Patent Publication Number: US-7210557-B2

Title: Low profile acoustic flooring

Description:
TECHNICAL FIELD OF THE INVENTION 
   The present invention relates to acoustics and methods of sound-proofing rooms, and more particularly to methods of mounting an acoustic structure such as an acoustic enclosure upon a host surface such as a floor of a room enclosing the acoustic structure. 
   BACKGROUND OF THE INVENTION 
   In the field of acoustics, one often desires to place an acoustic structure upon a host surface such as the floor of a host building enclosing the acoustic structure. For example, an acoustic enclosure such as a sound-proof room is placed on a floor inside a building. Such acoustic enclosures include those described in U.S. Pat. No. 6,581,724 issued to Acoustic Systems, Inc., a division of ETS Lindgren, L. P., the assignee of the present invention. 
   In many applications one desires to prevent sound waves from being transmitted between the host surface and the acoustic enclosure. For this reason, the acoustic structure is mounted upon the surface using a sound absorbing mechanism. An expanded view of an assembly for mounting an acoustic enclosure upon a floor of a host building is shown in  FIG. 1 . Resting upon the host floor  100  are isolators  120  and  130 . Each isolator assembly is formed from an upper conventional C-channel  150  and a lower conventional C-channel  160 . Between these two channels is a sound absorber  140 , which absorbs vibrations between the floor  100  and upper channel  150 . Absorber  140  substantially prevents transmission of sound between host floor  100  and an acoustic floor  1000 . Absorber  140  may be made of elastomer or other known material. Resting upon isolators  120  and  130  is acoustic floor  1000  formed by a lower floor plate  170  and an upper floor plate  180  supported by vertical supports  190 . In the region between the upper and lower plates is placed sound absorbing material to form the acoustic floor. 
   Acoustic floor  1000  is of a height X and isolators  120  and  130  are of a height Y. The total height of the step from the host floor  100  to the top of the acoustic floor  1000  is X+Y. This reduces the space between the acoustic floor and the interior ceiling of the acoustic enclosure, the height of the interior ceiling being limited by the height of the ceiling of the host room within which the acoustic enclosure is located. 
   Further, when a ramp is required, for example, to comply with the Americans with Disabilities Act, or to roll equipment into and out of the acoustic enclosure, the height of the step, X+Y, dictates the length of the ramp. For example, the length of the ramp may be required to be not less than X+Y inches times one foot per inch. Thus, if the height of the step is 7.5 inches, the ramp must be 7.5 feet long! 
   Moreover, in some instances, there must be no step at all. That is, the floor of the acoustic enclosure must be level with a host floor, as indicated by the raised floor section  111 . This results in considerable difficulty installing the acoustic floor because the acoustic floor must be leveled. If not level, the acoustic floor must be removed so that shims can be placed under the isolators to level the floor. As can be imagined, this can be a laborious, time-consuming task. 
   For at least these reasons, there is a need for a method for mounting an acoustic structure upon a host surface that reduces the step height of the floor of the acoustic structure and enables easy leveling of the floor of the structure. 
   SUMMARY OF THE INVENTION 
   The present invention provides a method for mounting an acoustic structure upon a host surface that reduces the step height of an acoustic floor and enables easy leveling of the acoustic floor. According to the present invention, an acoustic isolator is partially but substantially recessed within the acoustic floor so that only a bottommost portion of the isolator extends below the acoustic floor to make contact with the host floor. Because the acoustic isolator is recessed substantially within the acoustic floor, the step size is substantially reduced. Thus, the isolator provides acoustic isolation between the host floor and the acoustic floor without substantially increasing the height of the acoustic floor above the host floor. 
   According to another aspect of the invention, a leveling mechanism is provided that enables leveling of the floor from above with the floor in place. The leveling mechanism is also substantially or totally recessed within the body of the acoustic floor. Access is provided to the leveling mechanism from above to enable in-place leveling of the acoustic floor. In this way leveling adjustments can be made without removing the floor or any part thereof. 
   The foregoing has outlined rather broadly aspects, features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional aspects, features and advantages of the invention will be described hereinafter. It should be appreciated by those skilled in the art that the disclosure provided herein may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. Persons of skill in the art will realize that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims, and that not all objects attainable by the present invention need be attained in each and every embodiment that falls within the scope of the appended claims. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which: 
       FIG. 1  is an expanded view of a prior art method of mounting an acoustic floor upon a host surface. 
       FIG. 2  is an embodiment of an inventive isolator and leveling mechanism, installed near an end of an acoustic floor according to the method of the present invention. 
       FIG. 3  is an end view of an embodiment of the present invention. 
       FIG. 4  is an end view of an alternative embodiment of the present invention. 
       FIG. 5  is a diagram of an isolator puck. 
       FIG. 6  is a diagram of a plurality of acoustic floor panels installed with isolators of the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 2  illustrates an embodiment of an inventive isolator installed near an end of an acoustic floor according to the method of the present invention. Acoustic floor  1000  comprises an upper steel plate  210  and a lower steel plate  220 . A C-channel  230  made of nominally 11-gauge steel is at an end of acoustic floor  1000 . Another similar C-channel  240  is placed inward from the end of acoustic floor  1000  a distance sufficient to accommodate the isolator assembly to be herein described. 
