FR2502774A1 - METHOD AND APPARATUS FOR DISPENSING VISCOUS VARIABLE VISCOSITY CONCENTRATES IN EXACTLY DOSABLE QUANTITIES OF VARIABLE VOLUME - Google Patents

Abstract

TO DISTRIBUTE VISCOUS CONCENTRATES, IN PARTICULAR ORGANIC SUBSTANCES, A CYLINDRICAL PUMPING VOLUME IS DELIMED BY A HOLLOW CYLINDRICAL BODY 15 AND TWO NON-RETURN VALVES 14, 25 PROVIDED AT THE ENDS AND AT LEAST DURING THE PUMPING STROKE, IT IS CLOSED. RADIALLY, SO THAT VOLUME VARIATIONS ONLY OCCUR IN THE AXIAL DIRECTION OF THE PUMPING VOLUME. THE DOSAGE PRECISION THUS OBTAINED ALLOWS, WITH A SIMPLE AND LOW COST STRUCTURE, TO DISTRIBUTE VERY SMALL QUANTITIES AT A FREQUENCY, TO DISTRIBUTE VERY SMALL QUANTITIES AT A FREQUENCY OF PUMPING CYCLES CORRESPONDING TO THE FREQUENCY OF THE NETWORK OPERATES AN ELECTROMAGNETIC ACTUATION COIL 5.

Description

1 2502774

  The invention relates to a method and an apparatus for dispensing viscous concentrates of variable viscosity in exactly dosable quantities of variable volume, in which, by cyclic variation of the pumping volume of a hollow body made of flexible or elastic material, the concentrate is aspirated. of the volume of

  reserve a container through an anti-valve

  return and is ejected, on the distribution side, by a

second non-return valve.

  Distribution sections designed as a dosing pump and fitted with two non-return valves

  serving as input and output are known as diff-

  different modes of execution. For example, patent GB 827,778 shows a metering pump in which the distribution section is designed as a pipe

  flexible which can be crushed radially with a dis-

  positive actuation and which, by its own elasticity, resumes its full section. Under dependence

  of the pressure variation in the distribution section

  bution, the inlet valve or the outlet valve opens.

  Such a structure is difficult to handle and does not

  allows, moreover, that a relatively imprecise dosage.

  Consequently, devices of this kind are suitable for soap dispensers, or the like, in which the

  dosing accuracy doesn't really matter.

  In addition, the devices used to actuate the section

  distribution are extremely expensive.

  However, it is also already known to provide as a distribution section a bellows-shaped fold projecting radially outwards and which

  can be compressed in axial direction between elements

  actuating elements in the form of a plate so as to act as a metering pump. Here again, the distribution section can be in the form of a bellows in

  rubber to which rubber valves correspond

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  beak-shaped dantes are added as check valves

  back (see US Patent 2,554,570). This known device also takes up an appreciable place and therefore is not suitable for installation in automatic dispensers, or the like. In addition, the dosing volume is relatively imprecise, so that it is

  extremely difficult to get an exact dosage.

  In the metered distribution of certain concentrates

  very viscous, a very precise dosage is necessary.

  Since the space available for installation in vending machines for drinks, for example, is extremely reduced, the metering device must have a design that takes up as little space as possible. A very special problem lies in the

  because concentrates of organic substances

  rissables pose extremely difficult hygienic problems, especially when the metering unit or its attachments are soiled with drops of

  these substances. It is therefore necessary to

  maintain and clean the parts frequently, which is extremely complicated and difficult and requires strict supervision if all of these are to be taken into account

hygienic necessities.

  In previously known metering devices

  with tubular pump or tubular distribution section

  In addition, if the deformation of the elastic material of the pipe is only small, the elastic return force of the pipe section is relatively reduced. It is only in the case of larger deformations that the restoring force also increases. However, the magnitude of the restoring force also influences the possibility of exact recovery of the shape and therefore the precision of the dosage. Consequently, with these devices, it is only possible to debit relatively large volumes and only with a relatively reduced repetition frequency. By

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  relatively large volumes, for example, volumes of 0.4 cm3. In addition, a preload in the initial position of the pipe sections is not

  possible when the hose is filled, since

  thread the pipe sections into the actuating device, for example a tubular pump, and that in this case, no deformation should occur

  in order to prevent the escape of drops of liquid.

