Vacuum cleaner with improved brush

Abstract

A vacuum cleaner is provided with a suction nozzle and a cylindrical rotary brush. The brush includes a plurality of generally longitudinally extending rows of uniform bristle tufts. Alternate tufts in alternate rows are spaced at about twice the distance as the remaining more closely spaced tufts and prepare the carpet for sweeping by the latter.PRIOR ART OF INTERESTU.S. Pat. Nos. 1,044,488, Case, 11/19/12; 1,970,355, Bennet, 8/14/34; 2,281,798, Prince, 5/5/42; 2,459,007, Taylor, 1/11/49; 2,659,921, Osborn, 11/24/53; 3,716,889, Goldstein, 2/20/73; 3,815,170, Brooks et al, 6/11/74.BACKGROUND OF THE INVENTIONVacuum cleaners have long been considered one of the most effecient devices for removing debris from carpets and the like. Many modern cleaners, when of the upright type, often comprise a power head portion having a vacuum nozzle, a rotary brush in the nozzle for engaging the carpet, and a brush drive motor; as well as an upright handle or stick pivoted to the head and including a suction motor and a storage chamber for receiving the material removed from the carpet.The rotary brush has usually comprised a cylindrical core having rows of brush bristle tufts. In many prior constructions, the tufts were arranged longitudinally along the core surface in straight or spiral rows, with adjacent tufts being close together and equally spaced.Various attempts have been made over the years to improve the ability of the rotary brush to loosen debris on the surface and deep within the carpet so that the material may be readily sucked through the nozzle into the storage means. For example, in the above-mentioned Prince U.S. Pat. No. 2,281,798, a rigid beater bar is used in conjunction with the brush row. In Taylor U.S. Pat. No. 2,459,007, it is suggested to provide alternate rows of short stiff tufts and long flexible tufts. In Osborn U.S. Pat. No. 2,659,921, it is suggested to use three rows of brush bristle tufts, each of a different stiffness. In Goldstein U.S. Pat. No. 3,716,889 it is suggested to provide alternate "agitator elements" in each row, with alternate rigid and resilient elements.It is readily apparent that all of these "improved" brushes are subject to the disadvantage of increased cost of manufacture, as compared with the aforementioned rotary brush wherein all the rows comprise identical equally spaced tufts of the same length. It is expensive to provide multiple types of tufts or other agitator elements in the same brush and has required special tufting machinery and/or multiple passes through a single machine. Furthermore, rigid agitator elements or beater bars subject the carpet to undesirable wear.SUMMARY OF THE INVENTIONThe present invention solves the aforementioned problems, and is based on the very surprising discovery that complete removal of alternate tufts from alternate tuft rows in a brush wherein the tufts are otherwise all uniform provides a substantially increased cleaning efficiency in a vacuum cleaner of the type indicated. Such a result was wholly unexpected since the normal expectation was the opposite, that is, if bristle tufts were removed from a brush, the brush would not perform as well.While the present inventors' solution to the aforementioned problems may seem simple in retrospect, it nevertheless has created an improved cleaning concept using a low cost brush which subjects the carpet to less wear.

Description

Claims

1. A vacuum cleaner comprising:

a. a head member adapted for reciprocable movement over a carpet,

b. an elongated carpet engaging nozzle disposed in said head member,

c. means for creating suction at the nozzlecarpet interface to move debris through said nozzle,

d. a handle on said head member,

e. and a rotatably driven brush disposed in said nozzle and engageable with the carpet, said brush comprising:

1. an elongated cylindrical core,

2. and a plurality of generally longitudinally extending circumferentially spaced rows of flexible brush bristle tufts extending radially outwardly from said core,

3. said tufts being of the same height and strength,

4. at least a portion of the tufts in alternate rows being equally and closely spaced a selected distance to form a substantially continuous line,

5. the tufts disposed circumferentially from said closely spaced tufts being widely and equally spaced at twice said selected distance,

f. said widely spaced tufts forming means to penetrate the carpet in a discontinuous line during driven brush rotation to loosen deeply embedded debris and prepare the carpet surface for subsequent debris removal by said closely spaced tufts as said vacuum cleaner is moved across the carpet.

2. The vacuum cleaner of claim 1 wherein said widely spaced tufts are disposed in a plurality of spaced parallel transverse planes passing through said core, said planes containing every other of said closely spaced tufts.

3. The vacuum cleaner of claim 2:

a. wherein one-half of each said row contains said widely spaced tufts and the other row half contains said closely spaced tufts,

b. and wherein the tuft spacing of circumferentially adjacent rows is reversed.

4. A rotatable brush adapted to be drivingly disposed in the nozzle of a vacuum cleaner, such brush comprising:

a. an elongated cylindrical core,

b. and a plurality of generally longitudinally extending circumferentially spaced rows of flexible brush bristle tufts extending radially outwardly from said core,

c. said tufts being of the same height and strength,

d. at least a portion of the tufts in alternate rows being equally and closely spaced a selected distance to form a substantially continuous line,

e. the tufts disposed circumferentially from said closely spaced tufts being widely and equally spaced at twice said selected distance,

f. said widely spaced tufts forming means to penetrate the carpet in a discontinuous line during driven brush rotation to loosen deeply embedded debris and prepare the carpet surface for subsequent debris removal by said closely spaced tufts.

5. The brush of claim 4:

a. wherein one-half of each said row contains said widely spaced tufts and the other row half contains said closely spaced tufts,

b. and wherein the tuft spacing of circumferentially adjacent rows is reversed.