Improvements in Electric Lamps and in the Holders or Sockets therefor.
Year: 1894

page_text: Date of Application, 17th Feb., 1894
Complete Specification Left, 5th June, 1894-Accepted, 1st Dec., 1894
Improvements in Electric Lamps and in the Holders or Sockets
therefor.
We, DAVID HUNTER and WILLIAM ALEXANDER JACK of 101 St. Vincent
Street, Glasgow, Electrical Engineers, do hereby declare the nature of this inven-
tion to be as follows
Our invention, which relates specially to incandescent lamps and the holders or
sockets therefor, has mainly for its object to construct a combination switch holder,
which whilst being very simple in its construction and action shall be more effective
and reliable than the ordinary "Edison-Swan" and other, key or like switch-
holders.
In carrying out our invention under one arrangement, we make the cap of the
vacuum or other bulb of the incandescent lamp of vitrite, ebonite or other hard or
moderately hard insulating material and the filament terminals which are embedded
in the material, are connected to preferably flattened contact pieces or strips.
These pieces or strips may be of semi-circular, round, oval, rectangular or other
suitable shape and they may be fitted concentrically within the cap or radially or
otherwise across it. The cap is, as usual, provided with two projecting pins, which,
when the lamp is fitted to the holder, lock into two bayonet joint slots cut in the
shell or casing of the holder.
The usual bayonet ☐ shaped slots are made with a short vertical extension and a
comparatively lengthened horizontal extension.
When the lamp is fitted and locked to the holder, its terminal contact pieces
press against and bear on the usual spring plug contacts of the holder.
When it is desired to switch on or off the electric current, all that is necessary is
to merely turn the bulb or its cap partially round to either the right or left hand
so as to, either move the filament terminal contacts against and into contact with
the plug-contacts of the holder or away from and out of contact with them.
The surfaces of the contacts are always kept clean by the rubbing or
abraiding action caused by the contacts grinding against one another when being
turned.
In cases where the leads of the holder have concentric terminals, of which the
outer one may be the casing, it is necessary to, when turning the lamp bulb or cap
so as to switch off the current, lift the filament contact piece or pieces up out of
contact with one or both of them as the case may be. This is effected by making
the slotted extensions inclined and providing them with locking nicks or recesses
for the reception of the pins of the lamp cap.
If desired the lamp cap may be made with a milled edge or its equivalent, or
have one or more arms or projections on it to enable it to be easily turned; or, the
pins may be lengthened for the same purpose.
In some cases grooves may be made in the holder instead of slots.
The invention can be applied to the ordinary holders or sockets.

page_text: COMPLETE SPECIFICATION
Improvements in Electric Lamps and in the Holders or Sockets.
therefor.
We, DAVID HUNTER, and WILLIAM ALEXANDER JACK of 101 St. Vincent
Street, Glasgow, Electrical Engineers, 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 :-
Our invention which relates specially to incandescent lamps and the holders or
sockets therefor, has for its object to construct a combination switch holder,
which, while being very simple in its construction and action, shall be more
effective and reliable than the ordinary "Edison-Swan" and other key or like
switch-holders.
And in order that our said invention may be properly understood we have
hereunto appended an explanatory sheet of drawings, whereon.
Fig. 1 is a front elevation of an incandescent lamp with our improved holder.
Fig. 2 is a vertical section of the same.
Fig. 3 is a plan view of the cap of the incandescent lamp showing the filament
terminals.
Fig. 4 is an inverted plan view of the holder showing the usual spring plug
contacts.
Figs. 5 to 10 show slight modifications of the device.
On the drawings, a is the holder, b the glass bulb, c the filament, e, e¹ the spring
plug contacts, ff the filament terminals, g the lamp cap, and the casing of the
holder.
In carrying out our invention, under one arrangement, we make the cap g of the
vacuum or other bulb of the incandescent lamp of vitrite or ebonite or like hard or
moderately hard insulating material and the filament terminals f, f¹ which are
embedded in the material are connected to flattened contact pieces or strips such
as i, (Fig. 3). These pieces or strips may be of semi-circular, round, oval,
rectangular, or other suitable shape. The cap is, as usual, provided with two
projecting pins j, j', which, when the lamp is fitted to the holder, lock into two
bayonet-joint slots k, k¹ cut in the shell or casing of the holder.
The usual bayonet L shaped slot at each side of the casing his made with a
short vertical extension and a comparatively lengthened horizontal extension m.
Recesses n, n' are made at each end of the horizontal extension for the reception
of the projecting pins j, j¹.
When the lamp is fitted and locked to the holder, its terminal contact pieces i, i¹
press against and bear on the usual spring plug contacts e, e¹ of the holder.
When it is desired to switch on or off the electric current, all that is necessary is
to merely turn the bulb, or its cap, say a revolution, partially round to either
the right or the left hand, i.e., so that the pins j, j traverse the slots m from the
recesses n to n¹ or vice versa. This turning of the cap or bulb causes the filament
contacts i, i to move either into contact with the plug contacts e, e' of the holder
or away from and out of contact with them.
The surfaces of the contacts are always kept clean by the rubbing or abraiding
action caused by the contacts grinding against one another when being turned.
In order to make a quick break the slots m may be made as shown at Fig. 5.
In cases where the leads of the holder have concentric terminals, of which the
outer one may be the casing, it is necessary, when turning the lamp bulb or cap so
as to switch off the current, to lift the filament contact piece or pieces away out
of contact with one or both of them as the case may be. This can be effected by
making the slotted extensions m of the casingh inclined and providing them with
locking nicks or recesses n, n' at each end for the reception of the pins j, j of the
lamp cap as shown at Fig. 6.
.

