Improvements in Steam Engines.
Year: 1899

page_text: Improvements in Steam Engines.
I, HUGO LENTZ, Mechanical Engineer, of Bruenn, in the Empire of Austria,
do hereby declare the nature of this invention to be as follows;-
--
My invention relates to a novel construction in a steam engine, the object being
to provide a very cheap, simple and efficient device of this character, and consists
in the features of construction and combinations of parts hereinafter fully
described.
In the accompanying drawings illustrating my invention:
Fig. 1 is a central vertical longitudinal section of a steam engine constructed
in accordance with my invention taken on the line 1-1 of Fig. 2.
Fig. 2 is a horizontal section of same on the line 2-2 of Fig. 1.
Fig. 3 is a transverse section of same on the line 3-3 of Fig. 2.
Referring now to said drawings, A indicates the cylinder which is contracted
at its forward end B. The differential piston C moves in said cylinder A and
contracted end B and consists of a cylinder which is open at its forward end,
through which the pitman D enters, which is pivotally connected with said piston
in a usual and well known manner.
Said pitman D is connected at its other end with the crank 1 of the crank
shaft 2. Said crank 1 moves in a casing 3 in which said cylinder A terminates
and which forms an exhaust chamber from which steam is exhausted through tho
exhaust pipe 4.
The head E of piston C moves in the large end of the cylinder A and divides
the latter into two chambers 5 and 6, said chamber 5 being ring shaped and form-
ing the high pressure chamber and chamber 6 circular and forming the low
pressure chamber.
Said piston head E is provided with an opening 7 connecting the chambers 5
and 6 and with an opening 8 connecting the chamber 6 with the interior of said
piston C. Said openings are controlled by a slide valve 9 moving in a guide 10
on said head E and connected at its middle portion with an extension 11 of the
pitman D which passes through said opening S and enters an opening 12 in said
valve 9.
Steam enters a chamber 13 below the contracted portion B of cylinder A, and
thence enters the valve chamber 14 in which the valve 15 moves and which controls
the inlet port 16 into the chamber 5 of cylinder A. Said valve 15 is operated
from an eccentric 17 on shaft 2, in an obvious manner.
When said piston C has reached the forward limit of its stroke, as shown in
Fig. 2, said valve 15 has uncovered port 16 and steam is admitted to chamber 5.
In this position of the piston the valve 9 will obviously he in the same position
as when said piston reaches the rearward limit of its stroke as shown in Fig. 1,
thus closing both openings 7 and 8 in said piston head E.
The admission of steam will obviously force said piston toward the rearward
limit of its movement, turning the crank 1 in the direction indicated by the arrow.

page_text: This movement of the piston C obviously causes a transverse movement of said
valve 9 in a direction to uncover the exhaust port 8 through which the steam in
chamber 6 is exhausted, such exhaust port 8 remaining open and the passage 7
remaining closed during the entire rearward stroke of the piston. The valve 15
can be set to cut off the steam supply at any point in the rearward stroke. Upon
the beginning of the return stroke of the piston, the valve 9 uncovers the open-
ing 7, whereupon the steam expands and rushes into the chamber 6, thus forcing
the piston upon its return stroke owing to the differential cross sectional areas of
said chambers 5 and 6, as will be apparent. Near the end of the return stroke
of the piston the passage 7 is again closed and upon the beginning of the next
stroke the port 8 is again opened, as is likewise the valve 15.
In this manner I obviously produce an extremely simple and efficient compound
engine which has also the advantage that it can be readily converted into a full
pressure engine.
To convert said engine into a full pressure engine the valve 15 is entirely
removed. The action of the valve 9 remains exactly the same and entirely
controls the engine, the sole difference in operation residing in the fact that in
running the engine as a compound the return stroke is effected by expansion only,
while running as a full pressure engine full pressure is obtained both ways.
My engine is very efficient as a full-pressure engine or compound engine and
its simplicity and the total absence of all complicated valve mechanism make it
cheap and durable. By means of the casing 3 all vital parts are thoroughly pro-
tected and by partially filling said casing with oil, together with the condensed
steam remaining therein, the pitman can also be made to serve as a lubricating
member, thus enabling me to dispense with oil cups to a large extent.
Dotad Tanu 96th 1900
HARRIS & MILLS,
23, Southampton Buildings, London, W.C., Agents.
Improvements in Steam Engines.
I, HUGO LENTZ, of 14, Gomperzgasse, Bruenn, in the Empire of Austria,
Mechanical Engineer, do hereby declare the nature of this invention, and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
My invention relates to a novel construction in a steam engine, the object being
to provide a very cheap, simple and efficient device of this character, and consists
in the features of construction and combinations of parts hereinafter fully
described and claimed.
In the drawings accompanying my Provisional Specification illustrating my
invention Fig. 1 is a central vertical longitudinal section of a steam engine con-
structed in accordance with my invention taken on the line 1-1 of Fig. 2.
Fig. 2 is a horizontal section of same on the line 2-2 of Fig. 1.
Fig. 3 is a transverse section of same on the line 3-3 of Fig. 2.
Referring now to said drawings, A indicates the cylinder, which is contracted
at its forward end B. The differential piston C moves in said cylinder A and
contracted end B and consists of a cylinder which is open at its forward end,
through which the pitman D enters, which is pivotally connected with said piston
.in a usual and well known manner.
Said pitman D is connected at its other end with the crank 1 of the crank
shaft 2. Said crank 1 moves in a casing 3 in which said cylinder A terminates

