GB2205392A

GB2205392A - Raising and lowering of columns

Info

Publication number: GB2205392A
Application number: GB08813360A
Authority: GB
Inventors: Gregory Leslie
Original assignee: CHRISTY LIGHTING Ltd
Current assignee: CHRISTY LIGHTING Ltd
Priority date: 1987-06-06
Filing date: 1988-06-06
Publication date: 1988-12-07
Anticipated expiration: 2008-06-06
Also published as: GB2205392B; GB8713339D0; GB8813360D0

Abstract

A method is disclosed for displacing a column such as a lighting column supporting floodlight assemblies between raised and lowered conditions by pivotal movement about hinge means. Displacement means is caused to act between the column and a fixed surface to effect such pivotal movement and column displacement. The displacement means comprises a displacement element and gear means engaged therewith for converting input rotational drive to linear displacement of the displacement element. The displacement means is preferably a machine screw comprising a worm wheel driving an elongate lead screw.

Description

RAISING AND LOWERING OF COLUMNS The Invention relates to the ralsing and lowering of columns by pivotal movement about hinge means. The invention is particularly, but not exclusively, concerned with lighting columns in which a column has a lighting assembly mounted to Its upper end, such lighting columns being used for flood lighting In sports stadla and for road and street lighting. In one alternative, the columns may be aerlal columns (le columns mounting a reception or transmission aerial for communicatIons applications).

Lighting columns have been in use for a large number of years and are widely used for road and street lighting and in such other areas as sports stadia. Lighting columns comprise a column having an illumination assembly such as flood lights mounted to the top. Columns range In height from moderately high street lamps typically having a height in the range 6 to 12 metres to tall stadia flood lighting columns and lighting columns used in such road lighting contexts as Illumination at intersections, the latter perhaps having a height as high as 18 to 30 metres.

Although It Is possible for access to an illumination assembly to be achieved by means of a ladder or elevation platform in the case of relatively short columns, access taller columns is not practical in this way. In practice, access to the IlluminatIon assemblies of all columns tends to be achieved by constructing the column with a hinge about which the column may be pivoted so that It can be lowered to the point where the axis of the column Is generally parallel to the ground and at an 5 elevatlon of no more than a few feet.

Raising and lowerlng operatlons for lighting columns have In the past always been carried out by using a hydraulic Jack or ram engaged with the column side. This has long been recognised to be Inconvenient since hydraulic rams represent high capital cost and in additlon, of course, a power unit such as a petrol-driven motor needs also to be provided In order to drive the ram. Perhaps of greater signifIcance, hydraulic rams, however well engineered, usually do not provide smooth raising and lowerlng but Instead are somewhat Jerky and produce a significant transient column displacement when powered-on or powered-off.This may, for example, happen at the point where a column reaches verticality but transient column displacements or "Jerks" are more common the more a column approaches horlzontallty. This is a most undesirable feature In a column which cannot readily be compensated for in column design.

For some years, very tall lighting columns of the kind already referred to have been in wide use throughtout the world. Such columns require hydraulic rams of considerable size, thus emphasising the capital cost disadvantages already outlined above, and are particularly prone to possibly hazardous transient column displacement when powered-off or powered on.

Despite the above-mentloned disadvantages, however, lighting columns have continued to be raised and lowered using hydraulic rams and associated petrol-driven engines or electrical motors (or perhaps manually operated) and this remains a conventlonal system of ralsing/lowerlng at the present time. This is particularly the case for tall columns although winch-and-wire systems, despite their hazards due to wire breakage risks, are also in common use for smaller columns.

According to one aspect of the invention, there is provided a method of displacing a column secured to a substrate such as the ground or structure supported thereon between a ralsed and a lowered condition by pivotal movement about hinge means which method comprises causing displacement means to act between said column and a fixed surface to effect said pivotal movement and column displacement, character i zed In that said displacement means comprises means for convertIng input drive to linear displacement of a displacement element coupled non-hydraulically to said means (eg mechancially) for applying said linear displacement between said column and said fixed surface to displace said column. The input drive Is preferably rotational drive supplied from a hand power tool such as an electric drill or other electrical hand power tool.

