IMPROVEMENTS IN SAFETY LAMPS FOR MINES AND THE LIKE
Year: 1885

page_text: I, WILLIAM PHILLIPS THOMPSON, Fel. Inst. P.A. of the Agency for Foreign Patent
Solicitors, 6 Lord Street, Liverpool, in the County of Lancaster, and 323 High
Holborn, in the County of Middlesex, Civil Engineer, do hereby declare the nature
of the said invention for IMPROVEMENTS IN SAFETY LAMPS FOR MINES AND THE
LIKE (a communication from abroad by Monsieur Eugéne Cuvelier of Thomery
in the Republic of France Inventor) and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement :-
"
In
The present application for Letters Patent has for its object an improved safety
fastening for lamps for use in mines and the like. The opening of lamps of this
improved construction is effected by the action of a fluid acting under pressure or
aspiration this fluid may consist of water or a suitable oil preferably mineral, or
other convenient liquid, or a gas or air may be employed.
This method of closing is designed to prevent the miners from opening their lamps
whilst in use.
In the lamp room a sort of table is set up covered with leather, caoutchouc or
other suitable material, which is in communication by means of a pipe with a
vessel containing air, gas, or liquid under pressure or from which the air has been
exhausted, the lamp is placed on this table in such a position that its orifices
correspond to the aperture of the tube, and the application of the pressure or
aspiration causes the fastening of the lamp to act.
Referring to the annexed drawings:-
-
Figures 1 and 2 represent a closing device by means of the application of a
Bourdon manometric tube.
Figure 3 is a vertical section.
Figure 4a plan and
Figure 5 a transverse section of a modification of the improved method of
closing obtained by combination of a spring with a manometric tube controlling the
closing bolt by hydrostatic or pneumatic pressure.

page_text: Figures 7 to 15 shew two modifications of the system with bolts attached to
pistons actuated by pressure or exhaustion.
Figures 16, 17, 18 shew a modification of the actuating mechanism of the bolt
at the top of the lantern.
The type preferred by the inventor is that shewn in Figures 1 and 2. The
mechanism is composed essentially of a Bourdon manometric tube A fixed in a half
circle, in the interior of the oil receiver B and connected at one end to a nipple C
fixed at a given point of the outer frame: its other end is provided with a little
transverse stop D which enters an eyelet formed for this purpose in the lower part
of the bolt E. The nipple C is perforated with two openings F at a right angle by
which the injection of the gas or liquid is effected for opening the lamp. The tube A
is constructed sufficiently strong to maintain the bolt E in the groove contrived for
this purpose in the part G which holds the upper part of the lamp and which is
screwed in the usual way upon the cover H of the receiver B. A leather washer
or other arrangement prevents the escape of oil when the lamp is inclined in that
direction. In order to open the lamp, a gas or liquid is injected under pressure
through the aperture F, which causes the tube A to lengthen in the direction
indicated by the arrow, and to push down the bolt E whereon the upper part of
the lamp can be unscrewed; the elasticity of A restores this bolt to its original
position as soon as the tube ceases to be subjected to pressure.
It is obvious that if desired the tube A might form a complete circle, thereby
increasing its elasticity and consequently reducing the pressure necessary to cause
the displacement of its end, it may be arranged horizontally in the receiver of the
lamp, and a little geared mechanism on a support soldered to the bottom of the
receiver interposed between its movable end and the bolt.
In the modifications shewn in Figures 3, 4, 5, and 6 the control of the safety
bolt is effected by the action and reaction of a Bourdon manometric tube and of an
opposing spring.
