AU736430B2 - Movable median strip - Google Patents

Description

-1-

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION "S 0 000* 0 *0 FOR A STANDARD PATENT

ORIGINAL

Name of Applicant: 4* AUTHORITY, NEW SOUTH WALES John Sydney WINNING and Gary Wayne DIXON John Sydney WINNING and Gary Wayne DIXON Actual Inventor: Address of Service: Invention Title: BALDWIN SHELSTON WATERS MARGARET STREET SYDNEY NSW 2000 "MOVABLE MEDIAN STRIP" Details of Associated Provisional Application No. P06074 dated 8 April 1997 The following statement is a full description of this invention, including the best method of performing it known to us:- -2- The present invention relates to an elongate partition arrangement adapted to divide a generally flat surface, and more particularly to a movable partition.

The invention has been developed primarily for use as a median strip to separate traffic lanes and will be described hereinafter with reference to this application. It will be appreciated, however, that the invention is not limited to this particular field of use.

It is well known to provide median strips in the form of rigid generally slab like structures formed from concrete or other materials for the purpose of dividing roadways to separate traffic lanes. Such median strips typically incorporate bevelled edges, to prevent damage to wheels and tyres when inadvertently struck by wayward vehicles. Such median V 10 strips are reasonably effective in separating lanes of traffic moving in opposite directions, and have contributed substantially to a reduction in the accident rate in heavy traffic areas.

S A problem arises, however, in that traffic flow patterns can vary considerably at different times of the day, particularly in cities. For example, in many locations a large 0% number of vehicles may travel into the central business district in the morning, and leave in the afternoon. Consequently, during the morning peak period, it is often necessary to dedicate a majority of lanes to inflowing traffic, and vice versa in the afternoon.

Accordingly, to make optimum use of limited road space, it is often desirable to vary the position of median strips during the day.

To this end, it is also known to provide movable median strips which typically comprise a series of elongate segments interconnected to form a composite strip. Each element is typically supported on wheels to permit a degree of movement across the surface of the road. It is also known to provide a drive mechanism to facilitate lateral displacement of some or all of the segments to the desired position.

A long standing problem with such arrangements, however, has been the difficulty in effectively transmitting traction from the drive mechanism to the road surface, which is often rough, slippery, broken or uneven. The problem is exacerbated in the case of oil spillages or gravel surfaces, which further reduce contact friction.

One known form of drive element takes the form of a rubberised cylindrical steel roller intended to establish a line of surface contact with the road, corresponding to the length of the roller. In practice, however, because of the coarse surfaces typically associated with bitumen roads, which are often combined with uneven or undulating profiles, the contact in practice is often limited to several points or asperities, providing minimal frictional engagement. Consequently, in practice, activation of the drive mechanism often fails to effect the desired transverse movement of the median strip, at S •least to the required degree. This situation often necessitates manual intervention which is S"inefficient, time consuming and potentially dangerous.

•It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative.

Accordingly, the invention as presently contemplated provides a movable partitioning apparatus for use as a median strip to divide traffic lanes, said apparatus including a plurality of generally elongate partition elements connected in longitudinal alignment to form a composite strip, support means adapted movably to support the partition elements in a stable manner on a road surface, pivotal connection means adapted respectively to connect adjacent partition elements so as to permit relative rotation about respective pivot axes generally perpendicular to the road surface, selectively operable drive means including a transversely oriented drive track engageable with the road surface to effect lateral displacement of at least one of said partition elements, and limit means -4disposed to limit the extent of relative rotation between adjacent partition elements such that lateral displacement of any one of said partition elements beyond a predetermined limit progressively changes the relative angular relationship between successive partition elements, whereby the position and effective curvature of the composite strip may be selectively varied by said drive means.

Although the invention may be applied to two or more partition elements, it is preferred that a relatively large number of elements, for example at least five, are used.

