IE20070823A1 - A foldable column - Google Patents

Abstract

A foldable column (1) comprises a lower column section (5) and an upper column section (7) pivotally mounted on the lower column section (5) substantially mid way along the length of the upper column section (7). Latch means (29) are provided to releasably latch the column sections (5,7) together in use when the upper column section (7) is pivoted about the lower column section (5) into an upright position. The latch means (29) comprises a hooked formation (33) fixedly mounted to one column section (5,7) and a moveable part (31) slidably mounted on the other column section (5,7) which latchingly engages the hooked formation (33) when the upper column section (7) is in the upright position. <Figure 7>

Description

The present invention relates to a foldable column.

It is known to provide a foldable column comprising a lower column section, and an upper column section pivotally mounted on the first column section, the upper column section having a street lamp or the like mounted thereon. The upper column section can then be lowered by pivoting the upper column section about the lower column section to enable the street lamp or the like to be repaired, maintained or replaced. The lower column section can be adapted to be mounted in or secured to the ground directly, or the lower column section can be secured to an in-situ base column section or a base column section which is adapted to be mounted in, or secured to, the ground.

According to the invention there is provided a foldable column comprising a lower column section and an upper column section pivotally mounted on the lower column section, the lower column section having a transverse cross section which comprises two C-shaped portions, one of which is larger than that of the other, part of the upper column section having a cross section substantially identical to the larger C-shaped portion of the lower column section, that part of the upper column section resting against the C-shaped portion of smaller cross section when the upper column section is an upright condition so that the column sections define a single substantially contiguous column.

Although each C-shaped portion may be angular, preferably each Cshaped portion is curved; if W / ο 8 2 j Preferably the part of the upper column section, and the C-shaped portion of the lower column section are each of substantially semi-circular cross section.

Preferably the upper column section is pivotally mounted on the lower 5 column section at a pivotal mounting part way along the length of the upper column section such that the part of the upper column section that rests against the lower column section extends below the pivotal mounting when the upper column section is in an upright condition.

The present invention may be carried into practice in various ways, but 10 embodiments will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 is a side view of a foldable column in accordance with the present invention in a first condition; Figure 2 is a side view of the foldable column of Figure 1 but in a 15 second condition; Figure 3 Figure 1; is a sectional plan view taken through line A-A of Figure 4 Figure 1; is a sectional plan view taken through line B-B of 20 Figure 5 Figure 1; is a sectional plan view taken through line C-C of Figure 6 is an enlarged front view of a lower part of the foldable column of Figure 1 and 2; £°7082j Figure 7 is a sectional side view of the lower part of the foldable column shown in Figure 6; Figure 8 is a sectional front view of the lower part of the column shown in Figure 6; Figure 9 is sectional plan view taken on line D-D of Figure 8; and Figure 10 is a sectional plan view taken on line E-E of Figure 8.

Referring initially to Figures 1 and 2, a foldable column 1 comprises a base column section 3, a lower column section 5 mounted on the base section 3, and an upper column section 7 pivotally mounted on the lower column section 5. The uppermost end of the upper column section 7 is provided with a street light 9 although any other device, e.g. a video surveillance camera or speaker, may alternatively be provided as required.

As can be seen from Figure 2, the upper column section 7 can be pivoted about the lower column section 5 so as to be lowered to enable the street lamp to be maintained, repaired or replaced. A cable 11 is secured between the lowermost end of the upper column section 7 and the lower column section 5, and can be used to winch the upper column section 7 from the collapsed position shown in Figure 2, to the upright position shown in Figure 1.

The base column section 3 is adapted to be secured to the ground in standard manner such as by extending the base section 3 to form a ‘root’ in the ground, or by securing the base section 3 to the stump of an existing column using a concrete mortar mix. Alternatively the base IE 070823 section 3 may be flange-mounted by means of a plate welded to the base section 3 secured to a foundation using holding-down bolts.

The base column section 3 is of hollow tubular form and is provided with a lockable access door 13 to enable a user to gain access to electrical circuitry and other equipment housed therein. The upper end 14 of the base column section 3 is planar and is formed with a plurality of equispaced bores 15 which extend annularly around the planar upper end 14 of the base section 3 in circular arrangement. The bores 15 are clearance bores and comprise part of adjustment means as will be described hereinafter. The bores 15 surround a central hole 17.

Referring to Figures 4, 5 and 6, the lower column section 5 comprises a hollow tube the lower end of which is of substantially circular and constant cross section of a diameter which enables the lower end of the lower column section 5 to be inserted into the central hole 17 of the base section 3. The remainder of the lower column section 5 comprises a transverse cross section comprising two C-shaped portions 16, 18 of semicircular shape, the portions 16, 18 being formed each side of the plane passing through the longitudinal axis of the lower column section 5. One C-shaped portion 16 is of a greater diameter than the other C-shaped portion 18. This feature can be seen from Figure 4.

