WO2001001912A1

WO2001001912A1 - Wheel stretcher

Info

Publication number: WO2001001912A1
Application number: PCT/SE2000/001265
Authority: WO
Inventors: Bror Erik Andersson
Original assignee: Bror Erik Andersson
Priority date: 1999-06-18
Filing date: 2000-06-16
Publication date: 2001-01-11
Also published as: SE514570C2; SE9902317L; SE9902317D0

Abstract

Wheel stretcher for transportation of a patient, comprising a framework (1) and a pair of wheels (11) attached to the framework. The wheels (11) are displaceably arranged relative to the framework (1) in its longitudinal direction.

Description

WHEEL STRETCHER

DESCRIPTION

FIELD OF THE INVENTION AND PRIOR ART

The present invention is related to a wheel stretcher for transportation of a patient, which stretcher comprises a framework and a pair of wheels attached to the framework.

The notation transportation of a patient shall be interpreted in a wide sense and comprises all kinds of transportation where different types of transportation vehicles or ambulance vehicles are used, and the wheel stretcher is used for moving sick or injured persons to and from as well as in and out of the vehicle. Preferably, said pair of wheels shall be used as a support against the ground in connection with said moving.

Previously known wheel stretchers of this kind and different ambulance vehicles are often arranged to make it possible to insert and position the wheel stretcher in the ambulance vehicle with the sick or injured person still lying or sitting on the wheel stretcher. For this purpose, wheel stretchers according to prior art are provided with further support wheels. Those could be arranged in one or both ends of the stretcher and could be mounted in the framework of the stretcher.

According to prior art, it is known to arrange a pair of wheels for use as a support at said moving of sick or injured persons in one end of one or a plurality of bars which are pivotably arranged relative to the framework of the stretcher. Thereby, it is possible to pivot the bar or bars and lock it/them in a position so that it/they forms/form support legs for the stretcher. According to prior art, the pair of wheels at the end of the legs has a quite small diameter. Thanks to their small diameter they require a small space which facilitates the movement of the legs to a position close to the framework when the stretcher is to be placed in an ambulance vehicle. Since the wheels are so small, it is difficult or even impossible to move the stretcher on the wheels on extremely soft or uneven grounds or in stairs when a person of normal weight is placed on the stretcher.

Stretchers according to prior art could be provided with handles which are telescopic from one end of the framework. When only one person handles the stretcher with a sick or injured person lying on it, the handles could be pulled out and work as lever arms for the person who is handling the stretcher to achieve balance or a, for the purpose appropriate, weight distribution over said pair of wheels. The position of the wheels is often displaced in a direction towards the end of the framework where said handles are arranged, which often results in that the person handling the stretcher has to press down the handle towards the ground to achieve such a balance or another suitable weight distribution. The force directed against the ground from the pair of wheels is then the sum of the weight of the stretcher, the weight of the person lying on the stretcher, and the downward force on the handle applied by the person who is operating the stretcher. This total force directed against the ground is often considerable and is, of course, increasing the difficulties when the stretcheris rolled on a soft or uneven ground.

SUMMARY OF THE INVENTION

The object of the present invention is to obtain a wheel stretcher

^{ comprising a framework and a pair of wheels attached to the framework, whereby the wheels are arranged in such a way fa- cilitating the handling of the stretcher with a person lying/sitting on it and the pair of wheels are used as support wheels during the movement of the stretcher on a ground, such as an earth surface, a floor, a stair, or similar. Mainly, the stretcher shall be so constructed that a position of balance of the stretcher is easier achieved for a single person handling the stretcher with a person on it. The need of heavily pressing one end of the stretcher against the ground or lifting the end from the ground to achieve balance, or any other suitable weight distribution will be reduced. The stretcher shall also be so arranged that it admits considerations to the fact that the point of balance of the stretcher when it is loaded, is or will be displaced in any direction of the longitudinal axis of the stretcher. Such a displacement of the point of balance shall not require any change in the force applied by the person who is handling the stretcher to keep it in balance, for example in a horizontal position, when the stretcher is only supported by said pair of wheels.

This object is achieved with the initially defined wheel stretcher which is characterized by the pair of wheels being displaced relative to the framework in its longitudinal direction.

