WRAPPING APPARATUS AND METHOD WITH A WRAPPING MATERIAL SEVERING DEVICE COMPRISING AN OWN ACTUATOR

Abstract

An object former surrounds a chamber and forms an object in the chamber. A web moving member moves a web of wrapping material towards a wrapping material inlet guiding into the chamber. The web is injected into the chamber. The object in the chamber is wrapped. A moveable severing member of a severing device severs the web. A movement of the web moving member is coupled with a movement of the moveable severing member from a parking position into an intermediate position. A severing actuator moves the moveable severing member from the intermediate position into a web severing position. thereby severing the web.

Claims

1. A wrapping apparatus for wrapping an object contained in a chamber, comprising: a wrapping material inlet leading into the chamber, the wrapping apparatus comprising: a web moving member positioned outside of the chamber; a web moving actuator; and a severing device comprising a moveable severing member being moveable between a parking position and a web severing position; and a mechanical coupling element for coupling the web moving member with the moveable severing member, wherein the web moving member is moveable with respect to the wrapping material inlet between at least one remote position and an adjacent position and arranged for moving a web of wrapping material towards the wrapping material inlet while being moved into the adjacent position, wherein the web moving actuator is arranged for moving the web moving member with respect to the wrapping material inlet between both positions, wherein the wrapping apparatus is arranged to inject the moved web of wrapping material through the wrapping material inlet into the chamber, wherein the severing device with the moveable severing member being moved into the web severing position is arranged to sever the web at a severing location positioned outside of the chamber after the web is injected into the chamber, wherein the severing device further comprises a severing actuator operable independently from the web moving actuator, wherein the moveable severing member is further moveable into an intermediate position, wherein the moveable severing member being in the intermediate position is spaced apart from the web and has a smaller distance to the web compared with the moveable severing member being in the parking position and a larger distance compared with the moveable severing member being in the web severing position, wherein the mechanical coupling element couples a movement of the web moving member from a first position into a second position with a movement of the moveable severing member from the parking position into the intermediate position wherein the wrapping apparatus is arranged to temporarily keep the web moving member in the second position, thereby causing the mechanical coupling element to simultaneously keep the moveable severing member in the intermediate position, and wherein the severing actuator is arranged to move the moveable severing member from the intermediate position into the web severing position and from the web severing position back into the intermediate position.

2. The wrapping apparatus according to claim 1, wherein the mechanical coupling element couples a movement of the web moving member from the adjacent position serving as the first position intto the or at least one remote position serving as the second position with a movement of the moveable severing member from the parking position into the intermediate position.

3. The wrapping apparatus according to claims claim 1, wherein the mechanical coupling element couples a movement of the web moving member from the or at least one remote position into the adjacent position with a movement of the moveable severing member from the intermediate position into the parking position.

4. The wrapping apparatus according to claims claim 1, wherein the wrapping apparatus is arranged to trigger the severing actuator to move the moveable severing member into the web severing position when the web moving member is in the or in one remote position.

5. The wrapping apparatus according to claims claim1, wherein the wrapping apparatus comprises a position sensor arranged to detect the event that the web moving member or that the moveable severing member has reached a given position with respect to the wrapping material inlet, and wherein the wrapping apparatus is arranged to trigger the severing actuator for moving the moveable severing member into the web severing position depending on signals from the position sensor.

6. The wrapping apparatus according to claims claim 1, wherein the wrapping apparatus comprises a locking member for locking the moveable severing member at the web moving member, and wherein the wrapping apparatus is arranged to selectively lock the moveable severing member by means of the locking member or to release the locking connection established by the locking member.

7. The wrapping apparatus according to claims claim 1, wherein the web moving member comprises a supporting plate being moveable with respect to the wrapping material inlet between at least one remote position and an adjustment position, wherein the moveable supporting plate is arranged to support from below a leading segment of the web, wherein the web moving actuator is arranged to move the supporting plate, and wherein the mechanical coupling element couples a movement of the supporting plate from a first position into a second position with a movement of the moveable severing member from the parking position into the intermediate position.

8. The wrapping apparatus according to claim 7, wherein the wrapping apparatus is arranged such that the moved web supported by the supporting plate remains slack until the web reaches the wrapping material inlet.

9. The wrapping apparatus according to claims claim 1, wherein the moveable severing member comprises; a knife; and a pivotal lever member being mechanically connected with the web moving member, wherein the knife is mounted at a free end of the lever member, and wherein the mechanical coupling element is coupled with the lever member.

10. The wrapping apparatus according to claims claim 1, wherein the wrapping apparatus comprises a guiding member for guiding the web moving member between the first and the second position, and wherein the moveable severing member is mechanically connected with the guiding member.

11. The wrapping apparatus according to claims 1, wherein the wrapping apparatus comprises a web movement sensor arranged to measure a value indicative of the distance over which the web is moved towards the wrapping material inlet, and wherein the wrapping apparatus is arranged to trigger depending on signals from the web movement sensor the severing actuator to move the moveable severing member into the web severing position.

12. The wrapping apparatus according to claims claim1, wherein the severing device comprises an energy storing device, wherein a movement of the moveable severing member from the web severing position into the intermediate position increases the kinetic energy stored in the energy storing device, and wherein the severing actuator is arranged to move the moveable severing member from the intermediate position into the web severing position by using kinetic energy taken from the energy storing device.

