GB2220014A - Portable stepped staging - Google Patents

Abstract

Staging particularly for use in group photography comprises spaced support assemblies each comprising a rearwardly inclined truss member 151 supported by a first pair of legs 156, 157 arranged in an inverted-V configuration. The truss member 151 carries support brackets 155 for decking members (not shown) which bridge the truss assemblies in a stepped configuration. A bracing bar 158 joins the lower ends of the legs 156, 157, from which a pair of tie bars 159, 160 extend to the from end of the truss member 151. The truss member may be in several sections 152, 153, the upper sections being supported by a second pair of legs 165, 166 which are also arranged in an inverted-V configuration, and the lower ends of these logs are connected to the lower ends of the first pair of legs 156, 157. <IMAGE>

Description

2 22- 0 0 14 P135 STAGING

TECHNICAL FIELD OF THE INVENTION

This invention is concerned with staging of the kind comprising a plurality of decking members arranged in a stepped configuration for supporting a group of people such as in group photography or a standing or seated audience.

BACKGROUND ART

Existing staging structures are heavy and bulky to transport and are slow and difficult to erect, particularly on uneven or sloping ground. For example, in one such structure each decking member is supported by two or more timber trestles which must each be individually erected and levelled. In other existing staging the decking members are supported by a scaffolding arrangement comprising numerous bars, clamps and other components which must all be connected together. That structure also has many individually adjustable feet which must all be correctly adjusted to avoid potentially dangerous stresses being produced in the structure. There is also a large wooden structure in commercial use which requires a team of erectors and a fleet of about seven lorries to transp6rt it.

United States Patent No. 4 747 238 discloses portable audience seating in which the decking members are supported by spaced rearwardly inclined truss members.

2 P135 Each truss member is in turn supported by spaced pairs of props or legs arranged in an inverted-V configuration, and the lower ends of each pair of legs are joined by a bracing bar. However, since the legs are not positively connected to the truss members such an arrangement would not be feasible for supporting trusses with a steep inclination of around 45 degrees such as is required for group photography. Moreover, each pair of legs must be individually and accurately levelled to prevent undesirable stresses from being produced in the truss members.

United States Patent No. 1 839 679 discloses a similar form of staging, but here each pair of legs is positively connected to the respective truss member at their upper ends, and a single tie bar connects the centre of each bracing bar to the bottom of the respective truss. Whilst the structural strength and stability of such an arrangement may be better than that of US Patent No. 4 747 238, it is still considered that such an arrangement would not be acceptable for tall structures with steeply inclined truss members. Similar considerations apply to the structures disclosed in US Patent No. 2 651 081 and British Patent No. 695 774.

BRIEF SUMMARY OF THE INVENTION

An overall consideration in the development of the present staging has been to provide a form of staging which is quick and simple to erect even on uneven ground, which up to about seven rows can be erected by one man alone, and up to about eleven rows can be 3 P135 erected by just two men, and which above all is stable under normal conditions of use.

The present invention provides staging comprising:

- at least two transversely spaced truss members, - a respective pair of legs arranged in an inverted-V configuration to support each truss member in a rearwardly inclined position, - respective bracing means for determining the relative spacing of each pair of legs, - a pair of tie bars each linking the bottom portion of a respective leg to the front portion of the respective truss, and - a plurality of decking members bridging the truss members at different levels.

This basic structure can be used to provide a lightweight easily erectable staging up to about five rows of decking. Furthermore, as will be explained below, the structure can be extended to provide up to about eleven rows whilst still retaining the important features of ease of assembly and stability.

An important advantage of the present ar-rangement over that disclosed in the above-mentioned US Patent is that the use of dual tie bars accurately determines the location of the legs relative to the front end of the respective truss. In addition to minimising possible 4 P135 misalignment problems during assembly this ensures that the structure is considerably less likely to become unstable should it be subject to lateral forces that might cause displacement of the feet, e.g. due to high winds or misuse.

Preferably each pair of legs is pivotally connected to the respective tie bars on a substantially horizontal pivot axis. Each truss member is preferably pivotally connected to -the associated tie bars for movement in a substantially vertical plane. Although the truss member may be permanently connected to the tie bars or the legs, both of these connections are preferably releasable so that the relatively heavy truss member can be separately transported.

