FR2569457A1 - VALVE FOR DEBITTING LIQUIDS, IN PARTICULAR GLUE - Google Patents

Abstract

VALVE 4 IS PROVIDED WITH TWO CHAMBERS12, 11 COAXIALS, SEPARATED FROM ONE ANOTHER IN A TIGHT MANNER, THE FIRST OF WHICH IS LIKELY TO BE CONNECTED TO A SOURCE OF COMPRESSED AIR10 FOR THE ACTUATION OF VALVE4 AND THE SECOND CAN BE PUT INTO COMMUNICATION WITH THE SUPPLY SOURCE1 FOR THE LIQUID TO BE DEBITTED AND IS PROVIDED WITH AN OUTLET19 FOR THIS LIQUID, CLOSED BY A SHUTTER21 CONNECTED TO ACTUATION MEANS15, 16 PLACES IN THE FIRST BEDROOM12; THE OPENING OF THE OUTLET 19 FOR THE DISTRIBUTION OF THE LIQUID IS OBTAINED BY THE PUSHING OF THE SHUTTER21 TOWARDS THE EXTERIOR OF THE VALVE BODY4, SO AS TO USE THE SAME SHUTTER21 AS A CLEANING ELEMENT OF THE OUTLET 19 .

Description

- 1- 2569457

  VALVE TO DELIVER I: JIDES, ESPECIALLY D) AND THE GLUE

  The present invention relates to a valve for dispensing liquids, in particular glue, applicable

  for example on automatic conditioners

  packaging or packaging of products.

  The valve to which the present invention refers can be applied for example to the glue distribution circuit of a cigarette packaging machine where the glue leaving a reservoir reaches a tank, from which it is transferred, to the help of

  metering devices, on blank or sheet legs

  wrapping material intended to wrap

  pre-arranged groups of cigarettes.

  In these circuits it is obviously necessary

  re to provide, between the tank and the tank, a support

  Pope able to allow and maintain the filling

  age of the tank depending on the working conditions of the machine and therefore on the quantity of glue withdrawn, progressively, from the tank using the metering devices.

  To this end, the use of valves is already known.

  pneumatically operated pes with shutter, mo-

  bile inside the valve body between two po-

  extreme positions, on command of a small sliding piston

  in a tightly separated room from it

the in which the glue flows.

  In correspondence with one of these positions, called closing, the shutter is pressed, using

  springs acting on the small piston, against the

  valve liquid outlet head.

  The passage of the shutter from said closed position to the second position, called the open position,

  is obtained by sending a f l u x of compressed air a-

  sliding on the small piston against the action of said springs. Practically the small piston, moving

  in its respective chamber, pulls the shutter towards the

  valve, removing it from the orifice or mouth

  liquid outlet; the liquid can therefore pass through

  towards the valve, from the tank to the tank.

  The actuation of the small tire-operated piston

  material can be obtained by means of a con-

  checking the level of glue inside the tank; this element can be placed in the electrical circuit for actuating a solenoid valve, which in turn is placed in the pneumatic installation connecting the glue flow valve to the source of the machine which generates the air.

  compressed. The distribution of the glue therefore takes place by

  termittence as a function of the “on” (ON) / “off” (OFF) signals given to said solenoid valve by

  the glue level control element which is so-

killed inside the tank.

  We have found that over time,

  dance of the orifice of the glue outlet mouth, because of the presence of successive superpQsitions or stratifications of glue which tend to dry out when the glue does not come out of the valve, there is the formation of a bead which causes a deviation from the normal trajectory followed by the adhesive flowing into the tank; in

  consequence of this, if the valve is located at the

  mity of the tank, we can have a dispersion of the col-

  the outside of said tank, which results in a per-

  te of product and the smearing of certain parts of the machine. It has also been found that once this stratification effect causes the partial or total blockage -3 of the orifice of the valve outlet mouth and consequently the need for intervention by the operator in order to clean the orifice and restore the optimal operating conditions of the valve. By studying this problem the Applicant has envisaged an improvement of the valves of the aforementioned type, which is the subject of the present invention and thanks

  to which the glue outlet mouth is constam-

  cleaned by the shutter during the opening stage

valve ture.

  In addition, by virtue of the particular shape given to the shutter, the problem of deviations of the jet of glue leaving the valve is eliminated and in this way the glue certainly falls into the tank.

reception located below.

  The object of the present invention is therefore to provide a valve for delivering liquids, in particular

  glue, able to overcome the disadvantages

  above and also able to ensure the chu-

  glue in the receiving tank arranged at this

  effect, without any deviation from the trajectory

re planned.

  Another object of the invention is to provide a valve of the aforementioned type quite similar, as regards its implementation, to those already existing and therefore capable of being put in an easy and safe way in the distribution circuits liquids or glue

  already existing in machines of known type.

