GB2037131A

GB2037131A - Soil cultivating machines

Info

Publication number: GB2037131A
Application number: GB7939065A
Authority: GB
Original assignee: Amazonen Werke H Dreyer SE and Co KG
Current assignee: Amazonen Werke H Dreyer SE and Co KG
Priority date: 1978-11-15
Filing date: 1979-11-12
Publication date: 1980-07-09
Also published as: GB2037131B; FR2452858A1; FR2452858B1

Abstract

A soil cultivating implement having at least one cultivating tine (10) adapted to be rotatably driven via a drive shaft and which tine extends towards the ground and is connected to a tool holder (1) and non-rotatably to the outer region of at least one leaf spring (7) with the long or longitudinal side of the cross-section of which spring extending parallel to the driving shaft and abutting against a hub portion of the drive shaft, characterised by the feature that the tool holder (1, 15) is located to be rotatable on the drive shaft (4, 17) and the hub portion (5, 16) is provided with an extension (13, 32) extending in longitudinal direction of the cross-section of each leaf spring (7, 20) so that in normal use the springs, tines, and tool holder rotate with the hub portion but that when a tine strikes, for example, a stone, the springs supporting the tines rotate relative to the driven hub portion. The springs may be given an adjustable pre-tension. <IMAGE>

Description

SPECIFICATION Soil cultivating implement The present invention relates to a soil cultavating implement having at least one cultivating tine adapted to be rotated via a driving shaft and directed towards the ground, which time is connected to a tool holder and non-rotatably to the outer region of at least one leaf spring, the long or longitudinal side of the cross section of which spring extends parallel to the driving shaft and abuts against a hub portion of the drive shaft.

A soil cultivating implement is already known from the German Offenlegungsschrift, wherein the tool holder is comprised of two non-rotatable plates located on the drive shaft and interconnected by means of screws and between which plates three leaf springs abutting against the hub portion are located mutally spaced equidistantly laterally, and one each on the outer ends (i.e. in all three cultivating tines) and directed towards the ground.

The object of this arrangement is that the cultivating tines when striking against stones in the ground may yield to avoid or at least minimize damage to these times and the components positively connected thereto, whereby after passing a stone spring back into their original position on the tool holder.

An adverse feature, however, herewith is that despite this resilient arrangement the cultivating tines, especially when impacting large stones, are unable to yield far enough, i.e. after a certain recoil against the direction of rotation of the tool holder they are forcibly dragged'overthe stone, so that frac to rue of the tines of their securing parts or permanent deformation of the leaf springs due to overstressing are unavoidable.

The object of the invention is to attain uninterrupted operating of the soil cultivating implement even in extremely stoney grounds.

According to the present invention there is provided a soil cultivating implement having at least one cultivating tine adapted to be rotatably driven via a drive shaft, and which tine extends towards the ground and is connected to a tool holder and nonrotatably to the outer region of at least one leaf spring with the long or longitudinal side of the cross-section of which spring extending parallel to the driving shaft and abuts against a hub portion of the drive shaft, characterised by the feature that the tool holder is located to be rotatable on the drive shaft and the hub portion is provided with an extension extending in longitudinal direction of cross-section of each leaf spring.

Owing to this measure, the tool holder when its cultivating tine strikes against a stone, is able to rotate in a direction of rotation opposite to that of the driving shaft after overcoming the stress of the leaf springs, whereby the cultivating tine slides along the stone and is moved laterally past this stone. After passing the stone, due to the abutment of the extension of the tool holder located on the hub portion, the tool holder, and hence the cultivating tine, moves again in the direction of rotation of the driving shaft.

In a preferred embodiment, the invention furthermore provides for two diamterically opposite cultivating tines to be connected in a similar manner two German AS 19 18 929. If in this case the hub portion is fitted with two diametrically opposite extensions, then the additional advantage is obtained if the cultivating tines after half a turn of the hub portion towards them, assume the same position relative to the driving shaft. This is of importance whenever several tool holders are spaced juxtaposed at right angles to the direction of travel and the circular paths of the cultivating tines overlap tool holders adjacent thereto, whereby the cultivating tines of these adjacent tool holders assume an offset position at an angle thereto.By this means the cultivating tines of adjacent tool holders are prevented from colliding with each other during their rotation.

