Modular Conveyor Corner
The challenge, presented by a large automobile engine plant, was to create a heavy duty conveyor that could be operated even if electrical power and the source of compressed air was lost. A reduced production rate was acceptable but production had to continue. In common heavy duty conveyors the fixtures, often weighing up to 1000 pounds, were lifted above the conveyor side rail and then transferred off in a perpendicular path to make corners or to divert fixtures off the main line to repair spurs or parallel operations. The fixture was also lifted when it was necessary to rotate the fixture for various assembly processes that might require a different face of the engine to be presented. The modular conveyor described in Case #7 already satisfied this requirement but a new design was required for corners and fixture rotate stations.
The solution was to place four rollers, mounted at 45 degree angles to the normal conveyor path, at the same elevation as the straight conveyor rollers. By rotating the rollers in a direction that was at a 45 degree angle to the required path the applied forces offset each other and the fixture traveled in the desired direction. For example if the desired direction is to the right all the rollers are operated so the motion is to the right. The lower left and upper right rollers rotate toward the lower right corner. The upper left and lower right rollers rotate toward the upper right corner. If the desired direction is upward all the rollers are operated so the motion was upward. The lower left and upper right rollers rotate toward the upper left corner. The upper left and lower right rollers rotate toward the upper right corner. If the fixture needs to be rotated about its center all the rollers rotate in the same direction. Pneumatically operated guides help guide the fixture during these motions.
Admittedly, it takes a good amount of effort to manually push a fixture through such a corner unit but the customer was extremely happy. This conveyor module proved to be extremely reliable. It also allowed corner modules, lift & transfer modules, and lift & rotate modules to be replaced with just one module providing great flexibility. This flexibility was improved by making it interchangeable with the straight conveyor section described in Case #7. Major system changes were completed over a weekend due to this modular construction.
(Click on the picture to view more information on the corner.)