According to a preferred embodiment of the stretcher, the pair of wheels are displaceably arranged substantially parallel with the longitudinal direction of the framework. Thereby, an invariable distance between the pair of wheels and the framework could be maintained during movement of the wheels to a position substantially in the center of, or close to, the point of balance of the stretcher. If the pair of wheels are arranged on one or several legs protruding from the framework, the displacement could be achieved by a displacement of the connection point of the legs to the framework. In such a way, the direction of loading on the legs at a given position of the framework will be the same despite the displacement of the wheels along the framework in its « longitudinal direction. That is not the case if the displacement instead is achieved by pivoting the legs around a stationary point of connection between those and the framework. According to another preferred embodiment, the pair of wheels is arranged to be positioned in a first position at a distance from the framework and a second position closer to the framework. This admits a positioning of the wheel stretcher inside an am- bulance vehicle with the pair of wheel arranged in the second position to save space. Each of the wheels are preferably arranged so that, in the second position, its plan of propagation can be positioned essentially parallel with the stretcher, i.e. the plan of propagation of the framework. This means that the stretcher could be provided with quite large wheels without negatively affecting the space required for the wheels and thereby the stretcher when the wheels are arranged in the second position. Large wheels are preferred for reasons mentioned above for the purpose of achieving an easy handling of the stretcher, in particular when a single person is handling it with a person lying or sitting on it.

According to another embodiment said bars are pivotably arranged relative to the framework for achieving said displacement whereby the stretchers comprises means for maneuvering the bars for movement of the wheels between the first and the second position . Said means could be a wire arrangement or similar, by which the pivoting of the bars relative to the framework is controlled. This makes it considerably easy to handle the stretcher. The stretcher comprises preferably a handle in an area of one end of the wheel stretcher and said maneuvering means is preferably arranged reachable in the area of the handle for further facilitating the handling of the stretcher.

Further, the stretcher preferably comprises means for controlling the displacement of the wheels in the longitudinal direction of the framework. Those means could comprise a wire arrangement and a rack i device for parallel displacement of the bars relative to the framework. Those means for controlling the displacement of the pair of wheels are also preferably arranged reachable in an area of the previously mentioned handle, or at least from one end of the stretcher, easy to reach for the person handling the stretcher.

Further advantages with and features of the stretcher according to the invention will become clear from the following detailed description and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Hereinafter follows a detailed description of exemplified embodiments of the wheel stretcher according to the invention with reference to the appended drawings on which: fig . 1 is a side-view of the wheel stretcher according to the invention, fig. 2 is a side-view similar to the one shown in fig. 1 but with the main support wheels of the wheel stretcher displaced in the longitudinal direction of the wheel stretcher, fig. 3 is a side-view similar to the one shown in figs. 1 and 2 but with the main support wheels of the stretcher folded to a position underneath the stretcher and close to the stretcher, fig. 4 is a detailed view of one part of the underside of the stretcher when the wheels are folded in accordance to fig. 3, figs. 5 and 6 are detailed views seen from below of a mechanism for displacing the pair of wheels from the position according to figs. 1 and 2 to a position according to figs. 3 and 5, and the reverse, fig. 7 shows a mechanism for controlling the displacement of the pair of wheels between the positions in figs. 1 and 2, which mechanism is activated with a handle for displacement of

. the pair of wheels, fig . 8 shows a mechanism according to fig. 7 in a locked po- ^{ sition without activation by the handle, fig . 9 is a side-view of an alternative embodiment of a stretcher according to the invention , fig. 10 is a side-view according to fig. 9 with the pair of support wheels folded up, fig. 1 1 is a view seen from below of portion of the stretcher according to fig. 9, and fig. 12 is a view seen from below a portion of the stretcher according to fig. 10.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Figs. 1 -8 show a preferred embodiment of a wheel stretcher according to the invention. The stretcher comprises a framework 1 which is elongated and comprises two parallel beams 2, held together of a plurality of cross-beams 3, by which two are outlined in figs. 7 and 8. The framework 1 also comprises length- adjusting means in the form of two lengthening beams 4, which are telescopic and arranged relative to the beams 2 and could be pushed out from these for lengthening the framework 1. At the opposite, short sides of the stretcher are handlers 5, 6 arranged for facilitating the operation of the stretcher. The han- dies are arranged in pairs, whereby one of the pairs of handles 5 is arranged in the end of the telescopic lengthening beams 4.

The stretcher further comprises support members 7, 8 for a person lying or sitting on the stretcher. The support members 7, 8 are hinged a the framework 1 and pivotably relative to it so that it forms legs and/or back supports with different adjustable angles for the person who is on the stretcher. It is also possible to arrange support members 7, 8 displaceable in the longitudinal direction of the stretcher, for example by providing a slide or similar which can be displaced in the longitudinal direction of the stretcher and on which the hinges between the support members 7, 8 and the framework 1 are arranged. The support < members 7, 8 define a bunk .

In both of its opposite ends, i.e. at the short sides, the stretcher 1 is also provided with small support wheels 9, 10, intended to support the wheels 1 against the ground, in particular in an ambulance vehicle, in which the stretcher is arranged to be places. The wheels 9 and 10 are quite small, which makes the stretcher less bulky. The stretcher further comprises a pair of wheels 1 1 adapted to function as main support wheels when the stretcher is moved on the ground. The wheels of the pair of wheels 1 1 have a considerably larger diameter than the wheels 9, 10, preferably more than twice as large a diameter as theirs. The wheels of the pair of wheels 1 1 are attached to the framework 1 by bars 12, 13, more particularly to the beams 2.

The bars 12 are displaceably arranged relative to the framework 1 in its longitudinal direction. For this purpose, the stretcher comprises a sled 14, which is displaceably arranged relative to the framework 1 and to which the bars 12, 13 are attached. The sled 14 rests on the beams 2 of the framework and could be arranged to either slide or roll against the framework for the displacement in the longitudinal direction of the framework. The bars 12, 13 and the sled 14 are arranged in such a way that the pair of wheels 1 1 is displaceable relative to the framework 1 along at least one area, in which the point of balance of the loaded stretcher normally could be expected. Thanks to the dis- placeability of the pair of wheels 1 1 consideration can be taken to the displacement of the point of balance, caused by different weight distribution and position of the .person on the stretcher, the inclination of the stretcher, i.e. the inclination of the framework 1 relative to the ground and the gravitation forces etc. The position of the pair of wheels 11 is adjusted in dependence of the position of the point of balance of the stretcher in each case so that a principal equilibrium is always achieved on both sides of the pair of wheels 1 1 , i.e. the connection point between the bars 12, 13 and the framework 1 , without any considerable feat of strength being required from the operator.

The stretcher comprises means 15 for controlling the displacement of the pair of wheels 1 1 in the longitudinal direction of the framework. The means 15 comprises a first engagement member 16 fixed to the framework 1 and a second^'corresponding engagement member 17 connected to the sled 14 and the bars 12, 13, a wire 18 connected to the means 19 for mutual displace- ment of the engagement members 16, 17 to and from an engagement position. The first engagement member 16 is here composed of a rack which is arranged in the longitudinal direction of the framework 1 and connected to at least two crossbeams 3. The rack 16 is connected to the cross-beams 3 through levers which also define control means 19. The levers 19 are arranged in such a way that they, when they are activated by the wire 18, can be pivoted and thereby moving the rack out of the engagement position with the second engagement member 17. The principle is shown in figs. 7 and 8.

The wire 18 reaches all the way to one of the handles 5 at one end of the framework 1 . There, it is easy to reach for the operator who is handling the stretcher. In the preferred embodiment, the means 15 is also comprising a control lever 20, which is flexibly connected to the handle 5 and to which one end of the wire 18 is attached. Turning of the control lever 20 results in the mutual displacement between the engagement members 16, 17 by which the sled 14 will become free for displacement along the framework 1.

In this example, the second engagement member 17 comprises a part of a rack which is considerably shorter than the rack 16 and which is_*attached to the sled 14.

The stretcher further comprises means 21 for locking at least one of the wheels of the pair of wheels 11 when the means 15 is activated for achieving the displacement of the pair of wheels 1 1

« - bars 12, 13 - sled 14 relative to the framework 1 . The means

21 comprises a wire 22 which in one of its ends is connected to a lever 23 and in its other end is connected to a breaking arrangement (not shown) of the pair of wheels 1 1 . Through the lever 23, the position of one of the ends of the wire 22 is mechanically affected by the displacement of the first engagement member 16 which displacement is achieved by affection of the wire 18. This function is advantageous, since a locking of the pair of wheels 1 1 considerably facilitates the displacement of the sled 14 relative to the framework 1 , in particular if only one person is handling the stretcher.

The pair of wheels 11 are arranged to be positioned in a first position at a distance from the framework and a second position closer to the framework 1 . The first position is shown in figs. 1 and 2 and the second position is shown in figs. 3 and 4. Since the bars 12, 1 3 are pivotably attached to the sled 14, they are also pivotably attached to the framework 1. Each bar 12, 13 comprises two bar portions 24, 25 and 26, 27, respectively, pivotably attached to each other. The bar portions 24, 25; 26, 27 are pivotably attached to each other to admit positioning of the wheels of the pair of wheels 1 1 in such a way that the plan of propagation is mainly parallel with the plan of propagation of the stretcher, which is shown fig. 3. The bars 12, 1 3 are also arranged in such a way that a mutual displacement of the wheels of the pair of wheels in the longitudinal direction of the framework 1 is accomplished by moving the bars 12, 13 to the second position of the pair of wheels. Thereby, the use of large wheels is made possible without having the drawback of their occupying an unnecessarily large space. The size of the displacement is preferably the same or larger than the diameter of the wheel.

For pivoting the bars 12, 13, the stretcher comprises means 28 for moving the pair of wheels 1 1 between the first and the second position. In the example shown, the means 28 comprises a piston cylinder adapted to displace a mutual tie bar joint of the « bars 12, 1 3 in the longitudinal direction of the framework for pivoting the bars 12, 13. The piston cylinder is fixed to the sled 14. The piston cylinder can be either electrically or mechanically activated. Therefore, the means 28 preferably also comprises (not shown) a connection, for example a wire connection, which extends to the area of the handle of the stretcher, preferably any of the handles 5. The piston cylinder is preferably activated by the affection of said connection in the area of the handle 5. The means 28 for folding the bars 12, 13 in and out can preferably comprise further piston cylinders (not shown) for a mutual pivoting between the bar portions 24, 25 and 26, 27. Such piston cylinders are preferably activated by the activation of the above described piston cylinder. All of the above mentioned piston cylinders could be activated in opposite directions or in only one direction, and thereby requiring corresponding return springs of the means 28 for the corresponding restoring of the bars 12, 13 at deactivation of the piston cylinders. The piston cylinders can be either pneumatically or hydraulically working piston cylinder arrangements.

Figs. 9-12 show an alternative embodiment of the stretcher according to the invention. In the same way as in the above described embodiment, the stretcher comprises a framework 101 , longitudinal beams 102, lengthening beams 104, handles 105, 106 arranged on the opposite ends of the framework 101 , support members 107, 108, wheels 109, 1 10 arranged at opposite ends of the framework 101 , a pair of wheels 1 11 arranged to function as main support wheels during the movement of the stretcher in support against a ground, and bars or legs 112, 113 attaching the pair wheels 11 1 to the framework 101. The bars 1 12, 113 are attached to a sled 114 which preferably is displaceable in <the longitudinal direction of the stretcher along the framework 101. The displacement and the activating of the dis- placement are preferably done with means similar to those described_. above in the first embodiment of the stretcher.

« However, in the alternative embodiment, the bars 112, 113 have a design which differs from that of the bars in the first embodi- ment. The bars 1 12, 113 are substantially being pivoted only in the longitudinal direction of the framework. In the end of the bars 1 12, 113 closest to the pair of wheels 1 11 hinges 1 15 are arranged for folding both wheels of the pair of wheels 1 1 1 in under the framework in such a way that the plan of propagation of the wheels is substantially parallel with the plan of propagation of the framework of the stretcher.

For pivoting of the bars 112, 1 13, it is suitable to arrange piston cylinders and, if necessary, return springs (not shown) which are suitable activated by a wire connection or similar from an area of the handles 105 of one end of the stretcher.