13. The wrapping apparatus according to claim 1, wherein the web is guided around at least one guiding member, and wherein the or at least one guiding member is arranged o enable a movement of the web towards the wrapping material inlet and to prevent a movement of the web in the opposite direction.

14. An object forming and wrapping apparatus comprising, an object former providing a chamber; and the wrapping apparatus according to claim 1, wherein the object forming former is arranged to form an object n the provided chamber, wherein the wrapping apparatus is arranged to inject a web into the chamber, wherein the object forming and wrapping apparatus is arranged to wrap at least one surface of the formed object in the chamber into the injected web, and wherein the severing device is arranged to sever the web at the severing location after the web is injected.

15. A method for wrapping an object while the object is contained in a chamber, wherein a wrapping material inlet guides into the chamber, wherein the method is performed by using a wrapping apparatus comprising: a web moving member being moveable with respect to the wrapping material inlet between at least one remote position and an adjacent position; a web moving actuator; a severing device with a moveable severing member being moveable between a parking position and a web severing position; and a mechanical coupling element, wherein the method comprises the steps of: the web moving actuator moving the web moving member from the or one remote position into the adjacent position; the moved web moving member moving a web of wrapping material towards the wrapping material inlet which leads into the chamber; injecting the moved web through the wrapping material inlet into the chamber; moving the moveable severing member into the web severing position after the web is injected into the chamber; the movement of the moveable severing member causing the moved moveable severing member to sever the web at a severing location outside of the chamber; and the web moving actuator moving the web moving member from the adjacent position into the or one remote position, wherein the mechanical coupling element transfers a movement of the web moving member from a first position into a second position onto the moveable severing member, wherein the severing device further comprises a severing actuator (25) which can be operated independently from the web moving actuator and the moveable severing member is further moveable into an intermediate position, wherein the step that the movement of the web moving member is transferred onto the moveable severing member comprises the further step that the movement of the web moving member from the first position into the second position causes the mechanical coupling element to move the moveable severing member from the parking position into the intermediate position, thereby decreasing the distance between the moveable serving member and the web, wherein the moveable severing member being moved into the inteimediate position remains in a distance to the web, wherein the method comprises the further steps of temporarily keeping the web moving member in the second position; and the mechanical coupling element simultaneously keeping the moveable severing member in the intermediate position, wherein the step that the web is severed comprises the step of the severing actuator moving the moveable severing member from the intermediate position into the web severing position, and wherein the method comprises the further step of the severing actuator moving the moveable severing member from the web severing back into the intermediate position.

16. The wrapping method according to claim 15, wherein the mechanical coupling element transfers a movement of the web moving member from the adjacent position serving as the first position into the or into one remote position serving as the second position onto the moveable severing member such that the moveable severing member is moved from the parking position into the intermediate position.

17. The wrapping method according to claim 15, further comprising he step of the mechanical coupling element transferring a movement of the web moving member from the or from one remote position into the adjacent position onto the moveable severing member such that the moveable severing member is moved from the intermediate position into the parking position.

18. The wrapping method according to claim 15, wherein the step that the web moving member is moved from the or one remote position serving as the first position into the adjacent position serving as the second position causes the moveable severing member to be moved from the intermediate position into the parking position and after the web is inserted into the chamber the steps are performed that the web moving member is moved back from the adjacent position into the or into one remote position, causing the mechanical coupling element to move the moveable severing member from the parking position into the intermediate position, and the severing actuator moves the moveable severing member from the intermediate position into the web severing position.

19. An object forming and wrapping method comprising the steps of: an object former providing a chamber forming an object in the provided chamber; injecting a web of wrapping material into the chamber by using the method according to claim 15 while the formed object is in the chamber; wrapping at least one surface of the object i the chamber into the injected web; and the severing device severing the web at the severing location.

20. The wrapping apparatus according to claim 2, wherein the mechanical coupling element couples a movement of the web moving member from the or at least one remote position into the adjacent position with a movement of the moveable severing member from the intermediate position into the parking position.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0090] FIG. 1 shows schematically in a side view the round baler comprising the wrapping apparatus according to the embodiment of the invention;

[0091] FIG. 2 shows in a detailed side view the web moving member of the baler of FIG. 1 in the remote position and the moveable severing member in the intermediate position after the severing device has severed the web for the previous bale;

[0092] FIG. 3 shows in the viewing direction of FIG. 2 the web moving member in the adjacent position and the moveable severing member in the parking position;

[0093] FIG. 4 shows in the viewing direction of FIG. 2 the web moving member again in the remote position after the web is injected and while the web moving member tensions the inserted web and the moveable severing member is again in the intermediate position;

[0094] FIG. 5 shows in the viewing direction of FIG. 2 the web moving member in the remote position and the moveable severing member being moved into the web severing position.

