The present invention relates to an acoustic transducer or loud speaker and especially to an acoustic transducer panel formed of a foamed polymer material and laminated to an acoustic panel.
An acoustic transducer or loud speaker is a device for converting variations of electrical energy into corresponding variations of acoustical energy or sound. A loudspeaker generally has a diaphragm, such as a paper cone, which is resiliently mounted to a frame and is set in motion by an armature which is energized by the speaker current. A dynamic or moving coil loudspeaker has the armature vibrating in a magnetic field and consists of a coil attached to a conical diaphragm. An electro-dynamic speaker has the moving coil oscillating inside an electro-magnet which is energized with direct current while a permanent magnet moving coil speaker has the coil oscillating in a cavity of a specially shaped permanent magnet. Thus the loud speaker uses the electro-dynamic principal for the conversion of the electric oscillations into mechanical vibrations which in turn produce sound waves in the air.
The present invention relates to this type of speaker but especially to such a speaker formed into a foamed polymer panel which can have a ceiling tile facia or the like laminated thereto for directing the acoustical energy into a room without any visible grills or speaker components. The present invention is also related to a panel having the diaphragm and the resilient diaphragm suspension and a portion of the supporting frame formed in a single piece of molded foamed polymer material having different densities in the different portions of the panel and having a flexible insert attached in a recess to form the diaphragm suspension.
In the past a variety of U.S. patents have mounted dynamic speakers directly into ceiling tiles and these can be seen in the Stallings, Jr. U.S. Pat. No. 4,057,689 for a high-fidelity sound reproduction system having a plurality of sound modules mounted on a number of baffle plates to define a ceiling and in the U.S. Pat. No. 4,484,658 to Grote for a speaker support assembly. The Grote patent mounts a dynamic loud speaker to a support assembly having a baffle and brackets and having the baffle located below a ceiling panel with the speaker extending through the ceiling panel. The Walker U.S. Pat. No. 4,123,621 is for an acoustical speaker device adapted to be recessed into the ceiling of a room. Similarly, the Junk U.S. Pat. No. 3,666,040 is a ceiling mounting ring for a speaker cone for mounting the speaker into the ceiling of a room. The Sepmeyer U.S. Pat. No. 3,985,200 is for a background sound system in which a loud speaker is bolted directly to a ceiling panel of a suspended ceiling. The Marquiss U.S. Pat. No. 4,385,210 is for an electro-acoustical planar transducer which uses a planar diaphragm driven by a strategically located coil driven permanent magnets. The voice coils are used to drive the planar diaphragms. In the Bertagni U.S. Pat. Nos. 3,801,943 and 3,596,733 flat diaphragm sound transducers are disclosed in which a foamed plastic diaphragm is driven by a coil within a permanent magnet with the permanent magnet supported to a metal frame for driving the flat diaphragm.
In contrast to this prior art, applicant has an improved system for use with ceiling tile facias and the like in which the ceiling tile facia matches the remaining ceiling tiles is laminated to a foamed polymer panel molded specifically to act as a planar diaphragm as well as the resilient diaphragm suspension and new supporting frame for supporting the magnet and magnet supporting frame thereon by using both molded shapes and variable densities in the foamed polymer materials.