GB1560392A

GB1560392A - Tipping vehicle

Info

Publication number: GB1560392A
Application number: GB27098/76A
Authority: GB
Original assignee: OAH HOMES Ltd
Current assignee: OAH HOMES Ltd
Priority date: 1975-08-08
Filing date: 1976-06-29
Publication date: 1980-02-06
Also published as: IT1076926B; CA1073501A; ZA755124B; ES450538A1; DE2635419A1; AU1657076A; FR2320207A1; NL7608569A; JPS5220518A; BR7605063A; ZM7676A1

Description

(54) TIPPING VEHICLE (71) We, O. A. T. HOMES (PRO PRIETARY) LIMITED, a company registered according to the laws of the Republic of South Africa, of 19 Anemone Road, Primrose, Germiston, Transvaal, Republic of South Africa, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to tipping vehicles, such as trucks, semi-trailers and special units having a tipping body, which are used for transporting materials such as sand and bricks, and in particular to a mechanism for effecting tipping of the body either to the rear or to the side of the tipping vehicle.

According to conventional practices, the tipping body is pivotally connected to the chassis of the vehicle along a horizontal transverse axis located towards the rear of the chassis or a horizontal longitudinal axis towards the centre of the chassis. A hydraulic ram (or in some cases a plurality of rams) is connected directly, or by a com- pound lever system or other components between the chassis and the body to effect tipping when needed. Lever systems are used to ensure effective application of the thrust of the ram or to amplify the elongation or stroke of a short ram.

It is necessary for the tipping mechanism to be as compact as possible, and for this reason the ram lies as close to the horizontal as possible when the body is in its normal lowered position. Very large forces are exerted in the ram and on its mountings during the first stages of tipping, when the direction of movement of the tipping body is at a relatively large angle to the axis of the ram. For this reason a powerful ram must be used if the maximum load permitted by road traffic legislation is carried by the vehicle, and extremely robust supports must be provided to withstand these forces in any stress-bearing members on which the ram is mounted and, if they are employed, in the linkages of the lever system and in their mountings on the ve hiele chassis. Robust supports must also be provided for any other members to which these forces are transmitted.

A cylinder of 15 to 20 cm. diameter is usually used for the ram. With a cylinder of this size the extended length of the ram is, for reasons well known in the art, substantially less than the extended length of a ram having a cylinder of smaller diameter and the same retracted length as the large ram.

An object of the invention is to provide a tipping vehicle in which the above-described problems are alleviated.

According to the invention, there is provided a tipping vehicle comprising a chassis, a body mounted on the chassis for tipping movement relative thereto about a generally horizontal tipping axis between lowered and raised positions, a pair of extensible rams for tipping the body about the tipping axis, each ram being connected independently of the other between the body and the chassis with the point of connection of one of the rams to the chassis being closer to the tip ping axis than the point of connection of the other ram to the chassis, the arrangement being such that, when the body is in its lowered position, the lines of action of the rams converge upwardly and have opposite inclinations with respect to a vertical plane which is disposed between said points of connection of the rams to the chassis and which is parallel to the tipping axis, said one of the rams being arranged to act as a main ram and apply force to the body throughout all of its tipping movement and said other of the rams being arranged to act as an auxiliary ram and apply force to the body at least during movement of the latter between the lowered position and a position intermediate said lowered and raised positions.

In this way, the rams can be made with cylinders of relatively small diameter, which are substantially cheaper than large cylinders and which impose considerably lower stresses on the members to which they are connected.

In a preferred form, both of the rams are arranged to apply force together to the body during movement of the latter between its lowered and intermediate positions, and said one of the rams only is arranged to apply force to the body during movement of the latter beween its intermediate and raised positions. Desirably the tipping vehicle further comprises means accommodating lost motion between said other of the rams and the body as the latter is moved between its intermediate and raised positions. With this arrangement, the combined forces of the main and auxiliary rams are brought into play in the initial stage of tipping.When the body reaches said intermediate position the auxiliary ram ceases to apply force, to the body, but by then the main ram is partially extended and the angle between its line of action and the vertical is substantially reduced, so that it is well poised to apply the full force necessary in the remaining part of the tipping movement. Preferably at least two main rams are used so as to spread the load over two longitudinal chassis members.

Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: - Figure 1 is a perspective view of a part of a tipping vehicle according to the present invention, some parts being omitted for the sake of clarity; Figure 2 is a side view of part of a modification of the tipping vehicle of Figure 1, showing the connection of main and auxiliary rams to a tipping body of the vehicle; and Figure 3 is a semi-schematic side view of certain parts of the vehicle of Figure 1.

The tipping vehicle shown in Figure 1 is in the form of a truck and has a conventional wheeled chassis 10 having mounted adjacent its rear end brackets 12 for the pivotal attachment of a tipping body thereto. Of the tipping body, only a frame beam 14 and a few other particulars such as crossmembers 15 are shown. Mounted in boxtype housing 16 on the chassis 10 is a pair of main hydraulic rams 18. Each ram 18 is pivoted at its lower end to a fixed mounting on the chassis 10 adjacent the axle nearest the tipping axis or the wheel suspension points closest the tipping axis, and is pivoted at its other end to a respective attachment plate 19 (only one shown) firmly connected to the tipping body. Each of the main rams 18 is conventional and comprises a piston movable within a cylinder.These rams can be of considerably less diameter than is usual, and for instance may have 63 cm diameter cylinders.

Forwardly of the main rams 18 is disposed a pair of auxiliary rams 20 each of which is connected between a lower attachment point on the chassis 10 and an upper attachment point on a respective one of the plates 19, the lower attachment points being disposed above longitudinal members 10' of the chassis. Each ram 20 comprises a piston rod 22 movable within a cylinder 24, and has provision for lost motion between the rod and the cylinder once the ram has reached its normal maximum extended length. For example, the piston rod 22 of each auxiliary ram can be telescopically engaged with another rod (not shown) which is the standard tubular rod for certain types of hydraulic rams.

If desired, further main and auxiliary rams, or even only one auxiliary ram can be provided. To ensure the most economical use of the maximum limits laid down by current road traffic legislation, there will normally be four rams.

In a modification of the above-described construction, shown in Figure 2, a subframe 26 is mounted on the chassis 10 in a conventional manner by means of a hard wood beam. The cylinders of the main rams 18 are pivotally mounted in channelsection flanges 29 which are secured to cross-beams 30 extending between longitudinal members of the sub-frame 26. The piston rods of the main rams are pivotally connected respectively to the attachment plates 19 on the tipping body.

Only a part of one of the auxiliary rams 20 is shown in Figure 2. This ram at one end thereof is connected to cross-members (not shown) on the sub-frame 26, and at the other upper end thereof carries a linkage 32 which pivotally interconnects the ram and a flange of a cross-member 34 on the tipping body. The upper end of the ram 20 is adapted to seat in a recess bounded by the respective attachment plate 19 and frame beam 14 in such a manner that it can become disengaged from the recess.

In each of the constructions described above, tilting of the tipping body is accomplished by extending under power both the main rams 18 and the auxiliary rams 20 for an initial part of the tilting movement.

During this operation, in the Figure 1 embodiment the piston rods 22 remain telescopically compressed, and in the Figure 2 embodiment the upper end of each ram 20 remains seated in the respective recess in the tipping body. When the auxiliary rams have reached their maximum extension under power, the main rams 18 continue to tilt the tipping body. In the Figure 1 embodiment, this causes the piston rods 22 to extend telescopically. In the Figure 2 embodiment it causes the ends of the rams 20 to disengage from their respective recesses, although the upper ends of the rams 20 remain connected to the tipping body through the linkage 32 so that they will properly locate in the recesses in the tipping body when the tipping body subsequently descends.

The arrangemellt for the auxiliary rams described above with reference to Figure 2 can be inverted so that each ram at one end is pivoted on the respective attachment plate 19 and at its other end carries the linkage 32, which is now pivoted to the chassis. Furthermore, each auxiliary ram can be pivotally connected at its ends to both the tipping body and the chassis by respective linkages 32.

