CERTAIN IMPROVEMENTS IN DOUBLE-ACTING PUMPS
Year: 1855

page_text: LETTERS PATENT to Alexandre Tolhausen, of No. 7, Duke Street, Adelphi,
London, County of Middlesex, Sworn Interpreter at the Imperial Court
of Paris, for the Invention of "CERTAIN IMPROVEMENTS IN DOUBLE-ACTING
PUMPS." A communication from D. W. Clarks, United States.
Sealed the 6th June 1856, and dated the 26th December 1855.
PROVISIONAL SPECIFICATION left by the said Alexandre Tolhausen at
the Office of the Commissioners of Patents, with his Petition, on the
26th December 1855.
I, ALEXANDRE TOLHAUSEN, of No. 7, Duke St.; Adelphi, London, County
5 of Middlesex, Sworn Interpreter at the Imperial Court of Paris, do hereby
declare the nature of the said Invention for "CERTAIN IMPROVEMENTS IN
DOUBLE-ACTING PUMPS," being a communication from D. W. Clarks, United
States, to be as follows:-
This Invention relates to that description of double-acting pump in which
two pistons are employed, working in the same cylinder, the water being
taken in & discharged alternately in the middle & at the two ends of the
cylinder, by the reciprocating action towards & from each other of the two
pistons working therein.
The first improvement consists in communicating the reciprocating move-
5.ment to the two pistons by means of two cranks or eccentrics geared together,
& arranged intermediately or between the two pistons; by this means avoiding

page_text: complexity of stuffing boxes, & the passage of one piston rod through the other
piston.
A second improvement consists in giving one of the two pistons the "lead"
of the other, so that although the two pistons moving in the one cylinder
alternately advance & recede simultaneously, for the most part towards &
from each other, one changes the direction of its motion in advance of the
other, & both move for some distance in the same direction, thereby keeping
up, as nearly as is practicable, a perfectly continuous suction, & relieving the
pump from those destructive shocks or jerks which take place at the change
of motion, when the change is effected in both pistons simultaneously.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Alexandre Tolhausen in the Great Seal Patent Office on the
19th June 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDRE
TOLHAUSEN, of No. 7, Duke Street, Adelphi, London, County of Middlesex,
Sworn Interpreter at the Imperial Court of Paris, send greeting.
WHEREAS Her most. Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-sixth day of December, in the year of our
Lord One thousand eight hundred and fifty-five, in the nineteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Alexandre Tolhausen, Her special licence that I, the said Alexandre
Tolhausen, my executors, administrators, and assigns, or such others as I,
the said Alexandre Tolhausen, 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 Kingdom of Great
,Britain and Ireland, the Channel Islands, and Isle of Man, an Invention
for "CERTAIN IMPROVEMENTS IN DOUBLE-ACTING PUMPS," a communication from
D. W. Clarks, United States, upon the condition (amongst others) that I,
the said Alexandre Tolhausen, my executors or administrators, by an instru-
ment 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 imme-
diately after the date of the said Letters Patent.

page_text: NOW KNOW YE, that I, the said Alexandre Tolhausen, 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:
This Invention relates to that description of double-acting pumps in which
two pistons are employed, working in the same cylinder, the water being taken
in and discharged alternately in the middle and at the two ends of the cylinder,
by the reciprocating action towards and from each other of the two pistons
working therein..
The first improvement consists in communicating the reciprocating move-
ment to the two pistons by means of two cranks or eccentrics geared together,
and arranged intermediately or between the two pistons; by this means avoid-
ing complexity of stuffing boxes, and the passage of one piston rod through the
other piston.
'
A second improvement consists in giving one of the two pistons the "lead.""
of the other, so that although the two pistons moving in the one cylinder
alternately advance and recede simultaneously, for the most part towards and
from each other, one changes the direction of its motion in advance of the
other, and both move for some distance in the same direction, thereby keeping
up, as nearly as is practicable, a perfectly continuous suction, and relieving the
pump from those destructive shocks or jerks which take place at the change
of motion, where the change is effected in both pistons simultaneously.
The Invention is illustrated in the accompanying Drawing, in which Fig. 1
is a vertical section of a pump, in the plane of line x, y, of Fig. 2, looking in
the direction of the arrow shown pointing to the said line in the said Fig. ;
Fig. 2 is an elevation of the pump, the valve box being towards the spectator,
and the cover thereof removed; Fig. 3 is a face view of the crank motions
by which the pistons are operated. Similar letters of reference indicate corre-
sponding parts in the several Figs.
A is the pump cylinder, both ends of which are closed; B is the valve box;
C, the suction pipe; D, the discharge pipe; E, E, E,* the three passages
leading from the cylinder to the valve box, the two former passages leading
and communicating with that portion of the cylinder between the ends thereof
and the pistons, and the latter with that portion of the cylinder between the
pistons; the passages E, E, being separated from the passage E* by an
upright partition p, which is shown in Fig. 2 in dotted outline. The valve
box contains two inlet valves c, c, arranged one on each side of the partition p,
and two discharge valves d, d*, similarly arranged; F, F, are the pistons,
which are connected by links H, H, with two eccentric wrist pins a, a, secured