The limit means are preferably adapted to limit the maximum extent of relative rotational displacement between adjacent partition elements to around 200.

10 In the preferred embodiment, a proximal partition element is adapted to be anchored to the road surface and remain fixed, whilst the remote element incorporates the drive means, such that the composite strip tends to form an arc of variable curvature between the two. The limit means are preferably adjustable on an individual basis, allowing the strip to assume more complex curves.

Preferably, each pivotal connection comprises a hinge assembly adapted to permit at least a limited degree of relative rotational displacement of adjacent partition elements about a hinge axis generally normal to the road surface, the hinge axis being off-set to one side of a centre line of the strip.

Preferably, the limit means include a lost motion link comprising a pin slidable within an elongate slot along a longitudinal path of predetermined length. The pin and slot are preferably off-set to the other side of the centre line of the strip. In this arrangement, the ends of each slot define the respective positions of maximum relative rotational displacement between the corresponding pair of adjacent partition elements.

In the preferred embodiment, the remote partition element houses a drive assembly in the form of an electric, hydraulic or pneumatic drive motor, a controller, and a transversely oriented drive track assembly. Preferably, the drive track comprises a series of parallel elongate track segments hingedly interconnected to form a track chain. At least five and preferably about ten of the track segments are preferably adapted to engage the surface of the road at any one time. The track segments are preferably formed from metal. As a design improvement rubber may be vulcanised onto the surface of the metal segments to provide significantly improved adhesion with the road surface and improved tractability.

The control mechanism may provide for manual actuation; or alternatively may V incorporate a timer, a radio controller, or other remote control means. The controller may also be adapted to interact with position sensors mounted in the road, for example as limit S. switches or as part of a more complex feed back control loop to prevent movement of the median strip beyond predetermined position(s).

preferred embodiment of the invention will now be described, by way of example only, with reference to the accompany drawings in which:- Figure 1 shows a movable partitioning apparatus adapted to form a median strip on a roadway, according to the present invention; Figure 2 is perspective view showing the drive track assembly adapted for use in the remote partition element of the apparatus of Figure 1; Figure 3 is a perspective view showing a support wheel for the partition elements; Figure 4 is a perspective view showing the pivotal connection joining adjacent partition elements of the apparatus of Figure 1; Figure 5 is a perspective view showing complementary limiting means according to the invention; and -6- Figure 6 is a diagrammatic cut-away view showing the remote partition element of the median strip of Figure 1 incorporating the track drive assembly of Figure 2.

Referring to the drawings, the partition apparatus of Figures 1 to 6 comprises a series of partition elements or modules la to Id of elongate form. The modules are connected end to end by pivotal connection means in the form of a hinge coupling 2 as shown in Figure 4, and limit means in the form of a motion limiting connection 3, as shown in Figure 5. Each module 1 is movably supported on a road surface by a series of support wheel units 4, as shown in more detail in Figure 3. The remote end module la accommodates a drive motor for driving a drive track unit 5 as shown in Figure 2. The apparatus is constructed such that by operation of the motor in the module 1 a, the track drive unit 5 is driven to move module l a laterally in an arc in either direction, for example to adopt the position in dotted lines in Figure 1. The relative motion of two adjacent modules is governed by the hinged connection 2 and the motion limiting connection 3 between the modules. As will be described in detail below, the module la is displaced until the limit of motion relative to the next module is taken up whereupon this module is moved in an arc with the first module la. The total displaceability of the first module la thus depends on the total of the freedom of movement between all the adjacent pairs of modules in the series.

As shown in Figure 1, the shape of each module is that of a conventional median strip, normally formed from concrete to define a permanent central dividing strip between carriageways. The illustrated apparatus is intended to be connected through a steel anchoring plate to the end face of a permanent concrete median strip, each of the modules having the same cross-section which is generally that of a trapezium. Each module is fabricated from steel sheets suitably strengthened where necessary and welded together to -7form a box structure. Removable semi-flexible posts (not shown) can be mounted at spaced intervals along the modules to provide a clearer warning to drivers of the existence of the partition strip. The posts can also have a suitable reflective coating.

