IMPROVEMENTS IN ROTARY DIGGING MACHINES, AND IN TEETH FOR THE SAME
Year: 1867

page_text: LETTERS PATENT to George Davies, of No. 1, Serle Street, Lincoln's Inn,
in the County of Middlesex, and No. 87, St. Vincent Street, in the City
of Glasgow, Civil Engineer and Patent Agent, for the Invention of
"IMPROVEMENTS IN ROTARY DIGGING MACHINES, AND IN TEETH FOR THE
SAME." A communication from abroad by George Granville Lobdell, of
Wilmington. State of Delaware. United States of America.
Sealed the 17th September 1867, and dated the 25th March 1867.
PROVISIONAL SPECIFICATION left by the said George Davies at the.
Office of the Commissioners of Patents, with his Petition, on the 25th.
March 1867....
I, GEORGE DAVIES, of No. 1, Serle Street, Lincoln's Inn, in the County of
Middlesex, and No. 87, St. Vincent Street, in the City of Glasgow, Civil
Engineer and Patent Agent, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN ROTARY DIGGING MACHINES, AND IN TEETH FOR THE SAME,”
(being a communication to me from abroad by George Granville Lobdell,
of Wilmington, State of Delaware, United States of America;) to be as
follows:
. The first part of this Invention consists of a toothed cylinder and clearing
and pulverizing discs, and of mechanism by which the said toothed cylinder
and dises may be raised from or lowered to the surface of the ground, the
whole being attached to a frame mounted upon wheels.

page_text: The second part of the Invention consists in the use in rotary diggers of
teeth bent to the peculiar curve fully described hereafter, so that they may
penetrate the soil without dragging the same, and so that on leaving the soil
they may turn it up abruptly, the action of the teeth being similar to that of
a spade in the hands of a gardener. The teeth are of a form and are secured
in a manner described hereafter, so as to insure strength, easy penetration of
the soil, and the turning-up of the same with the best effect, and so that the
teeth can be readily detached from and as readily secured to the cylinder. The
side frames of the machine are connected together by cross bars; these frames
are mounted upon wheels, the rear wheels turning upon separate short axles
secured one to each side frame, and the axle which carries the front wheels
being hinged to a king bolt which turns on the frame, so that the axle may
vibrate on the king bolt and the wheels may accomodate themselves to
inequalities of the ground. The main shaft turns in bearings which are
arranged to slide in vertical guides forming part of the side frames, and from
each of these bearings projects a vertical rack which is also arranged to slide
in the said guides. Gearing into each of the racks is a pinion upon an upper
transverse shaft which turns in bearings in a plate secured one to each
of the side frames near the top of the same, and upon the same shaft are two
pulleys connected to other pulleys on another transverse shaft by ropes in the
following manner:-To the periphery of one of the first-named pulleys the
rope is secured, then wound round the pulley one or more times, and passes
from below the same to one of the second-named pulleys, passed round the
latter from below, and secured to its periphery; a similar rope or chain is
secured to the other pulley first named, passed one or more times round it,
and from the top of this pulley to the other second-named pulley, over and
round the latter, to which it is secured. The second-named shaft has a cog
wheel gearing into a smaller wheel upon a third shaft which is provided with
a hand wheel. The second and third shafts turn in the present instance in
bearings secured to the vertical posts of the frame. The digging cylinder,
which is secured to the main shaft, may consist of two discs secured to the
said shaft and connected together by cross bars to which the teeth are secured.
The peculiar shape of the teeth and the method of securing them to the cross.
bars forms the second part of the Invention, and will be fully described.here-
after. Two levers or arms are hung to and vibrate on the main shaft, one
upon each side of the digging cylinder, and on each side of the latter and
secured to the shaft is a large cog wheel, and from these latter wheels motion
is communicated to a train of small cog wheels, two of which turn on pins
projecting from the levers, and the last wheels of the series are secured to a