DETAILED DESCRIPTION OF EMBODIMENT

[0095] In the embodiment the invention is used on board of an agricultural vehicle which forms and wraps round-cylindrical bales in a drum-shaped bale forming chamber. This bale forming and wrapping apparatus (round baler) is schematically shown in the side view of FIG. 1 and is pulled by a tractor (not shown) or by a further other agricultural harvester over ground in a travelling direction TD (in FIG. 1 from right to left). The baler of the embodiment [0096] picks up loose crop material (hay, straw, grass, e.g.) from the ground and conveys the picked-up crop material through a feeding channel (not shown) in a direction opposite to the travelling direction TD, [0097] optionally cuts the crop material while it is conveyed through the feeding channel, [0098] presses the conveyed crop material through a crop material inlet into a drum-shaped bale forming chamber, [0099] rotates the injected crop material, [0100] forms under pressure in the bale forming chamber Ch from the injected and rotated crop material an increasing round-cylindrical bale B, [0101] wraps in the bale forming chamber Ch the circumferential surface of the formed bale B into wrapping material (a net or several strands of twine or plastic sheet), and [0102] ejects the wrapped bale B out of the bale forming chamber Ch.

[0103] The ejected bale B is deposited on the ground. In one embodiment a wrapper behind the bale forming chamber wraps the bale into plastic sheet (baler-wrapper combination). In one embodiment a tilting unit (quarter turn) tilts the wrapped round-cylindrical bale B such that the bale is deposited on the ground on a front face.

[0104] The baler of FIG. 1 comprises [0105] a pick-up unit with several spring-mounted pick-up tines (not shown), [0106] a casing surrounding the bale forming chamber Ch wherein the casing comprises a stationary front housing and a pivotal tailgate (not shown), [0107] a driven conveyor rotor 39 with several rigid tines, [0108] a driven lower starter roller 42, [0109] a driven upper starter roller 6 mounted on a shaft 18 and comprising a conveying surface 8, [0110] several parallel driven pressing belts 40 surrounding the drum-shaped bale forming chamber Ch, [0111] two deflecting rollers 41.1, 41.2 and further deflecting rollers (not shown) which deflect the pressing belts 40, [0112] a guiding roller 44 and further guiding rollers (not shown) which guides the pressing belts 40, and [0113] a wrapping apparatus 29 with an unrolling station which rotatably holds a supply reel 32 for wrapping material.

[0114] The conveyor rotor 39 conveys the picked-up crop material through a feeding channel towards the bale forming chamber Ch. The conveyor rotor 39 engages from above or from below into the feeding channel and can cooperate with a cutting assembly (not shown). The upper starter roller 6 and the lower starter roller 42 form the two borders of a crop material inlet 43 which guides into the bale forming chamber Ch.

[0115] Crop material is injected through this inlet 43 into the bale forming chamber Ch. Several longitudinal ribs are mounted on the circumferential surface 8 of the upper starter roller 6 and belong to the conveying surface 8. It is possible that such ribs are also mounted on the circumferential surface of the lower starter roller 42. The rollers 41.2, 44 are rotatably mounted at the pivotal tailgate. The driven starter rollers 42, 6, the roller 41.1 and the further deflecting or guiding rollers are rotatably mounted at the stationary front housing or at the pivotal tailgate. The pressing belts 40 and the starter rollers 6, 42 surround the drum-shaped bale forming chamber Ch in which the round-cylindrical bale B is created.

[0116] The horizontal rotating axes of the conveying rotor 39 and of the rollers 6, 41.1, 41.2, 42, 44 are perpendicular to the travelling direction TD and to the drawing plane of FIG. 1. FIG. 1 shows the rotating directions of the rollers 6, 42, 41.1, the conveying direction of the pressing belts 40, and the direction in which the bale B is rotated. The starter rollers 6, 42 are driven clockwise around rotating axes perpendicular to the drawing planes of FIG. 1. The upper starter roller 6 is mounted on the drive shaft 18 (perpendicular to the drawing plane). The drive shaft of the lower starter roller 42 is not shown.

[0117] In the embodiment the wrapping device 29 is mounted at a front plate of the stationary front housing, i.e. in front of the bale forming chamber - seen in the travelling direction TD.

[0118] In addition to the unrolling station the wrapping device 29 of the baler of FIG. 1 comprises [0119] a moveable supporting plate 3 belonging to a web moving member, [0120] a downholder unit 48 connected with the supporting plate 3 and positioned above the supporting plate 3, preferably implemented as an ensemble of pivotal flaps mounted at a traversal rod, [0121] two stationary web deflecting rollers 14, 21, [0122] a web movement sensor 26 which counts the number of rotations of the roller 21, [0123] a moveable web deflecting roller 20 connected with the moveable supporting plate 3, [0124] a stationary web guiding roller 24 which is biased against the web deflecting roller 21, and [0125] a severing device with a moveable knife 5 and a stationary anvil 19.

[0126] The term stationary roller means that the roller can only rotate around its own rotational axis but cannot be shifted laterally. In the embodiment the rollers 14, 21, 24, 20 are idle rollers.

[0127] FIG. 1 shows a situation in which the bale B in the chamber Ch is formed and the wrapping procedure has not yet started. A web 30 of wrapping material extends from the supply reel 32 to a severing location 50 outside of the bale forming chamber Ch. This situation occurs after the previous bale has been wrapped and the web 30 has been severed at the severing location 50. The web 30 is guided around the rollers 14, 21 and 20. The web 30 is guided through the space between the rollers 21 and 24. A wrapping material inlet 15 is positioned between the rollers 6, 41.1 and guides into the bale forming chamber Ch.

