U.S. patent application number 11/592705 was filed with the patent office on 2008-05-08 for rodless modular conveyor belt.
Invention is credited to James J. Harrison.
Application Number | 20080105519 11/592705 |
Document ID | / |
Family ID | 39332282 |
Filed Date | 2008-05-08 |
United States Patent
Application |
20080105519 |
Kind Code |
A1 |
Harrison; James J. |
May 8, 2008 |
RODLESS MODULAR CONVEYOR BELT
Abstract
A conveyor belt assembled of modular plastic components is
retained together without the usual connecting rods or pins. In one
embodiment the modules, each of which has series of finger-like
projections or knuckles both at forward and rear ends of the
module, the projections are tapered to narrows in width from top to
bottom. The projections at either the forward or rear side have
laterally extending posts or dowels at one side of each projection,
each with a length that extends through only part of the width of
the gap between adjacent projections. In the opposite set of
projections are holes, similar to the aligned holes that are
present when module rows are connected by rods. With the
projections being tapered, modules of adjacent rows can be put
together by interdigiting the projections with the modules of
adjacent rows held at an angle, preferably an acute angle beyond
90.degree.. When the modules are brought back toward alignment to a
common plane, the pivot posts of one module become locked in the
holes of the module of the adjacent row.
Inventors: |
Harrison; James J.;
(Bernville, PA) |
Correspondence
Address: |
Thomas M. Freiburger
P.O. Box 1026
Tiburon
CA
94920
US
|
Family ID: |
39332282 |
Appl. No.: |
11/592705 |
Filed: |
November 3, 2006 |
Current U.S.
Class: |
198/853 |
Current CPC
Class: |
B65G 17/08 20130101 |
Class at
Publication: |
198/853 |
International
Class: |
B65G 17/06 20060101
B65G017/06 |
Claims
1. A modular plastic conveyor belt of the type with projections or
knuckles extending in fore and aft directions from each module of a
multiplicity of modules assembled together, assembly of the belt in
a wide variety of widths and lengths, with the projections of
adjacent module rows interdigited and retained together along hinge
lines, the belt being without connecting rods or pins extending
through the interdigited projections, and comprising: each module
having a center section and a plurality of said projections or
knuckles extending integrally from the center section in first and
second sets that extend in opposite directions from each of two
ends of the center section, forward and aft relative to travel of
the belt, the projections of the first set having, on each of
substantially all such projections, an integral pivot post
extending laterally along said hinge line and part way through a
space formed with a neighboring projection of the first set, and
the projections of the second set having, on each of substantially
all such projections, a recess in a lateral side of the projection
positioned to be engaged by a pivot post of a projection of the
first set, and the projections, pivot posts and recesses being so
configured and arranged that to assemble serially adjacent modules
together in adjacent module rows, or to disassemble such modules,
the modules of the adjacent rows must be angled such that the
modules of one row turn down angularly relative to the modules of
the adjacent row, until the first projections with pivot posts can
interdigit with the second projections and engage the posts in the
recesses of the second projections, and such that the modules of
the adjacent rows are locked together when returned toward a common
planar configuration.
2. A conveyor belt according to claim 1, wherein the projections,
pivot posts and recesses are so configured and arranged that to
assemble adjacent modules together in adjacent module rows, the
module of one row must be rotated through an angle of at least
about ninety degrees relative to the module of the adjacent row,
and such that the modules of adjacent rows are locked together
through angles of zero degrees to at least about ninety
degrees.
3. A conveyor belt according to claim 2, wherein the modules must
be rotated through an angle of at least about 120.degree..
4. A conveyor belt according to claim 1, wherein the projections of
the first and second sets are tapered, narrowing from top to bottom
of the projection, thus providing a gap between the interdigited
projections of adjacent modular rows, allowing a preselected amount
of relative lateral movement between the modules of adjacent rows
when the modules of adjacent rows are angled to an assembly
configuration, and wherein the first projections have said pivot
posts only on one side of each projection, such that the lateral
movement afforded by the deeply angled adjacent modules of adjacent
module rows provides clearance for the pivot posts to be moved
laterally into alignment with the recesses of the second
projections so that the modules can be assembled, said recesses in
the second projection comprising generally cylindrical
openings.