The column Is, for example, a support column for lighting means, for example, a column which supports one or more floodlight assemblies and having a height of, for example, up to 30 metres, eg from 8 to 25 metres.

Conveniently, the column includes a base plate for fixture to the substrate, a first hinge member secured to the base plate and a second cooperative hinge member secured to a lower portion of the column, the two hinge members being coupled together to provide for pivotal displacement of the column relative to the substrate.

The fixed surface Is conveniently part of a frame secured relative to the substrate.

The displacement element may displace as a response to reaction between a helical surface and a cooperative surface, for example, a helical groove and a key or a helical groove and a helical ridge. For example, the element may be formed with (or coupled to a further member formed with) a helical groove such as a screw thread reacting with a helical fridge of a worm wheel. In such an arrangement, the worm wheel may be rotated by reactlon of one or more teeth thereof with a helical surface, for example of a drive input shaft for driving said worm wheel.

In any event, the displacement means will general ly comprise a member which displaces In response to rotational drive connected to a drive-receiving member which Is positlonally secured to said fixed surface so as to vary the spacing between said column and said fixed surface.

The linear displacement applied between said column and sald fixed surface may ralse the column to a relatively upright orientation with Increased spacing between the fixed surface and said column and lower the column to a relatively less upright orIentation with decreased spacing between the fixed surface and said column, the latter In such a case conveniently comprising a relatively short substrate-supported first portion and a relatively tall second portion, the two portions being hinged adJacent their confronting ends by hinge means disposed spaced apart from the substrate by the first column portion.

Preferred displacement means comprises a machine screw.

In a further aspect, the Invention provides a column assembly comprlsing a column, a column mounting plate having the column secured thereto and provided with means for fixture to a substrate, hinge means enabling the column to pivot between an upright disposition and an approximately horizontal dispositlon In which the length of the column is Juxtaposed to the substrate sufficiently for access thereto, and machine screw assembly support means secured to the mounting plate and comprlsing means for supporting a machine screw assembly spaced above the substrate so that said assembly acts between the support means and the column to apply Linear displacement therebetween, said support means Including means responsive to changes in inclination of the column during pivoting to effect compensatory changes In the orientation of a machine screw assembly having its screw fixed pivotally to the column in use.

Such an assembly Is conveniently arranged so that in use said linear displacement applied between said column and said support means ralses the column to a relatively upright orientation wlth increased spacing between the support means and said column and lowers the column to a less upright orlentatlon with decreased spacing between the support means and said column. Conveniently, the column comprises a relatively short substrate-supported first portion and a relatively tall second portion, the two portions being hinged adJacent their confronting ends by hinge means disposed spaced apart from the substrate by the first column portion.

Alternatively, of course, the assembly described Is such that in use linear displacement applied between said column and said support means raises the column to a relatively upright orientation wlth decreased spacing between the support means and said column and lowers the column to a less upr ig-ht orientation with Increased spacing between the support means and said column. In such a case the column preferably Includes a base plate for fixture to the substrate, a first hinge member secured to the base plate and a second cooperative hinge member secured to a lower portion of the column, the two hinge members being coupled together to provide for pivotal displacement of the column relative to the substrate.

In any of the assemblies according to the Invention, the column is hinged at or near Its lower substratecontacting end, a support frame is secured adJacent the column to the substrate, a machine screw has a housing secured removably to the frame and a worm or other elongate member defining a cam surface extending from the housing Is secured by Its end remote from the housing to the column so that Its displacement linearly varies the spacing between the machine screw housing and frame on the one hand and the column on the other hand.

The Invent ion includes wlthin Its scope a column assembly comprising a column displaceable between a ralsed and lowered condition by pivotal movement about hinge means of the assembly, means defining a fixed surface, and displacement means operative to act between said column and said fIxed surface to effect said column displacement, characterized In that said displacement means compr i ses gear means for convert I ng i nput rotatlonal drive to linear displacement of a displacement element for applying said linear displacement between said column and said fixed surface to displace said column.

