The present invention relates to apparatus for wrapping articles and is primarily but not exclusively concerned with the wrapping of bales of crop such as hay, straw or the like with a plastics material.

It is known to wrap bales of crop with plastics film in order to convert the crop to silage and machines have been known for some time for carrying out such wrapping operations. Such a bale wrapping machine comprises a turntable on which the bale is mounted, the turntable also including a drivable support such as a pair of rollers or a belt so that the bale may be rotated simultaneously about two axes of revolution.

One end of a roll of plastics material may be attached to the bale and the rotation of the bale about its two axes of revolution will cause material to be unrolled from the roll of plastics material and wrapped around the bale until the bale is completely wrapped with plastics material.

The rotation of the bale about its axis of revolution may be caused by motive means, for example a hydraulic or electric motor and hence the operation may be carried out almost entirely automatically with he exception of the initial attachment of the plastics film to the bale and the cutting of the film after the bale has been completely wrapped.

Both the aforesaid operations which have to be carried out manually not only increase the time necessary to wrap the bale but also involve certain danger to the operatives since it is necessary to approach the machinery and hence it is necessary to ensure the machinery is turned off and furthermore there can sometimes be some difficulty in attaching the plastic film to the bale the conventional manner of effecting connection being to tie the plastics film to the bale string and since the string is necessarily tied tightly around the bale it may be quite difficult to thread the plastic film between the string and the bale.

It is an object of the present invention to provide new and improved apparatus that overcomes or minimises the problems mentioned above.

According to one aspect of the present invention we provide an apparatus for wrapping articles, said apparatus comprising attachment means for effecting attachment of a wrapping material to the article and wrapping means to cause relative movement between the wrapping material and the article wherein the attachment means comprises wrapping material holding means movable with the article relative to wrapping material storage means and to hold the wrapping material during the relative movement and wherein the holding means is adapted to release the material after a predetermined extent of relative movement of the article has occurred relative to the wrapping material storage means.

Preferably the holding means is adapted to re-engage with the wrapping material after wrapping of the article has been completed to enable re-attachment of the wrapping material with a subsequent article.

Preferably cutting means are provided adapted to cut the wrapping material after wrapping of the article has been completed.

The holding means may comprise a releasable clamping means and conveniently release means may be provided, the release means being effective to release said clamping means after a predetermined extent of relative movement of said article has occurred relative to the wrapping material storage means.

The wrapping means may comprise a stationary base on which the storage means is mounted and a support means for supporting the article for rotation about an axis relative to the base.

The support means may support the article for rotation about two axes.

The support means may comprise a turntable which is rotatable about a substantially vertical axis relative to the base and the turntable carrying a support for rotating the article about a substantially horizontal axis.

Preferably the release means for the holding means comprises an operating member mounted for revolution with the article to be wrapped and adapted to

contact a release mechanism which is at a first location relative to said wrapping material storage means to cause release of the holding means.

The release mechanism may comprise a priming part and a release part, the operating member being adapted to engage the priming part after a partial revolution of the turntable and hence of the article relative to the wrapping material storage means, engagement between the operating part and said priming part priming the release mechanism such that on completion of a further revolution of said article said operating member engages said release part to release the holding means.

Alternatively and preferably, the release mechanism comprises a release part movable, by means responsive to a predetermined extent of revolution of the article, between an inoperative position, in which it is out of the path of movement of the operating member, and an operative position, in which it is in the path of said movement so as to be engaged by the operating member to cause release of the holding means.

The means responsive to a predetermined extent of rotation may comprise an electrical counting means, responsive to signals generated in response to article rotation, to provide an output signal for a release mechanism drive means to move the release part between from said inoperative position to said operative position. The drive means may comprise a solenoid.

On completion of wrapping the article may be removed from the wrapping machine by lifting, tipping or rolling. Movement of the article from said machine is preferably adapted to cause location of the wrapping material in operative relationship with the holding means and engagement of the holding means with the wrapping material so that the wrapping material is held by the holding means to enable the wrapping apparatus to effect secure engagement of the wrapping material with the next article to be wrapped.

