Improvements in Holders for Electric Glow Lamps.
Year: 1889

page_text: Date of Application, 3rd Apr., 1889
Complete Specification Left, 1st July, 1889-Accepted, 20th July, 1889
PROVISIONAL SPECIFICATION.
Improvements in Holders for Electric Glow Lamps.
I, ALEXANDER BERNSTEIN, of 2, Marlborough Mansions, Victoria Street, Pimlico
in the County of London, and Mühlenkamp, Hamburg, in the Empire of Germany,
Electrical Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention relates to holders for glow lamps arranged in series.
Such holders have to fulfil very different conditions from those which are required
for an arrangement of lamps in parallel. In the latter case the removal of one lamp
from its holder has no influence on the other lamps in the same circuit; but when
lamps are placed in series, an interruption of the circuit would occur if no provision
were made against such interruption.
Hitherto I have accomplished this by means of the automatic cut-out, but since
I have placed the automatic contact inside the lamp, a new construction of the holder
has become necessary.
The holder must answer to the following conditions, videlicet.
Firstly It must only allow the removal of a lamp from its holder after a short
circuit has been made in the holder itself.
Secondly The arrangement of the short circuit must be such that the current
cannot be turned on unless a lamp is placed into the holder.
I have fulfilled these conditions by the following means:-
The lamp holder is provided with two metal sleeves which are of suitable size to
receive two pins attached to the lamp cap and through which the conductors of the
lamp are passed. These sleeves are widened out at their lower ends for the reception
of the screws, by means of which the conducting wires are fastened, and are fastened
to a plate of insulating material which latter is attached to the base plate of the
holder.
In order to obtain a good contact between the pins of the lamp and the sleeves
one side of each sleeve is composed of a flat spring in such a manner that when the
pins.of the lamp are put into the sleeves the springs are bent outwards whereby a
pressure is produced between the springs and pins.
In order to obtain a short circuit between the metal sleeves and therefore to short
circuit the lamp, in case there is one in the holder I make use of an S-shaped piece
having its bearing in the insulation plate and provided with a handle.
In order to secure a good contact between the S-shaped piece and the metal
sleeves, I again make use of two flat springs which are attached to the said sleeves.
I have stated above that if a short circuit is made in the holder without a lamp being
put in it must be impossible to break the short circuit as otherwise the main circuit
would be broken or an arc be formed. It is therefore necessary to secure the S-shaped
piece in position. This is accomplished by means a pin which is fastened to one of
the springs and engages with the said piece. If, however, a lamp is put into the
holder the flat springs are pressed outwards and the pin on the spring comes out of
engagement with the S-shaped piece so that the latter can be turned by means of
the handle.
To prevent the lamp from being withdrawn before the current is short circuited a
pin having a knob is attached to the lamp cap in such a manner that when the
S-shaped piece is turned for the current to pass through the lamp it will engage
beneath the said knob so that the removal of the lamp is impossible.
Dated the 2nd day of Annil 1900

page_text: Figure 6 is an underside view.
Figure 7 is a view of a detail.
a is the base-plate or foundation of the holder and b is a plate of insulating material
which is secured to the said foundation; in the drawing à screw e is employed for
effecting the attachment of the said "insulating plate.
d, dare two metal sleeves which are adapted to receive pins e, e, attached to the
lamp-cap, and which are secured to the insulating plate 6; one end of each sleeve being
adapted to receive a screw f, as shown in Figs. 1 and 2, by means of which the
conducting wires are secured."
In order to obtain a good contact between the pins ee of the lamp and the sleeves
d, d' one side of each sleeve is composed of a flat spring such as 9, or g), which
springs are attached to the tubes d, d', respectively. These springs are bent inwards,
as shown in fig. 5, in such a manner that when the pins e, e are introduced into
the sleeves d, d the said springs are moved outwardly, whereby the springs are caused
to bear with a certain amount of pressure upon the pins e, e..
In order to obtain a short circuit between the metal sleeves and therefore to short
-circuit or cut out the lamp, in case there is one in the holder, I make use of a switch-
piece of S-shape, having its bearing in the plate band provided, on the opposite
iside of the plate from that upon which the switch-piece h works, with a handle i by
means of which the switch-piece can be operated.
To ensure a good contact between the switch-piece and the sleeves g, g¹, I again
make use of flat springs j, j which are attached to the sides of the said sleeves, as
shown most clearly in figs. 1 and 2.
7

page_text: I have before stated that the removal of a lamp from its holder must only be possible
after a short circuit has been made in the holder itself. If this were not the case the
main circuit would be broken or an arc be formed. It is therefore necessary to lock
the switch piece h in such a manner that it cannot be operated to break the short circuit
until a lamp is introduced into the holder. This is accomplished by means of a pink,
which is attached to the free end of the spring g and adapted to engage with one
extremity of the switch-piece h, as shown in fig. 2. This extremity is bevelled, as
shown at in fig. 7 so that it can pass freely beneath the said pink. If, however, a
lamp is put into the holder the flat springs g, g¹ are pressed outwards by the pins e, e
and the pink is moved out of engagement with the switch-piece 1, so that the
latter can then be turned by means of the handle i.
To prevent the lamp from being withdrawn before the current is short circuited a
pin m having a knob n at its extremity is attached to the lamp cap, in such a manner
that when the switch-piece is turned for the current to pass through the lamp it will
engage beneath the said knob, as shown in fig. I so that the removal of the lamp is
impossible.
o is a metal casing which encloses the mechanism hereinbefore described, the said
casing being attached to the foundation by screws, as shown in fig. 1. o¹ is a plate
which serves to close the slot formed in the said casing to allow the latter to pass over
the handle i.
The operation of the apparatus herein before described is as follows, that is to say,
when no lamp is in the holder the switch-piece is in the position shown in fig. 2 so
as to complete the circuit between the sleeves d, d', the switch-piece being prevented
from moving, or being moved, by the pink on the spring g, as hereinbefore described,
so that the current is short circuited. When a lamp is placed in the holder the
spring g is pressed outwards, so that the pin & is disengaged from the switch-piece /;
the latter can then be turned to the position shown in fig. 1, so as to engage beneath
the knob; the current then passes through the lamp, and the latter cannot be again
removed from the holder until the switch-piece is returned to the position shown in
fig. 2 to short circuit the lamp.
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 holder for glow-lamps in series, comprising a switch-piece, which, when no
lamp is in the holder, is adapted to form a short circuit for the current, and which,
when a lamp is in the holder, serves to cause the current to pass through such lamp
and prevents the removal of the same until the current has been again short circuited,
substantially as described.
(2) The manufacture and use of the improved lamp-holder hereinbefore described
and illustrated in the accompanying drawing.
Dated the 1st day of July 18ea
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.