The following Is a specific description intended to Illustrate two particular embodiments of the Invention, reference being made to the accompanying drawings In which:- Flgure 1 Is a schematic drawing showing a lighting column constituting a first embodiment of the Invention; Flgure 2 shows in more detall and on an enlarged scale the part of the lighting column shown In Figure 1 within the enciclement ll; Flgure 3 Is a view similar to that of Figure 2 but showing the column in Its lowered condition, as opposed to its raised condition; Figure 4 is a view similar to that of Figure 3 but showing an alternative embodiment of the invention;; Flgures 5a, 5b and Sc show, In semi-exploded form, the support frame of Figure 4 In various stages of assembly; Figure 6 shows in cross-section the machine screw assembly shown In Flgure 3; Figure 7 shows a plan vlew of the machine screw assembly of Figure 6, partially in cross-section, taken from the direction of the arrow Vll shown In Figure 6; and Flgure 8 shows a modified embodiment, similar to that of Figure 3, agaln with the column In its lowered condition.

As shown I n Figure 1, the lighting column comprises a column 1 and Illuminatlon assembly 2. The latter comprises an array of six sodium floodlights 3 mounted to a lighting carriage 4. Column 1 comprises a plurality of telescoping mild steel tubes of octagonal cross section each tube taperlng slighting towards its upper extremity so as to be recelvable, but to a limited extent, wlthin the opening of the base of the tube next In sequence above. Each tube Is formed from sheet steel and Is seam welded by a weld extending the tube length.

In general, the tubes will be galvanized to increase durability.

An additional base tube 5 is securely fixed to a base plate 6 which is in turn bolted to a concrete block foundation formed In substrate soll according to building regulations. Base tube 5 has a hinge 7 by means of which the column 1 may be pivoted in the direction Indlcated by the arrow A In the figure. A steel frame 8 Is secured to base tube 5 and mounts a machine screw 9 whose lead or lift screw 10 is secured by a pin to steel girth band 11 received about one of the lower tubes of column 1 and secured thereto by welding. The machine screw may be any of those commercially avallable but that available from the Duff Norton division of Consolidated Pneumatic Tool Co Ltd as the Standard Duff Norton 1800 Series Rotating Screw Jactuator is preferred.

As shown In more detail In Figures 2 and 3, hinge 7 comprises a pair of opposed plates 7a welded to two opposed faces of the octagon of lower column tube la. A hinge pin 7b Is recelved through openings In the plates 7a and through similar openings in register therewlth and formed In the upper part of elongate plates 7c welded to opposed faces of the octagonal cross-sectlon of base tube 5. Hinge pin 7b mounted for rotation relative to plates 7a but Is welded within the openings In plates 7c.

The lower opening of tube 1a Is closed by a sllghtly oversized steel plate 12. In similar fashion, the base tube 5 has Its upper opening closed by an oversized steel plate 13 so that, with plates 12 and 13 In interfacial contact as shown In Figure 2, the column 1 Is seated firmly upon base plate 5.

Frame 8 shown In Figures 2 and 3 is formed from tubular steel members of rectangular cross-section welded together and secured to base plate 6. A pair of horizontal tubular members 14 are spaced apart in parallel and together cantlievered from a pair of upright members 16. The cantilever is supported by a palr of inclined spaced apart parallel support members 15 secured to the lower portlons of uprights 16 by welding and to the outer ends of members 14. A plate 17 is mounted by pins 18 between members 14. A machine screw assembly 9 Is mounted to plate 17. The drive screw 10 of the machine screw Is secured by pin 10a to girth band 11. A drive input coupling 20 Is provided to receive rotational drive from a power drill.

The arrangement shown In Figure 8 Is similar to that shown in Flgures 2 and 3 and like parts are shown designated with like reference numerals. Thus, as will be seen in Figure 8, a lighting column 1 comprises a plurality of telescopically Joined tubes such as tube la.

Tube la has a base plate 12 which serves to enable it to seat upon the top of base tube 5 when the hinge 7 Is closed and the column is vertical (le raised). Base tube 5 has a steel base plate 6 secured to a concrete block foundation. Frame 8 comprises members 14, 15, 16 and supports upon a plate 17 a machine screw 9 whose worm or lift screw 10 is secured by pin 10a to a sleeve 1b. The latter has a complementary octagonal cross-sectlon to that of the tube la which It overlies and to which it is secured by welding (welds not shown). Sleeve 1b has plates 7a of hinge 7 formed thereon together with mounting 10c which, of course, receives pin 10a therein.

