Improvements in Excavators.
Year: 1887

page_text: Date of Application, 9th July, 1887
Complete Left, 7th Apr., 1888
Complete Accepted, 8th June, 1888
Improvements in Excavators.
We HENRY OSBORNE BALDRY of 21 Queen Anne's Gate, Westminster in the
County of Middlesex, Civil Engineer and JOSEPH THOMAS PULLON of 3 Albert Grove
Headingley near Leeds in the County of York Civil Engineer do hereby declare the
nature of this invention to be as follows:-
The object of our Improvements is to simplify the construction and working of
excavators and at the same time to increase the efficiency of the same.
Our Improvements refer more especially to such excavators in which the excavation
or cutting out of the ground is effected by a series of travelling buckets connected to
an endless chain, the material in the buckets being emptied as the buckets overturn
round the top tumbler.
One of the main objects of our Improvements is to provide for the moving forwards
or backwards from or to the machine, of the endless chain of buckets (in order to
increase the range of the machine) by moving forward or backward the top tumbler
shaft, as is frequently done in the case of dredgers.
arms,
An excavator constructed in accordance with our Improvements consists of a two
armed lever hinged or centred about the junction of the two arms. The top tumbler
for carrying the bucket chains is carried at the upper end of one of these whilst
the end of the other arm is provided with a nut. By rotating a screw, which passes
through the nut just mentioned, the lever can he moved about the hinge on which it is
centred, thereby moving the top tumbler (carrying the bucket chain) inwards or
outwards, from or to the working face cut by the buckets. In place of the screw and
nut, a worm and rack centre, or other equivalent mechanisin may be employed for
moving the two armed lever above referred to. The arm carrying the lever is
double.
In place of the above mentioned double armed lever, a single armed lever, hinged
to the lower part of the main frame casting (to be hereafter referred to) may be used,
such single armed lever having a nut, attached about one third the length from the
hinge of the lever, into which the above mentioned screw works.
The loose tumbler is carried at the lower end of the buckett trough, and the lower
part of the trough is carried by blocks and wire rope or chain from the end of a

page_text: moveable jib which however is usually fixed in position by the rods, though chain
gearing for raising and lowering the jib may be substituted.
The main frame of the excavator can be rotated horizontally about a central hollow
pivot, the strain on the pivot being partially relieved by 3 bearing wheels, running on
à conical race. The bearings for the axes of the two armed lever, and jib, before
mentioned are fixed in or to the main frame casting so as to rotato with it. The main
frame casting and with it the bucket levers or arms, and the double jib are capable of
being rotated through about 180 degrees.
The main frame casting and conical race are fixed at the forward end of a carriage
mounted on wheels, which latter run on rails. At the back end of the carriage is mounted
the engine and boiler for driving the mechanism of the excavator. The engine actuates a
second motion shaft carrying a bevel wheel driving an inclined connecting shaft provided
at the opposite end with a second bevel wheel. This last gears into a bevel wheel on the
lower end of a central vertical shaft passing axially through the pivot of the main frame
casting. The upper end of this central vertical shaft carries another bevel wheel
which drives a horizontal cross shaft. On this horizontal cross shaft are placed two
bevel wheels facing each other, one fixed and the other loose, both gearing with the
bevel wheel at the top of the central vertical shaft. This arrangement provides for a
reversal of the motion of the various operations to be hereafter referred to. Attached
to each of the bevel wheels on the horizontal shaft is a spur wheel, each of the latter
gearing into loose pinions on three other parallel shafts. These shafts are by preference
placed respectively in front, behind, and above the main horizontal cross shaft. Between
the loose pinions on each of the three shafts is a friction or other clutch sliding on a
feather, controlled by means of levers.
The front cross shaft is provided outside of the pinions with two drums, keyed
thereon. To these drums are attached wire ropes or chains leading first round pulleys
on the bottom pin of the jib, and thence round a pulley at the head of the jib and
connected by blocks or other equivalent, attached to the bucket trough near its lower
end. This arrangement serves to raise and lower the lower end of the trough and
bucket chain. The front horizontal cross shaft is provided also with a differential brake,
so that the bucket chains and trough cannot accidentally fall away and at the same
time may if desired be lowered by the brake instead of by the gearing.
The top horizontal cross shaft is similarly furnished with a pair of loose pinions
and a clutch for rotating the shaft in either direction. Near one end of the shaft
is keyed a worm, gearing into a wormwheel on the upper end of a vertical shaft, at
the end of which is a pinion gearing into teeth on the conical race for slewing.
