Improvements in Fastenings for Miners' Safety Lamps and in Keys for use with such Fastenings.
Year: 1889

page_text: Date of Application, 9th July, 1889
Complete Specification Left. 3rd Apr., 1890-Accepted 17th May, 1890
PROVISIONAL SPECIFICATION.
Improvements in Fastenings for Miners' Safety Lamps and in Keys
for use with such Fastenings.
I, MICHEL LONGLE, of Heuseux, Belgium, Manufacturer of Arms, do hereby
declare the nature of this invention to be as follows:-
Up to the present time many fastenings for miners' lamps have been used, con-
sisting of an ordinary screw-bolt passed through certain parts of the oil reservoir,
and the upper part of the lamp, but in consequence of this screw usually having a
square head it can be easily removed by the aid of one of a number of very primitive
instruments.
According to the present invention this kind of fastening is used but under con-
ditions which render it impossible to remove the screw-bolt except by aid of a special
construction of key which forms part of the present invention.
Fig. 1 is a front elevation partly in section of a miners lamp, the part in section
shewing my improved locking arrangement.
Fig. 2 represents the fastening screw bolt detached the ring shaped collar of which
is shown in section.
Figs. 3 to 8 are views of a key hereinafter described for locking and unlocking the
lamp.
.
The screw-bolt a which locks or fastens parts of the lamp together is provided
at the end of the screw thread noarest the square head, with a shoulder or collar o
Figs. 1 & 2 to prevent the screw being forced inward too far.
To prevent the lamp being opened with any ordinary instrument, the screw-bolt
is provided at its lower extremity with a strong ring or collar a¹ that is rivetted
to but is moveable about a pin or pivot a² that forms a continuation or part of
the screw-bolt. The diameter of this ring or collar a' is greater than the diagonal
of the square head as so that there is but little clearance left between it and the
sides of an elongated small passage or keyhole which extends downward in the
example shewn to the base of the lamp. The lengthening of the passage or key-
hole b has for object to prevent a workman from readily getting at the moveable
ring or collar a' which constitutes the head of the screw a or from making use
of pincers or other similar instruments, instead of a special key such as hereinafter
described, for the purpose of catching hold of the square head a³ and by such
means opening and shutting the lamp.
In order to unscrew the screw-bolt a it is necessary to grip its square head a³
for which purpose a key of a peculiar construction is used.
Fig. 3 is an elevation of this key.
Fig. is a similar view but partly in vertical section, and showing the key
gripping the head of screw-bolt a ready for screwing up or unscrewing such bolt
as required.
Fig. 5 is an elevation of that part of the key which is fixed to the handle.
Fig. 6 is a plan showing the key, gripping the screw bolt which is shown in
horizontal section taken through the square head a³;
Fig. 7 is a cross section in the line A B of Fig. 3.
Fig. 8 is a cross section on the line C D of Fig. 5.
Figs. 6 to 8 are drawn to an enlarged scale.
The key comprises a cylindrical piece or stem c Fig. 5 fixed to a handle and
provided with four longitudinal grooves g c¹ (Fig. 8) extending from the handle to
within a short distance of its upper extremity. Its upper end portion is hollowed
out centrally (Fig. 4) to a suitable depth or length (in Fig. 5) in such a manner
that the stem has at this point a tubular form of a thickness less than the depth

page_text: of the grooves c'. By this construction it follows that the stem c is pierced by holes m
corresponding to the upper parts of the grooves c¹ Figs. 3 & 5.
Strips or springs i of steel slightly bent, are placed, in the grooves c¹ and held
together by screws i¹ and a sliding collar d which works on the stem c.
C
In consequence of the curvature of the strips or springs i these springs grip the
stem c Fig. 3 and their upper bent ends tend to spring into the holes m.
A collar or
sleeve 9 Figs. 3 & 5 slides on the stem c and tends to compress and stiffen the
springs i. This collar or sleeve y is in contact with the sliding collar d and partici-
pates in the notion of the latter, its upward movement being effected directly by the
sliding collar its downward movement being effected by the downward movement
of the springs which are compressed and act against the collar or sleeve.
as the springs i are free to move back into the position shown in Fig. 3 their upper
ends become flush with the holes m in the tubular portion Fig. 5.
As soon
In using the improved key the tube shaped portion thereof which fits exactly into
the annular space formed between the ring or collar a¹ and the inner side of the
passage or keyhole bis moved over the square head a³ until the ring or collar a¹ is
in contact with the bottom of the tubular portion 1. If the sliding collar d be now
moved upward the springs i are advanced in their grooves and the collar or sleeve g
follows the movement of d.
The springs being forced inwards, their upper ends spring into the holes m in the
piece e slide along the flat sides of the square head a³ of the screw bolt a and by
moving into the space between the screw bolt and the upper slotted part they are
pressed by the latter against the sides of the square head a³ the screw bolt being thus
gripped as in a vice (see Fig. 6) since the springs i are in contact with the slotted
tubular portion of the key. The collar or sleeve a increases the pressure on the
springs; in some cases it may be dispensed with. The screw bolt thus gripped can
be screwed up or unscrewed at will for locking and unlocking the parts of the lamp.
To release the screw it is only necessary to draw back the sliding collar d the collar
or sleeve g and the springs i following its backward motion.
Dated this 9th day of July 1889.
COMPLETE
SPECIFICATION.
Improvements in Fastenings for Miners' Safety Lamps and in Keys
for use with such Fastenings.
I, MICHEL LONGLE, of Heuseux, Belgium Manufacturer of arms, 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 :-
Up to the present time many fastenings for miners' lamps have been used, con-
sisting of an ordinary screw-bolt passed through certain parts of the oil reservoir, and
the upper part of the lamp, but in consequence of this screw usually having a square
head it can be easily removed by the aid of one of a number of very primitive
instruments.
According to the present invention this kind of fastening is used but under con-
ditions which render it impossible to remove the screw-bolt except by the aid of a
special construction of key which forms part of the present invention.
Referring to the drawings filed with my Provisional Specification
Fig. 1 is a front elevation partly in section of a miner's lamp, the part in section
shewing my improved locking arrangement.
Fig. 2 represents the fastening screw bolt detached, the ring shaped collar of which
is shewn in section.
Figs. 3 to 8 are views of a key hereinafter described for locking and unlocking the
lamp.
The screw-bolt a which locks or fastens parts of the lamp together is provided at

