— \ — A HINGE MECHANISM

The present invention relates to a hinge mechanism especially, but not exclusively for use in conjunction with shafts such as lamp posts.

Most lamp post designs require maintenance engineers to scale the post or use lifting equipment to reach their upper parts. In order to undertake maintenance engineers must arrange for lifting equipment to be installed at the site or must take health and safety risks by scaling the post. Both solutions restrict the flexibility and efficiency of lamp post maintenance. Recent changes in the law also aim to prevent working at height in order to reduce levels of danger.

Previously proposed hinge mechanisms aim to reduce the need for engineers to work at height by replacing substantial parts of the post in question. Common methods require the replacement of the part of the post which is planted in the ground or the replacement of the whole upper part of the post. Further previous designs involve complex hinge mechanisms which are expensive to manufacture and difficult to install.

It is an aim of the present invention to provide a hinge means for use in conjunction with shafts such as lamp posts which enables one part of the shaft to be lowered and raised relative to the other part for maintenance purposes, and also allowing the shaft to be fixed in a position under normal operating circumstances. It is a further aim of the present invention to provide a hinge means which is easily and cheaply manufactured .

Accordingly the present invention is directed to a hinge means for connecting two shaft elements comprising a saddle section and an axle bracket for joining to one of the shaft elements, wherein the saddle section is equipped with connection means to enable it to be releasably fixed to a first shaft element.

Preferably the connection means are locking bolts.

Advantageously the saddle section is welded to a second shaft element.

Preferably the axle bracket is equipped with an axle.

Advantageously the axle is formed of co-joined domehead bolts.

Advantageously the saddle section has a cross-sectional profile to fit the cross-sectional profile of one of the shaft elements .

Preferably the axle bracket has a surface profile to match a surface profile on one of the shaft elements.

Additionally, the hinge means can comprise one or more support sleeves fitted inside one or more of the shaft elements. The support sleeve (s) are attached to the shaft element preferably by screws or bolts. The support sleeve (s) have the advantage that they enable the locking bolts to be attached in the case where the shaft element is not of sufficiently strong material.

Preferably the axle bracket meets a shaft element at an angle and whose axle is displaced downwards from the upper shaft element such that when the hinge means is in the open position the two shaft elements are substantially separated. Alternatively, the axle is displaced upwards from the lower shaft element.

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The advantage of this configuration is that the shaft elements can be accessed independently for installation or maintenance .

The present invention provides a simplified hinge means which requires fewer parts and which is easier to manufacture than previous designs. The hinge of the present invention can be installed relatively simply on existing posts or included in the manufacture of new posts.

The hinge of the present invention can be installed on a existing post by cutting the post at a point along its length and securing the hinge to both shaft elements. If required, support sleeve (s) can be installed to strengthen the modified post. Alternatively the hinge can be manufactured integrally on a new base portion of a post to which an upper shaft is secured. Yet alternatively, the hinge and shaft elements can be manufactured as a single piece.

Newly manufactured posts including the hinge means can be transported to the desired site in two parts which simplifies transportation logistics.

The present invention is also directed to the method of manufacture of the hinge means described above wherein a piece of sheet material is cut to a desired shape and size and folded over a former and shaped to the desired shape and size. The hinge means of the present invention can be manufactured to fit a wide variety of shaft diameters and profiles. This is achieved by the use of an appropriate size of former.

An embodiment of the present invention will now . be described in relation to the accompanying drawings, in which:

Figure 1 shows a side view of such a hinge means;

Figure 2 shows a cross-sectional view of the hinge means shown in Figure 1;

Figure 3a shows a plan view of a piece of sheet material cut to the preferred shape and size;

Figure 3b shows a side view piece of sheet material shown in Figure 3a folded over a former to produce the desired shape;

Figure 4 shows a side view of the releasable part of such a hinge means showing an adaptor sleeve as a method of attachment to a shaft element with a locking bolt to secure the hinge in position;

Figure 5 shows a lamp post equipped with the hinge of the present invention in a fixed position under normal circumstances and a lowered position for maintenance/ and

Figure 6 shows a side view of such a hinge means with a spring and ratchet system.

