GB2190642A - Film wrapping machine - Google Patents

Abstract

A film wrapping machine for wrapping a film, e.g. heat-shrinkable film, around a container X comprising a rotary turntable assembly 10 having a plurality of peripheral container-receiving supports 31, 32 for transporting containers from one station to another, a film supply unit 212 for supplying film to a respective support, and a plurality of reciprocable and rotatable film retaining suction members 50, one for each respective support and being carried by the turntable assembly. During the rotation of the turntable assembly, the film retaining suction members are successively lifted to a raised operative position where they suction grip the leading end of the film and are then rotated around the respective support 31 to wind the film to tubular form about the containers. Each film retaining member has two spaced suction slots or rows of apertures, the leading slot or row being operative to grip the leading film end and the trailing slot or row being operative on rotation of the member to grip the trailing region of the wound film. The lapped ends of the wound film are then heat fused by a reciprocable head 170. Alternatively, the head may press adhesively united ends. In one modification, (Figures 6(a), 6(b)), elongate film support elements 61-64 are lifted with the member 50 and then spaced around the container on rotation of the member to provide container-embracing film-support legs about which the film is wound. In another modification (Figures 7-8), the spatula-shaped members 50 are replaced by tubular shaped members adapted to surround the respective containers. <IMAGE>

Description

SPECIFICATION Film wrapping machine Background of the invention (Field oftechnology) The present invention relates to a film wrapping machine forwrapping articles with films, particularly heat-shrinkable films.

The articles which the film wrapping machine according to the present invention can handle may be any type of container such as, for example, bottles, cans orcups of anyshape,forexample, either cylindrical or round. The films which thefilm wrapping machine according to the present invention utilizes may be a protective film for minimizing any possible scattering offragments of the container when the latter is broken orfor minimizing the unauthorized opening ofthe container by perons other than the purchaser, or a decorative film for aesthetic purpose or for presenting commercials associated with the contents in the container.

(Description ofthe prior art) It has been widely practised to wrap containers or the like with heat-shrinkable films forthe purpose of protection and/or decoration. It has also been practised to wrap the necks and the caps ofthe containers together with the heat-shrinkable films for the purpose of avoiding any possible accidental separation of the caps from the necks. Whatever the purpose is, the wrapping of a heat-shrinkable film cutfrom a roll offilm into a predetermined size is hitherto carried out by turning it around a container with its opposite ends overlapping with each other, then fusion-bonding the overlapping ends ofthefilm together to form a film tube surrounding the container, and subjecting the containerwiththefilm tube to a heat-treatment so that the film tube can shrunkto fitto the container.

Afilmwrapping machine capable of performing the above described wrapping method is disclosed in, for example, the United States Patent No.4,245,452, issued January 20, 1981,to the same assignee ofthe present invention, an essential portion ofwhich machine is reproduced in FigureS oftheaccompanying drawingsforthe purpthe purpose of discussion of the prior art.

Referring to Figure 9, reference numeral 300 represents a rotary turntable assembly adapted to be driven in one direction, shown by the arrow, about a support shaft 400 for transporting containers X successively from and back to an article supply station. Reference numeral 301 represents a plurality of article holders rigidly mounted on an outer peripheral portion ofthe rotary turntable assembly 300 in equally spaced relationship with respect to the circumferential direction ofthe rotary turntable assembly 300, each of said article holders 301 having a recess 302 defined therein for the receipt of the respective container X.Reference numeral 303 represents a pair of film wrapping arms carried by each article holder 301 for pivotal movement between opened and closed positions and operable to turn the film F generally around the respective container Xthen received in the recess 302 ofthe associated article holder 301. Reference numeral 304 represents a pair offollow-up arms movably carried by each article holdere 301 and operable to assistthe film wrapping in association with the respective film wrapping arms 303. Reference numeral 305 represents a film supporting spatula provided for each article holder 301 and adapted to be held in contact with the side wall ofthe respective container X.

Although not shown, the priorartfilmwrapping machine also comprises a cam mechanism so designed asto permitall ofthe pairs ofthefilm wrapping arms 303 and all of the pairs ofthe follow-up arms 304 to be successively moved between the opened and cloed positions during the rotation of the rotary turntable assembly 300 about the support shaft 400 past a particular processing station and also asto permit all ofthefilm supporting spatulas 305 to be moved up and down in synchronism with the movement ofthe respective pair ofthe film wrapping arms 303 between the opened and closed positions.

The prior artfilm wrapping machine of the above described construction opereate in the following manner, Assuming thatthe heat-shrinkablefilm Fis supplied into the empty recess 302 in the associated article holder 301 and the respective container Xis subsequently supplied onto such a recess 302 with thefilmFpositionedradiallyoutwardlyofthe container X, the associated film supporting spatula 305 is lowered from above to a position where it is brought into contact with the sidewall ofthe container X.Simultaneously therewith, the associated pair of the film wrapping arms 303 and the associated pair of the follow-up arms 304 are sequentially moved from the opened position towardstheclosed position to encompassthe containerXwherebythefilm Fpositioned inside the recess 302 and surrounding the containerX inthe article holder301 is turned around the containerwith its opposite ends overlapping with each other and also with the film supporting spatula 305. The overlapping ends of the film Fwhich are also overlapping the film supporting spatula 305 are then applied with an adhesive and are clamped together by a presser head pressing the overlapping ends of the film F against the film supporting spatula 305.In this way, thefilm Fcan becompletelywrapped around the containerwith the overlapping ends thereof bonded together, and thereafter, the container having the film tube is removed outofthe associated recess 302 in the article holder 301 forthe transportation to the next subsequent processing station located exteriorly of the rotaryturntable assembly 300.

It has subsequently been found that the prior art film wrapping machine ofthetype described above has a problem in that,whenthefilm wrapping arms 303 of each pair of pivoted to the closed position to encompass the respective container X with the film turned therearound, the opposite ends of the film F are often overlapped with each other in a manner displaced in a direction longitudinally ofthe container X and/or slackened. Also, the necessity of each ofthe film supporting spatulas 305 to be moved up and down in association with the movement of the associated film wrapping arms brings about another problem in that not only is the film wrapping machine rendered to be complicated in structure, but also a high speed film wrapping capability is hampered.

Summary ofthe invention Accordingly, the present invention has been developed with a view to substantially eliminating the above discussed problems inherent in the prior art film wrapping machine and has for its essential objectto provide an improved film wrapping machiane which is effective to automatically wrap the films successively around the articles with no possibility ofthe overlapping ends of each film being displaced.

Another important object of the present invention is to provide an improved film wrapping machine of the type referred to above, which is reliable in operation and capable of handling the articles at high speed for wrapping the films around the articles.

Afurtherobjectofthe present invention isto provide an improved film wrapping machine of the type referred to above, which can handlethe articles of any shape if they can supportthemselves on, for example, a surface.

In orderto accomplish these objects of the present invention, a film wrapping machine for successively turning films around articles so asto form a film tube encircling each article according to a preferred embodiment of the present invention comprises a rotary turntable assembly supported for rotation in one direction about a support shaft and movable from and back to an article supply station pasta film supply station and an article delivery station during one complete rotation thereof, all of said stations being disposed in the vicinity ofthe periphery ofthe rotaryturntableassembly;; a plurality of article supports provided in the rotary turntable assembly at a peripheral portion thereof for rotation together with said rotary turntable assembly aboutthe support shaft and spaced an equal distance from each other in a direction circumferentially ofthe rotaryturntable assembly, each of said article support being operable to carry the respective article fortransporting from the article supply station towards the article delivery station; an article supply unit disposed atthe article supply station for supplying the articles successively onto the respective article supports in the rotaryturntable assembly as the rotary turntable assembly during the rotation thereof arrives atthe article supply station; and a film retaining member provided for each article support and supported in the vicinity of the respective article support for rotation about an axis parallel to the support shaft between inoperative and operative positions and also for movement in a direction parallel to the support shaft between raised and lowered positions.

The film retaining member has suction openings defined therein in at least two leading and trailing rows, the leading and trailing rows of the suction openings being spaced a predetermined distance from each other in a direction conforming to the direction of rotation of the film retaining member.

The leading row ofthe suction openings is adapted to retain a leading end of the associated film by the effect of a suction force whereas thetrailing row of the suction openings is adapted to retain a trailing end of such associated film by the effect of a suction force. The film retaining member is rotated about the associated article on the article support from the inoperative position towards the operative position only when and after it has been moved from the lowered position towards the raised position.

