[0001] This invention relates to an improved support for lighting equipment of the kind
used in the illumination of theatres studios and other areas where special lighting
effects are required.
[0002] The operation of theatres and studios necessitates the use of illumination often
of high intensity and provided by light sources which have to be positioned in particular
ways in order to enable certain desired lighting effects to be achieved. These effects
are normally obtained by the use of numerous lights which are attached to a support.
The latter usually takes the form of a frame the size and shape of which depends upon
the dimensions of the area to be illuminated. The simplest form of frame can consist
of a single straight member which might extend horizontally above a stage. However
depending upon circumstances a frame can have a more complex shape incorporating several
arms extending in different directions.
[0003] In order to facilitate the supply of supports manufacturers make available straight
lengths of frame in differing lengths. In addition they provide supports having a
variety of shapes for example in the shape of an L, X, Y and + so that a user can
assemble a frame of required size and shape from what in effect is a kit of components.
[0004] The supports in current use are made in different ways. However one form comprises
three cylindrical main members arranged in parallel as a triangle and secured together
by struts. The main members consist generally of metal tubes to which electric lights
and other devices for example loudspeakers can be fixed by G clamps so that they can
be pointed in any desired direction.
[0005] One of the main problems affecting not only the manufacture but also the use of the
support stems from the large number of lights which they are required to carry and
the extensive wiring associated with the lights.
[0006] The weight of all these items is considerable. Consequently the supports have to
be correspondingly strong. A greater problem is associated with the wiring itself
which has to be disposed of in an aesthetic way and also in accordance with stringent
safety regulations. In general the wiring from the different appliances is collected
together and enclosed in trunking which is located as closely to the support as circumstances
permit. The extent, nature and weight of the wiring which the frame is required to
carry imposes certain limitations in the design of the frame components and as a result
the manufacturer finds the need to manufacture and maintain stocks of a considerable
variety of frame components which are costly to produce. A further problem stemming
from the wiring is that the assembly of a supporting frame together with its attachments
and wiring is very time consuming.
[0007] The present invention is directed to a support for electrical devices which avoids
many of the problems associated with existing supports.
[0008] Accordingly this invention provides a support for electrical devices connected to
wiring comprising a plurality of members secured together to form a frame wherein
one of the members is hollow and a wall in the hollow member is provided with an opening
extending longitudinally of its length and means for securing the wiring within the
member.
[0009] The effect of this invention is that one or more of the members is utilised as trunking
for the wiring and in this way various advantages are obtainable. Thus the cost of
separate trunking is avoided. The wiring of a support is achieved more quickly and
with better aesthetic effects than hitherto. Furthermore the ends of the components
of the support and cornerpieces can be adapted more easily so as to enable strong
and complex supports to be assembled quickly from components which are less expensive
and less numerous than those which are in current use.
[0010] This invention is illustrated but not restricted by the following drawings in which:
Figure 1 is an end view of one preferred form of support made according to the invention
Figure 2 is an exploded side view of the support shown in Figure 1
Figure 3 is an exploded end view of an alternative form of support.
Figures 4 and 5 are views taken in perspective of a part of a support having an alternative
form of construction.
[0011] In Figures 1-3 the support shown generally as a frame (1) consists of a trunking
member (2) and main members (3 & 4) arranged in parallel in the form of a triangle.
The members can be constructed of any strong material for example aluminium or steel
tubing which is secured together by struts (5) preferably by welded joints. Trunking
member (2) is in the form of a cylindrical box provided with an opening (6) extending
lengthwise of the member and provided with a lid (7) which conveniently forms a push-fit
with the side walls of member (2). However if desired the lid can be fixed by other
means for example nuts, bolts or screws. A wall of trunking member (2) is provided
with a series of apertures (8) to enable wiring from each individual applicance (not
shown) attached to members (3 & 4) to enter the member (2). If desired the apertures
can be supplemented or replaced by electrical connections for example surface or flush
mounting sockets (6) to enable the wire of each individual appliance to be connected
to wiring in the trunking member.
