Improvements in Potato-digging Machines.
Year: 1896

page_text: 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, l'ark
Road, Peterborough, in the County of Northampton, Merchant, do hereby declare
the nature of this invention to be as follows:-
The invention relates to improvements upon an invention described in the
specification of Letters Patent No. 1229 of the present year, whereby we greatly
improve the operation of the machine and deliver the potatoes to a hopper ex-
tending beyond the side of the machine so as to deliver them to a cart travelling
alongside, or if desired to baskets carried by the digger.
According to our present invention we dispense with the rakes or beaters and
with the curved conductor at the rear of the share described in the above men-
tioned specification, and in lieu thereof we employ a short elevator, the lower
end of which has its working face on a line or thereabouts with the face of the
share, whilst the upper end is above and projects somewhat over the lower end
of the elevator described in the aforesaid Specification.
This lower elevator is narrower and is worked at a slower speed than the upper
elevator and, in order to prevent injury to the machine by stones, we hinge a
portion of the rear end of the share so that when a stone is lifted by the lower
elevator, such hinged portion of the share shall give way and allow the stone to
pass without injury to the machine.
By these arrangements the earth will become disintegrated and separated from
the potatoes, partly by falling over the upper end of the lower elevator on to the
lower end of the upper elevator, and partly by the increased speed of this latter
elevator as compared with the lower one.
We also shorten the upper elevator and lower the topping screen and riddles,
which are of course placed in position to receive the potatoes &c from the upper
elevator. We also apply to the rear of the screens a third elevator carried by a
suitable frame and rotating wheels and arranged crosswise of the end of the
machine; the part of this elevator extending across the end of the machine is
preferably horizontal or nearly so, and the part extending beyond the side of the
machine is of a suitable length and angle to carry the potatoes and deliver them
into a hopper which delivers them to a cart travelling alongside the machine or
to a basket carried thereby; or this latter elevator may have its lower end at
the centre of the back of the machine and be arranged in a continuous incline,
in which case the potatoes from the screens would be guided towards the lower
end of the elevator, and the latter would be capable of being arown over from
one siue to the other of the machine to suit circumstances.
The elevators may be of any convenient construction and motion is given to

page_text: their onerating wheels from the potato digging machine by any suitable
arrangement of gearing.
Nth 18OC
HARRIS & MILLS,
23 Southampton Buildings, London, W.C.,
Agents.
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 relates to improvements upon an invention described in the
specification of Letters Patent No. 1229 of the year 1896, whereby we greatly
improve the operation of the machine.
Our invention is illustrated in the accompanying drawings in which Fig. 1
is a side view, Fig. 2 a plan, Fig. 3 a front view and Fig. 4 a rear view of a
potato digger provided with our present improvements.
Fig. 5 is an elevation, seen from the right hand side of the machine, of parts
carrying and giving motion to the topping screen and showing the shaking
riddles and their supports.
Fig. 6 is a side elevation of parts carrying and giving motion to the shaking
riddles, the topping screen being shown in section.
Fig. 7 is a sectional elevation and Fig. 8 is a plan of part of the endless elevating
screen.
Fig. 9 is an edge view and Fig. 10 a plan of two links of said elevating screen
drawn to a larger scale.
Fig. 11 shows a modified arrangement of driving gear.
In carrying our invention into effect we employ a framing a supported by a
pair of wheels b fixed to a rotating shaft c, and by a pair of smaller wheels d
imounted 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 lever f. For this purpose the lever f is pin-jointed to the upright e', and is
adjustably connected at one end to the link a', whilst its other end is held by
a hook a. g is a share fixed to dependent arms a attached to the frame a and
acting to lift each row of potatoes and the earth in which they have grown to the
lower end of a short endless elevator h, the working face of which is on a line
or thereabouts with the face of the share, whilst the upper end is above and
projects somewhat over the lower end of an endless elevating screen j. This lower
elevator his narrower and is or may be worked at a slower speed than the upper
elevator and in order to prevent injury to the machine by stones, we hinge a
portion of the rear end of the share so that when a stone is lifted by the lower
elevator h, such hinged portion g' of the share shall give way and allow the
stone to pass without injury to the machine.
By these arrangements the earth will become disintegrated and separated from
the potatoes, partly by falling over the upper end of the lower elevator h on to the
lower end of the upper elevator j and partly by the vibration of this latter clevator
and its increased speed as compared with the lower elevator h when such increased
spee! is used.