A five-sided flange 1c forming an integral extension to sleeve 1b receives an equivalent portion of the cross section of base tube 5 therein when the column is vertical.

Flange 1c substitutes for plate 13 of the embodiment shown In Figures 2 and 3 in providing a means by which the plate 12 of the column 1 may seat upon and be secured to the base tube 5. In practice, base tube 5 may contain electrical power equipment for energing a lighting cluster mounted at the summit of the column 1. Access to such equipment may conveniently be via a door (not shown) provided In the side of the base tube 1 opposed to frame 8. Needless to say, flange 1c may conceal such door when the column Is in its vertical operational conditlon so as to prevent Illicit access through the door to the power equipment. There Is an economic advantage In avoiding the need for plate 13 which is made of costly thick gauge steel.

The machine screw assembly shown in Flgures 3 and 8 is represented in greater detail In Figures 6 and 7. As shown in the latter figures, a housing 40 has a tubular extenslon 41 extending therefrom. A lift screw 10 Is received and movable within the cavity defined by the housing 40 and tubular extension 41 In combinatlon. The cavity of housing 40 houses a pair of annular bearings 42, 43 which are fixed to the housing wall and which retain worm wheel 44 upon screw 10. Worm wheel 44 has internal threading 45 engaged with the helical threading of screw 10, and external axial teeth 46. A drive input shaft 47 has a helical ridge 48 enmeshed with teeth 46 and terminates in a coupling 20 for connection to the power drill previously referred to.Nipple 49 serves to facilitate introduction of lubricant to the assembly and Its drainage therefrom.

Power supply for the illumination assembly is provided by cables (not shown) provided in conventional manner, usually by subsoll ducting.

To Install a new 30 metres column In, for example, a stadium, a concrete block foundation is cast In a pit 2.6 metres square and having a depth of 3 metres. Fixture bolts are cast as Inserts wlthin the block, their threaded shanks penetrating the concrete surface.

In soil capable of bearing a pressure of 160Kn/m, such a block size is satisfactory but In less suitable substrates, a larger block size or other special measures may be called for.

When cured a base plate 6 with tube 5 is offerred to the top surface of the block, and nuts threaded onto the fixture bolts previously referred to after the latter have been eased through openings provided in base plate 6 for the purpose. Frame 8, pre-assembled, is then fixed to base plate 6 ready fitted with machine screw 9 secured to plate 17 of the frame 8.

The remainder of column 1 is now assembled on site by telescopically mounting the various tubes to each other In a generally horizontal position, starting with the largest tube, tube la, which Is fixed to tube 5 by means of hinge 7 as a first step in telescopic assembly, the screw 10 of screw assembly 9 Is secured to pin 10a.

Assembly of the tubes Is by offering each tube to the previously assembled tube and forcing it home by using a mallet or the like.

An electrical power drill is then fitted with an attachment and the attachment coupled to the drive Input 20 of the machine screw 9. Drive from the power drill rotates shaft 47 of the machine screw assembly at eg a maximum of 400rpm, causing the worm wheel 44 to rotate and thus causing the lifting screw 10 of the machine screw assembly 9 to extend from the machine screw housing 40 and exert force upon the assembled column. The assembled column is then ralsed until lt reaches vertical. Drive Is then disconnected, verticality being monitored by visual examination of the Interface between the plate 12/and base tube 5 (for example by observing for contact at the plate 12/plate 13 Interface or adequate proximity between flange ic and base tube 5).

Fixing bolts (not shown) are then passed through plates 12 and 13 (in the case of the embodiment of Flgures 2 and 3) and secured by nuts (not shown) to fix the column in position, or (in the case of the embodiment of Figure 8), the column is fixed in position by passing bolts through flange 1c Into threaded bores provided In appropriate faces of the base tube 5.