[0012] The support described above can constitute a component of a more complex support
by attachment of extension pieces or angled components. In this connection main members
(3 & 4) and trunking member (2) are all provided with bolt holes (9). A spigot (10)
is then inserted into the end of each of main members (3 & 4) until holes (9) and
(11) are in register thereby enabling a bolt to be inserted and the spigot and the
member to be secured together. A similar procedure is followed with respect to trunking
insert (12) having bolt holes (13 & 14). The trunking insert is slid into the end
of the trunking member (2) until holes are in register after which the insert and
the trunking member can be bolted together. Each of members (2, 3 and 4) have now
extending from them half a spigot or trunking insert having spare bolt holes on to
which straight or branched supports can be bolted.
[0013] In Figure 3 the trunking member (2) consists of two hemispherical walls (2 & 7) which
can be united by the methods described above. The main members (3 & 4) consist of
aluminium or steel having a circular cross section.
[0014] The form of the trunking member or members which is made depends on such safely regulations
which may have to be observed. Thus where the regulations stipulate that the wiring
in the trunking shall be completely enclosed then the lid (7) should preferably extend
the full length of trunking member (2). However where regulations permit, other forms
of trunking members can be used. For example member (2) can comprise a tube having
a circular cross section and the wall of the tube is provided with a longitudinal
aperture. Wiring can be secured within the trunking by the use of circular spring
clips. The opening in the wall of the trunking member can be either continuous or
discontinuous.
[0015] The present supports are especially advantageous in the construction of complex structures.
These can be made by first fixing the ends of two or more main members and a trunking
member to a base plate to form an assembly and then securing the assembly to a connecting
member. A single connecting member may have several assemblies connected to it each
incorporating a number of main members. This aspect of the invention is illustrated
in Figure 4 in which a connecting member (41) comprises a hollow metal sphere having
two access holes (42). An assembly of main members (43 & 44) and a trunking member
(52) is formed by welding the ends of the members to base plate (45). The latter is
then secured to connecting member (41) by bolts (not shown) which pass through bolt
holes (46) in the base plate (45) and corresponding holes (47) in the connecting member.
Access holes (42) enable tools to be inserted into the member for the purpose of tightening
the bolts.
[0016] The main members (43 and 44) and the trunking member (52) comprise tubes of rectangular
cross section. The trunking member is provided with a longitudinal opening (48) to
permit the insertion of wiring which passes through hole in the wall of the connecting
member (41). The wiring is secured within the trunking member by a push-on lid (not
shown). The ends of the members remote from the base plate (45) are provided with
holes to enable the assembly to be connected to further lengths of main and trunking
members to enable the completion of the final structure. The main and trunking members
are connected together by reinforcing struts (51) and are welded on to one face of
the base plate, the reverse side of which is shaped to enable it to conform with the
curved surface of the spherical connecting member. Additional assemblies of main and
trunking members can be fixed in a similar way to other parts of the surface of the
connecting member which being curved enables assemblies to project from it at different
angles and in different planes. If desired each main or trunking member can be attached
directly to the connecting member. However in general the use of some form of base
plate is preferred. The connecting member can be in different forms and have different
shapes. For example Figure 5 illustrates a part of a support in which the member is
a hollow cylinder (55) in which the open end (56) provides access to enable bolts
(57) to be inserted through holes (58) in the cylinder into base plate (59). In general
the use of a cylindrical connecting member is preferred. The member can have any regular
shape. For example it can be hexagonal, square, triangular oval etc. Preferred members
are hollow although they can be mainly solid provided that they incorporate any cavities
which may be required to enable bolts or other fixing means to be used to connect
the member to other members forming the support.
1. A support for electrical devices connected to wiring comprising a plurality of
members secured together to form a frame wherein at least one of the members (2)is
hollow and a wall forming part of the hollow member is provided with an opening (6)
extending longitudinally of its length and means (7) for securing the wiring within
the hollow member.
2. A support according to Claim 1 wherein the support comprises three members arranged
in parallel in triangular relationship and connected together by struts.
3. A support according to either of Claims 1 and 2 wherein each of the members has
a rectangular cross section.
4. A support according to any one of the preceding claims wherein the means for securing
the wiring within the hollow member is a lid.
5. A support according to any one of the preceding claims wherein the hollow member
incorporates additional appertures to provide access for wiring from individual devices.
6. A support according to any one of the preceding claims wherein the hollow member
is provided with one or more electrical connections
7. A support according to any one of the preceding claims wherein one end of each
member is secured to one side of a base plate and the reverse side of the base plate
is secured to a connecting member.
8. A support according to Claim 5 wherein the connecting member is a hollow cylinder.
9. Supports as hereinbefore described with particular reference to the drawings.