Improvements in the Charges of Detonating Railway Fog Signals.
Year: 1896

page_text: Date of Application, 26th Nov., 1896
Complete Specification Left, 23rd Sept., 1897-Accepted, 23rd Oct., 1897
PROVISIONAL SPECIFICATION.
Improvements in the Charges of Detonating Railway Fog Signals.
I, THOMAS JENKINS trading as T. Jenkins and Company, of Moland Street, in
the City of Birmingham, Fog Signal Manufacturer, do hereby declare the nature
of this invention to be as follows:-
This invention relates to the charges of audible or detonating fog signals for
railway purposes and has for its object, to dispense with the use of percussion caps,
anvils and like ignition devices, and also partly substituting the usual gun-powder
charges by employing charges capable of exploding by themselves when brought
under the influence of percussion.
Thus the cases of ordinary fog signals contain an explosive charge of gun pow-
der and nipples or anvils fitted with percussion fulminate caps for igniting the
said charge when an engine or the like passes over it and owing to such cases
being bulky in order to carry sufficient explosive to give the required loud report,
they are liable to skid whereas by making them flat this tendency to be pushed
along by the advancing wheels is overcome.
According to my present invention I take a shallow or flat case of the duplex
or other type, and charge the interior or the compartments of the same with a
detonating explosive mixture composed, for instance, of chlorate of potash (1 part),
flowers of sulphur (1 part) and fine dry silver sand (2 parts), the said ingredients
being intimately mixed. Any other percussive composition or chemical substance
that will explode with a detonation on being struck or crushed and is not too destruc-
tive in its action, may be employed as the charge, such as mixtures of chlorate of
potash with nitre and sulphur, or with sugar or starch and prussiate of potash, or
any fulminating salts known in the arts, viz., the fulminates of mercury or silver.
These detonating or fulminating charges are either placed loose within the
cases, like ordinary gun-powder charges, or where found desirable, they may be
enclosed in gelatine capsules or small paper cartridges, a number of which are
placed loose in the case.
1000
Improvements in the Charges of Detonating Railway Fog Signals.
I, THOMAS JENKINS trading as T. Jenkins and Company, of Moland Street, in
the City of Birmingham, Fog Signal Manufacturer, do hereby declare the nature
[Price 8d.1

page_text: of this invention and in what manner the same is to be performed, to be particu-
larly described and ascertained in and by the following statement:-
This invention relates to audible or detonating fog signals for railway purposes,
and has for its object, to dispense with the use or employment of ordinary detona-
tors, such as percussion caps and anvils, or like charge-ignition devices or
adjuncts, and also to dispense, or partly dispense, with the ordinary powder
charges, and to substitute for them detonating explosive charges, capable of being
fired, or exploded by themselves, ignited, when struck or crushed, or subjected to
the influence of percussion, whereby such signals are lessened in weight and bulk,
and the cost of their manufacture is considerably reduced, and owing to the
signals being less bulky, they are not liable to be skidded along a rail by the
advancing wheels of an engine, and they give, when exploded, a relatively louder
report than ordinary cap-and-powder charged signals.
According to my present invention I take a shallow or flat case of the duplex
or other type, and charge the interior or the compartments of the same with a
detonating explosive mixture composed, for instance, of chlorate of potash (1 part),
flowers of sulphur (1 part) and fine dry silver sand (2 parts), the said ingredients
being intimately mixed. Any other percussive composition or chemical substance
that will explode with a detonation on being struck or crushed and is not too destruc-
tive in its action, may be employed as the charge, such as mixtures of chlorate of
potash with nitre and sulphur, or with sugar or starch and prussiate of potash, or
any fulminating salts known in the arts, such as the fulminates of mercury and
silver.
Further, the explosive charge may be composed of red phosphorous (two parts),
potassium chlorate (six parts), sodium bi-carbonate (four parts) and powdered glue
(three parts).
It is proposed to mix the ingredients of the several compositions intimately
together, preferably with a sufficient quantity of water to make a safe paste, and
whilst in such a condition, to charge or fill up the cavities or compartments of a
signal shell or case with the same, or to place the paste in small trays or dishes
or shallow cups or shells, but preferably only partly filled, so that when such
trays or dishes are placed within the signal cases, after being dried, the closing up
of the cases in a press or the like, cannot prematurely detonate the charges, as
the edges of the dishes or trays serve for stops for preventing the walls of the
shell or case being crushed down upon the detonating charge.
These detonating or fulminating charges may be placed in a loose powder in
the cases, alike unto ordinary gun-powder charges, or they may be enclosed, either
as powder or in small cakes or pellets, in paper or tin-foil cases, or placed in metal
or paper dishes, or they may be enclosed in gelatine or other suitable capsules, a
number of which may be placed within the interior of case and be held in suitable
positions by resting in cavities or sets formed in the shells, or they may be
cemented or glued in place.
In the event of signal cases being charged with the explosive compound in a
moist state, I may provide within the interior of the case, a small pierced chamber
or wire gauze cage, within which is located a small crystal of anhydrous copper
sulphate, or other material which will absorb and retain to itself, the moisture
from the composition after the closing together of the component shells.
Figure 1 of the accompanying drawings represents, upon an enlarged scale, a
vertical section of a triple-closed and duplex capless railway fog signal, the com-
partments of which are charged with cakes of detonating composition according
to my invention.
Figure 2 is a plan of the same showing the arrangement of the charge in dotted
lines.
Such a capless detonating fog signal is made up of three shells a, b and c, triple
closed at their edges a¹, and forming two chambers or cavities d and e, in which