   The isolator assembly includes a bolt  250  with a threaded section  255  that is threaded through an acorn nut  260  and into a swivel leveling mount  270  which swivels about a point  201 . A swivel leveling mount with a 5000 lb load rating may be obtained from McMaster Carr, part number 6103k22. See www.mcmaster.com. A bolt that will fit this part is part number 92240a723. An acorn or dome nut that this bolt will thread through is part number 94301a160. 
   Attached to, or integrated into, swivel leveling mount  270  is an isolator puck  280  made of a hard but compressible elastomer or other strong compressible material. Isolator puck  280  may be attached to swivel leveling mount  270  with screws. A clearance such as a circular hole is provided in lower plate  220  to enable the bottommost end of isolator puck  280  to project below the acoustic floor. Isolator puck  280  absorbs sound waves that might otherwise transmit between the host floor and the acoustic floor. Further, acoustic absorbing material is preferably placed in regions  235 ,  236 ,  237  and  238  to absorb sound. 
   The arrows marked W in  FIG. 2  point to regions where parts are welded to form the isolator. Acorn nut  260  is welded to a steel plate  295  with a circular hole for bolt  250  to pass there through. Steel plate  295  is welded to a C-channel  290 , so that bolt  250  is free to turn while acorn nut  260  is held fixed. Bolt  250  is threaded into and terminates at its lower end in swivel leveling mount  270 . In this way the height of the acoustic floor in the vicinity of the isolator is adjustable, for as bolt  250  is turned the height of the acoustic floor changes. Access to turn bolt  250  is provided by cutting or drilling a circular hole in upper plate  210  and in C-channel  290  sufficient to insert a tool over the head of the bolt to apply torque. 
   Because the isolator of the present invention is substantially recessed in the acoustic floor  1000 , the step size of the acoustic flooring, that is, the height from the host surface upon which the isolator rests to the top of the acoustic floor, is substantially reduced. 
     FIG. 3  shows an end cross-sectional view, A, of the low-profile acoustic isolator and leveling mechanism of the present invention. C-channel  290  may be made of 11 gauge steel of thickness, t, and cut to a width, a. As bolt  250  is turned clockwise, threaded section  255  threads downward through acorn nut  260 , thereby lifting the acoustic floor as the height, c, increases. As bolt  250  is turned counter-clockwise, threaded section  255  threads upward through acorn nut  260 , thereby lowering the acoustic floor, as the height, c, decreases. Thus, the present invention provides a leveling mechanism substantially recessed within the acoustic floor and connected to an acoustic isolator, also substantially recessed within the acoustic floor, and moveably connected to the acoustic floor so that when the leveling mechanism is adjusted, the floor moves vertically with respect to the position of the isolator. 
   Note that the bolt  250  can be adjusted so that when the floor is leveled, the bolt head remains recessed within or flush with the top panel  210  of acoustic floor  1000 . This avoids protrusion of bolt  250  above the acoustic floor surface. 
     FIG. 4  shows an end view of a simpler embodiment wherein steel plate  295  is itself threaded to receive threaded section  255  of bolt  250 , thus eliminating the acorn nut  260  from the structure. This embodiment may be less preferable since plate  295  would have to be very hard steel to withstand the load placed on the acoustic floor. A milder steel can be used in the preferred embodiment depicted in  FIG. 3  because the hard steel bolt is welded to plate  295  and thereby substantially distributes the load. 
     FIG. 5  shows an embodiment of an isolator puck  5280  formed of a sound absorbing elastomeric material  5020  with a steel cup  5010  on the bottom and a steel washer  5030  on top. This part may be obtained from Ace Mountings Co., Inc. http://www.acemount.com/. Swivel leveling mount  270  may be screwed to puck  5280 . 
   A plurality of acoustic isolators as just described can be distributed uniformly to provide adequate support for the anticipated load on the acoustic floor. Further, once the floor is in place, the entire floor may be quite accurately leveled in place by adjusting each leveling bolt as needed. The ability to level the floor in-place is a substantial advantage, especially when the top of the acoustic floor must be level with a raised floor. 
     FIG. 6  shows a top view of two acoustic floor panels  601  and  602  joined at an edge. Each floor panel comprises acoustic isolators, one on each corner of the panel. An access cutout  60  for each isolator enables access to bolts  250  to level the floor from above. The outer circle  61  shows the circumference of a cutout in the bottom panel of the acoustic floor to allow the isolator puck  280  to contact the host floor. In the configuration shown in  FIG. 6 , each panel can be separately adjusted in height and leveled without removing a floor panel. Obviously, multiple acoustic floor panels can be installed this way. Note that a flexible removable dust cap can be inserted to cover each cutout  60 , to cover the holes in the upper surface of each acoustic floor panel. The cap can be removed to adjust the leveling mechanism and then replaced. 
   Thus, the present invention provides a method for constructing an acoustic enclosure with acoustically isolated adjustable flooring. Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. The invention achieves multiple objectives and because the invention can be used in different applications for different purposes, not every embodiment falling within the scope of the attached claims will achieve every objective. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.