GB2116011A

GB2116011A - A reciprocating harrow

Info

Publication number: GB2116011A
Application number: GB08301770A
Authority: GB
Inventors: Franz Grosse-Scharmann; Reinhard Higgen
Original assignee: Amazonen Werke H Dreyer SE and Co KG
Current assignee: Amazonen Werke H Dreyer SE and Co KG
Priority date: 1982-01-28
Filing date: 1983-01-21
Publication date: 1983-09-21
Also published as: GB8301770D0; DE8201995U1; FR2520184B1; FR2520184A1; GB2116011B; NL8300335A

Abstract

A reciprocating power harrow including a supporting frame (2) and at least two harrow beams (3 or 4) one behind the other and each extending transversely to the direction of travel, each harrow beam being divided transversely into at least two portions and, during operation, being set in vibrating or reciprocating motion transversely to the direction of travel by the power supply of an agricultural tractor or processing machine via a drive mechanism, which drive mechanism comprises at least one primary shaft (7) extending in the direction of travel and being provided with a toothed wheel, and the rotational movement of the drive is converted into a vibrating or reciprocating movement, whereby each of the divided harrow bars has its own drive which, in each case, comprises an oscillating or reciprocating mechanism and is combined to form a compact transmission unit (10), such drive having a drive shaft (11) which is associated with the respective oscillating mechanism and is provided with a toothed wheel, and whereby the toothed wheel of the primary shaft (7) is in driving connection with at least one of the two toothed wheels (13) of the drive shafts (11). <IMAGE>

Description

SPECIFICATION A reciprocating harrow The invention relates to a reciprocating harrow including a supporting frame and at least one harrow beam which extends transversely to the direction of travel and is provided with ground cultivating tines, the or each harrow beam being divided into at least two portions and, during operation, being set in reciprocating motion trans verselytothe direction of travel by the power source of an agricultural tractor or processing machine via a drive mechanism, which drive mechanism comprises at least one primary shaft extending in the direction of travel and being provided with a toothed wheel and is such that the rotational movement of the drive is converted into a vibratory or reciprocatory movement, whereby each of the divided harrow beams has its own drive which each comprises a vibrating or reciprocating mechanism and is combined to form a compact transmission unit, such drive having a drive shaft which is associated with the respective vibrating or reciprocating mechanism and is provided with a toothed wheel, and whereby the toothed wheel of the primary shaft is in driving connection with at least one of the two toothed wheels of the drive shafts.

A reciprocating harrow of this type is already known from Swiss Patent Specification No. 499 251.

This harrow is arranged behind a cultivator, the rear frame member serving simultaneously as the frame for the reciprocating harrow. This vibratory or reciprocating harrow comprises a harrow beam which is divided into two portions. Each portion of the harrow beam is set in reciprocating motion by its own reciprocating mechanism which is in the form of a crank drive. The drives of the reciprocating mechanisms are combined to form one compact transmission unit. In this arrangement flywheels are provided with a toothing and are in direct driving connection, said flywheels being accommodated in a housing, while the crank drives are situated externally of and behind the housing. The primary shaft is displaced laterally from the centre and arranged above the flywheels, so that the toothed wheel disposed on the primary shaft is only in driving connection with one flywheel.

Firstly, this reciprocating harrow is disadvantageous because only one harrow beam is arranged behind the cultivator. A seed bed cannot be prepared thus i.e. the desired fine crumbling of the ground cannot be achieved with a single harrow beam.

In addition, this reciprocating harrow has its primary shaft arranged at a very high level and it is also arranged eccentrically relative to the power take-off of the tractor, so that highly disadvantages connection conditions exist for the jointed shaft which joins the power take-off shaft of the tractor and the primary shaft i.e. the hinged shaft is angled both in the horizontal plane and in the vertical plane.

Because the hinged shaft is arranged at a high level, damage is frequently sustained by the hinged shaft when the machine is removed by the power lift of the tractor.

A reciprocating harrow is also known from Ger man Gebrauchsmuster (Utility Model) No. 1 963 630, in which two harrow beams are arranged one behind the other when viewed in the direction of travel, and such harrow beam members arranged one behind the other when viewed in the direction of travel are set in backward and forward motion by a reciprocat ing mechanism. This harrow is advantageous because of the compact arrangement of the drive in a transmission housing.