page_text: cakes f, f, of detonating explosives are placed, and either resting in sets as at c',
or not.
Figures 3 and 4 represents a vertical section and a plan of another form of cap-
less signal, in which the cakes of detonating material are placed in shallow
dishes g, with the surface of the compound coming within a distance of their edges,
so that the said trays or dishes are only about three parts filled.
Fig. 5 represents a capless duplex signal having horizontal chambers, and
composed of shells a, b and c, triple closed at a', and having chambers d and e,
in which the cakes f, or detonating explosive compounds are placed.
Figure 6 represents a vertical section of my invention as applied to a multiple
chambered fog signal having three longitudinal chambers and
Figure 7 is a plan of the same.
This signal is composed of three shells a, b and c, collectively united by a
triple-closed edging a, and forming three chambers d, e, e, in which cakes or the
like f, or detonating explosive compound are placed.
Figure 8 represents a single chambered fog signal a, fitted with a tray g, con-
taining (at the time of closing together the shell sections), moist detonating com-
pound f, said tray having upon its bottom, a supplementary pierced cage or
chamber g', wherein a crystal of anhydrous sulphate of copper is placed for the
purpose of absorbing and retaining in itself the moisture from the charge after
the closing together of the shells. The said compound is charged into the trays
in a partly dried state for the purpose of rendering the process of enclosing the
same in the signal unquestionably safe to the operative.
Figure 9 represents in vertical section, and Figure 10 in plan, another form of a
chamber capless signal a, charged with detonating explosive cakes h, and having
a cleft i, made across the top shell a', to receive the affixing strap .
Figure 11 represents a vertical section, and Figure 14 of a plan of a similar
form of capless signal to that represented in Figures 9 and 10, but in which the
cleft i, is made deeper, thereby forming a duplex or double-chambered signal
from two component shells only.
Figure 13 represents a vertical section of another form of capless duplex
chambered fog signal.
Figure 14 is a plan of the top component shell a, separately, and
Figure 15 is a plan of the inner shell b, whilst the base or third shell c, is pre-
ferably curved or concaved in its cross direction only so as to fit snugly upon the
curved face of the rail.
Figure 16 represents a vertical section and Figure 17 a topside plan of a
duplex capless fog signal, the chambers of which are charged with detonating
compound in a loose powdered or granular form.
Figure 18 represents a vertical section and Figure 19 an underside plan of
another form of capless detonating signal constructed according to my inven-
tion. In this arrangement an ordinary powder exploding charge j, is employed,
whilst the ignition charge consists of a small cake, pellet or other priming h, of
detonating or firing compound, inserted in the cupped or dished sinking a²,
formed in the head a³, of an anvil or table a', formed integral with, or attached to,
the base a, of the signal a and adapted to ignite the powder charge. If neces-
sary two or more such priming charges may be arranged in suitable positions upon
the base and the signal may be made up in two, three or more compartments, each
with separate firing and exploding charges.
Having now particularly described and a certained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:
First. A capless railway fog signal, consisting of a single, duplex or multiple-
chambered casing, charged with a detonating substance, compound or compo-i-

page_text: tion that will explode with a report when struck, crushed or subjected to the
influence of percussion.
Secondly. A capless railway fog signal, consisting of a single, duplex or multiple
chambered casing, charged partly with ordinary powder, and partly with a
detonating or igniting substance, mixture or composition that will explode or fire
when struck, crushed or subjected to the influence of percussion.
Thirdly. The combination with a duplex or multiple chambered capless fog
signal, of independent detonating explosive charges, substantially as described
and set forth.
Fourthly. The combination with a single, double or multiple chambered capless
fog signal, of detonating explosive charges in the form of cakes or pellets, or
enclosed within supplementary cases, capsules, trays or other fixed or loose car-
riers, substantially as described and set forth.
Fifthly. The specific forms of capless railway fog signals, as herein described
and represented in the several figures of the drawings.
10th of Santambor 1907
THOMAS JENKINS,
By Henry Skerrett,
24 Temple Row, Birmingham, Agent for Applicant.
THOMAS JENKINS,
By Henry Skerrett,
24 Temple Row, Birmingham, Agent for Applicant.