IMPROVEMENTS IN AND RELATING TO MACHINERY FOR DIGGING AND SEPARATING POTATOES
Year: 1881

page_text: LETTERS PATENT to Robert Alexander Clark, of Liverpool, in the County
of Lancaster, for an Invention of "IMPROVEMENTS IN AND RELATING TO
MACHINERY FOR DIGGING AND SEPARATING POTATOES,"
PROVISIONAL SPECIFICATION left by the said Robert Alexander Clark
at the Office of the Commissioners of Patents on the 17th February 1881.
ROBERT ALEXANDER CLARK, of Liverpool, in the County of Lancaster.
"IMPROVEMENTS IN AND RELATING TO MACHINERY FOR DIGGING AND SEPARATING
POTATOES."
This Invention is for a machine for digging potatoes. My model as at present
constructed consists of the following principal parts: First, a pivotted scoop or
plough, whose angle can be adjusted by plough arms held by the person actuating;
it is preferably pivotted on the main frame. Second, a continuation of this scoop
in the form of a trough with perforated or riddle bottom; this latter passes
through the yoke to which the journals of the wheels are attached. Third, said
yoke and journals. Fourth, revolving riddle on friction rollers or otherwise run
by bevel gearing from a carrying wheel; its axis is in the longitudinal centre line
of the machine. Fifth, a frame carrying the said revolving riddle and yoke.
Sixth, shafts and outer frame. Seventh, slide to stop end of riddle and prevent
potatoes falling out while the bag is changed, if desirable. Eighth, tail board on
which bag is placed. Ninth, ring and hooks, or their equivalent, for holding
mouth of bag and keeping it open. Tenth, the four wheels; two of these, especially
the one driving the bevel gearing, I prefer to be armed with transverse strips of
iron across the tire to increase friction. Eleventh, seat for driver. Twelfth, steel
springs, spring brushes, or their equivalent, fastened to a stationary bar abutting
against the riddle, to keep it clean in very tenacious soils; for very strong soils a
series of heavy beads with large holes strung on a small rod, and bearing on the
riddle will answer the same purpose. These riddle cleaning devices on ordinary
occasions will probably be found very unnecessary.
Another appliance which will be found very useful for working in small fields
is as follows: On the rear end of the frame carrying the riddle I fix a stout staple
or pair of staples or socket. Into this a lever is inserted, and when one comes to
a headland the attendant can insert the bar and lift the hind wheels off the ground,
and so assist the the turning round of the machine.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Robert Alexander Clark in the Great Seal Patent Office on the
17th August 1881.
ROBERT ALEXANDER CLARK, of Liverpool, in the County of Lancaster.
"IMPROVEMENTS IN AND RELATING TO MACHINERY FOR DIGGING AND SEPARATING
POTATOES."
This Invention is best described by aid of the accompanying Drawings, in
which Fig. 1 is a plan; Fig. 2, vertical elevation.
A is a scoop composed of iron or steel with a sharp edge. It is pivotted at B to
the trough D. C is a rod jointed to the scoop, and held by screw hand wheel C₁
at any required distance from the end. By adjusting this rod the height of the
end of the scoop is regulated. D is a trough, preferably fixed in the main frame
and forming a continuation of the scoop; to assist in carrying the potatoes,
et cetera, up this trough I sometimes make its bottom a rotating chain platform J,
rotated by gearing from the carrying wheels, as shown. I prefer also to place an
assisting circular finger wheel W, as shown, to assist the material into the trough.
This trough is perforated to let out the small dirt; the trough passes up through
yoke E. This yoke carries the axle of the front wheels, and in smaller machines
forms a part of the axle, the journals projecting from it at each side; by this
means I bring the trough lower down and thus feed into the cylindrical riddle at
a lower height. F, revolving riddle with axis in centre line of machine formed of
iron bars, strongly braced by outside frame bars f, f, and running on friction
wheels in frames at each end. The hinder frame resembles the yoke E in that it
carries the journals of the wheels T; the forward frame H is braced to the yoke E
by four stays V, V, two above and two below, not shown in Fig. 1.
I, I, bevel gear to work the riddle F from driving wheels S; J, chain platform
worked by chain or belt gear from axle of driving wheels S; K, outer frame to
which the traces or shafts are attached by means of crossbar M; N, bearer to
support weight of trough; P, lever behind to assist in turning the machine round,
it is let into socket p on the yoke or frame G; Q, a series of heavy balls on a
chain which (not revolving with the riddle) serve to clear it by impact from dirt
sticking in the meshes; R, interior scoop carrying potatoes from platform ♬ to
riddle F; S, fore wheels; T, hind wheels.
In working, the scoop A is let down to the required angle, the support of the
trough N being as thin as possible, so as to afford as little obstruction as possible;
the machine is then propelled forward by the horses; the dirt, potatoes, et cetera,
are forced up the scoop A, spout D, and down R into riddle F; it runs out at end
into a bag, or merely in a stream on the ground, as desired.
Having now described my Invention, I wish it to be understood that there is
no single part of this machine that taken separately or used for a different purpose
I consider new, but that what I believe to be new and desire to protect under
Letters Patent is,-
The manufacture of machinery for digging and separating potatoes, arranged
and constructed substantially as herein described, and especially the following
particulars :-
First. The combination in a potato digging and separating machine of digging
apparatus with a cylindrical or conical riddle revolving with its axis in or close to
and parallel with the centre line of the machine.
Second. The yoke E arranged with journals rigidly attached thereto, and with
a hiatus in the centre to allow of the passage of a trough through the widest part
when the diameter of the riddle is too small, or there be other impediments to its
conveniently passing above the axle as in the Drawing.

page_text: Third. The combination of the adjustable spade A, troughs D and R, or their
equivalents, and the longitudinal revolving riddle F, substantially as described.
Fourth. The riddle cleaning device, consisting of a chain of heavy beads, or its
equivalent in combination with a riddle for use in potato digging machines.
In witness whereof, I, the said Robert Alexander Clark, have hereunto set
my hand and seal, this Fifteenth day of August, in the year of our Lord
One thousand eight hundred and eighty one.
DADEDA A
T
ROBERT
(14.5.)