Patent ID: 8308134
Filing Date: 2012-11-13
Classification: B66F

Abstract:
1. A mobile jack for a vehicle, the jack comprising: a movable base including a plurality of rollers adapted for moving and positioning the jack upon a generally horizontal support surface; an upper platform adapted for lifting loads, the upper platform movable between at least one lowered position and at least one lifted position; a pair of scissor lifting assemblies each lying in a vertical plane located adjacent to and spaced apart from one another, the scissor assemblies adapted for lifting the upper platform, each of the scissor assemblies having a first scissor leg having an upper and lower ends, the lower ends of the first legs pivotally fixed to the movable base and the upper ends of the first legs translating along the upper platform, and each of the scissor assemblies having a second scissor leg pivotally fixed to the first scissor leg at a horizontal scissor axis, the second legs having an upper and lower ends, the lower ends of the second scissor legs translating along the movable base, the upper end pivotally mounted to the upper platform; a pair of hydraulic cylinders adapted for lifting the upper platform between the lowered and lifted positions, a first one of the hydraulic cylinders operatively connected between the upper end of the first scissor legs and the lower end of the second scissor legs, the other of the hydraulic cylinders operatively connected between the upper end of the second scissor legs and the lower end of the first scissor legs; and a lock assembly adapted for locking the upper platform in at least one lifted position independent of the actuation of the hydraulic cylinders, the lock assembly having a locking arm pivotally mounted on the movable base at a first end and the locking arm having a locking element at a second end, wherein when the upper platform is in at least one of the lifted positions, the lower ends of the second scissor legs slide inboard with respect to the first scissor legs, and the locking arm thereby pivots so that the locking element is lowered and supported by the base outboard of the lower ends of the second scissor legs, thereby preventing the second scissor legs from sliding back to the lowered position.