AN INTEGRATED DEVICE WITH WHEELAND SKI FOR A WALKER Introduction : The invention relates to a walker in which at least the front wheels are provided with skis or skids arranged for supporting the walker on snow, also in case the snow substrate is uneven. It is known to arrange a front ski on snow scooters and fixed skids for winter use on prams for children, and also known to arrange skis or skids on walkers, but the model seen by the applicant has only a ski in front for winter usage, and is thus useless in the moment the user comes in from outdoor snow conditions and shall move about indoor with the walker on a plain floor. The present invention provides a solution that may be used both outdoor on snow, outdoor on snow-free ground, and indoor, without the need for any kind of adjustment of the walker.

Background of the invention, problem to be solved The applicant manufactures walkers that are sold to elderly users in Norway.

The users not only desire to use the walker indoor, but often outdoor, and also during the winter outdoor. Existing walkers will soon get stuck in the snow even for a thin layer of snow, and even small bumps in the snow may incur the user of the walker to loose the steering or the ability to move ahead, or both. The user must then lift the walker out of the snow, and again try to find a new track, or use the walker as a"walking frame", the use as a walking frame being a much more effort demanding way of movement. It belongs to the nature of the case that users of walkers are somewhat weak, and snow may represent a significant obstacle if the walker is of no use in snow.

Prior art in the field Arranging a front ski on walkers is known, but such is of no use if the user shall move along a snow-free portion of the path.

US Patent 5 224 506 describes a walker or support frame having front wheels and ski-like skids at the rear. Such a device may hardly be steered in the snow and does not solve the problem of front wheels getting stuck in the snow.

US Patent 5 692 762 shows a spring-loaded sliding device for arrangement on the rear legs of a walking frame provided with tiny wheels at the front. The sliding device at the rear legs may slide along the ground when the rear legs are lifted slightly from the ground, and yield so as for an ordinary rubber knob to

engage with the ground when vertical load of the rear legs is resumed. Such a device may not relieve the problem of front wheels getting stuck in snow. The sliding device according to the US Patent will not be able to run in snow as the rubber knob would be forced down into the snow and thus arrest any kind of rolling motion.

US Patent 5 441 285 describes a"half barrel"-shaped broad skid for being arranged below the front wheels of a shopping cart equipped with non-turning rear wheels. The barrel skid has a bearing about an athwart horizontal axis ahead over the front wheels. The device may thus not be steered when it comes into the snow, as the steering front wheels no longer may come into contact with the substrate anymore. Whereas a walker has rather short axle separation between the front and rear wheels, and should have low weight, such a solution having a half barrel below the front wheels would render a walker heavy and the user would kick into the barrel when he or she walks, in addition to the fact that the walker with the barrel mounted would be rather difficult to steer.

Short summary of the invention A solution to the above-mentioned problems is an integrated device with wheel (1) and ski (6) for a walker, of which said wheel (1) is arranged on a wheel shaft (3) in a wheel fork (2) being arranged for being rotated about a generally vertical axis in a fork bearing (7) on a walker frame (4), said walker being characterised by the following features: * said ski (6) being longer and wider than said wheel (1) and said ski being provided with a longitudinal generally centrally arranged recess (9) arranged for the wheel's rolling periphery to run through said recess (9), in which said ski (6) is provided with a bracket (12) arranged in a rocker bearing about a horizontal bracket axle (11) on said wheel fork (2), so as for said wheel (1) to run freely on flat, bare substrates and said ski (6) being able to run in snow. The central recess facilitates that the wheel may run on the bare substrate e. g. along bare or uncovered asphalt paths of which there are portions of the road of which the snow has been completely removed, or on indoor floors e. g. in shops or halls. The ski will take over the supporting function if the walker rolls into a snow layer being thicker or looser than for the wheel to be able to support in the snow, but the wheel will continue to turn about its axle and carry a portion of the weight in the portion of the ski of which the wheel protrudes.

Short figure captions Fig. 1 shows a walker wheel in a rotating fork with a ski according to the invention in which the ski is arranged to be rocked about a bracket fixed to the fork and in which the wheel extends a small portion down through a recess in the ski.

Fig. 2 shows the ski having the tip rocked upwards as counted in the running direction and in a position of which the ski is about to run into somewhat deeper snow and in which the ski is about to take over the supporting function for a portion of the vessel's weight on the snow, and in which the wheel no longer runs immediately on the ground.

Fig. 3 is a side elevation view of a walker with a front wheel with ski according to the invention. Here, the bracket is fixed to an axle directly on the fork, and not on a plate being arranged on the fork. The direction of running is toward the right side of the sheet.

Fig. 4 shows a schematic section through and partial outline of the wheel and the ski shown in Fig. 1, Fig. 2, or Fig. 3. Please notice the recess in the ski that allows the wheel to roll on a bare ground and that the ski may be rocked about the bracket's axle mounted on the fork.

A description of a preferred embodiment of the invention Figure 1 shows a walker wheel (1) in a rotating fork (2) with a ski (6) according to the invention in which the ski is arranged for being able to be rocked about a bracket (12) directly or indirectly attached to the fork (2) and in which said wheel (1) extends a small distance down through a gap or recess (9) in said ski.

