Plastic bag dispensing apparatus for supermarkets and the like

Abstract: Apparatus suitable to be located in supermarkets and the like for dispensing in open position plastic bags for carrying therein items purchassed on site, comprising a reel consisting of a continuous strip of plastic bags joined together, a device that unwinds said reel and brings the continuous bag strip to a superposed opening device that takes one bag off the continuous strip, opens the bag and supports it during the filling thereof with the items introduced through a hopper located immediately above the open bag.

Description: The present invention relates to an apparatus intended to be placed in supermarkets and in other similar points of sale to dispense one at a time plastic stic bags unwound from a reel, open them and keep them open under a hopper through which either the customer or the supermarket personnel may introduce the purchased items that must be taken away. It is known that in supermarkets and in other analogous points of sale the items purchased by a certain customer are taken away by the latter by means of plastic bags provided by the supermarket and filled by hand by the customer himself. This is a particularly uncomfortable operation, requiring a lot of time and patience by the customer who has to keep the bag open with one hand, while taking the items one at a time with the other hand from a trolley, or from the check-out counter plane, to insert them in the bag. Furthermore, the bags are very often provided in the form of packs or continuous strips, so that the customer has also to pull the bags away from the pack and from the continuous strip one at a time in order to fill them, this resulting in further nuisance and loss of time for the customer. From GB 2.055.084 A it is already known an apparatus which automatically supplies and opens a single bag from a continuous strip, the bag being kept open to allow its filling with purchases. This known apparatus is however incorporated in a check-out counter so that it is not available to the customer in advance before he reaches the cheek-out area. Moreover the known apparatus keeps open the bag during its filling by means of a pair of lateral suction jaws with the inconvenience that the lateral suction on the smooth surface of the bag sides is not sufficient for firmly holding the bag when heavy purchases, such as bottles, are inserted therein. Further inconveniences of the above mentioned known apparatus are that it requires the use of means for unwinding and driving the continuous strip of bags and separate additional means for detaching therefrom the leading bag. Thus it results in a somewhat complicated and bulky apparatus which, moreover, carries out the unwinding of the bag strip from the reel by directly pulling the strip itself, with the risk of a premature detachment of a bag due to the inertia and/or the friction of the reel. It is therefore the object of the present invention to provide an apparatus which is fully independent from the check-out counter and is not subject to the above-mentioned inconveniences. This object is achieved according to the present invention by an apparatus comprising an unwinding device consisting in a motordriven rubberized roller which unwinds the reel and a strip driving device which also detaches the leading bag through the action of two pairs of facing belt units, sequentially arranged, of which the lower pair is suitable to insert its direction of rotation whole the upper pair holds the leading bag of the strip, whereby detaching it therefrom. The apparatus preferably comprises as well a loading device that supports the bottom of the bags during the filling thereof, and ejects the filled bags. The apparatus according to the present invention has the advantage of having a very simple structure and therefore high reliability and low cost. Moreover, the apparatus is of very reduced size, whereby it can be conveniently placed at any point in the supermarket, even in the proximity to the check-out counters. This would involve the further advantage that the supermarket personnel might help or even stand in for the customers in the bag filling operations. This and other advantages of the apparatus according to the present invention will be apparent to those skilled in the art from the following detailed description of an embodiment thereof, with reference to the accompanying drawings in which: Fig. 1 is a side elevational view of the apparatus according to the present invention; Fig. 2 is an elevational view orthogonal to that of Fig. 1; Fig. 3 is a view from above of Fig. 1; Figgs. 4A to 5D are detailed views of the bag opening device during four operative steps; and Figgs. 6 to 8 are a perspective view of a variation of the embodiment of the preceding figures during three operative steps. Referring now to Fig. 1, the bag reel referenced as a whole by No. 1 can be seen on the right. This reel consists of a continuous strip 2 of bags 3 wound about a central core 4. The end parts of this central core protrude laterally from the sides of reel 1 and rest on the slanted edge 5 of a panel that partly covers laterally the housing of reel 1. The latter rests at its lower part on the rubberized roller 6 that makes it unwind when said rubberized berized roller is rotated by motor reducer 7 by means of chain 9. Motor reducer 7 can work only when microswitch 10 is not depressed by the rocking lever 11. At the upper end of this lever there is roller 12, about which there winds the continuous strip 2 of bags 3 that is shown in the Figure by a broken line. When a bag 3 should be brought to hopper 8 so as to be opened and filled by the cashier, the latter presses on a button that actuates motor reducer 27 that controls the bag dispensing means. This means drags upwards strip 2 that is thus tensioned, whereby the tension roller 12 is given an upward push that causes the upper end of the rocking lever 11 to lift. The lower end of lever 11 will also lift and will thus no more depress microswitch 10 that actuates