Improvements relating to Pumps, and to Mechanism for Operating the same.
Year: 1895

page_text: Date of Application, 24th Oct., 1895-Accepted, 7th Dec., 1895
COMPLETE SPECIFICATION.
Improvements relating to Pumps, and to Mechanism for Operating
the same.
J. CONSTANTYN PIETER HOLST, Gzoon, of No. 108, 2e Jan Steen Straat,
Amsterdam, in the Kingdom of Holland, Engineer, do hereby declare the nature
of this invention and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement:-
The object of this invention is to render it possible to employ high plunger or
piston-speeds or high rates of revolution in the operation of reciprocating pumps,
whilst the liquid moves at an uniform velocity in an uninterrupted stream.
My said invention relates chiefly to apparatus such as I have described in the
Specification of former Letters Patent granted to me and dated 20th September
1894 No. 17883.
In my improved apparatus a number of mechanically-connected buckets (each
acting during a fraction of a revolution of the crank shaft) operate one after
another to pump the liquid forward at an uniform velocity in such a manner that
these successive uniformly-traversed parts of the strokes or what may be termed
the operative travels of the pistons, are distributed over or correspond collectively
to the whole of one revolution of the driving shaft.
For the purpose of carrying my said invention into practice, peculiarly
constructed gearing is interposed between the crank, which revolves at a constant
angular velocity, and the plunger-rod of the pump, whereby the motion of the
connecting rod, which, as is well known, is normally unequal, is rendered uniform
to the required extent.
The crank-motion which has been known heretofore, attains its maximum speed
at one point of each stroke of the piston only. By the aid of this improved
arrangement, however, the plunger-rod is caused to move in such a manner that the
maximum speed is maintained constant for a comparatively extended period of
time which may equal, for example, one-third or one-fourth of a revolution.
This uniform velocity of the liquid, which is obtained by the uniform motion of
the pistons during successive fractions of a revolution of the shaft, is therefore the
resultant unit of all these fractions; so that by the employment of a number of
pumps arranged either one behind the other or side by side and operated according
to this system by the aid of a set of cranks, properly geared together and occupying
proper positions relatively to each other, a connected series of pumps may be
erected, whereby, during the whole time taken up by one revolution of the shaft,
an uniform velocity of the liquid is ensured.
E.
Supposing, for example, an equalizing mechanism be thus inserted, which will
produce constant speed during a quarter of a revolution of the main shaft, then,
four buckets, or to speak more accurately, four pumps, should be employed to
make the speed uniform throughout. Or, assuming that the interposed mechanism
ensures uniformity of motion during one-third of a revolution of the shaft, then
three buckets, or three pumps, will be required to produce continued uniformity in
the rate of flow of the liquid. Hence, in the former case, the cranks should be
situated at 90°, and in the latter, at 120° to each other; the result being that the
successive phases or stages of the movements of the pistons will be evenly
distributed within the time occupied by one revolution of the shaft, each piston, in
its turn, having to perform all the work of the pump arrangement during a fraction

page_text: of a revolution of the shaft, the magnitude of which, as before explained, depends.
upon the number of pistons which the system of pumps comprises.
In all cases, the bodies of the pumps are connected with each other in such a
manner that the outlet orifice of each pump directly communicates by means of a
channel or port with the suction orifice of the next succeeding punip, uninterrupted
circulation throughout the system or set of pumps being thus provided for.
Where four buckets or bodies of pumps are employed, they should preferably be
arranged in pairs, tandem fashion, the buckets I and III being connected into one
pair, and the buckets II and IV forming the other pair, each pair having a plunger-
rod in commou, and such plunger-rods being, respectively, driven by cranks placed
at 90° to each other.
In such an arrangement, the circulation valves in the buckets mounted upon the
same pump-rod, should open in opposite directions, since virtually the cranks of
these pistons are placed apart at an angle of 180°. But at all times one piston
only is in operation, during a predetermined fraction of the forward stroke, the
other coming into operation during a corresponding fraction of the backward stroke.
Thus each piston acts upon the fluid during one quarter of a revolution, while,
during the three remaining quarters of the revolution of the main-shaft, it leaves
the fluid to be acted upon by, the other pistons, allowing it to pass freely through
its valves..
A pump constructed in this manner is capable of delivering an uniform and
uninterrupted current of fluid at a considerable rate of velocity, without the
assistance of any air reservoir or any suction or force valves; in fact, without the
use of any accessory means for regulating the flow.
In the accompanying drawings, the improved system of pumps is illustrated, by
way of example, in several forms, all of which show the manner in which the new
gearing is fitted and operated.
