Lug folding apparatus for a packaging device

Abstract: Disclosed herein is a lug folding apparatus for a packaging machine in which box-like item fed into pockets are circularly continuously conveyed, during which a packaging sheet is wound along the surface of each of said box-like items, the wound box-like items are transferred from the continuous circular conveyance to a linear conveyance, and extended ends of the packaging sheet protruded in square from both sides of the box-like item are folded along both sides thereof, said lug folding apparatus comprising a continuously rotating lug folding wheel (1) provided with a plurality of pockets (1f) into which are fed said wound box-like items at equal intervals in the outer periphery thereof, a low speed conveyor (2) which is partly in contact with a moving orbit of said pockets and moves in parallel at a speed lower than a horizontal moving speed of said pockets, and a horizontal conveying path opposite to said low speed conveyor, wherein the pockets are circularly moved while maintaining their horizontal state by the rotation of said lug folding wheel, said pockets being provided with space portions to which projections of the low speed conveyor and the conveying path are access, and projections in contact with the box-like items within the pockets to press and feed them toward openings of the pockets, said projection being projected toward the conveying path.

Description: BACKGROUND OF THE INVENTION The present invention relates to a lug folding apparatus for a packaging machine in which a packaging sheet such as cellophane, polypropylene, and so forth is applied to a box-like item, for example, such as cigarettes packaged by a package or paper. More specifically, the present invention relates to an apparatus in which box-like items fed into pockets are continuously conveyed in a circular fashion, during which continuous conveyance packaging sheets are applied along the surfaces of the box-like item, the continuous circular conveyance is changed to a linear conveyance of the box-like items, and extended ends of the packaging sheets protruded squarely from both ends of the box-like items are folded along the both ends thereof. Heretofore, the lug folding apparatus for a packaging machine of this kind is disclosed, for example, in Japanese Patent Laid-Open Publication No. Hei 2(1990)-85109, the apparatus disclosed comprises (a) a continuously rotating winding wheel provided in the outer periphery thereof with a plurality of pockets at equal intervals, (b) an intermittently rotating tray conveyor provided in the outer periphery thereof with a plurality of pockets at equal intervals (c) a chain conveyor which has access to a predetermined section in the outer periphery of the winding wheel and a predetermined section in the outer periphery of the tray conveyor and curved in the form of a recess, and which includes a plurality of pockets in the same spacing as the spacing of arrangement of the pockets of the winding wheel and the pockets of the tray conveyor, and (d) a linear conveyor disposed downstream of the tray conveyor. The box-like items within the pockets are circularly conveyed by the continuous rotation of the winding wheel, and packaging sheets are held so as to cover openings of the pockets during the circular conveyance, thereafter the pockets of the winding wheel are linearly opposed to the pockets of the continuously moving chain conveyor to deliver the box-like items from the pockets of the winding wheel to the pockets of the chain conveyor whereby the packaging sheets are wound along the surfaces of the box-like items into U-shape and at the same time one narrow flap at the extended end is folded, thereafter both ends of the U-shaped packaging sheets protruding from the pockets are folded along the outer surfaces of the box-like items and heat-bonded. The other narrow flap at the extended end is folded when the box-like items are delivered from the pockets of the chain conveyor to the pockets of the tray conveyor, and the box-like items are transferred from the pockets of the tray conveyor to the linear conveyor when said pockets stop, and both wide flaps are successively folded while being horizontally conveyed by the linear conveyor. However, in the conventional lug folding apparatus for a packaging machine as described above, the box-like items continuously conveyed by the pockets of the winding wheel and the pockets of the chain conveyor are transferred from the pockets of the intermittently rotating tray conveyor to the linear conveyor. This leads to a problem in that the operating speed of the tray conveyor cannot be increased, and as a result, the winding wheel and the chain conveyor cannot be operated at high speeds, and therefore the processing speed is so limited as not to increase the speed, failing to provide a large quantity of packages in a short period of time. Further, the narrow flap at the extended end is merely