NEW OR IMPROVED EXPANSION GEAR FOR DIRECT-ACTING STEAM PUMPING ENGINES
Year: 1872

page_text: LETTERS PATENT to James Tangye, of the Firm of Tangye Brothers,
of Birmingham, in the County of Warwick, Manufacturers, for the
Invention of "NEW OR IMPROVED EXPANSION GEAR FOR DIRECT-ACTING
STEAM PUMPING ENGINES."
Sealed the 29th April 1873, and dated the 7th December 1872.
PROVISIONAL SPECIFICATION left by the said James Tangye at the
Office of the Commissioners of Patents, with his Petition, on the
7th December 1872.
I, JAMES TANGYE, of the Firm of Tangye Brothers, of Birmingham,
in the County of Warwick, Manufacturers, do hereby declare the nature
of the said Invention for "NEW OR IMPROVED EXPANSION GEAR FOR DIRECT-
ACTING STEAM PUMPING ENGINES," to be as follows:-
My Invention consists of expansion gear for direct-acting steam
pumping engines constructed and arranged in the following manner :-
To the steam or water piston of the pumping engine, but by preference
to the steam piston, I connect a bar or rod, which passes out through the

page_text: cylinder cover, the said bar or rod working through a stuffing box in the
said cover.
The said bar or rod partakes of the reciprocating motion of
the piston of the engine. To the outer end of this rod and at right angles
thereto I attach an arm, and to the other end of this arm I attach
another bar or rod parallel to the axis of the cylinder and guided by
brackets attached to the cylinder. The last-named bar or rod I term the
"plug_rod."
The said plug rod travels to and fro in the same manner
as the piston rod of the engine, and by means of stops or plugs properly
secured to and adjusted on it the said "plug rod" effects the cutting off
of the steam in the following manner :—
The main slide valve is moved in any convenient way so as to
admit steam and opens the exhaust port to either end of the cylinder
at the proper moments. In addition to this valve I employ a cut-off
valve, which slides in contact with the face of the main valve, and by its
action cuts off steam at the required position of the stroke of the piston.
This cut-off valve is moved by means of a tumbler and spindle or other
convenient way, the plugs or stops on the " plug rod" striking an arm
so as to move the cut-off valve into the proper position for cutting off
the steam.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James Tangye in the Great Seal Patent Office on
the 30th May 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
TANGYE, of the Firm of Tangye Brothers, of Birmingham, in the County
of Warwick, Manufacturers, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventh day of December, in the
year of our Lord One thousand. eight hundred and seventy-two, in the
thirty-sixth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said James Tangye, Her special license, that
I, the said James Tangye, my executors, administrators, and assigns, or
such others as I, the said James Tangye, my executors, administrators,
and assigns, should at any time agree with, and no others, from time to
time and at all times thereafter during the term therein expressed, should
and lawfully might make, use, exercise, and vend, within the United

page_text: Kingdom of Great Britain and Ireland, the Channel Islands, and Isle
of Man, an Invention for "NEW OR IMPROVED EXPANSION GEAR FOR DIRECT-
ACTING STEAM PUMPING ENGINES," upon the condition (amongst others)
that I, the said James Tangye, my executors or administrators, by an
3 instrument in writing under my, or their, or one of their hands and
seals, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said James Tangye, do hereby declare
the nature of the said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by
the following statement thereof, that is to say :—
My Invention consists of expansion gear for direct-acting steam
pumping engines constructed and arranged in the following manner :—
To the steam or water piston of the pumping engine, but by preference
to the steam piston, I connect a bar or rod, which passes out through the
cylinder cover, the said bar or rod working through a stuffing box in the
said cover.
The said bar or rod partakes of the reciprocating motion of
the piston of the engine. To the outer end of this rod and at right
angles thereto I attach an arm, and to the outer end of this arm
I attach another bar or rod parallel to the axis of the cylinder and guided
by brackets attached to the cylinder. The last-named bar or rod I term
the "plug rod." The said plug rod travels to and fro in the same
manner as the piston rod of the engine, and by means of stops or plugs
properly secured to and adjusted on it the said plug rod effects the cutting
off of the steam in the following manner :-
The main slide valve is moved in any convenient way so as to admit
steam and open the exhaust port to either end of the cylinder at the
proper moments. In addition to this valve I employ a cut-off valve,
which slides in contact with the face of the main valve, and by its action
cuts off steam at the required position of the stroke of the piston. This
cut-off valve is moved by means of a tumbler and spindle or other con-
venient way, the plugs or stops on the plug rod striking an arm so
as to move the cut-off valve into the proper position for cutting
off the steam.