The bracing means may bridge the respective tie bars, but since a spreading load will be exerted directly onto the legs the bracing means preferably bridges the legs, ideally at their lower ends.

If, as mentioned above, it is required to use a longer truss member for supporting a larger number of decks, say up to fifteen feet or so in length, the upper portion of each truss member is preferably supported by a further pair of legs arranged in an invered-V configuration, the lower ends of which are connected with the lower ends of the first pair of legs.

The use of common f eet for the two pairs of legs has been f ound to have several positive advantages over an arrangement in which the two pairs stand on separate f eet as in the above-mentioned US Patent. The task of levelling three feet is considerably easier than that P135 of levelling five feet. Also, from an engineering point of view this is far superior since it ensures that both the mid and top regions of the truss member are equally supported and the risk of undesirable stresses or instability being produced in the structure is far less should one or more of the feet sink into soft ground for example. For the same reason the first pair of legs are preferably permanently connected to the respective tie rods so that they cannot be omitted from the structure under any circumstances.

With larger numbers of decks (e.g. from about five upwards) the truss member may comprise at least two interconnectable sections for ease of transportation. Preferably the first pair of legs support a lower section adjacent to its upper end and a separate upper section is supported by the second pair of legs.

The invention also provides a set of at least two stackable spacer elements for use in levelling a staging structure, each stacked element other than the lowermost being of smaller width than the one immediately below it, the upper surface of each element being provided with location means for engagement with and lateral location of a foot of the staging, and the opposed upper and lower faces of each adjacent pair of spacer elements being adapted for relative lateral location of the two elements.

The said location means may comprise a projection for engagement in a recess in the foot of the staging or a well for reception of the foot of the staging.

The lower surface of the lowermost element is 6 P135 preferably adapted for engagement with and lateral location of a ground plate.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is exemplified in the accompanying drawings in which:

Figure 1 is a perspective view of a single truss assembly for use in staging in accordance with the invention, Figure 2 is a detailed side view of the lower end of the truss member of the assembly, Figures 3 and 4 are detailed end and side views respectively of the lower end of one of the support legs for the truss member, Figure 5 is a detailed side view of the connection between the support legs and the truss member, Figure 6 is section VI-VI of Fig. 5, Figure 7 is a vertical section through the connection of Fig. 5 taken perpendicular to section VI-VI, Figure 8 is a vertical section through a set of spacer cups for use in levelling the truss assembly, 7 P135 Figure 9 is a plan view of photographic staging incorporating several such truss assemblies, and Figures 10a - e are skeletal perspective views showing various stages in the erection of each truss assembly.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring to Fig. 1, the truss member 151 is of rectangular box section and comprises a lower section 152, and an upper section 153. The upper surfaces of the truss sections carry a series of longitudinally spaced Vshaped brackets 155 for supporting decking members, the lower section carrying five brackets and the upper section six brackets. The lower truss section 152 is rearwardly inclined and is supported at its upper end by a forwardly inclined first pair of legs 156, 157 arranged in an inverted-V configuration. The bottom ends of the legs are bridged by a bracing bar 158 to accurately determine their spacing. From each end of the bracing bar a respective tie bar 159, 160 extends forwardly to join the lower end of the truss. Towards their forward ends a cross bar 161 is welded to both tie bars 159, 160. An apertured plate 162 extends rearwadly from the centre of the cross bar, the purpose of which will be explained below. The lower ends of legs 156, 157 and of the. truss 151 are each supported on respective ground plates 163.

The upper truss section 153 is supported part way along its length by a second forwardly inclined pair of legs 8 P135 165, 166 which are again arranged in an inverted-V configuration. The lower ends of these legs are connected with the lower ends of the first pair of legs in a manner to be described, and they are bridged by a bracing bar 167. These rear legs 165, 166 are also bridged part way along their length by a further bracing bar 168.

