GB2473859A

GB2473859A - A cantilevered traffic pole suitable for mounting beside a roadway

Info

Publication number: GB2473859A
Application number: GB0916923A
Authority: GB
Inventors: Steven Harris; Spencer Jefferies; Joe Sapak
Original assignee: CROWN UK Ltd
Current assignee: CROWN UK Ltd
Priority date: 2009-09-25
Filing date: 2009-09-25
Publication date: 2011-03-30
Anticipated expiration: 2029-09-25
Also published as: EP2480723A1; WO2011036432A1; GB0916923D0; GB2473859B

Abstract

The traffic pole 100 comprises a trunk 102 having a cross-arm 108, and a manually operated height adjustment mechanism 114,116. The trunk is pivotable about a pivot axis 120 such that the cross-arm is movable between an operational position in which the cross-arm projects over a roadway 104, to a maintenance position wherein the cross-arm projects alongside the roadway. The height adjustment mechanism is arranged to permit translational movement of the cross-arm relative to the trunk along the pivot axis. The height adjustment mechanism may include a lock to place the height adjustment mechanism in an inactive state when in the operational position, thereby prohibiting adjustment of the cross-arm height. The height adjustment mechanism may be locked in the inactive state when the cross-arm is pivoting about the pivot axis. When the height adjustment mechanism is in the unlocked configuration, the cross-arm may be prevented from pivoting about the pivot axis.

Description

TRAFFIC POLE

The invention relates to cantilevered traffic poles, i.e. support structures for holding objects such as road signs, traffic light signals, dot-matrix information signs, speed cameras, advertising boards or the like over a roadway.

Conventional cantilevered traffic poles comprise an upright trunk attached at its base to the ground adjacent a roadway and a cross-arm having a proximal portion secured to an upper end of the trunk and extending transversely thereto to provide a distal portion located over the roadway. The cross-arm can be mechanically fixed to the trunk using any conventional fixing, e.g. bolts, welding or the like. The trunk may be partially embedded in the ground.

A load (e.g. road sign or dot-matrix information board) is attached to the cross-arm at its distal portion. For example, the load may be hung or directly affixed (or even formed integrally with) to the cross arm. The weight of the load is completely supported by the traffic pole.

A problem with this arrangement is that maintenance (e.g. repairs, replacement or the like) of the load is difficult.

Either maintenance is performed with the load in situ or the load must be dismounted for maintenance to take place elsewhere. In both cases, access to the load above the roadway is required, which necessitates road or lane closure.

For tall poles, lifting or crane equipment may be needed to gain access to the load.

At its most general, the present invention proposes a cantilevered traffic pole with a manually pivotable and height adjustable cross-arm. In use the cross-arm may be manually pivoted away from the roadway, e.g. to a position where it runs alongside the roadway, and manually lowered to permit maintenance of the load to take place at the roadside without requiring road or lane closure or lifting equipment.

Herein, manual operation may mean operation without the aid of auxiliary power sources, e.g. an electric battery or motor. 1-lowever, manual operation does contemplate manually driven operations that are enhanced by mechanical advantage obtained through the use of levering, gearing, counterweights or the like.

According to a first aspect of the invention, there may be provided a traffic pole for mounting beside a roadway, the traffic pole comprising: an upstanding trunk; a cross-arm mounted as a cantilever on the trunk, the cross-arm being manually pivotable about a pivot axis, which extends vertically through the trunk, between an operational position for projecting transversely from the trunk over the roadway and a maintenance position for projecting transversely from the trunk alongside the roadway; and a manually operated height adjustment mechanism arranged to permit relative movement of the cross-arm relative to the trunk along the pivot axis if the cross-arm is in the maintenance position.

The provision of manually operable pivoting and height adjustment mean that the traffic pole does not require a power source or control electronics, which makes them usable even in remote locations that lack a power supply and can save on manufacturing and maintenance costs.

To provide extra safety, the traffic pole may be arranged to prevent the cross-arm from being lowered into the roadway.

This may be achieved by providing an interaction between the pivoting mechanism and height adjustment mechanism that allows lowering of the cross-arm only after it has been rotated to the maintenance position. In particular, the height adjustment mechanism may be locked in an inoperable state to prevent relative movement of the cross-arm relative to the trunk along the pivot axis if the cross-arm is in the operational position.

The height adjustment mechanism may be selectively locked and unlocked when the cross-arm is in the maintenance position. For example, the traffic pole may include a cross-arm locking structure pivotable with the cross-arm about the pivot axis between an active state when the cross-arm is in the maintenance position and an inactive state when the cross-arm is in the operational position, wherein in the active state, the cross-arm locking structure is movable between a locked configuration in which relative movement of the cross-arm relative to the trunk along the pivot axis is obstructed and an unlocked configuration in which relative movement of the cross-arm relative to the trunk along the pivot axis is permitted, and in the inactive state, the cross-arm locking structure is fixed in the locked configuration. In other words, a physical obstruction may be built into the pole to prevent height adjustment, which physical obstruction can only be removed when the cross-arm is in the maintenance position.

For extra safety, the obstruction may remain in place during pivoting, i.e. the cross-arm locking structure may be fixed in the inactive state during pivoting between the operational and maintenance positions.

For yet further safety, pivoting may actually be prevented when the height adjustment mechanism is activated.

In other words, in its unlocked configuration, the cross-arm locking structure may be arranged to obstruct pivoting of the cross-arm about the pivot axis.