The alternative embodiment comprises further a fourth pair of wheels 1 16 arranged at the end of the longitudinal beams 102 which are arranged close to the lengthening beams 104. The fourth pair of wheels 1 16 has a size and a function which are substantially corresponding to the size and the function of the pair of wheels 109, 110.

It should be noted that a number of different alternatives and embodiments of the stretcher according to the invention will be apparent to a man skilled in the art without leaving the scope of invention, such as it is defined in the enclosed claims supported by the description and the drawings.

Claims

1. Wheel stretcher for transportation of a patient, comprising a framework (1; 101) and a pair of wheels (11; 111) attached to the framework, characterized in that the wheels (11; 111) are displaceably arranged relative to the framework (1; 101) in its longitudinal direction.

2. Wheel stretcher according to claim 1, characterized in that the wheels (11; 111) are displaceably arranged substantially parallel with the longitudinal direction of the framework (1; 101).

3. Wheel stretcher according to claim 1 or 2, characterized in that the pair of wheels (11; 111) are connected to one or several bars (12, 13; 112, 113) which are displaceably arranged relative to the framework (1 ; 111).

4. Wheel stretcher according to claim 3, characterized in that the bar or bars (12, 13; 112, 113) are displaceable relative to the framework (1; 101) parallel to its longitudinal direction.

5. Wheel stretcher according to any of the claims 1-4, characterized in that the pair of wheels (11; 111) are arranged to be positioned in a first position at a distance from the framework and in a second position closer to the framework (1; 111).

6. Wheel stretcher according to claim 5, characterized in that it comprises one or several bars (12, 13; 112, 113) by which the wheels (11; 111) are connected to the framework (1; 101) and which are movably arranged for moving the wheels (1; 111) between the first and the second position.

« 7. Wheel stretcher according to claim 6, characterized in that said bars (12, 13; 112, 113) are pivotably arranged relative to the framework (1 ; 101) for achieving said movement.

8. Wheel stretcher according to claim 6 or 7, characterized in that it comprises means (28) for maneuvering^' the bars (12, 13; 1 12, 113) for movement of the wheels (1 1 ; 11 1 ) between the first and the second position.

9. Wheel stretcher according to claim 8, characterized in that the wheel stretcher comprises a handle (5; 105) in an area of one end of the wheel stretcher and that said maneuvering means (28) are arranged to be activated from the area of the handle (5; 105).

10. Wheel stretcher according to any of the claims 1 -9, characterized in that it comprises control means (15) for controlling the displacement of the wheels (1 1 ; 1 1 1 ) in the longitudinal direc- tion of the framework (1 ; 101 ).

1 1 . Wheel stretcher according to claim 10, characterized in that the control means (15) are arranged for activating from an area of the handle (5; 105) of the wheel stretcher.

12. Wheel stretcher according to claim 10 or 1 1 , characterized in that it comprises means (21 ) for braking the wheels (1 1 ; 1 1 1 ) when the control means (15) is activated for displacement of the wheels (1 1 ; 11 1 ) relative to the framework (1 ; 101 ).

13. Wheel stretcher according to any of the claims 5-12, characterized in that the wheels in the second position are placed at the underside of the wheel stretcher with their plan of propagation essentially parallel to the plan of propagation of the wheel stretcher.

14. Wheel stretcher according to any of the claims 1 -13, char- t acterized in that it is elongated and arranged for moving in and out of an ambulance vehicle.

15. Wheel stretcher according to claim 14, characterized in that it comprises a further pair of wheels (9, 10; 109, 1 10, 116) adapted to support the wheel stretcher at said in and out movement.

16. Wheel stretcher according to any of the claims 3-15, characterized in that the displaceable pair of wheels (11 ; 1 11 ) is intended to be arranged in its first position for supporting the wheel stretcher against the ground at transportation of patients and intended to be arranged in its second position when the wheel stretcher is moved into and resting in an ambulance vehicle.

17. Wheel stretcher according to any of the claims 15 or 16, characterized in that said further pair of wheels (9, 10; 109, 110,

1 16) has a considerably smaller diameter than said displaceable pair of wheels (1 1 ; 1 1 1 ).