U.S. patent application number 11/059745 was filed with the patent office on 2006-06-22 for conveyor belt guide.
This patent application is currently assigned to Brandt Industries Ltd.. Invention is credited to Marc Eberle, Bradley Zazula.
Application Number | 20060131138 11/059745 |
Document ID | / |
Family ID | 36594312 |
Filed Date | 2006-06-22 |
United States Patent
Application |
20060131138 |
Kind Code |
A1 |
Eberle; Marc ; et
al. |
June 22, 2006 |
Conveyor belt guide
Abstract
A belt guide apparatus for attachment to a belt conveyor
comprises top and bottom plates. Walls extend between the top and
bottom plates. The plates and walls form a belt envelope that
defines a belt opening that substantially corresponds to a
cross-section of the endless belt such that the endless belt can
slide freely through the belt opening yet is substantially
prevented from moving laterally or vertically. A front entrance of
the belt envelope is configured to funnel the endless belt into the
belt opening, and when attached to the belt conveyor the belt
envelope is oriented such that the right and left walls are aligned
with a desired path of the endless belt, and the endless belt
passes through the belt opening.
Inventors: |
Eberle; Marc; (Balgonie,
CA) ; Zazula; Bradley; (Regina, CA) |
Correspondence
Address: |
FROST BROWN TODD, LLC
2200 PNC CENTER
201 E. FIFTH STREET
CINCINNATI
OH
45202
US
|
Assignee: |
Brandt Industries Ltd.
|
Family ID: |
36594312 |
Appl. No.: |
11/059745 |
Filed: |
February 17, 2005 |
Current U.S.
Class: |
198/841 |
Current CPC
Class: |
B65G 15/64 20130101 |
Class at
Publication: |
198/841 |
International
Class: |
B65G 15/62 20060101
B65G015/62 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 21, 2004 |
CA |
2,490,586 |
Claims
1. A belt guide apparatus adapted for attachment to a belt conveyor
comprising an endless belt with a conveying run and a return run,
the apparatus comprising: right and left top plates; right and left
bottom plates; a right wall extending between the right top plate
and the right bottom plate; and a left wall extending between the
left top plate and the left bottom plate; wherein the right and
left top plates, right and left bottom plates, and right and left
walls form a belt envelope that defines a belt opening that
substantially corresponds to a cross-section of the endless belt
such that the endless belt can slide freely through the belt
opening yet is substantially prevented from moving laterally or
vertically; wherein a front entrance of the belt envelope is
configured to funnel the endless belt into the belt opening; and
wherein the belt envelope, when attached to the belt conveyor, is
oriented such the right and left walls are aligned with a desired
path of the endless belt, and the endless belt passes through the
belt opening.
2. The apparatus of claim 1 adapted for attachment to the belt
conveyor such that a flat portion of the endless belt passes
through the belt opening.
3. The apparatus of claim 2 wherein the flat portion of the endless
belt is a portion of the return run of the endless belt.
4. The apparatus of claim 1 wherein the right and left top plates
are connected to form a top plate extending from the right wall to
the left wall.
5. The apparatus of claim 1 wherein the right and left bottom
plates are connected to form a bottom plate extending from the
right wall to the left wall.
6. The apparatus of claim 1 wherein ends of a belt are connected by
a belt lace to form the endless belt.
7. The apparatus of claim 1 wherein the belt conveyor is adapted to
transfer packages and wherein the conveying run of the endless belt
is substantially flat.
8. The apparatus of claim 1 wherein the belt conveyor is adapted to
transfer bulk material and wherein the conveying run of the endless
belt is troughed.
9. The apparatus of claim 8 wherein the conveying run of the
endless belt passes through a tube.
10. The apparatus of claim 1 adapted for attachment to the belt
conveyor adjacent to an end roller of the belt conveyor.
11. The apparatus of claim 1 wherein the belt conveyor comprises an
S-drive, and wherein the apparatus is adapted for attachment to the
belt conveyor adjacent to the S-drive such that the return run of
the endless belt passes through the belt envelope prior to passing
through the S-drive.