In one embodiment, the cross-arm locking structure may comprise a shaft (e.g. rod or other axially extending elongate element) having a cross-arm blocking element projecting therefrom (e.g. protruding outwardly therefore e.g. transversely thereto), the cross-arm blocking element being engagable with a cooperating portion (e.g. recess or the like) on the cross-arm. When the cross-arm locking structure is in the active state, the shaft may be manually rotated between an engagement orientation in which the cross-arm blocking element is engaged with the cross-arm and a disengagement orientation in which the cross-arm blocking element is disengaged from the cross-arm, but when the cross-arm locking structure is in the inactive state, the shaft may remain fixed in the engagement orientation. This may be achieved by providing a key formation that is both fixed relative to the pivot axis and intersects with the shaft if the cross-arm is in the operational position or pivoting between the operational position and the maintenance position, and a corresponding formation on the shaft that is cooperable with the key formation only if the shaft is in the engagement orientation.

Thus, the shaft must occupy the engagement orientation for the cross-arm to be physically capable of leaving the maintenance position.

Similarly, the trunk may be arranged to lock the shaft in the disengagement orientation when the cross-arm is lowered.

Maintaining the shaft in the disengagement orientation prevents accidental pivoting of the cross-arm when it is lowered because the shaft cannot cooperate with the key formation. In one embodiment, the trunk includes a plate that drops (e.g. under gravity) relative to the trunk when the cross-arm is lowered to act as a barrier to rotation of the cross-arm blocking element. When the cross-arm is raised, it may engage with and push the plate upwards relative to the trunk to permit rotation of the cross-arm blocking element (i.e. return the cross-arm blocking structure to the active state) . In summary, the cross-arm blocking structure may only be in the active state if both the cross-arm is raised and in the maintenance position.

The cross-arm locking structure may include a handle operably connected to the shaft to permit manual rotation thereof, the handle extending outside the trunk and being movable between an aligned position if the cross-arm locking structure is in the inactive state and a projecting position ifthe cross-arm locking structure is in the active state.

The handle may thus provide a visual check for the activation status of the height adjustment mechanism.

Pivoting the cross-arm about the pivot axis may be achieved by securing the cross-arm at a fixed position relative to the trunk and rotating the trunk itself, e.g. about its own axis. Thus, the traffic pole may comprise a base member e.g. for mounting beside the roadway, wherein the trunk is rotatably mounted on the base member. For example, the trunk may comprise a slewing ring mounted in the base member to rotate about the pivot axis. The base member may comprise a platform, e.g. a robust platform fixable relative to the ground adjacent a roadway. The slewing ring may thus be located at or towards the base of the trunk to facilitate access in operation. For example, the slewing ring may be manually operated by a rotary tool, e.g. turn handle or the like. For additional safety, the handle may be detachable to prevent unauthorised operation. Thus, the slewing ring may be operably coupled to an external rotary port arranged to receive (e.g. interlock with) the rotation tool.

The pivoting mechanism (which may also be referred to as the rotation or swivel mechanism) may also be lockable. The traffic pole may include a pivot lock member manually movable between a clamping configuration in which pivoting of the cross-arm about the pivot axis is prevented, and a release configuration in which pivoting of the cross-arm about the pivot axis in permitted. The pivot lock member may operate by providing selective engagement between the trunk and the base member (or other relatively rotating parts) . For example, the pivot lock member may be manually movable between a clamping configuration in which the trunk is secured to the base member to prevent relative rotation therebetween, and a release configuration in which the trunk is rotatable relative to the base member.

In one embodiment, the pivot lock member may comprise a blocking element mounted on the trunk, the blocking element protruding from the trunk to engage the base member in the clamping configuration. For example, the blocking element may comprise a rod aligned with the pivot axis, the rod being mounted in a guide formed in the trunk, which guide constrains the rod to be movable only along its length, and wherein the pivot lock member includes a handle operatively coupled to the rod for movement between the clamping configuration, in which the rod projects below the trunk to engage the base member, and the release configuration, in which the rod is disengaged from the base member.

As with the lock for the height adjustment mechanism, it may be desirable to have a visual indication of the state of the pivot lock member. The handle may provide such an indication. For example, the handle may extend outside the trunk, and be movable between an aligned position if the pivot lock member is in the clamped configuration and a projecting position if the pivot lock member is in the release configuration. Thus, the angle of the handle relative to the trunk may reflect the configuration of the pivot lock member.

The traffic pole may include either one or both of the cross-arm locking structure and the pivot lock member. If the traffic pole does includes both, additional security may be provided by securing the handles for each mechanism together if the cross-arm is in the operational position. In other words, the handle of the pivot lock member may be securable to the handle of the cross-arm locking structure when they are both in their respective aligned positions.

The height adjustment mechanism may be arranged to facilitate manual operation. For example, the cross-arm may have a strong but relatively lightweight structure, such as a truss, e.g. formed of a aluminium.

The cross-arm may comprise a carriage slidably mounted on the trunk, e.g. via bearings or the like, and the height adjustment mechanism may comprise a counterweight connected to carriage over a fulcrum mounted in the trunk. The fulcrum may comprise one or more pulleys, and the carriage may be connected to the counterweight by one or more cables, which extend over a respective pulley. The carriage may be constrained to move along tracks or channels formed in the trunk. The carriage may have formations formed thereon which engage with the tracks or channels In use, the cross-arm may support a load away from the trunk. The load, and therefore the cross-arm as a whole, may have a variable mass. The counterweight may be adjustable to provide a moment about the fulcrum that counteracts the moment of the cross-arm and load about the fulcrum. The counterweight may balance the cross-arm and load so that the cross-arm may remain suspended at any selected height.

