EP0646527B1

EP0646527B1 - Adhesive tape supplying device in a packaging machine

Info

Publication number: EP0646527B1
Application number: EP19930307754
Authority: EP
Inventors: Heiemon Akiyama; Minoru Sato
Original assignee: Tokyo Automatic Machinery Works Ltd
Current assignee: Tokyo Automatic Machinery Works Ltd
Priority date: 1993-09-30
Filing date: 1993-09-30
Publication date: 1997-11-26
Anticipated expiration: 2013-09-30
Also published as: DE69315434T2; EP0646527A1; DE69315434D1

Description

Field of the Invention

This invention relates to a packaging machine in which substantially rectangular-shaped contents such stacks of papers or books, longitudinal zig-zag folded and overlapped belt-like clothes or fabrics or accumulated boxes are wrapped by a packaging sheet such as a craft paper. More particularly, the machine is one in which a packaging sheet is wrapped around the outer surface of the contents and the sheet is sealed with at least one length of an adhesive tape, while the packaging sheet and the contents are placed on a mounting surface of an elevator and are being transported in a vertical direction from a packaging starting position under an ascending or descending of the elevator.

Description of the Prior Art

A packaging machine of this kind is disclosed in the gazette of Japanese Patent Publication No. 3-14685, and includes a paper feeding table, on which packaging sheets are piled, and which is located at the side of an ascending or descending passage of the elevator. The table is arranged to be inclined upwardly toward the upper end of the ascending or descending passage, and only one packaging sheet is separated and fed onto the elevator, the contents are placed on the predetermined position on this packaging sheet, the elevator is lowered to fold both ends of the packaging sheet into a substantial U-shape, then both ends are overlapped along the upper surface of the contents to complete the wrapping stage. Subsequently, the wound contents are horizontally transported from the elevator toward a discharging table, and thereby the end portions of the packaging sheet are folded inwardly along the side surfaces of the contents. Thereafter, the upper flaps of the sheet ends are folded down along the side surfaces of the contents, and concurrently a length of adhering tape fed out by a tape feeding mechanism from a supply is adhered to both overlapped ends of the packaging sheet and
sealed. Next, the lower flaps are folded along the outside of the folded upper flaps and the extremity ends of the outermost overlapped lower flaps are folded along the upper surface of the contents, and lengths of adhering tape fed out by the tape feeding mechanism are adhered to the upper surface of the contents together with the extremities end of the lower flaps by an adhering mechanism and sealed.
A similar machine is disclosed in Swiss Patent Specification No. 390776.
However, in the prior art packaging machines as described above, since the adhering tape is fed out and adhered to the packaging sheet upon completion of the winding operation and the completion of the folding operation, these prior art machines have some problems in that an exclusive stage for adhering the adhering tape is necessary during the stage of wrapping the contents and the tape feeding mechanism and the tape adhering mechanism are arranged at the positions reserved for the wrapping of the ends of the wound packaging sheet and in such positions there are guides to be used for winding or folding operations, and the tape feeding mechanism must be arranged so as not to interfere with these members, with the result that size of the entire machine becomes not only large but also its configuration becomes complicated.
In addition, the machines of the prior art have another problem in that they require a separating means utilizing an adhering power or a frictional power to positively separate only one packaging sheet from the entire accumulated packaging sheets.
In addition, because the paper feeding table where the packaging sheets are accumulated is inclined, space for the packaging sheets in a lateral direction laterally from the ascending or descending passage of the elevator becomes necessary and the machine becomes elongated in a lateral direction.
In view of the aforesaid prior art, it is an first object of the present invention to perform a sealing of the packaging sheet while the sheet is being covered.
It is a second object to separate only one packaging sheet at the downstream end without utilizing any sucking power or frictional force.
It is a third object is a utilization of the dead space of the machine while only one packaging sheet at the downstream end may easily separated without utilizing sucking power or frictional force.
It is a fourth object to keep the packaging sheet at the downstream end at the specified position without the accumulated packaging sheets having to be moved up and down.

SUMMARY OF THE INVENTION

According to the invention there is provided a packaging machine in which a packaging sheet is wrapped around contents to be packaged by positioning the sheet and contents above an elevator in a packaging start position, and by moving the elevator relative to the sheet and contents in an ascending or descending path, and wherein a length of adhering tape is used to seal the packaging sheet, characterized in that the device comprises a packaging sheet positioning mechanism for positioning the packaging sheet in a tape receiving position, a tape feeding-out mechanism for feeding-out and supporting adhering tape from a supply of such tape, a tape cutting mechanism for cutting the length of adhering tape from the supply, an adhering mechanism movable toward and away from the packaging sheet when in the tape receiving position for adhering the length of adhering tape to the packaging sheet so that part of the length of tape projects from the sheet, and a sheet feeding-out mechanism for supplying the packaging sheet with the length of tape adhered thereto along a feeding-out passage from the tape receiving position to the packaging start position.
Preferably, the packaging machine provides that the packaging sheet is wound around the contents into tubular form, and the adhering mechanism is adapted to apply the length of tape to the leading end only of the packaging sheet, which leading end is arranged to overlie the trailing end when the sheet is wrapped into tubular form around the contents.
According to another preferred feature, the sheet feeding-out mechanism is controlled in such a manner that when the wrapping operation is carried out, regardless of the size of the packaging sheet for the contents, the leading and trailing ends of the overlapped packaging sheet at the outside of the contents are arranged at the central position of the contents.
Additional lengths of tape may be applied to the sheet at the sides thereof for holding each of the extended ends of the packaging sheet projecting in a rectangular tubular form from the side surface of the contents and for sealing the said extended ends when folded over the side surfaces of the contents.
In another preferred arrangement, the sheet positioning mechanism is adapted to position accumulated packaging sheets in the receiving position and the sheet feeding out mechanism is adapted to feed the sheets one-by one and to the packaging start position, and wherein the machine is adapted to receive packaging sheets accumulated below the said elevator in a substantially horizontal disposition along a bottom surface of a frame of the machine so that the leading ends of these packaging sheets are bent upwardly along side surfaces of the frame, the sheet positioning mechanism being arranged to engage the leading ends to bend them initially toward the adhering mechanism, to have the length of tape applied to the top sheet, then to be moved in a counter-bending direction to separate the remaining sheets from the top sheet.
The machine may include a stopper abutting against the trailing ends of the packaging sheets, said stopper being arranged in such a manner that it can be moved relative to the trailing ends, and including a sensor for sensing the position of the leading ends of the sheets, and said stopper being arranged to be adjustably moved in response to the output from the sensor.
Preferably, for the change in a movement of the packaging sheets from the bending direction to the counter bending direction, the positioning mechanism has a partial bending means for folding partially an extremity end of the bent packaging sheet
In a particularly preferred arrangement, the feeding-out passage for the packaging sheet lies at right angles to the ascending or descending path of the elevator, and the machine includes a pair of sheet supporting means extending in a direction at right angles to the sheet supplying direction, and a slipping surface arranged over both sheet supporting means along the lower surface of the feeding-out passage, which sheet supporting means can be moved together along the feeding out passage in the direction of feed on the packaging sheet, and retracted in the opposite direction.
