GB2620644A - A vehicle for mixing concrete - Google Patents

Abstract

A vehicle for mixing concrete comprises an operator cabin 2, a horizontal chassis 4 comprising a load support frame 14 that has longitudinal axis substantially parallel to the ground. Rotatable mixing drum 16 with over skin 18 and drum ring 19 is supported on chassis 4 such that the longitudinal axis A of mixing drum 16 is inclined relative to the longitudinal axis X of the frame and driven by motor 26. The mixing drum comprises a drum ring and being configured to hold and mix a load. Chassis 4 also comprises a rear pedestal 22 on which drum ring 19 is supported, and which also has a pair of drum rollers (24a, 24b Fig 3) in contact with drum ring 16. At least one stop 40 is provided to prevent lateral movement of drum 16 beyond a predetermined distance from a centreline of the vehicle, or to limit vertical movement of drum 16 so that lateral movement thereof beyond a predetermined distance from the centre line is prevented (see Fig 2). Stop(s) 40 may be a low friction material in the form of a rotatable roller or non-rotatable component. The provision of stop(s) 40 intends to reduce the chances of vehicle roll-over by providing a rebalance and reduction in movement which may cause the vehicle to lose its centre of gravity. A stop contact detection system may also be included to alert the operator when a stop component has been touched, as well as a load sensor to indicate when a load exceeds allowable conditions which may also cause roll-over.

Description

A vehicle for mixing concrete Technical Field

The present invention relates to a vehicle for mixing concrete. More specifically, the present invention relates to a vehicle for mixing concrete comprising a mechanism for reducing the likelihood of vehicle roll-over. The present invention also relates to a method for alerting a driver of a vehicle for mixing concrete when the conditions for vehicle roll-over are being approached.

Background

Vehicles for mixing concrete are used to transport concrete to a work site whilst mixing the cement and aggregate payload. An operating concern with vehicles for mixing /5 concrete is that roll moments that are generated when the vehicle is turning can cause the mixing drum to move to an off-centre position, which can cause the vehicle to rollover. As the vehicle turns, centrifugal force acts on the vehicle in a direction opposite to the direction of the turn. When the vehicle is moving at a speed too high for the radius and camber of the turn, there is a potential that conditions for the mixing drum to move to an off-centre position will be met and therefore an increased chance of vehicle roll-over.

These centrifugal forces are of particular concern when considering the mixing drum, which can often have a mass of in excess of 20 Tons and a high centre of gravity. The lateral forces on the load when cornering can push the load up the internal wall of the mixing drum and the centrifugal forces are compounded by the rotation of the mixing drum, which can cause the load to 'climb' the mixing drum, further raising the centre of gravity of the mixing drum. The forces acting on the mixing drum can cause the mixing drum to move off its contact points with the vehicle. In such an event, the mixing drum becomes loose and is able to swing under the above mentioned forces. The loose and swinging mixing drum increases the potential for the vehicle to roll-over.

Summary

According to the present invention, there is provided a vehicle for mixing concrete. The vehicle comprises a cabin configured to allow an operator to control the vehicle; a chassis comprising a frame configured to support a load on the vehicle, the frame having a longitudinal axis that is substantially parallel to the ground; a rotatable mixing drum supported on the chassis such that the longitudinal axis of the mixing drum is inclined relative to the longitudinal axis of the frame, the mixing drum comprising a drum ring and being configured to hold and mix a load; wherein the chassis comprises a rear pedestal on which the drum ring of the mixing drum is supported; the rear pedestal comprising a pair of drum rollers configured to contact the drum ring; and at least one stop configured to limit vertical movement of the rotatable mixing drum such that lateral movement of the mixing drum beyond a predetermined distance from a jo centreline of the vehicle is prevented.

In some embodiments, the at least one stop may be spaced from the rotatable mixing drum such that there is a gap between the at least one stop and the rotatable mixing drum.

In some embodiments, the size of the gap between the at least one stop and the rotatable mixing drum may be in the range of to mm to 20 MM.

In some embodiments, the size of the gap may be defined by the smallest distance between the rotatable mixing drum and the at least one stop, when the mixing drum is supported by the pair of drum rollers.

In some embodiments, the at least one stop may be positioned so as to contact a contact element of the mixing drum when the mixing drum moves off of at least one of the pair of drum rollers.

In some embodiments, the at least one stop may be mounted on the rear pedestal.

In some embodiments, the contact element may comprises a first portion and a second portion, wherein the first portion and second portion may extend substantially perpendicularly relative to each other, and wherein the at least one stop may be mounted closer in the radial direction to the longitudinal axis of the mixing drum than the second portion of the contact element and configured to constrain movement of the mixing drum in the vertical direction. -3 -

In some embodiments, the second portion of the contact element may extend substantially parallel to the longitudinal axis of the mixing drum.

In some embodiments, the second portion of the contact element may extend towards the rear of the vehicle.

In some embodiments, the second portion of the contact element may extend towards the front of the vehicle.

/o In some embodiments, the contact element may extend about the opening of the mixing drum.

In some embodiments, the contact element may be formed by the drum ring.

