BACKGROUND OF THE INVENTION

[0001] The present invention relates to furniture with acoustical treatments incorporated therein. Surfaces bearing micro-perforations are known as providing sound attenuation in the range of 100 Hz to 2000 Hz. As such, patterns of micro-perforations on a structure are used as sound absorbing features.

[0002] The acoustics of a commercial or residential working environment, meeting room, conference room or office are directly related to the comfort and ability of persons in those areas to communicate in person, remotely or virtually. A typical residential or office space includes vertical walls that comprise hard surfaces that reflect soundwaves and, in some cases, amplify them. Furniture including desks, filing cabinets, and other structures typically have flat, hard walls that also reflect soundwaves. In such environments, it may be difficult for people in those spaces to not only hear the spoken word but to communicate with each other. Incorporating sound attenuating features into the typical objects within a room area would enhance the ability of its occupants to clearly hear the spoken word and to communicate. It would also be advantageous if sound attenuating features could be incorporated into objects typically found in such spaces without in any way significantly affecting the aesthetic design of such objects. It is with these goals in mind that the present invention was developed.

[0003] The following prior art is known to Applicants.

[0004] U.S. Patent No. 4,701,066 to Beam et al. discloses a decorative sound absorbing panel for furniture. In this device, sound absorbing panels are assembled around furniture. The present invention distinguishes from this invention as incorporating sound absorbing features into the furniture itself. [0005] U.S. Patent No. 5,424,497 to Dias et al. discloses a sound absorbing wall pane which incorporates fibrous sound absorbing material as well as a honeycomb structure in order to absorb sound. The present invention differs from the teachings of this invention as contemplating sound absorbing furniture with the sound absorbing features incorporated into the furniture itself.

[0006] U.S. Patent No. 6,272,795 to Brauning discloses movable office furniture which may include shelf partitions that are produced from a sound absorbing material. This patent does not disclose the use of micro-perforations.

[0007] U.S. Patent No. 9,369,805 to Wilson discloses an acoustic absorber which comprises an absorption layer composed of an open-pored porous material which is flexurally stiff and absorbs soundwaves. This patent fails to teach or suggest incorporating micro- perforated structures into furniture for sound attenuation purposes.

[0008] U.S. Patent No. 9,521,911 to Hebenthal discloses a furniture system for adjusting sound levels in children’s rooms which includes sound absorbing structure.

However, this patent fails to teach or suggest the use of micro-perforations for sound attenuating purposes.

[0009] Published Application No. US 2009/0277715 Al to Scharer et al. discloses a furniture system for influencing the acoustics of a room. This published application discloses perforations having a diameter of about 5 mm. These are not micro-perforations which typically have a diameter ranging from 0.25 mm to 0.65 mm. Accordingly, Scharer et al. fail to teach or suggest the present invention.

[0010] German Publication DE10214778 Al discloses a sound absorbing panel that includes micro-perforations with a diameter of “less than 2 mm, preferably 1 mm.” The present invention differs from the teachings of this publication as contemplating micro- perforations having a diameter in the range of 0.25 mm to 0.65 mm.

[0011] Published European Patent Application EP2039841 Al discloses furniture incorporating sound absorption principles that include a perforated plate. There is no teaching or suggestion in this publication of the use of micro-perforated structures incorporated into furniture without changing the aesthetics of the furniture.

[0012] German Publication DE202010017487U1 discloses the general concept of a perforated structure.

SUMMARY OF THE INVENTION

[0013] The present invention relates to furniture with acoustical treatments. In the present invention, acoustical furniture systems have incorporated therein micro-perforated, preferably vertical, elements, which are incorporated into, for example, cabinet doors, drawer facades, and other vertical non-operable structural surfaces. While it is preferred that the micro-perforations be provided in strictly vertical surfaces, surfaces that are angled and have a vertical component may also have such treatments.

