U.S. patent application number 09/732298 was filed with the patent office on 2001-06-28 for cutting element for a rotary cutting machine.
This patent application is currently assigned to KUHN S.A.. Invention is credited to Neuerburg, Horst.
Application Number | 20010004826 09/732298 |
Document ID | / |
Family ID | 9554172 |
Filed Date | 2001-06-28 |
United States Patent
Application |
20010004826 |
Kind Code |
A1 |
Neuerburg, Horst |
June 28, 2001 |
Cutting element for a rotary cutting machine
Abstract
A cutting element for a rotary cutting machine comprising
several adjacent cutting members each of which is intended, during
work, to rotate about an upwardly directed respective axis. Said
cutting element comprises an active zone intended to cut plants and
a connecting zone intended to connect said cutting element to a
support of a respective one of said cutting members of the cutting
machine. Said connecting zone has, in cross section, a relatively
flat central part, a first edge inclined toward one side of a plane
of extension of said central part, and a second edge inclined
toward the other side of said plane of extension.
Inventors: |
Neuerburg, Horst; (Saverne,
FR) |
Correspondence
Address: |
OBLON, SPIVAK, McCLELLAND,
MAIER & NEUSTADT, P.C.
FOURTH FLOOR
1755 JEFFERSON DAVIS HIGHWAY
ARLINGTON
VA
22202
US
|
Assignee: |
KUHN S.A.
4, Impasse des Fabriques
SAVERNE CEDEX
FR
|
Family ID: |
9554172 |
Appl. No.: |
09/732298 |
Filed: |
December 8, 2000 |
Current U.S.
Class: |
56/255 ; 56/295;
56/6 |
Current CPC
Class: |
A01D 34/736
20130101 |
Class at
Publication: |
56/255 ; 56/295;
56/6 |
International
Class: |
A01D 034/73 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 23, 1999 |
FR |
99 16870 |
Claims
What is claimed as new and desired to be secured by Letters Patent
of the United States is:
1. Cutting element for a rotary cutting machine comprising a
multiplicity of adjacent cutting members each of which is intended,
during cutting, to rotate about an upwardly directed respective
axis, said cutting element comprising an active zone intended to
cut plants and a connecting zone intended to connect said cutting
element to a support of a respective one of said cutting members,
wherein said connecting zone has, in cross section: a relatively
flat central part, a first edge inclined toward one side of a plane
of extension of said central part, and a second edge inclined
toward another side of said plane of extension.
2. Cutting element as claimed in claim 1, wherein said active zone
is inclined with respect to said connecting zone about a
longitudinal axis of said cutting element, an intermediate zone
making the join between said active zone and said connecting
zone.
3. Cutting element as claimed in claim 2, wherein said inclined
edges of the connecting zone continue as far as said intermediate
zone.
4. Cutting element as claimed in claim 2, wherein an orientation of
said inclined edges of the connecting zone follows a direction of
the inclination of said active zone with respect to said connecting
zone.
5. Cutting element as claimed in claim 2, wherein said active zone
comprises two cutting edges and the inclination of said active zone
with respect to said connecting zone is such that an active cutting
edge of said cutting element is, during cutting, closer to a ground
over which the cutting machine is travelling than an inactive
cutting edge of said cutting element.
6. Cutting element as claimed in claim 2, wherein said inclined
edges of the connecting zone have a rounded angle on an opposite
side to the intermediate zone.
7. Cutting element as claimed in claim 1, wherein said connecting
zone comprises, in said central part, a hole allowing the passage
of a connecting element intended to connect said cutting element to
said support of the respective cutting member.
8. Cutting element as claimed in claim 7, wherein said connecting
element connects said cutting element to said support of the
respective cutting member in an articulated manner.
9. Cutting element as claimed in claim 7, wherein a height of said
inclined edges of the connecting zone is determined so that at
least one of said inclined edges protects said connecting element
during work.
10. Cutting element as claimed in claim 1, wherein said cutting
element is made from a flat section piece of trapezoidal cross
section.
11. Rotary cutting machine comprising several adjacent cutting
members each of which is intended, during cutting, to rotate about
an upwardly directed respective axis and comprises a support and at
least one cutting element, wherein said cutting element is a
cutting element as claimed in any one of claims 1 to 10.
12. Rotary cutting machine as claimed in claim 11, and which is a
mower, in which said supports for the cutting members each consist
of a disk.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a cutting element for a
rotary cutting machine comprising a multiplicity of adjacent
cutting members each of which is intended, during cutting, to
rotate about an upwardly directed respective axis, said cutting
element comprising:
[0003] an active zone intended to cut plants, and
[0004] a connecting zone intended to connect said cutting element
to a support of a respective one of said cutting members of said
machine.
