Pivot for castor wheels for cleaning equipment and the like

Abstract

The pivot for castor wheel for cleaning equipment or the like, with new elements structured to absorb and counteract the stresses to which the wheel is generally subjected during use, allows cleaning equipment and the like to be used in areas and sectors compatible with the materials used for the various parts that compose it.

Claims

1. A pivot for rotation of a caster wheel for a cleaning appliance, the pivot including a stem of a protruding pivot made of a plastic/resinous material, the pivot being connected to a collar that rests on a ring nut made of wear-resistant material housed inside a first top seat of a casing, said pivot being held on a bottom by a flange that rests on a ring housed inside a second bottom seat of the casing.

2. The pivot of claim 1 wherein all or part of the vertical load of the pivot is transferred by means of the collar to the ring nut.

3. A pivot for rotation of a caster wheel for a cleaning appliance, the pivot including a stem of a protruding pivot made of a plastic/resinous material, the pivot being connected to a collar that rests on a ring nut made of wear-resistant material housed inside a first top seat of a casing, wherein the collar-ring nut pair has a circumferential raised part and respective hollow distanced from an axis of the pivot and on the outermost radial part of the collar-ring nut pair.

4. The pivot of claim 3 wherein the circumferential raised part and respective hollow have a vertical component capable of absorbing and resisting tilting moments and/or shifting of the pivot to prevent scraping thereof against a first top seat of the ring nut.

5. The pivot of claim 4 wherein said collar and said ring nut have one or more series of coaxial and concentric lips that create a labyrinth for preventing dirt from entering between the facing surfaces between the collar and the ring nut.

6. A pivot for rotation of a caster wheel for a cleaning appliance, the pivot including a stem of a protruding pivot made of a plastic/resinous material, the pivot being connected to a collar that rests on a ring nut made of wear-resistant material housed inside a first top seat of a casing, wherein a lower part of the stem of the pivot is held by a flange against an extension, wherein said flange has an extended surface that rests on a ring that is housed inside the casing in a second seat.

7. The pivot of claim 6 wherein the flange-ring pair has a circumferential raised part and respective hollow on its facing surface, distanced from an axis of the pivot and on the outermost radial part of said flange-ring pair.

8. The pivot of claim 7 wherein the circumferential raised part and respective hollow have a vertical component capable of absorbing and resisting tilting moments and/or shifting of the pivot to prevent scraping thereof against a first top seat of the ring nut.

9. The pivot of claim 6 wherein links between the ring nut and collar and links between the flange and the ring keep the pivot in a vertical position, an axis of the pivot capable of absorbing and countering the tilting moments to which the pivot is subjected.

10. The pivot of claim 9 wherein the pivot is entirely a non-metallic plastic, resin, or rubber polymer.

Description

DESCRIPTION OF THE DRAWINGS

(1) The technical characteristics of the invention, according to the aforesaid aims, are clearly noted in the content of the claims reported below, and its advantages will become more readily apparent in the detailed description that follows, made with reference to the accompanying drawings, which illustrate a preferred embodiment, purely exemplary and not limiting, in which:

(2) FIG. 1 shows a common castor wheel with metallic bearings that support a metal pivot;

(3) FIG. 2 shows a vertical section of the various components of the wheel of the invention arranged in exploded manner; and

(4) FIG. 3 shows the object of FIG. 2 assembled.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

(5) With reference to the figures, we see that a traditional pivoting or revolving wheel 1 has a pivot 2 whose vertical axis of rotation Y-Y is perpendicular and is cantilevered with respect to the main axis of rotation X-X of the rotating wheel 3.

(6) All the forces transmitted from the equipment or devices above are applied to the pivot 2.

(7) Said pivot 2 is usually fitted with a collar abutment 4. Said collar 4 rests on the inner ring of an underlying ball bearing 5 arranged within a housing 6 specially crafted in the support structure 7 of the castor wheel 3.

(8) Said support structure 7 is usually also made of metal or possibly a plastic material.

(9) In the event that the structure 7 is made of plastic, the pivot 2, in addition to being in abutment with its abutment collar 4 on the upper bearing 5, is retained in the lower end part within a second lower bearing underneath the upper bearing, to be able to absorb and counteract the tilting moments of the pivot 2 due to its cantilevered arrangement with respect to the main axis of rotation X-X of the castor wheel 3.

