Sunday, June 7, 2009

What is the Pivot Point on Your Power Wheelchair?

If you already own a power wheelchair, then you will already know how it maneuvers indoors. However, you may not know why it maneuvers that way.

The drive wheel on your power chair is the reason the chair maneuvers the way it does. There are several other factors that determine how your power chair maneuvers, but the main reason is the drive wheels.

Power chairs, like vehicles come in rear wheel drive, front wheel drive and center or mid wheel drive. They each have a different pivot point, which determines how the chair will maneuver. The pivot point is where the drive wheel axle line and the power base’s centerline cross. The chair maneuvers and turns around this point.

On a rear wheel drive power wheelchair the pivot point can be found in the rear of the power chair behind where you sit. The majority of the power chair is in front of the pivot point. This is the old stand-by and the most stable chairs in most cases. If you own one of these types of chairs, you may have noticed when going up steep hills, the chair will lean back on its anti-tip tubes to prevent the chair from tipping backwards. The top speed for this chair is about 6 mph. Because it is rear-wheel drive it has the largest turning radius. If you have owned one of these types of chairs and are planning on replacing with a different type of drive wheel, keep in mind the tie-down you use in your van will need to be replaced to accommodate the new style chair.

On a front wheel drive power wheelchair the pivot point will be in the very front of the chair with the majority of the chair behind it. This means you will be sitting behind the pivot point on this type of chair. This chair is very stable in uneven terrain with up and down hills. Of the three types of chairs, the front wheel drive power chair will move over obstacles well. Since most of the chair will be behind you, you will need to adjust the way you turn to accommodate the rear of the chair. This type of chair drives a lot like a forklift. The maximum speed for this type of chair is slower than all of the others. It will range from 5 to 5.5 mph because the front wheel drive chairs have a tendency to “fish tail” at a higher rate of speed. The turning radius is only slightly smaller than that of the rear wheel drive chair.

On a mid wheel drive or center wheel drive power wheelchair the pivot point is directly beneath you. It is in the middle of the chair with the chair on top of the pivot point. You will have equal parts of the chair in front and behind you and your center of gravity is about the same as the pivot point. With this type of chair you will have a much smaller turning radius than the rear wheel and front wheel drive chairs. The speed of this chair is limited to about 5.5 mph. If you ride on uneven terrain on a regular basis, you may want to reconsider buying one of these chairs. These chairs have a tendency of getting stuck if you are riding on uneven terrain or up and down steep curbs. The front or the rear wheels will get stuck, which will suspend the drive wheel so they cannot touch the ground.

Your specific lifestyle and needs should determine the chair you buy. So consider your choices carefully.

Courtesy: http://www.mobilitywheelsonline.com
Chris I.

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