The height adjustment mechanism may include a winching mechanism arranged to move the carriage and counterweight with respect to the fulcrum. For example, the winching mechanism may be arranged to rotate one or more of the pulleys over which cables connecting the carriage and counterweight extend to move the cable over the pulley. If the moment of the counterweight balances the moment of the cross-arm and load, the winching mechanism may be arranged to move the carriage and counterweight in a manner to preserve the balance.

The winching mechanism may be manually operated by a rotary tool, e.g. a turn handle or the like, which may be operably coupled to the pulley by a gearing arrangement to provide mechanical advantage. The handle may be detachable to prevent unauthorised operation.

To facilitate manual operation of the height adjustment mechanism, it may be desirable for the carriage to be supported on the trunk wholly by a bearing or bearings that permit relative movement therebetween during height adjustment. However, it may be undesirable for the load from the cross-arm always to be transmitted to the trunk through the bearings, e.g. because prolonged loading may damage the bearings. Accordingly, the cross-arm and trunk may include selectively interengagable portions which act to physically secure the cross-arm and trunk together as one piece and hence provide a means for transferring load other than through the bearings.

The interengagable portions may be fully engaged if the cross-arm is in the operational position. Interengagement may be achieved by relative movement between the interengagable portions along the pivot axis. For example, the interengagable portions may comprise engagement elements include locator pins, e.g. pointing along the pivot axis, receivable in pin seats. The locator pins may be fixed to the cross-arm and the pin seats may be fixed to the trunk. The cross-arm may be liftable to effect interengagement and lockable in the interengaged position.

In one embodiment, interengagement may be effected during pivoting of the cross-arm from the maintenance position to the operational position. For example, the traffic pole may comprise a sloped ramp element fixed relative to the pivot axis, the cross-arm being engaged with the ramp element during pivoting from the maintenance position to the operational position, e.g. to cause it to lift into the interengaged position. A locking member may be inserted to prevent relative axial movement between the cross-arm and trunk in the interengaged position.

In one embodiment, the cross-arm locking structure described above may be adapted to provide the means for effecting interengagement. The key formation (which locks the shaft in the engaged orientation) may be the sloped ramp element. During pivoting the shaft thus moves along its axis relative to the trunk. Since the shaft is engaged with the cross-arm via the cross-arm blocking element, the cross-arm may move with the shaft if the cross-arm blocking element is prevented from moving in the direction of the pivot axis relative to the cross-arm.

An embodiment of the traffic pole is described in detail below with reference to the accompanying drawings, in which: Fig. 1 is a schematic front view of a traffic pole that is an embodiment of the present invention; Fig. 2A is a schematic perspective view of a lower portion of a trunk of the traffic pole of Fig. 1 in a clamping configuration; Fig. 2B is a close up view of the base of the traffic pole of Fig. 1 in the clamping configuration; Fig. 3A is a schematic perspective view of a lower portion of a trunk of the traffic pole of Fig. 1 in a release configuration; Fig. 33 is a close up view of the base of the traffic pole of Fig. 1 in the release configuration; Fig. 4 is a schematic perspective partially transparent view of a lower portion of the traffic pole of Fig. 1 connected to a manually operated pivot drive mechanism; Fig. 5 is a schematic perspective view of a base member of the traffic pole of Fig. 1; Figs. 6A to 6E are various views of the base member and junction between the cross-arm and trunk of the traffic pole of Fig. 1 during pivoting from an operational position to a maintenance position; Fig. 7A is a view of a cross-arm blocking element engaged with the cross-arm and trunk of the traffic pole of Fig. 1 in a locked configuration; Fig. 73 is a view of the handle for moving the cross-arm blocking element in its locked configuration; Fig. 8A is a view of a cross-arm blocking element disengaged from the cross-arm and trunk of the traffic pole of Fig. 1 in an unlocked configuration; Fig. 83 is a view of the handle for moving the cross-arm blocking element in its unlocked configuration; Fig. 9A is schematic perspective view of a handle for a manually operated height adjustment mechanism of the traffic pole of Fig. 1 in an unlocked position; Fig. 96 is schematic perspective view of a handle for a manually operated height adjustment mechanism of the traffic pole of Fig. 1 in a locked position; Fig. lOA is a perspective view of the top of the trunk in which the cross-arm is cut away to show the inner components when the cross-arm blocking element is in an engagement orientation; and Fig. lOB is a perspective view of the top of the trunk in which the cross-arm is cut away to show the inner components when the cross-arm blocking element is in a disengagement orientation and the cross-arm is lowered.

Fig. 1 depicts a traffic pole 100 that is an embodiment of the invention. The traffic pole 100 comprises an upstanding (e.g. vertical) trunk 102 which is mounted on the ground next to a roadway 104 (e.g. motorway, freeway, traffic junction or the like) via a base member 106. The trunk 102 may be a rigid elongate support structure. It may be tubular or box-like. In this embodiment, the trunk 102 comprises a hollow casing having an oblong cross-section. The casing is hollow to enclose the counterweight and pulleys that are part of the cross-arm height adjustment mechanism discussed below.

A cross-arm 108 is mounted as a cantilever on the trunk 102. The cross-arm 108 is arranged to support a load 109 at its distal end, i.e. an end opposite to the junction with the trunk 102. The load 109, which may be a road sign, dot matrix information sign or the like, may be suspended from the cross-arm via brackets 112 or other robust attachment elements.

