GB2166033A - Mowing machine - Google Patents

Abstract

A mowing blade drive for a harvesting machine, for example an automotive mowing and chaff-cutting machine or a combine-harvester, is variably mountable and detachably assembled in unit mode of construction from two housing halves (6, 6'), the resulting housing being fastened between two partition plates (3, 3') in the central region of a base frame arranged underneath a cutting mechanism trough. A crank sheave (11), which has a crank pin (12) equipped with connecting rods (13, 13') and which is connected with a drive shaft (9), and an eccentric sheave (14) are mounted in the housing. Received between bearing arms (21, 21') pointing forwardly in fork-like manner are ball- and-socket bearing bushes of the angle levers (19, 19'), which at one arm are connected by bearings (17, 17') with the connecting rods (13, 13') and at the other arm by bearings (24, 24') with mowing blades (25). The drive is covered by a cover plate provided with presser members exerting a pressure on the blade. <IMAGE>

Description

SPECIFICATION Mowing machine The present invention relates to a mowing machine, for example a stalk fodder harvesting machine, a chaff-cutting machine or combineharvester.

A cutting mechanism drive for cutting mechanisms of great working width is described in DD-PS 206 458, which drive makes possible a narrow mode of construction of the side walls and avoids drag tracks on the crop side. Crankshafts extend at both sides from a drive shaft mounted behind a rear wall of a cutting mechanism trough. Angle levers arranged at both sides underneath the trough extend at their ends outwardly through the side walls and are connected by way of push rods extending forwardly outside the side walls. The ends, projecting forwardly through passages of the trough, of the angle levers are connected within the side walls with blade head plates and covered at all sides by blade presser members.

Although this construction avoids the formation of drag tracks at the crop boundary, there is the disadvantage that a drive shaft, which extends over the entire width of the cutting mechanism, inclusive of bearing plates which are arranged at both sides and receive crank sheaves and crank spigots, is required due to the arrangement of the angle levers in the region of the side walls and the push rods outside the side walls. Furthermore, the drive elements arranged in the region of the side walls cause increased vibrations and an appreciable noise loading occurs.

A frontal cutting mechanism, which possesses a central drive and is mountable at the front side of a tractor or the like, is disclosed in DE-OS 1962 701. A drive device, which is formed of drive transmission parts lying in vertical and horizontal planes, is connected at the power take-off shaft of the tractor. The horizontal drive parts are arranged at an Lshaped carrier block and engage directly at both blades of the mowing mechanism, whereagainst the vertically extending transmission parts are coupled with the power take-off shaft to be movable at their upper ends.

This frontal cutting mechanism possesses the disadvantage that two oscillating rocker levers are required for each mowing blade of the double blade cutting mechanism, and intermediate rods and additional bearing or articulation points are required between the horizontal and vertical rocker levers. A drive of that kind is not usable in automotive harvesting machines equipped with a drum and transverse conveying worm. In the case of a central drive, an additional bevel gear would have to be included.

A cutting mechanism with mechanical drive device for the mowing blades is disclosed in DD-PS 206 059. A set of toothed wheels and a crank sheave are mounted on a frame carrier behind a divided double blade beam. Each toothed wheel is connected by way of a lever system with a mowing blade. The drive of the crank sheave is not more closely illustrated, but can be realised in a crop cutting mechanism with this central drive arrangement only by way of an additional bevel gear. This drive is specially designed for very wide double blade cutting mechanisms, in which the double blades are divided into at least two halves in a cutting mechanism.

There is scope for a mowing blade drive which is variably mountable in the cutting mechanism in a particularly light mode of construction, brings about an appreciable noise reduction and requires relatively little setting work.

According to the present invention there is provided a mowing machine comprising a mowing blade mounted for reciprocating movement, drive means arranged to impart reciprocating movement to the blade and mounted as a unit in a selected position in the machine on frame means thereof and below a cutting mechanism trough, and a cover associated with the trough and covering the drive means, the drive means comprising housing means, two rotary members mounted in the housing means and carrying a crank pin therebetween, one of the rotary members being connected to a drive shaft, a connecting rod rotatably connected to the crank pin, a bell crank lever pivotably connected at one arm thereof to the connecting rod and at the other arm thereof to the mower blade, and mounting means pivotably mounting the bell crank lever at its fulcrum between two mounting members.

In a preferred embodiment, the drive means, which is variably mountable, is detachably assembled in unit construction from two housing halves and is fastened between metal partition plates in the middle region of a base frame arranged underneath a cutting mechanism trough, wherein a crank sheave with its crank spigots, which is equipped with connecting rods, and a terminating eccentric sheave is connected with the drive shaft and mounted in the housing halves. Ball-and-socket bearing bushes of the levers, which are connected at one end at bearing points with the connecting rods and at the other end in blade head bearings with mowing blades and covered over by a cover plate matched to the cutting mechanism trough, are received between bearing eyes pointing forwardly in fork-like manner.

The housing halves, which are connected together by means of threaded fastening elements at joint faces, are fastened by screws in mounting brackets to rails fastened to the partition plates and, in the region of the joint faces, to a base plate connected to the frame means.

