A Porcelain Insulator Disc for Capped Incandescent Lamp Holder.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
A Porcelain Insulator Disc for Capped Incandescent Lamp Holder.
I, WILLIAM DOUGLAS HASSALL, No. 80, Caroline Street, Birmingham, Electric
Light Fitting Maker, do hereby declare the nature of this invention to be as
follows:-
Made in the form of a circular block, with two mortice holes. to receive metal
base of spring buffer, base of buffer bei. fixed securely in mortice holes with
screws at bottom of insulator, the mortice holes having side caverties to admit the
heads of terminal screws which bind the wires for connecting purposes, the screws
being worked at an angle. This method of fixing screws make it very convenient
for wiring, and are got at much easier than on the ordinary insulator now in use.
The metal parts on mortice block insulator are perfectly insulated, the base of
buffer spring fitting into mortice holes of insulator, below the level of the face
of insulator, it is also well protected from outer case, being fixed in insulator in
this form, giving a higher insulation to the holder, and capable of a greater resist-
ance of the high tension system now in use. The block itself is more substantial
than the ordinary insulator, having only the holes for screws, mortice holes, and
caverties for screw heads, with a slot at side to keep it in position when fitted into
outer case.
Dated this 21st day of December 1897.
A Porcelain Insulator Disc for Capped Incandescent Lamp Holder.
I, WILLIAM DOUGLAS HASSALL, of No. 80, Caroline Street, Birmingham
Electric Light Fitting Maker, 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:-
This invention consists of the herein described improved porcelain insulator
disc or circular block for capped incandescent lamp holders. The said disc or
circular block is so arranged as to be not liable to break and to form perfect in-
sulation and enable the conducting wires to be readily and securely connected
to the terminals.
I will describe my invention by referring to the accompanying drawing on
which Fig. 1 is a general view of my improved porcelain insulator disc
or circular block and Fig. 2 is a plan of the same; Fig. 3 is a general view

page_text: and Fig. 4 is a plan of the said insulator disc or circular block with the terminal
screws and spring buffers fixed thereto; Fig. 5 shews the said insulator disc or
circular block applied to a capped incandescent lamp holder and Fig. 6 is an
inverted plan of the said disc or block with the conducting wires and connections.
The same letters of reference indicate the same parts in all the figures of the
drawing.
My invention is made in the form of a circular porcelain block A provided
with two mortise holes a¹ a² to receive the metal bases B1 B2 of the usual spring
buffers C C and having the porcelain insulating rib a between the two mortise
holes a¹ a². The bases B B2 of the spring buffers are fixed securely in the
mortise holes by the screws D1 D2 which pass through holes a³ a in the bottom
of the insulator block A into the metal bases B1 132 the heads of the screws D¹ Da
fitting in corresponding recesses formed in the bottom of the block A.
E' E are
the two terminal screws which bind the wires F1 F2 to the metal bases B¹ B2 these
wires passing through holes a ao in the block A. At a short distance above the
bottom of the block A. there is formed a projecting bead or collar a which as
shewn by Fig. 5 rests in the top of the metal outer casing G and is there secured
by the metal cap H which is secured to the outer casing G by the screwed collar I
which is screwed on to the cap H and is made with an inner flange ¹ to take
against a bead or flange g which is formed round the top of the outer casing G.
In order to prevent the circular block from turning in the outer casing G and.
cap H the said block is made with two side slots aa8 which engage with corre-
sponding inwardly projecting parts g² g³ of the outer casing G and with corre-
sponding projecting parts (not shewn on the drawing) formed in the interior of
the cap H. It is to be understood that the cap H and outer casing G and ring I
form no part of my invention.
It will be seen that the metal parts connected with the wire F1 are perfectly
insulated from the metal parts connected with the wire F and that the whole
of the metal parts are effectually insulated from the metal outer casing and cap
thus the block will effectually resist the high voltage power now in use with
incandescent electric lamps.
Having now particularly described and ascertained the nature of my said in-
vention, and in what manner the same is to be performed, I declare that what I
claim is:
The improved porcelain insulator disc or circular block A for a capped incan-
descent lamp holder made with the cavities a¹ a² to receive the spring buffers and
terminals and otherwise constructed substantially as herein before described and
illustrated by the accompanying drawing.
Dated this 21st day of September 1898.