Patent Description:
Loudspeakers for concerts, nightclubs and music festivals may be rigged in vertically aligned arrays. In such arrays, the loudspeakers may be suspended from a temporary or permanent structure, with each loudspeaker being suspended from the loudspeaker above. For the remainder of this document, the term scaffold is used for ease, although this may be interpreted as a temporary or permanent structure. It will be appreciated that the loudspeakers are typically housed in a speaker enclosure that is more regular in shape and therefore more easily formed into an array. The term loudspeaker or speaker may be used herein to encompass a speaker enclosure containing a loudspeaker.

In arrays of loudspeakers, the loudspeakers typically are arranged as one or more columns and are required to be angled relative to each other so as to provide the desired vertical coverage of sound. In certain arrangements, the speakers will be angled to produce an arced or curved array, which may form a "J" shape.

Typically, each column comprises a top loudspeaker which is attached to a lifting frame. The other loudspeakers of the column are suspended from each other by links and by pivotal arrangements, typically at the front and rear providing a range of inter-loudspeaker angles. In order to deploy some systems of this type, a lifting beam is attached to a frame, which in turn is attached to connecting plates of a first loudspeaker enclosure, which may be connected to either side of the loudspeaker enclosure.

The frame is lifted and further speakers added to the column. After each loudspeaker has been attached, the lifting frame is raised to allow room for the next level of loudspeakers to be mounted.

When the array is suspended from the scaffold off the ground, the loudspeakers are rotated or tilted with respect to each other in a vertical plane. In order to produce the curved array, a lever hoist is attached to the rear of a lower speaker of the array. The lever hoist is tensioned rearwards and the lower speaker is drawn upwards and to the rear, rotating one or more of the speakers with respect to each other and forming the curve.

The act of curving the array, for example as described above, moves the centre of gravity of the overall array, and consequently the angle of inclination or declination of the array. Further, the differently aligned load may affect an angle at which the speaker array is directed towards the audience, which may compromise audio performance. <CIT> relates to an articulated speaker rigging system and method. <CIT> relates to a theatre rigging system. <CIT> relates to a tensile truss mast.

Exemplary methods and apparatus are able to control the angular displacement of the array whilst under load, i.e. whilst the loudspeaker array is suspended. According to the invention in an aspect, there is provided a loudspeaker rigging apparatus according to claim <NUM>. Also disclosed herein is a loudspeaker rigging apparatus for suspending a plurality of loudspeakers from temporary or permanent structure, the loudspeaker rigging apparatus comprising: a beam configured to be secured to an uppermost speaker in an array of speakers; and a trolley coupled to the beam and moveable along at least part of a length of the beam, the trolley comprising a rigging point configured for connection to the rigging or scaffold, wherein the beam may be angularly displaced with respect to a horizontal plane when the rigging point is connected to the rigging or scaffold.

Movement of the rigging point alters the alignment of the rigging point with respect to the centre of gravity of the load exerted by the array.

Optionally, the rigging apparatus further comprises a trolley driver configured to provide a force for moving the trolley along the at least part of the length of the beam.

Optionally, the trolley driver comprises a threaded lead screw, and wherein the trolley comprises a threaded aperture through which the lead screw is received, such that rotation of the lead screw causes linear movement of the trolley.

The trolley comprises at least one rotatable element in contact with a surface of the beam and configured to rotate on movement of the trolley.

Optionally, the at least one rotatable element comprises at least one wheel.

The at least one rotatable element of the trolley is configured to contact a downward facing surface of the beam, such that at least a part of the load resulting from suspension of the array of loudspeakers is supported by the at least one rotatable element.

Optionally, an outer wall of the beam forms an internal cavity in which the trolley is received and that permits movement of the trolley along at least part of the length of the beam.

Optionally, an internal upper surface of the internal cavity forms the downward facing surface.

Optionally, the rigging apparatus further comprises an actuator configured to rotate the lead screw.

Optionally, the actuator comprises an electric motor.

