Author Topic: Douglas Patents of Note 07  (Read 6411 times)

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Offline Doug

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Douglas Patents of Note 07
« on: 07 Dec 2007 at 05:14 »

Improvements in or relating to Spring Frames for Cycles and Motor Cycles.

Patents of Note 07
Patent No.: 17,336
Application: Jul. 28, 1913
Complete: -
Accepted: Oct. 30, 1913

Unlike most patents, Douglas must have got it right the first go.  They filed their complete specifications at the time of initial application.  Regardless they still did not use the idea!  There are other patents of this period for a cantilevered leaf sprung swing arm suspension; patent images of which have previously appeared in the New ConRod magazine of years past.  Though rare, it seems Douglas did actually make a few of the cantilevered leaf sprung swing arm suspension, and it was included in their catalog of 1916.  But not apparently this one; and it is not hard to see why.  Though the rear fork must have been tremendously stiff, the link arrangements would probably have been a liability, though braced better than most front fork links of the day.  Douglas was always a bit stingy with the links on their front forks!  No doubt this design with its extension coil springs also gave the opportunity for the suspension to collapse at both ends!

2007 D. Kephart, Glen Mills, PA, USA