page_text: Having explained the nature of my Invention I will proceed to
describe with reference to the accompanying Drawing the manner in
which the same is to be performed.
Figure 1 represents partly in longitudinal vertical section and. partly
in side elevation, Figure 2 in plan, Figure 3 in side elevation, and
Figure 4 in end elevation a portion of a direct-acting steam pumping
engine, containing expansion gear constructed according to my Inven-
tion. The pump or water cylinder is omitted in the Drawing. The
same letters of reference indicate the same parts.
a is the steam cylinder and b is the piston working therein; c is the
main slide valve of the ordinary kind for admitting steam and opening
the exhaust port to either end of the cylinder. To the steam piston 6 I
connect a bar or rod d, which passes out through the cylinder cover a²,
the said bar or rod d working through the stuffing box e in the said cover.
To the outer end of the said bar or rod dan arm d² is attached, and to the
said arm ď³ another bar or rodf called the plug rod is attached, the said
bar or rod f being situated and working parallel to the axis of the
cylinder a. The plug rod f is guided by brackets g, g, attached to the
cylinder a. By the reciprocating motion of the piston 6 a like motion is
given through the bar d and arm d³ to the plug rod f. On either side
the plug rod fare adjustable stops or plugs h, i, for cutting off steam
from the cylinder a at the proper times. The said stops h, i, consist of
flat plates (see Figures 2 and 3), and are connected to and adjusted on
the plug rod by slots and screw bolts at k, k. The said cutting off of
the steam is effected by a cut-off valve 1, which slides in contact with
the face of the main valve c. This cut-off valve is moved by the
tumbler m on the horizontal spindle n, the said spindle having on its
outer end a forked arm p, p², p³, which said arm is acted upon alternately
by the stops h, i, of the plug rod f. The limbs or branches p³, p³, of the
forked arm p are situated on either side of the plug rod f, and the stop h
acts upon the limb p² to cut off steam when the piston is making its
advance stroke, and the stop i on the opposite side of the plug rod
acts upon the other limb p³ when the piston is making its return
stroke..
In the Drawing the stops h, i, are represented adjusted on the plug
rod to cut off steam from half stroke of the piston to the end of its
stroke, and the piston is represented making its advance stroke, the
steam having been cut off by the stop / striking and lifting the limb p

page_text: of the arm p and causing the said arm to operate through the spindle n
and tumbler m upon the cut-off valve l.
.
It will be seen by referring to Figure 3 that when the limb p³ of the
arm p is lifted by the stop / coming under it the other limb på descends
behind the stop on the opposite side of the plug rod f ready to be
acted
upon by the said stop i on the return stroke of the said plug rod.
The. arm.p retains the inclined position given to it until the piston b
makes its return stroke, when the stop i striking against the limb p³ of
the arm p brings the said arm into the position indicated in dotted lines
in Figure 3, and the steam is thus cut off during the latter half of the
return stroke of the piston. In this way the reciprocating motion of the
plug rod actuated by the piston 6 effects the cutting off of the steam
at half stroke of the said piston.
I do not think it necessary to describe the motions of the principal
slide valve c, as the motions of the said valve do not differ from those of
slide valves in engines of the ordinary construction.
Where it is wished to cut off the steam at less than half stroke I prefer
to use the arrangement of the forked arm represented on a large scale in
Figure 5 in place of that represented in Figures 2, 3, and 4. In this
arrangement a plate p is keyed to the spindle n of the cut-off valve l,
the said plate p carrying stops q, r; 8, t, are two arms turning loosely
upon the axis n and pressed against the stops q, r, respectively by the
springs u, v. The arms s, t, are thus capable of yielding in the direction
of approaching each other, but cannot separate to a greater angle than
that represented.
Having now described the nature of my Invention and the manner
in which the same is to be performed, I wish it to be understood that I
do not limit myself to the precise details herein described and illustrated,
as the same may be varied without departing from the nature of my
Invention, but I claim as my Invention the construction and combination
of parts herein-before described and illustrated in the accompanying
Drawing, constituting new or improved expansion gear for direct-acting
steam pumping engines, that is to say, the combination of a cut-off valve
with the ordinary slide valve, and giving motion to the said cut-off valve
by means of a forked arm actuated by stops on a sliding rod or bar, the
said rod or bar receiving motion from the piston of the steam or water
cylinder of the engine, substantially as described and illustrated.

page_text: Also the modification of the forked arm described. and illustrated in
Figure 5 of the accompanying Drawing.
In witness whereof, I, the said James Tangye, have hereunto set
my hand and seal, this Twenty-ninth day of May, in the year
of our Lord One thousand eight hundred and seventy-three.
Witness,
GEORGE SHAW.
JAMES TANGYE. (L.S.)