EP1155669A2

EP1155669A2 - Wheel chair with adjustment of the position of the supporting wheels

Info

Publication number: EP1155669A2
Application number: EP01111639A
Authority: EP
Inventors: Berto Vassilli
Original assignee: Vassilli SRL
Current assignee: Vassilli SRL
Priority date: 2000-05-16
Filing date: 2001-05-14
Publication date: 2001-11-21
Also published as: EP1155669A3; IT1315695B1; ITPD20000128A1

Abstract

It is a wheelchair for disabled persons where there is the possibility of varing the lying posture of the bearing wheels (19) to obtain an incline which spaces them out at the base and approaches them on the top and / or to obtain a convergence. This has been reached by equipping the wheelchair with two axle shafts (19) angled between them with variation of the angle position and with variation of the lying posture of the plane defined by them (Fig. 3).

Description

This invention applies to wheelchairs and, more specifically, to the wheelchairs for disabled persons with the adjusting of the lying of the bearing wheels.
The wheelchair is composed structurally by a frame, made of two pipes which run parallel, suitably spaced out, one over the other; these pipes, after having outlined the width and the depth of the seat, go on and down on the front to support a footrest.
The two pipes are initially linked on the sides by plates (which extend on the lower part) and then in the intermediate area by a distance cross piece of the width, suitably lowered, in order not to interfere with the seat cloth surface and on the front lower side by the brackets which support the forks of the drive front casters.
The side linking plates of the tubes of the bearing structure in the lowered section have three holes one under the other in sequence, suitably spaced out.
By choosing to fit the wheel axle into one of the three holes, you will settle the height of the seat surface compared to floor.
To each side linking plate of the two pipes of the bearing structure, a further plate is applied integrally, this elevates and is equipped in a lower position with a buttonhole situated vertically and on an upper position and lined up with the lower buttonhole of a slit.
Said buttonhole and slit represent the seats where the pegs of a bracket engage, applied to one of the uprights of the backrest structure.
The backrest is fixed to the structure when the upper peg of the bracket is fit in the slit. The backrest if raised upwards removes the engagement of the upper peg of the bracket from the plate slit and can be folded over onwards so as to be set against the seat.
For the execution of the flanks, there are provided two rolled sections with a curvilinear profile on the upper part so as to partially and approximately form the armrests.
These rolled section flanks are hinged on the upper part on the uprights of the backrest structure and are engaged through a slit on a peg provided laterally on the pipes of the bearing structure. By this achievement, when you want to operate the backrest to get it lower or to raise it up, the movement of the side plates is at the same time activated.
It has not been said that the pipes of the bearing structure of the wheelchair are equipped laterally with a set of holes provided to apply the linking plate slightly onwards or backwards by choice.
This allows to change the seat depth.
Other possibility to vary the seat depth is obtained by exchanging, from right to left and viceversa, the brackets applied to the uprights of the backrest structure, since the pegs for the coupling to the lateral linking plate applied to said bracket, are shifted compared to the axle centre of said uprights of the backrest.
One of the determinants of this patent is the execution of the bearing wheels axle obtained by the composition of two axle shafts which can be connected according to angled configurations, which:

allows the variation of the wheel track;
allows the inclination variation of the wheels with widening of the rest support;
allows also to vary the convergence of the wheels.