In this embodiment, the cross-arm 108 comprises a support element 110 made of aluminium truss that is encased in a protective cover 111.

The proximal end of the cross-arm 108 comprises a carriage 114 slidably mounted on the trunk 102. In this embodiment, the trunk has an indented channel 116 in each of its side walls in which runners (not shown), e.g. bearings or the like, mounted on the carriage 114 are conveyed. Each channel 116 extends upwards from a dead stop 118 towards the base of the trunk 102 in a direction parallel to an upright axis 120 of the trunk. The cross-arm 108 is therefore movable along the axis of the trunk 102. In this embodiment, the carriage 114 comprises a pair of flanges, each flange overlying a channel on a respective side wall of the trunk 102. Each flange is attached to the support element 110 (e.g. by bolts or welds or the like) and comprises an upwardly extending fin and a downwardly extending fin from which protrude the runners that are received in the channels.

Similarly to conventional traffic poles, the height of the cross-arm 108 is adjustable. In other words it is possible to select the distance of the carriage 114 from the dead stop 118. In this embodiment, the height adjustment mechanism is manually operated. The weight of the cross-arm 108 and load 109 is balanced by a counterweight (not shown) contained inside the trunk 102. The counterweight is connected to the cross-arm by one or more cables over a pulley system that acts as a fulcrum. The height adjustment mechanism is arranged so that upon axial movement of the cross-arm the counterweight moves relative to the fulcrum so that the respective moments of the cross-arm and counterweight only each side of the fulcrum are matched. Such height adjustment mechanisms are known. Whilst the use of a counterbalanced height adjustment mechanism is advantageous, it is not essential to the present invention.

The base member 106 may be a plate that is immovably fixed relative to the ground. In this embodiment the base has a twelve slot arrangement arranged to pass over studs that protrude up from screw pile foundations. The base plate is then secured with nuts top and bottom. N39 studs may be used.

According to the invention, the trunk 102 can be rotated about a pivot axis (which in this case corresponds to the trunk's axis 120) with respect to the base member 106. The mechanism for this is described with reference to Figs. 4 and 5.

In use, the trunk is rotated to swing the cross-arm 108 from an operational position over the roadway 104 (as shown in Fig. 1) to a maintenance position where it is aligned with the roadway, e.g. pointing into the page in Fig. 1. In this embodiment, the trunk may be rotated through 90° with respect to the base member to transfer from the operational position to the maintenance position. However, the invention is not limited to 90° rotation. For example, the invention may be provided on a traffic pole located on a corner, where a smaller or larger angle of rotation may be required to align the cross-arm with the roadway.

Fig. 2A depicts the lower part of the trunk 102 mounted on the base member 106. The bottom end of the channel 116 and dead stop 118 are visible. Below the dead stop 118, the trunk 102 comprising a housing 124 having a door 126. In this embodiment, the housing 124 contains a drive port for receiving a handle to operate the cross-arm height adjustment mechanism. This is discussed below with reference to Figs. 9A and 96.

The base member 106 has an upstanding circular wall 140 thereon, which contains a slewing ring 122. The trunk 102 flares out at its base into a circular flange 142, which sits on the circular wall 140. In Figs. 2A and 3A, the base of the trunk 102 and the circular wall 140 are shown as transparent so that the slewing ring 122 is visible. The slewing ring 122 comprises two concentric relatively rotatable rings. In this embodiment, an inner ring is fixed (e.g. bolted) to the base member 106 (see e.g. Fig. 5) and an outer ring is fixed (e.g. bolted) to the trunk 102. The outer circumferential surface of the outer ring has teeth formed thereon for engaging a drivable gear 130. Rotation of the drivable gear 130 causes rotation of the outer ring of the slewing ring 122, whereby the trunk 102 pivots on its axis relative to the base member 106. The drivable gear 130 is contained in a casing 128 mounted on the base member 106.

In this embodiment the traffic pole has locking mechanisms to prevent accidental pivoting of the trunk 102 and height adjustment of the cross-arm 108. These locking mechanisms are manually operated by handles 132, 134 located on the outside of the trunk 102 in a lower region thereof (e.g. in a position that is easily accessible to a person) The handles 132, 134 protrude through respective opening in the outside wall of the trunk 102. For example, a swivel lock handle 134 protrudes through slot 136. Fig. 2A shows both handles 132, 134 in their locked position. In this embodiment, the handles 132, 134 are arranged to overlie one another in their locked positions so that they can be secured together, e.g. by a padlock or other locking means, to prevent unauthorised operation. For this purpose, each handle 132, 134 has a through hole 138 (see Fig. 3A) for receiving a chain or padlock arm. The through holes 138 are aligned when the arms are in their locked positions.

To prevent accidental pivoting of the trunk when in the operational position, a swivel lock mechanism is provided, which is now described with reference to Figs. 2A, 2B, 3A and 3B.

