Note: Descriptions are shown in the official language in which they were submitted.
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Express Mail No. - ER452964417US
Description
RECIPROCATING SLAT CONVEYORS
Technical Field
[0001] This invention relates to improvements in reciprocating slat conveyors
and, in particular, to the provision of slats constructed from plastic and
support
beams constructed from metal and to physical forms of both the slats and
support
beams which results in a savings in materials and a savings in installation
labor.
Background of the Invention
[0002] Reciprocating slat conveyors basically comprise elongated slats which
are divided into sets and groups. A popular reciprocating slat conveyor is
composed
of three sets and a number of groups which start on one side of the conveyor
and
extend over to the other conveyor. Each group includes one slat from each set.
That is, group I starts with a slat from set I, followed by a slat from set II
that is
followed by a slat from set Ill. This pattem is repeated from group-to-group
across
the width of the conveyor. AIl of the slats are driven together in a conveying
direction
for an interval of travel (the stroke length). At the end of the stroke, the
slats are
stopped and are then returned to a start position, one set at a time. When all
of the
slats are back to a start position, the cycle is repeated. An example drive
assembly
is disclosed by U.S. Patent No. 4,793,469, granted December 27, 1988, to
Raymond
K. Foster. This patent presents a very comprehensive description of the
operation of
the drive mechanism and the way it moves the slats of the conveyor. The
contents
of Patent No. 4793,469 is hereby incorporated herein by this specific
reference.
[0003] U.S. Patent No. 5,447,322, granted September 5, 1995, to Raymond K.
Foster, discloses a system of plastic conveyor slats and metal support beams
for the
slats.
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[0004] German Patent Publication DE 3,731,612 Al, published September 19,
1987, and naming Albert Rappen as inventor, discloses a conveyor slat (Fig.
12)
which may be constructed from plastic and a support frame which may be
constructed from metal.
[0005] An object of the present invention is to provide a reciprocating slat
conveyor that is an improvement on all of the above discussed prior art
conveyors.
[0006] An object of the present invention is to provide a conveyor composed
of a plurality of longitudinal support beams which can be easily and quickly
bolted or
riveted to subframe members and conveyor slats that can be easily and quickly
snapped into a position on the support beams.
Brief Summarv of the Inventlon
[0007] The longitudinal support beams of the present invention have a bottom,
a pair of laterally spaced apart sidewalls extending upwardly from the bottom,
and a
top comprising opposite side parts which project laterally outwardly from the
tops of
the sides. The bottom and the sides form lower comers where they meet and the
sides and the side parts of the top form upper corners where they meet. An
open
space is defined between the sides and the side parts of the top. The side
parts of
the top have outer edge portions and upwardly directed support surfaces which
extend substantially the full width of the side parts of the top.
[0008] The conveyor slats of the invention are elongated members. Some
embodiments have a downwardly projecting center portion that is sized to fit
within
the open space in its support beam. Each such conveyor slat includes side
portions
having lower surfaces which rest on the slat supporting surfaces of the
support
beams. The side portions of the slats extend laterally outwardly beyond the
outer
edges of the side parts of the tops of the support beams. Each slat has a pair
of slat
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sidewalls extending downwardly from the side portions of the conveyor slat. A
lock
flap extends upwardly and inwardly from each slat sidewall to an upper edge.
The
upper edges of the lock flaps are positioned below the side parts of the top
of the
support beam in the slat is supported on the support beam with its.central
portion in
the open space. According to the invention, the conveyor slat is formed from a
plastic material and the support beam is formed from metal.
[0009] In preferred form, the longitudinal support beam sit down on
longitudinally spaced apart transverse support beams. Fasteners connect the
bottoms of the longitudinal support beams to the transverse support beams.