page_text: shaft which turns in suitable bearings in the opposite levers, and upon which
are a number of discs having teeth so arranged as to be midway between the
row of teeth secured to the digging cylinder. As the levers are hung upon
the main shaft their angle can be altered without throwing the wheels out of
gear, the adjustability of the levers being accomplished by means of screw rods
which are hinged to one of the cross bars of the frame, one of the screw rods
passing through each of the arms, above which it is furnished with a nut, a
spiral spring intervening between the under side of the lever and a collar on
the screw rod.
The second part of the Invention relates to a peculiar construction of the
teeth of a rotary digger and to the mode of securing them to the digging
cylinder, the teeth, being bent to such a peculiar curve that as the cylinder.
moves and its circumference assumes several progressive positions the tooth
continues to coincide with the first point of penetration until the point where-
the tooth meets the circumference of the cylinder coincides with the said point,
or, in other words, until the entire tooth has penetrated the soil. It will be
seen, therefore, that as the tooth penetrates the soil there is no drag on the
latter, the tooth passing into the soil precisely as does an ordinary spade in
the hands of a gardener preparatory to the raising of a portion of the soil in
front of the spade. The effect of the tooth on the soil as it leaves the same
differs entirely from its action on penetrating the soil, for after the penetration.
of the entire tooth, and on the continued forward movement of the cylinder,
the tooth immediately commences to raise the soil abruptly, precisely as a
gardener raises the soil in front of his spade after the latter has been inserted
to the desired depth. The exact curve of the tooth will depend upon its
length and the diameter of the cylinder to which it is attached; these having
been determined on any one familiar with the construction of machinery and
mechanical drawing can readily produce the desired curve from the above
description of the same.
O SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said George Davies in the Great Seal Patent Office on the
25th September 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
DAVIES, of No. 1, Serle Street, Lincoln's Inn, in the County of Middlesex,
5 and No. 87, St. Vincent Street, in the City of Glasgow, Civil Engineer and
Patent Agent, send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fifth day of March, in the year of our Lord
One thousand eight hundred and sixty-seven, in the thirtieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said George Davies, Her special licence that I, the said George Davies,
my executors, administrators, and assigns, or such others as I, the said
George Davies, 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
ROTARY DIGGING MACHINES, AND IN TEETH FOR THE SAME," being a communication
to me from abroad by George Granville Lobdell, of Wilmington, State of
Delaware, United States of America, upon the condition (amongst others)
that I, the said George Davies, my executors or administrators, by an instru-
ment 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 I, the. said George Davies, 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 in writing, and on reference to the accompanying Drawings, that
is to say:-
The first part of this Invention consists of a toothed cylinder and clearing
and pulverizing discs, and of mechanism fully described hereafter, by which
the said toothed cylinder and discs may be raised from or lowered to the
surface of the ground, the whole being attached to a frame mounted upon
wheels.
The second part of the Invention consists in the use in rotary diggers of
teeth bent to the peculiar curve fully described hereafter, so that they may
penetrate the soil without dragging the same, and so that on leaving the soil
they may turn it up abruptly, the action of the teeth being similar to that of
a spade in the hands of a gardener. The teeth are of a form and are secured
in a manner described 'hereafter, so as to ensure strength, easy penetration of
the soil, and the turning up of the same with the best effect, and so that the
teeth can be readily detached from and as readily secured to the cylinder.
Such being the nature and object of the said Invention for "Improvements

page_text: in Rotary Digging Machines, and in Teeth for the same," I will now proceed
to describe more in detail the manner in which the same is to be or may be
performed or carried into practical effect; and in order that the same may be
distinctly understood I have annexed hereunto a Sheet of Drawings illustrative
thereof, and have marked the same with figures and letters of reference
corresponding with those in the following explanation thereof, that is to
say:
On reference to the accompanying Drawing, Figure 1 is a side view of the
improved rotary digging machine; Figure 2, a transverse vertical section on
the line 1, 2, (Figure 1); Figure 3, a plan view; Figure 3½, a view, partly
in section, of the front axle and wheels; Figure 4, a side view of one of the
improved teeth drawn to an enlarged scale; Figure 5, a transverse section
of the same on the line 3, 4, (Figure 4); Figure 6, a transverse section of
the tooth on the line 5, 6, (Figure 4); Figure 7, a section of the line 7, 8,
(Figure 4); Figure 8 represents the rim of a rotary digger with its teeth all
drawn to au enlarged scale, and Figure 9, a diagram illustrating part of the
Invention.
On reference to the first part of the Invention illustrated in Figures 1, 2, 3,
and 3, A and A' are the side frames of the machine, and are connected
together by cross bars a, a; these frames are mounted upon wheels, as shown
in Figures 1, 2, 3, and 3, the rear wheels B, B, turning on separate short
axles secured oue to each side; frame, and the axle C, which carries the front
wheels W, W, being hinged to a ring bolt Y which turns on the frame, as
seen in Figure 3, so that the axle may vibrate on the ring bolt, and the
wheels may accomodate themselves to inequalities of the ground. D is a
shaft turning in bearings b, b, which are arranged to slide in vertical guides
x, x, forming part of the side frames A and A¹, and from each of these bearings
projects a vertical rack c, which is also arranged to slide in the said guides.
Gearing into each of the racks c is a pinion d upon a transverse shaft F, which
turns in bearings in a plate e secured one to each of the side frames near the
top of the same, and upon the same shaft F are two pulleys f, f, connected to
pulleys h, h, on the shaft G by ropes g, g¹, in the following manner: To the
periphery of one of the pulleys of the rope is secured, then wound round the
pulley one or more times, and passes from below the same to one of the
pulleys h, passed round the latter from below and secured to its periphery.
A similar rope or chain g is secured to the other pulley f, passed one or more
times round it, and from the top of this pulley to the second pulley h of the
shaft G, over and round the latter, to which it is secured. The shaft G has a
cog wheel gearing into a smaller wheel upon a shaft H, which is provided with