In some embodiments, the contact element may comprise a first portion formed by the drum ring and a second portion extending from the first portion.

In some embodiments, the contact element may extend from an opening of the mixing drum.

In some embodiments, the at least one stop may be located further from the frame of the chassis than the pair of drum rollers.

In some embodiments, the at least one stop may be located further from the frame of the chassis than the centre of gravity of the mixing drum and a load within the mixing drum.

In some embodiment, the at least one stop may be located at a greater distance from the centreline of the vehicle than at least one of the pair of drum rollers.

In some embodiments, the at least one stop may be located closer to the cabin than the pair of drum rollers.

In some embodiments, the at least one stop may be located between 30 and 90 degrees 35 about the longitudinal axis A of the mixing drum from the centre of the pair of drum rollers. -4 -

In some embodiments, the at least one stop may be located at a lesser distance from the centreline of the vehide than at least one of the pair of drum rollers.

In some embodiments, the at least one stop may be located further from the cabin than the pair of drum rollers.

In some embodiments, the at least one stop may be located between o and 30 degrees about the longitudinal axis A of the mixing drum from the centre of the pair of drum jo rollers.

In some embodiments, the at least one stop may comprise a contact surface configured to contact the mixing drum formed by a low friction surface.

In some embodiments, the low friction surface of the at least one stop may be a

rotatable roller.

In some embodiments, an outer surface of the rotatable roller may be formed by a low friction material.

In some embodiments, the low friction surface may be a non-rotatable surface formed by a low friction material.

In some embodiments, the at least one stop may further comprise a contact detection system comprising a contact sensor that is configured to determine whether the mixing drum has contacted the at least one stop and send a signal to an output device when the mixing drum contacts the at least one stop, the output device being configured to alert an operator of the vehicle when the mixing drum contacts the at least one stop.

In some embodiments, the at least one stop may further comprise a load sensing system comprising a load sensor configured to determine the load experience by the at least one stop when the mixing drum contacts the at least one stop and send a signal to an output device, the output device being configured to alert an operator of the vehicle when the load exceeds a predetermined value representative of conditions of an imminent roll-over. -5 -

Brief Description of the Drawings

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Fig.i shows a perspective side view of a vehicle for mixing concrete; Fig. 2 shows a schematic rear view of a vehicle for mixing concrete including a load at rest and during rotation; Fig. 3 shows a schematic rear cross-sectional view in a plane orthogonal to a longitudinal axis of a mixing drum of a vehicle according to an embodiment of the jo invention; Fig. 4 shows a schematic side cross-sectional view of a contact element formed partially by a drum ring of a vehicle according to an embodiment of the invention; and Fig. 5 shows a schematic side cross-sectional view of a contact element formed around an opening of a mixing drum of a vehicle according to an embodiment of the invention.

Detailed Description

Referring to Fig. 1, a side perspective view of a vehicle 1 for mixing concrete. The vehicle 1 is a concrete mixing truck. The vehicle 1 comprises a cabin 2 and a chassis 4. The vehicle typically has three sets of wheels. A first set of wheels 6 may be located at the cabin 2, and a tandem set of wheels 8 may be located on the chassis 4. The tandem set of wheels 8 may comprise a front truck set of wheels 10 and a rear truck set of wheels 12.

or The chassis 4 may comprises a frame 14. The frame 14 forms a base onto which further features of the vehicle 1 can be mounted. The frame 14 extends generally horizontally such that its longitudinal axis X extends substantially parallel to the ground. The plane that extends vertically from the longitudinal axis X that extends along the centre of the vehicle 1 may be referred to as the centreline Y of the vehicle 1. The vehicle 1 further comprises a mixing drum 16. The mixing drum 16 is configured to hold and mix concrete. The mixing drum 16 is configured to mix a load 17 by rotating about its central longitudinal axis A, as will be described in more detail hereinafter. In the present embodiment, the load 17 is concrete.

The mixing drum 16 comprises an outer skin 18 and a drum ring 19. The drum ring 19 extends about the circumference of an outer surface of the outer skin 18 of the mixing -6 -drum 16. The plane in which the drum ring 19 extends is substantially perpendicular to the central longitudinal axis A of the mixing drum 16. The drum ring 19 may be stronger than the drum skin 17. The drum ring 19 may be formed from, for example, but not limited to, a ring of hard steel.

The mixing drum 16 is supported by the frame 14 of the chassis 4. The chassis 4 comprises a first pedestal zo located at the front of the frame 14, also known as a front support, and a second pedestal 22, located at the rear of the frame 14, also known as a rear support stool. The mixing drum 16 is supported by the first and second pedestals 20, 22 and allowed to rotate relative thereto.

As shown in Fig. 1, the second pedestal 22 extends further from the frame 14 than the first pedestal zo. Therefore, the second pedestal 22 at the rear of the frame 14 has a greater height than the first pedestal zo at the front of the frame 14. The difference in height of the first and second pedestal zo, 22 allows the rear of the mixing drum 16 to be supported at an elevated height compared to the front of the mixing drum 16. That is, the central longitudinal axis A of the mixing drum 16 is inclined relative to the longitudinal axis X of the frame 14 of the chassis 4.