page_text: The endless elevating screen ; as described in our before mentioned specifica-
tion, is formed of two main outer chains j, connected together at suitable intervals
by cross bars attached to lugs formed on certain of the links of the chains j
and a series of slacker chains which, being connected to the cross bars ; so as
to fall below the main chains j and by the aid of cross rods passed through
links of the chain 2, form pockets to receive and securely carry the potatoes
up to the top of the elevating screen j. The pockets thus formed also, by their
having a considerable amount of vibratory motion both in travelling forwards
and in passing over their supporting wheels, assist in separating the earth from
the potatoes and in clearing earth from themselves. The elevating screen A
is constructed in similar manner to the elevating screen j. At each side of the
endless elevating screens hj respectively is arranged a guard a of sheet iron or
other suitable material, which is attached to and carried by the frame of the
machine and is of such width as to prevent the potatoes on the said elevators from
falling sideways out of the pockets thereof.
When the potatoes with their tops and with the weeds which have grown with
them, have passed over the top of the elevating screen j, they fall on to an endless
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. A guard k is fitted at the outer
or rear side of the topping screen k to prevent any tops or un-riddled potatoes
from falling into the receiver m.
The potatoes after having passed through the endless topping screen, fall on
to a pair of superposed shaking riddles or screens 22 each consisting of two
vertical sides, a closed front, an inclined screening bottom and an open rear end
for delivery of the screened potatoes. The upper screen 71 has a more open
screening bottom than that of the lower screen P. The larged potatoes are
retained by the upper screen whilst the smaller potatoes and accompanying
earth fall on to the lower screen 12 where the potatoes are separated from the
earth which latter falls through to the ground whilst the potatoes from both
screens fall into a box or receiver m whence they may be allowed to fall into
baskets carried beneath such receiver. The receiver m is provided with a rear
guard m and with movable bottoms or sliding doors m which can be closed when
the baskets m are to be removed and re-opened when the latter are replaced.
Motion is given to the endless elevating screens, topping screens, and shaking
riddles or screens in the following manner.
On the main wheel shaft c is fitted a chain wheel n which is capable of being
put into or out of gear with the shaft c by means of a clutch n¹ operated by
means of a lever n
Motion is communicated from the chain wheel n' by means of a chain n³ to a
chain wheel o¹ fixed on a cross shaft o, on which are also mounted spur pinions o
which gear with spur pinions 18 mounted on the cross shaft 77, near each end
thereof.
The main chains j of the upper endless elevating screen are mounted on chain
wheels fitted on the cross shaft 7 at top and on chain wheels on the cross
shaft at bottom. On one end of the cross shaft is mounted a chain wheel 711
which, by means of a chain h³ rotates a chain wheel he fitted on a cross shaft h¹
on which are mounted the chain wheels A, which operate the main chains of
the lower endless elevating screen, the bottom end of the lower endless elevating
screen is supported by chain wheels 5 and rollers fitted on a cross shaft he carried
by brackets fixed to the arms a*. The topping screen k is formed of two endless
main chains connected at intervals by cross bars and by other chains a 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 and guide
rollers ; the driving chain wheels are fixed on a shaft on which is fixed

page_text: a grooved pulle k, over which and over guide pulleys ³ (seen more clearly at
Fig. 5) runs a driving band or chain 10 receiving motion from a driving pulley
on the shaft 7. The pair of superposed shaking riddles (see Fig. 6) are
mounted in brackets 13 carried on the framing a, rocking levers 7 are pinned at
their ends to the top and bottom, riddles respectively, the rocking motion being
communicated to each by a rod 17 fixed to the bottom end of one of the rocking
levers, the other end being fixed to a crank pin or eccentric on the shaft 19, on
which latter is fixed a chain wheel 10 driven by a chain from the chain
wheel fixed on the cross shaft ; a fly wheel 13 may be fitted to the crank
shaft P.
In the modified arrangement of driving gear shown at Fig. 11 a large chain
wheel, fitted on the main wheel shaft c, communicates motion by means of a
chain n³ to a chain wheel o' fitted on a cross shaft o which shaft may be mounted
on any convenient part of the framing a. On the cross shaft o is fitted a spur
pinion o which gears with a spur pinion 8 fitted on a cross shaft 1 placed with
this arrangement alongside the cross shaft o.
On one end of the shaft 1 is fitted a chain wheel 2 which communicates
motion by means of a chain 3 to a chain wheel 4 on a shaft on which the
wheels actuating the top of the upper endless elevator j are mounted. On the
other end of the cross shaft 1 is a chain wheel 5 which communicates motion by
means of a chain h³ to a chain wheel ha fitted on a cross shaft h', on which the
chain wheels actuating the upper end of the lower endless elevator h are mounted.
The advantage of this modified arrangement of gearing is, that by increasing
or decreasing the size of the chain wheels 2 o¹ and 4 and 5 and h the normal
and relative speeds of the upper and lower endless elevators, can be increased or
decreased as desired.
Having now particularly described and ascertained the nature of our said in-
vention and in what manner the same is to be performed we declare that what we
claim is:
1. In potato digging machines the combination of a potato lifting share, a
short endless elevating screen having its working face on a line or thereabouts
with the face of the share and a longer endless elevating screen having its lower
end below the upper end of the shorter elevating screen and delivering the
potatoes by its upper end to a topping screen and shaking riddles, substantially
as herein set forth.
2. In potato digging machines the combination of a potato lifting share, a
hinged portion at the rear of such share, a short endless elevating screen having
its working face on a line or thereabouts with the face of the share and a longer
endless elevating screen having its lower end below the upper end of the shorter
endless elevating screen, substantially as herein set forth."
3. In potato digging machines the combination of a potato lifting share, a
short endless elevating screen and a longer endless elevating screen arranged and
operated, substantially as herein set forth.
4. In potato digging machines the combination of a potato lifting share, a
short endless elevating screen and a longer endless elevating screen having a
greater speed than the shorter substantially as herein set forth.
5. The improvements in potato digging machines, substantially as herein set
forth.
HARRIS & MILLS,
23 Southampton Buildings, London, W.C.,
Agents.