nut
works the said coiled springs bearing upon the contact pieces of the lamp terminals
have before been proposed or used but this arrangement presents the disadvantage
that the pressure of the springs varies with the thickness of the wire secured by the
nut. To overcome this objection the nuts are made separate from the springs and are
caused to press each lead wire upon a plate to each of which one of the coiled springs
is fixed so that whatever thickness the lead wires may be the pressure of the springs
remains the same.
In order to form a convenient switch (for lighting and extinguishing the lamp)
instead of using the coiled springs for the connection with the lamp terminals the
connection may be made by means of blade springs bent upwards from or attached
to the plates on which the binding nuts press the lead wires, these blade springs
standing normally in such a position that they do not complete the circuit to the
lamp. Between the said blade springs there is mounted on a spindle projecting out-
side the holder and provided with a bandle for turning it an eccentric or cam shaped
piece which when turned in one position allows the springs to leave contact with the
terminals or conducting piece leading to the lamp but when turned into the other
position the said excentric or cam piece forces the springs outwards so that they each
bear on a terminal or conducting piece and complete the circuit to the lamp. This
electric connection may be made by means of brasses and spiral springs secured in a
vitrite or other non-conducting disc set in the lamp holder, the aforesaid blade springs

page_text: bearing on the one end of these brasses and spiral springs when the circuit to the lamp
is completed, the other end of each of the said brasses and spiral springs bearing on
the lamp terminals.
Dated this 1st davr of November 1980.
J. H. JOHNSON & Co.,
Agents.
COMPLETE SPECIFICATION.
Improvements in Fittings and Switches for Incandescent Electric
Lamps.
I JAMES YATE JOHNSON of 47 Lincolns Inn Fields in the County of Middlesex
Gentleman do hereby declare the nature of this Invention (which has been commu-
nicated to me from abroad by Theodore Mace of Montclair Essex County New Jersey
in the United States of America Merchant) 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 the fittings by means of which the bulbs of incandescent
electric Lamps are detachably connected to the chandelier bracket or the like with
which they are used and to switches by means of which the electric current is turned
on to or off from the lamp.
I will describe the Invention with reference to the accompanying Drawing Figure 1
of which shews in section a fitting complete including a switch and shewing a part of
the bulb of the lamp with which it is used. Figure 2 is a plan of the same with the
bulb removed. Figure 3 is a section (of an arrangement without a switch) showing
the mode of forming the fitting so that the positive support is given by metal and
shewing also the shade connection. Figure 4 is a perspective view of the exterior of
the same and Figure 5 is a plan of the interior of the same and Figure 6 is an eleva-
tion and plan shewing the device for connecting the lead wires with the springs
which give contact with the lamp terminals. Figure 7 shews the socket for attach-
ment to the electrolier bracket or the like with the metal arms to take the strain
as hereinafter described. The switch for turning the current onto and off from
the lamp is shewn clearly in Figures 1 and 2 and is hereinafter fully described
but I will first describe the other parts of the fitting as it will facilitate the
description of the switch but I premise that the switch is not limited to use with
the particular details of the fittings which I shall describe.
In order to give a positive support to the bulb and shade, especially where a
comparatively brittle substance such as vitrite is used, the screwed metal socket a
Figures 1 and 3 by which the connection of the support with the electrolier
bracket or the like is provided with metal arms wings or supporting pieces b
preferably embedded in the vitrite or like body c of the support and having at
their ends 62 means whereby the holding tube which carries the bulb or bulb and
shade is connected thereto. Such means may consist for instance of screws d as
shewn in Figures 1, 2 and 7 screwing into the ends of the wings b and consti-
tuting projections which engage with bayonet joint slots e in the holding tube f
which screws can be tightened up so as to pinch and firmly secure the holding
tube in position. Or instead of the screws d the connection may be made by
bending over the ends 62 of the wings or supports 6 as shown in Figure 3 so as
to form projections which pass into recesses 9 and g³ formed respectively in the
holding tube and in a ring screwed thereon so that when the ring his
screwed up on the tube f the recesses in the holding tube are brought out of
coincidence with the recesses g² in the ring hand the said ring presses on the
projections of the wings or supports and thus holds the parts firmly together.
The screw in the holding tube also serves for the attachment of the shade of the

