Abstract:
A rigging system for angularly adjusting the output portions of a plurality of loudspeaker cabinets wherein each of the cabinets includes a pair of rotatably adjustable rigging disks which protrude outwardly thereof which are selectively receivable within an adjacent cabinet. Each cabinet has a first locking element for securing the disks therein with respect thereto and second locking element or elements for selectively securing protruding portions of disks of an adjacent cabinet whereby an angle of the output portions of each cabinet may be adjusted from substantially a planar orientation to a curved orientation to thereby change the overall wavefront characteristics of sound issuing from a vertical array of attached loudspeaker cabinets.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention is generally directed to rigging systems used to secure a plurality of loudspeakers in a vertical array and more specifically to a rigging system which incorporates speaker mounted disks which may be selectively adjustably rotated and secured in a position to thereby change an angular orientation or tilt angle of loudspeaker cabinets relative to one another without suspension cables and the like. The rigging system is designed in such a manner that a single person may easily configure a plurality of loudspeakers into a predetermined angular relationship in a vertical array depending upon the acoustical characteristics to be obtained within a specific environment. 
   2. Brief Description of the Related Art 
   Speakers which are used in environments such as theaters, churches, concert halls and the like are generally arranged relative to one another depending upon the acoustical characteristics of the environment. The speakers which generally have similar audio output characteristics are aligned with respect to one another in order to optimize the audio output characteristics of the speaker system. The relationship of the outputs of the speakers will vary depending upon not only the environment but also based upon the type of transducers being utilized within the speaker housings. By varying the orientation of the outputs of the plurality of speakers, it is possible to alter the audio wavefront characteristics to blend or separate sounds being transmitted in order to obtain optimal sound characteristics. 
   It is known to provide various suspension systems for speaker arrays, for instance, for supporting a plurality of vertically aligned speakers so as to vary an output angle of the front face of each speaker cabinet to thereby obtain a curved or overlapping wavefront of sound. By way of example, in U.S. Pat. No. 4,660,728 to Martin, a sound system having a suspended array is disclosed wherein cables extend along opposite sides of a plurality of cabinets. Locking elements are provided for securing the cabinets at various positions along the cables in order to vary the spacing or angle of the output portion of the cabinets relative to one another. The cables may be in the form of a suspension chains and are supported by an overhead boom. The inner portions of the speakers are pivotally secured with respect to one another and the lowermost speaker cabinet is engageable with a spaced suspension element which causes an arcuate configuration to be placed on the main suspension cables or chains and thus the speaker array. 
   Such an arrangement is extremely bulky and complex and requires several people to manipulate to accurately position the speakers relative to one another. Further, there is no predetermined adjustment possible and, therefore, the exact positioning of the speakers relative to one another is not possible without measuring the spacing between each speaker relative to the suspension cables or chains. Such a system is not conducive to quick assembly or disassembly. Also, the speakers must be connected at both their front and rear to one another or the suspension elements. 
   In order to provide a more internal system for securing speakers in a line array, innovations have been made to rigging systems such that speaker cabinets include onboard connecter elements for securing the speakers to each other in a predetermined angular relationship. By way of example, in U.S. Pat. No. 6,640,924 to Messner, a rigging system is disclosed wherein a plurality of speakers are provided having pivotal adjustment elements including cam plates having a plurality of spaced openings. The plates are pivotally attached at one point to a corner of one speaker and, depending upon the opening in the cam plate selected for securing an adjacent speaker, an angle between the speakers is selectively obtained. Unfortunately, with such a system, the speakers must be connected not only at their forward portion by the adjustable cam plates but must also be pivotally connected at their rear portion to secure the speakers in a predetermined angled relationship relative to one another. Further, the type of adjustment mechanism requires that the speakers be lifted and maneuvered relative to one another in order to adjust the cam plates. This requires additional work on the part of the installer and may often require two or more individuals to set up an array into a predetermined configuration. 
   Other examples of rigging systems utilized between adjacent speakers are disclosed in U.S. Pat. No. 4,757,544, to Guy, and U.S. Pat. No. 6,536,554, to Andrews at el. 
