FR2783463A1 - Rolling support for medical usage, has wheel held by bracket mounted on support shaft, carried in spring loaded sliding housing, which has lower edge profiled to fit on to roller cam fitted to support shaft. - Google Patents

Abstract

The rolling support for medical transport consists of an assembly of pivoting wheels, of which, at least one (4') is designed to be locked into a preferred direction of rolling. This wheel is carried in a bracket (6), fixed to a shaft (5), which is normally free in rotation, around its own axis. A collar (7) is mounted to slide on the shaft and spring loaded towards the wheel. The lower edge of the collar is provided with a cam housing (72), designed to cooperate selectively with a roller (51), fitted on the shaft.

Description

The present invention relates to a device for medical use or

  paramedic of a person's rolling support, such as a bed, an armchair or a stretcher.

  In particular in hospitals or nursing homes, it is widely used to provide beds provided with swivel wheels capable of facilitating movement, for example from a bedroom to an examination room, etc. Similarly, patient support stretchers, as well as

  wheelchairs for people with reduced mobility are fitted with such swivel wheels.

  As soon as the movement of these devices takes place substantially in the

  same direction, the operation is relatively easy.

  On the other hand, we encounter difficulties when it is necessary to make a change-

  direction, for example to go from a room to a corridor, etc. We have already proposed beds equipped with four wheels with integrated brake, which

  can be operated by a single pedal usually located on the side of the footboard.

  One of the wheels has an additional function called "directional", which means that it can be locked in the direction of movement of the bed, without being able to pivot on itself as do the other wheels. This blocking is enough to give the bed a uniform direction,

  so its movement is greatly facilitated.

  In fact, this system prevents oversteering of the bed due to the weight of the patient.

  In practice, the pedal is able to occupy three positions. The first is that in which the four wheels are crazy in rotation, that is to say can adopt

any orientation.

  The second is the one in which a wheel is directional and the three

others are crazy in rotation.

  Finally, the third is that in which all four wheels are braked.

  In use, it turns out that this system forces users to activate

  often the pedal during bed transfers.

  But the directional position is very little used because the depressing on the pedal during the displacement of the bed is a very ergonomic maneuver and not really

  known to hospital staff.

  Other systems include an operating lever which actuates a

  cam housed inside a journal on which is fixed a yoke which equips the wheel.

  Again, it is necessary to intervene positively on the lever to

  put the wheel in a directional position, which is not very practical.

  Document FR-A-2 479 104 describes a device for recalling

  automatically the swivel wheels of a manual carriage in a specific direction.

  Each swivel wheel is mounted in a yoke articulated around an axis

  vertical, relative to a fixed support integral with the base of the carriage.

  The yoke is provided with a cylindrical rod which is arranged perpendicular to the

  rement to the axis of rotation of the wheel. On this slide two shoes biased towards each other by two coil springs acting in opposite directions. They rest elastically on a cam made up of two spaced fingers, arranged between the hooves

  and integral with the fixed support of the yoke.

  Such a device is capable of occupying two equilibrium positions angularly 90 apart. It operates in "all or nothing", which means that the wheels fitted with such a device cannot occupy an intermediate position between the two equilibrium positions. This is inconvenient when it is desired to move a bed equipped with such a device, for example in a "biased" direction, between the two directions.

  corresponding to the equilibrium positions.

  The purpose of this is to overcome these drawbacks.

  In other words, it aims to provide a device for medical or paramedical support for the rolling support of a person, such as a bed, an armchair or a stretcher, of which at least one wheel can be made directional automatically, without ,

  however, this does not prevent the wheel from occupying, if necessary, other positions of equilibrium.

  This device is of the type which comprises a set of pivoting wheels of which at least one is capable of being chocked in a preferred direction of rolling, this wheel being articulated on a yoke, with an elastic system with cam and cam follower capable of chocking said wheel in said preferred direction of rolling, but capable of authorizing the angular spacing of the wheel with respect to this direction, under the effect of a

  effort directed essentially transversely to said direction.

