Wrapping apparatus for round balers

A round baler comprising a bale chamber in which crop material is formed into a bale, crop material pick-up means operable to deliver crop material to the bale chamber, apparatus for wrapping a formed bale with sheet material comprising feed rolls operable to feed the sheet material so that it can engage the formed bale and be wrapped therearound, and a knife operable to sever the sheet material when the formed bale has been wrapped with a predetermined length thereof. A further roll is disposed between the feed rolls and the formed bale for applying the sheet material in its full nominal width to the formed bale.

BACKGROUND OF THE INVENTION 
This invention relates to agricultural baling machines and more especially 
to such machines known as round balers which produce cylindrical bales of 
crop material. 
When round balers were first introduced, a completed bale was wrapped with 
twine in order to retain its shape during subsequent handling, just as the 
previous rectangular bales were tied with twine. However, in order to 
achieve satisfactory wrapping of a round bale, the twine has to be 
reciprocated back and forth along the length of the formed bale as the 
latter is rotated. This is relatively time consuming which is 
disadvantageous, bearing in mind that the formation of the next bale 
cannot be commenced until the formed bale has been wrapped and discharged 
from the machine. 
With this problem in mind, it has been proposed to wrap a round bale with a 
sheet of synthetic plastics material. The wrapping of a round bale with a 
sheet material requires appreciably less time when compared with that 
taken to wrap a bale with twine or ribbon-like synthetic plastics material 
because only one and a half to two wraps are required. However, the use of 
such sheet material has generated a new problem, namely that of securing 
the wrapping, and numerous attempts have been made to solve this 
difficulty. To this end, it has been proposed to replace the solid sheet 
synthetic plastics by netting which self-adheres to a formed bale without 
the need to take any special steps in this respect. Such a disclosure is 
made in U.S. Pat. No. 4,569,439 and in U.S. Pat. No. 4,599,844 there is 
disclosed a specific arrangement for severing applied netting from a 
source roll thereof. 
While the use of netting has been found satisfactory, there is one problem 
associated therewith which also tends to be present in the use of solid 
sheeting. The problem is that of the material reducing in width as it is 
pulled from the source roll and thus not being utilized to full advantage 
in wrapping a bale. 
SUMMARY OF THE INVENTION 
According to the present invention there is provided a round baler 
comprising a bale chamber in which crop material is formed into a bale, 
crop material pick-up means operable to deliver crop material to the bale 
chamber, means for wrapping a formed bale with sheet material comprising 
feed means operable to feed the sheet material so that it can engage the 
formed bale and be wrapped therearound, means operable to sever the sheet 
material when the formed bale has been wrapped with a predetermined length 
thereof, and the improvement wherein means are disposed between the feed 
means and the formed bale for applying the sheet material in a 
predetermined width to the formed bale. 
The term "sheet material" refers to not only netting but also solid sheet 
material or the like. 
The provision of the sheet material applying means, between the sheet 
material feed means and the formed bale in a manner to apply the sheet 
material to the bale in a predetermined width, overcomes the problem of 
the sheet material reducing in width as a result of the sheet material 
being pulled from the source roll thereof. 
Conveniently, the sheet material applying means are in the form of a roll 
having oppositely directed augering means at the respective ends which, in 
use, serve to spread the sheet material to, or retain it in, its full 
width. Some sheet materials may be such as to accommodate spreading beyond 
their nominal width so as to be stretched in width before being applied to 
a formed bale. Such sheet materials can be employed with the present 
invention. 
The roll may be plain with each end provided with spiral flight means which 
may be formed from wire of generally circular cross-section. 
The roll may be static, driven or free-wheeling and may be replaced by 
alternative means for applying the sheet material in a predeterined width 
to the formed bale. For example, the means may be a surved or V-shaped bar 
or plate. 
It is preferable to locate the sheet material applying means as close as 
possible to the formed bale. This conveniently may be done in the path of 
incoming crop material from the pick-up means so that this crop material 
serves to take the sheet material to the bale. Thus the sheet material 
applying means preferably is disposed in the throat of the bale chamber 
through which crop matrial enters the latter but, as this throat needs to 
be clear so as not to present any obstruction to incoming crop during 
actual bale formation, the sheet material applying means may be movable 
between an operative position to which it lies in the bale chamber throat, 
and a retracted, inoperative position in which it is clear of the bale 
chamber throat. 
The feed means for the sheet material preferably are driven initially to 
feed the free end of the sheet material into the vicinity of incoming crop 
material from the pick-up means. This drive preferably is interrupted when 
the sheet material has engaged the formed bale and continued rotation of 
the latter serves to pull the sheet material from the source roll thereof. 
This is preferred so that there is no conflict between the driven feed 
means and the pull exerted by the bale. 
The severing means operable to cut the sheet material when a formed bale 
has been wrapped with a predetermined length thereof preferably is movable 
between a retracted, inoperative position and an operative position in 
which it crosses the path of the sheet material and thus severs the same. 
The severing means preferably is linked with the sheet material applying 
means such that, when the severing means are retracted, the sheet material 
applying means are in the operative position and vice versa.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring first to FIG. 1, the baler is basically of conventional design 
and is generally similar, for example, to that disclosed in U.S. Pat. No. 
