IMPROVEMENTS IN ENGINES ACTUATED BY Engineer for an PRESSURE OF FLUID, SUCH AS STEAM.
Year: 1883

page_text: LETTERS PATENT to Thomas Edwin Craven of Leeds in the County of York,
Invention of IMPROVEMENTS IN ENGINES ACTUATED BY
Engineer for an
PRESSURE OF FLUID, SUCH AS STEAM. Communicated to him from abroad by
George William Price, a person resident at Baltimore, in the State of
Maryland, United States of America
COMPLETE SPECIFICATION filed by the said Thomas Edwin Craven at the
Office of the Commissioners of Patents on the 11th December 1883.
.
THOMAS EDWIN CRAVEN of Leeds in the County of York Engineer IMPROVEMENTS
IN ENGINES ACTUATED BY PRESSURE OF FLUID, SUCH AS STEAM communicated
to me from abroad by George William Price, a person resident at Baltimore in the
State of Maryland, United States of America,
This Invention has reference to steam actuated valves, to a mode of actuating
the same, and to a reversing attachment that may be combined therewith, and will
be clearly understood from the following description thereof, reference being had to
the accompanying drawings in which the same letters are used to denote the same
parts wherever they occur.-Fig. 1. is a sectional elevation of a steam chest
shewing the valves and the reversing attachment. Fig. 2. is a sectional plan of the
same through the line x, x, of Fig. 1.-Fig. 3, is a cross-sectional elevation of the
steam chest on the line y, y, Fig. 1. shewing the main slide valve, and also the
reversing attachment.-Fig. 4 is a cross-sectional elevation of the steam chest on
the line z. z, shewing the valve K, and the steam passage c, the contrary end of the
steam chest being similarly provided with a steam passage c¹ and valve K.-
Figs. 5, and 6, are sectional plans of the steam chest and valves, also shewing the
connection between the steam chest and the cylinder.-The construction and mode
of operation embodied in this invention I proceed to describe.
Let A, Figs, 5 and 6, represent the cylinder of a steam engine, B, the piston,
and C, the piston rod.-Near the ends of the cylinder, but removed therefrom a
distance greater than the thickness of the piston, are arranged two outlets or
passages D, and D¹, communicating with the respective ends of the steam chest E.
-The exact size of these communicating steam passages will vary of course with

page_text: the size and capacity of the engine, the area requiring only to be sufficient to
provide steam enough to actuate the valves in the steam chest. It will be seen
that when the steam enters the cylinder at the end marked A, and forces the
piston B, to the other end and beyond the passage D', a portion of the steam will
escape through the said passage D1. and proceed to the steam chest E, the same
result will obtain through the corresponding passage D, when the piston is forced
to the opposite end of the cylinder. The steam thus passing through the passages D,
and D¹, entering the steam chest at opposite ends with each stroke of the piston, is
used to actuate the valves by direct action as I will explain :-
The steam pipe F, Figs 5, and 6, leading from the boiler enters the steam
chest E, as shewn, G is the exhaust pipe, the parts H, H' H", are portions of the
main valve, The part H shaped with its sides parallel, is located centrally
between the parts H, and H", and is regulated in thickness or width by the
distance or length of its stroke or is equal to about one third the width or distance
between the two openings or ports L. L'.-The distance on the other side of the
steam chest travelled by the valve, being the same, it follows that the steam chest
should be so constructed that the distance between the innersides of the exhaust
ports v, and vl, should be approximately the same as the distance between the
innersides of the openings or ports L, L'.-The parts H. H'. H", may be cast solid
with the valve stems I, 1', and cut out to proper shape, or they may be keyed upon
the said stems if desired.
Upon the valve stems I, I¹, are arranged respectively the valves K, and K 1.
These valves K, and K¹, are not rigidly fixed upon the said stems I, and I', but
are mounted freely thereon, and are actuated endwise to and fro as required by the
collars a, and a 1, in one direction, and by the nuts b, and 61, in the opposite
direction. The parts H, and H", of the main valve are constructed so that when
steam is entering the cylinder through the pipe or port L, one side of the part H",
coincides with steam port F, and the other side with the port L. Fig. 5.-The
part H, performs the same service in the same manner at the other end of the
steam chest Fig. 6. thus securing duet or alternate communication from the steam
pipe F, to the cylinder A.-L, L¹, are pipes or ports forming communication
between the steam chest and cylinder and serve the double purpose of conducting
the steam to the cylinder from the steam pipe F, and also from the cylinder to the
exhaust pipe G, after it has perforined its work. c, c¹, are outlets communicating
from the steam chest to the exhaust pipe G. The main valve is slotted at M, so as
to admit easily the end of the lever O. This lever is pivotted at P, to a cap
projecting from the lid or cover of the steam chest, To the top of this cap is
attached a spring R, the other end of which is attached to the arm of the lever
projecting beyond the fulcrum P.-The operation of the apparatus is as follows:-
Steam from the boiler enters the steam chest E, and passing through the port h¹, of
the valve in the direction of the arrow, enters the pipe or port L, and is thus
conducted to the cylinder behind the piston as shewn. The steam thus introduced
forces the piston to the opposite end of the cylinder whilst the pipe or passage D,
leading to the steam chest is closed by the valve K, The piston is now forcing
the steam which has been previously used at the contrary end of the cylinder (now
exhaust steam) through the pipe or port L', and through the port h, of the main
valve into the exhaust pipe G, whereby it escapes.-When the piston has passed
the port or passage D', a portion of the steam enters therein and passes to the
steain chest behind the part H, of the main valve, the valve K₁, being perforated
or formed with open work to allow steam to pass through it freely. The outlet c',
being closed by the valve K¹, this end of the steam chest is filled with the steam
which forces the main valve H H¹H", in the opposite direction during which
movement the collar b¹, on the stem I¹, comes in contact with the valve K³, where-
upon this valve also is moved forward, opening the outlet c', thus allowing the
steam contained in the end J', of the steam chest to escape through the said
outlet c². and the exhaust pipe G, and at the same time closing passage D², and
preventing the entrance of steam to this end of the steam chest, When the main