   SUMMARY OF THE INVENTION 
   The present invention is directed to a rigging system for a plurality of loudspeaker enclosures or cabinets. The cabinets may include different types of transducer elements depending upon a specific array, however, the speaker cabinets are designed to include internal adjustable rigging disks which may be selectively rotated in order to vary an angle between adjacent speaker cabinets and wherein a pair of disks associated with each cabinet are selectively engageable by locking elements associated with an adjacent cabinet, which locking elements both secure and stabilize two adjacent cabinets. 
   Each speaker cabinet of the rigging system includes a pair of upper and lower slots in the upper and lower surface thereof. A left and right pair of disks of each cabinet are rotatably mounted within the cabinet and are designed to either extend downwardly through the slots in the lower wall of the cabinet or upwardly through the slots in the upper wall of the cabinet adjacent to each side of the cabinets. In the preferred embodiments, the disks extend upwardly through the slots in the upper wall of the cabinets such that by placing one cabinet on top of an adjacent cabinet, the protruding portion of each disk extends through the lower slots in the upper cabinet. 
   Each pair of rotatable rigging disks may be locked in a selected position relative to a cabinet by a first locking element. In some embodiments, a single locking element is provided for each cabinet which locking element is engageable with one or the other of the disks of the cabinet and wherein the disks are interconnected on a common shaft so as to rotate together. In other embodiments, each disk is independently rotatable, in which case, a pair of first locking elements is provided in order to secure the disks in a selectively adjusted position, however, each disk is designed to be rotated to the same degree in order to effect assembly of an array of speaker cabinets. 
   Each of the speaker cabinets further includes second locking elements for selectively engaging in outer openings in the protruding disk portions of an adjacent speaker cabinet. Spaced stabilizing pins or screws are also provided adjacent each disk receiving slot and are used to engage pairs of notches in each of the disks which are adjacent each outer opening to thereby create two points of stabilized contact adjacent the second locking elements. In this manner, only three points of contact are provided adjacent each side of the cabinet and there is no requirement for spaced pivot connections between adjacent cabinets, as the case with prior art rigging systems. As the first locking elements secure the disks relative to one cabinet and the second locking elements and disk notches rigidly secure the adjacent cabinets in a fixed angular relationship with respect to one another, there is also no need for suspension cables, wires, ropes, chains or the like. 
   In a preferred embodiment invention, each of the cabinets is somewhat trapezoidal in cross section in a plane taken from the front or output portion of the speaker cabinet to the rear portion thereof such that the upper and lower walls of each cabinet taper toward one another from the front output portion to the rear of the cabinet. In preferred embodiments, this angle is generally approximately 5° both along the upper and lower walls of each cabinet. This allows the cabinets to be retained in close proximity to one another when making angular adjustments in an assembled array. 
   The rigging disks of the present invention are preferably formed having an outer generally arcuate peripheral portion along which are spaced a plurality of first openings for selectively receiving the second locking elements of the invention. Specifically configured notches are provided on opposite sides of each of the first openings to provide stabilization. Each rigging disk further includes a plurality of inner generally arcuately spaced secondary openings or inner openings for selectively receiving the first locking means which may be in the form of a locking pin insertable through an inner opening which is positioned in a predetermined location relative to one of the outer openings. In this manner, a first set of inner and outer openings are positioned relative to one another and relative to the rotational axis of each disk such that when the first locking elements of a cabinet engage the first inner openings and the second locking elements of an adjacent cabinet engage the first outer openings, the cabinets are connected such that the frontal output portions of each speaker cabinet are aligned in a generally planar array. By changing the rotational position of each of the disks, the cabinets can be pivoted relative to one another to an extent which is determined by the size and configuration of each of the rigging disks. 
   In preferred embodiments, each of the rigging disks further includes a generally planar outer peripheral portion or segment which is designed to generally align with an adjacent slot in the cabinet in which the rigging disk is mounted so that, when the rigging disks are not in use and the cabinets are dissembled, the rigging disk does not extend outwardly of the cabinet, assuming the disk is rotated such that the flat segment aligns with the adjacent slot in the cabinet. 
