GB2159113A - Bottom shield for tractors - Google Patents

Abstract

A bottom shield which forms a smooth streamlined undercarriage cover for use when the tractor is driven in high crops consists of a twistable frame (1) across which a smooth cloth of e.g. tarpaulin material is stretched tightly. The frame is mounted under the tractor (T) between its wheels. in front the frame is connected to the front axle (A) and is designed to move with the latter so that the frame is twisted. Hence the bottom shield can be mounted as close as possible to the tractor undercarriage and thus prevent damage to the crop when the tractor is driven through it. The bottom shield has an inclined front end (11), and at the rear it is extended backwards under a lift-suspended field sprayer (S). The frame carries straw dividers (12, 13) in front of the tractor wheels. The bottom shield can be suitably adjusted sidewise and lengthwise for adaptation to different track widths and tractor types. <IMAGE>

Description

SPECIFICATION Bottom shield for tractors The invention relates to a bottom shield for tractors, and as further defined of the kind mentioned in the introduction to claim 1.

When the tractor is driven through high crops, e.g. during spraying of grain or rape at a late stage of growth, the crop is subjected to considerable driving damage, i.e. damage caused by wheels and undercarriage by flattening the crop in the wheel tracks and breaking ears and straws under the tractor. A direct waste of grains also occurs when a crop is sprayed immediately before harvest, e.g.

against couch grass, in which case the grains are easily shaken off the ears or bellows during passage of the tractor. It is a well-known fact to equip the tractor with straw dividers mounted in front of the wheels and having the effect of forcing the stems to the sides of the wheel tracks. When the sprayer is of the towed type, it is also equipped with straw dividers.

Straw dividers can to a certain degree prevent direct flattening of the crop in the wheel tracks, especially when the field is laid out with wheel tracks, but the straw dividers have incidentally no influence on the damage caused by the undercarriage, i.e. wheel axles, steering, rear-axle assembly, etc. This damage can be limited by equipping the tractor with a smooth streamlined bottom cover.

The bottom cover has the effect that crops are passed in a more sliding and thus careful way. A bottom cover is known in the form of a rigid plate shield for mounting on a Land-Rover or a similar vehicle. This bottom cover is not suited for ordinary farming tractors, primarily because of the considerably mobility of the front axle which cannot take place within the rigid bottom sheild.

For the purpose of eliminating the said disadvantage, it is proposed according to the invention to arrange the bottom shield as specified in the characterizing part of claim 1. In the form indicated the bottom shield is arranged to follow the movements of the front axle since the bottom cover as a whole can be twisted. Hence the bottom shield can be mounted close to the tractor bottom (front axle, steering, rear axle assembly, etc.) which is the primary requisite of the least possible damage to a crop during passage through it. The cloth stretched on the frame can, if required, have a special friction-reducing smooth surface, e.g. teflon or polyamide. The smooth surface reduces the damage further by allowing the crop (stems and ears) to pass over the bottom in a sliding even stream.

When the crop is close to being ripe with the risk of grains falling off, this careful treatment is very important.

The bottom shield is relatively cheap to manufacture and easy to mount and dismount. The twistability is obtained in special frame joints or by making the frame of a flexible material, e.g. spring steel or plastic. In an embodiment as specified in claim 2 the frame can easily be adapted to different tractor models and track widths. The mounting irons of the frame are, as far as possible, arranged for universal mounting on typical tractor elements such as front axle and drawbar. These elements are only slightly different from one tractor make to another. The adjustability and twistability of the frame are according to the invention obtained expediently as specified in claim 3. The profiled pipes are easy to assemble in twistable and telescopic pipe joints without major constructional arrangements.The pipe joints, which only have to be adjustable lengthwise, are arranged with slits and external clamping bolts in a way known in itself to squeeze the outer pipe together on the inner pipe.

Mounting of the covering cloth is done expediently as specified in claim 4. The cloth can then easily be adapted to the frame in its different sizes.

By mounting straw dividers as specified in claim 6 directly on the frame, the expenditure of special mounting irons for the straw dividers can be saved.

The invention is to be explained further in connection with a preferred embodiment shown on the drawing, where Figure i shows a bottom frame, viewed from above, with the covering cloth removed, Figure 2 the bottom frame with appertaining straw dividers, shown mounted on a tractor, Figure 3 a section showing the front axle mounting irons of the frame, viewed in the direction of arrow III in Figure 2, and Figure 4 the rear mounting irons of the frame, viewed in the direction of arrow IV in Figure 2, in an enlarged section.

In the embodiment shown on the drawing the bottom shield consists in all essentials of a profiled pipe frame 1 and a cloth of tarpaulin material stretched tightly over it. The cloth, which is fixed with strings, or similar fixing materials, is not shown on the drawing.

