Russell
Jennings starts his US
Patent No.12,318 text with a desciption of what was wrong
with the current style of auger bit (usually ascribed to L'Hommedeau):
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The
design that Russell Jennings patents is at left in the patent drawing
and at the top of the detail at right. The L'Hommedeau style
which
he deprecates is at right in the patent drawing and at the lower right
of the detail view of the drawing at right.
Various styles of
maker's mark:
Only one bit, the No.5 (5/16ths inch) has the patent date, Jan. 30,
1855, stamped on the shank, so it's older than 125 years.
Various steel-rule dies were used ...
4
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11
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5
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5
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6
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12
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7
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13
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8
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14
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9
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15
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10
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16
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Each
shank is stamped with the size of the hole to be drilled, expressed in
16ths of an inch. One bit, the 7 1/2, is an intermediate size,
15/32nds of an inch (confirmed by micrometer measurement). I'll
have to fill in with a real No.7 !
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Nearly
all the bits had to have their cutting edges and spurs touched up in
order that they cut cleanly and draw into the wood. They were all
tested on both soft wood and dogwood, a hard, dense wood native to
southeast Pennsylvania. One bit had been sharpened on the wrong
side of the cutting edges and had to be touched up quite a bit
more. All are relatively unworn.
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Here's that No.7 size bit
(drills a 7/16ths inch hole) to fill out the above set.
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This bit didn't need any
sharpening !
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