folded when the box-like item is forced into the pocket, and when the box-like item is extruded from this pocket, the flap once folded sometimes returns to the original unfold state. Particularly, in the case where packaging sheets are films such as cellophane, polypropylene and so forth, the flap is liable to return to the unfolded state, resulting in a defective folding. Thus, there occurs a problem in that many defective products are generated. In view of the above-described prior circumstances, it is an object of the present invention to transfer wound box-like items from a continous circular conveyance to a linear conveyance without stopping the box-like items. A further object of the present invention is to re-fold a narrow flap after being extruded from a pocket. SUMMARY OF THE INVENTION According to the invention there is provided a lug folding apparatus for a packaging machine in which box-like items fed into pockets are circularly continuously conveyed during which a packaging sheet is wound around each of said box-like items, the wound box-like items are transferred from the continuous circular conveyance to a linear conveyance, and extended ends of the packaging sheet protrude squarely from both ends of the box-like item, and are folded along both ends of said box-like item characterised in that said lug folding apparatus comprises a continuously rotating lug folding wheel provided with a plurality of pockets at equal intervals in the outer periphery thereof and into which are fed said wound box-like items, a low speed conveyor which cooperates with and moves in parallel with a moving orbit of said pockets at a speed lower than a horizontal moving speed of said pockets, a horizontal conveying path opposite to said low speed conveyor, wherein the pockets are circularly moved while maintaining a horizontal state by the rotation of said lug folding wheel, said pockets being provided with spaces in which projections of the low speed conveyor and the conveying path are received so that the projections contact with the box-like items when in the pockets to press and feed them out of the pockets, and into the conveying path. Preferably, folding pawls opposite to the narrow rear flaps at the extended ends of a preceding box-like item are projected on the pocket of the lug folding wheel, and on left and right sides of the conveying path, and folding guides opposite to the narrow front flaps at the extended end are fixedly arranged on the same plane as the left and right sides of a box-like item to be horizontally conveyed. According to the aforementioned technical means of the present invention, as the lug folding wheel continuously rotates, pockets into which box-like items are fed are circularly conveyed while maintaining their horizontal state, and the projections of the low speed conveyors are moved into register with the pockets to engage the box-like items whereby the box-like items are relatively pressed and fed toward the openings of the pockets due to a difference of a horizontal moving speed between the pockets and the low speed conveyor, and transferred to a horizontal conveying path. Then, the box-like items transferred to the conveying path are horizontally conveyed by the projections of the low speed conveyor whereby folding pawls of the faster moving succeeding pockets catch up, and the rear narrow flaps of the preceding box-like items being horizontally conveyed are folded. Thereafter, the narrow front flaps comes into contact with the folding guides to fold the front flaps, and the rear flaps are kept in the folded state. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a longitudinal sectional front view of a lug folding apparatus for a packaging machine showing an embodiment of the present invention; Fig. 2 is a partially enlarged longitudinal sectional side view taken along line (2) - (2) of Fig. 1; Fig. 3 is a partially enlarged cross-sectional plan view taken along line (3) - (3) of Fig. 1; Fig. 4 is a reduced longitudinal sectional front view showing the whole packaging machine; and Fig. 5 is a perspective view to an enlarged scale of a wound box-like item useful in explaining the invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS To facilitate an understanding of the present invention, which relates to the packaging of a box-like item, the box-like item faces are given reference signs as is the packaging sheet in which the box-like item is wrapped as repeated reference to these faces and the packaging sheet is made hereinafter. As the packaging sheet is folded around the ends of the box-like item and as the invention involves the movement of the box-like items from a lug folding wheel to and along a horizontal conveying path the arrangement of the box-like item faces in relation to the direction of conveying along said conveying path is also important and the following initial and introductory explanations is therefore given in relation to Fig. 5. The box-like