Rotary mower

The invention relates to rotary mowers driven from below. According to the invention, shafts (18) and wheels (23) have at least their operational dimensions approximately identical, and alternate wheels (23) take two different positions in relation to the shafts (18). Moreover, when one of the disks (5, 6) is inclined in relation to an adjacent disk, the wheel (23) of the disk most inclined toward the front is farther from the disk (5, 6) than the wheel (23) is from the adjacent disk (5, 6). Moreover, the housing (4) comprises a sliding member (30) which at least partially closes the front part and/or the lower part of the housing (4).

FIELD OF THE INVENTION 
This invention relates to a rotary mower provided with at least two cutting 
elements placed on the upper face of a housing and each connected to an 
upwardly directed shaft which is guided in rotation in a bearing extending 
to the upper part of the housing. The cutting elements are driven in 
rotation by driving means housed in the housing. 
BACKGROUND OF THE INVENTION 
A mower of this general type is known the drive means of which consists of 
wheels keyed on upwardly directed shafts and driven in rotation by a belt. 
This drive mechanism does not make it possible to assure a synchronous 
transmission of movement. The belt can slip on the wheels during working 
of the mower when one or the other of the cutting elements, which are 
connected to the wheels, is braked or locked for any reason, such as 
obstacles, piles of heavy hay, etc. 
When desynchronization between two adjacent wheels reaches a certain value, 
and if the cutting elements are located at the same level, the cutting 
tools mounted on the cutting elements can collide. These collisions can 
cause breaking of the cutting tools or of their fastenings. 
Considering the high rotating speed of the cutting elements, a cutting tool 
that is broken or torn from its cutting element can cause serious 
accidents to persons in the vicinity of the mower or even to the machine 
operator. Further, a cutting element that is equipped with a broken 
cutting tool or on which a cutting tool is missing performs unsatisfactory 
work. 
To reduce this serious drawback, the known mower has two adjacent cutting 
elements offset vertically in relation to one another, so as to turn in 
different planes of rotation. Thus, the cutting tools of two adjacent 
cutting elements can no longer collide with one another even if the 
positions of the cutting elements are desynchronized. 
The drawback of this known mower resides in the fact that the upwardly 
directed shafts of different adjacent cutting elements are different. This 
therefore requires the production of two or more kinds of shafts, which 
causes an increase in the cost of the machines. 
Another mower of this type is known which also had adjacent cutting 
elements turning in different planes of rotation. On this mower, the 
upwardly directed shafts on which the cutting elements are mounted are 
identical, and the offset between the cutting elements is obtained with 
braces placed between the shaft and the cutting element which must be 
higher. 
This other known mower has two drawbacks. 
A first drawback resides in the fact that, during remounting of a high 
cutting element after a repair or a cutting element change, the repairer 
may fail to replace the braces between the shaft and cutting element. In 
this case, there is a serious risk of an accident as explained above. 
A second drawback resides in the fact that it is necessary to produce 
additional parts, in this case, braces. This, therefore, also raises the 
cost of the machine. 
Again, another mower is known which comprises a pair of adjacent cutting 
elements, one of which is inclined in relation to the other. This 
inclination enables the cutting elements to turn in different planes of 
rotation, while having front points of the end paths described by the 
cutting tools mounted on the cutting elements approximately at the same 
level in relation to the ground surface. 
When this design is applied to mowers with cutting elements driven from 
below such as those now known (i.e., by simply inclining one of the 
cutting elements in relation to the adjacent cutting element), the cutting 
height becomes undesirably great. Considering the size of the cutting 
elements of these known mowers, the housing located under the cutting 
elements must have a sufficient thickness to allow the transmission means 
(such as a belt, for example) to go from the wheel of one cutting element 
to the wheel of the adjacent cutting element. This is undesirable. 
Another great drawback of certain known mowers resides in the fact the 
front part of the housing slides on the ground and protects the cutting 
elements. The front part of the housing therefore is subjected to heavy 
wear and more or less great impacts which can wear out the housing. 
Moreover, since the housing is made in one piece, it is necessary to 
change it completely, which involves considerable expenses for the user. 