The frame 1 is designed for mounting under a tractor T (Figure 2) with a front frame section la connected to the front axle A and a rear frame section ib connected to the drawbar supporting iron.

The frame sections are composed of longitudinal side members 2 and a number of cross members 3.

The frame 1 is made of pipes of different dimensions. The pipes have telescopic joints for length adjustment. These pipe joints are located partly in the side members 2 of the frame, and partly in the cross members 3 so that the frame can be adjusted both lengthwise and sidewise. The two sections 1a and 1b are assembled in the same way by telescoping the side members into each other. The width of the front section la is adapted to the distance between the front wheels, their steering angles being taken into account. The rear section 1b is adapted to the distance between the rear wheels.

During the motions of the front axle A the frame is twisted in its entirety since the front frame section 1a follows the front axle, and the rear section ib follows the rigid tractor body. The twistability of the frame is a result of the mobility of the single pipe joints since the telescoped pipes can be turned relative to each other.

The front mounting irons of the frame 1 are shown in Figure 3. The mounting irons, which are placed with one on either side, are designed for bolting to the side of the front axle A in the holes which have already been made in the axle for tread adjustment. The mounting iron on either side consists of a butt-strap 4, a vertically adjustable supporting rod 5, a cross girder 6, and a cross member 3 welded to it which are included in the front section 1a of the frame. The length of the cross girder 6 can be adjusted owing to the adaptation of the frame to different tractor front axles.

The butt-strap 4 is bolted to the front axle and is provided with oblong bolt holes 4a for this purpose.

The rear mounting irons of the frame are shown in Figure 4. A horizontal fixing piece 7 designed for bolting to the lower side of the drawbar bearing housing has a tubular traverse 8 on the lower side.

This traverse is connected to a cross member 3 through arms 9 and butt-straps 10. The cross member 3 is part of the rear section 1 b of the frame. The cross member has a clamping device 3a for fixing the frame adjustment sidewise. The clamping device 3a is of the usual type with a pipe slit and clamping bolts.

The rear section 1b is extended backwards under a lift-suspended field sprayer S Figure 2. The front section 1a has an upwards inclined front end 11 which imparts a runner shape, which is aimed at, to the bottom shield. The frame 1 carries straw dividers 12 in front of the rear wheels of the tractor.

Other straw dividers 13 are mounted with connection to the front wheel suspension and follow the front wheel steering angles. In the cases where the field sprayer is of the towed type, the field sprayer is provided with a separate bottom shield. This shield may be arranged in the same way as described in the foregoing.

In a preferred embodiment, the lift-suspended field sprayer is also provided with a separate bottom shield so that the sprayer can be lifted and lowered freely.

Claims (7)

1. A bottom shield for tractors and of the kind which forms a smooth streamlined undercarriage cover, especially for use during driving in high crops; for example, during spraying at a late stage of growth, characterized in that it chiefly consists of a twistable frame (1), mounted under the tractor (T) between its wheels, which frame is fixed with a front frame section (1a) connected to the front axle (A) in order to be able to move together with it, and a rear frame section (1b) rigidly connected to the drawbar or some other fixed structural member at the rear of the tractor, and that a smooth cloth of flexible foil of textile material, preferably a laminated material of tarpaulin quality, is stretched tightly over the frame (1) so that it forms a streamlined unbroken cover under the tractor, chiefly of a runner shape.

2. A bottom shield as claimed in claim 1, characterized in that the frame (1) can be adjusted sidewise and lengthwise, chiefly by adjustment of either frame section (1a, 1b) separately, for adaptation to different shaft distances, track widths, and tractor types.

3. A bottom shield as claimed in claim 1 or 2, characterized in that the frame is chiefly formed of profiled pipes of different dimensions, which pipes are telescoped into each other so that movable (twistable) joints are obtained where they are assembled, and that the adjustability sidewise and lengthwise is due to the telescopic effect of the profiled pipes in the said andlor other pipe joints.

4. A bottom shield as claimed in claim 1, characterized in that the covering cloth is provided with eyelet holes along the edges, and that the cloth is stretched tightly over the frame by means of strings or similar fixing materials which are attached to the frame after its adjustment lengthwise and sidewise.

5. A bottom shield as claimed in claim 1, characterized in that the bottom shield is extended backwards under a sprayer (S) suspended from the tractor lift, or alternatively forms an independent shield under a towed field sprayer.

6. A bottom shield as claimed in claim 1, characterized in that the frame (1) carries straw dividers (12, 13) at least for the rear wheels of the tractor.

7. A bottom shield for a tractor, substantially as hereinbefore described with reference to and as shown in the accompanying drawings.