Figures 1 and 2 are diagrams each representing an arrangement for obtaining a
constant speed in the operation of pump-pistons, each bucket being, adapted,-in
one form, to perform its stroke during one quarter of a revolution of the crank-
shaft, and, in the other form, during one-third of a revolution!..
Figures 3 and 4, are, respectively, a side elevation and a sectional top, view or plan,
both representing a quadruple-pump arrangement, coupled to, and immediately
joining, a driving engine comprising two-cylinders, such as a compound engine, the
novel mechanisin being interposed between the piston-rods of the steam-engine and
the plunger-reds of the pumps..
Figure 5 represents a treble pump body, being a side elevation, partly in section;
of the same. The novel 'equalizing gear is here immediately connected with the
crank-pin
My improved gearing, or mechanism remains substantially, the same, no matter
whether the pump is operated from the extended-pistou-rod- of the steam-engine
(Figures 1 'and-3) or from the crank.
'
In both cases; the-driving point A, which, in the arrangements shown in
Figures 1 and 3, is the end point of the extended piston-rod of the steam engine,
and in the arrangement represented in Figures 2 and 5, is constituted by the
crank-pin itself, is placed in connection with, or coupled to, a triangular
lever ABC; the opposite terminal point B. of the longest-side A.B,, of the
triangle being connected with the plunger-rod E. of the pump. (which rod. is
arranged to move in a straight line), such connection being effected through the
medium of the link or coupling bar D; and the apex C of the said triangle-being
controlled so as to move in an arc of the circle, by means of a swinging.bar F
pivoted at the fixed point G.
In the arrangement shown in Figure 1, the mechanism is supposed to operate at
an uniform 'speed during, one-fourth of a revolution of the shaft, or in other
words, within an angle of 90°..
One of the two cranks, which are accordingly set at 90° to each other (this
being, of course, the arrangement requisite for a quadruple-pump system), will

page_text: always be moving through either of these two arcs of a circle: 0-8, or p―q.
The extreme positions of a complete stroke are lettered a and b, while the
extreme positions of the effective (portion of the) stroke are marked thus:
0 and 8.
Let, then, the angles of 90°, 0-8 and p-q, (being quarters of a circle) be
divided into eight equal parts. Then the corresponding points of division will be
situated, as shown, in the paths of the apices of the correspondingly named
triangles A B C. respectively. Now the diagram, Figure 1, shows that the
distance 0-8 of the path travelled over by the terminal point E of the coupling
rod D, is also divided into eight equal parts, the consequence being, that, over this
portion of the path of the said terminal point, the velocity of the pump-piston will
continue constant.
In carrying out this arrangement, the pump system should be fitted with two
pairs of buckets, and in such a manner that those buckets which are driven by the
same rod may act alternately, that is to say, that one piston of each pair forces
the water onward during the outward stroke (0-8) and the other, during the
inward stroke (p-9).
In Figure 2 there is shown a pump mechanism arranged for operation at a
constant velocity during one-third of a revolution of the shaft, or whilst such shaft
describes an angle of 120°.
The extreme or terminal positions of the complete stroke of the triangular
lever A B C are, here also, at a and b, while the limits of the effective stroke are
marked 0 and 8.
Now if the arc of a circle 0-8, which here measures 120°, is here again divided
into eight equal parts, and the points of division are marked off along the respective
paths of the apex of the triangle A B C and of the rectilinearly moving
point E, the resulting diagram will show that the traces 0-8 on the path of the
terminal point E of the coupling rod D will also divide that length into eight
equal parts whence it follows that, through this distance, the velocity of the
pump-piston will be constant.
In this case, three cranks would have to be placed upon the main shaft of
the engine in this order: 0, 8 and C, so that at all times, there should be one crank
moving through the arc of a circle 0-8, that crank being always the operative one
for the time being.
In the quadruple pump arrangement illustrated in Figures 3 and 4, two buckets
are secured to each of the plunger-rods D D', and are connected to the extensions
of the piston-rods A A' of the compound steam engine, through the medium of the
improved gearing or coupling mechanism A B C (Figure 1).
The pumps are erected one behind the other with their pistons paired thus:-
I and III on one rod, and II and IV on the other rod, the connection between
the said pumps being made by a junction tube H K L provided for the purpose.
The whole thus forms one connected pump system which the fluid enters at M,
flows through it in the direction of the arrow, and issues therefrom at N.
The buckets shown in the drawings are constructed in such a manner that
the sectional area of the liquid stream remains invariably the same throughout
the whole pump; the piston-rod itself assuming, for the purpose, the shape of a
plunger.
