GB2031351A

GB2031351A - Additional Wheel Structure for a Tractor

Info

Publication number: GB2031351A
Application number: GB7836750A
Authority: GB
Original assignee: Unverferth Manufacturing Co Inc
Current assignee: Unverferth Manufacturing Co Inc
Priority date: 1978-09-14
Filing date: 1978-09-14
Publication date: 1980-04-23
Also published as: GB2031351B; BR7905858A

Abstract

Some tractor manufacturers are now offering new tractors having provision for mounting an additional wheel at the side of each driving wheel, and many operating advantages are claimed for this mode of operation. The invention provides an additional wheel structure, which may be applied to old, existing tractors by removing the wheel nuts and substituting eye nuts, engaging a number of toggle clamps (16) equal to the number of eye nuts with a tube (12) bent into a circle and welded into the inside rim of the additional wheel, placing each toggle clamp (16) opposite one of the eye nuts, placing the additional wheel at the side of the existing wheel with an annular spacer between the wheel rims, engaging hooks or J-bolts (23) connected to the toggle clamps (16) in the eyes of the eye nuts, and tightening the toggle clamps (16) to fix the additional wheel in position. <IMAGE>

Description

SPECIFICATION Additional Wheel Structure for a Tractor This invention relates generally to tractors for use in agriculture, and more particularly to the provision of an additional wheel structure for mounting at the side of each driving wheel of a tractor, and to a method of mounting the additional wheel.

Considerable interest has recently been shown in the possibility of mounting an additional wheel at the side of each driving wheel of a tractor and many advantages are claimed for the addition.

Since twice as many driving wheels are used improved traction and a higher pull on the tractor drawbar result. This enables operation at higher speeds, resulting in increased efficiency and the saving of time and money. A saving in fuel is also possible. In normal operation, tractor tyres are subject to a great deal of skidding, but by the use of extra wheels the amount of skidding is reduced, thereby reducing tyre wear. Since a much greater area of tyre is in contact with the soil there is less compaction of the soil, to give increased crop yields by allowing better root development, soil aeration and moisture intake. The additional wheels also improve the ability to operate efficiently on very soft, wet ground or on very uneven ground.Due to the higher tractive effort it is possible to pull larger and heavier accessories and, finally, there is a reduction in vibration, so that the driver has a more comfortable ride, thereby reducing fatigue.

Some tractor manufacturers are already providing new tractors which include provision for mounting the extra wheels when required, but the object of the invention is to provide a wheel structure and a method of mounting which enable an additional wheel to be attached to each driving wheel of an existing tractor in a very short space of time.

In one aspect, the invention provides a method of mounting an additional wheel at the side of an existing tractor driving wheel, comprising the steps of removing the wheel nuts from the existing wheel and substituting eye nuts, engaging a number of toggle clamps equal to the number of eye nuts with a tube bent into a circle and welded to the inside of the rim of the additional wheel, placing each toggle clamp in a position opposite one of the eye nuts, placing the additional wheel at the side of the existing wheel with an annular spacer band between the wheel rims, engaging hooks or J-boits connected to the toggle clamps in the eyes of the eye nuts, and tightening the toggle clamps to fix the additional wheel into position.

In another aspect the invention provides an additional wheel structure for mounting at the side of an existing tractor driving wheel comprising a wheel rim for the additional wheel, a tube bent into a circle with a gap between its ends welded on to the inside of the wheel rim, eye nuts for placing on the wheel studs of the existing wheel in place of the normal wheel nuts, an annular space band for placing between the rims of the two wheels, toggle clamps inserted in the opening between the ends of the tube and spaced around the tube to positions opposite respective eye nuts, and hooks or J-bolts connected to the toggle clamps engaged in the eyes of the eye nuts, the additional wheel being secured to the existing wheel by tightening the toggle clamps.

An embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a view of a wheel rim for a tractor including the invention; and Figure 2 shows the mounting of the additional wheel, to a iarger scale.

Referring to the drawings, Figure 1 is a view of the inside of a wheel rim 11 for a tractor. In accordance with usual practice there are numerous annular steps to provide high strength with minimum weight. A tube 12 is bent to a circle, with a gap 13 between its ends, and is welded in position in a step of the wheel rim.

In fixing the additional wheel the tractor is first driven on to a plank or step so that the tyre of the existing wheel is two or three inches above ground level. The customary whee! securing nuts are then removed one by one and replaced by eye nuts 1450 that the existing wheel is secured to the spider or driving flange 1 5 by the eye nuts.

