Note: Descriptions are shown in the official language in which they were submitted.
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RECIPROCATING CONVEYOR
BACKGROUND OF THE INVENTION
This invention relates to slat type reciprocating
conveyors, and more particularly to an improvement over
such reciprocating conveyors typical in the art, and more
specifically, an improvement in the construction and
overall efficiency of my earlier reciprocating cor.veyor
systems.
Reciprocating slat type conveyors provided
heretofore generally have utilized groups of slats
arranged for movement both vertically and longitudinally,
or arranged for uniform movement in one longitudinal
direction and sequential movement in the opposite
direction. ~or most materials, these conveyors commonly
result in a step advance of material, followed by a
partial retraction of material as the retraction of the
slats occurs during that phase of operation.
Accordingly, these arrangements have been found to be
slow, and wasteful of time and drive power.
My earlier reciprocating conveyors disclosed in U.S.
20 Patent Nos. 3,534,875 and 4,143,760 overcame the
disadvantage6 and limitations of earlier slat type
reciprocating conveyors. However, I have discovered that
my earlier constructions involve structural features that
are not always necessary in all types of conveyor needs,
25 and are therefore less efficient in certain conveying
applications.
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SUMMARY OF THE INVENTION
In its basic concept, this invention provides a slat
type reciprocating conveyor system formed with first
alternating, laterally spaced, longitudinally
reciprocating elongated slats joined together to one
drive means for simultaneous movement, and second
alternating laterally spaced, longitudinal reciprocating
elongated slats joined together to a second drive means
for simultaneous movement independently of the first
slats, and a permanently fixed, elongated slat interposed
between said first and second reciprocating slats,
whereby all first and second reciprocating slats may be
moved simultaneously together in a load conveying
direction by operating both drives, and said first or
second movable slats may be retracted in the opposite
direction while said second or first slats, respectively,
remain stationary, and hence a load remains stationary by
being supported upon the fixed slats and one or the other
of the stationary first or second movable slats while the
other movable slats are retracting.
It is by virtue of the foregoing basic concept that
the principal objective of this invention is achieved;
namely, the provision of a slat type reciprocating
conveyor which requires only two sets of reciprocating
conveyors to conveys material in one direction without
moving the material in the reverse direction during the
retraction operation of the reciprocating slats in the
operating cycle of the apparatus.
Another important object of this invention is to
provide a reciprocating conveyor of the class described
in which the drive mechanism of the conveyor comprises
only two drive means and the drive means are of
commercially available components requiring minimum cost.
Still another object of this invention is the
provision of a reciprocating conveyor of the class
described which may be utilized as providing a truck bed
capable of operation to load material onto a truck and to
unload material from the truck as well as a conveyor that
may be utilized in conventional industrial conveyor
applications.
A further object of this invention is the provision
of a reciprocating conveyor of the class described which
overcomes the limitations and disadvantages of
reciprocating conveyors of the prior art.
A still further object of this invention is the
provision of a reciprocating conveyor of the class
described which is of simplified construction for
economical manufacture, reliability of operation and ease
of maintenance.
The foregoing and other objects and advantages of
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this invention will appear from the follo~ing detailed
description, taken in connection with the accompanying
drawings of a preferred embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a fragmentary schematic plan view of a
portion of a reciprocating conveyor system embodying the
features of this invention, parts otherwise hidden being
shown in broken lines.
Fig. 2 is a fragmentary end view on an enlarged
9cale of the conveyor of Fig. 1 illustrating a portion of
the novel, simplified construction of the conveyor bed
and its support structure.
Fig. 3 is a fragmentary end view of a bearing mount
for the reciprocating slats of the conveyor of this
invention, the broken lines indicating the installed,
operative position of the bearing mount prior to
installation of a reciprocating slat thereon.
DESCRIPTIOM OF THE PREFERRED EMBODIMENT
The reciprocating conveyor of this invention can be
utilize~ in a number of various industrial applications,
such as elongated delivery conveyors or as truck beds to
facilitate movement of material onto and off of a truck.
Regardless of its application however, the conveyor is
supported by a framework which includes longitudinally
spaced, laterally extending support beams 10 that may
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mount opposite, fixed side walls 12 as needed or desired.