   It is the primary object of the present invention to provide a rigging system for loudspeaker cabinets or enclosures which is designed to be mounted within the speaker cabinets in such a way that no secondary suspension components are required for connecting adjacent speakers to one another in a vertical array and such that all connecting elements are carried by each speaker in an array so that the components are not misplaced during transport, assembly or disassembly of the array. 
   It is yet another object of the present invention to provide a rigging system for loudspeaker speaker cabinets which allows predetermined angular adjustment to be made between adjacent cabinets very easily and quickly by simply rotating rigging disks to a predetermined position and thereafter locking the disks with locking elements associated with each of the cabinets. 
   It is also an object of the present invention to provide a method for assembling a plurality of loudspeaker cabinets in a predetermined array wherein the loudspeaker cabinets may be manipulated by a single individual and wherein the angle between adjacent cabinets is easily determined by selected rotational adjustment of rigging disks associated with each cabinet, after which the cabinets may be easily assembled relative to one another. 
   It is a further object of the present invention to provide a rigging system for loudspeaker cabinets which is of simplified structure when compared to prior art devices and which provides a very cost effective manner for securely engaging a plurality of loudspeaker cabinets in a predetermined vertical array without the use of tools or other implements. 
   It is another object of the present invention to provide a rigging system for securing loudspeaker cabinets in vertical arrays wherein the rigging components, when not in use, are simply adjusted to a position where they do not interfere with the routine handling, transportation or storage of the cabinets. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A better understanding of the invention will be had with reference to the accompanying drawings wherein: 
       FIG. 1  is a front perspective view of one of the loudspeaker cabinets of the present invention; 
       FIG. 2  is a top plan view of the loudspeaker cabinet of  FIG. 1 , a view taken from the bottom being a mirror image thereof; 
       FIG. 3  is a front elevational view of the loudspeaker cabinet of  FIG. 1 ; 
       FIG. 4  is a rear elevational view of the loudspeaker cabinet of  FIG. 1 ; 
       FIG. 5  is a view taken from the left side of the loudspeaker cabinet of  FIG. 1 ; 
       FIG. 6A  is a side view of one of a left side rigging disk of the present invention showing the orientation of the various elements of the disk relative to a rotatable axis thereof; 
       FIG. 6B  is a view similar to  FIG. 6A  showing a right side disk; 
       FIG. 6C  is a top plan view of the disk of  FIG. 6A ; 
       FIG. 7  is a partial cross sectioned view illustrating, the manner in which the rigging disks of the invention are locked and stabilized with respect to an adjacent cabinet in an array; 
       FIG. 8  is an assembly view of a pair of adjacent loudspeaker cabinets prior to being secured relative to one another utilizing the rigging system of the present invention; 
       FIG. 9  is a view similar to  FIG. 8  wherein two adjacent loudspeaker cabinets have been assembled using the rigging system of the present invention and wherein the front output portions of the speakers are shown as being aligned in a planar array; 
       FIG. 10  is an illustrated view of a plurality of vertically arrayed loudspeaker cabinets showing the cabinets being angularly connected to create a curved iso-phase wave emanating from the array; and 
       FIG. 11  is a cross sectional view taken along lines  11 - 11  of  FIG. 7 . 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   With continued reference to the drawing figures, the rigging system of the present invention is designed specifically for mounting a plurality of loudspeaker cabinets into a vertical array, such as shown at  20   FIG. 10 , wherein the orientation between each loudspeaker cabinet may be set at a predetermined angle or the cabinets may be aligned such that the outputs therefrom form a planar acoustical wavefront as opposed to a slightly curved wavefront as illustrated in the drawing figure. 
   The present invention incorporates a rigging system which is specifically designed to be retained within each of the loudspeaker cabinets. In this respect, the rigging system does not rely on exterior components to secure the loudspeaker cabinets to one another in a predetermined angular array and, thus, offers a benefit over prior art rigging systems. 
