A LIFT-SUSPENDED MOWING MACHINE

Abstract: A mower (1) with a mowing aggregate is pivotally connected with a frame (7) for mounting on the lift-suspension of a tractor (8) in order, by a swinging movement, to be movable between a working position outside the track of the tractor and a transport position. In the working position a moment of force may be transferred from the tractor to the mower (1) to lift it as a whole, for instance during turns in the field. To eliminate the risk of a lateral tilting of the tractor the mower comprises at least one support wheel (9, 10) which is pivotal around an upwards directed axis (11, 12) and is suspended for raising and lowering between an inactive raised position, when the mowing aggregate is lowered for a windrowing working position, and an active supporting position, in which the support wheels (9, 10) at least partially carry the weight of the mower (1) in its raised position.

Description: A LIFT-SUSPENDED MOWING MACHINE. The invention relates to a lift-suspended mower with a mowing aggregate suspended in a carrier construction which is pivotally connected with a frame for mounting on the lift-suspension of a tractor, the mowing aggregate with accompanying carrier construction being pivotally movable between a working position, in which the mowing aggregate and the carrier construction are positioned laterally out- side the track of the tractor and a transport position, in which the mower is present behind the tractor within its track, means being provided for transmission of a moment of force from the tractor to the mower to lift it as a whole. Mowers of this type are well-known and may in the transport position either be swung about a horizontal axis parallel with the direction of travel to an upright posi¬ tion or be swung about a vertical axis to a position behind the mower. If such mowers are built with a very big pass width, which partly makes them heavy, and which partly makes them in the working position extend far out to the side of the tractor, problems will arise in lifting them by means of the lift of the tractor, because they act on the tractor with a considerable moment. This problem particularly occurs, when during mowing, at turns in the field it is desired to lift the mower from the working position in order to be able to pass already cut crop. The moment act¬ ing on the tractor may thereby give rise to an increased risk of tilting of the tractor. The problem is smaller when the mower is in transport position, either because the moment, with which the mower acts on the tractor is smaller (at an upright transport position) , or because the tractor is better to absorb the moment (in the transport position behind the tractor) . EP-A- 0 361 573 discloses a mower of the type men¬ tioned by way of introduction, which at each side of the mowing aggregate and behind it is provided with support wheels carrying the mowing aggregate partially during work. The mowing aggregate is spring-relieved relative to the support wheels which are not rotatable and are lifted together with the mower when it is lifted. This mower is thus not able to solve the above-mentioned problem. From EP-A- 0 486 414 a mower is known which is suspended in a carrier frame which at one end is connected with the three-point suspension lift and which at its other end is carried by a carrier wheel which in the working position is always in contact with the ground. In this known construction no lifting moment is transferred from the tractor to the mower, the aforementioned risk of tilt¬ ing not existing. Another embodiment of this mower known from EP-A- 0 570 314 is at its one side height-adjustably connected with the three-point suspension of the tractor, and at its other side height-adjustably connected with a ground wheel. In this mower no lifting moment of force is transferred from the tractor to the mower. The object of the invention is to provide a mower of the type mentioned by way of introduction, which mower ob¬ viates the above-mentioned problem. With a view to meet this object a mower of the type according to the invention is characteristic in that the mowing aggregate with accompanying carrier construction comprises at least one weight relieving support wheel which partly is pivotal about an upwards directed axis partly by means of a pivoting device is lowerable and raisable rela¬ tive to the mowing aggregate by swinging about a substan¬ tially horizontal axis, a hydraulic cylinder being con- nected with said pivoting device, said cylinder being adapted when the mower is connected with the tractor to be connected with the hydraulic system of the tractor in series with the lift of the tractor in order, in the work¬ ing position of the mower, particularly in connection with turns in the filed, to make it possible to simultaneously lift the mowing aggregate with accompanying carrier con¬ struction and lowering of the relieving support wheel/s thereby permitting passage of the mowing aggregate over already mowed crop. Hereby the weight-relieving support wheel automatically starts functioning in the working position exactly when it is needed in connection with the lifting of the mower, and a reduction of the moment, to which the tractor is subjected by the mower in its lifted position, is attained without any reduction of the man¬ oeuvrability of the tractor and the mower. From US-A- 4,193,458 it is in connection with a ground-tilling agricultural machine in form of a tractor- harrow