Improvements in Potato Diggers.
Year: 1899

page_text: COMPLETE SPECIFICATION.
Improvements in Potato Diggers.
I, DAVID BUCHANAN, of 9, Clive Road, Auburn, in the Colony of Victoria,
Mechanical Engineer, do hereby declare the nature of this invention, and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:-
This invention relates to machines for digging potatoes or other like root crops,
and cleaning, bagging, or laying the said potatoes or the like in rows or heaps
as desired. The machine is characterized by having an adjustable inclined curved
screen or riddle at the front of which is a soil cutting edge or share and within
which is an elevating screw or carrier which has an incurved rounded entering
edge, and which revolves automatically as the machine is drawn forward. It has
also all parts requiring to be adjusted during the progress of the machine in the
field accessible to the driver without requiring the latter to leave his seat. That
is to say the screw can be started or stopped, the machine front can be raised or
lowered to adjust the depth of cut, and the potatoes can be tipped out at will,
when any desired quantity has been raised and accumulated in the receptacle pro-
vided for the purpose.
In combination with these features are various parts which will be fully under-
stood by reference to the accompanying drawings and the explanations below. In
these drawings Figure 1 exhibits a side elevation of my machine. Figure 2 repre-
sents a plan view of parts thereof; Figure 3 exhibits a rear elevation of various
parts and Figure 4 shows an elevating screw alone.
In these drawings A represents an inclined adjustable riddle having at its low
The
front end a mouth with a share or cutting edge B of any suitable form.
upper rear aperture of the riddle has any suitable discharge edge C. Inside of
this riddle which has the sectional form of an arc of a circle, is a screw D, upon a
spindle E, supported upon any suitable bearings. By means of bevel wheel F
gearing into bevel wheel G on a transverse shaft H carrying a small sprocket
wheel I connected by a chain with a larger sprocket wheel loosely mounted upon
the axle K of the traction wheels L of the machine, the drawing of the machine
forward by any animal yoked to the pole N will cause the screw D to rotate auto-
matically and act as an elevator. There is a clutch M (operated by handle M¹)
one part of which is upon shaft or axle K and engages with the other part upon the
larger sprocket wheel to work screw 1). The cutting mouth B of the riddle is
bolted on, to be replaced when worn, and is regulated to work at a sufficient depth
below the surface of the ground to go underneath the potatoes or other like roots,
and to maintain the depth desired, there is provided at the front a roller (), the
axle of which is swung on the fore ends of cranked levers P, each of which is
secured in position by a bracket Q bolted to the respective lever P. Each bracket Q
can be moved backward or forward and is fastened (as by a bolt Q passing through
a slot in the bracket and through a hole in the frame of the machine-various parts
of which frame are marked Z) in any position to suit the depth required. The
earth line exterior to the machine when at work is shown. When the machine is

page_text: in use the soil and potatoes are forced to enter into the open mouth of the riddle,
and the screw which prevents an incurved rounded surface, D at the entering
end so as not to cut or bruise the potatoes or roots, pushes the latter up the inclined
riddle with a motion which causes the soil during the ascent to be separated and
dropped through the spaces between the bars A of the riddle. The edge D¹ of
the screw blade passes sufficiently close to the bars of the riddle to cut up the
weeds and the tops or haulmis of the potato plants which also fall between the
said bars together with the soil. The speed of the screw is so arranged that it will
carry up the potatoes etc. at a comparatively rapid rate i.e. rather faster than the
machine travels forward so that the material cannot accumulate and choke the
screw. The potatoes may be delivered into a removable box S which has a
movable door or bottom T. By keeping the said bottom open the potatoes raised
will be caused to fall in rows, or after allowing the box to fill to any desired
degree the driver may open it with a lever U which is operated by hand or foot
and has suitable connections U with said door T. This will let the potatoes fall
out into a heap. The design of the box S may be varied at will. Instead of
using a box, bags or other receptacles may be attached in any known way for the
reception of the potatoes direct from the discharge C. To raise the front of this
machine out of the ground the driver turns by hand or moves with his foot a
handle on a small winch, the barrel of which is marked W and so winds up a wire
cord or the like V, which, in any suitable way as by passing over a pulley X
(Fig 1), connects the said barrel with the part having the mouth B as at X. This
connection might be made direct by a lever. R shows a ratchet and pawl at each
side of the spindle of the winch barrel W whereby the barrel is prevented from
running back during or after winding up. There are several points in which
modifications of details might be made without departing from the spirit of this
invention. For example the closing of the door T of the box S may be assisted
or accelerated by a spring.
It will be observed that the base of box S is rounded and that the door is located
on one side of its pivot T in such a manner that the door will close automatically
by gravity as soon as the handle or lever U is released. Owing to the shape of
the box base, the door will be easy to open because it has not to sustain the whole
weight of the box contents, and because immediately it begins to open, the weight
it does sustain begins to diminish owing to the escape of the lowermost potatoes
forming such weight. This arrangement of door also avoids undue friction of
and damage to the potatoes. Instead of a roller O there might be a wheel or pair
of wheels.
Having now particularly described and ascertained the nature of this
invention and in what manner the same is to be performed, I declare that what
I claim is—
1. In a potato digger the combination with an inclined curved riddle having at
its low front end a mouth with a share or cutting edge, of a roller in front of and
adjustably connected relatively to the said riddle, and a winch and connections
therefrom to the machine front, all substantially as and for the purposes set forth.
2. In a potato digger the combination with an inclined curved riddle of a screw
elevator within the same having an incurved rounded entering edge, and at its dis-
charge end bevel gear operated by sprocket and chain mechanism whereby the
said screw will by the turning of the traction wheels of the machine be revolved
so as to carry potatoes or the like up the riddle at a comparatively rapid rate, sub-
stantially as and for the purposes set forth.
3. In a potato digger the combination with a riddle and elevating screw, gear for
rotating said screw by the forward motion of the machine, a clutch for connecting
and disconnecting said gear, a roller (wheel or wheels) in front of said riddle, con-
nections between said roller (wheel or wheels) and riddle for adjusting the cutting
depth of the latter, and a lever or winch to lift the front of the machine off the
ground, all substantially as and for the purposes set forth.

page_text: 4. In a potato digger having an inclined curved riddle having an elevating
screw, having an incurved rounded entering edge, said screw being adapted to
push potatoes up the said riddle and dirt and haulms through the bars thereof,
the combination therewith of a box or potato receptacle S having a door T with
pivot T and connections U₁ to handle whereby the door can be opened and the
box emptied at will, and whereby the door of said box will close automatically
when the lever or handle U is released substantially as set forth.
Dated this 24th day of April 1899.
F. W. GOLBY,
36, Chancery Lane, London, W.C., Patent Agent for the Applicant.