U.S. patent application number 11/595307 was filed with the patent office on 2007-05-31 for fluid measurement/division device and process.
Invention is credited to Walter Divisi.
Application Number | 20070122295 11/595307 |
Document ID | / |
Family ID | 37526992 |
Filed Date | 2007-05-31 |
United States Patent
Application |
20070122295 |
Kind Code |
A1 |
Divisi; Walter |
May 31, 2007 |
Fluid measurement/division device and process
Abstract
The fluid measurement/division device comprises a plurality of
cylinders in which a first and a second piston are slidably
inserted to operate alternately as a dosing piston or as a piloting
piston for the dosing piston. The first and said second piston
present reduced diameter regions which, together with the surface
of the cylinders, define at least three constant volume
distribution chambers and two variable volume pumping chambers. The
device comprises a plurality of conduits connecting said cylinders
together and to the outside, to allow or prohibit hydraulic
connection in relation to the position assumed by the first and by
the second piston, such that when the first piston is in the dosing
stage and, by translating, it dispenses fluid and passes to the
piloting stage, the second piston passes from the piloting stage to
the dosing stage via a neutral stage.
Inventors: |
Divisi; Walter; (Surrey,
GB) |
Correspondence
Address: |
LADAS & PARRY
Suite 2100
5670 Wilshire Boulevard
Los Angeles
CA
90035-5679
US
|
Family ID: |
37526992 |
Appl. No.: |
11/595307 |
Filed: |
November 9, 2006 |
Current U.S.
Class: |
417/392 |
Current CPC
Class: |
G01F 3/18 20130101; G01F
11/04 20130101; F16N 25/02 20130101; F16N 27/00 20130101 |
Class at
Publication: |
417/392 |
International
Class: |
F04B 17/00 20060101
F04B017/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 25, 2005 |
IT |
MI2005 A 002259 |
Claims
1. A fluid measurement/division device comprising a plurality of
cylinders in which a first and a second piston are slidably
inserted to operate alternately as a fluid dosing piston or as a
piloting piston for the dosing piston, wherein said first and said
second piston present reduced diameter regions which, together with
the surface of said cylinders, define at least three constant
volume distribution chambers and two variable volume pumping
chambers, said device comprising a plurality of conduits connecting
said cylinders together and to the outside, to allow or prohibit
hydraulic connection in relation to the position assumed by said
first and by said second piston, such that when said first piston
is in the dosing stage and, by translating, it dispenses fluid and
passes to the piloting stage, said second piston passes from the
piloting stage to the dosing stage via a neutral stage.
2. A device as claimed in claim 1, wherein said connection conduits
comprise: a first conduit to connect a first distribution chamber
of the first cylinder to a first distribution chamber of the second
cylinder, a second conduit to connect a second distribution chamber
of the first cylinder to a second distribution chamber of the
second cylinder, a third conduit to connect a third distribution
chamber of the first cylinder to a third distribution chamber of
said second cylinder, a fourth conduit to connect a first pumping
chamber of the first cylinder to a second distribution chamber or
to a third distribution chamber of said second cylinder, a fifth
conduit to connect the second pumping chamber of said first
cylinder to the first distribution chamber or to the second
distribution chamber of said second cylinder, a sixth conduit to
connect a first distribution chamber or a second distribution
chamber of said first cylinder to a first pumping chamber of said
second cylinder, a seventh conduit to connect said second
distribution chamber or said third distribution chamber of said
first cylinder to said second pumping chamber of said second
cylinder, an eighth conduit to connect said first distribution
chamber of said first cylinder to the outside, a ninth conduit to
connect said second distribution chamber of said first cylinder to
the outside, and a tenth conduit to connect said third distribution
chamber of said first cylinder to the outside.
3. A device as claimed in claim 1, further comprising a block
defining said first and second cylinder and said first, second and
third connection conduit.
4. A device as claimed in claim 2, wherein said block also defines
said fourth, said fifth, said sixth, said seventh, said eighth,
said ninth and said tenth connection conduit.