12. A belt conveyor comprising: front and rear end rollers mounted
on a frame, and an endless belt mounted on the end rollers and
driven such that a top conveying run of the endless belt moves from
the front roller toward the rear roller along a top of the frame,
and a bottom return run of the endless belt moves from the rear
roller toward the front roller along a bottom of the frame; at
least one belt guide comprising: right and left top plates; right
and left bottom plates; a right wall extending between the right
top plate and the right bottom plate; and a left wall extending
between the left top plate and the left bottom plate; wherein the
right and left top plates, right and left bottom plates, and right
and left walls form a belt envelope that defines a belt opening
that substantially corresponds to a cross-section of the endless
belt such that the endless belt can slide freely through the belt
opening yet is substantially prevented from moving laterally or
vertically; and wherein a front entrance of the belt envelope is
configured to funnel the endless belt into the belt opening;
wherein the at least one belt guide is mounted on the frame such
the right and left walls are aligned with a desired path of the
bottom return run of the endless belt, and such that the bottom
return run of the endless belt passes through the belt opening.
13. The belt conveyor of claim 12 wherein the right and left top
plates are connected to form a substantially planar top plate
extending from the right wall to the left wall.
14. The apparatus of claim 12 wherein the right and left bottom
plates are connected to form a substantially planar bottom plate
extending from the right wall to the left wall.
15. The apparatus of claim 12 wherein the belt conveyor is adapted
to transfer packages and wherein the top conveying run of the
endless belt is substantially flat.
16. The apparatus of claim 12 wherein the belt conveyor is adapted
to transfer bulk material and wherein the top conveying run of the
endless belt is troughed.
17. The belt conveyor of claim 16 wherein the top conveying run of
the endless belt passes through a tube.
18. The apparatus of claim 12 comprising a belt guide mounted to
the frame adjacent to the front end roller such that the bottom
return run of the endless belt passes through the belt opening
prior to passing over the front end roller.
19. The apparatus of claim 12 comprising a belt guide mounted to
the frame adjacent to the rear end roller such that the bottom
return run of the endless belt passes through the belt opening
after passing over the rear end roller.
20. The apparatus of claim 12 comprising an S-drive, and a belt
guide mounted to the frame adjacent to the S-drive such that the
bottom return run of the endless belt passes through the belt
opening prior to passing through the S-drive.
Description
[0001] This invention is in the field of belt conveyors and in
particular mechanisms for properly tracking the conveyor belt with
respect to the conveyor rollers.
BACKGROUND OF THE INVENTION
[0002] Belt conveyors are used in a wide range of applications for
transporting both individual packages and bulk material such as
grain, ore, gravel, and the like. Such belt conveyors typically
comprise a top conveying run on which the load is placed, and a
bottom return run. The ends of the belt are connected together by a
belt lace or like device to form an endless belt mounted on end
rollers at each end of the belt conveyor.
[0003] Typically package belt conveyors have a flat top conveying
run supported on a plate or rollers, while bulk belt conveyors have
outer edges of the belt on the top conveying run raised to form a
trough to retain the bulk material on the belt. The top conveying
run may be supported in the troughed configuration by rollers or
plates, and in many applications the conveying run passes through a
tube that supports it in the troughed configuration. At the ends of
the conveyor with either a troughed or flat conveying run, the belt
is flat as it passes over the end rollers, and typically the return
run is flat and is supported by idler rollers, plate sections or
the like spaced at suitable intervals under the conveyor.
[0004] The mechanisms used to drive the belt will vary depending on
the conveyor length, load, configuration, and like conditions. In a
simple configuration, a motor can be used to drive one of the end
rollers of the conveyor. Friction between the belt and drive roller
causes the belt to move with the surface of the roller. Where
increased force is required to drive the belt because of long
length, high load, or the like, the return run typically passes
through an S-drive mounted under the conveyor. In the S-drive,
idler rollers cause the belt to wrap farther around the drive
roller, increasing the frictional force between the belt and drive
roller and allowing more power to be transferred from the drive
roller to the belt.
