Note: Descriptions are shown in the official language in which they were submitted.
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Pri r Art of_ nteres~
~~ 990,487 Lilleberg 4/25/11
'`2,399,698 Stein 5/ 7/46
.~3,547,287 Cunningham 12115/70
,~3,661,287 McCarty et al 5/ 9/72
Ba`ckg`rou`n`d `o`f the`Invention
This invention relates to apron attitude adjustment
for loading and conveying machines.
Broadly, such machines utilize a front end gathering
implement to sweep rock, sand, ore or other loose material onto
a self-contained conveyor for transport to a discharge location,
usually disposed at the rear of the machine. An apron is`disposed
nt the forward conveyor end, has a front end edge adapted to move
forward~y along the ground with the machine and a rear end portion
spaced slightly above the conveyor to deposit material thereonto.
The gathering implement is normally mounted to the fron~ portion
of the machine frame, extends substantially ahead of the apron
and is adapted to force material up the inclinèd apron. u
Vehicle transport means, such as crawler treads`, support
the machine on the ground and may be positioned substantially
behind the apron and front frame portion to movè the center of
gravity of the entire device rearwardly in view of the substantial `
weight forces at the front.
~ The loading and conveying machines under consideration
25 here can be utilized in tunneling operations, although it is `
contemplated that they may find more extensive use above ground. ;
In any event, they are often subject to variations in level of
terrain, both during actual loading and also during transport
from place to place. `
In order to accommodate rough terrain, and for transport
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purposes, it has been found desirable to pivotally mount the
conveyor intermediate its ends and also to pivotally mount the
rear of the apron to the machine frame and as low as possible.
Pivotal adjustment of these elements has been accomplished by
suitable hydraulic cylinders and the like.
It has been found that such machines will have diffi-
culty în ~raversing rough terrain in that the fron~ components
of the machine will undesirably engage a hill or rise in ~he
ground unless the components are properly positioned.
These machines have a basic "approach angle" defined
by the level ground plane and a forwardly and upwardly inclined
plane tangential to the arc described by the front of ~he treads
and extending through the lower front frame cornex. Except on
flat ground, the angular space defined by these two planes must
be kept clear of machine elements to avoid undesirable contact
with ground undulations.
When rough terrain is to be encountered, the apron can
be pivoted upwardly to clear the angular upper approach plane.
However, it has been discovered that although the apron pivot
20 ` is disposed above the approach plane, pivotal raising of the
fron~ end of the conveyor will cause the conveyor to undesirably
engage the ràised apron before the conveyor can clear the plane.
In addition, during operation of the machine, it may
be desirable to adjust the rear discharge height of the conveyor.
This necessitates pivoting o the conveyor about its intermediate
pivot axisJ thus changing the clearance space or gap between the
apron and conveyor. Any substantial increase in this gap will
place undesirable loads on the conveyor mechanism and machine
frame, in view of the substantial weight and bulk o~ the materials
30 ~ being loaded onto the machine and the relative motion of the parts.
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Summary of the Invent.ion
The present invention is directed to a structural
concept which solves the aforementioned problems.
Accordingly, the present invention provides a machine
for loading and conveying loose material such as rocks and the
like: (a~ transport means for supporting and moving said
machine on the ground, the ~ront end portion of said transport
means describing an arc,
(b) a frame carried by said transport means and
extending above and forwardly thereof,
~c) material gathering means mounted to said frame
and overhanging the front end thereo~
(d) an elongated inclined conveyor extending from the
front toward the rear of the machine for transporting material,
(e) conveyor mounting means disposed on said frame
and with said mounting means securing said conveyor for pivotal
: movement aboùt a first transverse horizontal axis,
(f) an apron disposed at the front of the machine and
extending forwardly of said frame and above said conveyor for
receipt of material from said gathering means and for transfer :
of said material to said conveyor,
(g) apron mounting means disposed between the rear
portion of said apron and said frame to mount said apron for
pivotal movement about a second transverse horizontal axis, `
(h) the construction being such that said machine ; "
provides a forwardly extending appraoch space with the ground
and with said space defined by a fist plane co-extensive with i.. ..
the ground and a second plane extending upwardly and tangential
to said arc and forwardly through the lower front corner portion ``
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of said frame,
(i) means for pivoting said apron about said second
named axis so that the front apron portion is movable between
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a lowered downwardly inclinea position wherein it intersects
saia second plane and is disposed within said approach space,
and a raised position above its said lowered position,
(j) means for pivoting said conveyor about said first-
named axis so that the front conveyor end portion is movable
between a lowered position wherein it intersects said second
plane and is disposed within said approach space, and a raised
pOSition wherein it is disposed above said space.
(k) and means separate from said apron pivoting
means to selectively adjust the angular attitude of said apron
so that it is disposed above said approach space and out of
interfering engagement with said conveyor when both said apron
~nd conveyor are in their said raised positions.
It is contemplated that the rear pivot of the apron be
constructed to be vertically shiftable through a substantial
range above the approach angle. This, combined with the apron
angle adjustment mechanism, will selectively change the angular
attitude of the apron so that it completely clears the approach
plane while not obstructing the conveyor.