page_text: In order to turn the lamp easily its cap may be provided with a milled edge ring,
or its equivalent, o as shown at Fig. 7, or it may have one or more arms such as p
Fig. 8. When an arm such as p is used it may be made as an extension of one of
the pins as shown at Fig. 8, or it may be secured to the body of the cap.
The
Fig. 9 shows the casing of the holder made at each side with a horizontal
slot m and a vertical extension m¹. A spring g is fitted on the outside of the casing
at each side. In this case the pins of the cap are inserted in the slots m at each
side of the holder and then pushed into the lower end of the vertical slots m²,
against the action of the springs q, and caused to rest in the lower recesses n.
arrangement such that, when the pins of the cap rest in the lower nicks n, the
terminals are out of contact, but, when the pins are in the upper recesses, the
terminals are in contact. In order to switch on the current all that is necessary is
to push up the cap until the pins on it rest in the upper recesses n¹ and to switch off
the current all that is necessary is to pull the cap down again until the pins rest in
the lower recesses n.
The springs 9 at each side retain the pins in the recesses n or n³.
In order to give a grinding contact the slots m' may be slightly inclined as
shown in dotted lines.
If desired, with overhead lamps having holders made as shown at Fig. 9, the pins of
the cap or the cap itself may be connected by cords, wires, or rods, to a suitable pulley
or lever arrangement, whereby the cap can be raised and lowered, and the pins
made to traverse the slots m, at will, so as to switch on or off the current.
The invention can be applied, as shown in plan at Fig. 10, to lamps having two
filaments one say a 16 candle power and the other a four candle power.
In this
figure r,, represent the terminals of the four candle power filament and s, s', the
terminals of the 16 candle power filament. By turning the bulb or cap either the
one filament or the other can be switched on or off at pleasure. If desired the cap
or bulb Figs. 1 and 2 can be turned by means of a lever or like arrangement.
In some cases grooves may be made in the holder instead of slots.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
consider novel and desire to claim is :
1. The combination of a lamp cap made with vitrite, ebonite, or equivalent, in
which the filament terminals are embedded; of contacts for the filament terminals
made of flattened strips so arranged that when the current is being switched on by
turning or moving the lamp bulb or cap they grind or rub against the contacts of the
holder and of a holder having slots m therein, substantially as herein before
described with reference to the drawings annexed.
2. The arrangement of slotted socket or holder with its retaining springs 9,
substantially as herein before described with reference to Fig. 9 of the drawings
annexed.
Dated this 4th day of June 1894
H. D. FITZPATRICK,
70, Wellington Street, Glasgow, Agent.