Improvements relating to Electrical Fittings.
Year: 1891

page_text: Date of Application, 25th Sept., 1891
Complete Specification Left, 25th June, 1892-Accepted, 30th July, 1892
PROVISIONAL SPECIFICATION.
Improvements relating to Electrical Fittings.
CHARLES SCOTT SNELL of Culver Park, Saltash, Cornwall, Engineer, and
WOODHOUSE AND RAWSON UNITED LIMITED, of 88 Queen Victoria Street,
London, E.C. Electrical Engineers, do hereby declare the nature of this invention
to be as follows :-
The object of this invention is to effect a simple and inexpensive construction of
accessories used in electrical work, and relates more especially to such fittings as
ceiling roses, fusible cut-outs, wall sockets, lamp holders and the like.
In carrying out our said invention, we make use of a base of any suitable
insulating material, more or less fire and water proof, and capable of being readily
moulded, such as all kinds of ceramic ware or equivalent thereto, and we so form it,
that the terminal or contact plates or similar fittings are held in position as regards
vertical movement by projecting lugs, and horizontal movement is prevented by the
shanks of the screws in the metal work used for attaching the leads or the like.
The screws form therefore steady pins by working in clearance holes or recesses in
the base, these holes not passing completely through the material, and therefore
all through holes " for this purpose are avoided. For instance in a small
circular fuse, we may prevent the two contact plates from lifting by passing them
under the extreme ends of the dividing blade or ridge, cut away for the purpose,
the screw shanks dropping into recesses prepared for the purpose, and preventing
any further movement.
In ceiling roses and wall sockets, the contact plates would be similarly held. In
the latter case, the plug being of a double shouldered outline fits into contacts
arranged as a female type of the same form and the aperture when the plug is
withdrawn may be covered by an escutcheon similar to a keyhole.
In a double pole fuse, we may have similarly a divided ridge with lugs at both
sides projecting over contact plates, which may be attached to the base in the same
way as explained above, or may be of such a form as to allow them to be easily
withdrawn for the purpose of sweating cables to them, and be replaced and then
held in position by screws fitting into recesses in the base, which screws may be the
same as hold down the fuse.
In a lamp holder, the plate forming part of or used in connection with a spring
plunger, would be held down to the insulated base by blades similar to those above
explained and supplementary blades forming any given angle therewith may be
used to prevent the loose ends of the connected leads from causing short circuit, and
the lead holes may be so arranged with regard to the plate that the turning screw
holding same will tend to keep the loose ends inwards towards the insulated blades,
instead of outwards, towards the surrounding metal case.
September 24th 1891.

page_text: COMPLETE SPECIFICATION.
Improvements relating to Electrical Fittings.
CHARLES SCOTT SNELL of Culver Park, Saltash, Cornwall, Engineer and
WOODHOUSE AND RAWSON UNITED LIMITED of 88 Queen Victoria Street,
London E.C. 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 :-
The object of this invention is to effect a simple and inexpensive construction of
accessories used in electrical work, and relates more especially to such fittings as
ceiling roses, fusible cut-outs, wall sockets, lamp holders and the like.
In carrying out our said invention, we make use of a base of any suitable
insulating material more or less fire proof and water proof and capable of being
readily moulded, such as all kinds of ceramic ware or equivalent thereto, and we so
form it that the terminal or contact plates or similar fittings are held in position as
regards vertical movement by projecting lugs, and horizontal movement is
prevented by the shanks of the screws in the metal work, used for attaching the
leads or the like. The screws form therefore steady pins by working in clearance
holes or recesses in the base, these holes not passing completely through the
material and therefore all through holes for this purpose are avoided. For
instance in a small circular fuse, we may prevent the two contact plates from lifting
by passing them under the extreme ends of the dividing blade or ridge, cut away
for the purpose, the screw shanks dropping into recesses prepared for the purpose,
and preventing any further movement.
"
In ceiling roses and wall sockets, the contact plates would be similarly held. In
the latter case, the plug being of a double shouldered outline fits into contacts
arranged as a double female type of the same form and the aperture when the plug
is withdrawn may be covered by an escutcheon similar to a keyhole.
In a double pole fuse we may have similarly a divided ridge with lugs at both
ends projecting over contact plates, which may be attached to the base in the same
way as explained above, or may be of such a form as to allow them to be easily
withdrawn for the purpose of sweating cables to them and be replaced and then
held in position by screws fitting into recesses in the base, which screws may be the
same as hold down the fuse.
In a lamp holder, the plate forming part of, or used in connection with, a spring
plunger, would be held down to the insulated base by blades similar to those above
explained and the supplementary blades forming any given angle therewith may be
used to prevent the loose ends of the connected leads from causing short circuit, and
the lead holes may be so arranged with regard to the plate, that the turning screw
holding same, will tend to keep the loose ends inwards towards the insulated blades.
instead of outwards towards the surrounding metal case.
The better to explain our meaning reference is made to the accompanying
drawings in which similar letters refer to similar parts.
. Figs. I and II are plan and side elevation respectively of a circular single pole
cut-out adaptable also as a ceiling rose without fuse.
Fig. III is a part section, part elevation of the same.
Figs. IV, V and VI are similar views referring to a larger type of the same,
terminals being used in place of screws for the leads.
Figs. VII and VIII are plans of ceiling roses with fuses.
Fig. IX is a part section part elevation of the type shown by Fig. VII.
Fig. X is a part section part elevation and Figs. XI and XII a plan sectional
elevation respectively of a double pole cut-out.
Fig. XA shows a detail of the socket to take the lead.
Fig. XIII is an end elevation of the cover.
Fio XIV to YY doi:1
11

