Improvements in Insulating Blocks connected with Holders for Incandescent Electric Lamps.
Year: 1897

page_text: Improvements in Insulating Blocks connected with Holders for
Incandescent Electric Lamps.
I, JAMES BOOTH, of Cheapside Works, Birmingham, Manufacturer, do hereby
declare the nature of my said invention to be as follows:-
In insulating blocks for holders for electric incandescent lamps as hitherto
made there is a comparatively thin bar of porcelain or similar material placed
between the two contact pieces. This bar while fulfilling its purpose while whole
is liable to be broken and become useless for its purpose of keeping those metallic
parts in connection with the contact pieces, which necessarily are of opposite
polarity from any accidental contact which would result in a 'short circuit."
To effect this object I make the insulating block of one solid cylindrical piece
of porcelaine or suitable insulating and non combustible material shaped as
follows.
The upper part of this block is of a smaller diameter than the rest (or I may
construct the block with a flange) and is provided with recesses which take into
projections in the lamp holder to prevent it revolving therein.
Or I may have the projections on the block fitting into slots in the lamp
holder for the same purpose. I make two cylindrical holes through the block the
axis of each of these holes is parallel to the axis of the cylindrical block. In
each of these holes I place a cylindrical casing containing a contact plunger with
its helical spring.
In the upper part of each cylindrical hole for the contact plunger case there is
an annular collar projecting inwards. This serves for a purchase for the head of
a screw which passes in and takes into a tapped hole in the upper part of the
contact plunger case thereby securing the contact plunger case to the cylindrical
block.
About half way down the cylindrical block I form two cylindrical holes lying in
the same horizontal plane with their axis parallel to each other at right angles
to the axis of the cylindrical block.
In each of these holes I place a cylindrical piece of metal to the outer end of
which one of the conductors of the flexible wires is attached by means of a set
screw.
The inner end of each piece of metal abuts against and is in contact with the
upper end of the metallic case of the contact plungers. The upper end of the
case and the inner end of the piece of metal which touches it are each cut away
in the form of a step and fit against each other so that they prevent each other
from turning.
The vertical screws which hold the plunger cases in their places also by means
of the step shaped pieces firmly hold each metallic piece against its own contact

page_text: plunger case thereby ensuring good electrical contact between each vertical ·
plunger case and its horizontal metallic piece.
41
בד
100x
Improvements in Insulating Blocks connected with Holders for
Incandescent Electric Lamps.
I, JAMES BOOTH, of Cheapside Works, Birmingham, Manufacturer, do hereby
declare the nature of my said invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:
Hitherto insulating blocks for incandescent electric lamps have been made
with a thin bar of porcelain or similar material placed between the two contact
pieces, this bar is liable to be broken and become useless for its purpose of keep-
ing those metallic parts in connection with the contact pieces which necessarily
are of opposite polarity from any accidental contact which would result in a
short circuit.
To remedy this I make the insulating block of one solid cylindrical piece of
porcelain or other suitable insulating and non combustible material.
And in order that this my said invention may be more particularly described
and ascertained reference is hereby made to the accompanying drawings in which
similar letters of reference indicate corresponding parts in each figure where
they occur.
Figure 1 is a plan view of an insulating block with parts removed.
Figure 2 is a sectional view of same taken on the line A, B.
Figure 3 is a view as Figure 2 with parts in position.
Figures 4-5 are respectively views in elevation and section of one part detached
from the insulating block.
Figures 6-7 are respectively views in elevation and section of the other part
detached from the insulating block.
The
a is the insulating block formed of one solid cylindrical piece of porcelain or
other non-combustible material having the flange b and provided with recesses c_c,
for engaging with projections in the interior of the lamp or shade holder, or its
equivalent, the block a having projections to engage recesses in the lamp or
shade holder. 61 is a cross bar to prevent any contact of the electric wires. dd
are the two cylindrical holes parallel to the axis of a, which receive the cylin-
drical case e which contain the contact plunger f with the helical spring g.
cylindrical holes are each provided with the annular collars d d serving as a
purchase for the screw h, which takes into the tapped hole in the contact
plunger case e and secures the same to the cylindrical blocks a. ii are the
two parallel cylindrical holes, at right angles to the axis of the block a which
receive the cylindrical piece of metal to which is connected the conductor of
the flexible wire by the set screw which takes into the tapped hole k¹. The
upper end of the case e is formed as a step which fits on to or against the
step of. The vertical screw h serving to hold the plunger case e, against
the cylindrical form ; thereby ensuring a good electrical contact between each
plunger case e and the metallic piece j.
By referring to the drawings and specification only one half of the action is
illustrated and described.
:

page_text: I would observe in conclusion that I do not limit myself to form and configura-
tion of parts as shewn on the drawings as these I may vary or modify without
departing from the principle of my said invention.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:-
In "Improvements in insulating blocks, connected with holders for incan-
descent electric lamps."
1. The combination, the insulating block a formed of one solid piece and
constructed with the flange band recesses c c, the cross bar b¹ the cylindrical
holes d d with collars d¹¹ the case e with step the plunger f with spring g;
fixed by the screw h. The cylindrical holes i and the cylindrical piece of
metal with step and set screw k, substantially as and for the purposes herein
before described.
2. The general construction combination and arrangement of parts forming
insulating blocks, for incandescent electric lamps, substantially as herein before
described and illustrated by the drawings.
Q
1
'
1000
THOS. KENDRICK,
50, Cherry Street, Birmingham, Agent.
THOS.
KENDRICK,
50, Cherry Street, Birmingham, Agent.