Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Electric Home Appliance Co., Ltd.

Yoshihiro Noguchi

Yutaka Takahashi

Hideharu Tanaka

Toshihisa Imai

Ken Morinushi

Toshio Nakajima

Takahiro Yanagida

Tomohisa Imai

The present invention concerns a method of preparing a porous structural unit comprising a plurality of layers having different specific gravities by pressing and heating a material including resin particles between opposing molds having a temperature difference to thereby cause the fusion or bonding of the resin particles, and a porous structural unit which improves acoustic absorption properties and heat insulation properties and in which the specific gravity is continuously changed.

Method of preparing a porous structural unit

A sound attenuator has at least one sound absorber composed of a hollow body of a hard porous material and an outer or inner layer of air, and exhibits good sound-absorbing property even in a low frequency range, even if the hollow body has a small wall thickness. The hollow body may be provided with projections or a semicircular or otherwise shaped part or parts, or both, serving to maintain the outer or inner layer of air in proper shape. The device is inexpensive and yet is very reliable in quality. When the device is long, the projections in linear form are particularly useful for restraining any flanking transmission of noise and thereby enabling the device to achieve a higher rate of attenuation per unit length. The sound-absorbing property of the device can be controlled over a wide range of frequencies if the hollow body has a porosity varying continuously in a specific direction. The device exhibits an improved sound-absorbing property particularly in a low frequency range if the hollow body is provided with a skin layer on its wall surface facing an air passage.

Sound attenuator

A blower comprises an impeller which can function to raise the pressure of a fluid and delivers it; a driving device for driving the impeller; and a fan casing which includes a fluid path to inspire the fluid from the outside and deliver it to the outside through the impeller; wherein the fan casing is at least partly formed by a hard porous structural unit whose specific gravity is continuously changed in at least one of the direction of thickness and a direction of surface.

Blower having a sound-damping structure

Porous structural unit and a method of preparing the same

A floor detector for a power brush of a vacuum cleaner comprises a lift sensor S1 and a floor sensor S2. The lift sensor S1 has a movable member which yieldably displaces when the power brush is placed on a relatively soft floor while the floor sensor S2 has a movable member which yieldably displaces when the power brush is placed on a relatively hard floor. Each of movable members is detected its movement by a corresponding light sensor which provides a signal representative of the movements. The signals from the light sensors are sent to a control circuit which controls a drive source for driving the brush member of the power brush. In this manner, the brush member is rotated when the power brush is placed on a relatively soft floor such as a carpeted floor and is not rotated when the power brush is placed on a relatively hard, flat, smooth floor.

Floor detector for vacuum cleaners

A coffee mill comprises a coffee bean pulverizing cutter held in a mill casing, a space for catching skin slivers and fine fragments of coffee beans and a cutter receiving space communicated with the catching space. Air flow is produced between these spaces during pulverizing the coffee beans to move the skin slivers to the catching space.

Growing community of inventors

Hanazono, Japan

Yoshihiro Noguchi