To Inspect or repair the illuminatIon assembly 2, the column can be lowered by applying reverse drive to drive coupling 20. In practice, drive coupling 20 has a shaft penetrating the screw assembly so that clockwise drive can be apply led to the worm gear by coupling to one end of the shaft and counter-clockwise drive applied using the same power drill to the opposed end. Reverse drIve causes the screw 10 to be drawn into Its housing thus lowering the column to a visually monitored horizontal orientation Just above the ground.

Once a column has been raised and secured, the machine screw assembly 9 can be removed and put into store or used for ralsing/lowerlng another column, in this way, the capital cost of the equipment being distributed over a number of columns. A sports stadium, for example, might be equlpped with six lighting columns and rely for their maintenance on one machine screw assembly only.

It has been found that use of the system shown In Figures 1 to 3 and Figure 8 ralses/lowers columns smoothly wlthout the "Jerklness" of conventlonal systems using hydraulic Jacks. By a degree of tailoring to maximum column size, a machine screw assembly can be used for a range of columns and has modest energy requirements and requirements for plant for drive generation, a simple widely available and Inexpensive power tool providing the amount of drive required even for raising very tall columns through the machine screw gearing. The Illumination electrical power requirements can be harnessed to provide an electrical supply for the power tool, convenlently at a plug point provided as part of the column base assembly.

In the alternative embodiment shown in Flgure 4, the arrangement Is very broadly similar to that represented In Flgures 2 and 3 and like parts are represented by like reference numerals. Of course, it will be appreciated that frame 8 is Inverted relative to the corresponding component shown In Figures 2 and 3, base members 21 of the embodiment shown In Figure 4 being secured by bolts 22 to base plate 6. Plate 17 Is thus mounted by its pin 18 to the apex of the frame so that the drive screw 10 of machine screw assembly 9 acts upon column 1 to raise the column as the screw Is drawn into Its casing and to lower the column as the drive screw extends from the casing.

Needless to say, the embodiment Just descrlbed could be modified In the same fashion as the embodiment of Figures 2 and 3 is shown modifled In Figure 8.

The Invention as described earlier wlthout reference to the drawings may Include any one or more features of the invention as described with reference to the drawings.

Claims

1. A method of displacing a column secured to a substrate between a raised and a lowered condition by pivotal movement about hinge means which method comprises causing displacement means to act between said column and a fixed surface to effect said pivotal movement and column displacement, characterized in that said displacement means comprises a displacement element and gear means engaged therew I th for converting input rotational drive to linear displacement of the displacement element, said linear displacement being app I led between said column and said f I xed surface to displace said column.

2. A method as claimed in Claim 1 wherein the column Is a support column for lighting means.

3. A method as claimed In Clalm 2 wherein the column supports one or more floodlight assemblies.

4. A method as claimed in any one of Claims 1 to 3 wherein the column has a height of up to 30 metres.

5. A method as claimed In Claim 4 wherein the column has a height of from 8 to 25 metres.

6. A method as claimed in any preceding claim wherein the column Includes a base plate for fixture to the substrate, a first hinge member secured to the base plate and a second cooperative hinge member secured to a lower portion of the column, the two hinge members being coupled together to provide for pivotal displacement of the column relative to the substrate.

7. A method as claimed n any preceding claim whereln the fixed surface is part of a frame secured relative to the substrate.

8. A method as clalmed in any preceding claim wherein the displacement means comprises a member acting between said column and said fixed surface to vary the spacing therebetween In response to reactlon between a cam surface and a follower.

9. A method as claimed in any preceding clalm wherein the displacement means comprises a member which displaces In response to rotatlonal drive connected to a drive receiving member which Is positional ly secured to said fixed surface so as to vary the spacing between said column and said fixed surface.

10. A method as clalmed in any preceding claim whereln said linear displacement applied between said column and said fixed surface raises the column to a relatively upright orientation with Increased spacing between the fixed surface and said column and lowers the column to a relatively less upright orientation with decreased spacing between the fixed surface and said column.

11. A method as claimed In Claim 10 wherein the column comprises a relatively short substrate-supported first portion and a relatively tall second portion, the two portlons being hinged adjacent their confronting ends by hinge means disposed spaced apart from the substrate by the first column portion.