[0005] A problem with belt conveyors is that the belt must be
tracked properly, meaning it must be maintained in alignment with
the end rollers, idler rollers, and S-drive rollers. Such belts
tend to move laterally along the surface of the rollers toward one
roller edge or the other where the belt edge will rub against
support brackets and the like and be damaged. Typically adjustments
are provided to track the belt by moving the ends of the rollers
forward or rearward. In an initial adjustment the end rollers and
S-drive rollers are squared with the proper belt path, such that
the belt should track properly. During use however, conveyor belts
have a tendency to wander laterally and frequent tracking
adjustment is required in prior art belt conveyors. Such adjustment
is conventionally accomplished by moving one end of an end roller,
or one end of a drive roller, to tighten or loosen the belt.
[0006] This tracking problem has been well recognized in the prior
art. U.S. Pat. No. 779,666 to Robins Jr. for example provides guide
rollers oriented perpendicular to the edges of the belt on the
conveying run and return run of a belt conveyor. When the belt
moves laterally the belt edges contact the guide rollers and
inhibit the lateral movement. The belt edges however tend to curl
upward and climb the guide rollers, allowing the belt to move out
of alignment and causing damage to the belt.
[0007] U.S. Pat. No. 4,917,232 to Densmore discloses flanged guide
rollers oriented to rotate about axes perpendicular to the belt
edges and spaced along the conveying and return runs of a conveyor
belt following a curved path. Lateral movement of the belt is
inhibited when the edges of the belt contact and rotate the
rollers. The flanges extend over the edges of the belt to prevent
the edges of the belt from curling up and climbing the guide
rollers.
[0008] U.S. Pat. No. 6,390,289 to Hoggan discloses, contrary to the
guide rollers of Densmore, flanged guide rollers spaced along the
conveying and return runs of a conveyor belt but oriented to rotate
about axes parallel to the belt edges. The flanged rollers inhibit
lateral movement of the belt when the edges of the belt contact the
flanges extending downward. In Hoggan the rollers extend over the
edges of the belt to prevent the edges of the belt from curling up
when they contact the flanges.
[0009] Prior art flanged guiding rollers used to maintain tracking
provide resistance to lateral belt movement only at discrete points
along the belt edge. Providing such guide rollers is costly both in
terms of initial cost and continued maintenance. Further, the top
conveying run of a bulk conveyor is often enclosed in a tube, such
that guide rollers cannot be conveniently provided on that portion
of the belt.
[0010] Rather than forcing the belt to track properly using guide
rollers, U.S. Pat. No. 2,655,251 to Bankauf discloses conveyor
rollers that skew in response to lateral belt movement in order to
maintain the belt in the center of the rollers.
SUMMARY OF THE INVENTION
[0011] It is an object of the present invention to provide a belt
guide apparatus for maintaining proper tracking in a belt conveyor
that overcomes problems in the prior art.
[0012] The present invention provides in one embodiment, a belt
guide apparatus adapted for attachment to a belt conveyor
comprising an endless belt with a conveying run and a return run.
The apparatus comprises right and left top plates and right and
left bottom plates. A right wall extends between the right top
plate and the right bottom plate and a left wall extends between
the left top plate and the left bottom plate. The right and left
top plates, right and left bottom plates, and right and left walls
form a belt envelope that defines a belt opening that substantially
corresponds to a cross-section of the endless belt such that the
endless belt can slide freely through the belt opening yet is
substantially prevented from moving laterally or vertically. A
front entrance of the belt envelope is configured to funnel the
endless belt into the belt opening, and when attached to the belt
conveyor the belt envelope is oriented such the right and left
walls are aligned with a desired path of the endless belt, and the
endless belt passes through the belt opening.