The back horizontal cross shaft is similarly provided with a pair of loose pinions
and clutch and with a worm at one end gearing into a worm wheel on one end of a
horizontal shaft, having attached on the other end the screw working in the nut fixed
to one of the arms of the before mentioned hinged double armed lever.
At one end of the main horizontal cross shaft is a face friction clutch which can be
put into gear with a chain wheel, the chain of which drives a chain pinion running
loose in front and close to a similar loose chain pinion on the hinge pin shaft of the
before incntioned two armed lever. These pinions are locked together by shearing
bolts. A chain round this second pinion drives a similar pinion on one end of the
shaft carrying the top bucket tumbler.
On the before mentioned inclined connecting shaft is keyed a worm which gears
with a loose worm wheel on a horizontal cross shaft running in bearings on the
carriage frame. This shaft is provided with a clutch by means of which it can be
connected to the worm wheel for driving, and also with a differentiall brake. On the
outer ends of this horizontal cross shaft beyond the main carriage frame are fixed two
drums, to which are attached chains or ropes, which can be hooked to attachments on
the sleepers or rails. These serve for hauling forward and holding the excavator up
to its work.
The second motion shaft driven by the engine is provided at the outer ends with
gipsy drums for incidental haulage purposes.
The main carriage frames are provided with pockets or brackets, for holding the
.

page_text: girders employed to spread the foundation of the excavator when at work. These
pockets or brackets are arranged so that they can be opened at one side for inserting
or removing the cross girders. The ends of the cross girders are furnished with
hydraulic jacks, which can be worked by the engine.
The buckett trough is covered in at the upper end, the cover being curved about the
axis of the top tumbler shaft as its centre. The buckets empty into a short spout
covered in the cover being curved at its upper end to the same radius as, but outside
and overlapping the covered portion of the bucket trough. This spout is carried-loose
by hinge brackets on the top tumbler shaft outside the bucket trough. The cross
section of the spout.at its upper end is rectangular, but the bottom gradually changes
to a semi circle at its lower end. The spout conducts the material into a fixed hopper,
on the upper edge of which, the spout rests loose. The upper end of the hopper at the
point where, the lip of the spout rests is conical and curved to a corresponding radius
or radii. The fixed hopper is arranged to deliver on either or both sides of the
excavator at will by means of a shutter at its inclined upper part and also at its
mouths.
A consideration of the essential features of our Invention shews more particularly that
our object has been to provide an excavator capable of performing a variety of operations
and having advantages which are at present only to a partial extent furnished by other
machines now in use.
In the well known Dunbar and Ruston Excavator or Navvy two meu are required
to attend to the working of the machine, whilst in our improved machine all the
operations can be more efficiently performed by one man only. Also with the above
named excavator a minimum width of excavation of 30 to 40 feet is requisite, thus
precluding the driving of a narrow gullet. Our machine is capable of operating in a
minimum width of 14 to 15 feet at rail level; also as it is capable of being rotated
through a larger are (ris. 180 degrees) than those now in use, and moreover owing to
our special arrangement of rocking bucket arm and raising and lowering mechanism,
its range of width
greater than that of other machines of equal size; and it is
also capable of taking off and completing the upper part of slopes much flatter
than is at present possible and which is now effected by supplementary manual
labour.
Another advantage attained by our improvements is that the moter works continuously,
merely driving idle gear, which can be connected separately or in any desired com-
bination with the mechanism for the various operations, and the special arrangement
of friction clutches obviates or lessens very materially the wear and tear and liability
of the various parts of the machine to fracture.
Our arrangements for tipping the material are also more convenient than those
hitherto adopted either for "bucket" or "shovel "excavators. The arrangements for
the advance of the whole machine as the work progresses and the holding of it up to
the working face by means of ropes or chains to attachments on the sleepers or rails
carrying the machine enable a lighter machine to be employed than is now usual for a
given class of work, or on the other hand with our machine of equal size heavier or
more rapid work can be executed. The employment of hydraulic jacks worked from
the engine leads to a considerable saving of time when the whole machine has to be
moved forward in working; and in combination with our arrangements for mounting
and dismounting the machine leads to a great saving in time and cost of performing
the same.