[0128] When the current bale B in the bale forming chamber Ch has reached the required diameter and has to be wrapped, the web 30 is moved towards the bale forming chamber Ch and is injected through wrapping material inlet 15 into the bale forming chamber Ch. The wrapping material inlet 15 is positioned below those segments of the belts 40 which are guided around the roller 41.1 and above the upper start roller 6. After being injected into the bale forming chamber Ch, the web 30 is clamped between the rotated bale B and the bale forming means (the rollers 8, 42 and later the pressing belts 40) and is pulled from the supply reel 32 without using the web moving member 3, 20, 48. This event causes the supply reel 32 to rotate.

[0129] In one implementation the stationary roller 14 serves as a spreader roller which spreads the moved web 30 of wrapping material. Thanks to the spreader roller 14 it is ensured that the web 30 keeps its full width and the entire circumferential surface of the bale B in the bale forming chamber Ch is wrapped, i.e. the web 30 reaches from front face to front face of the bale B.

[0130] In one implementation the number of revolutions of the deflecting roller 21 is counted by the sensor 26. As the roller 24 is biased against the roller 21, nearly no slippage between the roller 21 and the web 30 occurs. The counting starts when the wrapping procedure for a bale commences. The counted number serves as a value indicative of the length of the web 30 pulled from the supply reel 32.

[0131] FIG. 1 shows the supporting plate 3 in a remote position in which the supporting plate 3 has the maximal possible distance to the wrapping material inlet 15. The supporting plate 3 can be moved in both directions as indicated by the double arrow DA (to be described below). In one implementation (shown in the figures) the supporting plate 3 is orientated horizontally and can be moved in to horizontal directions with respect to the wrapping material inlet 15. In a further implementation (not shown) the supporting plate 3 is orientated in a descending sloping direction. The supporting plate 3 can be moved in this descending direction towards the wrapping material inlet 15 and in an opposite ascendingly directing away from the wrapping material inlet 15. The web deflecting roller 20 is moved together with the supporting plate 3 and can rotate around its own rotating axis but cannot otherwise be moved with respect to the supporting plate 3. In one implementation the web deflecting roller 20 is rotatably mounted at the supporting plate 3.

[0132] In addition the knife 5 of the baler of FIG. 1 can be moved in a vertical direction towards the anvil 19 for severing the web 30. The severing location 50 is arranged between the supporting plate 3 being in the remote position and the wrapping material inlet 15. The embodiment of FIG. 1 can also be implemented with a severing device wherein the knife 5 operates in a horizontal or sloping direction or wherein the knife is stationary and an opposing element is moveable. In FIG. 1 the knife 5 is shown in a parking position.

[0133] On its way from the supply reel 32 towards the wrapping material inlet 15 the web 30 is guided around the deflecting rollers 14, 21, and 20. The severing device 5, 19 is arranged downstream from the supporting plate 3 and downstream from the downholder unit 48 for the web 30, i.e. it severs the web 30 at the severing location 50 positioned between the supporting plate 3 being in the remote position and the wrapping material inlet 15. The term downstream refer to the direction in which the web 30 is conveyed towards the wrapping material inlet 15.

[0134] The supporting plate 3, the downholder unit 48, and the moveable web deflecting roller 20 cannot be moved relative to each other and belong to the web moving member of the embodiment. In the embodiment the web moving member 3, 20, 48 can be moved between two end positions with respect to the wrapping material inlet 15, namely a remote position and an adjacent position. In the embodiment the web moving member 3, 20, 48 is moved from one end position to the other end position continuously, i.e. without an interruption.

[0135] The knife 5 belongs to a moveable web severing member. The knife 5 and the stationary anvil 19 belong to a web severing device.

[0136] As can be seen in FIG. 1, a slack loose portion 31 of the web 30 extends from the front edge 46 of the web 30 (at the severing location 50) backwards to the supporting plate 3. A slack leading segment 35 rests on the supporting plate 3 and is kept by the downholder unit 48 on the supporting plate 3. In the embodiment this slack leading segment 35 extends from the leading edge of the web 30 to the deflecting roller 20, i.e. comprises the leading loose leading portion 31. The leading portion 35 protrudes from the supporting plate 3. The leading edge 46 of the web 30 points towards the wrapping material inlet 15.

[0137] FIG. 2 to FIG. 5 show a detailed cross-sectional view onto one embodiment of the bale forming and wrapping apparatus of FIG. 1 in a vertical center plane which is positioned in the middle of the bale forming and wrapping apparatus and which extends in the travelling direction TD. The viewing direction is that of FIG. 1.

[0138] FIG. 2 shows the supporting plate 3 positioned in the largest possible distance to the wrapping material inlet 15, i.e. being in the remote position. This remote position of the web moving member 3, 20, 48 is achieved after the web 30 for the previous bale has been injected into the bale forming chamber Ch and the previous bale has been wrapped. The severing device with the knife 5 has severed the web 30 at the severing location 50.

