A Selective Database of U. S. Patents Relating to Spiral Screwdrivers: 1868 - 1931
Compiled by Clifford D. Fales
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Some notes about what is included in the spiral screwdriver database...........
Generally, the patents included here are those which are commonly associated with spiral screwdrivers. There is a great deal of cross-over among patents for spiral screwdrivers, ratchet screwdrivers and push (Archimedian) drills. A number of patents for ratchet screwdrivers/mechanisms are included because the ratchet mechanism is used in combination with many spiral screwdrivers.
The patents included in this database will however, by way of the illustration or text, relate in some way to spiral screwdrivers. A few included patents are for accessories or ancillary devices.
The patent titles included in the database are taken from the patent illustration page; for some patents, the title on the text page is different from the title on the illustration page, e.g. IMPROVEMENT IN SCREWDRIVERS vs SCREWDRIVER.
Patent titles can be misleading; a number of patents relating to spiral screwdrivers are not titled: "Spiral Screwdriver." They may be titled something like: "Means for Converting Motion, Bit Stock, Rotary Tool Driver or even Ratchet Screwdriver or Ratchet Mechanism."
The basic USPTO classification into which the spiral screwdriver falls is 74/127; this is based upon the manner in which the item functions. In case you are interested, the USPTO definition of this classification looks like this.
There are more than 400 patents which fall into the class/subclass 74/127. Many of these relate to patents for items other than spiral screwdrivers; I have selected 86 which are related to spiral screwdrivers for this database.
Some of the patents included are not within 74/127 classification. They are included because because they are used in conjunction with a specific spiral screwdriver patent, i.e. a ratchet may be incorporated into a spiral screwdriver. Accessories, add-on and retro-fit devices for spiral screwdrivers are also included.
This file has only basic information from the source patents supplemented by limited comments; it may be expanded in the future. Your feedback is welcome.
Other tool articles by Clifford Fales:
The Hedge/Clark Connection - An Unusual Rule
(originally appeared in The GRISTMILL of Mid-West Tool Collectors Association, March 1997, Vol. 47)
How Thick is "Extra Thick?"
(originally appeared in The GRISTMILL, of Mid-West Tool Collectors Association, March 1989, Vol. 54,)
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