WO2004108046A1

WO2004108046A1 - Wheelchair without metal components for the physically handicapped

Info

Publication number: WO2004108046A1
Application number: PCT/ES2004/000251
Authority: WO
Inventors: Agustin Gual De Torrella Le-Senne
Original assignee: Detect 21 España S.L.
Priority date: 2003-06-05
Filing date: 2004-06-02
Publication date: 2004-12-16
Also published as: ES2255348A1; ES2255348B1

Abstract

The invention relates to a wheelchair without metal components for the physically handicapped, which is preferably made of plastic and comprises a body, rolling means and accessories. The body is preferably configured as a single piece and serves as support for the rolling means and the accessories. The rolling means comprise a front wheel assembly consisting of one or two small pivoting wheels and a back wheel assembly having two wheels that are provided with drive means joined by clips and braking means. The pivoting wheels comprise a support with a fixed friction bearing and a pivoting rod, in addition to two parts with running surfaces that are connected to one another by means of a clip, one of said parts having a movable friction bearing. The back wheels are supported on the body by means of polymer bearings that are mounted on lateral supports, means being provided for axially fixing said bearings. The invention can be preferably used in airport security controls and corrosive environments.

Description

WHEELCHAIR WITHOUT METAL COMPONENTS FOR PHYSICAL DECREASES

The present patent falls on a wheelchair without metal components for the physically handicapped, with the particularity of having absolutely no metal parts or components.

The chair consists of body, bearings and accessories. The body of the chair will fulfill two basic functions:

On the one hand it will be the seat where the user will be located. As such you must be comfortable and comply with ergonomics standards.

On the other hand it will be the only structural element that will support the dynamic and static loads resulting from! User weight and speed and accelerations of the set.

So we must achieve a resistant element that supports these loads and whose shape is appropriate for the transport of people. And all considering that we can not use any metal component.

A solution for this purpose would be to make the entire body of a polymeric material so that it could be obtained from a single plastic injection mold so that the piece would come out directly when unmolding. In this way we would obtain a relatively cheap and easy to manufacture body.

In principle, what has been thought of is a monocoque siSSa formed of plastic foams. This has the advantages of being lightweight while resistant and easily moldable. On the other hand, these types of materials have the advantage of being aseptic, which enables the chair for use in hospitals. On the other hand, different types of foams could be combined to make the chair more comfortable. For example, soft foams could be used that covered a structure of a stronger foam thus increasing the comfort of the chair.

As we mentioned in the initial introduction, the shoots are divided into two clearly differentiated types, which are the front and rear wheels. The front are characterized by being responsible for maintain the balance of the chair as well as guide it (they are the steering wheels), while the rear wheels are responsible for both supporting most of the load that supports the chair as well as transmitting the movement of movement, in case it is the handicapped person who moves. Thus, in order to fulfill these tasks it is clear that its design must be totally different.

Advantage:

The advantages of the present patent are derived from this descriptive report, although below we cite the most essential ones with a purely enunciative and non-limiting nature, namely:

- On the one hand, a wheelchair that can go through security controls that are based on metal detection. These controls are very common and effective and prevent unwanted weapons or metal objects from being introduced into public enclosures (airports, soccer fields ...). Currently, a user of a wheelchair, to pass these types of controls, is forced to get out of the chair helped by the companions, and pass the detector. At the same time, the chair is inspected by security agents to verify that no type of weapon has been hidden between the chair's irons. This procedure is extremely uncomfortable for the disabled and very unreliable in terms of the detection of weapons, since it could easily hide tubes or other parts that would not be detectable by a simple visual inspection.

On the contrary, a chair without any metallic part could pass through the control without bothering the user and it would be impossible to pass any metallic object since it would be detected by the control itself. So it would be a more comfortable and much safer solution for the passage of physically handicapped by security controls.

- On the other hand you get a chair that gives absolutely no problem in environments or adverse uses for metal, such as in boats, where the salinity and humidity of the environment quickly oxidize metal objects or hospitals, where patients shower in the chair. And thus any use in which the deterioration of the metal is a problem. This report is not intended to describe the description of an embodiment with one of the possible designs of this invention.

For a better understanding of this report, the accompanying drawings that show an example of non-limiting embodiment of the object of the invention and in which:

Figure N ° 1 is a diagram of the body of the chair with its rolled components.

Figure IM ° 2 represents the chair body in section and perspective.

Figure 3 represents a side view of the body of the chair. Figure 4 is a schematic and perspective view of the support.

Figure 4 is a schematic view of the support of the chair body.