The excavator above described may be regarded as developed from the ordinary
portable slewing type of crane with hinged jib, but most of our above mentioned
Improvements can be applied in the design of an excavator based upon the ordinary
fixed post and jib pivotted crane. In this case the top tumbler shaft instead of being
carried at the end of a hinged lever is preferably carried in bearings moveable in
slots or races provided near the upper part of the post. The motion is effected from
the machine by bevel transmissions, and worm and rack or screw gearing at the
slots.
In bucket excavators it is of great advantage to impart an accelerated movement to

page_text: the bucket when emptying (e. when passing over the top tumbler shaft.) Such
acceleration practically happens in most cases, but we increase this acceleration by
the following construction of bucket attachment. Two eye pieces for each chain
are fixed at the back of the bucket, forming one link of the chain. The first of these
is near the upper end of the bucket, and the second is approximately at the centre of 5
the bucket's length.
We also provide a lip on the back of the bucket at the top, so that any material
falling into the bucket trough is swept forward by said lip.

page_text: Improvements in Excavators.
We, HENRY OSBORNE BALDRY of 21 Queen Anne's Gate, Westminster in the County
of Middlesex Civil Engineer, and JOSEPH THOMAS PULLON of 3 Albert Grove
Headingley near Leeds in the County of York Civil 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 object of our Improvements is to simplify the construction and working of
Excavators, and at the same time to increase the efficiency of the same.
Our Improvements refer more especially to such Excavators by which the excavation
or cutting out of the ground is effected by a series of travelling buckets, connected to an
endless chain; the material in the buckets being emptied as the buckets overturn over
the top tumbler. One of the main objects of our Improvements is to provide for the
moving forwards or backwards from or to the machine, of the endless chain of buckets,
(in order to increase the range of the machine,) by moving forwards or backwards the
top tumbler shaft; as is frequently done in the case of dredgers.
An Excavator constructed in accordance with our Improvements consists of a two
arned lever, hinged or centred about the junction of the two arms. The top tumbler
for carrying the bucket chains is carried at the upper end of one of these arms, whilst
the end of the other arm is provided with a nut. By rotating a screw, which passes
through the nut just mentioned, the lever can be moved about the hinge on which it
is centred, thereby moving the top tumbler (carrying the bucket chain) inwards or
outwards from or to the working face cut by the buckets. In place of the screw and
nut, a worm and rack sector, or other equivalent mechanism may be employed for
moving the two armed lever above referred to. The arm carrying the top tumbler is
double.
In place of the above mentioned two armed lever, a single armed lever hinged at its
lower end to the main frame casting, (to be hereafter referred to), may be used;
such single armed lever having a nut or curved rack, attached about to the
length from the hinge of the lever, into which the above mentioned screw or worm
works.
The loose tumbler is carried at the lower end of the bucket trough, and the lower
part of the trough is carried by blocks, and wire rope or chain, from the end of a
moveable jib; which however is usually fixed in position by tie rods, though chain
gearing for raising and lowering it may be substituted.
The main frame of the excavator can be rotated horizontally about a central hollow
pivot, the strain on the pivot being partially relieved by three bearing wheels, which
run on a conical race. The bearings for the axes of the two armed lever and jib
above mentioned, are fixed in or to the main frame casting, so as to rotate with it.
The main frame casting and with it the bucket lever or arms and the double jib are
capable of being rotated through an arc of about 180 degrees.
The main frame casting and the conical race are fixed at the forward end of, a
carriage, mounted on wheels, which latter run on rails. At the back end of the
carriage is mounted the boiler and engine for driving the mechanisan of the excavator.

page_text: The engine actuates a second motion shaft carrying a bevel wheel which by means
of a second bevel wheel drives an inclined shaft. This inclined shaft by means of
bevel gearing drives a central vertical shaft passing axially through the hollow pivot
of the main frame casting. The upper end of this central vertical shaft carries a
bevel wheel, which gears into two other bevel wheels on the same horizontal cross
shaft one of these being fixed or keyed to the shaft, and the other loose thereon.
This arrangement provides for a reversal of the motions of the various operations to
be hereafter referred to. Attached to each of the bevel wheels on the main horizontal
cross shaft is a spur wheel, each of the latter gearing with three loose pinions on three
other parallel (i.e. horizontal cross) shafts. These three shafts are by preference placed
respectively in front, behind, and above the main cross shaft. Between the loose
pinions on each of the three shafts is a friction or other clutch, sliding on a feather,
controlled by means of levers.