[0139] The web moving member 3, 20, 48 remains in this remote position while the current bale B is formed in the bale forming chamber Ch and until a given wrapping start condition is fulfilled. Preferably the wrapping start condition is fulfilled if the bale diameter reaches a given threshold. This diameter threshold can be the required final diameter or a slightly smaller diameter value. Thanks to the remote position sufficient space for providing the slack leading segment 35 during the entire movement towards the wrapping material inlet 15 is provided, i.e. the web segment from the supply reel 32 to the leading edge 46or a part of this segmentremains slack until the web 30 is injected into the bale forming chamber Ch. In addition the remote position provides a gap through which debris can pass through the gap between the leading segment 35 on the supporting plate 3 and the wrapping material inlet 15. The debris can drop onto the conveyor rotor 39.

[0140] In the embodiment the leading segment 35 of the web 30 rests on the supporting plate 3, is kept by the downholder unit 48, and remains slack at least while the current bale B is formed in the bale forming chamber Ch and while the wrapping device 29 is not used. The loose leading portion 31 of the leading segment 35 comprises the leading edge 46 of the web 30 and protrudes from the supporting plate 3 towards the wrapping material inlet 15. In the embodiment of FIG. 2 to FIG. 5 the slack leading segment 35 starts in the web deflecting roller 20, extends to the leading edge 46, and rests on the supporting plate 3. It is also possible that the leading segment 35 starts in the roller 14 or even in the supply reel 32.

[0141] In the embodiment of FIG. 2 to FIG. 5 the supporting plate 3 is connected with a frame 1 of the round baler by means of a parallelogram guider. This parallelogram guider comprises the following parts: [0142] a front guiding lever member 2.1 with a right front guiding lever arm and a corresponding left front guiding lever arm, [0143] a rear guiding lever member 2.2 with a right rear guiding lever arm and a corresponding left rear guiding lever arm, and [0144] a bearing member 2.3 for the supporting plate 3 with a right bearing and a corresponding left bearing.

[0145] The term front and rear refer to the travelling direction TD. The supporting plate 3 is carried by the bearing member 2.3 and is positioned between the two bearings. The slack leading segment 35 of the web 30 rests on the supporting plate 3 and extends substantially from the left bearing to the right bearing of the bearing member 2.3. The downholder unit 48 keeps the leading segment 35 on the supporting plate 3.

[0146] The lever arms of the front guiding lever member 2.1 are pivotally connected with the frame 1 in a front pivoting axle 9.1 being perpendicular to the travelling direction TD and to the drawing plane of FIG. 2 to FIG. 5. The lever arms of the rear guiding lever member 2.2 are pivotally connected with the frame 1 in a rear pivoting axle 9.2 being parallel to the front pivoting axle 9.1. A distance between these parallel pivoting axles 9.1, 9.2 occurs. The pivoting axles 9.1, 9.2 are not moved while the web moving member 3, 20, 48 is moved out of the remote position towards the wrapping material inlet 15. The bearing member 2.3 is pivotally connected with the front guiding member 2.1 in a front pivoting axis 10.1 and with the rear guiding member 2.2 in a rear pivoting axis 10.2. The axles 10.1, 10.2 are parallel to the axles 9.1, 9.2. A distance between the parallel pivoting axes 10.1, 10.2 occurs.

[0147] FIG. 2 further shows [0148] a guiding member actuator 7 for the parallelogram guider 2.1, 2.2, 2.3, [0149] the moveable web deflecting element 20 (in the embodiment: a deflecting roller) which deflects the web 30 and which is rotatably mounted at the bearing member 2.3 and extends at least from the left bearing to the right bearing of the bearing member 2.3, and [0150] the two stationary web deflecting rollers 14, 21 for the web 30.

[0151] In FIG. 2 to FIG. 5 the optional guiding roller 24 and the web movement sensor 26 are omitted.

[0152] Preferably the guiding member actuator 7 is a double-acting actuator. In one implementation the guiding member actuator 7 comprises a right hydraulic piston-cylinder device and a corresponding left hydraulic piston-cylinder device. Expanding the actuator 7 causes the supporting plate 3 to be moved towards the wrapping material inlet 15. It is also possible that the guiding member actuator 7 comprises only one piston-cylinder device or a further actuator, e.g. an electrical motor. The guiding member actuator 7 is pivotally connected with the front guiding lever member 2.1 in a lower pivoting axis 12 and with the frame 1 in an upper pivoting axis 13.

[0153] FIG. 2 also shows a part of the upper starter roller 6 with the conveying surface 8 mounted on the drive shaft 18.

[0154] FIG. 2 further shows the moveable knife 5 with a cutting edge 51 extending perpendicular to the drawing plane. This cutting edge 51 of the knife 5 extends over the entire width of the web 30 and is mounted at the free end of a pivotal knife lever member 4 comprising a right knife lever arm and a corresponding left knife lever arm. The knife 5 is mounted between the knife lever arms. In its lower end the knife lever member 4 is pivotally connected with the bearing member 2.3 in a pivoting axle 11 which also extends perpendicular to the drawing plane of FIG. 2 and which is positioned between the knife 5 and the pivoting axis 10.2. The axle 11 and the rear guiding lever member 2.2 establish a mechanical connection between the supporting plate 3 and the knife lever member 4 carrying the knife 5.