The lower column section 5 is provided, towards its lower end, with a radially outwardly extending peripheral flange 19 and a conical reinforcement 21 which tapers inwardly from the upper surface of the flange 19 to the lower column section 5. The lower surface of the flange 19 is provided with four projections in the form of captive bolts 23 which are equi-spaced about the flange 19 and which extend downwardly in a direction parallel to the longitudinal axis of the lower column section 5.

It 0/0823 An aperture 25 is formed in the wall of the lower column section 5, above the conical reinforcement 21, the aperture comprising a circular region 26 and a narrow elongate region 27 which extends axially along the lower column section 5.

The lower column section 5 is mounted on the base column section 3 by inserting the lower end of the lower column section 5 into the central hole 17 of the base column section 3. As the lower column section 5 is lowered into the hole 17, the four captive bolts 23 are received in respective bores 15 formed in the planar upper end 14 of the base column section 3. The lower column section 5 is secured to the base column section 3 by fitting nuts onto the threaded bolts 23 below the planar upper end 14.

It will be appreciated that the plurality of bores 15 in the planar upper end 14 enables the lower column section 5 to be mounted in a variety of different angular positions relative to the base column section 3. This is because, if the lower column section 5 is rotated relative to the base column section 3, the bolts 23 can be aligned with a different set of four bores 15. Thus the plurality of bores 15, and the four bolts 23, comprise adjustment means to enable the angular position of the lower column section 5 to be adjusted relative to the base section 3.

The upper column section 7 comprises a tube 20 of circular cross section on which the street light 9 is mounted, and an elongate region 22 extending from the lower end of the tube 20, the elongate region 22 being of substantially semi-circular cross section. The elongate region 22 is of substantially the same size and diameter as the larger Cshaped portion 16 of the lower column section 5. Thus the elongate region 22, when the upper column section is in the upright position, encases the smaller C-shaped portion 18. However, the elongate IE C70823 region 22 of the upper column section 7, and the larger C-shaped portion 16 of the lower column section 5 are both exposed and are both of substantially the same diameter and thus the appearance of the upper and lower column section is of a single substantially contiguous column as the elongate region 22 is flush with the longitudinal half 16.

Referring now to Figures 7 and 8, a latch mechanism is shown generally at 29 and comprises a movable part 31 movably mounted on the lower column section 5, and a fixed part 33 fixedly mounted on the upper column section 7.

The movable part 31 comprises an elongate plate comprising a central rectangular region 35 each longitudinal side of which has an outwardly inclined rectangular region 37. The central rectangular region 35 is formed with two longitudinally spaced elongate slots 39 and an upper latching aperture 41 comprising a first elongate portion which leads to a second elongate portion of lesser width than the first elongate portion.

The plate 31 is slidingly mounted on the inside of the lower column element by two bolts 43, each of which extends through a respective elongate slot 39. The width of each bolt 43 is less than the length of each slot 39 and thus the plate 31 can be slid upwardly and downwardly within the lower column section 5 as indicated by arrow 44, the movement being limited by the bolt 43 in each slot 39 abutting the upper or lower end of the respective slot 39.

Two circular holes 42 are formed in the lower part of the plate 31 and in the lower column section 5 respectively and can be aligned so that a padlock can be inserted therethrough to lock the plate 31 in position relative to the lower column section 5. ΙΕ ΰ 708 23 The fixed part 33 of the latch means comprises a hooked plate which extends radially inwardly from the lower most end of the upper column section 7. The hooked plate 33 comprises a substantially rectangular lower portion 47 and a substantially triangular upper portion 48, one end margin 49 of the rectangular lower portion 47 being secured to the inside of the upper column section 7, the opposed end margin 50 of the hooked plate 33 being distal from the upper column section 7. The triangular upper portion 48 extends upwardly from distal end margin 50 towards an apex 51 of the hooked plate 33 so as to define an inclined sliding surface 53. There is a small clearance 52 between the apex 51 of the hooked plate 33 and the inner wall of the upper column section 7 and it is to be noted that this clearance 52 is slightly greater than the thickness of the sliding plate 31.

It will be appreciated that the height of the hooked plate 33 from the apex 51 to the lower margin of the rectangular portion 47 is less than the length of the latching aperture 41 formed in the elongate plate 31 and also less than the aperture 25 formed in the wall of the lower column section 5. Thus the hooked plate 33 can pass through these apertures 25. 41 when the upper column section 7 is in an upright condition so as to project radially inwardly into the lower column section 5.

One end of the cable 11 is secured to part of the hooked plate 33 using any suitable method including, for example, a bolt or split pin or the like. The other end of the cable 11 is secured inside the lower column section 5 so that the cable 11 is stored within the lower column section 5 when the upper column section 7 is in the upright condition.