5. A device as claimed in claim 1, wherein said pistons carry
magnets embedded in their ends, to cooperate with corresponding
magnets of proximity sensors positioned at the ends of said
cylinders.
6. A device as claimed in claim 5, wherein said pistons have convex
ends.
7. A device as claimed in claim 6, wherein closure elements for the
ends of said cylinders present recessed ends to receive said convex
ends of said pistons.
8. A device as claimed in claim 1, wherein said device defines a
module provided with two cylinders.
9. A device as claimed in claim 1, further being provided with
one-way valves provided at the entrance of the outlet communication
conduits.
10. A device as claimed in claim 9, further being provided with
magnets to sense or count the number of runs made by the pistons,
each of said magnets being placed at the end of an adjustable
support.
11. A device as claimed in claim 10, wherein said pistons are
asymmetric and are formed with the chambers of one piston staggered
one another, in such a way that in every situation the piston
acting as piloting piston opens its chambers before the other
piston.
12. A device as claimed in claim 11, wherein the two pistons have
different length one with respect to the other.
13. A fluid measurement/division process using a device comprising
a pair of cylinders, in each of which a piston slides presenting
three reduced diameter regions defining three distribution chambers
and two variable volume pumping chambers connected together by a
plurality of conduits, wherein it feeds the fluid to a piloting
cylinder in which the piloting piston defines that chamber of the
dosing cylinder into which the fluid is to be fed, the piloting
piston translating to pass to the dosing stage, the dosing piston
translating to dispense the fluid and pass to the piloting stage,
in its passage from the piloting stage to the dosing stage said
piloting cylinder passing through a neutral stage.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a fluid
measurement/division device and process.
BACKGROUND OF THE INVENTION
[0002] In particular, the device and process of the present
invention are usable to divide a fluid flow rate, for example to
obtain from an inlet flow two or more outlet flows of equal flow
rate, with possible measurement of the flow rate. If only one flow
is obtained at the device outlet, the device is used (and operates)
as a flow rate measurement device, i.e. it exactly measures the
delivered flow rate without effecting any flow rate division.
DISCUSSION OF THE RELATED ART
[0003] Devices of the indicated type are currently formed with at
least three cylinders, in each of which a piston is slidably
inserted.
[0004] Each piston is provided with two reduced diameter regions
which define two distribution chambers inside the cylinder. Each
cylinder also defines two pumping chambers at its ends.
[0005] The three cylinders are connected together by a plurality of
conduits, such that the conduits alternately connect together one
or other of the chambers defined between each cylinder and the
respective piston.
[0006] During operation of the traditional device, each of the
pistons is in a different operating stage.
[0007] In particular, while a first piston is in a dosing stage
(and dispenses a predetermined quantity of fluid contained in a
pumping chamber, forcing it to leave the device), a second piston
is in a piloting stage (and causes the fluid to operate the dosing
piston).
[0008] Finally a third piston is in a neutral stage, in which it
does not act on the fluid (delivering it to the outside) and is not
operated by the fluid; during this stage the piston contained in
the cylinder in the neutral stage moves from the piloting position
to the dosing position; if this stage were not present, the device
would lock because the liquid would not be able to continuously
operate the pistons such that they alternate their function by
passing from the piloting stage to the dosing stage.
[0009] However, the described devices of traditional type are large
and heavy because of the minimum number of cylinder/piston pairs
required for their operation; in this respect, at least three
cylinder/piston pairs are required, each of which effects one of
the described stages during operation, while the other
cylinder/piston pairs effect the others.
[0010] The traditional devices are also costly to construct because
of the large number of components required.
SUMMARY OF THE INVENTION
[0011] The technical aim of the present invention is therefore to
provide a fluid measurement/division device and process by which
the stated technical drawbacks of the known art are eliminated.
[0012] Within the scope of this technical aim, an object of the
invention is to provide a device of small size and reduced weight;
this advantageously enables devices to be constructed which can be
handled and installed easily, even in difficultly accessible or
narrow positions.
[0013] Another object of the invention is to provide a device and
process which are economical to implement, in particular compared
with traditional devices.