An embodiment of the invention will now be described by way of example only with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig.1 is a longitudinal front elevation view in section showing a packaging machine according to the preferred embodiment of the present invention, and the packaging starting position and the packaging completion position being concurrently illustrated;
Fig.2 is a cross sectional top plan view of the machine of Fig. 1;
Fig.3 is a partial enlarged sectional top plan view taken along the line (3) (3) of Fig. 1;
Figs.4 (a) to (d) show in partial longitudinal front elevation and in section the sequence of the feeding-out stages of the packaging sheet;
Figs.5 (a) to (g) are partial longitudinal front elevations in section for showing the sequence of the winding stages;
Fig.6 is a partial enlarged cross sectional top plan view for showing the folding of the side flap;
Fig.7 is a partial enlarged cross sectional top plan view for showing the stage just before the completion of the folding of the side flap; and
Fig.8 is a partial enlarged cross sectional top plan view for showing the folding of the upper flap.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings, one preferred embodiment of the present invention will now be described.
As shown in Figs.1 and 2, packaging sheets A are piled up in a vertical direction and lie in a substantially horizontal direction on a paper feeding table 1 which can be ascended or descended. The longitudinal direction of the sheets A coincides with the longitudinal direction of the frame F. The extremity ends Al of the sheets A are bent in an upward direction as shown, in order that a bending operation for bending the bent extremity ends Al .by means of a positioning mechanism 3 followed by a recovering operation for recovering them to the initial position may be effected as explained herein. This is to enable sheets to be moved to a sealing position in which sealing tapes can be applied to the top sheet A1'. The adhering tapes Cl, C2f C2 are applied by tape feeding-out mechanisms 2, 2, 2 to the packaging sheet A at the downstream end, and at the same time the top packaging sheet A having the adhering tapes Cl, C2, C2 adhered thereto is separated from the other sheets by the sheet feeding-out mechanism 4 which feeds it through the inverse L-shaped feeding-out passage A' onto the elevator 6.
The paper feeding table 1 is arranged along the bottom surface Fl of the frame F and below the ascending or descending passage 6b of the elevator 6 to be described later. A substantial horizontal mounting surface la is arranged centrally of the width direction of the frame F and may be reciprocated in a vertical direction. Its width is shorter than the width of the minimum size packaging sheet A for the machine and U shaped side guides lb, lb which are fixed from moving vertically, are oppositely arranged at the right and left sides of the mounting surface la so that the packaging sheets A are mounted and supported by the mounting surface la over side guides lb, lb.
The mounting surface la where is lies against the bottom surface of the bent part of the packaging sheets A bent upwardly is also bent upwardly to frame end F2, and a resilient projection lc such as a sponge, for example, is located at the central position of the bent part. This projection forcibly contacts the bottom surface of the bent part of the packaging sheets A. A flexible pressing sheet ld formed by a material such as fluorine resin may be slid upwardly from the resilient projection lc and is fixed on the mounting surface la. The pressing sheet ld is wound around a rising lever 3a of the positioning mechanism 3 to be described later, and is pulled by the resilient member le such as a spring, for example, to provide a tensioned support for the bottom surface of the bent part of the sheets A.
Accordingly, the central position of the bent part of each of the bent packaging sheet A bulges out upwardly from the resilient projection lc so as to be bent in a bow-like form, and at the same time the mounting surface la is higher than the inner surface of each of the side guides lb, lb, thereby the substantially horizontal portions A2 of the sheets A bulge out upwardly in a bow-like form. An abutting guide lf is arranged and fixed in a position opposing against the top surface of the bent part of the packaging sheets A, and the extremity ends Al' of the packaging sheets A are in use further bent by the positioning mechanism 3 whereby the upper surface of the bent part of each of the packaging sheets A is pressed against the abutting guide lf.
In addition, the side guides lb, lb are supported in such a way that they may be adjusted and moved in a right and left direction, and the tape feeding-out mechanisms 2, 2 at the right and left sides of the machine are cooperatively arranged above the side guides and may be adjusted in position by an adjusting driving part such as a pulse cylinder, for example, by the same length in the right and left direction corresponding to the size variation in the width direction of the packaging sheets A. The stopper lg is vertically arranged at the position opposing the end edge A2' of the mounted packaging sheets A in such a way that the stopper can be adjusted and moved in the length direction of the frame F by an adjusting and driving part, such as a pulse cylinder, for example, the adjusting and driving part being controlled in its operation by a control part not illustrated, whereby the stopper lg is moved horizontally in response to the output of a sensor lh to be described later.
The sensor lh is arranged near the extremity ends Al' of the bent packaging sheets A, and more particularly, near the oscillating supporting surface 2d of the centrally located tape feeding-out mechanism 2, and when the extremity ends Al' of the packaging sheets A are bent to te dotted line position of Fig. 1, to be abutted against the adhering tapes Cl, C2, C2, the sensor detects the position of the extremity ends A1' and if necessary, the adjusting and driving part of the stopper lg is operated until the extremity ends A2' of the packaging sheets A are moved horizontally toward the extremity ends Al' of the packaging sheets A.
The tape feeding-out mechanisms 2, 2, 2 are constructed such that feeding-out rollers 2a, 2a, 2a abut against the adhering surfaces of the rewound adhering tapes Cl, C2, C2 and supporting surfaces 2b, 2b, 2b contact the non adhered surfaces of the adhering tapes Cl, C2, C2.
The adhering tape rolls C, C, C are rotatably supported, and the cutters 2c, 2c, 2c co-operate with the supporting surfaces 2b, 2b, 2b. In the preferred embodiment of the present invention, the central tape feeding-out mechanism 2 feeds out the adhering tape Cl from the adhering tape roll C along the supporting surface 2b in the width direction as shown in Fig.3, and the tape right and left feeding-out mechanisms 2, 2 feed out the adhering tapes C2, C2 from the adhering tape rolls C, C along the supporting surfaces 2b, 2b in a vertical direction.
The oscillating and supporting surfaces 2b, 2b are cooperatively arranged in such a way that they may be projected out toward the feeding-out passage A'. At the downstream ends of these supporting surfaces 2b, 2b, 2b, are projections 2e, 2e, 2e for preventing double sheet adhering and these project toward the feeding-out passage Al at each of the oscillating and supporting surfaces 2d, 2d, 2d as required. Each of the feeding-out rollers 2a, 2a, 2a, the cutters 2c, 2c, 2c and the oscillating and supporting surfaces 2d, 2d, 2d are cooperatively related and driven by a driving part such as a stepping motor, for example.
The driving part for the tape feeding-out mechanisms 2, 2, 2 is controlled by the control part in the same manner as that of the adjusting driving part for the stopper lg. The oscillating supporting surfaces 2d, 2d, 2d are spaced apart from the feeding-out passage of the packaging sheet A before feeding of the packaging sheet A and are held there, and the feeding-out rollers 2a, 2a, 2a are rotated after manual operation of the sheet feeding-out starting switch Sl or packaging starting switch S2. Each of the adhering tapes Cl, C2, C2 is fed out from the adhering tape rolls C, C, C by a predetermined length up to the oscillating supporting surfaces 2d, 2d, 2d while applying folding lines lengthwise of the tape.
After the positioning mechanism 3 is moved in a direction approaching to the oscillating supporting surfaces 2d, 2d, 2d, only the cutter 2c for the central tape feeding-out mechanism 2 is operated and the oscillating supporting surface 2d is moved toward the feeding-out passage A' just after cutting the adhering tape Cl and then it returns to the initial state. The pressing roller 4b of a sheet feeding-out mechanism 4 is moved near the oscillating supporting surfaces 2d, 2d, 2d, and the cutters 2c, 2c of the right and left tape feeding-out mechanisms 2, 2 are operated, and just after cutting the adhering tapes C2, C2, the oscillating supporting surfaces 2d, 2d are projected only for the predetermined time toward the feeding-out passage A', and returned to the initial state. Following this, the feeding-out rollers 2a, 2a, 2a are slightly reverse rotated as required.