motor reducer 7 that in turn actuates the rubberized roller 6 causing reel 1 to unwind. The provision for edge 5 of the reel-covering panel - against which abut the protruding ends of core 4 - being slanted makes reel 1 be always supported by the rubberized roller 6 that controls the unwinding thereof. Strip 2 is then guided around idle rollers 13, 14 that drive it downwards until having it gripped by the two lower driving belt units 15 and 16. Belt unit 15 consists of a plurality of flat belts intended to come in contact with one face of a bag 3. Their number depends of course on the sizes of bag 3 and in the herein illustrated embodiment they are nine, so as to act on the whole face of bag 3. Driving belt unit 15 cooperates with driving belt unit 16, of like number and size, which acts on the opposite face of bag 3. Belt units 15 and 16 rotate about the lower rollers 17, 18 and the driving rollers 22, 23 respectively. Roller 17 is provided with a lever 19 by which it is possible to lift said roller when strip 2 must be inserted between belts 15, 16 when replacing an exhausted reel by a new one. The lifting of roller 17 by means of lever 19 - sketched in broken line in Fig. 1 - takes place by using a first interposed roller 20 as lever fulcrum. A second interposed roller 21 is mounted between the lower rollers 17, 18 and the driving rollers 22, 23 and is for making belts 15, 16 run under one another in close contact at the upward bent of the pathway of strip 2. Belts 15, 16 are actuated by driving rollers 22, 23, roller 22 alone being actually motor-driven, whilst roller 23 is linked to roller 22 by a pair of toothed wheels each of which is keyed onto each one of the rollers. Roller 22 is rotated by motor reducer 27, and the rotation of roller 22, thanks to the said pair of toothed wheels, involves the rotation of roller 23. On roller 22 there is also mounted a pinion 24 which, by means of chain 28, is linked to a corresponding pinion 25 mounted on the superimposed upper roller 29. In this manner the rotatory motion of roller 22 is transferred to the upper roller 29, and from this to the upper roller 30 by means of a pair of toothed wheels analogous to the one linking driving rollers 22 and 23 to each other. Thus motor reducer 27 motor drives both the rollers 22, 23 with their relevant lower belt units 15, 16, and the upper rollers 29, 30 with the two relevant upper belt units 31, 32. Belts 15, 16 of both lower units press upon each other about the second interposed roller 21, gripping therebetween the continuous bag strip 2 which, when the belts are rotated, is accordingly driven upwards in the direction of the superposed opening bag device. The upper belts 31, 32 too, as they rotate facing each other, hold in between the continuous strip 2 coming from the underlying dispensing device and drive it towards the superposed bag opening device. Between the bag dispensing device and the superposed opening device thereof there is interposed the loading device comprising a motor reducer 33 that controls driving pulley 34 which, through cable 35 and idler 36, makes slide 37 - to which the bag loading plate 38 is secured - move up and down. The latter consists of two half-plates separated by a central aperture 39 through which the empty bags can pass in their ascending motion. Each single bag 3 is detached from the continuous strip 2 by reversing the direction of rotation of rollers 29, 23 and of the relevant belts 15, 16, whilst rollers 29, 30 are kept firmly still. This is made possible by two freewheels keyed on roller 29, whose function will be described hereinafter with reference to Fig. 2. The reversing of the rotation of motor reducer 27 and rollers 22, 23 is controlled by elements 41, 41′ of a photocell array between which the continuous strip 2 passes. As already said, this strip consists of a continuous succession of bags 3 wherein the bottom of each bag is joined to the upper end of the handles of the subsequent bag. It follows that the continuous strip 2 has a periodical alternation of full and empty spaces, the empty ones consisting of the zones defined by the two handles and the upper edge of each bag. During the upward motion of strip2, the full zones obscure both elements 41, 41′ of the photocell that are lit up again in correspondence of the empty zones of the strip. Therefore, when the lower edge of a bag crosses the photocell line, the elements thereof are lit and cause the inversion of the direction of rotation of motor reducer 27 as well as rollers 22, 23 with the relevant belt units 15, 16. By effect of such inversion, which is made possible by freewheel 26 and 26′, belt units 15, 16 drive/downwards the continuous strip 2, whilst the foremost bag 3 of such film is held between the two belt pairs 31 and 32 that are stationary owing to freewheel 26′ present on roller 29 being locked. This brings about the tearing of the two small strip portions that join the bottom of bag 3 to the upper end of both handles of the subsequent bag of the continuous strip 2. After bag 3 has been thus detached from the continuous strip 2, the direction of rotation of motor reducer 27 goes back to its original condition before the inversion, whereby rollers 22, 23 with their relevant belts 15, 16 start driving up wards strip 2 again, whilst the single detached bag is driven by the upper belts 31, 32 all the way under hopper 8. When bag 3 has arrived at hopper 8, it is opened by the opening device and takes on the shape illustrated in broken line in Fig.1. The same Figure shows, still in broken line, the uppermost position reached by the two half-plates of the bag loading plate 38, on which rests the bottom of each bag 3 as it is being filled. Such half-plates are in the said uppermost position at the beginning of the filling step of bag 3, so as to prevent the single items - introduced therein through hopper 8 - from bumping too violently against the bottom of bag 3, because of an excessive drop. A too violent bumping of the items against the bottom of bag 3 may cause them to be