AN IMPROVED STEAM-TRAP
Year: 1884

page_text: I ARTHUR H. KUHLMANN of 23 Gt St Helens in the City of London, Civil Engineer
do hereby declare the nature of the said Invention for AN IMPROVED STEAM-TRAP
to be as follows:-
Having found after many experiments that the existing apparatus for drying
steam are not reliable & efficient, I came to the following improvement;
I constructed a vessel & fitted it with a differential framework, combined of two'
metals of different degrees of expansion.
This vessel is of cylindrical form & of cast iron, has a large opening at the top'
for introduction of the framework, a second smaller aperture at the bottom (water
outlet) & two openings sideways to insert the apparatus in the steam pipes.
To produce the automatic opening & closing of the bottom outlet, the framework
consists of horizontal bars of little expanding metal. Joined at their ends to thom
& inclined towards these bars in a more or less acute angle, are rods (tubes) of
metal of greater expansion. These tubes are joined pair for pair in the axis of the
vessel by a disconnected vertical bolt.
The vessel being filled with steam, the frame expands & as explained the inclined
members more than the horizontal ones. The surplus of the linear expansion of
the former, therefore must convert itself into an axial movement & the bolt
mentioned will descend & close the outlet. On the contrary, the frame being
surrounded by the accumulated water & its members contracted the bolt will' rise
again, allowing the water to escape,

page_text: COMPLETE SPECIFICATION.
I, ARTHUR H. KUHLMANN, of 23 Great Saint Helens, in the City of London,
Civil Engineer do hereby declare the nature of said invention for "AN IMPROVED
STEAM TRAP" (a communication to me from abroad by W. Kuhlmann of Offenbach
on the Main) and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
Having found after many experiments that the existing apparatus for drying
steam are not reliable and efficient, I have devised the following improvement:
I construct a vessel and fit it with a differential framework, formed of two
metals having different degrees of expansion under heat. This vessel is of cylin-
drical form, has a large opening at the top for the introduction of the framework,
a second similar aperture at the bottom (water outlet) and one or two openings
sideways to insert the apparatus in the steam pipes.
To produce the automatic opening and closing of the bottom outlet, the frame-
work consists of horizontal bars of metal having a small coefficient of expansion.
At the ends of these bars and inclined towards at a more or less acute angle there
are joined rods (tubes) of metal of greater expansion. Those tubes are joined pair
by pair in the axis of the vessel by a disconnected vertical bolt. The vessel being
filled with steam, the frame expands the inclined members increasing in length
more than the horizontal ones. The surplus of the linear expansion of the former
therefore must convert itself into an axial movement, and the bolt mentioned will
descend and close the outlet. On the contrary, the frame being surrounded by the
accumulated water the members will contract and the bolt will rise again allowing
the water to escape.
Referring to the accompanying drawing, within a casing or shell (shown in
section) having inlet and outlet openings, there is arranged an expansion apparatus. K
connected with the conical valve v and with a spindle extending outwardly; the
latter serves to adjust and regulate the expansion apparatus.
The expansion apparatus K is formed of several parts or limbs joined to a body
and serves as a regulator or moving mechanism for the conical valve (or other
closing organ) which is moved from its seat with sufficient displacement and
without joints, levers or wearing parts; the sensibility and the efficiency of the
apparatus are thereby onhanced.
The parts or limbs g are arranged in such a manner that the curved rods
(pipes) b. b which are capable of greatest expansion are firmly connected at their
extremities with the straight rod a which is less expansive so that during a change
of temperature they transmit their change of length in the direction of the axis of
the spindle. The amount of displacement of the valve for a given change of
temperature depends upon the angle & between the two rods a and b.
The lift of the conical valve can be increased by making the angle & small and
by employing several parts or limbs connected together.
When the steam enters the casing the expansion apparatus K expands and closes
the valve until the condensed water accumulates, when it contracts and opens the
Baid valve.

page_text: When the steam is turned off the valve opens and serves as an air inlet and
outlet.. It also discharges all the water and prevents accidents from its freezing in
cold weather. By means of the screw and hand wheel the valve can be raised and
steam blown through to clear out any dirt that may accumulate.
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
1. The combination with expansion apparatus formed of metals having different
co-efficients of expansion of an outer casing, so that the said apparatus may be
exposed to variations of temperature on the external surface, or both externally
and internally substantially as described.
2. The combination of expansion apparatus such as hereinabove described with
a valve and an external casing substantially as described and illustrated.
3. The improved steam trap or condensed water outlet constructed, arranged and
operating substantially as described with reference to the drawings.
A. H. KUHLMANN,
23, Gt. St. Helens.
W. Lloyd Wise,
46, Lincoln's Inn Fields, London, W.C.,
Applicant's Agent.