4,366,665. Briefly, the baler comprises crop material pick-up means 1 
operable to pick up crop material from the ground and deliver it to a 
throat 2 of a bale chamber 3 formed by a floor conveyor or lower apron 4 
and an expandable upper apron 5. The bottom and top of the throat 2 are 
defined by the floor conveyor 4 and the drive sprockets 8 for the upper 
apron 5, respectively. The bale chamber 3 is split into two with one 
portion being in the form of a tailgate 9 which can be raised by hydraulic 
cylinders 11 in order that a completed bale 12 can be discharged from the 
machine. A tongue 13 is attached to the frame 7 for connection to a 
tractor or other vehicle used to tow the baler. 
The baler further comprises a source of sheet material for wrapping a 
completed bale in the form of a roll 14 of a net of a nominal width and 
rotatably mounted on the frame 7. Feed means are provided for feeding the 
sheet material 15 from the roll 14, the feed means comprising a driven 
roll 16, a similarly-sized freely rotatable pinch roll 17, and a small 
pinch roll 18. The sheet material is fed from the source roll 14 under the 
feed roll 18, over the feed roll 17, and down between the feed rolls 16 
and 17. The feed rolls 16,17 and 18 are shown in greater detail in FIG. 2 
and reference will now be made to this figure, as well as FIGS. 3 and 4. 
The driven feed roll 16 carries a pulley 19 and is driven via a belt 22, 
from a pulley 21 attached to a shaft 23 of the drive sprockets 8 of the 
upper apron 5. Drive is imparted to the feed roll 16 when the belt 22 is 
tensioned by a tension pulley 24 rotatably mounted on the end of one arm 
25 of a bell-crank lever 26 pivoted at 27 on the adjacent side wall of the 
machine. The other arm 28 of the bell-crank lever 26 is pivotally attached 
to an actuating member 29 of a linear actuator 31 also mounted on the side 
wall of the machine. 
Severing means in the form of a knife 32 is mounted on a support 33 pivoted 
about the axis 34 of the feed roll 16. The support 33 has a pin 36 which 
extends through the associated side wall of the baler to receive one end 
of a double or S-shaped hook 37, the other end of which engages a pin 38 
on the end of the armature 39 of a solenoid 41 mounted on a bracket 42 
attached to the baler side wall. A compression spring 43 extends between 
the pin 36 on the support 33 and an aperture in a bracket 44 also mounted 
on the baler side wall. 
The support 33 has a mounting bracket 45 extending therefrom and to which 
is pivotally attached one end of an arm 46, the other end of which is 
pivotally attached to a bracket 47 carried by a further arm 48 
intermediate the ends thereof. One end of the arm 48 is pivotally attached 
to the member 6 attached to the frame 7 and shielding the upper apron 
drive sprocket 8 proximate thereto. The distil end of the arm 8 carries 
one end of sheet material applying means in the form of a freely rotatable 
roll 49. The other end of the roll 49 is rotatably carried by a swing link 
(not shown) similar to the arm 8. 
As shown in FIG. 4, the roll 49 is plain except that, at each end, it is 
provided with oppositely and outwardly directed auger flights 51 in the 
form of circular cross-section wire wound around the roll. 
In use of the baler, crop material is picked up by the pick-up 1 and fed to 
the bale chamber 3 through the throat 2 and is rolled into a cylindrical 
bale between the lower and upper aprons 4 and 5 in a conventional manner. 
When the bale has reached either the maximum size for the machine or a 
size required by the operator, it is wrapped with the sheet material in 
the form of the netting 15, in the following manner. 
The linear actuator 31 is energized to retract the actuating member 29 
thereof from the extended position shown in broken lines in FIG. 3 to the 
fully retracted position shown in full lines in FIG. 3. This movement of 
the actuating member 29 rocks the bell-crank lever 26 about its pivot 27 
in a clockwise direction as seen in FIG. 3, whereby the tension pulley 24 
is raised and engages and tensions the belt 22 so that drive is imparted 
to the feed roll 16. On rotation of the feed roll 16, the pinch feed rolls 
17 and 18 are also rotated through friction and the sheet material 15 is 
fed from the source roll 14 and the free end thereof thus is lowered 
towards the pick-up 1. At this point, the pick-up 1 is still operative and 
is thus feeding further crop material into the throat 2 and this crop 
material contacts the lowered sheet material 15 and therefore carries the 
latter into the throat 2 to the formed bale 12. As soon as this occurs, 
the forward movement of the baler is stopped as it is undesirable to feed 
further crop material to the bale when the latter is being wrapped. As the 
sheet material 15 passes beneath the completed bale 12 which is being 
rotated within the bale chamber 3, the bale 12 then pulls the sheet 
material 15 and, in order to avoid any conflict between this pulling 
action and the feeding effected by the feed rolls 16,17 and 18, the drive 
to the feed roll 16 is interrupted so that the feeding of the sheet 
material 15 is taken over solely by the rotating bale 12. 