The chassis 4 further comprises a pair of drum rollers 24. The pair of drum rollers 24 comprise a port side roller 24a and a starboard side roller 24b, shown in Fig. 2 and Fig. 3, which are located on opposing side of a centreline Y of the vehicle 1. In the present embodiment, the drum rollers 24a, 24b are attached to the rear pedestal 22, or rear support stool. The drum rollers 24a, 24b engage a rear part of the mixing drum 16. In or the present embodiment, the drum rollers 24a, 24b engage the drum ring 19. The drum rollers 24 support the mixing drum 16 on the rear pedestal 22 and allow rotation of the mixing drum 16 about its central longitudinal axis A. The first pedestal 20 of the vehicle 1 may further comprise a gearbox 25, which controls rotation of the mixing drum 16 to mix the concrete. The gearbox 25 may be configured to allow rotation of the mixing drum 16 about three orthogonal axes. Thus, the mixing drum 16 can pivot about the first pedestal 20 in any direction. The vehicle 1 may further comprise a drum motor 26. The drum motor 26 may be configured to provide the rotational force to rotate the mixing drum 16. The drum motor 26 can be powered by an electric motor, by a hydraulic motor, or by the engine of the vehicle 1. The gearbox 25 may connect the drum motor 26 to the mixing drum 16 to transmit and convert the -7 -power supplied by the drum motor 26 to the correct rotational speed of the mixing drum 16.

The vehicle 1 may further comprise a chute 27, which is located proximate to a discharge opening 28 of the mixing drum 16, such that the load 17 can be delivered via the chute 27 from the mixing drum 16 to a worksite.

Due to the elevated height at which the rear of the mixing drum 16 is supported by the rear pedestal 22 compared to the front of the mixing drum 16 on the front pedestal 20 or inclined angle between the frame 14 and the central longitudinal axis A of the mixing drum 16, the discharge opening 28 of the mixing drum 16 is elevated. This enables the mixing drum 16 to carry a larger load 17 without spilling the load 17 out of the discharge opening 28.

Referring now to Fig. 2, it can be seen that the larger the load 17 within the mixing drum 16, enabled by the inclination of the rear of the mixing drum 16 relative to the frame 14, raises the centre of gravity of the mixing drum 16 and its load 17. Therefore, when the mixing drum 16 is not rotating the centre of gravity, shown by the label COG, in Fig. 2, of the mixing drum 16 and the load 17 is centred relative to the centreline-line Y, or longitudinal axis X, of the vehicle 1. In Fig. 2, the centre of gravity COG, of the mixing drum 16 and the load 17 is shown as being higher than the pair of drum rollers 24 with respect to the frame 14. However, it will be understood that this is merely for illustration purposes, and that in most, but not necessarily all, cases, the centre of gravity COG, of the mixing drum 16 and its load 17 may be below or at least in line with or the position of the pair of drum rollers 24.

When the load 17 is not being rotated it is in what is known as a dead load position 17A. When in the dead load position 17A, an upper surface 30 of the load 17 is substantially level, i.e. horizontal. The height of the centre of gravity COG1 of the dead load 17 is determined by the volume and density of the load 17 within the mixing drum 16.

Furthermore, the centre of gravity COGI of the mixing drum 16 and the load 17 is vertically in line with the rotational axis A of the mixing drum 16 when there are not lateral forces of the mixing drum 16 due to the vehicle 1 turning.

To mix the load 17 in the mixing drum 16, the mixing drum 16 is rotated about its longitudinal axis A. The mixing drum 16 may be rotated clockwise as shown in Fig. 2 by -8 -arrow C when viewed from the rear of the vehicle 1, i.e. the opposite end of the vehicle 1 to the cabin 2. Thus, the following description relates to forces and centre of gravity in relation to clockwise rotation of the mixing drum 16. However, it will be appreciated that the mixing drum 16 may alternatively be rotated anti-clockwise and that all the forces and positioning of the centre of gravity may be opposite to the description given below.

As the mixing drum 16 rotates in the clockwise direction C, the load 17 is caused to move by the motion of the mixing drum 16. The load 17 rises, or shifts laterally, up the jo port side of the inner surface of the mixing drum 16. The leftwards lateral shift of the load 17 also causes the load 17 to rise up the inner surface of the mixing drum 16, which causes the centre of gravity, shown by label COG, in Fig. 2, to move upwards and to the left of the centreline Y of the vehicle 1, when viewed from the rear of the vehicle 1.

When the load 17 is being rotated it is in what is known as a live load position 17B. The live load position 17B and the load's centre of gravity COG2 is determined by the volume, density, and viscosity of the load 17 and the rotational velocity of the mixing drum 16 and the geometry of the internal screw. The live load position 17B and the load's centre of gravity COG, is also effected by the movement of an internal screw (not shown in the drawings) within the mixing drum 16. Different configurations of the internal screw, such as radius and pitch will affect the extent to which the load is mixed and/or lifted up the internal surface of the mixing drum 16. These factors will further affect the live load position 17B and the load's centre of gravity COG,. When in the live load position 17B, an upper surface 32 of the load 17 is inclined with respect to the or horizontal or dead load position 17A. A part of the upper surface 32 of the load 17 in the live load position 17B may be above the location of the upper surface 30 of the load 17 when the load 17 is in the dead load position 17A, as shown in Fig. 2. Furthermore, a part of the upper surface 32 of the load 17 in the live load position 17B may be below the location of the upper surface 30 of the load 17 when the load 17 is in the dead load position 17A, as shown in Fig. 2.

The movement of the centre of gravity COG of the load 17 away from the centreline Y of the vehicle land vertically upwards during rotation of the mixing drum 16 further narrows the operating window of the vehicle 1 before the mixing drum 16 becomes unseated from the pair of rollers 24, i.e. enters an off-centre position, and/or conditions for roll-over are met. -9 -

More specifically, the raising and movement of the centre of gravity away from the centreline Y of the vehicle 1 means that less centrifugal, or lateral, force is required for the mixing drum 16 to come off of the pair of drum rollers 24 that support the mixing drum 16. Once the lateral force due to turning, based on corner radius and camber, and vehicle velocity, is sufficient for the mixing drum 16 to move off at least one of the rollers and/or up and over one of the pair of drum rollers 24, then the mixing drum 16 and load 17 are able to swing away from the centreline Y of the vehicle 1 unopposed. The large movement in the centre of gravity COG, as well as the momentum of the large jo mass and the impulse created if/when the movement of the mixing drum 16 is halted, increases the likelihood of the vehicle 1 rolling-over.

The aim of the present invention, as outlined below, is to prevent the centre of gravity COG of the mixing drum 16 and load 17 from moving to such an extent that the mixing drum 16 of the vehicle 1 is caused to move off of at least one of the pair of drum rollers 24 into an off-centre position when the vehicle operator navigates a turn too quickly. By preventing, or at least limiting, the mixing drum 16 from moving vertically relative to the rest of the vehicle 1, the present invention also aims to reduce the risk of vehicle roll-over.

Referring to Fig. 3, a schematic cross-sectional view of an embodiment of the invention is shown. The cross-sectional view shown in Fig. 3 is of a plane that extends orthogonally to the longitudinal axis A of the mixing drum 16. The cross-sectional view shown in Fig. 3 illustrates a cross-section of the mixing drum 16 and the rear pedestal 22 of a vehicle 1 for mixing concrete.

The schematic cross-sectional view of Fig. 3 shows the rear pedestal 22 and the pair of drum rollers 24 extending from the rear pedestal 22. The pair of drum rollers 24 are located centrally on the rear pedestal 22. That is, each of the rollers 24a, 24b of the pair of rollers 24 are spaced by the same distance from the centreline Y of the vehicle 1.

Each of the drum rollers 24a, 24b of the pair of drum rollers 24 extend to the same vertical height. Thus, when the mixing drum 16 rests on the pair of drum rollers 24, the mixing drum 16 is located centrally on the rear pedestal 22. That is, the central longitudinal axis A of the mixing drum 16 is located in the same vertically extending plane as the centreline of the vehicle 1. in addition, the centre of gravity COG of the -10 -mixing drum 16 and the load 17 is located between drum rollers 24a, 24b of the pair of drum rollers 24 in the horizontal direction.

In Fig. 3, there is shown an embodiment of the present invention. Fig. 3 shows a schematic cross-sectional view of the embodiment. The cross-sectional view shown in Fig. 3 is of a plane that extends orthogonally to the longitudinal axis A of the mixing drum 16.

The schematic cross-sectional view of Fig. 3 shows the rear pedestal 22 and the pair of /o drum rollers 24 extending from the rear pedestal. The pair of drum rollers 24 are located centrally on the rear pedestal 22. That is, each of the rollers 24a, 24b of the pair of rollers 24 are spaced by the same distance from the centreline Y of the vehicle 1.

In the present embodiment, the vehicle 1 further comprises at least one stop 62. The at least one stop 62 is configured to prevent, or at least constrain, movement of the mixing drum 16 beyond a predetermined distance from the centreline Y of the vehicle 1. The at least one stop 62 of the present embodiment is configured to limit vertical movement of the mixing drum 16 relative to the vehicle 1. The at least one stop 62 forms a vertical restraint system. By limiting the vertical movement of the mixing drum 16 relative to the vehicle 1, the vertical restraint system provides protection against the mixing drum 16 'bouncing'.

In known vehicles, bouncing of the mixing drum 16 can occur when the vehicle 1 experiences a significant vertical force, for example, when travelling over a bump in the or road. Under the vertical forces, the mixing drum 16 may move vertically upwards relative to the remainder of the vehicle 1 and this causes the mixing drum 16 to be moved out of contact with the pair of drum rollers 24. The mixing drum 16 may bounce off of the pair of drum rollers 24 when the mixing drum 16 moves downwards under gravity. The impulse of the downward moving mixing drum 16 may cause damage to the rear pedestal 22. When the mixing drum 16 is out of contact with the pair of drum rollers 24, lateral accelerations can cause the mixing drum 24 to swing freely away from the centreline of the vehicle iand potentially cause a roll-over event.

Therefore, by providing a vertical restraint system, the distance that the mixing drum 35 16 can move from the drum rollers 24 is reduced and the bouncing of the mixing drum 16 is reduced. Therefore, the movement of the mixing drum 16 and the impact forces on the rear pedestal 22 of the vehicle 1 are reduced.

In the embodiment shown in Fig. 3, the vehicle 1 comprises two stops 62a, 62b. That is, the vehicle 1 comprises a port side stop 62a and a starboard side stop 62b. The port side stop 62a is configured to constrain movement of the mixing drum 16 to the right of the centreline Y of the vehicle 1. The starboard side stop 62b is configured to constrain movement of the mixing drum 16 to the left of the centreline Y of the vehicle 1. Although the present embodiment has two stops 62, it will be appreciated that the jo vehicle 1 may comprise a single stop 62 or more than two stops 62. For example, the vehicle I may comprise a single centrally located stop 62 that is located on the centreline Y of the vehicle 61 between the drum rollers 24a, 24b of the pair of drum rollers 24.

The at least one stop 62 is configured to provide a surface against which the mixing drum 16 abuts when the mixing drum 16 becomes unseated from its central position of the pair of drum rollers 24. That is, when the lateral forces acting on the mixing drum 16 exceed a minimum value, the mixing drum 16 lifts off of one of the pair of drum rollers 24 and begins to roll over the other one of the pair of drum rollers 24. As the mixing drum 16 continues to move away from the centreline Y of the vehicle 1, the momentum of the mixing drum 16 increases. However, by placing the at least one stop 62 in the path of the mixing drum 16, the momentum gained by the mixing drum 16 before it contacts the at least one stop 62 is significantly less, such that the at least one stop 62 may prevent further movement of the mixing drum 16 away from the centreline or Y of the vehicle or even cause the mixing drum 16 to return to its normal central position.

The at least one stop 62 may comprise a contact surface 64 that is configured to contact the mixing drum 16 to resist any further movement of the mixing drum 16 away from the centreline Y of the vehicle 1. The contact surface 64 is configured to contact the drum ring 19 of the mixing drum 16 when the mixing drum moves under lateral forces. In some embodiments, the contact surface 64 configured to contact the mixing drum 16 is formed by a low-friction surface 65. A low-friction surface 65 is advantageous because, without friction, the low-friction surface prevents the mixing drum 16 from gripping the stop 62 and rolling over the stop 62. That is, the drum ring 19 slips against the low-friction surface 65 rather than gripping and rolling over it.

-12 -In the present embodiment, the at least one stop 62 is formed by a rotatable roller 66. The rotatable roller 66 has an outer circumferential surface 67, which can be considered to be a low-friction surface 65 because it is free to rotate under contact such that it will rotate in the opposite direction to the rotation of the mixing drum 16 and the mixing drum 16 will only slip on the rotatable roller 66. In some embodiments, the outer circumferential surface 67 of the rotatable roller 66 may be formed by a low friction material. The low-friction material may be, for example, but not limited to, nylon.

The roller 66 is connected to the chassis 4 by a support arm 68. The support arm 68 may connect the roller 66 to the rear pedestal 22. Alternatively, the support arm 68 may connect the roller 66 directly to the frame 14 of the chassis 4. The support arm 68 is configured to withstand at least the lateral load of the mixing drum 16 and the load 17 moving away from the centreline Y of the vehicle 1 as well as restricting vertical movement away from the pair of drum rollers 24 caused by, for example, the vehicle 61 driving over bumps. The support arm 68 may be configured to withstand a lateral load of up to between 0.5g and ig, for example, 0.7g. That is, the support arm 68 may be configured to withstand a lateral load of up to about 20T.

In an alternative embodiment, the low-friction surface 65 may be formed by a non-rotatable surface, i.e. not a rotatable roller 66. That is, the low-friction 65 may be designed such that it is a low-friction contact surface located at the end of a support arm 68. A non-rotatable low-friction contact surface may be profiled in order to reduce or the likelihood of the mixing drum 16 gripping against and rolling over the stop 62.

In the present embodiment, the at least one stop 62 may be in permanent contact with the mixing drum 16. That is, the contact surface 64 of the at least one stop 62 may be in permanent contact with the drum ring 19 of the mixing drum 16. In such an arrangement, movement of the mixing drum 16 in the vertical and lateral directions can be effectively prevented.

Alternatively, in the present embodiment, the at least one stop 62 may be spaced from the mixing drum 16 such that there is a gap between the at least one stop 62 and the 35 mixing drum 16. The size of the gap between the at least one stop 62 and the mixing drum 16 is defined by the smallest distance between the at least one stop 62 and the -13 -mixing drum 16. The size of the gap between the at least one stop 62 and the mixing drum 16 is in the range of 5 mm to 50 mm. The size of the gap between the at least one stop 62 and the mixing drum 16 is more preferably in the range of to mm to 20 /11/11.

The at least one stop 40 may be mounted on a compressible member 68 on the rear pedestal 22 of the chassis 4 of the vehicle 1. The compressible member 68 may be configured to reduce the impact force of the mixing drum 16 when it contacts the at least one stop 62. Thus, the forces related to the impulse created when the mixing drum 16 contacts the at least one stop 62 may be reduced and the chance of the vehicle rolling /o over due to the swinging mixing drum 16 is reduced. The compressible member 48 may be, for example, but not limited to, a spring or bushing. The bushing may optionally be made of rubber.

Furthermore, the at least one stop 62 may further comprise a contact detection system 51. The contact detection system 51 may comprise a contact sensor 52. The contact sensor 52 may be configured to determine whether the mixing drum 16 has contacted the at least one stop 40. The contact sensor 51 may further be configured to send a signal to an output device 53 in the cabin 2 when the mixing drum 16 contacts the at least one stop 62. Alternatively, the signal may be sent by a separate controller 54. The output device 53 may be configured to alert an operator of the vehicle 1 when the mixing drum 16 contacts the at least one stop 62. The output device 53 may comprise, for example, but not limited to, a speaker configured to play a warning sound or a video output device configured to display a warning or a flashing light.

or In addition, the at least one stop 62 may further comprise a load sensing system 55. The load sensing system 55 may be a part of the contact detection system 51. The load sensing system 55 may comprise a load sensor 56. The load sensor 56 may be configured to determine the load experience by the at least one stop 62 when the mixing drum 16 contacts that at least one stop 62. The load sensor 56 may further be configured to send a signal to an output device 57 in the cabin 2 when the mixing drum 16 contacts the at least one stop 62. Alternatively, the signal may be sent by a separate controller 58. The output device 57 may be configured to alert an operator of the vehicle 1 when the load on the mixing drum 1 exceeds a predetermined value. The value may be representative of the conditions of an imminent roll-over of the vehicle 1. The output device 53 may comprise, for example, but not limited to, a speaker configured to play a warning sound or a video output device configured to display a warning or a flashing -14 -light. In addition, the load sensing system 55 may be used to determine when the at least one stop 62 require replacing due to experiencing an excessive loading event.

In the present embodiment, the at least one stop 62 is mounted closer in the radial direction to the longitudinal axis A of the mixing drum 16 than the drum ring 19, as will be explained in more detail hereinafter. Furthermore, as can be seen from Fig. 3, the at least one stop 62 is located at a greater distance from the centreline Y of the vehicle 1 than at least one 24a, 24b of the pair of drum rollers 24.

/0 As a result on the wider placement of the at least one stop 62 compared to the pair of drum rollers 24, the at least one stop 62 is also located closer to the cabin 2 than the pair of drum rollers 24 to ensure that contact between the at least one stop 62 and the mixing drum 16 still occurs on the drum ring 19 due to the inclination angle of the longitudinal axis of the mixing drum 16.

It will be appreciated that in the embodiment that comprises a centrally located stop 62, the centrally located stop 62 will be located at a smaller distance from the centreline Y of the vehicle 1 than the rollers 24a, 24b of the pair of drum rollers 24, i.e. on the centreline Y of the vehicle 1. In such an embodiment, the placement of the stop 62 on the centreline Y of the vehicle 1 means that the stop 62 is also located further from the cabin 2 than the pair of drum rollers 24 to ensure that contact between the at least one stop 62 and the mixing drum 16 still occurs on the drum ring 19 due to the inclination angle of the longitudinal axis of the mixing drum 16.

or Referring now to Fig. 4, it can be seen that the drum ring 19 of the present embodiment has been modified in order to provide a contact element 70, which restricts vertical movement of the mixing drum 16, having contact surface for the radially inward positioned at least one stop 62. That is, the drum ring 19 has been modified such that the contact surface 64 of the at least one stop 62, which is located radially closer to the longitudinal axis A of the mixing drum 16 than the drum ring 19, can still contact the drum ring 19 to prevent movement of the mixing drum 16 relative to the chassis 4 of the vehicle 1. Thus, in the present embodiment, the contact element 70 is the drum ring 19. However, as outlined hereinafter, the contact element 70 may be a separate device to the drum ring 19.

-15 -In the present embodiment, the contact element 70 includes the drum ring 19. That is, the drum ring 19 forms the contact element 70.It will be understood that the drum ring contacts the pair of drum rollers 24 in the usual manner whilst the modified part of the drum ring 19 is configured to contact the at least one stop 62. The contact element 70 comprises a first portion 71 and a second portion 72. The first portion 71 of the contact element 70 is formed by the drum ring 19. The drum ring 19 is similar to the drum ring 19 described above. In the present embodiment, the first portion 71 and the second portion 72 of the contact element 70 extend substantially perpendicularly relative to each other. That is, the first portion 71 of the contact element 70 extends substantially radially from the longitudinal axis A of the mixing drum 16. The first and second portions 71, 72 of the contact element 70 extend circumferentially about the outer surface of the mixing drum 16. It will be appreciated that in some embodiments, the first portion 71 and second portion 72 of the contact element 70 may extend at any angle to each other, other than substantially perpendicular, as long as the contact element 70 is able to contact the at least one stop 62 to restrict vertical movement of the mixing drum 16 relative to the remainder of the vehicle 1.

The second portion 72 of the contact element 70 extends substantially parallel to the longitudinal axis A of the mixing drum 16. However, in an alternative embodiment the second portion 72 of the contact element 70 may extend substantially parallel to the longitudinal axis X of the frame 14 of the chassis 4 of the vehicle 1.

The contact element 70 of the present invention comprises a first contact surface 73 and a second contact surface 74. The first contact surface 73 is formed by an outer or circumferential surface of the drum ring 19. In Fig. 4, the first contact surface 73 of the contact element 70 is formed by an outer circumferential surface 75 of the first portion 71 of the contact element 70, i.e. the outer circumferential surface of the drum ring 19. In an alternative embodiment, the first contact surface 73 may be formed by the outer circumferential portion of the second portion 72 of the contact element 70. The second contact surface 74 is formed by an inner circumferential surface of the contact element 70. In Fig. 4, the second contact surface 74 of the contact element 70 is formed by an inner circumferential surface 76 of the second portion 72 of the contact element 70, i.e. modified drum ring 19.

The contact element 70 is configured such that the first contact surface 73 formed by the outer circumferential surface 75 of the first portion 71 of the contact element 70 is -16 -in permanent contact with the port and starboard side rollers 24a, 24b of the pair of rollers 24, when the mixing drum 16 is not subject to any lateral or vertical forces. Furthermore, the contact element 70, i.e. modified drum ring 19, is configured such that the second contact surface 74 formed by the inner circumferential surface 76 of the second portion 72 of the contact element 70 is proximate to the contact surface 64 of the at least one stop 62. In Fig. 4, the second contact surface 74 of the contact element 70 is spaced from the at least one stop 62 by a gap 69. However, in some embodiments, the second contact surface 74 of the contact element 70 may be in permanent contact with the at least one stop 62.

In Fig. 4, the second portion 72 of the contact element 70 is shown extending rearwardly, i.e. away from the cabin 2 of the vehicle 1. In an alternative embodiment, the second portion 72 of the contact element 70 may extend forwardly, i.e. towards the cabin 2 of the vehicle 1. Advantageously, a rearwardly extending second portion 72 of the contact element 70 provides a larger space between the inner circumferential surface 76 of the second portion 72 of the contact element 70 and the outer surface of the mixing drum 16, than a forwardly extending second portion 72 of the contact element 70. Therefore, a larger at least one stop 62 can be used to restrain the motion of the mixing drum 16 relative to the chassis 4 of the vehicle 1.

Referring back to Fig. 3, it can be seen that the at least one stop 62 is located closer to the frame 14 of the chassis 4 than the centre of gravity COG of the mixing drum 16 and the load 17 within the mixing drum 16. By having the contact surface 65 of the at least one stop 62 below the centre of gravity COG of the mixing drum 16 and it load 17, the or centre of gravity COG of the overall vehicle 1 is kept lower. Furthermore, by placing the contact surface 65 of the at least one stop 62 below the centre of gravity COG of the mixing drum 16 and its load 17, the contact surface 65 of the at least one stop 62 can be placed closer to or in contact with the drum ring 19 to prevent movement of the mixing drum 16 relative to the chassis 4 of the vehicle 1.

The at least one stop 62 that is located radially inward of the second portion 72 of the contact element 70, i.e. modified drum ring 19, is able to reduce the likelihood of the mixing drum 16 moving relative to the chassis 4 of the vehicle 1 because the at least one stop 62 constrains vertical movement of the mixing drum 16. When the mixing drum 16 experiences large enough lateral forces, the mixing drum 16 can become unseated from at least one of the pair of drum rollers 24. In order to move laterally, the mixing drum -17 - 16 must roll over at least one of the pair of drum rollers 24 and to do so, the mixing drum 16 must move vertically up and over one of the pair of drum rollers 24. However, by placing at least one stop 62 proximate to or in contact with the second contact surface 74 of the contact element 70, the vertical movement of the mixing drum is inhibited. Thus, by preventing the initial vertical movement of the mixing drum 16, the subsequent lateral motion of the mixing drum 16 relative to the centreline Y of the vehicle 1 is prevented.

In an alternative embodiment shown in Fig. 5, the contact element 70 for the radially jo inward positioned at least one stop 62 may be located in a position different to the modified drum ring 19 as described above. For example, the contact element 70 may be located at the rear of the mixing drum 16. That is, the contact element 70 comprising the first and second portions 71, 72 may extend about the opening 28 of the mixing drum 16. In the embodiment shown in Fig. 5, the second portion 72 of the contact element 70 may extend towards the front of the vehicle 1. In some embodiments, the second portion 72 of the contact element 70 may extend towards the rear of the vehicle 1.

