provements in Direct Acting Steam Pumps.
Year: 1897

page_text: PROVISIONAL SPECIFICATION
Improvements in Direct Acting Steam Pumps.
We, TANGYES LIMITED, of Cornwall Works, Soho, in the County of Stafford,
Engineers, and JOHN NICHOLAS FLOYD, of Cornwall Cottage, Murdock Road,
Handsworth, in the County of Stafford, Mechanical Engineer, do hereby declare
the nature of this invention to be as follows:-
The said invention consists of the improvements hereinafter described in direct
acting steam pumps, both of the kind known in commerce as simplex and duplex
direct acting steam pumps, in which the main slide valves are operated by the
action of the pistons of the steam cylinders striking against tappets projecting
into the said steam cylinders.
In the working of direct acting steam pumps as at present constructed the wear
on the pistons of the steam cylinders and on the tappets is so great that the
efficiency of the said direct acting steam pumps soon diminishes and consequently
the parts of the said direct acting steam pumps have to be submitted to frequent
repair.
The improvements constituting the said invention have for their object partly
to reduce the wear of the parts hereinbefore referred to of the said pumps and
partly to facilitate the repair of the said parts when worn.
According to one of the improvements constituting the said invention we arrange
two passages
or ports, one in advance of the other, at each end of
the steam cylinder. The passages or ports nearest the ends of the cylinder
alternately admit steam into the steam cylinder and when on the exhaust side of
the piston permit of exhaust steam passing through them and through screwed
plugs, cocks or valves which are opened on the exhaust stroke of the piston into
the other or main exhaust passages whereby they are made to assist the other port
or main exhaust passages in the clearing of the cylinder until the piston has passed
the main exhaust passage when the said steam inlet passage is utilised for the final
exhaust. The tappet at each end of the cylinder which effects the control of the
main slide valve is arranged between the steam inlet and main exhaust passages.
It will be understood that as soon as the piston has passed the main exhaust
passage on its exhaust stroke the said exhaust takes place only through the steam
inlet passage and screwed plug, cock or valve communicating with the exhaust
passage. Consequently the completion of the exhaust is very much retarded and
takes place so slowly that the exhaust steam between the end of the cylinder and
the advancing piston forms a buffer or cushion for the latter and reduces its speed
to such an extent that the force of the blow or impact between the said piston and
the tappet and the wear consequent thereon is reduced to a minimum.
In direct acting steam pumps of the ordinary kind the tappet passages are placed
in communication with the ends of the steam cylinder so that the steam from the
tappet passage on the exhaust side of the piston passes into the end of the cylinder
and escapes by the port or passage at that end of the cylinder. In direct acting
steam pumps provided with the improvements herein before described the cushion-

page_text: ing pressure in the end of the cylinder prevents the passage of the steam from the
tappet passage into the said end of the cylinder hence it is necessary to provide the
undersides of the tappet valves with special pipes or passages communicating with
the exhaust pipe or communicating directly with the atmosphere. By this means
the exhaust steam from the tappet passage is permitted to escape.
In direct acting steam pumps of the kind commonly called "special" pumps
cushioning is effected by live steam admitted by the slide valve which opens
immediately the tappets are struck. The pistons of the said pumps striking
directly against the ends of the stalks of the tappet valves causes the said tappet
valves to wear somewhat unevenly and to leave their seatings. This necessitates
the re-grinding or re-seating of the said tappet valves from time to time and to
obviate this we employ loose stems or stalks for the tappet valves the upper ends of
which stems or stalks bear against the undersides of the tappet valves the lower
ends projecting into the steam cylinder. On the piston striking one or other of
the loose tappet stems or stalks the said stem or stalk acting directly on the under-
side of the tappet valve lifts it vertically in a straight line and thus obviates the
uneven wear of the valve and its seating and the periodic re-grinding or re-seating
of the valve herein before referred to.
Tappet valves with loose stems or stalks of the kind described are applicable
to direct acting steam pumps other than direct acting steam pumps of the kind
commonly called " special" pumps.
66
The said invention further consists of the use of cross tappet pipes for duplexing
"special" pumps whereby the said "special" pumps may be worked as duplox
pumps or as simplex pumps. By the use of the said crossing tappet pipes the
piston of one cylinder may either be made to operate the slide valve of its own
cylinder or to operate the slide valve of the second or parallel cylinder.
Dated this Seventh day of October 1897.
•
Improvements in Direct Acting Steam Pumps.
We, TANGYES LIMITED, of Cornwall Works, Soho, in the County of Stafford,
Engineers, and JOHN NICHOLAS FLOYD, of Cornwall Cottage, Murdock Road,
Handsworth, in the County of Stafford, Mechanical Engineer, do hereby declare
the nature of the said invention and in what manner the same is to be per-
formed to be particularly described and ascertained in and by the following
statement:-
"
The said invention consists of the improvements hereinafter described in direct
acting steam pumps, of the kind known in commerce as special" steam pumps
in which the main slide valves are operated by the action of the pistons of the
steam cylinders striking against tappets projecting into the said steam cylinders.
In the working of direct acting steam pumps as at present constructed the wear
on the pistons of the steam cylinders and on the tappets is so great that the
efficiency of the said direct acting steam pumps soon diminishes and consequently
the parts of the said direct acting steam pumps have to be submitted to frequent
repair.
The improvements constituting the said invention have for their object partly
to reduce the wear of the parts herein before referred to of the said pumps and
partly to facilitate the repair of the said parts when worn.