5. A conveyor belt according to claim 4, wherein the pivot posts
have a length relative to the configurations of the projections
such that in planar configuration of adjacent rows, the pivot posts
extend into the recesses at least about 0.08''.
6. A conveyor belt according to claim 4, wherein, when the modules
of adjacent rows are rotated to an angle that is sufficient to
allow assembly of the adjacent modules, the amount of lateral
movement afforded between the interdigited modules is at least
about 0.08''.
7. A conveyor belt according to claim 4, wherein, when the modules
of adjacent rows are rotated to an angle that is sufficient to
allow assembly of the adjacent modules, the amount of lateral
movement afforded between the interdigited modules is at least
about 25% of the maximum width of any projection.
8. A conveyor belt according to claim 4, wherein the conveyor belt
comprises a solid top conveyor belt, said center section being
substantially closed, and with very small gaps defined between
interdigited projections when the modules of adjacent rows are
substantially at zero degrees and co-planar.
9. A conveyor belt according to claim 1, wherein the projections of
the first and second sets of projections are essentially
non-tapered, the projections of the second set each having a slot
in a lateral side of the projection, extending from a bottom of the
projection upwardly and outwardly toward the end of the projection
to an upper slot end positioned to retain a pivot post during
operation of the belt, whereby adjacent modules of adjacent module
rows can be assembled in the angled position by sliding the pivot
post of the first projections of one module up into the slots of
the second projections of the other module until the pivot posts
reach the upper ends of the slots, then the adjacent modules can be
rotated to the normal co-planar configuration.
10. A conveyor belt according to claim 9, wherein the slots are
curved.
11. A conveyor belt according to claim 9, wherein the first
projections have the pivot posts on both lateral sides, and wherein
the slots are formed on both sides of the second projections, in
the case of generally all projections.
12. A plastic belt module for use in forming a modular plastic
conveyor belt of the type of with projections or knuckles extending
in fore and aft directions from each module, for assembling a belt
in a wide variety of widths and lengths with the projections of
adjacent module rows interdigited and retained together along hinge
lines, and such that a belt assembled from such modules is without
connecting rods or pins extending through the interdigited
projections, the module comprising: the module having a center
section and a plurality of said projections or knuckles extending
integrally from the center section in first and second sets that
extend in opposite directions from each of two ends of the center
section, forward and aft relative to travel of the belt, the
projections of the first set having, on each of substantially all
such projections, an integral pivot post extending laterally along
said hinge line and part way through a space formed with a
neighboring projection of the first set, and the projections of the
second set having, on each of substantially all such projections, a
recess in a lateral side of the projection positioned to be engaged
by a pivot post of a projection of the first set, and the
projections, pivot posts and recesses being so configured and
arranged that to assemble serially adjacent modules together in
adjacent module rows, or to disassemble such modules, the modules
of the adjacent rows must be angled such that the modules of one
row turn down angularly relative to the modules of the adjacent
row, until the first projections with pivot posts can interdigit
with the second projections and engage the posts in the recesses of
the second projections, and such that the modules of the adjacent
rows are locked together when returned toward a common planar
configuration.
13. A plastic belt module as in claim 12, wherein the projections,
pivot posts and recesses are so configured and arranged that to
assemble adjacent modules together in adjacent module rows, the
module of one row must be rotated through an angle of at least
about ninety degrees relative to the module of the adjacent row,
and such that the modules of adjacent rows are locked together
through angles of zero degrees to at least about ninety
degrees.
14. A plastic belt module as in claim 12, wherein the projections
of the first and second sets are tapered, narrowing from top to
bottom of the projection, thus providing a gap between the
interdigited projections of adjacent modular rows, allowing a
preselected amount of relative lateral movement between the modules
of adjacent rows when the modules of adjacent rows are angled to an
assembly configuration, and wherein the first projections have said
pivot posts only on one side of each projection, such that the
lateral movement afforded by the deeply angled adjacent modules of
adjacent module rows provides clearance for the pivot posts to be
moved laterally into alignment with the recesses of the second
projections so that the modules can be assembled, said recesses in
the second projection comprising generally cylindrical
openings.
15. A plastic belt module as in claim 14, wherein the pivot posts
have a length relative to the configurations of the projections
such that in planar configuration of adjacent rows, the pivot posts
extend into the recesses at least about 0.08''.