Furthermore, the adjustability of angular attitude of
the apron makes it possible to maintain the desired gap with the
conveyor, no matter what the vertical position of the conveyor
~ront end.
In addition, the dig-in angle of the apron during orward
movement o~ the mac~ine during loading may be quickly adjusted
~y means of the inventive concept.
Brief Description of the Drawings
The accompanying drawings illustrate the best mode
presently contemplated by the inventor for carrying out the
invention.
In the drawings:
Fig. 1 is a side elevation of a loading and conveying
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machine constructed in accordance with the invention;
Fig. 2 is a top plan view of the machine;
Fig. 3 is an enlarged fragmentary side elevation taken
on line 3-3 of Fig. 2, of the apron adjustment mechanism, with
parts broken awa~ and sectioned, and showing several positions
thereof;
Fig. 4 is a front view of the apron adjustment mechanism,
with parts broken away and sectioned, taken on line 4-4 of
Fig. 3; and .
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FIG, 5 is a horizontal section taken on line 5--5 of
Fig. 4.
Description of the Pre~erred Embodiment
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As shown in the drawings, the invention is embodied in
a ma~erial loading and conveying mechanism having vehicle trans-
por~ means such as crawler treads 1 which support the machine
on the ground 2 and are driven by any suitable means, not shown,
to move the machine during ioading operations and for travel
between operating sites. The front end portion o~ treads l deseribe
an arc`and the trea`ds form part of an assembly which supports the
machine frame 3 which includes side rails 4, brace elements 5,
and a forwardly mounted box 6 which may enclose the operator's
cab, A pair o~ vertical mounting plates 7 are disposed on the
front ace of box 6.
lS The machine disclosed herein includes a gathering imple-
mènt assembly 8 adapted to engage loose rocks 9 or the like and
sweep them up an inclined apron I0 where they move onto a conveyor
assembly ll for transport to the rear of the machine.
As best shown in Figs. 1 and 2, gathering implement
assembly 8 fo~ardly overhangs the machine and generally comprises
a boom structure 12 mounted for horizontal swinging pivotal move-
ment about a vertical axis 13, with the swinging control including
a pair o~ swing cylinders 14 being selectively controlled rom
the operator's cab in the usual well-known manner. Boom struc-
25 ture 12 carries a suitable material handling implement, such as
a gathering tool 15, with angular vertical positioning of the ~;
elements being accomplished via a series of cylinders 16,17 and 18;
all controllable from the cab in the usual well-known manner. ~ -
Conveyor assembly 11 is shown as being elongated and
extending from forwardly of frame box 6 to substantially behind
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the rear frame portion of the ~achine. ~ssembly 11 c~mprises
a generally rectangular unitary framework 19 having an endless
conveyor belt 20 extending from front to rear. Belt 20 comprises
a pair of ~ransversely spaced parallel roller chains 21, joined
by conveying elements 22 which serve to move the ~aterial rear-
wardly. The chains of belt 20 are trained around a pair of
rotatable front sprockets 23 and a pair of rotatable rear sprockets
24, with a motor 25 for driving the latter. Chains 21 are supported
on upper and lower rails 26 extending along the framework, and
form upper and lower flights.
Conveyor assembly 11 is shown as having a relatively
long forward section 27 of steep inclination, and a shorter
rearward sectian 28 of lesser incline. In fact, as shown in
~ull lines in Fig. 1, section 28 may be disposed substantially
lS horizontal during machine operation.
Conveyor assembly 11 is pivotally mounted for vertical
adjustment. For this purpose, a pair of spaced vertical forward
struts 29 are mounted to the front section 27 of framework 19 and
join with a pair of fixed machine frame brackets 30 for pivoting
o the ront portion of the assembly about a horizontal axis 31.
Additionally, a paîr of spaced verticai rearward struts 32 are
mounted to the rear section 28 o~ framework 19 and join, through
a cross brace 33 and suitable pivotal connections, with the upper
end o a conveyor positioning cylinder 34, as on horizontal
axis 35. The lower end of cylinder 34 is pivotally mounted to
rame 3, as on horizontal axis 36. Cylinder 34 may be actuated
from the cab by any suitable well-known mechanism to selectively
adjust the conveyor. The phantom showing in Fig. 1 is for travel
position, wherein front section 27 is raised slightly and rear
section 28 is lowered substantially.
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Apron lO is adapted to normally ride on the ground ahead
of conveyor assembly 11 and is shown as having a cen~ral plate-
like bed 37 with a front edge 38, a narrow rear edge 38A and
suitable raised side me~bers 39 which form a channel or throat
through which material is forced by forward machine movement
and/or gathering implement assembly 8. The transverse rear
edge 38A of bed 37 is spaced slightly above the front end of the
~Ipper fli~ht of conveyor belt 20 and provides a clearance space
or gap 40 for transfer of material from the apron ~o the conveyor.
See Fig. 3. This gap should be kept at a minimum, and is selec-
tively adjustable as will be described.
