Improvements in Potato Digging Machines.
Year: 1896

page_text: Date of Application, 17th Jan., 1896-Accepted, 14th Mar., 1896
COMPLETE SPECIFICATION.
Improvements in Potato Digging Machines.
We, CHARLES JOSEPH MOULTON, of High Street, Chatteris, in the County of
Cambridge, Ironmonger, and ARTHUR JAMES KEEBLE, of Walton House, Park
Road, Peterborough, in the County of Northampton, Merchant, 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 :-
The invention has for its object various improvements in potato digging
machines with a view to render them more satisfactory in their action.
Our invention is illustrated in the accompanying drawings, in which :-
Fig. 1 is a side elevation, Fig. 2 a plan, Fig. 3 a front view and Fig. 4 a rear
view, of our improved potato digger.
Fig. 5 is an elevation, seen from the right hand side of the machine, of parts for
carrying and giving motion to the topping screen.
Fig. 6 is a side elevation of parts carrying and giving motion to the shaking
screens or riddles at the rear of the machine.
Fig. 7 is a plan view of the shaking screen or riddle separately.
Fig. 8 is a cross section through the curved inclined conveyor showing the
relative position of the rakes or beaters.
Fig. 9 is a sectional elevation and Fig. 10 is a plan of part of the endless elevating
screen.
Fig. 11 is an edge view aud Fig. 12 a plan of two links of the said elevating
screen drawn to a larger scale, and Fig. 13 is a view drawn to an enlarged scale of
sliding doors for shutting the outlets of the shaking riddles or screens.
In carrying our invention into effect we employ a framing a supported by a pair
of wheels b fixed on a rotating shaft c and by a pair of smaller wheels d mounted
on a fore carriage e supporting the front of the frame a, which latter is capable of
being raised and lowered in relation to the fore carriage e by means of a hand
wheel f¹ fixed on the shaft of a screw f taking into a worm wheel f' formed on the
outside of a nut working upon the screw e rising from the fore carriage e. g is a
share fixed to the frame a and acting, when the front of the latter is lowered, to
lift each row of potatoes and the earth in which they have grown to a certain level,
where a series of rakes or beaters on a revolving shaft h strike the combined
mass, disintegrate the soil, and separate it to a large extent from the potatoes as
the latter travel up a curved and inclined conductor i to the lower end of an
inclined endless elevating screen j. The curved and inclined conductor i is, for a
short distance from its junction with the share g, curved to a radius somewhat
larger than that of the rakes or beaters h', whence it is continued at an incline to a
short distance above the lower end of the endless elevating screen j, and such
conductor i is also hollowed or curved transversely so as to give the potatoes and
earth lifted by the share g a tendency to move towards the longitudinal centre
thereof. The rakes or beaters h¹ are formed of arms h* having at their ends three
rigid prongs, the centre one of which, from its junction with the arm h*, is inclined
away from the other prongs so as, when moving towards the mass of earth and
potatoes, to touch such mass before the other prongs, thus assisting in disintegrating
the mass and preventing the potatoes from wedging between the prongs. The
lengths of the prongs are so regulated as to follow the transverse contour of the
conductor i.

