Patent Application
20080044053
Embodiments of the invention will now be described with reference to the accompanying figures, wherein like numerals refer to like elements throughout. The terminology used in the description presented herein is not intended to be interpreted in any limited or restrictive manner simply because it is being utilized in conjunction with a detailed description of the preferred embodiments of the invention. Furthermore, embodiments of the invention may include several novel features, no single one of which is solely responsible for its desirable attributes or which is essential to practicing the inventions herein described.
Perforated metal grills are desirable for in-ceiling and in-wall speakers because they provide a clean appearance and tend to hold their shape even when repeatedly removed and replaced on the speaker body. It still may be difficult to install and remove a metal grill. Further, it has been found that stronger materials, such as steel, are more resistant to permanent deformation and maintain their friction fit with the speaker baffle over time.
However, it is not uncommon for the rearward facing flange of the grill to fit too tightly or loosely into the speaker baffle because of the tolerances associated with manufacturing. When the grill is too tight, the installer deforms the rearward facing grill flange inward to align the flange with the groove in the baffle. If the grill is too loose, the installer deforms the natural round shape of the grill to an oval shape so as to increase the interference between the groove and the rearward facing flange. Even if an adequate fit is achieved between the rearward facing flange and the baffle, the fit may be lost over time as the user removes and replaces the grill to access the switches or controls located behind the grill. Installation and removal is even more problematic when the speaker is an in-ceiling speaker requiring the installer or user to work over their head while standing on a ladder.
Even though steel grills are preferred over weaker metals such as aluminum for the reason discussed above, steel has its own disadvantages. For example, a steel grill is apt to rust over time in environments prone to exposure to excessive humidity or salt water. While speakers include other steel components which may also rust over time, the grill is the only component that is visible to the user. In this case, a non-ferrous material such as aluminum would be preferred notwithstanding the disadvantages of using a weaker material discussed above.
Certain embodiments as will be described below relate to a speaker having a grill assembly that may be easily attached to the speaker body. The preferred embodiment of the grill assembly includes one or more magnets disposed around an outer surface or periphery of the grill. The magnet may be a permanent magnet or an electromagnet that generates an electric filed. For speaker embodiments having an electromagnet, an electric current is applied to the electromagnet. Upon application of the electric current, the electromagnet generates the magnetic field. The speaker body includes one or more corresponding members or slugs disposed so as to align with the magnets of the grill assembly. The slug may be a metal or other material that is attracted to a magnetic field. A magnetic bond is formed between the slugs and magnets and secures the grill assembly to the speaker body.
The grill 106 may or may not be fixedly attached to the flange 108. The grill 106 and flange 108 may be a unitary piece. The flange 108 may be made of, but not limited to, plastic, metal, and/or other similar materials. In one advantageous embodiment, the flange 108 is made of plastic and fixedly attached to an aluminum grill 106 around the inside diameter of the flange 108.
In the illustrated embodiment, the bottom surfaces of the magnets 112 are attached to the underside of the flange 108 while the top surfaces of the magnets 112 are left exposed. The exposed surfaces of the magnets 112 are brought in close proximity to the speaker body 104 so as to attract a material of the speaker body 104 that has a degree of magnetization that responds to the magnetic field of the magnet 112. For example, slugs made of iron, steel, and the like have a sufficient degree of magnetization. In certain embodiments, the location of the one or more of the magnets 112 are switched so that the magnet 112 is attached to the speaker body 104 and the slug is attached to the grill flange 108.
Though the magnets 112 are shown to be round, they may be of any other geometric shape. In the exemplary embodiment, four magnets are positioned around an outer periphery of the flange 108. The number and arrangement of magnets may be changed in any way which permits a stable attachment between the grill assembly 102 and the speaker body 104. In some embodiments, at least two magnets are desirable in order to permit a stable attachment. In other embodiments, a single magnet that extends around a substantial portion of the circumference of the flange 108 is employed. The magnets 112 may be attached to the flange 108 by various means known in the art. For example, the magnets 112 may be insert-molded into the flange 108 or attached to the flange 108 with an adhesive. In the illustrated embodiment, the top surface of the magnet 112 is disposed above the adjacent surface of the flange 108.
In the exemplary embodiment, the magnet 112 is exposed through the thru hole 118 and comes in mechanical contact with the slug 116. The remainder of the grill flange 108 is not in mechanical contact with, but still in close proximity to, the speaker flange 114. The dimensions of the components of the speaker assembly 100 may be adjusted to accommodate the tolerances associated with mass production. In embodiments having a thru hole 118, the slugs 116 and the magnets 112 are insulated from open air exposure upon assembly and therefore protected from corrosion.
The installer may initially coarsely align the grill assembly 102 with the speaker body 104. The installer may or may not precisely clock the magnets on the grill 10 with the slugs on the speaker body 104. If the installer clocks the magnets to the slugs, the grill 102 may not need to be rotated after the grill assembly 102 contacts the speaker flange 114. If the installer does not clock the magnets 112 relative to the slugs 116 or if the magnets 112 are not close enough to the slugs 116 to attract the slugs 116 when the grill 102 is against the flange 114, the installer may simply rotate the grill 102 until the magnets come in close proximity to the slugs 116.
Once the magnets 112 are close enough that the slugs 116 are magnetically attracted to the magnets 112, the magnetic attraction or force snaps the grill assembly 102 into place. The snapping of the grill assembly 102 into place provides a physical and audible confirmation to the installer that the installation is complete. As described above, mechanical contact may be limited to the magnets 112 and slugs 116. In other embodiments, the grill flange 108 is in contact with the speaker flange 114 with or without mechanical contact between the magnets 112 and slugs 116. By utilizing magnets 112 for the mechanical interface, the contact between the other components of the grill assembly 102 and the speaker body 104 is minimized so as to reduce any mechanical buzzing or vibration of the speaker grill 102.
In some embodiments, the outside diameter of the grill assembly 102 is slightly larger than of the speaker body 104. With such an embodiment, the grill assembly 102 overhangs the speaker body 104. The overhang self centers the grill assembly 102 over the speaker body 104 and also makes removal of the grill assembly 104 easy. The installer simply needs to slip a small screwdriver, the tip of fingers, or similar tool under the outer lip of the grill assembly 104 to pry it off by breaking the magnetic bond between the magnets 112 and slugs 116.
The foregoing description details certain embodiments of the invention. It will be appreciated, however, that no matter how detailed the foregoing appears in text, the invention can be practiced in many ways. As is also stated above, it should be noted that the use of particular terminology when describing certain features or aspects of the invention should not be taken to imply that the terminology is being re-defined herein to be restricted to including any specific characteristics of the features or aspects of the invention with which that terminology is associated. The scope of the invention should therefore be construed in accordance with the appended claims and any equivalents thereof.
