MENTS IN MINERS' SAFETY LAMPS."
Year: 1877

page_text: PROVISIONAL SPECIFICATION left by Jean Baptiste Maric Prosper
Closson at the Office of the Commissioners of Patents on the 11th April
1877.
JEAN BAPTISTE MARIE PROSPER CLOSSON, of Paris, France, but temporarily of
"IMPROVE-
2, Laurence Pountney Hill, in the City of London, Civil Engineer.
MENTS IN MINERS' SAFETY LAMPS."
My Invention of improvements in miners' safety lamps has reference to the con-
struction of the fastening mechanisın, as herein-after described, so that the rod or
pin which, with other parts is enclosed, is in a suitable box, and is by a spring
caused to enter a recess in the upper or removeable part of the lantern for locking;
it is for unlocking depressed mechanically by a partial turn of the said upper or
removeable part in the same direction as for closing the said rod or pin, after having
been so depressed, being kept in its lowered position during the opening of the lamp
by the operation of a magnet applied externally to the box, and which, through a
novel arrangement, transmits magnetic action to mechanism within the box which
operates to retain the rod, or pin, and other parts in the positions to which they
have been mechanically moved, thus leaving the upper or removeable part free
to be unscrewed and removed.
Fig. 1 of the accompanying Drawings shews (closed) part of a Mueseler lamp
embodying my improvements.
A rod a, passing through the part A of the portion M of the lamp enters a recess
made in the part B (which is screwed on to the part A, and carries the second
portion N of the said lamp) and effects the locking. To this end the rod a, termi-
nating at its lower end in the small cylindrical portion b, is impelled in an upward
direction by the spring c. This spring bears upon the bottom of a box Da',
which encloses all the mechanism, and is soldered to the bottom of the lamp.
Fig. 2 shews the position of the parts which obtains when the upper part of the
lamp is unlocked in readiness for opening.
Closing. Assuming that the two portions M and N of the lamp are still separate,
that, in other words, the lamp is open, to close it I connect the portions M and N
by screwing the part B to the part A.
As will be seen in Figs. 5 and 6, the recess B is of the form shewn at f, g, h,

page_text: As the direction of turning to close the lamp is that of the arrow 1 when the rod a
meets the point f, it enters the recess f, g, h. Motion in a direction suitable for
opening the lamp (shewn by the arrow 2) is then impossible, the lamp is closed;
but owing to the form off, g, h, motion in the direction of the arrow 1 is still possible
until the part B is screwed right home. For closing, therefore, advantage may be
taken of almost the whole of the thickness of the piece B.
Opening. When the lamp is closed, that is to say, when the rod a has reached
point (Fig. 5) for the last time that this is possible when moving in the direction
of arrow 1, motion in the direction of arrow 2 is naturally impossible; but the
part B is not yet screwed quite home, and a motion, although a very slight one, is
still possible in the direction of arrow In this motion the recess f, g, k assumes
the position shewn by f, g, h, in Fig. 5, and the rod a assumes the position
shewn in Fig. 6 and in Fig. 2. The spring is then compressed in such a
manner that the piece b, which is of soft iron, is in contact with the bottom
of the box D a¹. The spring and the rod a are thus in the position suitable for
opening; they have been brought into this position by mechanical means; the
essential point is to maintain the spring, and consequently the rod in these positions,
without having for this purpose to gain access to the mechanism in the box. This
result is obtained by means of a natural magnet, or an electro-magnet, arranged as
shewn at d, d¹, (Fig. 3), and forming part of the bottom of the box. The part b of
the rod a having been brought into contact with the case by mechanical means as
described, the office of the magnet is, not to cause a movement or an attraction
from a distance, but simply to retain the part b in the depressed position shewn in
Fig. 2 by attraction on contact with the bottom of the box D a. But it is
really only on actual contact that magnets exert any attractive force on soft iron.
The means used for acting on the soft iron b, when contact takes place, without
opening the box D a', are as follows:-Let us suppose that we have (Fig 7) a
magnet H, and a piece of soft iron K, the piece K will be kept on the magnet by
attraction with a certain degree of force. If pieces P and P³, similar to the piece.
K, be placed on the poles of the magnet H (Fig. 8), each of them will be held, but
much less forcibly, by the magnetic action of these poles P and P'; but if the
piece K be placed on the polarized pieces P, P¹, (Fig. 9), it will be held by attraction
on these pieces P, P¹, quite as forcibly as it was before by the magnet H. Now
this principle is applied to the box Da. The said box is of brass, but its bottom
is made in two portions, d, d, (Fig. 3), of soft iron, separated by a brass plate. It
is on these two pieces, d and d', that the two poles of the magnet are made to act.
By this contrivance the magnetic action is transmitted to the inside of the box
through d, d, and the attractive force is made independent of the case.
If desired, all the portions of the mechanism may easily be made capable of being
cleaned. To this end it is only necessary to prolong the rod a below the part b,
and cause it to enter a recess in the bottom of the box Da, to prevent turning of
the said bottom, and so that in the position for closing, the piece b will not touch
the top of the enlarged lower portion of the box, and will be removed from it a
distance equal to the depth of the above-mentioned recess. The bottom of the box
is then screwed on but cannot be turned, and so unscrewed, until the two portions
M and N of the lamp are separated.
Method of Using the Lamp.-Fig. 4 shews the arrangement of a magnet H with
the lamp which it is intended to open. By the side is a bar of wood I, provided
with a piece of soft iron intended to counteract the force of the magnet when it is
desired to remove the lamp after having opened it, and serving also as a guard to
the magnet. This piece of mechanism is not, however, indispensable, provided the
lamp be always withdrawn by sliding the polarized parts d and d on to the poles
of the magnet. An ordinary guard plate must then be employed.
The lamp may be handed to the miner open so that he may satisfy himself
as to its condition; it is then closed by screwing the part B on to the part A.
On regaining the surface the miner returns his lamp; it is screwed quite up;
the points d and d¹ are then placed on the poles of the magnet, and by turning in
the direction of arrow 2 the lamp is opened.

page_text: The miner cannot, without a magnet, tamper with his lamp, the mechanism of
which is inside, nor is he likely to have a magnet with him owing to its cost and
weight.
By combining lightness of the portions a, b, with the force of the spring, reducing
the former and increasing the latter, the opening of the lamp by any means except
the magnet may be rendered impossible.
Care must be taken to provide a small rim to the part B, as shewn, for preventing
the insertion of a blade for lowering the rod a.
I would also observe that my arrangements for lowering the rod or pin by
mechanical means, and transmitting to the interior the magnetic action, permits of
the desired effect being produced with a very weak magnet, which is essentially new,
in the case of a piece of mechanism entirely enclosed; but the weight of the parts
u, b, and the force of the spring, may be varied in such a way as to determine the
power (and consequently the weight and price) of the magnet to any degree that
may be desired.
This new method of closing and opening is applicable not only to the Mueseler
lamp, but also to other classes of safety lamps.