On other mowers it is know to fasten on the front part of the housing 
additional parts by means of which the cutter bar slides over the ground 
and which protect the cutting elements. These parts can then be replaced 
when they are worn out. These additional parts, however, make the cutter 
bar heavy, which already requires a lightening device so that the cutter 
bar will rest lightly on the ground during operation. Moreover, these 
additional parts raise the cost of the mower. 
OBJECT OF THE INVENTION 
This invention aims at remedying the various drawbacks of known mowers. 
SUMMARY OF THE INVENTION 
A first principal characteristic of the invention resides in the 
combination of the following: 
(1) the upwardly directed shafts and the wheels that are fastened there 
have at least their operational dimensions approximately identical, and 
(2) a wheel can take two different positions in relation to the shaft, so 
that, for a high cutting element, the wheel is farther away from the high 
cutting element than the wheel of a low cutting element. With this 
arrangement, it is no longer necessary to produce two different shafts or 
additional braces for the two adjacent cutting elements to turn in 
different planes of rotation. The problems of costs and storage of parts 
are thus eliminated. Also, the risks of accidents as a result of poor 
remounting during repair are also eliminated. 
The two positions that a wheel can take in relation to the shaft can be 
judiciously selected so that the part of the wheel where the transmission 
of movement occurs is approximately at the same level in relation to the 
housing in either of the two positions in relation to the shaft. 
Preferably the shafts and/or the wheels are identical. 
A simple embodiment of the invention is obtained when the hub of the wheel 
is axially offset in relation to the axis of symmetry of the part where 
the transmission of movement occurs. For a high cutting element, the hub 
is essentially located above the plane of symmetry, and, for a low cutting 
element, the hub is essentially located below the plane of symmetry. 
Advantageously, the wheel is connected to the shaft by a detachable 
connection. 
According to an additional characteristic of the invention, the bearings of 
the two adjacent cutting elements are different. 
According to an additional characteristic of the invention, it is possible 
to lower the cost of the mower still more if the bearings of two adjacent 
cutting elements are identical. In this case, the bearings can take two 
positions in relation to the housing, or the upper part of the housing can 
comprise bulges which raise the bearings of the high cutting elements. 
According to the second principal characteristic of the invention, one of 
the cutting elements in a pair of adjacent cutting elements is inclined in 
relation to the other cutting element in the pair, and the wheel of the 
cutting element most inclined toward the front is farther from the 
associated cutting element than the wheel of the other cutting element. 
With this characteristic, it is possible to design a mower having a pair of 
adjacent cutting elements one of which is inclined in relation to the 
other without increasing the cutting height, while allowing a transmission 
means (such as a belt, for example) to go from one wheel to the other. The 
fact that the wheel of the cutting element most inclined toward the front 
is farther from the cutting element than the wheel of the adjacent cutting 
element allows the two wheels to extend in planes relatively close to one 
another. 
According to a third principal characteristic of the invention, the mower 
housing comprises sliding means which at least partially close the front 
part and/or lower part of the housing. Advantageously, these sliding means 
are removably mounted on the housing. 
The sliding means according to the invention therefore form an integral 
part of the mower housing. Accordingly, the weight of the cutter bar can 
be kept low without its being necessary to change the entire housing when 
the sliding means are worn out. 
According to an additional characteristic of the invention, the sliding 
means also protect the cutting elements in the front. 
The shape of these sliding means can be optimized when they are made by a 
casting process.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
FIG. 1 shows a cutter bar (1) of a mower (2). The mower (2) further 
comprises a hitching mechanism (3) which is only partially represented. 
The hitching mechanism makes it possible to hitch the cutter bar (1) to a 
farm tractor, for example. 
The cutter bar (1) comprises a housing (4) in which means extend for 
driving a plurality of cutting elements such as high disk (5) and low disk 
(6). The disks (5, 6) extend to the upper part of the housing (4) and are 
provided with cutting tools such as knives (7). The low disk (6) located 
at the end of the cutter bar (1) remote from the hitching mechanism (3) is 
surmounted by a rotary windrowing device (8). The rotary windrowing device 
(8) cooperates with a stationary windrowing device (9) to reduce the width 
of the windrow of cut hay placed behind the cutter bar (1). 