[0010] Preferably, one side portion of each slat includes a longitudinally
extending, laterally outwardly projecting lip, having a lower surface. The
second side
portion of each conveyor slat has a longitudinally extending side portion with
an
upper edge that is positioned below the lower surface of the lip. When the
slats are
installed, the lower surface of the lip on one slat confronts and contacts the
upper
edge of the second side portion on the adjacent slat.
[0011] Preferably, the side portion that includes the upper edge is in the
nature of a flap that is connected at its bottom to the adjacent sidewall of
the slat.
[0012] Preferably, the lateral distance between the outer edges of the side
parts of the top is less than the lateral distance between the sidewalls of
the
conveyor slat and is greater than the lateral distance between the upper edges
of the
lock flaps when the slat is on the support beam and the upper edges of the
lock flaps
are below the outer edges of the side parts of the top of the support beam.
Preferably, the lock flaps are bendable so that the conveyor slat can be set
down
onto the support beam with the lock flaps contacting the outer edges of the
side
parts of the top of the support beam. A downward movement of the conveyor slat
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towards the support beam will cause contact between the outer edges of the
side
parts of the top of the support beam and the lock flaps. Such downward
movement
will cause the outer edges of the side parts of the top to push the. lock
flaps apart and
allow them to snap into a lock position below the outer edges of the side
parts of the
top. When the lower surfaces of the side parts of the conveyor slat are in
supported
positions on the support surfaces of the support beam, the upper edges of the
lock
flaps are positioned below the outer edges of the side parts of the top of the
support
beam.
[0013] Other embodiments of the invention includes slats that have shoulders
provided at the outer edges of the side parts of the top of the support beam.
These
slats are snapped in place and contact between the outer edges of the support
beam
and the shoulders on the slats holds the slat centered with respect to the
support
beam. The downwardly projecting center portion is omitted from these slats.
[0014] The present invention includes providing plastic slats that are slid
endwise onto the tops of the support beams, i.e. the slats do not snap down
onto the
support beams.
[0015] Other more detailed features of the invention are described in the
description of the illustrated embodiment and are particularly pointed out in
the
appended claims.
Brief Description of the Several Views of the Drawings
[0016] Like reference numerals referred to like parts throughout the several
views of the drawing, and:
Fig. 1 is a fragmentary pictorial view of an embodiment of the invention, such
view being taken from above and looking towards the top, one end and one side
of
the conveyor structure that is shown by Fig. 1;
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Fig. 2 is an exploded pictorial view of the assembly shown by Fig. 1, with the
conveyor slat for the support beam shown on the right side of the view being
omitted;
Fig. 2A is an enlarged scale end view of one of the conveyor slats;
Fig. 2B is an enlarged scale end view of one of the support beams;
Fig. 3 is a fragmentary sectional view taken substantially along line 3 - 3 of
Fig. 1;
Fig. 4 is an enlarge scale fragmentary view of a portion of Fig. 3 showing
where one side portion of a first conveyor slat meets an adjacent side portion
of an
adjoining conveyor slat;
Fig. 5 is an end elevational view showing three support beams and two slats
on an adjacent pair of the support beams, such view showing the elimination of
the
downwardly projecting center portions from the slats, such view showing the
side
edges of the two side parts of the top of the support beam closely confronting
shoulders on lower side portions of the slats. The lateral space between the
shoulders is slightly wider than the lateral space between the side edges of
the
support beams. The shoulders and side edges cooperate to maintain the slats
substantially centered on the support beams;
Fig. 6 is a view like Fig. 5, but minus the snap-on" flaps on the conveyor
slats, such conveyor slat being constructed to be slid endwise onto the
support
beams; and
Fig. 7 is a view like Fig. 6, but showing downwardly projecting center
portions
on the slats that are sized to fit within the open spaces in the support
beams.