deformed or even torn, not to mention the risk of being damaged. After the available room inside bag 3 has been filled with articles, the loading plate 38 lowers until an intermediate position at which bag 3 is subjected to a second filling step. At the end of such second step, the loading plate 38 lowers further down until its lowest position (illustrated too in broken line in Fig.1), that lies at the same height as ejection plate 43. After the filling plate 38 has passed from its intermediate to its lowest position, no filling of bag 3 takes place, because the difference of height between such positions is just for having the upper level reached by the items inside the bag further lowered accordingly, in order to prevent the items from bumping against the bag opening device during the ejection of the filled bags. The filled bags 3 are shifted sideways by an ejector 44 that drives them towards the outside of the device making them slide along the ejection plate 43. In Fig. 1 ejector 44 is illustrated in unbroken line in its resting position, whilst it is sketched in dotted line in the ejection step of the filled bag 3′, illustrated too in dotted line. A guard 45 prevents the filled bag 3′ from falling down or overturning before the customer may take it away. The reciprocating horizontal motion of ejector 44 is controlled by a slide 46 (shown in Fig.1) linked by a cable 47 to the pulley 49 actuated by motor reducer 50. Cable 47, that engages slide 46 with ejector 44 linked thereto in a reciprocating horizontal motion, rotates around idler 48 as well. The loading device of the apparatus according to the present invention comprises as well a photocell array 51, located immediately below the upper edge of hopper 8. These photocells detect the maximum level reached by the items introduced in bag 3 and, should the photocells be still obscured at the end of the filling process, they would prevent the motor reducer 50 - that controls the motion of ejector 44 - from moving. Thus there can be avoided that a bag over-filled with items be subjected to the ejector's action, with the consequent risk of having the bag opening device jammed, and the bags damaged along with their content. Once the excess items have been taken away from the bag, photocells of array 51 are lit up again and do not block motor reducer 50 any longer, so that ejector 44 can resume its working. The bag opening device comprises a right pliers 53 cooperating with a facing left pliers 52, as well as a pair of tiltable flaps 54, 55 located perpendicular to the pair of pliers 52, 53. As can be seen in the Figure, pliers 52, 53 are immediately below the two opposite sides of hopper 8, whilst, slightly below the other two opposite sides of this hopper, there are located the tiltable flaps 54, 55. These flaps, when the device is stationary, are in the horizontal position and obstruct hopper 8, preventing items from being passed through it when there is no bag 3 ready to receive them. When, on the contrary, bag 3 is ready to receive such items, namely it lays in the position illustrated in broken line in Fig.1, the two flaps 54,55 are tilted downwards as shown in Fig. 1 where flap 55 only can be seen, because flap 54 is located at the opposite side of hopper 8. Behind flap 55 are shown in broken line the two idlers 56, 57 of the upper driving belt units 31, 32 respectively. Pliers 52, 53 are actuated by motor reducer 60 through cable 58 and pulleys 59, 61. One pliers is linked to the upper branch of cable 58 and the other to the lower branch thereof so that, under the driving action of cable 58, the pliers can shift from a position of maximum distance, being illustrated in Fig. 1, to a meeting position, laying at the center line of hopper 8. When pliers 52, 53 meet, they grip the top edges of the two opposite faces of a plastic bag 3 which is then opened when pliers 52, 53, by moving away from each other, move as well the opposite bag faces that were firmly gripped by the pliers themselves. Immediately after pliers 52, 53 have been spaced apart from each other, flaps 54, 55 are tilted downwards by effect of the electromagnet 62 action (see Fig. 2). When flaps 54, 55 are wholly tilted downwards, they keep spaced apart the other two opposite faces of bag 3, that is the sides corresponding to the bellows of the bag itself. In such a position bag 3 is therefore completely open in the shape of a rectangle immediately below hopper 8, the two opposite faces being firmly held by pliers 52, 53, and two opposite sides being held by the downwardly tilted flaps 54, 55. The way in which the bag opening device works will be described hereinafter in greater detail, with reference to Figgs. 4A to 5D. Referring now to Fig. 2, which is an elevational view orthogonal to that of Fig.1, there can be seen on the left (this time frontally) pliers 53 holding the top portion of bag 3 in open position. The opposite pliers 52 is not of course visible in this figure, unlike flaps 54, 55, which are shown in profile in tilted position. The tilting of flaps 54, 55 is actuated by electromagnet 62 by means of the rocking lever 63, one end of which is hingedly fixed to hub 64 of flap 54, and the other is hingedly fixed to hub 65 of the tiltable flap 55. The rocking lever 63 is linked to electromagnet 62 by means of arm 66. The end part of lever 63 in proximity to electromagnet 62 has an extension 67 that, when lever 63 lowers under the action of a return spring (not shown), presses on the security sensor 68. By effect of the excitation of electromagnet 62, arm 66 is pushed upwardly causing the rotation of the rocking lever 63, whose ends make hubs 65, 64 rotate clockwise and anticlockwise, respectively. The rotation of the two hubs involves the tilting downwards of flaps 55, 54, secured to both the said hubs. The working of this mechanism will be described hereunder in greater detail, with reference to other Figures. In Fig. 2 there can be seen the upper half of bag 3 that rests on plate 38, and is ready to be filled through hopper 8. The lower end of bag 