An Improved Protective Mantle for Miners Safety Lamps.
Year: 1889

page_text: Date of Application, 4th May, 1859
Specification Accepted, 8th June, 1889
An Improved Protective Mantle for Miners Safety Lamps.
I, CARL HEINRICH WOLF of the Town of Zwickau in the Kingdom of Saxony and
German Empire, Manufacturer, do hereby declare the nature of my said 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 improvements in miners safety lamps and consists in the
employment of a protective mantle by means of which the lamp is protected against
the action of the fire damp. If a safety lamp with my mechanical igniting device is
extinguished when a mixture of gas and air is present in the mine, the interior of the
lamp will be immediately filled with the gas in the mine. On again lighting the lamp
by means of the igniting device, an explosion will ensue, which cannot be sufficiently
held back by the wire cylinder so as to render it impossible for the flame to be
driven through the wire cylinder and thus cause an explosion of the fire damp,
when, however, the protective mantle is employed, all danger of explosion will be
effectively prevented.
In the accompanying drawings,
Figure 1 is an elevation of the lamp with my improved protective mantle attached,
the latter being partly broken away to better show the construction
Figure 2 is a vertical section, and
Figure 3 a horizontal section of the protective mantle, drawn on an enlarged
scale.
Figure is a horizontal section of a modified construction of the protective
mantle.
The protective mantle is composed of two cylinders, a, b, placed one within the
other and provided with suitable corrugations, the outer edges of the outer mantle, a,
being slotted at c, and the inner edge of the inner mantle, at c¹, so that the slots c
and c in the two walls of the double mantle form a zigzag line and the slots of
the one mantle will thus be located opposite the full part of the other mantle.
By means of this device the force of an explosion is broken, while the small slots
allow only a small quantity of the explosive fire damp to enter the lamp so that
the force of an explosion is broken against the corrugations or folds of the outer
mantle.

page_text: The protective mantle acts in like good manner when strong currents of air strike
the exterior of the lamp.
Figure 4 represents a simpler construction of the protective mantle according to
which only one cylinder a¹ instead of two mantles is employed.
In order to attain the same result as described in reference to the double mantle,
that is, to weaken or break the action of the currents of air or gas from the interior
or exterior, the slots are not made in the apex of the corrugations or folds but in
the side walls of the folds or corrugations.
In this manner I attain the result that the air or gas currents are broken by
impinging against the massive edges of the corrugations or folds, and that they form
a kind of eddy, thereby entirely neutralising the force of the said currents which
could otherwise produce an extinguishing of the flame of the lamp.
Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed, what I claim is :-
1: A protective mantle for miners safety lamps, consisting of corrugated or folded
mantles a placed one in the other and provided with narrow slots or rows of
perforations C, in the corrugations or folds, said slots c, c¹ not standing in line
with each other in order to weaken the action of air or gas currents from the
interior towards the exterior or vice versa, substantially as and for the purpose set
forth in the foregoing specification, and illustrated in Figs. 1 to 3 of the accompanying
drawings.
2: A protective mantle or casing for miners safety lamps consisting of the cor-
rugated or folded mantle a¹, the side surfaces of the said corrugations being provided
with slots or perforations c³, whilst the edges remain solid, substantially as and for the
purpose set forth in the foregoing specification, and illustrated in Figure 4 of the
accompanying drawings,
Dated this 4th day of May 1889.
C. H. WOLF.
Per W. H. Beck,
115, Cannon Street, London, E.C.,
Agent.