Improvements in Cord-grips for Electric Lamp Holders.
Year: 1898

page_text: Date of Application, 16th Aug., 1898
Complete Specification Left, 12th May, 1899-Accepted, 5th Aug., 1899
PROVISIONAL SPECIFICATION.
Improvements in Cord-grips for Electric Lamp Holders.
I, ALFRED WATSON, of the Firm of A... Watson and Company, of Hockley Street,
in the City of Birmingham, Manufacturer, do hereby declare the nature of this
invention to be as follows;-
This invention relates to cord-grips for electric lamp holders, and has for its
object, a simpler and more efficient grip for taking the strain of supporting the
lamp off the connections of the same.
In one form of my invention, the lamp holder may consist of a tubular ferrule,
with the lower end formed with bayonet slot or other connections for the lamp,
whilst the upper end is fitted interiorly with an insulator provided with terminal
plates, cord connections and contacts as usual and having an extended rib crossing
the middle of the upper end, with the holes for the lead wires coming respectively
upon the opposite sides of the terminal plates which may lie within sinkings on
either side of the rib.
Fitting upon the topside of the insulator is the cord grip, which is made of
earthenware or other insulating material and has a transverse channel directed
diametrally across the middle of its underside, and adapted to take over the pre-
ferably taper-sided rib of the insulator to prevent the one part rotating on the
other and also to give the necessary twist to the cords for the purpose hereinafter
described. Directed upwardly through the body of the grip are a pair of lead
holes, each considerably out of line with the holes or passages in the insulator,
so that when the channel of the one part is taken over the rib of the other, the
cords are considerably twisted and are drawn or forced into V-sectioned or other
contractions formed at the sides of the lower or foot parts of the lead holes in the
grip, by the pull exerted through the weight of the suspended lamp and its
fittings, thereby relieving the connections of the insulator from all strain.
The foot of the grip has an annular flange against which an inside collar of
a union ring or nut takes and worms onto the outside screwed upper end of the
lamp holder, thus securely clamping the cord-grip and lamp holder together.
As a modified form of my invention, I make the cord or lead grip of two annular
and conoidally formed sectional parts or sleeves fitting one over the other, and
with the leads or cords passing and being gripped between the opposed faces of
the same, which are secured to one another by a union ring screwing onto the
lamp holder as before. I prefer to provide downward keep grooves in either one
or other of the annular sleeves, of a less depth, than the cords themselves, in order
to keep the said cords in place or in their proper relative positions, so that when
the union nut is screwed home, the cord becomes clampeil between the opposed
sections.

page_text: Improvements in Coru-grips for Electric Lamp Holders.
I, ALFRED WATSON, of the Firm of A. Watson and Company, of Hockley Street,
in the City of Birmingham, Manufacturer, 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 relates to cord-grips for electric lamp holders, and has for its
object, a simple and efficient form of grip, so constructed as to relieve the lead
wire.connections of the strain of supporting the lamp.
Figure 1 of the accompanying drawing represents-an elevation of a lamp holder
fitted with a cord-grip constructed in accordance with one form of my invention.
Figure 2 is a transverse vertical section of the said lamp holder and cord grip,
and Figure 3 is another similar section but taken in a direction at right angles to
that of Figure 2.
Figure 4 is an underside plan of the cord grip, which is superimposed upon
the insulation block of the lamp holder.
Figure 5 is a plan of the top end of the said holder showing the insulation
block, in which the wire connections and contacts are fitted; located therein.
Figure 6 is a topside plan of Figure 1, but with the cables or lead wires removed.
Figure 7 represents, upon an enlarged scale, an elevation of the cord grip
separately and Figure 8 show's a similar view to that represented in Figure 4
but upon the larger scale.
Figure 9 is a cross section of the said grip upon the dotted line ¹, Figure 8
and Figure 10 is another section thereof upon the dotted line all, of the same
view.
The same letters of reference indicate corresponding parts in the several figures
of the drawing.
In the form of my invention represented in the said figures, the lamp holder
consists of a tubular body part a, with the lower end formed with bayonet slot con-
nection a, for the lamp whilst the upper end is fitted interiorly with an insulation
block b, made of china or porcelain or other non-conducting material and pro-
vided with cord connections 61, contacts and other fittings, as usual, having an
extended rib 3, crossing the middle of the upper end, with the connections b,
for the lead wires e, being fitted respectively with sinkings or recesses 6', coming
upon the opposite sides of the said transversely disposed rib.
Fitted so as to rest upon the topside of the insulator is the cord grip d, which
is of conoidal form and is made of earthenware or other insulating material and
has a transverse channel 4, directed diametrally across the middle of its under-
side, and adapted to take over the rib 3, of the insulation block to prevent the
one part rotating on the other and also to give the necessary twist or set to
the cords for the purpose hereinafter described. Directed upwardly through the
body of the grip are a pair of lead holes 2, each considerably out of line with the
cord holes or passages 6, of the cord connections 6', in the insulator, so that
when the channel of the one part is engaged over the rib of the other, the grip and
the insulation block are set or retained in such relative positions that the cords f,
in passing from the outside of the holder to their respective connections, are
considerably twisted and are also drawn or forced into V-sectioned or other con-
tractions, formed at the sides of the lower or foot parts of the lead holes in
the grip, by the pull exerted thereon by the weight of the suspended lamp and its
fittings, such weight being borne entirely by the grip, which effectually relieves
the connections of the lamp holder from all strain.

page_text: The foot of the grip has an annular flange +, against which an inside collar e¹,
of a union ring or nut e, takes with the inside of the said ring worming onto the
outside screwed upper end of the lamp holder, thus securely clamping the cord-
grip and lamp holder together. Instead of a rib on the one part engaging in a
groove or channel in the other part, any other suitable means may be employed
for retaining the cord grip and lamp holder fittings in their proper relative
positions with the cord or lead holes out of a direct line with one another.
As a modified form of my invention, (which is shown in section in Figure 11)
I make the cord or lead grip of two annular and conoidally formed sectional
parts or sleeves g, h, fitting one over the other, and with the leads or cords f
passing and being gripped between the opposed faces of the same, which are
secured to one another by a union ring e screwing onto the lamp holder as before.
I prefer to provide downward keep grooves such as ', in either one or other of
the annular sleeves, of a less depth than the cords themselves, in order to keep
the said cords in place or in their proper relative positions, so that when the
union nut is screwed home, the cord becomes clamped between the opposed
sections.
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:
First: A cord grip for electric lamp holders, consisting of a block of insulat-
ing material suitably connected to the lamp holder and having cord lead holes
with their inner ends shaped to a wedge, V or equivalent figure and into the
contracted parts of which the said cords are drawn, substantially as and for the
purpose described and set forth.
Secondly: A cord grip for electric lamp holders consisting of a block of
insulating material suitably connected to the lamp holder and having a pair of
cord lead holes whose inner ends are of a V, wedge or equivalent shape and with
the said holes disposed out of a vertical line with the cord connections of the
said holder, so that the cords are thereby twisted and drawn into the contracted
parts of the V-ended holes, substantially as and for the purpose described and
set forth.
Thirdly: In a cord grip for lamp holders of the kind referred to in the pre-
ceding claims, retaining the said grip in its assigned position relative to the
nsulating block of the lamp holder by a rib or equivalent projection on the
one part engaging in a channel or sinking in the other part, substantially as
lescribed and set forth.
1101
1