page_text: According to one of the improvements constituting the said invention we arrange
two passages or ports, one in advance of the other, at each end of
the steam cylinder. The passages or ports nearest the ends of the cylinder
alternately admit steam into the steam cylinder and when on the exhaust side of
the piston permit of exhaust steam passing through them and through screwed
plugs, cocks or valves which are opened on the exhaust stroke of the piston into
the other or main exhaust passages whereby they are made to assist the other port
or main exhaust passages in the clearing of the cylinder until the piston has passed
the main exhaust passage when the said steam inlet passage is utilised for the final
exhaust. The tappet at each end of the cylinder which effects the control of the
main slide valve is arranged between the steam inlet and main exhaust passages.
It will be understood that as soon as the piston has passed the main exhaust
passage on its exhaust stroke the said exhaust takes place only through the steam
inlet passage and screwed plug cock or valve communicating with the exhaust
passage. Consequently the completion of the exhaust is very much retarded and
takes place so slowly that the exhaust steam between the end of the cylinder, and
the advancing piston forms a buffer or cushion for the latter and reduces its speed
to such an extent that the force of the blow or impact between the said piston and
the tappet and the wear consequent thereon is reduced to a minimum.
In direct acting steam pumps of the ordinary kind the tappet passages are placed
in communication with the ends of the steam cylinder so that the steam from the
tappet passage on the exhaust side of the piston passes into the end of the cylinder
and escapes by the port or passage at that end of the cylinder. In direct acting
steam pumps provided with the improvements hereinbefore described the cushion-
ing pressure in the end of the cylinder prevents the passage of the steam from the
tappet passage into the said end of the cylinder hence it is necessary to provide the
undersides of the tappet valves with special pipes or passages communicating with
the exhaust pipe or communicating directly with the atmosphere. By this means
the exhaust steam from the tappet passage is permitted to escape.
In direct acting steam pumps of the kind commonly called " special" pumps
cushioning is effected by live steam admitted by the slide valve which opens
immediately the tappets are struck. The pistons of the said pumps striking
directly against the ends of the stalks of the tappet valves cause the said tappet
valves to wear somewhat unevenly and to leave their seatings. This necessitates
the re-grinding or re-seating of the said tappet valves from time to time and to
obviate this we employ loose stems or stalks for the tappet valves, the upper ends of
which stems or stalks bear against the undersides of the tappet valves, the lower
ends projecting into the steam cylinder. On the piston striking one or other of
the loose tappet stems or stalks the said stem or stalk acting directly on the under-
side of the tappet valve lifts it vertically in a straight line and thus obviates the
uneven wear of the valve and its seating and the periodic re-grinding or re-seating
of the valve hereinbefore referred to.
Tappet valves with loose stems or stalks of the kind described are applicable
to direct acting steam pumps other than direct acting steam pumps of the kind
commonly called special pumps.
14
Figure 1 of the accompanying drawings represents in side elevation, partly in
section, a direct acting steam pump containing the improvements constituting the
said invention and Figures 2 and 3 represent a longitudinal and cross section
respectively of the same; Figure 4 is a section of one half of the steam cylinder
of the pump taken on the dotted line, Figure 2; and Figures 5, 6 and 7
represent sections of details hereinafter particularly described.
The same letters of reference indicate the same parts in the several figures of
the drawings.
a is the steam cylinder of the pump and a', as are the two ports or passages at
each end of the cylinder a communicating with the steam chest b. The
passages a², a2 alternately admit steam to the cylinder a, and the passage a² which
is on the exhaust side of the piston d during the piston's stroke assists the other