In fact, the axle is made up essentially by two axle shafts linked in the central device so as to take on a variety of angled positions.
If the lying posture of the axle shafts on angled configuration is on a vertical plane, we will have the incline variation of the wheel planes (for example increase of the distance of the contact points on floor and corresponding decrease of the distance of the top points).
If the lying posture of the axle shafts on angled configuration is out of the vertical plane, we will have, besides the incline variation of the wheel planes, also a convergence variation of the wheels.
Finally, if the lying posture of the axle shafts in angled configuration is on a horizontal plane, that is, parallel to floor, the wheel planes will be on a vertical lying posture and only the convergence can be varied.
Another important manufacturing feature is the fixing of the axle shafts in angled position to the plates parallel one another, which fix the wheelchair structure.
In fact, when the axles shafts are angled between them, they cross said plates not perpendicularly but on inclined manner.
It is to be underlined hereby that the ends of the axle shafts wchich cross the plates are externally threaded and therefore threaded ring nuts can fitted in them, after and before the plates crossing.
The fixing is obtained by screwing on the two opposite sides of each plate on the axle shaft (tubular) externally threaded, two threaded ring nuts which press against one of the two opposed faces of the plate, pairs of washers; one of these washers presenting a plane face and a face with spherical cap hollow, and the other washer presenting a plane face and a face with spherical convexity .
The washers of each pair, one of which ,as said above, presenting a spherical hollow face and the other a spherical convexity face, will implement, if in the male-female coupling the holes axles are coaxial, a body with the two external faces parallel between them; if instead the coupling is with the hole axles shifted one compared to the other, they will implement a body with the two external faces inclined between them (so taking a wedge-shaped configuration).
The higher the shifting of the hole axles , the higher the inclination of the external faces between them is.
As the washers adapt themselves in their coupling so as to take on an incline of their external faces complementary to the inclination with which the axle shaft crosses the fixing plate of the bearing structure of the wheelchair, the use of said pairs of washers (whose hole is positively increased compared to the external diameter of the axle shafts) allows by screwing in the ring nuts fitted on the axle shaft, to secure the said two pairs of washers (that placed on the inside surface and that placed on the outside surface) by force against the plate, so making the axle shaft consequently integral with the plate itself.
It is still to be specified that the ends of the axle shafts which appear to be threaded are engaged by screw in the tubular section of the axle shaft which is in the internal side under the wheelchair.
By screwing in or unscrewing the ends of the axle shaft from the tubular section with which it is coupled, you can vary or adjust the wheel track from one or both sides of the wheelchair.
What is stated above is clarified by drawing Tables attached.
Fig. 1 shows a wheelchair front view. It can be noticed that the axle is made up by the two axle shafts angled between them and the inclined bearing wheels with an increase of their distance from floor. You can notice the lowered pipe in order not to hinder the seat, which helps to keep the pipes in the bearing structure joined up.
Fig. 2 shows the wheelchair of the picture 1 on the backside. It can be noticed that the bearing structure is made up by two parallel pipes spaced out one from the other and placed one over the other.
Fig. 3 is an axonometric representation of the wheelchair which shows the back side and a flank.
Fig. 4 shows the wheelchair side view (the front drive wheels are not drawn). It can be noticed here too that the bearing structure is made up by two parallel pipes, spaced out from each other, placed one over the other.
Fig. 5 represents a schematization of a wheelchair side view which shows:

the bearing structure composed by a pair of parallel pipes spaced between them placed one over the other;
the linking plate of the two pipes provided with holes in the lower part for passage of the wheel axle;
the plate which elevates from the linking plate underneath, provided with a buttonhole and with a slit for the coupling of the bracket integral with the uprights of the backrest structure;
the side provided with a slit for handling;
the bracket which keeps the pipes of the bearing structure united, going down onwards, and which supports the fork of the driving caster.

Some holes can be noticed in the pipes of the bearing structure, This allows to adjust the seat depth.
Fig. 6 represents the wheelchair which is schematized in Fig. 5, where the succession of the positions taken on by the backrest and by the side between the upright position and the position leaning against the seat.
Fig. 7 represents the wheelchair which is schematized in the Fig. 5, now with removed side flank. It is shown that the plate fixing the pipes composing the bearing structure is provided with a set of holes placed on side of the central holes for the wheel axle. This set of holes allows the plate to be positioned in a different way compared to the pipes which make up the bearing structure.
Fig. 8 shows the bracket which keeps the pipes of the bearing structure united at the end of their slope on the front.
Fig. 9 shows the detail (enlarged) of the bracket integral with the uprights of the backrest structure , engaged with its pegs in the plate which elevates from the lower plate , linking laterally the pipes of the bearing structure and where the holes for the axle are provided. By fitting the above-mentioned bracket on the opposed upright of the backrest with a rotation by 180°, being the pegs spaced out from the upright axle, we can obtain a variation of the seat depth.
Fig. 10 shows separately what is represented in picture 9.
Fig. 11 shows out of coupling the rolled element of a flank, provided with hinging hole and with slit which represents the rail for its movement, linked to the movement which the backrest is enabled to do.
We have marked with 1 the pipes which make up the bearing structure; with 2 the plates linking pipes 1, making up the bearing structure, provided in the lower part with holes for the passage of the axle 19 of the wheels 15; with 3 the plates which elevate from the lower plates 2 provided with a buttonhole 5 and a slit 6 for coupling of pegs supported by brackets 4 integral with uprights 11 of the backrest 17; with 7 the rolled flanks provided with holes 8 and slits 9 for their synchronized movement with the movement of structure 11 of the backrest 17. With 12 and 13 the brackets which keep the pipes linked in the bearing structure at the end of their slope; with 14 the levers of the braking devices; with 15 the bearing wheels; with 16 the rings for the manual movement of the wheels 15; with 18 the seat, with 19 the angled axle wheels, linked in the central device 20; with 21 the drive castors, with 22 the footrest, with 23 the lowered crosspiece under the seat which links on the front side the pipes of the bearing structure; with 24 the washer with a spherical convexity face and with 25 the washer with a spherical cap, from whose coupling, by shifting the axle of the holes, we obtain a body with the external surfaces inclined between them; with 10 the crosspiece which links the backrest uprights.
From what described and illustrated, it comes out the remarkable extent of the innovation of this patent. Any creation, even improved, which an expert person would carry out when using the teaching of this patent, let remain into the patent.