Support wheel units 4, as shown in Figure 3, are mounted at each corner of each module. Each support wheel unit comprises a wheel 11 rotatably mounted on an axle extending between cheek plates 10 which are rotatably mounted about respective hinge pins to a mounting plate 9 screwed to the box structure of each module. A bridge plate extends between the cheek plates 10 at a central portion, although the bridge plate is not shown in the drawing. Helical compression springs 12 are mounted between this bridge plate and the underside of the mounting plate 9 to provide suspension for the wheel 11.

The arrangement is such that normally the module is completely supported by the wheels and so can be moved laterally when desired. However, in the event that a heavy vehicle inadvertently drives onto a module, unless excessively expensive and strong wheel units "-are provided, damage would result but for the fact that the springs 12 compress such that the peripheral base of the module abuts the road surface, thereby supporting the applied weight.

For the purpose of moving the modules (refer to Figures 1 and the track drive unit arrangement 5 installed in module 1 a is employed. The drive track unit is constructed in a similar manner to the support wheel units 4 but a broad track chain 6 including a plurality of individual track segments is provided for transmitting motion. Preferably, between five and ten segments of the track are in contact with the ground at any one time, to facilitate transmission of the drive. The track chain 6 is driven conveniently by a hydraulic motor 7.

The track drive unit also includes compression springs (not shown) which engage the support shafts 5. Movement of the module is controlled by an electrical switch located -8beneath an access panel at the anchored end of the median. A three phase motor is used to power the hydraulics, such that the direction of travel may be reversed simply by swapping phases in the motor.' Figure 5 illustrates the motion limiting connection between adjacent modules 1 a and 1 b which are shown partially in outline only. The modules are connected by a unit comprising first and second castings 16 and rod end 17 which are attached to the respective end walls of the modules la and lb. As best shown in Figure 5, the rod end 17 is anchored relative to the module 1 by means of a screw thread which is fixed on the rod end 17. The rod end 17 is fixed relative to the casting 16 at its right hand end as viewed in Figure 5 by a e vertical pin 18. The pin is slidable within an elongate slot along a longitudinal path of :"predetermined length. The pin and slot are disposed on the opposite side of the centre line of the partition element with respect to the hinge connection. In this way, the ends of the slot define the positions of maximum relative rotational displacement between the corresponding pair of adjacent partition elements.

Referring now to Figure 4, the hinge connection between adjacent modules l a and b is shown. The hinge connection comprises a first mounting plate 13 screwed to the end of one module, the mounting plate 14 having outwardly extending spaced lugs between which a vertically extending hinge pin 15 is mounted.

The end module l a is shown in a modified form in Figure 6. The module is adapted to be moved by laterally spaced track drive 6 which is driven by hydraulic motor 7. The motor 7 is in turn driven by a hydraulic circuit which includes hydraulic pump 19 driven by the electric motor.

-9- The electric motor is switched on to drive the hydraulic pump 19 to pressurise the circuit, and direction is controlled electrically by the three phase motor rotation. In this way the track drive rotates to move the module.

When the module reaches the desired end position, proximity switches are triggered in the control module by location strips in the road surface. These signal the electric motor to switch off and can also signal the control system, to indicate that the selected position has been reached.

The track drive mechanism of the invention has been found to be effective in o:eo transmitting drive over rough, wet, undulating or broken surfaces in a reliable efficient and effective manner, thereby facilitating manual, automated, or remote control depending upon the desired level of functionality. Hence, the invention represents a commercially significant improvement over the prior art.

Although the invention has been described with reference to specific examples, it ••will be appreciated by those skilled in the art that the invention may be embodied in many other forms. For example, the control mechanism may provide for manual actuation, or alternatively may incorporate a timer, a radio controller, or any other direct or remote control means. Moreover, any number, shape or configuration of partition elements may be used within the general functional limitations of the invention. Furthermore, a variety of alternative pivotal connection and motion limiting arrangements are also contemplated.