[0014] As is known to those skilled in the art, micro-perforations used as sound attenuating structures typically have diameters ranging from 0.20 to 0.70 mm, preferably 0.25 mm to 0.65 mm. Micro-perforations at this dimension range are relatively invisible at a normal viewing distance of several feet and thus do not detract from the aesthetic appeal of the furniture in which they are incorporated.

[0015] While micro-perforations are known as a sound attenuating feature, they have never been used incorporated into furniture. Applicants have designed furniture in which such micro-perforations are incorporated and have found that such structures effectively attenuate soundwaves particularly within the range of the spoken word such as 100 to 2,000

Hz.

[0016] Helmholtz absorbers typically include perforations at least 1 mm in diameter and typically 4-12 mm in diameter. Such structures require an acoustical absorbing material behind the perforations in order to effectively absorb sound and prevent its reflection back into the space where the Helmholtz absorber is located. By contrast, the present invention contemplates use of micro-perforations on preferably vertical surfaces with the micro- perforations falling within the range of 0.20 to 0.70 mm. Micro-perforations of that size do not require any sound absorbent material to the rear. It is also known that such micro- perforations can be cylindrical or, if desired, they can be frustoconical with the smaller diameter being at the rear surface and the larger diameter at the front surface. Typically, micro-perforations are formed in a surface employing a laser drilling device which creates frustoconical micro-perforations. A laser drilling device creates a circular cross-section for micro-perforations. Punching may also be employed to form micro-perforations and any other device for creating micro-perforations may be employed.

[0017] Every hard surface has a boundary layer comprising a thin skin of air covering the surface. Micro -perforated panels are best described as Helmholtz resonators with extremely small holes. They provide sound absorption through high viscous losses as air passes through the holes that are only a bit larger than the boundary layer. This provides inherent damping that eliminates the need for any fiberglass or other porous sound absorbing materials in the air cavity between a perforated sheet and the reflective surface behind it.

[0018] In determining the effectiveness of the present invention, Applicants tested a piece of furniture first as normally manufactured with solid vertical surfaces, and then modified the piece of furniture to replace the solid vertical surfaces with micro-perforated surfaces. The results were dramatic. From the entire frequency range from 100 Hz to 5000

Hz, the furniture with the micro-perforations registered significantly higher in Sabins than was the case with the original furniture, as much as 4-5 Sabins higher, although this is exemplary. This indicates to Applicants that the present invention can effectively attenuate soundwaves within a room where furniture modified in accordance with the teachings of the present invention may be located.

[0019] Disclosed herein are numerous examples of furniture that may have enhanced sound absorption in accordance with the teachings of the present invention. Exemplary pieces of furniture disclosed herein include desks, cabinets, shelving systems, as well as free- standing objects that may suitably employ micro-perforations to attenuate sound. Also disclosed are structures employed in furniture in accordance with the teachings of the present invention, including panels having a front veneer with micro-perforations, a porous central core allowing soundwaves to freely convey therethrough, and a rear veneer with micro- perforations.

[0020] Accordingly, it is a first object of the present invention to provide furniture with acoustical treatments.

[0021] It is a further object of the present invention to provide such furniture in which the acoustical treatments consist of vertical surfaces modified by providing them with a pattern of micro-perforations.

[0022] It is a yet further object of the present invention to provide such furniture with micro-perforations having a diameter in the range of 0.20 mm to 0.70 mm. [0023] It is a still further object of the present invention to provide such micro- perforations which are generally cylindrical in configuration.

[0024] It is a still further object of the present invention to provide such micro- perforations that are frustoconical with their larger diameter being closer to the front surface of the structure in which the micro-perforations are formed.

[0025] It is a yet further object of the present invention to provide such an invention in which the micro-perforations are small enough to be barely visible to the human eye.

[0026] It is a still further object of the present invention to provide furniture with such micro -perforations which reduce sound in a room where the furniture is located, registering significantly higher Sabins when sound attenuation is measured.

