1942 – Hopping Tank – Henry Wallace (American)
Patent number: 2371368
Filing date: Oct 16, 1942
Issue date: Mar 13, 1945
See full patent details here.
Blurb from patent describiting capabilities and uses.
This invention relates to a vehicle, and more particularly to a tank which is propelled by means of an operating leg.
One Of the objects of this Invention is to provide a tank having an extensible leg capable of imparting a series of vertical oscillations to the tank, and having means to very the angle of inclination of the leg to obtain directional movement of the tank.
Another of the objects of the invention is to provide a tank which is adapted to traverse difficult terrain.
Yet another object of the invention is to provide a tank which is propelled in such a manner that its progress is intermittent, thereby rendering it a difficult target.
Still another object Is to provide a tank provided with means whereby the direction of its course may be rapidly changed, thereby rendering it a difficult target.
Yet another object Is to provide a tank which provides an improved mount from which to aim a gun due to its mode of progress.
Yet another object is to provide a tank which provides the means whereby the direction of vision of each gunner remains approximately the same.
A further object Is to provide a tank which, when at rest, affords adequate protection for the propelling mechanism, thereby permitting its use as a pill box.
With these and other objects in view, this invention embraces broadly the concept of providing a tank which is propelled by means of a collapsible leg. When in collapsed position the leg is fully protected by the wall of the tank, thereby permitting the use of the device as a pill box without exposing the operating mechanism.
The leg Is fully extended to operating position by means of an expansible force, such as compressed air or an explosive charge. During its travel, the tank is stabilized by the action of a gyroscope.
The tank is propelled by the bounding effect imparted by the reciprocable movement of a ground engaging element which is nested in the leg. This movement is effected by the combustion of fuel oil within the leg on a Diesel principle.
This operation is controlled from a pilot's turret.
There's some discussion on the Seifert Hopper (see pdf found here) that describes obvious issues around effects on acceleration/deceleration on the body. Animals were used in his study.