Figure 3 shows the basic geometry of the vehicles described above with reference to Figures 1 and 2. In each of these vehicles, the axes of each associated pair of main and auxiliary rams converge upwardly and are oppositely inclined with respect to a vertical plane which is disposed between the connection points of the rams to the chassis and which is parallel to the tipping axis.

The longitudinal axis of each main ram is preferably inclined at a maximum of substantially 52" to the vertical when tipping starts and the forces in the rams are at a maximum. The auxiliary rams 20 have their axes inclined at a somewhat greater angle to the vertical, preferably about 63".

In a first stage of tipping, both the main and the auxiliary rams apply force through a common source of pressure liquid (not shown), and tipping proceeds until the angles between each main ram 18 and the vertical are reduced to about 25". At this stage the auxiliary rams 20 are fully extended and for the remaining part of the tipping operation the rods 22 merely telescope outwards in the embodiment of Figure 1, or disengage from the respective recesses in the tipping body in the embodiment of Figure 2 to provide lost motion.

The rams 18 carry the full load in the second stage of tipping, which ends when the rams 18 are fully extended and stand substantially vertical.

The sequence of operations reverses when the tipping body is retracted back to its lowered position on the chassis.

The rams 18 and 20 are located fully underfloor of the vehicle body and also do not project below the chassis, yet they are able to tilt the tipping body when it is fully loaded. The same cannot be said of conventional tipping mechanisms unless they are provided with complicated compound levers which are susceptible to breakdown.

The invention can also be applied to "side-tipping" vehicles in which event at least one pair of oppositely inclined rams is provided transversely across the chassis and body. Means for forming a longitudinal pivot axis between the chassis and the body are provided on either side of the vehicle, either of the means being disengageable so that there is only one pivot axis at any time.

The rams are made to be identical so that, depending on which side of the body is to be tilted, either of the opposed rams can be termed the "main" ram and the other the "auxiliary" ram. Obviously, more than one pair of rams can be provided if greater loads are to be tipped. Preferably there are at least two such pairs of rams so as to minimize any local forces that are applied to the chassis. Again the rams are located close to the suspension points of the vehicle so as to minimize any bending moments on the chassis.

In all of the embodiments discussed above, each main ram 18 is directly connected between a pivot on the chassis and a pivot on the body. In other embodiments (not shown) the main rams can be indirectly connected at either end, e.g. through one or more linkages, if this is desirable or when fitting of the rams into a particular body and chassis configuration makes it necessary.

The main rams are preferably connected to the chassis at points adjacent the wheel suspension mounting points on the chassis.

In the event of a chassis having a single wheel-axle adjacent the tipping axis, then the connection points are positioned approximately above the wheel-axle. If the vehicle has a double-axle configuration, then the connection points are positioned on the chassis to be approximately above the mid-point between the two axles. This con figuration ensures that any bending moments applied to the chassis by the main rams are minimal. Thus, for carrying the same load as a vehicle having a conventional tipping mechanism the chassis is better protected against the danger of bending than is the chassis of a vehicle having the conventional tipping mechanism.Similarly, the provision of an auxiliary ram to assist the main ram at the start of tipping ensures that any loads applied to the chassis are well distributed over it, and this factor enhances the protection of the chassis against bending forces.

The chassis of a vehicle with a tipping mechanism as described above will have a longer life than a vehicle fitted with a conventional tipping mechanism because any load applied to the chassis is well distributed over its length and bending moments imposed on the chassis are minimised.

In a similar vein, it can be seen that, because of the lighter chassis construction which can be used with the tipping mechanism, for a given maximum permissible load a vehicle fitted with such a tipping mechanism can carry a higher payload than a vehicle fitted with a conventional tipping mechanism.

WHAT WE CLAIM IS: - 1. A tipping vehicle comprising a chassis, a body mounted on the chassis for tipping movement relative thereto about a generally horizontal tipping axis between lowered and raised positions, a pair of extensible rams for tipping the body about the tipping axis, each ram being connected independently of the other between the body and the chassis with the point of connection of one of the rams to the chassis being closer to the tipping axis than the point of connection of the other ram to the chassis, the arrangement being such that, when the body is in its lowered position, the lines of action of the rams converge up- wardly and have opposite inclinations with respect to a vertical plane which is disposed between said points of connection of the rams to the chassis and which is parallel to the tipping axis, said one of the rams being arranged to act as a main ram and apply force to the body throughout all of its tipping movement and said other of the rams being arranged to act as an auxiliary ram and apply force to the body at least during movement of the latter between the lowered position and a pisition intermediate said lowered and raised positions.

