IMPROVEMENTS IN DIGGING MACHINERY
Year: 1866

page_text: PROVISIONAL SPECIFICATION left by Ormrod Coffeen Evans at the
Office of the Commissioners of Patents, with his Petition, on the 15th
March 1866.
I, ORMROD COFFEEN EVANS, Citizen of the United States of America, but
now temporarily residing at 64, Stanley Road, Balls Pond Road, Islington,
in the County of Middlesex, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN DIGGING MACHINERY," to be as follows:-
b
The nature of my Invention is clearly indicated in the accompanying
Drawing, and consists in a series of broad-faced wheels a revolving upon the
ground side by side, and supported upon the same shaft, the series of broad-
faced wheels a having teeth 6 so arranged, and each so fixed upon an axis 6'
on the side of the rim of the wheel a, as that by means of guides c they (the
teeth) in succession are made to assume nearly a vertical position when thrust
into the ground by the weight of the machine; and again, just behind the
vertical centre of the wheels the teeth are actuated by means of trips d, and
together with the motion of the wheels forward are so forced in succession
backward, outward, and upward out of the ground as to break, upheave, and
comminute the soil, the teeth 6 being caused to feather nearly within the
periphery of the wheels preparatory to moving the machine from field to field.
on the same wheels. For the purpose of supporting and carrying the wheels a,
only one of which is shown in the Drawing, I construct a light frame e, of
either iron or wood, and of sufficient size to allow the wheels with the teeth a
attached to revolve freely inside. This frame e on each side rests on and is
affixed to the shaft a¹, on which the wheels a revolve. A pole e¹ (or "thills"
instead), by which the machine is drawn, is firmly fixed to the front end of the

page_text: frame c. In case, however, a seat is provided for the driver on the frame e it
will be necessary to introduce under its front end either trucks or a castor for
the purpose of support, and so to hinge or attach the pole to the frame or
trucks that it may be raised or lowered without changing the horizontal
position of the frame e.
In describing the digging part of the machine it will be necessary only to
describe one section, or one wheel a and teeth 6, together with mechanism for
guiding the teeth into and tripping them out of the groud, as others on the
same shaft a¹ are but duplicates of the one I am about to describe. Within
about an inch and a half of the face of the wheel a through holes in the rim
from side to side (and at such equal distance from each other as may be
required from the size of the wheel a and length of teeth 6 used) are inserted
tubular arbors b¹ projecting on each side of the rim in distance the thickness
of the teeth fixed on them. The ends of the arbors and sockets of the teeth
are made square to correspond, one with the other. Bolts are inserted into
and through these arbors, the beads of which bear against the teeth on one
side of the rim, and the nuts against those on the other side. Thus secured
to the arbors each pair of teeth and arbor revolvo together, and thus secured
to the wheel freedom of action, is obtained. On one side of the wheel the
sockets of the teeth are made at the extreme top end, and on the other
side of the wheel the teeth are about one-third longer, but in length from
point to socket are the same. These heads or parts 6%, which rise abovo the
sockets, have their tops turned at right angle outward about an inch from the
side face of each tooth b. For changing relatively the angle of the teeth both
to the radii of the wheel and to the ground in different parts of the periphery
of the wheel a at the same time, I provide the segment of a whcel or disc f
(or perhaps from the nature of its action it may more properly be termed a
cam surface) with an adjustable or fixed roller dat one extremity, and an
aljustable slideway or guide c at the other, and is in diameter about two
inches greater, more or less, than is the distance across, the side of the head of
one tooth when adjusted in line with the radius of the wheel to the top of the
head of another on the opposite side when adjusted in like manner. This
cam surface f is arranged on the shaft a' at the side of the wheel a, and in
line with the teeth, and is so arranged that the roller d below is behind the
vertical centre of the wheel a, and the slideway or guide c in front is fixed by
an arm immediately above the horizontal centre of the wheel a. "The arm of
the slideway or guide c is attached horizontally to the outside side of the
cam f, and is so adjusted that it stands out from the side of the wheel far
enough to allow the teeth 6 to pass freely inside. At the extremity of this

page_text: arm and on the inside is fixed the slideway or guide c, at such angle top
outwards as will cause the projections on the heads of the teeth 6 as they
move downward to touch against and slide inward against the guide c, an
action which throws the points of the teeth b outward to regulate the distance
from each other as they enter the ground. The face of the roller d at the
other extremity is in line with the face of the cam f, and the face of the cam f
immediately behind the roller d is recessed at g. By this arrangement, the
cam f being stationary, as the wheel revolves the teeth b, after having been
gradually inserted into the ground by the onward motion of the machine, are
tripped suddenly out of the ground as their heads come in contact with and
pass under the roller d, as well as that on their heads leaving the hind part of
the roller they are allowed by means of the recess g to fall points downward
to the ground, an action which throws off any grass, straw, vines, or rubbish
that may have been lifted by them in their previous action. Then again as
their heads come in contact with the upper face corner f* of the recess they
aro lifted into an obtuse angle points upward with the radius of the wheel.
This position is maintained by their heads pressing against the face of the
cam f until near the top, when by their own weight they fall forward, feathering
upon those in front of them. These devices, viz., cam surface f, slideway or
guide c, roller d, and recess 9, severally act upon the teeth in such manner as
to allow the machine to back and turn at short angles with safety to the teeth
as when moving forward. So also, if the cam surface f is turned back on the
shaft a', the shaft being stationary, about a quarter the machine may be
moved from field to field with as much safety to the teeth 6 as when working,
the change in the position of the cam surface f causing the teeth to feather
under the wheel either in its forward or backward movement. And in order,
therefore, that the operator may be enabled to adjust the cam
for the above-named purpose, a curved recess a³ is formed in the boss of the
cam surface f and next the shaft a in such manner as will allow the cam to
turn back upon the axis a¹ about a quarter of a revolution. A pin handle h
also is fixed in the upper front side of the cam f, so that by taking hold of it
and turning the cam until the handle h rests on the frame e, where it is
secured by a catch, clasp, or other device, the machine is ready to be travelled
on common roads or to traverse fields the same as a common roller.
surface at will