page_text: lamp which is held between the loose collar and the screwed collar k screwed
onto the tube f. The wings b carry the whole of the weight of the lamp whilst
the vitrite or other material only has to provide form and insulation.
The use of coiled springs upon nuts which screw upon screws and constitute
pinching nuts or binding screws for the attachment of the lead wires passing
through a slot in the screw on which the nut works; the said coiled springs
bearing upon the contact pieces of the lamp terminals, have before been proposed
or used but this arrangement presents the disadvantage that the pressure of the
springs varies with the thickness of the wire secured by the nut.
To overcome
this objection according to this invention the nuts are made separate from the
springs as shown in Figure 3 and also as shown in the detached modified arrange-
ment Figure 6 and in which latter arrangement the nuts press each lead wire
upon a separate plate m to each of which plates one of the coiled springs n is
fixed so that whatever thickness the lead wires may be the pressure of the springs
remains the same. In the arrangement Figures 3 and 4 the springs are secured
to stems screwed at their bases upon which screwed portion the binding nut is
mounted. In order to form a convenient switch (for lighting and extinguishing
the lamp) instead of using the coiled springs and the connection with the lamp
terminals for the purpose the arrangement illustrated by Figures 1 and 2 is
employed in which the connection is made by means of two blade springs pp
which are respectively bent upwards from or attached one to each of the
plates in the part a, on which plates the binding nuts press the lead wires
these blade springs p standing normally in such a position as shown in dotted
lines that they do not complete the circuit to the lamp by pressing on the
Between these
conducting sockets with which the springs & are in contact.
blade springs p p there is mounted on a spindle g an eccentric or cam shaped piece "
which when the spindle q is turned into one position by means of a handle fast on the
projecting end thereof allows the springs p to break contact with the sockets * or
other terminals or conducting pieces leading to the lamp but when turned into the
other position (shewn in full lines) the said eccentric or cam piece forces the
springs p outwards so that they each bear on one of the sockets or other terminals
or conducting pieces and complete the circuit to the lamp. Or the reverse may take
place that is to say the contact may be broken by forcing the springs apart by the
cam piece and the contact made when the pressure of the cam is removed.
The electric connection with the lamp terminals is preferably made by means of the
sockets and spiral springs & secured in a vitrite or other non-conducting disc t set in
the tube of lamp holder the blade springs p bearing on the one end of these sockets &²
when the circuit to the lamp is completed the ends of each of the spiral springs s
bearing on the lamp terminals but I do not limit myself to the use of this form of
connection with the said switch.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. A switch for incandescent electric lamps the said switch consisting of blade
springs and a cam or eccentric for forcing the said springs into or out of contact with
contacts for completing or breaking the circuit through the lamp as required substan-
tially as herein before described.
2. A fitting for the bulbs of incandescent electric lamps consisting of a screwed
socket of metal for connecting the fitting to a chandelier bracket or the like the said
screwed socket being embedded in vitrite or other suitable insulating material and
being provided with metal wings or arms having screws or projections for engaging in
slots in the lamp holder tube so that the strain or weight is borne by the metal substan-
tially as herein before described.
3. The general combination and arrangement of parts constituting a combined
holder and switch for incandescent electric lamps substantially as hereinbefore
described and illustrated by Figures 1 and 2 of the accompanying drawings.

page_text: 4. The means for securing the part a tube f and shade together substantially as
herein before described and illustrated in Figures 3 and 4 of the accompanying
drawings.
5. The arrangement of contact springs which are independent of the nuts which
pinch the lead wires as and for the purpose herein before described and shewn in
Figures 34 and 5 and Figure 6 of the accompanying drawings.
Dated this 21st day of August 1889
J. H. JOHNSON & Co.,
Agents.