The front cross shaft is provided outside of the pinions, with two drums keyed
thereon. To these drums are attached wire ropes or chains, leading round pulleys on
the bottom or hinge pins of the jib, and thence round a pulley at the head of the jib,
and connected by blocks or other equivalent attached to the bucket trough near its
lower end. This arrangement serves to raise and lower the lower end of the trough
and bucket chain. The front horizontal cross-shaft is provided also with a differential
brake, so that the bucket chains and trough cannot accidentally fall away; or they
may if desired be lowered by the brake instead of by the gearing.
The top horizontal cross-shaft is similarly furnished with a pair of loose pinions
and a clutch for rotating the shaft in either direction. Near one end of the shaft is
keyed a worm gearing into a worm wheel on the upper end of a vertical shaft, at the
lower end of which is a pinion gearing into teeth on the conical race for slewing.
The back horizontal cross-shaft is similarly provided with a pair of loose pinions
and clutch, with a worm at one end gearing into a worm wheel on one end of a
horizontal shaft, having attached on the other end the screw working in the nut fixed
to one of the arms of the before mentioned hinged double-armed lover.
At one end of the main horizontal cross-shaft is a face friction clutch, which can be
put into gear with a chain wheel, the chain of which drives a chain pinion running
loose in front and close to a similar loose chain pinion on the hinge shaft of the before
mentioned two armed lever. These pinions are locked together by shearing bolts. A
chain round this second pinion drives a similar pinion on one end of the shaft carrying
the top bucket-tumbler.
On the before mentioned inclined driving shaft is keyed a worm, which gears with
a loose worn wheel on a horizontal eross shaft running in bearings on the carriage
frame. This shaft is provided with a clutch, by means of which it can be connected
to the worm wheel for driving, and also with a differential brake. On the outer ends
of this horizontal cross shaft beyond the main carriage frame, are fixed two drunis, to
which are attached chains or ropes, which can be hooked to attachments on the
sleepers or rails. These serve for hauling forward and holding the excavator up to
its work.
The second motion shaft driven by the engine is provided at the outer ends with
gypsy drums for incidental haulage purposes.
The main carriage frames are provided with pockets or brackets for holding the
girders employed to spread the foundation of the excavator when at work. These
pockets or brackets are arranged, so that they can be opened at one side for inserting
or removing the cross girders. The ends of the cross girders are furnished with
hydraulic jacks, which can be worked by the engine.
The bucket trough is covered in at the upper end, the cover being curved about the
axis of the top tumbler shaft as its centre. The buckets empty into a short spout,
covered in; the cover being curved at its upper end to the same radius as, but outside
and overlapping the covered portion of the bucket trough. This spout is carried loose
by binge brackets on the top tumbler shaft outside the bucket trough. The cross
section of the spout at its upper end is rectangular, but the bottom gradually changes
to a semicircle at its lower end. The spout conducts the material into a fixed hopper,

page_text: on the upper edge of which, the spout rests loose. The upper end of the hopper at
the point where the lip of the spout rests is conical, and curved to a corresponding
radius. The fixed hopper is arranged to deliver on either or both sides of tho
excavator at will, by means of a shutter at its inner upper part. and also at its mouth.
A consideration of the essential features of our Invention shews more particularly
that our object has been to provide an excavator capable of performing a variety of
operations, and having advantages which are at present only to a partial extent
furnished by other means now in use.
In the well known Dunbar and Ruston Excavator or Navvy, two men are required
to attend to the working of the machine; whilst in our improved machine all the
operations can be more efficiently performed by one man only. Also with the above
named Excavator a minimum width of excavation of 30 to 40 feet is requisite, thus
precluding the driving of a narrow gullet. Our machine is capable of operating in a
minimum width of 14 to 15 feet at rail level; also as it is capable of being rotated
through a larger arc (wi:-180° degrees) than those now in use, and moreover
owing to our special arrangement of rocking bucket arm or levor, and raising and
lowering mechanism, its range of width is greater than those of equal size, and it
is also capable of taking off and completing the upper part of slopes much flatter than
is at present possible, and which is now effected by supplementary manual labour.
Another advantage attained by our Improvements is, that the motor works
continuously, merely driving idle gear; which can be connected separately or in any
desired combination with the mechanism for the various operations; and the special
arrangement of friction clutches obviates or lessons very materially the wear and tear
and liability of the various parts of the machine to fracture.
