Abstract: Clearance of a minefield is effected using first and second ground-engaging drive units (63 and 64), each of which includes a milling or grinding drum (6). The first drive unit (63) is connected to the front of a multi-purpose vehicle or tractor (62) and the second drive unit (64) is connected to the rear of the vehicle or tractor (62) to form a mine clearance apparatus which can be driven over the land to be cleared of mines with the vehicle or tractor (62) supported clear of the ground by the first and second drive units (63 and 64). The milling or grinding drum (6) of the first drive unit (63) grinds up the surface vegetation and the milling or grinding drum (6) of the second drive unit (64) grinds up a layer of soil and any anti-personnel mines contained therein.

Abstract: An athletic shoe includes substantially horizontal chamber substantially within a heel portion of a midsole, the chamber having atmospheric communication at its lateral sides. The chamber includes an upper substantially rigid horizontal plate having at least four apertures therein and a lower substantially rigid horizontal support plate having a corresponding plurality of at least four apertures. Flexible resilient unitary sleeves integrally join respective vertical pairs of the apertures of the upper and lower plates respectively. Disposed within each of the resilient sleeves are resilient members each having spring constant and spring rate greater than that of the sleeves.

Abstract: An athletic shoe includes substantially horizontal chamber substantially within a heel portion of a midsole, the chamber having atmospheric communication at its lateral sides. The chamber includes an upper substantially rigid horizontal plate having at least four apertures therein and a lower substantially rigid horizontal support plate having a corresponding plurality of at least four apertures. Flexible resilient unitary sleeves integrally join respective vertical pairs of the apertures of the upper and lower plates respectively. Disposed within each of said resilient sleeves are resilient means each having spring constant and spring rate greater than that of said sleeves.

Abstract: The instant invention is an improved sport shoe having a spring biased heel with operator insertable foam inserts for varying the biasing ability of the heel. The foam inserts are colored allowing instant determination of the type of activity the shoe is suitable for. The inserts allowing the wearer of the shoe to customize the shoe for a particular activity. High deceit foam inserts provide support for basketball or the like jumping sports. Medium deceit foam inserts provide support for aerobic or the like activities. Low deceit foam inserts provide support for low impact activities such as jogging and no foam inserts provide unlimited spring range suitable for cushioned walking.