GB2148084A

GB2148084A - Tine attachment assemblies

Info

Publication number: GB2148084A
Application number: GB08426846A
Authority: GB
Inventors: David Eric Patterson; Charles David Richardson; Howard William Chandler
Original assignee: National Research Development Corp UK
Current assignee: National Research Development Corp UK
Priority date: 1983-10-25
Filing date: 1984-10-24
Publication date: 1985-05-30
Also published as: GB8328459D0; GB8426846D0

Abstract

Rigid tines 12 are connected with the frame member 24 of a cultivator or like soil-working implement by a parallelogram-shaped linkage 14 including a tensioned resilient block 23 designed to bias the arrangement into the tine-closed position shown. The resilient nature and relative dimensions of the linkage allow the tines 12 to vibrate in a backwards and forwards soil-shattering motion with little change in the depth of work. The parallelogram nature of the linkage ensures that throughout this vibratory motion the angle of attack of the tine shares remains substantially unchanged. In alternative embodiments, the resilience is provided by trapped resilient elements in compression or by one or more tension bars or spring steel members. <IMAGE>

Description

SPECIFICATION Tine attachment assemblies The present invention relates to tine attachment assemblies for cultivators and like soil-working implements.

The fixed tine chisel plough was used fairly widely in the 1960's and early 1970's as a means of speeding up cultivators and providing less clods than traditional ploughing.

With the introduction of direct drilling and further moves to shallower cultivations, the fixed tine cultivator became less popular because of the rather cloddy tilth produced compared to the newer techniques. In this period the heavy duty spring tine cultivator became very popular and currently it has largely displaced the fixed tine cultivator. The major advantage of the heavy duty spring tine cultivator is its ability to shatter soil and produce a suitable tilth from cereal stubble. However, over the last few years, farmers have found that the heavy duty spring tine cultivator has a major disadvantage. On cereal stubble, the spring tine leg moves backwards altering the angle of incidence of the share to the soil surface, thus reducing significantly its ability to penetrate into the soil.Various manufacturers have attempted to overcome this problem by reducing this movement in their machines but there is still a difficulty of penetration with the best of them.

An object of the present invention is to provide a means whereby the advantages of existing spring tine cultivators can be retained without their attendant disadvantages.

According to the present invention, an attachment assembly for attaching one or more rigid tines to the frame of a cultivator or like soil-working implement comprises a resiliently-varying parallelogramshaped linkage dimensioned so as to allow only a substantially backwards and forwards vibratory motion of the one or more tines when so attached.

The fact that the linkage will collapse and expand resiliently means that the implement will in use exhibit the soil-shattering vibration associated up to now only with spring tine cultivators. The fact that the linkage is a parallelogram linkage, will ensure that throughout this vibratory motion the tine shares will maintain substantially the same angle of incidence to the soil surface so that penetration efficiency is not impaired. The fact that the parallelogram linkage is dimensioned so as to allow only a substantially backwards and forwards vibratory motion of the tines will ensure that the depth of work of the tines will only be subject to minimum variations in use of the assembly, e.g. not more than plus or minus 5% of the depth of work.

Conveniently, the resilience is provided by one or more tensioned resilient elements and/or by one or more compressed resilient elements and/or by one or more torsion bars or spring steel members.

The invention also includes a tine assembly incorporating the attachment and a cultivator or like soil-working implement, e.g. sub-soiling equipment, when incorporating the tine assembly.

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figures 1 and 2 show partially diagrammatic side views of a first tine assembly at two different extremes of the vibratory motion; and Figures 3 and 4 show partially diagrammatic sections of part of a second embodiment in the same positions.

Thus referring now to the drawings, a mounting member 10 for one of a plurality of rigid tines 12 forms part of a parallelogram linkage 14 comprising a second member 16 and two pairs of pivotted links.

These links join the two members together for relative movement in a horizontal plane. Only one link of each pair (identified by reference numerals 18,19) is visible in the drawing.

Bonded to the member 16 and the shafts 20 joining the links 18, 19 is a rectangular block 23 of tensioned resilient material, such as rubber for example. The block 23 embraces a frame member 24 of the cultivator and, being in tension, it will urge the members 10, to their minimum separation position shown in Figure 1 but wili nevertheless also allow the tines to move from the "closed" position of Figure 1 to the "open" position of Figure 2 if soil conditions so require. Stops (not shown) will preferably be provided to limit this movement of the tines.

Variations in depth of work of the tines because of the arc of movement of links 18, 19 will be minimal because of the relatively short length of these links compared with the work depth of the tines.

The arrangement is biassed towards the Figure 1 position by virtue of the torsional stresses produced in the block 23 by the clockwise rotation of the bonded shafts 20 as the links move towards their Figure 2 position.

If desired, the top member 16 of the assembly and, optionally, the resilient block 23, can extend across the full width of the implement to serve as a common element for each tine assembly.

Alternatively, each tines may be separately attached to the frame member 24 by its own individual linkage 14 and this will normally be the preferred arrangement.

A suitable proprietory item for providing the resilient couplings illustrated in Figures 1 and 2 is a Flextor Unit as currently available from Bramber Engineering Limited of Sheffield.

In an alternative embodiment, the tensioned resilient block or blocks 23 of the first embodiment are replaced by two or two pairs of compression units (one for each pair of links 18, 19). One of these units is indicated by reference numeral 25 for links 18 in Figures 3 and 4 which depict the two extremes of position shown in Figures 1 and 2.

As will be seen, unit 25 comprises, in essence, a square-sectioned casing 27 containing four solid cylindrical elements 29 of rubber or other suitably resilient material. The elements 29 are pressed into the corners of the casing 27 by a square-sectioned block or blocks 31 secured to the top ends of links 18.

In use, as the links rotate anti-clockwise from the unloaded position of Figure 3 towards the fully loaded position of Figure 4, each of the elements 29 will be increasingly compressed by the elementengaging face of the associated block 31 so that on removal of the load, these elements will urge the block 31, and with it the associated links 18 (or 19) back towards the Figure 3 position.

A suitable proprietory item for units 25 is Indespension Unit currently available from Mechanical Services (Trailing Engineering) Limited of Bolton.

In a further alternative, the resilient blocks 23 of Figures 1 and 2 could be used for one pair of links and the solid cylindrical elements 29 could be used for the remaining pair.

In place of the rubber block or blocks 23 and the resilient elements 29, any other suitably resilient means may be used instead in any of the various arrangements referred to above. For example one or more torsion bars could be used for this purpose or one or more spring steel members etc.

It is an advantage of the illustrated assemblies that they can readily be fixed to the original frames of conventionally-designed fixed-tine cultivators.

Claims

1. An attachement assembly for attaching one or more rigid tines to the frame of a cultivator or like soil-working implement comprising a resilientlyvarying parallelogram-shaped linkage dimensioned so as to allow only a substantially backwards and forwards motion of the one or more tines when so attached.

2. An assembly as claimed in Claim 1 in which the resilience is provided by one or more tensioned resilient elements.

3. An assembly as claimed in Claim 1 or Claim 2 in which the resilience is provided or is also provided by one or more compressed resilient elements.

4. An assembly as claimed in Claim 1, Claim 2, or Claim 3, in which the resilience is provided or is also provided by one or more tension bars or by one or more spring steel members.

5. An assembly substantially as hereinbefore described with reference to and/or as illustrated in Figures 1 and 2 or Figures 3 and 4 of the accompanying drawings.