IMPROVED METHOD OF AND APPARATUS FOR CONNECTING BRANCH PIPES TO MAINS
Year: 1884

page_text: COMPLETE SPECIFICATION.
I JOHN FRICK, Engineer to the Waterworks of Cuyaba in the province of
Matto Grosso, in the Empire of Brazil, do hereby declare the nature of my
invention for "IMPROVED METHOD OF AND APPARATUS FOR CONNECTING BRANCH
PIPES TO MAINS" and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
My Invention relates to an improved method of and apparatus for connecting
branch pipes to water mains particularly whilst the latter are under pressure, the
object of my invention being to simplify the operation and dispense with the brass
ferrules generally used. My Invention comprises an improved drilling apparatus
provided with a valve adapted to give passage to the tool and to close or be readily
closed against the water when the tool is withdrawn.
Lastly it comprises a new method of making the connection between the branch
pipe and main whereby the use of the common ferrule is dispensed with and much
time and labor saved, this method being also in part applicable in connecting with
a main not under pressure.
Reference is to be had to the accompanying drawings forming part of this
Specification and illustrating the method and apparatus of my invention. Figure 1
is a vertical section of one form of drilling apparatus with automatic valve for use
in drilling and tapping the main under pressure. Figure 2 is a plan and Figure 3
an end elevation of the same. Figure 4 is a section of the valve separately.
Figures 5 and 6 are sections of a similar apparatus provided with a rotary plug
instead of a valve. Figure 7 shows a combined drill and tap. Figure 8 shows the
method of expanding a lead ferrule into the tapped hole. Figures 9 and 10
illustrate the mode of fixing a plug in the ferrule for the purpose of permanently
securing the lead ferrule and of forming a temporary stoppage whilst the branch
pipe is being soldered to the ferrule. Figure 11 shows the connection complete,
previous to opening communication between the main and branch pipe.
The drilling apparatus shown in figures 1 to 4 consists of a cast iron casing A
having a saddle piece corresponding to the circumference of the main or otherwise

page_text: adapted to fit tight against the main to which it is secured, whilst in operation, by
chains or other means. Fitted in this casing is an indiarubber valve B of the
sectional form shown in figure 4 said valve being adapted by its shape and
its elasticity to give passage to and fit closely around the stems of the various
tools used, and to close upon the withdrawal of the same; the form of the valve
being such that the closing tendency will be increased by the pressure of water in
the main. The covor A¹ of the casing is tapped to receive a tubular pressure
screw C to give the necessary feed to the tools for which the screw also forms a
guide. The tool stems have a shoulder D against which the pressure screw bears
either directly or preferably through the intervention of a ring of balls. The
valve, just described, is automatic, whilst that shown in figures 5 and 6 requires
to be turned by hand. It consists of a rotary plug E, turning in a seat in a
casing A, and having a thoroughfare corresponding to the diameter of the tool, the
pressure screw being similar to that before described. The plug is turned by a
lever handle.
The operation of making the connection is as follows. The drilling apparatus
figure 1 being chained tightly to the pipe with an indiarubber washer interposed
to make a joint, a hole is first drilled and then tapped with the combined drill and
tap shown in figures 1 and 7. This combined tool is a common drill and taper tap
formed in one, the distance between the two being sufficient to allow the drill to
have finished cutting before the tap enters the hole. This done, the tool is wholly
withdrawn, and a drift F, having a soft metal ferrule G (of the form shown in
figure 8) slipped on its tapered end, is then introduced through the valve and
placed in the tapped hole as in figure 8. By means of the pressure screw or by
blows the drift is then driven in through the ferrule until the latter is expanded
into, and fills, the thread of the tapped hole in the main. If necessary a second
drift of larger diameter may be used to complete the expansion of the ferrule.
The drift is then withdrawn and replaced by a mandrel H, terminating in a pin h,
which carries a concavo-convex copper washer i of the form shown in figure 9a
and a brass or gun metal plug k of the form shown in figures 9, 10, 11. This plug
is conical externally to fit tightly in the soft metal ferrule after the latter has been
expanded as above mentioned; and it has also an oppositely coned bore the larger
end being towards the water pressure. This bore is tightly plugged for a portion
of its length with a capillary substance which readily dissolves in water such as
powdered sugar or salt 1, tightly rammed into the bore, the said substance being
protected from the water at both ends by a layer of wax or other adhesive
waterproof substance represented by the two thick black lines m m³ in figure 10.
The plug, thus prepared, and placed together with washer i on the nose h of the
mandrel B, is introduced in the same way as the preceding tools and driven tightly
into its seat in the ferrule. The washer being placed with its convex face towards
the mandrel is flattened by the act of driving the plug into its seat, this flattening
causing it to expand and imbed its edges in the soft metal ferrule, thus effectually
holding the plug k in its seat. This spreading of the washer is facilitated by
splitting it radially as in figure 9º.
The mandril and drilling apparatus is then removed and the projecting part of
the ferrule expanded or cupped as in figure 11. by suitable means. The outer
layer m of wax & is then removed, and the branch pipe n with stop cock attached
is then soldered in the cupped ferrule as in figure 11. Communication is then
opened between the main and branch pipes by introducing a little water into the
latter through the stop cock, which water dissolves the sugar or other stopping lin
the plug, and the wax m² being no longer supported thereby, yields to the pressure
in the main.
The plug & now has a clear thoroughfare, and remains in position where it acts
as a liner to keep the soft metal ferrule firmly embedded in the thread of the
tapped hole

