FR2794989A1 - Linear grill for theatre has a catwalk has profiled tubes extending between stops and with gaps to allow passage of backdrops - Google Patents

Abstract

The grill for a theatre forms a catwalk (17) for the backdrop panel (15) carriers when the height available does not allow positioning of a normal catwalk. The grill is formed of profiled tubes (16) with spacing between them (17) to allow passage of the decor backdrop panels. Each tube is supported by a stop at each end.

Description

The invention relates to improvements made to arrangements such as technical or more specific ceilings in theaters, making it possible to move mobiles, generally vertically and in the direction of gravity or in the opposite direction.

For a good illustration of the application of the device of this invention, the invention relates to the support of systems of the kind of horizontal supports intended, in a scenic space, to support scenic lighting or sets, more commonly designated scenographically by teams or carriers, can be retained as an example.

In this particular case chosen by way of example, and in no way constituting any limitation of the invention of the common provisions consist in suspending (fig 1) a horizontal tube (1) by cables (2) returned by pulleys (3) to a collecting pulley (4) with several grooves so that they are harnessed to a counterweight (5).

The counterweight (5) is urged in its vertical stroke by a rope (6) coupled to its upper part and returned by pulleys (7) and (8) to the lower part of the counterweight.

Thus, manual operation is possible by pulling on the line (6) and the latter can be blocked by a brake (9).

Another arrangement (Figure 2) allows the remote control of the counterweight rod by replacing the operating line (6) with a steel cable (10) which is wound on the drum (11) of a motor unit (13 ).

A direct operation without counterweight (Figure 2) can be carried out by winding the cables (2) directly on a drum (11) integral with a motor unit (13) and in this case the total load is taken into account in the calculations of the torque exerted on the drum (11) and on the motor unit (13).

In common techniques, the technical ceiling located on a theater stage is called a grill and may or may not include a false grill.

These arrangements receive the pulleys (3) which return the cables (2).

False grills are static equipment hung on the ceiling without circulation decking and the installation and maintenance of the carriers is generally done from the stage by means of elevation: ladders, scaffolding, etc ...

It is preferable to install a grill under the false grill at a distance allowing the circulation of the personnel but this arrangement can only be adapted when the height under roof is largely sufficient so that the carriers, coming from abutting below, completely retract the decor in public view.

The object of this invention is to create a circulating grill when the height is insufficient. The decorations are generally made in the form of flat surfaces (15) in Figure 3 in fabric or other material whose thickness is small.

The diameter of the carrier is often more important than the decor itself. The spacing of the carriers is dependent on the thickness of the balancing counterweights (5) or the drums of the power units (11).

For the maintenance of false grills from below, it can be used "flying bridges", narrow gangways suspended under the false grill and taking the place of a few carriers but allowing access only to a few carriers adjacent to them at hand.

These impractical flying bridges are dangerous because of the will of the machinists to want to access the carriers too far from their guardrails.

Their multiplication makes the false grill not very exploitable.

In the particular case chosen by way of example and not in any way constituting a limitation of the invention, a few dimensions allow a better understanding of the invention.

 Square tubes of 0.10 m side (16) fig.5 are arranged in the direction "courtyard garden" that is to say transversely to the general axis hall scene at a spacing (17) of 0.10 m which allows a step between carriers (18) of 0.20 m to be used.

It is in this longitudinal emptiness of the entire width of the stage that the carriers and the decorations can circulate vertically while going up under the grill.

Each tube is carried individually by a support (19) at each end and at each "muffle path" element of the false grill consisting of 2U (20) in the "far face" direction parallel to the general room-stage axis, and which carries the cable return pulleys located above the carriers.

The lines (21) located at each muffle path (20) or at other corresponding spacings used, are arranged to leave a large free passage between them as shown in the plan view of Figure 5 The staggered arrangement thus created a large passage equivalent to that of grills with false grills.

The circulation on the linear grill is done with particular attention to avoid that the foot is in one of the voids (17) especially in the circulation parallel to the structures. Privileged circulation is to be arranged in this direction and in particular at the base of the carriers or bridges for scenic lighting whose retraction under the false grill is not useful, by having folded perforated sheet panels (22) of 2 or 3 times 0.20m fitting the square tubes (16) fig 6.

It should be noted that the linear grill is advantageously constructed from aluminum alloy profiles as well as the perforated circulation sheets.

It is obvious that other privileged passages can be arranged in this way such as those going from the face to the distance at the ends. If volumetric decorations are installed, 1 or more square tubes (16) can be easily deposited by the adjacent access by installing regulatory body guards protecting the hopper thus created.

The lines (21) integral with the false grill can be put in place by trimmers as shown in Figure 7 in which 2 dishes (23) are clamped on the 2 U of the muffle path (20) with a vacuum corresponding to the diameter of the hanger which can thus be adjusted perfectly.

The natural stiffness of the square tubes is complemented by the embedding of the lines which must be made in large sections.

It goes without saying from the foregoing that the intervention is in no way limited to those of its modes of application any more than to those of the embodiments of its various parts having been more especially envisaged; on the contrary, it embraces all its variants.

It is obvious that this linear grill object of this invention is not intended to replace all the grills but it offers a possibility of arranging the scenes of low height to make them more exploitable without danger and with greater ease when the height cannot be alienated by installing a traditional grill.

Accessories can be arranged punctually in the form of a "ski tip" (24) in FIG. 8 to facilitate the passage of the carriers, in particular below during their ascent and possibly to facilitate their descent.

Claims (4)

1) Device making it possible to create a surface which can be circulated, in particular under the false grill in theaters, without hindrance for the rise of the sets, characterized in that it consists of profiled tubes (16) whose spacing between them (17) allows the passage of decorations (15) 2) Device according to claim 1, characterized in that each tube (16) is carried by a support (19) at each end. 3) Arrangement according to any one of the preceding claims, characterized in that sheet metal panels (22) of 2 or 3 times the pitch of the tubes make it possible to create privileged circulations. 4) Arrangement according to any one of the preceding claims, characterized in that it comprises intermediate lines (21) in staggered rows which do not impede circulation, and the embedding of which makes it possible to increase the stiffness of the profiles.