A transmission-gear housing (10) is located at the end of the cutter bar 
(1) located on the side of the hitching mechanism (3). The 
transmission-gear housing (10) serves to transmit the movement from a belt 
(11) to drive means located in the housing (4) of the cutter bar (1). For 
this purpose, the transmission-gear housing (10) comprises a pulley (12) 
on which the belt (11) is wound. The belt (11) is also wound on another 
pulley (not shown) which is supported by the hitching mechanism (3) and 
which receives the movement from the power take-off of the tractor by 
means of a transmission shaft (also not shown). 
Under the transmission-gear housing (10) is placed a shoe (13) which allows 
the inward end of the cutter bar (1) to slide over the ground and which 
prevents cut hay from catching on the transmission-gear housing (10). 
A support (14) which holds a protective device (15) is located above the 
cutter bar (1). 
As may be seen in the later figures, the drive means housed in the housing 
(4) cannot prevent disks (5, 6) from desynchronizing during work. To keep 
the knives (7) from colliding, high disks (5) turn in different and higher 
planes of rotation than those in which low disks (6) turn. Knives (7) can 
thus sweep zones that are common in plan view without the knives (7) being 
able to touch one another even if they sweep the zones at approximately 
the same time after being desynchronized. 
FIGS. 2a and 2b show a first embodiment of the invention. 
FIG. 2a shows the arrangement of a high disk (5). The high disk (5) is 
provided with knives (7) which are mounted there by a connection allowing 
each knife (7) to pivot backward and line up under the high disk (5) in 
case an obstacle is encountered. Each high disk (5) is fastened to a 
driver (16) by a number of bolts (17). The driver (16) itself is fastened 
on an upwardly directed shaft (18) by a pin (19). The shaft (18) is guided 
in rotation in a bearing housing (20) by means of two roller bearings 
(21). The bearing housing (20) is fastened on the housing (4) by bolts 
(22). The shaft (18) is connected to a wheel (23) inside the housing (4). 
This connection is preferably detachable. In the case of FIG. 2a, the 
connection is made by means of a key (24) which makes the connection in 
rotation and by means of a snap ring (25) and a shoulder (251) on the 
shaft (18) which make the connection in translation. 
The wheel (23) is driven by an endless transmission element such as the 
hexagonal belt (26). 
The housing (4) consists of an approximately planar cover (27) and a bottom 
(28). The bottom (28) is trough-shaped and comprises a rear part (29) of 
folded sheet metal and sliding means (30). The sliding means (30) allow 
the cutter bar (1) to slide on the ground (31). For this purpose, the 
sliding means (30) have the shape of a ski. Since the sliding means (30) 
are subjected to heavy wear, it is preferable to be able to change them 
rapidly. For this purpose, the sliding means (30) are removably fastened 
to the rear part (29) and the cover (27) by two bolts (32) (see FIGS. 7 
and 8), and, in the front, are fastened to the cover (27) only by a bolt 
(33). The cover (27) and the rear part (29) are connected at the back by 
bolts (34). 
To avoid weighing down the housing (4), the sliding means (30) are an 
integral part of the housing (4). It should be particularly noted that the 
sliding means (30) close the front part of the housing (4) and at least 
partially close the lower face of the housing (4). 
FIG. 2b shows the arrangement of a low disk (6). The parts identical with 
those of FIG. 2a are designated by the same reference number. The low disk 
(6) is also provided with knives (7). The low disk (6) is fastened on a 
driver (16) with bolts(17). Just as above, the driver (16) is fastened on 
an upwardly directed shaft (18) by a pin (19). 
The shaft (18) is guided in rotation in a bearing housing (35) by two 
roller bearings (21). The bearing housing (35) is fastened on the top of 
the housing (4) (i.e., on the cover (27)) by bolts(22). 
As can be seen in FIG. 2b, the shaft (18) of the low disk (6) penetrates 
deeper into the housing (4) than the shaft (18) of the high disk (5). This 
greater penetration of the shaft (18) is permitted by the bearing housing 
(35), which is smaller than the bearing housing (20) of the high disk (5). 
