FR2621888A1 - APPARATUS FOR VACUUM PACKAGING OF PRODUCTS IN FLEXIBLE BAGS - Google Patents

Abstract

The present invention relates to an apparatus for vacuum packaging products in flexible bags, comprising a support frame 1, two jaws 4, 5, a seal 10 on at least one of said jaws 4, 5, a welding rod 14 on at least one jaw, a fixed suction nozzle 15 arranged to extend between them beyond said seal (s) 10, said jaws being closed, a suction pump 19 connected to said nozzle 15. - According to invention, it comprises at least one elongate element 17 arranged to protrude from said nozzle 15 to extend between and beyond said jaws 4, 5 to penetrate into a bag to facilitate the evacuation of air and retract in the nozzle 15 out of the bag, and control means 16, 24, 28 thereof. - The invention applies to the vacuum packaging of products in flexible bags.

Description

1 The present invention relates to an apparatus for the vacuum packaging of

  products or articles in containers, such as bags and envelopes, made of materials

flexible and weldable.

  Packing machines have long been known for evacuating air from bags or envelopes containing the products to be packaged, for example food products or

  analogous materials, and heat seal the opening thereof.

  Such known machines have two jaws between which the opening of a container made of a flexible and weldable material, such as a plastic bag or envelope containing the product to be packaged, is placed, and means for extracting it. , generally comprising one or more nozzles in communication with the inlet of a suction pump and designed to move forward

  so as to enter the opening of the bag or envelope

  eg to extract most of the air from the container, and backwards away from the opening of the bag before it is sealed. Along the jaws, a pair of welding rods are generally provided, each

  including an electrical resistance.

  In such known machines, there are often problems of excessive narrowing of the opening of the container during the evacuation of the air or problems of maintaining the vacuum between the evacuation of the air and the sealing operation. . This is due to the fact that the container, both for air evacuation and sealing operation, is arranged with its opening clamped between the jaws which are provided with suitable soft clamping joints, between which extend the suction nozzle. In fact, it can happen that, as soon as the suction begins, the opening of the container collapses around and in front of the nozzle, thereby blocking it, so that sufficient extraction of air from the interior of the container is either prevented or obtained after an excessively long period of time, or, even if the desired degree of vacuum is reached, air leakage into the interior of the container may occur during the rearward movement of the nozzle resulting in equally undesirable consequences. An object of the present invention is to provide an apparatus for the vacuum packaging of various products, which is very simple in structure, and convenient to use and

  does not have the drawbacks indicated above.

  For this purpose, the apparatus for vacuum packaging products in flexible bags or envelopes, of the type comprising a support frame, two jaws, at least one of which is pivotally mounted relative to the other, of so as to open by moving away from one another and to close one over the other, actuation means for the or each pivoting jaw, at least one tight seal on an active face d '' at least one of said jaws, at least one welding rod on at least one jaw which is arranged spaced from said one or more seals, at least one fixed suction nozzle arranged adjacent to said jaws so as to extend between they beyond said one or more seals when said jaws are in a closed position, a suction pump connected to said one or more nozzles, is remarkable, according to the invention, in that it comprises at least one relatively elongated element thin arranged to project from said nozzle so as to extend e between and beyond said jaws to enter a bag or envelope to facilitate the evacuation of air therefrom, and to retract in the nozzle out of the bag or envelope when the evacuation of the air is over, and means

  for the rod-shaped element.

  1 Advantageously, the or each elongated element present at the

  minus a groove or longitudinal channel.

  In addition, said control means may comprise a sleeve tightly connected to and arranged on a straight part of said fixed nozzle, a cylinder receiving said sleeve telescopically, fixing means for fixing the or each elongated element. to said cylinder, so that said elongate member extends through the cylinder, the sleeve and the nozzle, and means

for the cylinder.

  Preferably, said actuating means comprise a

  double action pneumatic cylinder.