The coupling between tie bars 159, 160 and the truss section 152 is shown in detail in Fig. 2. The tie bars are of square box section and are welded to a common head 169 which contains a transverse downwardly open, forwardly inclined slot 170. A pair of rearwardly extending spaced parallel plates 171 are welded to th rear of the truss, and these are bridged by a horizontal pin 172. When the staging is in its assembled state as shown, the head 169 is received between the plates with the pin located in slot 170. Because of the rearward inclination of the truss and the forward inclination of the slot the head is held captive beteween the plates. The tie bars can only be uncoupled from the truss by pivoting the truss about the pin 172 in a vertical plane towards a vertical position and lifting the head 169 with a slight forward movement.

The lower end of the truss is welded to a substantially horizontal bottom plate 174, from which an upright cylindrical foot 175 having a partspherical lower end 176 projects downwardly to swivellably rest in a well 177 in the respective ground plate 163.

Fig.s 3 and 4 show how the opposite end of tie bar 160 is coupled to the legs 157 and 166.Bracing bar 158 9 P135 and leg 157 are both of square box section and are both welded to a common block 178. An upright cylindrical foot 179 again having a part- spherical lower end 180 extends downwardly from the block, and a pin 181 having a head 182 extends substantially horizontally from the block in the opposite direction to the bracing bar 158. The tie bar 160 terminates in an eye ring 183 which is held captive on the pin 181 along with a washer 184 which is located between the eye and the block. There is a similar pin and eye arrangement at the opposite end of the bracing bar 158, both pins being axially aligned so that relative pivotal movement can take place between the tie bars 159, 160 and the legs 156, 157 about the axis of pins.

The second pair of legs 165, 166 are also of square box section and each terminates in a downwardly directed fork 185. Each arm of the fork carries at its lower end an outwardly projecting peg 185', 185", and the head 182 has a pair of opposed vertical flats 182', 182". With the rear legs 165, 166 in a substantially vertical position the forks 188 can thus be dropped over the pins 181 between the eyes 183 and pin heads 182, with the flats 182' and 182" passing between the pegs 185' and 185". The rear legs can then be pivoted about the axis of pins 181 into a forwardly inclined operative position so that the forks 185 are held captive on the pins 181 by the pegs 185', 185".

Fig.s 5 and 6 show how the first pair of legs 156, 157 are coupled to the lower truss section 152. The upper ends of the legs are welded to a common fork head 186 which comprises a base portion 187 which is joined to the legs, from which two generally parallel spaced arms P135 188, 189 project away from the legs Adjacent to their roots the arms are bridged by a small diameter pin 190, and towards their free ends the arms contain aligned holes 191 to receive a fixing pin 192. The upper end of the lower truss section forms an open socket 193 and the opposite side walls of this socket again contain aligned holes 194 (Fig. 6) to receive the fixing pin. Thus, with the socket 193 received between the arms of the fork 186 the fixing pin 192 can be inserted through holes 191 and 194 to connect the fork to the truss.

The lower face of the truss is provided with a stop 196 located a short distance below the socket 193. This is used during erection of the staging, as will be described below. The second pair of legs 165, 166 are connected to upper truss section 153 by a similar pin and fork head arrangement to that just described. Instead of the stop 196 being below the fork head however, a similar stop is provided just above the head. The legs 165, 166 are provided with inwardly directed opposed stop members 201, 202 (Fig. 1) a short distance below the bracing bar 168. These are again used in assembly as described below.

Referring to Fig. 5, the lower end of the upper truss section 153 carries an axial spigot 198, which is also of hollow box section. This spigot is a close sliding fit within the socket 193, and includes a transverse slot 199 extending axially from the outer end of the spigot to receive the pin 192. Thus, the spigot can be slid into the socket with the pin 192 in place. For safety purposes a gravity catch is provided to hold the two truss sections together, and this is shown in Fig.

7. The catch 231 is located within the spigot 198 and P135 comprises an arm 232 which is pivoted at one end 233 to lie against the lower wall of the spigot projecting towards the free end of the spigot. Part way along the arm 231 there is secured a release button 234 which projects through the bottom wall of the truss section 153, and at the free end of the arm a hook portion 235 having an inclined leading edge 236 projects through an aperture 237 in the wall of the spigot. Thus, as the spigot is inserted into the socket 193 the wall of the socket engages the inclined edge 236 and pivots the catch so that the hook portion retracts into the spigot. However, once the spigot is fully inserted into the socket 193 the hook portion 235 becomes aligned with a hole 238 in the wall of the socket so that the catch is free tb return under gravity to the position shown. The hook portion 235 thus prevents the spigot from being withdrawn from the socket 193. The catch can only be released by manually pushing the release button 234 to pivot the catch to the retracted position.