16. A plastic belt module as in claim 14, wherein, when the modules
of adjacent rows are rotated to an angle that is sufficient to
allow assembly of the adjacent modules, the amount of lateral
movement afforded between the interdigited modules is at least
about 0.08''.
17. A plastic belt module as in claim 14, wherein the defined
between interdigited projections when the modules of adjacent rows
are substantially at zero degrees and co-planar.
18. A plastic belt module as in claim 12, wherein the projections
of the first and second sets of projections are essentially
non-tapered, the projections of the second set each having a slot
in a lateral side of the projection, extending from a bottom of the
projection upwardly and outwardly toward the end of the projection
to an upper slot end positioned to retain a pivot post during
operation of the belt, whereby adjacent modules of adjacent module
rows can be assembled in the angled position by sliding the pivot
post of the first projections of one module up into the slots of
the second projections of the other module until the pivot posts
reach the upper ends of the slots, then the adjacent modules can be
rotated to the normal co-planar configuration.
19. A plastic belt module as in claim 18, wherein the slots are
curved.
20. A plastic belt module as in claim 18, wherein the first
projections have the pivot posts on both lateral sides, and wherein
the slots are formed on both sides of the second projections, in
the case of generally all projections.
Description
BACKGROUND OF THE INVENTION
[0001] This invention concerns modular conveyor belts formed of
integrally molded plastic modules interfitted together to form
belts of any desired length and a broad range of different widths.
The invention more particularly relates to elimination of pins or
rods that normally extend through interdigited knuckles or
projections of adjacent rows of modules to retain the rows together
to form the belt.
[0002] Conveyor belts of the general type with which this invention
is concerned are shown in KVP U.S. Pat. Nos. 5,181,601, 5,645,160,
and 5,706,934. In particular, one embodiment of the current
invention relates to a configuration shown and described in U.S.
Pat. No. 5,706,934.
[0003] All of the above patents show modular plastic conveyor belts
wherein rods or pins, sometimes very long, extend through apertures
in the interdigited knuckles or projections of modules of adjacent
rows, to hold the adjacent rows together while allowing pivoting
motion between the module rows, particularly to allow travel over a
driving sprocket or roller. Connecting rods or pins contribute to
the cost of the conveyor belt, are subject to wear, often unevenly
along the pin, and must be retained in the belt against lateral
movement and migration, as well as being removable when repair or
replacement is needed.
[0004] A modular conveyor belt manufactured by Ashworth Bros., Inc.
under the name PRESTOFLEX includes modules which snap together in
serial relationship, with deflection of the plastic material
providing for the snap-together connection. The structure of the
connection is very different from the invention described
below.
[0005] It is an objective of the current invention to eliminate
connecting rods or pins in modular conveyor belts formed of module
rows having a multiplicity of knuckles or projections extending
forward and back, with a reliable, robust and easily operated
structure.
SUMMARY OF THE INVENTION
[0006] In one embodiment, the belt of this invention has modules
with tapered knuckles or projections at forward and rear sides of
each module. These modules, similar to those of U.S. Pat. No.
5,706,934 referenced above, are for a non-radius belt that forms a
solid or substantially closed upper surface for conveying products.
The tapered configuration, with a wide top and a narrower bottom on
each knuckle or projection, provides that the modules when in
normal configuration of a continuous plane are very tight at the
pivot joints, with only very small gaps, such that conveyed
articles, even quite small, will not fall through the belt.
However, at the back or underside of the belt the narrowed
dimension of the tapered knuckles provides relatively wide open
spaces between the knuckles for cleaning; also, the tapered shape
tends to promote some self-cleaning of the hinge joint as the
module rows pivotally shift in assumed angled positions relative to
one another on a drive sprocket or roller drum.
[0007] Pursuant to the current invention, such a belt is modified
to eliminate connecting rods at the hinge lines. Instead, the
knuckles or projections at one side of the belt (forward or rear)
include integral, laterally-projecting pivot posts or dowels that
extend part-way through the gap between adjacent such knuckles.
