TRACTOR COUNTERWEIGHT ASSEMBLY

The invention relates to a counterweight assembly for attachment to the front or rear of a tractor.

The continuing trend for agricultural machinery to grow in size goes hand-in-hand with the increasing size and power of tractors. Technical advances have allowed the power of tractors to increase without a proportionate increase in overall weight. In some applications this is advantageous, for example where soil compression is to be avoided. However, in order to transmit the power of the tractor to the ground without excessive wheel slippage, it is known to provide counterweights on either the front or the rear of the tractor depending on the application.

US-2007/0261866 discloses a single-piece tractor weight which can be attached to the three- point linkage of the tractor by means of transverse pins and a top-link hitching point. The weight can be attached to the front or the rear of the tractor.

In accordance with a first aspect of the present invention there is provided a counterweight assembly for attachment to a front or rear attachment point on a tractor, the assembly comprising a main weight block having an upper face, a lower face and attachment means to engage with said attachment point, and a plurality of further weight blocks, wherein at least one of the upper face and lower face serves to cooperate with a surface of one of said further weight blocks, wherein the further weight blocks are stacked in a vertical direction and locked in position relative to the main weight block, each further weight block being locked to an adjacent weight block by respective locking means to allow each further weight block to be secured in position one at a time. Advantageously, the provision of separate locking means allows a user to add or remove one further weight at a time.

The vertical stacking of additional weights permits the locking together of the weights without the need to provide separate lifting means simultaneously to hold the weights in position. An additional weight block can be simply lifted atop the main weight block where it will remain supported whilst the respective locking means are secured.

Preferably, both the upper face and the lower face serve to cooperate with respective surfaces of the further weight blocks, thereby increasing the capacity of the assembly to accept further

cooperating weight blocks by simply stacking weights onto both the top and the bottom surfaces of the first weight. This delivers a simple route to balancing the additional weight around the main weight and prevents significant movement of the original position of the centre of mass.

In a preferred embodiment, the main block further comprises a plurality of horizontally extending parallel slots for receiving fork prongs of a fork-lift truck. This allows the main weight block to be easily handled when not attached to the tractor. Furthermore, in the case of the main block being attached to the front of a tractor by means of engagement with a lip on the tractor frame, a fork-lift truck can be employed to lift the weight onto the tractor with little hassle.

In another embodiment of the invention, the assembly comprises sets of aligned holes extending through the further weight blocks, wherein each respective locking means comprises bolts inserted in one of said set of aligned holes. This allows the user to simply stack weight blocks onto the main weight block and slide a bolt through the aligned holes thus securing them in place relative to one another one at a time.

Horizontal movement between the first and second weight blocks can be restricted by including at least one raised projection, or lug, and a cooperating receiving indent on the respective adjacent cooperating surfaces. This aids in aligning the weight blocks with respect to one another before the locking means are engaged.

The assembly may be attached to the tractor by one of a number of means. In the case where three-point linkage is adopted the attachment means may comprise an upright post which provides the top link attachment point for the linkage and is inside the outline of the first weight block, and wherein the second weight block includes a receiving slot which aligns with the post when locked to the first weight block. Advantageously this exploits the upright post to provide a means of aligning the second, and any subsequent, weight blocks to the first weight block, and provides a means to prevent, to some degree, horizontal movement between the weights.

The assembly may further comprise a recess on each of two opposing vertical faces, the recesses each serving to receive a drawbar of an attached implement.

The invention provides a flexible and simple route to stack multiple weights together. Any weight blocks added to the main (or first) weight block therefore preferably comprise an

upper face and a lower face, both of which include a cooperating surface which each serves to cooperate with a surface of an adjacent further weight block. This allows a simple laminate- type structure to be constructed comprising a plurality of weight blocks stacked in a vertical direction and all locked in position relative to the main weight block.

In accordance with a second aspect of the invention there is provided a weight block suitable for use with an assembly according to the first aspect of the invention and having an upper face and a lower face which each serve to cooperate with a surface of a respective further weight block.

Further advantages will become apparent from the following description of the invention, by way of example only, with reference to the accompanying drawings in which:

Figure 1 is a perspective, partially exploded, front view of a tractor counterweight assembly according to one embodiment of the invention;

Figure 2 is a perspective rear view of the tractor counterweight assembly of Figure 1 ;

Figure 3 is a perspective, partially exploded, rear view of a tractor counterweight assembly according to a second embodiment of the invention; and,

Figure 4 is a perspective, exploded rear view of the tractor counterweight assembly of Figure 3.

Referring to the Figures 1 and 2, a counterweight assembly 10 comprises a first weight block 11, a second weight block 12, and third, fourth and fifth weight blocks referenced at 13, 14 and 15 respectively. The first weight block 11 has an upper face 21, a lower face 22, a front face 23, a rear face 24, and two side faces 25.

The first weight block 11 further comprises first and second attachment means disposed on the front and the rear face respectively.

On the front face 23 there is disposed a hook-shaped member 30 for engagement with a lip on the forward end of a tractor (not shown), the member 30 being mounded as an integral part of the first weight block 1 1. By means of simply lowering the assembly 10 onto the forward end of the tractor, the hook-shaped member 30 can hook over the lip, provided on most tractor models. The significant weight of the assembly 10 serves to hold the hook-shaped member 30

in position on the tractor. However, if desired, further locking means can be provided to lock the assembly to the front of the tractor.