Figure 5 is a view of the wheel axle.

Figure 6 is the brakes, with an external view and a vertical cut.

Figure 7 represents the means of driving the user. Figure N ° 8 represents the footrests.

Figure 9 is a perspective of the brake and its adaptation to the wheel.

According to the attached designs, the chair object of this patent will consist of three main parts, which will be: - The body of the chair (Ref. 1 of fig. 1), which is properly the part where the user feels

- The bearings (Ref. 2 of fig. 1) which includes the wheels and all the necessary elements to achieve a smooth and easy rolling. We find two types of totally differentiated shoots, which are the front and the rear.

- And all the accessories that, while not essential for the operation of the chair, are very useful and helpful. These would be essentially the brakes (3), grips (4), handles (5), footrests (6) and armrests (7).

As an example in the designs, a simple shape and geometry appears that would be easy to manufacture from a mold, either for a plastic foam or for any other type of moldable plastic (eg PP) of the body (Fig. 1 )

In illustrations 1 and 2 of figure 2, two views of this body can be seen that would come directly from the mold. It should be noted that although there is only one support for the front wheels (Ref. 8 of fig. 2), it would be exactly as feasible to put two front wheels so that the stability of the chair was ensured. However, putting one alone would reduce production costs, as we will see, the assembly of the wheels is not easy. Also in Figures 2 and 3 the sections of the previous views are seen. Thus, the distribution of the materials can be observed, giving more thickness to the parts that will bear more load (union between the backrest and the seat). It is also clear that the sides (3) are, on the one hand, the wheel supports, on the other they are the armrests and they are also a necessary reinforcement for the entire structure of the chair, which provides the necessary stiffness and reliability. It is clear that these sides are basic in this design. Thus, in the event that due to their size or due to mold issues, it was not possible to leave them directly from the mold, they should be separated and joined to the seat by welding (if materials permit), polymeric screws or any other system that allows that fixation. In this way different materials could be used for the seat and for the sides, being able, for example, to use softer materials for the seat (softer foams) thus making it more comfortable and more resistant materials on the sides. After unmolding the chair there is a rough body (1), with the supports for the axes and the basic structure. This should be reworked. So, the Bearing housings for large wheel axles (9), or small wheel housing (10), must be machined to provide them with the necessary tolerances and even, depending on the material we use to manufacture the body, They should add more resistant caps that support without wearing down the demands of the accommodations. Likewise, they should be prepared for certain additives such as the armrests, footrests, handles to push the chair or other additions that have to be made.

If, for economic or technical reasons, this type of design is not feasible, it is possible to use structures of generic bars or other solutions that meet the requirement of not using any metallic component.

Breaks:

The tread consists of front and rear train Front train: In the figures you can see an example of a chair with a single front wheel. This is due to a simple cost reduction. In case of instability in the chair, it would be easy to introduce a second front wheel. Next, a possible wheel design is developed that would allow a perfect shoot as well as the basic requirement of not containing absolutely any metallic components. Any similar assembly that could be cheaper or for any reason more suitable for this function, would also be valid in this patent.

Thus, this design consists of a general support (Ref. 8 of Fig. 2) which is the one that by means of a bearing (standart) in the upper part (figure 9) will be subject to the supports that remain in the lower part of the body of the chair and that have already been reworked to house said bearing (10 of figure 2). This support may be of a normal material that is not excessively expensive, resistant and can be injected obtaining acceptable tolerances. This piece will not be much in demand and will suffer little wear as we will see later. That is why an easy to obtain and cheap piece is intended. The central cavity of this support will be mounted bearings 11. These will be of a more resistant material (for example Nylon 66) since they will be tightened to the support and will serve as a slide to the bearings 12, which will be mounted on the piece 14, but will not require much tightening. So, we will have a set of bearings that will roll over each other. The bearings (2) will be stationary (so they will be fixed and tight to the support) and the bearings 12 will be the ones that will roll. The internal bearings must be of different materials from the external ones, and being the mobile bearings, they may be of a less hard material (eg DELRIN 500). This set of materials (the Nylon with the DELRIN) has a low coefficient of friction, which provides a smooth slip and without too much rolling resistance. Anyway any set of resins or other materials that provide good friction, wear little over time and withstand possible shocks due to potholes or other irregularities, would be equally useful in this application. To finish the assembly of this train, the piece 13 is adjusted, which is an axle finished in a clip, so that it will be responsible for holding the entire assembly together.

