My other blog is which is an archive of my works.......... Robert Ho REQUEST FOR STATEMENTS at


About Me

My photo
My archive of works is at

11 April 2008

Idea Invention of Portable Ramps for Wheelchairs

1. This idea is primarily for those who are wheelchair-bound but will also be useful for movers, deliverymen, ambulance men, etc, and all those who need to push heavy trolleys up a step, etc. It is a simple idea, to have 2 small, carryable, convenient, portable, flexible ramps so that those on wheelchairs or pushing heavy trolleys can negotiate up the ramps onto the higher landing or floor. [For example, the front step from my flat is 117mm and that of my mother in law new flat is 102mm. My idea allows for a FLEXIBLE Ramp that will ramp different steps/heights like these common obstacles]. A small step like these front door steps can prevent many wheelchair bounds from leaving their flats or movers from easily pushing heavy trolleys up or down the step.

2. For a wheelchair-bound person, suddenly coming to a step or higher stepped floor is a huge obstacle. Often, the only alternative is to push yourself along further parallel, to find a natural ramp, but every additional metre for a wheelchair person is a metre too far. This idea means that the moment you come to a higher stepped floor, you simply take out your 2 portable, flexible, ramps, place them onto the step, 1 ramp for the left wheel, 1 for the right, then push yourself up the ramps onto the higher floor, then, using the strings attached to each ramp and tied to your wheelchair for convenience, you simply pull the ramps [after you have used them to climb onto the higher floor] into your hands and then keep/hook them onto the wheelchair and continue your way, until the next step. Going down a step may not be a problem but if so, this procedure can also be done, although trickier in terms of the handicapped placing the ramps, unless he/she has a stick to push the ramps into position. A short, foldable stick or rod either loose or attached to each ramp may make this positioning easier. Especially if specially designed with the Ramps for pushing the ramp/s into position onto and against the step.

3. Thus, while these Ramps must be long enough to allow easy rolling up/down the ramp, they cannot be too long or big, otherwise, not very portable or convenient to store or hook onto the wheelchair, etc. I here suggest some dimensions but since it is such a cheap and simple idea, you can quickly and cheaply make different prototypes to test how wheelchair users, movers, deliverymen, etc, can or will use them.

4. Material: suggest steel -- cheap, easily formed, strong and thin enough, about 2 to 3 millimetres thick, corrugated or fluted in both directions for non-slip even when wet, or coated with non-slip surface such as rubber, etc. The whole Ramp could be coated in rubber or rubberised compounds for non-slip. The parts resting on the floor or upper part of the Step should also be rubberised for non-slip for greater safety.

5. Cross-section shape: Basically U-shape, like this: |_________________| . The bottom of the "U" is about 200mm to 300mm wide. If too narrow, it will be harder to place both ramps, correct distance apart, such that the 2 wheels or 2 sets of wheels [front and back if 4-wheeler] can easily 'find' the ramps. If too broad, clumsy. The LIPs along the entire lengths of the ramps are GUIDES for the wheel/s so the wheel/s don't veer off the ramp. I suggest about 50mm high LIPS or GUIDES. The LIPs have to prevent the wheel/s from veering off the ramp but also take holes at/near the JOINT or HINGE [joining the Sloping Part and the Flat Part] to allow for the Stiffening of the 2 parts of each Ramp or the Rigidising of the 2 parts of each Ramp so that when the heavy wheel/load presses down on the Sloping part of the Jointed or Hinged Ramp, the Flat part of the Ramp [on the upper part of the step] does not flip up and the Ramp collapses downward onto the lower floor.

6. Length: Each Ramp consists of 2 parts Jointed or Hinged together, so that when folded, the Flat Part can fold INSIDE the Sloping Part. So if the Inside LIP to Inside LIP distance of the Bottom of the Sloping Part is say, 200mm, then the Flat Part, to fit inside the Sloping Part must be no more than 200mm OUTER dimensions of LIP to LIP, minus at least 2-4mm tolerance for easier fit to allow for distorted shaping or misshapened parts due to heavy use, etc. Give more tolerance because this won't affect the effectiveness of the Ramps. Also allow for the thicknesses of the non-slip rubber, etc. As for the Lengths of the Sloping and Flat Parts of each Ramp, I suggest the Length of the Sloping Part be about 450mm and that of the Flat Part to be about 120mm. Feel free to develop other dimensions or variants or models for different purposes.

7. Thus, each Ramp will have a Sloping Part, hinged or flexibly jointed to a Flat Part. The Flat Part is the horizontal part placed onto the flat upper part of the floor or step. A sideways view in words would be: the Sloping Part has its lower portion on the lower floor of the Step, sloping upwards to the top of the Step where it is jointed or hinged to the Flat Part of this Ramp, this Flat Part resting flat on the upper part of the Step.

8. Why the Joint or Hinge? Because this is the simplest solution to different heights of steps to be negotiated, because you never know how high the step you will come across. With a Flexible Joint or Flexible Hinge, the Flat Part always rests FLAT on the top of the step while the Sloping Part flexibly slopes down from the Joint or Hinge, either sloping more steeply when the step is high or less steeply when the step is low. As mentioned, this contraption works only if the Flat Part does NOT flip up when the heavy wheel presses down on the Sloping Part due to the natural Lever action. How? There are many ways and more ways than I know or can think of. 1 way is to have many holes on both the LIPs of the Flat Part and the Sloping Part near the Joint or Hinge and these LIPs should OVERLAP each other so that a metal PIN can simply be pushed through a hole in the LIP of the Flat Part, through a corresponding hole in the overlapping LIP of the Sloping Part, thus RIGIDLY locking the Sloping and Flat Parts into position. If PINs are used, there should be 1 pin for each of the 2 LIPs sets for each ramp for evenness. More importantly, the 2 pins for each ramp should be pushed in from the INSIDES of the "U" and this probably means that each pin should be attached to the inside thus forcing the pin to only be pushed from the inside. This is to prevent the pins from being 'pushed out' by the wheel/s as may be the case if the pins are pushed in from the outside of the LIPs towards the insides of the "U". Also, the head of the pin should be a sort of Round Head, like a round head screw, to prevent the wheel/s 'catching' onto the pin.

9. To make the Flexible Ramp more convenient to carry, the Sloping Part could be made of Telescopic Sections, such that the full length of about 450mm is made up of say, about 3 sections that slot inside each other, to be pulled out telescopically when needed. Note that each section cannot be fully pulled out but must have an overlap with its next section of at least about 50mm, this Overlap giving sufficient strength and rigidity so the Sloping Part sections don't buckle when the weight of the wheelchair or load is pressing down upon the joining sections.

10. [SEPARATELY]. Here is an additional Idea for wheelchairs and other wheeled users. It will be good to develop a Rachet Wheelchair or better still, develop a Ratchet Device that can be bought cheaply and RETROFITTED onto wheelchairs. This Ratchet Mechanism will help wheelchairs and other wheelers because when going up a slope or any ramp, the Ratchet will allow the wheel to turn forward and prevent any backward rotation so the wheelchair cannot roll backward down the slope. Preferably, this Ratchet Mechanism should be retrofitted once onto the existing wheelchair and thereafter, only locked into Use Position only when needed as in going up a slope and the wheelchair user is not confident of rolling all the way without stopping and hence the ratchet mechanism will prevent any backward rolling.

11. No patents or copyright for these ideas. However, you may be able to trade mark your designs. Check with your Patent lawyer.