These are connectable in interdigited fashion with the projections
or knuckles of the modules from an adjacent module row, such
modules being with apertures or recesses to receive the pivot posts
of the first module row. The modules of the two different rows can
only be assembled together into interdigited relationship (or
disassembled) when they are held at an angle relative to one
another, e.g. about ninety degrees or more acute. In that position,
the tapered shapes of the knuckles provide for some lateral spacing
and lateral movement between the module rows, enabling the pivot
posts to be positioned alongside the apertures and then extended
into the apertures as the two module rows are brought back to the
planar configuration.
[0008] In another embodiment, the projections are not tapered, but
engagement is still made with the modules of adjacent rows held at
a sharp angle. One set of projections again has pivot posts, while
the other has slots into which the posts can be inserted and, by
rotation of the modules of adjacent rows, locked into position when
the adjacent modules are rotated to planar relationship.
[0009] In the second embodiment, the slotted recesses in the second
set of knuckles preferably curve upwardly toward the end of the
module along the side of the knuckle, from the open end of the slot
at the bottom of the knuckle up to an upper position at the level
of the pivot posts in the other or first set of knuckles. In a
preferred embodiment the pivot posts extend into the slots a
minimum of about 0.10'', even when the adjacent modules are
maximally shifted laterally in the direction away from post
insertion, due to the tolerances in manufacture and the resulting
"give" for slight lateral movement of the interdigited modules. The
series of modules or module rows cannot separate because in the
planar configuration of belt travel, the modules of succeeding rows
butt nearly against each other, with the rounded projections of one
module nearly in contact with a surface between projections on the
next module. There's no opportunity in this configuration for the
pivot posts to slide back down the slots, even if the belt ceases
to be in tension. The succeeding modules are "locked" together
unless and until an operator deliberately angles the adjacent
module rows through an angle preferably more than ninety degrees,
to an acute angular orientation, at which point the one module row
can be released from the other.
[0010] With the slotted embodiment just described, the pivot posts
or dowels preferably are present on both sides of each knuckle or
projection, and the counterpart knuckles have their slots on both
sides, for greater interengagement and greater tensile
strength.
[0011] It is therefore among the objects of this invention to
eliminate the need for connecting pins or rods in modular plastic
conveyor belts, through provision of integral pivot posts that
engage with apertures or slots in modules of a succeeding module
row, the connection between the modules being made by deliberately
angling the adjacent modules or module rows. These and other
objects, advantages and features of the invention will be apparent
from the following description of preferred embodiments, considered
along with the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a perspective view showing the upper side of a
portion of a conveyor belt employing the principles of the
invention, in a first embodiment.
[0013] FIG. 2 is an exploded view showing an end view of one module
and an angled view of an adjacent module to be assembled together
with the one module, as part of a conveyor belt of the type shown
in FIG. 1.
[0014] FIG. 3 is a close-up view showing a portion of the assembly
after the two modules have been brought together from the position
of FIG. 2.
[0015] FIG. 4 is a side elevation view showing two modules or
module rows which have been assembled together at an acutely angled
orientation, prior to rotating the modules to a position in a
common plane.
[0016] FIG. 5 is a perspective view showing the upper side of a
portion of a modular conveyor belt according to a second embodiment
of the invention.
[0017] FIG. 6 is a perspective view showing a portion of the same
conveyor belt, at an edge of the belt.
[0018] FIG. 7 is a side elevation view, exploded, indicating a
module or module row about to be assembled into another module or
module row, with the adjacent modules held at an angle for
assembly.
[0019] FIG. 8 is an enlarged view showing a portion of FIG. 7, but
with the one module being advanced toward the other module such
that pivot posts of one module enter slots of the other module.
[0020] FIG. 9 is a view similar to FIG. 8, showing the one module
further advanced toward full assembly with the other module.
[0021] FIG. 10 is another view similar to FIGS. 8 and 9, but
showing the modules together with the pivot posts of the one module
fully inserted into the slots of the other module, with the modules
still held at an assembly angle.
[0022] FIG. 11 is an enlarged detail view showing two modules about
to be assembled, and showing two pivot posts on each projection of
the one module, to enter a pair of slots in projections of the
other module.