Both piece 14 and 15 will be finished off with a more elastic tread (4b and 5b of Figure 3) (for example of a synthetic resin or any type of rubber that is sufficiently resistant). These treads must be mounted so that they do not escape the rims "in curves or axial loads. Thus, streaks can be made on the rim or any type of shape that prevents displacements in the axial direction of the tires.

Rear Train

As we have said before, this will be responsible for supporting most of the load that the chair can withstand. In addition, in a state of charge, you should roll smoothly and smoothly. For this, as will be detailed below, a solution based on a combination of polymer bearings in series production has been used. These are naturally expensive, but guarantee smooth train operation In addition to being able to support the weight of up to 200kg without deteriorating. The assembly is explained in detail below:

In fig. 4 you see a section that will be referenced throughout the following explanation. Thus the assembly consists of the wheel (15) "which includes the tire (Ib) and the axle (le). Two polymeric standard bearings" (11), ^Λ a bearing cover "(17) ^{w and} an axle cover" ( 18) and ^λλ a standart key ". Apart, of course, the bearing holders (5a and 5b) that have already been mentioned in the section ^w chair body".

Thus, the wheel 15 will be a polymeric wheel (composite) like those manufactured in series, being able to be 24 ", 22" or any other measure. This presentation has been made by taking a standard 24 "wheel to which any of the normal Ib tires (solid so that there is no type of metal valve) could be mounted. So starting from a standard wheel should be" join "an axle either by welding or modifying the tool (molds) and directly manufacturing the wheel with the axle or even with clips or other type of joint that although not as resistant, is able to withstand what is necessary. This way we would have a set that would already be the wheel and axle attached. In this case the axle is 50 mm in diameter and of course it should be of a non-metallic material, ideally, polymeric (since it will withstand more shocks due to irregularities of the ground better than the ceramic materials, characteristic for its rigidity.) Depending on the material used, the diameter may be more or less thick.In any case, a 50mm shaft is oversized and may be normally use smaller diameters, but in this way the largest possible diameter is represented, which with any single material (any polyamide, PP, POM, PET or other simple material) would withstand the stresses to which it can be subjected. The bearings chosen in this design are ball bearings that are already manufactured in series. So it could be bearings whose hoops were made of POM (or PPS), the PA or PPS cage and the AISI 316 balls. These combinations are, for example, widely used in the automotive industry. normal temperatures However, any other combination of materials that endures sufficiently would also be acceptable.

Also the chosen bearings are oversized and could withstand loads of up to 1300 N under dynamic loads. However, for that measurement of axes they would be the only fit.

Thus, the shaft must be constructed with the necessary tolerances to house the bearings or if these tolerances cannot be obtained directly from the factory, the shaft must be reworked until it is achieved. However, if we design the shaft of equal diameter along its entire length, it will be difficult to mount the bearing 2b, since to mount it in its situation it must slide along the entire axis. On the other hand, the bearing 16 ^ΛΛ will always be less subdued than the 16 b, which will always be the one that holds most of the load. But this will be the farther a bearing is from the other. Thus, the ideal solution would be to mount a bearing 16 b larger than 16 ". At least it must have an internal diameter larger than 16. This will greatly facilitate the mounting of the bearings and reduce the cost of the axes should it be necessary to rework it, since it will not be necessary to rework the axle along its entire length and it will be enough to turn the bearing seats, so that the axis would be as specified in Figure 5.

Once the bearing 16 b has been located at the end of the shaft (being in contact with the end chamfer), the tube 18 will be coupled, whose mission will be to fix the position of the bearing 16 with that of the 16 b _f so that no have relative movement in the axial direction. In this way the bearing 16 b (which is the free bearing of the assembly) will not escape from the housing 5b.

The resulting assembly (wheel plus axle plus bearing 16 b plus clamping tube 18) will be mounted in its housings so that the bearing 16 b in the recess 5b. Then we will introduce bearing 16 and fix it with a 6 'key. In this way the axis will already be fixed and will not be able to move towards the outside of the chair, but it will I could move in. To avoid this movement we will mount the cover 17 that will be fixed with polymeric standard screws.

In this way the shafts will roll perfectly since we will have the free bearing set (16) and will have the forces compensated in the axial direction thanks to the 6 'key and the cover 18. In any case these two measures will not be able to withstand axial forces excessively high, since the most important forces will be given by the weight of the chair patient plus the possible irregularities of the floor (potholes, steps ...) in the radial direction. If it were found that more axial endurance is necessary, other solutions such as polymer nuts threaded to the shaft could be used instead of more reinforced cotters and covers attached to the chair by means of screws and dowels. This will be something that should also be defined based on the materials used to build each of the elements. Thus, a possible bearing assembly is defined that would meet all the requirements imposed in this design. However, any other variant that also complies with the requirements would be equally valid.

