Improvements in and connected with Appliances for Making Apertures in and Establishing Branch Connections with Main and other Pipes, Tubes, and like Conduits Charged with Water or other Liquid, or with Gas, or Compressed Air or Steam.
Year: 1890

page_text: The decision of the Comptroller-General, of the 22nd day of February 1893,
allowed, under Section 18 of the Patents, &c. Act, 1883, an Amendment of
this Specification.
Date of Application, 1st Dec., 1890
Complete Specification Left, 24th Aug., 1891-Accepted, 26th Sept., 1891
PROVISIONAL SPECIFICATION.
Improvements in and connected with Appliances for Making Apertures
in and Establishing Branch Connections with Main and other
Pipes, Tubes, and like Conduits Charged with Water or other
Liquid, or with Gas, or Compressed Air or Steam.
1, HENRY WILLIAM PEARSON, of Bristol Water Works, in the City and
County of Bristol, Civil Engineer, do hereby declare the nature of this invention
to be as follows:-
This invention has for its object to enable apertures to be made in, and branch
connections established with main and other pipes, tubes and like conduits while
charged under pressure with water or other liquid, or with gas or compressed air,
or steam; thus obviating necessity for stopping the flow of the water or other
liquid, gas or compressed air or steam whilst the pipes are being pierced and the
branches connected. Expense, trouble, inconvenience and danger due to such
stoppages are, under this invention, accordingly avoided.
This invention relates, firstly, to the drilling tool whereby the necessary apertures
are cut. The drilling tool, the spindle of which is passed through a stuffing box
and an adjoining throat, is, besides being fitted with a cup drill of an ordinary kind,
furnished with a central drill or boring bitt the leading end of which projects beyond
the cutting edge of the cup drill. Accordingly, when in operation, the central
drill pierces the pipe being cut in advance of the cup drill.
Hinged in the said central drill are a pair of arms which are so arranged that
when the drill in which they are hinged is boring the pipe they are folded or
compressed within the body of the drill, but when the latter has penetrated the
pipe and the hinge of the arms has passed in clear of the wall thereof, the arms
spread in opposite directions and assume a position at right angles or approximately
so to the spindle. The disc cut out by the cup drill which follows up the central
drill is transfixed on the latter and is withdrawn therewith and so prevented from
falling into the pipe and becoming an obstruction therein and forming a nucleus for
collecting sediment.
This invention relates, secondly, to means for preventing escape into the external
atmosphere of water, gas or compressed air or steam issuing from a pipe cut as
above described.
According to this invention the branch outlet chamber which is secured on the
pipe and is, as is usual, fitted with a controlling cock, contains a cup shaped valve
hinged in a lug projecting from the inner end of the throat above referred to as
adjoining the stuffing box. This cup-shaped valve has a horn which projects
upwards behind the drill head so that when, after an aperture has been cut, the
drill is being withdrawn, the drill head comes into contact with the horn of the
valve and thus the latter is tilted on its hinge and so drawn to bear against a seat
provided for it inside the mouth by which the branch outlet chamber communicates
with the aforesaid throat. To obtain a tight joint the valve is preferably fitted
CD: 017