Vacuum Cleaner

Not Applicable

Not Applicable

Not Applicable

1. Field of the Invention

The invention relates to a vacuum cleaner, particularly to a cylinder-type vacuum cleaner.

2. Description of the Related Art

Very few vacuum cleaners, upright or cylinder, are designed to be stably positioned on a flight of stairs. UK patent No. 658328 discloses a cylinder-type machine having skids attached to the underside of the cylindrical housing, the skids having notches located therein so that the machine can be "hooked" onto a stair nosing. This allows the user use of both hands to operate the hose or wand of the cleaner. A similar but improved design is described in our pending UK patent application No. 2292881A and corresponding PCT application No. WO 96/07350. An alternative design is illustrated in DE-U-9302645.

None of these prior art machines is designed or intended to be moved up or down a flight of stairs other than by the user lifting the entire machine and repositioning it on another convenient part of the flight of stairs. This can be quite cumbersome, especially if the user must also keep hold of the hose or wand during repositioning of the machine. It would be more convenient if the machine could be dragged or slid up the flight without having to physically lift the body of the machine but the configuration of each prior art machine is such that dragging or sliding is difficult and awkward and results in a substantial jolting of the machine. This can be detrimental to the operation of the machine.

U.S. Pat. No. 3,015,123 illustrates a vacuum cleaner which is intended to be slid or pulled up a flight of stairs, but the stability of the machine is insufficient for safe use.

An object of the invention is to provide a vacuum cleaner which can be easily manoeuvred on a flight of stairs.

The invention provides a vacuum cleaner as set out in claim 1. Advantageous features of the invention are set out in the subsidiary claims.

The shaping of the forward end of the housing to include an upwardly inclined nose adapted to present a smooth, inclined surface to a stair nosing so as to facilitate sliding of the machine up a flight of stairs means that upward sliding of the machine is smoother and less jolting so that the likelihood of damaging the machine by such action is minimised.

Embodiments of the invention will now be described with reference to the accompanying drawings, wherein:

FIG. 1 is a side sectional view of a vacuum cleaner according to the invention positioned on a flight of stairs; and

FIGS. 2a-2d illustrate progressive positions of the vacuum cleaner when caused to slide upon a flight of stairs in the upward direction.

FIG. 3a and 3b shows an alternative embodiment of the invention.

A vacuum cleaner according to the present invention is illustrated in FIG. 1. The vacuum cleaner 10 consists essentially of a housing 12 having a base 14 and a cover 16. A hose 18 is connected to the cover 16 of the housing 12 by means of a swivel coupling 20. Positioned inside the housing 12 are dust separating apparatus 22, a motor 24 and connection means for causing the vacuum cleaner to operate so as to draw dirty air into the housing 12 along the hose 18, to separate dirt and dust particles from the air flow, and to expel clean air to the atmosphere. The interior workings of the machine 10 do not form an essential part of the present invention and will not be described any further here.

The base 14 of the cover 12 incorporates a recess 26 which can accommodate the nosing of a stair tread. By means of this shaping, which forms the subject of our pending UK patent application No. 2292881A and PCT application No. WO 96/07350, the machine 10 can be positioned on a flight of stairs in a stable manner. The base 14 of the cover 12 rests on adjacent stair treads A, B at contact portions 28a, 28b.

When the machine 10 is in use, there is a desire on the part of the user to drag the machine 10 up the flight of stairs merely by pulling on the hose 18. In order to facilitate the sliding of the machine 10 up the stairs in the direction of the arrow 30, a nose or shaping 32 is provided on the forward end of the housing 12. The nose 32 projects forwardly of the casing 12 and is inclined upwardly with respect to the general plane of the base 14 of the cover 12 such that, when the user applies a pulling force to the hose 18 in the direction of arrow 30, the nose 32 presents a smooth surface to the nosing of the stair C immediately above the uppermost stair B on which the machine is currently resting. Sufficient pulling force in the direction of arrow 30 will cause the machine 10 to be pulled upwardly over the flight of stairs and the nosing 32 facilitates the smooth upward passage of the machine 10 by virtue of its shaping. The lower surface 34 of the nose 32 provides a surface by means of which the forward portion of the machine 10 is guided smoothly over the nosing of stair C.

FIGS. 2a-2d illustrate the upward motion of the machine 10 when an upward force is applied to the hose 18 in the direction of the arrow 30. The position illustrated in FIG. 1 is again illustrated in FIG. 2a and will now be regarded as a starting position. Contact portions 28a and 28b are in contact with the treads of stairs A and B. The foremost extremity of nose 32 is in contact with or adjacent the nosing of stair C.

Application of a pulling force in the direction of the arrow 30 causes the machine 10 to ride upwardly over the stairs. Contact portions 28a and 28b move out of contact with the treads of stairs A and B and the machine is then supported on the nosings of stairs B and C by contact with the surface of the recess 26 (or another portion of the base 14 of the housing 12) and with the lower surface 34 of the nose 32 respectively. Continued pulling in the direction of the arrow 30 causes the machine 10 to ride further up on the nosings of stairs B and C until the machine is supported by contact with the base 14 of the housing 12 on either side of the recess 26. Eventually, the nosing of stair C will come into contact with at least one wall of the recess 26 whereupon the contact portions 28a, 28b will be brought into contact with the treads of stairs B and C. Further movement in the direction of arrow 30 will ensure that the contact portions 28a, 28b are positioned sufficiently far from the nosings of stairs B and C for the machine 10 to be stably supported. The new stable position is identical to that shown in FIG. 2a but with the machine 10 resting on stairs B and C instead of stairs A and B.

The embodiment illustrated in the accompanying drawings shows that the housing 12,12' incorporates cyclonic means for separating dirt and dust from the air flow drawn in through the hose 18,18'. This is a preferably feature but should not be regarded as limiting to the present invention.