The invention now seeks to provide a simply constructed drive which, at the same time, is reliable for reciprocating harrows having a large working width, while avoiding excessive and disadvantageous loading on individual drive members.

According to the present invention, there is provided a vibrating or reciprocating harrow including a supporting frame and at least one harrow beam which extends transversely to the direction of travel and is provided with ground cultivating tines, the each harrow beam being divided into at least two portions and, during operation, being set in reciprocating motion transversely to the direction of travel by the power source of an agricultural tractor or processing machine via a drive mechanism, which drive mechanism comprises at least one primary shaft extending in the direction of travel and being provided with a toothed wheel and is such that the rotational movement of the drive is converted into a vibratory or reciprocatory movement, whereby each of the divided harrow beams has its own drive which each comprises a vibrating or reciprocating mechanism and is combined to form a compact transmission unit, such drive having a drive shaft which is associated with the respective vibrating or reciprocating mechanism and is provided with a toothed wheel, and whereby the toothed wheel of the primary shaft is in driving connection with at least one of the two toothed wheels of the drive shafts, characterised in that at least two harrow beams are arranged on behind the other when viewed in the direction of travel, whereby the members of the harrow beams are arranged one behind the other when viewed in the direction of travel and are set in reciprocating motion by a respective vibrating or reciprocating mechanism, in that the primary shaft and the toothed wheel disposed on the primary shaft are centrally arranged between the drive shafts or respectively the toothed wheels of the two vibrating or unbalance or wobble mechanisms, and in that the toothed wheel of the primary shaft is in direct driving connection with each of the toothed wheels of the drive shafts.

As a result of these features, even with reciprocating harrows having a large working width, it is possible to combined them with a follower roller and a coupled-on drill, whereby these implements which are arranged one behind the other are situated so closely behind each other that they can be lifted clear of the three point power-lift hydraulics of a tractor because the overall centre of gravity is a long way forward. In addition, there is a substantial saving in material owing to the lack of complex and costly drive elements.

It therefore becomes possible to combine the reciprocating harrow with a drill because two harrow beams are each divided into two members and are arranged one behind the other. The vibratory harrow is thus capable of preparing a very good seed bed with a desirably crumbled structure, so that seeds can be sown immediately in this seed bed without the need for further tilling.

In addition, the primary shaft is disposed in the centre of the reciprocating harrow between the drive shafts or respectively the toothed wheels of the oscillating mechanism, so that the primary shaft is in exact alignment with the power-take-off shaft of the tractor when viewed in the direction of travel.

Moreover, the primary shaft is likewise also situated at the same level as the power-take-off shaft of the tractor. Substantially no unnecessary developments are provided for the hinged shaft. Because the toothed wheel of the primary shaft is in direct driving connection with each of the toothed wheels of the drive shafts, a particularly advantageous drive is provided. This drive is also distinguished by its sturdy and compact construction.

Because the drives, together with their reciprocating mechanisms, are arranged in a housing, the delicate members of the drive are accommodated in a protective chamber in a particularly compact manner.

For rational manufacture, maintenance of replacement parts and maintenance of stocks, the invention provides that each drive is arranged in a closed transmission housing in the manner known from German Gebrauchsmuster (Utility Model) No. 1 963 630, and that the two transmission housings are screwed together to form one transmission unit. In such case, the transmissions may be used individuallyfor reciprocating harrows having small working widths, and two transmissions which are joined together to form one transmission unit may be used for reciprocating harrows having large working widths.

Further details and particular features of the invention are to be found in the subclaims and the description of the examples and the drawings.

The invention will be described further, byway of example, with reference to the accompanying drawings, in which Figure 1 is the front view of a reciprocating harrow; Figure 2 is the plan view, in partial section, of a transmission unit according to the invention for a reciprocating harrow; and Figure 3 is the plan view, also in partial section, of a further embodiment of transmission unit for a reciprocating harrow according to the invention.