Our arrangements for tipping the material are also more convenient than those
hitherto adopted either for bucket or shovel excavators. The arrangements for the
advance of the whole machine as the work progresses, and the holding of it up to the
working face by means of ropes or chains, to attachments on the sleepers or rails
carrying the machine, enable a lighter machine to he employed than is now usual for
a given class of work; or on the other hand with our machines of equal size, heavier
or more rapid work can be executed. The employment of hydraulic jacks worked
from the engine leads to a considerable saving of time when the whole machine has to
be moved forward in working; and in combination with our arrangements for
mounting and dismounting the machine, leads to a great saving in time and cost of
performing the same.
The excavator above described may be regarded as developed from the ordinary
portable slewing type of crane with hinged jib, but most of our above mentioned
improvements can be applied in the design of an excavator based upon the ordinary
fixed post and jib pivotted crane. In this case the top tumbler shaft instead of being
carried at the end of a hinged lever, is preferably carried in Dearings moveable in slots
or races provided near the upper part of the post. The motion is effected from the
machine by bevel transmissions and worm and rack or screw gearing at the slots.
In bucket excavators it is of great advantage to impart an accelerated movement to
the bucket when emptying, (ie. when passing over the top tumbler shaft). Such
acceleration practically happens in most cases, but we increase this acceleration by the
following construction of bucket attachment. Two eye pieces for each chain are fixed
at the back of the bucket, forming one link of the chain. The first of these is near
the upper end of the bucket, and the second is approximately at the centre of the
bucket length.
We also provide a lip on the back of the bucket at the top, so that any material
falling into the bucket trough is swept forward by said lip.

page_text: projects to one side at right angles to the carriage frame of the excavator. Fig. 4. is
a hack or end view on line A B Figs. 1. and 2. Figs. 5, 6 and 7 are respectively
sections on lines CD. E F. and G H. Fig. 1. The same reference letters indicate
the same parts in all the views.
The top tumbler a for carrying the bucket chains, b. rests with its axle e in bearings
firmly fixed to the upper end of the two armed lever d d. This lever is hinged on
the shafte at the junction of its two arms. The end of the lower shorter arm dis
provided with a nut f, carried on trunnions fitted into bearings at the end of the
arm . By rotating the screw g which fits in this nut f, the lever d ' can be moved
about the shaft c, thereby moving the top tumbler a inwards or outwards from or to
the working face being cut by the buckets. In place of the screw and nut f, a worm
actuating a curved rack centred on the shafte may be employed for moving backwards
or forwards the top arm d. This upper arm d which carries the top tumbler shaft e is
double.
In place of the above described double armed lever, a single armed lever hinged at
its lower end to the main frame casting, (to be hereafter referred to) may be used;
such single armed lever having a nut or curved rack attached at about one fourth to
one third the length from the hinge of the lever, into which the above mentioned
screw or worm works.
The loose tumbler his carried at the lower end of the bucket trough i, and the
lower part of the trough is carried by blocks k, and wire ropes or chains, from the
end of a moveable jib m m hinged at m'; but the jib is usually fixed in position by
tie rods n, though a set of chains and pullies might be employed for altering at will
the position of the jib.
The bearings for the shaft of the loose tumbler h are arranged slide in slots or
guides formed in the casting 41 the bearings being attached or connected at the one
end to screws 42. These screws 42 can be rotated simultaneously from the cross
shaft 43 by means of bevel or worm gearing. The bevels or worin wheels on the
scrows 42 are tapped and serve as nuts for the screws 42, by which means the rotation
of the cross shaft 43 draws back or pushes forwards simultaneously the bearings of
the tumbler shaft h. The object of this arrangement is to ensure an equal take up at
both ends of the tumbler shaft, should the driving chains become slack and require
adjustment.
2
The main frame o of the excavator can be rotated horizontally about the hollow
pivot p, the strain on the pivot being partially taken by the three bearing wheels
or rollers
which run on the conical race r. The bearings for the shaft and for
the hinge m of the jib are cast on or bolted to the main frame casting o, so as to
rotate with it about the hollow pivot ppl, carrying the bucket trough i and buckets s
through the same horizontal arc. The main fraine casting o and the conical race are
placed at the forward end of a carriage t, mounted on wheels which latter run on
rails. At the back end of the carriage is mounted the boiler and engine v for
driving the mechanism of the excavator. The engine actuates a cross motion shaft w,
which drives an inclined shaft æ by means of bevel or worm gearing. This inclined
shaft by means of the bevel gear y drives a vertical shaft, passing axially through
the pivot of the main frame casting. The upper end of this central vertical shaft z
carries a bevel wheel 1, which latter gears with the loose and fast bevel wheels 2. 2.
