A seat cushion pad adapted for use over a seat cushion or against a back cushion. The pad is provided with a motor-driven vibration generator of the unbalanced motor type. The motor has a housing to which is coupled one end of an undulatory spring, which extends from the motor housing substantially throughout the area of the pad, acting as a vibration-transmitting device which transmits vibration throughout the area of the pad and to the body of a user sitting or leaning thereon. The end of the spring opposite from that coupled to the motor housing is free or unanchored, so that the vibration amplitude of the spring is not restricted and reduced to zero by an end anchorage.

Nonrotating vibrator motors are mounted on a rigid member in furniture. Electric power at different frequencies or energy levels is supplied to the respective vibrator motors. Frequency differences in the vibrations result in moving interference waves being produced in the rigid member which waves are imparted to the user of the furniture who experiences a massaging effect. Means are provided for enabling the user to control the frequency differential and amplitudes of the driving currents.

A filter condition sensor and indicator is disclosed. A filter condition sensor and indicator that responds to the presence of a predetermined collection of material in a filter operatively positioned in an output air flow path. A small by-pass air flow path is connected to the output air flow path and is separate from the filter. A heated thermistor is positioned in the by-pass air flow path. Electrically connected in series with the heated thermistor is an indicator light that illuminates when the resistance in the circuit is decreased due to predetermined cooling of the heated thermistor. In this way, a predetermined collection of material in the filter increases the flow of air in the small by-pass air flow path for cooling the heated thermistor and for lowering the resistance in the circuit to illuminated the indicator light. Even in those instances where a multi-speed fan is located in the output air flow path, the present invention overcomes changing fan speeds and changing air velocity by coupling the thermistor in a circuit which changes the voltage and current through the thermistor depending on the fan setting.

An article of furniture that includes a curved lower outer surface so that the article of furniture or chair can be rocked back and forth, the chair including stop members for limiting rocking motion or movement of the chair, and wherein reinforced portions are provided for supporting occupants of the chair so that the occupants will not sink down too far in the chair.

Two vibrator motors are removably attached to opposite rail portions of a bed frame or bed rail by clamp arms which project laterally from one side of each motor housing to hold the motor in a position which is offset from the bed springs. The rail-engaging ends of the clamp arms are covered by resilient caps which grip the rail to prevent the clamp arms from being shaken loose by the vibrator motor. The other ends of the clamp arms of each motor are connected to an elongated bracket which is cast as an integral part of the motor housing, and one of the clamp arms is adjustable relative to the other clamp arm.