Fig. 8 shows a set of spacer cups for use in levelling the truss assembly should it be required to erect the staging on uneven ground, e.g. a sports field. The left half of the drawing shows the cups as castings whereas the right half shows turned cups. The drawing shows a set of four circular cups A to D which are seated upon each other, the width of the cups generally reducing in diameter f rom the bottom cup D to the top cup A. The upper f ace of each cup contains a central well 205 which, apart from cup A, is similar in size to the well formed in ground plates 163, one of which is represented in the drawing as E. Well 205' of cup A is slightly smaller in diameter than those of the other

12 P135 cups, the reason for which will be explained shortly. Each well generally comprises an upright cylindrical side wall 206 which leads into a concave part-spherical bottom wall 207, the radius of curvature of which matches the underside of feet 175 and 179. The upper faces of the two lowermost cups C and D include annular recesses 208, 209 respectively, to receive and laterally locate depending cylindrical spigots 210 211 respectively, provided on the undersurface of cups B and C respectively. Ground plate E has an upstanding collar 212 surrounding its well 177, and the lowermost cup D has a recess 213 in its under-side t6 fit over and laterally locate the cup on the ground plate. The underside of cup A has a central spigot 214 which fits into and provides lateral location in any of the wells 205 of the other four cups or in well 177 of the groundplate.

It will be noted that in cups A and B the respective lift X, X' between the upper surface of the cup and the upper surface of the cup immediately below it is half that of cups C and D, (Y, Y' respectively). The overall lift between the well 205 of the upper cup and the well 177 of ground plate E can be varied by using different combinations of cups. A total of six different lift combinations can be provided using the cups, namely E+ A, E+D, E+D+A, E+D+C, E+D+C+B and E+D+C+B+A. Normally two sets of cups will be provided for use with the rear groundplates. On level ground the combination E+D gives the rpquired truss inclination (say 44 degrees) but on uneven ground the truss can be restored to this inclination by changing the cup combination under one or both rear legs as required.

13 P135 The use of cups of reducing diameter provides stability against sideways loads even where a large lift is required. Furthermore, the configuration of the cups ensures that no cup of greater or the same diameter can be located on top of another. In particular it will be noted that since the well 205' of cup A is smaller than that of the other cups another cup A cannot be located on this cup since its spigot 214 will not fit within the well.

Other lifts can be achieved by using greater numbers of cups and/or different individual lifts. The cast cups could be of any cross section, e.g. square instead of circular.

Fig. 9 shows how six truss assemblies for example can be used in staging for use in group photography. Each adjacent pair of trusses 151a-f are connected together by a number of decking members 215 each joining the corresponding brackets 155 of the two trusses. The decking members are coupled to the brackets for articulation in vertical and horizontal planes. (The decking members and the arrangement by which they are joined to the respective trusses may be as described in copending Application No. 87. 11 221.) Thus, when upwards of three trusses are used the staging can be curved into an arc as shown. The decking members of the central staging section 216 are the same length as those of the two adjacent sections 217, 218 but the trusses 151b and 151e are brought forward relative to trusses 151c and 151d so that the four inner trusses remain substantially parallel. Although the rear decking members of the outer sections 219, 220 are the same length as those of the other sections, the 14 P135 remaining decking members decrease in length from back to front so that the end trusses 151a and f are radially aligned with the camera. In addition, the support structures for the end trusses are asymmetric so that the outermost support legs are vertical and do not project beyond the end trusses where they would be in camera shot. Narrower ground plates 163' may also be used with the outer trusses, as shown. Apart from this the end truss assemblies are as described above.

The main structural members of the truss assemblies are all of lightweight metal for ease of transportation and handling.

