The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 02, 1982
Filed:
Jan. 15, 1981
James C Allen, Andover, MA (US);
Other;
Abstract
The present invention is a device for use in combination with a loudspeaker system, that includes a speaker enclosure, in order to effectively enlarge the volume of the speaker enclosure thereby increasing the apparent compliance of the speaker enclosure. The loudspeaker system also includes a vibratable cone. The device may also permit the varying of the mass of the moving system with respect to frequency. The device for effectively enlarging the volume of the speaker enclosure includes a gas having a Joule-Thomson coefficient of less than zero above its inversion temperature, and an inversion temperature below the ambient temperature of the environment in which the device is to be used. The device also includes a displaceable walled container, or a bag or sack which is formed from a soft and pliable material, having an expansible and contractable volume which is used for enclosing the gas within the speaker enclosure and which is adapted to seal the gas therein, being substantially permeable to mechanical vibrations, but substantially impermeable to the gaseous mediums on either side thereof. The device is placed in the speaker enclosure in back of the vibratable cone in order to increase the compliance that the vibratable cone sees.