When the upper column section 7 is in the upright position, the hooked plate 33 extends into the lower column section 5. The upper edge of the latching aperture 41 of sliding plate 31 rests in the clearance 52 between IE 0 70 823 the triangular upper portion 48 of the hooked plate 33 and the upper column section 7. Gravity acts downwardly on the sliding plate 31 which therefore retains the upper column section 7 in the upright position. This is achieved because, if the upper column section 7 begins to pivot outwardly of the lower column section 5, the end of the triangular upper portion 48 of the hooked plate 33 abuts the slidable plate 31 which resists further movement of the hooked plate 33 and the upper column section 7. The sliding plate 31 is then in a latched position.

To lower the upper column section 7 to the collapsed position, the user 10 first opens the access door 13 in base section 3. The padlock (not shown) which locks the sliding plate 31 in the latched position is then unlocked and removed. The sliding plate 31 is slid upwardly within the lower column section 5 so that the upper margin of the latching aperture 41 in the sliding plate 31 is above the apex 51 of the hooked plate 33. The hooked plate 33 is then free to move through the latching aperture 41 in the sliding plate 31 as the upper column section 7 pivots from the upright condition to the collapsed condition in the direction of arrow 54.

The pivoting movement of the upper column section 7 is limited by the cable 11 which extends and passes through the aperture 25 in the lower column section 5 as the hooked plate 33 moves outwardly and upwardly of the lower column section 5. When the cable 11 has reached its maximum length, the cable 11 tightens and resists further movement of the upper column section 7. The street light 9 on the upper end of the upper column section 7 is then in a position where it can be repaired, maintained or replaced as necessary.

The upper column section 7 is raised by pulling on the cable or rope 11 until the hooked plate 33 is adjacent the aperture 25 in the lower column fcO7Q6Zi section 5. The cable ll is fed into the lower column section 5 through the aperture 25 formed therein. A winch mechanism (not shown) can be provided to winch the cable 11 so as to pull the upper column section 7 to the upright position, The distal margin 50 of the hooked plate 33 enters the aperture 25 formed in the lower column section 5 and the forward edge of the upper triangular portion 48 of the hooked plate 33 is received in the latching aperture 41 formed in the sliding plate 31. As the upper column section 7 is pivoted further, the inclined upper edge 53 of the triangular portion 48 engages the upper end of the latching aperture 41 in the sliding plate 31, further pivotal movement causing the upper end of the latching aperture 41 in the sliding plate 31 to slide along the inclined upper edge 53 of the triangular portion 48 towards the point 51 of the hooked plate 33. This sliding movement causes the sliding plate 31 to move upwardly relative to the lower column section 5 until the upper end of the latching aperture 41 of the sliding plate 31 passes beyond the apex 51 of the hooked plate 33.

The sliding plate 31 then drops as the upper end of the latching aperture 41 of the sliding plate 31 follows the end of the triangular portion 48 towards the lower rectangular portion 47. The sliding plate 31 is then located in the clearance 52 between the end of the triangular portion 48 and the upper column section 7. When in this position, as can be seen from Figure 7 and 8, the sliding plate 31 latches the hooked plate 33 in position so that the upper column section 7 is latched in the upright position. The padlock can then be inserted through the holes 42 to lock the sliding plate 31 in place, and the access door 13 in the base column section 3 can then be closed and locked.

IE 070823 Thus, as the upper column section 7 is raised to the upright position the latch mechanism 29 automatically latches the upper column section 7 when it is fully raised. There is thus no other action needed by the user to secure the upper column section 7 in the upright position and the risk of the upper column section falling accidentally into the collapsed position is thus reduced.

Although a particularly advantageous latch mechanism has been described and illustrated, it will be appreciated that other designs of latch mechanism may alternatively be used. For example it would be possible to mount the movable part of the latch mechanism on the upper column section, and the fixed part on the lower column section.

Claims (4)

1. A foldable column comprising a lower column section and an upper column section pivotally mounted on the lower column section, the lower column section having a transverse cross section which comprises two C5 shaped portions, one of which is larger than that of the other, part of the upper column section having a cross section substantially identical to the larger C-shaped portion of the lower column section, that part of the upper column section resting against the C-shaped portion of smaller cross section when the upper column section is an upright condition so 10 that the column sections define a single substantially contiguous column.

2. The foldable column of claim 1 wherein each C-shaped portion is curved.

3. The foldable column of claim 1 or claim 2 wherein the part of the upper column section, and the two C-shaped portion of the lower column 15 section are each of substantially semi-circular cross section.

4. The foldable column of any one of claims 1 to 3 wherein the upper column section is pivotally mounted on the lower column section at a pivotal mounting part way along the length of the upper column section such that the part of the upper column section that rests against the lower 20 column section extends below the pivotal mounting when the upper column section is in an upright condition.