  Another notable factor, which adversely affects the accuracy of dosing in devices

  known, is that during the decrease in the volume of pump-

  page, the tubular distribution section is subjected to other variations of shape which are uncontrollable by the increased pressure which appears inside. These uncontrollable variations can also be tolerated only if

  dosing volumes are distributed to each cycle

  laterally large, so the influence of these va-

riations remains low.

  Relative to this, the object of the invention is to

  perfect the process defined more precisely above

  above and the corresponding apparatus, so that the drawbacks mentioned are avoided and that the smallest quantities can be dispensed with very high precision and a high frequency of cycles. he

  the device used to carry out the process must

  dice is very space-saving design so that

  can easily be installed even in a tight space

  treint, for example a vending machine

  drinks, or even add it after the fact.

  According to the invention, this problem is solved by a

  process characterized in that one varies cyclically-

  the pumping cylindrical volume in the direction of its longitudinal axis, between stops, and that with each reduction in volume, the hollow cylindrical body is rigidly supported from the outside, against

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  shape variations in radial direction outward

  laughing, as well as by an apparatus for implementing the method, characterized in that the pumping volume is provided in a hollow cylindrical body of flexible or elastic material 1 to which is added an actuating element axially compressing the body, and in this that a hollow cylindrical envelope is provided and encloses the hollow cylindrical body externally, keeping its shape, at least in the phase

volume decrease.

  According to the invention, the pumping action is carried out by axial reduction of a cylindrical pumping volume, which is at the same time supported externally so as to keep its shape during the reduction process, so that it cannot uncontrolled deformations occur when the pumping pressure increases or, consequently, variations in the volume of

  dosage. So even in the case of very small quan-

  tities dosed per cycle, extremely high precision and accuracy are obtained in the dosage. The axial compression of the cylindrical metering volume fulfills the necessary condition for the body

  hollow cylindrical limiting the pumping volume above

  an axial preload can be chosen in the initial position, which can be chosen in advance, in the direction of an increase in volume. As a result, sufficiently large restoring forces are obtained even for the

  smaller volume variations. In addition, the com-

  axial pressure of the pumping volume, in combination with very high accuracy even in the case of a

  very small dosing volume, allows 1.

  dosing cycle at a frequency corresponding to the network frequency, therefore from 50 to 60 Hz. The high frequency and the small volume which can still be dosed very precisely ensure a wide range of

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  adjustment of the total quantity to be dispensed, only-

  by control of the number of metering pulses.

  In devices controlled at the frequency of the

  bucket, this command can be executed very simply and reliably. Despite the preload in the pumping volume's rest position, the dispensing section can be easily and surely threaded into the actuating device without undesirable distribution of drops of liquid. As a result,

  hygienic problems that arise in case of fouling-

  Also removed from the device.

  The layout is further improved by

  the fact that the important parts for the function-

  are completely enclosed in a rigid guide tube which is permanently or detachably connected to a container, preferably disposable, intended for transport, storage and distribution.

some cash.

  Thanks to the high cycle frequency, an almost continuous distribution of the liquid is obtained using a chain of successive dosing cycles

  quickly, whose length is adjustable at will.

  The sleeve-shaped body can be simply flexible and additional elements such as

  spring elements, or the like, provide the pre-

  charge and return required. However, preferably

  rence, the sleeve-shaped body is formed of elastic material and connected integrally to elements

  rigid, hub-shaped, non-return valves.

  Small dimensions of the distribution section

  allow installation in a vending machine

  matic with a very small footprint. Another advantage of the new device allows even to equip a toroidal electromagnetic coil with devices

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  existing dispensers to switch from a time-controlled setting to a quantity or volume-controlled setting if, as a result of variations in the consistency of the liquid, the time-controlled dosing leads to inaccuracies. Such variations in consistency have no influence on the dosing accuracy

in the apparatus according to the invention.

