WRAPPING APPARATUS

Abstract: Apparatus for wrapping a load with strip material, the apparatus including a main frame or the like (2), a load support means (9) mounted for rotation about a first axis of rotation relative to the main frame or the like of the apparatus, said load support means incorporating a load support arrangement (18, 19) which is such that the load (L) can be rotated with respect to the load support means about an axis transverse to the direction of the axis of rotation of the support means, and means (50) for mounting a supply of plastics wrapping material in strip form whereby rotation of the load (L) about one or both said axes causes the strip material to be wrapped around the load whereby the load is respectively partially or wholly wrapped.

Description: rapping apparatus. This invention relates the packaging of bulk materials formed into a bale, pack or the like. In particular, the present invention is concerned with but not restricted to the handling of baled material such as straw or silage or other material in like divided form for use as animal feedstock. In relation to the handlinq of baled material for use as feed material for animals it is a common practice to feed animals during the winter or other periods when it is not possible for the animal to feed in the open with a feed stock commonly called silage which is produced from for example, alfa, grass, hay and- straw by a process in which the wilting straw or hay undergoes a controlled bacteriological change process for the success of which it is essential to exclude atmospheric air in order to avoid the risk of the material rotting or otherwise decaying in such fashion as to render the material unsuitable as a feed for animals. There are a number of methods of storing the hay or straw for the purposes of silage production including large storage containers known as silos which comprises substantially sized and highly expensive structures. In view of the expense and other factors involved with the maintenance of such structures, these structures are generally speaking not readily usable by other than very large farms or the like or suitable where relatively small quantities of feed are required at a particular point of time. In order to make the production of silage a convenient and economic possiblity by those having relatively small herds of cattle and thus a relatively small feed demand at any one time or those who prefer not to utilise large permanently erected structures fox silage production a silage producing technique has been introduced which involves forming bales of the hay or straw and then hermetically enclosing the bale in a plastics material so that the requisite silage production processes can take place within the container of plastics material. One method of hermetically enclosing the bale is to introduce the straw or hay into a plastics bag and then seal the bag. It has been found that whilst the process of introducing the bale into a plastics bag appears to be relatively simple operation difficulties have been found in the utilsation of such containers, including those arising from the problem of ensuring a hermetic sealing of the container. With a view to ovecoming such difficulties it has been proposed to wrap bales by means of a continuous strip of plastics material one of whose characteristics of use is that it has to be pre-stretched by an optimum amount in order that it will be effective as a a bale wrapping material. The bale is wrapped in such manner that the baled material is effectively totally enclosed or shrouded in several layers of the plastics strip. To achieve the required wrapping it is necessary to wrap the bale in such manner that all air is excluded fro the baled material and that respiration of the baled material is prevented. In order to obtain and ensure the requisite air tightness the wrapping strip of plastics material, which is delivered to a wrapping position from a reel thereof has to be maintained under a tension controlled within Q predefined limits. In addition, in order to achieve the total plastics enclosure it has been found necessary to be able to rotate the bale about two axes at right angles to each other. In the case of the so-called 'big' bale which has a cylindrical shape it is necessary 5 to rotate the bale about its longitudinal axis and al-so about a second axis transverse to the longitudinal axis and passing through the centre of the bale. In addition, the rotation of the bale in these two directions of rotations is such that the each part of o the surface thereof is progressively moved into a setting in which it can be brought into the wrapping position. It is also to be noted that the preferred wrapping technique is in the end-to-end sense accompanied with rotation of the bale through a 5 predetermined angle about its longitudinal axis at the finish