Fig.s 10a-e show the sequence in which each truss is erected. First, the tie bars 159, 160 with legs 156, 157 attached are laid on the ground in the required position. As shown, the legs are held in a common plane with the tie bars during storage and transport by means of pin 192 which is inserted through the fork head 186 and apertured plate 162. The lower truss section 152 is then coupled with head 169 of the tie bars by dropping the head onto the pin 172 with the truss section in a nearvertical or forwardly inclined position, and then pivoting the truss section 152 in a vertical plane towards its normal rearwardly inclined position. The pin 192 is then withdrawn so that the legs can be lifted. If required, the pin 190 of the fork head can be temporarily rested on stop 196 at this stage, as shown in Fig. 10b. The legs are then lifted so that the fork head slides along the truss section 152 until the pin apertures 191 of the head are in register with apertures 194 of the socket portion 193, whereupon the pin 192 is inserted therethrough. Some P135 of the decking members can now be added to ensure the correct spacing of the trusses. In addition, gauge bars can be temporarily fitted between adjacent trusses at say the first and fifth row levels to assist in obtaining the correct truss spacing. If five row staging is required all the decks can be added to complete the assembly of the staging.

If eleven row staging is required the rear legs 165, 166 are added by dropping the forks 185 onto pins 181 as described. The stops 201 and 202 can now rest on the first legs 156, 157 as shown in Fig. 10c so that the fork head 186 of the rear legs is raised slightly above that of the front legs. The f ork head of the rear legs is the connected to the upper truss section 153 by the respective pin 192 (Fig. 10d). The upper stop 196 allows the truss to be temporarily rested on the pin 190 of the upper fork head using this stop before the fixing pin is inserted. The lower end of section 153 is then grasped and pushed upwards to enable the spigot 198 to be slid into the socket 193 of the bottom truss section (Fig. 10e). Finally the remaining decking members can be added.

Any levelling of the truss assemblies that may be required can be carried out at any stage before the decks are added. The staging is dismantled in the opposite sequence to which it is erected.

The upper truss sections 153 may be in two or more sections, for example a middle four row section joined to an upper two row section by a spigot and socket joint just above the upper fork head 186. Thus, seven row staging could be made by adding the two row 16 P135 extension to the basic five row section, or nine rows by omitting the top two row section. Smaller five or seven row staging could be constructed using this same principle, the only difference being that the inclination of the single pair of supporting legs would be closer to that of the rear legs 165, 166.

k 17 P135

Claims (31)

1. Staging comprising:

a pair of mutually spaced support assemblies, each support assembly comprising, a truss member having front and rear ends, a first pair of legs arranged in an inverted-V configuration to support said truss member with a rearward inclination, upwardly, each leg of said first pair of legs having upper and lower ends, first connection means positively connecting said first pair of legs to baid truss member to prevent movement of said legs longitudinally of said truss member, bracing means for determining the spacing of said lower ends of said first pair of legs, and a pair of tie bars each linking said lower end of a respective leg of said f irst pair of legs with said front end of said truss member; and a plurality of decking members bridging said truss members of said support assemblies in a stepped configuration.

2. Staging according to Claim 1, in which each pair of legs is pivotally connected to the associated tie bars for pivotal movement about a' substantially horizontal pivot axis.

3. Staging according to Claim 2, in which each pair of legs is nonreleasably connected to the 18 P135 associated tie bars.

4. Staging according to Claim 3, in which each pair of legs carry aligned headed pivot pins which each receive an eye ring secured to a respective tie bar.

5. Staging according to any preceding claim, in which each truss member is pivotally connected to the associated tie bars for pivotal movement about a substantially horizontal pivot axis.

6. Staging according to Clai-m 5, in which each of the truss members is releasably connected to the associated tie bars.

7. Staging according to Claim 6, in which each pair of tie bars is secured to a common head containing a downwardly open slot to receive a substantially horizontal pivot pin secured to the respective truss member.

8. Staging according to Claim 7, in which the said slot is forwardly inclined in an upward direction.

9. Staging according to any preceding claim, in which each of the truss members is releasably connected to the respective pair of legs.

10. Staging according to Claim 9, in which each pair of legs is secured to a respective fork head which is releasably secured to the truss member by a fixing pin inserted through aligned apertures in the truss member and the fork head.