At this point, it should be mentioned that either simultaneously with the 
energization of the linear actuator 31, the solenoid 41 is energized which 
retracts the armature 39 thereof and thus swings the support 33 clockwise 
as seen in FIG. 2, thereby raising the pin 36 against the action of the 
spring 43. Thus, the knife 32 is swung out of the path of the sheet 
material 15 to the retracted position shown in broken lines in FIG. 2. 
This rotational movement of the support 33 moves the arm 46 from the full 
line position to the broken line position of FIG. 2 in which the material 
applying roll 49 occupies the broken line position which is its operative 
position in which it is located in the throat 2. 
The obstruction which the roll 49 presents in the throat is immaterial in 
as much as, at this stage, the feeding of further crop material into the 
bale chamber 3 soon is to be terminated as already explained. Therefore, 
the roll 49 does not form an unacceptable obstruction to the last bit of 
incoming crop material. The sheet material 15 then being pulled from the 
source roll 14, engages the roll 49 and the oppositely directed flights 51 
thereon, in effect, auger the opposed edges of the sheet material 
outwardly in order that the sheet is maintained substantially in its full 
nominal width, thus counteracting the natural tendency of the width to 
reduce in width on being pulled from the source roll 14. Accordingly, the 
sheet material 15 is applied to the completed bale in a predetermined 
width so that maximum use is made of the sheet material in order to wrap 
the bale. It may be necessary to provide some guide means or stop means 50 
at one or both sides of the roll 49 to ensure that the sheet material, in 
being maintained in its full nominal width on being applied to the 
completed bale 12, does not foul any components of the baler (i.e., is not 
spread too widely). 
Returning to the de-energization of the linear actuator 31, this is 
effected, as already stated, in order to allow the sheet material 15 to be 
pulled freely from the source roll 14 by the rotating bale 12. However, at 
the time de-energization of the linear actuator 31 is effected, the 
solenoid 41 remains energized. However, a timer (not shown) is energized 
in order to effect de-energization of the solenoid 41 at a predetermined 
time after the de-energization of the linear actuator 31. When the timer 
operates to effect this de-energization of the solenoid 41, the knife 32 
is released and thus rotates swiftly anti-clockwise under the action of 
the apron 43, as well as of gravity, to contact and thus sever the sheet 
material 15. On severing of the sheet material 15, the bale 12 continues 
to be rotated so that the thus freed end of the sheet material being 
wrapped around the bale is taken up and the wrapping of the bale is 
completed. 
Upon completion of wrapping, the baler tailgate 9 is raised and the wrapped 
bale is discharged to the ground. The form of the sheet material used in 
the illustrated embodiment, namely that of netting, is self-adhering so 
that no special means have to be taken to secure the cut end of the 
netting. This self-adhesion is effected by the crop material engaging and 
extending through the netting to a certain extend which, in effect, holds 
the netting thereon. 
As the knife 32 moves to the operative position to sever the sheet material 
15, the consequential rotational movement of the associated support 33 
moves the arm 48 back to the full line position of FIG. 2 and thus, the 
material applying roll 49 is retracted to the inoperative position in 
which it is located clear of the throat 2 of the baler and thus does not 
obstruct crop entering the bale chamber 3 from the pick-up 1 when the 
baler is moved forward again in order to pick up further crop material and 
to commence formation of the next bale. 
The provision of the sheet applying roll 49 in accordance with the present 
invention ensures satisfactory wrapping of a bale on each occasion in that 
the nominal width of the sheet material 15 is maintained and thus used to 
full advantage in wrapping a bale. This represents an important advance in 
the art because repeatability in wrapping quality is maintained and time 
is not lost in checking whether a bale has been wrapped correctly using 
the full width of the sheet material and if not, re-wrapping the bale 
before discharging it from the baler. Accordingly, the productivity of a 
baler incorporating the present invention is increased. 
The form of the roll 49 can be varied. For example, the roll could be 
driven or held stationary rather than being freely rotatable as in the 
illustrated embodiment. Furthermore, the roll 49 could be replaced by a 
fixed member such as a bar or plate so shaped so as to effect the desired 
spreading of the sheet material 15 in order to maintain at least its 
nominal width. If the sheet material being used is capable of being 
stretched beyond its nominal width, then the material applying means can 
be desired so as to effect stretching of the material to a predetermined 
width and applying the material at that width to a formed bale. 
It should be noted that the feed means for the sheet material 15 may be of 
any form and, for example, the third roll 18 in the illustrated embodiment 
may either be dispensed with or separated from the roll 17 so as not to 
provide a pinch roller action therewith. 
It also should be noted that the feed means 16,17,18 and the sheet material 
applying means 49 may be provided at another position relative to the bale 
chamber 3, i.e., the feed rolls 16,17,18 and the applying roll 49 do not 
necessarily have to be associated with the pick-up 1 and the bale chamber 
throat 2. Instead said components e.g. may be provided generally at the 
top of the baler to feed the sheet material 15 into the bale chamber 3 
through the gap inbetween a pair of bale forming members in case these 
bale forming members are in the form of rolls such as the rolls 50f, 40j 
shown in U.S. Pat. No. 4,566,379.