Detailed Description of the iiiustrated Embodiment
[0017] As shown by the drawings, the embodiment illustrated by Figs. 1 -
comprises a plurality of longitudinaily spaced apart transverse frame members
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that are each a part of a substructure. A plurality of longitudinally
extending, side-by-
side support beams 12 are connected to the members 10. Each support beam 12
supports an elongated conveyor slat 14 for back and forth movement lengthwise
of
the support beam 12. In a typical conveyor, the length of the conveyor slats
14 and
support beams 12 may lie between twenty-four and forty feet. The conveyor may
be
twenty-four slats wide, divided into to three sets of eight slats per set. The
slats 14
are arranged laterally across the conveyor, a slat 14 from first set, then a
slat 14
from the second set and then a slat 14 from the third set. Then, this pattern
is
repeated all the way across the conveyor. As is well known, in use, this type
of slat
conveyor is operated to move all of the slats 14 together in a conveying
direction for
a stroke length of 10 inches to 12 inches, for example. As the slats 14 move,
they
move with them the load that is on the slats 14. At the end of the stoke, the
slats 14
are retracted, one set at a time. That is, set one is retracted to a start
position.
Then, set two is retracted to a start position. Then, set three is retracted
to a start
position. Next, all of the slats 14 are moved again in the conveying direction
for
another stroke length. This.pattern of operation is repeated until material on
the
conveyor is either loaded or unloaded, depending on the direction of
operation.
[0018] The transverse frame members 10 are shown in the form of flat bars.
However, they will most likely be I-beams or channel beams.
[0019] Referring to the drawings, the support beams 12 are in the form of
upwardly opening channels having relatively wide flanges 16, 18 extending in
opposite directions at the top of the beam 12. Each channel is formed by a
boitom
20 have inside boundaries and sides 22, 24 which extend upwardly from the side
boundaries of the bottom 20. Sides 22, 24 are spaced apart and are parallel to
each
other and are perpendicular to the bottom 20. The flanges 16, 18 form side
parts of
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a top. These side parts 16, 18 are connected to upper boundaries of the sides
22,
24. Side part 16 extends substantially perpendicular to side 22 and side part
18
extends substantially perpendicular to side 24. The corner is formed where
side
parts 16 meets side 22 and where side part 18 meets side 24. Parts 16, 22 are
connected together at corner 26 and parts 18, 24 are connected together at
corner
28. Preferably, top parts 16, 18 are thicker at the corners 26, 28 and they
gradually
become thinner as they extend outwardly to side edge portions 30, 32.
Preferably,
the center portion of the bottom 20 is thickened at its center. The support
beams 12
are preferably connected to the sub frame beams 10 by the fastener 36 that
extends
through the thickened region 34 and then through the frame members 10.
(0020] The central portion of the support beams 14 is open at the upper end of
the channel. This allows insertion of the fasteners 36 downwardly to the
bottom 20
and also permits the use of instillation tool that is inserted downwardly into
this open
space 30.
[0021 ] Fig. 2A is an end view of one of the conveyor slats 14 it has a top 32
that extends the full width of the slat 14. The bottom of the top 32 has a
central
portion 34 and side portions 36, 38. As best shown by Fig. 3, the central
portion 34
fits down into the space 30 between the corners 26, 28 at the same time, the
lower
surfaces 40, 42 on sections 36, 38 rest on the upper slats supporting surfaces
44, 46
on the side parts 16, 18 of the top of the support beam 12. Central portion 34
plugs
into the opening 30 and centers the slat 14 on the support beam 12. Flat 14
have
sidewalls 48, 50 that depend from the outer boundaries of the top 32. Sidewall
48
extends downwardly to a corner 52. Sidewall 50 extends downwardly to a corner
54.
Pair of lock flaps 56, 58 extends upwardly and inwardly from the corners 52,
54.
Lock flap 56 has a top edge 60 and lock flap 58 has a top edge 62. As shown by
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Fig. 4, when the conveyor slat 14 is installed on the support beam 12, the
side edge
portions 30, 32 of the top parts 16, 18 of the support beam 12 are positioned
between the edges 60, 62 and the surfaces 40, 38.