A particu'larly functional reliable design is obtained without impairing the resilient yieldability of the cultivating tines whenever two groups of leaf springs are provided, the hub portion of the driving shaft being extended between the two groups and the extensions abut on both sides of the groups of leaf springs and between these groups having an arcuate surface, the diameter of which is larger than the spacing between the two groups of leaf springs in their operational position. A stable position of the cultivating tines relative to the hub portion is attained in their operating position as also is a lowwear rotation of the hub portion between the leaf springs when striking against a stone by the cultivating tines.

A particulariy resilient yieldability of the cultivating tines is obtained when each group has at least four plate of leaf springs and the thickness of each spring is a maximum of3 mm.

In a simple embodiment, the invention herewith provides that the cultivating tines are located between the two groups of leaf springs and are nonrotatably connected to the tool holder. In another preferred embodiment, the cultivating tines are secured to the tool holder and the leaf springs nonrotatably connected to the tool holder. This method of arrangement permits the leaf springs to assume any optional fixed position relative to the leaf springs.

If the leaf springs are interconnected in the region of their outer ends by adjustable bracing or tension means and mutally displaceable in their longitudinal direction, then the leaf springs may be given a certain pre-tensioning or stressing. This pre-tension is of importance especially when using the cultivating appliance in particularly heavy grounds which put up a considerable resistance to the cultivating tines, in order to avoid a frequent raking of the leaf springs over the extensions of the hub portion. An embodi mentfavourable in its simplicity is provided by the adjustable bracing means being helical and also projecting through the leaf springs and slots are provided in the leaf springs forthis purpose and extend in a longitudinal direction thereof.

The invention will be described further, by way of example, with reference to the accompanying drawings, in which: Fig. lisa longitudinal section through a tool hol der; Fig. 2 is a section on the line I-I of the tool holder of Fig. 1; Fig. 3 is a plan view from below of an alternative embodiment of a tool holder; and Fig. 4 is a longitudinal section through the tool holder of Fig. 3.

A tool holder 1 is shown in Fig. 1 and 2 and comprises a mounting member2 and a mounting plate 3 which are rotatably mounted on a driving shaft 4. A hub portion 5 is located between member 2 and plate 3 and is non-rotatably connected to the driving shaft. Flat plate or leaf springs 7 are provided abutting on both sides to the hub portion 5 and are divided into two groups 6. The springs 7 with the longitudinal side I of their cross section parallel to the driving shaft 4, the springs each have a thickness a of 1.5 mm and are interconnected at their outer ends by bracing means in the form of bracing screws 8. At the positions at which the bracing screws 8 project through the plate springs 7, slots 9 are provided in the leaf springs and extend in the longitudi nal direction thereof.

Two cultivating tines 10 directed towards the ground are retained by the leaf springs 7 and by means of the bracing means 8 also, and the upper end of each cultivating tines is passed through recesses 11 in the holding member 2 and in the holding plate 3. Spacing members 12 are arranged on both sides of the upper ends of the cultivating tines 10. Finally, the hub portion 5 between the two groups 6 of the leaf springs 7 is provided with two opposing extensions 13 each of which having an arcuate surface 14 and whose diameter is greater than the spacing a between the groups 6 of springs 7.

Thus, if the leaf springs 7 are to be given a certain pre-tension, or the pre-tension thereof is to be changed, it is only necessary after slackening the bracing screws 8 on both sides of the driving shaft 4 to remove one or two spacers 12 and for the bracing screws to be subsequently tightened again. The bracing screws 8 may be replaced as bracing means, for example, by adjustable clips made of solid or resilient material.

In the embodiment shown in Figs. 3 and 4, a hood shaped tool holder 15 is rotatably mounted on hub portion 16 which is non-rotatably mounted on driving shaft 17. A backing plate 18 is screwed on the lower surface ofthe hub portion 16, which portion 16 for sake of clarity is only partly shown in Fig. 3. Leaf or plate springs 20 are provided between bearing 19 of the hub portion 16 for the tool holder 15 and backing plate 18 and are divided into two groups 6. The side of the longitudinal sided of the cross-section of the springs also extends parallel to the driving shaft 17 and the springs abut against the hub portion 16 on both sides.

