Mowing device

Abstract: A mowing device (1) comprises behind its cutting members (5) a swath former (57) consisting of a worm rotor (63) conveying the cup crop transversely (58) of the travelling direction (2) of the mowing device. In order to surely convey the cup crop irrespective whether the volume of the cut crop is small or great the worm rotor (63) rotates in such a sense that its front (61) moves upwardly (62).

Description: The invention relates to a mowing device, comprising a frame extending transversely of the direction of movement of the mowing device, cutting members supported by said frame and being rotatably mounted on said frame so as to rotate about substantially vertical shafts by means of driving gear, carried by said frame, said cutting members having knives rotating in a horizontal plane and a rotor comprising at least one swath former provided with at least one helical strip, said rotor being adapted to rotate about a horizontal axis transverse of the direction of movement and being journalled on the frame and conveying the crop laterally towards at least one delivery place and driving means for driving said rotor, said rotor extending transversely over the delivery place and comprising conveying means divided over the length of the delivery place, whereby the substantially horizontal axis of the rotor is located behind the substantially vertical axes of the cutting members. A mowing device of this type is known from FR-A-application 2,417,249. Herein the cut crop is rearwardly transported beneath the screw rotor in a transport channel bounded on the one hand by the rotor and on the other hand by a steel trough. For this purpose the rotor turns downwards at its front side. The crop is often firmly pinched between the rotor and the trough and slits sideways. The resulting friction may give rise to loss of leaf, damage of stalks and/or loss of juice and at any rate said friction means loss of energy, so that the driving means must have a great strength. The crop handled with this mowing device is compressed in the channel between the rotor and the trough. The transport channel between the rotor and the trough may become clogged in the case of a small passage of the transport channel, when long and/or dense or lying crop has to be cut, whereas in the case of a large passage of the transport channel, when short and/or thin crop has to be worked, the transport operation leaves to be desired. The invention has for its object to provide an improvement in the swath former. For this purpose tne driving means drive the rotor in a sense such, that the rotor moves upwards at its front, or with other words that the side of the helical strip of the rotor facing the delivery place on the top side of the rotor converges with the direction of movement of the mowing device, whereby at the delivery place said conveying means convey the crop upwardly and rearwardly over the rotor, a screen being arranged above the rotor, said screen preventing the crop from being ejected away from the rotor by centrifugal force and ventilation effect directed towards the screen the construction of the mowing device being such that during mowing operation owing solely to the forward speed of the mowing device and to the rearward pushing force of the cutting members cut crop is pressed in engagement with said swath forming rotor with adequate pressure for swath forming operation at the front of the swathforming rotor, whereby said crop being gripped by said rotor and being moved in transverse direction carries along with it the cut crop still located in front thereof and above the cutting members. It might be feared, that the crop would not be satisfactorily laterally displaced. However, it appeared that owing to the rearward advance of the cut crop by the cutting members rotating about vertical axes, the stream of the crop is urged against the worm rotor with such a pressure that the crop is sufficiently engaged for the lateral displacement. Since the trough behind and beneath the rotor is omitted, the mowing device according to the invention can be constructed with a comparatively low weight and a relatively low height. It is noted that U.S.-A-3,363,407 discloses a mowing device having a scissor-bar, in which two swath formers are arranged at either sides of a central delivery place. Thus swath formers are each onstituted by a rotor built up from a cylinder and a helical strip at its periphery. Said rotor is driven upwards at its front side, or with other words, the side of the helical strip of the rotor facing the delivery place on the top side of the rotor converges with the direction of movement of the mowing device. This known mowing device, however, has at its delivery place just an aperture for rearwardly delivering the crop by forwardly conveying the mowing device over the field. The rearward delivered crop slides immediately downwardly on the field. When the crop should be treated further, for example for loading a carriage or for conditioning it in a conditioner, it should be picked up from low level, which is cumbersome. While picking up the crop, the danger exists that also stones are picked up from the ground, which stones are not welcome in the carriage or in the conditioner. This known mowing device does not have a rotor extending over the delivery place and the latter disclosure does not teach that it is advantageous and possible conveying the crop upwardly and rearwardly over the rotor as the present invention does, particularly in combination with mowing members rotating about vertical axes. From US-A-3.474.602 