Figure 7 shows an alternative configuration for the axle bracket with the hinge means in the closed position

Figure 8 shows the same configuration with the hinge means in the open position

Figure 9 shows a post in two parts in the absence of the hinge means

Figure 10 shows a post in two parts with the hinge means present

Figure 1 shows an embodiment of the present hinge means comprising a saddle section 10 and an axle bracket 12 connected to shaft elements 14. The saddle section 10 is releasably fixed to one shaft element 14 by one or more locking bolts 16 which pass through one or more holes 15 cut in the saddle section 10. The saddle section 10 is fixed to the other shaft element by means of a welded joint 18. The shaft elements 14 can pivot about an axle or axle bolts 20.

Figure 2 shows a sectional view of the preferred embodiment of the present hinge means comprising a U-shaped saddle section 10 and an axle bracket 12 comprising the arms of the U-shape. The saddle section 10 is releasably fixed to a shaft element 14 and optionally a support sleeve 13. One of the shaft elements 14 is releasably fixed by a locking bolt 16 which penetrates through the bottom of the U-shape. Additional optional locking bolts 17 further secure the saddle section to the sleeve 13 or shaft elements 14. On the other

side from the locking bolts 16 of the saddle section 10 one of the shaft elements 14 is secured to the axle bracket 12 by axle bolts 20.

Figure 3a shows a piece of sheet material 22 ready for shaping. Holes (24, 26) may be drilled in the desired places for alignment before or after shaping. Holes 24 align with the locking bolts (not shown) , holes 26 align with the axle (not shown) .

Figure 3b shows the sheet material 22 in side view and sectional view folded into its preferred shape around a former 28.

Figure 4 shows a shaft element/adaptor 30 which fits in a shaft element 14 and is held in place by welding or alternatively by a locking bolt 36. This enables a shaft element with a pre-determined radius to be fitted to an existing shaft to speed installation of the hinge means.

Figure 5 shows shaft elements 14 in an upright position 32 under normal conditions and in a lowered position 34 under maintenance conditions with lock bolts 16 removed.

Figures 6 to 10 show alternative configurations using the same features. Figures 7 and 8 show an embodiment of the axle bracket 12 whereby the axle bracket meets a shaft element 14 at an angle such that when the hinge means is in the open position the two shaft elements 14 are substantially separated.

A further preferred embodiment of the present invention includes a known tensioned spring and ratchet system to control the freedom of relative movement of the shaft elements. This feature counterbalances the lever forces as the column shaft is raised or lowered.

The spring and ratchet system can be installed by inserting a support sleeve which is connected to one end of a spring into one of the shaft elements. The support sleeve is attached to the shaft element preferably using screws or bolts. The other end of the spring can be attached to the other shaft element preferably via a pull chain.

In a preferred embodiment the position of the point along the shaft element to which one end of the pull chain is attached is independent of the cam and can be moved along a slot to adjust the spring tension. This gives the advantage

that the tension of the spring can be adjusted if the shaft has no access means.

Figure 6 shows the hinge means of the present invention with such a spring system installed. A spring 1 is held by mounting means to the shaft element 14 and coils about a pull rod 2 with an adjustment nut 3. A pull rod washer 7 inside the shaft element 14 guides the pull rod 2 within the shaft element 14 and maintains the tension of spring 1 when the hinge mechanism is in the lowered position. The pull rod 2 is attached at one end to a pull chain 4 which is connected to an anchor 5. The anchor 5 is attached to the shaft element 14 by means of a bolt 9 moveable in a slot (not shown) in the shaft element 14.

Numerous variations and modifications may occur to the reader without taking the resulting construction out of the scope of the present invention.