Also as in the aforesaid embodiment, the outer ends of the leaf springs 20 are interconnected by bracing elements in the form of bracing screws 8 four bracing screws 8 however, being provided in all.

At the positions where the bracing screws 8 pass through the leaf springs 20, slots 9 are provided which extend in the longitudinal direction of these springs. Moreover, the outer ends of the springs 20 each project into one of the recesses 21 which are located in the downwardly arched side wall 22 of the tool holder 15.

Hub portion 17 is provided between the groups 6 of the leaf springs 20 with the two opposing extensions 23, against which the leaf springs 20 abut on both sides and which extensions in turn have an arcuate surface 14 between the groups 6 of leaf springs 20, the diameter d of which is greater than the spacing a between the groups 6 of springs 20. To vary the pre-tension of the springs 20 it is only necessary for the bracing screws 8 to be tightened or slackened. This simple kind of adjustment of the pre-tension is possible, for the reason that the cultivating tines 24 are screwed directly to the tool holder 15 independently of the springs 20.

The two embodiments, in use, function as fol lows:- The driving shaft 4 or 17 and hence the cultivating tines 10 or24 are driven in a direction of rotation characterised by the arrow 25 and at the same time propelled forwardly in the direction of travel indicated by the arrow 25. Thus, if one of the cultivating tines strikes against a stone, then this tine stops, whilst the hub portion 5 or 16 is able to continue rotation between the groups 6 of leaf springs. Owing to the forward propulsion movement in the direction of arrow 26, the tool holder 1 or 15 is turned by the stone in an anti-clockwise direction 25, the cultivating tine abutting against the stone moves at the same time inwardly along the stone until it can slide past and the tool holder 1 or 15 with the cultivating tines is again positively connected to the hub portion 5 or 6 and hence to the driving shaft 4 or 17.

Claims

1. A soil cultivating implement having at least one cultivating tine adapted to be rotatably driven via a drive shaft and which tine extends towards the ground and is connected to a tool holder and nonrotatably to the outer region of at least one leaf spring with the long or longitudinal side of the cross-section of which spring extends parallel to the driving shaft and abuts against a hub portion of the drive shaft, characterised by the feature that the tool holder is located to be rotatable on the drive shaft and the hub portion is provided with an extension extending in longitudinal direction of the crosssection of each leaf spring.

2. A soil cultivating implement as claimed in claim 1, in which two diametrically opposite cultivating tines are connected with the tool holder.

3. A soil cultivating implement as claimed in claims 1 and 2, in which the hub portion is provided with two extensions diametrically opposite each other.

4. A soil cultivating implement as claimed in any of claims 1 to 3, in which two groups of leaf springs are provided, in which the hub portion of the driving shaft extends between the two groups and in which the extensions abut on both sides against the groups of leaf springs and between these groups have an arcuate surface -the diameter of which surface is greater than the spacing between the two groups of leaf springs in the operating pOsition.

5. A soil cultivating implement as claimed in claim 4, in which each group has at least four leaf springs and in which the thickness of each leaf spring is a maximum of 3 mm.

6. A soil cultivating implement as claimed in claim 4 or 5, in which the cultivating tines are located between the two groups of leaf springs and are nonrotatably connected to the tool holder.

7. A soil cultivating implement as claimed in claim 4 or 5, in which the cultivating tines are secured to the tool holder and the leaf springs are connected non-rotatably with the tool holder.

8. A soil cultivating implement as claimed in claim 6 or 7 in which the leaf springs are interconnected in the region of their outer ends by means of adjustable tension means and are mutally displaceable in their longitudinal direction.

9. A soil cultivating implement as claimed in claim 8, in which the adjustable tension means are screw shaped and project through the leaf springs and in which forthis purpose slots are formed in the plate springs extending in the longitudinal direction thereof.

10. A soil cultivating implement constructed and arranged to operate substantially as herein described with reference to and as illustrated in Figs.

1 and 2 or Figs. 3 and 4 of the accompanying drawings.