Thefilmwrapping machine also comprises a film supply unit disposed at the film supply station for supplying the film onto the respectice film retaining member each time the rotary turntable assembly is broughttothefilm supply station, said film retaining member being moved from the lowered position to the raised position upon the arrival ofthe rotary turntable assembly atthe film supply station such thatthe leading end ofthefilm can be sucked bythe leading row of the suction openings by the effect of the suction force, the film with its leading end sucked by the leading row ofthe suction openings being exteriorlyturned around the associated article as the film retaining member is rotated from the inoperative position towards the operative position, said film being completely turned around the associated article with a portion ofthefilm adjacent the trailing end sucked by the trailing row of the suction openings permitting the trailing end to overlap the leading end; a heater unit provided for each article support and carried by the rotary turntable assemblyfor movement between projected and retracted positions in a direction close towards and away from the associated article on the article support, said respective heater unit being moved from the retracted position to the projected position in unison with the movement of the associated film retaining memberfromthe inoperative position to the operative position, said heater unit when moved to the projected position being pressed against the associated film retaining memberwith the overlapping ends ofthefilm around the article consequently fusion-bonded together to complete a film tube; and an article delivery unit disposed at the article delivery station for removing the articles with the respective film tube successively out from the associated article supports as the rotary turntable assembly during its continued rotation is brought to the article delivery station.

Preferably, the film retaining member comprises a film retaining spatula having a hollow defined therein and adapted to be communicated with a source of vacuum, and said leading and trailing rows ofthe suction openings being defined in communication with the hollow on one surface of the film retaining spatularfacing in a direction opposite to the associated article.

Preferably, the film retaining spatula comprises a pair of generally strip-like plates connected together in face-to-face relationship with each other, one of said plates having at least one recess defined therein whilethe otherofthe plates having the rows of the suction openings defined therein, said recess forming the hollow when the plates are connected together.

With the film wrapping machine so constructed, when the rotarytu rntable assembly being rotated arrives at a film supply station, the film retaining member is moved from the lowered position to the raised position in readiness for the receipt of the respectivefiml from the film supply unit. Atthistime, the leading row of the suction openings in thefilm retaining member is aligned with the leading end of the film and then picks upthe leading end ofthefilm by the effect of the suction force, removing thefllm from thefilm supply unit asthefilm retaining member in the raised position is rotated from the inoperative position towards the operative position.

The film so removed from thefilm supply unit is, during the continued rotation of the film retaining member towards the operative position, turned around the associated article until that portion ofthe film adjacent the trailing end thereof is sucked onto the trailing row of the suction openings in thefilm retaining member.

When that portion of the film adjacent the trailing end is thus sucked onto the trailing row ofthe suction openings in thefilm retaining memberwhichhas completed a substantially 360" rotation on the way towards the operative position, the trailing end ofthe film overlaps the leading end thereofwhilethe remaining portion ofthefilm encircles the respective article.Theoverlapping endsofthefilm are, during the continued rotation of the rotaryturntable assembly from the film supply station towards the article delivery station and afterthe film retaining member has been rotated to the operative position, fusion-bonded orwelded together to complete the film tube surrounding the article.

According to another preferred embodiment ofthe present invention, the film wrapping machine of the construction described above is further provided with a plurality offoldable erecting memberforeach film retaining member and similar in shape to the associated film retaining member. The foldable erecting members for each film retaining member are supported for movement together with the associated film retaining member, butare held in a folded condition when the associated film retaining member is in the lowered position and also in the inoperative position.These foldable erecting members are unfolded as the associated film retaining member is moved from the inoperative position towards the operative position about the associated article, said foldable erecting member when unfolded being spaced a distance from each other in a direction circumferentially ofthe associated article to support the fil m turned exteriorly around the associated article.

Thefilmwrapping machine according tothe second preferred embodiment of the present invention functions substantially in a manner identical with that according to the first preferred embodiment thereof. However, the additional use of thefoldabel erecting members brings about such an effect that, even if each article is of a design comprising, for example, a radially outwardly swelling body and a slender neck of progressively decreasing outer diameter continued from the swelling body, the film turned therearound can be supported by the unfolded and, therefore, circumferentially equally spaced erecting members without being slackened due to its flexibility, permitting the film to represent a generally cylindrical shape with the article positioned inside the film.This is possible because the foldable erecting members are unfolded to assume respective positions spaced a generally equal distance circumferentially around the article asthefilm retaining memberundergoesa substantially 360 rotation from the inoperative position towards the operative position.

According to a third preferred embodiment of the present invention, instead of the film retaining member, the use is made ofafilm retaining barrel.

The film retaining barrel is provided for each article supportandsupported in the vicinity ofthe respective article support for rotation about an axis parallel to the support shaft between inoperative and operative positions and also for movement in a direction parallel to the support shaft between raised and lowered positions. As in the case with the film retaining member, the film retaining barrel has suction openings defined therein in at leasttwo leading and trailing rows, the leading and trailing rows of the suction opening being spaced a predetermined distance from each other in a circumferential direction thereof.The leading row of the suction openings is adapted to retain a leading end of the associated film by the effect of a suction force whereas thetrailing row ofthe suction openings is adapted to retain a trailing end of such associated film by the effect of a suction force. The film retaining barrel of the above construction is rotatable about the associated article on the article support from the inoperative position towards the operative position only when and after it has been moved from the lowered position towards the raied position.

In the machine according to the third embodiment ofthepresentinvention,thefilm isturnedaround each article with the film retaining barrel positioned between the article and the film. However, after the overlapping ends ofthe film have been fusion-bonded orweldedtogether,thefilm retaining barrel is withdrawn from the raised position towards the lowered position, leaving the complete film tube in the form as surrounding the article.

In anyevent,the provision oftheuniquefilm retaining memberorthe unique film retaining barrel according to the present invention has made it possibleto form the film tube around the respective article with no possibility ofthe overlapping ends of thefilm displaced in a direction longitudinallyofthe article such as occurring in the priorartfilm wrapping machine.Should the overlapping ends of thefilm are bonded togetherwhile displaced, and when thefilm tube so formed, that is,thefilm with its overlapping ends welded together, is subsequently heat-shrunken to fit the shape of the respective article, not only does the resultant article completely wrapped with the film fail to provide an aesthetic beauty, but also a subsequent trimming process station would be required to cut a portion of each side edge of the film adjacent one ofthe opposite ends which is displaced outwardly from that of the other of the opposite ends of the same film.

Also, the use of the foldable erecting members such as in the machine according to the second preferred embodiment of the present invention is advantageous in thatthe film being turned, or turned, around the respective article can be supported with no possibility of being slackened.

Therefore, where each article to be handled by the machine according to the present invention is, for example, a container made of magnetizeable metallic material or synthetic resin, and in the event that electrostatic attractions tends to occur between the container and the film being turned orturned,the film being turned orturned can be so keptbythe foldable erecting members that the subsequentlu formed film tube can assumeagenerallycylindrical shape.

It is to be noted that the film retaining barrel used in the machine according to the third preferred embodiment ofthe present invention has a dual function, that is, a combination of the function accomplished bythefilm retaining memberandthat accomplished by the foldable erecting members.

Brief description ofthe drawings The present invention will become more clearly understood from thefollowing description of preferred embodiments, when taken in conjunction with the accompanying drawings. However, the embodiments and the drawings are given forthe purposes of illustration and explanation only, and are not to betaken as being limitative ofthe present invention in any way whatsoever, whose scope is to be determined solely bythe appended claims.Inthe drawings, like reference numerals denote like part in the several, and: Figure lisa schematic top plan view of a film wrapping machine according to a first preferred embodiment of the present invention; Figure 2 is a longitudinal sectional viewed a portion of the film wrapping machine shown in Figure 1; Figure 3 is an exploded view of one ofthe film retaining spatulas used in the film wrapping machine shown in Figure 1; Figure 4(a) is a schematic top plan view, with a portion shown in section, showing the sequence in which each film is turned around the respective container during the rotation of a rotary turntable assembly used in the film wrapping machine of Figure 1;; Figure 4(b) is a schematic side view showing the sequence of fil m wrapp. ng in timed relationship with that shown in Figure 4(a); Figure 5is a schematic side view showing an example in which the film turned around the respective container is heat-treated to permit the film to be heat-shrunken; Figures 6(a) and 6(b) are views similar to Figures 4(a) and 4(b), respectively, showing the operation of the film wrapping machine according to a second preferred embodiment of the present invention;; Figures 7(a) and 7{b) are views similarto Figures 4(a) and 4(b), respectively, showing the operation of thefilmwrapping machineaccordingtoathird preferred embodiment ofthe present invention; Figure 8 is a perspective view of a film retaining barrel used in the machine according to thethird embodiment ofthe present invention; and Figure 9 is a schematicfragmental top plan view of the prior artfilm wrapping machine.

Decription ofthe preferred embodiments Afilm wrapping machine, i.e., a machinefor automatically wrapping articles, for example, cylindrical containers X, successively with respective films, according to a first preferred embodiment ofthe present invention will now be described with referenceto Figures 1 to 4.Thefilm wrapping machine shown therein comprises a rotary turntable assembly 10 for the transportation of the cylindrical containers X to be wrapped, which rotary turntable assembly 10 is, during one complete rotation thereof in a manner as will be described later, movable from and back to an article receiving station past a plurality of processing stations including an article delivery station, all ofthese stations being defined in thevicinity of and radilly outwardly of the turntable assembly 10.