   Each of the loudspeaker cabinet  22  houses acoustical transducers for generating various sounds at varying frequencies. By way of example, each cabinet in a loudspeaker array may include identical acoustical components such as a low frequency driver, a mid frequency driver and a compression driver. 
   Each cabinet  22  includes a front output portion  23  and a closed rear wall  24 , a top or upper wall  25 , which is generally identical to a lower or bottom wall  26 , and opposite sides  27  and  28 . In preferred embodiments of the invention, the cabinets have a trapezoidal-shape cross-section wherein the upper and lower walls taper inwardly toward one another from the front  23  to the rear  24  of the cabinet. Preferably, the amount or degree of the taper is at an angle of approximately 5° with respect to the horizontal. The tapering of each speaker cabinet provides for a more uniform and closely fit array of speaker cabinets even when angled relative to one another in an array as shown in  FIG. 10 . 
   The rigging system associated with each cabinet includes a pair of spaced left and right side rigging disks  30  and  31  which are rotatably mounted within the cabinets such that portions of the periphery thereof extend outwardly through slots  32  provided adjacent each side  27  and  28  of the speaker cabinet. The slots  32  are shown in  FIG. 1  as being adjacent to the sides and in the upper wall  25  of the cabinet. Similar slots  32  are also provided in the lower wall  26  of the cabinet for purposes of receiving the protruding portion of disks of an underlying speaker cabinet  22 . The disks  30  and  31  are generally formed as mirror images of one another. 
   It should be noted that, although the invention will be described with respect to the rigging disks  30  and  31  protruding from the upper wall  25  of the cabinets, it is possible that the rigging disks may be mounted so as to extend from the slots  32  formed in the lower wall  26  of the speaker cabinets with the upper slots  32  being empty and unobstructed for receiving a protruding portion of a disk extending below a speaker cabinet of a cabinet in an array. 
   With specific reference to  FIGS. 6A-6C , the rigging disks  30  and  31  of the present invention are shown in greater detail. Each disk includes a mounting opening  33  which is designed to be seated on a stub shaft  34  which extends to a control knob or handle  35  as shown in  FIG. 1 . The disk is designed to be securely engaged relative to the operating handle or knob  35  by screws  36  which engage in holes  37  in each disk so that the disk may be easily manually manipulated by rotating the knobs which are easily accessible along the sides of the speaker cabinet. 
   Each disk includes a somewhat arcuate outer portion  38  and a generally planar portion  39 . The generally planar portion  39  is spaced from the rotational axis “A” of the disk a distance such that the planar portion will generally not extend outwardly of the slots  32  when the planar portion is aligned relative to the slots by manipulation of the knob or handle  35 . In this respect, the rigging disks may be rotated to a non-obstructing position where no portion thereof extends outwardly of the speaker cabinets when the cabinets are disconnected from an array for purposes of storage or transportation. 
   Each rigging disk  30  and  31  further includes a plurality outer angularly spaced openings  40 A- 40 F which are aligned in predetermined orientations with respect to the rotational axis “A” of each disk such that when a selected one of the openings  40 A- 40 F are positioned outwardly of the speaker cabinet, as is illustrated in  FIGS. 8 and 9 , the opening is aligned to be secured by a locking element associated with an adjacent speaker cabinet, as will be described in greater detail hereinafter. In the embodiment shown, there are six adjustment positions with respect to the rigging disk which create six angles of orientation between adjacent cabinets. Opening  40 A is positioned or oriented relative to the central axis “A” such that when a disk is rotated to expose the opening  40 A relative to an adjacent speaker cabinet, locking of the cabinets relative to the opening  40 A will cause the front output portion of the speakers to be aligned generally as shown in  FIG. 9 , wherein they are in planar relationship with respect to one another. By rotating the rigging disk to align the various other openings  40 B- 40 F relative to the adjacent speaker, different angles are created between the speaker cabinets in order to orient the output portions thereof to create a more curved iso-phase wave output over the full extent of the speaker array  20 . 