[0023] FIG. 12 is a bottom view in perspective, showing a portion
of a belt with two modules connected together in planar
configuration.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0024] In the drawings, FIG. 1 shows in a first embodiment a
portion of a belt 10 according to the invention, wherein adjacent
modules 12 and 14, or module rows, are retained together along a
hinge line 16 without connecting rods or pins. Connection between
adjacent module rows is effected with pivot posts 18 which are
integrally molded with the modules, extending laterally from
projections or knuckles 20. These projections 20 extend as a set of
essentially similar projections in one direction from a center
section 22 of the module, and another group or set of projections
24 extend in the opposition direction, both along the line of the
direction of travel. Herein and in the claims the term "first
projections" is often applied to the projections 20, and the term
"second projections" or "second set of projections" is often
applied to the projections 24. However, this is not to imply any
particular direction of travel; if there is a preferred direction
of travel, either the projections 20 with the posts 18 or the
projections 24 without such posts can extend forward in that
direction. Similarly, the terms "fore and aft" or "forward and
rearward" are merely used to differentiate the two ends of each
module (relative to the direction of travel) and are not to be
considered as limiting of the positions of the projections that
include the posts 18.
[0025] In this embodiment, the projections 20 and 24 are tapered in
shape, wider at a top surface 26 and narrower at a bottom side 28.
This is for reasons of a bottom-side open area and cleanability in
solid top conveyor belt, as explained in U.S. Pat. No. 5,706,934,
which is incorporated herein by reference. Due to the shape of the
projections in this embodiment, the interdigited modules, even
though leaving very small spaces 30 in the planar configuration
wherein the module rows are essentially co-planar as shown in FIG.
1, afford considerable lateral movement when the adjacent module
rows are folded together, to about ninety degrees or beyond, such
as shown in FIGS. 2, 3 and 4. The angularity of the tapered
projections, along with the narrow bottom end, comes into play such
that the angled sides of the projections can be nested close
together to provide a relatively large gap 32 between projections
of the interdigited modules in this preferably acutely angled
orientation, permitting some lateral shifting movement between the
modules in this position.
[0026] The opposing projections or knuckles 24 on each module 22,
as seen particularly in FIG. 1 and FIG. 4, have openings or
recesses 34 within which the pivot posts 18 become seated when the
adjacent module rows are assembled together. Although these
recesses 34 could be relatively shallow, only extending a portion
of the way through the projections 24, they are preferably through
holes.
[0027] FIG. 2 shows one module 22 at an oblique angle, preferably
rotated more than ninety degrees relative to an adjacent module 22
shown above, the two modules being in position to be assembled. The
lower module 22 is pushed up into the interdigited position of the
projections 20 and 24 as shown in FIG. 3, still in a sharply angled
position relative to each other, preferably in an acute angle
beyond ninety degrees from the normal planar configuration. In FIG.
3 (as in FIG. 2) the modules are held at a sufficiently sharp angle
that the posts 18 have cleared the wall 36 of each of the
projections 24 so as to be positioned adjacent to the aperture or
recess 34 of each of the second set of projections 24. FIG. 4 also
shows this acutely angled position of the two modules. This drawing
also shows the preferably angled or rounded shape of the edges 38
of the center section 22 of each module, for better nesting
together of adjacent modules and module rows so as to provide as
closed and solid a top surface of the belt as possible.
[0028] From the position shown in FIGS. 3 and 4, the modules or
module rows are turned back to the generally co-planar
configuration as shown in FIG. 1. As soon as a certain position of
angularity is reached, the pivot posts 18 become locked into the
apertures or recesses 34, due to the closing of the gap between the
interdigited projections as the two modules are rotated toward the
co-planar position. Once the planar position of FIG. 1 is reached,
the posts 18 extend at least about 0.06'', at a minimum, more
preferably at least about 0.08'', into each recess, to provide
adequate tensile strength in the belt.
[0029] Thus, the invention provides for simple and efficient
assembly of module rows together, without the need for connecting
pins. Although the invention is illustrated with a pair of modules
that may in themselves form the width of the belt, it should be
understood that a module row can be made up of one or several
modules. Thus, a belt might be six inches or twelve inches in
width, with a single module in each row, or it may be forty-eight
inches in width or wider, made up, for example, modules of six inch
width and twelve inch width, interleaved such that edge-to-edge
joints between adjacent modules do not continue through more than a
single row, a configuration sometimes known in the industry as
"brick-laid".