[0013] In a second embodiment the invention provides a belt
conveyor comprising front and rear end rollers mounted on a frame,
and an endless belt mounted on the end rollers and driven such that
a top conveying run of the endless belt moves from the front roller
toward the rear roller along a top of the frame, and a bottom
return run of the endless belt moves from the rear roller toward
the front roller along a bottom of the frame. A belt guide
comprises right and left top plates; right and left bottom plates;
a right wall extending between the right top plate and the right
bottom plate; and a left wall extending between the left top plate
and the left bottom plate. The right and left top plates, right and
left bottom plates, and right and left walls form a belt envelope
that defines a belt opening that substantially corresponds to a
size of a cross-section of the endless belt such that the endless
belt can slide freely through the belt opening yet is substantially
prevented from moving laterally or vertically. A front entrance of
the belt envelope is configured to funnel the endless belt into the
belt opening. At least one belt guide is mounted on the frame such
the right and left walls are aligned with a desired path of the
bottom return run of the endless belt, and such that the bottom
return run of the endless belt passes through the belt opening.
[0014] In the belt guide of the invention the belt passes through a
belt envelope with an opening substantially equal in size to the
cross section of the belt and aligned on the desired path of the
belt, generally a path along the middle of the end and drive
rollers of the belt conveyor. Thus the belt is restricted to that
path while passing through the belt guide, and the belts tendency
to move laterally on the rollers is reduced. One or more belt
guides can be provided on a belt conveyor, depending on size,
configuration, loading and like conditions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] While the invention is claimed in the concluding portions
hereof, preferred embodiments are provided in the accompanying
detailed description which may be best understood in conjunction
with the accompanying diagrams where like parts in each of the
several diagrams are labeled with like numbers, and where:
[0016] FIG. 1 is a schematic side view of a belt conveyor with a
flat top conveying run and with a belt guide of the invention
mounted such that the bottom return run of the belt conveyor passes
through the belt guide;
[0017] FIG. 2 is a perspective view showing the belt guide of FIG.
1;
[0018] FIG. 3 is a cross-sectional side view of the belt guide of
FIG. 1;
[0019] FIG. 4 is a front view of the belt guide of FIG. 1;
[0020] FIG. 5 is a cross-sectional view of the endless belt of the
belt conveyor of FIG. 1;
[0021] FIG. 6 is a top view of the belt guide of FIG. 1 showing the
belt passing through the belt guide;
[0022] FIG. 7 is a schematic cross-sectional view of an alternate
embodiment of the belt guide of the invention;
[0023] FIG. 8 is a schematic cross-sectional view of the belt guide
of FIG. 1;
[0024] FIG. 9 is a schematic side view of a belt conveyor with a
troughed top conveying run and with three belt guides of the
invention mounted such that the bottom return run of the belt
conveyor passes through the belt guides.
DETAILED DESCRIPTION OF THE INVENTION
[0025] FIG. 1 illustrates a belt conveyor 1 of the present
invention wherein the top conveying run of the endless belt is
substantially flat, typical of a belt conveyor adapted to transfer
packages and like discreet articles. The belt conveyor 1 comprises
front and rear end rollers 2, 4 mounted on a frame 6, and an
endless belt 8 mounted on the end rollers 2, 4 and driven such that
a top conveying run 8T of the endless belt 8 moves in the belt
travel direction B from the front roller 2 toward the rear roller 4
along a top of the frame 6, and a bottom return run 8B of the
endless belt 8 moves from the rear roller 4 toward the front roller
2 along a bottom of the frame 6. In the illustrated embodiment the
endless belt 8 is driven by a motor 9 rotating the rear end roller
4. The front and rear end rollers 2, 4 are mounted on the frame 6
perpendicular to the desired path of the endless belt 8.
[0026] A belt guide 10 of the invention is mounted to the frame 6
adjacent to the rear end roller 4 such that the bottom return run
8B of the endless belt 8 passes through the belt guide 10 after
passing over the rear end roller 4. A further belt guide 10A is
mounted to the frame 6 adjacent to the front end roller 2 such that
the top conveying run 8T of the endless belt 8 passes through the
belt guide 10 after passing over the front end roller 2.
[0027] The belt guide 10 can be installed on a variety of belt
conveyors, both as original equipment and on existing conveyors.