[0022] The conveyor slat 14 preferably comprises a plurality of longitudinally
extending ridges 70. The sides of the ridges converge from the bottom up to a
relatively sharp apex line. These ridges serve to dig into solid loads for
keeping
them straight on the slats 14.
[0023] One side of each slat 14 includes a longitudinally extending laterally
projecting lip 72 having a lower surface 74. The opposite side of the conveyor
slat
14 includes a side portion 76 that maybe in the nature of a flap having an
upper edge
78. As shown by Fig. 4, when the conveyor slats14 are installed on the support
beams 12, the lip 72 on one side of each slat 14 over hangs the edge 78 on the
opposite side of the adjacent slat 14. As best shown by Fig. 4, lip surface 74
confronts and most likely contacts edge surface 78.
[0024] The slats 100 and support beams 102 shown by Fig. 5 have the same
basic configuration as the slats 14 and support beams 12 shown by Fig. 3. A
difference is that the downwardly projecting central portion is omitted from
the slats
100. In this embodiment, the slats are centered by shoulders 104 formed in
lower
sidewall portions of the slats. In this embodiment, the upper side parts 16,
18 of the
beams 102 have opposite outer side edges 106, 108 that are positioned close to
the
shoulders 104. The sideways dimension between the edges 106, 104 is slightly
smaller than the spacing between the two shoulders 104. As can be seen, if the
slat
100 should want to move sideways, there will be contact between an edge 106,
108
and the adjoining shoulder 104 that will prevent such movement.
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[0025] Fig. 6 shows slats 110 which do not include the flaps 58, 68. As a
result, it is necessary to install the slats 110 on the beams 102 by sliding
the beams
endwise onto the upper side portions 16, 18 of the guide beams 102. In this
embodiment, the outer edges 106, 108 on the guide beams 102 are contiguous the
inside surfaces of the sidewalls 48', 50'. Again, in this embodiment, the side-
to-side
spacing of the inner surfaces of the sidewalls 48', 50' is only slightly
larger than the
side-to-side spacing of the guide beam edges 106, 108.
[0026] Fig. 7 shows a further embodiment of the conveyor slat/support beam
assembly. This embodiment is like the embodiment shown by Fig. 6 except that
the
slat 112 is provided with a downwardly projecting center portion 114 that is
like the
center portion 34 of slat 14. Each slat 112 is slid endwise onto its support
beam 102
such as the slats 100, 110.
[0027] Preferably, all of the fasteners 36 are huck bolts. Of course,
conventional bolts may be used. Also, pop rivets may be used. There are
fasteners
that can be installed from one side of a member. As shown in U.S. Patent No.
5,996,772, granted December 7, 1999, to Raymond Keith Foster, the bolts or
rivets
can be installed by a tool that is inserted down into the open space between
the
sidewalls 22, 24 of the beams 12, 102. The contents of U.S. Patent No.
5,996,772
are herein incorporated by reference.
[0028] In the embodiment shown by Figs. 5- 7, the side members 76 perform
the same function as they do in the first embodiment. Each side member 76
presents an upper edge 78 that is positioned to confront the bottom 74 of the
associated lip 72. In the embodiment shown by Figs. 6 and 7, the slats 110,
112 are
installed one at a time. For example, referring to Fig. 6, if the slat 110 on
the left is
installed when the slat 110 on the right is being installed, at the start of
the
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installation of the slat on the right, there will have to be an inward
movement on the
flap 76 so that the left side of the slat 110 that is being installed will
slide along the
flap 76 on the installed slat 110.
[0029] The illustrated embodiments are only examples of the present
invention and, therefore, are non-limitive. It is to be understood that many
changes
in the particular structure, materials and features of the invention may be
made
without departing from the spirit and scope of the invention. Therefore, it is
our
intention that our patent rights not be limited by the particular embodiments
that are
illustrated and described herein, but rather are to be determined by the
following
claims, interpreted according to accepted doctrines of patent claim
interpretation.