on the centre cross shaft 3. This arrangement provides for a reversal of the various
motions to be hereafter referred to. A spur wheel attached to each of the bevel
wheels 2. 2 gears with loose pinions on the other three cross shafts 4, 5, and 6, placed
by preference respectively in front, behind, and above the main horizontal cross
shaft 3. Between the loose pinions on each of the three shafts 4, 5, and 6, is a friction
clutch 7 sliding on a feather controlled by means of linkwork, levers, and rods from
the handwheel 4, and hand levers 51, and 61, respectively.
The front cross shaft 4 is provided with two drums 8 keyed thereon outside
the pinions. To these drums are attached the wire ropes 7, leading first round
pulleys 9 at the bottom or hinge m¹ of the jib, and thence round pulleys 10 at the
head of the jib, and blocks k and pulleys k' attached to the bucket trough near its

page_text: lower end.
This arrangement serves to raise and lower the lower end of the bucket
trough and loose bucket tumbler. The front horizontal cross shaft 4 is provided also
with a differential brake 11, so that the bucket chains b and trough i cannot
accidentally fall away; or these may if desired be lowered by the brake 11 instead of
by the gearing.
The top horizontal cross shaft 6 is similarly furnished with a pair of loose pinions
and friction clutch 7 for rotating the shaft in either direction. Near one end of the
shaft is keyed a worm 12 gearing with a worm-wheel on the upper end of a vertical
shaft 13, at the lower end of which is a pinion gearing into internal teeth within the
conical race for slewing.
The back horizontal cross shaft 5 also is similarly provided with a pair of loose
pinions and friction clutch, and with a worm 14 at one end, gearing into a worm-
wheel 15 on one end of a horizontal shaft 16, having attached on the other end, the
screw g working in the nut, which is carried at the end of the arm d¹.
At one end of the main horizontal cross-shaft 3 is a face friction clutch 17, which
can be put into gear with a chain wheel, the chain 18 of which drives a chain pinion
running in front of and close to a similar chain pinion, both running loose on the
hinge shaft e. These chain pinions are locked together by shearing bolts, which give
way when the buckets meet with an unusually great obstruction. A chain 19 round
this second pinion drives through a similar pinion the top tumbler shaft c.
On the before mentioned inclined driving shaft a is keyed a worm 20, which gears
with a loose worm wheel 21 on a horizontal cross shaft 22, running in bearings in
the carriage frame t. This shaft 22 is provided with a friction clutch by means of
which it can be connected to the worm wheel 21 for driving, and is also provided
with a differential brake 23. On the outer ends of this horizontal cross shaft 22
beyond the main carriage frame, are fixed two drums 24, to which are attached
chains or ropes 25 hooked to attachments 26 on the sleepers or rails. These serve
for hauling forward and for holding the excavator up to its work.
The second motion shaft w driven by the engine, is provided at the outer ends with
gypsy druins for incidental haulage purposes.
The main carriage frame is provided with pockets or brackets 27 for holding the
girders employed for spreading the foundation of the excavator when at work. These
pockets are arranged so that they can be opened towards the front or back of the
excavator for readily inserting or removing the cross girders. The ends of the girders
are furnished with hydraulic jacks, served from a steam accumulator worked from
the engine.
2.
The bucket trough i is covered in at the upper end, the cover being curved about
the axis of the top tumbler shaft è as a centre. The buckets empty into a short
spout or shoot 28 which is covered in, the cover being curved at its upper end, so as
to be outside and overlapping the covered portion of the bucket trough i. This
spout 25 is carried loose by hinge brackets (see Fig. 5) on the top tumbler shaft
outside the bucket trough ?. The cross section of this spout at its upper end is
rectangular, but the bottom gradually changes to a semi-circle at its lower end.
The spout 28 conducts the material into a fixed hopper 29, on the upper edge of
which, the mouth of the spout 28 rests loose. The upper end of the hopper is conical,
and the lip is curved to the same radius as the mouth of the spout, the centre for
the same being taken vertically above the axis or pivot about which the excavator
swivels. The fixed hopper 29 is made to deliver on either or both sides of the
excavator at will by means of double shoots or branches 291, and a flap or shutter 30
at its inner upper part. The lower portions of the branches 29' are hinged so as to
double up out of the way, when this is necessary for transport. The mouths are
provided with curved balanced shutters 31 for cutting off the delivery.