Preferably the cutting means are located on the holding means and are effective to cut the material whrα wrapping of the article has been completed and

the holding means is engaged with the wrapping material on, for example, discharge of a wrapped article from the machine.

Discharge of a wrapped article and any subsequent movement of the machine prior to the loading of a further article may cause the release mechanism to return to an initial position in which a first contact between said operating member and the release mechanism comprises contact between the operating member and the priming part.

Preferably, however, said means responsive to a predetermined extent of rotation provides a first output signal for the drive means to move the release part from said operative position to said inoperative position after engagement of the release part by the operating member.

Conveniently the holding means releases the wrapping material after one and a half revolutions has occurred but before two complete revolutions have occurred. It has been found that approximately one and a half to two revolutions ensures that the wrapping material is, by virtue of the resultant partial overlap, firmly secured to the bale whilst the constraint of the wrapping material cause by the holding means is not detrimental to the wrapping of the article.

Preferably the machine comprises an article discharge means comprising a tipping device which enables the article to be tipped from the turntable and conveniently the turntable is itself mounted not only for rotational movement but also for tipping movement at least when aligned in a predetermined position.

Conveniently, said predetermined aligned position in which tipping of the turntable is possible is also the position whereby the holding means are adapted to engage with the wrapping material subsequent to wrapping of an article to not only once again hold the wrapping material but also to sever the wrapping material at a position between the holding means and the article that has been wrapped.

The holding means may be moved to locate the wrapping material in said operative relationship with the holding means by virtue of said tipping movement.

The tipping movement may also cause the holding means to engage with the wrapping material to hold the wrapping material.

The holding means may be moved to said engaged position by means of a fluid pressure driven motor and fluid may be transferred to drive the motor by an actuator which is operated as a result of said tipping movement.

The actuator may comprise a piston and the cylinder device having an operating member to cause displacement of the piston within the cylinder as a result of relative movement between the cylinder and the base on said tipping movement.

The cylinder may be mounted on the turntable and the operating member may engage an abutment on the base.

The holding device may comprise an over-dead-centre linkage which is moved into a first, over-dead-centre position by the fluid motor to cause the holding means to hold the wrapping material whilst the release means may displace the linkage out of said over-dead-centre position.

Preferably said wrapping apparatus comprises a bale wrapping apparatus.

Preferably the wrapping material holding means is mounted on the turntable.

The wrapping apparatus may be mounted on a trailer.

The bale wrapping machine may also be provided with means for raising a bale from the ground and loading the bale onto the wrapping machine.

The means for raising a bale from the ground and loading the bale on to the wrapping machine may load the bale onto the turntable when the turntable has been rotated through 90° from said predetermined aligned position in which tipping of the turntable is possible.

The automatic wrapping material holding means enables an operator towing such a machine to lift a bale from the ground completely wrap the bale and discharge the bale from the wrapping machine without having to leave the vehicle towing the machine. Preferably the vehicle is an agricultural tractor, the

turntable and, where provided, the bale lifting means being powered from a hydraulic pump normally provided on agricultural tractors.

The holding means may comprise a pair of generally upwardly extending elongate members.

Said members may be relatively pivotable about a generally horizontal axis. The invention will now be described in more detail by way of example only with reference to the accompanying drawings wherein:-

FIGURE 1 is a perspective illustration of a bale wrapping apparatus incorporating one embodiment of holding and cutting means of the present invention;

FIGURE 2 is a diagram of the holding and cutting means and operating mechanism therefor;

FIGURE 3 is a plan view of the mechanism shown in Figure 2;

FIGURE 4 is an end elevation of the mechanism shown in Figures 2 and 3,

FIGURE 5 is a perspective illustration of a second embodiment of a bale wrapping apparatus embodying the present invention,

FIGURE 6 is a side elevation, partly broken away, of a holding and cutting means of the embodiment of Figure 5,

FIGURE 7 is an end elevation of the holding and cutting means of Figure 6,

FIGURE 8 is a diagrammatic side elevation of the machine of Figure 5,

FIGURE 9 is a cross-sectional view, to an enlarged scale, showing a hydraulic actuator of the machine of Figure 5, and

FIGURE 10 is a diagrammatic plan view of the apparatus of Figure 5.