The difference in height between the two bearing housings (20) and (35) 
corresponds to the offset between the high disk (5) and the low disk (6). 
To allow the hexagonal belt (26) to turn approximately in the same plane, 
the part of the wheels (23) of a high disk (5) and of a low disk (6) where 
the transmission of movement occurs (i.e., a groove (36) in the wheel 23) 
is approximately in the same plane. This result is obtained by the fact 
that the wheel (23) of a low disk (6) occupies a position in relation to 
its shaft (18) different from that occupied by the wheel (23) of a high 
disk (5). To do this, the wheels (23) have a hub (38) which is offset in 
relation to the plane of symmetry (37) of their groove (36). Thus, in the 
case of a high disk (5), the hub (38) of the wheel (23) is essentially 
located above the plane of symmetry (37) of the groove (36), while in the 
case of a low disk (6), the hub (38) of the wheel (23) is essentially 
located below the plane of symmetry of the groove (36). 
In FIGS. 2a and 2b, it can also be seen that the disks (5) and (6) are both 
provided with a stop means (39) which limits the rotation of the knives 
(7). This makes it possible to protect the bearing housings (20), (35) 
when a knife (7) lines up under the disks (5), (6). Moreover, the stop 
means (39) can also serve to stiffen the disks (5, 6). 
A second embodiment of the invention is shown in FIGS. 3a and 3b. Parts 
identical with those described above are designated by the same reference 
number and will not be redescribed in detail. 
In this example, disks (5 and 6) are directly provided with a driver (40) 
which is fastened by welding. The unit is then connected to an upwardly 
directed shaft (41). Connection in rotation is made by a splined bore made 
in the driver (40). The splines in the splined bore engage splines (42) on 
the shaft (41). The connection in translation is made by a nut (43) and a 
shoulder (431) on the shaft (41). The shaft (41) is guided in rotation in 
a bearing housing (44) by two roller bearings (21). In this example, the 
bearings housing (44) of high disks (5) and low disks (6) are identical. 
The offset in height of the high disk (5) is obtained by inserting between 
the bearing housing (44) and the top of the housing (4) a brace (45) the 
thickness of which is equal to the offset to be obtained between a high 
disk (5) and a low disk (6). 
The brace (45) is advantageously fastened by bolts (46) that also fasten 
the bearing housing (44) to the top of the housing (4). For this purpose, 
it is seen that the bolts (46) are longer than bolts (47) which fasten the 
bearing housing (44) of a low disk (6) to the top of the housing (4). 
So that the bolts (46) and (47) will not have to absorb all the forces that 
the disks (5, 6) can receive during operation, the bearing housing 
(44)-brace (45) unit of a high disk (5) and the bearing housing (44) of a 
low disk (6) are centered in a bore (48) in the housing (4). In the case 
of a high disk (5) (FIG. 3a), the bearing housing (44) is centered in the 
brace (45) with a lower roller bearing (21). For this purpose, the brace 
(45) contains a bore (49) into which the lower roller bearing (21) 
partially penetrates. The brace (45) in turn is centered in the housing 
(4) thanks to a centering shoulder (50) which penetrates into the bore 
(48) in the housing (4). In the case of a low disk (6), the lower roller 
bearing (21) directly penetrates partially into the bore (48) in the 
housing (4). 
It will be noted that, during servicing of a high disk (5), it is not 
possible to mount the high disk (5) poorly, since the brace (45) remains 
in place. 
FIGS. 4a and 4b represent a third embodiment of the invention. Parts 
identical with those described above are designated by the same reference 
number and will not be redescribed in detail. 
In this example, the disks (5 and 6) are directly provided with a driver 
(51) which is welded to the associated disk. The unit is mounted on an 
upwardly directed shaft (18) and fastened there by a pin (19). The shaft 
(18) is guided in rotation in a bearing housing (52) by two roller 
bearings (21). In this embodiment, the bearing housing (52) of the high 
disks (5) and of the low disks (6) are identical. The bearing housing (52) 
have two support faces (53 and 54). The support faces (53 and 54) are 
axially offset from one another by a distance equal to the offset that 
should exist between the high disks (5) and the low disks (6). Moreover, 
the support faces (53 and 54) are also radially offset from one another. 