The rotary turntable assembly 10 comprises an uprightsupportshaft 11 rotatably mounted on any suitablesupportsurface,forexample,a machine base, an upper, an intermediate and a lower circular turntables 12,13 and 14 rigidly mounted on the support shaft 11 for rotation in a horizontal plane togethertherewith and spaced a distance from each other in a direction axially ofthe support shaft 11.

Whilethesupportshaft 11 may be supported in any manner,for example, by means of one or more machineframes,thesupportshaft 11 sofarshown has a lower end rotatably received in a bearing box through,forexample, roller bearings 16. The intermediateturntable 13 has its outer peripheral portion formed with a plurality of, for example, six, circular cutouts 17 equally spaced from each other in a direction circumferentially of the turntable 13.

The film wrapping machine also comprises article support equal in a numbertothe number of the circular cutouts 17 in the intermediateturntable 13 and generally identified by 30. All of the article supports 30 are of identical construction, and each article support 30 comprises an article receiving block 31 rigidly secured at its opposite ends to the upper and lowerturntables 12 and 13, and a rotatable mount 32 for the support of the respective cylindrical container X.

The rotatable mount32 of each article support 30 is rotatably received in the respective circular cutout 17 in the intermediateturntable 13through any suitable bearing 34for rotation in a plane perpendicular to, and about an axis parallel to, the support shaft 11.

For the pu rpose as wil I become clear from the subsequent description, each rotatable mount 32 has a generally arcuate opening 35 extending completely across the thickness thereof, said arcuate opening 35 providing a respective passage through which an associated film retaining spatula 50 can move in a direction parallel to the supportshaft 11.

Each ofthe article receiving block 31 has a surface area facing outwardly of the intermediate turntable 13, which surface area is recessed radially inwardly oftheintermediateturntable 13 so as to define a generally U-shaped space36which opens radially outwardly ofthe intermediate turntable 13 and which is so curved as to follow the curvature ofthe cross-sectional contour of each cylindrical container Xto be handled bythe machine so that, when the cylindrical containerX is placed on the associated rotatable mount 32 as will be described later, the outer peripheral wall of the cylindrical container Xso mounted can be partially received in the generally U-shaped space 36 delimited by the radially inwardly recessed surface area.Also, each article receiving block 32 is formed with a vertically extending slot 37 of predetermined width opening across the wall of the respective article receiving block 32 in a direction radiallyofthe intermediate turntable 13frdefining a radial path forthe passage thereth rough of a respective presser head 171 which will be described later, it being, however, to be noted that each presser head 171 is movable between a radially inwardly retracted position, at which the head 171 is retracted out of the associated slot 37, and a projected position at which the head 171 is brought into contact with the film retaining spatula 50.

As best shown in Figure 3, each retaining spatula 50 comprises a generally rectangular outer plate 53 having a plurality of, for example, two, rows of suction perforations 51 and 52 defined therein in a direction lengthwise thereof and an inner plate 55 similar in shape to the outer plate 53 and having a surface area adjacent the outer plate 53 formed with a generally U-shaped recess 54. The outer and inner plates 53 and 55 are generally arcuately curved about an axis parallel to the lengthwise direction thereof so as to follow the curvature of the cross-sectional contourofthecylindrical containerXandare connected together in face-to-face relationship with each other by means of a plurality of set screws (not shown) passed through screw holes 56 in the outer plate 53 and then threaded firmlyto the inner plate 55.In this assebled condition, portions ofthe U-shaped recess 54 which correspond in position to the arms ofthe shape ofthefigure "U" assumed by such recess 54 are aligned with the respective rows ofthesuction perforations 51 and 52. Forthe purpose which will become clearfrom the subsequent description, the U-shaped recess 54 in the retainer spatula 50 is fl uid-con nected with a source of vacuum through any suitable tubing by way of a valving mechanism operable to selectively interrupt and initiate the supply of a vacuum to the retainer spatula 50.

It is to be noted that, instead ofthe use ofthe rows of the suction perforations 51 and 52, at least one slit may be employed for each of that portions ofthe recess 54 which correspond in position to the arms ofthe shape of the figure " U " assumed by the recess 54.

The film retaining spatula 50 is rigidly mounted on a hollow shaft 70 having a center hollow 71 defined therein in an axial directin thereof, said center hollow 71 forming a suction passage through which the U-shaped recess 54 is communicated with the vacuum source (not shown). More specifically, the retaining spatula 50 has a perforation 57 defined in the inner plate 55 thereof in communication with the U-shaped recess 54, and is secured at a lower end thereof to a coupling member 72 having a connecting passage 73 defined therein with the perforation 57 communicated with one end ofthe connecting passage 73.The coupling member72 is in turn mounted rigidly on an upper end ofthe hollow shaft 70 with the opposite end ofthe connecting passage 73 held in communication with the center hollow71. In securing the film retaining spatula 50 to the coupling member72, two set screws are passed through screw holes 58, defined in the outer and inner plates 53 and 55 as bestshown in Figure 3, and then firmlythreaded to the coupling member 72.

The hollow shaft 70 foreach rotatable mount 32for the support of the respective cylindrical container X is supported for rotation about its own longitudinal axis and also for movement between raised and lowered positions in a direction axially thereof. For this purpose, a tubular guide assembly 90 is provided, which comprises an outer barrel 91 rigidly mounted on the lowercircularturntable 14soasto extend completely through the thickness of the lowerturntable 14 in alignment with the respective circular cutout 17 in the intermediate turntable 13, and an innner barrel 93 coaxially received within the outer barrel 91 for rotation relative to the outer barrel 91 and retained in position within the outer barrel 91 by a plurality of bearings 92.The hollow shaft 70 slidably extend through the inner barrel 93 for axial movement relative to the inner barrel 93, but is rotatably together with the inner barrel 93 because the hollow shaft 70 has its outer peripheral surface formed with at least one axially splined groove in which a corresponding key 94 rigid with the inner barrel 93 is engaged. Connection ofthe lower end of the hollow shaft 70 with the vacuum source (not shown) is carried out by means of a flexible tubing 74 having one end fluid-connected to the lower end of the hollowshaft70 by means of a rotary coupler75 of any known construction so designed asto permitthe rotation of the hollow shaft 70 relative to the rotary coupler75 while maintaining a fluid connection therebetween.

For moving each hollow shaft 70 up and down between the raised and lowered positions forthe purpose which will be described later, a cam barrel 100 is rigidly mounted on the support surface in coaxial relationship with the support shaft 11, the top ofwhich is formed into a cam surface 101 of a predetermined profile required to move the hollow shaft 70 up and down during the rotation ofthe turntable assembly 10 as will be described later. A carrier block 103 for each hollow shaft 70 is mounted on the lower end of the respective hollow shaft 70 for movement together with the hollow shaft 70 in an axial direction of the hollow shaft 70, but for rotation relative thereto by means of one or more bearings 105, and carries a roller 102 rotatably mounted thereon by means of a horizontally extending shaft 104.The roller 102 so supported by the carrier block 103 rests on the cam surface 101 and can roll thereover as the turntable assembly 10 rotates. The carrier block 103 has a vertically extending guide hole 106 through which a depending guide rod 107 having one end rigidly secured to the lowerturntable l4extendsslidablysothatthe up-and-down movement of the carrier block 103 and, hence, the hollowshaft71 resulting from the rolling ofthe roller 103 on the profiled cam surface 100 incident to the rotation oftheturntable assembly 10 can be advantageously stabilized.

Aturntable drive mechanism for driving the turntable assembly 10 about the support shaft 11 comprises an externally toothed ring gear 120 having its outer periphery, formed with gear teeth, and coaxially secured to the outer periphery ofthe lowerturntable 14so as to permitthe toothed outer peripherythereofto partially protrude radially outwardly therefrom. The turntable drive mechanism also comprises a drive gear 121 positioned radially outwardly of and in the vicinity of the lowerturntable 14 and constantly meshed with the externally toothed ring gear 120, said drive gear 121 being drivingly coupled with an electric motor (not shown) byway of any suitable drive transmission system including a reduction gear unit (also not shown).Accordingly, itwill readily be seen that during,the rotation ofthe drive gear 121 driven bythe electric motor, a drive is transmitted to the lowerturntable 14and, hence, the turntable assembly 10 as a whole and, therefore, theturntable assembly 10 is rotated about the support shaft 11.