[0030] A second embodiment of the rodless conveyor belt of the
invention is shown in FIGS. 5 through 12. In this form of the
invention the modules 40 have first and second groups of link ends
or projections 42 and 44 that are not tapered. Again, this is
preferably a solid top conveyor belt as shown, for straight travel.
The belt portion 45 shown in FIGS. 5 and 6 is for illustration
only, and the belt may be assembled in any desired length and a
wide variety of widths, as in the above-described embodiment. In
FIG. 6 module row ends, to be positioned at an edge of the belt,
are shown on the modules 40. In a belt of single-module rows, these
closing ends 46 will be present at each module end, but in the
typical wider belt, the modules of adjacent rows will be
interleaved or "brick-laid" such that joints between laterally
adjacent modules are staggered rather than contiguous from row to
row.
[0031] As seen in the drawings, the non-tapered link ends or
projections 42 and 44 are assembled somewhat similarly to the above
embodiment, but not utilizing lateral gaps formed via tapering of
the projections. Instead, the second set of projections 44 each
have slots 48, the upper end of each of which acts as an aperture
or recess to seat an integral pivot post 50 extending laterally
from a projection of the first set of projections 42. Preferably,
but not necessarily, the posts 50 are formed on both sides of each
of the first projections 42, with the receiving slots 48 formed on
both sides of each of the second projections 44.
[0032] FIG. 12 shows the belt portion 45 in bottom perspective,
indicating the preferred open structure of the integrally molded
plastic module 40. Thus, deep hollows 52 are molded into the bottom
side of the center section 54 of each module. The projections 42
and 44 preferably are solid, except for the slots 48 on each side
of the second set of projections 44.
[0033] FIGS. 7 through 11 indicate the manner of assembly and
disassembly of succeeding modules in adjacent module rows. In FIG.
7 a lower module 40 is shown below and in position to be assembled
together in interdigited relationship with an upper module 40. The
drawing shows in dotted lines a wall 56, also visible in other
drawings, that forms a limiting boundary for the position of the
first projections 42 as they are moved up toward assembled
position. This wall 56, from which the second projections 44
extend, requires that the lower module be oriented at a deep angle,
preferably more than ninety degrees as shown, relative to the upper
(horizontal) module 4 assembly to take place. The wall 56 would
block entry of the pivot post 50 into the slots 48 if orientation
were angled more toward the co-planar relationship. At the same
time, this wall 56 is in very close proximity to the outer end 60
of the first projections 42 when the modules are fully assembled
and co-planar, and this closely positioned relationship can be seen
in FIGS. 5, 6 and 12. The slot 48 preferably is curved upwardly and
outwardly (toward the forward or aft end of the module), as shown
in the drawings. This again helps produce a geometry that provides
for convenient assembly and reliable locked connection when the
modules are co-planar or pass through the typical angles involved
in operation of the belt and travel around sprockets.
[0034] FIG. 8 shows the modules partially assembled, with the
integral pivot posts 50 beginning to enter the slots 48 in the
adjacent modules. The tip end 60 of the projection of the first set
of projections 42 is very close to the limiting wall 56 on the
upper module, shown in dotted lines. The lower module is at a
sufficiently sharp angle relative to the upper module that assembly
can be made.
[0035] In FIG. 9 the assembly has progressed to the point shown,
where the pivot post 50 is about halfway up through the curving
slot 48. In FIG. 10 the insertion of the lower module into the
upper module, with the projections interdigited, is complete. The
lower module has moved upwardly and outwardly relative to the upper
module, and it may not be rotated to the co-planar position of the
two modules or module rows.
[0036] FIG. 11 shows the two modules 40 in a position which may be
approximately that of FIG. 7, indicating the slots 48 at both sides
of the projections 44 and that the space 62 between adjacent second
projections 44 preferably is tapered slightly, from wider at the
bottom to narrower in the upper regions, for positive engagement
between the slots 48 and the pivot post 50.
[0037] The above described preferred embodiments are intended to
illustrate the principles of the invention, but not to limit its
scope. Other embodiments and variations to these preferred
embodiments will be apparent to those skilled in the art and may be
made without departing from the spirit and scope of the invention
as defined in the following claims.
* * * * *