page_text: valve HHH", is forced to the other end of the steam chest as above described,
the steam entering the steam chest through the pipe F, passes to the other end of
the cylinder through the port h, of the main valve and through the port or pipe L³,
whilst the exhaust steam escapes through the pipe L, and valve port h, to the
exhaust pipe G.-The operations at the end J, of the steam chest continue
identically with those previously described with reference to the end J', thus it will
be seen that with each successive stroke of the piston, the valves are actuated by
the direct action of the steam, alternately opening and closing the ports and
automatically regulating the entrance and exit of the steam as required. The
apparatus as above described needs no additional arrangement to constitute a
complete working engine. It may however sometimes happen that the steam will
not throw the valve or valves to the end of the stroke, This will be understood by
reference to the drawings and the following explanation:-The piston.B. having
passed beyond the aperture D, and the steam having passed through this passage
into the steam chest (the valve K, being open in the centre by perforations) the
steam exerts a pressure against the end of the steam chest and the end H", of the
main valve, moving the main valve H H'H", until the collar b, coming in contact
with the valve K, moves this valve until it closes the pipe or passage D 1 at the
same time opening the outlet c, from which the steam will escape. This position is
shewn in Fig. 5.
At this stage it will sometimes occur that the valves will not have travelled the
full length of the stroke, the steam exhausting before the stroke is completed.-
An effectual remedy for this is the arrangement of reversing attachment illustrated
in Figs. 1, and 3. When the steam has forced the main valve beyond the centre,
the tension of the spring R, is exerted upon the lower arm of the lever O, pressing
the point of the lever against the wall slot M, in the main valve, and forcing this
valve, with its stems and their valves K, and K¹ to the extreme end of the stroke.-
The tension of this spring R, is exerted at each side as the lever passes the centre,
forcing the valves home in the direction of their stroke.
The reversing attachment constitutes a distinct feature of the invention. It
will be seen that whilst the engine is running, it is only necessary to hold the lever
by its handle in order to stop the movement of the valves, then by pushing or
pulling the lever handle in the opposite direction to that in which it was previously
moving, the movement of the piston will be reversed and the engine will continue
to run in the direction in which it is started, it may thus be reversed instantly
while the lever O, may at all times be used for the ordinary purposes of a starting
bar, for warming the cylinder, starting or stopping the engine and giving direction
to its motion. It will also be seen that the main valve H H H, may be
constructed square or circular in form or of any other desired shape, but if circular,
it would be advisable to construct a keyway and key for its guidance, or to
employ some other method to prevent it from turning on its axis.-The valve
stems may also be made if desired, to run through stuffing boxes in the ends of the
steam chest, but this is not necessary.-In order to effectually prevent the valves
from turning, and at the same time to provide against leakage through wear, they
may be constructed in the shape shewn in cross-section in Figs. 3, and 4.-The
steam chest as shewn in these Figures is trough shaped, that is to say:-with the
sides converging towards the bottom, the valves are constructed to fit into this
trough shaped steam chest, so as to work freely and steam tight therein, so that as
they wear away by use they may always conform to the shape of the bearing and
remain steam tight.-To provide against leakage, on the top side of the valve
grooves are arranged in the lid of the steam chest as shewn at S, Fig. 1. These
grooves cross the lid from side to side and in them are fitted closely metallic
packing pieces T, which rest upon the top of the main valve H, HH", and
remain stationary during the movement to and fro of the valve or valves, these
packing pieces are capable of adjustment so as to take up wear of the valve and to
keep the same constantly steam tight.
Having described the nature of the said invention and the manner of carrying

page_text: ame into practical effect as communicated to me as aforesaid, I would have it
rstood that what is considered to be novel and original and is therefore
ed is
-The combined arrangement of the steam chest E, main valve HHH",
valves K, and K³, pipe F, ports v, and v 1, and passages L, and L', substantially
as described and illustrated.
-In a steam engine the combination of a steam cylinder A, piston B, steam
outlets D, and D', steam chest E, steam pipe F, exhaust pipe G, valve
HHH", valves K, and K¹, exhaust outlets c, and c, and passages L,
and L' substantially as described.
The use in a steam chest, of valves such as K, and K', constructed with open
work or perforations to allow steam to pass and exert its pressure upon the
ends of the steam chest, and of a main valve H H² H, substantially as
described.
Providing the steam chest E, with valves K, and K¹, in combination with the
valve stems I, and 11, arranged to slide in the said valves, and having
shoulders a, and a', and collars b, and b¹, substantially as described.
Providing the steam chest E, containing the valves K, and K', operated by
the shoulders a, and a', and nuts or collars b, and b', with passages D, and D¹,
and outlets c, and c¹, the arrangement and operation being such as to stop
the flow of steam to the steam chest, and open the outlets for steam to the
exhaust at or near the end of the stroke substantially as described.
Providing a steam chest with a reversing attachment consisting of a lever O,
with spring R, the said lever taking into a slot M, in the main valve, so
that by operating the lever, the engine can be started, stopped or reversed
at will substantially as described.
Witness whereof, I, the said Thomas Edwin Craven, have hereunto set my
and and seal this Eighth day of December, in the year of our Lord One
housand eight hundred and eighty three.
THOUG
זז דד בדרד
AD TR