Improvements relating to Digging Machines.
Year: 1893

page_text: Date of Application, 4th Sept., 1893
Complete Specification Left. 2nd June, 1894-Accepted, 21st July, 1894
PROVISIONAL SPECIFICATION.
Improvements relating to Digging Machines.
I, THOMAS COOPER of Great Ryburgh in the County of Norfolk, Engineer, do
hereby declare the nature of this invention to be as follows:-
In digging machines as at present constructed, it is not possible readily to
change the position of the digging blades, according to the contour of the ground
over which the machine is working; consequently, if the main driving or carrying
wheels sink into a depression in the land, the diggers bury themselves, so to speak,
and if the wheels run over a rise, the diggers barely (if at all) enter the
ground.
This is obviously a great defect, and it is the object of this invention to overcome
this defect, and otherwise improve the working of this class of machine.
To this end, the invention consists in mounting the digger shaft in adjustable
bearings, the position of which will be regulated by a feeler, which will press upon
and follow the surface of the ground, and which will act on suitable mechanism to
raise or lower the digger shaft as required.
Difficulty has also been experienced in turning these machines at the headland,
within their own length, and the invention also consists in a simple arrangement
of mechanism which will allow of this being more satisfactorily effected than
heretofore.
In carrying out my invention, I may mount, on the axle of the wheel which
drives the digger shaft, a pair of bracket arms, which carry the bearings for the
digger shaft, so that the shaft may be raised or lowered in the arc of a circle.
The movement of these arms may be effected in any convenient manner, say, for
example, by excentrics mounted on a suitable shaft, and connected with the digger
shaft, or the bearing for the same, by suitable connecting rods or links. The
position of these excentrics is changed, so as to raise or lower the links, by a worm
and worm wheel, which are actuated in any convenient manner from the working
parts of the machine, or otherwise.
These parts are thrown into gear by the action of the feeler, which may be a
shoe or a roller, sliding or rolling on the ground, and carried by a rod pendent
from one arm of a bell crank lever, the other arm being in connection with the
worm-actuating mechanism.
The fulcrum of this lever will be on the firebox or other part of the digger, and
will therefore rise and fall with the machine, while the feeler rod, being always the
same length, will cause the bell crank to rock in either direction."
A pressure spring may be used to lower the feeler into a depression, or bring it
to a normal position.
It will be obvious that a variety of mechanisms could be employed to raise or
lower the digging forks or blades, such, for instance, as a steam or hydraulic
cylinder, but whatever the mechanism employed, it would be actuated by the feeler
described.
For the turning gear, I employ a compensating gear of the ordinary construction,
and upon one of the bevil wheels, and also at the opposite end of the shaft, I
provide brake drums and bands, so that either end of the shaft may be locked or
retarded, as required, and the driving wheel at the opposite end will go round so
much the faster, the steering wheels, of course, being placed in the necessary
position, in the ordinary manner.
Dated this 4th den of Sentember 1893
NEWTON & SON,
Agents for the Applicant.

page_text: CODE DELE DECIFICATION.
Improvements relating to Digging Machines.
I, THOMAS COOPER, of Great Ryburgh, in the County of Norfolk, 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 :-
The engine which forms the subject of the present invention, is intended to be
used for traction and general agricultural purposes, and is also fitted with digging
mechanism for tilling and cultivating the soil. It is to the improvement of this
digging mechanism that the present invention is more particularly directed.
Engines for general agricultural purposes fitted with cultivating mechanism,
Lave already been made subjects of invention and of patents, and some of these
have been found to work admirably under favourable conditions. It is my present
object to produce an engine capable of doing the best work under all conditions
and circumstances.
A source of failure in practical working, which has not hitherto been surmounted,
lies in the absence of a satisfactory method of automatically regulating the depth
of stroke of the digging forks, according to the varying level of the surface
traversed by the engine. Engines which have done good work, when travelling
over an even surface, have been found to alternately bury the diggers and miss the
ground altogether, when put to work over ridge and furrow, or other irregular
ground.