As mentioned above, Fig. 2A shows a lower portion of the trunk 102 with the swivel lock handle 134 in its locked position. Fig. 28 shows a close up of the engagement between the trunk 102 and the base member 106, except that the outer casing of the trunk 102, the slewing ring 122 and the circular wall 140 are omitted to permit the inner components to be visible. Here it may be seen that the circular flange 142 is fixed to the slewing ring 122 (e.g. by bolting through holes 146) . The swivel lock handle 134 is connected to a pivot lock member 148, which is movable relative to the trunk 102 upon operation of the handle 134. In this embodiment, the pivot lock member 148 comprises a rod 149 connected via a flexible joint 150 (e.g. hinge) to a blocking member 152. The blocking member 152 is constrained to move in a substantially axial direction by sleeve 154 between a clamping configuration in which pivoting is prevented and a release configuration in which pivoting is permitted. The base member 106 includes a blocking element 156 that is arranged to restrict the motion of the blocking member 152 in the clamping configuration. In this embodiment, the blocking element 156 projects upwards from the base member 156 and in the clamping configuration the blocking member 152 protrudes from the bottom of the trunk 102 to abut the blocking element 156. Other arrangements may be possible. For example, the base member 106 may include a recess for receiving the blocking member 152 in the clamping configuration.

To deactivate the swivel lock, the swivel lock handle 134 is lifted from its locked position into an unlocked position that is shown in Fig. 3A. In this embodiment, the handle 134 is rotated about a pivot which raises the rod 149. The clamped and release configurations are shown in Figs. 2B and 33.

Figs. 2B and 3B also show the lower end of the cross-arm locking shaft 160, which is connected to the cross-arm lock handle 132. Operation of the cross-arm lock mechanism is discussed below with reference to Figs. 7A, 7B, 8A and SB.

After the swivel lock is deactivated, the trunk 102 may be rotated about its pivot axis. In this embodiment this is achieved manually by mounting a swivel drive mechanism 161 on the casing 128, as shown in Fig. 4. The casing 128 has a drive port 162 formed therein (shown in Fig. 5), into which a rotatable shaft 166 may be inserted to engage with the drivable gear 130. The shaft 166 is surround in this embodiment by a housing 164 (shown as transparent in Fig. 4 to allow the shaft 166 to be seen) . The shaft 166 and housing 164 may be permanently attached to the casing. To enable manual rotation of the shaft 166 a turn handle 170 is operably coupled to the shaft 166 via a gearing mechanism 168. For example, the gearing mechanism may be a worm gear box such as the CMQ5O-Qll0 model of SITI SpA, but the invention need not be limited to this type of device.

Fig. 5 also shows features of the base member 106 located in the space inside the slewing ring 122. There are three formations projecting upwards from the base member 106. These three formations are the blocking element 156 described above, a guide wall 172 and a ramp element 174. The guide wall 172 is provided under the path taken by blocking element 152 to stop the blocking element 152 from dropping into any other position other than its intended locked position (shown in Fig. 2B) . This means that the operator cannot rotate the swivel lock handle 134 into a locked position unless the cross-arm is in the exact desired operational position. The ramp element 174 is engagable with the cross-arm locking shaft to restrict the angular position of the cross-arm at which the cross-arm height adjustment mechanism can be unlocked, as discussed below.

Figs. 6A to 6E show how the configuration of the cross-arm locking mechanism changes during pivoting of the trunk 102 from the operational position to the maintenance position.

Figs. 6A and 6D show the configuration of a cross-arm blocking element 180 attached to the top of the cross-arm locking shaft in the operational and maintenance positions respectively.

Figs. 6B and 6E show the corresponding configurations of bottom of the shaft 160, which is shaped to engage with the ramp element 174. Fig. 6C shows the bottom of the shaft 160 sliding on the ramp element 174 during pivoting.

In this embodiment, the bottom of the shaft has a cut-out formed therein that is shaped to receive the ramp element 174 only when the cross-arm blocking element 180 is an engaged orientation (as shown in Figs. 6A and 6D) in which it is engagement with the cross-arm 108. The cross-arm 108 has a bracket 182 formed on the opposite side of the cross-arm blocking element 180 from the trunk 102. The bracket 182 has a slot 184 for receiving the blocking element 180 in its engaged orientation. The trunk 102 has a corresponding recess on the opposite side. During pivoting and in the operational position, the ramp element 174 thus acts as a keyway to fix the cross-arm blocking element 180 in the engaged orientation. In the maintenance position the cross-arm locking shaft 160 moves beyond the ramp element 174 and is permitted to rotate. However, the shape of the cut-out in the shaft 160 means that the trunk can only pivot towards the operational position if the cross-arm blocking element 180 is in the engagement orientation. The shaft is also prevented from rotating when the cross-arm is lowered, as explained below with reference to Figs. 1OA and lOB.

In this embodiment the ramp element 174 has a slope that acts to push the shaft 160 upwards as the cross-arm moves to the operational position. This urges the cross-arm blocking element 180 against the upper edges of the slots 184, 185, thereby lifting the arm and taking some or all of the load off the counterweight support mechanism (discussed above) . To provide further structural rigidity, the cross-arm 108 and trunk 102 may have formations 191, 193 formed thereon which interlock when the cross-arm 108 is urged upwards in this manner. For example, the cross-arm 108 may have upwardly extending projections 191, e.g. spikes or the like, which are receiving in corresponding recesses 193 on the trunk. An example of this arrangement is shown in Figs. 1OA and lOB.

After the trunk 102 is pivoted into the maintenance position so that the bottom of the cross-arm locking shaft 160 is clear of the ramp element 174 (as shown in Fig. 6E), the cross-arm locking shaft enters an active state, where it may be rotated between an engagement orientation and disengagement orientation. This rotation is illustrated in Figs. 7A, 73, 8A and 83.

Fig. 7A shows the top of the cross-arm locking shaft 160, with the cross-arm blocking element 180 in the engagement orientation, where it is received in the slots 184 of the brackets 182. Also visible is the carriage 114 in the channel 116 on the side wall of the trunk 102. A pulley 188 that forms part of the counterweight balance mechanism is also shown.

