Custom compression latch eliminates damage and vibration

A forklift truck maker has eliminated accidental damage and excess vibration problems by using a custom compression latch to secure engine covers. Dean Palmer reports

A customised compression latch, which closes by turning a handle through 180°, has been developed to solve a noise and vibration problem for a manufacturer of forklift trucks. Southco's 'Folding T-handle' compression latch is being used to secure engine covers and doors on Bobcat's telescopic forklift trucks. The latch provides reinforced retention of the forklift's engine cover on its support. The user turns the handle of the latch through 180° which operates a cam to secure the cover into the chassis. For safety and a valuable visual check on closure, the handle folds down flush and can then be locked in a position with a key. With a compression force of 300N, the latch ensures an effective seal which eliminates vibration. Patrice Caulier, business unit manager at Bobcat, explained: "If an engine cover is not properly closed, it can swing open while the forklift is in operation and become damaged or torn off by the wind. This poses a safety hazard and incurs repair costs. Between 1998 and 2002, out of 10,000 telescopic forklift trucks delivered, we heard of this happening in some 50 instances. The problem can be caused by an inadequate latch or even by the driver simply forgetting to check before starting the truck. "We needed to find a reliable system that would be robust enough for any operational conditions and would also help eliminate driver error and a latch that would also minimise noise caused by vibration," he added. After consulting Southco's website and interactive product selector guide, Bobcat's design engineers asked Southco to customise a suitable latching solution. A single key, similar to a passenger car key, was what Bobcat wanted to operate the ignition, doors and engine covers. Southco therefore had to incorporate different barrels in the latch and fit an extra plate on each cover. Caulier continued: "The T-handle means that forklift truck drivers can do a quick visual check to ensure the engine cover is secured and so we can eliminate the problem of accidental opening during operation." One year after fitting the new latch to its trucks, there has not been a single instance of engine covers flying open during operation.