IMPROVEMENTS IN MECHANICAL DIGGERS FOR CULTIVATING LAND
Year: 1884

page_text: 1 MARLBOROUGH ROBERT PRYOR of Weston Manor Stevenage in the County of
Herts Esquire do hereby declare the nature of said Invention for "IMPROVEMENTS
IN MECHANICAL DIGGERS FOR CULTIVATING LAND" to be as follows:-
:-
The object of my Invention is to avoid certain disadvantages of the arrangements
now in use for operating and controlling the digging forks of mechanical diggers.
In such diggers as ordinarily constructed the crank shaft operating the digging
forks is situated near the ground and very near the forks and therefore liable to
injury from rust and dirt and further has to be driven by a very small spur wheel
or pinion which as its speed is usually much slower than that of the crank shaft of
the engine or other motor driving the machine makes it necessary to employ
gearing such that the speed is first diminished and then again increased in
transmission whereby a considerable loss of efficiency is incurred.
My Invention also renders the machine more easily adjustable to suit different
kinds of digging work.
According to my said Invention the crank shaft which is carried in bearings
fixed to the frame of the machine is placed at the top of the fork handles which
are preferably straight or nearly so the crank pins passing through eyes or bearings
in the upper ends of the fork handles. The crank shaft is preferably driven by a
spur wheel keyed therein. The forks are constrained to enter the soil and act upon
it in the way required by links pivotted at one end at points in the fork handles
not far from the middle of their length and at the other end to centres rigidly
connected with the framing of the machine whilst the machine is at work but
preferably so arranged as to admit of adjustment to adopt the machine to produce
different kinds of work. These centres I call fixed centres. In general the fixed
centres of the links are upon a bar or countershaft connected to the frame of the
machine and held in a position in front of the digging forks relatively to the
direction of motion of the machine; the digging forks being at the rear of the frame
of the machine and throwing the dug soil behind them but the fixed centres may be
supported independently of each other and they may in some cases be carried at
the back of the machine. behind the digging forks. The links themselves are
preferably made so that their working length between centres may be increased or
diminished and the position of the centres on the fork handles can be easily altered
so as to permit of the adjustment of the machine.

page_text: The forks themselves are carried at the lower ends of the fork handles either
rigidly or by pins or hinges allowing play in one direction while when the forks
are acting upon the ground they bear against a fixed or adjustable stop fixing their
position during the effective part of their stroke; this play may be controlled by
springs or balance weights. To control the speed at which the whole machine
passes over the ground to be cultivated and thereby to regulate the width of the
spit of earth dug at each stroke of the forks the main road or carrying wheels of
the machine may be connected by gearings pitch chains or other suitable means
directly or indirectly to the crank shaft operating the forks and the said road or
carrying wheels may be provided with shoes or spikes to prevent them slipping
such spikes may preferably slide freely through holes in the wheel tyres being
attached within the tyre to rods nearly as long as the radius of the wheels such
rods being hinged or otherwise attached to an eccentric strap working on an
eccentric through which the axle of the road wheels passes, these spikes may be
made to project from the wheel face into the soil to any required degree by
adjusting the position of the eccentric and cannot become so covered with soil as
to become choked and inoperative.
J. HENRY JOHNSON,`
47, Lincoln's Inn Fields, London, W.C.,
Agent for the said Marlborough Robert Pryor.
I, MARLBOROUGH ROBERT PRYOR of Weston Manor Stevenage in the County of
Herts Esquire do hereby declare the nature of said invention for "IMPROVEMENTS
IN MECHANICAL DIGGERS FOR CULTIVATING LAND" and in what manner the same
is to be performed, to be particularly described and ascertained in and by the
following statement :—
The object of my Invention is to avoid certain disadvantages of the arrangements
now in use for operating and controlling the digging forks of mechanical diggers.
In such diggers as ordinarily constructed the crank shaft operating the digging
forks is situated near the ground and very near the forks and therefore is liable to
injury from rust and dirt and further has to be driven by a very small spur wheel
or pinion which (as its speed is usually much slower than that of the crank shaft
of the engine or other inotor driving the machine) makes it necessary to employ
gearing such that in transmission the speed is first diminished and then increased
again whereby a considerable loss of efficiency is incurred.,
My Invention also renders the machine more easily adjustable to suit different
kinds of digging work.
According to my said Invention the crank shaft, which is carried in bearings
fixed to the frame of the machine, is placed at the top or upper part of the fork
handles which are preferably straight, or nearly so the crank pins passing through
eyes or bearings in the upper ends of the fork handles. The crank shaft is
preferably driven by a spur wheel keyed thereon. The forks are constrained to
enter the soil and act upon it in the way required by links pivotted at one end at