Optionally, the rigging apparatus further comprises a motor controller for receiving operating instructions for the actuator from a remote device, and controlling the motor based on the received instructions.

Optionally, the rigging apparatus further comprises an inclinometer, configured to detect the angle of displacement of the beam with respect to the horizontal plane.

Optionally, the inclinometer comprises inertial sensors configured to determine angular displacement.

Optionally, the rigging apparatus further comprises a display configured to receive and display data indicative of the angle of displacement.

Optionally, the trolley is housed, at least partially, within the beam.

Optionally, the rigging point protrudes from an upper surface of the beam and is retained within a longitudinal slot formed in an outer wall of the beam.

The rigging point comprises a single suspension point about which the beam may rotate.

According to the invention in an aspect, there is provided a rigged loudspeaker array comprising a loudspeaker rigging apparatus according to any disclosed herein.

According to the invention in an aspect, there is provided a method according to claim <NUM>. Also disclosed herein is a method for suspending a plurality of loudspeakers from a temporary or permanent structure, the method comprising: securing an uppermost speaker in an array of speakers to a beam; connecting a rigging point of a trolley to the temporary or permanent structure, wherein the trolley is connected to the beam and moveable along at least part of a length of the beam, and wherein the beam may be angularly displaced with respect to a horizontal plane when the rigging point is connected to the temporary or permanent structure; tensioning the array of speakers; and adjusting a position of the trolley along the length of the beam for achieving a desired angular displacement of the beam.

The method may include corresponding steps associated with any of the physical features of the rigging apparatus disclosed herein and, in particular, above.

Generally, disclosed herein are methods and apparatus for realigning a load of a suspended speaker array. This may be required after tensioning the lever hoist to place the suspended array into a "curve. In some exemplary arrangements, the speaker array may be suspended via a beam that is connected to a rigging or scaffold in such a way that the beam is able to rotate in a vertical plane or, put another way, to be angularly displaced with respect to a horizontal plane. When the speaker array is initially connected to the rigging, the beam may be level. After tensioning the speaker array, the centre of gravity of the array is shifted, which vertically rotates the beam, leading to misaligned and potentially unsafe loads. Methods and apparatus disclosed herein are arranged to realign the load of the speaker array.

It is noted that the term "tensioning" when referring to a suspended speaker array refers to drawing the array into the "J" shape. This typically requires tensioning of a chain of the lever hoist, as explained below. It is noted that the "tensioning" of the array may actually result in compression between the speakers at the rear and a tensioning of the speakers at the front, as they rotate in an articulated fashion to form the curve.

<FIG> shows a rigging apparatus <NUM> comprising a beam <NUM>. The apparatus further comprises a frame <NUM> that is connected to the top speaker of an array <NUM>. The frame <NUM> is connected to the beam <NUM>. Specifically, in the example shown the frame <NUM> runs laterally along a width of the top speaker and is connected to a pair of connecting plates <NUM> on either side of the speaker (only one side shown). The connecting plates allow speakers to be connected to other speakers and/or to the frame. The frame <NUM> runs transverse to the beam <NUM> and is fixedly connected thereto. In exemplary arrangements, the frame <NUM> may be connected to the beam <NUM> by one or more pins that are removable, such as pip-pins.

The remaining speakers in the array <NUM> are each connected to and suspended from the speaker above. One or more of the connections may be configured to allow relative rotation of adjacent speakers.

The rigging apparatus further comprises a rigging point <NUM> for connection to the scaffold (not shown). The rigging point <NUM> forms part of a trolley, which is not shown in <FIG> but is described in detail below. The rigging point <NUM> is configured to permit angular displacement of the beam with respect to a horizontal plane. In the example shown in <FIG>, the rigging point comprises a single fixing, embodied as an aperture through which a shackle, pin, or other fixing may be passed when fixing the rigging apparatus <NUM> to the scaffold. As will be appreciated, the beam may therefore rotate in a vertical plane about the aperture in the rigging point.