In this modification, the bolt P which keeps the lamp closed is terminated at its
lower end by a projection Q upon which presses a spring R which tends constantly
to press down the bolt and consequently to effect the opening of the lamp: on the
other hand the bolt P is kept raised by two supports S placed facing each other
below the projection Q and which are themselves sustained by means of a metallic
ring T soldered to a ring or support on the lower part of the lamp. This ring T
serving thus to resist the thrust of the spring R to guide the lower part of the bolt
and to prevent it from escaping from the tube V which holds it. In order to allow
the bolt P to be lowered, it suffices to open the two stops S a distance exceeding
the projection of Qfrom the bolt: this movement may be produced by the aid of a
bent tube W arranged in the manner already described. As shewn in the drawing
a flattened tube W is arranged in the lower part of the lamp curved in an arc of a
circle like the tube of a manometer and the free extremities of which support the
stops S. At the side opposite to the bolt, this tube is soldered to the body M of
the lamp and is pierced by an opening I communicating with the exterior, is placed
entirely out of reach of any external contact by means of the piece U soldered
underneath the lamp, the bottom J of which is moreover provided with a metallic
check K arranged to prevent any introduction of a foreign body at the point of
junction of U and J and to prevent any one from displacing the stops S by means
of a knife for instance or other object introduced at this point.
In order to effect the opening of the lamp the aperture I is pressed firmly against
a tube suitably fixed, and communicating with a reservoir of liquid or air under
pressure. On turning a stop-cock fixed in the tube, the air or fluid rushes into the
tube W, both ends of the same diverge carrying with them the stops S and the
bolt P, propelled by the spring R, descends immediately a distance sufficient to
admit of the screwing of frame which bears the wire gauze and which screws on
the threaded part L.
To prevent any accident happening from too great a divergence of the two arms
of the tube W these are arranged at N stops fixed on the frame of the lamp for the

page_text: purpose of restricting the divergence of the said arms of the tube W within the
limits necessary for allowing the automatic descent of the bolt P. A similar.
arrangement is applicable when the movement of the stops S results from an
exhaustion of the air in the tube W by suction or aspiration: as shown at Figure 6
the ends of the tube W are crossed, all the other details of the mechanism remaining
as above described. As soon as the tube W is exhausted the ends of the same
approach each other, and the arms being crossed move the stops S sufficiently to
allow, of the descent of the bolt P.
..It is obvious that instead of two stops, a single one connected to one end only of
the tube might be used, but there would be a danger that on receiving a vigorous
side blow, this end of the tube might be displaced sufficiently to release the bolt P,
whereas by the plan above described of having two stops one attached to each
extremity of the tube W any accident of this kind is avoided.
In order to prevent any possibility of the lamp being opened by workmen by
sucking out of or blowing into the tube W, care must be taken to give this tube
strength sufficient to resist any but a high pressure or in the case of lamps operated
by compression or exhaustion of air, a minute hole may be pierced in the tube W,
large enough to cause a certain escape of air which will render the use of more
powerful mechanism necessary for the opening of the lamp, than can be surrep-
titiously obtained by the users..
When the lamp is trimmed and got ready for use, the frame which bears the
wire gauze is replaced on it, so that the aperture for the bolt is opposite this latter:
The bolt is then raised by means of a projection sliding in the channel cut for this
purpose in the piece O forming the upper part of the chamber V of the said bolt or
by other suitable means until it is in its proper place where it is gripped and held
fast by the stops S.
Figures 7, 8, 9, 10, 11, shew a modification of the arrangement already described
consisting essentially of a bolt a lodged in a tube 6 fixed vertically in the inside of
the recipient c of the lamp and enclosing a spring d which acts upon the little
piece e forming the lower part of this bolt and tends to keep it constantly lifted,
in the position shewn at Figure 7 where it penetrates through an orifice formed
in f which forms the screw circumference for uniting the two portions of the lamp.
To prevent any tampering with this bolt from the outside it is protected at its
outer part by a metal plate g in the shape of a hood, in the same way the lower
part of the tube b is also protected by a metal plate h: lastly the air passages
pierced in the circumference of the guide piece i which crosses the upper end of the
bolt a are not placed in a straight line (see Figure 11). This arrangement prevents
the passing of any tool into the upper part of the tube b, even supposing the hood g
were detached.
Upon the bottom j of the lamp a cross-piece k is soldered, the lower portion of
which reaches exactly the level of the lower circumference 7 of the receiver c of the
lamp.
To open the lamp the chamber formed by the piece k is subjected to aspiration
and a vacuum formed, the piston e together with bolt a falls, and the lamp can be
opened by unscrewing the ring f.
