초록 ▼

A machine with a series of three operating stations, of which the first station arranges the full trays in a predetermined pattern while the second station closes the full trays with a film and in which the third station discharges the full trays. The stations are equidistant from each other. A tran

A machine with a series of three operating stations, of which the first station arranges the full trays in a predetermined pattern while the second station closes the full trays with a film and in which the third station discharges the full trays. The stations are equidistant from each other. A transfer structure has combs that have a length such as to occupy simultaneously two consecutive such stations and that are provided with the teeth that can grasp the trays, lift the groups of trays and then move longitudinally to transfer the groups of trays from one station to the next, then lower the tray to deposit the groups of trays in the new stations.

대표청구항 ▼

1. A machine for packaging products in rigid or semirigid trays sealed across the top by a thermoplastic film, for producing packs with a modified or nonmodified atmosphere, having intermittent operation, comprising: a first station arranged to prepare groups of product-filled trays arranged with a

1. A machine for packaging products in rigid or semirigid trays sealed across the top by a thermoplastic film, for producing packs with a modified or nonmodified atmosphere, having intermittent operation, comprising: a first station arranged to prepare groups of product-filled trays arranged with a predetermined mutual spacing in one or two parallel rows;a second station arranged to close and heat-seal a cover onto the top edge of said groups of trays, after removing the air from said trays and replacing said air with a modified atmosphere useful for the preservation of the packaged products and with a subsequent cutting mechanism to separate the closed trays from a length of film from which said closing cover is taken;a third station arranged to discharge the groups of trays with the packed product;a transfer structure which cyclically and simultaneously transfers the groups of trays with the product from said first station to said second station and from the said second station to said third station,said first and third stations being equidistant from the second station in the horizontal direction, said transfer structure comprising moving and lifting combs that operate alongside said stations, that have a length such as to occupy simultaneously two consecutive such stations and have teeth which can be inserted transversely into engagement with the front and rear of the groups of the row or rows of trays, and then be raised so as to lift said groups of trays and remove them from a surface on which they were resting, then move longitudinally to transfer the groups of trays from the first and second stations to the station immediately following, then be lowered to deposit the groups of trays in the new stations, then be withdrawn laterally from said groups of trays, and finally be returned, by a longitudinal movement, the reverse of the previous movement, to the starting condition in order to be able to repeat the operation of moving the trays for the first and second stations to the immediately following station,said moving and lifting combs being movable along three orthogonal axes, namely along an X axis for horizontal movements towards and away from the groups of trays, a Y axis for horizontal movements for the transfer of trays from one station to the next, and a vertical Z axis for lifting and lowering movements,the moving and lifting combs each being fixed to the lower end of a respective vertical arm which has slides allowing it to run on complementary vertical guides mounted on a forearm housing a sealed actuator, which actuator operates a crank mechanism having a crank button connected to an adjustable link, the other end of which link pivots on a pin fixed to said arm, in such a way that the comb connected to the fixed arm can receive from said link and crank assembly the necessary variation in upward and downward motion along said Z axis, the forearm being provided at its top with horizontal slides to travel on corresponding straight guides oriented along the X axis and fixed to the underside of a carriage, mounted on top of which are slides which travel on straight horizontal guides oriented along the Y axis and connected to a base frame which is in the upper part of the second station of the machine, which frame is closed on its underside by closing walls that separate an upper chamber in which the X- and Y-axis comb actuating structure is confined and separated from the lower chamber in which the products are packaged, to avoid contaminating the lower chamber and to ensure that the actuating structure can be washed without damage to the parts contained in the upper chamber. 2. A machine according to claim 1, in which the teeth of the moving and lifting combs have a channeled profile, which allows the combs to operate, on trays of different depths or heights. 