Each hollow shaft 70 can be rotated togetherwith the inner barrel 93 of the tubular guide assembly 90 bya drive transmitting shaft 130 rotatablyextending through the intermediateturntable 13 in a direction perpendicularthereto and having upper and lower end portions thereofjournalled to the upper and lowerturntables 12 and 14, respectively, by means of associated bearings 131 and 132, it being, however, that the lower end of the drive tramsmiting shaft 130 protrudes fu rther downwards from the lower turntable 14 and is provided with a sector gear 133 rigidly secured thereto for swinging motion in a plane perpendicularto the drive transmitting shaft 130.The sector gear 133 is in turn drivinglyengaged wth a pinion gear94 integrally formed with, or otherwise rigidly mounted on, a lower end ofthe inner barrel 93 which extends outwardly from the outer barrel 91 in a direction downwards as viewed in Figure2.

The drive transmitting shaft 130 is adapted to be driven about its own longitudinal axis by a suitable drive mechanism (not shown) in opposite directions one at a time in synchronism with the rotation ofthe turntable assembly 10 about the support shaft 11 so thatthe hollow shaft 70 can be rotated in opposite directions one at a time about its own longitudinal axis together with the inner barrel 93 of the tubular guide assembly 90.The rotation ofthe hollow shaft 70 effected in the manner as hereinabove described brings about a revolution ofthe film retaining spatula 50, rigidly mounted on the upper end ofthe hollowshaft70throughthecoupling member72as hereinbefore described, between an inoperative position, at which the film retaining spatula 50 is positioned on one side ofthe containerX on the rotary mount 32 remote from and generally 1 80" spaced from the slot 37 in the associated article receiving block 31 as shown in Figure 2, and an operative position at which the same retaining spatula 50 is positioned in front of the slot 37.

Specifically, when the hollow shaft 70 is rotated about its own longitudinal axis in one of the opposite directions,forexample,in afirstdirection,the spatula 50 is moved about the longitudinal axis of the cylindrical containerX, placed on the rotary mount 32, from the inoperative position towards the operative position in a counterclockwise direction as viewed in Figure 1, but when the hollow shaft 70 is rotated in the other of the opposite direction, say, in a second direction, the spatula 50 i moved about the longitudinal axisofthesamecontainerXonthe rotary mount 32 from the operative position towards the inoperative position in a clockwise direction as viewed in Figure 1.

Positioned above the upperturntable 12 for each rotary mount 32 is a spatula 150 which comprises a shaft 151 extending through a hole 18, defined in the upperturntable 12, in a direction perpendicular thereto and supported thereby for rotation about its own longitudinal axisthrough a bearing 155, and a disc 152 rigidly secured to a lower end of the shaft 151 for rotation together therewith. The disc 152 has its peripheral portion recessed radially inwardly thereof to define a holder recess 154 for receiving therein an upper end ofthefilm retaining spatula 50 when the hollow shaft70 is upwardly shifted from the lowered position to the raised position as will be described later.An upper end of the shaft 151 has a pinion gear 153 rigidly mounted thereon, which pinion gear 153 is constantly meshed with a sector gear 134that is rigidly mounted on an upper end of the drive transmitting shaft 130 and positioned above the upperturntable 12. Accordingly, it is clear that the spatula holder 150 can be rotated about the associated shaft 151 in synchronism with the rotation of the drive transmitting shaft 130 atthe sametime as the hollow shaft 70 is rotated about its own longitudinal axis.

As hereinbefore described, the rotaryturntable asembly 10 is rotatable about the support shaft 11 from the article receiving station back to article receiving station past the intermediate processing stations including the article delivery station and a film wrapping station. At the film wrapping station, a generally rectangular film F is turned around each cylindrical containerX with its opposite end held in overlapping relationship with each other.These overlapping ends ofthe respective film F is retained in overlapping relationship by the film retaining spatula 50, in a manner as will be described later, and are subsequently fusion-bonded together when the film retaining spatula 50 is revolved from the inoperative position to the operative position as a result ofthe rotation of the hollow shaft 70 effected by the rotation of the drive transmitting shaft 130. For fusion-bonding the opposite ends ofthe generally rectangularfilm Fturned around the cylindrical containerX in cooperation with the film retaining spatula 50, a heater unit generally identified by 170 is employed for each rotary mount 32.

The heating unit 170 includes, in addition to the presser head 171 referred to herein before in connection with the article receiving block 31, a heater 172 built in the presser head 171 to heatthe latter two a temperature generally requiredforthefilm Fto be fused. The heater unit 170 is supported for movement between the retracted and projected positions in a direction radially of the rotary turntable assembly 10 by means of upper and lower link mechanisms each comprising a pairofupperor lower links 178 and 179 which extend parallel to each other.While shafts 173 and 174 spaced a distance from each other in a direction perpendicularto the support shaft 11 slightly extend through the heater unit 170 with their respective opposite ends protruding upwardly and downwardly therefrom, the upper and lower links 178 are rotatably connected at one end with the opposite ends ofthe shaft 173 and at the other end with the drive transmitting shaft 130.Similarly, the upper and lower links 179 are rotatablyconnected at one end with the opposite ends ofthe shaft 174 and at the other end with a rotary shaft 175 having its opposite ends journalled respectively to the upper and intermediate turntables 12 and 13 by means of associated bearings 176 and 177, it being, however, to be noted that onlythe upper end ofthe rotaryshaft 175 extends through the associated bearing 176, carried bythe upperturntable 12, so as to terminate above the upperturntable 12. As a matter ofdesign, the rotary shaft 175 is spaced from the drive transmitting shaft 130 a distance equal to the distance between the shafts 173 and 174.

Atriggerleverl80foreach rotary shaft 175 is rigidly mounted on the upper end ofthe respective rotary shaft 175 for rotation togethertherewith so as to extend therefrom in a direction perpendicularto the longitudinal axis of the rotary shaft 175. The free end ofthetrigger lever 180 carries a trigger pin 181 loosely inserted therein, which trigger pin 181 is engageable with a drive mechanism (notshown)so designed asto reciprocately rotate the trigger pin 181 through a predetermined angle.Thus, it will readily be seen that, when the trigger pin 181 is rotated bythe drive mechanism (notshown) in one direction through the predetermined angle, the rotary shaft 175 is rotated so asto cause the heater unit 170 to move from the retracted position towards the projected position in synchronism with the revolution of the film retaining spatula 50 from the inoperative position towards the operative position, but when the trigger pin 181 is rotated by the same drive mechanism (not shown) in the opposite direction through a predetermined angle, the rotary shaft 157 is rotated so as to cause the heater unit 170 to move from the projected position towards the retracted position in synchronsim with the revolution of the film retaining spatula 50 from the operative position back towards the inoperative position.

It is to be noted that, although in theforegoing example each ofthe heater units 170 employed one for each rotary mount 32 has been described and shown as carried by the rotaryturntable assembly 10, it may be positioned laterally outwardly of an in the vicinity ofthe outer perimeter of the rotary turntable assembly 10.

As best shown in Figure 1, at the article receiving station, an article feeding mechanism is arranged which comprises an article feeder 200 through which cylindrical containers X are successively supplied towards the article receiving station, and a sprocket wheel 201 interposed between one end ofthe article feeder 200 adjacent the rotary turntable assembly 10 and the rotary turntable assembly 10 for feeding the cylindrical containersXone byoneontothe respective article support 30.For this purpose, the sprocket wheel 201 is rotatably mounted on a stationaryshaft 201 so asto lie and partially protrude into the space between the upper and intermediate turntables 12 and 13 and has its peripheral portion formed with a plurality of recesses 203 spaced an equal distance from each other in a direction circumferential ly thereof.As can readily be understood by those skilled in the art, the sprocket wheel 201 is rotated about the shaft 202 at a peripheral velocity substantially equal to the peripheral velocity ofthe rotary turntable assembly 10 so thatthe cylindrical containers S being fed along the articlefeeder200 can be delivered bythe sprocket wheel 203 one by one onto the respective article supports 30, particularly the respective rotary mounts 32.

The article receiving station is followed byafilm supply station at which a film supply unit is disposed for supplying each film F onto the respective cylindrical container X mounted on the associated rotary mount 32 and being transported by the rotary turntable assembly 10 towards the article delivery station. The film supply unit comprises a film supply roll 210 rotatably mounted on a shaft 211 supported bythe machine e base o r m ach i or machineframeworkanda film feeder 212 operatively interposed between the film supply roll 210 and the rotary turntable assembly 10.Thefilm feeder 212 includes a pairof spaced support rolls 213 and 214 and a generally endless film feed belt 215 drivinglytrained between these support rolls 213 and 214, said film feed belt 215 being so designed asto retainthefilm F under suction on an outer surface of that operative run of the film feed belt 215 which confronts the the rotary turntable assembly 10. One ofthe support rolls 213 and 214 is operatively coupled with an electric motor (not shown) through a suitable reduction gear unit (also notshown) so thatthefilmfeed be1t215 can be driven in a direction perpendicularto the support shaft 11 with the operative run thereon running in a direction conforming to the direction of rotation of the rotaryturntable assembly 10.