Thus, the support face (54) is radially farther from the axis (55) of the 
bearing housing (52) than the support face (53). 
Thus, for a high disk (5), the support face (53) of the bearing housing 
(52) rests on an upper part (56) of the housing (4) and is fastened there 
by bolts (57). In this case, the upper part (56) of the housing (4) has a 
small bore (58) which allows passage of the shaft (18) through the housing 
(4). The small bore (58) has a radius smaller than the distance radially 
separating the support face (53) from the axis (55) of the bearing housing 
(52). 
For a low disk (6), the support face (54) of the bearing housing (52) rests 
on the upper part (56) of the housing (4) and is fastened there by bolts 
(59). In this case, the upper part (56) of the housing (4) has a large 
bore (60) which allows passage both of the shaft (18) and of the support 
face (53) through the housing (4). The large bore (60) has a radius larger 
than the distance radially separating the support face (53) from the axis 
(55) of the bearing housing (52) but smaller than the distance radially 
separating the support face (54) from the axis (55) of the bearing housing 
(52). 
In the third embodiment of the invention, the wheel (23) is also removably 
connected to the shaft (18). As shown in FIG. 5, the connection in 
rotation is assured by a flat surface (61) made on the shaft (18) which 
cooperates with a broached hole (62) made in the hub (38) of the wheel 
(23). 
The housing (4) is made slightly differently from the preceding examples. 
The upper part (56) of the housing (4) is folded toward the back in a 
prone U shape so that the back part (63) of the bottom (28) is planar. As 
in the preceding examples, the sliding means (30) are fastened on the back 
part (63) by bolts (32) to form the bottom (28). The bottom (28) is then 
fastened to the upper part (56) with bolts (33) and (64). 
FIGS. 6a and 6b show a fourth embodiment of the invention. Parts identical 
with those described above are designated by the same reference numbers 
and will not be redescribed in detail. 
In this example and as can be seen in FIG. 6a, the high disk (5) is 
inclined downwardly toward the front so that, at the front of their paths, 
the knives (7) of each high disk (5) pass approximately at the same 
distance (65) from the ground (31) as the knives (7) of a low disk (6), 
while, at critical spots, the knives (7) rotate at different levels. The 
work performed by the mower is thus more satisfactory. 
In this example, the shafts (18) of the high disks (5) and the low disks 
(6) are guided in rotation in identical bearing housings (66). Bearing 
housings (66) are fastened on an upper part (67) of the housing (4) by 
bolts (59) which are the same for high disks (5) and low disks (6). The 
offset in height of the high disks (5) is obtained by bulges (68) made in 
upper part (67) by stamping, for example. The bulges (68) extend to the 
places where the high disks (5) are fastened to the upper part (67). 
Moreover, the bulges (68) serve to determine the inclination of the high 
disks (5). 
In addition, the summit of the bulges (68) extend relatively close to the 
stop elements (39) of the disks (5 and 6). The stop elements (39) can thus 
perform an additional function that they have performed in the preceding 
examples only in the case of low disks (6). This additional function 
consists in creating a baffle which avoids winding of plant debris or any 
stringlike bodies around the bearing housing (66) and which brake 
introduction of such plant debris or any stringlike bodies between the 
disks (5, 6) and the bearing housing (66). Roller bearings (21) are thus 
effectively protected, which increases their working life. 
It will be noted that the brace (45) placed under the high disk (5) of the 
example of FIG. 3a can also, within the scope of the invention, extend 
under the stop means (39) of the high disk (5) to form a baffle braking 
the introduction of plant debris or stringlike bodies under the high disk 
(5). 