Grips (Fig 7):

The function of these grips is to make it easier for the person sitting in the chair to propel themselves without anyone's help. So in the figure you can see the arrangement of this grip that will be hooked to some holes in the wheels by means of several clips. Otherwise you could screw or weld or glue or look for any other simple solution to achieve this bond.

Handles: These cavities will be practiced in the body of the chair and if necessary (depending on the material of which the body of the chair is made) it will be covered with some type of padded material. This way we will get more comfortable handles.

Footrest (Fig. 8): This is a very important piece to make the chair more comfortable and safe. Thus it will be necessary for these footrests to be foldable to facilitate the user the operation of sitting as well as that of getting up. In this way, when carrying out any of these operations, the footrests must be raised, so that the user can get as close as possible to the seat of the chair and not have to drop on the chair.

Thus, the mechanism of this folding is simple and is visualized in fig. 8: It will consist of some "horns" that will be fixed to the chair by means of the mechanism illustrated. On these horns the platforms where the feet are supported will be inserted so that the set works like a hinge.

To support the feet on the platforms, these will be lowered until they rest on a small projection that will be fixed to the chair.

Armrests: These will be two soft and white additions that will be attached to the upper part of the sides of the chair. So they will be screwed or otherwise attached to the chair.

Accessories

Brakes (Fig 9): The brakes are of great importance. Its function is clearly to immobilize the chair and they are of great importance when it comes to lifting or sitting the patient as well as when the chair is stopped on slopes or even on a level.

The brakes shown in Figure 9: They consist of a gear ring (15) that will be integral to the rear wheel axle, a brake shoe (16) that will be attached to the crown to brake by means of a lever (17) that will activate the user, so that the shoe will slide through guides (18) that are in solidarity with the chair. In this way, when the brake is activated (the tips of the crown matching the recesses of the shoe) the wheel will be fixed located on the bearing 16 b in the end of the shaft (being in contact with the end chamfer), the tube 18 will be coupled, whose mission will be to fix the position of! bearing 16 with that of 16 b, so that they have no relative movement in the axial direction

Claims

I ^a .- "Wheelchair without metal components for the physically handicapped" preferably performed on the subject! plastic characterized by consisting of a body, bearings and accessories. The preferably single-piece body whose sides are simultaneously armrests and wheel supports. The body will have the necessary tires to support the armrests, footrests and handles to push the chair.

The treadings consist of a general support (Ref. 8 of fig. 2) which is the one that by means of a bearing in the upper part (figure 9) will be subject to the supports that remain in the lower part of the body of the chair. In the central cavity of this support the bearings 11 will be mounted. These will be of a more resistant material, since they will be tightened to the support and will serve as a slide to the bearings 12, which will be mounted on the part 14. The bearings (2) will be stationary and bearings 12 will be the ones that will roll.

There is an adjustment piece 13 that ends in a clip. Both piece 14 and 15 will be finished off with a more elastic run (4b and 5b of figure 3).

2 .- "wheelchair without metal components for physically handicapped" characterized in that the rear train consisting of rolling wheel (15)

"which includes the tire (Ib) and the axle (le). Two polymeric standart bearings" (11), "a bearing cover" (17) "an axle cover" (18) and "a standart key", A part , of course, the bearing holders (5a and 5b). The resulting assembly (wheel plus axle plus bearing 16 b plus clamping tube 18) will be mounted in its housings so that the bearing 16 b in the recess 5b. Then we will introduce bearing 16 and fix it with a 6 'key. In this way the axis will already be fixed and cannot be moved towards the outside of the chair, but it could be moved inwards. To avoid this movement we will mount the cover 17 which will be fixed with standard polymer screws. 3 .- "wheelchair without metal components for physically handicapped" as first and second claim characterized in that the chair is provided with means normal drive attached to the wheels by several clips.

4 ^a .- "Wheelchair without metal components for physically handicapped" according to claim one to third characterized in that it will be equipped with morbid handles as well as folding footrests.

It will also be equipped with armrests.

5 .- "wheelchair without metal components for physically handicapped" according to claim one to four characterized by being provided brake consisting of a ring gear (15) to be secured to the axle of the rear wheels, a brake shoe (16 ) which will be attached to the crown to brake by means of a lever (17) that the user will operate, so that the shoe will slide through guides (18) that are in solidarity with the chair.