[0027] It is a yet further object of the present invention to provide acoustical furniture with broad bandwidth absorption extending down to 100 Hz to complement additional traditional absorbing surfaces like T-bar ceiling systems and fabric panels.

[0028] It is a still further object of the present invention to employ micro-perforated panels in the design of furniture including, as one example, integrated working desks consisting of a desktop, a side desk, upper, lower and side cabinets, and a vanity screen, said panels consisting of front and rear micro-perforated veneers and a central porous core.

[0029] It is a yet further object of the present invention to micro-perforate panels of storage cabinets, shelving, and free-standing furniture objects.

[0030] It is a still further object of the present invention to employ micro-perforated panels for other solid objects in a work office besides desk structures such as storage cabinets and others. [0031] These and other objects, aspects and features of the present invention will be better understood from the following detailed description of the preferred embodiments when read in conjunction with the appended drawing figures.

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 shows a traditional Helmholtz absorber with perforations having diameters greater than 1 mm.

[0033] Figure 2 shows an example of a prior art office furniture integrated desk assembly.

[0034] Figure 3 shows an acoustical furniture facade in an impedance tube used to tes acoustical characteristics.

[0035] Figure 4 shows three layers of structures in accordance with the teachings of the present invention incorporated into furniture.

[0036] Figure 5 shows front, side, and cross-sectional views of a cabinet door made in accordance with the teachings of the present invention.

[0037] Figure 6 shows front and cross-sectional views of a drawer front made in accordance with the teachings of the present invention.

[0038] Figure 7 shows an integrated desk assembly similar to that which is shown in

Figure 2 but with vertical surfaces from the assembly of Figure 2 replaced with micro- perforated structures in accordance with the teachings of the present invention.

[0039] Figure 8 shows a detailed view of a micro-perforated absorber in which the perforations have diameters in the range of 0.25 to 0.65 mm. [0040] Figure 9 shows graphs of impedance and absorption versus frequency in Hz.

[0041] Figure 10 shows a graph of the level of Sabins versus frequency comparing prior art furniture with furniture manufactured in accordance with the teachings of the present invention.

[0042] Figure 11 shows a graph of reverberation time versus frequency in Hz comparing prior art furniture with furniture in accordance with the teachings of the present invention.

[0043] Figure 12 shows a storage device including storage cubicles as well as drawers

[0044] Figure 13 shows a free-standing storage device having a plurality of openings providing volumes where objects can be stored and displayed.

[0045] Figure 14 shows a wall-mounted storage device having a plurality of openings providing volumes where objects can be stored and displayed.

[0046] Figure 15 shows a free-standing rectangular cubic object including vertical surfaces that may be improved with micro-perforations.

[0047] Figure 16 shows a free-standing object having angled surfaces that may be improved with micro-perforations.

[0048] Figure 17 shows a free-standing object having angled surfaces that may be improved with micro-perforations.

[0049] Figure 18 shows an exploded perspective view of a panel made up of a central core with openings therethrough surrounded by micro-perforated panels. [0050] Figure 19 shows a further example, an exploded perspective view of a panel made up of a central porous core surrounded by micro-perforated panels.

[0051] Figure 20 shows a yet further example, an exploded perspective view in which the core has a series of parallel slots.

[0052] Figure 21 shows a further example, an exploded perspective view in which the core has slots extending completely therethrough.

SPECIFIC DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0053] Traditional approaches to absorb low and mid frequencies have relied on

Helmholtz resonators, as shown in Figure 1. While effective, this approach utilizes relatively large perforations with diameters between 4-12 mm, which visually impact the surfaces treated, and also require porous material in the rear cavity. Microperforated panel (MPP) devices, described by Ma in the 1960s, are Helmholtz resonators with very small holes. They provide absorption through high viscous losses as air passes through the holes that are only a bit larger than the boundary layer which is a thin skin of air covering every surface. This inherent damping eliminates the need for fiberglass or other porous materials in the air cavity between the perforated sheet and any reflective surface behind it although such materials do enhance sound attenuation. From a technical standpoint, consider a simple absorber formed by a cavity with a covering sheet. The covering sheet could either be perforated to form a

