Author Topic: Douglas Patents of Note 10  (Read 6465 times)

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Offline Doug

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Douglas Patents of Note 10
« on: 19 Feb 2008 at 03:00 »

Improvements in or relating to Cooling Devices for the Pistons of Internal-combustion Engines.

Patents of Note 10
Patent No.: 127,757
Application: Jul. 13, 1918
Complete: Jan. 11, 1919
Accepted: Jun. 11, 1919

The cooling fan H, H2 indicates this design to be for a stationary engine. Still, it would have to be very stationary indeed, as at anything over an idle one wonders if any meaningful amount of air could have time to pass through the narrow ports E2, F2 and through ports in the piston E, F and across the cavity under the crown A, A2. A further unfortunate detail is the location of the ports relative to the fan blades. Perhaps pressure was not the goal; instead air passing from the eye of the fan and being flung off the tips was to draw air across the piston as it passed the port. Whether the idea blew or sucked they did not say, and who are we now to pass judgment. Though the piston had a long skirt to seal the ports in the cylinder wall when the piston ascends, one assumes that they were further disposed out of the plane shown in the cross section such that the hole for the gudgeon pin did not inadvertently ventilate the crankcase as it passed by the ports.

At first it looks like the auxiliary cylinder exhaust ports one sees on very early engines, till you note the piston does not descend enough to uncover them to the combustion byproducts. However with just one compression ring and a short distance separating the ports and the crown, perhaps they would have functioned as exhaust ports after all!

2007 D. Kephart, Glen Mills, PA, USA