The drive shaft arranged underneath the cutting mechanism trough and on one side behind the frame means is connected by way of a flexible coupling with the crank sheave. The crank sheave as well as the eccentric sheave, which is, for example, screw-fastened at the end face by means of a conical connection on the crank spigot and located by a cone-andkey connection or the like, are received in rolling bearings in the housing halves. Arranged in the bearing eyes of the housing halves are slots, in which setting plates, which are provided with ball pins and resting at both sides on the ball-and-socket bearing bushes, are connected by set screws extending through clamping plates. The cover plate of the mowing blade drive can be provided at its front edge with friction strips, which act as blade presser members and the pressing pressure of which is settable by a set screw.For damping of vibrations and noise, the mowing blade drive means, which can be withdrawable on the rails and on the base plate from the cutting mechanism trough, is lined with silent blocks or the like between the mounting brackets and the rails and base plate.

The mowing blade drive means, which is assemblable in unit mode of construction, can, for the purpose of providing a one-sided drive of a mowing blade at one side of the cutting mechanism or of two one-sided mowing blade drives arranged within the side walls, be rebuilt so as to be formed out of only one housing half or casing, a crank spigot constructed to be shortened and with only one connecting rod, and a cover member fastened to the casing and receiving the eccentric sheave and associated bearing.

Embodiments of the present invention will now be more particularly described by way of example with reference to the accompanying drawings, in which: Fig. 1 is a plan view of the mowing blade drive of a first machine embodying the invention; Fig. 2 is a cross-section on the line A-A of Fig. 1; Fig. 3 is a cross-section on the line B-B of Fig. 1; Fig. 4 is a plan view of the mowing blade drive of a second machine embodying the invention; Fig. 5 is a schematic illustration of a centrally arranged mowing blade drive; Fig. 6 is a schematic illustration of onesided mowing blade drives arranged at both sides; and Fig. 7 is a schematic illustration of a onesidedly arranged mowing blade drive.

Referring now to the drawings, there is shown part of a mowing machine comprising a base frame 2 extending underneath a cutting mechanism trough 1, the frame being interrupted by two metal partition plates 3 and 3' in the central region of a cutting mechanism.

Rails 4 and 4' are fastened to the two partition plates 3 and 3' respectively and a base plate 5 connects the partition plates 3 and 3' with the frame 2. The mowing blade drive comprises two housing halves 6 and 6' which are fastened by brackets 7 and 7' on the rails 4 and 4' and by further brackets or feet 8 and 8' on the base plate 5. A drive shaft 9 is connected by way of a flexible coupling 10 with a crank sheave 11 carrying a crank spigot 12. Connecting rods 13 and 13 are mounted on the crank spigot 12, which extends through both housing halves 6 and 6'.

An eccentric sheave 14 is plugged onto, and fastened by a nut at the end face, a conical extension at the end of the crank spigot 12, wherein the eccentric sheave 14 is locked in its setting relative to the crank spigot 12 by a taper and key connection 15 or the like. As a result, the two components cannot be mounted one rotated relative to the other and the synchronism of the connecting rods 13 and 13' is ensured. The crank sheave 11 is received in the housing half 6 and the eccentric sheave 14 in the housing half 6' in large rolling bearings 16 and 16' appropriate to the loads. The connecting rods 13 and 13' are received at their free ends in bearings 17 and 17' at the ends, pointing to the plane of a joint location 18 of the housing halves, of two angle levers 19 and 19' respectively.The housing halves are firmly connected at the location 18 by means of threaded fastening elements 20. The housing halves 6 and 6' have fork-shaped bearing eyes 21 and 21', respectively, which point outwardly from the region of the brackets 7 and 7'. The angle levers 19 and 19' are received by ball-and-socket bushes 22 and 22' thereof between these bearing eyes. Blade head bearings 24 and 24', which point forwardly and are disposed above blade head plates 23 and 23', of the angle levers 19 and 19' set mowing blades 25 and 25 into oscillating movement when the connecting rods are moved by the crank sheave 11 and crank spigot 12. Counterbearings 26 encompassing the blade head plates 23 and 23' are mounted in the end region of the same for taking up the bending moment which arises through the spacing from the centre of gravity of the mowing blades to the articulation points at the blade head plates. In order that an exact setting of the angle levers relative to the mowing blades can take place, slots 27 are arranged in the bearing eyes 21 and 21', as illustrated in Fig. 3. Set screws 29 led through clamping plates 28 are connected with mounting plates 30, which are disposed adjacent to the ball-and-socket bushes 22 and 22' and the ball pins 31 of which have balls received in sockets in the bushes 22 and 22'.The forwardly disposed blade head bearings 24 and 24' are covered by a cover plate 32, which is adapted to the shape of the cutting mechanism trough 1 and is provided at its front edge with friction strips 33 acting as blade presser members.

The setting of the pressing pressure on the mowing blades takes place by way of set screws 34.

