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The Post-Hole Digger: Two Shovels on a Hinge and a Point Between Them
Karen

Created by

Karen

27. September 2026SE
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The Post-Hole Digger: Two Shovels on a Hinge and a Point Between Them

A fence post needs a hole as narrow as the post and as deep as a forearm. A spade makes a wide pit; a pair of shovels hinged together can take the earth out in plugs from a hole barely wider than the blades. Jacob H. Lowry of Lenoir City, Tennessee, filed US 884,177 on 11 June 1907; it was granted on 7 April 1908. Two shovels with handles are hinged by lugs and a bolt, with studs that stop them when the handles are parallel. One shovel's head carries a sliding sleeve with a detachable digging point, so that either the shovels or the point can be pushed ahead — the point to loosen the earth in the centre of the hole. This rung works out how many bites a hole takes and digs one.
Beginner
About 3 hours

Instructions

1

Volume, bites and lifts

Loading Jupyter Notebook...
2

The first tool that made a hole

A pointed stick loosens earth; Lowry's central point does the same job. The embedded blueprint makes one.
3

Read US 884,177

Lowry's object is "to combine with one of the shovels which form the post hole, a sleeve which is connected to such shovel for vertical longitudinal movement and to which the handle is attached, and a point for digging up the earth at the center of the post hole". Shovel 1 has a tubular head 2 in which a sleeve 3 slides; handle 4 bolts into the sleeve. The lower end of the head is curved inward to form concave cam surfaces 6. A wedge-shaped digging point 8 has a stem 9 held in the sleeve by a set screw and shoulders 10 that bear on the cam surfaces. Drawing the sleeve up lets the shovel reach below the point; "By forcing the sleeve downwardly, the point may be projected beyond and below the shovel and employed to loosen the earth at the center of the hole". Shovels 1 and 12, with handles 4 and 13, have lugs 14 "pivotally connected together by a bolt 15, thereby effecting a hinge connection between the shovels", and studs 16 at their tops that meet when the handles are parallel.
4

Dig a post hole and count the lifts

Mark a spot and cut the turf with the digging shovel. Drive the post-hole digger in with its handles together, spread them to grip, and lift. Tip the plug onto a sheet and weigh it on the scale. Repeat to 60 cm, measuring the depth after every lift with the tape. Compare your number of lifts and plug weights with the notebook, and note where the soil changes. Set a stake in the hole and backfill in layers, ramming each one.

Materials for this step:

Bamboo PolesBamboo Poles1 piece

Tools needed:

Post Hole DiggerPost Hole Digger
Digging ShovelDigging Shovel
Tape MeasureTape Measure
Weighing ScaleWeighing Scale
BucketBucket
Leather Work GlovesLeather Work Gloves
5

A post-hole digger that will not lift

Post-hole digger troubleshooting.

Flow

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6

History and honest limits

**Jacob H. Lowry** of Lenoir City, Tennessee, filed US 884,177 on 11 June 1907; it was granted on 7 April 1908. Its claims are for the shovel with the sliding sleeve and the digging point that can be projected at will. **Honest limits.** Soil density, fill fraction and bite depth in the notebook are examples; real bites depend heavily on moisture and stones.

Materials

1

Tools Required

6

CC0 Public Domain

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