  Yet another object of the invention is to provide

  a very simple construction valve in which

  the, by effect of the arrangement of the different parts -4 -

  that make it up and thanks to the solution given to the fer-

  outlet mouth measurement, we obtain, during the

  opening tap, a favorable pressure action in the chamber in which the liquid to be discharged flows, this pressure promoting the initial exit of the liquid

of the valve.

  The said aims are achieved by the present invention.

  due to the fact that it refers to a flow valve

  ter liquids, in particular glue, comprising a chamber connected to a liquid supply conduit to

  flow, a liquid nozzle for the valve

  pe, a shutter of said nozzle, means of action-

  ment of the shutter for opening and closing the valve, characterized in that said shutter is provided with an end which precisely penetrates into a liquid outlet mouth of the aforementioned nozzle and is movable between a position, for closing said valve, internal to the outlet mouth, and a position, for opening said valve, external to said nozzle

  and it comprises, adjacent to said end, a door

  essentially frustoconical, whose large base

  is oriented towards said end, which extends

  ge, under valve opening conditions, ex-

of said nozzle.

  By this solution the shutter, during the

  tap to open the valve liquid outlet mouth, causing any glue layers to break

  dried around the orifice of said mouth each time

  valve opening. The particular conformation

  lière, substantially mushroom-shaped, obturating

  tor allows to have, at the outlet of the liquid from the bottom

  pope, by the effect of surface tensions between the li-

  -5- quide and the external surface of the same shutter, the grouping of the "nets" which compose the jet of liquid,

  which results in the formation of a homogeneous jet without ef-

  surrounding fusion of large drops of the same liquid, in accordance with the aims sought by the invention. The characteristics of the valve object of

  the invention will be better illustrated by the description

  which follows from a preferred embodiment, given to sim-

  as a nonlimiting example with reference to the accompanying drawings in which:

  - Figure 1 schematically shows a power circuit

  glue tank and a tank o metering means trans-

  glue on sections of casing material-

  usable for wrapping products;

  - Figure 2 shows schematically and in section the sou-

  pope object of the invention with the shutter in position

  closing the outlet outlet of the liquid

  Pope; and - Figure 3 shows the valve as shown in

  Figure 2 but with the shutter in the open position

  of the liquid outlet from the valve.

  Referring to said figures, there is indicated at 1 a glue tank connected by means of a conduit 2 to a chute 3 for entering the glue into the valve.

  in question, indicated overall in 4.

  We have assigned the number 5 to a tank intended to contain the glue leaving the tank 1, in which

  metering means, indicated overall in 6, sample

  sells the glue in order to transfer it onto sections of wrapping material 7 moving along a supply line at a station for wrapping and

the packaging of products.

  -6 At 8 a line is indicated connected to the valve 4, which, through a solenoid valve 9, puts the same valve 4 in communication with a source 10 which generates compressed air. The solenoid valve 9 is controlled by a sensor element 9a associated with the tank and able to detect the level of adhesive inside.

  of it and order the opening or closing

solenoid valve setting 9.

  Looking at Figures 2 and 3 we can notice

  quer that the valve 4 has two chambers 11 and 12 coaxial, the first of which is in direct communication

  with chute 3 and the second is separated from the first

  tightly by means of a diaphragm 13.

  This diaphragm 13 is clamped on its periphery between the edges of the parts 4a and 4b forming the valve body 4; the inner edge of the diaphram 13 is fixed by means

  a collar 14 to the body of a small piston 15 coulis-

health in room 12.

  A spring 16 takes care of keeping the small piston 15 pressed in an end-of-travel position which can be defined "all-back", the diaphragm 13 being tensioned in such a way that it forms a sort of basin whose concavity is oriented towards the chamber 11. At 17 the connection mouth of the pipe 8 is indicated to the valve 4; this mouth allows the entry of compressed air into the chamber 12 so as to cause

  the downward movement of the small piston 15 in opposition

  sition to the action of the spring 16, this bringing the small piston from said "all-back" position to a "forward" position (see Figure 3), which will

  described in more detail later.

69457

-7-

  In 18 we indicated the outlet nozzle of the

  that of valve 4, which is in communication

  with the chamber 11 and extends coaxially thereto.

  The nozzle 18 is provided with an outlet mouth 19 of cylindrical shape, which normally is blocked by the ex-

  calibrated end 20 of a shutter 21 directly

  linked to the body of the small piston 15. The shutter 21 comprises

  te a substantially rod-shaped body 22 which,

  near the outlet mouth 19, has a cross section

  considerably lower than that of the calibrated end; the section of the nozzle 18 is such that it allows the formation of a chamber between the shutter 21 and the internal wall of the same nozzle 18; this chamber is sufficient to authorize the free passage of the liquid which, entering chamber 11 through the chute 3, tends

  to flow from the valve 4 through the nozzle 18.

  At 23, a substantially frustoconical connection portion is indicated between the calibrated end

  and the rod-shaped body 22 of the shutter 21.

  After describing the valve object of the

  vention in its essential parts, we will now

describe how it works.

