Post hole digger
A post hole clam-shell digger, also called post hole pincer or simply post hole digger, is a tool consisting of two articulated shovel-like blades, forming an incomplete hollow cylinder about a foot long and a few inches wide, with two long handles that can put the blades in an "open" (parallel) position or a "closed" (convergent) position.
The tool is used to dig holes in the ground, typically from a few inches to a about a foot in diameter, for general purposes such as setting
Comparison with earth augers
An earth auger is another tool that is used to dig holes in the ground, consisting of a rotating shaft with one or more blades attached at the lower end. A hand-powered auger is generally easier to use than a clam-shell digger, and can in principle dig deeper and remove more dry, sandy soils. It naturally creates a round and straight hole, but only of a fixed diameter. The shovel like shape of a clam-shell-type digger allows it to be used to dig holes of any shape and any diameter greater than that of the open blades.
History and patent info
Clam-shell-type pole diggers seem to be a relatively recent invention, newer than earth augers. A patent was filed by J. Lawry of Lenior City, Tennessee in 1908.[1] The patent has the traditional clam-shell design with an extra spike in the center.[citation needed]
References
- ^ Jacob H. Lawry (1907) "Post-hole digger". US Patent , filed on 1907-06-11, granted on 1908-04-07, expired on 1925-04-07.
External links
Media related to Post hole diggers at Wikimedia Commons