[0014] The technical aim, together with these and other objects are
attained according to the present invention by a fluid
measurement/division device and process in accordance with the
accompanying claims.
[0015] Advantageously, the device and process of the invention are
also usable when the fluid which they are required to handle
operates at high or very high pressure (up to and beyond 2000
bar).
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Further characteristics and advantages of the invention will
be more apparent from the ensuing description of a preferred but
non-exclusive embodiment of the fluid measurement/division device
and process according to the invention, illustrated by way of
non-limiting example in the accompanying drawings, in which:
[0017] FIGS. 1-4 show a schematic view of the device in four
different successive operating stages;
[0018] FIG. 5 shows a schematic view of a part of an end of a
cylinder and of a piston slidable therein, in an embodiment of the
device particularly suitable for use with devices operating at high
pressure;
[0019] FIG. 6 shows a schematic upper view of the device of the
invention in a different embodiment;
[0020] FIG. 7 shows a schematic section through line VII-VII of
FIG. 6;
[0021] FIG. 8 shows a lateral side view of the device of FIG.
6;
[0022] FIG. 9 shows a schematic section of the device of FIG. 6;
and
[0023] FIG. 10 shows a particular of one way valves mounted on the
outlet conduits of the device of FIG. 6.
DETAILED DESCRIPTION OF THE INVENTION
[0024] With reference to said figures, these show a fluid
measurement/division device indicated overall by the reference
numeral 1.
[0025] The device 1 comprises two cylinders 2, 3 in which a first
and a second piston 4, 5 are slidably inserted.
[0026] Each of the two pistons 4, 5 operates alternately as a fluid
dosing piston or as a piloting piston for the dosing piston.
[0027] The dosing piston dispenses fluid to the outside (by its
movement), while the piloting piston defines the path for the
fluid, which is directed towards the dosing piston to control its
movement.
[0028] Advantageously, the first and second piston 4, 5 present
reduced diameter regions which, together with the surface of the
cylinders 2, 3, define three constant volume distribution chambers
6a, 7a, 8a and two variable volume pumping chambers 9a, 10a for the
first cylinder 2, and three constant volume distribution chambers
6b, 7b, 8b and two variable volume pumping chambers 9b, 10b for the
second cylinder 3.
[0029] The device 1 comprises a plurality of conduits connecting
the cylinders 2, 3 together and to the outside (for example to
interact with a machine), to allow or prohibit hydraulic connection
in relation to the position assumed by the first and second piston
4, 5.
[0030] Advantageously, with reference for example to FIG. 1, when
the first piston 4 is in the dosing stage and translates to
dispense fluid (arrow F1) to pass to the piloting stage, the second
piston 5 is in the piloting stage and passes to the dosing stage by
passing through a neutral stage.
[0031] The neutral stage enables operation of the device of the
invention to be continuous in that, if it did not exist, the
piloting piston would be unable to pass to the dosing stage and the
device would lock.
[0032] As shown in the accompanying figures, the connection
conduits comprise: a first conduit 11 to connect a first
distribution chamber 6a of the first cylinder 2 to a first
distribution chamber 6b of the second cylinder 3, a second conduit
12 to connect a second distribution chamber 7a of the first
cylinder 2 to a second distribution chamber 7b of the second
cylinder 3, and a third conduit 13 to connect a third distribution
chamber 8a of the first cylinder 2 to a third distribution chamber
8b of the second cylinder 3.
[0033] The connection conduits also comprise a fourth conduit 14 to
connect the first pumping chamber 9a of the first cylinder 2 to the
second distribution chamber 7b or to the third distribution chamber
8b of the second cylinder 3, a fifth conduit 15 to connect the
second pumping chamber 10a of the first cylinder 2 to the first
distribution chamber 6b or to the second distribution chamber 7b of
the second cylinder 3.
[0034] A sixth conduit 16 is provided to connect the first
distribution chamber 6a or the second distribution chamber 7a of
the first cylinder 2 to the first pumping chamber 9b of the second
cylinder 3, and a seventh conduit 17 to connect the second
distribution chamber 7a or the third distribution chamber 8a of the
first cylinder 2 to the second pumping chamber 10b of the second
cylinder 3.
