US2540917A - Suction cleaner having stepped front wheels to provide nozzle adjustment - Google Patents

Description

Feb. 6, 1951 2,540,917

C. H. TAYLOR SUCTION CLEANER HAVING STEPPED FRONT WHEELS TO PROVIDE NOZZLE ADJUSTMENT Filed Sept. 15, 1946 WITNESSES: INVENTOR CHARLES H.TAYLOF. U W

ATTORNEY Patented Feb. 6, 1951 SUCTION CLEANER HAVING STEPPED FRONT WHEELS TO PROVIDE NOZZLE ADJUSTMENT Charles H. Taylor, West Springfield, Mass., as-

signor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application September 13, 1946, Serial No. 696,798

My invention relates to suction cleaning apparatus, more particularly to a suction cleaner constructed so that the nozzle is automatically posit oned with respect to the surface of the carpet being cleaned. The term carpet is used generically herein, to include rugs or any other floor covering of a fabric or textile character.

It is an object of my invention to provide a suction cleaner having improved nozzle adjustment characteristics, more particularly a, suction cleaner which will provide adjustment between a loosely woven and a closely woven relatively thin carpet, moving the nozzle to a lower position for the more loosely woven carpet. By a relatively thin carpet is meant a relatively low nap carpet, or a carpet of small dimension between the top and bottom sides of the carpet.

It has heretofore been proposed to provide automatic adjustment of the nozzle with respect to the surface of the carpet by inherent construction of the suction cleaner, the principal characteristic of which is large diameter and wide tread of the front wheels. By providing large contact area between the front wheels and the carpet, the weight per unit area is low, so that the front wheels do not penetrate deeply into the carpet but are maintained near the surface of the carpet and thus maintain the mouth of the nozzle in proper relation to such surface regardless of the thickness of the carpet. The front wheels do, however, penetrate further into a thick or high nap carpet than into a thin, or low nap carpet, but this is compensated to some extent by the tilting of the cleaner produced by the rear wheels penetrating more deeply than the front wheels. Such construction provides adjustment as between different thicknesses of rugs, but it does not provide substantial adjustment as between different types of carpet of a given thickness.

In accordance with the present invention, I provide front wheels of such characteristics, but which wheels have the tread divided into portions of different diameter, and which wheels may be referred to as stepped wheels. The form of the wheels is such that for relatively thin carpets, only the tread portion of greatest diameter penetrates the carpet, at least to an extent to carry a substantial portion of the weight. Such relatively narrow tread portion sinks more deeply into a loosely woven carpet than into a closely woven carpet. This is desirable because it is more difficult to seal the nozzle lips with respect to the loosely woven carpet, so that a lower position of the nozzle is required to ob- 1 Claim. (Cl. 15-362) tainthe desired air seal. When used on a closely woven thin carpet, however, the wheels do not sink to as great an extent and the nozzle lips are maintained at a higher position, which is desirable to avoid too great a suction on the carpet.

These and other objects are effected by my invention as will be apparent from the following description and claim taken in connection with the accompanying drawings, forming a part of this application, in which:

Fig. l is a side elevation of a suction cleaner incorporating the invention;

Fig. 2 is a bottom plan view thereof; and

Figs. 3 and 4 are fragmentary vertical sections showing one of the front wheels on a relatively thin carpet and a relatively thick carpet, respectively.

Referring now to the drawing in detail, the suction cleaner includes a casing Or body member 10 having a. floor nozzle H at the front. A brush roll i2 is rotatably mounted within the nozzle in conventional manner. A conventional fan motor unit (not shown) is housed within the casing H] to provide suctionin the nozzle H. A conventional dust bag i3 is also provided.