The film supply unit of the construction described above is so designed that the film F supplied from the film supply roll 210 is, during the movement of the film feed belt 215, sucked onto the operative run ofthefilmfeed belt215 and is then, while retained on the operative run of the film feed belt 215 by the effect of a partial vacuum,transported by the film feed belt 215 towards one ofthe cylindrical containersXwhich is broughttothefilm supply station so that the film Fcan be turned around such one ofthe containers.As a matter of design, the film feed belt 215 is driven at a velocity equal to the peripheral velocity of the rotary turntable assembly 10 so thatthe film F and the associated cylindrical container X can be broughtto thefilm supply station in synchronism with each otherforthe reason which will become clear from the subsequent description.

At the article delivery station, there is disposed an article take-out unit substantially identical in construction with the article feeder unit. More specifically, the article take-out unit comprises a delivery sprocket wheel 230 identical with the feed sprocket wheel 201 and rotatably mounted on a shaft 231, supported bythemachinebaseorframework, and having a plurality of article receiving recesses 232, and a guide chute 233 identical in construction with the article feeder 200. As can readily be understood by those skilled in the art, the article take-outunitoperates in a manner generally reverse to the article feeder unit.In other words, during the rotation of the deiivery sprocket wheel 230 with the article receiving recesses 232 successively brought in alignment with the respective cylindrical articles X being successively broughtto the article delivery station as a result of the rotation of the rotary turntable assembly 10, the cylindrical containers X are successively picked up bythe delivery sprocket wheel 230 and then delivered onto the guide chute 233 leading to,forexample, an article inspection station.

It isto be noted that, so far as the sprocket wheels 201 and 230 are of identical construction in all aspects, the both must be driven atthesame velocity. However, the present invention is not limited to the use ofthe sprocket wheels 201 and 230 of identical construction, but the sprocket wheels 201 and 230 may have different diameter and/orthe number ofthe article receiving recesses in one ofthe sprocketwheels 201 and 230 may differ from that in the other of the sprocket wheels 201 and 230 so far as the both are driven atthe same peripheral velocity. It is also to be noted that a single drive mechanism may be employed for driving all of the sprocket wheels 201 and 230 and thefilm supply unit212.

Hereinafter,theprofileofthecam surface 101 in the cam barrel 100 and the operation ofthefilm wrapping machine of the construction described hereinbefore will be described with particular reference to Figure 4(a) and 4(b). It is to be noted that Figure 4(a) illustrates, in schematic partially sectioned top plane view, the sequence beginning from the supply of one ofthe cylindrical containers X onto the corresponding rotary mount32 in the rotary turntable assembly 10 until such one ofthe cylindri-cal containers X has been completely wrapped with the film F, whereas Figure 4(b) illustrates the sequence in schematic side view together with the shape of the cam surface 101.

Assuming that the rotary turntable assembly lOis driven counterclockwise, as viewed in Figure 1, about the support shaft 11, and when one ofthe article supports 30 in the rotary turntable assembly 10 is brought into alignment with the article supply station, the corresponding film retaining spatula 50 is held in the inoperative position and the associated hollow shaft 70 carrying such film retaining spatula 50 is held in the lowered position as shown by I in Figure 4(b). so long asthe hollow shaft 70 is held in the lowered position, the associated film retaining spatula 50 in the inoperative position has its top end situated below the associated rotary mount 32.

During this condition, both of the arcuate opening 35 in each rotary mount 32 and the associated holder recess 154 in the disc 150 positioned immediately above said arcuate opening 35 in alignment therewith are exactly aligned with the film retaining spatula 50 then held in the inoperative position as clearly shown by I in Figure 4(b). Also, as shown in I in Figure 4(a), the associated heater unit 170 is held in the retracted position.

When one of the cylindrical containers X being successively fed by the feed sprocket wheel 201 is mounted on a corresponding one ofthe rotary mount 32 of the article support 30 then aligned with the article supply station, the hollowshaft70 start its ascending motion from the lowered position towards the raised position because of the roller 102 rolling on an upwardly inclined area of the cam surface 101 as can be understood from Figure 4(b).

Simultaneouslytherewith, the film retaining spatula 50 associated with such rotary mount 32 and carried by such hollow shaft 70 is lifted, passing through the arcuate opening 35 in the rotary mount 32 until it is inserted into the holder recess 154 in the associated disc 152. The ascending motion ofthe hollow shaft 70 resultingfromthe roller 102 rolling onthe upwardly inclined area of the cam surface 101 terminates when the top end ofthefilm retaining spatula 50 is received in the holder recess 154 as hereinbefore described. Simu Ita neously with tht termination ofthe ascending motion of the hollow shaft70,thefilm retaining spatula 50 is communicated with the vacuum source to renderthe film retaining spatula 50 to be ready for retaining the film F under suction in a mannerwhich will be described subsequently.

During the continued rotation ofthe rotary turntable assembly 10, the cylindrical container so mounted on the rotary mount 32 of the associated article support30 is brought to the film supply station. Asthe film retaining spatula 50 still held in the inoperative position approaches the film supply station together with the cylindrical container X, a leading end F,ofthefilm Fbeingfed bythefimfeed belt215 in the manner as hereinbefore described is aligned with a leading row ofthe suction perforations 51 in the film retaining spatula, it being to be noted that the term "leading " hereinabove and hereinafter used is in relation to the direction of movement of the film feed belt215 orthe rotary turntable assembly 10.

As soon as the leading row of the suction perforations 51 is aligned with the leading end F, of the film F,thefilm F is removed from thefilm feed belt 215 and then sucked onto the film retaining spatula 50 as shown by II in Figures 4(a) and 4(b). At this time, the trailing row of the suction perforations 52 in the film retaining spatula 50 are open to the atmosphere and will I su bsequ ently work with the trailing end F2 ofthe same film F as will be described later.

Simultaneouslywith the suction of the leading end F1 of the film F onto the film retaining spatula 50 in the manner as hereinabove described, the hollow shaft 70 in the raised position is driven in one direction to cause the film retaining spatula 50 two move from the inoperative position towards the operative position about the longitudinal axis ofthe hollow shaft 70 together with the associated rotary mount 32 supporting the cylindrical container X. As the film retaining spatula 50 isso moved, the film F retained by the film feed belt 215 is progressively peeled off from the film feed belt 215 while being turned around the cylindrical containerXonthe associated rotary mount 32 as shown by Ill in Figures 4(a) and 4(b).This is posible because thefllm retaining spatula 50 is passed through the arcuate opening 35 in the rotary mount 32 and received in the holder recess 154 in the disc 152 when and so long as the hollow shaft 70 is moved to the raised position, enabling both ofthe rotary mount 32 and the disc152 to be rotated together with the revolution of the film retaining spatula 50 between the inoperative and operative positions, it being to be noted thatthe inoperative and operative positions ofthefilm retaining spatula 50 is spaced substantially 5400 aboutthe longitudinal axis of the hollow shaft 70 for the purpose which will now be described.

Whenthefilm retaining spatula 50 being moved from the inoperative position towards the operative position about the longitudinal axis ofthe hollow shaft 70 revolves substantially 360" about the longitudinal axisofthehollowshaft70,thetrailing row of the suction perforations 52 are brought into alignment with a portion ofthefilm Fadjacentthe trailing end F2 thereof F having substantially turned around the cylindrical containerX, permitting the film Fto be completely removed from the film feed belt 215with thetrailing end F2 consequently sucked onto the film retaining spatula 50so asto overlapthe leading end F, ofthe same film F, as shown by IVin Figures 4(a) and 4(b). In this condition,thefilm Fso turned around the cylindrical containerX represents a generallytubular shape enough to surround the cylindrical containerX.Thereafter,thefilm retaining spatula 50 retaining the leading and trailing ends F1 and F2 in overlapping relation to each other continues its movement towards the operative position about the longitudinal axis ofthe hollow shaft 70 to bring the overlapping ends F1 and F2ofthe film into alignment with the slot 37 in the associated article receiving block 30 substantially as shown by V in Figures 4(a) and 4(b).

Simultaneouslywith the arrival ofthefilm retaining spatula 50 at the operative position after having completed its 540" revolution, the associated heater unit 170 is moved from the retracted position towards the projected position to permit the presser head 171 to project through the slot 37 in the article receiving block 31 so that the presser head 171 is brought into contact with the overlapping ends F1 and F2ofthefilm Fasshown byVin Figures 4(a) and 4(b) with the consequence thatthe overlapping ends F1 and F2ofthefilm Fare sandwiched between the film retaining spatula 50 and the presser head 171 of the heater unit 170.The contact of the presser head 171 with the overlapping ends F1 and F2 ofthefilm F results in the fusion-bonding ofthe overlapping ends F1 and F2 to provide a joint a substantially as shown byVI in Figure 4(b).

