Robust low profile shaker

Abstract

An electrodynamic shaker apparatus is disclosed for providing shaking and/or vibrational motion. The shaker includes armature and stator assemblies as well as a distributed spring assembly. The shaker apparatus of the present invention is robust, supports increased off-center loads, and has a low profile such that it may be easily placed under an item of furniture in order to impart vibrational motion in response to electrical signals from a variety of sources.

What is claimed is: 
     
         1 . A moveable assembly for use in connection with audio/video equipment for
 imparting variable motion to an object of furniture, comprising:   a bottom portion;   a moveable top portion opposing the bottom portion; and   an electromagnetic assembly, a portion of the electromagnetic assembly being integrated with the top portion and another portion of the electromagnetic assembly being integrated with the bottom portion in order to produce variable motion in at least the top portion in synchronization with electrical signals from the audio/video equipment.   
     
     
         2 . A moveable assembly as in  claim 1 , further comprising a spring assembly for providing resilient support between the bottom portion and the top portion. 
     
     
         3 . A moveable assembly as in  claim 1 , wherein the electromagnetic assembly comprises at least one coil portion and at least one magnetic portion. 
     
     
         4 . A moveable assembly as in  claim 3 , wherein the coil portion comprises at least one of the following: a wound voice coil operatively attached to the top portion, a coil configured on the surface of the top portion, and a coil embedded in the top portion. 
     
     
         5 . A moveable assembly as in  claim 3 , wherein the magnetic portion comprises:
 a magnet for interacting with the coil portion in order to produce the variable motion; and   at least one metallic pole piece for interacting with the magnetic field of the magnet.   
     
     
         6 . A moveable assembly as in  claim 5 , wherein the metallic pole piece comprises:
 a bottom pole operatively connected to the bottom portion;   an outer pole configured about the magnet; and   a top pole configured at least partially above the magnet, all poles being operative together to focus the magnetic field of the magnet substantially through the coil portion.   
     
     
         7 . A moveable assembly as in  claim 1  wherein the top portion comprises a top plate for contacting at least a portion of the object of furniture such that variable motion may be imparted to the object of furniture in the presence of the electrical signals. 
     
     
         8 . A moveable assembly as in  claim 7 , wherein the electrical signals comprise at least one of the following; entertainment related audio signals, entertainment related audiovisual signals, and entertainment related motion signals. 
     
     
         9 . A moveable assembly as in  claim 2 , wherein the bottom portion comprises:
 a base plate having a first side for supporting at least a portion of the spring assembly and at least a portion of the electromagnetic assembly; and   a second side for contacting at least a portion of a fixed surface.   
     
     
         10 . A moveable assembly as in  claim 9 , wherein the fixed surface comprises a floor. 
     
     
         11 . A moveable assembly as in  claim 2 , further comprising at least one pin for receiving at least a portion of the spring assembly and for providing transverse support to the spring assembly. 
     
     
         12 . A moveable assembly as in  claim 1 , wherein the object of furniture comprises at least one of the following: a chair, a couch, a seat, and a recliner. 
     
     
         13 . A moveable assembly as in  claim 1 , further comprising a bushing material operatively configured inside the moveable assembly for providing transverse support during variable motion. 
     
     
         14 . A moveable assembly as in  claim 2 , wherein the spring assembly comprises at least one discrete spring located at the periphery of the electromagnetic assembly such that at least part of the spring is co-planar with at least part of the electromagnetic assembly. 
     
     
         15 . A moveable assembly as in  claim 2 , wherein the spring assembly comprises at least one of the following: a material having springlike characteristics interspersed within the moveable assembly, and an elastomeric material. 
     
     
         16 . A moveable assembly as in  claim 2 , wherein the height of the spring assembly is substantially equal to the distance between the bottom portion and the top portion. 
     
     
         17 . A moveable assembly as in  claim 1 , further comprising an integrated electrical connector on an outer portion of the moveable assembly for facilitating electrical connection between a power source and the electromagnetic assembly.