To close the lamp the pieces are screwed together again, the bolt a being pushed.
back by the ring f until it arrives opposite the opening in this ring to receive it,
into which it enters automatically under the pressure of the spring d. If hydro-.
static pressure be employed to open this pattern of lamp; the arrangement
preferred is that shewn in Figure 12: between the piston e and the guide piece i
a tube of convenient size is interposed which can be placed in communication with
a receiver containing compressed air or liquid.
Figures 12, 13, 14, 15 represent a modification of the closing device above.
described, and specially designed to be operated by a vacuum. In this. modification
the spring d obtaining its point of support on the guide piece i is designed to hold.
down constantly the piston and consequently the bolt a which is in one piece with

page_text: it so as to bring it into the low position represented in Figures 12 and 13 where it
does not pass into the ring f in one piece with the screw of the lamp, thus per-
mitting the lamp to be freely opened: but as soon as the bolt a is lifted and passed
into the opening designed for it it is held firm in this position by a button or stop t
in one piece with a spring blade u (shewn in plan Figures 13 and 14) which is fixed
between the bottom of the lamp and a closing plate v connected to its lower part.
As soon as the lower end of the bolt a rests upon the stop t the lamp can not be
opened until this stop is withdrawn, leaving the bolt free to redescend to the
position shewn in Figures 12, 13: this displacement of the stop t is effected as
follows:
The lower part of the bottom j carries a metal plate x extending to the level of
the lower portion of the lamp and provided with apertures of suitable shape and
size so that when a vacuum is formed in these channels the spring u which fills the
whole height of the free space between the bottom j of the receiver cand the closing
pláte is drawn back, which releases the catch t holding the bolt a: at this
moment the action of the spring d draws down the bolt and enables the lamp to
be opened. For the purpose of giving the outer air free access to the side of the
spring blade u opposite to that on which the vacuum is formed, suitable openings
are made some in the piece x the others in the part e of the lamp: these openings
being of such shape that no article can be passed through them for the purpose of
releasing the bolt, or they may be protected by pieces y fastened to the bottom j
and which moreover serve to uphold the closing plate v so that it cannot be dis-
placed by a sudden shock. To close the lamp, the bolt a is raised into the position
in which it can pass into the loop f in one piece with the screw. For this purpose
the upper part of the bolt is made accessible from the outside and provided with a
catch or projection z against which a flat tool may be pressed to raise the bolt a
and thus close the lamp which is now fast bolted because as soon as the bolt is
raised the catch t replaces itself automatically under its lower part in such a
manner that it is impossible to depress it by means of z the catch t being sustained
by the closing plate v securely soldered or riveted beneath the lamp.
Efforts might be made to dislodge the stop t under the bolt, by striking sharp
blows on the lamp in the requisite direction: to prevent any possibility of such
attempts succeeding the blade spring u fits between rounded or sharp pieces
arranged on the inside part of the piece x the width between which is less than the
length of the spring which consequently exceeds them somewhat: moreover small
pieces of metal w are fixed to the ends of this spring forming counterweights, and
which at the moment of the shock, tend to cause the spring w to bend in the
opposite direction to that which it might take under the weight of its stop t which
is attached about its centre. The spring being thus drawn in two opposite directions
will not move, and the closure will be maintained. The above described opening
and closing mechanism for safety lamps may also be actuated by hydrostatic or
pneumatic pressure acting on the spring w to cause it to bend and determine the
displacement of the stop t which holds the bolt. It will in this case only be
necessary to arrange suitable orifices for the entrance of the compressed gas or fluid
and others for the escape of the air contained in the spaces of the pieces forming
the mechanism.
Figures 16, 17, 18 represent another modification of the invention in which the
closing mechanism, instead of being in the lower part of the lamp is arranged in
the upper part. The bolt in this case forms one of the metal bars which protect
the, wire gauze against outside blows. The actuating of this bolt may be effected
by hydrostatic pneumatic or spring pressure as preferred.