The rigging apparatus <NUM> further comprises an actuator, which in the example shown is an electric motor <NUM>, although other actuators may be used. The actuator is referred to as the electric motor <NUM> for the remainder of this description. The electric motor <NUM> is described in relation to the other features of the rigging apparatus <NUM> below.

The rigging apparatus further comprises an inclinometer <NUM>. In the example shown, the inclinometer uses solid state inertial sensors to determine an angle of incline, but other types of inclinometer may be used. The lever hoist <NUM> is suspended from a rear portion of the beam <NUM>. The lever hoist <NUM> comprises a chain <NUM>, although other tensionable load bearing elements may be used, a hook <NUM> for connection to a lower (and optionally the lowest) speaker in the array <NUM> or an additional frame connected to the lower loudspeaker in the array, and a lever <NUM>.

The connection of the hook <NUM> to the lower speaker of the array <NUM> is shown in <FIG>. The lever hoist chain <NUM> is tensioned in the direction of the arrow <NUM> by operation of the lever <NUM> in a ratchetting fashion to form the speaker array <NUM> into curve. In other arrangements, this tensioning may be provided by a winch that is controlled by the (or a further) electric motor <NUM>.

<FIG> shows an isometric view of the beam <NUM>. The beam <NUM> houses the trolley <NUM>. An outer wall of the beam <NUM> forms an internal cavity <NUM> along at least part of the length of the beam <NUM>. For the purposes of description, the outer wall of the beam <NUM> is not shown in <FIG> so that the trolley <NUM> and the internal cavity <NUM> are visible.

The internal cavity <NUM> allows movement of the trolley <NUM> along at least part of the length of the beam <NUM>. The beam <NUM> comprises a trolley driver in the form of a lead screw <NUM>, however other arrangements of trolley driver may be used. For example, the trolley <NUM> may comprise a motor or other means of propulsion arranged to move it along the beam <NUM>. The lead screw <NUM> extends along a length of the beam <NUM> and in the example of <FIG>, along the entire length of the beam <NUM>. The lead screw <NUM> is threaded and passes through a correspondingly threaded aperture in the trolley <NUM>. Therefore, rotation of the lead screw <NUM> translates into linear movement of the trolley <NUM> along the length of the lead screw <NUM>.

The electric motor <NUM> is coupled to the lead screw <NUM> such that operation of the electric motor <NUM> rotates the lead screw <NUM>, optionally via a gearbox. The electric motor <NUM> may be operated in a forward or reverse direction to control the position of the trolley <NUM> along the beam <NUM>.

As discussed below, the rigging apparatus <NUM> further comprises a mechanism for transmitting data from a remote device to the electric motor <NUM>. The data may be transmitted over a wired or wireless medium. The rigging apparatus may further comprise a computer processor configured to transform the received data into instructions for operation of the electric motor <NUM>, and optionally other features of the rigging apparatus <NUM>. The processor is therefore able to control operation of the electric motor <NUM> based on data received from the remote device.

The trolley <NUM> comprises the rigging point <NUM>. In the example shown in <FIG>, the rigging point <NUM> includes a shackle <NUM> bolted through the aperture. A hook <NUM> is passed through the shackle <NUM>. The skilled person will be able to envisage many other means of suspending the beam <NUM>. As mentioned above, the beam <NUM> may be rotated in a vertical plane or, put another way, angularly displaced with respect to a horizontal plane. In the example of <FIG>, the beam <NUM> is able to rotate about the pin securing the shackle <NUM> to the rigging point <NUM>.

The trolley also comprises one or more wheels 130a-130d (only wheels 130a and 130b can be seen in <FIG>). The trolley <NUM> in the example of <FIG> comprises four wheels, two on either side, although only the two wheels 130a, 130b on one side of the trolley <NUM> are shown. However, it will be appreciated that other arrangements may use any friction reducing device such as a rotatable element, for example a sphere or roller, and that there may be any number of such rotatable elements.