(10) The object of the invention consists of a plastic pivot 8 arranged with its o n rotation axis Z-Z orthogonal and cantilevered respect the main rotation axis 9 of the castor wheel.

(11) In addition to the device of the invention, also the castor wheel and the relative pivot are made of a plastic/rubbery material, or other another resinous polymer.

(12) Said pivot 8 has along its extension a collar 9 connected to it, which extends diametrically.

(13) Both the pressure component of the weight above the equipment and the relative stresses of the tilting moments are transferred from said pivot 8 to said collar 9.

(14) The weight and overturning moment are absorbed and countered by a ring nut 10 specially profiled with diameter dimensions corresponding to the above-mentioned collar 9.

(15) Thanks to the extended surface, the specific localized pressure has modest local values.

(16) However to make the movement of rotation of the pivot 8 around its axis Z-Z even more fluid, said ring 10 is expected to be made of an anti-friction and anti-wear material.

(17) Even the stresses of the tilting moments turn out to be a low value, due to the considerable radial extension of the collar 9 and the respective ring nut 10.

(18) Profitably the outer circumferential ends of the collar 9 and of the respective ring nut 10 are profiled with one or more series of coaxial lips 11, 12 that form a sort of labyrinth that prevents, or greatly restricts, dirt or the like getting in between the contact surfaces between the collar 9 and ring nut 10.

(19) In order to make the fluidity of the rotation movement of the pivot 8 even more effective, all or part of the stresses are transmitted from the collar 9 to the ring nut 10 by means of a circumferential raised part 13 and relative hollow 14 arranged coaxially on the contact surface spaced from the axis Z-Z and preferably on the outermost radial part.

(20) In this way both the pressure and above all the tilting moment are no longer transferred by contact on a flat surface but on a raised section 13 shaped in a curvilinear and preferably semi-circular manner that slides within a corresponding seat 14 profiled in a specular manner.

(21) This avoids, in particular, that the stem 15 of the pivot 8 can creep inside the through-seat 16 of the ring nut 10, since the lateral displacements are restrained by the vertical fronts, or with a vertical component, internal and external (diametrically opposite to the axis), of the raised part 13 and countered by the vertical fronts, or with a vertical component, external and internal (diametrically opposite to the axis), of the recess 14.

(22) All the above-mentioned stresses are transferred with specific small values, and in any event still admissible, by the ring nut 10 to the casing 17, since said ring nut 10 is housed in a first seat 18 on the top of the casing 17.

(23) The lower part of the stem 15 of the pivot 8 after passing through the ring nut 10 and a hole 19 of the casing emerges in the inner part 17 of the casing.

(24) Said lower part is retained by a flange 20, possibly by means of fastening elements, like for example a screw 21, to prevent unintended removal.

(25) Moreover, said flange 20 contributes, with its enlargement and its supporting profile on a ring 22, housed in the inside part of the casing 17, in a second seat 23, in preventing the stem 15 of the pivot 8 from directly sliding against the housings of the ring nut 10 and the ring 22.

(26) In fact, said flange 20 and the respective ring 22 are fitted in the facing areas with a raised part 24 and a corresponding hollow 25 whose vertical fronts, or with a vertical component, internal and external, prevent the tangential movement between the flange and ring and therefore prevent the stem 15 of the pivot 8 from coming into contact with the inner surface 26 of the through-hole of the ring.

(27) It is obvious that this lower constraint between the flange and the ring contributes to the upper connection between the ring nut and the collar in maintaining the pivot in the axis, namely vertical, absorbing and countering the moments to which it is subjected.

(28) We should finally add that the pivot 8 may itself be effectively an elastic device for retaining, after initial interference, within the corresponding seats of the equipment or device, possibly by tapering the top outside part and getting rid of the central core of the stem 15.

(29) It has thus been seen that the new castor wheel, equipped with all the elements made of a non-metallic material, and preferably plastic and/or another resinous or rubbery polymer, obtains all the benefits of robustness of a similar metallic wheel without the associated drawbacks due to wear or magnetic field properties.

(30) Related equipment or devices equipped with the wheels of the invention can therefore enter any premises, even those with limited or no electromagnetic interference without any danger of distorting diagnostic results or any serious consequences from a health viewpoint.