High volume, high performance, ultra quiet vacuum cleaner

• US 5,502,869 A
• Filed: 10/27/1994
• Issued: 04/02/1996
• Est. Priority Date: 02/09/1993
• Status: Expired due to Fees

• Current Assignee: Noise Cancellation Technologies, Inc. (NCT Group, Inc.)
• Original Assignee: Noise Cancellation Technologies, Inc. (NCT Group, Inc.)
• Inventors: Arnold, Michael F., Nowicki, Christopher P., Smith, Dexter G.
• Primary Examiner(s): MOORE, CHRISTOPHER K
• Application Number:
  US08/329,921
• Time in Patent Office: 523 Days
• Field of Search: 15/326, 381/71
• US Class Current: 15/326
• CPC Class Codes: A47L 9/0081 Means for exhaust-air diffusion; Means for sound or vibration damping

Abstract

An ultra quiet vacuum cleaner having a bag cavity (44), a motor/blower chamber (48) connected to said cavity by a flexible coupling (47) and an active, adaptive noise cancellation controller (52) so configured to quiet the exhaust of the air used to cool the motor/blower unit. Fast compensation and feedback compensation allow use of a straight, short duct (51) for superior cancellation performance.

Claims

1. A vacuum cleaner system adapted to cancel both tonal and broadband noise for quiet operation, said system comprising

an inlet means adapted to allow for the intake of solids and liquids,

motor/blower means associated with said inlet means and adapted to provide negative pressure at said inlet means to facilitate the intake of said solids and liquids,

said inlet means includes a cavity area which is acoustically designed to produce the lowest pressure drop and the cross-sectional area of the inlet means is adapted to impede the transfer of the acoustic energy to the cavity,

collection means associated with said inlet means so as to collect solids and liquids that are drawn into said inlet means by said negative pressure,

a relatively short, straight exhaust means,

active noise control means associated with said system and adapted to measure both tonal and broadband noise, the noise generated by said system, compensate for feedback from speaker to reference microphone and to produce an equal and opposite counter noise in said exhaust means so as to reduce the system generated noise.

2. A vacuum cleaner system as in claim 1 wherein said motor/blower means includes a sealed chamber means which is adapted to isolate the motor from the remainder of the vacuum system both acoustically and structurally.

3. A vacuum cleaner system as in claim 2 wherein said chamber means has an air inlet and said exhaust means being a straight duct and relatively short in relationship to said system.

4. A vacuum cleaner system as in claim 3 wherein said chamber air inlet is connected to said cavity means by a flexible coupling to provide for a smooth flow to minimize noise produced by turbulence and separation and to reduce structural vibrations.

5. A vacuum cleaner system as in claim 4 wherein there is a large impedance difference between said chamber and said flexible coupling.

6. A vacuum cleaner system as in claim 4 wherein said chamber means is constructed as a decoupled absorber/barrier which allows for reduction of low frequency noise while absorbing high frequency noise.

7. A vacuum cleaner system as in claim 1 wherein said exhaust means includes an exhaust duct which conducts cooling air used to cool said motor/blower means out of said system, said exhaust duct being straight and relatively short in relation to said system and having a loudspeaker means mounted thereon.

8. A vacuum cleaner system as in claim 7 wherein said active noise control means includes sensing means in the path of air passing through said exhaust duct to sense the noise and introduce a signal to said control means which is adapted to emit a noise canceling signal to said loudspeaker means.

9. A vacuum cleaner system as in claim 8 wherein said speaker means located in said exhaust duct means to allow for counter noise to interdict the motor/blower produced noise to cancel it including a speaker located adjacent the terminus of said exhaust duct, whereby counter noise can be introduced into said duct to cancel both tonal and broadband noise contained therein.