item A, such as a box of cigarettes is packaged by a packaging sheet B. As the box-like item A travels on the horizontal conveying path, it travels in the direction of the arrow C and having regard to this direction of travel (the conveying path direction) the box-like item A has the following faces, a front face A1, a rear surface A2, upper and lower surfaces A3, A4, and end surfaces A5. The sheet B packages the box-like item A so that it has extended ends B1 and these ends have narrow rear flaps B2, narrow front flaps B3, wide upper flaps B4, and wide lower flaps B5, and said flaps B2, B3, B4 and B5 are folded onto the adjacent end A5 of the box-like item A to complete the packaging. Keeping the above introductory explanation in mind, an embodiment of the present invention will now be described hereinbelow with reference to the accompanying drawings. In this embodiment, as shown in Fig. 4, cigarettes wrapped in a package or paper as box-like items A are continuously supplied at predetermined intervals by a horizontal conveyor 11. These box-like items A are picked up one by one by a conveying wheel 12 to deliver them to pockets 13a of a winding wheel 13. The box-like items A are delivered from the pockets 13a of the winding wheel 13 to pockets 14c of an applying wheel 14 whereby thermoplastic transparent films such as cellophane, polypropylene and so forth as packaging sheets B are wound in the shape of U along the surfaces of the box-like items A. Thereafter, both ends B6 and B7 (Fig.5) of the packaging sheet B are body-folded along the surface of the box-like item A while being conveyed by the applying wheel 14 and heat-bonded, after which the box-like items A (in the condition shown in Fig. 7) are delivered from the pockets 14c to pockets 1f of a lug folding wheel 1. The lug folding wheel 1 is disposed parallel to the applying wheel 14 which will be described later, and a horizontal power shaft 1a is provided in the center thereof. This power shaft 1a is linked to a driving source for the applying wheel 14 whereby the lug folding wheel 1 is continuously rotated so that the peripheral speed thereof is substantially the same as that of the applying wheel 14. Referring to Fig. 4, this power shaft 1a is drivingly connected to the center of a disk 1b, and the power shaft 1a is rotatably inserted into a sun gear 1c₁ of a planetary gear mechanism 1c. The sun gear 1c₁ is fixed so that it does not rotate with the power shaft 1a. In the outer periphery of the disk 1b, twelve support shafts 1d are rotatably supported to equal intervals and in parallel with the power shaft 1a. A plurality of planetary gears 1c₂ meshed with the sun gear 1c₁ of the planetary gear mechanism 1c are rotatably mounted on disc 1d, and connection gears 1e meshed with the planetary gears 1c₂ are also rotatably mounted. The connection gears 1e and the support shafts 1d are linked by a belt 1e₁ (or the planetary gears 1c₂ and the support shafts 1d may be directly meshed), and pockets 1f are secured to the support shafts 1d. Accordingly, the power shaft 1a causes the lug folding wheel 1 to be rotated counterclockwise whereby the disk 1b rotates counterclockwise and the pockets 1f are rotated in the same direction through the support shafts 1d. At the same time, the planetary gears 1c₂ of the planetary gear mechanism 1c rotate about the sun gear 1c₁ and rotate counterclockwise. With this, the support shafts 1d rotate clockwise so that the relative positions of the twelve pockets 1f are maintained at a predetermined angle, more specifically in the horizontal state irrespective of the rotational position of the lug folding wheel 1. These pockets 1f are formed into box-shapes having substantially the same size as the external dimension of the box-like items A and the pocket upsteam sides are open. The pockets are laterally divided into two sections so that spaces 1f₁ are provided opposite to left and right central portions of the box-like items A. In the left and right side ends on the downstream side, folding pawls 1f₂ project forwardly toward the narrow rear flaps B2 and B2 of extended ends B1 and B2 of the packaging sheet B of the preceding box-like items A. Slits 1f₃ are formed in parallel through which the wide upper flaps B4, B4 and lower flaps B5, B5 of the extended ends B1, B1 are inserted. The low speed conveyor 2 is constructed as follows. A belt 2a is horizontally extended above the lug folding wheel 1. In the outer periphery of the belt 2a, projections 2b which come to lie opposite to the front surface A1 and the rear surface A2 of the box-like item A are positioned to register with the spaces 1f₁ of the pockets 1f. The moving orbit of the projections 2b is partly in register with the upper end of the moving orbit of the pockets 1f, and a driving source thereof is linked to a driving source of the lug folding wheel 1 whereby the projections 2b are continuously moved at a lower moving speed than a horizontal moving speed of