[0155] Preferably the knife lever member 4 is locked at the rear guiding lever member 2.2 when the web moving member 3, 20, 48 is in the remote position. The knife lever member 4 is temporally also locked when the web moving member 3, 20, 48 is in an intermediate position. In the situation shown in FIG. 2 the knife lever member 4 and thereby also the knife 5 are in the intermediate position.

[0156] Moving the supporting plate 3 into the adjacent position (in FIG. 2 to FIG. 5 to the right), i.e. towards the wrapping material inlet 15, makes the knife lever member 4 rotating around the axle 11 away from the web 30 and away from the wrapping material inlet 15, in FIG. 2 to FIG. 5 anti-clockwise. Moving the supporting plate 3 into the remote position (in FIG. 2 to FIG. 5 to the left), i.e. away from the wrapping material inlet 15, makes the knife lever 4 rotating around the axle 11 towards the web 30 and towards the wrapping material inlet 15, in FIG. 2 to FIG. 5 clockwise.

[0157] The knife 5 and the knife lever member 4 as well as the anvil 19 belong to a severing device. The anvil 19 is not shown in FIG. 2 to FIG. 5. The parts 4 and 5 of the severing device together form the moveable severing member. FIG. 2 shows the moveable severing member 4, 5 in an intermediate position. FIG. 2 further shows a severing actuator 25 (to be explained below) having the form of two parallel lateral helical springs. In Fig.2 to FIG. 4 these helical springs 25 are pressed together and store kinetic energy.

[0158] FIG. 2 to FIG. 5 illustrate the operation of the wrapping apparatus 29. After the previous bale has been wrapped and the severing device 4, 5, 19 has severed the web 30 at the severing location 50, the piston-cylinder devices of the guiding member actuator 7 are or remain retracted and keep the web moving member 3, 20, 48 in the remote position (maximal distance to the wrapping material inlet 15). The moveable severing member 4, 5 is kept by the coupling element 2.2, 11 in the intermediate position. The web 30 is kept by the downholder unit 48 on the supporting plate 3 and is guided around the deflecting rollers 14, 21 and the web deflecting roller 20. Thanks to the downholder unit 48 the leading segment 35 does substantially not move with respect to the supporting platte 3 while the baler is moved over ground and also while the web moving member 3, 20, 48 is moved. The segment 35 from the roller 20 to the leading edge 46 is slack. FIG. 2 shows this situation.

[0159] The current diameter or a further parameter of the round-cylindrical bale B in the bale forming chamber Ch is measured. As soon as the bale diameter or a further measured bale parameter reaches a given threshold, the wrapping procedure is triggered. FIG. 3 shows a situation shortly after the wrapping procedure has started. The piston-cylinder device(s) of the guiding member actuator 7 are fully expanded and have io pivoted the parallelogram guider 2.1, 2.2, 2.3 around the axes 9.1, 9.2 towards the wrapping material inlet 15 (direction of arrow M). The web moving member 3, 20, 48 is moved towards the wrapping material inlet 15 into the adjacent position without being tilted or pivoted. During the guided movement the upper surface of the supporting plate 3 does preferably not pivot but remains with the same angle to the ground. The conveying surface 8 with the ribs has conveyed the leading segment 35 further towards the wrapping material inlet 15. FIG. 3 shows the web moving member 3, 20, 48 in the adjacent position with respect to the wrapping material inlet 15. The web 30 has just been introduced through the wrapping material inlet 15 into the bale forming chamber Ch.

[0160] In the embodiment the knife lever member 4 is linked with the parallelogram guider 2.1, 2.2, 2.3 in the pivoting axis 11. Pivoting the parallelogram guider 2.1, 2.2, 2.3 towards the wrapping material inlet 15 makes the pivotal knife lever member 4 to pivot around the pivoting axis 10.2 anti-clockwise and away from the wrapping material inlet 15. As the knife lever member 4 is locked at the rear guiding lever member 2.2, the knife lever member 4 is not pivoted with respect to the rear guiding lever member 2.2 during this movement. The helical springs 25 remain compressed. FIG. 3 shows the moveable severing member 4, 5 in a parking position with the maximal possible distance to the wrapping material inlet 15. The movement of the supporting platte 3 from the position of FIG. 2 to the position of FIG. 3 was transferred onto the lever member 4. Thereby the moveable severing device 4, 5 was pivotally moved from the intermediate position of FIG. 2 into the parking position (maximal distance) of FIG. 3.

[0161] In one implementation the web segment from the stationary roller 21 to the leading edge 46 is so long that no web 30 needs to be pulled from the supply reel 32 while the supporting platte 3 moves the leading segment 35 towards the wrapping material inlet 15. The part of the web 30 upstream from the roller 21 remains not conveyed until the leading segment 35 is injected into the bale forming chamber Ch. The web segment between the rollers 21 and 20 is only rotated around a rotating axis through the roller 21 and perpendicular to the drawing plane of FIG. 1 to FIG. 5 but is not conveyed and is not tensioned. Wrapping material is only pulled from the supply reel 32 after the web 30 is injected into the bale forming chamber Ch and while the inserted web 30 is first clamped and pulled between the starter roller 6 and the rotated bale B and later additionally between the pressing belts 40 and the rotated bale B.