Fig. 7B shows the cross-arm locking handle 132 in its engaged orientation. To move to the disengaged orientation, a user manually pulls the handle 132 away from the trunk to the position shown in Fig. 8B. The handle 132 is connected to cross-arm locking shaft through a slot 186 in the wall of the trunk 102.

Fig. 8A shows the top of the cross-arm locking shaft 160 in the disengaged position. The cross-arm blocking element is aligned between the bracket 182 and trunk 102, thereby permitting to bracket 182 to move relative to the trunk and pass the blocking element as the cross-arm is lowered.

Fig. 9A shows the housing 124 for the height adjustment mechanism mentioned with reference to Fig. 2A above with the door 126 removed to show the interior. The height adjustment mechanism comprises a port 190 for receiving a turn handle 192 for operation. The port 190 is operably coupled to the counterweight balance mechanism, e.g. a pulley, whereby rotation of the turn handle 192 caused a change in height of the cross-arm 108 (and corresponding balancing movement of the counterweight) . A square washer 194 rotates with the handle.

A locking element 196 (in this case a manually movable L-shaped piece) is movable mounted in the housing 124 to provide a selective physical lock for the height adjustment mechanism.

In Fig. 9A the locking element 196 is retracted in an unlocked position where the square washer is free to rotate. In Fig. 9B the locking element 196 is extended in a locked position in which it abuts an edge of the square washer and blocks its rotation.

To prevent accidental pivoting of the trunk when the arm is lowered, a mechanism is provided for automatically putting the cross-arm locking structure in the inactive (non-rotatable) state when the cross-arm moves below a threshold height. This mechanism is shown in Figs. iDA and lOB.

In Fig. 1OA, the cross-arm locking shaft 160 is in the engagement orientation, with the cross-arm blocking element received in the recess 184 of bracket 182 as discussed above. If the trunk 102 is subsequently pivoted so that the cross-arm 108 is in the maintenance position, the shaft 160 enters the active state, where it can be rotated to move the blocking element 180 into the disengagement orientation, as shown in Fig. lOB.

When the blocking element 180 is in the disengagement orientation, the cross-arm 108 may be lowered. As it is lowered, a barrier plate 195 drops under the force of gravity to block the recess 185 in the trunk 102 that receives the blocking element 180 in its engagement orientation. The barrier plate 195 drops until protruding fingers 197 rest on the blocking element 180, as shown in Fig. lOB. The barrier plate 195 prevents the cross-arm locking shaft from returning to the engagement orientation and therefore effectively puts the cross-arm locking structure into its inactive (non-rotatable state) . However, in this case, the cross-arm locking structure is fixed in an orientation that prohibits pivoting of the trunk because the shaft 160 cannot cooperate with the ramp element 174.

When the cross-arm 108 is raised again, the upwardly moving bracket 182 engages the protruding fingers 197 to lift the barrier plate 195 away from the recess 185 so that the cross-arm locking structure returns to its active state.

