Abstract: An internal combustion engine adapted to burn solid fuel including a piston-and-cylinder assembly including a valved inlet for combustion supporting air, a valved outlet for exhaust of combustion products, ignition means and a fuel valve for retaining a quantity of solid fuel out of the cylinder and opening on pressure reduction in the cylinder by piston movement beyond top dead center to introduce the quantity of fuel into the cylinder.

Abstract: An internal combustion engine which includes a main combustion chamber, and which is improved by the inclusion of an auxiliary combustion chamber, an ignition valve for controlling the establishment of communication between the main and auxiliary chambers, auxiliary fuel mixture feed means for feeding the auxiliary chamber, and an auxiliary piston in the auxiliary chamber for compressing the fuel mixture therein to ignition when the main chamber contains a compressed charge of fuel mixture, whereby opening of the valve means during ignition in the auxiliary chamber communicates combustion to the main chamber for ignition therein of a relatively lean fuel mixture.

Abstract: A plow construction including a frame extending rearward from a tractor and swingable up and down relative to the tractor, a rear frame part being swingable with the frame and rotatable relative thereto about a forward and rearward axis, plow discs carried by the rear frame part for ground tilling engagement and movable therewith about the forward and rearward axis for inversion of the discs to reverse the ground tilling direction, and a guide wheel carried by the frame for counteracting side draft forces of the tilling wheels.

Abstract: A chair construction including lower and upper back parts, wherein the latter is selectively positionable vertically relative to the former and carries a torso girding belt, thereby enabling a user's torso to be elevated at least partially from the seat for increased comfort during long usage.