IMPROVEMENTS IN MECHANICAL ATTACHMENTS FOR USE WITH INCANDESCENCE ELECTRIC LAMPS
Year: 1884

page_text: COMPLETE SPECIFICATION.
I, ROBERT PERCY SELLON of 112, Belvedere Road Lambeth, in the County of
Surrey Engineer do hereby declare the nature of my invention for IMPROVEMENTS
IN MECHANICAL ATTACHMENTS FOR USE WITH INCANDESCENCE ELECTRIC LAMPS and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:―
My Invention relates to Improvements in the construction of mechanical
attachments for use with "incandescence" la ups, for rapidly and readily effecting
the electrical connection and disconnection of the “incandescence” lamp with the
wire or wires from the source of electricity.
The manner in which I carry out my Invention will be readily understood
on reference to the drawings accompanying & forming part of this complete
specification.
My attachment consists of two parts, the "cap" shewn partly in section in
Fig: 1 and the "socket" also shewn partly in section in Fig: 4. This is the form
of my Invention, which I preferably employ.
"
:
The "cap Fig 1, I generally make out of a short length of round piping of
metal, wood or other suitable material. This "cap "I fasten, as shown in Fig: 1.,
to the incandescence lamp by means of Plaster of Paris or other suitable cement of
electrically insulating properties. I make the "cap" Fig: 1 of such a size as to
enable it to freely slide into the "socket" Fig: 4.
The method I employ for electrically connecting the lamp to the cap and other
details, will be readily understood on reference to Fig 1. of the accompanying
drawings.
37
"
Through the cement " a I lead wires "b. 61, electrically connected to the
terminals "ac" of the incandescence lamp, to suitable contact pieces, which
project slightly from the bush "
as shewn & I prefer to refer to as the " cap
contacts"
"dd" and which I make of metal or other suitable conductor of
electricity. These contacts "d. "I mount at a convenient radial distance, as
shewn in Fig: 2, from the axis line of my attachment, on the insulating bush "e"
and in the sides of the "cap" I suitably fix one or more pins "ff" as shewn,
which serve to secure the tubing to the bush "e." In some cases I make the
"cap" out of one piece of material, preferably of electrically insulating properties
as shewn in Fig: 3 of the drawings.

page_text: The socket, Fig: 4, into which the "cap" slides, I preferably make of metal
tubing, to which I attach a cap "g," which I fasten by any convenient means,
preferably employing a "female" screw, to the bracket or fitting for carrying the
attachment.
.
For mechanically fastening the "cap" Fig: 1 to the "socket" Fig: 4. 1 employ
the well known "bayonet joint" connection and for this purpose I cut one or more
slots "h" Fig: 4, in the sides of the "socket." In the slot or slots "h" I cut a
notch "so that when the "cap" is given the full "quarter turn" employed in
making the joint: the pin or pins."ff" Fig: 1, above referred to, in the sides of
the cap "bed into the notch "i" and the "cap" can only be removed from this
position by hand.
In one of the ends of the "socket," I fix a bush "j" Fig: 4 and I arrange to
3 to
avoid complication, that the screws "L. 11" not only fasten the bush "j
the cap "g" but also serve to fasten the cylindrical or tube portion of the
socket "mm" to them. In the bush "j" I drill two holes "n. n¹" preferably
parallel to the axis line of the attachment, through each of these holes I bring one
of the conducting wires, connected to the source of electricity. My object in
employing two holes is to prevent contact between the wires in the fitting & to
These
enalle me to employ two holes, I make the bush "j" removable.
conducting wires I fasten by means of the pins or screws o. o" which serve both
to secure the springs "p. p" to the cap "" and to fasten or bind the wires to the
springs "p. pl. These springs "p. pl" I refer to as the "socket contacts."
"
This
In Fig 4. I have shewn the edge of the "socket" divided up into fingers.
is the form in which I prefer to make the socket. My object in dividing the edge
up is, that should the lamp be placed in a position where there is much vibration,
the elastic pressure which those fingers exert on the lamp globe, when the lamp is
in the socket, in combination with the notch "i" keep the lamp firmly in the
holder. For positions where there is little or no vibration, I employ a form of
"socket" shewn in Fig: 6 of the drawings. In this case I keep the edge of the
-socket continuous, as dividing it up tends to weaken it somewhat, and to enable me
to keep it so & cut the necessary slots "h" I make the socket "bell mouthed
shewn.
"
JJ
as
The shaped springs "p. 21" I employ & the manner in which I dispose them
will readily appear from Figs. 4. 5. I fasten these springs in the bush "j" by
means of the screws or pins o. o¹" at one of their ends, and at their other or free
ends I bend them up, as shewn in the drawings and I place them at the same
radial distance from the axis line of the attachment as the contacts "dd" on the
cap Figs 1. 2, are placed.
As I give the quarter turn necessary to fix the cap and lamp in the "socket,"
the contacts "d. d¹" come into electrical contact with the springs "p p¹" which
are made of some suitable conductor of electricity, the contacts "d. d¹" being
caused to rise over the springs "pp," thereby compressing the latter in proportion
as the quarter turn is given: thus the same action which effects the mechanical
connection between the "cap" & "socket," also secures the making and main-
taining of an efficient electrical connection between them.
"
My object in making the insulating bush "j" and cap "g" removable from the
.tubing m m¹" in the socket, is to enable the necessary connections to be made
between the conducting wires and socket with great facility. In one modification
of my attachment, I use only one "cap contact" and one "socket contact," using in
this case the attachment itself which I make of conducting material as part of the
"t return lead. I sometimes also place, when convenient, the contact "d. ď¹” on
the socket & the springs "p. p¹" on the cap.
Having now particularly described & ascertained the nature of my said
Invention and in what manner the same is to be performed, I declare that what
I claim is :-
(i) The cap or receiver for incandescence. lamps substantially as herein before.
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page_text: ii) The socket or holder whereby the capped lamp is firmly held, the necessary
electrical contacts being at the same time automatically made: substantially
as herein before described, and shewn in the Figs 4. 5 & 6 of accompanying
drawings.
ii) The combination of the insulating bush
e," the projecting screws or
suitable contact pieces d d and the pins ff' substantially as described and
shewn in Figs 1.2 & 3 of the accompanying drawings.
v) In mechanical] attachments for incandescenco electric lamps the combination
of two metallic supports "m. m₁" exerting an elastic pressure upon the
lamp in combination with the bayonet slots "h" and notch "i" to retain
the lamp firmly in position, substantially as hereinbefore described.
v) The contact springs "p. p₁" held by the screws 0. o1" in combination with
the bayonet slot "h" and nutch "i" as hereinbefore described and shewn
in the accompanying drawings.
"
i) The screws . whereby the insulating bush "j" supports "m m¹" and
cap "g" are readily removable, for the purposes herein before described.
ii) The insulating bush "e" fitted with contact springs "p. pl" in com-
bination with the bush "j" and contact pieces "dd" fitted thereto, as
herein before described.
ii) The bush "j" fitted with two separate holes "n n¹" in combination with
the screws ". " whereby the bush is connected to the cap "g" but is
casily removable when desired, for the purposes hereinbefore described.
Dated this 4th day of December 1884.