U.S. patent application number 10/604033 was filed with the patent office on 2004-12-23 for tilt conveyor.
This patent application is currently assigned to THE LAITRAM CORPORATION. Invention is credited to Costanzo, Mark B..
Application Number | 20040256198 10/604033 |
Document ID | / |
Family ID | 33479192 |
Filed Date | 2004-12-23 |
United States Patent
Application |
20040256198 |
Kind Code |
A1 |
Costanzo, Mark B. |
December 23, 2004 |
TILT CONVEYOR
Abstract
A tiltable conveyor for offloading conveyed articles over a side
of a conveyor belt. The belt is preferably a modular conveyor belt
constructed of a series of belt rows hingedly interlinked to form
an article-conveying surface. The belt is supported by a carryway,
along which the belt is driven in a direction of belt travel by a
drive system. The carryway includes one or more tilt sections at
which one side of the belt is elevated relative to the other to
offload articles across the lower side. The belt may include
rollers or be molded of or coated with an inherently slick material
to facilitate offloading.
Inventors: |
Costanzo, Mark B.; (River
Ridge, LA) |
Correspondence
Address: |
LAITRAM, L.L.C.
LEGAL DEPARTMENT
220 LAITRAM LANE
HARAHAN
LA
70123
US
|
Assignee: |
THE LAITRAM CORPORATION
220 Laitram Lane Legal Department
Harahan
LA
|
Family ID: |
33479192 |
Appl. No.: |
10/604033 |
Filed: |
June 23, 2003 |
Current U.S.
Class: |
198/370.04 |
Current CPC
Class: |
B65G 47/945 20130101;
B65G 2201/0235 20130101 |
Class at
Publication: |
198/370.04 |
International
Class: |
B65G 047/10 |
Claims
What is claimed is:
1. A conveyor for offloading articles, comprising: a conveyor belt
forming an article-conveying surface extending laterally from a
first side to a second side and longitudinally in the direction of
belt travel; a belt carryway supporting the belt; a drive system
driving the belt along the carryway in the direction of belt
travel; and the belt carryway including a tilt section elevating
the first side of the belt relative to the second side to offload
articles carried on the article-conveying surface across the lower
second side of the belt at the tilt section.
2. A conveyor as in claim 1, wherein the conveyor belt further
includes a plurality of rollers rotatably mounted in the belt with
a salient portion extending above the article-conveying surface to
engage conveyed articles in rolling contact.
3. A conveyor as in claim 2, wherein the rollers are rotatable
about an axis parallel to the direction of belt travel.
4. A conveyor as in claim 1, wherein the conveyor belt is a modular
conveyor belt including a series of rows of belt modules hingedly
interlinked and wherein the belt modules are molded of an
inherently slick plastic material to provide a low-friction
article-conveying surface.
5. A conveyor as in claim 1, wherein the belt carryway at the first
side of the belt is elevated relative to the belt carryway at the
second side of the belt in the tilt section.
6. A conveyor as in claim 1, wherein the tilt section includes a
plurality of lateral slats forming the carryway, the lateral slats
being pivotable about a pivot axis parallel to the direction of
belt travel to tilt the belt with the first side of the belt
elevated relative to the second side of the belt.
7. A conveyor as in claim 6, further comprising a tilt control
connected to each of the slats to control the degree of tilt of
each.
8. A conveyor as in claim 7, wherein the tilt control comprises a
push rod engaging the slat at the first side of the belt.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Patent Application No. 60/260,620, filed Jan. 9, 2001.
BACKGROUND OF INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to a conveyor arrangement with a
tiltable offloading section along the conveyor path and, more
particularly, to such an arrangement preferably using a modular
conveyor belt.
[0004] 2. Background Discussion
[0005] In the material handling industry, especially the package
handling industry, it is often necessary to sort conveyed articles,
such as boxes, by size, weight, destination, or some other
parameter. One way of sorting articles is to offload them over the
side of a conveyor according to preselected sorting criteria at one
or more offloading stations. One way to offload articles over the
side of the conveyor is to push them. A push rod at one side of the
conveyor is actuated to push against the conveyed article and force
it off the opposite side to another conveyor or collection area.
Another example is a shoe sorter, in which a slat-type conveyor has
shoes that can controllably slide laterally in the gaps between
consecutive slats. The shoes push articles off the side of the
conveyor. These pushing systems work well in many applications, but
can be somewhat complex in that they often require tight
coordination between the pushing mechanism and the speed of the
conveyor. Often, especially with shoe conveyors, the conveyor frame
can be quite complex, with diverter channels and other arrangements
required to guide or control the motion of the shoes.