Said wheel (1) is arranged on a wheel shaft (3) in a wheel fork (2) arranged for being rotated about a generally vertical axis in a bearing (7) for said fork on a walker frame (4). The novel features of the wheel comprise: * The wheel is provided with a ski (6) being longer and wider than said wheel (1) and of which said ski (6) is provided with a generally centrally arranged recess (9) arranged for the wheel's rolling periphery to run through said recess (9). The ski (6) is provided with a standing bracket (12) in a rocker bearing in a horizontal bracket axle (11) being fixed directly or indirectly on to said wheel fork (2), so as for said wheel (1) to run freely on flat, bare ground and of which said ski (6) may run in snow if the substrate is snow. The central recess makes possible that the

wheel may run on the bare ground e. g. along bare asphalt covered roads where the snow has been completely removed, or on floors inside e. g. shops or halls. The ski will take over the supporting function if the walker is run into a snow layer that is thicker or looser than the wheel may support in the snow, but the wheel may still be able to continue rotating about its axis and carry a part of the load in the portion of the ski in which the wheel protrudes. The fact that the recess is centrally arranged also with respect to the sideways direction makes the ski and the wheel to continue to steer evenly during the transition from bare ground to snow. Under conditions of uneven snow depth between the right side and the left side of the ski, there is a risk that the ski will steer somewhat to the side, but this may be solved by arranging a so-called"shock cord", an elastic band with a non-elastic core, arranged between the rear portion of the ski and a portion of the walker's frame being behind the ski.

According to a preferred embodiment of the invention the wheel is provided with a horizontal guide pin (13) arranged on the wheel fork (2) running in a guide recess (15) in the upright standing ski bracket (12) in which the guide recess is coaxial with respect to the bracket axis (11), and in which said guide recess has a first and a second limitation (16,17) so as for the ski (6) to be rocked between two positions. The ski is carried somewhat in front of its central point so as for the forward portion in a neutral balance will be rocked slightly upwards, as shown in Fig. 2.

According to an additionally preferred embodiment of the invention the first limitation (16) in the guide recess arranged so as to prevent the rear portion of the ski from dragging along the ground on an even ground, and that the second limitation (17) in the guide recess (15) being arranged to prevent the front portion of the ski from rocking down to touch the ground on an even substrate.

In a preferred embodiment of the invention the wheel fork (2) is deviated in a rearward direction in order for the wheel axis to be situated behind the fork bearing's (7) vertical axis with respect to the driving direction. Almost all front wheels of walkers, shopping carts, and trolleys, are arranged in this way in order for the front wheels freely to follow in a desired direction commanded by a hand grip, the hand grip usually arranged closer to the rear wheels. The ski's bracket axle (11) is, in the preferred embodiment of the invention, arranged ahead of the wheel axle (3) on the wheel fork (2) and at the same time behind the vertical axis of the fork bearing (7), so as for the ski to drag a small distance behind its bearing point, and arranged for being rotated to a desired heading direction in the same

way as the wheel. If the bracket axle is arranged some distance ahead of the balance line of the ski, the ski will be inclined slightly upwards in the heading direction, and thus encounter small snow heaps in an advantageous posture and climb immediately. The ski may be provided with longitudinal grooves or ribs for improving the directional stability and the strength. Likewise, the ski may be provided with upwardly directed side edges to provide improved stiffness.

According to an additionally preferred embodiment of the invention, the ski (6) is in its horizontal position arranged in an elevation (h) less than a radius (R) of the wheel above the ground, as counted on flat, bare ground, i. e. below the axle of the wheel. Thus the"ploughing"resistance, due to the wheel's movement through the snow, will not pose any significant obstacle. Practice shows that when a small portion of the wheel protrudes down into the snow, through the recess of the ski, this will stabilise the ski to make it more directionally stable. Snow that might collect along the periphery of the ski will generally be scraped off by the central recess'edges so that no significant amounts of snow will collect on the wheel. In fact, this is an improvement as compared to existing walkers.

In Fig. 1 is shown an alternative embodiment of the invention of which a secondary mounting bracket (18) is attached to each fork leg of the fork (2) and holding the axle (18) on which the bracket (12) with the ski (6) can rock. This secondary bracket (18) may be attached in a desirable elevation on the fork (2) above the lower point of the wheel 81) so as for a desired elevation for the ski above bare ground is achieved. Such a desired elevation may thus be adjusted depending on the weight of the user, the snow conditions, or other circumstances.

The brackets (12,18) may also be provided with a quick release coupling so as for the bracket (12) with the ski (6) arranged for being removed from and mounted on the walker without the use of tools.

Fig. 3 is a side elevation view of a walker with a front wheel with skis according to the invention. Here, the bracket is attached to an axle directly on the fork and not on a plate arranged on the fork. The heading direction is to the right in the drawing.

Fig. 4 shows a schematic section through and partial outline of the wheel and the ski from Fig. 1, Fig. 2, and Fig. 3. Please notice the recess in the ski, allowing the wheel to roll on a bare substrate, and that the ski may be rocked about the bracket's axle mounted on the fork.