page_text: Con-
or exhaust passage a¹ on the same side of the piston din clearing the cylinder
of exhaust steam the exhaust steam escaping by the passage a² passing through
holes or openings a³, at, which can be more or less opened or closed by the screw
plug c (see Figures 5 and 6) into the main exhaust passage of the cylinder. On
the piston d in its stroke passing the exhaust passage a¹ the exhaust can only take
place through the passage a² and holes or openings a³, a leading from the same.
sequently the final clearing of the cylinder is considerably retarded and the exhaust
steam between the piston and the end of the cylinder acts as a buffer or cushion by
which the speed of the piston d is reduced and the impact between the piston a
and the tappet e (indicated in dotted lines in Figure 3) which is situated between
the end of the cylinder and the passage a is so slight that the wear on the parts is
reduced to a minimum. In order to permit of the escape of the steam on the
exhaust side of the slide valve f, pipes or passages g, g are connected to the ends of
the steam chest 6 which pipes crossing, open into the tappet boxes h, h at the
opposite ends of the steam cylinder a (see Figure 1) and opening into the said
tappet boxes h, h on the underside of the tappet valves i, i is a longitudinal passage
communicating at with the atmosphere or communicating with the exhaust pipe.
On the piston d striking the stalke of the tappet valve and thereby raising the said
valve the steam on the exhaust side of the slide valve f passes by the crossing
pipe through the open tappet valve into the longitudinal passage k from which it
escapes into the atmosphere at k¹.
In order to regulate the escape of the exhaust steam from the steam chest b and
thereby control the rate of motion of the slide valve f from end to end of the
stcam chest we prefer to arrange screwed plugs g', gl (indicated in dotted lines
only in Figure 1) in the exhaust pipes g, leading from the steam chest b by
opening or closing which screw plugs g', g¹ more or less the motion of the slide
valve may be adjusted to any desired rate of speed. These improvements aro
applicable to direct acting pumps provided with tappet valves of the ordinary
construction or with the improved tappet valves hereinafter described.
According to another of the improvements constituting the said invention which
improvement is more especially applicable to direct acting steam pumps of the
kind commonly called "special" pumps we make the stalke of the tappet valve e, i
(see Figure 7) separate from the valve proper i by which arrangement the true
vertical up and down motion of the said valve is ensured and the undue wear
attendant on valves of the ordinary construction where the tappet stalk is in one
piece with the valve is obviated.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed we declare that we claim
as the said invention:-
First The improvements in direct acting steam pumps hereinbefore described
and represented in the accompanying drawings the said improvements consisting
essentially in providing the cylinder at each end with two
the passage
passages,
near the end of the cylinder being for the admission of steam and the other passage
for the exhaust, the steam admission ports or passages having holes or openings,
provided with screw plugs or valves for regulating the said holes or openings,
by which holes or openings the steam admission ports or passages when on the
exhaust side of the piston are utilised to assist in clearing the exhaust steam and
to permit of the exhausting of the cylinder at a reduced rate on the piston passing
the exhaust port or passage proper substantially as and for the purpose hereinbefore
described and illustrated.
Secondly-In direct acting steam pumps the combination with crossing pipes or
passages connecting the tappet boxes or passages of the steam cylinder with the
opposite ends of the steam chest of a longitudinal passage opening under the tappet
valves and communicating at or about its middle with the atmosphere or with the
exhaust pipe whereby steam on the exhaust side of the slide valve is permitted to
escape; also the combination with the said crossing pipes or passages of screw

page_text: plugs or valves for regulating the size of the openings in the said pipes or passages
substantially as herein before described and illustrated in the accompanying
drawings.
Thirdly The improvement in direct acting steam pumps hereinbefore described
and illustrated in Figure 7 of the accompanying drawings the said improvement
consisting essentially in making the tappet stalk of the tappet valve separate from
the valve proper substantially as and for the purpose described and illustrated.
Dated the 23rd day of May 1898.