Claims

CLAIMS1. A traffic pole for mounting beside a roadway, the traffic pole comprising: an upstanding trunk; a cross-arm mounted as a cantilever on the trunk, the cross-arm being manually pivotable about a pivot axis, which extends through the trunk, between an operational position for projecting from the trunk over the roadway and a maintenance position for projecting from the trunk alongside the roadway; and a manually operated height adjustment mechanism arranged to permit relative movement of the cross-arm relative to the trunk along the pivot axis if the cross-arm is in the maintenance position.
2. A traffic pole according to claim 1, wherein the height adjustment mechanism is locked in an inactive state to prevent relative movement of the cross-arm relative to the trunk along the pivot axis if the cross-arm is in the operational position.
3. A traffic pole according to claim 2 including a cross-arm locking structure pivotable with the cross-arm about the pivot axis between an active state when the cross-arm is in the maintenance position and a primary inactive state when the cross-arm is in the operational position, wherein in the active state, the cross-arm locking structure is movable between a locked configuration in which relative movement of the cross-arm relative to the trunk along the pivot axis is obstructed and an unlocked configuration in which relative movement of the cross-arm relative to the trunk along the pivot axis is permitted, and in the primary inactive state, the cross-arm locking structure is fixed in the locked configuration.
4. A traffic pole according to claim 3, wherein the cross-arm locking structure is fixed in the inactive state during pivoting between the operational and maintenance positions.
5. A traffic pole according to claim 3 or 4, wherein in its unlocked configuration, the cross-arm locking structure is arranged to obstruct pivoting of the cross-arm about the pivot axis.
6. A traffic pole according to any one of claims 3 to 5, wherein the cross-arm locking structure comprises a shaft having a cross-arm blocking element projecting therefrom, the cross-arm blocking element being engagable with a cooperating portion on the cross-arm, and wherein in the active state, the shaft is manually rotatable between an engagement orientation in which the cross-arm blocking element is engaged with the cross-arm and a disengagement orientation in which the cross-arm blocking element is disengaged from the cross-arm, and in the primary inactive state, the shaft is fixed in the engagement orientation.
7. A traffic pole according to claim 6, wherein the cross-arm locking structure includes a key formation that is fixed relative to the pivot axis to intersect with the shaft if the cross-arm is in the operational position or pivoting between the operational position and the maintenance position, and wherein the shaft includes a corresponding formation cooperable with the key formation only if the shaft is in the engagement orientation.
8. A traffic pole according to claim 6 or 7, wherein the cross-arm locking structure includes a handle operably connected to the shaft to permit manual rotation thereof, the handle extending outside the trunk and being movable between an aligned position if the cross-arm locking structure is in the inactive state and a projecting position if the cross-arm locking structure is in the active state.
9. A traffic pole according to any one of claims 6 to 8, wherein movement of the cross-arm relative to the trunk along the pivot axis below a threshold position is arranged to transfer the cross-arm locking structure from the active state into a secondary inactive state, in which the shaft is fixed in the disengagement orientation
10. A traffic pole according to any preceding claim comprising a base member for mounting beside the roadway, the trunk being rotatably mounted on the base member.
11. A traffic pole according to claim 10, wherein the trunk comprising a slewing ring mounted in the base member to rotate about the pivot axis, the slewing ring being operably coupled to an external rotary port arranged to receive a rotation tool for manual operation.
12. A traffic pole according to any preceding claim, including a pivot lock member manually movable between a clamping configuration in which pivoting of the cross-arm about the pivot axis in prevented, and a release configuration in which pivoting of the cross-arm about the pivot axis in permitted.
13. A traffic pole according to claim 10 or 11 including a pivot lock member manually movable between a clamping configuration in which the trunk is secured to the base member to prevent relative rotation therebetween, and a release configuration in which the trunk is rotatable relative to the base member.
14. A traffic pole according to claim 13, wherein the pivot lock member comprises a blocking element mounted on the trunk, the blocking element protruding from the trunk to engage the base member in the clamping configuration.
15. A traffic pole according to claim 14, wherein the blocking element comprises a rod aligned with the pivot axis, the rod being mounted in a guide formed in the trunk, which guide constrains the rod to be movable only along its length, and wherein the pivot lock member includes a handle operatively coupled to the rod for movement between the clamping configuration, in which the rod projects below the trunk to engage the base member, and the release configuration, in which the rod is disengaged from the base member.
16. A traffic pole according to claim 15, wherein the handle extends outside the trunk, and is movable between an aligned position if the pivot lock member is in the clamped configuration and a projecting position if the pivot lock member is in the release configuration.
17. A traffic pole according to claim 16 when claim 10 is dependent on claim 8, wherein the handle of the pivot lock member is securable to the handle of the cross-arm locking structure when they are both in their respective aligned positions.
18. A traffic pole according to any preceding claim, wherein the cross-arm comprises an carriage slidably mounted on the trunk and the height adjustment mechanism comprises a counterweight connected to carriage over a fulcrum mounted in the trunk.
19. A traffic pole according to claim 18, wherein the cross-arm is arranged to support a load away from the trunk and wherein the counterweight is adjustable to provide a moment about the fulcrum that counteracts the moment of the cross-arm and load.
20. A traffic pole according to claim 18 or 19 including a winching mechanism arranged to move the carriage and counterweight with respect to the fulcrum.
21. A traffic pole according to claim 20, wherein the moment of the counterweight is arranged to balance the moment of the cross-arm, and the winching mechanism is arranged to move the carriage and counterweight in a manner to preserve the balance.
22. A traffic pole according to any preceding claim, wherein the cross-arm and trunk include selectively interengagable portions arranged to physically secure the cross-arm and trunk together.
23. A traffic pole according to claim 22, wherein the interengagable portions are arranged to move relative to each other along the pivot axis during pivoting of the cross-arm between the maintenance position and operational position.
24. A traffic pole according to claim 22 or 23, wherein the interengagable portions include locator pins receivable in pin seats.
25. A traffic pole according to claim 24, wherein the locator pins are fixed to the cross-arm and the pin seats are fixed to the trunk.
26. A traffic pole according to claim 23 including a sloped ramp element fixed relative to the pivot axis, the ramp element being operably coupled to the interengagable portions on the cross-arm during pivoting from the maintenance position to the operational position.