Helmholtz design or be solid but flexible to form a membrane absorber. The impedance is given below, including the mass term given in Equation 1 the resistance ('m) and the impedance of the cavity as the last term. These are the acoustic mass and resistance, respectively, due to the perforated sheet or membrane. The surface impedance of the resonant system is given by { 1) where k = 2π/λ is the wavenumber in air, d is the cavity depth; m is the acoustic mass per unit area of the panel, ω is the angular frequency, p is the density of air, and c is the speed of sound in air.

[0054] A full expression for the mass is given by

{2)

[0055] The last term in the equation is due to the boundary layer effect, and v

- 15 x 10-6 m2s- 1 is the kinemetric viscosity of air. This last term is often not significant unless the hole size is small, say, submillimeter in diameter. 8 is the end correction factor, which, to a first approximation, is usually taken as 0.85 and derived by considering the radiation impedance of a baffled piston. Hence, using micro-perforations between 0.20 and

0.70 mm, we do not require porous absorption in the cavity and the perforations are not visible at normal viewing distances. In Figures 5 and 6, Applicants illustrate a schematic view of the layers comprising the micro-perforated panel.

[0056] With reference to Figure 5 a cabinet door is designated by the reference numeral 10 and in the example shown is rectangular. A side view in Figure 5 of the cabinet door 10 shows the hinges 11 and 13. With regard to the detail portion of the figure, reference is also made to Figure 4 for a better understanding that the facing 15 is micro-perforated, the core 17 has perforations greater than 1 mm in diameter and the back face 19 is also micro- perforated. Figure 6 shows a drawer front 20 and the detail shows the front portion 21 as wel as a core 23 similar to the core 17 shown in Figure 4. If desired, a micro-perforated back face

(not shown) may be provided. The right hand image in Figure 6 shows a veneer with frustoconical micro-perforations formed by a laser drilling device.

[0057] Figure 4 shows an image of the micro-perforated face, the perforated core, and the micro-perforated rear face forming the inventive structure. In Figure 3, the micro- perforated facade is shown in an impedance tube with an empty rear cavity of 12 inches, to mimic the depth of a typical cabinet for testing purposes.

[0058] The complex impedance (top) and normal incidence absorption measured in an impedance tube with a cavity depth of 12 inches are shown in Figure 9. The vertical line at

200 Hz marks the frequency at which the Reactance crosses zero, resulting in a maximum in the absorption coefficient, for this configuration. The impedance tube is typically used as an engineering guide, since a relatively small sample size can be used, and the complex impedance can be studied. Evaluation of the normalized Resistance informs whether the sample offers too little or too much resistance to air. When it is ideally equal to 1, the absorption is at a maximum. In Figure 9, the Resistance is roughly 0.7 and hence the absorption is 0.9.

[0059] Once the micro-perforated panel is designed and tested in an impedance tube such as shown in Figure 3, a complete system can be measured in a reverberation chamber, using a sample size of, for example, 120 sq. ft. A comparison of the random incidence absorption coefficient for the non-acoustical and the micro-perforated version (the present invention) are shown in Figure 10. The data clearly show the broad bandwidth of the acoustical furniture. When a planar sample of known surface area is measured, the Equivalen

Absorption Area can be divided by the surface area to yield the traditional absorption coefficient. In this case, the effective absorption is shown as the Equivalent Absorption Area

(sometimes called Sabins). The higher the Sabins number, the greater the sound absorption.

Figure 10 shows the superior performance of the furniture illustrated in Figure 7 as compared to that of Figure 2. In particular, Figure 10 shows that the Figure 7 furniture increased sound absorption compared to that of the Figure 2 furniture by up to 4-5 Sabins in the frequency range of 100 Hz to 5,000 Hz. The indication of sound absorption up to 4-5 Sabins is merely exemplary. It is possible to achieve sound absorption to greater levels. Figure 11 is a graph of reverberation time versus frequency and shows a reduction in reverberation time resulting from addition of micro-perforations in the subject furniture.