After the formation ofthe joint a at the overlapping ends F1 and F2 ofthefilm F, the heater unit 170 is moved back towards the retracted position, leaving the film tube Fain the form as surrounding the associated cylindrical container X. It is to be noted that, where thefilm used is made a material having no capability of being fusion bonded, an adhesive applicator may be employed for applying a layer of adhesive or bonding agent between the overlapping ends F1 and F2ofthefilm priortothe movement ofthe heater unit 170 from the retracted position towards the projected position so that, when the heater unit 170 is eventually moved towards the projected position, the presser head 171 can cooperate with the film retaining spatula 50 to firmly bond the overlapping ends F1 and F2 ofthefilm together. In such case, the presser head 171 may not havethe heater or heater builttherein.

Afterthe complete formation of the joint a in the film tube Fa,that is,thefilm F having its opposite ends F1 and F2 fusion-bonded together, the hollow shaft 70 is further rotated substantially 1800 to permit the film retaining spatula 50 two return to the inoperatve position accompanied by the rotation of the associated cylindrical containerXtogetherwith the film tube Fa surrounding such cylindrical coantainerXasshown byVI in Figures 4(a) and 4(b).

Shortly before or substantially simultaneouslywith the return ofthefilm retaining spatula 50 to the inoperative position in the manner as hereinabove described, the film retaining spatula 50 is disconnected from the vacuum source (not shown), and thereafter, the hollow shaft 70 starts its descending motion towards the lowered position accompanied by a corresponding descending motion of the film retaining spatula 50. Therefore, the film retaining spatula 50 positioned in a space between the outer peripheral surface ofthe cylindrical container X and the fil m tu be Fa is withdrawn downwardly out of such space as shown by VII in Figures 4(a) and 4(b). This is possible becausethe roller 102 descendsalong a portion of the cam surface 101 which is downwardly inclined as shown in Figure 4(b).

Thus, it will readily be seen that, during the passage ofthe rotary turntable assembly 10 past the flm supply station, process steps of lifting the film retaining spatula 50, receiving the film Ffromthe film feed belt 215, turning thefilm F around the cylindrical containerX, bonding the overlapping ends F1 and F2 ofthefilm Fsoturned aroundthe cylindrical coantainerX, and withdrawig the film retaining spatula 50 out of the space between the cylindrical containerX and the film tube Fa are performed sequentially.

Thereafter, and during the further continued rotation ofthe rotaryturntable assembly 10 about the support shaft 11, the cylindrical containerX are successively brought to the article delivery station at which the cylindrical containers Xwrapped loosely with the respective film tubes Fa are delivered by the delivery sprocket wheel 230 one by one onto the delivery chute 233 while each empty rotary mount 32 of the associated article support 30 is allowed to return to the article receiving station. The delivery chute 233 may be of any known construction with or without a conveyance belt used, and along this delivery chute 233 is moved a row ofthe cylindrical containersX having the respective film tubes Fa loosely wrapped therearound.The row ofthe cylindrical containers X are transported to a heat treating station at which the cylindrical containersX are succesively heat-treated by any suitable heating means 250 as shown in Figure 5, for example, applying a blast of heated air or by radiating infrared rays of light, to permitthefilmtubes Fatso heat-shrink, thereby completing the film wrapping.

After this heat-treatment, each film tube Fa is heat-shrunken to encircle the respective cylindrical containerX under interference-fit.

In describing the film wrapping machine according to the foregoing embodiment ofthe present invention, reference has been made to the cylindrical container X. However, it is to be noted that the machine according to the present invention can work satisfactorily with any type of articles, for example, containers of a shape having a generally barrel-shape or ball-shaped body or of a shape wherein the body is swelling and the mouth is progressively constricted from the body. Wherethe container of the shape wherein the body is swelling and the mouth is progressively constricted from the body (which container is hereinafter referred to as a "swelling container"), it may happen that the film turned around the swelling containerwill not retain its shape because ofthe lack ofthe self-supporting capability resulting from the flexibility ofthe film and,therefore,the high speed wrapping ofthefilms around the swelling containerwill be somewhat hampered. This possibility can be minimized bythe use ofthewrapping machine according to any one of the second and third preferred embodiments of the present invention which will now be described.

Figures 6(a) and 6(b), as is the case with Figures 4(a) and 4(b), illustrate the sequence beginning from the supply of one ofthe swelling containerXaonto the corresponding rotary mount 32 in the rotary turntable assembly 10 until such one of the swelling containerXa has been completely wrapped with the film. In describing the second preferred embodiment of the present invention with reference to Figure 6(a) and 6(b), onlythe difference between the previously described embodiment and the second embodiment will be described forthe sake of brevity.

Referring now to Figures 6(a) and 6(b), a plurality of, for example, four, strip-like erecting rods 61,62, 63 and 64,which may be similar in shape to thefilm retaining spatula 50, are employed for each article support 30 in the rotary turntable assembly 10. These erecting rods 60 are operable to supportthefilm F which has been turned around each swelling containerXa. When and so long as the film retaining spatula 50 is held in the operative position regardless of the position of the hollow shaft 70, the erecting rods 61 to 64 are folded together with thefilm retaining spatula 50 as if they altogether represent a single rod-like integer.On the other hand, the erecting rods 61 to 64 in the folded condition as hereinabove described can move together with the film retaining spatula 50 in a direction parallel to the support shaft 11. Also, as the subsequent description make it clear, the erecting rods 61 to 64 can be unfolded, as the film retaining spatula is revolved 360" from the inoperative positiontowardsthe operative position so that the erecting rod 61 to 64 can be positioned radially outwardly ofthe associated swelling container Xa is in circumferentially equally spaced relationship with each otheraboutthe associated swelling container Xa while one ofthe erecting rods is held in overlapping relationship with the film retaining spatula 50.

More specifically, when one of the swelling container Xa is fed onto the rotary mount 32 of one of the article support30then aligned with thearticle supply station as shown by I in Figures 6(a) and 6(b), the film retaining spatula 50 is lifted as a result ofthe movement ofthe hollow shaft 70 from the lowered position towards the raised position, accompanied by a corresponding upward movement of the erecting rods 61 to 64 in folded condition.

Then, as shown by II in Figures 6(a) and 6(b), the leading end F1 ofthefilm F is sucked ontothefilm retaining spatula 50 positioned radially outwardly of the erecting rods 61 to 64 with respect to the swelling container Xa on the rotary mount 32 as a resultofthe communication ofthefilm retaining spatula 50 with the vacuum source, and substantially simultaneously therewith, the film retaining spatula 50 starts its revolution from the inoperative position towards the operative position at a speed synchronized with the speed of movement ofthefilm feed belt 215 as shown by lil in Figures 6(a) and 6(b).

Subsequent to the start of movement of the film retaining spatula 50 towards the operative position, one of the erecting rods which is positioned closest to the swelling container Xa, that is, the erecting rod 61 is left at a position between the film feed belt215 andtheswelling containerXawithoutbeing moved together with the film retaining spatula 50.

Afterthefilm retaining spatula 50 being moved towards the operative position has completed its 90 revolution about the swelling container Xa, the erecting rod 62 which has been positioned next to the erecting rod 61 when in the folded condition is left at a position spaced 90 from the position where the erecting rod 61 is held still, that is, the inoperative position of the film retaining spatula 50, as shown by IVin Figures 6(a) and 6(b).Similarly, as the film retaining spatula 50 completes 1 80" and 270 rotations from the inoperative position aboutthe swelling container Xa as shown by IV and V in Figures 6(a) and 6(b), the erecting rods 63 and 64 are left at respective positions spaced 1800 and 2700 from the inoperative position.

As has been described in connection with the previous embodiment of the present invention, when the film retaining spatula 50 has completed about 3600 rotation, the film F fed by the film feed belt 215 is completely removed from thefilmfeed belt 215withthetrailing end F2 thereof sucked onto the film retaining spatula 50, as shown byV in Figure 6(b), thus overlapping the leading end F1 thereof.

Thereafter, the film retaining spatula 50further continues its revolution towards the operative position without being accompanied by the movement of any one of the erecting rods 61 to 64 which are left spaced 900 from each other in a direction circumferentially of the swelling container Xa. These erecting rod 61 to 64 so positioned circumferentially of the swelling container Xa and insidethefilm Fturnedaroundtheswelling container Xa cooperate together to substantially avoid, or minimize, the deformation of local portions ofthefilm Fsoturned around the swelling container Xawhilesupportingthefilm F.

Upon the arrival of the film retaining spatula 50 having the overlapping ends F1 and F2 ofthefilm F retained thereby, the heater unit 170 is moved from the retracted position towards the projected position with the presser head 171 consequently pressed againstthefilm retaining spatula 50to effect the fusion-bonding ofthe overlapping ends F1 and F2 of the film Fto complete the film tube Fa as hereinbefore described in connection with the previous embodiment ofthe present invention and as shown by Vl in Figures 6(a) and 6(b).

In the embodiment shown in and described with reference to Figures 6(a) and 6(b), each of the rotary mount 32 is shown as having a diametersmallerthan the diameterofthe circular path along which thefilm retaining spatula 50 is moved between the inoperative and operative positions. In such case, during the revolution ofthefilm retaining spatula 50, a friction may take place between the outer peripheral surface ofthe bodyoftheswelling containerXa and the film Fturnedtherearound.