the pockets 1f. Further, in the low speed conveyor 2, a spacing which is slightly longer than the width of the box-like item A in a horizontally conveying direction is formed so as to meet the timing at which the pockets 1f enter the moving orbit of the prjections 2b by the rotation of the lug forlding wheel 1. Draw off pushers 2c are provided to extrude the box-like items A inserted into the projections 2b toward the conveying path 3 which will be described later. The draw-off pushers 2c are disposed for vertical reciprocation and lie to the left and right sides of the upper surface A3 of the box-like item A inserted into the projections 2b, and the driving portion thereof may be linked to the driving source of the lug folding wheel 1 and the low speed conveyor 2 or may be linked to the high speed conveyor 5 (which will be described later) as shown whereby when the projections 2b having the box-like items A inserted therein and arrive at a predetermined position, the draw-off pushers 2c are moved downward to allow the box-like item A to take a horizontal attitude by downwardly extruding it. The conveying path 3 is horizontally laterally provided in register with the spaces 1f₁ of the pockets 1f and extends from the upper portion of the lug folding wheel 1 toward a high speed conveyor 5 and lies opposite and parallel to a straight line portion of the low speed conveyor 2 and a straight line portion of the high speed conveyor 5. A spacing shorter than the vertical dimension of the box-like item A is formed between the upper surface and the extreme end of the projections 2b of the low speed conveyor 2, and a through-hole 3a through which a push plate 6a of a conveyor 6 which will be described later is inserted is provided in the conveying path 3. On the left and right sides of the conveying path 3, folding guides 4, 4 opposite to narrow front flaps B3, B3 of extended ends B1, B1 wound on the box-like items a along the respective side edges are fixedly arranged on the same vertical surface as the left and right ends A5, A5 of the box-like items A within the pockets 1f, and the extreme ends of the folding guides 4, 4 are arranged in the proximity of the moving orbit of the folding pawls 1f₂ of the pockets 1f whereby when the projections 2b of the low speed conveyor 2 having the box-like items A inserted therein arrive at a predetermined position, the folding pawls 1f₂, 1f₂ are brought into contact with the rear flaps B2, B2 substantially simultaneously with the abutment of the extreme ends of the folding guides 4, 4 with the front flaps B3, B3. The high speed conveyor 5 is constructed as follows. A pair of left and right belts 5a, 5a are horizontally extended downstream of the low speed conveyor 2. In the outer periphery of the belts 5a, 5a, a plurality of pressing and feeding pawls 5b, 5b opposite to the rear surfaces A2 of the box-like items A are projected at equal intervals on the same vertical surfaces of the left and right sides of the box-like items A within the pockets 1f. The upstream end of the moving orbit of the pressing and feeding pawls 5b, 5b is partly superimposed on the downstream end of the moving orbit of the low speed conveyor 2, and the driving source thereof is linked to the driving source of the lug folding wheel 1 whereby the pressing and feeding pawls 5b, 5b are continuously moved at the moving speed equal to or higher than the horizontal moving speed of the pockets 1f of the lug folding wheel 1 in synchronism with the rotational speed of the lug folding wheel 1. Further, the high speed conveyor 5 is met to the timing at which the projections 2b are moved into the moving orbit of the pressing and feeding pawls 5b, 5b by the operation of the low speed conveyor 2 to move the pressing and feeding pawls 5b, 5b. At the downstream of the pressing and feeding pawls 5b, 5b, stop pawls 5c are projected, as needed, in a spaced relation of the same dimension as the width of the respective box-like item A in a horizontally conveying direction. Further, at the downstream of the high speed conveyor 5, a conveyor 6 having push plates 6a opposite to the rear surfaces A2 of the box-like items A stood upright at equal intervals is laterally provided below the through-hole 3a of the conveying path 3. Above the conveyor 6, folding up guides 7, 7 for folding up wide lower flaps B5, B5 and folding down guides 8, 8 for folding down wide upper flaps B4, B4 are fixedly arranged on the left and right sides of the conveying path 3. At the downstream of the folding up guides 7, 7 and the folding down guides 8, 8, seal heaters 9, 9 (Fig. 4) are disposed to deposit the extended ends B1, B1 of the packaging sheet B folded along the left and right ends A5, A5 of the box-like item A, and at the downstream thereof, an article removing device 10 is disposed to remove defective articels generated during the packaging process and specific box-like items A for quality control. The operation of the above described