IMPROVEMENTS IN SAFETY FUSES and in
Year: 1888

page_text: Date of Application, 16th Jan., 1888
Specification Accepted, 17th Feb., 1888
I WILLIAM BENNETTS of Roskear Fuse Works, Camborne Cornwall Manufacturer,
do hereby declare the nature of my said invention of IMPROVEMENTS IN SAFETY
FUSES and in the manufacture thereof and in what manner the same is to be
performed to be particularly ascertained in and by the following statement :-
A fuse made in accordance with this invention consists besides the usual igniting
parts of coatings, or layers, or strata, some of which shall be incombustible or nearly
so and impervious to the fire or sparks liable to be given off by the combustible core,
whilst others shall be waterproof, so that the fuse will be very durable and capable of
being used even where fire damp or other explosive gas or material may be present.
It will be obvious that this fuse inay be used particularly in coal mines or similar
places where danger might arise from the sparks or fire frequently emitted when
ordinary fuses are burned.
The water-proof coating will also adapt the fuse for employment under water or for
blasting with any form of water jacketted cartridge.
The fuses of my invention may conveniently be prepared as follows.
I take the following substances in the proportions stated or approximately in such
proportions:
Phosphate of Soda about 60 per cent.
Glue
China clay
15
"
23 "
"
"
"
The whole is mixed with water. The water is first boiled and the glue dissolved
therein, the phosphate of soda is thereupon added and the whole is well mixed. A
little while after the china clay is added and the whole is well mixed by stirring and
kept boiling for about two hours. Through a bath of this composition kept at boiling
point, I slowly draw the ordinary spun fuse and afterwards wind it on a drum and
thoroughly dry it. The fuse so coated is next covered with tape, also passed through
the aforesaid composition, and again dried. It is now coated with gutta percha, India-
rubber or other suitable water-proof material, again covered with tape, and again
drawn through the composition above described. The number of coatings or layers

page_text: may vary according to circumstances. I prefer that the outermost layer should be of
tape, and composition so as to protect the more delicate gutta percha or the like
against abrasion.
I am aware that various means have heretofore been adopted for preventing the
emission of sparks by fuses, also that fuses have been ere this made waterproof and I
therefore do not claim these features by themselves.
my said
Having now particularly described and ascertained the nature of
invention and in what manner the same is to be performed, I declare that what I
claim is :-
Firstly. The manufacture of safety fuses the outside covering of which contains
one or more layers or strata of the composition of Glue, phosphate of soda and china
clay substantially as described for the purpose of preventing the passage of fire or
sparks.
Secondly. A Safety fuse whose outer covering contains alternate layers of fire
resisting material, and of water-proof material as and for the purposes set forth.
Dated this 16th day of January 1888.
BERNHARD DUKES,
226, High Holborn, London, W.C.,
Agent for the Applicant.