page_text: It may be mentioned here that it has been found by experiments conducted by us
that the beaters or rakes are able to do the work of disintegrating more efficiently
when constructed in several series, preferably three, side by side on the shaft as
shown in the drawings and in such relative positions as to form a zig-zag line when
seen from the ends, which is obtained by using double the number of beaters in
the central series to those at the sides. With this arrangement it will at once
be evident that the earth dug up with the potatoes for disintegration receives the
blows from the beaters in three different directions and besides being induced
thereby to make its way from the conductor in a straight line toward the endless
elevating screen, is thrown from side to side under the consecutive blows of the
beaters in the several series following each other in rapid succession.
The endless elevating screen is formed of two main outer chains ; connected
together at suitable intervals by cross bars attached to lugs j formed on certain
of the links of the chains j, and a series of slacker chains which, being connected
to the cross bars ji so as to fall below the main chains j and by the aid of cross
rods passed through links of the chains, form pockets to receive and securely
carry the potatoes up to the top of the elevating screen. The pockets thus formed
also, by their having a considerable amount of vibratory motion both in travelling
forwards and in passing over the supporting wheels, assist in separating the earth
from the potatoes and in clearing earth from themselves. At each side of the
endless elevating screen is arranged a guard, not shown in the drawing, of sheet
iron or other suitable material, which is attached to and carried by the frame of the
machine and is of such a width as to prevent the potatoes on the elevator from
falling sideways out of the pockets thereof. When the potatoes, with their tops
and weeds which have grown with them, have passed over the top of the elevating
screen j, they fall on to a transversely travelling topping screen k, the spaces of
which are sufficiently large to allow all the potatoes to pass therethrough, but
which will hold back and separate the tops and weeds therefrom and carry the
latter away to the side of the machine where they will fall to the ground.
The potatoes, after having passed through the topping screen, fall on to a
shaking riddle or screen consisting of two vertical sides, an inclined front, two
superposed screens, and a guide bar for the potatoes to each screen. The upper
screen is made of coarser mesh than that of the lower screen 2 and has moreover
one corner made solid, as shown at Fig. 7, or such corner may consist of a finer
screen. The larger potatoes retained by the upper screen are delivered, guided
by the inclined guide bar P, into a suitable receiver m, whilst the potatoes which
pass through the top screen are delivered by the lower screen 1, guided by the
inclined guide bar , into a receiver ".
In order to afford facility for closing the outlets of the screens 11, at the time.
when full receivers m m are being removed and empty ones substituted therefor,
we employ the arrangement represented at Fig. 13 consisting of four metal rods
fixed across the outlet ends of the screens and fitted with sliding doors which
can be slidden along the rods 13 to close the outlets of the screens 12 or to leave
them open as may be required.
Other numbers of riddles or screens and potato receivers may be used if desired.
This action of the riddles or screens not only sorts the potatoes but further
separates the soil from them, such soil falling through the spaces of the riddles or
screens on to the ground. The solid or finer part of the screen is provided for
the purpose of preventing small potatoes from falling through that corner of the
upper sereen beyond the guide bar of the lower screen, whence they would fall
either into the receiver m for the larger potatoes or down to the ground.
Motion is given to the rotating rakes or beaters, endless elevating screen, topping
screen, and sorting riddles or screens in the following manner.
On the shaft are fixed chain wheels A, which are rotated by chains receiving
motion from chain wheels fixed on a hollow shaft c* mounted on the shaft c.
On the hollow shaft c are also mounted chain wheels n, which are capable of
being locked with the shaft e or set free thereof by clutches n'operated by levers a.

page_text: Motion is communicated from the chain wheels n by chains n³ to chain wheels o²
mounted on a cross shaft o. The main chains of the endless elevating screen are
mounted on chain wheels fixed respectively on cross shafts jj', and on this.
latter,, are fixed toothed wheels, which are driven by toothed wheels o² fixed on
the shaft o. The topping screen k is formed of two endless main chains k
connected together at intervals by cross bars k¹ and by other chains k² fixed to
such cross bars and having cross rods passed at suitable distances through the
links thereof. This endless topping screen k runs over driving chain wheels k* and
guide wheels ; the driving chain wheels k are fixed on a shaft * on which is
fixed a grooved pulley k', over which and over guide pulleys 8 runs a driving band
or chain 10 receiving motion from a pulley fixed on the shaft. The riddle / is
mounted on rocking arms carried by the framing a and the end of an eccentric
rod is connected to the said riddle, whilst its strap is operated by an eccentric 18
fixed on a shaft 19, on which latter is fixed a chain wheel 10 driven by a chain ("
from a chain wheel 2 fixed on the cross shaft j'.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
1. In potato digging machines having a frame a supported by wheels and d
and provided with a digging share 9 and means for raising and lowering the latter,.
the combination therewith of a curved inclined conductor i connected with the
share, rotating arms or beaters the prongs of which are of lengths to follow the
curve of the conductor i, an endless elevating screen j formed with a number of
pockets, an endless travelling topping screen k receiving the potatoes, tops and
weeds from the elevating screen j, a pair of shaking screens 11 receiving the
potatoes from the topping screen k and delivering the sorted potatoes to receivers mm*,.
substantially as herein shown and described.
2. In potato digging machines of the character herein described, the peculiar
construction and combination of curved inclined conductor i and of rakes or
beaters h', substantially as herein shown and described.
3. In potato digging machines of the character herein described, the peculiar
construction of endless elevating screen ; substantially as herein shown and
described.
4. In potato digging machines of the character herein described, the combination-
of an endless elevating screen j, an endless topping screen k, a shaking riddle
containing two or more screens 12 around which the endless topping screen travels
in a direction transversely of the machine, and doors for shutting the outlets of the
screens, substantially as herein shown and described.
5. In potato digging machines of the character herein described, the employment
of an endless topping screen constructed and arranged substantially as herein shown.
and described.
Dated this 17th dow of Januar 1806
HARRIS & MILLS,
23 Southampton Buildings, London, W.C., Agents.