[0162] The web segment between the roller 21 and the leading edge 46 is so long and the remote position of the web moving member 3, 20, 48 is selected such that the web 30 is not moved with respect to the rollers 14, 21, 20 while the supporting platte 3 moves the leading segment 31 towards the wrapping material inlet 15 (transition from FIG. 2 to FIG. 3). The web 30 is only pulled from the supply reel 32 and moved and tensioned when the upper starter roller 6 and the rotated bale B have clamped the injected web 30.

[0163] In the situation shown in FIG. 3 the inserted web 30 has just been clamped between the rotated bate B and the surface 8 of the upper starter roller 6. The circumferential velocity of the bale B is larger than the moving velocity of the web moving member 3, 20, 48. The supply reel 32 is decelerated by a brake after the web 30 has been injected. Thereby the web 30 will now be tensioned. The roller 21 is rotated and the sensor 26 counts the number of rotations.

[0164] FIG. 4 shows the continuation of the wrapping procedure for this bale B. After the conveying surface 8 and the rotated bale B have securely grasped and clamped the web 30 and pull the web 30 from the supply reel 32, the piston-cylinder device(s) of the guiding member actuator 7 are retracted again and shift the web moving member 3, 20, 48 back in the remote position of FIG. 2or in a further remote position (not shown). In one implementation a sensor detects the event that the conveying velocity of the web 30 rapidly increases. This event is a clue for the event that the web 30 has successfully been injected and been clamped. The detection of this event triggers the step of moving the web moving member 3, 20, 48 back into the remote position.

[0165] The injected web 30 remains clamped by the conveying surface 8 and later by the belts 40 on the one side and the rotated bale B on the other side. The web 30 remains guided around the web deflecting roller 20. Therefore that segment of the web 30 which extends from the roller 20 to the wrapping material inlet 15 is now tensioned. This tensioning improves the wrapping procedure and ensures that the inserted web 30 covers the entire circumferential surface of the bale B without wrinkles.

[0166] As already mentioned the moveable severing member 4, 5 is connected with the web moving member 3, 20, 48 in the pivoting axis 11. Therefore the step of moving the web moving member 3, 20, 48 back into the remote positon is transferred onto the moveable severing member 4, 5. Thereby the moveable severing member 4, 5 is moved back from the parking position into the intermediate position.

[0167] FIG. 5 shows the termination of the wrapping procedure. The web moving member 3, 20, 48 remains in the remote position of FIG. 4 until the bale B is completely wrapped. Web 30 is pulled from the supply reel 32 until a required number of layers of wrapping material are placed around the bale B in the bale forming chamber. In one implementation the number of rotations of the roller 21 is counted by the sensor 26 and serves as a value indicative of the length of the pulled web 30. The web moving member 3, 20, 48 remains its remote position, i.e. its position in FIG. 4 is the same than that in FIG. 5. The movement of the moveable severing member 4, 5 from the intermediate position (FIG. 2) into the parking position (FIG. 3) and back into the intermediate position (FIG. 4) is caused purely by [0168] the movement of the web moving member 3, 20, 48 and [0169] the mechanical connection between the web moving member 3, 20, 48 and the moveable severing member 4, 5.

[0170] During these two movements the knife lever member 4 remains locked at the rear guiding lever member 2.2.

[0171] The transition from FIG. 4 to FIG. 5 starts with the step that the knife lever member 4 is released, i.e. is no longer connected with the rear guiding lever member 2.2. The stored kinetic energy is thereby released. In the situation shown in FIG. 5 a severing device actuator, e.g. an actuator comprising two lateral springs 25 or an electric motor (not shown), has further pivoted the severing device 4, 5 around the pivoting axis 11 towards and through the web 30. Thereby the severing device 4, 5 has been moved from the intermediate position of FIG. 4 into the web severing position of FIG. 5. The web 30 is severed at the severing position 50 between the knife 5 and the anvil 19 (not shown in FIG. 2 to FIG. 5). After the web 30 is severed, a new leading segment 35 with a new leading edge 46 is formed.

[0172] In the embodiment an actuator (not shown) releases the locking device between the rear guiding lever member 2.2 and the knife lever member 4. The compressed helical springs 25 expand and quickly rotate the knife lever member 4 clockwise around the axis 11.

[0173] The web 30 is tensioned after being injected and in particular until being severed. The tension causes the new leading segment 35 to be contracted after the web 30 is severed. A feedback of this contraction onto the rest of the web 30 should be avoided. The web 30 should stay in contact with the guiding rollers 14, 21, 20. Therefore the roller 24 is biased against the roller 21. The web 30 is guided through the space between the rollers 20, 21 and is touched from two opposing sides by the circumferential surfaces of the rollers 21, 24. In addition a free-wheel clutch enables the roller 24 only to rotate in one direction (in FIG. 1 anti-clockwise) but prevents the roller 24 from rotating in the opposite direction (in FIG. 1 clockwise). Therefore the contracting leading edge 35 cannot move the web 30 towards the supply reel 32. An undesired feedback is inhibited.

