Patent ID: 7677125

Claim:
A rack and pinion assembly comprising: first and second slide assemblies; first and second rack gears positioned near the first and second slide assemblies and comprising a plurality of rack teeth spaced apart from one another longitudinally along the rack and a profile between adjacent teeth defining valleys between each pair of teeth and at least one rack having at least a final two irregular teeth comprising a spacing that is greater than a common rack tooth profile such that a tooth spacing is increased in a valley between the two irregular teeth and an adjacent prior valley between one of the irregular teeth and a regular tooth; first and second rotatable spur gears each having gear teeth in operable enmeshed communication with the teeth and valleys of the first and second rack gears respectively, the spacing of the two irregular teeth being of a dimension such that the spur gear teeth will enmesh with valleys prior to and between the irregular rack teeth, the dimension being such that only a single gear tooth of the spur gears can be positioned in the valley between the two irregular teeth, the dimension being such that the rotatable spur gears will freely rotate after a first gear tooth engages the valley prior to the two irregular teeth to allow a second gear tooth to engage the valley between the final two irregular teeth, and the spacing dimension allowing for longitudinal movement of a spur gear tooth within the valley prior to the two irregular teeth and the valley between the two irregular teeth to allow a drawer assembly, to which the rack gears are attached, to sealingly close.