page_text: a hand wheel j. The shafts G and H turn in the présent instance in bearings
secured to the vertical posts x and x¹ of the frame. The digging cylinder,
which is secured to the shaft D, may consist of two discs I and I secured to
the said shaft and connected together by cross bars J, to which the teeth K are
secured. The peculiar shape of the teeth and the method of securing them
to the cross bars forms the second part of the Invention, and will be fully
described hereafter. Two levers or arms M are hung to and vibrate on the
shaft D, one upon each side of the digging cylinder, and on each side of the
latter; and secured to the shaft D, is a large cog wheel L, and from the wheels L
motion is communicated to a train of small cog wheels K, K', and K², the two
former turning on pins projecting from the levers M, and the last wheels K²
of the series being secured to a shaft P which turns in suitable bearings in
the opposite levers, and upon which are a number of discs Q having teeth t
so arranged as to be midway between the row of teeth secured to the digging
cylinder, Figure 3. As the levers M are bung upon the shaft D their angle
can be altered without throwing the wheels L and K out of gear, the adjusta-
bility of the levers being accomplished by means of screw rods p, p, which are
hinged to one of the cross bars a of the frame, one of the screw rods passing
through each of the arms, above which it is furnished with a nut r, a spiral
spring 9 intervening between the under side of the lever and a collar on the
screw rod.
The operation of the machine is as follows:-With the digging cylinder
elevated, as shown in the Figure I., so that its teeth shall be free from contact
from the ground, the machine can be readily transported from to place
upon its wheels B and B'. When it is desired to begin the operation of
digging the hand wheel j is so turned that through the medium of the gearing
above described the cog wheels d upon the shaft F will lower or permit the
descent of the racks c, the bearings 6 of the shaft D, and consequently of the
digging cylinder; this action of the pinions on the racks is continued so as to
force its teeth into the ground until they have penetrated to the desired extent
and until the wheels B, B, have been elevated above the ground, in which
case the entire weight of the rear portion of the frame and its attachments is
exerted on the digging cylinder. In soils of a very soft character, however,
the wheels B, B, may be permitted to rest lightly on the ground so as to
partially relieve the digging cylinder from the weight of the frame. Simul-
taneously with the lowering of the cylinder the levers M, M, being hung to
the shaft D, will be lowered together with their gearing and discs Q, the
teeth of the latter penetrating the soil to the desired extent. The machine is
now inoved forward in the direction of the arrow I, Figure I., either by animals