Extension or retraction guides 2f, 2f formed by bending resilient material such as spring steel plate, for example, in a zig-zag form are placed between the tape feeding-out mechanisms 2, 2, 2, whereby the right and left tape feeding-out mechanisms 2, 2, 2 can be adjusted and moved in the right and left direction in response to the size variation of the packaging sheets A so as to prevent the extremity ends Al' of the packaging sheets A positioned at the downstream end from being advanced to between the tape feeding-out mechanisms 2, 2, 2.
The positioning mechanism 3 positions the substantial horizontal ring lever 3a against the oscillating supporting surfaces 2d, 2d, 2d of the tape feeding-out mechanisms 2, 2, 2 by being abutted against the bottom surfaces of the extremity ends A' of the packaging sheets A. Even if the amount of the packaging sheets A in the accumulated pile is reduced, it may be positively pushed against the oscillating supporting surfaces 2d, 2d, 2d.
The rising lever 3a is cooperatively related to a driving part such as a stepping motor, for example, to cause the rising lever 3a to be reciprocated by the driving part, and at the same time, a horizontal wedge lever 3b moves to a position opposing against the lower part of the feeding out roller 4a so as to form a sheet bending means, these levers being connected to oscillating pieces 3c, 3c provided with the resilient members 3d, 3d such as springs. The wedge lever 3b is pressed in a direction towards the lower part of the feeding-out roller 4a, and fixed stoppers 3e, 3e abut against the oscillating pieces 3c, 3c so that when the rising lever 3a is moved away from the oscillating supporting surfaces 2d, 2d, 2d of the tape feeding-out mechanisms 2, 2, 2, the wedge lever 3b is caused eventually to be moved in a direction away from the lower part of the feeding-out roller 4a.
The driving part for the positioning mechanism 3 is controlled in its operation by the control part, and the rising lever 3a is moved toward the direction in which the extremity ends A1' of the packaging sheets A are returned to their initial condition before the feeding-out of the packaging sheet A. The oscillating supporting surface 2d of each of the feeding-out mechanisms 2, the rising lever 3a and the wedge lever 3b move in a direction in which the extremity ends Al' of the packaging sheets A are bent after the adhering tapes Cl, C2 C3 have been fed out by each of the feeding-out rollers 2a, and the extremity end Al' of the top packaging sheet A is pressed against the oscillating supporting surface 2d of each of the tape feeding-out mechanisms 2. Thereafter, the rising lever 3a is moved away at a speed slower than that at which it approached the surfaces 2d, and for example, the lever may retreat a the of 1/3 of the approaching speed. The lever is moved away from the oscillating supporting surfaces 2d, 2d, 2d and is returned to its initial state.
The sheet feeding-out mechanism 4 comprise the feeding-out roller 4a which is lower than the oscillating supporting surface 2d of each of the tape feeding-out mechanisms 2, and the pressing roller 4b is arranged to be reciprocable in a direction toward and away from the feeding-out roller 4a.
The central part of the pressing roller 4b opposite the central adhering mechanism is covered by non-adhering material 4c such as silicone rubber, for example, to prevent the adhering tape Cl from sticking thereto. The feeding-out roller 4a and the pressing roller 4b are cooperatively related with a driving part such as a stepping motor, for example, so that the feeding-out roller 4a is intermittently rotated by the driving part, and then the pressing roller 4b is reciprocated to co-operate with the feeding-out roller 4a.
The driving part for the sheet feeding-out mechanism 4 is controlled in this operation by the control part, the pressing roller 4b is initially spaced apart from the feeding-out roller 4a while the rotation of the feeding-out roller 4a is stopped. Then the pressing roller 4b is moved to the feeding-out roller 4a after the rising lever 3a of the positioning mechanism 3 is moved away. The feeding-out roller 4a is rotated only while the right and left oscillating supporting surfaces 2d, 2d are retracted and the packaging sheet A is held between the feeding-out roller 4a and the pressing roller 4b to be fed out to a sheet transporting mechanism 5. The sheet is fed along the feeding-out passage Al while being bent in a corrugated form, and the pressing roller 4b is moved away from the feeding-out roller 4a after the elevator 6 is lifted up to its upper limit position and then it is returned to its initial state.
The sheet transporting mechanism 5 comprises a transporting roller 5a and reciprocable pressing rollers 5b which are arranged to engage the sheet to feed same but so as not to interfere with the passing positions of the adhering tapes Cl, C2, C2. Operation of the rollers 5a, 5b is by means of a driving part such as a stepping motor, for example, which is cooperatively related to the transporting roller 5a and the pressing roller 5b,so that the transporting roller 5a is rotated by the driving part and the pressing rollers 5b is reciprocated against the transporting roller 5a.
The driving part for the sheet transporting mechanism 5 is controlled in its operation by the control part, the pressing rollers 5b are moved away from the transporting roller 5a and held while the transporting roller 5a is being stopped. The pressing rollers 5b approach and are pressed against the transporting roller 5a substantially concurrent with the approaching of the pressing roller 4b of the sheet feeding-out mechanism 4 to the roller 4a, and at the same time the packaging sheet A fed out under the rotation of the transporting roller 5a is pushed out horizontally and transported up to the packaging starting position Pl, and after the transported packaging sheet A is supplied to the downstream end sheet supporting means 5c to be described later, the pressing roller 5b has moved away from the transporting roller 5a, and the rotation of the transporting roller 5a is stopped and it is returned to its initial state.
The downstream end sheet supporting means 5c is horizontally and laterally arranged in the right and left direction at substantially the same height as that of the upper end position of the transporting roller 5a. The downstream end of supporting means 5c is bent upwardly.
A sliding surface 5d is arranged between the transporting roller 5a and the supporting means 5c along the lower surface of the downstream end of the feeding-out passage Al. This sliding surface 5d may be fed out in the sheet supplying direction, the sliding surface 5d being formed by a material such as fluorine resin, for example, in flexible sheet form, the length of the sheet being greater than a distance from the transporting roller 5a to the downstream end sheet supporting means 5c and the width of the sheet being substantially the same as that of the maximum length size of the packaging sheet A. In addition, the sliding surface 5d is divided into a plurality of segments in the right and left direction so as not to interfere with the transporting roller 5a. The sliding surface is wound around the transporting roller 5a, and the upstream end of the sliding surface 5d in the sheet supplying direction is fixed to each of the winding rods 5e, resiliently wound by a resilient member such as a spring, for example. The winding rods 5e are rotatably and laterally arranged below the transporting roller 5a, and the downstream ends of the sliding surface are fixed to the upstream end winding guide 7 to be described later.
At the packaging start position Pl, there are reference guides 21, 21 opposite each of a set of opposing side surfaces B1 B1 of the contents B. There are vertical reference surfaces 22 opposite the side surfaces B2, B2. These guides and reference surfaces are arranged above the elevator 6 to be described later, and when the contents B are placed on the packaging starting position Pl to be enclosed by these members, the side surfaces Bl, Bl, B2 of the contents B are abutted against each of the reference guides 21, 21 and the reference surfaces 22, 22 and their positions are set.