Claims (13)

1. A movable partitioning apparatus for use as a median strip to divide traffic lanes, said apparatus including a plurality of generally elongate partition elements connected in longitudinal alignment to form a composite strip, support means adapted movably to support the partition elements in a stable manner on a road surface, pivotal connection means adapted respectively to connect adjacent partition elements so as to permit relative rotation about respective pivot axes generally perpendicular to the road surface, selectively operable drive means including a transversely oriented drive track engageable with the road surface to effect lateral displacement of at least one of said partition elements, and limit means disposed to limit the extent of relative rotation between adjacent partition elements such that lateral displacement of any one of said partition elements beyond a predetermined limit progressively changes the relative angular relationship between successive partition elements, whereby the position and effective curvature of the composite strip may be selectively varied by said drive means.

2. A movable partitioning apparatus as claimed in claim 1, wherein the limit means are S"adapted to limit the maximum extent of relative rotational displacement between adjacent partition elements to around 200.

3. A movable partitioning apparatus as claimed in claim 1 or claim 2, wherein said apparatus includes a proximal partition element which is adapted to be anchored to the road surface and remain fixed, whilst a remote element includes said drive means, such that the composite strip tends to form an arc of variable curvature between the two.

4. A movable partitioning apparatus as claimed in claim 3, wherein the limit means are adjustable on an individual basis, allowing the strip to assume more complex curves. -11- A movable partitioning apparatus as claimed in any one of the preceding claims, wherein each pivotal connection includes a hinge assembly adapted to permit at least a limited degree of relative rotational displacement of adjacent partition elements about a hinge axis generally normal to the road surface.

6. A movable partitioning apparatus as claimed in claim 5, wherein the hinge axis is off-set to one side of a centre line of the strip.

7. A movable partitioning apparatus as claimed in any one of the preceding claims, wherein the limit means include a lost motion link including a pin slidable within an elongate slot along a longitudinal path of predetermined length. S10 8. A movable partitioning apparatus as claimed in claim 7, wherein the pin and slot are *0o* off-set to the other side of the centre line of the strip.

9. A movable partitioning apparatus as claimed in any one of claims 3 to 8, wherein the remote partition element houses a drive assembly in the form of an electric, hydraulic or •pneumatic drive motor, a controller, and a transversely oriented drive track assembly.

10. A movable partitioning apparatus as claimed in claim 9, wherein the drive track includes a series of parallel elongate track segments hingedly interconnected to form a track chain.

11. A movable partitioning apparatus as claimed in claim 10, wherein at least five of the track segments are adapted to engage the surface of the road at any one time.

12. A movable partitioning apparatus as claimed in any one of claims 10 or 11, wherein the track segments are formed from metal.

13. A movable partitioning apparatus as claimed in any one of claims 10 or 11, wherein the track segments are formed from metal and rubber. -12-

14. A movable partitioning apparatus as claimed in any one of claims 9 to 13, wherein the control mechanism is adapted for manual actuation, or alternatively includes a timer, a radio controller, or other remote control means. A movable partitioning apparatus as claimed in claim 14, wherein the controller is adapted to interact with position sensors mounted in the road, for example as limit switches or as part of a feed back control loop to prevent movement of the median strip beyond predetermined position(s).

16. A movable partitioning apparatus for use as a median strip substantially as herein gdescribed with reference to any one of the embodiments of the invention shown in the accompanying drawings. DATED this 8th Day of April, 1998 CHIEF EXECUTIVE FOR ROADS AND TRAFFIC AUTHORITY, NEW SOUTH WALES Attorney: STUART M. SMITH /g Fellow Institute of Patent Attorneys of AustraliaC g of SHELSTON WATERS