of each end-to-end complete rotation. In addition, in situations where the hay, straw or other material is required for more immediate use the bales thereof are partially wrapped with a wrapping 0 serving essentially to hold the material in the baled state. In the case of the so-called large bale this partial wrapping is called barrel wrapping. It is an object of the invention to provide improved apparatus for wrapping such baled material. Broadly, according to an aspect of the invention there is provided a load wrapping apparatus, including a main frame or the like, a load support means mounted for rotation about a first axis of rotation relative to the main frame or the like of the apparatus, said load support means incorporating a load support arrangement which is such that the load can be rotated with respect to the load support means about an axis transverse to the direction of the axis of rotation of the support means, means for mounting a supply of plastics wrapping material in strip form whereby rotation of the load about one or both said axes causes the strip material to be wrapped around the load. whereby the load is respectively partially or wholly wrapped. Preferably, the rotation of the load support means is produced by direct drive from the output shaft of a motor and the rotation of the load on the support means is obtained by direct drive. According to a second aspect of the invention there is provided a load wrapping apparatus including a main frame or the like, a load support surface for the load to be wrapped rotatably mounted to the main frame, means for rotating the load support surface about a first axis, means for rotating the load whilst on the support surface whereby the load is rotated about second axis of rotation transverse to the first axis braking means for enabling stopping of the rotation o the load about a selected one of said axes, stri material dispenser means for enabling delivery o material in strip form for wrapping the load during th rotation thereof, the arrangement being such that whe the load is subjected to rotations about both said axes the load can be fully wrapped as to be totally enclosed by wrapping material, and such that on utilising the braking means to arrest rotation about the selected one of the axes whilst continuing rotation about the other one of said axes the load is partially wrapped on the surface thereof that is rotated about said other one of said axes. Preferably, the dispenser means is adapted for displacement between a first position in which it is arranged to effect said total wrapping and a second position in which is is arranged to effect a partial wrapping. Conveniently, the load support means is so pivotally mounted to the main frame that the support means can be tilted to discharge a wrapped load, and wherein the braking means is adapted so as to have an additional function of tilting the support means when it is required to discharge a load. In accordance with a further aspect of the invention there is provided a method for controlling the tensioning of strip material including the step of interposing a friction braking arrangement in the feed path of the strip material from a supply thereof to a utilisation location. Preferably, the friction braking arrangement includes a a roller arranged to be driven by movement of the strip material from a supply to a location of use, and a friction brake for constraining the freedom of rotation of the roller rotation. Conveniently a selectively adjustable eccentric cam arrangement is provided to adjusting the braking effect. For a better understanding of the invention and to show how to carry the same into effect reference will now be made to the accompanying drawings in which:- Figure 1 is a schematic perspective view of a first embodiment of apparatus for enabling the wrapping of a load such as a bale of straw or hay, the Figure illustrating a load support means enabling rotation of the load about two axes transverse to each other; Figure 1 is an enlarged view of a detal of Figure i; Figure 2 is an oblique view of the apparatus of Figure 1 illustrating the apparatus when in an intermediate setting, as arises during unloading of a wrapped load from the apparatus; Figure 3 is a part sectional detailed elevation of part of the drive mechanism for effecting said rotation; Figure 4 is a part sectional elevation of part of the arrangements • for rotationally mounting the load support means; Figure 5 schematically illustrates an arrangement for locking the load support means against rotation about a first axis, and for effecting load discharge g tilt of the load support means on completion of a wrapping operation; and Figure 6 is a schematic sketch illustrating a detail involved in the operation of the load support means; 5 Referring to Figures 1 and 2, these illustrate a load wrapping apparatus incorporating a rotatable load suporting turntable assembly 1 mounted for rotation upon a generally rectangular base frame 2 supported by legs 3. 