The support beams 10 are embodied herein as I beams, and
are spaced apart as needed along the length of the
conveyor bed.
A plurality of longitudinally extending fixed slats
14 are secured to the support beams 10 in laterally
spaced apart positions across the width of the conveyor,
the slats extending the length of the conveyor bed. The
longitudinally extending spaces formed between the fixed
lO slats 14 receive first and second reciprocative slats 16,
18 arranged for longitudinal sliding movement in both
directions between the opposite longitudinal ends of the
conveyor. In the embodiment illustrated, the fixed slats
14 are provided with lateral e~tensions configured to
15 afford mounting for slat connectors in the form of
combination bearings and retainers for the reciprocating
slats 16, 18 as will now be described.
~ ig. 2 best illustrates the mounting arrangement for
the moving slats of the conveyor of this invention. As
20 shown, each fixed slat 14 is configured with laterally
extending horizontal end members 14' having upwardly
projecting terminal ends 14"~ A slat connector (Fig. 3)
is configured to be disposed within the groove defined by
the members 14' and 14" as shown, and an angle iron 20
25 overlies an intermediate portion 22 of the connector in
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the groove to reinforce its attachment therein. Alisned
bores (not shown) extend through the angle iron 20, the
intermediate portion 22, the slat end member 14' and the
support beam 10 in order that a bolt 24 may releasably
secure each assembly in place on each support beam.
As will be apparent in examining Fig. 2 and Fig. 3,
the slat connector embodied herein is best manufactured
by extrusion of a plastic resin having ~ low coefficient
of friction and in the shape seen in solid lines in Fig.
3. It preferably includes the notch 26 positioned to
permit the pro~ecting bearing portion 28 to be folded
down into the angular configuration shown in broken lines
in Fig. 3. In this position, the bearing portion 28
provides an angular supporting bearing surface for the
outer, tapered edges of the reciprocating slats 16, 18.
The connector also includes an opposite end segment
of generally inverted U shape which is mounted on the
upstanding terminal end 14". The upper closed portion of
the end segment 30 forms a bearing support for a
reciprocative slat 16 or 18 and the outer, downwardly
extending angular end portion 30' forms a guide for the
reciprocative slat. For this purpose, the reciprocative
slat is provided with a pair of downwardly extending
guide webs 32 which match the shape of the angular end
portions.
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Locking tabs 34 on the lowar ends of the webs 32 of
reciprocating slats 16, 18 are provided to underlie the
lower ends of the angular end porti7s 30' and thereby
secure the reciprocative slat against upward dislacement.
Thus attachment is achieved by pressing downward on the
slat to force the tabs 34 past the resilient angular end
portions 30', whereupon the latter spring back to overlie
the tabs 34.
As seen in Fig. 2, the fixed slats 14 and the
reciprocating slats 16, 18 all are configured so that
their upper surfaces are disposed at the same height,
thus forming a substantially level bed surface upon which
material may be disposed. It is also seen that the width
of the upper, material-supporting surface of the fixed
slats 14 is configured to be less than the width of the
upper surface of the reciprocating slats 16 and 18. The
purpose of this feature of construction will be explained
in detail later.
With reference again to Fig. 1 of the drawings, each
first reciprocating slat 16 is secured by a connector 36
to a common drive link means illustrated herein as a
transverse connecting drive beam 38. The other
reciprocating slats, second slats 18, are similarly
connected to each other through a second connector 40 to
a common transverse connecting drive beam 42. Thus,
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simultaneous movement of all of the first slats 16 in
both directions is permitted independently of the
simultaneous movement of the second reciprocating slats
18, and vice versa.
Drive means, illustrated herein as a pair of double
acting hydraulic cylinders 44 and 46 are each mounted at
one end to a fixed part of the framework such as one of
the lateral support beams 10. The opposite ends of the
hydraulic cylinders are connected to the respective drive
lO beams. Thus hydraulic cylinder 44 is connected to drive
beam 38 and hydraulic cylinder 46 is connected to drive
beam 42. Accordingly, extension or retraction of the
piston cylinder 44 moves all first reciprocating slat 16
uniformly and simultaneously in one longitudinal
15 direction or the other, and similar independent operation
of the other hydraulic cylinder 46 results in the
uniform, simultaneous movement of the second
reciprocating slats 18 in one direction of the other.