  Furthermore, clamping means can be provided to actuate at least one jaw to be clamped against the other before implementation of the or each welding rod. In particular, said clamping means may comprise at least one sliding block mounted fixed on a rotary bar, an arm fixed to said bar and making

  projection and drive means for said arm.

  According to another characteristic of the invention, the apparatus comprises means of connection between said arm and said drive means, said drive means

  comprising said double action cylinder.

  According to yet another characteristic of the invention, said drive means comprise at least one solenoid. Preferably, said actuating means comprise at

minus a cylinder.

  The figures of the appended drawing will make it clear how the invention can be implemented. In these figures,

  identical references denote similar elements.

  Figure 1 is a schematic perspective view of an apparatus according to the invention. Figure 2 is a side elevational view of a plate

  side or lever of the device of figure 1.

  Figure 3 is a sectional view of a guide device.

  Figure 4 is a perspective view of an apparatus according to

the invention manually operated.

  Figure 5 is a schematic perspective view of another embodiment of the packaging apparatus under

vacuum according to the invention.

  Figures 6 and 7 are cross sections of two

  configurations of an elongated element.

  Referring to Figures 1 to 3, it will be seen that a vacuum packaging device according to the invention comprises a support frame comprising a front support frame 1 and a rear frame 2 which is or can be erected. A plate-shaped jaw 4 is fixed to a front cross-member 3 of the support frame 1 and extends substantially over the entire length of the cross-member 3. Another plate-shaped jaw 5 is carried by a pair of side plates or levers 6 and 7 which are articulated, or can pivot, at 8 and 9 respectively, around a common longitudinal pivot axis parallel to the jaws 4 and 5. Thus, the jaw 5 can be opened (raised) and closed (lowered) relative to the fixed jaw 4 by turning 1 its side plates 6 and 7 about their pivot axis. On each active face of the jaws 4 and 5, a tight seal is provided 10. At the front edge of each jaw, a longitudinal welding rod (resistance), 13 and 14 respectively, extends parallel to the seal 10 and is spaced from this, and is preferably protected externally by a layer of coating material, by

  example of Teflon (registered trademark).

  In the central area of the jaws 4 and 5, a nozzle 15 is attached to the side. rear of plate 4 and extends from rear of plate 4 to above and beyond the seal 10. The nozzle 15 may have its free end flattened, while its other end, remote from the jaws, is connected sealingly to a guide sleeve 16 in which is mounted, in a movable manner, an elongated rod-shaped element 17, for example comprising a cable, a cord of steel wire, a rod of material

  plastic or metallic and the like (Figure 3).

  The nozzle 15, or the sleeve 16, is connected by means of a conduit 18 to the inlet of a pump driven by motor 19,

  via an electric control valve 20.

  More particularly, with reference to FIG. 3, it can be seen that the sleeve 16 has a threaded end 21 coupled to the nozzle 15 and a threaded and widened intermediate part 22 for removably fixing the sleeve 16 to a lug or a support plate 23 fixed, for example welded, to the

  crosspiece 3. The remaining part of the sleeve 16 is outside

  smoothly and arranged to slide, telescopically

  that, in an external receiving and guiding cylinder 24. The latter has one end from which 1 the sleeve 16 projects, having one or more annular seats receiving seals 25, while its other end has a part internal thread 26 for receiving, in a removable and leaktight manner, a closure plug 11 to which is fixed one end of the rod or of the metal wire 17. Thus, the rod or the metal wire 17 extends through an internal axial cavity 27 of the sleeve 16 and through the nozzle 15. The telescopic movement of the elements 16 and 24 can be imparted by a double-acting pneumatic cylinder 28, the piston rod of which is fixed, for example by means of a crosspiece or clamp 12, at the end of the cylinder 24 closed by the plug 11. Thus the sleeve 16, the cylinder 24 and the jack 28 constitute control and guide means for

the elongated element 17.

  The side plates 6 and 7 carrying the upper movable jaw 5 can be actuated by one or two double-acting pneumatic cylinders 29. To this end, each cylinder 29 and the cylinder 28 are functionally connected to the control valve electric 20 which is arranged to establish the fluid communication of the different cylinders

  with either a compressor 30 mounted on the central shaft

  pump 19, either with a storage tank

compressed air 31.

