AN IMPROVED CON- STRUCTION OF TAP OR Cock
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by Jean Gairal at the Office of the
Commissioners of Patents on the 5th February 1880.
JEAN GAIRAL, Segnor Doctor, of Carignan, France. "AN IMPROVED CON-
STRUCTION OF TAP OR Cock."
The facility with which taps or cocks in constant use get out of order after very
little service without the possibility of being properly repaired has led me to the
construction of a cock with piston rod suitable for all kinds of liquids and secure
from frost.
This cock, in the manufacture of which I preferably use casting, may be made
of copper or of any other metal, or even of wood. It is composed of a tube forming
the body of the cock, of a piston, of a piston rod, of a valve, a lever, a plug, and
two nuts.
The tube has two parts quite distinct, the one in front the other behind, separated
on the inside the one from the other by a partition pierced in the centre with a
small hole for the passage of the piston rod. On the front part, which is cylindrical,
rise exteriorly two small projections or lugs. These lugs are separated from each
other by a mortice, which penetrates into the interior of the tube for the passage
of a lever, and they are further pierced through for the passage of a pin, either
plain or screwthreaded, serving to support and form hinge for the lever. Inside
this part of the tube is lodged the piston, which carries the piston-rod and the
plug. The back part is conical, and plain grooved or screw threaded. Its orifice
is bored on the inside in order that the valve, which is to close it, may fit exactly
therein, and it has beneath and in front a spout, by which the liquid runs off. It
may have a vent hole above for the circulation of air within it, and there is also a
slight incline to facilitate the outflow.
The piston is a metal cylinder of a length and thickness in proportion to the
bore of the back part of the tube; it is also provided with an opening intended to
receive the part of the lever which actuates it. One of its ends is free, while the
other is tapped to receive one of the ends of the piston-rod, which may be screwed
into it or cast with it.
The piston-rod is a galvanised wire rod; it may however be made of any other
metal, galvanized or not, or even of gutta percha, whalebone, or other suitable
material. It has a diameter of, say, from 1 to 1 of an inch, more or less; its
length is in proportion to that of the tube, and its two ends are screwthreaded, so
as on the one hand to screw into the piston, and on the other hand to the two nuts,
071

page_text: which hold the valve firmly fixed between them. This valve, in the form of a
cone, is of cork; it may also be of india-rubber, gutta percha, or of metal, plain or
covered with india-rubber, and if this latter is tapped to be screwed on to the
piston-rod the nuts, round or square, and of various dimensions, may be dispensed
with.
The plug held in the fore part of the tube consists of a stopper of cork, india
rubber, wood, or gutta percha a little stouter than the piston, so that it may enter
only by pushing it with a little force up to the partition; it is pierced through the
centre for the passage of the piston-rod, which after traversing it passes through
the said partition, runs along the interior of the tube interior of the tube in its
entire length, and comes out at the free end to receive the valve.
The lever is a piece of metal, say, 2 inches in length, more or less, divided into
two parts of about equal length, and set in an inverse direction. Thus the first or
inner part is flattened from right to left, say, about an inch broad by 1/8 of an
inch thick, and it is pierced through the centre with a hole for the passage of a
plain or a screw-threaded pin, intended to support it upon the lugs; it is this part
of the lever which acts on the piston to give it a to and fro motion, and to keep it
fixed after the manner of a buttress. The other part forming the handle of the
lever is flattened from front to back, and it is there that it is grasped to set it at
work.
The various pieces which I have above enumerated being combined give for
result a simple to and fro motion produced by the lever acting on the piston to
move the piston-rod backward or forward to open and close the cock. Thus when
the lever is fully inclined or laid down towards the reservoir which contains the
liquid the cock is entirely closed by the valve which enters within the tube,
whereas it is open if the lever is fully inclined or laid down in the opposite
direction.
When the cock is closed it retains no liquid within it, because it actually opens
and closes inside the reservoir to which it is fitted, and it is owing to this arrange-
ment that it is guaranteed from becoming frozen.
The two nuts differ from each other not only in their shape but also by their
functions. Thus the first, flat and even, presses upon the valve to keep it fixed
upon the piston-rod, whereas the other, with wings, is of a nearly conical form,
serves to support the valve, and at the same time acts as guide for the piston-rod.