The elevator 6 is arranged in relation to the reference guides 21, 21 in such a manner that it may be reciprocated in a vertical direction, the width size of the mounting surface 6a in the length direction of the frame F, being of a size where two pieces of contents B of the maximum size are mounted side-by-side in the sheet feeding direction, the size in the right and left direction being such that the contents B of the maximum size can be accomodated.
A driving part such as a stepping motor, for example, is cooperatively arranged to ascend or descend the mounting surface 6a.
The elevator 6 is controlled in its operation by the control part, so that the mounting surface 6a is lifted up to its upper limit position and held before feeding-out of the packaging sheet A. Then the mounting surface 6a is descended down to a position near its lower limit position substantially concurrent with the starting operation of the feeding-out roller 4a of the sheet feeding-out mechanism 4. The mounting surface 6a is lifted up to its upper limit position just after the winding guides 7, 7 to be described later are moved to a position just below the reference guides 21, 21 and then the mounting surface 6a approaches the winding guides 7, 7.
Next, as the contents B are mounted on the packaging sheet A and the sheet pressers 7b, 7b are moved away from the upper surfaces 7a, 7a of the winding guides 7, 7, the contents B is descended down to the lower limit position wherein the upper surface of the contents is below the winding guides 7, 7 and compression receiving plates 8, 8.
Subsequently the contents B is ascended by a predetermined amount until the upper surface B3 is forcibly contacted by the compressive receiving plates 8. It is slightly descended after the downstream side winding guide 7 is moved to the central upper positions of the compressive receiving plates 8, 8. The mounting surface 6a is ascended or descended in such a way that lateral folding guides 9 are at desired height positions in relation to both side flaps A4 of the partially folded sheet A, regardless of the height size of the contents B. The mounting surface 6a is lifted upon completion of the advancement of the pusher 10 and returned to its initial state.
The machine includes as shown the pair of wrapping guides 7, 7 for winding the packaging sheet A around the contents B, compressive receiving plates 8, 8 which can be projected into the ascending or descending passage 6e of the elevator 6 to lie opposite the upper surface B3 of the descended contents B, the lateral folding guides 9 for folding the side flaps A4 of the expanded end parts A3, A3 of the wound packaging sheet A along each of the opened side surfaces B2, B2 of the contents B.
The pusher 10 is provided for horizontally transporting the contents B along the mounting surface 6a of the descended elevator 6 and at the same time upper holding guides 11, 11 serve to hold the lower flaps A5, A5 of the expanded ends A3, A3 of the packaging sheet A along the side surfaces B2, B2 of the contents B. Folding guides 12, 12 are arranged above the upper holding guides 11, 11 in order to fold down the upper flaps A6, A6 of the expanded ends A3, A3 along the side surfaces B2, B2 of the contents B.
The winding guides 7, 7 are plates and their upper surfaces 7a, 7a are substantially kept horizontal. Opposite inner ends 7b, 7b are parallel to the side surfaces Bl, Bl of the contents B. The length of plates 7a, 7a is longer than the longest size of contents B to be received on the machine, and resilient members 7c, 7c such as a sponge or a leaf spring, for example, are fixed to the lower surfaces of plates 7a, 7a as required. The plates 7a, 7a may be arranged below the reference guides 21, 21 in a vertical direction and in such a manner that they may be reciprocated in the sheet supplying direction along the upper surface B3 of the descended contents B, by a driving part such as a stepping motor, for example, which is connect to each of them. The plates may be moved up and down and alternatively reciprocated by the driving parts.
The driving parts for the winding guides 7, 7 are controlled in their operations by the control part, and the winding guide 7 are arranged at the upstream side in the sheet supplying direction in the initial state is held near the transporting roller 5a or at a position just below the reference guide 21, whilst the winding guide 7 arranged at the downstream side is held near the downstream end supporting means 5c. The upstream end winding guide 7 is moved in the sheet supplying direction at the same speed as the supplying speed of the packaging sheet A after the extremity end Al' of the packaging sheet A reaches the upstream side winding guide 7 and then the upstream side winding guide 7 moves toward the downstream side winding guide 7.
Extremity end Al' of the supplied packaging sheet A is moved from the upstream side winding guide 7 to the downstream side winding guide 7, and from the downstream winding guide 7 onto the downstream supporting means 5c. Thereafter the winding guides 7, 7 are moved in a direction opposite to the sheet supplying direction up to the position just below the reference guides 21, 21, and each of the upper surfaces 7a, 7a is slightly moved upward as the elevator 6 is ascended to its upper limit position. The inner ends 7b 7b are arranged in substantially the same vertical plane as the upstream and downstream side surfaces Bl. Bl of the contents B. The winding guides 7, 7 are slightly moved down as the elevator 6 is descended, and they are moved by a predetermined amount toward each other, just after the elevator 6 is descended down to its lower limit position.
In addition, just after the elevator 6 is slightly ascended and the upper surface B3 of the contents B is placed against the compressive receiving plates 8, 8 the upstream side winding guide 7 is moved to the central part of the upper surface B3 of the contents B, and downstream winding guide 7 is moved with a slight delay toward the upstream side winding guide 7. Upon completion of this movement, the upstream side winding guide 7 is moved in the opposite direction, whilst the downstream winding guide 7 is moved to a central position in relation to the compressive receiving plates 8, 8 and then returned to its initial state.
Further, the upper surfaces 7a, 7a of the winding guides 7, 7 are engaged by the sheet pressers 7d which comprise weights, in that the weights may be moved in the vertical direction toward and away from the sheet pressers 7d. Each of the sheet pressers 7d is cooperatively related to driving parts 7e, 7e comprising for example solenoids, which are arranged above the sheet pressers so that the sheet pressers 7d can be moved up and down by these driving parts 7e, 7e to be moved toward and away from the upper surfaces 7a, 7a of the winding guides 7, 7.
The driving parts 7e, 7e for the sheet pressers 7d are controlled in their operations by a control part whereby the sheet pressers 7d are initially moved up before the packaging sheet A is fed out by the transporting roller 5a of the sheet transporting mechanism 5. The sheet pressers 7d are moved down just after the elevator 6 is descended down to its lower limit position and the sheet pressers 7d forcibly contact the upper surfaces 7a, 7a of the winding guides 7, 7. Upon completion of the approaching of the winding guides to the centre of the surface B3, the sheet pressers 7d are moved up so as to be returned to their initial states.
The compressive receiving plates 8, 8 have at their upper surfaces coatings of non-adhesive agent such as silicone, The compressive receiving plates 8, 8 are arranged in such a manner that they may be reciprocated in the right and left direction to lie between the winding guides 7, 7 and the upper surface B3 of the descended contents B. When the plates are projected into the ascending or descending passage 6b the ends are arranged to lie just above the ends of the upper surface B3 of the contents B in the sheet supplying direction. These compressive receiving plates 8, 8 are cooperatively related with the driving parts such as a stepping motor, for example, and each of the plates is moved in the right and left direction by these driving parts.
The driving parts for the compressive receiving plates 8, 8 are controlled in their operations by the control part so that the compressive receiving plates 8, 8 are held out of the ascending or descending passage 6b of the elevator 6 so as not to interfere with the descending of the packaging sheet A and the contents B on the elevator 6 as it moves form the initial state. The plates are returned from above the contents B out of the ascending or descending passage 6b of the elevator 6 to the initial state.