Interposed between adjacent moving slats 16 and 18
20 is a fixed slat 14 which does not move at any time. The
conveyor thus described may then be configured as wide as
desired simply by utilizing additional reciprocating
slats 16, 18 and fixed slats 14 as may be necessary, with
all additional slats 16 and 18 being connected to the
25 corresponding one of two hydraulic cylinders 44 and 46
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through the associated transverse drive beams 38 and 42.
Thus, with a load such as a box (not shown) disposed
on the conveyor bed at the onfeed end thereof, for
example the bottom in Fig. 1, the operation of the
5 conveyor of this invention is as follows: First, the
hydraulic cylinders 44 and 46 are both operated together
to retract the pistons, simultaneously moving the drive
beams 38 and 42, and hence all reciprocating slats,
toward the top in Fig. 1. Because the surface area of
10 the reciprocating slats 16 and 18 against the box is
significantly greater than the surface area of the fixed
slats 14 against the box, the friction of the box against
the fixed slats is not great enough to prevent it from
moving with the moving slats, and hence the box is
15 carried forward.
When the retract stroke of the cylinders is
completed, the fluid flow of one cylinder, for example
44, is reversed, and its piston is fully extended, moving
all of the slats 16 in the opposite direction (toward the
20 bottom in ~ig. 1) while the fixed slats 14 and the
reciprocating slats 18 remain stationary. Because the
combined surface area of the unmoving slats 14 and 1~
against the box is grester than the surface area of the
moving slats 16, the friction of the box against the
25 unmoving slats prevents the box from moving rearward as
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the slats 16 move rearward. Once the slats 16 are fully
retracted, they remain stationary with the slats 14 as
the slats 18 then are retracted. The box doesn't move
rear~ard for the same reason just detailed above.
Once the slats 18 are retracted, the cylinders are
again operated in unison to move all reciprocating slats
16 and 18 uniformly forward. The cycle just described
repeats continuously to move the box from the onfeed end
of the conveyor to the outfeed end.
Accordingly, it is seen that the present invention
provides a conveyor which utilizes a much simplified
construction that requires only two power sources and t~o
sets of reciprocating slats to accomplish a completely
satisfactory conveying of material. The system requires
only the longitudinal sliding movement of the two sets of
reciprocating slats, while eliminating all backward
movement of material being transported by the conveyor.
It is also apparent that the conveyor of this
invention may include various structural changes as
alternatives for parts shown in the preferred embodiment.
For example, although double acting hydraulic cylinders
as drive means are preferred for their simplicity and
efficiency, other conventional drives may be used to
engage the two drive beams 38 and ~12 for independent
movement forward and backward. Also, as an alternative
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to the addition of more rows of reciprocating and
stationary slats to increase the width of the conveyor,
the slats may be configured wider in order to maintain a
minimum number of bed slats required for a desired use.
Further, although the slat support, mounting and
bearing assemblies illustrated are preferred for their
simplicity, strength and reliability, various other
conveyor applications may require alternative assemblies
arranged to be more specifically suited to particular
10 needs, while still providing the basic construction of
the reciprocating slat conveyor of this invention capable
of operating in the manner just disclosed~
Still further, although the fixed and reciprocative
slats may be made in a variety of ways from a variety of
15 materials, it is preferred for simplicity and minimum
cost that they be made by the extrusion of aluminum or
other suitably extrudable material.
From the foregoing therefore, it will be understood
that the present invention provides a reciprocating slat
20 type conveyor that, by virtue of its novel construction,
utilizes a greatly simplified bed construction, drive
means and linkages operating in a simple manner to
provide a conveying of material without wasted movements
of the material during the conveying operation and with
25 minimum power. It is also understood that various
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changes, other than those already discussed, may be made
in the size, shape, type, number and arrangement of parts
described hereinbefore, without departing from the spirit
of this invention and the scope of the appended claims.
Having thus described my invention and the manner in
which it may be used, I claim:
