WO2000058567A1

WO2000058567A1 - Load handling apparatus and vehicle including such apparatus

Info

Publication number: WO2000058567A1
Application number: PCT/GB2000/001095
Authority: WO
Inventors: Alan Richard Reece; Peter John Renwick
Original assignee: Pearson Engineering Limited
Priority date: 1999-03-30
Filing date: 2000-03-30
Publication date: 2000-10-05
Also published as: AU3441600A

Abstract

A vehicle (10) having a load handling apparatus for moving a snow plough (14) between first and second positions about a transverse pivot axis (20) is disclosed. The snow plough (14) is mounted to vehicle body (12) about axis (20) via a support frame (22), and linear actuators (24, 26) are connected between the support frame (22) and the vehicle body (12). The positions of the linear actuators (24, 26) on the vehicle body (12) are offset relative to each other, such that the turning moment produced by one of the actuators is zero when the snow plough (14) is located substantially vertically above the axis (20), the turning moment produced by each actuator is zero at a respective orientation of the support frame (22), and the actuators (24, 26) do not produce a zero total turning moment at any orientation of the support frame (22) between its first and second positions.

Description

LOAD HANDLING APPARATUS AND VEHICLE INCLUDING SUCH APPARATUS

The present invention relates to load handling apparatus and to vehicles carrying such apparatus, and relates particularly, but not exclusively, to such vehicles adapted to travel at speed and/or to travel over rough terrain.

Large plant vehicles are increasing called upon to travel at high speeds, either to maintain a speed equivalent to that of normal traffic on increasingly busy roads, or simply to get from one place to another as quickly as possible, thus reducing non-productive time in transit. Clearly, it is important that the stability of such a vehicle be maintained when travelling at speed.

In vehicles carrying a heavy forward mounted implement, such as a snowplough or bulldozer shovel, the heavy implement moves the centre of gravity of the whole vehicle forward. When travelling on soft or uneven ground this results in an increased tendency for the vehicle to lean forward and the front of the vehicle to dig into the surface on which it is travelling, either by the front mounted implement or the front of a body of the vehicle contacting the surface on which it is travelling.

Attempts have been made to prevent a front mounted implement from contacting the surface on which it is travelling in such situations by lifting the implement above the surface on which it is travelling. However, this is only a partial solution to the problem, since the weight of the implement is still located towards the front of the vehicle, and may result in the field of vision of the vehicle operator being impaired.

It is also an advantage for a large plant vehicle to be able to work with various different implements mounted on it at different times. However to repeatedly change from one implement to another may be time consuming and/or require transport of the vehicle to a workshop. Examples of front ounted interchangeable implements are shown in Figures 1 and 2. If both implements are simultaneously mounted on a vehicle, in such a way that one implement can be moved out of the way of the working position of the other, and vice versa, the time required to switch from one implement to another is considerably reduced.

However, if such a vehicle has two front mounted implements, the difficulties of excess weight at the front of the vehicle are increased and the front of the vehicle is more likely to come into unintended contact with the surface on which it is travelling during transport. Furthermore, if one implement is lifted a short distance out of the way of a second implement's working position, the vehicle operator's view may be obscured.

Preferred embodiments of the present invention seek to overcome the above disadvantages of the prior art .

According to an aspect of the present invention, there is provided a load handling apparatus for moving a load between first and second positions about a non-vertical axis, the apparatus comprising :-

a support frame for supporting a load and pivotably mounted to a support body via a non-vertical axis; and

a plurality of linear actuators for producing a turning moment to pivot said support frame between said first and second positions about said axis, wherein

(i) each said linear actuator is connected between a respective first pivot on said support frame and a respective second pivot on said support body;

(ii) said first and/or second pivot of at least one said linear actuator is offset from said first and/or second pivot of at least one other said linear actuator in a direction transverse to said non-vertical axis,

such that the turning moment produced by at least one said linear actuator is zero in at least one position of the load located substantially vertically above said axis, and the turning moment produced by each said linear actuator is zero at a respective orientation of the support frame between said first and second positions, and said linear actuators do not produce a zero total turning moment at any orientation of the support frame between said first and second positions.

By providing a plurality of linear actuators which do not produce a zero total turning moment at any orientation of the support frame, this provides the advantage that it is possible to construct a lighter and more compact load handling apparatus than in the case of the prior art. This is particularly advantageous in the case of the load handling apparatus being mounted to a vehicle, since the disadvantages of a heavy load such as an implement being arranged at the front of the vehicle are minimised. Furthermore, by providing a plurality of linear actuators such that the turning moment produced by at least one said linear actuator is zero in at least one position of the load located substantially vertically above the non-vertical axis, this provides the advantage that the apparatus can be constructed in such a way that the minimum total turning moment generated by the linear actuators occurs at or around that part of the movement between the first and second positions where the minimum moment is required, i.e. at or about where the load passes vertically above the axis. This in turn gives the advantage that matching between the delivered and required moments can be optimised, so that the apparatus does not inefficiently generate vastly more moment than required at certain part of its movement.

Said support frame may comprise at least one support member. In a preferred embodiment, said support frame comprises a pair of substantially parallel support members.

Said first and/or second pivots may be arranged in pairs such that the pivots of each said pair are angularly offset relative to each other in planes transverse to the axis of pivotal movement of the support frame between said first and second positions .

In a preferred embodiment, the position of at least one said first and/or second pivot is adjustable.

Each said linear actuator is preferably a hydraulic actuator.

The apparatus may further comprise hydraulic drive means for driving said hydraulic actuators such that hydraulic fluid is supplied at substantially the same pressure to each said actuator independently of the speed of movement of said actuators .

The apparatus may further comprise switching means adapted to operate at different positions of the movement of the support frame to reverse the direction of motion of each said actuator.

The axis may be substantially horizontal.

According to another aspect of the present invention, there is provided a vehicle comprising:

(a) drive means for enabling the vehicle to move; and

(b) a load handling apparatus as defined above, wherein said support body is a body of the vehicle.

Preferably, the load comprises a first implement mounted to said support frame, and the support frame is pivotally mounted relative to said vehicle body about a transverse axis and is adapted to be moved between a first working position in which the implement is located towards the front of the body and a first stowed position in which the implement is located towards the rear of the body.

By pivotally mounting an implement relative to the body of the vehicle such that the implement can be moved from a working position towards the front of the vehicle to a stowed position towards the rear of the vehicle, this provides the advantage of moving the centre of gravity away from the front of the vehicle, thus reducing the tendency of the front of the vehicle to contact the surface on which it is travelling during transport. By providing a plurality of linear actuators which do not produce a zero total turning moment at any orientation of the support frame, this utilises the surprising discovery that it is possible to construct an apparatus which acts on an implement in a non-symmetrical manner, so that for example, an apparatus having two actuators can be constructed, but because of the non-symmetrical arrangement of the actuators, one produces a non- zero moment when the other produces a zero turning moment. Prior to the above discovery, there had been a strong prejudice in the art against constructing such apparatus in which the turning moment is not produced symmetrically on both sides of the apparatus.

By arranging each linear actuator to produce a zero turning moment at a respective orientation of the support frame between the first and second orientations, this provides the advantage that the moment produced by each individual actuator can be arranged to have greater magnitude at or near to the first and second orientations. This in turn reduces the mismatch between the load and actuator characteristics, thus enabling more efficient use of the linear actuators. As a result, the cost of manufacture of the apparatus can be reduced by comparison with the prior art, since expensive linear actuators having a moment producing capacity far in excess of that required do not need to be provided. In addition, m the case of an apparatus having only two actuators, the angular range over which an apparatus equipped with only two actuators can effectively operate is increased. The further advantage is provided of enabling the apparatus for moving the implement to be constructed more compactly.

The vehicle may further comprise a second implement mounted to said vehicle body and having a second working position and a second stowed position, wherein said first implement can move between said first working position and first stowed position when said second implement is in said second stowed position.

According to a further aspect of the present invention, there is provided a vehicle comprising :-

(a) a vehicle body;

(b) drive means for enabling the vehicle to move;

(c) a first implement having a support frame, wherein the support frame is pivotally mounted to said body about a transverse axis and adapted to be moved between a first working position in which the implement is located towards the front of the body and a first stowed position in which the implement is located towards the rear of the body; and

(d) a second implement mounted to said body and having a second working position and a second stowed position, wherein said first implement can move between said first working position and said first stowed position when said second implement is m said second stowed position.

The vehicle may further comprise a plurality of linear actuators for producing a turning moment to pivot said support frame between said first working and first stowed positions, wherein the turning moment produced by each said linear actuator is zero at a respective orientation of said support frame between said first working and first stowed positions, and said linear actuators do not produce a zero total turning moment at any orientation of the support frame between said first working and first stowed positions .

In a preferred embodiment, said second implement comprises a plurality of members pivotably interconnected to enable the second implement to move between said second stowed position and said second working position, the vehicle further comprising a plurality of further linear actuators acting between at least one pair of said interconnected members for producing a turning moment to pivot said members to move the second implement between said second stowed position and said second working position, wherein, for the or each said pair of members, the turning moment produced by each said further linear actuator is zero at a respective orientation of said pair of members relative to each other, and said further linear actuators do not produce a zero total turning moment at any orientation of the said pair of members between said second working and second stowed positions.

This provides the advantage that the unexpected benefit of using a plurality of first linear actuators defined above can be applied to deploying the second implement, with the accompanying advantage that the maximum deployment power can be achieved with the most compact actuator construction.

At least one said implement may be a crane.

At least one said implement may be an articulated digging arm.

In a preferred embodiment, said second implement in said second stowed position is contained within the volume enclosed by the movement of the support frame of said first implement from said first working position to said first stowed position. Preferably, said first implement is a forward mounted plough.

Alternatively, said first implement may be a bulldozer shovel.

Preferred embodiments of the invention will now be described, by way of example only and not in any limitative sense, with reference to the accompanying drawings, in which:

Figure 1 is a schematic elevation view of a prior art vehicle having two implements, including a bulldozer shovel and a crane ;

Figure 2 is a schematic elevation view, corresponding to Figure 1, of a prior art vehicle having two implements, including a snowplough and a crane;

Figure 3 is a schematic elevation view of a vehicle of a first embodiment of the present invention and having three implements, the first implement being in the stowed position thereof ;

Figure 4 is a schematic elevation view of the vehicle of Figure 3 showing the arc of movement of the first implement as it moves from the stowed to the working position;

Figure 5 is a schematic elevation view of the vehicle of Figure 3 with the first implement in the working position thereof.

Figure 6 is a plan view of the vehicle of Figure 5;

Figure 7 is a schematic perspective view of an apparatus of the vehicle of Figures 3 to 6 for moving the first implement between the working and stowed positions thereof;

Figure 8 is an elevation view of the apparatus of Figure 7; Figure 9 is a graph showing the torque delivered by the apparatus of Figures 7 and 8, compared with the torque required to move a load at various positions through 180 degrees about a horizontal axis;

Figure 10 is an elevation view of a vehicle of a second embodiment of the present invention having two implements, one of the implements being in the working position thereof;

Figure 11 is a plan view of the vehicle shown in Figure 10;

Figure 12 is an elevation view of the vehicle of Figure 10 with an implement m the stowed position; and

Figure 13 is a plan view of the vehicle shown in Figure 12.

Referring to Figure 3, a vehicle 10 of a first embodiment of the invention has a body 12 onto which is mounted a first implement 14 in the form of a snowplough. There is also mounted on body 12 a second implement 16 m the form of a crane and a third implement 18 m the form of a bulldozer shovel.

Snowplough 14 is pivotally mounted to vehicle body 12 about a transverse pivot axis 20 via support frame 22. Support frame 22 is further connected to vehicle body 12 by linear actuators 24 and 26 m the form of hydraulic cylinders. Figure 3 shows snowplough 14 in the stowed position 28, crane 16 m the stowed position 30 and shovel 18 in the working position 32 thereof.

In Figure 4, crane 16 remains in stowed position 30 and shovel 18 is in a stowed position 34. Snowplough 14 and support frame 22 are movable by means of hydraulic cylinders 24 and 26 from stowed position 28 to working position 36 (shown m Figure 5) . In moving from stowed position 28 to working position 36, cross-member 38 of support frame 22 defines an arc 40 (as shown in Figure 6) . In stowed position 30, crane 16 fits within the volume defined by arc 40 and the accompanying movement of side members 42 and 44 of support frame 22.

Referring to Figure 7, support frame 22 comprises side members 42 and 44, and cross-member 38, the support frame 22 being pivotable about a pivot axis 50. The transverse pivot axis 50 passes through a pair of attachment members 52 , 54 having pivots 56 and 58 to which the ends of respective linear actuators in the form of hydraulic cylinders 24, 26 are attached. It can be seen from Figure 7 that pivot 56 on attachment member 52 lies generally vertically above the pivot 60, whereas pivot 58 on attachment member 54 is displaced from a line 62 extending vertically through pivot 60. The opposite ends of the hydraulic cylinders 24, 26 are attached to the legs 42, 44 at respective pivots 64, 66 . It will be appreciated by persons skilled in the art that more or less than two side members 42,44 could be used.

As shown in more detail in Figure 8, the pivot 58 on attachment member 54 is angularly offset by approximately 30° in an anticlockwise sense as shown in the Figure relative to the pivot 56 vertically above the pivot axis 50 on attachment member 60. As a result, the hydraulic cylinders 24, 26 shown in Figures 7 and 8 are throughout most of the process of pivoting support frame 22 about pivot axis 50 at different points in their respective strokes, as a result of which the turning moment applied to the portal frame 22 about pivot axis 50 by each hydraulic cylinder 24, 26 will generally be different. The cylinders 24, 26 are so arranged that the total moment applied to the portal frame 22 about pivot axis 50 by the cylinders 24, 26 is never zero in moving the portal frame 22 between the working positions and stowed position.

Figure 9 shows a graph of the torque delivered by the apparatus of Figures 7 and 8 at orientations of the load relative to the horizontal between 0 and 180 degrees. The graph also shows the torque required to move the load about the axis through 180 degrees between the two horizontal orientations of the load. It can be seen from Figure 9 that the torque delivered by the apparatus is slightly higher than that required throughout the entire movement of the load, i.e. there is close matching between the required and delivered torques. It can therefore be seen that the present invention has the advantage that at no part of the movement of the load is the apparatus delivering significantly more torque than is required. This enables the linear actuators to be used to maximum effect, thus enabling the device to be constructed more compactly than in the prior art .

Referring to Figures 10 to 13, in which parts common to the embodiment of Figures 3 to 9 are denoted by like reference numerals but increased by 100, a vehicle 110 of a second embodiment of the invention has a body 112 carrying a platform 113 which can rotate about a pivot 115. A crane 116 is mounted to the platform 113 by means of a pivot 117 and can be rotated about pivot 117 between a working position shown in Figures 10 and 11 and a stowed position shown in Figures 12 and 13. Pivoting of the crane 116 about pivot 117 is controlled by means of a load handling apparatus similar to that used to pivot the snowplough 14 of Figures 3 to 6, except that hydraulic cylinders 124 and 126, which operate in a similar manner to the cylinders 24, 26 of the embodiment of Figures 3 to 9 and whose operation will therefore be understood by persons skilled in the art, act between the platform 13 and crane 116 having a single member instead of a pair of side members 42 , 44.

As a result of the use of offset cylinders 124, 126, the total turning moment applied to the crane 116 about pivot 117 by the cylinders 124, 126 is non zero in moving the crane 116 between the working and stowed positions, as a result of which pivoting of the crane 116 can be achieved using smaller cylinders than in the prior art. This enables a particularly compact construction of the crane when in its stowed position. The movement of the hydraulic cylinders 24, 26, 124, 126 is controlled by reversing the flow of hydraulic fluid into the cylinders 24, 26, 124, 126 when they reach their shortest length in order to effect a smooth forward or backwards movement. This can be achieved by a variety of conventional control means (not shown) which will be familiar to persons skilled in the art. Such control means operate by taking a signal that indicates the position of the support frame 22 or crane 116 and using it to drive a hydraulic changeover valve.

It will be appreciated by persons skilled in the art that the above embodiment has been described by way of example only and not in any limitative sense, and that various alterations and modifications are possible without departure from the scope of the invention as defined in the claims. For example, persons skilled in the art would appreciate that vehicles having three or more implements are also intended to be encompassed by the scope of the appended claims, and that the load handling apparatus can have linear actuators acting between a single support member and a support body, or between more than one support member and the support body. Furthermore, the load to be handled by the apparatus is not limited to being an implement on a vehicle, but could be for loading and unloading skips, for example, from a vehicle or support platform. In addition, instead of, or in addition to, offsetting the pivots on the support body relative to each other, the pivots on the support frame can be offset relative to each other to achieve a comparable effect.

Claims

Cl aims

1. A load handling apparatus for moving a load between first and second positions about a non-vertical axis, the apparatus comprising : -

2. An apparatus according to claim 1, wherein said support frame comprises at least one support member.

3. An apparatus according to claim 2, wherein said support frame comprises a pair of substantially parallel support members .

4. An apparatus according to any one of the preceding claims, wherein said first and/or second pivots are arranged in pairs such that the pivots of each said pair are angularly offset relative to each other in planes transverse to the axis of pivotal movement of the support frame between said first and second positions.

5. An apparatus according to any one of the preceding claims, wherein the position of at least one said first and/or second pivot is adjustable.

6. An apparatus according to any one of the preceding claims, wherein each said linear actuator is a hydraulic actuator .

7. An apparatus according to claim 6, further comprising hydraulic drive means for driving said hydraulic actuators such that hydraulic fluid is supplied at substantially the same pressure to each said actuator independently of the speed of movement of said actuators .

8. An apparatus according to any one of the preceding claims, further comprising switching means adapted to operate at different positions of the movement of the support frame to reverse the direction of motion of each said actuator.

10. An apparatus according to any one of the preceding claims, wherein said axis is substantially horizontal.

11. A vehicle comprising :-

(a) drive means for enabling the vehicle to move; and

(b) a load handling apparatus according to any one of the preceding claims, wherein said support body is a body of the vehicle.

12. A vehicle according to claim 11, wherein said load comprises a first implement mounted to said support frame, and the support frame is pivotally mounted relative to said vehicle body about a transverse axis and is adapted to be moved between a first working position in which the implement is located towards the front of the body and a first stowed position in which the implement is located towards the rear of the body.

13. A vehicle according to claim 12, further comprising a second implement mounted to said vehicle body and having a second working position and a second stowed position, wherein said first implement can move between said first working position and first stowed position when said second implement is in said second stowed position.

14. A vehicle comprising:

(a) a vehicle body;

(b) drive means for enabling the vehicle to move;

(c) a first implement having a support frame, wherein the support frame is pivotally mounted to said body about a transverse axis and adapted to be moved between a first working position in which the implement is located towards the front of the body and a first stowed position in which the implement is located towards the rear of the body ; and

(d) a second implement mounted to said body and having a second working position and a second stowed position, wherein said first implement can move between said first working position and said first stowed position when said second implement is in said second stowed position.

15. A vehicle according to claim 14, wherein said vehicle further comprises a plurality of linear actuators for producing a turning moment to pivot said support frame between said first working and first stowed positions, wherein the turning moment produced by each said linear actuator is zero at a respective orientation of said support frame between said first working and first stowed positions, and said linear actuators do not produce a zero total turning moment at any orientation of the support frame between said first working and first stowed positions .

16. A vehicle according to any one of claims 13 to 15, wherein said second implement comprises a plurality of members pivotably interconnected to enable the second implement to move between said second stowed position and said second working position, the vehicle further comprising a plurality of further linear actuators acting between at least one pair of said interconnected members for producing a turning moment to pivot said members to move the second implement between said second stowed position and said second working position, wherein, for the or each said pair of members, the turning moment produced by each said further linear actuator is zero at a respective orientation of said pair of members relative to each other, and said further linear actuators do not produce a zero total turning moment at any orientation of the said pair of members between said second working and second stowed positions.

17. A vehicle according to any one of claims 13 to 16, wherein at least one said implement is a crane.

18. A vehicle according to any one of claims 13 to 17, wherein at least one said implement is an articulated digging arm.

19. A vehicle according to any one of claims 13 to 18, wherein said second implement in said second stowed position is contained within the volume enclosed by the movement of the support frame of said first implement from said first working position to said first stowed position.

20. A vehicle according to any one of claims 13 to 19, wherein said first implement is a forward mounted plough.

21. A vehicle according to any one of claims 13 to 19, wherein said first implement is a bulldozer shovel .

22. A vehicle substantially as hereinbefore described with reference to Figures 3 to 9 and 7 to 13 of the accompanying drawings .