[0035] Finally, an eighth conduit 18 is provided to connect the
first distribution chamber 6a of the first cylinder 2 to the
outside, a ninth conduit 19 to connect the second distribution
chamber 7a of the first cylinder 2 to the outside, and a tenth
conduit 20 to connect the third distribution chamber 8a of the
first cylinder 2 to the outside.
[0036] The device 1 suitably comprises a block 22 defining the
first and second cylinder 2, 3 and also at least the first, second
and third connection conduit 11, 12, 13.
[0037] In a preferred embodiment, shown in FIGS. 1-4, the block 22
also defines the fourth, fifth, sixth, seventh, eighth, ninth and
tenth connection conduit 14-20.
[0038] The device advantageously defines a module provided with two
cylinders. Several modules can be connected together, but in all
cases the cylinders are operationally connected together in
pairs.
[0039] The operation of the fluid measurement/division device of
the invention is apparent from that described and illustrated, and
is substantially as follows.
[0040] The fluid enters through the conduit 19 as indicated by the
arrow F2 and is directed into the second chamber 7b of the second
cylinder (which is in the piloting stage).
[0041] In the second cylinder 3 the second piston 5 enables the
fluid to transit through the fourth conduit 14 to enter the first
pumping chamber 9a of the first cylinder 2.
[0042] This causes the first piston 4 to translate as indicated by
the arrow F3; this translation causes the fluid contained in the
second pumping chamber 10a of the first cylinder to pass through
the fifth conduit 15, to pass through the first chamber 6b of the
second cylinder and through the first conduit 11, to be dispensed
to the outside through the eighth conduit 18.
[0043] The device then assumes the configuration of FIG. 2.
[0044] In this configuration the first cylinder 2 acts as the
piloting cylinder, as the fluid enters the first conduit 2 (arrow
F2) and is directed into the second pumping chamber 10b of the
second cylinder 3 (which operates as a dosing cylinder).
[0045] The second piston 6 then translates as indicated by the
arrow F5, to dispense the fluid contained in the first pumping
chamber 9b of the second cylinder 3 (as indicated by the arrow F1)
through the sixth conduit 16 and the eighth conduit 18; the device
then assumes the configuration shown in FIG. 3.
[0046] The fluid continues to enter through the ninth conduit 19
and passes through the second distribution chamber 7a of the first
cylinder 2 and the second conduit 12 to reach the distribution
chamber 7b of the second cylinder 3 (which is in the piloting
stage), in which the second piston 5 directs the fluid through the
conduit 15 (arrow F6) and into the second pumping chamber 10a of
the first cylinder, this latter translating as indicated by the
arrow F7 to dispense the fluid contained in the first pumping
chamber 9a, as indicated by the arrow F8 (by passing through the
fourth conduit 14, the third conduit 13 and the tenth conduit 20);
in this manner the device assumes the configuration of FIG. 4.
[0047] The fluid, which continues to enter the device through the
conduit 19 as indicated by the arrow F2, enters the second chamber
7a of the first cylinder 2 (which operates as a piloting cylinder);
in this cylinder the piston directs the fluid into the sixth
conduit 16 and then into the first pumping chamber 9b of the second
cylinder 3 (which operates as a dosing cylinder).
[0048] The fluid entering the chamber 9 of the cylinder 3 causes
the piston to translate as indicated by the arrow F9, the fluid
contained in it then passing through the seventh conduit 17 from
which, via the third chamber 8a of the first cylinder 2, the fluid
leaves the device through the tenth conduit 20 (as indicated by the
arrow F8).
[0049] The device then returns to the configuration of FIG. 1 and
the cycle recommences.
[0050] A proximity sensor 26 is provided at each of the two ends of
each cylinder 2, 3 to sense the movements of the pistons 4, 5; this
enables the dispensed fluid to be measured. A single sensor
associated with each cylinder could instead be provided.