The rear edge of apron 10 is mounted for pivoting abou~
a ~ransverse horizontal àxis 41, and means are provided to pivot
the apron about said axis. For this purpose, and as best shown
lS in Figs. 1-3, a pair of brackets 42 are mounted on plates 7, with
each bracket being pivotally connected to the upper end of an
apron pivot cylinder 43, as at 44. The lower ends of cylinders 43
are pivotally mounted to transversely spaced portions of apron 10,
as at axis 45. Cylinders 43 are of the double acting type and
are controlled from the cab in any suitable well-known manner to
lift and lower the apron; hold it in any desired raised position,
or to permit it to float with its front edge 38 on the ground, as
shown in full lines in Fig. l. The cab control panel 46 for the
cylinders is shown schematically in Fig. 3.
As best shown in Fig. 1, the construc~ion of the machine
provides an "approach angle" 47 de~ined by a lower plane 48 co-
extensive with the ground 2, and an upper plane 49 which is ~ ~
tangential to the arc described by the front of treads 1, as at 50, `
and extends forwardly and upwardly through the lowermost ront
corner 51 of frame 3. The approach space 52 between planes 48 and 4
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. must be kept f~ee of machine elements, such as apron 10 and
conveyor 11, during machine m~vement over rough ~errain.
During normal operation of the machine on level ground,
as shown in Fig. 1, the approach angle problem is of little
S consequence. Thus, as shown in full lines, conveyor 11 may be
pivotally positioned with its front end intersecting approach
plane 49 and disposed in space.52. This front end should nonmally
be as low as possible to minimize ~he distance rocks 9 must be
lifted. In addition, during machine operation it is desirable
; 10 that the pivot 41 of working apron 10 be as low as possible so
that the rearward thrust forces on the apron are transmitted to
the frame as horizontally as possible. While pivot 41 is disposed
above approach plane 49 and space 52, apron 10 itself ex~ends~
~gularly do~nwardly to the ground, thus also intersecting
plane 49 and disposed within space 52. See also Fig. 3.
. When it is desired to move the machine in a manner
that approach space 52 must be cleared of machine elements, apron
pivot cylinders 43 are retracted to raise the apron body upwardly.
However, it has been found that when cylinder 34 .is retracted to .
pivotally raise the ront end of conveyor 11, the conveyor will
engage the apron before the conveyor can clear space 52. ~ .
To solve this problem, the apron attitude adjustment
means includes means to selectively shift the apron pivot axis 41
to a posi~ion wherein the apron body will completely clear space 52
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said space. For this purpose, and as best shown in Figs. 3-5,
a ver~ical guide 53 is secured to each mounting plate 7 and extends
upwardly from adjacent lower frame corner Sl. A follower or slide
block 54 is mounted in each guide for vertical travel therein. .
Each slide block 54 is provided with a forwardly extending ear 55
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to which is pivotally attached a corresponding clevis 56 on the
rea~ard portion of apron 10. The connection between these
elements defines the apron pivot axis 41. Each slide block 54,
and thus axis 41, is vertically shiftable by a motive means such
S as a shift cylinder 57 which is pivotally mounted at its upper
end to a bracket 58 on the respective plate 7, and at its lower
end to an ear 59 extending upwardly from slide bloc~ 54. Cylin-
ders 57 are actuated from the cab in any suitable well-known way
to raise and lower axis 41 and thus the rear of the apron to any
of an infinite number of desired positions.
Before the front end of conveyor 11 is raised, not only
is apron 10 pivoted upwardly by cylinders 43, but the rear of the
apron and axis 41 are raised by shift cylinders 57. The resul-
tan~ raised positions of both the apron and conveyor are best
shown in phantom in Fig. 3. All elements will now be above
approach plane 49, leaving no obstructions in space 52.
The described structure has a number of advantages in
addition to eliminating interference between the apron and conveyor
&bove the approach space.
During operation of the machine, it may be desirable to
adjust the height o the discharge end of the conveyor to accommo-
date various dump receptacles, o~her conveyors and ~he like. A5
soon as conveyor 11 is pivoted to a new position, the size of
gap 40 chsnges. It may bè decreased to the point where edge 38A
may be contacted by the conveyor. Or, it may be increased until
there is too great a material drop distance. The ver~ical adjust-
ment mechanism for apron axis 41 provides a means to maintain
gap 40 at a desired optimum dimension, no ~atter what the position
of conveyor 11.
In addition, if apron edge 38 should ve downwardly
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below grade, due to a depression in the ground surface, the
Optimum dimension of gap 40 can be maintained by raising
apron axis 41.
- Furthermore, in some instances it may be desired to
change the dig-in angle of apron 10 as the machine moves
forwardly. Changing the angle may assist gathering i~plement
assembly 8 in loading unwiedly rocks and the like onto the
machine. This may readily be accomplished by changing the
vertical position of apron axis 41, while leaving cylinders 43
in float condition, to thereby change the angular attitude of
the apron while its front edge 38 remains on the ground.
While numerous cylinders and associated elements have
been shown and described herein, either singly or in pairs, any
number o~ such elements may be utilized without departing from the
spirit of the invention.
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