a mowing device is known comprising a scissor bar and a swath former positioned behind the sclssor bar, said swath former consisting of a horizontal rotor with helical strips, moving upwards at the front of the rotor. In this prior art mowing device the cut crop is conveyed into engagement with the rotor by means of a reel, well known in the art, and consisting of a rotor positioned in front of the swath former and above the scissor bar and having crop engaging members which pick up the cut crop and convey it into engagement with the swath forming rotor. The screen may terminate at its lateral rear sides in swath boards which additionally narrow the swath to be formed and/or provide more sharply defined boundaries of the swath. The above mentioned and further features of the invention will be explained in the following description of a few embodiments of mowing devices according to the invention with reference to a drawing. The drawing shows schematically in: Fig. 1 a perspective view of a preferred embodiment of a mowing device in accordance with the invention; Fig. 2 an enlarged sectional view taken on the line II-II in Fig.1; and Fig. 3 a sectional view corresponding to Fig. 2 of a further mowing device in accordance with the invention. Each of the mowing devices shown in the figures comprises a frame 60 extending transversely of the direction of movement 2 and is mainly formed by an elongated beam 3 and side screens 17 and 18 fastened to the ends of said beam. The mowers 10 of Fig.1 and 2 and the mower 23 of Fig. 3 comprise each a plurality of cutting members 5 rotatable about substantially vertical shafts 4 and arranged above the beam 3, a known driving gear (not shown) arranged inside the beam 3 and driving the cutting members 5 and consisting of a series of pinions, at least one supporting member 9 for holding the mower on the field 8 and a swath former 57. The frame 60 of the mowers 1, 10, 11 and 23 can be hitched by means of a conventional auxiliary frame 13 with a threepoint suspension gear 12 to the side of a tractor (not shown), whilst the afore said driving gear (not shown) is actuated via a driving system 14 by a shaft 15 to be linked to the power take-off shaft, of the tractor. The mower can be fastened to a vehicle straight in front thereof. The cutting members 5 rotate pairwise with high speed in opposite senses indicated by arrows 16. The present invention is particularly important for a mower 10 and 23 in which each cutting member 5 mainly comprises a knife carrier formed by a disc 35 having two protruding knives 26 and being journalled directly above a flat beam 3. The knives 26 of neighbouring cutting members 5 are relatively off-set in the directions of the arrows 16. Each one of the mowers illustrated in the drawing comprises a rotor 63. This rotor 63 comprises two swath formers 57 taking over the cut crop from the cutting members 5 and displacing the same in the transverse direction 58 towards a delivery place 75, said rotor being rotatable about a substantially horizontal axis 59 and being journalled in the side screens 17 and 18 of the frame 60 of the mower. The front side 61 of the rotor 63 is driven upwards in the direction indicated by the arrow 62 by means of driving means consisting, for example, as shown in Figs. 1 and 2 of a driving gear 19 and a universal shaft 20. These driving means drive the rotor 63 with a high speed of, for example, 1000 rev-min, whereas the cutting members 5 are driven with an even higher speed of, for example, 3000 rev/min. Figs.1 and 2 show that the bottomside of the rotor 63 is located at an even lower level than the plane of movement 67 of the knives 26 and that at the level of the knives the rotor 63 is near and behind the hindmost arcs 65 of the circles of the knives 26. The rotor 63 comprises a central cylinder 68 around which is wound and welded a helical strip 69. The strip 69 extends from each of the two ends 71 and 72 of the mower 1 approximately up to a central delivery place 75. The strip 69 is wound at one end 71 and at the other end 72 of the mower 1 in opposite direction around the cylinder 68 in a manner such that the side 21 of this helical strip 69 facing the delivery place 75 on the top side thereof converges with the direction of movement 2 of the mower 1. The angle of convergence a thus formed is small, for example, of the order of magnitude of 10° and may be 11°, 13° or 7°. For the rotor 63 a high number of revolutions and a small pitch of the helix is chosen. The rotor 63 is not covered on the front side and on the rear and bottom sides. In the area of the delivery place 75 the cylinder 68 of the rotor 63 is provided with at least one catch 7, constituted by a lying strip joining the strip 69, said catch 7 throwing the crop over and across the rotor 63 to the rear on the field (Fig. 1). During the mowing operation of this mower 1 the cut crop is guided over and across the rapidly rotating cutting members 5 to the rear and owing to the forward speed of the mower 1 and to the rearward pushing force of the cutting members the crop is moved into engagement with the rotor 63, which conveys it in the transverse direction 58. The cut crop 76 already gripped by the rotor 63 and moving in the transverse direction 58 carries along with it the cut crop 77 still located in front thereof and above the cutting members 5, since all cut crop is entangled and/or pressed together. The cut crop 76 readily slides rearwardly and in the transverse direction 58, because the sliding resistance of the cut crop 77 on the common transport surface of