The mowing blade drive can be assembled in the described mode or in different variants, as illustrated in Figs. 5 to 7. For one-sided drive of a mowing blade 25 from one side of the cutting mechanism ortwo one-sided drives arranged between side walls 35 and 35', the drive consists of only one housing half or casing 6, a crank spigot 12 which is shorter and carries only one connecting rod 13, and a cover member 36, which is fastened at the joint location 18 and receives the eccentric sheave 15 and associated rolling bearing 16'.

In use, the drive shaft 9 is driven by the machine engine and imparts drive by way of the flexible coupling 10 to the crank sheave 11. The spigot 12, the end of which is fastened in the eccentric sheave 14 mounted in the other housing half 6', is moved by the driven crank sheave 11. The two connecting rods 13 and 13' (or in the case of one-sided drive the single connecting rod 13) connected to the crank spigot are reciprocatingly displaced and in turn reciprocatingly displace the angle levers 19 and 19' about their ball-andsocket bearings between the bearing eyes 21 of the housing halves. The levers, which are connected by their forwardly pointing ends through the blade head bearings 24 and 24' with the two mowing blades 25 and 25', set the blades into oscillation.The angle levers thus operate in opposite sense, whereby the forces for the mowing blade drive are approximately cancelled and act mainly within the housing. Through the exact mounting and the common arrangement of the connecting rods 13 and 13' and the angle levers 19 and 19' in the housing halves, the regulation of the association of the mowing blades in the principal direction of movement of the blades becomes redundant as do expensive setting devices and setting operations connected therewith. Further advantages lie in the easy disassembly of the mowing blade drive manufactured in unit mode of construction. After loosening the screw connections from the rails 4 and 4' of the partition plates 3 and 3' and from the base plate 5 as well as the separation of the drive shaft 9 from the flexible coupling sheave 10 and the mowing blades from the blade head bearings of the angle levers, the entire mowing blade drive can be drawn out rearwardly underneath the cutting mechanism trough. The possibility of universal use for a one-sided mowing blade drive on one side as well as also from two sides of the cutting mechanism can be realised through re-building using standard parts. Also to be emphasised is the noise reduction achievable through the damped fastening.

Claims (15)

1. A mowing machine comprising a mowing blade mounted for reciprocating movement, drive means arranged to impart reciprocating movement to the blade and mounted as a unit in a selected position in the machine on frame means thereof and below a cutting mechanism trough, and a cover associated with the trough and covering the drive means, the drive means comprising housing means, two rotary members mounted in the housing means and carrying a crank pin therebetween, one of the rotary members being connected to a drive shaft, a connecting rod rotatably connected to the crank pin, a bell crank lever pivotably connected at one arm thereof to the connecting rod and at the other arm thereof to the mower blade, and mounting means pivotably mounting the bell crank lever at its fulcrum between two mounting members.

2. A machine as claimed in claim 1, the drive means being mounted in a central region of the frame means and between two partition elements.

3. A machine as claimed in claim 2, the housing means comprising two housing parts connected together at a join location thereof by threaded fastening means and mounted by mounting brackets on rails fastened to the partition elements and on a base plate connected to the frame means.

4. A machine as claimed in claim 3, the housing means being arranged to be slidable on the rails after release of the fastening means.

5. A machine as claimed in either claim 3 or claim 4, comprising means for inhibiting transmission of sound and vibration arranged between the brackets and the rails and base plate.

6. A machine as claimed in any one of the preceding claims, wherein said one of the rotary members is connected to the drive shaft by way of a flexible coupling and the other one of the rotary members is provided with a tapered bore receiving a tapered extension of the crank pin and with means securing the crank pin extension against rotation in and removal from the bore, the two rotary members being rotatably mounted in the housing means by bearings with rollable elements.

7. A machine as claimed in any one of the preceding claims, said mounting means comprising a respective ball and socket joint connecting the bell crank lever to each mounting member.

8. A machine as claimed in claim 7, wherein each of the ball and socket joints comprises a ball pin provided with a ball engaged in a socket in the bell crank lever and with a fastening plate adjustably fastened to the respective mounting member by means of threaded fastening elements extending through slots in the mounting member.

9. A machine as claimed in any one of the preceding claims, wherein the cover is provided at an edge portion thereof with presser elements exerting an adjustable amount of pressure on the blade.

10. A machine as claimed in any one of the preceding claims, the housing means comprising a casing receiving said one rotary member and the crank pin and a cover member secured to the casing and receiving the other rotary member.

11. A machine as claimed in any one of claims 1 to 9, comprising a further such mowing blade mounted for reciprocating movement in opposite phase to the first-mentioned blade, a further such connecting rod rotatably connected to the crank pin, and a further bell crank lever pivotably connected at one arm thereof to the further connecting rod and at the other arm thereof to the further blade.

12. A machine as claimed in claim 11, the housing means comprising two housing halves each receiving a respective one of the rotary members and a respective half of the crank pin.

13. A mowing machine substantially as hereinbefore described with reference to Figs.

1, 2, 3 and 5 of the accompanying drawings.

14. A mowing machine substantially as hereinbefore described with reference to Figs.

4 and 7 of the accompanying drawings.

15. A mowing machine substantially as hereinbefore described with reference to Fig. 6 of the accompanying drawings.