Claims

Wheelchair for disabled persons with the adjusting of the lying posture of the bearing wheels, characterised in that the wheel axle is composed by two axle shafts (19) linked in the center by means of a pin (20) and which can be locked so as to take on a variety of angulations according to the results which you want to obtain as lying posture of the wheels (15) fitted on the end of said axle shafts (19).
Wheelchair for disabled persons with the adjusting of the lying posture of the bearing wheels according to claim 1, characterised in that, by positioning the hinging axle (20) of the two axle shafts (19) perpendicular to the plane where the axle shafts lie on angled configuration, if said plane is vertical, the lying posture of the wheels (15) fitted on end of said axle shafts (19), takes on slopes opposed between them, negative or positive, without any convergence or divergence in the forward movement direction of the wheelchair.
Wheelchair for diabled persons with the adjusting of the lying posture according to claim 1, characterised in that by positioning the hinging axle (20) of the two axle shafts perpendicular to the plane where the two axle shafts ( 19) lie on angled confirguration, if said plane is horizontal, the lying posture of the planes of the wheel (15) fitted on end of said axle shafts (19) takes on slopes opposed between them which cause only convergence or divergence in the forward movement direction of the wheelchair.
Wheelchair for disabled persons with the adjusting of the lying posture according to claim 1, characterised in that by positioning the hinging axle (20) of the two axle shafts (19) perpendicular to the plane where the two axle shafts ( 19) lie on angled configuration, if said plane is neither horizontal nor vertical, the lying posture of the planes of the wheels (15) fiited on end of said axle shafts (19) takes on slopes opposed between them which affect both verticality and horizontality.
Wheelchair for disabled persons with the adjusting of the lying posture of the bearing wheels according to one or more of the previous claims, characterised in that the extent of the slope of the lying posture of the wheels (15) depends on the extent of the angulation of the two axle shafts (19).
Wheelchair for disabled persons with the adjusting of the lying posture of the bearing wheels according to claim 1, characterised in that to fix the axle shafts (19) angled between them to the linking plates (2) of the bearing structure (1) of the wheelchair, on said axle shafts crossing (19) the plates (2), on a not perpendicular way, pairs of washers (24,25) spherical coupled between them, capable of taking on shapes to suit the required slope, tighten against the two faces of the plates by means of the ring nut screwed on the axle shafts externally threaded.
Wheelchair for disabled persons with the adjusting of the lying posture of the bearing wheels, characterised in that to contain the crosswise overall dimension, there are applied for the bearing structure of the wheelchair two pipes (1) of lower diameter instead of one of higher diameter, which run parallel, properly spaced out one over the other, which after having outlined the confirguration of the seat, go down on the front to support the footrest (22) and the brackets (12,13) which support the forks of the drive wheels (21).
Wheelchair for disabled persons with the adjusting of the lying posture of the bearing wheels according to claim 7, characterised in that the connecting of the two pipes (1) making up the bearing structure of the wheelchair is executed on the two sides by plates (2) screwed on the pipes, which are provided in the lower part with holes for the passage of the axle shafts (19) of the bearing wheels (15) and in the upper part (3) are provided each with a vertical buttonhole (5) and a slit (6) on the top, lined up with the buttonhole underneath (5) for the coupling of the pegs supported by the brackets (4) integral with the uprights (11) of the backrest (17) structure.
Wheelchair for disabled persons with the adjusting of the lying posture of the bearing wheels according to claim 7 or 8, characterised in that the backrest (17) with an initial raising upwards, separates from the plate (3) with a buttonhole (5) and slit (6) and can be folded over onwards, leaning against the seat (18).
Wheelchair for disabled persons with the adjusting of the lying posture of the bearing wheels according to claim 7 or 8 or 9, characterised in that the sides (7) approximately shaped on top as armrests are made up by rolled sections hinged (8) on top to the uprights (11) of the backrest (17) and provided with a long slit (9) which engages in a peg, having head fixed to one of the pipes (1) of the bearing structure, this long slit being configurated in such a way that, by the folding over of the backrest against the seat, the sides are lowered concomitantly sliding downwards.