A reciprocating power harrow is illustrated in Figure 1 and includes a power transmission unit 1, a rigid supporting frame 2 which is tightly screwed to the transmission unit 1, and two left-hand harrow bars or beams 3 and two right-hand harrow bars or beams 4 with said beams 3 and 4 being provided with the ground cultivating tines 5. The reciprocating harrow is connected to the three point power lift of an agricultural tractor or processing machine by means of a three point coupling 6. A follower roller and a drill may be arranged behind the reciprocating harrow in known manner (and is therefore not shown).

The harrow beams 3 and 4 are driven by the feed shaft of an agricultural tractor or processing machine for the power-take-off shaft via a hinged shaft which is connected to the primary shaft 7 of the transmission unit 1. The oscillating or reciprocating mechanism in the form of an unbalance or wobble body drive 8 is provided as the drive for the two left-hand harrow beams 3 situated one behind the other, and the oscillating or reciprocating mechanism also in the form of an unbalance or wobble body drive 9 is provided as the drive for the two right-hand harrow beams 4 situated one behind the other. The two wobble body drives 8 and 9 are combined to form the compact transmission unit 1 and are accommodated in the closed transmission housing 10.

The wobble body drives 8 and 9 each include a drive shaft 11, and toothed wheels 13 are nonrotatably disposed on such drive shafts 11 behind the wobble body drives 8 and 9 when viewed in the normal direction of travel 12. The primary shaft 7 is rotatably mounted between the drive shafts 11 at the same level as these drive shafts 11. A toothed wheel 14 is non-rotatably disposed on the rear end of the primary shaft 7 when viewed in the direction of travel 12. The toothed wheel 14 drives the wobble body drives 8 and 9 via the toothed wheels 13, thereby producing an oscillatory or reciprocating movement. This reciprocating movement is transmitted by rocker arms 15 to the harrow beams 3 and 4. The toothed wheels 13 have a different number of teeth compared with the toothed wheel 14.If desired, the toothed wheels 13 and 14 may be substituted by further similar toothed wheels having different numbers of teeth, so that, with the same input speed at the primary shaft 7, different oscillation frequencies are produced at the harrow beams 3 and 4. Driven reciprocating discs 16 are disposed on the drive shafts 11 at the rear end of the transmission unit 1 and act as flywheel or temporary energy store in known manner.

The embodiment illustrated in Figure 3 differs from the embodiment illustrted in Figure 2 in that in the embodiment of Figure 3 there is no central primary shaft in transmission unit 17. A primary shaft 18 is provided in the form of an extension of drive shaft 19 of the wobble body drive 8 and is connectable to the power-take-off shaft of an agricultural tractor or processing machine. In addition, the transmission unit 17 is comprised of two closed transmission housings 20 which are screwed together by means of screws 21 to form the transmission unit 17. The transmission housings 20 have such connecting pieces thatthey can be both screwed together to form transmission units 17 for reciprocating harrows having large working widths and installed individually for reciprocating harrows having smaller working widths. In addition,the driven reciprocating discs 23, which are each provided with a toothing 22, are disposed on drive shafts 19 at the rear end of the transmission unit 17 and are in direct driving connection with each other via said toothings 22.

Depending on how the wobble body drives 8 and 9 are aligned relative to each other, different types of movement relative to each other can be achieved for the harrow beams 3 and 4, thereby providing different advantages, namely by way of example: 1st Drive Method: The harrow beams 3 and 4 move in synchronism i.e. they oscillate in the same direction at each moment and pass through their respective dead centre points simultaneously. This ensures that no stones or other obstacles can penetrate between the divided harrow beams. Damage to the machine may be thus avoided.

2nd Drive Method The harrow beams 3 and 4 move in opposite synchronism relative to each other, i.e. they oscillate in opposite directions to each other and pass through their respective dead centre points simultaneously. This causes the machine to run very smoothly because the forces which are produced are always reciprocally cancelled.

3rd Drive Method The harrow beams 3 and 4 always move in each case with a phase shift at 90 relative to each other.

This ensures that there is substantially no need for any driven reciprocating discs which store the energy released by the harrow beams or respectively release the stored energy again to the harrow beams.