combination per se known to equip the working aggregate with a hydraulically activatable, weight-reliev¬ ing support wheel which is activated in the transport position to carry part of the weight of the working aggre- gate towed behind the tractor. In the ground-tilling working position this support wheel has to be constantly raised to avoid compacting of the ground surface tilled by the teeth of the harrow. During normal work in the field with this known machine it is not an aim that the working aggregate is raisable, not during turns either. If the hydraulic system of the tractor opens up the possibility that the hydraulic cylinder operating the sup¬ port wheel is double-acting, the support wheel will auto- matically be raised, when the mower is lowered, the support wheel thus not disturbing the function of the mower. In case of a single-acting hydraulic cylinder, a spring may be provided in connection with said pivoting device for keep¬ ing the support wheel lifted, when said hydraulic cylinder is not actuated for lowering of the support wheel. The mower preferably comprises a support wheel at each side of the mowing aggregate. Hereby a symmetrical lifting is ensured, whereby the mower in its raised posi¬ tion is prevented from swinging down at one side, whereby it might hit the ground should the occasion arise. In mowers of the type, where swinging of the mower between the working position and the transport position takes place around a substantially vertical shaft and the mower in its transport position is positioned behind the tractor in substantially horizontal position, problems of a too big moment acting on the tractor may also occur in the transport position. According to an embodiment of the invention these problems may in a manner known per se be solved thereby that said carrier construction is connected with at least one ground wheel for weight-relief of the mower in the transport position. In a further embodiment such a ground wheel may be mounted on an arm fastened to a shaft which is horizontally oriented in the transport position and substantially perpendicular to the direction of travel, said shaft being pivotally journalled on the mower, and a power means comprising a hydraulic cylinder has been established to rotate the shaft, thereby raising or lowering the transport wheel. The invention will be explained in detail in the following by means of embodiments with reference to the drawing, in which Fig. 1 shows a mower according to the invention connected with a tractor seen from behind, Fig. 2 the mower according to Fig. 1 seen from above, Fig. 3 the mower according to Figs. 1 and 2 seen from the right, Fig. 4 a view corresponding to Fig. 1 but of another embodiment of the mower, Fig. 5 the mower according to Fig. 4 seen from the right, Fig. 6 a further embodiment of the mower according to the invention seen from above and in the transport position, and Fig. 7 the mower according to Fig. 6 seen from the side. Figs. 1-3 shows a disc mower 1 which is divided in two sections each having their frame bars 2,3. The bars are mutually connected by a hinge 4, at which they are further suspended in a carrier arm 5 which is connected by a second hinge 6 with a carrier frame 7 suspended in the three-point suspension of a tractor 8. Apart from the two-piece design of the mower 1 which is the object of EP patent application no. 95610009.3 (not published), this is for that matter known. The novel feature of the mower is that it comprises support wheels 9,10, which are mounted at each their end of the mower 1 in such a way that they can rotate around an upwards directed axis 11,12. The connections of the support wheels 9,10 with the mower 1 comprise a pivoting device, in the embodiment shown a parallelogram pivot with arms 13,14 which in a manner known per se is designed in such a way that the support wheels 9,10 are height-displaceable rela¬ tive to the mower 1. Between the lower parallel arms 14 and the frame bars 2,3 hydraulic cylinders 15 are provided, by means of which the support wheels 9,10 may be lowered relative to the mower 1, as for instance shown in Fig. l. Fig. 1 shows the mower raised by means of the lift of the tractor 8 to a position above the working position. The support wheels 9,10 are lowered and carry at least a part of the weight of the mower 1, such that the moment, with which the mower 1 influences the tractor 8, has been re¬ duced. The hydraulic cylinders 15 are preferably connected with the hydraulic system of the tractor in series with the lift used for raising and lowering the mower, such that the support wheels 9,10 are automatically lowered to the posi¬ tion shown in Figs. 1 and 3, when the mower 1 is lifted by means of the lift. If the hydraulic system of the tractor 8 offers the possibility of the hydraulic cylinders 15 being double-acting, the support wheels 9,10 will automa¬ tically be raised from the ground, when the lift is acti¬ vated for lowering the mower 1 to the working position. With a single-acting hydraulic cylinder 15 the support wheels 9,10 can in the working position rest against the ground with their own weight. A hydraulic cylinder 26 serves in the transport position for swinging one half of the mower with the frame bar 3 to a substantially vertical position, as shown in Fig. 7 and described in the above EP application 95610009.3. In the embodiment according to Figs. 4 and 5, a drum mower la is at its side closest to the tractor connected by two arms 16,17 