A practicable method of raising and lowering automatically the diggers as the
engine travels over uneven surfaces, so as to ensure always the cultivation of the
soil to a proper and regular depth, as well as other improvements in connection
with a general purpose agricultural engine, including means for facilitating turning
short round, will now be described, reference being had to the accompanying
drawings, wherein corresponding parts are designated by like letters throughout.
Fig. 1, Sheet I, shews, in side elevation, the hind portion of an agricultural engine
embodying my improvements.
Fig. 2, Sheet II, is a partial plan of the same.
Fig. 3, Sheet III, is a back view of the digging forks and gear.
Fig. 4, Sheet IV, is a back view of the engine, with the digging gear
removed.
Figs. 5 and 6, Sheet IV, are details which will be hereafter described.
Figs. 7, 8, 9, 10, 11 and 12, Sheet V, are detached views of the feed-water tank,
and certain valve mechanism in connection with the digger raising or lowering
mechanism, Fig. 8 being a vertical section on line 1-2 of Fig. 10; Fig. 9 being
a section at right angles thereto, on line 3-4, Fig. 10; Fig. 10 being a horizontal
section on line 5-6, Fig. 9; Fig. 11 a horizontal section on line 7-8, Fig. 8 ;
and Fig. 12 a horizontal section on line 9-10, Fig. 9.
Figs. 13 and 14, Sheet VI, illustrate in side and end views a modification of the
mechanism for raising and lowering automatically the digger forks.
Figs. 15 and 16 are plan and end views of a portion of this regulating mechanism,
detached.
I have not thought it necessary to shew the whole of the engine in the
accompanying drawings, but only so much as is required to illustrate my present
invention.
The boiler A, the end only of which appears in the drawing, is of the usual type,
and carries upon it the engine cylinders, not shewn. B is the fire box behind the
boiler, and C is the tender behind the fire-box. D is the main axle, upon which
are mounted the main road wheels D¹ D2. These road wheels are driven by tooth
wheels d¹ d², attached thereto, and engaging with pinions e el carried by the counter
shaft E, which is mounted in bearings supported by wing plates attached to the

page_text: fire-box B. Upon the counter shaft E, is supported a differential gearing, such as
is sometimes found in traction engines, which enables the wheels to be driven
separately, or both together. This differential gearing comprises a pair of face
wheels, a driven toothed wheel F and a pair of bevil pinions f* fi*, mounted
diametrically opposite each other, within the wheel F, so as to be carried round
therewith; they are capable also of rotating at right angles thereto.
The bevil pinions f* fi* both engage with the face wheels ff', as best seen
at Fig. 4.
The pinion e is in one with the face wheel f, both being loose upon the counter
shaft E.
The face wheel f¹ is keyed to the counter shaft, as also is the pinion el. When
the wheel F is driven by the pinion g, keyed to the crank shaft G, the tendency
is to drive both face wheels ff by the teeth of the bevil wheels f* fi* engaging
therewith, and acting merely as locking devices connecting the two face wheels.
In this manner, both road wheels are driven evenly until one or other becomes
retarded, either by the steering gear, or by brake bands applied to the face
wheels for f¹, as shewn in the drawings. This braking or retarding of one wheel,
causes the bevil wheels f* * to run round, so as to continue to drive the wheel
on the opposite side without interruption. Thus, when one wheel is held fast by
means of the brake band operated by a lever in the hand of an attendant, and the
engine continues to be driven, the latter is turned short round on the fixed wheel
in a very small space. This is a matter of great importance, as much time is thus
saved when turning at the headlands.
Besides the pinion g, the crank shaft G carries a fly wheel H, situated at the
opposite end, and permanently keyed thereto. This fly wheel serves as a band
pulley, when the engine is used for stationary purposes, to drive a thrashing
machine, for instance.
It also serves the ordinary purposes of a fly wheel, in overcoming the dead points,
particularly when the diggers are in action.
Movement is conveyed to the diggers from the crank shaft G by the pinion g',
loose thereon, but capable of being fixed to the fly wheel by bolts h h engaging
with holes in the face of the pinion g' (see Fig. 4 and detached views Figs. 5 and 6).