  The invention is explained more precisely below.

  after about an example of execution represented by the schematic drawings, in which: Figure 1 shows in vertical section a container

  used for storage, transport and distribution

  tion, provided with a distribution section according to the invention

  tion; FIG. 2 represents the distribution section on a larger scale, in exploded view, and FIG. 3 is a view in vertical section, of a

  modified execution example of the distribution section.

  Preferably, in the invention it is a disposable container, which is used both for storage and transport as for metered distribution. Preferably,

  the distribution section is permanently connected

  nente this container, in the factory, and we throw it with

  him. The container is therefore an article of mass production.

  The container may be formed of an outer shell and a flexible inner bag containing the liquid and correspondingly collapsing during dispensing. In such a case, ventilation of the

  container is not required for dispensing. All-

  However, a practical container can also be provided.

  rigid to which is added a ventilation device

  can be operated for distribution.

  In addition, the container is preferably intended to contain, store and transport as well as

  distribute organic concentrates.

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  In the example according to FIG. 1, a container

  consists of an outer casing 1 and a re-

  flexible filling container 2, which collapses.

  This has a mouth 3 to which is fixed, preferably permanently, the dispensing section 4. In FIG. 1, the container is shown in the inverted position which it occupies during the metered dispensing of the liquid. In this position, the distribution section 6 is threaded at

  through the central opening of an electromagnetic coil

  genetics toroldale 5, which is fixedly installed in an automatic beverage dispenser. The coil is connected to a suitable control device, which allows, for example, to operate the toroidal electromagnetic coil 5 at the network frequency, and the number of frequency oscillations which the coil 5 must follow can be set on the

control device.

  Section 4 has a rigid guide tube

  6 made of synthetic material which, by its su-

  is connected permanently to the mouth 3 of the container. Over most of its length, the guide tube 6 has a section widened by the shoulder 35 (FIG. 2) and at the free end, a free section. To the guide tube 6 is added a rigid front cover 26, which has a

  central outlet pipe 27. In the example shown

  felt, the two parts 6 and 26 of the guide tube are connected together by a hub-shaped valve body 20, which has at its circumference a

  annular rim 22 which can be pushed close

  mement, by the two ends, the guide tube and the closing cover 26. In this way, the hub-shaped valve body 20 is at the same time rigidly connected to the guide tube 6 and to the cover.

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closing 26.

  A second similar valve body in the form of a hub 8 is housed with play in the enlarged part of the guide tube 6 so that it can move freely in this guide tube in the axial direction. On a tubular end of the body of synthetic material 8, turned upwards and towards the container 1, is firmly placed a magnetizable portion in the form of a socket 7 constituting an annular reinforcement and which is applied, by its annular frontal side lower, against the shoulder 9 of the valve body. The body 8 and the frame 7 thus form a rigid assembly, which can go up and down axially as such in the

  guide tube 6 along the double arrow 31.

  The ends facing one another of the valve bodies 8, 20 have housing and fixing parts 10, 11 and 19, 21 intended for the socket-shaped ends 16, 18 of a hollow cylindrical body 15. In the example shown, the latter is made of elastic material and therefore constitutes at the same time a spring element. The body 15 shown has thickened end parts 16 and 18 for fixing to the two valve bodies 8 and 20 as well as a thinned part placed in a fold 17 moving radially inwards. As a result of the connection of the hub-shaped bodies 8 and 20 via the body 15, a

  predetermined dosing volume is enclosed between these

  ties. The initial size of this volume is determined by

  the body recall action 15, in combination with the shoulder

  lement interior 35 of the guide tube 6 against which

  applies, in the rest position, the front surface an-

  upper annular ring 7.

  In the example shown, each valve body 8 has a central perforation 12, 24 into which the rod of a respective shutter can be inserted by clicking.

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  mushroom-shaped 14, 25, formed of elastic material

  tick. The conical thickening of the end of the rod locks the shutter on the hub-shaped valve body. The lip-shaped circumferential edge of the plate-shaped head of the shutter 14, 25 is applied in a sealed manner, under variable pressure, to the inner front surface of the respective hub-shaped body 8, 20. In this interior region is provided with several passage perforations 13, 23 arranged in a ring through which the liquid can enter or exit the metering volume. The elastic preload of the mushroom-shaped shutter material 14, 25 is sufficient, under static conditions, to prevent the passage of liquid through the perforations 13, 23. Only

  when pressure variations exceed

  sant the static conditions, the circumferential edges

  lip-shaped heads of the plate-like heads of the plugs deviate from the central front surface of the hub-shaped body 8, 20 to allow

liquid flow.

