Improvements in and relating to Steam Traps.
Year: 1898

page_text: Date of Application, 12th Sept., 1898
Complete Specification Left, 12th June, 1899-Accepted, 5th Aug.,
1899
PROVISIONAL SPECIFICATION.
Improvements in and relating to Steam Traps.
We, ISAAC SILIMWELL MCDOUGALL, of Port Street, Manchester, Engineer, THOMAS
SUGDEN, of Brooklyn," Underhill Road, East Dulwich, London, S.E., Engineer,
and NOEL NEWALL HAIGH, of Plane Street, Oldham, Engineer, do hereby declare
the nature of this invention to be as follows:-
This invention relates generally to that class of mechanism known as steam
traps in which the condensed water from steam pipes and other sources is
drained off automatically, while the steam itself is retained or trapped. The
invention relates more particularly to certain specific improvements in the con-
structional details of the trap known as the "McDougall" trap and covered by
Patent No. 12388 of August 7th 1890.
The invention consists generally in so constructing the working mechanism
of the McDougall" trap viz.: float lever, float, balance weight, equilibrium
valve, and testing device, that it can be constructed and fitted together as a
whole, outside of the body of the trap, and then placed in position in the casing.
This construction of course also facilitates the easy removal of the working parts
for inspection or repair. A further advantage of the invention consists in the
reduction of parts requiring machining and therefore a saving of expense.
The mode of carrying the invention into effect is as follows.-The exit port
for the condensed water is formed integral with the bottom of the trap casing
and at or about the centre of the said casing. This port at its top side communi-
cates with the trap body by an opening machined on that side to receive the
spigot of the flange carrying the equilibrium valve. A vertical strut or stirrup
of cast iron or other suitable material is constructed in such a manner that its
lower end is machined to fit on the flange of the equilibrium valve casing, and
its upper end in suitable bearings carries the pivot upon which the float lever
swings. The vertical strut or stirrup is of such a length that when placed in
position within the trap casing its upper end comes underneath a removable
cross bar. The said cross bar embeds within recesses formed in the side walls
of the trap or casing. This cross bar is tapped centrally to receive a bronze set.
pin fitted with a lock nut and the length of the vertical strut and the position
of the cross bar and set screw are so arranged that when the set pin is screwed
down the strut is forced against the bottom of the trap and held rigidly in
position.
The mode of using the parts herein before described is as follows:-The vertical
strut is fitted with the float lever at the top end and has attached to it at the
bottom end the equilibrium valve casing and valve. The link connecting this
valve to the float lever is then attached and adjusted and the tile float and the
balance weight are fitted at the respective ends of the said lever. The strut
carrying this mechanism is now placed within the trap casing so that the spigot
formed on the flange of the equilibrium valve casing enters the machined recess
prepared to receive it at the bottom of the trap. The cross bar is now placed in

page_text: position with its ends in the recesses in the walls of the trap casing, and the
bronze set pin is turned down until it binds the vertical strut between the cross
bar and the machined recess receiving the bottom of the equilibrium valve casing.
The whole working mechanism of the trap is thus placed within the casing and
held in position by one adjustment.
**
In the McDougall" trap a device is arranged whereby the float lever can be
operated at will in either direction so as to forcibly lift the equilibrium valve
from its seat and thus allow steam and water to blow through. This is easily
effected by an external lever, a stuffing box, and a spindle passing through into
the trap, the said spindle carrying a catch piece which allows in a central posi-
tion the ordinary operation of the trap, but which at either end of its motion
operates on the float lever. In the present construction the catch which embraces
the float lever is attached in a similar manner to a spindle passing through a
stuffing box, and this spindle outside the trap carries a small hand wheel. The
hand wheel near its outer rim has a hole drilled in it and this hole comes oppo-
site a similar hole in a boss or projection formed on the side of the trap casing,
so that by passing a pin through both holes the hand wheel can be locked in the
normal position when the trap is working: but on unlocking, it can be moved
either to the right or left and accordingly lift the equilibrium valve off from or
force it on to the seating.
It is preferred sometimes to combine with this construction an arrangement
for trapping the dirt or detritus often found in steam piping, such as fragments
of rubber packing rings, sand, or the like. To do this effectively the steam inlet
is preferably arranged on the top of the trap and from this inlet within the trap
body a pipe passes to a pocket formed adjacent to the equilibrium valve casing;
the condensed water falling from the pipe passes into the pocket first and must
rise over a partition on the same before it can reach the equilibrium valve to be
ejected. The dirt or detritus of any kind is thus effectually trapped and does
not clog or jam the valve.
Dated this 12th day of Sontamban 1000
MARKS & CLERK,
18, Southampton Buildings, London, W.C., and
13, Temple Street, Birmingham, Agents.
Improvements in and relating to Steam Traps.
We, ISAAC SHIMWELL MCDOUGALL, of Port Street, Manchester, Lancashire,
Engineer, THOMAS SUGDEN, of Brooklyn, Underhill Road, East Dulwich, London,
S.E., and NOEL NEWALL HAIGH, of Plane Street, Oldham, Lancashire, Engineers,
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:-
This invention relates generally to that class of mechanism known as steam
traps, from which the condensed water from steam pipes and other sources is
drained off automatically while the steam itself is retained or trapped. The
invention relates more particularly to certain specific improvements in the con-
structional details of the trap known as the "McDougall" trap and covered by
Patent No. 12388, of August 7th, 1890.
The invention consists generally in so constructing the working mechanism
of the "McDougall" trap, riz.-float lever, float, balance weight, and equili-

