IMPROVEMENTS IN AUGERS AND BITS
Year: 1883

page_text: LETTERS PATENT to Herbert John- Haddan, of Kensington, Middlesex, for an
Invention of IMPROVEMENTS IN AUGERS AND BITS communicated to him
from abroad by Hiram E. Fuller and Edmund C. .Bramhall both of
Washington, United States
'
PROVISIONAL-SPECIFICATION left by the said Herbert John Haddan at
the Office of the Commissioners of Patents on the 21st August 1883.
HERBERT JOHN HADDAN, of Kensington, Middlesex, ἐσ IMPROVEMENTS IN
AUGERS AND BITS," a communication to me from abroad by Hiram E. Fuller
and Edmund C. Bramhall both of Washington, United States,
The invention relates to Augers and Bits the object being to provide a bit
adapted to be operated with the minimum pressure, and to bore a smooth clean
cut hole.
Heretofore various arrangements of cutters, and spurs or depending guide lips
have been employed; but the same are defective in that a straight cutting edge is
presented to the wood or other material operated upon.
The invention consists in the combination with curved or downwardly arched
cutters, of depending guide spurs or cutters as hereinafter described.
The bit instead of presenting a straight cutting edge to the material to be bored,
presents a curved edge whose central portion will first come in contact with the
wood, thus giving the advantage of a gradual or shaving action which materially
lessens the pressure required to operate the bit. This advantage is particularly
valuable when the boring is to be done through the end of a piece of wood as it is
very difficult to cut through the grain with a straight cutting edge.
The depending spurs serve to guide the bit, and cut, and finish the bore:
At

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Herbert John Haddan in the Patent Office on the 21st February
1884.
HERBERT JOHN HADDAN, of Kensington, Middlesex
"IMPROVEMENTS IN
AUGERS AND BITS," a communication to me from abroad by Hiram E: Fuller 5
and Edmund C. Bramhall both of Washington, United States,
The invention relates to Augers and Bits the object being to provide a bit
adapted to be operated with the minimum pressure, and to boro a smooth clean cut
hole.
Heretofore various arrangements of cutters, and spurs or depending guide lips 1
havo been employed; but the samo are defective in that a straight cutting edge is
presented to the wood or other material operated upon,
The invention consists broadly in the combination with curved or downwardly
arched cutters, of depending guide spurs or cutters as hereinafter fully described.
The invention further consists in the details of construction, and combinations of 1
parts hereinafter fully described and pointed out in the claims.
In the drawings Fig 1 represents an elevation of a bit constructed in accordance
with the invention. . Figs. 2 and 3 represent enlarged' views of a portion of a bit
embodying the improvement.
A represents a double twist bit provided with the usual screw or gimlet point B. 2
C, C, represent the cutters or lower ends of the spirals of the bit. These cutters
are each downwardly curved or arched from the screw B to the outer edge of the
spirals. DD represent spurs or cutters depending from the ends of the spirals
adjacent to the outer edges of the curved cutters CC.
If desired the bit may be provided with upwardly projecting lips E E arranged 2
upon the upper edges of the spirals opposite the spurs D D.
It will be apparent from the construction thus shown and described that in the
use of the bit instead of presenting a straight cutting edge to the material to be
bored, a curved edge is presented whose central portion will first come in contact
with the wood, thus giving the advantage of a gradual or shaving action which 3
materially lessens the pressure required to operate the bit. This advantage is
particularly valuable when the boring is to be done through the end of a piece of
wood as it is very difficult to cut through the grain with a straight cutting edge.
The depending spurs serve to guide the bit, and cut, and finish the bore.
As illustrated in the drawings the edges of the cutters C, C, may be curved 3
horizontally as well as vertically if desired; but such horizontal curving must be
gradual, it being desirable to leave sufficient room to cut the thread upon the
point B.
It will be apparent that the invention comprehends the use of the depending
cutters, and curved cutting edges without the upwardly projecting lips E, E, and 4
I therefore do not limit myself to the precise construction shown but reserve to
myself the right to make such changes, and modifications, as may properly fall
within the scope of the invention.
It will also be obvious that the improvement is adapted to augers, and bits of all
kinds and sizes, and that the same is inexpensive in construction, and durable 4
in use.
Having fully described the invention what I claim as new and desire to secure
by Letters Patent' is:
1. In a bit the combination with a downwardly curved cutting edge of
.- ..
111 auth
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page_text: 2. In a bit the combination with a screw or gimlet point of a downwardly
curved or concaved cutting edge, and depending spurs or cutters, substantially as
set forth.
3. In a bit the combination with a screw or gimlet point of downwardly curved
cutters, depending spurs or cutters arranged at the outer edges of said cutters,
and upwardly projecting lips arranged opposite to said spurs, substantially as set
forth.
4. In a bit the combination with a screw or gimlet point of cutting edges curved
both downwardly, and horizontally, and depending spurs, substantially as set
forth.
5. In a bit the combination with a screw or gimlet point of cutting edges curved
both downwardly, and horizontally and depending spurs, and upwardly projecting
lips, substantially as set forth.
In witness whereof I the said Herbert John Haddan have hereunto set my hand
and seal this 21st day of February A.D. 1884.