  Upward, the stroke of the assembly formed by the body 8 and the annular armature 7 is determined by the internal shoulder 35 of the guide tube 6. Downward, the stroke of this assembly is determined by the fact that during the downward movement, the lower front edge of the part 10 of the hub-shaped body 8 abuts against the upper annular front edge of the part 21 of the hub-shaped body 20. By choosing the length of the parts 10 and 21, can, without changing the structure, easily modify and adjust exactly the stroke length of the mobile assembly 7, 8. When the bodies 8 and 20 move one

  towards each other, parts 10 and 21 enclose the former

  the hollow cylindrical body while keeping its

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  shape so that the body cannot expand

radially outward.

  Figure 1 shows roughly the parts in

  the natural grandeur of a preferred embodiment

  profitable, the stroke length being chosen, in practice, rather less than that shown by the

  figure 1. The amount of liquid coming out of the tubu-

  Lure 27 is determined by the number of pump strokes taking place at the network frequency. By

  you can adjust this quantity exactly,

  so much so that the individual volume distributed at each pump stroke can be adjusted extremely precisely even if it is very small. The liquid in the distribution section is hermetically protected against the action of oxygen in the air. It is seen that the arrangement can be manufactured in an extremely simple and inexpensive manner and has a very reliable operation and in particular, the handling is very simple and very safe and cannot lead to any fouling.

of the surrounding parts.

  Stroke limitation can also be ensured by other stop parts, for example on the tube

guide.

  To also avoid variations in the radial shape of the hollow cylindrical body, in the region of the fold directed radially inwards, it is advantageous to add to the fold or to each fold, in the region of

  its crest turned inwards, a ring of support

your rigid.

  Above all, it can be particularly advantageous

  also to give the crest of the fold a helical shape.

  In such cases, the crest may be added, as

  support element, a helically shaped spring element

  coldale, only axially compressible, which serves

  at the same time to the axial preload of the cylindrical body

  hollow dove 15. So this one doesn't need to be there 2502774

  itself elastic if it is simply formed of ma-

sufficiently flexible.

  It is also possible, under certain conditions, to do without the non-return valve on the outlet side.

25.

  To replace the non-return valve, the space delimiting the pumping volume is provided, on the outlet side, with an outlet pipe, which communicates freely with the pumping volume. Free width

  and the length of this outlet tubing are calibrated

  abutments such that the internal friction and the surface tension of the concentrate in the outlet manifold are sufficient to retain the column of concentrate axially unchanged in the outlet manifold, when the pumping volume is not changed and when it increases . The state of the unmodified pumping volume is that in which the non-return valve on the inlet side is closed. As the pumping volume increases, concentrate is drawn from the container into the volume of

pumping.

  In practical embodiments of this improved kind, the internal free width of the pumping volume was 8 to 12 mm. The stroke length could be adjusted between 1 and 2 mm. The running frequency was 50 Hz, but it could be varied from 10 to 100 Hz without disturbing the operation. We have tried liquids with viscosities from 1 to centipoise. The inlet side non-return valve had semicircular slots which could be covered as passage openings

  by the shutter. It has been found that when the tubu-

  outlet lure replacing the outlet valve had a length of 10 to 40 mm and an interior width of 1 to 3, we did not have to fear the drop of drops

concentrate.

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  Without the support of the bellows in the manner of a corset, irregular convexities occur which affect the accuracy of the dosage. With the new

  support, on the other hand, we were able to respect

  volume rances of barely measurable magnitude. A variant of the parts determining the pumping volume is represented by FIG. 3. In the cylindrical body 40, which can be connected by its upper end to the concentrate container, is inserted an upper bush 42, which has at its upper end a rim protruding

  outwards. A corresponding lower socket

  dante 43 is provided in the lower end of the

  body 40 and connected integrally to a pre-

  feeling the outlet pipe 49. In the example shown, it has been assumed that the lower bush 43 can slide with play in the lower end of the body 40. Also the lower bush 43

  has an outwardly projecting rim.