The pinion g' engages with the intermediate wheel I, which turns loosely upon the
sleeve bearing E of the counter shaft E.
The intermediate wheel I engages with another wheel I¹ (see Fig. 2), fast upon
a horizontal transverse shaft J, upon which also is another wheel J', by means of
which and the wheel k, the digger shaft K is driven. The bearings of the digger
shaft K are slung in radial arms jj pivotted concentrically with the shaft J, so
that the raising or lowering of the digger shaft K does not disengage the wheels J¹
and k, or interfere in any way with the continued driving of the latter by the
former during the automatic adjustment I am about to describe.
The digger shaft K, besides having bearings in the radial arms j j¹ before
mentioned, is supported by a pair of links, pendent from the transverse rod L,
which is carried by radial arms 1* * fast on the rock shaft L*, mounted in
bearings in the framing of the tender. This shaft L* has upon it a crank arm L₁*,
by means of which the transverse shaft L*, actuated by suitable power, as here-
after explained, is rocked, and caused to lift or lower the rod L with the digger
shaft K, and all thereon suspended.
The digging forks m, which. according to Fig. 3 of the drawings, are four in
number, and of 5 prongs each, are operated by cranks k¹ formed in the digger
shaft K. These cranks k¹ are embraced by loose sleeves or collars m', to which
the forks are bolted. A reciprocating movement is thus imparted to the forks
as the shaft is rotated, which reciprocation is controlled and regulated by links m²
jointed to the sleeves m³, and to loose radial arms m³ carried by the transverse
rod L, and caused to give to the forks an oval, or approximately oval, strok●,
admirably adapted for tilling operations.

page_text: Adjustment of the links m³ and arms m³ as regards their length, will effect a
variation in the stroke of the forks, when such variation is desired.
I now come to that part of my invention which deals with the automatic raising
and lowering of the digger forks, to accommodate the work to the inequalities of
the soil over which the engine is travelling.
It has been seen how the digger shaft K is loosely mounted or slung, so that it
can be raised or lowered by rocking the shaft L without disengaging the gear
wheels and k, the one from the other.
The rocking of the shaft L*, it has been said, is effected by the arm or lever L₁*,
actuated by suitable power. The power which I prefer to employ is an hydraulic
cylinder N, attached to the side of the engine, as shewn best at Fig. 2 of the
drawings.
n, which
The in and out movement of the cylinder piston is in this way utilised for raising
and lowering the digger shaft and forks attached thereto.
The piston rod of this cylinder is connected by a cross-head with the rod
is jointed to the rod L* before named.
In order to make the raising and lowering of the digger shaft automatic, and
dependent upon the contour of the surface over which the engine is travelling, the
valves of the hydraulic cylinder are put into connection with a shoe or feeler,
o is the feeler
which trails upon the ground, and follows the inequalities thereof.
(see Fig. 1) upon the lower end of a pendent rod o', pivotted to one arm of a
bell-crank lever p.
This bell crank lever p is fulcrummed between the arms of a framing P, one end
of which is fulcrummed on the rod p¹ (see Fig. 4), supported in brackets beneath
the fire box. The other end of the framing is supported by a screw O, pendent
from the rod L, by means of which screw the position of the frame P with regard
to the ground, may be adjusted by hand, before work is commenced. 02 is a loop
spanning the arms of the frame P (see Fig. 3). This loop is pierced to form a
guide for the rod o' of the feeler o; it also forms an abutment for the coiled
spring, which surrounds the said feeler rod, to work against. 03 is a strengthening
rod attached to the feeler o, and jointed to the frame P, for the purpose of
maintaining the feeler rod in a vertical position.
The bell-crank lever p has only a limited rocking movement on its fulcrum, by
reason of the lugs p* which strike against the framing P above and below, and
check the movement. The arm of the lever p, opposite to that whereon the feeler
rod o' is pivotted, is jointed to a rod q, which is pivotted to the arm g' fixed on the
rock shaft Q (see Fig. 4). Another arm q2 on the same rock shaft, is connected
with the valve gear of the hydraulic ram, so that the rocking of the bell-crank p,
by reason of the up and down movement of the feeler, operates to open and close
the valves, and consequently to work the same.