Typically, in order to avoid interfering with the material being
conveyed, belt guides will be mounted such that the bottom return
run 8B rather than the top conveying run 8T passes through the belt
guide, but if desired belt guides can also be placed in the
position of belt guide 10A such that the top conveying run passes
through the belt guide.
[0028] As illustrated in FIGS. 2-4, the belt guide 10 comprises a
top plate 12 and a bottom plate 14. A right and left walls 16
extend between the top plate 12 and the bottom plate 14 and the top
plate 12, bottom plate 14, and walls 16 form a belt envelope that
defines a belt opening 20 that substantially corresponds to a size
of a cross-section of the endless belt 8, illustrated in FIG. 5,
such that the endless belt 8 can slide freely through the belt
opening 20 yet is substantially prevented from moving laterally or
vertically.
[0029] The belt guide 10 is mounted on the frame 6 such that the
right and left walls 16 are aligned with a desired path of the
bottom return run 8B of the endless belt 8. In FIG. 1, the desired
path will generally be a path centered laterally on the rear end
roller 4. The belt guide 10 is placed adjacent to the rear end
roller 4 with the walls thereof aligned with that path so that as
the endless belt 8 comes off the rear end roller 4 its travel path
is restricted to the desired path just after it comes off the rear
end roller 4.
[0030] Similarly a second belt guide 10 can be placed adjacent to
the front end roller 2 so that the endless belt 8 is restricted to
the desired path just prior to passing over the front end roller 2.
While it is contemplated that the belt guide will provide improved
tracking regardless of where it is located on the bottom return run
8B of the endless belt 8, it is also contemplated that a location
in proximity to one of the end or drive rollers will be preferred
in practice. While the belt guide 10 of the invention can be made
in varying lengths, from a short length such that the top and
bottom plates 12, 14 are like bars, to a length in the order of a
multiple of the width of the endless belt 8 as illustrated in FIGS.
2 and 6, it is contemplated that shorter belt guides are likely to
cause more wear on the belt than longer ones.
[0031] The front entrance 22 of the belt envelope is configured to
funnel the endless belt 8 into the belt opening 20. In the
embodiment illustrated in FIGS. 2-4 and 6, the front entrance 22 is
formed by bending the top plate 12 upward, the bottom plate 14
downward, and the walls 16 outward. FIG. 10 illustrates an
alternate embodiment wherein edges of the top and bottom plates
112, 114 at the front entrance 22 are rounded, either by welding a
cylindrical rod along the edges, or by grinding or otherwise
forming a rounded edge. Similarly the edges of the walls of belt
guide 110 would be rounded.
[0032] Rounding or bending the edges of front entrance 22, 122 to
funnel the belt into the belt opening 20, 120 reduces wear on the
edges of the endless belt 8. As well, endless belts are often made
by joining the ends of a conveyor belt with a belt lace 26, such as
shown in FIG. 6, and such a lace could catch on sharp edges, and so
same should be avoided. Further, where a belt lace 26 is present,
the cross section of the endless belt 8 at the lace may be somewhat
larger than in the rest of the belt. Care must be taken that the
belt opening 20 is large enough to allow the belt lace to pass
through.
[0033] In the belt guide illustrated in FIGS. 2-4, and 6 the top
and bottom plates 12, 14 extend from the right wall to the left
wall, however it is contemplated that a center portion of the belt
guide could be left open as in the belt guide 210 schematically
illustrated in cross section in FIG. 7. The belt guide 210
comprises right and left top plates 212R, 212L and right and left
bottom plates 214R, 214L. A right wall 216R extends between the
right top plate 212R and the right bottom plate 214R, and a left
wall 216L extends between the left top plate 212L and the left
bottom plate 214L. As in the belt guide 10 of FIGS. 2-4, and 6, the
plates 212R, 212L, 214R, 214L and walls 216R, 216L form a belt
envelope that defines a belt opening 220 that substantially
corresponds to a size of a cross-section of the endless belt 208,
such that the endless belt 208 can slide freely through the belt
opening 220 yet is substantially prevented from moving laterally or
vertically. The plates 212R, 212L, 214R, 214L do not allow the
outer portions and edges of the endless belt 208 to move
vertically, and the walls 216R, 216L prevent lateral movement.