[0174] After the web 30 has been severed, the severing actuator moves back the moveable severing device 4, 5 from the web severing position of FIG. 5 into the intermediate position of FIG. 2. While this movement is performed, the web moving member 3, 20, 48 remains in the same remote position. Therefore the severing actuator of the embodiment is a double-acting actuator. Preferably the severing actuator comprises two single-acting actuators, namely a quick actuator 25 for quickly moving the moveable severing member from the intermediate position into the web severing position and a slow actuator for the opposite movement. The opposite movement needs not to be performed very quickly.

[0175] Preferably the quick actuator comprises an energy storing device, e.g. the helical or circular spring 25. The operation of the slow actuator fills the energy storage with kinetic energy. This kinetic energy is used for quickly moving the moveable severing device 4, 5 from the intermediate position into the web severing position.

[0176] In one implementation the cutting edge 51 of the knife 5 hits an anvil 19 (not shown in FIG. 2 to FIG. 5) after the knife lever member 4 has been rotated and the knife 5 has hit the web 30. In an alternative implementation the tension of the web 30 is so high that the knife 5 can penetrate and sever the web 30 without hitting an anvil 19. In yet a further implementation the severing device clamped the web 30 and the clamped web 30 is torn as the bale B and the bale forming means continue to pull at the web 30.

[0177] In both implementations a new slack leading segment 35 with a new leading edge 46 is formed and rests on the supporting platte 3, cf. FIG. 5. The new leading edge 46 is positioned at the knife 5. The severing actuator moves the severing device 4, 5 from the web severing position back into the intermediate position against the force of the springs 25. The procedure as just described will be performed again for the new bale.

[0178] Reference signs used in the claims will not limit the scope of the claimed invention. The term comprises does not exclude other elements or steps. The articles a, an, and one do not exclude a plurality of elements. Features specified in several depending claims may be combined in an advantageous manner.

TABLE-US-00001 LIST OF REFERENCE SIGNS 1 frame which carries the parallelogram guider 2.1, 2.2, 2.3 2.1 front guiding lever member of the parallelogram guider, comprises two front guiding lever arms 2.2 rear guiding lever member of the parallelogram guider, comprises two rear guiding lever arms, carries the pivoting axle 11 2.3 bearing member for the supporting plate 3, comprises two lateral bearings 3 moveable supporting plate, carries from below the slack leading segment 35, guided by the parallelogram guider 4 pivotal knife lever member for the knife 5, comprises two knife lever arms pivotally connected with the rear guiding lever member 2.2 in the axle 11, belongs to the moveable severing member of the severing device 5 knife, mounted on the free end of the pivotal knife lever arms of the knife lever member 4, belongs to the moveable severing member of the severing device 6 upper starter roller, delimit the crop material inlet 43 from above, has the conveying surface 8 7 guiding member actuator for the parallelogram guider 8 conveying surface of the starter roller 6 9.1 pivoting axle between the frame 1 and the front lever member 2.1 9.2 pivoting axle between the frame 1 and the rear lever member 2.2 10.1 pivoting axle between the front lever member 2.1 and the bearing member 2.3 10.2 pivoting axle between the rear lever member 2.2 and the bearing member 2.3 11 pivoting axle between the rear lever member 2.2 and the lever arms of the knife lever member 4 for the knife 5 12 pivoting axle between the guiding member actuator 7 and the front lever member 2.1 13 pivoting axle between the guiding member actuator 7 and the wrapping device frame 1 14 upper stationary deflecting roller for the web 30, serves as a spreader roller 15 inlet for the web 30 of wrapping material, positioned between the upper starter roller 6 and the belt segment guided around the deflecting roller 41.1 16 idler roller for pulling the web 30 from the supply reel 32, biased against the driven roller 17 17 driven roller for pulling the web 30 from the supply reel 32 18 driven shaft for the starter roller 6 19 stationary anvil, serves as the opposing severing element for the knife 5 20 moveable deflecting roller for the web 30, connected with the supporting plate 3, in one implementation mounted between the bearings 2.3 21 driven stationary deflecting roller for the web 30, mounted at the frame 1 24 web guiding roller with a free-wheel clutch 25 severing actuator in the form of two lateral helical spring 26 web movement sensor, counts the number of rotations of the roller 21 29 wrapping device, comprises an unrolling station for the supply reel 32 30 web of wrapping material 31 free loose portion of the web 30, belongs to the slack leading segment 35 32 supply reel with wrapping material 35 slack leading segment of the web 30, rests on the supporting plate 3, points to the wrapping material inlet 15 35 new slack leading segment of the web 30 39 conveyor rotor 40 pressing belt(s), guided around the deflecting rollers 41.1, 41.2 41.1, deflecting rollers for the pressing belt 40 41.2 42 lower starter roller, delimits the crop material inlet 43 from below 43 crop material inlet, delimited by the starter rollers 6 and 42 44 guiding roller for the pressing belt 40 46 leading edge of the web 30, positioned at the severing location 50 46 new leading edge of the web 30, positioned at the severing location 50 48 pivotal downholder unit for the web 30 50 severing location at which the severing device 4, 5, 19, 25 severs the web 30 51 cutting edge of the knife 5 B round-cylindrical bale in the bale forming chamber Ch drum-shaped bale forming chamber DA double arrow, shows the possible directions in which the supporting plate 3 can be moved. M direction in which the web moving member 3, 20, 48 is moved when carrying the leading segment 35 TD traveling direction of the baler