Year: 1885

page_text: I, CHARLES JACKSON of 134 Robin Hoods Chase, Nottingham, Engineer do
hereby declare the nature of this invention to be as follows:-
This invention has for its object the manufacture of cocks and taps which will
remain tight under steam or water pressure, which are easily and cheaply manu-
factured and in which the plug is not liable to set fast in its seat.
For these purposes I bush the shell of the cock or tap with moulded asbestos-
I proceed as follows:-
I prepare the asbestos fibre with a solution containing a resinous matter such as
shellac or other matter which will serve to bind the asbestos together. I then
form from the prepared fibre the bushing or thimble for the tap or cock. This
I can do by winding the fibre upon a mandril and then I compress and mould the
asbestos when in a plastic state under heavy pressure.
Afterwards I dry the bushing and heat it sufficiently highly to change the
shellac or like material employed and render it insoluble.
The bushing may be pressed when in its place in the shell of the cock or tap.
I then bore through it the requisite passages or waterways.
The shell of the cock may be of iron and the plug of brass.

page_text: I CHARLES JACKSON of 134 Robin Hoods Chase Nottingham Engineer 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:
1
This Invention has for its object the manufacture of cocks and taps which will
remain tight under steam or water pressure, which are easily and cheaply manu-
factured and in which the plug is not liable to set fast in its seat.
For these purposes I bush the shell of the cock or tap with moulded asbestos-
I proceed as follows:—
I prepare the asbestos fibre with a solution containing a resinous matter such as
shellac or other matter which will serve to bind the asbestos together. I then
form from the prepared fibre the bushing or thimble for the tap or cock.
This
I can do by winding the fibre upon a mandril and then I compress and mould the
asbestos when in a plastic state under heavy pressure.
Afterwards I dry the bushing and heat it sufficiently highly to change the
shellac or like material employed and render it insoluble.
The bushing may be pressed when in its place in the shell of the cock or tap.
I then bore through it the requisite passages or waterways.
The shell of the cock may be of iron and the plug of brass.
;
In order that my said invention may be most fully understood and readily
carried into effect I will proceed to describe more in detail the manner in which
I prefer to operate.
I take a taper wooden mandrel of the size of the plug of the cock which it is
intended to bush. I wind on this core asbestos fibre which has just previously
been soaked in a solution of shellac in methylated spirit-this treatment renders
the asbestos strongly adhesive and it retains the form given to it in winding.
A sufficient quantity having been thus in this way accumulated, the mandril is
drawn out, and the bundle of asbestos is transferred to a metal mould which is
divided longitudinally into two parts. The mould receives into it a taper metal
core or plug of metal corresponding to the plug of the cock and there is a cavity in
the mould around the plug of the size of the bush which it is desired to produce.
The central part of the plug is tapered to the form of the plug of the cock and
it has two cylindrical ends which fit corresponding passages in the ends of the
mould. The two parts of the mould are brought together and made to compress
the asbestos bush whilst the smaller parallel end of the plug is in the cavity of the
mould, and the pressure is then completed by driving home the taper plug. In
this operation both the mould and the mandrel should be heated.
The asbestos bush thus produced is a somewhat taper tube or thimble of a
length equal to about twice the diameter of the plug cock and thickness say from
sixteenth to three sixteenths of an inch more or less and dependent on the size of
the cock or tap.
The bush when released from the mould is placed together with others in a tray
and it is exposed in an oven to a temperature of about three hundred degrees
Fahrenheit for several hours.

page_text: After this treatment the bush is inserted into its place in the shell of the cock
or tap in which it is to be employed and which may be slightly recessed to receive
it for the bush at this stage is when hot to some extent pliable and compressible.
The bush is now pressed firmly into its place and a solid plug is driven into it-
The cock with the bushing within it is then placed in an oven hotter than before
heated to a temperature of nearly four hundred degrees and here it remains for
some hours the plug is then driven out. Afterwards the waterways are cut
through the bush and the plug belonging to the cock or tap is inserted and secured
in its place.
When the cock or tap is required to be tight under steam at a high temperature
say over 25 pounds I find it well to substitute for the shellac solution a black
stoving varnish; this is capable of bearing a higher temperature than the shellac
and cocks and taps bushed with it should be prepared for use by exposure to a
temperature of over 400 degrees for many hours.
In some cases I give greater tenacity to the bushing by weaving or plaiting a
roving or cord of asbestos fibre into a tubular form in place of obtaining this form
simply by winding the asbestos fibre on to a mandril.
In all other respects I then proceed in the manner already described.
My invention is applicable also to cocks and taps in which disc valves are
employed closing against a valve face.
In bushing such cocks and taps, I turn a circular undercut groove in the valve
where it comes into contact with the face and I fill this groove by heavy pressure
with asbestos fibre saturated and bound together with shellac solution or varnish.
Preferably I prepare the asbestos by forming it into rovings or cords and
plaiting or weaving these into flat rings adapted to fill the groove turned in the
face of the metal valve.
When the bushing of asbestos has been forced into the groove or recess by heavy
pressure the valve is stoved, as already described and the valve is then finished by
turning the asbestos to a true face.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is:-
Bushing cocks and taps with a bush of asbestos fibre bound together with
shellac or like material, then moulded under pressure and afterwards changed by
exposure to heat substantially as described.
Dated this 93rd day of June 1886