Claims

1. Avibrating or reciprocating harrow including a supporting frame and at least one harrow beam which extends transversely to the direction of travel and is provided with ground cultivating tines, the or each harrow beam being divided into at least two portions and, during operation, being set in reciprocating motion transversely to the direction of travel by the power source of an agricultural tractor or processing machine via a drive mechanism, which drive mechanism comprises at least one primary shaft extending in the direction of travel and being provided with a toothed wheel and is such that the rotational movement of the drive is converted into a vibratory or reciprocatory movement, whereby each of the divided harrow beams has its own drive which each compruises a vibrating or reciprocating mechanism and is combined to form a compact transmission unit, such drive having a drive shaft which is associated with the respective vibrating or reciprocating mechanism and is provided with a toothed wheel, and whereby the toothed wheel of the primary shaft is in driving connecting with at least one of the two toothed wheels of the drive shafts, characterised in that at least two harrow beams (3) are arranged one behind the other when viewed in the direction of travel (12), whereby the members of the harrow beams (3 or 4) are arranged one behind the other when viewed in the direction of travel (12) and are set in reciprocating motion by a respective vibrating or reciprocating mechanism, in that the primary shaft (7) and the toothed wheel (14) disposed on the primary shaft (7) are centrally arranged between the drive shafts (11 ) or respective ly the toothed wheels (13) of the two vibrating or unbalance or wobble mechanisms (8), and in that the toothed wheel (14) of the primary shaft (7) is in direct driving connection with each of the toothed wheels (13) of the drive shafts.

2. A reciprocating harrow as claimed in claim 1, in which the primary shaft (7) is arranged at least approximately at the same level as the drive shafts (11) of the oscillating or unbalance mechanisms (8,9).

3. A reciprocating harrow as claimed in claim 1, in which the drives, together with their oscillating or unbalance mechanisms (8, 9) are disposed in a housing (10, 20).

4. A reciprocating harrow as Claimed in claim 1, in which each drive (8, 9) is disposed in a closed transmission housing (20), and the two transmission housings (20) are screwed together to form one transmission unit (17).

5. A reciprocating harrow as claimed in claim 1, in which the transmission ratio between the primary shaft (7) and the drive shafts (11) can be varied by substituting said toothed wheels (13, 14) by toothed wheels having different numbers of teeth.

6. A reciprocating harrow as claimed in claim 1 in which the harrow beams (3, 4) are driven in such a way that they each have a phase shift of 90 degrees.

7. A reciprocating harrow constructed and arranged to operate substantially as herein described with reference to and as illustrated in Figures 1 and 2 or Figures 1 and 3 of the accompanying drawings.

8. A vibrating or reciprocating harrow including a supporting frame and comprising one or a plurality of harrow beams which are each divided into at least two members and which members when viewed in the direction of travel, are arranged one behind the other and are provided with ground cultivating tines, said harrow beams, during operation, being set in reciprocating motion transversely to the direction of travel by the power supply of an agricultural tractor or processing machine via a drive mechanism, which drive mechanism comprises at least one primary shaft extending in the direction of travel, and wherein the rotational movement of the drive is converted into a vibratory or reciprocating movement, whereby each of the divided harrow beams, arranged one behind the other, has its own drive which each comprises a vibrating or reciprocating mechanism and is provided with a drive shaft, characterised in that the two drives (8, 9) are combined to form a compact transmission unit (1, 17).

9. A harrow as claimed in claim 8, in which one of the drive shafts (19) of the oscillating mechanism (8) is also provided with an extended portion (18) which extends in the direction of movement of the tractor driving the reciprocating harrow, and this extended portion (18) is connected to the power take-off shaft of the tractor driving the reciprocating harrow.

10. A harrow as claimed in claim 8, in which one drive shaft (19) of the vibrating or reciprocating mechanism (8) is also in the form of a primary shaft (18).

11. A reciprocating harrow as claimed in claim 8, in which a driven disc is disposed on each of the drive shafts of the vibratory or reciprocating mechanisms, and the driven discs (23) are each provided with a toothing (22), and these toothings (22) are in driving connection with each other either directly or via an intermediate wheel.