A pair of rear wheels [4 are mounted on the casing in adjacent the rear thereof, as shown on the drawing. A pair of front wheels 15 are mounted on the casing toward the front of the casing, just rearwardly of the nozzle, as shown in the drawing. The wheels may be mounted in any suitable manner, except that they are mounted to rotate on axes which are fixed with respect to the casing. In the illustrated embodiment, the rear wheels :4 are shown as mounted on the opposite end portions of a shaft 01' axle 56 carried by a bracket 2% fastened to the casing. Each of the front wheels i5 is shown as mounted on a shaft or axle ll, the ends of which are received in recesses formed in bosses I8 and held in such recesses by screws [9.

A handle 22 is pivoted to the cleaner casing on an axis parallel to and between the axes of the front and rear wheels, as shown on the drawing. In the illustrated embodiment, there is a helical torsion spring 23 wound around the shaft on which the handle 22 is pivoted and serving to bias the cleaner relative to the handle 22 in counterclockwise direction, as seen in Fig. 1; in other Words, tending to lift the front end of the cleaner to reduce the penetration of the front wheels into the carpet. t

The front wheels are formed with a tread which is relatively wide and of relatively great diameter, thereby providing relatively great contact area on the rug. Thus, the weight per unit area is relatively low so that the front wheels do not sink so deeply into thick carpets but are maintained more nearly at the surface, and therefore, maintain the nozzle in more-nearly uniform relation to the surface of the carpet for carpets of different thickness.

In accordance with the present invention, the

tread of the front wheels is dividedinto portionsof different diameter, each portion being of a width substantially as great as that of any of the rear wheels. In the illustrated embodiment, for example, each front wheel comprises-three tread portions 24, 25 and 26, the; widths of which;

are inch, e5 inch and 3 inch, respectively, and whose diameters are 2 inches, t-. inches and 1 inches, respectively.

The dimensions of the several tread portions of the front wheels of a, cleaner of given characteristics, such as its. weight and the-force, of the torsion spring 23, are suchv that when the cleaner is used ona relatively thin carpet, only the tread portion of greatest diameter penetrates the carpet and supports thefront end of the cleaner. The other tread portions of lesser diameter are spaced above the surface of the carpet, as shown in Fig. 3, or at leastpenetrate so slightly that they. do notcarry any appreciable weight. Due to. the reduced tread width and contact area, the weight per unit area of contact with the carpet is greater thanif. the full width of the tread contacted the carpet. Thus, the front wheels penetrate more deeply into. a loosely woven thin carpet than into a more. closely woven. thin carpet.

This-is desirable for the reasons explained above.

The nozzle is then While I have shown my invention in but one form, it will be obvious to those skilled in the are that it is not so limited, but is susceptible of various changes and modifications without departing-{from the spirit thereof.

What I claim'jis:

A suction cleaner comprising a casing having afloor nozzle at the front, a rear wheel or wheels 7 mounted on the casing adjacent the rear thereof, 10'

anda pair" of front wheels mounted on the casing', adjacent: said nozzle, said wheels being mounted on axes which are fixed with respect to the. casing, each front wheel having tread portionsipf different diameters, each tread portion b'eing o'f: azuniform diameter and of a width substantially as great as that of any of the rear wheels andsubstantially not less than inch, the difference between the greatest and the smallest diameters of said tread portions being substantially no greater than A; inch and substantial-ly not less than inch, whereby on a relatively thin or low-nap carpet, only the tread 110131310115 of greatest diameter penetrates the carpet sufficiently to carry any appreciable weight and on a, relatively thick or high-nap carpet, the tread portions havesufiicient tread area to support the; nozzle with a limited penetration or sinl's CHARLES-H. TAYLOR.

REFERENCES CITED The fol lowingreferencesare of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 809,266 LaFever Jan. 2, 1906 1,033,563 English July 23, 1912 1 ,181,094" McDaniel Apr. 25, 1916 1,265,789 Kirby a. May 14, 1918 2,203,001 Taylor June 4, 1940 2,232,766- Boyle Feb. 25, 1941 2,244,132 Taylor JiiheB, 1941 2,267,765 Taylor Dec. 30, 1941 Davi's- Nov. 23, 1943

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