  Advantageously, a bar 32 is rotatably mounted on the movable jaw 5 and carries one or more

  sliding pusher blocks 33, as well as a transverse arm

  sal 34 integral with the latter which can be actuated, thereby causing the rotation of the bar 32 and the action of the sliding blocks 33 against the bar 5 by means of a traction cable 35 which is connected either to the cylinder 24 or to the piston rod of the jack 28, ie at the cross member 12 and has a length such that it is pulled only at 1 the end of each extension stroke of the jack 28, as

this will become evident below.

  The operation of a vacuum packaging device as described above is quite simple. First of all, the jaws 4 and 5 are open and the operator places the opening of an envelope or a flexible bag in which a vacuum must be created and which must be tightly closed flat on the lower jaw 4, while ensuring that the elongate element 17 projecting from the nozzle 15 has entered the envelope or the bag. By pressing an appropriate control push button or a pedal (not shown), an electrical control signal is supplied to the valve 20, which operates the jacks 29, thereby causing the jaw 5 to close on the jaw 4 without forcing said jaws against one another but by moving them close enough to each other to guarantee airtightness. Once the jaws 4 and 5 are closed one on the other, the motorized pump

  19 is implemented, for example by means of micro-commu-

  nozzles, not shown, actuated by the cylinders 29. The motorized pump 19 sucks the air from the envelope or the bag to be sealed via the conduit 18 and the nozzle 15, being assisted in this by the element in rod form 17 which extends deep into the envelope or the bag to be sealed, can come into contact with the products contained therein and guarantee rapid

  evacuation of substantially all the air contained therein.

  Obviously, the rod-shaped element 17 prevents the wall of the bag or envelope from adhering to the nozzle 15, while maintaining an active connection between the interior of the envelope or bag, the product or the article therein and the nozzle 15. This is best achieved when the element 17 has one or more grooves or longitudinal channels 170, as shown in Figures 6 and 7. Once 1 has been reached the desired degree of vacuum, for example measured by an appropriate vacuum gauge (46 in Figure 5), the actuator 28 is actuated which, in turn, causes the extension of the telescopic elements 16 and 24, thereby causing the backward movement inside the sleeve 16 of the elongated element 17. During the final stage of the air extraction, the retraction of the element 17, a wire or wire 35 is pulled by tightening thus firmly the upper plate 5 against the lower plate 4, and at the same time a micro-switch (not shown) arranged behind the rod piston of the jack 28 supplies electric current to the resistors 13 and 14 arranged in the plates 4 and 5 to heat seal the bag or the plastic envelope. Instead of a cable 35, one or more solenoid controls can be provided to actuate the upper jaw 5 by supplying them with electric current when the elongated element 17 is moved rearward in the nozzle 15. In this way, uniform and uninterrupted heat sealing is achieved along

  of the entire extension of the opening of the bag or the envelope

  eg as the latter is no longer obstructed by the element

  elongated 17. After the completion of the thermosou-

  dage, which operation can be controlled by a timer (not shown) also arranged to stop the motorized pump 19, the jacks 29 are actuated to open or raise the upper jaw 5. The packaging envelope, now vacuum and closed way

  waterproof, can then be removed from the device.

  Figure 4 illustrates a manually operated version of a vacuum packaging apparatus according to the invention. In this case, the raising and lowering of the upper jaw 5 is caused by a lever 37 which extends laterally on one side of the apparatus and is arranged to actuate a rotary rod 38 on which is fixed a 1 pair of articulation arm 39 for the jaw 5. An abutment arm 40 is also fixed on the rod 38, which prevents the elongated element 17 from coming out of the nozzle 15 when the jaw 5 is closed on the jaw 4, as this will be explained in more detail below. On the other side of the device, there projects a second actuating lever 41 which controls a respective rotary rod 42 parallel to the rod 38 and arranged to control the telescopic movements of the two components 16 and 24. The rod 42, in turn, carries an abutment arm 43 designed to abut against the arm 40 on the rod 38 to allow the rod-shaped element 17 to protrude only if the upper jaw 5 has been raised. The operation of the apparatus of FIG. 4 is also similar to that of

  the device shown in Figures 1 to 3.

