WO2008041956A2

WO2008041956A2 - Spring-loaded wheel in a swivel housing

Info

Publication number: WO2008041956A2
Application number: PCT/SI2007/000032
Authority: WO
Inventors: Gregor Deuric
Original assignee: Kolektor Liv Predelava Plastike D.O.O.
Priority date: 2006-10-06
Filing date: 2007-09-19
Publication date: 2008-04-10
Also published as: SI22364A; WO2008041956A3

Abstract

The swivel housing with the spring-mounted wheel (5) overcomes the problem of unstable positioning of a vacuum cleaner (3), said instability being overcome by the spring- damped vertical movement of the axle (31) and of the wheel (25) toward the body of the vacuum cleaner (3) caused by the load of the vacuum cleaner (3) acting on the swivel housing with the spring-mounted wheel (5), the purpose of which is to transfer the weight of the vacuum cleaner (3) to the underlying surface (11). With the vertical movement of the axle (31) and the wheel (25), the transfer of the weight of the vacuum cleaner (3) to the underlying surface (11) is accomplished via another device, mounted on the vacuum cleaner (3), namely via the swivel housing with the spring-mounted wheel (5), thereby ensuring stable positioning of the vacuum cleaner (3) on the underlying surface (11).

Description

Spring-loaded Wheel in a Swivel Housing

The invention relates to a spring-loaded caster wheel in a swivel housing, particularly a component of a vacuum cleaner, designed to facilitate maneuvering of the vacuum cleaner along the floor surface, the said caster wheel being mounted in the said swivel housing in such a manner that in addition to the basic rotations, vertical movement of the caster wheel toward the body of the vacuum cleaner is allowed as well.

The inventive caster wheel overcomes the problem of poor adhesion of the vacuum cleaner to an uneven floor surface, as well as the problem of poor stability of the vacuum cleaner when the suction wand with attachments is parked on the vacuum cleaner. The inventive solution is characterized in that it is of very simple construction and only takes up little space.

Several designs of wheeled swivel housings are known in the art, such as the one set forth in Patent GB 1184136, wherein the main function of the wheeled swivel housing is to make the vacuum cleaner capable of following the user more easily and of changing direction during use. In addition, other approaches regarding wheeled swivel housings are known in the art, as per patents EP 0439465 (Bl) and US 4509227, respectively, wherein additional rotary elements are disclosed, designed to take over loads from the swivel housing and transfer them to the body of the vacuum cleaner as such. A further known solution is disclosed in JP 4117929, which additionally provides shock absorption capabilities to the caster wheel and enables the same to move toward the body of the vacuum cleaner in case of increased load. However, the said solution is both impractical and costly, requiring additional elements in the assembly to ensure the shock absorbing function, and a lot of space for implementation.

The vacuum cleaner is composed of the vacuum cleaner body, wherein a motor is mounted, the said motor generating, by means of a turbine, an air flow, which, via a system composed of suction tools, a rigid wand and a flexible hose, removes dust from the surface to be cleaned and transports it via the said system to a collection chamber, which is located in the body of the vacuum cleaner and which may be embodied as a dust bag with a permeable surface or as a cyclone collector. The vacuum cleaner sticks to the underlying floor by means of wheels, generally two rear wheels rotatable around an axis transversal to the axis of the vacuum cleaner, and a front caster wheel mounted in a swivel housing. Consequently, the front caster wheel as such rotates about an axle extending parallel to the floor surface and offset therefrom for the caster wheel's radius, which axle is fitted in the swivel housing. The swivel housing pivots around an axis extending vertically to the floor surface, the rotation axle of the front caster wheel being located at a distance X from the axis of attachment of the swivel housing. Although vacuum cleaners are generally equipped with single wheeled swivel housings, vacuum cleaners having two or more wheeled swivel housings are also known in the art. When two wheeled swivel housings are employed, bringing the overall number of wheels of the vacuum cleaner to at least four, the stability of the vacuum cleaner typically improves, mainly due to the interaxial distance between the two swivel housings, the ease of manipulation and the agility of the vacuum cleaner in use being enhanced as well. However, when a vacuum cleaner having two or more wheeled swivel housings is used, a problem arises in that on an irregular floor the vacuum cleaner may sway uncontrollably and give the impression of being unstable. In addition, with said embodiments, bumps of the caster wheel against the flooring occur as a result of the vacuum cleaner swaying on the floor, which are harmful to the structure of the vacuum cleaner and also cause a disturbing noise. Consequently, vacuum cleaners employing two wheeled swivel housings do exhibit a greater stability against capsizing, but they lack static stability, given that on uneven surfaces a problem occurs in that one of the wheels - usually one of the front-mounted swivel caster wheels - hovers freely in midair. Likewise, vacuum cleaners are known, wherein the rear wheels are substituted by wheeled swivel housings as well, giving vacuum cleaners with four or more wheeled swivel housings, wherein, however, the maneuverability and the stability of the vacuum cleaner are reduced.