Referring first to Figure 1, a chassis 10 is provided with wheels, one of which is shown at 11 and has mounted thereon a turntable 12. The turntable 12 carries a bale support 13 comprising a pair of spaced rollers 14 around which are entrained elongate belts 15, 16 and 17.

The turntable 12 is mounted for rotary movement relative to the chassis 10 about a substantially vertical axis and the rollers 13 or 14 or at least one of which may be rotated to drive the belts 15, 16 and 17 so as to rotate a cylindrical bale 18 about a substantially horizontal axis.

A roll of wrapping material, such as plastic film, is shown at 21 and material holding and cutting means is shown at 22, the holding and cutting means is secured to the turntable 12 and adapted to rotate therewith.

The turntable 12 is also mounted for tipping movement relative to the chassis so that a bale may be tipped off the turntable 12 when it has been fully wrapped.

The holding and cutting means is illustrated in more detail in Figures 2, 3 and 4.

The holding and cutting means comprises a generally upwardly extending movable member 25 and a generally upwardly extending fixed member 26 having respective guide members 27 and 28.

The member 25 is pivotable about a generally horizontal axis from an open position as shown in the drawings to a closed position in which is abuts the member 26 in a manner that will be described hereinafter.

One or both of the members 25 and 26 may be provided with a cutting plate, such as that shown at 29, positioned such that any article placed between the members 25 and 26 and extending from one side to the other will be severed by the cutting plate 29 when the members 25 and 26 are brought together.

The holding and cutting means 22 is shown in Figure 1 mounted on the turntable 12, also secured on the turntable 12 is an operating member 30. The operating member 30 is mounted on the turntable 12 and rotates therewith and is mounted for limited movement along its longitudinal axis. It is connected near one end to a pair of links 31 and 32, the outer end of link 32 being secured by a pivotal member 33 to permit only of limited pivotal movement.

Movement of the operating member 30 in a direction towards left as shown in Figure 2 will cause the outer end 34 of link 31 to move in an upwards

direction. The outer end 34 is connected to a movable member 25 upwards movement causing the member 25 to be pivoted in an anti-clockwise direction about an axis 35 thus causing the holding member 25 to abut the holding member 26.

The operating member 30 has two ends, a first end indicated at 36 and a second end indicated at 36a,.

The holding and cutting means is mounted on the turntable 12 in a manner such that when the turntable 12 is tipped relative to the chassis 10 to tip a bale 18 a part of the chassis, indicated generally at 37, is operative through a helical spring 38 and abutment 39 fixed onto operating member 30 to move the operating member 30 towards the left when referring to Figure 2. Such a movement causes the holding member 25 to come into engagement with the holding member 26 and conveniently, if the wrapping material is placed between the holding members 25 and 26 it will be firmly held thereby.

If desired, manually operable means may be provided to initiate the operation of the holding members 25 and 26 into their holding position.

A bale 18 is then placed upon the belts 15, 16 and 17 and rotation of the turntable and rotation of the rollers 13 and 14 is commenced. The holding means 22 will pull material from the roll 21 and commence wrapping of the bale.

It is only required to hold the wrapping material until it has overlaid itself on the bale whereafter further holding is not required and indeed would be detrimental since the holding means 22 would pull the wrapping material away from its natural position.

In order to release the wrapping means, a release mechanism is provided, the release mechanism being indicated in Figure 1 at 40 and comprises a striker plate as shown in Figure 3 at 41 which is contacted by end 36a. of operating member 30.

The first time the end 37 contacts the striker plate 41, the striker plate is moved to a second position. However, the first contact between the end 37 of operating member 30 and the striker plate 41 does not cause release of the

holding means, after another complete revolution of the turntable 12, the end 37 once again strikes the plate 41, now in its second position, which causes movement of the operating member 30 in a direction to the right as shown in Figure 2 hence causing separation of holding members 25 and 26 releasing the material held thereby.

