The Columbia Steel Windmill.
The steel windmill, of which an engraving is here presented, possesses many features tending to increase its efficiency and durability. The frame of the wheel is constructed of drawn steel rods, the spokes bracing in both directions from the rim, which is directly over the centre of the hub, which while allowing a degree of elasticity to the wheel, renders it impossible for the wheel to collapse in any direction.
The fans are secured to the frame of the wheel in such manner as to form a true spiral, presenting an angle of fortyfive degrees to the wind at the inner end of the fan, gradually increasing the angle to eighty degrees at the rim of the wheel, thereby presenting the best possible angle to the wind at every part of the fan when considered relative to the action of the wind on the wheel when the wheel is in motion; also providing for the best clearance of the wind in passing through the wheel, avoiding entirely the back suction so noticeable in some makes. The hub is clamped to the main shaft with a bolt passing through the shaft and one side of the hub, and secured also by two steel set screws. The hub is hollow and projects back over the box, so that the weight of the wheel is supported by the entire length of the shaft in its bearing. The main shaft is of first quality steel shafting, and to it is attached the internal gear pinion, which in turn drives the internal gear wheel to which is attached the pitman. The pitman is connected at the upper end to the crosshead, which runs cn parallel guides made of steel shafting and contains swivel of actuating pipe. It will be noticed that this plan of gear carries the pitman on an almost perpendicular line when the windmill is doing its heaviest work on the up stroke of the pumping rods ; also that it brings the entire gear close to the centre of the turntable, obtaining the greatest strength for a given weight of material used in its construction. By the use of the internal gear device the speed of the w’heel is reduced to the normal speed at which it is practicable to operate a pump in a well of any depth and overcome the back lash on the dead centre, which is the objection to outside or spur gears, and more than double the power of the wheel when compared with a direct geared mill. The gearing is entirely protected from exposure to the weather.
The governing of the mill is secured by the action of the wind on the wheel, and by the direct pressure of the wind on a side vane equalizing the pressure of the wind on the opposite side of the wheel, in connection with an auxiliary spring, a uniform speed of the wheel is maintained in winds of varying intensity, and affording the wheel protection in storms. 1 hese mills, which are made eight or ten feet in diameter, are manufactured by Mast, Foos & Co. of Springfield, O.