   Each rigging disk further includes a plurality of inner openings designated  42 A- 42 G which are used to receive a first locking element associated with each speaker cabinet for locking the rigging disk in non-rotatable relationship with respect to the cabinet. 
   With reference to  FIGS. 1-7  and  11 , the first locking element or device may include a locking pin or rod  45  that extends through a mounting bracket  46  provided on in each side of the housing or speaker cabinet. A spring  47  is shown and is designed to normally urge the pin  45  inwardly of the cabinet such that, to disengage the pin from an associated rigging disk, force must be applied on the handle  48  associated with the locking pin to urge the pin outwardly relative to the side of the speaker cabinet whereby the pin is disengaged from one of the rigging disk locking inner openings  42 A- 42 G. When the locking pin  45  is disengaged, the rigging disk may be rotated by manipulation of the knob or handle  35  until a predetermined outer opening is aligned exteriorly of the speaker cabinet. To facilitate alignment, indicia  49  may be applied at various points on the outer portion of the disk which represents predetermined set angles of adjustment for the rigging disk, as shown in  FIGS. 6A and 6B . It should be noted that disks  30  and  31  are reversely formed so as to be mirror images of one another. 
   In the embodiment being described, each of the rigging disks includes its own separate locking pin  45 . It is possible, in some embodiments, that two rigging disks of each speaker cabinet may be mounted on a common support shaft such that they may be rotated simultaneously by a single knob  35  extending from only one side of the speaker cabinet. In such embodiments, only a single locking pin  45  may be necessary to engage within an inner opening  42 A- 42 G in order to lock the rigging disks relative to the cabinet. 
   As previously mentioned, the outer openings  40 A- 40 F in each rigging disk are specifically oriented to provide a different angle between adjacent speaker cabinets in an array. The openings  40 A- 40 F are generally not aligned on a radius with the openings  42 A- 42 G due to an offset position of the locking pin  45  relative to the rotational axis of “A” the disk. As shown in  FIG. 7 , when the rigging disk  30  is rotated such that the outer opening  40 E is oriented outwardly of the speaker cabinet, the inner opening  42 E is aligned to receive locking pin  45  to secure the rigging disk in position. Similarly, when the rigging disk is rotated such that outer opening  40 A is aligned to be secured to an adjacent cabinet, inner opening  42 A is aligned to receive a locking pin  45  to retain the rigging disk in position. A similar cooperation and orientation exists between outer and inner openings  40 B and  42 B,  40 C and  42 C,  40 D and  42 D, and  40 F and  42 F. Inner opening  42 G is provided for securing a disk in a position wherein the planar edge  38  is aligned with the slot  32  in the upper portion of the cabinet, as shown by the upper disk in  FIG. 7 . 
   In order to securely connect one speaker cabinet to an adjacent cabinet, each cabinet carries second locking elements or pins, such as ball alignment pins  50  which are manually engageable at each of the opposite sides of the cabinet. The locking pins  50  are designed to be removably pulled from the side walls of the housing and are selectively insertable into an aligned opening  40 A- 40 F of a protruding portion of a rigging disk extending from an adjacent speaker cabinet, once the rigging disk is inserted into the slot  22  adjacent to the locking pin  50 . It is preferred that locking pins  50  be provided at both sides of the speaker cabinet in order to provide support on each side of the speaker cabinet in an array of cabinets. 
   To securely stabilize the cabinets  22  relative to one another when joined in an array, each cabinet includes a pair of spaced stabilizing pins, rods, screws, rivets or the like  60  and  61  which extend between spaced disk mounting plates  62  and  63 , see  FIGS. 7 and 11 . The plates are secured at each of the sides of the cabinets. As shown in  FIG. 8 , prior to assembling two adjacent cabinets, each disk is rotated to a desired position and locked into place with the locking pins  45 . Thereafter, the upper cabinet  22 A is positioned over the lower cabinet  22 B and lowered until the disks  30  and  31  of the lower cabinet engage the stabilizing pins  60  and  61  of the upper cabinet, as shown in  FIG. 9 . In this position, the locking pins  50  are used to lock the disks to the upper cabinet  22 A. 