Where this friction is desired to be avoided, each rotary mount 32 may be made rotatable about and together with the associated hollow shaft 70 to renderthe swelling containerXa on the rotary mount 32 to rotate.

After the formation of the film tube Fa with the film retaining spatula 50 and the heater unit 170 positioned at the operative position and the projected position, respectively, the communication between the film retaining spatula 50 and the vacuum sourcethroughthe hollowofthe hollow shaft 70 is interrupted, and all ofthefilm retaining spatula 50 and the erecting rods 61 to 64 are withdrawn downwards out from the annular space between the outer peripheral surface of the body of the swelling containerXa and the film tube Fa.The swelling containerXa having the film tube Fa mounted thereon are then fed to the heat treating station in the manner as herein before described in connection with the previous embodiment sothat the film tube Fa can be heat-shrunkento complete the film wrapping.

The erecting rds 61 to 64 operable in the manner as herein before described with particular reference to Figure 6(a) and 6(b) are mounted on a corresponding number of support rods 81,82,83 and 84for movementtogethertherewith, or otherwise integrallyformed therewith. The support rods 81 to 84 are supported for movement between lowered and raised positions and also for rotation about the longitudinal axis ofthe respective swelling container Xa mounted on the associated article support mount 32.The movement of the support rods 81 to 84 between the lowered and raised positions, and hence, that of the erecting rods 61 to 64, is synchronized with the hollow shaft 70 whereas the angular movement of the support rods 81 to 84 about the longitudinal axis of the repectiveswelling container Xa and exteriorly around the associated article support mount 32 is synchronized with the angularmovementofthefilm retaining spatula 50.

Forthis purpose, although not shown, a drive mechanism and its associated linkage system which are separate from those associated with the film retaining spatula 50 are used to move the erecting rods 61 to 64 as well as the support rods 81 to 84 It is to be noted that the support rods 81 to 84 which have been described as comprised of the members separate from the erecting rods 61 to 64 may be integral extensions of the respective erecting rods 61 to 64, that is, may be integrallyformed with the respective erecting rods 61 to 64.

Instead of the use ofthefilm retaining spatula, which has been described in connection with the first embodiment shown in Figures 1 to 5, orthefoldable erecting rods in combination with the film retaining spatula which have been described in connection with the embodiment shown in Figures 6(a) and 6(b), a cylindrical film retaining barrel may be employed which will now be described with reference to Figures 7(a) and 7(b) and 8. The use ofthe cylindrical film retaining barrel, generally identified by 50a, in thefilmwrapping machine according to the present invention is advantageous in that the film turned around the container can be satisfactorily supported regardless of the shape ofthe container desired to be handled bythefilm wrapping machine.

Referring to Figures 7, the cylindrical film retaining barrel 50a has a length and an inner diameter sufficientto accommodate therein any one of the containers desired to be handled by the film wrapping machine according to the present invention. As best shown in Figure 8, a portion ofthe cylindrical film retaining barrel 50a has two rows of suction perforations 51 and 52 defined on the outer peripheral surface thereof so asto extend in a direction axially of the cylindrical barrel 50a, and whilethecylindrical barrel 50a is rigidly mounted on the hollowshaft70 in coaxial relationhipwiththe associated rotary mount32 through the coupling member 72 for rotation together therewith, each row of the suction perforations 51 and 52 are communicated with the center hollow71 in the hollow shaft 70 by way ofthe connecting pasage 73 in the connecting member 72 via a respective axial passage (not shown) defined inthewall ofthe cylindrical barrel 50a.

It is to be noted that, instead ofthe use ofthe rows ofthe suction perforations 51 and 52, slits may be employed and that one ortwo additional rows of suction perforations may be formed on another portion ofthe outer peripheral surface ofthe cylindrical barrel 50a circumferentiallyspaced about 150 from that portion thereof where the rows of the suction perforations 51 and 52 in a fashion similarto the two rows ofthe suction perforations 51 and 52 so thatthe film Fsubsequentlyturned around the respective container can be positively supported by the cylindrical barrel 50a sucking a pattern ofthefilm F generally intermediate between the opposite ends F1 and F2 thereof which are then sucked by the rows ofthe suction perforations 51 and 52.

The film wrapping machine according to the third embodiment of the present invention operates in a manner substantially similar to the film wrapping machine according to any one oftheforegoing embodiments. More specifically, assuming that one ofthe containers, for example, the containers Xa is mounted on the associated rotary mount 32 then aligned with the article supply station during the rotation ofthe rotaryturntable assembly 10 as shown by I in Figures 7(a) and 7(b), the associated cylindrical barrel 50a is upwardly moved to permit the containerXa to be situated insidethe cylindrical barrel 50a substantially as shown by II in Figure 7(a).

During the continued rotation of the rotary turntable assembly 10, and atthefilm supply station, the leading row of the suction perforations 51 in the cylindrical barrel 50a communicated with the vacuum source is brought into alignment with, and then sucks, the leading end F1 ofthe film F being supplied byte film feed belt 215 as shown by II in Figure 7(b). Upon the rotation ofthe cylindrical barrel 50a aboutthe longitudinal axis ofthe hollow shaft 70, the film F having its leading end F1 sucked bythe cylindrical barrel 50a in the manner as hereinabove described is pulled outwardsfromthe film feed belt215while being turned aroundthe cylindrical barrel 50a as shown by Ill in Figures 7(a) and 7(b).

Atthetimethecylindricalfilm retaining barrel50a has substantially completed 360 rotation, the trailing row ofthe suction perforations 52 is brought into alignmentwith a portion ofthefilm Fadjacent the trailing end F2 to attract said trailing end F2 towards the cylindrical barrel 50a by the effect of a suction force. Thus, as shown by IV in Figures 7(a) and 7(b), thefilm Fiscompletelyturned aroundthe cylindrical film retaining barrel 50a with the trailing end F2 overlapping the leading end F1 ofthe same film F.

Thereafter, the cylindrical film retaining barrel 50a is rotated a further 150" towards the operative position. As the cylindrical film retaining barrel 50a approaches the operative position, the heatee unit 170 in the retracted position is moved towards the projected position, and simultaneously with the arrival ofthecylindricalfilm retaining barrel 50a,the presser head 171 of the heater unit 170 is pressed againstthe cylindrical barrel 50a to effectthe fusion-bonding oftheoverlapping ends F1 and F2to complete the formation of thefilm tube Fa as shown byVin Figures 7(a) and 7(b).

As is the case with any one oftheforegoing embodiments, aftertheformation ofthefilm tube Fa, the cylindrical film retaining barrel 50a is withdrawn downwards leaving the film tube Fain the form as surrounding the container Xa, and the containerXa wrapped with the film tube Fa is subsequently transferred to the heat-treating station through the delivery station at which it is removed from the rotary turntable assembly 10 onto the delivery chute 233 by means of the delivery sprocket wheel 230.It is to be noted that, shortly before the downward movementofthe cylindrical film retaining barrel 50a subsequent to the formation ofthe film tube Fa, the communication between the suction perforations 51 and 52 and the vacuum source is interrupted.

Itisto be noted that, instead of the cylindrical film retaining barrels 50a, a similarfilm retaining barrels ofgenerallysquarecross-sectional shape may be employed if the containers desired to bewrapped with the heat-shrinkablefilms have a generally square cross-section.

Although the present invention has been fully decribed in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications are apparentto those skilled in the art. Some of the changes or modifications have been described, and such and other changes and/or modifications are to be construed as included within the scope of the present invention as defined by the appended claims unless they depart therefrom.