The lateral folding guides 9 are arranged below the winding guides 7, 7 and lie opposite the mid regions of the side flaps A4 of the extending ends A3, A3 of the packaging sheet A and in the same plane as the opened side surfaces B2, B2 in such a manner that they may be reciprocated in the sheet feeding direction. Also, two guides positioned at the downstream side from the contents B are arranged in such a manner that they may not be moved in the sheet supplying direction. Each of the guides is rotatably supported in the folding direction of the side flaps A4, abutting portions 9a of the guides 9,9 lying opposite and substantially parallel to the closed side surfaces Bl, Bl.
In addition, these lateral folding guides 9 have descending folding portions 9b which fold the sheet material toward the lower flaps A5, A5 as the abutting portions 9a and the side flaps A4 are abutted against each other. The intermediate portions of the inner surfaces of the guides pivot over the four corners of the side surfaces Bl, Bl, B2, B2 of the contents B. In the case that the extending length of each of the extending end portions A3 is longer than the half of the width of each of the open side surfaces B2, the elevator 6 and the upper folding guides 11, 11 are descended by a predetermined height, and in turn, in the case that the extending length of each of the extending end portions A3 is shorter than the half of the width of each of the open side surfaces B2, the elevator 6 and the upper folding guides 11, 11 are ascended by the predetermined height, in such a manner that the lower end of the descended folding portions 9b reach the bottom surface B4 of the contents B.
The lateral folding guides 9, 9 at the upstream side are cooperatively provided with a driving part such as a stepping motor, for example. The driving part is operated by the control part, the abutting portions 9a, 9a and the folding portions 9b, 9b are held at the positions where they do not interfere with the descending of the packaging sheet A and the contents B by the elevator 6. The abutting portions 9a, 9a are moved in the same direction concurrent with the advancing movement of the pusher 10, and they are retracted upon completion of transporting of the contents B by the pusher 10. Thereafter, returning projections 9c, 9c abut against and engage the guides after their retraction, so that they are forcibly rotated in a reverse direction opposite and returned to the initial state.
The downstream side lateral folding guides 9, 9 have temporary holding portions 9d, 9d such as permanent magnets or electromagnets. Thus, for example, the abutting portions 9a, 9a are held substantially parallel with the closed downstream side surface Bl of the contents B. This is transported by the pusher 10, and at the same time, the lower ends of these abutting portions 9b, 9b, formed with slant cam surfaces 9e, 9e, are rotated toward the folding direction but as movement takes place, guide surfaces 11a, 11a of the guides 11,11 engage the cam surfaces 9e,9e and thereby these lateral folding guides 9, 9 are forcibly rotated in a reverse direction opposite to the folding direction and returned to their initial stages.
The pusher 10 is reciprocably arranged and passes vertically through the elevator 6 and the upper end of the vertical transporting surface 10a is arranged below the compressive receiving plates 8, 8 and at the same time a driving part such as a stepping motor, for example, is arranged to reciprocate the pushing surface 10a.
The driving part for the pusher 10 is controlled in its operation by the control part, and the pushing surface 10a is held in an initial state in the same vertical plane as the upstream side surface Bl in the sheet supplying direction of the contents B. The pushing surface 10a is moved to advance substantially concurrent with the advancing of the upstream lateral folding guides 9, 9 toward the downstream side. It is stopped at the position where the closed downstream side surface Bl of the contents B is abutted against the downstream side lateral folding guides 9, 9, and it is moved forward again after the upstream side lateral folding guides 9, 9 are rotated onto the opened side surfaces B2, B2 of the contents B. It is stopped at the position where it is advanced to an arranged position of the downstream side lateral folding guides 9, 9. It is retracted toward the upstream side to the initial state during ascending of the elevator 6 or just after completion of the ascending operation.
The upper folding guides 11, 11 are placed on the same horizontal surface as those of the open side surfaces B2, B2 of the wound contents B and are vertically arranged near the downstream side of the contents. Upper slant sides lla, lla of the guides oppose the lower flaps A5, A5 and the guides are supported in such a way that they may be moved up and down, whereby upper slant sides lla, lla may be adjusted and moved so as to be slightly higher than the mounting surface 6a during its descending, regardless of the amount of descending amount of the elevator 6. Upon completion of the advancing movement of the pusher 10, the guides 11,11 are ascended from the open side surfaces B2, B2 of the contents B, and are abutted against the lower flaps A5, A5 transported by the pusher 10, which are folded along the opened sides B2, B2 and further they are ascended at the same speed as that at which the elevator 6 is ascended.
The folding guides 12, 12 are constructed such that supporting frames 12b, 12b are arranged above the upper folding guides 12, 12 and are adjustable in accordance with the variation in size of the length of the contents B in the right and left direction. Each of the inner ends 12a, 12a of these supporting frames 12b, 12b is arranged in such a way that it may be reciprocated in the right and left contacting direction, and at the same time there are provided weights 12c, 12c for applying the specified pressure in the direction to cause the inner ends 12a, 12a to approach each other. Stoppers 12d, 12d prevent the inner ends 12a, 12a from moving too close together. Returning means 12e, 12e are provided for moving the projected inner ends 12a, 12a in a reverse direction opposite to the projecting direction.
An input means 23 such as a key pad, for example, is for inputting an outer shape and a size of each packaging sheet A and the contents B and there is a sheet feeding-out starting switch Sl as well as the packaging start switch S2. These are arranged at the upper surface of the device where the packaging starting position Pl is arranged, the inputting means 23 being communicated with the aforesaid sheet feeding-out mechanism 4 and the sheet transporting mechanism 5 through the control part, the driving part for the sheet feeding-out mechanism 4 and the driving part for the sheet transporting mechanism 5, which are controlled in their operations in response to calculation by the control part every time the outer shapes and the sizes of the packaging sheet A and the contents B are changed. By this means, the feeding-out amount of the packaging sheet A is adjusted in such a manner that the extremity ends Al' of the overlapped packaging sheets A regardless of size may be arranged at the central position of the upper surface B3 of the contents B. At the same time the inputted value is displayed on a displaying part 23a such as CRT.
The sheet feeding-out start switch Sl and the packaging start switch S2 are connected with the driving part for the following;-
the tape feeding-out mechanisms 2, 2, 2, the adhering mechanism 3, sheet feeding-out mechanism 4, the sheet transporting mechanism, the elevator 6, the winding guides 7, 7, the compressive receiving plates 8, 8, the lateral folding guides 9, the pusher 10, and the upper folding guides 11, 11.
In addition, the packaging completing position P2 arranged at the downstream side from the packaging start position Pl has supporting means which project along the bottom surface B4 of the contents B. The supporting means comprises latches 13 which project a small amount toward the right and left ends of the bottom surface B4. They are urged by resilient members 13a such as springs, for example, from the supporting frames 12b, 12b of the folding guides 12, 12, and a latch 14 having a large projection engages the central part of the bottom surface B4. The latch can be fed into or fed out of the recess 6c formed at the downstream end of the mounting surface 6a. The upper end surfaces of these latches 13,14 are arranged at substantially the same height position as that of the surface of the folding guides 12, 12 and the bottom surface B4 of the contents B.
The latch 14 having a large projection is constructed such that a rising piece 14b is arranged on the base 14a arranged lower than the lower limit position of the mounting surface 6a in such a manner that it may be resiliently moved in the sheet supplying direction, by being supported by a resilient member 14c such as a spring, for example, placed between the rising piece 14b and the side surface F3 of the frame. In this way, the rising piece 14b is always pressed toward the upstream-side.
