fig1 - 7 show a main console 3 and a base 5 of one embodiment of the invention . a base 5 is adjacent to the main console 3 on a baseplate 6 . as shown in more detail in fig8 , two motors 8 inside of the base 5 are mounted adjacent and spaced apart from each other beneath the top surface of the base 5 . the motors 8 rotate eccentric weights ( shown in fig1 - 21 ) in opposite directions around substantially parallel axes running from the back to the front of the base 5 . vibration mounts 7 support the motors 8 above the baseplate 6 , while allowing vibration of the motors 8 in all three dimensions . when a user inputs a frequency of rotation , level of intensity , and duration of an exercise into a main 2 or secondary 4 display on the main console 3 , the motors 8 are driven with that frequency , intensity , or duration to produce a vertical sinusoidal vibration and a somewhat erratic horizontal vibration , on the top surface of the base 5 . as shown in fig1 - 4 and 8 , the main console 3 is substantially vertical and houses a main display 2 , a bottom or secondary display 4 , a power inlet and switch assembly 9 and an electronics console 11 . the electronics console 11 can be mounted directly to the main console 3 , as shown , or alternatively suspended from the main console 3 by suspension rubbers ( not shown ). such suspension may isolate the electronics console 11 from excessive vibration . in one embodiment , the main console 3 also houses a detachable transport assembly 10 , which can be detached during operation and attached for transport . a set of handlebars 1 extend from the main console 3 and are preferably made of steel with foam rubber grips . the base housing 5 is preferably made of fiber reinforced plastic ( frp ) along its upper and horizontal periphery and covered on its top surface by an anti - slip surface 13 , as shown in fig9 . as shown in fig2 , 3 , 5 , 8 and 12 , the base housing 5 surrounds a vibration mounting assembly 15 , a vibrating base assembly 19 and a motor assembly 8 , 80 . flexible straps 17 with hand or foot grips can be fixed at each end of the base housing to allow vibration from the platform to be transferred to muscles pulling the straps 17 . the baseplate 6 is shown in more detail in fig1 . the baseplate is preferably 13 mm thick steel with sufficient size and shape to support both the vibrating base assembly 19 and the main console 3 . preferably , the base plate 6 has enough mass to ensure stability during use and the stiffness to withstand the forces induced by vibration of the system . the baseplate 6 also isolates the system from the floor surface on which it is supported in order to minimize the dissipation of vibrational forces into the floor . in one embodiment , five height - adjustable rubber feet 20 project downward from the baseplate 6 to stabilize it on the floor , as shown in fig1 . a base housing 5 is molded from frp in the shape shown in fig1 - 8 . the vibrating base assembly 19 and vibration mounting assembly 15 within the base housing are shown in more detail in fig2 and 12 - 14 . mounted on the top surface of the baseplate are four vibration mounts 7 that support a motor mounting frame 15 . preferably , the vibration mounts 7 are formed of an elastomeric material that is capable of allowing three dimensional vibration of the motor mounting frame 15 . in one embodiment , the vibration mounts 7 are shaped with hollow , hexagonal cross sections that are mounted with a horizontal shaft transverse to the axes of rotation of the motors . in this embodiment , forces in that direction are damped more from the deformation of the vibration mount material than are the vertical forces . as shown in fig2 , 5 and 12 a , the motor mounting frame 15 includes a hollow , square , steel frame with mounting surfaces extending outward from the corners for mounting on the vibration mounts . a steel reinforcement 21 is fixed to two opposite sides of the square &# 39 ; s inner surface . a strip of steel 22 with mounting holes 24 is fixed in a horizontal orientation to the other two opposite sides of the square &# 39 ; s upper surface . the frp base housing 5 is molded into this strip of steel 22 to integrate it into the base housing . two motor housings 80 are mounted spaced apart with substantially horizontal and parallel axes on the underside of the frp - covered strip of steel 5 , 22 . the motor housings 80 are mounted onto either side of the central axis of strip 22 . in the embodiment shown , the housings 80 are mounted by bolts with anti - slip nuts . vibration - withstanding power cables 26 supply power from a motor connector , located within the base 5 beneath the motor mounting frame 15 . an alternate embodiment of the motor mounting frame 15 ′ is shown in fig1 b . the motor mounting frame 15 ′ is fixed to a larger steel surface 22 ′, as well as the steel reinforcement 21 ′ and vibration base assembly 19 ′ to increase the stiffness of the frame 15 ′. the motor housings 80 and motors 8 are shown in more detail in fig1 - 21 . each motor housing 80 encloses an identical motor 8 that rotates a set of eccentric weights 82 , 84 at substantially the same frequency and phase as the other motor 8 and in opposite directions . the motors 8 are wired in parallel and , in this embodiment , are bolted to the steel strip 22 . in one embodiment , these weights comprise several thin eccentric weights 82 of approximately 60 grams each and one main counterweight 84 weighing approximately 210 grams . the thin eccentric weights 82 rotate with the shaft and have a wide , teardrop shape , with their widths increasing with distance from the axis of rotation . using a multiplicity of eccentric weights allows the vibration characteristics to be modified , if desired , by adding or subtracting weights . the counterweight 84 is located between the motor 8 and the thin eccentric weights 82 . in one embodiment , the counterweight 84 is shaped similar to a teardrop , with its width increasing with distance from the axis of rotation . it rotates freely around the shaft and includes a rigid projection 86 on one side projecting away from the motor 8 and through the plane of rotation of the thin eccentric weights 82 . in the embodiment shown , the thin eccentric weights 82 can rotate around the shaft for almost a full rotation before they collide with the rigid projection 86 and cause the counterweight 