Year: 1898

page_text: I, WILLIAM OUTTERSON WOOD, of South Hetton, in the County of Durham,
Mining Engineer, do hereby declare the nature of this invention to be, as follows:
These improvements relate to electric miners' lamps and they consist in pro-
viding means for attaching and locking the upper portion or cage containing
the glass for the protection of the lamp and for unlocking and allowing of the
removal of said cage thus freely exposing the lamp.
According to my invention I provide the upper part of the battery or stand
for the lamp with a bayonet joint device or a suitable number of studs and
similarly the lower part of the cage is provided with corresponding bayonet
joint parts or with circumferential slots which are each at one end formed
large enough for the through passage of the heads of the studs and are at the
other end each formed sufficiently small to prevent the through passage of the
said heads of the studs. It therefore follows that the cage may be put on the
battery fair with the large ends of the slots fair with the heads of the studs
which pass through the slots. A slight turn is then given to the cage and the
latter and the battery or stand are connected. In order to prevent the unauthorized
removal of the lamp a locking device is employed such as a screw stud with
a head fashioned to be turned by a key and preferably sunk in the lower part
of the cage or in some other adjacent part but it is evident that any other form
of locking device may be employed all as found most convenient.
Dated this Twenty-seventh day of June 1898.
I, WILLIAM OUTTERSON WOOD, of South Hetton, in the County of Durham,
Mining 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:-
These improvements relate to electric miners' lamps and they consist in pro-
viding means for attaching or locking the upper portion or cage containing the
glass for the protection of the lamp and for unlocking and allowing of the
removal of said cage thus freely exposing the lamp so that the bulb can be
replaced in the mine.

page_text: Figure 1 of the accompanying sheet of drawings is an elevation of one form
of lamp constructed according to my invention and
Figure 2 is a sectional plan view on the line AB Figure 1.
I provide the upper part C of the battery or stand for the lamp with a ring D
or the like having a number of parts forming a bayonet joint device such as
for instance headed studs E and, similarly, the lower part F of the cage G is
provided with corresponding bayonet joint parts such as for instance the circum-
ferential slots H which are each at one end formed large enough as shewn
for the passage through same of the heads of the studs E. It therefore follows
that the cage G may be put on the ring D of the battery or stand with the
large ends of the slots H fair with the heads of the studs E and so that the
latter pass through the said slots.
A slight turn is then given to the cage G and the latter and the battery C or
stand are connected. In order to prevent the unauthorised removal of the lamp
a locking device is employed such as a screw stud I with say a square head or
so fashioned as to be capable of being turned by a key. This screw stud I is
mounted in an internally screwed lug K attached to or made in one with the
ring F and it is of such a length as to take into a recess or hole in the ring D.
The screwed stud I is further normally sunk below the surface of its enclosing
part so that it is impossible to turn it without a key, but it is evident that any
other form of locking device may be employed if desired.
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:-
1. Attaching the upper part or cage of an electric miners' lamp to its battery
or stand by means of a bayonet joint and locking said cage in position.
2. In a miners' electric lamp or lantern the application and use of a cage
enclosing the glass and incandescent lamp provided with circumferential slots H
and an internally screwed lug K having a screwed stud I and a ring D having
headed studs E and a recess into which the stud I takes substantially as
described and shewn.
Dated this Twente enranth da
1000
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.