Operation of the packaging machine will now be described. At first, the sheet supplying start switch Sl is manually operated, the tape feeding-out mechanisms 2, 2, 2 are started to operate to feed out each of the adhering tapes Cl, C2, C2 up to each of the oscillating supporting surfaces 2d, 2d, 2d by which they are supported, and subsequently the rising lever 3a of the adhering mechanism 3 and the pressing sheet ld are moved in a bending direction while holding the extremity ends Al of the upward bent packaging sheets A as shown in Fig.4(a). The entire packaging sheets A are bent along the abutting guide lf and at the same time the extremity end Al' of the top packaging sheet A is forcibly contacted to the oscillating supporting surfaces 2d, 2d, 2d and each of the adhering tapes Cl, C2, C2 is partially projected and partially adhered at the central part of the extremity end Al' and both right and left ends.
In the case that the position of the extremity end Al' is detected by the sensor lh indicating that the extremity end Al' does not reach up to the setting position, the stopper lg is moved to push out the accumulated packaging sheets A along the pressing sheet ld. Thereby, the extremity end Al' of the downstream side packaging sheet A to be bent reaches the setting position, and concurrent with this operation, the wedge lever 3b partially holds the extremity ends Al of the packaging sheets A by the resilient members 3d, 3d and forcibly presses them against the lower part of the feeding-out roller 4a and thus a part of each of the extremity ends Al is bent along the outer circumferential surface of the feeding-out roller 4a.
The cutter 2c of the tape feeding-out mechanism 2 opposing against the central sealing corresponding position is projected (only shown in Fig.3) to cut the adhering tape Cl, and after a slight delay, its oscillating supporting surface 2d is projected toward the feeding-out passage Al of the packaging sheet A to adhere the adhering tape Cl over the entire right and left direction.
Thereafter, the rising lever 3a starts gradually its movement toward the reverse direction, only the rising lever 3a is slowly moved away from the oscillating supporting surfaces 2d, 2d, 2d as shown in Fig.4(b), although the rising lever 3b partially holds the extremity ends A' of the packaging sheets A by the resilient members 3d, 3d and they are forcibly pressed against the lower part of the feeding-out roller 4a, resulting in that a counter bending recovering force is applied to the upper extremity ends Al' to cause the accumulated extremity ends Al' to be forcibly pulled apart from the extremity end Al' of the downstream end of the top packaging sheet A adhered to the adhering tapes Cl, C2, C2.
This pulling-out operation is effective even in the case that the accumulated amount of the packaging sheets is small, and the packaging sheets can be separated positively up to the final single sheet.
After separation, the wedge lever 3b is also moved away from the lower part of the feeding-out roller 4a as shown in Fig.4(c), and is returned together with the rising lever 3a in a counter-bending direction. During this returning operation, oscillating pieces 3c, 3c are abutted against the fixed stoppers 3e, 3e, and the wedge lever 3b is oscillated in a direction causing it to move apart from the lower part of the feeding-out roller 4a.
Subsequent to this operation, the pressing roller 4b is entered, as shown in Fig.4(d), between the entire extremity ends Al of the packaging sheets A which have been returned in a counter-bending direction, and the downstream extremity end Al of the top packaging sheet A. The roller 4b is forcibly contacted with the feeding-out roller 4a, thereafter, the cutters 2c, 2c of the tape feeding-out mechanisms 2, 2 at the right and left sealing positions are projected to cut the adhering tapes C2, C2. Just after this operation, each of the oscillating supporting surfaces 2d, 2d is projected toward the feeding-out passage A' and concurrent with this operation, the feeding-out roller 4a is rotated to cause the sheet A having the adhering tapes Cl, C2, C2 adhered thereto to be fed out toward the sheet transporting mechanism 5 along the feeding-out passage A'.
After a little delay, the extremity end Al' of the fed-out packaging sheet A advances between the transporting roller 5a and the pressing roller 5b of the sheet transporting mechanism 5, whereby the packaging sheet A is horizontally supplied towards the packaging start position Pl. The sliding surface 5d slides relative to the supporting roller 5a and is not fed out at this time.
When the extremity end Al' of the fed-out and supplied packaging sheet A is near the supporting roller 5a or the upstream side winding guide 7, held at the position just below the reference guide 21, the upstream side winding guide 7 starts to move in the sheet supplying direction at the same speed as the packaging sheet A. Also at this time, the sliding surface 5d fixed to the upstream side winding guide 7 is pulled in the sheet supplying direction, whereby the sliding surface 5d is unwound from the winding roll 5e, and is pulled out in the sheet supplying direction along the lower surface at the of the feeding-out passage A' at the same speed as the supplying speed of the packaging sheet A.
Accordingly, the packaging A, supported on the sliding surface 5d, is supplied without hanging downwardly. Thereafter, when the upstream side winding guide 7 has moved to near the downstream side winding guide 7, it is stopped, and the extremity end A1' of the packaging sheet A is moved from the sliding surface 5d over the downstream side winding guide 7 and onto the downstream side supporting means 5c, until the extremity end Al' lies sloped upwardly as shown in Fig.1 along the downstream side supporting means 5c. Transporting by the transporting roller 5a is now complete.
Upon completion of the supplying of the packaging sheet A, as the elevator 6 is ascended to its upper limit position, the winding guides 7, 7 are moved to the positions just below the reference guides 21, 21 and thereafter the sheet pressers 7d are moved downwardly to hold the packaging sheet A to prevent the positional displacement of the packaging sheet A. In this condition, with the contents B set on the packaging sheet A, the packaging sheet A deflected by the weight of the contents B to cause the lower surface B4 of the contents B to be abutted against the mounting surface 6a of the elevator 6.
Thereafter, upon manual operation of the packaging start switch S2, the sheet pressers 7d are moved upwardly to release the packaging sheet A, the elevator 6 starts to descend, and the packaging sheet A is formed to a substantial U-shape to lie along the bottom surface B4 of the contents B and both sides Bl, Bl as shown in Fig.5(a). When the descending operation of the elevator 6 is stopped, the sheet pressers 7d are moved downwardly to hold the packaging sheet A between the upper surfaces 7a, 7a of the winding guides 7,7 and concurrently, the compressive receiving plates 8, 8 are positioned above the contents B.
The winding guides 7, 7 are moved together by a predetermined amount and the elevator 6 is slightly ascended as shown in Fig.5(b) to cause the top surfaces B3 of the contents B to be engaged with the compressive receiving plates 8, 8 in such a manner that the contents B are compressed in a vertical direction, and the packaging sheet A opposing against the side surfaces B1,B1 becomes loose in a vertical direction. Subsequently, upstream side winding guide 7 is projected as shown in Fig.5(c) and then the downstream end winding guide 7 is projected as shown in Fig.5(d).
Thereby, the ends A1 and A2 are wound into U-shape around the winding guides 7, 7, inner ends 7b, 7b and the resilient members 7c, 7c. As the winding guides 7, 7 are protejcted, the tension applied to the packaging sheet A is larger than the frictional resistance between the packaging sheet A and the winding guides 7, 7, resulting in that each of end of the packaging sheet A is pulled out from between the upper surfaces 7a, 7a of the winding guides 7, 7 and the sheet pressers 7d. End portion A2 of the packaging sheet A is folded at first along the upper surface B3 of the contents B as shown in Fig.5(c).
Then, the extremity end Al of the packaging sheet A is also pulled out as shown in Fig.5(d). At this time, the adhering surface of the adhesive tape Cl is adhered to the bottom surface of the downstream side sheet presser 7d whereby the packaging sheet A is further fastened and folded along the upper surface B3 of the contents B. The folded end A2' is pushed against the upper surface B3 of the contents B by resilient members 7c, 7c so as to prevent it from being pulled back.