lug folding apparatus for a packaging machine will be described hereinbelow. First, the pockets 14c each having the box-like item A and the packaging sheet B fed therein as shown in Fig. 5 are circularly conveyed by the continuous rotation of the applying wheel 14. Thereafter, when the pocket 14c arrives at a point near the delivery position P2 to assume a straight line with the pocket 1f of the lug folding wheel 1, the pusher 14d is protruded, by a control cam, as shown in Fig. 1, and the box-like item A having been applied is extruded and delivered from the pocket 14c to the pocket 1f of the lug folding wheel 1. At the time, he narrow front flaps B3, B3 of the extended ends B1, B1 of the packaging sheet B protrude from the left and right ends A5, A5 of the box-like item A impinge on the open edge of the pocket 1f and are folded along the left and right ends A5, A5 of the box-like item A. The upper flaps B4, B4 and the lower flaps B5, B5 of the extended ends B1, B1 pass through the slits 1f₃ and protrude outwardly to left and right as shown in Figs. 2 and 3. Thereafter, the pockets 1f each having the box-like item A fed therein are circularly conveyed upwardly by the continuous rotation of the lug folding wheel 1. When the pocket 1f moves close to the low speed conveyor 2 into the moving orbit of the projections 2b, the left and right central portions of the box-like item A within the pocket 1 gradually move in between the projections 2b. The box-like items A are moved relatively retarded due to the difference between the horizontal moving speed of the pockets 1f and the horizontal moving speed of the projections 2b and are removed from the pockets 1f. In the case where the packaging sheet B is a film of cellophane, polypropylene or the like, as the box-like item A is removed from the pocket 1f of the lug folding wheel 1, the narrow front flaps B3, B3 of the extended ends B1, B1 may return to their unfolded state. If the thus removed box-like item A is put in between the projections 2b in the horizontal state, it falls on the conveying path 3 due to its own gravity. However, when the box-like item A is put in between the projections 2b in an inclined state, it is caught and does not fall. In this case, the box-like item A is changed to its horizontal state by the downward movement of the draw-off pusher 2c and falls on the conveying path 3. Thereafter, the box-like items A are horizontally conveyed at a speed lower than the horizontal moving speed of the pockets If along the conveying path 3 by the extreme ends of the projections 2b by the continuous operation of the low speed conveyor 2. The spacing between the preceding box-like item A and the box-like item A within the pocket 1f is gradually narrowed, and finally the succeeding pocket 1f catches up with the preceding box-like item A. The folding pawls 1f₂, 1f₂ impinge upon the narrow rear flaps B2, B2 of the extended ends B1, B1 of the preceding box-like items A, and the rear flaps B2, B2 are folded downstream along the left and right ends A5, A5 of the box-like items A. Substantially simultaneously therewith, the narrow front flaps B3, B3 of the extended ends B1, B1 of the box-like items A impinge upon the folding guides 4, 4, and the front flaps B3, B3 are again folded downstream along the left and right ends A5, A5 of the box-like items A to maintain the folded state. Immediately thereafter, the folding guides 4, 4 come into contact with the rear flaps B2, B2 after being folded by the folding pawls 1f₂, 1f₂ to maintain the folding state. Thereafter, the conveyance of the box-like items A is taken over from the projections 2b of the low speed conveyor 2 by the pressing and feeding pawls 5b, 5b of the high speed conveyor 5. The conveying speed is increased, and the pockets 1f circularly downwardly conveyed by the rotation of the lug folding wheel 1 are gradually moved away from the moving orbit of the projections 2b without coming into contact with the rear surfaces A2 of the box-like items A, and at the same time, the spacing between the preceding box-like items A and the succeeding box-like items A is spread. After the conveyance of the box-like items A has been taken over from the pressing and feeding pawls 5b, 5b of the high speed conveyor 5 by the pressing plates 6a of the conveyor 6, the wide lower flaps B3, B3 of the extended ends B1, B1 of the box-like items A are folded up by the folding up guides 7, 7. After this, the wide upper flaps B4, B4 are folded down by the folding down guides 8, 8. While in the illustrated embodiment, the cigarettes wrapped by a package or paper have been used as the box-like articles A, it is to be noted that the articles are not limited thereto but the box-like items A may be those other than the packaged cigarettes. Further, the high speed conveyor 5 has been disposed along the conveying path 3 downstream of the low speed conveyor 2 but other constructions may be employed if they operate similarly without being limited thereto. The present invention have the following effects. 