3, on the contrary, hangs floppy down, passing through the aperture 39 that separates the two half-plates of the loading plate 38 and that is provided for the bag to pass through in its ascending motion towards the superposed opening device. On the lower left side of Fig. 2 there can be seen the motor reducer 33 actuating pulley 34 that rotates the driving cable 35 of slide 37 that carries the loading plate 38. Farther up there is shown motor reducer 27 that motor drives roller 22 and, by means of this, roller 23 (not visible in this Figure) by means of the toothed wheel 69 that is in mesh with the analogous toothed wheel 69′ keyed on roller 23. The driving roller 22 is provided with pinion 24 which is linked through chain 28 to pinion 25 mounted on the upper roller 29. Chain 28 with pinions 24, 25 causes the rotary motion of roller 22 to be transferred to roller 29. The rotation of roller 29 brings about the rotation of the two upper belts 31 located at its end part which, as they rotate facing the two belts 32 (not visible in this Figure), drag upwardly the bag 3 plced therebetween. Roller 29 is provided with the toothed wheel 70 that is in mesh with an analogous toothed wheel keyed onto roller 30 (not visible in this Figure). In Fig. 2 is also shown on roller 29 the pinion 25 which is provided with the freewheel 26 that allows roller 29 to rotate clockwise only, i.e. according to the upwardly drag of strip 2 under the action of chain 28. When chain 28 reverses its rotation by effect of the inversion of rotation of motor reducer 27, freewheel 36 runs idle and roller 29 is not actuated any longer, with consequent stopping of the belt units 31, 32 that drag strip 2 upwardly. As strip 2 is also gripped between the underlying belts 15, 16 actuated by roller 22, when this roller reverses its direction of rotation strip 2 could transmit the anti-clockwise motion to roller 29 through belts 31, 32 which are at that moment at a standstill because the freewheel 26 id les. This would be an inconvenience because the reverse of the direction of rotation of motor reducer 27, of rollers 22, 23 and cf the two relevant lower belt units 15, 16 is a provision intended for detaching one single bag 3 from the continuous strip 2 (as was described in detail with reference to Fig. 1) and must take place as the upper belts 31,32 are absolutely stationary. In order to obviate such inconvenience, onto roller 29 is keyed a second freewheel 26′ which runs idle when roller 29 rotates clockwise,thus upholding the upward motion of strip 2, but is locked anti-clockwise. Thus freewheel 26′ prevents roller 29 from being rotated anticlockwise by strip 2 when the latter is dragged downwardly because of the inversion of rotation of motor reducer 27. In the free room between rollers 22 and 29 there are interposed the six small round belts 71 that rotate around rollers 22 and 29. Such small round belts are for properly guiding strip 2 in its transition motion from the point wherein it has been left by the lower belt unit 15, 16 to the point wherein it is gripped by the upper belt unit 31, 32. As can be seen in Fig. 2, the two more external of the lower belts 15 are set side by side so as to be twice as wide than the other five belts comprised between them. By virtue of this arrangement a better dragging of the lateral parts of strip 2, corresponding to the handles of each single bag 3, is obtained. The width of the said outer belts arranged side by side is just almost the same as that of the flattened handles of bag 3. On the lower right side of Fig. 2 is shown lever 19 by means of which it is possible to lift roller 17 and rotate it about the interposed roller 20 to insert between the two lower belt units 15, 16 the starting end of strip 2, coming from a new reel. On the upper part of Fig. 2 is shown ejector 44 with its slide 46 as well as the underlying idler 36 of the cable which controls the up and down motion of slide 37, that carries the filling plate of the bags. On the top part of Fig. 2 there is shown electromagnet 62 which is linked by means of arm 66 to the rocking lever 63,the ends of which are hingedly joined to hubs 64, 65, which carry the tiltable flaps 54, 55, respectively. For the sake of clearness in the drawing, Fig. 3 does not show the connection between rocking lever 63 and hub 65, but only the link between rocking lever 63 and hub 64. Such a link is effected by interposing therebetween a small lever 74, with one end pivoted to the end of rocking lever 63 and the other end secured to hub 64. An analogous small lever 75 (shown in Fig.1) performs the analogous link between the other end of lever 63 and hub 65 that carries flap 55. The way in which this mechanism works will be better illustrated hereinafter with reference to Figs. 5A to 5D. Referring now to Fig. 3, there can be seen in a top plan view motor reducer 60 that, by means of pulleys 59 and 61, rotates cable 58 to which are secured bracket 72, carrying pliers 52, and bracket 73, carrying pliers 53. Perpendicular to the two pliers there are arranged the tiltable flaps 54, 55 which in this apparatus are in the horizontal position, so as to prevent items inadvertently introduced through hopper 8 from entering bag 3. In the area beneath flaps 54 and 55 it is possible to see the two half plates of the filling plate 38 separated by split 39, through which runs bag 3, indicated by a broken line, as it is being brought upwardly by the upper belt units 31, 32. In Fig.3 it is shown the top part 83 of pliers 52, which is provided, on its lower face, with a plurality of spaced apart rubberized blocks 87 (Fig.4A). Un derneath part 83 there is the other component 84 of pliers 52. Such component (not visible in this Figure) has a series of recesses having dimensions and sizes almost identical to those of the rubberized blocks, and being spaced apart from one another exactly as said blocks are. Likewise, pliers 53 comprises too two components 85, 86 identical to those of pliers 52, but mounted the other way round. In the Figure one can in fact