The outer walls of the beam <NUM> form the internal cavity <NUM> and a longitudinal slot in an upper surface of the beam <NUM>. The rigging point <NUM> protrudes through the longitudinal slot, which permits travel of the trolley <NUM> and the rigging point <NUM> along the length of the beam <NUM>. The outer walls of the beam <NUM> also form internal upper surfaces either side of the longitudinal slot. The wheels 130a-130d are configured to contact the internal upper surfaces of the internal cavity <NUM> of the beam <NUM>. The wheels 130a-130d are therefore able to bear at least part of the load caused by the suspension of the speaker array <NUM>. In some examples, the wheels 130a, 130b bear a majority, and in some cases all, of the load.

The wheels 130a-130d reduce friction in the movement of the trolley <NUM> along the length of the beam <NUM>. This in turn means that less torque is required to be provided by the electric motor <NUM> to rotate the lead screw <NUM>, and that there is consistent and predictable movement of the trolley <NUM> for a given rotation of the electric motor <NUM> as stiction is removed.

As mentioned above, the frame <NUM> is fixedly connected to the beam <NUM> using pins 132a, 132b passed through apertures in the frame <NUM> and the beam <NUM> when they are aligned. The beam <NUM> may comprise a plurality of apertures configured to allow the frame <NUM> to be fixed to the beam <NUM> at a plurality of points along the length of the beam <NUM>.

<FIG> shows an isometric view of the trolley <NUM>. As described above, the trolley comprises a threaded aperture <NUM> configured to receive the lead screw <NUM>. Further, <FIG> shows all four wheels 130a-130d. The wheels 130a-130d sit proud of an upper surface of a main body <NUM> of the trolley <NUM>. Therefore, when the beam <NUM> is suspended from the rigging point <NUM> and the speaker array <NUM> is suspended from the beam <NUM>, the load generated by the speaker array <NUM> pulls the internal upper surfaces of the beam <NUM> either side of the longitudinal slot down onto the wheels 130a-130d.

The wheels 130a-130d are therefore able to bear the load. Pairs of wheels 130a-130d may be connected by an axle running through the main body <NUM> of the trolley <NUM>.

The rigging apparatus further comprises an inclinometer <NUM> configured to indicate an angle of the beam <NUM> to the horizontal plane. In an exemplary arrangement, the inclinometer is fixed to the frame <NUM>, as shown in <FIG>, although the inclinometer <NUM> could be located on the beam <NUM>. The inclinometer <NUM> may use, for example, inertial sensors to determine the angle of the beam with respect to the horizontal plane. The inclinometer <NUM> may provide data to the computer processor and then to a transmitter, which may be a transmitter/receiver formed by the transmitter and the receiver mentioned above. Data indicative of the angle of the beam <NUM> may be transmitted to the remote control device. It is noted that the remote control device may comprise a plurality of devices, each providing a specific function. For example, a first remote control device may provide display from the inclinometer <NUM> and a second remote control device may transmit operation instructions to the motor <NUM>.

<FIG> shows a schematic representation of at least a part of a rigging apparatus <NUM>, which may be a rigging apparatus <NUM>. The rigging apparatus <NUM> comprises a beam <NUM> one or more remote devices <NUM> and a motor controller <NUM>. The beam <NUM> includes an inclinometer <NUM> and an electric motor <NUM>, which may be the inclinometer and electric motor described above. An inclinometer display <NUM> and a remote control <NUM> may form the one or more remote devices <NUM>. In exemplary arrangements, the remote control <NUM> and the inclinometer display <NUM> may be separate devices or integrated into a single device. The motor controller <NUM> comprises a microprocessor <NUM> and a power supply <NUM>. The motor controller may be positioned on the floor or at a location at the top of the array and/or on the beam <NUM>.

The inclinometer <NUM> is arranged to determine and angular displacement of the beam <NUM> and transmit data indicative of that angular displacement to the inclinometer display <NUM>. A user is able to monitor the angular displacement via the display <NUM> and make inputs to the remote <NUM>. The remote <NUM> transmits data indicative of the inputs to the remote <NUM> to the microprocessor <NUM>. The microprocessor <NUM> generates commands to the power supply <NUM>, which outputs power to the motor <NUM> to control a position of the trolley (not shown).