27. A traffic pole according to claim 26 when claim 22 is dependent on claim 7, wherein the key formation is the sloped ramp element.AMENDMENTS TO THE CLAIMS HAVE BEEN FILED AS FOLLOWSCLAIMS1. A traffic pole for mounting beside a roadway, the traffic pole comprising: an upstanding trunk; a cross-arm mounted as a cantilever on the trunk, the cross-arm being manually pivotable about a pivot axis, which extends through the trunk, between an operational position for projecting from the trunk over the roadway and a maintenance position for projecting from the trunk alongside the roadway; and a manually operated height adjustment mechanism arranged to permit relative movement of the cross-arm relative to the trunk along the pivot axis if the cross-arm is in the maintenance position, wherein, if the cross-arm is in the maintenance position, the height adjustment mechanism is manually switchable between a locked configuration in which relative movement of the cross-arm relative to the trunk along the pivot axis is obstructed and an unlocked configuration in which relative movement of the cross-arm relative to the trunk along the pivot axis is permitted.2. A traffic pole according to claim 1, wherein the height adjustment mechanism is locked in an inactive state to prevent relative movement of the cross-arm relative to the trunk along the pivot axis if the cross-arm is in the operational position.3. A traffic pole according to claim 2 including a cross-arm locking structure pivotable with the cross-arm about S... the pivot axis between an active state when the cross-arm is in the maintenance position and a primary inactive state when * the cross-arm is in the operational position, wherein in the active state, the cross-arm locking structure * is movable between a locked configuration in which relative movement of the cross-arm relative to the trunk along the pivot axis is obstructed and an unlocked configuration in which relative movement of the cross-arm relative to the trunk * 40 along the pivot axis is permitted, and in the primary inactive state, the cross-arm locking structure is fixed in the locked configuration.4. A traffic pole according to claim 3, wherein the cross-arm locking structure is fixed in the inactive state during pivoting between the operational and maintenance positions.5. A traffic pole according to claim 3 or 4, wherein in its unlocked configuration, the cross-arm locking structure is arranged to obstruct pivoting of the cross-arm about the pivot axis.6. A traffic pole according to any one of claims 3 to 5, wherein the cross-arm locking structure comprises a shaft having a cross-arm blocking element projecting therefrom, the cross-arm blocking element being engagable with a cooperating portion on the cross-arm, and wherein in the active state, the shaft is manually rotatable between an engagement orientation in which the cross-arm blocking element is engaged with the cross-arm and a disengagement orientation in which the cross-arm blocking element is disengaged from the cross-arm, and in the primary inactive state, the shaft is fixed in the engagement orientation.7. A traffic pole according to claim 6, wherein the cross-arm locking structure includes a key formation that is fixed relative to the pivot axis to intersect with the shaft if the cross-arm is in the operational position or pivoting between the operational position and the maintenance position, and wherein the shaft includes a corresponding formation cooperable with the key formation only if the shaft is in the engagement orientation. * **** * 35 * ** *:. 8. A traffic pole according to claim 6 or 7, wherein the cross-arm locking structure includes a handle operably connected to the shaft to permit manual rotation thereof, the * handle extending outside the trunk and being movable between : * * 40 an aligned position if the cross-arm locking structure is in the inactive state and a projecting position if the cross-arm locking structure is in the active state.9. A traffic pole according to any one of claims 6 to 8, wherein movement of the cross-arm relative to the trunk along the pivot axis below a threshold position is arranged to transfer the cross-arm locking structure from the active state into a secondary inactive state, in which the shaft is fixed in the disengagement orientation 10. A traffic pole according to any preceding claim comprising a base member f or mounting beside the roadway, the trunk being rotatably mounted on the base member.11. A traffic pole according to claim 10, wherein the trunk comprising a slewing ring mounted in the base member to rotate about the pivot axis, the slewing ring being operably coupled to an external rotary port arranged to receive a rotation tool for manual operation.12. A traffic pole according to any preceding claim, including a pivot lock member manually movable between a clamping configuration in which pivoting of the cross-arm about the pivot axis in prevented, and a release configuration in which pivoting of the cross-arm about the pivot axis in permitted.13. A traffic pole according to claim 10 or 11 including a pivot lock member manually movable between a clamping configuration in which the trunk is secured to the base member to prevent relative rotation therebetween, and a release configuration in which the trunk is rotatable relative to the base member.*... 35 14. A traffic pole according to claim 13, wherein the pivot lock member comprises a blocking element mounted on the trunk, the blocking element protruding from the trunk to engage the base member in the clamping configuration.15. A traffic pole according to claim 14, wherein the blocking element comprises a rod aligned with the pivot axis, the rod being mounted in a guide formed in the trunk, which guide constrains the rod to be movable only along its length, and wherein the pivot lock member includes a handle operatively coupled to the rod for movement between the clamping configuration, in which the rod projects below the trunk to engage the base member, and the release configuration, in which the rod is disengaged from the base member.16. A traffic pole according to claim 15, wherein the handle extends outside the trunk, and is movable between an aligned position if the pivot lock member is in the clamped configuration and a projecting position if the pivot lock member is in the release configuration.17. A traffic pole according to claim 16 when claim 10 is dependent on claim 8, wherein the handle of the pivot lock member is securable to the handle of the cross-arm locking structure when they are both in their respective aligned positions.18. A traffic pole according to any preceding claim, wherein the cross-arm comprises an carriage slidably mounted on the trunk and the height adjustment mechanism comprises a counterweight connected to carriage over a fulcrum mounted in the trunk.19. A traffic pole according to claim 18, wherein the cross-arm is arranged to support a load away from the trunk and wherein the counterweight is adjustable to provide a moment about the fulcrum that counteracts the moment of the S...Se...I cross-arm and load. S *20. A traffic pole according to claim 18 or 19 including 35 a winching mechanism arranged to move the carriage and counterweight with respect to the fulcrum.21. A traffic pole according to claim 20, wherein the :.. moment of the counterweight is arranged to balance the moment * * 40 of the cross-arm, and the winching mechanism is arranged to move the carriage and counterweight in a manner to preserve the balance.22. A traffic pole according to any preceding claim, wherein the cross-arm and trunk include selectively interengagable portions arranged to physically secure the cross-arm and trunk together.23. A traffic pole according to claim 22, wherein the interengagable portions are arranged to move relative to each other along the pivot axis during pivoting of the cross-arm between the maintenance position and operational position.24. A traffic pole according to claim 22 or 23, wherein the interengagable portions include locator pins receivable in pin seats.25. A traffic pole according to claim 24, wherein the locator pins are fixed to the cross-arm and the pin seats are fixed to the trunk.26. A traffic pole according to claim 23 including a sloped ramp element fixed relative to the pivot axis, the ramp element being operably coupled to the interengagable portions on the cross-arm during pivoting from the maintenance position to the operational position.27. A traffic pole according to claim 26 when claim 22 is dependent on claim 7, wherein the key formation is the sloped ramp element. S*I * S 5*.S* .. S S. * S * S. * . . * .*S **.SS*S�S*S * . S. ** * . S * I