page_text: brium valve that it can be constructed and fitted together as a whole outside of
the body of the trap and then placed in position in the casing. The testing device
is so constructed as to allow of the working mechanism being inserted. This
construction facilitates the easy removal of the working parts for inspection or
repair, a reduction of the parts requiring machining, and therefore a saving of
expense in construction.
The mode of carrying the invention into effect is illustrated in the accompany-
ing sheet of drawings.
Fig. 1, is a vertical section through the trap casing showing the working
parts in position.
Fig. 2, is a similar vertical section but at right angles to Fig. 1.
Fig. 3, is a plan of the improved trap, and Figs. 4, 5, 6, and 7, are details.
The mode of carrying the invention into effect as illustrated in the drawings
is as follows: the exit port A for the condensed water is formed integrally
with the bottom of the trap casing B and at or about the centre of the said
casing. The port A at its top side communicates with the interior of the trap
body B by a machined opening C which receives the spigot D of the flange E
carrying the equilibrium valve casing F. A vertical strut or stirrup G of cast
iron or other suitable material is constructed in such a manner that its lower end
is machined to fit on the flange E of the casing F while its upper end in suitable
bearings H carries the pivot I upon which the float lever J swings. The vertical
strut or stirrup G is of such a length that when placed within the trap casing B
its upper end lies underneath a removable cross bar K. The said cross bar K
embeds within recesses L (as clearly shown in Fig. 4) formed on either side walls
of the trap or casing. This cross bar Ki centrally tapped to receive a bronze
set pin M fitted with a lock nut, and the length of the vertical strut G, the posi-
tion of the cross bar K and set screw are so arranged that when the set pin is
screwed down the strut is forced towards the bottom of the trap and held
rigidly in position, making a steam joint between the faces of the parts E and C.
The trap body B is closed when the mechanism is in position by means of a
cover B and the inlet A' for the steam and condensed water is preferably
arranged directly upon the top of the trap as clearly shown in Fig. 1. The
inlet A is preferably constructed as shown in Fig. 1, that is to say, it branches
out on one side into a pipe A2 and discharges on one side of a partition 132 into
the body of the trap. The equilibrium valve casing and valve are arranged as
clearly shown in Figs. 6 and 7 with the top mitre half N and the bottom piston
half N2 of the valve N opening into a passage F" which discharges into exit
port A.
The mode of using the parts hereinbefore described is as follows:-The vertical
strut G is fitted with the float lever J at the top end and has attached to it at
the bottom end the equilibrium valve casing F with its valve N. The valve N
is then connected by suitable pins and a link to the float lever J while the tile
float Qand balance weight R are fitted at their respective ends of the said float
lever. The strut carrying all this mechanism is now placed within the trap
casing so that the spigot I formed on the flange of the equilibrium valve casing
enters the machined recess prepared to receive it at the bottom of the trap.. The
cross bar K is now placed into position by inserting its ends within the recesses L
prepared to receive it and the bronze set pin M is screwed down until it binds
the strut between the cross bar and the machined recess thus holding it rigidly
in position and forming a steam joint. The whole working mechanism of the
trap is thus placed within the casing B and held in position by one adjustment.
In the McDougall" trap a device is arranged whereby the float lever J can
be operated at will in either direction so as to forcibly lift the equilibrium
valve N from its seating and thus allow steam and water to blow through the
exhaust port A, and in the trap as formally constructed, this is effected by an
external lever, a stuffing box and a spindle passing through into the trap, the
said spindle carrying a catch piece which allows in a central position the ordinary

page_text: operation of the trap but which at either end of its motion operates on the float
lever. In the present construction the catch piece S is arranged of the form
shown with two projecting pins T T embracing the float lever when in a top or
bottom position and this catch piece is attached to a spindle U passing through
a stuffing box V and having mounted on the exterior a small hand wheel W.
The hand wheel W near its outer rim has a hole X (Fig. 5) drilled through it
and a similar hole X is drilled in, a projection Y upon the trap casing so that
when the trap float lever J is in a normal or working position the hand wheel W
is keyed by a small pin Z through the holes or perforations X. The withdrawal
of this pin permits the movement of the catch piece S to right or left and to
accordingly lift the equilibrium valve off from or force it on to its seating.
It is preferred sometimes to combine with this construction an arrangement for
trapping the dirt or detritus often found in steam piping such as fragments of
rubber, packing rings, sand, or the like. To do this effectively the inlet A¹ is
preferably arranged on the top of the trap as shown in the drawings clear of
the cover B1 and from this inlet within the trap body the pipe A2 passes to a
pocket formed adjacent to the equilibrium valve casing by means of the parti-
tion B. The condensed water from the pipe A2 passes into the pocket first and
rises over the partition 132 on the same before it can reach the equilibrium valve
to be ejected. The dirt or detritus of any kind is thus effectively trapped and
does not clog or jam the valve.
Having now particularly described and ascertained the nature of our said in-
vention and what manner the same is to be performed, we declare that what
we claim is;-
"
1.) In steam traps of the "McDougall or similar type providing a strut or
stirrup upon which the internal working mechanism can be mounted and adjusted
apart from the body or casing of the steam trap and which is so proportioned
that the whole can be inserted in position within the said body or casing, all
as a means of facilitating and cheapening the construction, removal, inspection,
or repair of the steam trap.
"
2. In steam traps of McDougall" or similar type provided with a strut or
stirrup carrying the working mechanism, arranging a removable cross bar with
a central adjusting screw in such a manner that a single movement of the screw
will bind and secure the working mechanism in position within the body or
casing of the steam trap.
3.) The improved steam trap constructed and operating substantially as herein-
before described with reference to Figs. 1, 2, 3, 4, 5, 6, and 7 of the accompanying
drawings.
Dated this 12th day of June 1899.
MARKS & CLERK,
18, Southampton Buildings, London, W.C.,
13, Temple Street, Birgiingham, and 25, Cross Street, Manchester,
Agents.