[0060] Figure 1 shows a prior art traditional Helmholtz absorber panel which incorporates perforations having a diameter greater than 1 mm. Such a panel requires the rea thereof to face an absorbing material such as fiberglass or other material. This is required where large perforations are employed because the perforations themselves only allow sound waves to gain access to the rear portion. This is to be contrasted with micro-perforations in the range of 0.20 to 0.70 mm in which the perforations themselves provide sound attenuation and there is no need to provide a sound absorbing material to the rear.

[0061] Figure 2 shows a prior art desk assembly generally designated by the reference numeral 30 and having structures with vertical and horizontal surfaces, including a horizontal desk structure 31 and 33, a vertical cabinet door 35, additional vertical cabinet doors 37, 39,

41 and 43, an additional horizontal surface 45, additional drawers 47 and 49, a vertical support structure 51 having a vertical surface, and a storage area closed by doors 53 and 55. Cabinet doors and drawer fronts are optional.

[0062] With reference to Figure 7, the desk assembly 30 of Figure 2 is modified into the desk assembly 60 having structures with vertical and horizontal surfaces in which the doors and drawers with front vertical surfaces from Figure 2 are replaced by doors and drawers with front vertical surfaces 65, 67, 69, 71, 73, 77, 79, 81 (a wide vertical support leg), 83 and 85 with micro-perforated structures such as shown in Figures 4, 5 and 6, including a micro-perforated front face, a core with larger perforations and, if desired, a back micro-perforated face. The horizontal flat surfaces 61, 63 and 75 are unchanged from the respective structures 31, 33 and 45 from Figure 2. The door 65, for example, pivots about vertical hinges 66. The doors and drawers are optional but, where included, can be micro- perforated to enhance sound attenuation.

[0063] Figure 8 shows a preferred pattern of micro -perforations on a surface. The perforations have a diameter of between 0.20 mm and 0.70 mm. While one pattern of micro- perforations is shown, any desired pattern of perforations is conceivable. Since the micro- perforations are so small, they are barely visible to the naked eye. As such, more aesthetically pleasing patterns of micro -perforations are not necessary.

[0064] Figure 12 shows a storage device 120 that includes a plurality of storage cubicles 121 defined by rectangular walls as well as a plurality of drawers 122. The cubicles have rear surfaces 123 that may be provided with a pattern of micro-perforations. Similarly, the faces of the drawers 122 may be provided with micro-perforations along with the face 124 of the stand 125. [0065] Figure 13 shows a free-standing storage device 130 having a plurality of openings, for example, 131, 132, 133, 134, etc. This storage device is open to the rear. The side edges such as those designated by the reference numerals 135 and 136 may be provided with a pattern of micro-perforations.

[0066] Figure 14 shows a wall-mounted storage device 140 with a plurality of openings 141 formed by wall structures, for example, 142, 143, etc. The forward facing edges of the wall structures may be provided with micro-perforations.

[0067] Figure 15 shows a free-standing rectangular cubic object that may be placed within a room area and may be used as a seat or as a support for another object such as, for example, a planter (not shown). The object 150 shows vertical side surfaces, for example,

151 and 152, that may be provided with patterns of micro-perforations to help attenuate sound in the room where the object 150 is located.

[0068] Figure 16 shows another free-standing object 160 that may be used as a seat or as a support for another object, for example, a planter (not shown), and that includes a top surface 161 and side surfaces, for example, 162, 163, 164 and 165. These side surfaces are angled but they are not horizontal. Rather, they have both horizontal and vertical components. As such, the side surfaces may be provided with patterns of micro-perforations which will assist in attenuating sound in a room area where the object 160 is placed.