The differential brakes for the hoisting and lowering, and for the hauling and
holding mechanism, are controlled through levers and links from the foot levers 32
and 33 respectively.
The friction clutch lever 34 for the hoisting and lowering drum shaft 4, is actuated
by a hollow screw working in a nut 35 from the hand wheel and bevel gear 4. The

page_text: hand lever 36 by means of a horizontal shaft, passing through the before mentioned
hollow screw, and hell crank lever 37, levers 38, central rod 39, and links and rods 40
actuates the clutch of the holding and hauling drum shaft 22.
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 :-
In excavators which excavate the ground by a series of travelling buckets:-
1 A hinged lever carrying at its upper end the top tumbler shaft, and actuated by
scrow or worm gearing so as to move the top tumbler shaft to or from the working
fáce.
2º A bucket trough supported at its upper end on the top tumbler shaft, and at or
near its lower end from a jib by means of ropes or chains and blocks or pulleys.
3° A bottom or loose tumbler shaft carried in bearings moveable in guides
attached to the lower end of the bucket trough, and bevel or worm and screw gearing
for moving the bearings in said guides substantially as described and shewn in the
accompanying drawings.
4° A pivotted swivelling frame or standards carrying,—a—the before mentioned
hinged lever and jib, and--the mechanism for performing the various operations
herein set forth, substantially as described and illustrated in the accompanying
drawings.
5 The main cross shaft with fast and loose bevel and spur wheels actuated by the
axially centred bevel wheel, for the purpose of transmitting both direct and reversed
motion to the gearing, for swivelling, for hoisting and lowering the lower end of the
bucket trough, for transmitting direct motion to the chain gearing driving the top
tumbler shaft, and for advancing and receding the hinged lover carrying top tumbler
shaft, severally or collectively.
6° The three cross shafts with loose pinions and clutches and the worm screw and
spur gearings respectively as herein described for performing the various operations
of swivelling, hoisting and lowering the lower end of the bucket trough, and advancing
or receding the top tumbler shaft.
7° The use of a face friction clutch and chain gearing for driving the top tumbler
shaft, also the chain wheels centred on the axis of the hinged lever having shearing
bolts connecting them for preventing fracture when the travelling buckets meet with
an obstruction.
So The horizontal cross shaft with worm and friction gearing actuating the same,
differential brake, and holding and hauling drums,
90 Cross spreading girders provided at or near the ends with hydraulic jacks
worked from the engine and a steam accumulator, and pockets carrying the girders
all for the purpose of facilitating the advancing and fixing of the excavator in a fresh
position.
10° The overlapping cover or hood and spout or shoot hinged on the top tumbler
shaft for delivering the material into the hopper.
11° The hopper with double shoot or shoots, the latter having their lower parts
hinged and provided with hinged balanced shutters, substantially as herein described
and shewn in the accompanying drawings.
120 The arrangement of pin or eye pieces on the underside of the buckets, so as
to give an accelerated motion to the bucket when passing over the top tumbler,
substantially as herein described and shewn in the accompanying drawings.
13° The use of friction clutches for transmitting motion to the mechanism for
performing the various operations herein set forth, so that the motor can be worked
continuously and to lessen the risk of breakage, substantially as herein set forth and
shewn in the accompanying drawings.
14° The employment of differential brakes in connection with mechanism for
raising and lowering the lower end of the bucket trough, and for hauling forward
the excavator.
15° The arrangement of rope and pulleys attached to the lower end of the

page_text: bucket trough for ensuring an equal pull or strain on both ends thereof, when
raising or lowering the lower end of the bucket trough, substantially as herein
described and shewn in the accompanying drawings.
16° The arrangements of levers, links, rods, and hollow screw for giving to the
attendant the control at or from one convenient point over the mechanisni for
performing the various operations substantially as herein described and as illustrated
in the accompanying drawings.
17 The general arrangement and combinations of the various parts referred to in
the previous claims forming our improved excavator, substantially as herein set forth
and shewn in the accompanying drawings.
Dated this 6th day of April 1888. .
J. CLARK JEFFERSON, Assoc. R.S.M., Wh. Sc.,
2, East Parade, Leeds,
Agent to the two aforesaid Applicants.