It is the object of the present invention to disclose a structure of a spring-loaded caster wheel in a swivel housing that will ensure stability and maneuverability to the vacuum cleaner. According to the invention, the said object is achieved with a spring-loaded caster wheel in a swivel housing as set forth in and by the independent patent claim (s) .

Description of the Invention

The invention shall hereinafter be described with reference to a preferred embodiment thereof and the appended drawings, representing:

Figure 1: Vacuum cleaner having two swivel housings with spring-mounted caster wheels;

Figure 2: Cross section along line A-A of the swivel housing with the spring-mounted caster wheel;

Figure 3: Top plan of the swivel housing with the spring-mounted caster wheel;

Figure 4: 3-D view of the swivel housing with the spring-mounted caster wheel; and

Figure 5: 3-D view of the swivel housing with the spring-mounted caster wheel prior to assembly.

In itself, the swivel housing with the spring-mounted wheel 5 as per Figure 1 is composed of the swivel housing 15, the caster wheel 25, the spring 33, and the caster wheel axle 31, as shown in Figure 3. The assembly of the swivel housing 15 with the spring-mounted wheel 5 is characterized in that the spring 33, pushing the axle 31 into its seat 36 in the swivel housing, is bound in the said swivel housing 15 and acts on the axle 31 of the caster wheel 25 in reaction to the two binding points. When the axle 31 of the caster wheel 25 translates along the race 36, thus moving the said caster wheel 25, mounted on the axle 31, the spring 33 gives in, consequently exerting a greater force on the axle 31 of the caster wheel 25. The axle 31 of the caster wheel 25 does not rotate during its translation along the race 36, whereas the caster wheel 25, fitted on the axle 31, does rotate. When an overloading force, considerably greater than the mass of the vacuum cleaner with a completely filled dust bag, is applied to the body of the vacuum cleaner, the axle 31 of the caster wheel 25 gives in until it reaches the upper transversal rib 22, where the axle 31 abuts upon the transversal rib 22, thus preventing the caster wheel 25 from leaning against the body of the vacuum cleaner 3.

The housing 15 is preferably of circular cross-section and presents a cylindrical adaptor in the center thereof for connecting the housing 15 to the support column on the body of the vacuum cleaner 3. On one side of the housing 15 there is an opening in its casing and partly in its bottom, said opening having roughly the same size as the caster wheel. Said opening is walled and defines two vertical races 36, which serve as guides for the axle 31 of the caster wheel 25 and determine the free vertical movement of the axle 31 and of the caster wheel 25 toward the body of the vacuum cleaner 3. Axial movement of the axle 31 is prevented by two limiting walls 19. Between the limiting wall 19 and the vertical race 36 there is a slot 39 located at each end of the axle 31, wherein the arms of the spring 33 are bound, said arms being in permanent contact with the axle 31 of the caster wheel 25 and pressing against the said axle 31 vertically downwards, namely toward the ground. The said slot 39 guides the spring 33 in such a manner that the said spring 33 is held in contact with the axle 31 at all times, while being prevented from dislodging off the axle 31. The said spring 33 abuts upon the housing 15, while the two ends, or arms, thereof abut upon the axle 31. Between the arms of the spring 33, abutting upon the axle 31, and the housing 15, the spring 33 is held by a locking dent 27, which defines the force, exerted by the spring 33 against the axle 31 for a given vertical position thereof.

By employing the swivel housing with the spring- mounted wheel 5, a given caster wheel 25 is allowed to move, i.e. plunge, toward the body of the suction apparatus when subjected to loads caused by irregularities in the floor surface, due to which the caster wheel 25 tends to hover in midair. Whenever this occurs, the caster wheel 25, which is in contact with the underlying floor surface 11 at the time, must withstand higher loads from the vacuum cleaner than would be the case if both caster wheels 25 were sustaining the load. The system as such is so designed that the mass of the vacuum cleaner 3 gets equally distributed between both caster wheels 25, both caster wheels 25 being in permanent contact with the underlying surface at all times. There are no side effects such as noise, given that the weight transfer on the rotatable caster wheel is damped by the spring. In addition, the suction apparatus as such does not sway, nor does it give the impression of being unstable.

Claims

Patent Claims

1. Spring-loaded wheel in a swivel housing, mounted in a vacuum cleaner (3), characterized in that in the housing (15) there are two vertical races (36), wherein the axle (31) of the wheel (25) is fitted, against which axle a spring (33) presses.

2. Wheel according to Claim 1, characterized in that the axle (31) is guided along two vertical races (36) , delimited by two transversal ribs (22) and by the bottom of the housing (15) , a given intermediate position thereof being defined by the spring

(33) in dependence of the load.

3. Wheel according to Claims 1 and 2, characterized in that the spring (33) is held by locking elements (27), the said fact defining the characteristic of the spring (33) and the force, exerted by the said spring (33) against the axle (31) for a given vertical position thereof.