GB2522121A

GB2522121A - A post protection system

Info

Publication number: GB2522121A
Application number: GB1422083.4A
Authority: GB
Inventors: Stephen Mcgeough; Thomas Mcdonald
Original assignee: Innovative Products NZ Ltd
Current assignee: Innovative Products NZ Ltd
Priority date: 2013-12-13
Filing date: 2014-12-11
Publication date: 2015-07-15

Abstract

A housing 12 having a socket 14 for receiving a pole is provided for supporting and protecting a post. The device includes a retaining mechanism in the form of a clamping member 20 for securing the pole within the housing. An independently rotatable pressure distribution pad 38 is mounted on the distal end 32 of the clamping member for cushioning the contact point between the bolt and pole, the pad having a distal surface area that is greater than the distal end of the clamping member. The clamping member may be a threaded bolt, and the pad may have the form of a cylindrical cup that fits over the distal end of the bolt. The bolt and the internal surface of the pad may also have complementary locating means or grooves, and a split ring 36 may be used between the grooves to further retain the pad on the bolt.

Description

A Post Protection System

Field of the invention

This invention relates to devices and systems for supporting poles such as road traffic signs, lighting columns etc., and has particular application in avoiding damage to such poles.

Background of the invention

A device for supporting a pole typically comprises a housing for mounting in the ground) having an opening for receiving one end of the pole such that the opening is more or less flush with the surface of the ground, and having means for releasably retaining the pole within the opening.

For example, GB 2 254 349 discloses such a device. The releasable retaining means is provided within a chamber located (in use) below ground level and accessible by removal of a cover. The retaining means is a bolt which can be advanced into or retracted out of the opening within which the pole is received. The bolt is received in a nut which is fixed in the housing or chamber to prevent rotation, and the end of the bolt makes contact with the pole and retains it in the device.

During vehicular impact the pole swells at ground level causing the section inside the pole housing unit to lift, in turn dragging it across the retaining bolt. The large force generated by the movement of the pole can cause damage to the mechanism. Damage can similarly be caused when there is torsional loading of the pole, and the action of the clamping mechanism itself on the pole can damage the pole also.

A particular concern is to avoid damage to the surface of the pole below ground. Poles are designated as having a service life of several years. This service life is arrived at based on the assumption that the pole is undamaged, and in particular that protective coatings provided on the pole's surface are intact during the service life. Scratching or penetrating a protective plastic coating on a steel pole renders that assumption void and allows the pole to suffer from corrosion and other deteriorations, shortening its service life and potentially making the installation unsafe without this necessarily being apparent.

Disclosure of the invention

There is provided a device for supporting a pole, comprising a housing having a socket into which a pole can be received, and a retaining mechanism comprising a clamping member which can be actuated to advance the distal end of the clamping member into the socket and towards a pole, further comprising a pressure distribution pad mounted on the distal end of the clamping member which is freely rotatable with respect to the clamping member) the pad having a distal surface whose area is greater than that of the distal end of the clamping member.

This device also supports the end of the clamping means within the housing in such a way to eliminate the damaging forces applied to the clamping means during vehicular impact and torsion due to wind loads. This is achieved by the end of the bolt being constrained against lateral movement by being held in the pad, and the pad in turn being constrained in its chamber.

Preferably the clamping member is a bolt having a head at a proximal end thereof and a shaft leading to a distal end having a terminal surface, the shaft having a threaded section, the threaded section having a major diameter and a minor diameter, wherein the pressure distribution pad (also referred to herein as "the pad") receives the distal end of the bolt.

Preferably, the pad has a terminal contact surface at a distal end thereof whose area is greater than the area of the terminal surface of the bolt.

Preferably, the terminal contact surface of the pad has a maximum width greater than the major diameter and the minor diameter of the threaded section.

Preferably, said maximum width is at least 40% greater than the minor diameter of the threaded section.

Preferably, the terminal contact surface of the pressure distribution pad has an area greater than the sectional area across the minor diameter of the threaded section.

Preferably, said terminal contact surface area is at least 50% greater than the sectional area across the minor diameter of the threaded section.

Preferably, said terminal contact surface area is at least 100% greater than the sectional area across the minor diameter of the threaded section.

Preferably, said terminal contact surface area is 100% to 3000% greater than the sectional area across the minor diameter of the threaded section.

Preferably, the pad takes the form of a cylindrical cup having a cylindrical sidewall projecting from a base wall, wherein the cylindrical sidewall defines an internal socket into which the distal end of the bolt is received, and wherein the base wall has a flat or contoured external surface provides said terminal contact surface for contacting the pole.

Further preferably, the cylindrical sidewall has) on its inner surface, locating means for retaining the pad in position on the bolt.

Further preferably, there is provided a complementary locating means on the bolt at its distal end.

Further preferably, at least one of the locating means and the complementary locating means comprises a recessed groove.

Preferably) both the locating means and the complementary locating means comprise a respective groove, and there is further provided a locating ring which in use is disposed between the distal end of the bolt and the inner surface of the cylindrical sidewall, in engagement with the respective recessed grooves.

Preferably the locating ring is a split ring.

Preferably) the retaining mechanism comprises at least two of said clamping members.

Preferably) each clamping member has a respective pad.

Brief description of the drawings

Further details of the invention will be apparent from the following description of embodiments thereof, given by way of example only, with reference to the accompanying drawings, in which: Fig. 1 is a side elevation of a device for supporting a pole; Fig. 2 is a perspective view taken from above; Fig. 3 is a sectional plan view taken along the line Ill-Ill in Fig. 1; Fig. 4 is a detail of the view of Fig. 3; Fig. 5 is a sectional elevation view taken along the line V-V in Fig. 1; and Fig. 6 is a detail of the view of Fig. 5.