0 I the apparatus is to be towable by a tractor or the like the frame 2 will be adapted for mounting wheels (not shown) and, if necessary, the legs 3 will be pivotal between a frame support setting shown in the . Figures and a stowed or towing position (not shown). To 5 facilitate such towing the frame is provided with a tractor connecting or hitching assembly (not shown). The base frame 2 includes side rails 4 and 5 and end rails 6. The side rail 4 is spaced inwards of the associated ends of the rails 6 r and is provided with sets of mounting lugs or the like 8 (only one set being indicated) for mounting for pivotable movement about a horizontal axis a tiltable platform 8 upon which a turntable unit 9 is rotatably mounted so that the turntable unit 9 can be rotated by a drive unit 10 about a vertical axis when the tiltable platform 8 is in the position shown in Figure 1. The platform 8 incorporates a main support section 11 which mounts (as will be considered hereinafter) the drive unit 10. The section 11 is supported from two frame members 12,13 which are pivotally connected to the lugs or the like 7 provided on the main frame rail 4 so that the platform 8 is pivotable about the horizontal axis between a horizontal setting as shown in Figure 1 and an inclined position in which any load 'L' that may be on the turntable assembly can be readily discharged from the assembly. Figure 2 illustrates an intermediate position of the tiltable platform 8. The " tilting is conveniently effected by means of .a hydraulic or pneumatic ram arrangement 14 to be considered hereinafter (not shown). 5 The turntable unit 9 incorporates a frame structure 15 including a pair of end rails 16 connected a central main section 17 providing an upper surface of a generally rectangular overall shape, the conection being such that the end rails 16 effectively form with the Q central section 17 an H formation. Rolls 18 and 19 are rotatably mounted to the projecting ends of the rails 16 by way of bearing units 20 provided upon the proj cting ends. A drive arrangement (to be considered hereinafter) is provided for transmitting drive from the drive unit 10 to the rolls 18 and 19. An embodiment of the drive unit 10 for the turntable unit 9 is shown in the Figure 3. The drive unit 10 includes a hydraulic motor 21 mounted to the 10. central section 11. As will be :aeen the central section 11 includes upper and lower plates 22 and 23 which are stiffened with respect to each other in the vicinity of the motor 21 by channel cross-section stiffening members 24. The motor 21 is mounted top and 15 bottom by way of flanged bearing units 25 and 26. In the figure the units 25 and 26 are shown externally mounted. If more convenient, the bearing units could be selected so as to be internally mountable. As is indicated in the Figure 3 the output shaft 27 of the 2 Q motor 21 is coupled directly to the central section 11 of the turntable unit 9 whereby the latter is rotated directly. In the Figure the central section 11 is shown to include upper and lower plates 28 and 29. This direct drive avoids the use of gear boxes or the like 25 between the motor 21 and the turntable unit 9. A non-rotatable bevel gear 30 is arranged concentrically of the motor shaft 27 and is constrained to rotate with the shaft 27 and thus the turntable unit 9. In a first arrangement a second bevel gear 31 is directly mounted to the shaft 32 of the roll 18 of the roll pair 18 and 19 so that there is effectively a direct drive from the motor output shaft 27 to the roll 8 through the bevel gears 30 and 31. The rolls are are inter-connected by a chain drive {not shown in Figures 1 and 2) so that they rotate in unison upon rotational drive being applied to the tuntable unit 9 from the drive unit 10. Figure 4 illustrates a second arrangement for driving the rolls 18 and 19 the bevel gear 31 is arranged to drive the input shaft 33 to a chain drive system 34. For this purpose the chain drive system 34 includes chain wheels 35 and 36 respectively directly associated with the rolls 18 and 19 and constrained to rotate therewith. The chain drive system 34 also includes a chain wheel set 37 comprising a chain drive input wheel 38--and two drive output chain wheels 39 and 40 constrained to rotate together. As will be seen from the Figure the chain wheels 35 and 39 are drivingly interconnected, and the chain wheels 36 and 40 are drivingly interconnected. The drive input wheel 38 is coupled through a chain 41 to receive drive from one or the other of two drive input chain wheels 42 and 43. These wheels are free wheels and are such as to effect drive in the anti-clockwise direction as seen in the Figure. Of these drive input wheels 42 and 