<FIG> shows an exemplary flow chart of a method for rigging a speaker array <NUM>. A top speaker of the array <NUM> may be connected <NUM> to the beam <NUM> and the beam is connected to a lifting frame. As discussed above, in exemplary arrangements this is done via the frame <NUM>, although the speaker may also be directly connected to the beam <NUM> and/or the beam <NUM> and the frame <NUM> may be formed into a single element. In exemplary arrangements, the beam <NUM> is connected to a lifting frame or apparatus via forward and rearward lifting points 140a, 140b and lifted out of a case. The frame <NUM> is fixedly connected to the beam <NUM> such that rotation of the beam <NUM> results in corresponding rotation of the frame <NUM>. The beam <NUM> and the frame <NUM> are then lifted together and a top speaker is connected to the frame <NUM>.

The beam <NUM>, frame <NUM> and top speaker are lifted <NUM> by the lifting frame and a further speaker in the array <NUM> added to the bottom. This process is repeated until the array <NUM> is formed.

The beam <NUM> is connected to the rigging by the rigging point <NUM> such that the beam <NUM> is angularly displaceable with respect to the horizontal plane. That is, the beam is free to rotate in a vertical plane about the rigging point.

The lever hoist <NUM> is connected to a lower speaker in the array <NUM> and the chain <NUM> is tensioned <NUM> to form the curve. In other arrangements, the lever hoist <NUM> may be tensioned remotely using the, or a further, remote control device, which may transmit a signal to the, or a further, motor, which draws in the chain <NUM> in the direction of arrow <NUM>. As mentioned above, forming the curve changes the centre of gravity of the array <NUM> and therefore alters the position and direction of the load on the beam <NUM> relative to the rigging point. This can result in the beam <NUM> being angularly displaced with respect to the horizontal plane.

The user then checks <NUM> the angular displacement of the beam <NUM>. In the simplest case, this may be done by eye or by manual means. In exemplary arrangements, the angular displacement of the beam <NUM> is detected by the inclinometer <NUM> and transmitted to the remote control device <NUM>. The determined inclination may be displayed on the user interface <NUM>.

The user then adjusts <NUM> the position of the trolley <NUM> (and therefore the rigging point <NUM>) along the beam <NUM>. The user inputs instructions to the user interface <NUM>, which are transmitted to the electric motor <NUM>. The electric motor <NUM> rotates the lead screw <NUM> to move the trolley <NUM> along the length of the beam <NUM>.

The user is able to monitor the inclination of the beam <NUM> on the user interface <NUM> and adjust the position of the trolley <NUM> until the beam <NUM> achieves the required inclination or declination. In some cases this may mean that the beam <NUM> is made level. In other cases, the beam <NUM> may be inclined or declined so as to direct the array at a particular point. It will be appreciated that methods and apparatus disclosed herein allow adjustment of angle of beam whilst under load.

Claim 1:
A loudspeaker rigging apparatus (<NUM>) for suspending a plurality of loudspeakers from temporary or permanent structure, the loudspeaker rigging apparatus (<NUM>) comprising:
a beam (<NUM>) configured to be secured to an uppermost speaker in an array of speakers; and
a trolley (<NUM>) coupled to the beam (<NUM>) and moveable along at least part of a length of the beam (<NUM>) and comprising at least one rotatable element (130a-d)
in contact with a downward facing surface of the beam (<NUM>) such that at least a part of a load resulting from suspension of the array of speakers is supported by the at least one rotatable element, the at least one rotatable element being configured to rotate on movement of the trolley (<NUM>) along the length of the beam (<NUM>),
the trolley (<NUM>) further comprising a rigging point (<NUM>) configured for connection to the temporary or permanent structure, and configured to permit angular displacement of the beam with respect to a horizontal plane, the rigging point (<NUM>) comprising a single suspension point about which the beam (<NUM>) may rotate when the rigging point (<NUM>) is connected to the temporary or permanent structure.