Tractor with a mudguard

Abstract: A tractor has a mudguard 18 overlying a steerable wheel 16 of the tractor. The mudguard 18 is mounted for rotation with the wheel about a generally vertical axis and for pivotal movement relative to the wheel about a generally horizontal axis 24 parallel to the rotational axis of the wheel. A cam 32 causes the mudguard 38 to pivot about the horizontal axis 24 at least when the wheel 16 is approaching one of its maximum steering lock positions.

Description: The present invention relates to a tractor having a mudguard or fender mounted above a steerable wheel of the tractor. A tractor according to the preamble of claim 1 is known from US-A-5 169 167. If in a tractor the mudguards of the steerable wheels are mounted in a fixed position in relation to the body, then they do not offer adequate protection while the tractor is being steered. For this reason, the mudguards have previously been mounted on the axle for movement with the wheels about a generally vertical axis. There is however a problem with such an arrangement in that the steerable wheels of a tractor can rotate to a point where they come very close to the body of the tractor. For this reason, if the mudguards are fixed in relation to the wheel, they tend to foul the body when the wheel is near its maximum steering lock. Of course, such fouling must be avoided to prevent damage and in order not to restrict the turning circle of the tractor. In order to avoid the mudguards of steerable wheels fouling the body of tractor, it has already been proposed to provide complex linkages that steer the mudguards about a vertical axis relative to the axle and the wheel during steering movements so that in effect the mudguard rotates through a smaller angle than the wheel and avoids collision with the tractor body see e.g. FR-A-2 595 313. In its simplest form, such a linkage can merely introduce a lost motion between the mudguard and the wheel at the end of its travel to allow the mudguard to come to a rest away from the tractor body while the steerable wheel continues to rotate. In more complex linkages, the mudguard constantly rotates through a smaller angle than the steerable wheel over the entire steering range. Apart from the complexity inherent in such prior art proposals, they have the disadvantage that the mudguard does not fully overlie the wheel at the limit of steering movements and its effectiveness when the tractor is on full steering lock is reduced. It is therefore an object of the present invention to mitigate the foregoing disadvantages of the prior art. According to the present invention, a tractor is provided having a mudguard overlying a steerable wheel of the tractor, wherein the mudguard is mounted for rotation with the wheel about a generally vertical axis and for pivotal movement relative to the wheel about a generally horizontal axis parallel to the rotational axis of the wheel and wherein means are provided for causing the mudguard to pivot about the said horizontal axis at least when the wheel is approaching one of its maximum steering lock positions. The means for causing the mudguard to pivot may suitably comprise a wedge or cam surface fixed to the axle of the steerable wheel and acting on a member fixed in relation to the mudguard. The invention will now be described further, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a schematic plan view of a tractor, showing the position at which a mudguard risks fouling the body of the tractor; Figure 2 schematically shows the mounting of a mudguard above a steerable wheel; Figure 3 is generally similar to Figure 2 and shows the position adopted by the mudguard to avoid the fouling that is shown in Figure 1; and Figure 4 schematically shows a mechanism for pivoting the mudguard from its position in Figure 2 to its position in Figure 3 as the wheel approaches its maximum steering lock in one direction. Figure 1 shows a tractor having a body 10 with a front axle 12 and a rear axle 14. The front wheels 16 are steerable and each has a mudguard 18 that rotates with it about a vertical axis. As represented by the circle designated 20, there is a risk of the mudguard 18 fouling the body 10 when the tractor is being driven with a full steering lock. In the case of the illustrated tractor, it is only the rear end of a mudguard 18 that risks colliding with the tractor body but it is also possible that there may be a risk of fouling at the front end of the mudguard. To avoid the mudguard 18 fouling the body of the tractor 10, it is mounted in the manner shown in figure 2 on an L-shaped bracket 22 that is secured by means of a hinge 24 to a plate 26 fixed in relation to the top of the king pin for rotation with the wheel about a vertical axis. The second arm 28 of the L-shaped bracket 22 is connected to the plate 26 by means of a retraction spring 30 that pulls the bracket 22 into the position shown in Figure 2. As shown in Figure 4, a wedge or cam 32 is stationary mounted on the axle beam to cause the arm 28 to rotate through an angle α about the hinge 24 when the wheel approaches its maximum steering lock. This causes the bracket 22 to rotate about the wheel axis into the position shown in Figure 3 in which the rear end of the mudguard is pushed forwards to avoid fouling of the tractor body. In this position the mudguard 18 remains above the wheel and continues to provide protection against the spraying of mud. While the arrangement of a wedge has only been described with reference to pivoting the mudguard 18 forward when its rear end risks fouling the vehicle body, it is possible in an analogous way to provide for the mudguard 18 to pivot backwards if its front end should risk fouling the tractor body. While a wedge or a cam surface 32 fixed to the axle provides a convenient manner of tilting the mudguard about the wheel, it will be appreciated that lever linkages may be used to achieve the same effect of pivoting the mudguard to avoid its rear or front end from fouling the tractor body when the steerable wheel that it overlies approaches a maximum steering lock position.

Claims: A tractor having a mudguard (18) overlying a steerable wheel (16) of the tractor, wherein the mudguard (18) is mounted for rotation with the wheel (16) about a generally vertical axis; and the mudguard (18) is further mounted for pivotal movement relative to the wheel (16) about a generally horizontal axis (24) parallel to the rotational axis of the wheel (16), characterized in that means (32) are provided for causing the mudguard (18) to pivot about the said horizontal axis (24) at least when the wheel (16) is approaching one of its maximum steering lock positions. A tractor according to claim 1, characterized in that the means for causing the mudguard (18) to pivot comprises a wedge (32) or cam surface fixed to the axle of the steerable wheel (16) and acting on a member (28) fixed in relation to the mudguard (18). A tractor according to claim 2, characterized in that the member (28) is part of an L-shaped bracket (22) supporting the mudguard (18). A tractor according to claim 3 characterized in that the L-shaped bracket (22) is pivotable about a hinge (24) and is spring-biased towards a neutral position.

Inventors: SKELCHER MICHAEL D, SKELCHER, MICHAEL D.
Applicants: CNH UK LTD, CNH U.K. LIMITED
Application year: 2000
Main classification: B62D25
IPC codes: B62D25