Improved Method of Fixing Metal Parts of Electrical Fittings to Porcelain or other Refractory Substances.
Year: 1893

page_text: Date of Application, 28th Aug., 1893
Complete Specification Left, 9th May, 1894-Accepted, 16th June, 1894
PROVISIONAL SPECIFICATION.
Improved Method of Fixing Metal Parts of Electrical Fittings to
Porcelain or other Refractory Substances.
ANDREAS PETER LUNDBERG 18 Regina Road, Tollington Park London, N.,
Electrical Engineer, do hereby declare the nature of my invention for an
IMPROVED METHOD OF FIXING METAL PARTS OF ELECTRICAL FITTINGS TO
PORCELAIN OR OTHER REFRACTORY SUBSTANCES to be as follows:-
―:
One of the methods most generally in use at the present time, for fixing metal
parts to porcelain for electrical fittings, is that of tapping small threads into the
body of the porcelain & fixing the metal work on to it by means of screws of
the same pitch screwed directly into the body of the porcelain; this method is
objectionable on account of the porcelain being of such a brittle and unyielding
nature, readily breaking under any slight extra pressure; moreover the inequalities
of the firing process porcelain undergoes render this method unreliable & costly
from the large percentage broken in "making up," owing to variations of the
screw thread from this cause.
The object of my invention is to overcome these difficulties of fixing brass work
to porcelain or other refractory material, at the same time preserving the electrical
insulation of the fitting, without the use of "tapped porcelain." As an example
where my invention can be advantageously applied, I take a switch key or handle
of porcelain (but it is evident the same method can be applied to other fittings) &
provide near its base & through the body of the porcelain handle or key a rather
large horizontal hole & drill in the same line as this large cross-hole, smaller
vertical holes passing through from the base of the key into the large horizontal
hole.
When the brass fitting intended for this part is to be fixed, the large horizontal
hole is filled with wood, metal or other material, into which I screw the screws
holding the brass part, the screws passing through the small vertical holes aforesaid,
in this way making a satisfactory, strong & substantial fitting.
Dated this 28th day of August 1893.
ANDREAS PETER LUNDBERG.
COMPLETE SPECIFICATION.
Improved Method of Fixing Metal Parts of Electrical Fittings to
Porcelain or other Refractory Substances.
I, ANDREAS PETER LUNDBERG, of 18 Regina Road, Tollington Park, in the
County of London, Electrical Engineer, 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 :-
My invention relates to an Improved Method of Fixing Metal Parts of Electrical
Fittings to Porcelain or other Refractory Substances.
One of the methods most generally used at the present time, for fixing metal
parts to porcelain for electrical fittings, is that of tapping small threads into the
body of the porcelain, and fixing the metal work on to it by means of screws of
the same pitch, screwed directly into the body of the porcelain; this method is
objectionable on account of porcelain being of such a brittle and unyielding
nature, readily breaking under any slight extra pressure; moreover the inequalities
[Price 8d.1

page_text: figures marked thereon.
Fig. 1, is an elevation of the switch-key or handle.
Fig. 2, is a sectional view of Fig. 1.
Fig. 3, a plan at A.
Fig. 4, is a vertical section of a switch-key or handle with a slot.
Fig. 5, is a vertical section of the switch shewing the mode of fixing the covers.
Fig. 6, is a plan at B.
Parts of the figures are broken off for convenience.
As an example where my invention can be advantageously applied, I take a
switch-key or handle of porcelain (but it is evident the same method can be
applied to other fittings) and provide near its base and through the body of the
porcelain handle or key 6 a rather large horizontal hole d and drill in the same line
as this large cross-hole, smaller vertical holes e passing through from the base of
the key into the large horizontal hole d.
When the brass fitting intended for this part is to be fixed, the large horizontal
hole is filled with a plug a of wood, metal or other material, into which I screw the
screws c holding the brass part, the screws passing through the small vertical
holes aforesaid, in this way making a satisfactory, strong and substantial fitting.
If preferable I make a switch-key or handle bas in Figs. 4, and 6, with a slot f
and insert therein a screwed eyelet g, and I then pass the plug a through the hole
of the handle and eye of the screwed eyelet g; the whole being rigidly secured by
a nut h.
At each side of the base shewn in Fig. 5, I insert a plug a' of wood or other
suitable material for the purpose of fixing covers i by means of screws c.
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 :-
1. In a switch-key or handle, the combination of the holes d and e in the handle
with the plug a and screws c, substantially as herein described and according to
Figs. 1, 2, and 3, of the accompanying drawing.
2. In a switch-key or handle, the combination of the horizontal hole and slot
with the plug a and screwed eyelet g and nut h, substantially as herein described
and according to Figs. 4, and 6, of the accompanying drawing.
3. In a switch for fixing the cover or covers to bases as in Fig. 5, the com-
bination of a plug a¹ and screw c, substantially as herein described and according
to the accompanying drawing.
Dated this 9th day of May 1894.
J. P. BAYLY,
18, Fulham Place, W., Agent for the Applicant.