3. A machine according to claim 1, in which a plate in the form of a shuttle is fixed perpendicularly to the upper part of said carriage and runs in a sealed manner in a window in said frame, parallel to the Y axis and is sealed to allow said shuttle to move forwards and backwards, the upper part of said shuttle, which projects into the chamber carrying a strip attached to the run of an endless positive-drive belt oriented along the Y axis with its ends travelling around pulleys supported rotatably by brackets mounted on said frame, one of which pulleys is keyed to the slow shaft of a speed reduction unit driven by an electric motor with electronic speed and phase control, with two directions of rotation and with a brake, said motor being fixed to the same frame, there being in an intermediate part of said shuttle, a vertical seat through which there passes a shaft whose upper end is connected to a bevel gear pair driven by an electric motor with a brake and of the type having electronic speed and phase control, all of this being fixed to said strip, while the lower end of said shaft is connected to a positive-drive composed of a bevel gear pair, a horizontal shaft and a worm-and-helical-wheel gear supported by the carriage, which last component carries, keyed to it, a pinion with its axis in the Y direction, meshing with a rack oriented along the X axis and attached at one end to the forearm, which can therefore be displaced to insert and withdraw the teeth of the comb between and from the trays that are to be or have been transferred, said shuttle also being constructed to support a vertical pipe that carries all the electrical cables necessary for powering and controlling from a fixed panel all the X- and Z-axis motions which occur in the lower chamber. 4. A machine according to claim 1, including a robotic arm hung from each said carriage and connected to an upper plate for horizontal movement of the combs along the horizontal Y axis, the robotic arm having a forearm, an arm and a wrist which carries a corresponding comb, and wherein the rotations are all connected to the upper axis of the connection to said carriage, such that respective positive motion passes through said shuttle to operate each robotic arm by motion units which are located in the upper chamber of the machine, to impart to the combs said movements along the X and Z axes. 5. A machine according to claim 1, in which the second station comprises a lower housing with a chamber whose volume is variable in relation to the height of the trays to be closed and with a sealing structure which seals them off from the exterior, so that the amount of gas required for the internal conditioning of the trays is related in each case to the actual dimensions of said trays. 6. A machine according to claim 1, including a control panel with software which can be used, without in any way modifying the hardware of the machine itself, to select the method of optional internal conditioning of the trays before their closure, which may be done by evacuating the air from the trays, by injecting gas into said trays, by first evacuating and then injecting gas, or by evacuating and simultaneously injecting gas in areas of the trays separated from each other. 7. A machine for packaging products in rigid or semirigid trays sealed across the top by a thermoplastic film, for producing packs with a modified or nonmodified atmosphere, having intermittent operation, comprising: a first station arranged to prepare groups of product-filled trays arranged with a predetermined mutual spacing in one or two parallel rows;a second station arranged to close and heat-seal a cover onto the top edge of said groups of trays, after removing the air from said trays and replacing said air with a modified atmosphere useful for the preservation of the packaged products and with a subsequent cutting mechanism to separate the closed trays from a length of film from which said closing cover is taken;a third station arranged to discharge the groups of trays with the packed product;the first station comprising a horizontal conveyor having parallel belts having a predetermined tension in annular grooves of the parallel shafts and mounted on a base frame, wherein the shaft with the greatest diameter is driven by a motion unit, the upper run of the conveyor being constructed to be divided into two longitudinal lanes correlated in width to the width of the trays, by a longitudinal central guide connected to lower parts of said frame and provided with divider ends and by lateral guides projecting vertically a short distance from the upper run of the conveyor and connected to the frame in such a way that they can be adjusted to suit the dimensions of the trays, the upper run of which belts runs on small idle grooved rollers supported rotatably at either end by brackets connected to boxes having adjustment clamps on their underside and removably attached to guides positioned longitudinally and in the center of the base frame, to which they are fixed at either end by crossmembers, vertical rods emerging in a guided manner from the top wall of said boxes to support the base of prevention profiles whose vertical side has upwardly open teeth with rounded points, which in the rest position are positioned beneath the upper run of the conveyor so as not to interfere with the passing trays and which, on command, can be raised by linear actuators so that the teeth pass between and above the belts to create perpendicular barriers between said longitudinal guides to stop the trays on the upper run of the conveyor, their contact being distributed across the transverse surface of said trays, which as a result can be stopped precisely in accordance with a predetermined plan and order, the top wall of said boxes having sensors which face upwards to detect objects in the free space between a pair of adjacent belts to thus detect the presence or absence of a tray upstream of said prevention profiles.