  According to the invention, the yoke is fixed to a pin normally movable in rotation about its own axis and the system comprises a sleeve mounted sliding on said pin and resiliently biased towards the wheel, the lower edge of which comprises at least one cam path. , able to cooperate selectively with a rotating idler roller which

equips the journal.

  It therefore suffices to guide the device in a direction essentially perpendicular to the previous one so that the wheel passes from the position where it is chocked in a preferred direction of rolling to a position in which it can orient itself dc

  in any way, and vice versa.

  There is therefore no lever or operating pedal to operate, but only to effect a change of direction of the device, operation already implemented

  work by hospital staff with beds already known so far.

  Furthermore, according to other advantageous and non-limiting characteristics of this device: - said sleeve comprises two identical cam tracks which each cooperate with a roller, these rollers being arranged in a diametrically opposite manner, on either side of said pin; - Said cam track has the shape of a half-moon cutout, the concavity of which is directed towards the wheel; - The shape of the cut is such that said elastic system tends to bring the wheel in said preferred direction as soon as it occupies an angular position distant from said direction, at most 20; - Said elastic system comprises a spring interposed between said sleeve and a fixed element of the device, which tends to bias the wheel in the direction of the sleeve; - It comprises a wheel capable of being chocked in a preferred direction of rolling, on the side corresponding to its direction of advance, said pin being immobilized in translation along its own axis;

  - its two wheels placed on the side corresponding to its forward direction

  surround are likely to be stalled in a preferred direction of travel; - It includes an additional wheel capable of being chocked in a preferred direction of rolling, said pin being movable in translation along its own axis; - said additional wheel is placed on the side corresponding to its direction

advancement.

  Other characteristics and advantages of the invention will become apparent on

  reading of the detailed description which follows of a nonlimiting example of embodiment.

  This description will be made with reference to the accompanying drawings in which:

  - Figures 1 and 2 are simplified perspective diagrams of a bed equipped with an elastic system according to the invention, caused to be moved in two different directions of advancement: - Figures 3 and 4 are views in exploded perspective of said system,

  respectively in the privileged rolling position and in a so-called "multi-position

  directional ", the system equipping a so-called" additional "wheel; - figure 5 is a view similar to figure 3, the system equipping a wheel usually present on the device; - figure 6 is a diagram representing in perspective, the silhouette of a

  wheelchair, the two front wheels of which are fitted with the elastic system.

  As specified above, the present invention relates to a device for medical or paramedical support of a person's rolling support, such as a bed, a

armchair or stretcher.

  The expression "for medical or paramedical use" means both a device intended to be used in a hospital, a nursing home or a retirement home, as well as a device making it possible to support, while driving, a

  person with reduced mobility, whether this handicap is temporary or lasting.

  By the expression "stalled in a preferred direction of travel", is meant the possibility for a wheel to turn around its own axis, without being able

  rotate to occupy any orientation.

  Finally, "multi-directional" means the possibility for the wheel

  to occupy any orientations.

  Referring to Figures 1 and 2, said device according to the invention consists of a bed 1 for medical use including the bed base 2, equipped with foot panels and headboard

and 21, wears a mattress 23.

  This bed base rests on a metal frame 3 formed of longitudinal members and cross members which, in the representation of Figures I and 2, is detached from the bed base 2. It is of course here a freedom of representation intended to simplify the drawings for

  illustrate the object of the invention more clearly.

  In a manner known per se, the chassis 3 has the shape of a quadrilateral, in

  the occurrence of a rectangle, with a swivel wheel at each angle 4.

  According to the invention, this chassis is equipped with a fifth wheel

  additional 4 'which is likely to be wedged in a preferred direction of travel

ment, as will be seen below.

  This additional wheel is placed on the chassis, in a place where it is not likely to hinder the passage of equipment such as a table on casters, etc. It is preferably located on the side of the bed which corresponds to its direction

normal progress.

  Thus, if it is planned to move the bed with the "headboard" side facing in the direction of advance, the additional wheel will preferably be provided, but not

necessarily on this side.