[0006] Another side-offloading sorting system is the tilt tray, in
which a conveyor includes a series of trays, each of which contains
one or more articles. The trays are pivotable about a pivot axis
parallel to the conveying direction. When a tray reaches a
designated offloading station, the tray is tipped about its pivot
axis, depositing its load over the side of the conveyor. To prevent
articles from tumbling while being offloaded, the trays are
specially designed, and the tipping mechanism is carefully
controlled. These special-purpose conveyors tend to be rather
expensive. Furthermore, the individual trays limit the size of the
articles that can be sorted--a drawback in some applications.
[0007] The high degree of accuracy and control provided by sorting
conveyors like those described and their associated high costs are
not necessary in many non-critical applications. Thus, there is a
need for a low-cost and simple side-offloading conveyor for the
package handling industry.
SUMMARY OF INVENTION
[0008] These needs and others are provided by a conveyor having
features of the invention. The conveyor, which is designed to
offload articles, includes a conveyor belt, such as a modular
conveyor belt constructed of a series of rows of belt modules
interlinked hinge-like to form an article-conveying surface. The
belt is supported by a carryway defining a conveying path. The
article-conveying surface extends longitudinally along the carryway
and laterally from a first side to a second side defining the width
of the belt. A drive system drives the belt continuously or in a
stop-and-go fashion along the carryway in a direction of belt
travel. The carryway includes a tilt section at which the first
side of the belt is elevated relative to the second side to offload
articles carried on the article-conveying surface across the lower
second side of the belt.
[0009] In one version of the conveyor, the belt includes a
plurality of rollers mounted in the belt for rotation. A salient
portion of each roller extends above the article-conveying surface
to engage conveyed articles in rolling contact and facilitate their
side-offloading. Preferably, the rollers are cylindrical rollers
having an axis of rotation in the direction of belt travel. In
another version of the conveyor, the article-conveying surface is
flat and molded of a slick plastic material to provide a
low-friction sliding surface for offloading at the tilt
section.
[0010] In another version of the conveyor, the belt carryway at the
first side of the belt is higher than at the second side in the
tilt section. In still another version, the tilt section is made of
a number of lateral slats that are pivotable about a pivot axis
parallel to the direction of belt travel. A push rod can be used to
push on the underside of the slat to elevate its first side above
its second side to control the tilt of the conveyor belt in the
tilt section. Thus, a simple modular conveyor belt, such as is
available off-the-shelf, can be used to construct an inexpensive
side-offloading system.
BRIEF DESCRIPTION OF DRAWINGS
[0011] These and other advantages, features, and aspects of the
invention are described in more detail in the following
description, appended claims, and accompanying drawings, in
which:
[0012] FIG. 1 is a top diagrammatic view of a conveyor embodying
features of the invention;
[0013] FIG. 2 is an isometric view of a portion of one version of a
slatted carryway for use with the conveyor of FIG. 1;
[0014] FIG. 3 is an elevation view of a tilting mechanism for one
slat of the carryway of FIG. 2;
[0015] FIG. 4 is an isometric view of a portion of another version
of carryway usable with the conveyor of FIG. 1;
[0016] FIG. 5 is a top view of two roller-top conveyor belt modules
usable in the conveyor of FIG. 1; and
[0017] FIG. 6 is an isometric view of another version of belt
module that can be used in the conveyor of FIG. 1.
DETAILED DESCRIPTION
[0018] FIG. 1 shows a tilt conveyor embodying features of the
invention. The conveyor 10 includes a conveyor frame 12 having a
carryway 14 supporting a modular conveyor belt 16. The belt is
constructed of a series of rows A, B of belt modules 18, 19
connected side by side and end to end in a bricklaid pattern. In
the example shown in FIG. 1, each row includes two side-by-side
modules. Consistent with the invention, the belt could be
constructed with a single module per row or in a non-bricklaid
pattern. The rows are hingedly interlinked end to end to end to
allow the belt to articulate about drive and idler sprockets or
pulleys. A drive system 20, including a motor, is conventionally
connected to sprockets or a pulley by a shaft (not shown) supported
by a bearing block 22. The motor drives the belt in a direction of
belt travel 24. The other end of the belt is wrapped around an
idler pulley or sprockets supported by bearing blocks 23. The drive
system could be a simple start-stop control with or without manual
speed adjustment or a more sophisticated variable speed control
with intelligence, such as that provided by a programmable logic
controller 25 having other control outputs 27 and sensed inputs
27'.