The arrangement preferred by the inventor is as follows: In the upper part of
the lamp a metallic box A¹ is placed supported on plate B¹ into which three of the
bars C¹ are riveted. The fourth bar D1 is movable, it passes through the plate B¹
and the bottom of the box A¹ and ends at its lower extremity in a sort of bolt E
which passes both through the circular base F¹ of the screw of the lamp and into
•

page_text: the metallic ring G soldered on the receiver. When the bar D¹ is in the position
shewn in the drawing the lamp can be opened without difficulty: when on the
other hand this bar is lowered the bolt E¹ secures F¹ and G¹ together and the lamp
cannot be opened.
.
To retain this bar D¹ in the locked position the interior of the box A¹ is
constructed as follows: At the centre of the box is fixed a pivot H¹ upon which
swings freely a cross piece I¹ which occupies the whole height of the box and
touches the upper cover J' one side of this cross piece bears a stop or projection K¹
on the exterior arranged exactly above the bar D' which when lowered projects
against the stop and cannot be raised until the latter has been shifted.
The other part of I¹ is .controlled by a spring L' connected to a fixed stop M¹
screwed on the bottom of the box A' and which divides the space or chamber formed
by the moving piece I¹ into two equal parts. Lastly the box A¹ is pierced with two
orifices of which the one N¹ is designed to allow free access of air to the outside of
the cross piece I' and the other aperture P¹ is used to create a vacuum in the little
chamber formed by the fixed partition M¹ and the side of the movable division I¹
bearing the stop K¹. When this chamber is exhausted this part of I¹ is displaced
sufficiently to remove the stop K¹ and consequently release the bar which can then
be raised by hand and the lamp opened. To close the lamp, the two halves are first
screwed together then the bar D₁ is pressed down by hand so that its lower end E¹
which forms the bolt passes into the hole of the ring G¹ destined to receive it: at
this moment the stop K¹ actuated by the spring L¹ replaces itself automatically
above the bar D¹ and the lamp cannot be opened. The little tubes R¹ S¹ connected
to the orifices N¹ and P¹ in the interior of the box A are designed to prevent
anything being inserted whereby the moving piece I¹ could be displaced.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, as communicated to
me by my foreign correspondent, I declare that what I claim is
1. The combination of parts forming the improved system of securing safety
lamps substantially as above described and shewn in the annexed drawings.
2. In safety lamps the method of securing the bolt by means a flattened elastic
manometric tube placed in the body of the receiver, which tube is designed to be
actuated from the outside by hydrostatic or pneumatic pressure or by a vacuum
substantially as described and shewn in the accompanying drawings.
3. In safety lamps, the method of releasing the bolt which consists essentially
in the use of a manometric tube of suitable shape and section having at one or
each of its ends a stop or projection which when drawn back allows of the auto-
matic descent of the bolt, actuated by a spring and thereby permits of the lamp
being opened, substantially as described and shewn in Figures 3, 4, 5 and 6 of the
accompanying drawings.
4. In safety lamps, the use of a bolt actuated by a spring tending to fasten the
lamp, and placed in a tube fixed in the interior of the lamp in such a manner as to
be inaccessible from the outside, and not removable except by a rarefaction of the
air in the apparatus sufficiently strong to counteract the pressure of the spring
substantially as described and shewn in Figures 7 to 11 of the accompanying
drawings.
5. In safety lamps the arrangement for securing the bolt consisting in a spring
blade bearing a catch abutting on the lower part of the bolt, when it is pushed
home, which catch can only be withdrawn by exhausting the air or by hydrostatic
or pneumatic pressure, together with the arrangements described for securing this
spring blade and catch against shocks substantially as described and shewn in
Figures 12 to 15 of the accompanying drawings.
6. In safety lamps, the bolting mechanism consisting essentially of a box
placed in the upper part of the lamp, one of the bars protecting the wire gauze

page_text: constructed to serve as a locking bolt, and abutting upon a stop in one piece with a
balanced spring arranged so as to be completely irremovable from the outside or in
any other manner than by hydrostatic or pneumatic pressure, or by rarefaction of
the air substantially as described and shewn in the accompanying drawings
Figures 15 to 18.