Detailed description of preferred embodiments

Referring to Figs. land 2, there is generally indicated at 10 a device for supporting a pole, having the form of a cylindrical housing 12 defining a socket 14 into which a pole (not shown) can be received.

A chamber 16 is located adjacent the socket with the top of the chamber 16 and the top of the socket being defined by a common ground plate 18 which sits flush with the surface of the ground when the device 10 is installed underground. In use, a lockable cover plate (not shown) seals the chamber to prevent unauthorised tampering with the device.

Referring to Fig. 2, a retaining mechanism (shown in exploded view in Fig. 2) comprises a pair of bolts 20 which are threaded into a pair of nuts 22, the nuts being received in hexagonal holes 24 (only one of which is partly visible in Fig. 2)so that the nuts are prevented from rotation.

Each bolt has a head 26, and a shaft 28 carrying a threaded section 30 for cooperation with the nut, and leading to a distal end 32. Mounted on the distal end 32 of each bolt 20 by means of a retaining split ring 36, as will be described in more detail below, is a respective pressure distribution pad 38 in the form of a cylindrical cup.

Referring additionally to Figs. 3,4,5 and 6, it can be seen that the bolts are mounted one above the other (Fig. 5) to provide two clamping positions against a pole (not shown). Each pressure distribution pad 38 is fixed onto the distal end 32 of the bolt by the retaining ring 36 being located in engagement with a circular groove 40 on the inner surface of a cylindrical sidewall 42 of the pad 38 and also in a complementary recessed groove 44 on the surface of the distal end 32 of the bolt. In this way, the pad is held in position by a locating means on the pad and a complementary locating means on the bolt, so that rotation of the pad relative to the bolt is permitted.

As a result, the bolt can be tightened within the nut to advance the pad towards a pole. The pad, once in contact with the pole, stops rotating, and the bolt can be tightened without abrasively damaging the surface of the pole.

It can be seen that the pad takes the form of a cylindrical cup having a base wall 46 from which the cylindrical sidewall 42 extends. The external surface 48 of the base wall 46 can be circular, rectangular or hexagonal with a surface area (D, Fig. 4) significantly greater than that (d) of the terminal surface of the distal end of the bolt. The diameter of external surface 48 is also about 50% greater than the minor diameter MD (Fig. 4) of the threaded section, and thus than the maximum possible diameter of any bolt surface which could pass through the nut. The result is that the surface area of the pad's terminal contact surface is not only configured not to rotate abrasively against the pole, but also has a surface area which is 2 times greater than the area of the maximum surface that could pass through the nut (based on the minor diameter of the threaded section).

As a result the pole can be clamped more securely while removing the potential for surface damage to the poles coating while also reducing the damage caused to the locking means if the pole is impacted or subjected to unusually high forces above ground.

Claims

Claims 1. A device for supporting a pole, comprising a housing having a socket into which a pole can be received, and a retaining mechanism comprising a clamping member which can be actuated to advance the distal end of the clamping member into the socket and towards a pole, further comprising a pressure distribution pad mounted on the distal end of the clamping member which is freely rotatable with respect to the clamping member, the pad having a distal surface whose area is greater than that of the distal end of the clamping member.
2. The device of claim 1, wherein the clamping member comprises a bolt having a head at a proximal end thereof and a shaft leading to a distal end having a terminal surface, the shaft having a threaded section, the threaded section having a major diameter and a minor diameter, wherein the pressure distribution pad receives the distal end of the bolt.
3. The device of claim 1 or 2, wherein the pressure distribution pad has a terminal contact surface at a distal end thereof whose area is greater than the area of the terminal surface of the bolt.
4. The device of claim 3, wherein the terminal contact surface of the pad has a maximum width greater than the major diameter and the minor diameter of the threaded section.
5. The device of claim 4, wherein said maximum width is at least 40% greater than the minor diameter of the threaded section.
6. The device of claim 3, wherein the terminal contact surface of the pressure distribution pad has an area greater than the sectional area across the minor diameter of the threaded section.
7. The device of claim 6, wherein said terminal contact surface area is at least 50% greater than the sectional area across the minor diameter of the threaded section.
8. The device of claim 7, wherein said terminal contact surface area is at least 100% greater than the sectional area across the minor diameter of the threaded section.
9. The device of claim 8, wherein said terminal contact surface area is 100% to 3000% greater than the sectional area across the minor diameter of the threaded section.
10. The device of any of claims 2-9, wherein the pressure distribution pad takes the form of a cylindrical cup having a cylindrical sidewall projecting from a base wall, wherein the cylindrical sidewall defines an internal socket into which the distal end of the bolt is received, and wherein the base wall has a flat or contoured external surface provides said terminal contact surface for contacting the pole.
11. The device of claim 10, wherein the cylindrical sidewall has, on its inner surface, a locating means for retaining the pressure distribution pad in position on the bolt.
12. The device of claim 11, wherein there is provided a complementary locating means on the bolt at its distal end.
13. The device of claim 12, wherein at least one of the locating means and the complementary locating means comprises a recessed groove.
14. The device of claim 13, wherein both the locating means and the complementary locating means comprise a respective groove, and there is further provided a locating ring which in use is disposed between the distal end of the bolt and the inner surface of the cylindrical sidewall, in engagement with the respective recessed grooves.
15. The device of claim 14, wherein the locating ring is a split ring.
16. The device of any preceding claim, wherein the retaining mechanism comprises at least two of said clamping members.
17. The device of claim 16, wherein each clamping member has a respective pad.