  Advantageously, below the fixed jaw 4, it is possible to provide a removable lower plane 44 intended to act, in service, as a support plane for the bags or

envelopes to be closed.

  FIG. 5 shows a manually actuated vacuum packaging apparatus similar to that illustrated in FIG. 4 which has on its front wall 45 a vacuum gauge 46, a main switch 47, a lamp

alarm 48, potentiometer 49.

  The lower jaw 4 is fixed and secured to the chassis 1 and carries a welding bar 14. The waterproof seal 10 is shaped like an endless band located in a respective quadrangular seat 11 which delimits an internal zone 4a surrounded by the seal 10. The box-shaped upper jaw 5 is articulated at 50 to the lower jaw 1 4 and has a handle 51 which can be manually pressed on the lower jaw 4 and lifted therefrom. A suction opening 52 is in communication with the inlet of the pump 19 to evacuate the air from the zone 4a, and thus from the bag or the envelope to

  close tightly as explained above.

  A suction nozzle 53 can be arranged on the lower jaw 4 to be connected to the duct (not shown) to evacuate the air from jars and the like, for example to keep a food product under vacuum, in which case a valve works - suitable stop (not shown), for example of a manually operated type, should be placed

upstream of nozzle 53.

1 1

Claims (9)

  1 1 - Apparatus for the vacuum packaging of products in flexible bags or envelopes, of the type comprising a support frame (1), two jaws (4,5), at least one of which is pivotally mounted relative to the other, so as to open away from one another and to close one over the other, actuating means (29) for the or each pivoting jaw, at least a seal (10) on an active face of at least one of said jaws (k, 5), at least one welding rod (14) on at least one jaw which is spaced apart from said one or more seals (10) , at least one fixed suction nozzle (15) arranged adjacent to said jaws (4,5) so as to extend between them beyond said one or more seals (10) when said jaws are in a closed position , a suction pump (19) connected to said one or more nozzles - (15), characterized in that it comprises at least one relatively thin elongated element (17) arranged to protrude of said nozzle (15) so as to extend between and beyond said jaws (4,5) to penetrate into a bag or an envelope to facilitate the evacuation of the air from the latter, and to retract in the nozzle (15) out of the bag or the envelope when the evacuation of the air is finished, and control means (16,24,28) for the shaped element rod.   2 - Apparatus according to claim 1, characterized in that the or each elongated element (17)   has at least one groove or longitudinal channel (170).   3 - Apparatus according to claim 1 or claim 2,   characterized in that said control means comprises   nent a sleeve (16) sealingly connected to and arranged on a straight part of said fixed nozzle (15), a cylinder (24) receiving said sleeve (16) telescopically, fixing means (26) for fixing the or each elongate member (17) to said cylinder, so that said elongate member (17) extends through the cylinder (24), the sleeve (16) and the nozzle (15), and means for actuation (28) for the cylinder (24).   4 - Apparatus according to claim 3, characterized in that said actuating means (28)   include a double action pneumatic cylinder.   5 - Apparatus according to claim 3 or claim 4, characterized in that clamping means are provided for actuating at least one jaw to be clamped against the other before implementation of the or each rod welding (14).   6 - Apparatus according to claim 5, characterized in that said clamping means comprise at least one sliding block (33) fixedly mounted on a rotary bar (32), an arm (34) fixed to said bar and projecting and drive means for said arm. 7 - Apparatus according to claim 6, characterized in that it comprises connecting means (35) between said arm (34) and said drive means, said drive means comprising said cylinder to double action (28).   8 - Apparatus according to claim 6,   characterized in that said drive means -   include at least one solenoid.   9 - Apparatus according to any one of claims   above, characterized in that said actuating means include at least one cylinder.