page_text: Fig. XXIV illustrates the application of an escutcheon to a wall-plug.
Figs. XXV, XXVI, and XXVII refer to a lamp holder.
In Fig. I the course of the current is shown by the arrows, the fuse being
dotted, and as will be seen from Figs. II and III the contact plates A are
prevented from lifting by the shape given to the raised rib or blade B and the
horizontal travel is prevented by the shanks of the "lead" and fuse attachment
screws C.
Thus the plates are held without being secured to the rib or blade, thereby
avoiding extra holes or perforations and additional metal screws or bolts as well as
Itongues, pins or projections in the metal work with corresponding recesses on the
porcelain, or other more elaborate fixing devices.
The plates may be more or less "set" in the middle as shown, to accommodate
variations in the notches in the porcelain. The main ridge it will be seen conveniently
divides the fuse from the "leads."
For Figs. IV, V and VI the same description applies, the only difference being
the use of terminals to take heavier "leads."
In Fig. VII the course of the current is also indicated by arrows and the general
construction is similar, the difference being that three notched ridges or blades are
used as three plates have to be accommodated.
In Fig. VIII extra ridges E, E are formed to keep the main incoming leads
well apart from the flexible lamp leads.
Fig. X shows a centre ridge with offsets or side lugs B which are perforated
to take suitable sockets A, the base being also channelled to allow of the free
withdrawal of said sockets.
A socket is shown in Fig. X which can only be withdrawn by removing
the "fuse attaching" milled headed screw C, as this entering a recess (see G
Fig. X) in the base prevents horizontal movement, the side lugs may however be
slotted as shown dotted at H to allow the withdrawal of the socket without entirely
removing the screw.
The sides of the base see Fig. XII are channelled and a spring clip I
(for which the cover is suitably grooved, see section in Fig. X) holds the
cover on.
The general arrangement of this fitting causes the two conductors to be
effectually divided, and allows of free access to the fuse and other parts, at the
same time it keeps the cross section small enough to correspond with that of the
usual wooden casing.
Fig. XIV shows a small plug in which the contact plate A is held by a
notched lug B (see also Fig. XVI) whilst an equivalent formation in the circular
portions of the base marked B' produces a bayonet joint fastening, that is to
say the contact A¹ and A" (which have their circular portions arranged at
different elevations) are dropped into the respective vertical notches J¹ and J"
and then rotated slightly until the screws C¹ and C" come opposite the recesses
provided for them in the base. A few turns will then cause the said screws to enter
these recesses and thereby stop any further horizontal movement.
The contact A' being of smaller diameter than A" (see Fig. XX) and at a lower
elevation an intermediate insulating washer K is used and the general_outline
corresponds with that of Fig. XV which shows a double shouldered plug.
When the plug is in position the part A" forms connection with contact plate A¹
and the portion A connects with the contact plate A", the circuit being com-
pleted by the flexible leads which are attached to the terminal screws C and C"
Fig. XV and threaded through holes D' (see Figs. XVII and XVIII) and led to
a lamp or the like.
Fig. XIX shows a similar construction of wall plug to the above described,
except that the slots in the circular portion are vertical only, and the necessity for
a bayonet joint shape is obviated by screwing in an annular washer marked L in
Fig. XX which fig. appertains more directly to the type illustrated in Fig. XIX
than to that shown by Fig. XIV.

page_text: -conductor (see N Fig. XXIII) to lay in.
The contact A in Fig. XXII is identical with that described in reference to
Figs. X and XI but one marked A" is used to show the application of a flat
plate, see also end elevation Fig. XXIII.
Fig. XXIV shows a front elevation of a wall plug fitted with an escutcheon O
after the manner of a keyhole in a door, this can be turned aside as shown dotted
to allow plug to enter.
Figs. XXV and XXVI are elevation and sectional elevation from different
points of view of the lamp holder shown in plan by Fig. XXVII the plates
being held down in a similar manner to that above described for cut-outs and
ceiling roses.
Protecting ridges E are also shown dividing one lead and appurtenances from
the other.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
I. The construction or combination of the parts forming ceiling roses, cut-outs,
wall plugs or similar electrical fittings whereby all or part of the metal or current
carrying portions are prevented from moving vertically by the general arrangement,
and notching, of the porcelain lugs or ridges which thereby overlap and hold (as
regards vertical action) the fittings without further attaching or fixing screws,
bolts, pins or the like into the said lugs or their equivalent; other screws or.studs
being provided which prevent horizontal movement and perform the necessary
"lead or fuse" attaching functions substantially as described in reference to and
shown by the accompanying drawings.
II. The construction or combination of the parts forming single pole fuses and
ceiling roses consisting of a centre ridge with two or four notched lugs and contact
plates substantially as described in reference to and shown by Figs. I to IX in
the accompanying drawings.
III. The construction or combination of the parts forming a single or double pole
cut-out consisting of a centre ridge with two or four perforated lugs and socket
pieces substantially as described in reference to and shown by Figs. * to XIII in
the accompanying drawings.
IV. The construction or combination of the parts forming wall plugs substantially
as described in reference to and shown by Figs. XIV to XX in the accompanying
drawings.
V. The construction or combination of the parts forming a single or double pole
cut-out consisting of a centre ridge with two or four notched lugs and contact
plates substantially as described in reference to and shown by the parts A' A¹
Figs. XX and XXIII and in the accompanying drawings.
VI. The attachment to or combination with a wall plug of an escutcheon
substantially as described in reference to and shown by Fig. XXIV in the
accompanying drawings.
VII. The construction or combination of the parts forming a lamp holder
substantially as described in reference to and shown by Figs. XXV, XXVI and
XXVII in the accompanying drawings.
1000