[0019] The belt is preferably a modular plastic conveyor belt, such
as are available from Intralox, Inc. of Harahan, La., USA, a
subsidiary of the assignee of this invention. The belt in FIG. 1
forms a top article-conveying surface 26 extending longitudinally
in the direction of belt travel and laterally from a first side 28
to a second side 29 of the belt defining its width. In the
preferred version shown, the carryway portion of the belt is
continuous with no barriers that would limit the length of articles
placed thereon. It would, however, be within the scope of the
invention to provide lateral flights to compartmentalize the belt
into sections. The carryway includes a tilt section 30 at which
conveyed articles 32 can be offloaded over the second side of the
belt. (A typical sorting conveyor may include a number of tilt
sections. Only one is shown here for simplicity. Likewise, articles
are shown being offloaded over the second side of the belt; it is
within the scope of the invention to offload over the first side as
well.)In the tilt section, one version of which is shown in more
detail in FIGS. 2 and 3, the first side of the belt is elevated
relative to the second side so that articles can slide off. As
shown in FIGS. 2 and 3, the tilt section replaces the standard
carryway 14 with a group of slats 32 that can pivot about a pivot
axis 34 according to curved arrow 36 by means of a pivot joint 38
attached to each slat on its underside roughly midway between the
sides of the slat. A push rod 40 is pivotally attached to a pivot
connection 42 on the underside at an end of the slat. A
conveyor-frame-mounted cylinder 44 extends the push rod in the
direction of arrow 46 from a first position, in which the slat is
coplanar with the carryway 14, to a second tilted position, shown
in hatched lines, to cant the carryway and tip the supported belt
16 so that articles 28 can slide off the side in the direction of
arrow 48. Each of the slats can be attached to its own push rod and
cylinder, or a single push rod could be attached to a generally
convex push plate coacting with the undersides of the series of
slats to push them in unison. With the push rod arrangement, the
characteristics of the belt section can be changed from no tilt to
a range of tilts. The tilt can be coordinated with the drive system
by the controller 25 in FIG. 1.
[0020] Another version of tilt section 30 of the carryway is shown
in FIG. 4. In this example, the carryway 14' is preformed in a
tilted shape so that as the belt rides over the tilt section,
articles carried on it can slide off the lower side. The tilt
section could alternatively be formed of a flexible material made
to assume the tilted shape shown in FIG. 4 by a push plate 50,
shown in phantom, attached to a pivot and push rod. Thus, like the
tilt section of FIGS. 2 and 3, the tilt section of FIG. 4 can be
either passive or active.
[0021] Although metal conveyor belts or chains, and even fabric
belts, can be used with the conveyor of the invention, the
preferred belt is a modular plastic conveyor belt. These belts are
typically made by injection molding out of thermoplastic material.
The most common materials include polypropylene, polyethylene, and
acetal. Many belts usable in the conveyor of this invention are
readily available. For example, the belt section shown in FIG. 5
has many of the characteristics of the INTRALOXSeries 400 Roller
Top belt. The belt section shown comprises two modules 52, 53 each
having interleaved forward 54 and trailing 55 link ends, or hinge
eyes. The hinge eyes include a lateral bore 56 forming a passageway
across the width of the belt. A hinge pin, or pivot rod 58,
disposed in the passageway, holds adjacent modules together at a
hinge joint. A belt made of many rows of such modules is driven in
the direction of arrow 60 by, for example, motor-driven sprockets
engaging underside belt structure.
[0022] The belt modules also have recesses 62 opening onto the
conveying surface. Rollers--in this case, cylindrical rollers
64--are disposed in each recess. An axle 66 spanning each recess in
the direction of belt travel is retained in the module. A bore in
each cylindrical roller admits the axle so that the roller is free
to rotate about the axle. A salient portion 68 of each roller
protrudes above the article-conveying surface. Whenever an article
on the belt reaches the tilt section of the carryway, with the left
side as depicted in FIG. 5 higher than the right side, the article,
aided by the freely rotating rollers and gravity, slides easily off
the side of the belt in the direction of arrow 70. Thus, this side
transfer roller belt is effective at side-offloading in the tilt
section of a conveyor path.
[0023] A belt module similar to that in FIG. 5 is shown in FIG. 6.
The module 72 differs from those in FIG. 5 principally in that its
top article-conveying surface 74 is continuous, except for the
roller recesses 62. This module, when interconnected with other
similar modules into a belt, would also be effective at
side-offloading articles in a tilt section. In fact, if the module
is made of a slick material such as acetal, in some applications
the rollers are not even necessary. A module with a completely flat
surface, without recesses and rollers, would suffice to transfer
articles off the side in a tilt section.
[0024] Thus, the invention has been described with respect to
various versions of tilt carryway sections and belt constructions.
Even so, those skilled in the art will appreciate that other
modifications of the example versions are possible without
materially departing from the novel teachings and advantages of the
invention. For example, the rollers could be spherical as well as
cylindrical and could be rotatably retained without an axle. Other
methods of realizing a tilted carryway are also possible. As
another example, the belt could be a flat rubber or fabric belt
with embedded rollers or coated with a low-friction material, such
as materials containing TEFLON or silicon, to help articles slide
off the tilted belt. As the examples suggest, these and other
modifications are intended to be included within the scope of the
invention as defined by the following claims.
* * * * *