43 the wheel 42 is provided at one end of the shaft 37 which carries at its other end the bevel gear 31. The other driven chain wheel 43 is connectable to receive drive from an independant drive source 44 which can be a hydrauli motor. With this arrangement the chain 41 may b selectively driven either by way of the freewheel 4 from the drive unit 10, or independantly thereof fro the motor 44 through the frewheel 43. With this second arrangement the rolls 18 and 1 can, if desired, be rotated without it being necessar to rotate the turntable assembly 1. In the embodiment shown the two rolls 18 and 1 have different diameters and are mounted to ends of th the rails such that their axes of rotation lie in th same plane. The drives to the rolls are such that th rolls rotate at a matched peripheral speed. With the apparatus as so far described it will b appreciated that when a load 'L' is resting upon th rolls 18 and 19 rotation of the latter will cause th load to rotate about a horizontal axis i.e., in the cas of a cylindrically shaped load lying with its axis o symmetry horizontal about this axis, and that rotatio of the turntable unit 9 will cause the load 'L 1 to tur around a vertical axis coaxial with that of the shaft 27 of the drive unit motor 21. Since it desired to be able to wrap the load 'L' with a a continuous length of plastics strip the apparatus includes a support and dispenser unit 46 for the strip plastics wrapping material 47. The unit 46 includes a main support post structure 48 which is lenthwise adjustable and which carries a mounting arbour 49 for receiving a reel or drum of the plastics strip material 47. The unit 46 also includes a strip material prestretching and feed tension control device 50 including a pair of rolls 51 and 52 mounted for rotation about axes parallel to the axis of the reel arbour 49 whereby they are engageable by the strip material 47 as it moves in its feed path to the load 'L' to be wrapped. The support post structure is so mounted that it is movable to a stowed position when not required for use, and also if thought necessary positionable in an alternative operation position as will be considered hereinafter. As so far discussed the strip material 47 is pulled from the reel thereof by the rotational movement of the load 'L' . As indicated above it is important to ensure that the wrapping material 47 is maintained at or within a specified tension range so as to ensure that the requisite prestretching and thus tightness of wrapping of the load 'I, 1 is achieved. To ensure that the material will be fed to the wrapping region at the optimum tension required for the pre-streching of the plastics material the latter is passed through the tension control device 50. The latter includes rolls 51 and 52 by upper and lower support elements 53. The roll 51 is a driven roll in the sense that it is caused to rotate as a direct consequence of pull exerted thereupon by the material 47 being fed to the load 'L'to be wrapped. The roller 52 is an idler roller. It should be noted that ,if desired, additional idler rollers (not shown) can be provided. The rate of rotation of the driven roller determines the tension produced in the wrapping material 47. In order that the tension can be controllabl varied a friction braking arrangement 54 (Figure 1A) i provided for enabling the selective tension control c This friction brake arrangement 54 involves a flywhee 55 constrained to rotate at the speed of the drive roller 51 , and an eccentric cam 56 connected to receiv drive from the flywheel by way of a friction brake bel drive 57 which remains at rest. The cam 56 i 10 selectively rotatable about an axis parallel to that o . the flywheel and thus the driven roll 51. With thi arrangement the rate of rotation of the roll 51 can b adjusted by rotation of the eccentric cam 56 whic rotation varies the braking tension in the belt 57- an _ jt - thus the possible rate of rotation of the roller i relation to a strip material pull-off tension. Sinc the plastics strip film-like material is being pulle away from the reel 58 at a rate set by the rate o rotation of the turntable unit 9 it will be apparen 20 that by braking the pull-off from the reel of plastic material (by controlling the rate of rotation of th feed roller 51 ) , the plastics strip 47 will be tensione by an amount related to the braking effect produced b the belt 57. Hence, the tension in the plastics stri 47 will be altered according to alteration of the 25 rotation rate of the driven roller 51. In order totally to enclose the load 'L' with the strip material 47 the load 'L' is subjected to the rotation about both of the above mentioned axes of 30 rotation. In practice, the rates of rotation of the turntable unit 9 and that of the rolls 18 and 1 is so inter-related that the rate of rotation of the unit 9 about the vertical axis is