page_text: points in the fork handles not far from the middle of their length, and at the other
end to centres rigidly connected with the framing of the machine, whilst the
machine is at work, but preferably so arranged as to admit of adjustment to adapt
the machine to produce different kinds of work. These centres I call fixed centres.
In general the fixed centres of the Links are upon a bar or countershaft connected
to the frame of the machine and held in a position in front of the digging forks
relatively to the direction of motion of the machine, the digging forks being at the
rear of the frame of the Machine and throwing the dug soil behind them, but the
fixed centres may be supported independently of each other, and they may be
carried at the back of the machine behind the digging forks. The links themselves
are preferably made so that their working length between centres may be increased
or diminished, and the position of the centres on the fork handles can be easily
altered so as to permit of the adjustment of the machine.
The forks are connected to the lower ends of the fork handles either rigidly or
by pins or hinges allowing play in one direction, while when the forks are acting
upon the ground they bear against adjustable and fixable stop fixing their position
during the effective part of their stroke. This play may be controlled by springs
or balance weights.
To control the speed at which the whole machine passes over the ground to be
cultivated, and thereby to regulate the width of the spit of earth dug at each stroke
of the forks, the main road or carrying wheels of the machine may be connected by
gearing, pitch chains, or other suitable means, directly or indirectly to the crank
shaft operating the forks, and the said road or carrying wheels may be provided
with shoes or spikes, to prevent them slipping, such spikes may slide freely through
holes in the wheel tyres being attached within the tyre to rods nearly as long as
the radius of the wheels such rods being hinged or otherwise attached to an
eccentric strap, working on an eccentric through which the axle of the Road wheels
passes; these spikes inay be made to project from the wheel face in the soil to any
required degree by adjusting the position of the eccentric, and cannot become so
covered with soil as to become choked and inoperative.
And in order that my said Invention may be fully understood I shall now
proceed more particularly to describe the same and for that purpose shall refer
to the several figures on the annexed sheet of drawings the same letters of reference
indicating corresponding parts in all the figures.
Figure 1 is a side elevation and Figure 2 is a plan of a digger constructed
according to my Invention and Figure 3 is an enlarged detail. It is shewn as
a steam digger but of course it may be operated by any suitable motive power In
my drawing I have not considered it necessary to shew the spiked wheels to which
I have referred, as they form in themselves no part of my Invention.
I mount the crank shaft A which operates the diggers in bearings B fixed to the
upper part of the frame of the machine and I connect the upper ends of the fork
handles or rods C thereto by bearings or eyes D engaging the crank pins E of the
crank shaft A. This shaft is driven from the crank shaft F of the steam engine G
by gearing H The digging forks C2 are caused to enter the soil at the required
angle and act upon it in the way required, by links I pivotted at one end to the
fork handles C by the pin i.
Each of the links I is attached by the pin, i mounted in the lug n which is
adjustable on the fork handle or rod and fixable thereon by clamps ; the pin i
may be placed in any of the holes thus altering the effective length of the links I.
The links I are piyotted at their other ends on the transverse rod K which is carried
by a frame composed of the links L and the screwed rod or rods M in such a way that
the rod K is fixed relatively to the frame of the machine whilst the machine is at
work, but is capable of adjustment relatively to the frame of the machine so as to
alter the character of the stroke of the digging forks. The links L are attached
to the frame of the machine by pins which may be fixed or placed in any of the
holes in the frame of the machine, the rod or rods M passes or pass through a

page_text: projection or projections on the frame of the machine and are provided with a
'screw nut or nuts or wheels working on the said rod or rods so that the position
of the rod K can be varied by operating the said screw nuts or wheel.
The forks or diggers C are connected to their handles by pins or hinges as
shewn at k so as to be free to turn in one direction and in order to render them
rigid during their effective stroke a fixed or adjustable stop 6 is provided, against
which a lug b on the fork C³ is caused to bear by the weight of the fork itself or
by springs or balance weights if required.
The main road or carrying wheels N of the machine are driven from the shaft A
by gearing P and pitch chains Q and change wheels Q' allowing of variable speed.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed I declare that what
I claim is,
First. In mechanical diggers for cultivating land, arranging the crank or other
device for applying the operating power, at or towards the upper end of the digger
rods or handles, and attaching the controlling links or the equivalent controlling
device below the connection of the fork handles or rods, to the device for applying
the operating power.
Second. In mechanical diggers for cultivating land connecting the crank or other
device for applying the operating power at or towards the upper end of the digger
rods or handles and attaching the controlling links or the equivalent controlling
device below the connection of the fork handles or rods, to the device for applying
the operating power, the point or points of attachment of the said controlling
device being provided_with-means-whereby-they-may-be-adjusted according to
the work to be done substantially as herein before described and illustrated by my
drawings.
Third. In mechanical diggers for cultivating land the combination of the
adjustable stop b with the hinged fork or digger Carranged to operate substantially
as and for the purpose hereinbefore described and illustrated by iny Drawings.
Fourth. The general combination and arrangement of parts constituting a
mechanical digger as herein before described and illustrated by my Drawings.
Dated this third day of January 1885.