  According to the invention, this bed comprises an elastic system with cam and cam follower, which is capable of wedging the wheel 4 ′ in a preferred direction of rolling, while being capable of allowing the angular spacing of this wheel 4 'with respect to the preferred direction, under the effect of an effort directed essentially transversely with respect to this direction. Referring now to FIG. 3, a cross-member 30 of the

  bed frame 3, which extends parallel to the foot and to the headboard 20 and 21.

  On this crosspiece is fixed a support piece 31, of square section and

  with a vertical axis, traversed by an axial bore 32.

  In this support piece is partially engaged the pin 5 of the aforementioned wheel 4 '. In fact, it is an upper part 50 of this trunnion, of form

  cylindrical and of reduced diameter, which is engaged in the bore of the support part 31.

  The pin 5 can move in rotation on itself and in translation along its longitudinal vertical axis. Means not shown, for example of the type

  screws cooperating with a groove, make it possible to limit this displacement in translation.

  The lower part of the trunnion 5, of larger diameter and also cylindrical, carries at its lower end a "U" yoke 6. It is the base 60 of this yoke which receives said trunnion, while its parallel wings 61, vertical and directed

  down, receive the rolling axis of the wheel 4 '.

  According to the invention, the elastic system with cam and cam follower mentioned above, includes a sleeve 7 which is slidably mounted on the

pin 5.

  In the case shown here, it is an elongated piece of material

  plastic, of approximately square section and pierced with an axial bore.

  Between its planar upper face 74 and the support part 31 is interposed, surrounding the cylindrical rod 50, a helical spring 8. It is easily understood that this spring tends to slide downwards, that is to say in the direction of the 4 'wheel, the

  sleeve, as symbolized by the arrow f in Figure 3.

  Said sleeve therefore has two pairs of vertical, parallel faces

  between them, numbered 70 and 71 respectively.

  Its lower face 73 extends parallel to the upper face 74 and is not

not strictly flat.

  Indeed, it has, opening onto the faces 70, two identical cam paths 72 in the form of half-moon cuts, the concavity of which is directed towards the wheel 4 '. These cutouts constitute two parallel "grooves" arranged on the side and

other of its axial bore.

  Furthermore, the pin 5 is equipped with a pair of identical rollers 51, idle in rotation, the rolling axis of which is horizontal, that is to say perpendicular to the pivot axis of said pin. These rollers are arranged diametrically on the side and

  on the other side of the journal, so as to be able to cooperate with the cam tracks 72.

  This is also the position shown in Figure 3. This cooperation between the cam tracks and the rollers, is opposed to the-pin 5 can freely rotate about its own axis. In this way, the wheel 4 'is wedged in one direction

  privileged bearing symbolized by the double arrow g in Figure 3.

  This positioning corresponds for example to the situation in FIG. 1, the

  bed can only be moved longitudinally along a corridor.

  It is sufficient that only one wheel 4 ′ is equipped with the elastic system for the other wheels to adopt the same orientation. However, it is of course possible

  to equip two or more wheels.

  According to the invention, the elastic system is nevertheless capable of authorizing the angular spacing of the wheel 4 'relative to the preferred direction of the arrow g. Indeed, the setting force of the spring 8 is calculated so that under the effect of a force directed essentially transversely to the direction

  privileged bearing, we can make the 4 'wheel "multidirectional".

  This means that it suffices to direct the device, in this case the bed, in a direction generally perpendicular to the previous one, so that the wheel 4 'does not occupy

  plus its privileged rolling direction.

  In doing so, the rollers 51 tend to roll against the cam tracks 72, so that the pin 5 can pivot more than a quarter of a turn. The rollers are then in direct contact with the flat regions of the lower face 73 of the workpiece.

  plastic material 7. Thus the wheel 4 ′ can occupy multiple rolling directions.

  However, the profile of the cam track 72 has a radius large enough for the elastic system to tend to bring said wheel in the preferred direction, as soon as it occupies an angular position distant from this direction, at least

plus 20.

  It is possible to modify this profile so that the elastic system tends to bring the wheel back towards the preferred direction, when it occupies an angular position.

  more distant, for example of the order of 30 to 40.

  Of course, if we want to give the wheel 4 'the direction again

  privileged bearing mentioned above, it suffices to print in the bed a perpendicular directed force-

lie to the previous direction.