84 to rotate with them . this allows more efficient starting operation of the system . in one embodiment , the rigid projections 86 on each of the two counterweights 84 extend from opposite sides of their respective counterweights 84 , as shown in fig2 . with this arrangement , when the motors 8 are rotated in different opposing directions , the thin eccentric weights 82 will collide with different sides of the rigid projections 86 , causing the counterweight 84 to either rotate on the same side of the shaft as the eccentric weights 82 or on opposite sides . fig2 and 27 show the thin eccentric weights 82 of the motor 8 on the right in fig2 rotating in a direction that collides with the rigid projection 86 to force the weights to rotate on opposite sides of the shaft . fig2 and 28 show the weights when rotating in the opposite direction wherein the thin eccentric weights 82 and the counterweight 84 are rotating on the same side of the shaft . when the weights 82 , 84 rotate on the same side of the shaft , a greater vertical force is imparted to the vibrational platform , and the vertical amplitude of the vibration increases . therefore , the amplitude of vibration can be changed by reversing the opposing rotations of the motors . this can be controlled by an intensity setting on the displays . in the illustrated embodiment , rotation of the eccentric weights 82 , 84 by the two motors 8 in this fashion creates an imbalance in the vibrating platform , causing a vertical sinusoidal movement as well as a slight , erratic , horizontal vibration . as the motors 8 rotate at the same frequency and phase , the frequency of vibration felt by a user standing on the vibrating platform is dependent on the frequency of the ac signal that drives the motors 8 . preferably , the motors 8 are capable of being driven at a wide range of frequencies , and more preferably at frequencies between 25 hz and 70 hz . in one embodiment , the motors are also capable of rotating in either direction . by operating the motors 8 in different opposing directions , a higher intensity vertical vibration , as measured as amplitude , can be achieved . in one embodiment , the amplitude of the vertical vibration increases from 2 . 5 mm when the motors are rotating in the same direction to 5 mm when the motors are rotating in opposite directions . by varying the frequency and amplitude , various g - forces can be experienced by the user . as described above , the human body naturally resists g - force and vibration , and the muscles used in resisting are strengthened . in one embodiment , the g - forces felt at low amplitude settings ( approximately 2 . 5 mm ) are 2 . 28 g and 2 . 71 g at 35 hz and 40 hz , respectively , and at high amplitude settings ( approximately 5 mm ) are 3 . 91 g and 5 . 09 g at 35 hz and 40 hz , respectively . fig2 - 3 , 8 , 22 - 23 and 25 show the main console 3 and its connections in more detail . the main console 3 includes a main display 2 , a bottom or secondary display 4 , a power inlet and switch assembly 9 and an electronics console 11 . preferably , the main console 3 includes handlebars 1 that reach a height convenient for a user to grasp them with his or her hands . at the main display 2 , a user may receive instructions regarding possible input values and can input the time of exercise , the frequency of vibration , a high or low intensity level , and whether the exercise at those setting should be repeated . this information is sent to the secondary display 4 . in reference to fig2 and 24 - 25 the secondary display 4 shows on a digital led a countdown timer showing the remaining operating time , based on the value input into the main display 2 by the user . the panel also has “ start ,” “ stop ,” and “ repeat ” buttons to operate and restart the apparatus using the last values input by the user . in one embodiment , this secondary display 4 is mounted in a lower section of the main console 3 to allow users doing exercises that are low to the floor , such as push - ups , to operate the apparatus at a convenient height . the information input into the secondary 4 and main 2 displays is sent to the electronics console 11 via a multi core flat cable . fig2 and 22 show the electronics console 11 in more detail . the electronics console 11 includes an ac motor drive 100 and a controller 102 . the controller 102 receives signals from the main 2 and secondary 4 displays and communicates these settings to the motor drive 100 . in one embodiment , the electronics console 11 includes a programmable chip 104 and a power regulator 106 . the motor drive 100 receives ac power from a 110v or 220v power outlet , through the power inlet / switch assembly 9 and power regulator 106 . the motor drive 100 then outputs power to the motors 8 at a range of specified frequencies , based on the signals from the controller 102 . in one embodiment , the motor drive 100 outputs power at 30 hz , 35 hz , 40 hz or 50 hz , in response to signals from the controller 102 . in one embodiment , the motor drive 100 is constructed to drive the motors 8 to rotate in opposite directions in response to the user inputting a high intensity setting from the main display 4 . in one embodiment , the motor drive 100 is a delta vfd - m ( 220v ) or - s ( 110v ) model . in another embodiment , the motor drive 100 is a telemecanique altivar model . although the foregoing describes the invention in terms of embodiments , the embodiments are not intended to cover all modifications and alternative constructions falling within the spirit and scope of the invention , and are limited only by the plain meaning of the words as used in the eventual claims .
a body vibration apparatus includes an at least partially rigid platform , a first motor coupled to the platform such that movement of the first motor imparts force to the platform . the first motor has a first shaft that rotates a first eccentric weight in a first direction , phase and plane . a second motor is coupled to the platform such that movement of the second motor imparts force to the platform . the second motor has a second shaft parallel to the first shaft that rotates in a second direction , which , in one embodiment , is opposite the first direction . a second eccentric weight is coupled to the second shaft in the first plane . the second eccentric weight rotates with the second shaft at the first phase .