page_text: or by traction engine, or by an engine forming part of the machine, and as
the digging cylinder is drawn over the ground its rows of teeth K penetrate the
soil and turn it up behind in a manner fully described hereafter. During the
operation of the digging cylinder a rapid rotary motion in the direction of the
arrow is imparted through the gearing described to the shaft P and its discs Q,
the teeth t of which clear the soil, weeds, and roots from between the teeth
of the digging cylinder, at the same time pulverizing the ground. The extent
of penetration of the clearing discs Q into the ground may be regulated at
pleasure by operating the nuts r of the screw rods p, and the height of the
digging cylinder is as easily regulated by operating the hand wheel j, so that
the penetration of the teeth into the ground may be regulated at pleasure.
Owing to the peculiar arrangement of ropes or chains and pulleys described
above, the raising of the digging cylinder is accomplished through the medium
of one rope and its pulleys on one side of the machine, and the lowering of the
cylinder by the other role and pulleys at the other side of the machine.
may be remarked here that it is essential to the proper working of the
machine that the clearing and pulverizing discs should revolve in a direction
contrary to that of the digging cylinder.
It
The second part of the Invention relates to a peculiar construction of the
teeth of a rotary digger, and to the mode of securing them to the digging
cylinder, the teeth being bent to a peculiar curve, best illustrated by the
Diagram Figure 9, in which the letters represents a portion of the outer
circumference of the cylinder, the curved line t representing one of the teeth,
the point of which is about entering the ground represented by a horizontal
line X at x. As the cylinder is drawn over the ground in the direction of the
arrow the tooth will penetrate the soil, but it is of such a peculiar curve that
as the cylinder moves and its circumference assumes' the several progressive
positions illustrated by the red lines 1; 2, 3, &c. it continues to coincide with
the point (the first point of penetration) until the point y, where the tooth
meets the circumferences of the cylinder, coincides with the said point x, or,
in other words, until the entire tooth has penetrated the soil. It will be seen,
therefore, that as the tooth penetrates the soil there is no drag on the latter,
the tooth passing into the soil precisely as does an ordinary spade in the hands
of a gardener preparatory to the raising of a portion of the soil in front of the
spade. The effect of the tooth on the soil as it leaves the same differs
entirely from its action on penetrating the soil, for after the penetration of
the entire tooth, and on the continued forward movement of the cylinder,
the tooth immediately commences to raise the soil abruptly, precisely as
a gardener raises the soil in front of his spade after the latter has been

page_text: tooth will be readily
a Diagram, Figure 9,
inserted to the desired depth. This action of the
understood on reference to the red lines s¹ and t¹ in
the line representing the tooth as it is passing upwards out of the
ground, and the line s representing part of the circumference of the
cylinder. The exact curve of the tooth will depend upon its length and
the diameter of the cylinder to which it is attached; these having been
determined on any one familiar with the construction of machinery and
mechanical drawing can readily produce the desired curve on reference to
the Diagram, Figure 9, and the above description of the same. The tooth
represented by the black curved line t, Figure 9, is of suitable form for a
digging cylinder having a diameter proportioned to the length of the tooth
illustrated in Figure 8. In this case there are fewer teeth than on the
cylinder described above on reference to Figures 1, 2, 3.
On reference to the views Figures 4, 5, and 6 it will be seen that the
tooth K has a sectional form similar to that of a bayonet, that is, flat in front
and ribbed at the back, a form which possesses three advantages, first, it insures
strength in the right direction; second, it is of the best form to insure an
easy penetration of the tooth into the ground; third, the tooth being flat and
broadest in front it will turn up the soil with the best effect.
Figure 7 illustrates the manner of securing the teeth to the cross bars of
the cylinder. A recess is cut in the cross bar J of the form adapted to the
back of the tooth, and against the front of the latter a plate T is secured by
bolts u, u, after losening the nuts of which the tooth can be withdrawn for
repair or to make way for a new tooth.
Having now described the nature and object of the said Invention for
Improvements in Rotary Digging Machines, and in Teeth for the same,"
together with the manner in which the same is to be or may be performed or
carried into practical effect, I would remark in conclusion that I claim as
the Invention communicated to me by the above-named George Granville
Lobdell,―
Firstly, the combinations of the digging cylinder with the clearing and
pulverizing discs Q when arranged to operate together, substantially as
described.
Secondly, the levers M, M, hung to the shaft D of the digging cylinder and
carrying the clearing discs Q, and the gearing or its equivalent for operating
the same, all substantially as described.
Thirdly, imparting to the levers M, M, and their clearing discs an
adjustability separate from that derived from the shaft of the digging
cylinder.

page_text: Fourthly, the bearings b, b, of the cylinder shaft D, the racks c, guiding
pieces a, and pinions d, d.
Fifthly, the system of ropes or chains and pulleys herein described for
raising and lowering the cylinder.
Sixthly, the front axle C arranged to vibrate on the ring bolt Y, as set
forth.
Seventbly, the use in rotary diggers of teeth bent to the curve described for
the purpose specified.
Eighthly, the curved tooth K having the sectional form described for the
purpose set forth.
Ninthly, the tooth K adapted to a groove in the cross bar J and secured
thereto by a plate T, as and for the purpose herein specified.
In witness whereof, I, the said George Davies, have hereunto set my
hand and seal, this Twenty-fourth day of September, in the year of
our Lord One thousand eight hundred and sixty-seven.
GEORGE DAVIES.
(L.S.)