  In order to further improve the displacement of said support, it is of course very useful to provide that the vertical plane in which the horizontal axis of rotation of the wheels 4 and 4 ′ is contained is offset with respect to that which contains the vertical axis pivot

pin 5.

  In addition to its reminder function of the part 7 in the direction of the wheel 4, the spring 8 also contributes to keeping the wheel 4 'applied against the ground. Thus, whatever the configuration of the terrain on which the bed is moved, we are sure to have at least four of the five wheels that carry on the ground, which thus ensures perfect stability of the whole. The central position of the fifth wheel 4 ′ also improves the maneuverability of the bed, since the latter can easily pivot around a vertical axis passing through the point of contact of this fifth wheel, while reducing the turning radius. Of course, in a different embodiment, it is one of the four

  usual wheels of the bed which is provided equipped with said elastic system.

  The system shown in Figure 5 differs from the previous one in that it equips a wheel usually present on the bed, for example one of its four wheels. In this case, there is provided an elastic ring 33 engaging in a groove provided in the pin 5 and intended to oppose the movement in translation along the vertical axis of the latter. The system is said to be "non-floating". It is also

  interposed between the part 7 and the part 31 a ring 52 facilitating the pivoting of the wheel.

  This description has been made with reference to a hospital bed, but it is

  quite obvious that the present invention applies to any rolling support device with

medical or paramedical use.

  Thus, there is shown in Figure 5, the perspective silhouette of a wheelchair 1 'whose two front wheels 4' are equipped with said elastic system

"not floating".

Claims (9)

  1. Device for medical or paramedical use of a person's rolling support, such as a bed, stretcher or armchair, which comprises a set of swivel wheels (4, 4 ') of which at least one (4') is capable of being wedged in a preferred direction of rolling, this wheel being articulated on a yoke (6), with an elastic system (7; 51) with cam and cam follower capable of wedging said wheel in said preferred direction of rolling, but likely to allow the angular spacing of the wheel   relative to this direction, under the effect of an essentially transverse directed effort-   ment to said direction, characterized in that the yoke (6) is fixed to a pin (5) normally movable in rotation about its own axis and that the system comprises a sleeve (7) mounted to slide on said pin (5) and resiliently biased towards the wheel, the lower edge of which comprises at least one cam track (72), capable of cooperating   selectively with a madly rotating roller (51) which equips the pin (5).   2. Device according to claim 1, characterized in that said sleeve (5) comprises two identical cam tracks (72) which each cooperate with a roller (51), these rollers (51) being arranged in diametrically opposite manner, of go and other of said pin (5).   3. Device according to claim 1 or 2, characterized in that said cam path (72) has the shape of a half-moon cut, whose concavity is directed towards the wheel.   4. Device according to claim 3, characterized in that the shape of the cutout is such that said elastic system (7; 51) tends to bring the wheel (4 ') in said preferred direction as soon as it occupies a position angular away from said management, not more than 20.   5. Device according to one of claims 1 to 4, characterized in that   that said elastic system (7; 51) comprises a spring (8) interposed between said sleeve (7) and a fixed element of the device (31), which tends to bias the wheel (4 ') towards the sleeve (7).   6. Device according to one of claims 1 to 5, which comprises a   chassis (3) in the form of a quadrilateral, each angle of which is provided with a wheel (4, 4 '), characterized in that it comprises a wheel (4') capable of being wedged in a preferred direction of travel, on the side corresponding to its direction of advance,   said pin (5) being immobilized in translation along its own axis.   7. Device according to claim 6 which consists of a wheelchair (1 '), characterized in that its two wheels (4') placed on the side corresponding to its direction of advance are likely to be chocked in a preferred direction of rolling.   8. Device according to one of claims 1 to 5, which comprises a   chassis (3) in the form of a quadrilateral, each angle of which is provided with a wheel (4), characterized in that it comprises an additional wheel (4 ') capable of being wedged in a preferred direction of rolling, said journal (5) being movable in translation along its own axis.   9. Device according to claim 8, characterized in that said wheel   additional (4 ') is placed on the side corresponding to its direction of advance.