Improvements in the Manufacture of Safety Fuse suitable for Blasting and Mining purposes.
Year: 1898

page_text: Date of Application, 20th Dec., 1898
Complete Specification Left, 18th Sept., 1899-Accepted, 21st Oct., 1899
Improvements in the Manufacture of Safety Fuse suitable for
Blasting and Mining purposes.
We, WALTER FRANCIS REID, of Fieldside, Addlestone, in the County of Surrey,
Chemist, and EDWARD JOHN VAVASOUR EARLE, of 139, Queen Victoria Street, in
the City of London, Merchant, do hereby declare the nature of this invention
to be as follows:-
-
In the manufacture of waterproof safety fuse it has hitherto been customary
to coat the fuse containing the powder with one or more coatings of gutta-percha.
This material possesses the disadvantages of softening when warm and of becom-
ing brittle and friable if stored for any length of time, in both of which cases
the fuse ceases to be waterproof. To obviate these defects we construct a water-
proof safety fuse in the following manner. The core or inner part of the fuse is
made and covered with yarn in the usual way. It is then drawn through a nozzle
of a diameter slightly less than that of the finished fuse and during its passage
through the nozzle is saturated with a solution made as follows:-Castor oil or
linseed oil or any other oils containing ricinolein or linolein are nitrated by means
of concentrated nitric acid in the same way as glycerine in the manufacture of
nitro-glycerine. When thoroughly purified about two parts of the nitrated oil
are mixed with about one part of nitro-cellulose, preferably of a low percentage
of nitrogen. One part of this mixture is then mixed with about four parts of a
solvent of nitro-cellulose such as acetone, or, in the case of collodion or soluble
cotton, a mixture of ethylic ether and alcohol may be used. The mixture is
agitated until it becomes homogeneous and is applied to the fuse before passing
through the nozzle either by means of a paint-brush or any other well-known
device. According to the degree of impermeability or stiffness which it is
desired to give to the fuse this treatment with solution may be repeated several
times; for ordinary waterproof fuses for use in wet mines or under a head of
about 100 feet of water two coatings will be found sufficient. After leaving the
nozzle the fuse is passed through a heated chamber in order to evaporate the sol-
vent. A final coating of any desired colour is given to the fuse by drawing it
through a nozzle the internal diameter of which is the same as the external dia-
meter of the finished fuse. The back of the nozzle is funnel-shaped and into the
conical portion a paste is pressed of the following composition:-Two parts of
nitrated oil as above described, one part of nitro-cellulose, five parts of solvent.
Any desired pigment may be added in any proportions not exceeding the weight
of the fixed ingredients of the paste. After warming to 100° to 120° Fahrenheit
until the solvent is completely expelled the fuse is ready for use. The expulsion
of the solvent is complete when the weight of the fuse is found to remain constant.
Dated this 19th day of December 1898.

page_text: COMPLETE SPECIFICATION.
Improvements in the Manufacture of Safety Fuse suitable for
Blasting and Mining purposes.
We, WALTER FRANCIS REID, of Fieldside, Addlestone, in the County of Surrey,
Chemist, and EDWARD JOHN VAVASOUR EARLE, of 139, Queen Victoria Street, in
the City of London, Merchant, 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: -
In the manufacture of waterproof safety fuse it has hitherto been customary
to coat the fuse containing the powder with one or more coatings of gutta-percha.
This material possesses the disadvantages of softening when warm and of becom-
ing brittle and friable if stored for any length of time, in both of which cases
the fuse ceases to be waterproof. To obviate these defects we construct a water-
proof safety fuse in the following manner. The core or inner part of the fuse is
made and covered with yarn in the usual way. It is then drawn through a nozzle
of a diameter slightly less than that of the finished fuse and during its passage
through the nozzle is saturated with a solution made as follows:-Castor oil or
linseed oil or any other oils containing ricinolein or linolein are nitrated by means
of concentrated nitric acid in the same way as glycerine in the manufacture of
nitro-glycerine. When thoroughly purified about two parts of the nitrated oil
are mixed with about one part of nitro-cellulose, preferably of a low percentage
of nitrogen. One part of this mixture is then mixed with about four parts of a
solvent of nitro-cellulose such as acetone, or, in the case of collodion or soluble
cotton, a mixture of ethylic ether and alcohol may be used. The mixture is
agitated until it becomes homogeneous and is applied to the fuse before passing
through the nozzle either by means of a paint-brush or any other well-known
device. According to the degree of impermeability or stiffness which it is
desired to give to the fuse this treatment with solution may be repeated several
times, for ordinary waterproof fuse for use in wet mines or under a head of
about 100 feet of water two coatings will be found sufficient. After leaving the
nozzle the fuse is passed through a heated chamber in order to evaporate the sol-
vent. A final coating of any desired colour is given to the fuse by drawing it
through a nozzle the internal diameter of which is the same as the external dia-
meter of the finished fuse. The back of the nozzle is funnel-shaped and into the
conical portion a paste is pressed of the following composition:-Two parts of
nitrated oil as above described, one part of nitro-cellulose, five parts of solvent.
Any desired pigment may be added in any proportions not exceeding the weight
of the fixed ingredients of the paste. After warming to 100° to 120° Fahrenheit
until the solvent is completely expelled the fuse is ready for use. The expulsion
of the solvent is complete when the weight of the fuse is found to remain constant.
In order to expedite the final seasoning of the fuse, about three parts of the
five parts of solvent may be evaporated from the paste before it is applied as a
coating to the fuse. In this case a pressure of not less than one ton per square
inch will be required and the temperature must be kept as near as possible to the
boiling point of the solvent used.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is :-
1. The manufacture of safety fuse by coating it with a mixture of nitro-cellu-
lose and nitro-ricinolein or nitro-linolein substantially as described.
2. The manufacture of safety fuse substantially as described.
Dated this 14th day of Cantamhan 1500