  Between the lower section of the body 40 and the two pipes 42 and 43 roughly aligned one on the other and made of rigid material, for example

  made of synthetic material, an an-

  ring 47. In this annular cavity is arranged a spacer spring or preload spring 48, which bears by its two ends on the edges of the sockets 42 and 43 and tends to maintain the two sockets in the separated position represented by the

  Figure 3. In this embodiment, the tubing in-

  is connected to a frame ring 45, which

  can be operated by the electromagnetic device

  as not shown so that the lower tube 43 can be raised until it is applied against the upper tube 42 to execute a pumping stroke. The ends turned one

13 2502774

  towards the other of the two tubes are interconnected

  by a folded membrane 44, in a watertight but practical manner

  tick without force action. In the close position of the two pipes 42, 43, the fold 44 is closed almost completely. To avoid the occurrence of air compressions in the annular cavity 47 at the rate of the pumping strokes, the annular cavity 47 is connected

  to the outside atmosphere by slits or perfo-

  rations, these must be located as close as possible to the final position of the pumping stroke to ensure a short path to the air displaced by the variations in the volume of the annular cavity 47. In the upper rim region of the tubing 42 is provided the inlet valve, not shown, of the pumping chamber, which can be designed in a similar manner to the embodiment described above. The stroke of the lower tube 43 is indicated by the double arrow 46. The arrangement could also be such that the two tubes come closer and away from each other. The advantage of the embodiment shown is that it cannot penetrate the concentrate into the annular cavity 47. The tubing 49 can also have a structure such that it is not necessary to add a non-return valve to volume output

pumping.

  It is obvious that such an arrangement, which operates independently of the elastic return force of a rubber bellows, can also dose approximately pasty materials which can no longer

  be dosed with the restoring force that norma-

  an elastic body. In such a case, the magnetic forces must be increased accordingly. The elastic force can then also be determined from

analogously.

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  The dosing device can also be used for fluids other than syrups, or the like. Thanks to the pumping elements incorporated in the disposable assembly, its advantage, in particular in the case of perishable fluids, is that by voluntary manufacturing measures, the longevity of the membrane for example is limited, so that if the container is illegally refilled, the membrane

  and therefore the device quickly becomes unused

  corn. Hygienic problems are thus effectively avoided.

Claims (19)