page_text: in the faces of a pair of spur gears J, J*, arranged between the two pistons,
within the pump cylinder. One of these gears is made fast upon a driving
shaft I, working through a stuffing box K, and furnished with a crank, pulley,
or some other device for receiving rotary motion, and the other turns freely
on a fixed stud L. By rotating the shaft I, rotary motion is imparted from
the gear J to the gear J*, and a reciprocating motion is thus given by the
wrist pins to the two pistons. As the pistons move from each other towards
the ends of the cylinder, the water enters through the valve c* and passage
E into the cylinder between the pistons, and is discharged through the
passages E, E, and valve d, as is indicated by red arrows in Fig. 1.. When
the pistons approach each other this action is reversed, the water entering
through the valve c and passages E, E, and being discharged through the
passage E*, and valve d*. The arrangement of the wrist pins for the purpose
of giving a leading movement to the one piston, is illustrated in Fig. 3, the
leading movement is illustrated in Fig. 1. The gears J, J*, rotate respec-
tively in the directions of the arrows shown upon them in Fig. 3, where it will
be seen that the wrist a, which drives the lower. piston, is moved some distance
beyond the point where it changes the motion of that piston from an upward
to a downward direction, while the wrist a, which drives the upper piston, has
not yet arrived quite at the point where it changes the motion from a down-
ward to an upward direction. It will be understood by this that during the
interval which elapses between the changes of the movements of the two
pistons both move in a downward direction, as is illustrated by the arrows
marked on the two pistons in Fig. 1; in which Fig. the positions of the
pistons are made to correspond with the position of the wrists in Fig. 3; but
though the two pistons are moving in the same direction, the lower piston is
moving faster than the upper one, and consequently the distance between the
pistons is increasing, and the cylinder takes water from the suction pipe
between the pistons, and discharges it from the space between the lower piston
and lower end of the cylinder to the discharge pipe. The same effect is
produced at the other end of the stroke of the pistons. The shifting of the
valves and change of the direction of the water takes place at the middle of
the interval between the changes of direction of the pistons, and as there is
no suspension of the movement of the pistons at the time, there is no per-
ceptible stoppage in the action of the suction or discharge of water. This
renders the use of an air vessel unnecessary, so far as it is employed to produce
an uniform discharge of water. The intermediately arranged gear wheels and
the crank or eccentric motion afford peculiar facilities for giving the above-
described leading motion to the pistons.

page_text: Having thus described the nature and particulars of the said Invention,
I wish it to be understood that under the above in part recited Letters Patent
I claim,
1st, driving the two pistons of the double-acting double-piston pump, by
means of two cranks or eccentrics geared together and arranged between
the pistons, substantially as herein described.
2nd, giving the two reciprocating pistons such a movement relatively to
each other, that although the advance towards and recede from each other
simultaneously through the greater portion of their strokes, the change of the
direction of the movement of one piston takes place before that of the other,
and they travel for some time in the same direction, as herein described,
thereby producing as nearly as practicable a perfectly continuous suction,
and avoiding destructive shocks or jerks at the time of the change of the
direction of the movement.
In witness whereof, I, the said Alexandre Tolhausen, have hereunto set
my hand and seal, this Nineteenth day of June, in the year of our
Lord One thousand eight hundred and fifty-six.
A. TOLHAUSEN. (LS.)