12. A method as claimed in any preceding claim wherein said displacement means comprises a machine screw.

13. A method as claimed in any preceding claim whereln the column Is hinged at or near its lower substratesupported end, a support frame Is secured adJacent the column to the substrate, a machine screw has a housing secured removably to the frame and a screw extending from the housing is secured by its end remote from the housing to the column so that its displacement linearly varies the spacing between the machine screw housing and frame on the one hand and the column on the other hand.

14. A method of displacing a column between a raised and a lowered condition, substantial ly as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.

15. A column assembly comprising a column, a column mounting plate having the column secured thereto and provided with means for fIxture to a substrate, hinge means enabling the column to pivot between an upright disposition and an approximately horizontal disposition In which the length of the column is Juxtaposed to the substrate sufficiently for access thereto, and machine screw assembly support means secured to the mounting plate and comprising means for supporting a machine screw assembly spaced above the substrate so that said assembly acts between the support means and the column to apply I near displacement therebetween, said support means including means responsive to changes In Incilnatlon of the column durlng pivoting to effect compensatory changes in the orientation of a machine screw assembly having its screw fixed pivotally to the column In use.

16. An assembly as clalmed In Claim 15 and arranged so that in use said linear displacement applied between said column and said support means raises the column to a relatively upright orientation with Increased spacing between the support means and said column and lowers the column to a less upright orientation with decreased spacing between the support means and said column.

17. An assembly as claimed In Claim 16 wherein said column comprises a relatively short substrate-supported first portion and a relatively tall second portion, the two portions being hinged adJacent their confronting ends by hinge means disposed spaced apart from the substrate by the first column portion.

18. An assembly as clalmed in Clalm 15 and arranged so that in use said linear displacement apply led between said column and said support means raises the column to a relatively upright orientation with decreased spacing between the support means and said column and lowers the column to a less upright orlentatlon with Increased spacing between the support means and said column.

19. An assembly as claimed In Claim 18 whereln the column includes a base plate for fixture to the substrate, a first hinge member secured to the base plate and a second cooperative hinge member secured to a lower portion of the column, the two hinge members being coupled together to provide for pivotal displacement of the column relative to the substrate.

20. An assembly as claimed In any one of Clalms 15 to 19 wherein the column Is hinged at or near its lower substrate-contacting end, a support frame is secured adJacent the column to the substrate, a machine screw has a housing secured removably to the frame and a worm or other elongate member defining a cam surface extending from the housing is secured by its end remote from the housing to the column so that its displacement linearly varies the spacing between the machine screw housing and frame on the one hand and the column on the other hand.

21. A column assembly substantially as hereinbefore described with reference to, and as Illustrated in, the accompanying drawings.

22. A column assembly comprlsing a column displaceable between a raised and lowered condition by pivotal movement about hinge means of the assembly, means defining a fixed surface, and displacement means operative to act between said column and said fixed surface to effect said column displacement, characterized In that said displacement means comprises gear means for converting Input rotational drive to linear displacement of a displacement element for applying said linear displacement between said column and said fixed surface to displace said column.

23. A machine screw-and-support assembly comprising a machine screw assembly, means for supporting the machine screw assembly above a substrate on which said support means is disposed In use, said machine screw assembly being secured pivotally to the support means so that the angular attitude of the machine screw relative to the substrate may be altered.

24. An assembly as claimed In Claim 23 wherein the support means comprises a frame comprising elongate frame members and a plate to which the machine screw assembly Is mounted, said plate being supported between two of said frame members and being pivotal in relation thereto to change the orientation of the plane of said plate to the substrate.

25. A method of displacing a column secured to a substrate between a raised and a lowered condition by pivotal movement about hinge means which method comprises applying rotational drive from a hand power tool to means acting to convert said drive to linear displacemnt of a displacement element acting between said column and a fixed surface so as to pivot said column at said hinge means and thus effect raising or lowering of said column.

26. A method of displacing a column secured to a substrate between a raised and a lowered condition by pivotal movement about hinge means which method comprises mounting a machine screw so as to act between said column and a fixed surface and applying Input drive to said machine screw to effect a change In separation between the column and the fixed surface whilst the column pivots at said hinge means.