[0005] 2. Discussion of the Background
[0006] A cutting element such as this is already known to those
skilled in the art. Specifically, document WO 99/18769 describes a
disk mower equipped with blades each comprising:
[0007] a substantially flat first end with a hole for pivotally
connecting said blade to a shaft formed at the periphery of the
respective disk of the mower,
[0008] an also substantially flat second end equipped with two
cutting edges, and
[0009] a connecting zone connecting the first end and the second
end,
[0010] the first end and the second end lying in respective planes
which are substantially parallel and offset one with respect to the
other.
[0011] One of the specific features of this known blade lies in the
fact that the connecting zone has a substantially chevron-shaped
profile, the purpose of which is to increase the bending strength
of said blade.
[0012] Those skilled in the art know, from experience, that the
wear on a cutting element during work causes the cutting edge to
shift gradually toward the vertical mid-plane of said cutting
element. On this known blade, said gradual shift means that the
part of the cutting edge located in the connecting zone moves back
up along the slope of the chevron. The part of the cutting edge
located at the second end for its part remains in a plane
substantially parallel to the ground. In consequence, as soon as
wear begins, the cutting height along one and the same blade no
longer remains uniform, which results in a quality of work which
very quickly deteriorates.
SUMMARY OF THE INVENTION
[0013] The object of the present invention is to overcome this
drawback while allowing the cutting element to retain increased
bending strength.
[0014] To this end, the cutting element of the present invention
which comprises:
[0015] a first zone known as the active zone which extends at one
end of said cutting element and which is intended to cut plants,
and
[0016] a second zone known as the connecting zone which extends at
the other end of said cutting element and which is intended to
connect said cutting element to the support of the respective
cutting member,
[0017] wherein the connecting zone has, in cross section:
[0018] a relatively flat central part,
[0019] a first edge inclined toward one side of a plane of
extension of said central part, and
[0020] a second edge inclined toward the other side of said plane
of extension.
[0021] This profile with inclined edges gives the cutting element
remarkable bending stiffness. The active zone, which is relatively
flat, contains the entirety of the cutting edge(s). In spite of the
inevitable progression of wear, the cutting height remains
substantially uniform across the entire length of the cutting
element.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Other features of the invention which are to be considered
in isolation or in any possible combination will become apparent
from the subclaims and from the following description of one
nonlimiting exemplary embodiment of the invention which is depicted
in the appended drawings in which:
[0023] FIG. 1 depicts, in a top view with partial sections, a
rotary cutting machine according to the invention in a work
position,
[0024] FIG. 2 depicts, in perspective, one exemplary embodiment of
a cutting member equipped with two cutting elements according to
the invention,
[0025] FIG. 3 depicts, in a view in the direction of arrow III, the
cutting member of FIG. 2, in partial section,
[0026] FIGS. 4 to 7 depict various views of a cutting element
according to the invention fitted to the cutting member of FIGS. 2
and 3.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0027] FIG. 1 shows a rotary cutting machine produced in the form
of a disk mower 1. Said mower 1 is coupled to a tractor vehicle,
not depicted, which, during use, pulls it along in a direction of
forward travel 2.
[0028] Said disk mower 1 comprises a body 3 rolling along a ground
by means of two wheels 4 and a drawbar 5 connecting said body 3 to
said tractor vehicle. The body 3 comprises a cutting mechanism 6
which may or may not be equipped with a mechanism for treating the
cut product, and a chassis 7. Said chassis 7 in the known way
provides a connection between said drawbar 5 and the cutting
mechanism 6. Said cutting mechanism 6 is connected to said chassis
7 by means of a suspension system 8 which allows the cutting
mechanism 6 to move mainly upward, downward and in roll with
respect to said chassis 7 so as to follow the unevennesses of the
ground independently of said chassis 7. This disk mower 1 also
comprises transmission elements 9 which, in the known way, drive
the cutting mechanism 6 from a power take-off of the tractor
vehicle. For further details, those skilled in the art may refer to
document FR 2 759 531 where such a disk mower 1 is perfectly
described.
[0029] Said cutting mechanism 6 which, during work, rests at least
partially on the ground, comprises several cutting members 10, 10'.
In the exemplary disk mower 1 of FIG. 1, said cutting mechanism 6
comprises eight cutting members 10, 10' arranged at substantially
regular intervals in a direction 11 which, during work, is
substantially perpendicular to the direction of forward travel 2.