considerably greater than that about the horizontal axis so that during a complete revolution about the vertical axis the load 'L' is effectively stepped through a relatively small angular amount for example 5 to 10 degrees of arc about the horizontal axis so that by the time a load 'L 1 has been 0 effectively fully enclosed in the plastics material the load is encased in several layers of the plastics material 47. At the completion of a wrapping operation the drive to the turntable unit 9 and rolls 18 and 19 is stopped, the plastics strip cut from the supply and the -5 cut end firmly attached to the wrapped load. Afterwhich the load is discharged from the apparatus by tilting the platform as indicated ion Figure 2 by operation of the hydraulic arrangement 14. Through out this wrapping mode the dispenser 46 is 20 located in the position shown in Figure 1. When it is required partially to wrap the load, by rotation about a single axis the rotation of the turntable unit 9 is prevented by a braking mechanism 59 (schematically shown in Figure 5) whilst allowing rotation the load ! L' 25 supported on the rolls 18 and 19 of the turntable unit 9. With this arrangement the load would be partially wrapped. In the case of a cylindrically shaped load only the cylindrical surface thereof is wrapped thereby producing the a so-called barrel wrapping. For the 20 purposes of this mode of wrapping the dispenser and tensioning unit 46 is moved to a horizontal setting (not shown) in which the plane of strip material being fed to the load to be wrapped is horizontal. With this mode of wrapping the unit 46 is traversed lengthwise of the load in cases where the length of load to be wrapped is greater than the width of the strip plastics material 47. This traverse may be manual or arrangements for automatically effecting a traverse can be provided. The braking mechanism 50 in a first embodiment makes use of the hydraulic or pneumatic ram provided for tilting the platform 8. The ram arrangement 14 is additionally connected to control movement of a pivoted brake lever member 60 carrying a braking pad 61. The lever is pivoted to a convenient location on the tiltable platform 8 as to be displaceable by the ram arrangement 14 between a position A in which the turntable unit 9 is free to rotate and a braking position B in which the pad 61 engages with the turntable unit to prevent rotation thereof. The arrangement of the connection between the ram 14 and the lever member 60 is further such that, after the braking position B has been set, further operation of the ram arrangement 14 causes the tiltable platform 8 to tilt sufficiently far as to cause the load 'L' to roll off the turntable unit 9 and thereby discharge the load. In Figure 5 the line of action of the vertical axis of rotation of the turntable unit 9 and the axis of tilt of the platform 8 are respectively indicated by the line 62 and the intersection of the lines 63 and 64. Referring now to Figure 6 this Figure demonstrates the purpose of having rolls of different diameters. In practice, by providing differently sized rolls 18 and 19 it has been found that if the larger diameter roll 19 is effectively the lead roll in terms of rotation of the load 'L 1 whilst the load is being wrapped the load is bodily displaced towards the smaller roll 18. That is to say the centre of weight 64 of the load ! L f is offset towards the axis of rotation of the smaller roll 18 from the effective or true centre line 66 of the two rolls. This is shown in Figure 6. In practice / it has been found that any tendancy for the load to climb up the rolls 18 and 19 during the load wrapping procedure is eliminated so that the stablility of the load 'L 1 during wrapping is maintained. The rolls 18 and 19 can, if desired, carry an an endless belt or group of belts (not shown) if it is desired to provide a flexible support platform for a load '__' to be wrapped With this arrangement loads i.e., bales, of various sizes and shapes can be carried by the turntable unit 9, and which do not necessarily bridge the separation between the rolls. It will be appreciated that whilst a particular reference has been made to the wrapping of bales other forms of load could be so wrapped. In order to prevent a load fro-" travellin lengthwise of the rolls 18 and 19 sufficiently for th load L to slip-off the rolls 18 and 19, an upstandin roll 66 is provided at each end of the turntable 9 The rolls 66 are rotatable about vertical axes. Th height of the rolls 66 is sufficient to preven excessive axial movement of a load L lengthwise of th rolls 18 and 19. It will be appreciated that in th event that a load L contacts a roll 66 the fact that th roll 66 is rotable about a vertical axis ensures tha the discharge of a load L from the turntable 9 is no impeded as the roll 66 rotates in the sense of th discharging load L.