rapidly rotating cutting members 5 is particularly low. Therefore, the strip 69 need only have a small height b. This height may be less than 10 cm and the strip 69 preferably projects by about 6 cm above the cylinder 68. The cylinder 68 preferably has a large diameter d of, preferably, more than 20 cm. A satisfactory operation of the mower 1 shown in Figs. 1 and 2 was obtained with a width of the mowing area c of 240 cm, a cylinder diameter d of 24 cm, a height b of the strip 69 of 6 cm, a pitch f of 20 cm, a speed of the rotor 63 of 1000 rev/min, a speed of the cutting members 5 of 3000 rev/min, and a travelling speed of the mower 1 in the direction of the arrow 2 of 10 to 15 km/h. A great advantage of the mower according the invention is, that it allows mowing with a high travelling speed so that the mowing capacity is very high, whilst a satisfactorily workable swath 86 is left behind the mower 1, whereas on strips having a width g , no or substantially no stalks are deposited so that satisfactorily visible wheel tracks are left free for hay-making implements. Above the rotor 63 a wind screen 27 serving in addition as a safety screen is arranged. This wind screen 27 mainly comprises a screen frame 28 of steel tubes and a flexible foil 29 fastened to said tubes. At the delivery place 75 the wind screen 27 is held at a higher level above the rotor 63 than at the ends of the rotor 63 in order to prevent clogging of the delivery place 75. The level of the wind screen 27 is adjustable with the aid of setting rods 30, each of which is supported by a console 34 of a side screen 17, 18 with the aid of a split pin 32 inserted into a selected hole 31. The wind screen may form part of or constitute a safety screen. The mower 10 has a side screen 17 whose lower edge 36 of a front portion 38 extending as far as into the crop to be cut 37 is inclined downwards to the rear as far as slightly below the plane 67 of the knives 26. The lower edge 36 has an outwardly bent portion 42 curved around the circular path of movement 41 of the knives 26. Owing to this shape of the side screen 17 a clear separation is obtained between the crop not yet cut and the mowing area. Fig. 3 shows a mower 23 different from that of Figs. 1 and 2 in that the rotor 63 is arranged above the cutting members 5. The machine is consequently more compact and can therefore be constructed with a lower weight. Above the rotor 63 a curved metal screen 84 is arranged, which is fastened to side screens 18 and which guides the cut crop 76 and holds the same in contact with the rotor 63. This screen 84 prevents the crop 76 from being ejected away from the rotor 63 by centrifugal force and ventilation effect. On the rear side of this mower rearwardly extending swath boards 56 are arranged for limiting the delivery place 75.

Claims: A mowing device comprising a frame (60) extending transversely of the direction of movement of the mowing device (1), cutting members (5) supported by said frame (60) and being rotatably mounted on said frame (60) so as to rotate about substantially vertical shafts (4) by means of a driving gear (14, 15) carried by said frame (60), said cutting members (5) having knives (26) rotating in a horizontal plane and a rotor (63) comprising at least one swath former (57) provided with at least one helical strip (69), said rotor (63) being adapted to rotate about a horizontal axis (59) transverse of the direction of movement (2) and being journalled on the frame (60) and conveying the crop (67) laterally towards at least one delivery place (75) and driving means (19, 20) for driving said rotor (63), said rotor (63) extending transversely over the delivery place (75) and comprising conveying means (7) divided over the length of the delivery place (75), whereby the substantially horizontal axis (59) of the rotor (63) is located behind the substantially vertical axes (4) of the cutting members (5), characterized in that the driving means (19, 20) drive the rotor (63) in a sense such, that the rotor 63 moves upwards at its front, or with other words that the side of the helical strip (69) of the rotor (63) facing the delivery place (75) on the top side of the rotor (63) converges with the direction (2) of movement of the mowing device (1), whereby at the delivery place (75) said conveying means (7) convey the crop upwardly and rearwardly over the rotor (63), a screen (27 and 84) being arranged above the rotor (63), said screen (27, 84) preventing the crop (76) from being ejected away from the rotor (63) by centrifugal forces and ventilation effect, directed towards the screen, the construction of the mowing device being such that during mowing operation owing solely to the forward speed of the mowing device and to the rearward pushing force of the cutting members (5) cut crop (76) is pressed in engagement with said swath forming rotor (63) with adequate pressure for swath forming operation at the front of the swathforming rotor (63), whereby said crop (76) being gripped by said rotor (63) and being moved in transverse direction carries along with it the cut crop (77) still located in front thereof and above the cutting members (5). A mowing device (1) as claimed in claim 1, characterized in that at the delivery place (75) the conveying means consist of at least one strip (7) extending substantially horizontally.

Inventors: OOSTERLING PIETER ADRIAAN, VISSERS HERMANUS HENDRIKUS, OOSTERLING, PIETER ADRIAAN, VISSERS, HERMANUS HENDRIKUS
Applicants: MULTINORM BV, MULTINORM B.V.
Application year: 1980
Main classification: A01D57
IPC codes: A01D34, A01D57