   To prevent relative pivotal movement of the cabinets  22 A and  22 B, the stabilizing pins  60  and  61  engage the disks  30  and  31  at spaced points on opposite sides of the locking pins  50 . To further anchor the disks relative to the pins  60  and  61 , each disk has a plurality of spaced notches or seats  70 A/ 71 A- 70 F/ 71 F provided on opposite sides of each of the outer openings  40 A- 40 F in which the pins  60  and  61  are seated. This arrangement provides a secure and stabilized connection between two adjacent cabinets with three points of contact on each side of the cabinet. The primary points of the contact are between the pins  60  and  61  and the pairs of notches  70 A/ 71 A- 70 F/ 71 F of disks  30  and  31  and between the locking pins  50  and the disks. 
   With specific reference to  FIGS. 6A and 6B , the depth and/or configuration of each of the notches varies in order to provide a predetermined “pitch” angle between the lower cabinet  22 B and the upper cabinet  22 A. Thus, and by way of example only, when the disks of the lower cabinet are fixed to expose outer openings  40 A for locking with the upper cabinet, the pins  60  and  61  will rest in spaced notches  70 A/ 71 A which will create a pitch of approximately 0-0.28° between the cabinets such that the output portions of the cabinets are generally or substantially coplanar as shown in  FIG. 9 . By rotating the disks of the lower cabinet so that the outer openings  40 B are aligned for locking with the upper cabinet, the pins  60  and  61  of the upper cabinet will rest in notches  70 B/ 71 B which will create a pitch or tilt angle of approximately 0.05°. 
   An adjustment of the pitch or tilt angles to approximately 5.00°, or greater, may be obtained using the invention. The cooperation between notches  70 C/ 71 C and pins  60  and  61 , when the lower disks are set to lock at  40 C, will create a pitch of approximately 0.89°; between notches  70 D/ 71 D and pins  60  and  61 , when the lower disk is set to lock at  40 D, approximately 1.58°; between notches  70 E/ 71 E and pins  60  and  61 , when the lower disk is set to lock at  40 E, approximately 2.81°; and between notches  70 F/ 71 F and pins  60  and  61  when the lower disks are set to  40 F, approximately 5.00°. 
   The six positions of adjustment of each disk  30  and  31  are reflected by the indicia as shown at  0 , 1 , 2 , 3 , 4  and  5  on the drawings of  FIGS. 6A and 6B . Arrows for each position are also shown. In  FIG. 9 , the disks of cabinet  22 B are at their “O” position. 
   With reference to  FIG. 10 , a vertical array of loudspeaker cabinets  20  is shown depending from a support frame  80 . The frame  80 , in use, is elevated to lift the array to a desired height. The cabinets are shown such that the two uppermost cabinets  22 A and  22 B are joined as described with respect to  FIGS. 8 and 9 . Cabinets  22 C- 22 F are shown connected at different angles so as to create an array that presents a continuously curved wavefront which is a combination of sound energy from the six loudspeaker cabinets. 
   As shown in  FIG. 10 , the frame  80  also includes stabilizing pins  60 A and  60 B for resting or seating in the spaced notches  70 A/ 71 A- 70 F/ 71 F of the disks. Further, a locking pin, such as those shown at  50 , would be used to lock the uppermost disk  30  to the frame. 
   When it is desired to disconnect the speaker cabinets from one another, the locking pins  50  are removed thereby disconnecting the cabinets. After which, the locking pins  45  may be disengaged with respect to the rigging disks  30  and  31  so as to permit the disks to be rotated to a non use position wherein the flat portions  38  thereof align with the slots  32  in the speaker cabinets. 
   As described, no tools are necessary to effect the assembled relationship between the cabinets. Further, the cabinets need only to be connected using the two locking pins  50  as described. 
   The foregoing description of the preferred embodiments of the invention has been presented to illustrate the principles of the invention and not to limit the invention to the particular embodiments illustrated. It is intended that the scope of the invention be defined by all of the embodiments encompassed within the following claims and their equivalents.