see the top part 86 covering the underlying part 85. The latter has on its upper face, namely the one facing component 86, a series of rubberized blocks 88 (Fig.4A) which can pass through the correspondins recesses of part 86 that is visible in the Figure. As the device is working, pliers 52 and 53 advance until they meet and partly interpenetrate, holding bag 3 therebetween, the pliers structure being such that the rubberized blocks 88 of pliers 53 catch on two opposite faces of bag 3. As a matter of fact, as the two pliers 52 and 53, as well as their components 83, 84, 85, 86 are brought in mutual contact, the rubberized blocks 87 located on the lower surface of component 83 pass through the corresponding recesses of component 86 until they abut against component 84, while the rubberized blocks 88 of pliers 53 abut against component 86 after they have passed through the recesses of component 84 of pliers 52. In Fig. 4A to Fig. 5D is illustrated the working of the bag opening device shown during four different operative steps. In Figgs. 4A to 4D the device is shown by an elevational view corresponding to the one of Fig.1, whilst in Figgs. 5A to 5D the device is shown in an elevational view corresponding to that of Fig. 2. In Fig. 4A both pliers 52 and 53 are in the open position and have just started their mutual approaching motion under the action of motor reducer 60 through cable 58 as illustrated by the two small arrows under said Figure. Of pliers 52 is visible the top part 83 carrying below the rubberized blocks 87 that are intended to grant part 83 a better grip on the face of bag 3 when pliers 52 closes with bag 3 held between parts 83, 84 of the pliers itself. Part 83 of pliers 52 is pushed towards the underlying part 84 by spring 89. Likewise, spring 90 pushes against each other the parts 85, 86 of pliers 53 which, as already said above, has a totally identical structure as that of pliers 62, with the exception that it is mounted the other way round and offset with regard to it, so that the rubberized blocks of each pliers are in register with the corresponding recesses of the other pliers. In Fig. 4A both pliers are in the open position. The opening of pliers 52 is due to the fact that the top part 83 has been pushed upwardly upon lowering of the small lever 92, overcoming the resistance of spring 89. The lowering of the small lever 92, which has its fulcrum at 93 on lever 94, has been caused in turn by pin 95 that protrudes from the upper part of lever 94 and that has been brought downwardly by the slanted plane of groove 96 along a polyamidic material parallelepiped 97 within which slides the said pin 95. As it can be seen, groove 96 begins with a chute that is just for driving downwards pin 95, which remains lowered during the whole of its stroke along groove 96, that ends at the other extremity with a vertical upward-directed leg through which pin 95 can go up again under the pushing of spring 89. Likewise, in pliers 53 the lower part 85 is pushed downwards by pin 98 that runs along the groove 99 of the parallelepiped 100 of polyamidic material. In this case groove 99 has no upwardly directed leg, because parallepiped 100 is shorter than the facing parallelepiped 97. Therefore pin 98 can come out of groove 99, when the latter ends, under the pushing of spring 90. In Fig. 4B is illustrated the step when the two pliers 52, 53 meet each other and partially interpenetrate both horizontally and vertically, while bag 3 is interposed therebetween. In this position bag 3 is firmly held between parts 84, 87 on one side, and parts 86, 88 on the other side. Pin 95 has arrived in correspondence of the vertical leg of groove 96, so that it can rise, causing the lifting of lever 92 as well as the releasing of spring 90 which pusches against each other parts 83 and 84 of pliers 52, whilst a portion of bag 3 is interposed between them. Likewise, pin 98, having by this time arrived at the end of groove 99, will be free to rise pushing parts 85 and 86 of pliers 53 against each other in order to grip therebetween too another portion of bag 3. When both pliers are closed, bag 3 has three adjacent zigzag-folded portions comprised between them. The upper portion is comprised between the rubberized blocks 87 of parts 83 of pliers 52 and the upper surface of part 86 of pliers 53; the intermediate portion is comprised between the lower surface of part 86 and the upper surface of part 84; the lower portion is comprised between the rubberized blocks 88 of part 85 of pliers 53 and the lower surface of part 84 of pliers 52. Thanks to this arrangement, when pliers 52, 53 begin to move mutually apart, they become gradually disengaged, because blocks 87 of pliers 52 slide among the recesses of part 86 of pliers 53 and blocks 88 of pliers 53 slide among the recesses of part 84 of pliers 52. The upper and lower portions of bag 3 which are in contact with the rubberrized blocks 87, 88 are dragged by the latter. Since each portion consists of two superposed plastic sheets (i.e. the ones forming the two faces of bag 3), it happens that the outer surface of each sheet, being in contact with the rubberized blocks 87 or 88, is firmly held by these, whilst the inner surface of each sheet is free to slide on the inner surface of the other sheet thanks to the low friction coefficient of the strip of which the bag is made. By effect of these differences in friction, the two pliers 52, 53, when they move away from each other, carry with them the two opposite faces of bag 3 which is thus opened. In Fig. 4C there can in fact be seen pliers 52, 53 during their mutual moving apart, illustrated in the Figure by two small arrows. Bag 3 is gradually opened by the mutual moving apart of pliers 52, 53 which are both closed by action of springs 89 and 90, respectively. During its outward return stroke pin 95 slides inside groove 96 still, but lever 94 is by that time in inclined position under the action of coil spring 101 (see Fig. 3) that resiliently and hingedly joins the small lever 92 to the small lever 