Subsequently, the sheet pressers 7d are moved upwardly as shown in Fig.5(e), the downstream side winding guide 7 is projected to a central in relation to the compressive receiving plates 8, 8 as shown in Fig.5(f) so that the extremity end Al' of the packaging sheet is overlapped on the outside of the end portion A2' and at the same time, the overlapped end A2' and end Al' are held by the lower resilient member 7c of the downstream side winding guide 7 and the upper surface B3 of the contents B. The projected portions of the adhering tapes Cl, C2, C2 adhered to the extremity end Al' are therefore pushed against the end A2', so as to seal thereto.
Subsequently, the elevator 6 is slightly descended as shown in Fig.5(g) and the compression on the contents B is released and then the compressive receiving plates 8, 8 are pulled out to complete the winding stage. Thereafter the contents B is transported by the advancing movement of the pusher 10, and as shown in Fig.6, the downstream side surface Bl of the contents is abutted against the abutting portions 9a, 9a of the downstream side lateral folding guides 9, 9. At this time, the contents B are held and position set immovably between the temporarily stopped pusher 10 and the downstream side abutting portions 9a, 9a temporarily held by the temporary holding portions 9d, 9d.
In this condition, each of the abutting portions 9a, 9a is abutted against the downstream side surface Bl of the contents B, the folding portions 9b, 9b are descended toward the lower flaps A5, A5 of the end portions A3, A3. As each of the inner surface intermediate portions pivots over the corners between the upstream side surface Bl and the opened side surfaces B2, B2 by 1/4 rotation, the entire upstream side flaps A4, A4 are pulled downwardly, and upper portions of the base ends of these side flaps A4, A4 are tightly folded along the opened side surfaces B2, B2 of the contents B while pressing against the corners. Subsequently, contents B are transported by the pusher 10, and the folding portions 9b, 9b are descended toward the lower flaps A, A5 as the inner surface intermediate portions of the downstream folding guides 9, 9 pivot over the corners between the downstream side surface Bl and opened side surfaces B2, B2 by 1/4 rotation, thereby entire downstream side flaps A4, A4 are pulled downwardly, and upper portions of base ends of these side flaps A4, A4 are tightly folded while being pressed against the corners.
The contents B pass between the inner surfaces of the abutted and rotated lateral holding guides 9 and are guided to the downstream side of the mounting surface 6a. Base end portions of lower flaps A5, A5 are engaged and folded by the upper slant sides lla, lla of the upper folding guides 11, 11, thereby the folded side flaps A4 are prevented from becoming loose.
Subsequently, the closed downstream side surface Bl of the contents B is abutted against a rising piece 14b of the latch 14 as shown by a chain-dotted line in Fig.7. Subsequent transportation causes the contents B to be pushed to the predetermined position shown in Fig. 8, while the rising piece 14b remains press contacted to the closed downstream side surface Bl, and when the contents B reaches the predetermined position, the advancing movement of the pusher 10 is completed.
Concurrent with this operation, the upstream side lateral folding guides 9, 9 during their returning movement, are abutted against and engaged with the returning projections 9c, 9c as shown in Fig.8 whereby the upstream side lateral folding guides 9, 9 are forcibly rotated in a reverse direction and returned to the initial state. Subsequently, upper folding guides 11, 11 are ascended to cause the lower flaps A5, A5 to be folded on to the outside of flaps A4. Concurrently the upper slant sides lla, lla are abutted against and engaged with the slant cam surfaces 9e, 9e of the downstream side lateral folding guides 9, 9, whereby the downstream side lateral folding guides 9, 9 are forcibly rotated in a reverse direction and returned to their initial states.
Next, the mounting surface 6a of the elevator 6 is ascended, which pushes the contents B along the pushing surface 10a of the pusher 10 and the rising piece 14b of the latch 14 so that the upper surface B3 of the ascending contents B strickes against the stoppers 12d, 12d of folding guides 12, 12, resulting in that inner ends 12a, 12a of the folding guides 12, 12 are pushed against the opened side surfaces B2, B2 of the contents B at a specified pressure by the weights 12c, 12c.
With such an arrangement as above, the upper flaps A6, A6 are gradually folded down to be overlapped on outside of the lower flaps A5, A5, as shown in Fig.1, which shows the case that the projecting length of the upper flaps A6, A6 is shorter than the height size of the contents B. The adhering tapes C2, C2 adhered to the extremity ends of the upper flaps A6, A6 which are tensioned downwardly by the inner ends 12a, 12a of the folding guides 12, 12, are adhered to the lower flaps A5, A5, completing the sealing and edge folding step.
In the case that the projecting length of the upper flaps A6, A6 is longer than the height size of the contents B, the extremity ends of the flaps A6, A6 project downwardly to lie on the bottom surface B4 of the contents B. Upon completion of the folding-down operation, the inner ends 12a, 12a of the folding guides 12, 12 are projected along the bottom surface B4 of the contents B by the weights 12c, 12c and the contents B being ascended completely pass between the inner ends 12a, 12a of the folding guides 12, 12. The latches 13 are projected along the right and left ends of the bottom surface B4, and also the rising piece 14b of the latch 14 is projected along the bottom surface B4 near the central part.
When the mounting surface 6a of the elevator 6 is descended leaving the contents B is supported by these latches 13, 14, inner ends 12a, 12a of the folding guides 12, 12 are projected further by the weights 12c, 12c, so that the extremity ends of the upper flaps A6, A6 are folded along the bottom surface B4 of the contents B, and at the same time, they are adhered by the adhering tapes C2, C2 to complete the sealing.
When the packaging of the contents B is completed and the elevator is descended to receive the next contents, the packaged contents are supported by the latches 13,14 even if the folding guides 12, 12 are moved in a direction away from each other. In addition, in the case where the size of the packaging sheets A is changed, the control part automatically adjusts and moves the side guides lb, lb or stopper lf in response to the size inputted data, and as the side guides lb, lb are moved, the tape feedingout mechanisms 2, 2 at the right and left ends are moved in the right and left direction, and the feeding amount of the packaging sheet A by the sheet feeding-out mechanism 4 and the sheet transporting mechanism 5 are automatically changed.
In the case that that the outer shape and size of the contents B are changed is changed, the control part automatically changes the feeding amount of the packaging sheet A by the sheet feeding mechanism 4 and the sheet transporting mechanism 5, and automatically changes the descending amount of the elevator 6 and the height position of the upper folding guides 11, 11. Each of the reference guides 21, 21 and the winding guides 7, 7 is moved in the sheet supplying direction, the spacing between them is automatically changed.
In the aforesaid preferred embodiment, the packaging sheet A is folded into a substantial U-shape under andalong both side surfaces Bl, B2 of the contents B and whilst this is the preferred embodiment, the invention is not limited to this form, and the sheet A may lie on the upper surface of the contents and the elevator 6 ascended, whereby the packaging sheet A may be folded in an inverse U-shape along both side surfaces Bl, Bl of the contents B.