As can be seen in FIG. 1, the low disk (6) located at the end of the cutter 
bar (1) distant from the hitching mechanism (3) is surmounted by the 
rotary windrowing device (8). Since the rotary windrowing device (8) must 
laterally move the hay cut by the low disk (6), rather considerable power 
is required to drive it. For this reason, it is preferable that the 
hexagonal belt (26) be wound to the maximum on the wheel (231) which is 
connected to the outward low disk (6). Since the disks (5 and 6) rotate in 
opposite directions, it therefore happens that, at certain spots, the 
hexagonal belt (26) must go from the rear part of an inclined wheel (23) 
onto an adjacent wheel (231) (shown in FIG. 6a). The rear part of an 
inclined wheel (23) is higher than the adjacent wheel (231). The housing 
(4) therefore must have a certain thickness to allow the passage of the 
hexagonal belt (26). To keep this thickness as small as possible and thus 
to have an acceptable distance (65) (which is the cutting height), it is 
seen in FIGS. 6a and 6b that the wheel (23) of the high disk (5), inclined 
toward the front, is farther from the high disk (5) than the adjacent 
wheel (231) is from the adjacent low disk (6). The difference in level 
between the rear part of a wheel (23) and an adjacent wheel (231) 
therefore is small. 
However, it is possible, in other cases, that the hexagonal belt (26) 
engages inclined wheels (23) at their front parts. Since the front part of 
the inclined wheels (23) is approximately at the same level as the 
adjacent wheels (231) (see the hexagonal belt (26) shown in broken lines 
in FIGS. 6a and 6b), the hexagonal belt (26) can move approximately in one 
plane. 
This embodiment is very economical. For inclined high disks (5) and for low 
disks (6), the shafts (18), the wheels (23 and 231), the bearing housing 
(66), and the bolts (59) which fasten the bearing housing (66) to the 
upper parts (67) of the housing (4) are all identical. 
Moreover, in both cases, the bearing housings (66) are centered in the 
upper part (67) of the housing (4), and in both cases the stop elements 
(39) form a baffle with the upper part (67) of the housing (4). 
It is, of course, possible within the scope of the invention also to use 
this embodiment in the case where the high disks (5) are not inclined but 
simply axially offset in relation to the low disks (6). 
FIG. 7 shows the housing (4) more fully. The housing (4) is, for example, 
that of the mower of FIGS. 2a and 2b. As said above, the sliding means 
(30) are an integral part of the housing (4). Each sliding means (30) is 
fastened to the cover (27) and to the rear part (29) of the bottom (28) 
with two bolts (32) and a bolt (33). The arrangement of the bolts (32) is 
shown in section and on an enlarged scale in FIG. 8. Each sliding means 
(30) comprises two bosses (70) each of which contains a threaded hole 
(71). The rear part (29) of the bottom (28) is provided with braces (72) 
which are welded there and extend to the cover (27). The bolt (32) is 
engaged from the top so as to go through the cover (27), the corresponding 
brace (72), and the rear part (29) of the bottom (28). The bolt (32) is 
screwed in the threaded hole (71) of the corresponding boss (70). The 
stiffness of the housing (4) is thus reinforced by connecting the sliding 
means (30), the rear part (29) of the bottom (28), and the cover (27) 
together. 
FIG. 7 also shows, looking downwardly, that the front edge (73) of the 
sliding means (30) has an approximately circular form centered 
approximately on the axis of rotation of the corresponding disk (5, 6). 
Advantageously, the front edge (73) extends slightly beyond the end path 
described by the corresponding disk (5, 6) during its rotation. The 
sliding means (30) can thus also perform a function of protecting the 
front of the disks (5, 6). 
An element 74 is located in the space between two neighboring sliding means 
(30). The element (74), as can be seen in FIG. 9, is relatively pointed to 
reduce the risk of hooking of plant debris between two sliding means (30). 
The element (74) is fastened on the rear part (29) of the bottom (28) by a 
bolt (75) which goes through the element (74) and is screwed into a nut 
(76) welded on a vertical edge on the rear part (29) of the bottom (28). 
While the invention has just been described in the light of some examples, 
it will be understood that it will not be going outside the scope of this 
invention if these different examples are combined or if improvements are 
made thereto. In particular, the means for driving the disks (5, 6) can be 
different from the wheels (23, 231) and the hexagonal belt (26). They can, 
for example, consist of a cascade of friction wheels. 
Obviously, numerous (additional) modifications and variations of the 
present invention are possible in light of the above teachings. It is 
therefore to be understood that, within the scope of the appended claims, 
the invention may be practiced otherwise than as specifically described 
herein.