An Improvement in Casings for Electrical Switches, Safety Fuses, Ceiling Roses, and similar Fittings.
Year: 1891

page_text: Date of Application, 12th Mar., 1891
Complete Specification Left, 21st July, 1891-Accepted, 29th Aug., 1891
PROVISIONAL SPECIFICATION.
[Communicated from abroad by Heinrich Messing, of Offenbach */ Main,
Germany.]
An Improvement in Casings for Electrical Switches, Safety Fuses,
Ceiling Roses, and similar Fittings.
I, CHARLES DENTON ABEL of No. 28 Southampton Buildings Chancery Lane
in the County of London, Consulting Engineer and Patent Agent, do hereby declare
the nature of this invention to be as follows:-
In my Provisional Specification No. 17611 of 1890 I described means of securing
the cover to the base of an electrical push button in a simple manner giving great
facility for removing and replacing the cover. According to the present invention,
similar means of fixing a cover to a base are applied in the construction of au
electrical switch, safety fuse, ceiling rose or like fitting.
Such a switch is usually arranged within a casing consisting of a base of insulating
material, generally circular in form, and a cap which is screwed or otherwise fixed
to the base, and which has projecting up through it a spindle terminating in a
button or handle by which the switch is moved. A safety fuse or cut out is usually
enclosed in like manner within a casing consisting of a base and cap, and ceiling
roses and like fittings are similarly encased. For securing the cap of such a fitting
to the base according to this invention, a groove nearly semi-circular in sectional
profile is formed around the upper part of the base and into this groove is sprung
a ring of caoutchouc or like clastic material of circular section, so that about half
the thickness of the ring projects beyond the periphery of that part of the base in
which the groove is formed. The cap is made with an inwardly projecting lip at
its lower edge, the internal diameter of this lip being somewhat less than the
external diameter of the elastic ring. In putting on the cap, this lip at its lower
edge is forced over the ring which yields to let it pass, and then springs out above
the lip, thus holding the cap steadily in position, unless sufficient force be applied
to drag the lip over the ring when it is desired to take off the cap.
Dated this 12th day of March 1891.
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
An Improvement in Casings for Electrical Switches, Safety Fuses,
Ceiling Roses, and similar Fittings.
I, CHARLES DENTON ABEL, of No. 28 Southampton Buildings, Chancery Lane,
in the County of London, Consulting Engineer and Patent Agent, 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:-
In my Provisional Specification No. 17611 of 1890 I described means of securing
the cover to the base of an electrical push button in a simple manner, giving great
facility for removing and replacing the cover. According to my present invention,
similar means of fixing a cover to a base are applied in the construction of an
electrical switch, safety fuse, ceiling rose or like fitting, as I shall describe referring
to the accompanying drawings.
Fig. 1 is a section of a push button, having its cover held to the base according
to the present invention.

page_text: Figs. 2 and 3 are sections respectively on Y Y and Z Z of Figs. 4 and 5 which
are plans of a switch, these plans shewing the contact bar in its off and on attitudes
respectively.
Fig. 6 is an elevation of the base and one of the contact plates.
Figs. 7 and 8 are plans and Figs. 9 and 10 are sections on W W and X X
respectively of a ceiling rose and safety fuse.
The same letters are employed in the several figures to indicate corresponding
parts.
The base A has a cylindrical part B projecting upwards, in the periphery of
which is formed a groove of semicircular section into which is sprung a caoutchouc
ring C. The cap D has at its lower edge an inwardly projecting lip E having its
internal diameter somewhat less than the external diameter of the caoutchouc ring C.
On pushing the cap D down on the base, the lip E compresses the caoutchouc ring
inwards, and when it has passed, the ring springs out again so as to overlap the
lip E. Thus the cap is held in position with sufficient firmness to resist ordinary
accidental disturbance, but so that it can be pulled off when desired.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
Securing the cover of an electrical switch or like fitting to the base by means of
an inwardly projecting lip of the cover sprung over a caoutchouc ring of larger
diameter held in a groove of the base, substantially as described.
Dated this 21st day of July 1891.
ABEL & IMRAY,
Agents for the Applicant.