Also in the embodiment described, the lower flaps A5, A5 are folded up, and thereafter the upper flaps A6, A6 are folded down to be overlapped on the outside of the lower flaps A5, A5, but the invention need not be limited to this form. For example, after the upper flaps A6, A6 are folded down by the folding-down guides arranged between the downstream side lateral folding guides 9, 9 and the upper folding guides 11, 11, thereafter the lower flaps A5, A5 may be folded and overlapped by the upper folding guides 11, 11. The extremity ends of these lower flaps A5, A5 may be sealed by the adhering tapes adhering, and the extremity ends of the folded up lower flaps A5, A5 may be sealed by the adhering tapes after folding along the upper surface B3 of the contents B, by the projecting movements of the folding guides 12, 12.
The embodiment of the present invention has the following advantages.

1) The packaging sheet at the sealing postition is moved toward and away from the adhering tape fed out from the tape feeding-out mechanism by the adhering mechanism. Thereby, a part of the adhering tape is projected and adhered at the sealing position. Thereafter, the packaging sheet having the adhering tape adhered thereto is fed out by the sheet feeding-out mechanism to the packaging start position and during the completion of the folding of the packaging sheet during the packaging process, the projected part of the adhering tape is adhered and sealing is performed simultaneously while the packaging sheet is being packaged.
Accordingly, as compared with the prior art packaging device in which each of the adhering tapes is applied upon completion of the winding and upon completion of the folding, a separate stage for adhering tapes during the packaging stage of the contents B is not necessary. Also, each of the tape feeding-out mechanism and the adhering mechanism is not required to be arranged at the positions opposing against the overlapped ends of the packaging sheet when wound round the contents, resulting in that the entire device can be made small and its structure is also simplified.
2) The adhering mechanism moves the extremity end of the packaging sheet while the sheets are accumulated, and abuts the top sheet against the adhering tape which has been fed out and supported by the tape feeding-out mechanism. Thereby only the extremity end of the top packaging sheet is held, and thereafter, the extremity ends of the accumulated packaging sheets are moved in a counter-bending direction and moved away from the tape feeding-out mechanism. Thus, the recovering force of the packaging sheets in the counter-bending direction is utilized, leaving an entire extremity end of the top packaging sheet held at the adhering tape which results in that the adhering force or frictional force is not utilized and only the top packaging sheet is separated.
As compared with the prior art packaging device in which it is required to have separately a separating means utilizing an adhering or frictional force in order to perform a positive separation of only one packaging sheet from entire accumulated packaging sheets, the present invention does not require any separate arrangement of the separating means, and the machine of the invention is simplified and can be made small.
3) The packaging sheets are accumulated under the ascending or descending passage of the elevator in a continuous sheet arranging space, so that the maximum sheet arranging space can be assured and under utilization of the dead space is avoided.
Accordingly, as compared with the prior art packaging device having a paper feeding table on which the packaging sheets are slantly accumulated and the ascending or descending passage of the elevator is arranged side-by-side in a lateral direction with the table, the present invention can store the long packaging sheets in a compact manner without changing the size of the entire device in lateral and verticla directions.
4) A part near the extremity end of the bent packaging sheet is detected by a sensor, and it is moved when its position does not reach a set position, so that the extremity end of the packaging sheet will be pushed out until the extremity end reaches the set position. By this means, the downstream side of the packaging sheet can be kept at the specified position without moving the accumulated packaging sheets up and regardless of the amount of accumulated packaging sheets.
Accordingly, compared with the prior art system in which the accumulated packaging sheets are moved up and down and the packaging sheet located at the downstream end is maintained at the desired height regardless of the accumulated amount, the present invention provides a compact machine of a simplified structure.

Claims

A packaging machine in which a packaging sheet (A) is wrapped around contents (B) to be packaged by positioning the sheet and contents above an elevator (6) in a packaging start position (P1), and by moving the elevator (6) relative to the sheet (A) and contents (B) in an ascending or descending path, and wherein a length (C1,C2,C2) of adhering tape is used to seal the packaging sheet (A), characterized in that the machine comprises a packaging sheet positioning mechanism (3) for positioning the packaging sheet (A) in a tape receiving position, a tape feeding-out mechanism (2a,2b) for feeding-out and supporting adhering tape from a supply of such tape, a tape cutting mechanism (2c) for cutting the length (C1,C2,C2) of adhering tape from the supply, an adhering mechanism (2d) movable toward and away from the packaging sheet (A) when in the tape receiving position for adhering the length (C1,C2,C2) of adhering tape to the packaging sheet (A) so that part of the length of tape projects from the sheet (A), and a sheet feeding-out mechanism (4a,4b) for supplying the packaging sheet (A) with the length of tape adhered thereto along a feeding-out passage (A') from the tape receiving position to the packaging start position (P1).
A packaging machine according to Claim 1 in which the packaging sheet (A) is wound around the contents (B) into tubular form, and the adhering mechanism (2d) is adapted to apply the length (C1,C2,C2) of tape to the leading end (A1') only of the packaging sheet (A), which leading end (A1') is arranged to overlie the trailing end (A2) when the sheet (A) is wrapped into tubular form around the contents (B).
A packaging machine according to Claim 2, in which the sheet feeding-out mechanism (3) is controlled in such a manner that when the wrapping operation is carried out, regardless of the size of the packaging sheet (A) for the contents (B), the leading and trailing ends (A1,A2) of the overlapped packaging sheet (A) at the outside of the contents (B) are arranged at the central position of the contents (B).
A packaging machine according to Claim 2 or 3, wherein additional lengths of tape (C2,C2) are applied to the sheet (A) at the sides thereof for holding each of the extended ends (A3) of the packaging sheet (A) projecting in a rectangular tubular form from the side surfaces (B2) of the contents (B) and for sealing the said extended ends (A3) when folded over the side surfaces (B2) of the contents (B).
A packaging machine according to Claim 1 wherein the sheet positioning mechanism (3) is adapted to position accumulated packaging sheets (A) in the receiving position and the sheet feeding out mechanism (4a,4b) is adapted to feed the sheets (A) one-by one and to the packaging start position (P1), and wherein the machine is adapted to receive packaging sheets (A) accumulated below the said elevator (6) in a substantially horizontal disposition along a bottom surface (1a) of a frame (F1) of the machine so that the leading ends (A1') of these packaging sheets (A) are bent upwardly along side surfaces (1b) of the frame (F1), the sheet positioning mechanism (3) being arranged to engage the leading ends (A1') to bend them initially toward the adhering mechanism (2d), to have the length (C1,C2,C2) of tape applied to the top sheet (A), then to be moved in a counter-bending direction to separate the remaining sheets (A) from the top sheet (A).
A packaging machine according to Claim 5, including a stopper (1g) abutting against the trailing ends (A2) of the packaging sheets, said stopper (1g) being arranged in such a manner that it can be moved relative to the trailing ends, and including a sensor (1h) for sensing the position of the leading ends (A1') of the sheets, and said stopper (1g) being arranged to be adjustably moved in response to the output from the sensor (1h).
A packaging machine according to Claim 5 or 6, wherein, for the change in a movement of the packaging sheets (A) from the bending direction to the counter bending direction, the positioning mechanism (3) has a partial bending means (3b) for folding partially an extremity end of the bent packaging sheet (A).
A packaging machine according to Claim 1 in which the feeding-out passage (A') for the packaging sheet (A) lies at right angles to the ascending or descending path of the elevator (6), and the machine includes a pair of sheet supporting means (7) extending in a direction at right angles to the sheet supplying direction, and a slipping surface (5d) arranged over both sheet supporting means (7) along the lower surface of the feeding-out passage (A'), which sheet supporting (7) means can be moved together along the feeding out passage (A') in the direction of feed on the packaging sheet (A), and retracted in the opposite direction.