19 P135

11. Staging according to Claim 10, including a stop member secured to the underside of the truss member below the said aligned apertures therein for resting the fork head thereon during assembly.

12. Staging according to any preceding claim, in which the bracing means is permanently secured to the respective pair of legs.

13. Staging according to Claim 12, in which the bracing means comprises a bracing bar which is secured to the lower ends of the respective pair of legs.

14. Staging according to any preceding claim, in which an upper portion of each truss member is supported by a second pair of legs arranged in an invered-V configuration, the lower ends of which are connected with the lower ends of the f irst pair of legs.

15. Staging according to Claim 14, in which the second pair of legs is pivotally connected to the first pair of legs for pivotal movement about a substantially horizontal pivot axis.

16. Staging according to Claim 15 as appended to Claim 4, in which the lower ends of the second pair of legs each carry a downwardly directed fork member for reception on a respective one of the headed pivot pins.

17. Staging according to Claim 16, in which the head of each of the headed pins has a pair of opposed substantially parallel flats which are inclined with respect to the plane of the second pair of legs when P135 they are in their operative position, and each fork member carries a pair of pegs which are spaced apart by a distance which is slightly greater than the spacing between the said flats, the arrangement being such that during assembly of the staging the pegs pass either side of the said flats as the fork members are engaged with the headed pivot pins, and when the second pair of legs are in their operative position the pegs are unable to move past the head of the respective pivot pin thereby securing the fork members to the pivot pins.

18. Staging according to any of Claims 14 to 17, in which each of the truss members is releasably connected to the respective second pair of legs.

19. Staging according to Claim 18, in which each second pair of legs is secured to a respective fork head which is releasably secured to the truss member by a fixing pin inserted through aligned apertures in the truss member and the said fork head.

20. Staging according to any of Claims 14 to 19, in which each second pair of legs is provided with bracing means for determining their spacing.

21. Staging according to Claim 20, in which the bracing means for each second pair of legs comprises a bracing bar which is secured to the lower ends of the respective pair of legs.

22. Staging according to Claim 21, in which the bracing means for each second pair of legs comprises a bracing bar which bridges the said pair of legs part 21 P135 way along their length.

23. Staging according to Claim 21 or 22, in which the bracing bar or bars for the second pair of legs is/are permanently secured thereto.

24. Staging according to any of Claims 14 to 23, in which each second pair of legs carries a pair of inwardly directed stop members to rest in contact with the associated first pair of legs during assembly of the staging.

25. Staging according to any of Claims 14 to 24, in which each truss member includes at least two interconnectable sections, the first pair of legs support a lower section of the truss member adjacent to its upper end, and the second pair of legs support an upper section of the respective truss member.

26. Staging according to Claim 25, in which one of the interconnectable sections of each truss member includes a pivoted gravity catch which automatically engages the other truss section to lock the two sections together, the said catch being releasable by manually pivoting it against gravity out of engagement with the respective truss section.

27. A set of at least two stackable spacer elements for use in levelling a staging structure, each stacked spacer element other than the lowermost of said stacked spacer elements being of smaller width than the spacer element immediately below it, an upper surface of each element being provided with location means for engagement with and lateral location of a foot of said 22 P135 staging structure, and opposed upper and lower faces of each adjacent pair of spacer elements being adapted for relative lateral location of said adjacent pair of spacer elements.

28. A set of spacer elements according to Claim 27, in which the said location means comprises a well for reception of the foot of the staging.

29. A set of spacer elements according to Claim 27 or 28, in which the lower surface of the lowermost element is adapted for engagement with, and lateral location relative to, a ground plate.

30. Staging substantially as described with reference to the drawings.

31. A set of stackable spacer elements substantially as described with reference to Figure 8 of the drawings.

Published 1989 at The PatEnt Office, State House, 66'71 High Holborn, London WC1R 4TP. Furtner c 3pies maybe obtainedfrom The Patent Office. Sales Branch, St Mary Cray, Orpington. Kent BP.5 3RD. Printed by Multiplex techniquf. ltd, St Mary Cray, Kent, Con. 1/87