[0069] Figure 17 shows a further example of a free-standing object 170 having a flat top surface 171 that can be used as a seat or to support any desired object. The object 170 includes angled support walls 172, 173, 174 and others as shown. While these side walls are angled, they can still be provided with micro-perforations that can be helpful in attenuating sound within a room where the object is located.

[0070] Figure 18 shows structures generally designated by the reference numeral 180 that are similar to those shown in Figure 4. They include a front veneer 181 having a multiplicity of micro-perforations therethrough, a central core 182 with holes therethrough larger than 1 mm in diameter and a rear veneer 183 covered with a pattern of micro- perforations. The central core can be of any desired thickness, for example, 1/4” to 1 ¼’.

The central core can be made porous to sound by any desired means, such as, for example, holes larger than 1 mm in diameter, fibrous structures, honeycombing, structurally porous, etc. Cores may be made from MDF (medium density fiberboard).

[0071] Figure 19 shows an exploded view of a panel 190 made up of a central core

192 which is porous though not through the provision of holes formed therethrough and is surrounded by veneers 191 and 193 which correspond to the veneers 181 and 183 shown in

Figure 18.

[0072] Figure 20 shows another example 200 with a core 202 surrounded by veneers

201 and 203 corresponding to the veneers 181 and 183 of Figure 18. The core 202 includes a plurality of parallel grooves 204 which have been found to be helpful in attenuating sound.

[0073] Figure 21 shows a further example 210 which has veneers 211 and 213 corresponding the veneers 181 and 183 of Figure 18. The central core 212 has the provision of multiple slots 214 extending completely therethrough to facilitate transmission of any sound traveling through the veneer 211 to the veneer 213.

[0074] In the preferred embodiments of the present invention, micro-perforated structures are typically only employed on vertical surfaces. Horizontal surfaces are not as impinged by soundwaves and adding micro-perforations to those surfaces does not result in appreciable increase in sound attenuation. Where a horizontal surface is a desk top, micro- perforations might be problematic, since, for example, spilled liquids could enter the micro- perforations and leak into the area below. However, surfaces that are angled, having a vertical component, could, if desired, be provided with micro-perforated surfaces. However, non-functional horizontal surfaces, such as the cabinet tops, can be micro-perforated for additional sound absorption.

[0075] Materials from which the micro -perforated structures can be created comprise any materials that can be micro-perforated using a laser cutting tool or a punch press or drill.

The micro-perforations are typically formed using a laser cutting tool that can be configured to create micro-perforations that are either cylindrical or frusto conical (see Figure 6). Where frustoconical micro-perforations are formed, the smaller diameter is to the rear of the face and the larger diameter is at the front of the face. Alternatively, micro-perforations can be formed using a drill, a drill press, a punch press or any other device that can create small diameter holes within the range of 0.20 to 0.70 mm in a solid piece of material. Applicants note that use of a laser cutting tool enables creation of frustoconical micro-perforations. This is not possible when using a drill, a drill press or a punch press. Micro-perforated structures can be made of wood, synthetic wood, particle board, and metals such as aluminum, again, so long as the micro-perforations can be formed using a laser cutting tool.

[0076] In one preferred configuration, a panel can consist of a front facing wood veneer, a central MDF core having holes therethrough, and a rear facing wood veneer. An example of this configuration is shown in Figure 4 with reference to reference numerals 15,

17 and 19. The holes in the core can exist due to the structure of the core being a honeycomb configuration, fibrous, structurally porous or a rigid piece through which large holes greater than 1 mm in diameter are formed.

[0077] As such, an invention has been disclosed in terms of preferred embodiments thereof which fulfill each and every one of the objects of the invention set forth hereinabove and provide new and useful furniture with acoustical treatments of great novelty and utility.

[0078] Various changes, modifications and alterations in the teachings of the present invention may be contemplated by those skilled in the art without departing from the intended spirit and scope thereof.

[0079] As such, it is intended that the present invention only be limited by the terms of the appended claims.