Said cutting members 10, 10' are driven with a rotational movement
12, 13 about an upwardly directed respective axis 14. In this
example of a disk mower 1, two consecutive cutting members 10, 10'
have different respective directions of rotation 12, 13.
Specifically, if reference is made to FIG. 1, a first cutting
member 10 from the left rotates in a clockwise direction 12 when
viewed from above, while a cutting member 10' immediately next to
it rotates in a counterclockwise direction 13. It would, however,
within the context of the present invention, be very easy to
conceive of cutting machines with different distributions of the
direction of rotation 12, 13 between the various cutting members
10, 10'. Each cutting member 10, 10' is equipped with at least one
cutting element 15, 16 whose main purpose is to cut plant matter.
In the example of FIG. 1, the cutting members 10, 10' are each
equipped with two cutting elements 15, 16. However, this number is
nonlimiting and could perfectly well be higher than two.
[0030] FIG. 2 shows, in perspective and in further detail, one
example of a cutting member 10, 10' equipped with two cutting
elements 15, 16.
[0031] The cutting member 10, 10' in FIG. 2 comprises, in the known
way, a support 10a with an oval shape 17 with a raised cone
frustum-shaped central part 18 an upper face of which has four
fixing holes 19 and one centring hole 20. The way in which such a
cutting member 10, 10' is connected to the cutting mechanism 6 of a
disk mower is perfectly known to those skilled in the art. A
respective cutting element 15, 16 is connected near to each end of
a large diameter 21 of the support 10a, which support 10a for this
purpose has a respective dished part 23. Said support 10a is
slightly curved so that it has a slope 22 on each side of said
large diameter 21. The cutting member 10, 10' of FIG. 2 at least
substantially observes an axis of symmetry 24 which, during work,
is coincident with the axis of rotation 14 of said cutting member
10, 10' by virtue of the centring hole 20. As a rotational
frequency of said cutting members 10, 10' is high on this type of
cutting machine, a precaution such as this is necessary in order to
avoid excessive imbalance which would be detrimental to the
mechanical integrity of the cutting mechanism 6 as a whole.
[0032] For further details on this exemplary cutting member 10,
10', those skilled in the art may refer to document FR 2 774
853.
[0033] FIG. 3 shows a view of the cutting member 10, 10' of FIG. 2
in a direction of arrow III (the direction of the large diameter
21) defined in FIG. 2, the cutting element 15, 16 being shown in
section.
[0034] Each dished part 23 which, in this example, is welded to the
support 10a, has a hole 25. Said hole 25 comprises a substantially
cylindrical or slightly frustoconical upper section 26, an oblong
intermediate section 27 and a cylindrical lower section 28. These
various sections 26-28 are concentric, with their axis 29
substantially parallel to the axis of symmetry 24 of the cutting
member 10, 10'.
[0035] Said cutting element 15, 16 is connected to the respective
dished part 23 by means of a connecting element 30 which, in this
example, is made up of a screw 50 and of a nut 31. Said connecting
element 30 forms, between the cutting element 15, 16 and the
support 10a, an articulation, an axis 29 of which is, during work,
directed upward. This degree of freedom allows said cutting element
15, 16 to extend, under an action of centrifugal force due to the
frequency of rotation of the cutting member 10, 10', radially in a
direction of the large diameter 21 and to move aside in the event
of impact with an obstacle during work. Said screw 50 comprises,
from the bottom upward (FIG. 3), a head 32, a cylindrical section
33, an oblong section 34 and finally a threaded portion 51 onto
which the nut 31 is screwed. Said cylindrical section 33 both
guides the cutting element 15, 16 and centers said screw 50 in the
lower section 28 of the hole 25. The oblong sections 27, 34,
respectively of the dished part 23 and of the screw 50, prevent
said screw 50 from rotating with respect to said dished part 23.
Thus, the operations of tightening and loosening the nut 31 of said
screw 50 can be done with just one tool. It may also be noted that,
in the exemplary embodiment of FIG. 3, said nut 31 is completely
embedded in the upper section 26 of the hole 25 of the dished part
23 so that it can be protected against rapid wear due, in
particular, to repeated contact with the cut product. The cutting
element 15, 16 is stopped from translational movement in a
direction of the axis 29, downward, by the head 32 of the screw 50
and is stopped from translational movement, upward, by an underside
35 of the dished part 23. Note that the dimensions of the various
sections of the screw 50 and of the hole 25 mean that the distance
between the head 32 of the screw 50 and the underside 35 of the
dished part 23, once the nut 31 has been tightened onto the
threaded part 51 of the screw 50, is at least slightly greater than
a thickness of the cutting element 15, 16, which guarantees that
said cutting element 15, 16 will have the possibility of pivoting
unimpeded about an axis of the screw 50.