Claims: CLAIMS 1. Apparatus for wrapping a load with strip material, the apparatus including a main frame or the like, a load support means mounted for rotation about a first axis of rotation relative to the main frame or the like of the apparatus, said load support means incorporating a load support arrangement which is such that the load can be rotated with respect to the load support means about an axis transverse to the direction of the axis of rotation of the support means_ and means for mounting a supply of plastics wrapping material in strip form whereby rotation of the load about one or both said axes causes the strip material to be wrapped around the load whereby the load is respectively partially or wholly wrapped. 2. Apparatus as claimed in claim 1 , and wherein the rotation of the load support means is produced by direct drive from the output shaft of a motor and the rotation of the load on the support means is obtained by direct drive. 3896 _,,___. „ -19- PCT/GB87/008 3. Apparatus for wrapping a load with strip material the apparatus including a main frame or the like, a loa support surface for the load to be wrapped rotatabl mounted to the main frame, means for rotating the loa support surface about a first axis, means for rotatin the load whilst on the support surface whereby the loa is rotated about a second axis of rotation transverse t the first axis, braking means for enabling stopping o the rotation of the load about a selected one of sai axes, and strip material dispenser means for enablin delivery of material in strip form from a supply thereo for wrapping the load during the rotation thereof, th arrangement being such that when the load is subjecte to rotations about both said axes the load can be full wrapped as to be totally enclosed by wrapping material and such that on utilising the braking means to arres rotation about the selected one of the axes whils continuing rotation about the other one of said axes the load can be partially wrapped on the surface thereo that is rotated about said other one of said axes * 4. Apparatus as claimed in claim 3, and wherein th dispenser means is adapted for displacement between first position in which it is arranged to effect sai total wrapping and a second position in which is i arranged to effect a partial wrapping. 5. Apparatus as clai m ed in claim 3 or 4, and wherein the load support means is so pivotally mounted to the main frame that the support means can be tilted to discharge a wrapped load, and wherein the braking means is adapted so as to have an additional function of tilting the support means when it is required to discharge a load. 6. Apparatus as claimed in claim 4 or 5, and wherein the braking means incorporates a hydraulic cylinder, the arrangement being such that on operating the hydraulic cylinder a first operational setting is adapted to lock the support means against rotation and further operation of the hydraulic cylinder to a second operational setting is arranged to tilt the support means sufficiently to discharge a load therefrom. 7 Apparatus as claimed in claim 3,4,5 or 6, and wherein there is provided means for controlling the tensioning of strip material including a friction braking arrangement in the feed path of the strip material from a the supply thereof to a utilisation location. 8. Apparatus as claimed in claim 7, and wherein the friction braking arrangement includes a roller arranged to be driven by movement of the strip material from the supply to the location of use, 'and a friction brake for constraining the freedom of rotation of the roller rotation. 9. Apparatus as claimed in claim 8, and wherein a selectively adjustable eccentric cam arrangement is provided for enabling adjustment of the braking effect exertable by the friction brake. 10. Apparatus for wrapping a load with strip material, constructed and arranged to operate substantially as hereinbefore described with reference to the accompanying drawings.

Inventors: DRURY DAVID JAMES, DRURY NORMAN, DRURY, DAVID, JAMES, DRURY, NORMAN
Applicants: WRAP A ROUND LTD
Application year: 1987
Main classification: B65B11
IPC codes: A01F15, B65B11