94. In this position extension 102 of the small lever 94 does not rest against the lock pin 91 of the small lever 92 any longer. An analogous situation has risen as far as the corresponding parts forming pliers 53 are concerned. In Fig. 4D there can be seen both pliers 52,53 having by this time reached their maximum spaced apart positions, the two faces of bag 3 being mutually spaced apart to the utmost. Pin 95, having ar rived at the highest part of the mouth of groove 96, has wholly disengaged from this, allowing thus spring 101 to restore lever 94 to its vertical position. Thus its extension 102 is in abutment again against the lock pin 91 of the small lever 92. In this position, when pin 95 is driven again into groove 96 as a consequence of the mutual approaching motion of pliers 52, 53, it will cause the lowering of small lever 92 and the lifting of part 83 of pliers 52, which will thus be opened. By effect of this opening, bag 3 will be disengaged from pliers 52, and likewise from pliers 53. This will occur when, as will be further described hereafter, bag 3 has been filled with items up to the allowed top limit. In Fig. 4D is shown also flap 55 that has been tilted downwards, thereby causing the outward shift of one of the sides of bag 3 comprised within the two faces held by pliers 52, 53. Flap 55, besides pushing said side outwards, flattens as well the side bellows of bag 3 with its relevant handle. Flap 54, which is located at the opposite side (not visible in this Figure) performs, by tilting downwards, the same operation. Thus the opening device with both spaced apart pliers 52, 53 and the tilted flaps 54, 55 will keep bag 3 completely open, giving its mouth a substantially rectangular shape, corresponding to the shape of hopper 8 under which the bag is kept open. This permits a smooth introduction in bag 3 of the items purchased at the supermarket's. In Figgs. 5A to 5D the tilting movement of flaps 54, 55 is best visible in succession. In Fig. 5A there can be seen flaps 54, 55 in their horizontal position, corresponding to that of Fig. 3. In such position flaps 54, 55 carry out their other function, namely that of avoiding the accidental introduction of either hands or objects inside bag 3. In Fig. 5A is shown in broken lines the rocking lever 63, which is not actually in that position (i.e. close to pliers 53, of which parts 85, 86 are shown), but (as shown in Fig. 3) in the proximity to pliers 52. This phantom representation is just for better illustrating how the device works. The rocking lever 63 may oscillate about fulcrum 104, and is pivoted at 105 to arm 66 of electromagnet 62. When electromagnet 62 is not excited, arm 66 (being urged by a not shown spring) shifts downwardly, causing pin 105 to lower down and thus causing as well the lowering of the arm of lever 63 to the left of fulcrum 104. This involves the downwards rotation of lever 75, which has one end pivotally joined to the left end part of lever 63, and the other end secured to hub 65 of flap 55. The downwards rotation of lever 75 causes the anti-clockwise rotation of hub 65 which brings flap 55 in horizontal position, as illustrated in Fig. 5A. Concurrently with the lowering of the left arm of lever 63 about fulcrum 104, there occurs the rising of the right arm of lever 63. Such rising involves the upwardly rotation of lever 74, which has one end pivotally joined to the right end part of lever 63 and the other end secured to hub 64 of flap 54. The upwardly rotation of lever 74 causes the clockwise rotation of hub 64, which carries flap 54 in the horizontal position illustrated in Fig 5A. As can be seen in Figgs. 5B and 5C, during the interpenetration and subsequent moving apart of pliers 52, 53, the tiltable flaps 54, 55 remain in their horizontal position, whereby extension 67 (shown in Fig. 2) of lever 63 presses against safety sensor 68, so that the accidental pressing of either flap makes the machine stop at once. By effect of the excitation of electromagnet 62, arm 66 shifts upwardly again, lifting pin 105 and making lever 63 rotate about fulcrum 104. Owing to this rotation, the left end part of lever 63 rises, raising also the end of lever 75 which is pivotally joined thereto. By effect of such rising motion, the other end part of lever 75, joined to hub 65, makes the latter clockwise rotate, and flap 55 downwardly tilt (see Fig. 5D). The upwards rising of arm 66 also involves the lowering of the right end part of lever 63, namely the part on which there is pivoted an end of lever 74. By effect of such lowering, the opposite end of lever 74 makes hub 64 anti-clockwise rotate, and flap 54, secured thereto, downwardly tilt. As already said above, the downwardly tilting of flaps 54, 55 allows the items to have easy access to bag 3 through hopper 8, and helps keeping the handles and the upper part of the bellows of bag 3 spaced apart and covered. At the beginning of a working cycle the device is stationary and flaps 54, 55 and are in horizontal position and obstruct hoppers 8. When a customer needs to take a bag to fill it with the goods he has purchased, he only has to press on a pushbutton which actuates the servomotors 7 and 27 of the bag dispensing device. By effect of such actuation, reel 1 is unwound and one bag 3 is driven upwardly first by belt units 15, 16 and then by the small round belts 71. As the bottom of bag 3 has gone past the photoelectric cell array 41, 41′, these are no longer obscured by the bag and thus cause the inversion of rotation of motor reducer 27, which reverses thus the rotation of rollers 22, 23 as well as of the relevant belt units 15, 16. Such inversion and the concurrent stop ping of belts 31, 32 due to the freewheels 26, 26′ causes a single bag 3 to be detached from the continuous strip 2. Bag 3 is then brought beneath the mouth of hopper 8 and at this stage, the two pliers 52, 53 move simultaneously towards the centerline of hoppers 8 and catch the two opposite faces of bag 3. Both pliers come back then to their original position under the action of motor