[0051] It should be noted that in the time that passes between the
commencement of movement of any one of the pistons and the moment
in which it reaches its end-of-travel position, a sort of "neutral
stage" occurs. In this respect, during this time interval, which
can be varied either by structurally modifying the valve or by
modifying the piston movement velocity, that piston not in movement
is not piloted and remains at rest in its original position.
[0052] An embodiment of the device of the invention is described
hereinafter with particular reference to FIG. 5 which is
particularly suitable for use in plants with fluids of high or very
high pressure (up to and beyond 2000 bar).
[0053] For high pressure use, traditional proximity sensors are
unable to sense when the pistons 4, 5 reach the ends of the chamber
(because of the large wall thicknesses required to resist such
pressures).
[0054] In this respect, the block 22 defining the cylinders 2, 3 is
provided at its ends with closure elements 25 associated with
proximity sensors comprising a sensing element 26 and a slider or
element 27 slidable in a chamber 28.
[0055] The slider or element 27 is made of magnetic material and is
known to oscillate because it is drawn (arrow F14) by the sensor 26
when the piston 4 is distant from the end of the cylinder 2,
whereas when the piston 4 is brought to the terminal end of the
cylinder 2 the slider 27 is drawn towards the piston (arrow
F15).
[0056] In this manner the sensor 26 is able to sense (or count) the
strokes undergone by the slider 27.
[0057] To enable the piston 4 (preferably made of ferromagnetic
material but, in various applications, also of other
non-ferromagnetic materials) to draw the slider 27, the pistons
carry magnets 30 embedded in their ends, to cooperate with the
corresponding sliders or magnetic elements 27 of the proximity
sensors positioned at the cylinder ends.
[0058] In addition, to limit the negative effect on the magnetic
forces caused by the large wall thickness, the pistons present
convex ends, the cover elements 25 for the ends of the cylinders 2,
3 presenting recessed ends to receive the convex ends of the
pistons 4, 5.
[0059] The present invention also relates to a fluid
measurement/division process using the before described device.
[0060] The process consists of feeding the fluid to the piloting
cylinder, in which the piloting piston defines (directing it
thereto) that chamber of the dosing cylinder into which the fluid
is to be fed.
[0061] The piloting piston translates to pass to the dosing stage,
the dosing piston translating to dispense the fluid and pass to the
piloting stage.
[0062] In passing from the piloting stage to the dosing stage the
piloting cylinder passes through a neutral stage.
[0063] Modifications and variants in addition to those already
stated are possible.
[0064] Particularly, FIGS. 6-10 show a different embodiment of the
device of the invention having the same features as those of the
already described embodiment.
[0065] In addition, the device is provided with one-way valves 35,
36 respectively provided at the entrance of the outlet
communication conduits 18, 20; these valves allowing a more stable
and homogeneous leaving fluid flow to be achieved.
[0066] Moreover, as shown in FIGS. 6, 7, 8, in order to sense or
count the number of runs made by the pistons 2, 4, the device is
provided with magnets 37 placed at the end of adjustable supports
39 adjacent to every cylinder 2, 3 for example constituted by
screws engaged in threaded holes of the block of the device.
[0067] The count of the runs of the pistons in this case is made by
measuring the perturbations of the magnetic field generated by such
magnets 37.
[0068] In addition, in order to eliminate possible instability
problems, the pistons 4, 5 of the device are asymmetric, so that
they are formed with the chambers of one piston staggered one
another, in such a way that, in every situation, the piston acting
as a piloting piston opens its chambers before the other piston,
which acts as dosing piston.
[0069] Finally, additionally or alternatively to the trick of
staggering the chambers, the two pistons 4, 5 have different length
one with respect to the other and, particularly, one is shorter
that the other of about 1 millimetre.
[0070] It has been found in practice that the fluid
measurement/division device and process of the invention are
particularly advantageous because the device is extremely compact
and lightweight.
[0071] The fluid measurement/division device and process conceived
in this manner are susceptible to numerous modifications and
variants, all falling within the scope of the inventive concept;
moreover all details can be replaced by technically equivalent
elements.
[0072] In practice the materials used and the dimensions can be
chosen at will in accordance with requirements and the state of the
art.
* * * * *