Claims (5)

1. Afilmwrapping machineforsuccessively turning films around articles so as to form a film tube encircling each article, which machine comprises: a rotary turntable assembly supported for rotation in one direction about a support shaft, said rotary turntable assembly being, during one complete rotation, movable from and back to an article supply station past a film supply station and an article delivery station, all of said stations being disposed in the vicinity ofthe periphery of of the rotary turntable assembly;; a plurality of article supports provided in the rotary turntable assembly at a peripheral portion thereof for rotation together with said rotaryturntable assembly about the support shaft, said article supports being spaced an equal distance from each other in a direction circumferentially ofthe rotary turntable assembly, each of said article support being operable to carry the respective article during the rotation ofthe rotaryturntable assembiy; an article supply unit disposed at the article supply station for supplying the articles successively onto the respective article supports in the rotaryturntable assembly as the rotaryturntableassemblyduring the rotation thereof arrives at the article supply station;; a film retaining member provided for each article support and supported in the vicinity of the respective article supportfor rotation about an axis parallel to the support shaft between inoperative and operative positions and also for movement in a direction parallel to the support shaft between raised and lowered positions, said film retaining member having suction openings defined therein in at least two leading and trailing rows, the leading and trailing rows ofthe suction openings being spaced a predetermined distance from each other in a direction conforming to the direction of rotation of the film retaining member, said leading row of the suction openings being adapted to retain a leading end of the associated film by the effect of a suction force whereas the trailing row of the suction openings is adapted to retain a trailing end of such associated film by the effected a suction force, said film retaining member being rotatable aboutthe associated article on the article supportfrom the inoperative position towards the operative position onlywhen and after it has been moved from the lower position towards the raised position;; afilm supply unit disposed atthefilm supply station for supplying the film onto the respective film retaining member each time the rotary turntable assembly is broughttothefilm supply station, said film retaining member being moved from the lowered position to the raised position upon the arrival ofthe rotaryturntable assembly atthefilm supply station such that the leading end of the film can be sucked bythe leading row of the suction openings by effect the effectofthesuctionforce,thefilm with its leading end sucked by the leading rowofthe suction openings being exteriorly turned around the associated article as the film retaining member is rotated from the inoperative position towards the operative position, said film being completely turned around the associated article with a portion ofthe film adjacent the trailing end sucked by the trailing row of the suction openings permitting thetrailing end to overlap the leading end;; a heater unit provided for each article support and carried by the rotary turntable assembly for movement between projected and retracted positions in a direction close towards and away from the associated article on the article support, said respective heater unit being moved from the retracted position to be the projected position in unison with the movement ofthe associated film retaining memberfrom the inoperative position to the operative position, said heater unit when moved to the projected position being pressed againstthe associated film retaining member with the overlapping ends of the film around the article consequently fusion-bonded together to complete a film tube; and an articledeliveryunitdisposedatthearticle delivery station for removing the articles with the respective film tube successively out from the associated article supports as the rotaryturntable assembly during its continued rotation is brought to the article delivery station.

2. The machine as claimed in Claim 1, wherein thefilm retaining member comprises afllm retaining spatula having a hollow defined therein and adapted to be communicated with a source of vacuum, and said leading and trailing rows of the suction openings being defined in communication with the hollowon onesurfaceofthefilm retaining spatula facing in a direction opposite to the associated article.

3. The machine as claimed in Claim 2, wherein thefilm retaining spatula comprisesa pairof generally strip-like plates connected together in face-to-face relationship with each other, one of said plates having at least one recess defined therein while the other of the plates having the rows ofthe suction openings defined therein, said recess forming the hollow when the plates are connected together.

4. Afilm wrapping machine for successively turning films around articles so as to form afilmtube encircling each article, which machine comprises: a rotary turntable assembly supported for rotation in one direction about a support shaft, said rotary turntable assembly being, during one complete rotation, movable from and back to an article supply station past a film supply station and an article delivery station, all of said stations being disposed in the vicinity of the periphery of the rotaryturntable assembly;; a plurality of article supports provided in the rotary turntable assembly at a peripheral portion thereof for rotation together with said rotaryturntable assembly about the support shaft, said article supports being spaced an equal distance from each other in a direction circumferentially of the rotary turntable assembly, each of said article support being operable to carry the respectivearticleduring the rotation of the rota ry turntable assembly; an article supplyunitdisposed at the article supply station for supplying the articles successively onto the respective article supports in the rotaryturntable assembly as the rotary turntable assembly during the rotation thereof arrives at the article supply station;; a film retaining member provided for each article support and supported in the vicinity ofthe respective article supportfor rotation about an axis parallel to the support shaft between inoperative and operative positions and also for movement in a direction parallel to the support shaft between raised and lowered positions, said film retaining member having suction openings defined therein in at least two leading and trailing rows, the leading and trailing rows ofthe suction openings being spaced a predetermined distance from each other in a direction conforming to the direction of rotation of thefilm retaining member, said leading rowofthe suction openings being adapted to retain a leading end of the associated film by the effect of a suction force whereas thetrailing row ofthe suction opening is adapted to retain a trailng end of such associated film bytheeffectofasuctionforce,saidfilm retaining member being rotatable aboutthe associated article on the article supportfrom the inoperative position towards the operative position only when and after it has been moved from the lowered position towards the raised position;; a plurality offoldable erecting membersforeach film retaining member and similar in shape to the associated film retaining member, said foldable erecting members for each film retaining member being supported for movementtogetherwith the associated film retaining member, but being held in a folded condition when the associated film retaining member is in the lowered position and also in the inoperative position, said foldable erecting members being unfolded as the associated film retaining member is moved from the inoperative position towards the operative position about the associated article, said foldable erecting member when unfolded being spaced a distance from each other in a direction circumferentially of the associated article to support the film turned exteriorly around the associated article; a film supply unit disposed atthefilm supply station for supplying the film onto the respective film retaining member each time the rotary turntable assembly is brought two thefilm supply station, said film retaining member being moved together with the foldable erecting members from the lowered position to the raised position upon the arrival ofthe rotary turntable assembly atthe film supply station suchthatthe leading end ofthefilm can be sucked by the leading row of the suction openings by the effect ofthe suction force, the film with its leading end sucked by the leading row of the suction openings being exteriorly turned around the associated article in contact with the foldable erecting members as the film retaining member is rotated from the inoperative position towards the operative position, saidfilm beingcompletelyturnedaroundthe associated article with a portion ofthefilm adjacent the trailing end sucked by the trailing row ofthe suction openings permitting the trailing end to overlap the leading end;; a heater unit provided foreach article support and carried by the rotaryturntable assemblyfor movement between projected and retracted positions in a direction close towards and awayfrom the associated article on the article support, said respective heater unit being moved from the retracted position to the projected position in unison with the movement of the associated film retaining memberfrom the inoperative position to the operative position, said heater unit when moved to the projected position being pressed against the associated film retaining member with the overlapping ends of the film around the article consequently fusion-bonded together to complete a film tube; and an article delivery unit disposed at the article delivery station for removing the articles with the respective film tube successively out from the associated article supports as the rotary turntable assembly during its continued rotation is broughtto the article delivery station.

5. Afilm wrapping machine for successively turning films around articles so astro form a film tube encircling each article, which machine comprises: a rotaryturntable assembly supported for rotation in one direction about a support shaft, said rotary turntable assembly being, during one complete rotation, movable from and backto an article supply station past a film supply station and an article delivery station, all of said station being disposed in the vicinity of the periphery of the rotaryturntable assembly;; a plurality of article supports provided in the rotary turntable assembly at a peripheral portion thereof for rotation together with said rotaryturntable assembly about the support shaft, said article supports being spaced an equal distance from each other in a direction circumferentially ofthe rotary turntable assembly, each of said article support being operable to carrythe respective article during the rotation ofthe rotary turntable assembly; an article supply unit disposed at the article supply station for supplying the articles successively onto the respective article supports in the rotaryturntable assembly as the rotary turntable assembly during the rotation thereof arrives at the article supply station;; a film retaining barrel provided for each article support and supported in the vicinity ofthe respective article support for rotation about an axis parallel to the support shaft between inoperative and operative positions and also for movement in a direction parallel to the support shaft between raised and lowered positions, said film retaining barrel having suction openings defined therein in at least two leading and trailing rows, the leading and trailing rows ofthe suction openings being spaced a predetermined distance from each other in a circumferential direction thereof, said leading row of the suction openings being adapted to retain a leading end of the associated film by the effectofa suction force whereas the trailing row of the suction opening is adapted to retain a trailing end of such associated film by the effect of a suction force, said film retaining barrel being rotatable about the associated article on the article supportfrom the inoperative position towards the operative position only when and after it has been moved from the lowered position towards the raised position;; afilm supply unit disposed atthefilm supply station for supplying the film onto the respectice film retaining member each time the rotary turntable assemblyisbroughttothefilmsupplystation,said film retaining barrel being moved from the lowered position to the raised position upon the arrival ofthe rotary turntable assembly atthefilm supply station such that the leading end ofthefilm can be sucked by the leading row of the suction opening by the effect of the suction force, the film with its leading end sucked by the leading row of the suction openings being exteriorly turned around the associated film retaining barrel asthefilm retaining barrel is rotated from the inoperative position towards the operative position, said film being completely turned around the associated film retaining barrel with a portion of the film adjacent the trailing end sucked bythe trailing row ofthe suction openings permitting the trailing end to overlap the leading end; a heater unit provided for each article support and carried by the rotary turntable assembly for movement between a projected and retracted positions in a direction close towards and away from the associated article on the article support, said respective heater unit being moved from the retracted position to the projected position in unison with the movement of the associated film retaining barrel from the inoperative position to the operative position, said heater unit when moved to the projected position being pressed againstthe associated film retaining barrel with the overlapping endsofthefilm aroundthefilm retaining barrel consequently fusion-bonded togetherto complete a film tube; and an article delivery unit disposed at the article delivery station for removing the articles with the respective film tube successively out from the associated article supports as the rotary turntable assembly during its continued rotatin is brought to the article delivery station.