R E V E N D I C A T I 0 N S   1. Method for dispensing viscous concentrates of variable viscosity in exactly dosable quantities of variable volume, in which, by cyclic variation of the pumping volume of a hollow body of flexible or elastic material, the concentrate is sucked from the reserve volume of a container passing through a non-return valve and is ejected, on the distribution side, by a second non-return valve,   process characterized in that one varies cycli-   only the cylindrical pumping volume in the direction   tion of its longitudinal axis, between stops, and that with each reduction in volume, the hollow cylindrical body is rigidly held from the outside, against variations in shape in the radial direction towards the outside. 2. Method according to claim 1, characterized in that the hollow cylindrical body is elastically preloaded in the axial direction and in the direction of an enlargement of the pumping volume, in the form   corresponding to the largest output volume.   3. Method according to any one of the claims   1 or 2, characterized in that the cyclic variation of the pumping volume is carried out at the frequency of the electrical network.   4. Apparatus for implementing the method according to claim 1, comprising a distribution section in the form of metering pump which can be connected to the reserve volume of a container, in   particular of a container used to store,   carry and dispense the concentrate, and is connected in each case by its dispensing end, via a non-return valve opening in the dispensing direction, has an axially compressible pumping volume and can be thread in a 16 2502774   actuating device controlling the pumping volume, apparatus characterized in that the pumping volume is provided in a hollow cylindrical body (15) of flexible or elastic material to which is added an actuating element (7) axially compressing the body, and in that a hollow cylindrical envelope is provided and encloses the hollow cylindrical body (15) externally, keeping its   form, at least in the volume reduction phase.   5. Apparatus according to claim 4, character-   laughed in that the rigid shutters (8, 20) of the   two non-return valves (14, 25) are firmly connected   lying at the ends of the hollow cylindrical body (15) and can move relatively in the axial direction and have wall parts (10, 21)   which, at least in the position of greatest closeness   axially, enclose the body from the outside   cylindrical hollow (15) keeping its shape.   6. Apparatus according to any one of the claims.   cations 4 or 5, characterized in that the wall parts (10, 21) of the two non-return valves (14, 25) constitute at the same time the limitation stop - variable - of the movement of bringing the two together non-return valves.   7. Apparatus according to any desrevendi-   cations 4 to 6, characterized in that one of the valve bodies (20) is immobilely connected to a guide tube (6, 26) housing in a limited way the non-return valves, the actuating element and the hollow cylindrical body, and in which the other valve body (8) and the actuating element (7) which is connected to it are guided so as to be able to slide axially.   8. Apparatus according to claim 7, character-   in that the valve body assembly (8) and 17 2502774   of actuating element (7), in the position of greatest value of the pumping volume, is biased with   a predetermined preload in the direction of an increase   tation of the pumping volume, against an internal stop   back (shoulder 35) of the guide tube (6, 26).   9. Apparatus according to claim 8, character-   dried in that the hollow cylindrical body (15) is formed   made of elastic material and is clamped in the rest position, with axial compression, between the two bodies valve (8, 20).   10. Apparatus according to any one of the claims.   cations 4 to 9, characterized in that the action element-   The element is in the form of an annular reinforcement (7) and can move cyclically in the guide tube, at the same time as the valve body (8), thanks to an electromagnetic actuation device, at the frequency of network from 50 to 60 Hz.   11. Apparatus according to any one of the claims.   cations 4 to 10, characterized in that to the mobile assembly is added a spring element which   maintains under a preload in the initial position.   12. Apparatus according to any one of the claims.   cations 4 to 11, characterized in that the thickened ends (16, 18) of the hollow cylindrical body (15) made of elastic material are slid over circumference parts (11, 19) of the hub-shaped valve bodies (8, 20), and the hollow cylindrical body (15) has at least one protruding fold (17) radially inward.   13. Apparatus according to any one of the claims   cations 4âà 12, characterized in that the anti-   return are mushroom-shaped elements (14,) of elastically deformable material which can be inserted in the manner of press studs in a central perforation of the valve bodies in the form of 18 2502774   hub (8, 20) formed of synthetic material.   14. Apparatus according to any one of the claims   cations 4 to 13, characterized in that the guide tube is formed by a guide section (6) and a front cover (26) having a tubular outlet (27), which are connected by the intermediate   of the plastic body of the anti-valve return (20) integral with the frame.   15. Apparatus according to any one of the claims   cations 12 to 14, characterized in that the or each fold projecting inwards (17) is retained against   radial deformation by an annular support element rigid area.   16. Apparatus according to claim 15, character-   in that the crest of the fold (17) of the cylindrical body   hollow (15) is helical and formed of simple material   flexible or elastic, and as an element   support is provided a flexible axial coil spring-   firmly embedded in the ridge.   17. Apparatus according to claim 4, characterized in that on the outlet side, the pumping volume is freely connected, instead of an outlet non-return valve, to an outlet tubing with an interior width such that of a length such that the internal friction and the surface tension of the   concentrated in the outlet tubing is enough   keep the concentrate column axially unchanged in the outlet tubing, when the pumping volume is unchanged (non-return valve on the inlet side closed) and when this volume increases (suction stroke).   18. Apparatus according to any one of the claims.   cations 4 to 17, characterized in that the pumping volume is limited by two hollow rigid tubes (42, 43) and an inner ply (44) made of flexible material 19 2502774   connecting together their front ends facing one another, and in the annular cavity (47) between the pumping volume and the hollow cylindrical body (40) is disposed a coil spring (48) whose ends are press on the edges of the   opposite mites of the pipes (42, 43).   19. Apparatus according to claim 18, characterized   in that in the annular cavity open or   air vents (50) communicating with the atmos- outdoor sphere.