reducer 60 and open bag 3. Contemporarily, flaps 54, 55 are downwardly tilted, making the access to the bag 3 free, and holding the sides thereof during the filling steps. At the same time, the filling plate 38, under the action of motor reducer 33, has arrived at its highest position and supports bag 3 during its first filling step. In this step bag 3 does not rest on the filling plate 38 by its bottom, but by an area located slightly above the middle of the bag itself. In fact, in this step approximately the lower half of the bag (and therefore its bottom too) hangs loose downwardly through the aperture 39 that separates the two half-plates of the filling plate 38. The customer can introduce the items inside the upper half of bag 3 until the level of the items reaches the photocell array 51. At this point the customer, if he has some more items to take away, presses again on the starting pushbutton controlling motor reducer 33, which lowers the filling plate 38 until bringing it immediately below the bottom of bag 3, that is thus supported over the whole time necessary to further fill the bag. The customer can then insert other items inside bag 3 through hopper 8 until either there remain no more items to be packed or the uppermost level reached by such items in the bag has obscured photocell array 51. The customer presses then for the third time on the starting pushbuttons and makes the filling plate 38 further lower by a distance equal to the overall vertical dimensions of the opening device. By effect of such further lowering the uppermost level of the items in bag 3 is brought below the opening device. Bag 3 or can thus be laterally ejected without any hindrances at all after being released by pliers 52, 53 actuated by the motor reducer 60. However, in the event that, before this latest lowering of the bag, some items obscure the photocell arrays 51, these will block motor reducers 33, 50 and 60, preventing thus loading plate 38, pliers 52, 53 as well as ejector 44 from moving. The customer should then take the excess items out of the bag, re-press on the proper pushbutton and wait, if the photocells are no longer obscured, for motor reducer 33 to bring loading plate 38 again to the level of plate 43 and motor reducer 50 to actuate ejector 44 that laterally drives the filled bag (released by that time by pliers 52, 53) along the ejection plate 43 until making it reach the position of bag 3′ illustrated in Fig. 1. At this stage the customer may take hold of the filled bag 3′ by the handles and take it away. If the customer wishes to take away some more items, he will press once again on the starting pushbutton of the device, starting thus a new operating cycle thereof. The working of the bag dispensing devices, of the bag opening devices and of the filling devices is co-ordinated in a known manner by a microprocessor. By this reason no further detailed descriptions are necessary. Referring now to Figgs. 6 to 8, a preferred variation of the above described embodiment will be described. Such variation relates to a safety device consisting of a small gate 80 suitable to close the room above ejection plate 43 so as to leave it always free for the passage of ejector 44 and of the filled bag driven by the said ejector. Such gate prevents a filled bag - already ejected from ejector 44 - from backward tilting on the ejection plate 43, obstructing thus the passage of the subsequent filled bag. The gate is formed by two doors each consisting of a plurality of parallel horizontal comb-like pickets arranged along a post 81, 81′ that acts as door hinge. Ejector 44 too consists of a plurality of parallel horizontal spaced apart pickets exactly like those of which gate 80 consists. These pickets are mounted the one on top of the other along a vertical pin 82 occupying a room slightly inferior to the gap left between the two doors when they are side by side in closed position. Ejector 44 is mounted in such a way with respect to gate 80 that the pickets that make it up be at the same level as the gaps among the pickets making up the gate doors. By this arrangement, when the ejector in its reciprocating movement meets gate 80 in closed position, it is free to pass across it because pin 82 passes in the gap between the two gate doors and the pickets of ejector 44 pass among the pickets of the two doors. In Fig. 6 is shown ejector 44 as it pushes bag 3 - represented in broken lines as it is passing through the two doors of gate 80 opened by the bag itself - along plate 43. In Fig. 7 is shown ejector 44 as, while continually pushing bag 3, it has gone past gate 80, the doors of which have closed again by effect of two return springs (not shown for clarity of drawing) that act upon hinges 81, 81′ of said doors. Fig. 8 shows a subsequent operative step in which ejector 44 is coming back to its starting point after having freely crossed gate 80 in closed position. As it can be seen in the Figure, bag 3 cannot tilt backwards on plate 43 because it is hindered by gate 80, the doors of which can be opened only in the ejection direction of bag 3. The return springs keep gate 80 always in closed position, so as to prevent the customers from accidentally introducing their hands on the inside of the device during working thereof. The apparatus according to the present invention may be conveniently provided with a covering element that, though leaving the mouth of hopper 8 free and accessible, covers and protects the other parts of the apparatus. Thanks to its light structure, the apparatus according to the present invention can be easily shifted and placed in the most suitable areas of the supermarket or of other similar points of sale. To this end, the apparatus can be advantageously provided with wheels for shifting and brakes for stopping. Further additions and/or changes can be made by those skilled in the art to the embodiment hereinabove described and illustrated in the annexed drawings of the apparatus according to the present invention, remaining within the scope of the invention itself.

