WO2003032888A1

WO2003032888A1 - Portable step

Info

Publication number: WO2003032888A1
Application number: PCT/GB2002/004190
Authority: WO
Inventors: Ian Douglas Jackson; Sylvia Ann Wacker; Donald Malcolm Wood
Original assignee: BELLHOP Ltd
Current assignee: BELLHOP Ltd
Priority date: 2001-10-12
Filing date: 2002-09-12
Publication date: 2003-04-24
Anticipated expiration: 2004-04-12
Also published as: GB2380689B; GB2380689A; GB0124464D0

Abstract

Portable step comprising a block, having an aperture to receive teh foot of a walking stick, and a clamping mechanim, operative on insertion of the stick in the aperture to grip the foot of the stick so that the step is liftable with the stick connected thereto, and on tilting of the stick to release the stick for withdrawal thereof from the aperture.

Description

PORTABLE STEP

This patent application relates to the field of portable step units in particular for facilitating movement up and down stairs.

The simple task of climbing up and down stairs is a serious problem for a large number of people, for example those who suffer from a variety of diseases such as arthritis, the effects of strokes and multiple sclerosis or simply from the frailty that accompanies old age. Use of a conventional walking stick can assist, however the user still needs to have sufficient mobility to lift each leg over the height of each full step. A solution to this problem would be the installation of a stair lift such as those commonly available, however the cost of this is in many cases prohibitively expensive and, of course, only solves the mobility problem for one particular staircase.

Mobility may be improved by using a device of the type described in US3,884,327 (Zigman) in which there is disclosed a portable step unit, the attached carrying handle of which also serves as a walking cane or stick. The portable step unit, carried by the attached cane, acts as an intermediate step when placed on one step of a staircase or, as illustrated in Figure 1 of Zigman, can be used to provide a step for a person who would not otherwise be able to lift one or both legs sufficiently high to enable them to climb onto a bus.

A disadvantage of the device described in Zigman is that the walking cane/handle is permanently fixed to the portable step unit, meaning that the device may be unsuitably heavy and/or bulky for a frail person to carry from one location to another. This problem is exacerbated by the likelihood that the person may also need to carry their normal walking cane or stick in addition to the portable step unit .

This problem is addressed by the device described in US5,318,057 (Wallum). In this document, a combined stability cane and step unit is described in which the walking cane can be releasably attached to the step unit so that it may be separated from the step unit and used in its normal manner. However, the device described in Wallum may be difficult to use by frail or elderly persons since, in order to engage the walking cane with the step unit, the end of the cane must be inserted precisely into a relatively small aperture in the step unit and then twisted in a bayonet fashion to lock it in place. The aperture in the step unit is necessarily small so that the step unit can closely surround the cane in order to hold it rigidly in position. Furthermore, it may actually be disadvantageous to have the walking cane very rigidly held since a frail individual may need some movement in the cane in order to maintain their balance.

It is therefore an object of the present invention to provide a portable step which alleviates the above- described problems.

Throughout this application, reference to the "NHS" means the National Health Service of the United Kingdom.

According to a first aspect of the present invention, there is provided a portable step comprising a block, having an aperture to receive the foot of a walking stick, and a clamping mechanism, operative on insertion of the stick in the aperture to grip the foot of the stick' so that the step is liftable with the stick connected thereto, and on tilting of the stick to release the stick for withdrawal thereof from the aperture. Simple tilting of the stick, provides an easy means of releasing the stick from the clamping mechanism and means that the user can use their normal walking stick with the portable step. There is thus no need to carry the normal walking stick separately and in addition to the stick plus step arrangement described in the prior art.

Preferably, the clamping mechanism is a toggle mechanism which can toggle between an open position, in which the stick can be inserted into the aperture, and a closed position, in which the foot of the stick is clamped.

Ideally, the toggle mechanism has a spring-loaded base operated by downward pressure of the stick to toggle a side wall of the mechanism to clamp the foot of the stick. More preferably, the side wall is tiltable sideways by sideways tilting of the stick with respect to the step to toggle the base upwardly to release the foot of the stick from the clamping mechanism.

Preferably, the clamping mechanism is pivotally mounted within the block so that, even when the foot of the stick is gripped, some side-to-side movement (with respect to the step) of said stick is possible, within predefined limits. This gives the advantage of enabling the user to easily regain lost balance whilst using the portable step, since the walking stick is not totally rigidly held but permits limited side to side movement of the stick.

Preferably, said clamping mechanism is suitably sized and shaped to closely surround a ferrule attached to the foot of the stick, when the foot of the stick is gripped, and preferably, wherein the ferrule is compressed when the foot of the stick is gripped.

Preferably, the ferrule is a standard-sized NHS walking stick ferrule. Again, this has the significant advantage that, in many cases, the portable step can be used in conjunction with the user's normal walking stick or crutch.

In a preferred form, an upper surface of the block is provided with a friction-improving covering or coating. This further reduces the likelihood of the user slipping and losing his or her balance.

Ideally, the block is generally cuboidal and, preferably is approximately half the height of a normal stair.

Preferably, the underside of the block is open so as to minimise the surface area in contact with the stairs and, preferably, only the perimeter of the block is, in use, in contact with the stairs. By having a hollow box, or one with an open interior and underside, the overall weight of the portable step is reduced, making it readily portable. Furthermore, by reducing the contact area between the block and the stairs or ground, the portable step is more stable if the stairs/ground surface is uneven.

Preferably, said aperture is substantially larger than the foot of a standard walking stick. This makes it easy for a user who is visually impaired or has difficulty with hand-eye coordination to locate the stick correctly into the clamping mechanism.

Preferably, the side walls of the toggle mechanism are outwardly tapered in the open position and inwardly tapered in the closed position. This tapering means that the side walls can closely surround a tapered ferrule at the foot of the stick, when the toggle mechanism is closed. When the toggle mechanism is open, the outward tapering serves to guide the foot of the stick into the correct position to actuate the toggle mechanism.

Preferred embodiments of the present invention will now be more particularly described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of a portable step embodying the invention, in use;

Figure 2 is a cross-sectional view of the portable step, showing the location of the clamping mechanism;

Figure 3 is a side view of the clamping mechanism in the open position;

Figure 4 is a side view of the clamping mechanism in the mid-position;

Figure 5 is a side view of the clamping mechanism in the closed position;

Figure 6 is a simplified schematic illustration of the operating principle of the clamping mechanism;

Figure 7 is a side-view of 'an alternative embodiment of the clamping mechanism; and

Figure 8 is a top view of the clamping mechanism of Figure 7 in place within a block.

Referring firstly to Figure 1, the portable step (indicated generally by 1) is a device which provides a platform intermediate each stair to reduce the minimum level of mobility and the degree of effort required to ascend or descend a flight of stairs. The portable step comprises a block 2 which is generally cuboidal and may be made of aluminium or lightweight moulded plastic. The block needs to be lightweight in order to make it easily portable but also needs to be robust so that it can easily support the body weight of the user of the portable step. The height H of the block is ideally approximately half the height of a normal stair 3 so that the block can provide an intermediate step for the user.

Preferably, the upper surface of the block 2 is provided with a friction-improving coating or covering, such as a rubberised mat 4.

The portable step is designed to be used in conjunction with a standard NHS walking stick 5 or crutch. This type of walking stick or crutch has standard dimensions (in particular, a standard diameter) and is provided at its foot (i.e. its lowermost end) with a rubberised ferrule 6 (not shown in Figure 1) .

The portable step is further provided with a clamping mechanism (shown generally in Figure 1 as 7) which communicates with an aperture 8 in the upper surface of the block 2. By operating the clamping mechanism (as will be described in more detail below) the walking stick can be selectively clamped to or released from the block 2, as desired by user. The clamping mechanism is, optionally, a stand-alone unit which is separable from the block 2. In this case, the clamping mechanism is retained in the block by a removable pin which engages, for example, in a hollowed-out end of the axle which forms pivot P (see Figure 7) . When the pin is removed, the clamping mechanism can be lifted out through aperture 8. Figure 1 shows a side aperture 30 through which the pin can be withdrawn.

Figure 2 shows a cross sectional view of the portable step, showing where the clamping mechanism 7 is located within the block 2. The clamping mechanism 7 is preferably mounted as close to the perimeter of the block as possible in order to maximise the upper surface of the block on which the user will stand, in use. Preferably, the underside of the block 2 is open so as to minimise the surface area which would be in contact with the ground or stairs, in use. There is therefore a hollow region 9 inside the block 2 which reduces the overall weight of the portable step and makes the step more easily portable. A further advantage is that the surface area of the portable step which is actually in contact with the ground or stairs, in use, is minimised which means that the portable step is more stable on uneven ground or stairs. The parts of the block 2 which are, in use, in contact with the ground or stairs may be provided with a non-slip coating or bumper 10.

The operation of the clamping mechanism will now be described in more detail, with reference to Figures 3-6.

Referring to Figure 6, key parts of the clamping mechanism are as follows. There is provided a two-part receptacle for receiving the foot of a walking stick 5, preferably having a ferrule 6 thereon. The first part of the two-part receptacle comprises a base 11 and first solid wall 12 which have a fixed relationship to one another with an angle θ between them which is less than 90°. The base 11 and first sidewall 12 (hereafter together called "the base unit 13") are pivotable about point P shown in Figure 6 and form two sides of the receptacle .

Pivotally attached to the base unit 13 is a second side wall 14. The second sidewall 14 can pivot with respect to the base unit 13 about point Q.

The general operating principle is that downward movement of the walking stick 5 forces the lower regions of the two parts of the receptacle, outwardly away from one another. This causes the base unit to pivot about point P and the second sidewall to pivot about point Q so that the two sidewalls 12, 14 pivot inwardly, as shown in Figure 6, to closely surround the tapered ferrule 6, thus clamping the walking stick in place. The pivoting movement of the sidewalls is limited by a number of factors, which will be described in more detail below, but which include spring-loading between the base unit and the second sidewall, a framework of endstops

(described below) and a locking endstop 15 illustrated in Figure 6.

Figure 3 shows the clamping mechanism in an open position i.e. ready to receive a walking stick (which is not shown) .

Figure 3 shows the framework of endstops and levers which control the relative movement of the base unit 13 and second sidewall 14. It should be pointed out that only one half of the framework and lever arrangement is illustrated; an identical arrangement is in place on the opposite side of the receptacle.

The base unit 13 is connected to second sidewall 14 in three places. Firstly, there is a spigot 16 which is fixed with respect to second sidewall 14 and forms pivot Q. The spigot 16 is slidable in an elongate slot 17 in the first sidewall 12. A main lever 20 connects pivot P with a further pivot point R. A spigot 21 at point R is rigidly fixed to an intermediate lever 22 which, in turn, is pivotally attached at point S to both the second sidewall 14 and a support frame 23 which substantially surrounds (but is not attached to, the first sidewall 12) . Finally, there is provided a secondary lever 24 which is pivotally attached to point P and rigidly attached to the support frame at point T. Pivot points R and T are held in tension by means of a spring 25.

The entire arrangement comprising the base unit 13, second sidewall 14, levers 20, 22 and 24 and support frame 23 is pivotable about point P subject to the following limits. In the leftmost direction (as viewed in Figure 3) the pivoting about point P is limited by spigot 16 abutting locking endstop 15. In the rightmost direction (as viewed in Figure 3) the pivoting about point P is limited by contact between the uppermost region of the secondary lever 24 with a vertical frame section 26. Alternatively, the contact between lever 24 and vertical frame section 26 may be lower down than illustrated in the Figures, for example if lever 24 (or hairpin spring in the alternative embodiment mentioned below) has an outwardly curved or boomerang-like shape. This may improve the smoothness of the operating mechanism and hence may be preferable. Vertical frame section 26 is rigidly fixed with respect to the block 2. In an alternative embodiment (not illustrated) , the main lever 20, secondary lever 24 and spring 25 can be replaced by a suitably-sized hairpin spring. The operation of this alternative embodiment is identical to that already described; in particular the hairpin spring would be attached to points R and T and would pivot about point P.

When the foot of a walking stick is inserted into the receptacle, the key component parts move in the directions indicated by the double-headed arrows in

Figure 3. As the walking stick pushes downwardly on base

11, the ferrule on the foot of the stick pushes the lower regions of sidewalls outwardly away from one another. This causes the entire arrangement described in the preceding paragraph to pivot about point P until spigot

16 contacts the locking end stop 15. As further downward force is applied by the walking stick, spigot 16 travels along elongate slot 17 and the intermediate lever 22 starts moving downwardly at point S, causing point R to begin moving leftwardly.

When spigot 16 reaches the end of elongate slot 17, it drops off the end of locking endstop 15 and moves rapidly downwardly as shown in Figure 3.

An intermediate position is shown in Figure 4, wherein the intermediate lever 22 has moved downwardly sufficiently to now be over-centre and to allow the spring 25 to pull the levers at points R and T toward one another which in turn causes the first and second sidewalls 12 and 14 to be pulled together in order to surround the foot of the walking stick.

This movement continues until the fully closed position, shown in Figure 5, is reached, in which further leftward pivoting at point P is limited by contact between the upper region of main lever 20 with vertical frame section 27.

When the fully closed position, shown in Figure 5, is reached, the foot of the walking stick is firmly gripped within the two-part receptacle because sidewalls 12 and 14 are now tapered inwardly so that the receptacle closely surrounds the tapered ferrule on the foot of the walking stick. This prevents the walking stick from being simply lifted vertically upwards and out of the clamping mechanism and, in fact, if the walking stick is lifted vertically upwards, the entire portable step comes with it, meaning that the portable step can easily be moved from one stair to the next when the user is climbing or descending a staircase.

The embodiment of the clamping mechanism described above is such that it is suitably sized and shaped to receive the ferrule of a standard NHS walking stick or crutch. Of course, it can be envisaged that differently sized clamping mechanisms may be provided, so that the portable step can be used in association with other standard sizes of walking stick or crutch. If the clamping mechanism is removable from the block, as described above, it could readily be exchanged for one suitable for a differently sized walking stick.

If the user attempts to clamp a walking stick and ferrule which is smaller than that for which the portable step is intended, it is virtually impossible under normal operating conditions to operate the clamping mechanism, mainly because the lower regions of the two sidewalls are not pushed outwardly and hence spigot 16 does not slide in slot 17. This avoids the risk of the clamping mechanism partially or inadequately clamping the foot of the stick which may undesirably become dislodged. Preferably, the base 11 (see Figure 6) has a slightly smaller diameter than the ferrule 6, to ensure a tight fit which effectively pushes the lower regions of the sidewalls apart, in use.

Although the walking stick is firmly held within the clamping mechanism in its fully closed position, the walking stick is not held entirely rigidly. This is because some pivoting of the two-part receptacle and lever arrangement is still possible about point P. This small degree of pivoting is limited by abutment of the upper end of the main lever 20 with vertical frame section 27 (in the leftward direction) and upper frame section 28 (in the rightward direction) . Nevertheless, this limited pivoting, even when the clamping mechanism is closed, gives the significant advantage that the user can still obtain some side-to-side movement of the walking stick in order to gain his/her balance, but without disengaging the walking stick from the clamping mechanism. Some forward and backward movement of the stick is also possible when the stick is held by the clamping mechanism but, again, the stick cannot be simply lifted out of the clamping mechanism.

A positive action on the part of the user is required in order to disengage the walking stick. To open the clamping mechanism, the user needs to tilt the walking stick rightwardly (as shown in Figure 5) which causes the reverse of the above-described process to occur thus releasing the walking stick from the clamping mechanism.

In more detail, tilting of the walking stick rightwardly causes the two-part receptacle to pivot rightwardly about point P until the upper end of main lever 20 abuts the upper frame section 28 (as shown in Figure 4). As the tilting force continues to be applied, intermediate lever 22 starts moving upwardly, pivoting about pivot R. Once the intermediate lever 22 is over-centre, it snaps upwardly as a result of the spring 25 and hence forces the sidewalls 12 and 14 attached thereto, apart. .This opens the two-part receptacle so that the clamping mechanism is in the open position (as shown in Figure 3) and the walking stick can be simply lifted out of the mechanism.

The design of the clamping mechanism is such that it is virtually impossible under normal operating conditions to remove the walking stick without leaving the clamping mechanism in its open position. It is clearly very undesirable have the clamping mechanism closed when no stick is present because the user ^l would have to open the clamping mechanism using his fingers in order to allow the stick to be reinserted. This is potentially dangerous and is likely to be impossible for the user of limited mobility who is likely to use the portable step. However, since the clamping mechanism is such a close fit with the ferrule for which it is designed, if the receptacle has opened sufficiently to allow the tapered ferrule to be withdrawn, intermediate lever 22 is almost certain to spring upwardly because pivot point S is over- centre, thus fully opening the receptacle.

In the above-described embodiment, the clamping mechanism comprises a spring-loaded toggle mechanism which can toggle straightforwardly between an open position in which the stick can be inserted into the two-part receptacle and a closed position in which the foot of the stick is clamped. Alternative embodiments may be envisaged wherein, for example a pronged claw or the like may engage the tapered ferrule to clamp the foot of the stick.

In the above-described embodiment, two framework and lever arrangements are present, one on each of the two opposite sides of the two-part receptacle. The two framework and lever arrangements may be identical, or in an alternative embodiment, one set of the levers and/or frame sections may be slightly differently shaped so that interaction between the end regions of the levers and the vertical and upper frame sections (i.e. as endstops) does not occur. This reduces wear on these parts of the clamping mechanism. It has been found that such endstop action is effective even if it occurs on only one side of the two-part receptacle.

The above-described embodiment is designed so that the two-part receptacle closely surrounds the ferrule of a standard-sized NHS walking stick, crutch or the like. It can be envisaged that portable steps having differently- sized clamping mechanisms may be manufactured to accommodate differently sized sticks. The portable step of the present invention has the advantage that, in the open position, the open end of the two-part receptacle is much larger than the end of the walking stick which makes aiming the stick into the clamping mechanism much easier for the user who may be visually impaired or have difficulties with hand-eye co-ordination. The tapering of the two-part receptacle, in the open position, also helps to guide the foot of the walking stick into the correct position to actuate the clamping mechanism.

An alternative embodiment of the clamping mechanism is shown in Figures 7 and 8. In this embodiment, the clamping mechanism has been simplified to reduce its overall weight and complexity.

The endstop 15 and frame sections 26, 27 and 28 from Figure 3 are no longer part of the clamping mechanism shown in Figure 7. The function of these parts is served by suitably shaped formations on the interior of the block where the clamping mechanism is mounted. The formations could be integrally moulded with the block, or could be separate parts mounted inside the block. In either case, once the clamping mechanism is in position inside the block, the formations abut the clamping mechanism in the same way that the endstop 15 and frame sections 26, 27 and 28 abut the embodiment illustrated in Figure 3.

For example, a formation equivalent to endstop 15 extends upwardly from the base of the block in order to support spigot 16 of the clamping mechanism. Guide formations 31, 32 (shown in Figure 8) serve the same purpose as the upper frame sections 28 (shown in Figure 3) .

In the Figure 3 embodiment, support frame 23 has two functions. Firstly, it connects pivot points S and T. Secondly, it substantially surrounds the first sidewall 12 to limit its travel away from second sidewall 14. In the Figure 7 embodiment, the latter of these functions is served by axle 33 which forms pivot points T and passes around the back of the first sidewall 12. Since pivot point T is relatively further away from pivot point R (as compared to the Figure 3 embodiment) , the springs 25' are longer than those in the Figure 3 embodiment.

As has been mentioned above, the clamping mechanism works most effectively when it provides a tight fit around the ferrule on the foot of the walking stick being clamped. Since ferrules are generally made of resilient material (e.g. rubber), the base of the two-part receptacle can, in fact, be slightly smaller in diameter than the ferrule for which it has been designed. If this is the case, then when the ferrule (on the foot of a stick) is inserted into the clamping mechanism, it will engage the sidewalls before reaching the bottom of the receptacle (where the clamping mechanism would be triggered) . The frictional contact between the ferrule and the sidewalls will, if the portable step is light enough, be sufficient to allow the whole step to be lifted upon vertical raising of the stick. It may be advantageous to be able to lift the portable step using the stick, but without triggering the clamping mechanism, if the user wishes to pick up the step (e.g. to stow it away after use) .

Of course, if the ferrule (on the foot of a stick) is pushed further into the receptacle, the clamping mechanism is triggered. If the ferrule is slightly larger in diameter than the base of the receptacle, then the ferrule itself pushes the lower regions of the sidewalls 12, 14 outwardly away from one another. This causes spigot 16 to slide in slot 17 and the clamping mechanism is triggered as previously described.

The portable step of the present invention is lightweight, readily portable and relatively cheap to produce. In particular, the clamping mechanism is very simple to operate since it requires a simple downward force on the walking stick to engage the clamping mechanism and a positive sideways tilting of the walking stick to release it from the clamping mechanism.

Claims

1. Portable step comprising a block, having an aperture to receive the foot of a walking stick, and a clamping mechanism, operative on insertion of the stick in the aperture to grip the foot of the stick so that the step is liftable with the stick connected thereto, and on tilting of the stick to release the stick for withdrawal thereof from the aperture.

2. Portable step as claimed in claim 1 wherein the clamping mechanism is a toggle mechanism which can toggle between an open position, in which the stick can be inserted into the aperture, and a closed position, in which the foot of the stick is clamped.

3. Portable step as claimed in claim 2 wherein the toggle mechanism has a spring-loaded base operated by downward pressure of the stick to toggle a side wall of the mechanism to clamp the foot of the stick.

4. Portable step as claimed in claim 3 in which the side wall is tiltable sideways by sideways tilting of the stick with respect to the step to toggle the base upwardly to release the foot of the stick from the clamping mechanism.

5. Portable step as claimed in any of the preceding claims wherein the clamping mechanism is pivotally mounted within the block so that, even when the foot of the stick is gripped, some side-to-side movement

(with respect to the step) of said stick is possible, within predefined limits.

6. Portable step as claimed in any of the preceding claims wherein said clamping mechanism is suitably sized and shaped to closely surround a ferrule attached to the foot of the stick, when the foot of the stick is gripped and, preferably, wherein said ferrule is compressed when the stick is gripped.

7. Portable step as claimed in claim 6 wherein said ferrule is a standard-sized NHS walking stick ferrule .

8. Portable step as claimed in any of the preceding claims wherein an upper surface of the block is provided with a friction-improving covering or coating.

9. Portable step as claimed in any of the preceding claims wherein the block is generally cuboidal and, preferably is approximately half the height of a normal stair.

10. Portable step as claimed in any of the preceding claims wherein the underside of the block is open so as to minimise the surface area in contact with the stairs and, preferably, only the perimeter of the block is, in use, in contact with the stairs.

11. Portable step as claimed in any of the preceding claims wherein said aperture is substantially larger than the foot of a standard walking stick.

12. Portable step as claimed in any of claims 3-11 wherein the side walls of the toggle mechanism are outwardly tapered in the open position and inwardly tapered in the closed position.

13. Portable step as claimed in any of the preceding claims wherein at least part of the clamping mechanism is removable from and replaceable in the block.

14. Portable step as claimed in any of the preceding claims wherein at least part of the clamping mechanism is integral with the block.

15. Portable step substantially as described herein with reference to and as illustrated by any appropriate combination of the accompanying drawings.