page_text: 8
I prefer to use a ferrule of lead, but if greater strength of ferrule and a relatively
larger thoroughfare through the plug / be required, the ferrule may be made of
soft copper. In that case the modified construction of plug shown in figure 12
would be used. The plug consists of an outer shell & formed of a length of hard
metal tube (such as brass, gunmetal or phosphor bronze) tapered externally to fit
the ferrule and roughened internally by screw threading it, or otherwise adapted
to retain in place against the water pressure the soluble part of the plug next
described.
Within this shell is rammed or moulded a lining t of a plastic substance or
composition (such as glue with the addition of a little saccharine matter) which
will set hard without contraction and which is soluble in water. This substance is
moulded with a conical bore, as shown, which, when set, is tightly plugged with a
soluble capillary substance l, and protected by wax or other waterproof material m m¹
as in the former case. This plug is introduced, and fixed in place, in the ferrule
in the same way as before, a washer of hard copper alloy of the form shown in
figure 9b being used and caused to embed itself in the ferrule as before described.
With this plug the capillary stopping will quickly dissolve away and the rush
of water through the bore will gradually dissolve away the walls of the soluble
part of the plug leaving only the thin metallic shells which offers little or no
obstruction to the flow of water. Or the soluble part of the plug might in some
cases be made wholly of powdered sugar rammed into the shell.
In connecting a branch to an empty main the hole is drilled and threaded in the
common way. The soft metal ferrule is then expanded into the threads of the hole
and a perforated liner of copper or one of its alloys inserted if the ferrule be of lead.
This part of the system of making the connection may be used also for gas mains
when lead or composition branch pipes are used.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is :-
1st The herein described method of making the connection between a branch
pipe and a water main under high pressure, consisting in expanding a soft metal
ferrule by pressure into the threads of a tapped hole in the main, fixing therein a
perforated metal plug or liner filled with a temporary stopping formed of a substance
soluble in water and protected by a waterproof substance, and removing the said
stopping after the connection is made, substantially as berein specified.
2nd In making the connection between a branch pipe and a water main, the
employment, in the manner and for the purpose herein specified, of a temporary
plug formed of a soluble substance protected by a waterproof material which is
removed after the connection is made, substantially as herein described.
3rd In making the connection between a branch pipe and a water main, the
method of expanding a soft metal ferrule into the threads of the tapped hole in
the main, substantially as described.
4th In connecting a branch pipe and main, the employment, in combination, of
a soft metal ferrule fixed, by being expanded into the hole in the main, in combina-
tion with a tubular plug or liner to retain it in place substantially as shown and
described.
5th In connecting a branch pipe and water main, the combined employment of
a soft metal ferrule expanded into the hole in the main as described, a tubular plug
or liner for the same, and a washer to hold the liner in place, the said washer being
caused to imbed itself in the ferrule, substantially as shown and described.
6th An apparatus for drilling and tapping holes in water mains under pressure,
consisting essentially of a valve of indiarubber adapted to give passage to the tools
and to close automatically on the withdrawal of the same, and fitted in a casing
adapted to be clamped to the main and to form a guide for the tool, substantially
5 as described and shown in figures 1 to 4 of the drawings.

page_text: 7th An apparatus for drilling and tapping holes in water mains, consisting of a
rotary plug valve adapted to give passage to the tools and to close the said passage,
and fitted in a casing adapted to be clamped to the main, and furnished with a
pressure screw to guide and feed the tool, substantially as described and shown in
figures 5 and 6 of the drawings.