IMPROVEMENTS IN TERRIERS OR GROUND AUGERS
Year: 1869

page_text: LETTERS PATENT to Anton Bohlken, of Varel, Grand Dukedom of
Oldenburg, Architect, for the Invention of IMPROVEMENTS IN TERRIERS
OR GROUND AUGERS."
Sealed the 3rd May 1870, and dated the 10th November 1869.
PROVISIONAL SPECIFICATION left by the said Anton Bohlken at the
Office of the Commissioners of Patents, with his Petition, on the
10th November 1869.
1, ANTON BOHLKEN, of Varel, Grand Dukedom of Oldenburg,
Architect, lo hereby declare the nature of the said Invention for
"IMPROVEMENTS IN TERRIERS OR GROUND AUGERS," to be as follows:-
This Invention consists in constructing terriers or ground augers
with a central boss pointed at its lower extremity, and having on its
lower part a screw thread or blade formed or fixed thereon projecting
from the boss to a comparatively small extent only, while upon the
upper part of the boss is formed or fixed a screw blade of comparatively
[Price 8d 1

page_text: large diameter (corresponding with the diameter of the hole to be bored),
which large screw blade is of a greater pitch than the small screw
blade. From this construction it follows that if the terrier is driven
into the ground, by rotating the same by means of an ordinary auger
handle at the upper end of a rod fixed to the boss, the upper screw
blade in endeavouring to screw into the earth more rapidly than the
lower blade will allow the terrier to penetrate downwards, the earth
acted upon by the large screw blade will be effectually broken up and
loosened to the extent of its diameter, and in accumulating in a loose
condition upon the top of this blade as the terrier penetrates it can
readily be removed by withdrawing the terrier from time to time.
By
this arrangement the employment of circumferential cutting blades
for clearing the sides of the hole as in terriers of ordinary construction
and the resulting greatly increased friction in working the instrument is
entirely obviated.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Anton Bohlken in the Great Seal Patent Office
on the 9th May 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, 1. ANTON
BOHLKEN, of Varel, Grand Dukedom of Oldenburg, Architect, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Tenth day of November, in the year of
our Lord One thousand eight hundred and sixty-nine, in the thirty-third
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Anton Bohlken, Her special licence that I, the
said Anton Bohlken, my executors, administrators, and assigns, or such
others as I, the said Anton Bohlken, my executors, administrators, and
assigns, should at any time agree with, and no others, from time to time
and at all times thereafter during the term therein expressed, should
and lawfully might make, use, exercise, and vend, within the United
Kingdom of Great Britain and Ireland, the Channel Islands, and Isle of
Man, an Invention for "IMPROVEMENTS IN TERRIERS OR GROUND AUGERS,"
upon the condition (amongst others) that I, the said Anton Bohlken,

page_text: my executors or administrators, by an instrument in writing under my,
or their, or one of their hands and seals, should particularly describe
and ascertain the nature of the said Invention, and in what manner
the same was to be performed, and cause the same to be filed in the
Great Seal Patent Office within six calendar months next and immediately
after the date of the said Letters Patent.
NOW KNOW YE, that 1, the said Anton Bohlken, do hereby declare
the nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement thereof, reference being had to the accompanying
Sheet of Drawings, and to the figures and letters marked thereon, that
is to say)-
of comparatively large
the hole to be bored),
This Invention consists in constructing terriers or ground augers
with a central boss pointed at its lower extremity, and having on its
lower part a screw thread or blade formed or fixed thereon projecting
from the boss to a comparatively sinall extent only,
while upon the upper
part of the boss is formed or fixed a screw blade
diameter (corresponding with the diameter of
which large screw blade is of a greater pitch than the small screw
blade. From this construction it follows that if the terrier is driven
into the ground, by rotating the same by means of an ordinary auger
handle at the upper end of a rod fixed to the boss, the upper screw
blade in endeavouring to screw into the earth more rapidly than the
lower blade will allow the terrier to penetrate downwards, the earth
acted upon by the large screw blade will be effectually broken up and
loosened to the extent of its diameter, and in accumulating in a loose
condition upon the top of this blade as the terrier penetrates it can
readily be removed by withdrawing the terrier from time to time. By
this arrangement the employment of circumferential cutting blades for
clearing the sides of the hole as in terriers of ordinary construction and
the resulting greatly increased friction in working the instrument is
entirely obviated.
The terriers or ground augers hitherto in use have met with but
limited application on account of their impractibility and of the great
amount of nower required to work them swing finalu to the chance

page_text: of which the entrance of the auger into the ground is greatly facilitated,
and secondly owing to the before mentioned friction due to the
circumferential cutters which are requisite with them.
On the accompanying Drawing is shewn the construction of my before
described improved terrier or ground auger. A is a pointed metal boss
formed on or fixed to the stem or shaft B of the borer, and having at
its point a gimlet screw blade C, and above this a second screw blade
D of a diameter corresponding with the size of the hole to be bored.
This latter screw blade is of a greater pitch than the blade C, whereby
it is made to operate in the manner berein-before described.
The improved ground auger may be made of any desired size and of
any suitable metal.
Thus the boss A and blade C may be of cast metal,
while the blade D may for larger diameters be of sheet metal fixed to
the boss either by screws or by being imbedded in the cast metal of
the boss, or for smaller sizes the whole may be of cast metal, and
for very small sizes, such as 1 to 2 inches diameter, they may be
entirely of wrought iron. The respective pitches of the screw blades
may be varied according to the nature of the ground upon which the
instrument is intended to operate. The terriers or ground augers of
small diameter (say 2 inches) are applicable for camp telegraph posts,
rick or stack poles, and such like purposes; the 3 to 4 inch augers for
inspection of soil, for fixing posts for railings, &c., and also as heads to
cylindrical pump shafts for screwing these into the ground instead of
ramming them. The augers of from 5 to 12 inches diameter serve to
bore holes for the destruction of field mice, &c., for erecting large
telegraph posts, scaffold poles, as also for boring horizontal or inclined
holes beneath streets or roads for the reception of gas and water
pipes. Large terriers of from 12 to 18 inches diameter are principally
used as planting augers.
Having thus described the nature of my Invention, and in what
manner the same is to be performed, I wish it to be understood that I
do not limit myself to the arrangement thereof as shewn on the
accompanying Drawings, as this may be variously modified without
departing from the nature of my Invention; but what I claim is, the
construction and use of terriers or ground augers having two screw
blades of different diameter and pitch, the one serving to penetrate into
the ground while the other serves to enlarge the hole to the required

page_text: diameter, aud at the same time to loosen the earth to be removed,
substantially as herein-before described.
In witness whereof, I, the said Anton Bohlken, have hereunto set
my hand and seal, this Second day of May, in the year of our
Lord One thousand eight hundred and seventy.
ANT. BOHLKEN. (L.S.)