  Assume at the outset the position shown in FIG. 2 where the shutter 21 is in the position of

nozzle closed 18.

  When the sensor element 9a detects a lowering

  ment of the glue level in the tank 5 it sends a

  signal to the solenoid valve 9 which opens the line 8 per-

  putting the passage of compressed air from the general source

valve 10 to valve 4.

  The air entering through the mouth 17 pushes

  the small piston 15 downwards defeating the anta-

- 8 -

spring gonist 16.

  During this step the diaphragm 13 is closed.

  born in the position shown in FIG. 3 causing a slight reduction in the volume of the chamber 11 (and consequently a pressure on the liquid which completely fills this chamber as well as the interior chamber

  to the nozzle 18) which promotes the initial exit of the

  what about the nozzle 18. Obviously this function of the dia-

  sentence 13 is only possible if the supply of the

  glue from tank I to valve 4 takes place with a weak

  ble pressure or also if a check valve is

provided on duct 2.

  The small piston 15 is therefore brought to the posi-

  tion "all-ahead" and the calibrated end 20 of the ob-

  impeller 21 is brought to a position outside the nozzle 18, thus leaving free the orifice or outlet outlet of this nozzle and allowing the flow of

  the adhesive towards the tank 5. When the sensor element 9a

  check that inside the tank 5 the glue level

  desired has been reached, it sends a new signal to the

  solenoid valve g which interrupts communication again

  cation between the source 10 generating compressed air and

valve 4.

  At the same time the portion of chamber 12 com-

  taken between the small piston 15 and the connecting mouth 17 is placed in communication, in a manner known per se,

  with the external environment, so as to allow the

  exit 16 to return the valve 4 to its condition of

part illustrated in Figure 2.

  Looking at Figure 3 we can notice that when the shutter 21 is in the open position of the

  outlet 19 of the nozzle 18, the truncated portion

  pic 23 causes, by molecular adhesion, a flow

  laminar glue along its surface and by cons

  sequence the formation, downstream of the calibrated end

  , a depression as a result of which the jet

  thins, taking a perfectly cylindrical shape without

no deviation.

  In Figures 2 and 3 we can notice that

  the calibrated end 20 of the shutter 21 perfectly matches

  the outlet of the nozzle 18 and that

  possible layers of dried or partially dried glue

  adhering to the opening of the outlet mouth,

  during the valve opening step 4 (see fig.

  re 3) are broken and dragged outward by the

  same shutter 21 which in this way, at each stage

  pe valve opening, exerts a kind of net-

  cleaning of the nozzle outlet mouth 18 ensuring

  constantly perfect operation of the valve 4.

  In FIGS. 1 and 2 the outlet mouth 19 of the nozzle 18 and consequently the calibrated end 20 of the shutter 21 are of cylindrical shape but, according to a possible alternative embodiment, they can also be of slightly frustoconical whose large base is oriented towards the outside of the

nozzle 18.

--10 -

Claims (5)

R E V E N D I C A T I 0 N S   1. Valve (4) for dispensing liquids, in particular   glue, comprising a chamber (11) connected to a container   supply hose (2) for supplying the liquid to be delivered, a nozzle (18) for discharging the liquid from the valve (4), a plug   rator (21) of the nozzle (18), actuating means   shutter (21) for opening and closing   valve (4), characterized in that said ob-   impeller (21) is provided with an end (20) which penetrates   be precisely in a liquid outlet (19)   of the nozzle (18) and is movable between a position, from -   valve (4) closed, internal to the outlet mouth   tie (19) and a position, opening of the valve (4), external to the nozzle (18), and it comprises, adjacent to   said end (20), a substantially truncated portion   conical (23), the large base of which is oriented towards the ex-   end (20), which extends under open conditions   valve (4), outside of the nozzle (18).   2. Valve according to claim 1, character-   in that said shutter (21) has a body   in the form of a rod (22) terminating, by one of its ex-   hoppers, to said substantially frustoconical portion   (23) and, by its other end, to said means of access   which are housed in a room (12)   separated from the chamber (11) in a sealed manner and   try a small piston (15) subject to the action of a spring   exit (16) which pushes it towards an end-of-travel position, to which corresponds said internal position of the end (20) of the shutter (21), this chamber   separate (12) being capable of being connected to a source   that of compressed air (10) which pushes said piston (15), at 256945i - 11 -   opposition to the action of the spring (16), towards a second   end position, to which the   said external position of the end (20) of the shutter (21).   3. Valve according to claim 1 or 2, charac-   terized in that the outlet mouth (19) and the end   tee (20) of the shutter (21) are defined by sur- cylindrical faces.   4. Valve according to claim 1 or 2, ca-   characterized in that the outlet mouth (19) and the ex-   end (20) of the shutter (21) are frusto-shaped fuck.   5. Valve according to claim 2, charac-   because it has a flexible diaphragm (137   interposed between the chamber (11) and said separate chamber rée (12).