The reason for mounting the feeler and the lever which it operates on a swinging
frame, such as P, is as follows:-Not only is it desirable to adjust the height of the
feeler from time to time, as may be done by the screw O, but it is also necessary,
in operating the valves of the hydraulic cylinder or other source of power, that the
ram should be set in action and stopped at any point.
Were there not some provision to prevent it, the ram once set in action in one
direction or the other, would continue to operate, and lift or lower the diggers to a
greater degree than was desirable. I have, however guarded against this, by
providing that the initial movement in either direction of the bell-crank p, operated
by the feeler, shall be overtaken by the frame P, which, being connected by the
screw to the digger mechanism, continues to move in the same direction, so that
the independent movement of the bell-crank which works the valves, is neutralised
by the frame which follows it, and re-establishes the relative positions of the bell-
crank and frame whereon it is fulcrummed. In other words, it is only the
differential movement between the rod q, attached to the bell crank p at one end,
and the valve-actuating arm q' at the other, and the framing P, that produces the

page_text: moving of the said arm 71. So long as the fulcrum of the frame P and of the
rod q remain in a line, as shewn at Fig. 4, the frame and the rod may be moved
together, without affecting the differential or relative movement which alone
operates the valves through the arm q' and shaft Q operating the valve gear.
The coiled spring around the feeler rod o' tends to keep the feeler in contact with
the ground.
The cylinder of the hydraulic ram N, secured by brackets to the side of the
engine, is provided with a valve box R, containing valves, illustrated in detail on
Sheet V, for admitting water under pressure to either side of the piston, or allowing
it to escape, according to requirement.
It will be readily understood that the water under pressure necessary for working
the hydraulic cylinder, could be supplied by various means, such, for instance, as a
separate pump driven by the engine, and charging a suitable accumulator, or
pumping against a loaded valve. Taking water direct from the boiler would be a
very simple arrangement, but it will be obvious, that, for economy of working, it
would be very objectionable, and as it is desirable that no more additions should be
made to the working parts of the engine than possible, the following means have
been devised for giving a constant supply of water, under boiler pressure, to the
cylinder, at the temperature of water in the supply tank, by using the ordinary
boiler feed pump only.
In carrying out this arrangement, I use a boiler feed pump S of ordinary
construction (which, in the drawings, is a long stroke pump, drawing its supply
from the tank S¹ beneath the boiler, and driven from crosshead of engine). The
pump, which is fitted with the usual suction and delivery valves, is made of rather
larger capacity than necessary, to supply the boiler only, and it works in connection
with a receiver T, placed vertically in a suitable position at side of boiler. This
vertical pipe T is about double the capacity of the hydraulic cylinder, and, at its
top, is connected to the check valve t on side of boiler and to pump delivery pipe,
the latter being carried down nearly to bottom, as shewn in Fig. 7. The bottom of
reservoir is connected by pipe to the hydraulic cylinder valve box R. The check
valve on side of boiler is made with screw beneath, so that the valve can be raised
off its seat, when the receiver T is placed in communication with boiler, and subject
to same pressure.
The action of this arrangement is, that the valve box R of the hydraulic cylinder
is supplied with water at boiler pressure, but at same temperature as the feed water
from the tank, S¹, because the connection for supply and delivery from pump S are
at bottom of receiver, and as the pipe is vertical, the hot water from boiler remains
at the top. When the feed from the pump is more than the supply taken to the
cylinder, the hot water is forced back into boiler again. It is essential to
satisfactory working, that the valves for cylinder should be so arranged that a
small movement should operate them to full capacity, but that, when closed, the
water should be locked in the cylinder, so that the piston cannot move in either
direction; this is accomplished by the arrangement of valves to be seen in the
drawings (Sheet V).
These valves are arranged diagonally, so that when the lever is moved in one
direction, it lifts the pressure or admission valve for one end of the cylinder, and
the retaining and exhaust valve for other end of cylinder, and vice versa; the
length of the lifting spindles is such, that the exhaust and retaining valves are
closed before the pressure or admission valves, and thus the cylinder is always
fully charged.
