Cool Streetcar Pictures--from the Patent Office? ~ Thursday, September 28, 2006

An interesting source of historical techincal information, but one little-used by railfans, is the U.S. Patent Office. At http://www.uspto.gov, you can search for patents and look at scans of the text and drawings.

Unfortunately, finding really old patents is kind of tricky, because the patent office has only scanned them as images, so you can't do keyword searches on them. If you know the number of a patent from some other reference, you can jump right to it, but otherwise you'll need to be clever to find things.

One way to go about it is through citations. Like academic papers, Patents cite "prior art", earlier patents that describe existing solutions to whatever problem they're trying to solve. So if you can find a relatively recent patent through keyword searches, its references might lead you back to something in the era you're interesing, and the Patent Office website makes it easy to follow them; in patents stored as text, references to older patents are links you can click on.

When you finally find a patent you want to look at, the images are in TIFF format, which browsers do not always support. I installed a AlternaTIFF which let me see them.

So here's a few pictures I've downloaded. The first is from Patent No. 1,617,761 "Safety Car"; it central claim is that by paiting the front of a streetcar white, and shining lights on it, its visibility and safety will be improved. It is a nice drawing of a car of the Market Street Railway of San Francisco, the company which invented and used this idea:



Here's a more technical one, from Patent No. 1,138,357 "Car Truck", which is Brill's patent on their "Radiax" truck:



Here's two drawings from patents by Andrew Hallidie, inventor of the cable car, describing details of wire ropes (No. 339,646) and grips (No 610,353):



Cable cars are well covered by patents. In the 1870's and 80's, cable cars were the latest high tech industry, and one that companies were keen to control through what we now call "intellectual property".

Have fun, and while you're at it, check out some of my patents if you want.