[0036] FIGS. 4 to 7 show various views of the cutting element 15,
16 according to the present invention. FIG. 4 is a plan view. Based
on this, FIG. 5 is a view in section on arrow V, FIG. 6 is a view
along arrow VI and FIG. 7 is a view along arrow VII.
[0037] In this embodiment, said cutting element 15, 16 is made from
a flat section piece of trapezoidal cross section 36 comprising a
large base 47 and a small base 48. After shaping, said cutting
element 15, 16 has three distinct zones: a connecting zone 37, an
active zone 39 and an intermediate zone 38 which makes the join
between the two aforementioned zones 37, 39.
[0038] The trapezoidal cross section 36 allows said active zone 39
to have two tapered cutting edges 40, 40' without the need to
resort to additional shaping operations. The connecting zone 37
comprises, on one hand, a substantially flat central portion 43
equipped with a hole 41 allowing the passage of the screw 50 and,
on another hand, in this example, two edges 44, 45 which are
inclined with respect to said central portion 43. In fact, said
central portion 43 has a plane of extension 43a, and an edge 44 is
inclined toward one side of this plane of extension 43a, while
another edge 45 is inclined toward another side of said plane of
extension 43a. Each of said edges 44, 45 is thus bent in a
different direction so that the connecting zone 37 substantially
observes axial symmetry about a longitudinal axis 46 of the cutting
element 15, 16. Observance of said symmetry of axis 46 allows the
cutting element 15, 16 to be connected to the respective cutting
member 10, 10' with the large base 47 of the trapezoidal section 36
facing either downward or upward, thus offering the user the
possibility of making best use of said cutting element 15, 16. A
height of the inclined edges 44, 45 of the connecting zone 37 is
advantageously determined so that at least one of said inclined
edges 44, 45 protects the head 32 of the respective screw 50
against any knocks during work.
[0039] In the example of the cutting element 15, 16 depicted in
FIGS. 4 to 7, the active zone 39 is inclined with respect to the
connecting zone 37 by a slight rotation of one with respect to the
other about the axis of symmetry 46 of the connecting zone 37. This
inclination, which is such that an active cutting edge 40 is closer
to the ground on which the mower 1 is operating than is an inactive
cutting edge 40', has the objective, during work, of creating a
phenomenon of lifting the cut product so that said cut product is
carried away by the cutting members 10, 10' in an opposite
direction to the direction of forward travel 2. The existence of
two directions of rotation 12, 13 of the cutting members 10, 10'
entails the existence of cutting elements 15, 16 which have
different directions of inclination of the active zone 39 with
respect to the connecting zone 37. This accounts for the difference
between the cutting elements 15 equipping the cutting members 10
rotating in the clockwise direction 12 and the cutting elements 16
equipping the cutting members 10' rotating in the counterclockwise
direction 13. To make it easier to distinguish between these two
types of cutting element 15, 16 during mounting operations, these
have a specific marking 49. In the example of FIGS. 4 to 7, the
distinction is simplified by an arrow 49 impressed into the large
base 47 and into the small base 48 of the active zone 39 at the
time of shaping. Said arrow 49 indicates the direction of rotation
12, 13 that the cutting member 10, 10' to which said cutting
element 15, 16 is connected is to have.
[0040] The intermediate zone 38 ensures gradual transition between
the connecting zone 37 and the active zone 39. Each inclined edge
44, 45 of the connecting zone 37 continues as far as the
intermediate zone 38 to terminate at a cutting edge 40, 40' of the
active zone 39. Said inclined edges 44, 45 are oriented in the same
direction as the direction of inclination of the active zone 39
with respect to the connecting zone 37 so as to reduce the
deformation of the intermediate zone 38 during shaping of the
cutting element 15, 16. Excessive deformation of said intermediate
zone 38 could actually give rise to cracks detrimental to the
mechanical integrity of said cutting element 15, 16.
[0041] Said bent edges 44, 45 advantageously comprise, on the
opposite side to the intermediate zone 38, a rounded angle 52 so as
to limit the risk of catching on the cut product, as this would be
detrimental to the quality of the work done by the disk mower
1.
[0042] The cutting element 15, 16 and the disk mower 1 which have
just been described are merely one exemplary embodiment and
exemplary use which cannot in any way restrict the field of
protection defined by the following claims.
* * * * *