Figure 5, which is drawn to an enlarged scale and partly in section, represents
a bucket having a closed valve V. The buckets and their valves may, however,
be of any other suitable construction if preferred. The several valves of the
buckets I and III, and of the buckets II and IV are made to face each other in
the manner illustrated diagrammatically in Figure 4.
The gearing for the pump arrangement here shown should preferably be so fitted
that the pin situated at the apex C of the triangle A B C is extended on both sides,
or in both directions, so that it may be possible to suspend such triangle within a
double-armed swinging lever F F.

page_text: As before mentioned, owing to the insertion of the novel gearing between the
piston-rods A. A³ of the steam engine and the plunger-rods E of the pump, the
pistons situated upon the same rod perform their effective stroke alternately, and at
a constant speed in each case. by reason of the fact that the two cranks are
situated at 90° to each other; and the four pistons come into operation each in its
turn during a quarter of a revolution, each accordingly, producing one quarter of
the useful effect corresponding to a complete revolution.
Thus, as the piston I performs its inward stroke, to the right, under the action
of the crank P (see the direction indicated by arrows in Figure 4), the liquid will
be driven into the junction tube H, at a constant rate of speed, during one quarter
of a revolution; and the liquid contained in the remaining part of the pump
body will at the same time, by the aid of the intermediate pipes K and L, flow
through the valves of the buckets II, III and IV, which all open in the direction
in which the liquid current moves; since, during this period, the speed of the liquid
will be greater than the speed of motion of the buckets II and IV, and inasmuch
as the valve of the bucket III, which moves with the same speed but in the opposite
direction, opens against the said liquid current.
When the shaft has completed one quarter of a revolution, it is the turn of the
bucket II, operated by the crank R, to perform the "pumping" operation, whilst
the said bucket II performs its outward stroke. Then, as the crank P makes its
outward stroke, the bucket III performs its effective movement, and finally the
liquid is forced out of the pump through the orifice N by the bucket IV while the
crank R performs its inward stroke, with which the last quarter of the revolution
of the engine-shaft corresponds.
It will thus be seen that all the pistons of the pump move at a constant rate of
speed during their effective stroke; that, furthermore, cach bucket causes the
pump arrangement to perform its proper "pumping" action during one fourth of the
operation of the inain shaft; and that, in the meantime, the liquid escapes through
the valves of the other three buckets freely, all of such valves opening in proper
time to enable it to do so. Therefore, as will be understood, during the complete
revolution of the shaft, the liquid will traverse the pump at a rate of speed which
will invariably remain uniform. The pump (or arrangement of pumps) will
consequently supply an uniform current of liquid without any interruption and
without any variations in its speed of motion or quantity of supply: and this
circumstance enables the 'pump to be operated, throughout, at a greater speed,
or at a higher rate of revolution than is generally the case in driving pumps.
In Figure 5 of the drawings is shown a system of pumps arranged side by
side. The operation here takes place from three cranks mounted on the same
shaft and situated at an angle of 120° to each other; the improved triangular
gearing (such as is shown at A B C, Figure 2) being connected directly to the
crank-pin A.
The three pumps are here connected by suitable junction tubes or pipes which
extend, below each pump, from the front side of that pump to the rear of the next
following pump. Thus a complete system of circulating pipes is formed, the valves
of the three buckets operating in succession, being all arranged to operate in the
same direction.
In this case, as stated, each of the three pistons completes its effective stroke
during one third of a revolution of the shaft, or in other words whilst the shatt
describes an arc of a circle of 120°, and while so doing, it performs the proper
"pumping" operation at a constant maximum rate of speed, the liquid, in the
meantime, freely flowing through the valves of the two remaining buckets. Con-
sequently, during the whole time occupied by one revolution of the shaft, the liquid
will traverse the pump at au uniform rate of speed.
It will be seen that by the aid of the novel intermediate mechanism or gearing,
a set of pumps of this kind, even though treble instead of quadruple, will supply
a current of liquid uniformly and uninterruptedly moving at a high speed.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The improved means, substantially as hereinbefore described, whereby I
provide for obtaining an uninterrupted supply of liquid at an uniform velocity from
pumps fitted with reciprocating buckets.
2. Equalizing mechanism comprising a triangular lever which is controlled so
that one point thereof moves through an arc of a circle, another point thereof
being connected to the driving point (crank, cross-head or the like), whilst its third
point is, through suitable intermediate agencies, connected to the pump-rod,
substantially as, and for the purpose, above specified.
3. The pump combined with the equalizing mechanism substantially as described
with reference to the accompanying drawings and operating as and for the purposes
above specified.
The auth of Octaban 1905
D. YOUNG & Co.,
11 & 12 Southampton Buildings, London, W.C.,
Agents for the Applicant.