Improvements in Steam Traps.
Year: 1890

page_text: Date of Application, 19th Aug., 1890-Accepted, 20th Sept., 1890
COMPLETE SPECIFICATION,
Improvements in Steam Traps.
I, MATTHEW DUNLOP, of Neilston Thread Works, Neilston, in the County of
Renfrew, North Britain, 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, that is to say:
:-
My said invention has for its object to improve the construction of steam traps, or
apparatus for discharging water from pipes or other apparatus heated by steam.
In carrying out my invention I employ a float of copper, steel brass or other
suitable metal or impermeable material and I have hermetically enclosed in the float,
air, or any suitable gas compressed to about the maximum pressure of the steam
intended to be admitted to the pipes or apparatus to which the trap is to be connected:
and the pressure of the steam on the outside of the float is thus resisted by adequate
internal pressure so that the float can be made of sufficient strength without being
heavy. I apply the float directly over the outlet valve for the water, making it act
directly or indirectly on the valve. The minor details of my improved construction
are hereinafter explained, being shown on two accompanying sheets of explanatory
drawings.
Figure, 1, on sheet, 1, is a vertical section of one modification of my improved
stenm trap.
Figure, 2, is an elevation of a device for increasing the power of the float on the
outlet valve.
Figure, 3, is a section of a detail as at right angles to Figure, 1.
Figure, 4, on sheet, 2, is a vertical section showing a part of a second modification.
In these drawings the same reference numerals are used to mark the same or like
parts wherever they are repeated.
The parts of the steam trap shown in Figure, 1, are contained in a cast-iron box, 10,
provided with a cover, 11, and with an inlet branch, 12, near the top to be connected
to the steam pipe or other apparatus from which water of condensation is to be
drained. The outlet, 13, for the water is at the middle of the bottom of the box, 1.0,
and is in a piece screwed into the bottom, and formed with a cup-like part, 14,
extending above the valve seat and perforated to give the water access to the outlet.
The perforations in the cup-like part, 14, being above the bottom of the inside of
the box, 10, and also a little above the valve seat, any tendency of sediment or dust
to get on the valve seat and prevent complete closing of the valve, is prevented or
very much diminished. A vertical tube, 15, is fixed in the top of the piece, 14, and
extending up nearly to the top of the box, 10, serves as a guide for the float, 16,
which has fixed in it a tube, 17, of a size to slide easily on the fixed guide tube, 15.
The outlet valve, 18, is of a conical shape and is formed on the lower end of a
spindle, 19, which extends up inside of the fixed guide tube, 15. Near the upper end
of the valve spindle, 19, there is fixed across it a key, 20, which extends out on each
side through slots in the guide tube, 15, so as to be acted on by the top of the
float, 16, when the latter is raised by the accumulation of water in the box. A similar
key, 21, is fixed across the valve spindle, 19, at a short distance above the valve, 18,
and this key, as will be understood from Figure, 3, extends both ways through slots
in the fixed guide tube, 15, so as to be acted on when the float, 16, descends in con-
sequence of the water being discharged. The valve spindle, 19, is made with a
reduced extension below the valve, 18, and with a part, 22, which works through a
guide and is acted on by a lever, 23, on a spindle, 24. This spindle, 24, extends
through the side of a casting, 25, which is formed with a branch for a waste pipe, and
is fixed to the bottom of the box, 10. The spindle, 24 has fixed on it outside a
lever, 26, which has on it a weight, 27, for counterbalancing more or less of the
pressure of the steam on the valve, 18, this weight being adjustable.
[Price 6d1

page_text: In any case in which it may be thought desirable to cause the float, 16, to act with
some loverage when opening the valve, 18, the device shown in Figure, 2, may be
adopted. This device comprises a crosshead, 28, fixed at the top of the fixed guide
tube, 15, with a lever, 29, jointed to a stud at one end of it, and resting on the top of
the float, 16, whilst a second lever, 30, jointed to a stud at the other end rests on the
first lever, 29, and bears up against the cross key, 20, of the valve spindle, 19. The
levers, 29, 30, are arranged to increase the pressure on the cross key, 20, when the
float, 16, rises.
Ju the modification shown in Figure, 4, the outlet valve, 18, is not fixed to
the spindle, 19, which extends up through the float, 16, but is made with a short
spindle, 31, which has fixed on it a head movable with some play in a tubular
piece, 32, fixed to the bottom of the spindle, 19. This tubular piece, 32, has tooth-
like ribs formed on its outside with which there gear the teeth of a pinion, 33, fast on
a spindle, 34, having also fast on it a tumbler weight, 35. When the float rises its
action is first to turn up the weight, 35, until its centre of gravity gets to the other
side of a vertical plano through the pinion spindle, 34, and then the weight falling
over lifts up the tubular piece, 32, sufficiently high to completely open the valve, 18,
which it does quickly. With this arrangement the discharging action will be
periodical, the water being at each action all discharged down to a certain level,
which is not so low as to uncover the outlet to the steam, as the valve when once
opened will not closo again until the float can exert enough downward pressure to
turn over the tumbler weight back into its former position.
On the valve spindle, 22, below the outlet, 13, I, in some cases, fix a disk, 36, on
which the water falls when the valve, 18, is opened; and the impact of the water
falling in this way on the disk assists in closing the valve.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The improved combination of parts constituting my improved steam trap, sub-
stantially as herein before described with reference to Figure, 1, of the accompanying
drawings.
2. The modification of the apparatus with the leverage device shown in Figuro, 2,
of the accompanying drawings and substantially as hereinbefore described.
3. The modification of the apparatus with the tumbler weight device shown in
Figure, 4, of the accompanying drawings and substantially as herein before described.
4. Enclosing in a steam-trap float compressed air or gas to counterbalance or partly
counterbalance the steam pressure acting on the outside of the float, substantially as
hereinbefore described.
5. Providing a disk on the valve spindle below the outlet, substantially as and for
the purpose herein before described.
Dated this Eighteenth day of August 1890.
EDMUND HUNT,
Applicant's Agent.