The various embodiments described herein are presented only to assist in understanding and teaching the claimed features. These embodiments are provided as a representative sample of embodiments only, and are not exhaustive and/or exclusive. It is to be understood that advantages, embodiments, examples, functions, features, structures, and/or other aspects described herein are not to be considered limitations on the scope of the invention as defined by the claims or limitations on equivalents to or the claims, and that other embodiments may be utilised and modifications may be made without departing from the scope of the claimed invention. Various embodiments of the invention may suitably comprise, consist of, or consist essentially of, appropriate combinations of the disclosed elements, components, features, parts, steps, mean, etc., other than those specifically described herein. In addition, this disclosure may include other inventions not presently claimed, but which may be claimed in future.

Claims (10)

1. Claims 1. A vehicle for mixing concrete, the vehicle comprising: a cabin configured to allow an operator to control the vehicle; a chassis comprising a frame configured to support a load on the vehicle, the frame having a longitudinal axis that is substantially parallel to the ground; a rotatable mixing drum supported on the chassis such that the longitudinal axis of the mixing drum is inclined relative to the longitudinal axis of the frame, the mixing drum comprising a drum ring and being configured to hold and mix jo a load; wherein the chassis comprises a rear pedestal on which the drum ring of the mixing drum is supported; the rear pedestal comprising a pair of drum rollers configured to contact the drum ring; and at least one stop configured to limit vertical movement of the rotatable mixing drum such that lateral movement of the mixing drum beyond a predetermined distance from a centreline of the vehicle is prevented.
2. 2. The vehicle according to claim 1, wherein the at least one stop is spaced from 20 the rotatable mixing drum such that there is a gap between the at least one stop and the rotatable mixing drum.
3. 3. The vehicle according to claim 2, wherein the size of the gap between the at least one stop and the rotatable mixing drum is in the range of to mm to 20 MM.
4. 4. The vehicle according to claim 3, wherein the size of the gap is defined by the smallest distance between the rotatable mixing drum and the at least one stop, when the mixing drum is supported by the pair of drum rollers.
5. 5. The vehicle according to any one of claim 2 to claim 4, wherein the at least one stop is positioned so as to contact a contact element of the mixing drum when the mixing drum moves off of at least one of the pair of drum rollers.
6. 6. The vehicle according to any one of the preceding claims, wherein the at least one stop is mounted on the rear pedestal.
7. 7. The vehicle according to claim 6, wherein the contact element comprises a first portion and a second portion, wherein the first portion and second portion extend substantially perpendicularly relative to each other, and wherein the at least one stop is mounted closer in the radial direction to the longitudinal axis of the mixing drum than the second portion of the contact element and configured to constrain movement of the mixing drum in the vertical direction.
8. 8. The vehicle according to claim 7, wherein the second portion of the contact element extends substantially parallel to the longitudinal axis of the mixing drum.
9. 9. The vehicle according to claim 8, wherein the second portion of the contact element extends towards the rear of the vehicle.
10. 10. The vehicle according to claim 8, wherein the second portion of the contact dement extends towards the front of the vehicle.it The vehicle according to any one of claim 5 to claim 10, wherein the contact element extends about the opening of the mixing drum.12. The vehicle according to any one of claim 5 to claim 10, wherein the contact element is formed by the drum ring.13. The vehicle according to claim 12. wherein contact element comprises a first portion formed by the drum ring and a second portion extending from the first portion.14. The vehicle according to any one of claims to claim 10, wherein the contact element extends from an opening of the mixing drum.15. The vehicle according to any one of claim 6 to claim 14, wherein the at least one stop is located further from the frame of the chassis than the pal r of drum rollers.16. The vehicle according to any one of claim 6 to claim ii, wherein the at least one stop is located further from the frame of the chassis than the centre of gravity of the mixing drum and a load within the mixing drum.-20 - 17. The vehicle according to any one of claim 6 to claim 16, wherein the at least one stop is located at a greater distance from the centreline of the vehicle than at least one of the pair of drum rollers.18. The vehicle according to claim 17, wherein the at least one stop is located closer to the cabin than the pair of drum rollers.19. The vehicle according to claim 17 or claim 18, wherein the at least one stop is located between 30 and 90 degrees about the longitudinal axis A of the mixing drum jo from the centre of the pair of drum rollers.19. The vehicle according to any one of claim 6 to claim 15, wherein the at least one stop is located at a lesser distance from the centreline of the vehicle than at least one of the pair of drum rollers.20. The vehicle according to claim 19, wherein the at least one stop is located further from the cabin than the pair of drum rollers.21. The vehicle according to claim 19 or claim 20, wherein the at least one stop if 20 located between o and 30 degrees about the longitudinal axis A of the mixing drum from the centre of the pair of drum rollers.22. The vehicle according to any one of the preceding claims, wherein the at least one stop comprises a contact surface configured to contact the mixing drum formed by a low friction surface.23. The vehicle according to claim 22, wherein the low friction surface of the at least one stop is a rotatable roller.24. The vehicle according to claim 23, wherein an outer surface of the rotatable roller is formed by a low friction material.25. The vehicle according to claim 22, wherein the low friction surface is a non-rotatable surface formed by a low friction material.