2. A tipping vehicle as claimed in Claim 1, wherein both of the rams are arranged to apply force together to the body during movement of the latter between its lowered and intermediate positions, and said one of the rams only is arranged to apply force to the body during movement of the latter between its intermediate and raised positions.

3. A tipping vehicle as claimed in Claim 2, further comprising means accommodating lost motion between said other of the rams and the body as the latter is moved between its intermediate and raised positions.

4. A tipping vehicle as claimed in Claim 1, 2 or 3, wherein the chassis has a wheel suspension mounting point adjacent which is disposed the connection point of said one of the rams to the chassis.

5. A tipping vehicle as claimed in any preceding claim, wherein the connection points of said one of the rams to the body and the chassis are arranged such that the longitudinal axis of said one of the rams is substantially vertical when the body is in its raised position.

6. A tipping vehicle as claimed in any preceding claim, wherein the chassis includes longitudinal members, and the connection point of said other of the rams to the chassis is disposed above the level of the longitudinal members.

7. A tipping vehicle as claimed in any preceding claim, wherein the connection point of said other of the rams to the chassis is at a higher level than the connection point of said one of the rams to the chassis.

8. A tipping vehicle as claimed in any preceding claim, wherein the chassis includes longitudinal members and the connection point of said one of the rams to the chassis is not below the level of said longitudinal members.

9. A tipping vehicle as claimed in any preceding claim, wherein there is provided more than one ram which is arranged to act as a main ram.

10. A tipping vehicle as claimed in any preceding claim, wherein each of said rams is an hydraulic ram.

11. A tipping vehicle as claimed in any preceding claim, wherein said other of the rams is directly pivotally connected to the chassis.

12. A tipping vehicle as claimed in any one of Claims 1 to 10, wherein said other of the rams is pivotally connected to the chassis through a linkage.

13. A tipping vehicle as claimed in any preceding claim, wherein said one of the rams is directly pivotally connected to the chassis.

14. A tipping vehicle as claimed in any one of Claims 1 to 12, wherein said one of the rams is pivotally connected to the chassis through a linkage.

15. A tipping vehicle as claimed in any preceding claim, wherein said one of the rams is directly pivotally connected to the body.

16. A tipping vehicle as claimed in any one of Claims 1 to 13, wherein said one of the rams is pivotally connected to the body through a linkage.

17. A tipping vehicle as claimed in any preceding claim, wherein the maximum inclination of the longitudinal axis of said one of the rams to the vertical when the body is in its lowered position is substanti- ally 52".

18. A tipping vehicle as claimed in any preceding claim, wherein the maximum inclination of the longitudinal axis of said other of the rams to the vertical when the body is in its lowered position is substantially 63 .

19. A tipping vehicle substantially as hereinbefore described with reference to Figures 1 and 3, or Figures 1 and 3 as modified by Figure 2 of the accompanying drawings. -- -

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. vehicle fitted with a conventional tipping mechanism. WHAT WE CLAIM IS: -

1. A tipping vehicle comprising a chassis, a body mounted on the chassis for tipping movement relative thereto about a generally horizontal tipping axis between lowered and raised positions, a pair of extensible rams for tipping the body about the tipping axis, each ram being connected independently of the other between the body and the chassis with the point of connection of one of the rams to the chassis being closer to the tipping axis than the point of connection of the other ram to the chassis, the arrangement being such that, when the body is in its lowered position, the lines of action of the rams converge up- wardly and have opposite inclinations with respect to a vertical plane which is disposed between said points of connection of the rams to the chassis and which is parallel to the tipping axis, said one of the rams being arranged to act as a main ram and apply force to the body throughout all of its tipping movement and said other of the rams being arranged to act as an auxiliary ram and apply force to the body at least during movement of the latter between the lowered position and a pisition intermediate said lowered and raised positions.