Claims: Apparatus for dispensing and opening plastic bags from a continuous strip (2) wound on a reel (1), comprising a bag dispensing device for unwinding the strip (2) and detaching a single bag (3) therefrom, as well as an opening device provided with mechanical pliers (52, 53) for opening the bag (3) and for keeping it firmly open for the whole time necessary to fill it with the purchases, characterized in that the bag dispensing device comprises a rubberized roller (6) actuated by a motor reducer (7) and in touch with the reel (1) for unwinding the continuous bag strip (2), and two pairs of facing belt units (15, 16 and 31, 32), sequentially arranged, for gripping between them the strip (2), of which the lower upstream, pair (15,16) is suitable to invert its direction of rotation upper, while the downstream pair standing still, (31, 32) holds the leading bag (3) of the strip (2), whereby detaching it therefrom. Apparatus according to claim 1, characterized in that the mechanical pliers (52, 53) of the bag opening device are horizontally movable apart under the action of a motor reducer (60) for firmly grasping and pulling apart the two opposite sides of bag (3) which are kept apart by two tiltable flaps (54, 55) actuated by an electromagnet (62) by means of a rocking lever (63), said opening device being located immediately below an hopper (8) through which the purchases are introduced into the bag (3). Apparatus according to claim 1 further comprising a loading device characterized in that the loading device consists of a vertically movable plate (38) for supporting the bag (3) during its filling, and an horizontally movable ejector (44) for ejecting the full bag from the apparatus. Apparatus according to claim 1, characterized in that the lower belt units (15, 16) of the bag dispensing device rotate about a pair of driving rollers (22, 23) and a pair of lower rollers (17, 18), a roller (17) of the lower pair being movable from the other roller (18) by means of a lever (19) having its fulcrum on an interposed roller (20). Apparatus according to claim 1, characterized in that the pair of upper belt units (31,32) rotates about a pair of upper rollers (29, 30) and a superposed pair of idle rollers (56, 57). Apparatus according to claim 4, characterized in that the pair of driving rollers (22, 23) is actuated by a motor reducer (27) and is linked to the pair of upper rollers (29, 30) by means of a chain (28) that engages two pinions (26, 26′) mounted on one roller (22, 29) of each pair, respectively. Apparatus according to claim 4, characterized in that between the lower roller pair (17, 18) and the driving roller pair (22, 23) there is mounted another interposed roller (21) around which the belts of the two lower units (15, 16) rotate, facing one another. Apparatus according to claim 4, characterized in that it comprises a photocell array (41,41′) for detecting the passage of the bottom of a bag (3) and making the direction of rotation of driving roller (22, 23) accordingly reverse. Apparatus according to claim 3, characterized in that the loading plate (38) is made by two half-plates separated by an aperture (39) intended for letting bag (3) freely pass therethrough in its ascending motion. Apparatus according to claim 3, characterized in that ejector (44) consists of a plurality of parallel horizontal pickets secured to a central pin (82) and in that at the extremity of the ejection plate (43) is mounted a small gate (80) formed by two small doors consisting of parallel horizontal pickets comb-like arranged on posts (81, 81′) and openable only in the direction of ejection of the full bags. Apparatus according to claim 2, characterized in that each one of the pliers (52, 53) consists of a component (83, 85) having a surface provided with rubberized blocks (87, 88) and of another component (84, 86) provided with a plurality of recesses intended for letting said rubberized blocks freely pass, the components of each pliers (52, 53) being pushed one against the other by a spring (89, 90). Apparatus according to claim 2, characterized in that the electromagnet (62) is linked to the flaps (54, 55) by means of a rocking lever (63) having one end linked by a small lever (75) to the hub (65) of flap (55) and the other end linked by a small lever (74) to the hub (64) of flap (54). Apparatus according to claim 3, characterized in that the ejector (44) is moved by a motor reducer (50) which is controlled by a photocell array (51) located below the feeding hopper (8) and stopped when the photocells are obscured.

Inventors: CAPPI ANGELO, RIMONDI RENATO, CAPPI, ANGELO, RIMONDI, RENATO
Applicants: AWAX PROGETTAZIONE, A.W.A.X. PROGETTAZIONE E RICERCA S.R.L.
Application year: 1990
Main classification: B65B43
IPC codes: B65B43, A47F9