The wrapping of the bale then continues, the bale being rotated about two axes until the wrapping has been completed.

Rotation of the turntable 12 and rollers 13 and 14 is discontinued at a position wherein the holding means 22 is positioned immediately below the length of wrapping material extending from the roll 21 to the bale 18 and the tipping procedure of the turntable 12 is then initiated which causes the material between holding members 25 and 26. Further tipping of the turntable causing the mechanism 37 to act through spring 38 to move operating member 30 to the left as shown in Figure 2 thus bringing holding members 25 and 26 into contact with each other causing them to firmly hold the wrapping material 21 and at the same time cutting plate 29 will cause the material 21 to be cut on that side of the holding members 25 and 26 nearest to the bale 18 thus freeing the bale from the roll of wrapping material 21. The bale 18 may then be tipped from the turntable 12 and the wrapping material is firmly held in the holding means 22 so that a second bale may then be wrapped as soon as it is placed on the turntable 12.

Referring now to Figures 5 to 9, a bale wrapping machine is shown comprising a chassis or base 110 provided with wheels 111 and which has mounted thereon a turntable 112. The turntable 112 carries a bale support 113 comprising a pair of spaced rollers 114 around which are entrained elongate belts 115, 116.

The turntable 112 is mounted by means of a bearing assembly 117 on a sub-frame 118 which is pivotally mounted to the chassis 110 about an axis 119 by a pivot pin 120 received in apertures formed in the sub-frame 118 and the chassis 110. A hydraulic ram 121 extends between the sub-frame 118 and a bracket 122 on the chassis 110.

Suitable drive means to rotate the turntable 112 relative to the sub-frame 118 and to rotate the rollers 114 are provided in conventional manner and hence a cylindrical bale 118 is rotated about a vertical axis by virtue of rotation of the turntable 112 and about a horizontal axis by virtue of the rotation imparted by the support rollers 114.

The turntable 112 carries a pair of guide rollers 123 to retain the bale in position longitudinally of the rollers 114.

A roll 125 of wrapping material, such as plastic film, is carried on an arbour 126 and fed via a conventional tensioning device 127. The assembly of arbour 126 and tensioning device 127 is carried on a support post 128 which is fixed relative to the chassis 110.

A holding and cutting means 130 is secured to the turntable 112 to rotate therewith.

The holding and cutting means is illustrated in more detail in Figures 6 and 7.

The holding and cutting means comprises a movable member 131 and a fixed member 132, both of which extend generally upwardly.

The movable member is pivotable about a generally horizontal axis 133 by means of a member 134 having a roller 135 which engages a top surface 136 provided at the upper end of a first link 137a. which, together with a second link 13712, comprise an over-dead-centre linkage 138.

The second link 138 is disposed between, and is pivotally connect to, a pair of guide plates 139 by means of a pivot pin 140. The links 137a, 137k. are pivotally inter-connected by a further pivot pin 141 slidably carried on a cross- head 142. The upper end of the first link 137a. is guided for relevant sliding movement by a pivot pin 143 received in slots 139s. in the guide plates 139.

The cross-head 142 is connected to an operating member 144 which is journalled for sliding movement in a bush 145 mounted on the guide plates 140 and having a roller 146 at its outer end for engagement with a release mechanism hereinafter to be described. The cross-head 143 is also connected to a tubular

member 147 which slidably receives a rod 148 connected to a piston 149 slidably mounted in a cylinder 150 of a fluid operated motor in the form of a hydraulic ram. A coil compression spring 152 acts between the piston 149 and an end surface 147a. of the tubular member 147.

A coil tension spring 153 is connected between the pivot pins 140 and 143 of the over-dead-centre linkage 139 and a further coil tension spring 154 is connected between a peg 155 carried by one of the guide plates 139 and an extension arm 156 welded to the movable member 131.

A hydraulic actuator 160 is mounted on the turntable 112 and comprises a cylinder 161 which is fixed to the turntable 112 in conventional manner and a piston 162 which is spring biased by a coil compression spring 163 outwardly of the cylinder 161 and has an operating member comprising a piston rod 164 which carries a roller 165 which engages an abutment member 166 carried on the chassis 110. A flexible line 165 transmits hydraulic fluid between the actuator 160 and the fluid motor 151.