On the rear face 24 there is provided means for attachment of three-point linkage, typically provided at the rear of tractors and also often provided at the front. This includes two arm- hitching points 41, 42 and a top-link hitching point 43. The arm-hitching points 41, 42 each comprise holes in the first weight block for receiving a transverse pin (not shown) which engages with respective linkage arms provided on the rear or front of a tractor. The top-link hitching point 43 is provided on a post 45 which is removably secured to the rear face 24 of the first weight block 11 by means of two bolts (not shown) inserted through a securing plate 46 and corresponding holes 45a provided in the post 45. Simple tightening of the bolts clamps the securing plate 46 against the post 45, thereby holding it in position.

The assembly 10 can be mounted to the front of a tractor using either the hook-shaped member 30 hooked over the front lip, or using the three-point linkage 41, 42, 43. Furthermore, the assembly can be mounted to the rear of the tractor also using the three-point linkage 41, 42, 43.

This arrangement is particularly advantageous in the case where the user does not have access to a front loader which is a common conventional means used to lift and lower weight blocks onto the front lip of a tractor. The arrangement allows the assembly 10 to be simply mounted on the front or rear three-point linkage of a second tractor which can then transfer the assembly onto the front lip of the receiving tractor by simple lifting and lowering of the linkage. This significantly increases the flexibility in the use of the weight assembly 10 allowing the user to simply attach and detach the weight when required using limited resources.

The post 45 can be easily removed from the assembly 10 when not required. This permits better forward visibility when the assembly 10 is mounted on the lip at the forward end of the tractor for example.

The first weight block 11 is provided with drawbar receiving means in the form of a recess 48 on both the front and rear faces 23, 24. Therefore, when the assembly is mounted to a tractor by either attachment means, an implement can be attached to the assembly using a drawbar pin inserted through holes 49 provided in the recess. Examples of such implements include harrows and trailers.

In accordance with the invention, the weight blocks 1 1, 12, 13, 14, 15 are stacked in a vertical direction wherein, in this arrangement, the second weight block 12 is disposed on top of the first weight block 1 1, and the third, fourth and fifth weight blocks 13, 14, 15 are disposed underneath. Each weight block is provided with a pair of horizontally extending parallel slots 50 for receiving fork prongs of a fork-lift truck or front loader for example.

The second weight block 12 (and further weight blocks) can be added to the first weight block by simply lifting the weight blocks into place using a front-loader for example using the slots 50 provided.

The upper face 21 of the first weight block 11 serves to cooperate with the lower face of the second weight block 12, and comprises a raised projection 51 formed in the surface of the upper face 21. The projection 31 engages with a cooperating receiving indent (not shown) disposed on the lower face of the second weight block 12 and restricts horizontal movement between the first and second weight blocks 11, 12. This aids alignment of the second weight block 12 with the first weight block 11 when being attached. It will be appreciated that the projection and associated indent can take the form of any shape, size or number whilst still providing the same benefit. Moreover, the projections and indents can be provided on the opposite and adjacent surfaces.

The upright post 45 is inside the outline of the first weight block 11 provided by the rear face 24. The second weight block 12 (and each additional weight block) includes a receiving slot 55 which aligns with the post 45. This advantageously provides a means of horizontal alignment when the second weight 12 is being lowered into place using a front-loader for example.

Bolts 60 are inserted, and secured with nuts, in aligned holes 61 extending through the first weight block 11 and the second weight block 12 to lock them in position relative to one another.

Both the upper and lower faces of all weight blocks 11, 12, 13, 14, 15 serve to cooperate with adjacent weight blocks. For example, the upper face 71 of the second weight block 12 comprises a raised projection 75 which can cooperate with the lower face of a further weight block should one be so added.

The third weight block 13 is attached to the lower side of the first weight block 1 1. This can be done by the user simply lifting the third weight block into place, using a front loader for

example, and inserting bolts 60 through the aligned holes 61 provided. Subsequently, the fourth and fifth weight blocks 14, 15 can be mounted in the same way.

The horizontally extending and vertically aligned cut-outs 61 are arranged in two columns. Alternate columns are used to hold the respective bolt 60 in place for adjacent cooperating surfaces. For example, the third weight block 13 is secured to the first weight block 11 by a bolt inserted in the first column of cut-outs 61a. However, the fourth weight block 14 is secured to the third weight block 13 by a bolt inserted in the second column of cut-outs 61b.

The arrangement of two columns of cut-outs 61 as shown in the figures has two advantages in particular. Firstly, the cut-out 61 allows the respective bolts 60 to be slid in sideways which is a quick and easy route to locating the bolt. Secondly, the alternate use of the respective columns allows the simple addition and removal of individual additional weight blocks 13, 14, 15... etc, without having to interfere with the locking means of the other weight blocks already attached.

Despite the advantages of the horizontally extending cut-outs, it will be appreciated that vertical holes could instead be employed wherein the bolt heads and retaining nuts may be recessed into the sidewall of the weight block assembly.

The arrangement shown in Figures 1 and 2 therefore comprises a first weight block 11 having a second weight block 12 atop, and three weight blocks 13, 14, 15 mounted underneath. By incorporating the flexibility to add any number of further weight blocks either on top or underneath the main weight block 11, the assembly can be easily tailored to the users requirements.

For example, as shown in Figures 3 and 4, the assembly 10 can be arranged to have the second and third weight blocks 12, 13 stacked on top of the first weight block, whereas only the fourth and fifth weight blocks 14, 15 are fixably mounted to the lower face 22.

Although the described embodiments comprise a hook-shaped member disposed on the front face 23 of the first weight block, it is envisaged that this could instead be disposed on a side face 25.

In summary, there is provided a counterweight assembly for attachment to a front or rear attachment point on a tractor. The assembly comprises a main weight block having an ur^pr face and a lower face which serve to cooperate with respective surfaces of further weight

blocks which can be added, in a vertical stacking manner, as required by a user. The further weight blocks are locked in position relative to the main weight block by separate locking means. This allows each further weight block to be secured in position one at a time.