This particular invention is a vibrator that continually alters the intensity of the vibration without altering the speed of vibration, through a short range of wave amplitudes and through a short repeated cycle without using any complicated circuitry. In short, it is a vibrator that throbs.

Essential Features : The first essential feature of the device is the two interacting electric motors (1). Both of motors have an offset weight attached to their output shafts (6}. These two weights are very slightly different from each other either in their weight or the positions of their centres of gravity in relation to the output shafts, or both. This causes the motors to spin at slightly different speeds, which in turn causes them to drift in and out of synchronisation with each other. At any moment the respective vibrations of each motor may add together to create a higher vibration amplitude, or they may cancel each other out to some extent to reduce the vibration amplitude in the main body of the device.

Since the motors are continually drifting in and out of phase with each other the overall vibration in the body of the device will drift to and from these two amplitudes of vibration in a throbbing manner.

The second essential feature is the structure of the of the body of the device (2). This is a coil spring which allows transmission of the vibration from each of the motors while at the same time allowing the motors enough independence from each other so that they can maintain their separate frequencies. If the body is rigid, then the motors tend to be affected by each other enough to make them spin at the same speed. The flexibility of the spring also allows the user opportunities to apply pressure to desired areas of the body.

A less essential feature is that the silicone rubber sheath (4) that covers the spring allows it to be easily cleaned or boiled for hygiene.

Batteries (5) should be rechargeable NiMH, either by removal and placement in a battery charger or by plugging a battery charger into the device.

The Drawing: The drawing shows a longitudinal cross- section of the device showing the positional relationships between the two electric motors (1), the coil spring (2), the on/off switch (3), the silicone rubber sheath (4) and a number of NiMH batteries mounted around one end of the device (5).

Any connecting wires between the batteries, the switch and the two electric motors have been excluded from the drawing so as not to detract from the important features.