While the central portion of the endless belt 208 is not vertically
restricted, it is contemplated that by restricting vertical
movement of the outer portions of the endless belt 208, the belt
will be maintained in the desired location.
[0034] In the belt guide 10 of FIGS. 2-4, and 6, and as illustrated
in cross section in FIG. 8, the plates 212R, 212L, 214R, 214L of
FIG. 7 are simply connected to form a substantially planar top and
bottom plates 12, 14 extending from the right wall to the left wall
16R, 16L. It is contemplated that it also might be desirable to
provide apertures in the central portion of the top and bottom
plates 12, 14 in order to allow foreign material to exit the belt
guide 10.
[0035] FIG. 8 also illustrates a convenient structure for making
the belt guide 10 by forming a metal plate in a U-shape to provide
the bottom plate 14 and right and left walls 16R, 16L, and forming
another metal plate in corresponding U-shape to provide the top
plate 12 and flanges to attach, with bolts 28, screws, or like
fasteners, to the portions of the walls 16R, 16L extending above
the opening 20. The belt guide 10 can thus readily be installed on
the endless belt 8 by positioning the two U-shaped metal plates on
the top and bottom of the belt and fastening them together.
Suitable mounting brackets for installing the belt guide 10 will be
readily provided by those skilled in the art.
[0036] FIG. 9 illustrates a belt conveyor 301 adapted to transfer
bulk material wherein the top conveying run 308T of the endless
belt 308 is troughed and passes through a tube 330 that is mounted
on a frame or supporting structure that, for clarity of
illustration, is not shown. At the ends of the belt conveyor 301,
the endless belt 308 passes over front and rear end rollers 302,
304 the endless belt 308 flattens out such that the bottom return
run 308B is flat. The bottom return run 308B of the endless belt
308 of the belt conveyor 310 is supported on idler rollers 331 and
passes through an S-drive 332, such as is well known in the
art.
[0037] The illustrated embodiment shows a belt guide 310 mounted on
the frame adjacent to the front end roller 302, rear end roller
304, and upstream from the S-drive 332. The bottom return run 8B of
the endless belt 8 passes through a belt guide 310 prior to passing
over the front end roller 302 and prior to passing through the
S-drive 332, and just after passing over the rear end roller 304.
Thus the endless belt 8 is restricted to the desired path down the
middle of the rollers of the S-drive 332, and the front and rear
end rollers 302, 304 at locations adjacent to those rollers. Thus
maximum tracking guidance is provided by the three belt guides 310
illustrated in FIG. 8.
[0038] Typically, it is contemplated that the belt guide 310 of
such a troughed conveyor will be attached such that a flat portion
of the bottom return run 308B of the endless belt 308 passes
therethrough. As discussed above however, belt guides can also be
mounted on a flat portion of the top conveying run where desired,
and where same will not interfere with material being carried on
the endless belt.
[0039] Similarly, it is contemplated that a belt guide could be
positioned such that a troughed portion of the top conveying run of
endless belt passed therethrough, provided that the belt opening
was formed into the desired troughed path of the endless belt. It
is contemplated however that the expense of forming the belt guide
to provide the properly shaped belt opening, and the limited
locations for placing the belt guide where it will not interfere
with material being conveyed, will make it impractical and
undesirable, as well as unnecessary, to position the belt guide so
that a troughed portion of the endless belt passes
therethrough.
[0040] The foregoing is considered as illustrative only of the
principles of the invention. Further, since numerous changes and
modifications will readily occur to those skilled in the art, it is
not desired to limit the invention to the exact construction and
operation shown and described, and accordingly, all such suitable
changes or modifications in structure or operation which may be
resorted to are intended to fall within the scope of the claimed
invention.
* * * * *