The valve box (see Sheet V of the drawings) contains two pairs of valves, that
is to say, an admission valve and a retaining or exhaust valve for each end of the
cylinder. In the drawings, all the valves are shewn closed. The water under
pressure supply is at r (see Figs. 8 and 10); the valves are the pressure
valves, which, when opened, admit pressure to the one or other end of the
cylinder N. ** are the corresponding retaining or exhaust valves, communicating
with the eduction passage * delivering over the tank S¹.

page_text: The valve spindles are operated by means of a rocking plate U, forked to
embrace the spindles between collars fixed thereon. The rocking of this plate in
its bearings, by means of the arm u attached thereto, and the connecting rod u¹
jointed to the arm u, and arm ³ in connection with the feeler mechanism before
explained, gives the requisite movement to the valves in the required direction at
the right instant, and causes the hydraulic ram to lift or lower the diggers in the
manner already described. To operate the hydraulic mechanism by hand, a lever
arm g³, keyed to the shaft Q, is provided, which can be depressed by means of a
rod g
In Sheet VI of the drawings, I have shewn an alternative device for the
hydraulic ram, by means of which the digger may be raised and lowered.
The power in this case is derived from the fly wheel H, which is channelled
circumferentially (see Fig. 14), to receive a bowl on the summit of a short
axle V, which short axle has its bearing in the frame a, which is loosely mounted
on the horizontal shaft X. v is a bevil pinion on the same short axle V, engaging
with the bevil wheel a¹ fast on the shaft X, by means of which the latter is rotated.
is a worm on the end of the same shaft, and 3 is a segmental rack, by means of
which the digger shaft is raised or lowered, when the shaft X is rotated. The
channel in the fly wheel H is somewhat wider than the diameter of bowl v, so that
the latter may engage either with one side or with the other, and receive rotation
in either direction. The bowl v is moved from side to side, and held in contact
with the fly wheel by means of the frame x, which rocks on the shaft X. To this
frame is secured an arm y, jointed to the rod y', which again is jointed to the
arm y², fixed in the end of the jointed rod y³. The rod y³ is in connection with the
feeler through which the inequalities of the ground are communicated to the digger-
raising and lowering mechanism.
The rod y³, which is jointed at y*, and has a rocking movement in its bearings, is
supported by the lever P, whereon is carried the threaded nut which receives the
supporting adjusting screw O.
Parallel with the lever P and rod y³, is the rod Z, the fulcrums of the lever P,
rod Z, and joint of the rod y³, being all in line (see Fig. 15).
The rod Z carries the feeler o, which in this case is a small trailing wheel.
z is a fork attached to the bearings of the wheel o, and jointed at its summit to the
arm ², fixed on the rod y³. The fork is also jointed to the lever P.
ལྤ
It will thus be seen, that there is a differential movement between the rod y³
which works the driving pinion of the shaft a, and the lever P, but the latter being
under the control of the lifting mechanism of the digger gear through the screw O,
always overtakes the initial movement of the rod y in either direction, exactly in
the manner explained with respect to the automatic lifting and lowering mechanism
already described.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
:-
1. A steem digging apparatus for cultivating and tilling the soil, wherein the
digging mechanism is automatically raised or lowered, as required, to maintain an
even working depth during the travel of the engine over irregular or uneven
surfaces, substantially as described.
2. In a steam digging apparatus having gear for raising and lowering the digging
mechanism, a device for arresting automatically the movements of the raising and
lowering gear, such movements being started by means of a feeler following the
surface of the ground.
3. The means above described for actuating the valve mechanism of the hydraulic
apparatus which raises and lowers the digging mechanism.
4. The means above described for supplying water under pressure to the cylinder
of the hydraulic apparatus which raises and lowers the digging mechanisın.
5. The means herein before described, consisting of differential gear and brake

page_text: bands, or their equivalent, for facilitating the turning of the engine short round in:
a confined space.
1 of M1901
NEWTON & SON,
Agents for the Applicant.