page_text: the end of the screw thread nearest the squared portion a³, with a shoulder or collar o
Figs. 1 and 2 to prevent the screw being forced inward too far.
To prevent the lamp being opened with any ordinary instrument, the screw-bolt is
provided at its lower extremity with a strong ring or collar a¹ that is rivetted to but
is movable about a pin or pivot a² that forms a continuation or part of the screw-bolt.
The diameter of this ring or collar a¹ is greater than the diagonal of the squared part a³
so that there is but little clearance left between it and the sides of an elongated
passage or keyhole b which extends downward in the example shewn to the base of the
lamp. The lengthening of the passage or keyhole 6 has for object to prevent a
workman from readily getting at the movable ring or collar a', which constitutes the
head of the screw bolt a or from making use of pincers or other similar instruments.
instead of a special key such as hereinafter described, for the purpose of catching hold
of the squared part a³ and by such means opening and shutting the lamp.
In order to unscrew the screw-bolt a it is necessary to grip its squared part a³ for
which purpose a key of a peculiar construction is used.
Fig. 3 is an elevation of this key.
Fig. 4 is a similar view but partly in vertical section, and showing the key gripping
the squared part of screw-bolt a ready for screwing up or unscrewing such bolt as
required.
Fig. 5 is an elevation of that part of the key which is fixed to the handle.
Fig. 6 is a plan showing the key gripping the screw-bolt which is shown in
horizontal section taken through the squared part a³.
Fig. 7 is a cross section in the line A B of Fig. 3.
Fig. 8 is a cross section on the line (D of Fig. 5.
Figs. 6 to 8 are drawn to an enlarged scale.
The key comprises a cylindrical piece or stem c Fig. 5 fixed to a handle and
provided with four longitudinal grooves c¹ (fig. 8) extending from the handle to
within a short distance of its upper extremity. Its upper end portion is hollowed out
centrally (fig. 4) to a suitable depth or length (in Fig. 5) in such a manner that the
stem chas at this point a tubular form of a thickness less than the depth of the
grooves c. By this construction it follows that the stem c is pierced by holes m
corresponding to the upper parts of the grooves c¹ Figs. 3 and 5.
Strips or springs i of steel slightly bent, are placed in the grooves c¹ and held
together by screws i¹ and a sliding collar d which works on the stem c.
In consequence of the curvature given to the strips or springs i they grip the stem c
Fig. 3 and their upper bent ends tend to spring into the holes m.
A collar or
sleeve 9 Figs. 3 and 4, is arranged to slide on the stem c and compress and stiffen
the springs i. This collar or sleeve 9 is in contact with the sliding collar d and
participates in the motion of the latter, its upward movement being effected directly
by the sliding collar d and its downward movement by the downward movement of the
springs which are compressed and act against it. As soon as the springs i are free
to move back into the position shown in Fig. 3 their upper ends become flush with
the holes m in the tubular portion Fig. 5.
In using the improved key the tube shaped portion thereof which fits exactly
into the annular space formed between the ring or collar a¹ and the inner side of the
passage or keyhole 6 is moved over the squared part a³ until the ring or collar a¹ is
in contact with the bottom of the tubular portion 1. If the sliding collar d be now
moved upward the springs i are advanced in their grooves and the collar or sleeve g
follows the movement of d.
The springs i being thus forced inwards, their upper ends spring into the holes m
in the stem c slide along the flat sides of the squared part as of the screw-bolt a and
by moving into the space between the screw-bolt and the upper tubular part 1 they are
pressed by the latter against the sides of the squared part a³, the screw bolt being
thus gripped as in a vice (see Fig. 6) the springs i being in contact with the tubular
portion of the key. The collar or sleeve g increases the pressure on the springs ;
in some cases it may be dispensed with. The screw bolt thus gripped can then be
screwed up or unscrewed at will for locking and unlocking the parts of the lamp.

page_text: To release the screw,
it is only necessary to draw back the sliding collar d; the
collar or sleeve g and the springs i following its backward motion.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is-
1. A fastening device for a miner's safety lamp comprising a screw bolt a to
fasten the oil reservoir and upper part of the lamp together, this screw bolt having
a squared part a³, a ring or collar a¹ capable of rotary movement about the axis of
the bolt and of greater diameter than the diagonal of the squared part a³, and a
shoulder or collar at o, this screw bolt being, when in use, at the inner end of a
passage or keyhole b that extends downwards to the base of the lamp substantially as
herein described.
2. For operating the fastening device referred to in the preceding claim, a key con-
sisting of a cylindrical stem c formed with a tubular portion at its free end, lateral
holes m, and external longitudinal grooves c extending to the tubular portion and
provided with springs that are placed in the said grooves, a sliding collar d to which
the springs are connected and a collar or sleeve g arranged to slide on the key stem
and compress the said springs substantially as herein described for the purpose set
forth.
Dhe
1 1
0
10