|
Bearing plate moves while load stays still
|
10/08/2006
|
| |
Tom Shelley reports on some extraordinary developments in two-dimensional linear bearings
A plate carrying two matrices of bearings - one set on each side - can move freely beneath a load, while that load stays exactly where it is, regardless of whether it is light or heavy.
The balls in the 'Parafricta Plate' are arranged so that those in the lower surface matrix contact those in the upper surface matrix. If the lower surface of the plate is resting on a flat surface and the plate is moved, the lower balls engage the upper balls so that their uppermost surfaces move in a direction exactly opposite to the direction of movement of the plate. The result is that anything placed on the upper surface stays exactly where it is while the plate is free to move.
The idea is the brainchild of Tony Pike, one of five directors of the company promoting the device, APA Parafricta. It specialises in low friction solutions for patient handling and care. Another patented development is 'Parafricta Fabric' which has a low coefficient of friction - close to that of ice - an absence of stiction and a tensile strength close to that of steel.
The plate was originally developed in order to introduce an inflatable stretcher under a road traffic accident victim, but could also be used to protect built structures against earthquake and shear - and clearly has other engineering applications. It currently exists in the form of a plastic demonstration prototype with 'Nylon' balls but can be manufactured in any load-bearing material.
The company was formed in July 2004, with funding from its directors, the Oxford Trust, Nesta and several business angels. It is looking to access the fast-growing medical market, but it is also interested in finding partners and licensees for its technologies in engineering applications.
Patents have been granted in the UK for both the bearing plate, and for medical applications for the Fabric, with foreign applications pending.
Parafricta
Pointers
* Bearing plate can move freely beneath a load in two dimensions while that load stays exactly where it is
* It was originally developed to introduce an inflatable stretcher under a road traffic accident victim, but could also protect built structures against earthquake and shear
|
| |
Author
Tom Shelley
|
| |
| Email this article |
| |
|
|
|
|