to a hinge 18 of a carrier frame 19 suspended in the lift of the tractor 8. Also the mower, which like the one described above is of a type known per se is provided with support wheels 9,10 adapted in the same way as described in connection with Figs. 1-3. As will be seen from Fig. 5, a spring 20 may, however, in case of single-acting hydraulic cylinders 15, be connected to the parallelogram pivot 13,14, said spring keeping the support wheels 9,10 raised, when the mower is in the working posi¬ tion and the hydraulic cylinder 15 is not under pressure. To provide an extra lifting of the mower in the transport position in situations where the lift from the lift of the tractor is not sufficient, one of the arms 16 may as shown be provided with an extra hydraulic cylinder 28. Figs. 6 and 7 show a further development of the em¬ bodiment according to Fig. 1 in transport position behind the tractor 8. Transversely to the carrier arm 5 a pivot- able shaft 21 is mounted in this embodiment, said shaft being at the ends connected with swing arms 22,23 carrying ground wheels 24,25. In the embodiment shown, in which the mower like in Figs. 1-3 may be divided in two, a pivot arm 27 on the shaft 21 may be operatively connected with the hydraulic cylinder 26 for rotation of the shaft and subsequent rais¬ ing and lowering of the ground wheels 24,25, simultaneously with the mower half with the frame bar 3 moving to the position shown In Fig. 6 and the position shown in Fig. 7, respectively. In a machine not divided in halves the pivot arm 27 may be connected with a separate hydraulic cylinder. By means of the ground wheels 24,25 the mower 1 is at least partially carried, when it is transported in a position behind the tractor 8, as per εe known from the above US-A- 4,193,458. Besides, Fig. 7 shows the one half of the mower 1 swung up in a way which is described in detail in the above EP patent application no. 95610009.3.

Claims: C L A I M S 1. A lift-suspended mower (1) with a mowing aggregate suspended in a carrier construction (2,3) which is pivot- ally connected with a frame (7) for mounting on the lift- suspension of a tractor, the mowing aggregate with accom¬ panying carrier construction (2,3) being pivotally movable between a working position, in which the mowing aggregate and the carrier construction (2,3) are positioned laterally outside the track of the tractor and a transport position, in which the mower is present behind the tractor within its track, means being provided for transmission of a moment of force from the tractor to the mower (1) to lift it as a whole, c h a r a c t e r i z e d in that the mowing aggregate with accompanying carrier construction (2,3) comprises at least one weight-relieving support wheel (9,10) which partly is pivotal about an upwards directed axis (11,12) partly by means of a pivoting device (13,14) is lowerable and raisable relative to the mowing aggregate by swinging about a substantially horizontal axis, a hy¬ draulic cylinder (15) being connected with said pivoting device (13,14), said cylinder being adapted when the mower (1) is connected with the tractor (8) to be connected with the hydraulic system of the tractor in series with the lift of the tractor in order to in the working position of the mower, particularly in connection with turns in the filed, to make it possible to simultaneously lift the mowing aggregate with accompanying carrier construction (2,3) and lowering of the relieving support wheel/s (9,10) thereby permitting passage of the mowing aggregate over already mowed crop. 2. A mower according to claim 1, c h a r a c t e r¬ i z e in that in connection with said pivoting device a retaining spring (20) is provided for keeping the support wheel raised when said hydraulic cylinder (15) is not acti¬ vated for lowering the support wheel (9,10). 3. A mower according to claim 1, c h a r a c t e r- i z e d in that support wheels are present at each side of the mowing aggregate. 4. A mower according to claims 1, 2 or 3, c h a r a c t e r i z e d in that the connection (16) between the carrier construction of the mower and the frame mounted on the lift-suspension of the tractor comprises an additional hydraulic cylinder (28) for producing an addi¬ tional lifting of the mower in the transport position. 5. A mower according to any of the preceding claims, in which the swinging of the mower between the working posi¬ tion and the transport position takes place around a sub¬ stantially vertical shaft (6,8) and the mower in the trans¬ port position is behind the tractor in substantially hori¬ zontal position, c h a r a c t e r i z e d in that at least one ground wheel (24,25) is connected with said carrier construction (2,3) for weight relief of the mower (1) in the transport position. 6. A mower according to claim 5, c h a r a c t e r¬ i z e d in that the ground wheel (24,25) is mounted on an arm (22,23) which is fastened to a shaft (21) which is horizontal in the transport position and substantially perpendicular to the direction of travel, said shaft being pivotally mounted on the mower (1) , and a power means comprising a hydraulic cylinder (26) being provided for rotating the shaft (21) , thereby raising or lowering the transport wheel (24,25).

Inventors: FREUDENDAHL JOERN, NIELSEN HARALD RAUN, FREUDENDAHL, JOERN, NIELSEN, HARALD, RAUN
Applicants: FREUDENDAHL J FAB AS, JF-FABRIKEN - J. FREUDENDAHL A/S
Application year: 1995
Main classification: A01B63
IPC codes: A01B73, A01D34