 Hand-held retina photographing apparatus |
| I claim: 1. A portable apparatus for use in photographing an eye or the like, comprising first ... |
|
| Anchoring means for door lock plates |
| I claim: 1. An anchoring arrangement for a door plate of a lock, said plate being secured to a door ... |
|
| Pallet-bar lift and support apparatus |
| I claim: 1. A bar-lift and support apparatus for cargoe pallets including a pair of allochirally ... |
|
| Latch hook rug holder |
| I claim as my invention: 1. A latch hook rug holder for attachment to a table or the like, ... |
|
| Latch mechanism with jamb mounted latch bolt |
| The present invention overcomes these inadequacies of the conventional type of door lock by ... |
|
| Lock arrangement for a vehicle sliding door |
| It is an object of this invention to provide a vehicle sliding door lock arrangement which can ... |
|
| Waste matter removal implement and receptacle |
| It is a general object of the invention to provide a waste matter removal implement which is fully ... |
|
| Anti-shim safety device for preventing wrongful disengagement of door latches |
| I Claim: 1. In combination with structure defining a jamb and stop rail for a door, guard means to ... |
|
| Bumper strip for automobiles |
| OF THE DRAWINGS Attention is first directed to FIG. 1, which is a line drawing representing the "... |
|
| Strike plate for hook bolt lock sets |
| With the prior art drawbacks in view, it is a principal object of the present invention to provide ... |
|
|
Transducer with rearwardly disposed damping elements
| Details |
Inventors: Haeder, Gert Wilhelm;
Assignee: The Rank Organisation Limited (London, EN)
Primary Examiner: Stellar; George G.
Assistant Examiner:
Attorney, Agent or Firm: Brisebois & Kruger
A loudspeaker of the well known conical diaphragm moving coil type is provided with an annular, frusto-conical, cellular damping/deflection element on the magnet or magnet housing thereof. This element interferes with the rearward radiation of sound from the diaphragm and is of particular value when the loudspeaker is housed in a cabinet since it acts to inhibit the formation of standing waves due to reflection at the rear wall of the cabinet of the rearwardly directed radiation; this reduces the distortion of the forwardly radiated sound, caused by the rearwardly directed radiation reflected from the rear wall of the cabinet. A further cellular element, of generally cylindrical form, may be attached to the rim of the diaphragm so as to project rearwardly therefrom and surround the loudspeaker back to a line defined by the forwardmost part of the frusto-conical annular cellular element on the magnet or magnet housing. |
|
DETAILED DESCRIPTION I claim: 1.
In a loudspeaker of the type comprising: a substantially conical diaphragm, support means for said diaphragm, and means for causing said diaphragm to vibrate in dependence on a varying electrical input signal fed to said loudspeaker, whereby said diaphragm radiates acoustic vibrations forwardly from one face and rearwardly from the other face, the improvement wherein, there is provided a frusto-conical annular damping element of cellular material mounted on said support means of said loudspeaker in a position such as partly to absorb and partly to radially outwardly deflect acoustic vibrations directed rearwardly from said disphragm.
2.
The loudspeaker of claim 1, wherein said frusto-conical annular damping element is positioned, with the narrow end thereof nearest said diaphragm, such that rearwardly traveling acoustic waves from said diaphragm impinge on the conical face thereof.
3.
The loudspeaker of claim 1, wherein the cellular material of said damping element is partly porous, that is only a proportion of the cells thereof are intercommunicating.
4.
A loudspeaker assembly comprising a substantially closed cabinet housing at least one loudspeaker according to claim 1, said loudspeaker being mounted in an opening in a front wall of said cabinet.
5.
The loudspeaker of claim 1, wherein said diaphragm is substantially conical and there is further provided: a substantially cylindrical element of cellular material attached to the rim of said loudspeaker, said substantially cylindrical element extending rearwardly of said rim spaced from said frusto-conical annular clamping element, and acting so as partly to absorb and partly to deflect laterally directed components of the acoustic vibrations radiated from the rear face of said diaphragm.
6.
The loudspeaker of claim 5, wherein said substantially cylindrical element of cellular material is partly porous, that is only a proportion of the cells thereof are intercommunicating.
7.
A loudspeaker as in claim 1, having a moving coil and a magnet in a magnet housing, and wherein said damping element of cellular material is mounted on said magnet or said magnet housing of said loudspeaker
|
| Related patents |
|
|
Electronic muffler assembly with exhaust bypass
The present invention relates generally to active noise cancellation systems, and particularly to active noise cancellation systems for use in quieting the engine ...
|
|
|
Active exhaust silencer
The invention is an active silencer that can have a low-profile for canceling noise from an exhaust pipe, and a method of making the same. The active silencer has a ...
|
|
|
System and method for reducing engine noise
In the following detailed description, certain specific terminology is used for clarity purposes and for describing a particular embodiment of the system. However, the ...
|
|
|
Method of making a variable capacitor microphone
One of the objects of our invention is to provide a method of making a variable capacitor microphone comprising that maintains its polarization after a long period of ...
|
|
|
Micro-microphone
What is claimed is: 1. A micro-microphone for attachment to the clothing or directly to the body of a user, the micro-microphone comprising: a housing having a housing ...
|
|
|
Seismic source
We claim: 1. A water gun seismic source for emitting jets of water into an underwater environment to generate seismic signals comprising a housing having a jet aperture ...
|
|
|
Audio tape saturation simulator
In accordance with the invention, an analog tape saturation simulator is provided which produces the same results as analog tape saturation in a controllable environment ...
|
|
|
Karaoke apparatus creating vocal effect matching music piece
The present invention has been made under such a background and has an object to provide a karaoke apparatus which is capable of automatically selecting a proper vocal ...
|
|
|
Cipher mixer with random number generator
This invention solves these and other problems by providing a combination block cipher with an effective key length greater than that of its components. This invention ...
|
|
|
Modular athletic playing surface with tuned compliance
A horizontally extending athletic playing surface characterized by a relatively large degree of vertical compliance is formed by a mosaic array of modules closely spaced ...
|
|
|
Gutter-related 