A release mechanism 170 is mounted on the chassis, as shown in Figure 10, and comprises a release part 171 pivotally mounted for rotation about a horizontal axis 172 by means of a solenoid mechanism 173 for movement between an inoperative position in which the part 171 is out of the path of movement of the roller 146 and an operative position in which the part 171 is disposed for engagement by the roller 146. The solenoid mechanism 173 is actuated via an electronic circuit which counts the extent of revolution of the turntable 112.

The chassis 110 carries a conventional bale lifting device 180 which lifts the bale onto the support 113 when the turntable is disposed in the position shown in Figure 5.

Operation of the bale wrapping apparatus of Figures 5 to 10 will now be described.

A bale to be wrapped is loaded onto the support 113 with the turntable 112 in the position shown in Figure 5 by the lifting means 180. The wrapping material 125 is gripped by the gripping means 130 as hereinafter to be described

and the turntable is then caused to be rotated whilst the rollers 114 are also rotated so that the bale is rotated about two axes. After the turntable has rotated through slightly less than two rotations the electronic circuit energises the solenoid mechanism 173 to move the release part 171 into its operative position so as to be engaged by the roller 146 as the turntable rotates further. This engagement pushes the operating member 144 to the right in Figure 6 to displace the links 137a, 13732. from their operative over-dead-centre position, which they occupy when the holding means is in engagement with the wrapping material 125 to an inoperative position shown in Figure 6 and Figure 7. The wrapping material is thus released from the holding means and rotation of the turntable and of the rollers 114 continues until the bale is completely wrapped.

The turntable is then stopped in the position shown in Figure 8, i.e. at 90° to the position shown in Figure 5 and the hydraulic ram 121 actuated to tilt the turntable to the position shown in Figure 8 so as to discharge the bale therefrom and to move the holding means into position for engagement with the wrapping material 125 which is attached to the bale to be discharged. The positioning of the turntable so that the holding and cutting means 130 is disposed at the end thereof adjacent the wrapping material supply and which is raised ensures that the holding means is moved into position to dispose of the wrapping material between the members 131, 132 of the holding means and to cause the lower edge of the wrapping material to be raised and thus squeezed upwardly before the bale is discharged and before the actuator 160 has displaced hydraulic fluid into the motor 151 sufficiently far to overcome the force of the spring 152, in combination with the springs 153 and 154.

As the turntable approaches its uppermost position the spring force is suddenly overcome causing the cross-head 143 to move rapidly to the left in Figure 6 to move the links 137a, 137Ϊ2.to an over-dead-centre position and hence to cause surface pin 136 of the link 137a. to move upwardly to cause the movable member 131 to move towards the fixed member and thus clamp the wrapping material therebetween. Cutting blades 181 are provided between the movable

and fixed members so that in addition the wrapping material is severed so freeing the bale to fall from the turntable as the turntable reaches its uppermost position.

The turntable is then returned to its horizontal position and the actuator 160 is moved out of engagement with the abutment 166. The spring 152 returns the piston 149 to the right in Figure 6 and hence displaces hydraulic fluid back into the actuator 160 to displace the piston rod 164 downwardly, this movement being permitted since the roller thereof is not in engagement with the abutment 166 since the turntable is not in a tipped position. The holding means 130 remains in holding engagement with the wrapping material because of the over- dead-centre action of the linkage 139. The turntable is then rotated through a further 90° to the position shown in Figure 5 ready to receive another bale and for the operation to be repeated.

It will be appreciated that the above described apparatus are merely two embodiments of mechanism to operate the holding and cutting means the subject of the present invention and any suitable variation that effectively operates the holding and cutting mechanism may be used.

Whereas the wrapping apparatus has been described with reference to the wrapping of a bale of crop such as hay or straw, it is equally applicable for any article that has to be wrapped.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in the terms or means for performing the desired function, or a method or process for attaining the disclosed result, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.