1. As the lug folding wheel continuously rotates, the pockets having the box-like items fed therein are circularly conveyed while maintaining their horizontal state, and the projections of the low speed conveyor move into the pockets to engage the box-like items. Thereby, the box-like items are relatively pressed and fed toward the opening end of the pockets due to the difference in the horizontal moving speed between the pockets and the low speed conveyor and transferred to the horizontal conveying path. The wound box-like items are transferred from the continuous circular conveyance to the linear conveyance without being stopped. Accordingly, as compared to the conventional system in which the box-like items are transferred from the tray conveyor for intermittently rotating the box-like items continuously conveyed by the pockets of the winding wheel and the pockets of the chain conveyor to the linear conveyor, the lug folding wheel can be rotated at a high speed, and the low speed conveyor can be operated at a high speed, thus increasing the processing speed and making it possible to provide a large quantity of packages. 2. The box-like items transferred to the conveying path are horizontally conveyed by the projections of the low speed conveyor, whereby the folding pawls of the faster moving succeeding pocket catch up and the narrow rear flaps of the preceding box-like items are folded, after which the narrow front flaps come into contact with the folding guides to fold the front flaps and the folding state of the rear flaps is maintained. Thus, the narrow front flaps after the box-like item is removed from the pockets, may be re-folded. Accordingly, as compared to the conventional system in which the narrow flaps of the extended ends are merely folded when the box-like items are pushed into the pockets, and when being extruded from the pockets, the once folded flaps sometimes return to their original unfolded state, even if the packaging sheet is a film such as cellophane, polypropylene or the like, the narrow flaps are not returned to their original unfolded state after having been folded, defective folding is eliminated, and occurrence of defective goods can be prevented.

Claims: A lug folding apparatus for a packaging machine in which box-like items (A) fed into the pockets are circularly continuously conveyed, during which a packaging sheet (B) is wound around each of said box-like items (A), the wound box-like items are transferred from the continuous circular conveyance (1) to a linear conveyance (2,3), and extended ends (B1) of the packaging sheet (B) protrude squarely from both ends (A5) of the box-like item (A), and are folded along both ends of said box-like item A, characterised in that said lug folding apparatus comprises a continuously rotating lug folding wheel (1) provided with a plurality of pockets (1f) at equal intervals in the outer periphery thereof and into which are fed said wound box-like items (A), a low speed conveyor (2) which cooperates with and moves in parallel with a moving orbit of said pockets (1f) at a speed lower than a horizontal moving speed of said pockets, a horizontal conveying path (3) opposite to said low speed conveyor (2), wherein the pockets (1f) are circularly moved while maintaining a horizontal state by the rotation of said lug folding wheel (1), said pockets (1f) being provided with spaces in which projections (2b) of the low speed conveyor and the conveying path (3) are received, so that the projections (2b) contact with the box-like items (A) when in the pockets to press and feed them out of the pockets (1f), and into the conveying path (3). The lug folding apparatus for a packaging machine according to claim 1, characterised in that folding pawls (1f₂ opposite to narrow rear flaps (B2) of extended ends (B1) of preceding box-like items (A) are projected on the pockets (1f) of the lug folding wheel (1), and folding guides (4) opposite to the narrow front flaps (B3) of the extended ends (B1) on left and right sides of the conveying path (3) are fixedly arranged on the same plane as the left and right sides of the box-like items (A) to be horizontally conveyed. The lug folding apparatus for a packaging machine according to claim 2, characterised in that at the downstream of the folding guides , there are fixed folding up guides (7) for folding up the wide lower flaps (B5) of the extended ends (B1), and folding down guides (8) for folding down the wide upper flaps (B4). The lug folding apparatus for a packaging machine according to claim 1, 2 or 3, characterised in that at the downstream of the low speed conveyor (2), a high speed conveyor (5) is disposed along the conveying path (3).

Inventors: SHIGETA TOSHIO, SHIGETA, TOSHIO
Applicants: TOKYO AUTOMATIC MACH WORKS, TOKYO AUTOMATIC MACHINERY WORKS, LTD
Application year: 1993
Main classification: B65B11
IPC codes: B65B11