Self-cooled loudspeaker

DETAILED DESCRIPTION OF THE PRESENT INVENTION The present invention is directed to an electrodynamic loudspeaker which is self-cooled without the use of external blowers or other such structures.
Any conventional electrodynamic loudspeaker may be used, such as that depicted in FIG.
1, which includes the improvements of the present invention.
For example, a conventional electrodynamic loudspeaker 5 of the permanent magnet type consists of a cone 10 which is attached through adhesive means to a dome 20, forming a diaphragm 30.
The cone 10 and dome 20, which together form diaphragm 30, may be constructed from a stiff but well damped material such as paper.
The diaphragm 30 is connected to a speaker frame 40 constructed of a stiff antivibrational material such as aluminum, by means of an upper half roll compliance 50, which may be made from a flexible and fatigue resistant material which may include materials such as a urethane foam, a butyl rubber or a phenolic impregnated cloth.
Similarly, on its lower portion, the speaker frame 40 is connected to the intersection of the cone 10 and the dome 10 by a spider 60 which is made from a material similar in properties to the material of the upper half roll compliance.
By this connection, the diaphragm 30 is prevented from radial movement and thus is constrained to axial movement.
Also at the point of intersection of the cone 10 and the dome 20 is a former 70 made of high temperature resistant plastic which is also attached to cone 20.
A conductive coil 80 is attached to the former 70 also by a conventional adhesive.
By principles of electromagnetics, the current passing through the voice coil and the magnetic field produced by the permanent magnet cause the voice coil to oscillate in accordance with the electrical signal, and drive the diaphragm 30, producing sound.
On the lower portion of the loudspeaker 5 is the magnetic structure containing the permanent magnet 100 comprising a magnet 110, between a top plate 120 and a back plate 130.
Both of these plates are constructed from a material capable of being carrying magnetic flux such as steel