page_text: and which forms an exhaust chamber from which steam is exhausted through the
exhaust pipe 4.
The head E of piston C moves in the large end of the cylinder A and divides
the latter into two chambers 5 and 6, said chamber 5 being ring shaped and form-
ing the high pressure chamber, and chamber 6 circular and forming the low
pressure chamber.
Said piston head E is provided with an opening 7 connecting the chambers 5
and 6, and with an opening 8 connecting the chamber 6 with the interior of said
piston C. Said openings are controlled by a slide valve 9 moving in a guide 10
on said head E and connected at its middle portion with an extension 11 of the
pitman D which passes through said opening 8 and enters an opening 12 in said
valve 9.
Steam enters a chamber 13 below the contracted portion B of cylinder A, and
thence enters the valve chamber 14 in which the valve 15 moves and controls
the inlet port 16 into the chamber 5 of cylinder A. Said valve 15 is operated
from an eccentric 17 on shaft 2, in an obvious manner.
When said piston C has reached the forward limit of its stroke, as shown in
Fig. 2, said valve 15 has uncovered port 16 and steam is admitted to chamber 5.
In this position of the piston the valve 9 will obviously be in the same position
as when said piston reaches the rearward limit of its stroke, as shown in Fig. 1,
thus closing both openings 7 and 8 in said piston head E.
The admission of steam will obviously force said piston toward the rearward
limit of its movement, turning the crank 1 in the direction indicated by the arrow.
This movement of the piston C obviously causes a transverse movement of said
valve 9 in a direction to uncover the exhaust port 8, through which the steam in
chamber 6 is exhausted, such exhaust port 8 remaining open and the passage 7
remaining closed during the entire rearward stroke of the piston. The valve 15
can be set to cut off the steam supply at any point in the rearward stroke. Upon
the beginning of the return stroke of the piston, the valve 9 uncovers the open-
ing 7, whereupon the steam expands and rushes into the chamber 6, thus forcing
the piston upon its return stroke owing to the differential cross sectional areas of
said chambers 5 and 6, as will be apparent. Near the end of the return stroke
of the piston, the passage 7 is again, closed, and upon the beginning of the next
stroke the port 8 is again opened, as is likewise the valve 15.
In this manner I obviously produce an extremely simple and efficient compound
engine which has also the advantage that it can be readily converted into a full
pressure engine.
To convert said engine into a full pressure engine, the valve 15 is entirely
removed. The action of the valve 9 remains exactly the same and entirely
controls the engine, the sole difference in operation residing in the fact that in
running the engine as a compound the return stroke is effected by expansion only,
while running as a full pressure engine full pressure is obtained both ways.
My engine is very efficient as a full pressure engine or compound engine, and
its simplicity and the total absence of all complicated valve mechanism make it
cheap and durable. By means of the casing 3 all vital parts are thoroughly pro-
tected and by partially filling said casing with oil, together with the condensed
steam remaining therein, the pitman can also be made to serve as a lubricating
member, thus enabling me to dispense with oil cups to a large extent.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to he performed, I declare that what
I claim is
1. In a steam engine, the combination of a cylinder having two different
diameters, a hollow piston fitting the smaller diameter and having a head fitting
the larger diameter, an opening in said piston head establishing communication
between both sides of the same, an exhaust opening in said piston head com-
municating with the interior of the hollow piston, a slide valve mounted on the

page_text: head of said piston and operated by an extension of the pitman, substantially as
herein shown and described.
2. In a steam engine, the combination of a cylinder having two different
diameters, a hollow piston fitting the smaller diameter and having a head fitting
the larger diameter adapted to divide the latter into high and low pressure
chambers, an opening in said piston head establishing communication between the
high and low pressure chamber an exhaust opening in said piston head establishing
communication between the low pressure chamber and the interior of said piston,
a slide valve mounted on the head of said piston common to both openings therein
and operated by an extension of the pitman, substantially as herein shown and
described.
3. In a steam engine, the combination of a cylinder having two different
diameters, a hollow piston fitting the small diameter and having a head fitting
the larger diameter, said piston head being formed with two openings, the one
communicating between both sides of the said piston head and the other acting
as an exhaust opening, a slide valve mounted on the head of said piston and
operated by an extension of the pitman, and an oscillating valve enabling the
engine to be used as a compound engine or as a full pressure engine, substantially
as herein shown and described.
4. In a steam engine, the combination of a cylinder having two different
diameters, a hollow piston fitting such cylinder having an exhaust opening in its
head controlled by a slide valve operated by an extension of the pitman, and a
housing for the crank shaft acting as an exhaust chamber attached to or forming
part of the cylinder, substantially as herein shown and described.
5. In a steam engine, the combination of a cylinder having a contracted end,
a hollow piston and piston head, inlet and exhaust openings in said piston head,
a valve valve mounted on said piston head controlled by an extension of the
pitman pivoted to the piston and connected to the crank shaft, a housing for the
crank shaft and pitman, and an oscillating valve operated by an eccentric, sub-
stantially as herein shown and described.
Dated this 30th day of September 1899
HARRIS & MILLS,
23, Southampton Buildings, London, W.C., Agents.