The additional wheel is now placed at the side of the existing wheel with an annular spacer band between the rims of the two wheels. The spacer band is not visible in the drawings. A toggle clamp is then placed in position in line with each eye nut. The toggle clamp is an assembly which will be described in detail later. Each toggle clamp is placed in the gap 13 and then moved round the pipe 12 into a position in which it is opposite one of the eye nuts.

The toggle clamp comprises a tubular body 16 having a bore which is larger than the diameter of the pipe to allow a good clearance and is partly cut away, the gap being of such width that the toggle clamp may be slid on to the pipe 12 from the gap 13 and is then prevented from disengaging itself. The edge of the tubular portion rests between the pipe 12 and the surface 1 7 against which the pipe rests. A lug 1 8 projects outwardly from the body 1 6.

The toggle clamp comprises a bifurcated member 1 9 having two arms, respectively 20 and 21, with a sleeve 22 projecting at the opposite end to the arms 20 and 21. The sleeve is internally screw-threaded and receives a screwthreaded hooked member or J-bolt 23. The screw thread allows adjustment of the overall length of the toggle clamp. A lever 24 has an end portion which lies between the arms 20 and 21 of the member 19 and a pivot pin 25 connects the lever to the member 19. The inner end of the lever 24 is also bifurcated and is connected to the lug i8 of the body by a further pivot pin 26. The two pivot pins are so positioned that when the toggle clamp is in the operated or tightened-up position the pivot pin 26 is outside a line joining the centre of the respective eye nut and the pivot pin 25, so that the arrangement acts as a toggle or overcentre device. When the hooks or J-bolts 23 have been correctly adjusted in the sleeves 22 a considerable amount of force is required to pull the lever 24 into the operated or tightened-up position and for this purpose a tool consisting of a long hollow bar is provided. This is placed over the free end of the lever 24 and is used as a wrench to move the lever into the desired position. Once the toggle clamps have been adjusted by screwing the hooks or J-bars 23 into the sleeves 22 by the required amount the mounting of the additional wheel can be carried out in a few minutes, to provide all the advantages in tractor operation which have been noted earlier.

Claims

1. A method of mounting an additional wheel at the side of an existing tractor wheel, comprising the steps of removing the wheel nuts from the existing wheel and substituting eye nuts, engaging a number of toggle clamps equal to the number of eye nuts with a tube bent into a circle and welded to the inside rim of the additional wheel, placing each toggle clamp in a position opposite one of the eye nuts, placing the additional wheel at the side of the existing wheel with an annular spacer band between the wheel rims, engaging hooks or J-bolts connected to the toggle clamps in the eyes of the eye nuts, and tightening the toggle clamps to fix the additional wheel into position.

2. A method according to claim 1, comprising the steps of initially driving the tractor on to a plank or step so that the wheel to which the additional wheel is to be attached is above ground, removing one wheel nut and substituting an eye nut, and continuing to remove wheel nuts and substitute eye nuts one at a time.

3. An additional wheel structure for mounting at the side of an existing tractor driving wheel comprising a wheel rim for the additional wheel, a tube bent into a circle with a gap between its ends welded on to the inside of the wheel rim, eye nuts for placing on the wheel studs of the existing wheel in place of the existing wheel nuts, an annular spacer band for placing between the rims of the two wheels, toggle clamps for insertion in the gap between the ends of the tube and spacing around the tube to positions opposite respective eye nuts, and hooks or Jbolts connected to the toggle clamps for engagement in the eyes of the eye nuts, the additional wheel being secured to the existing wheel by tightening the toggle clamps.

4. A structure according to claim 3, in which the toggle clamp comprises a tubular body having a bore which is larger than the diameter of the tube and is partly cut away, so that the toggle clamp may be slid on to the tube from the gap between the ends of the tube, a bifurcated member having two parallel arms projecting at one end and a sleeve projecting at the opposite end, the sleeve being internally screw-threaded to accept the hooked member or J-bolt, a lever having an end portion lying between the said two parallel arms and connected by a first pivot pin to the bifurcated member and by a second pivot pin to a lug of the body, the two pivot pins being so positioned that when the toggle clamp is in the operated or tightened position the second pivot pin is outside a line joining the centre of the respective eye nut and the first pivot pin, thereby producing the toggle action.

5. A method of mounting an additional wheel at the side of an existing tractor driving wheel, substantially as herein described, with reference to and as illustrated in the accompanying drawings.

6. An additional wheel structure for mounting at the side of an existing tractor driving wheel, constructed and arranged substantially as herein described, with reference to and as illustrated in the accompanying drawings.