Note: Descriptions are shown in the official language in which they were submitted.
20297~
Title: BEARING FREE WHEEL AND RELATED
IMPROVEMENTS TO PALLET FLOW STORAGE SYSTEMS
Inventors: Michael William Arthur Leyland and
Gerard Michael Downs
Assignee: FLOW-RITE INC.
BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates to material handling and storage
equipment for commercial and industrial warehousing applications,
and in particular relates to an improvement to gravity feed pallet
flow storage systems.
Descri~tion of the Prior Art
. .
Material handling and storage equipment in some form is
widely used in industrial warehousing applications.
Escalating real property values and corresponding
increased space rental charges have led to an increased use of
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202975~
high density material handling and storage systems to reduce space
requirements. Common among these in applications where materials
are conveyed on pallets, are gravity feed pallet flow storage
systems. These systems typically employ a high density storage
arrangement requiring significantly reduced storage area due to
the reduced requirement for aisle space between adjacent rows of
stored material. These systems are designed so that material can
be fed in one end of the storage system and removed from the other
end without the necessity for accessing the material at
intermediate points. This is accomplished by provlding parallel
rows of conveying means configured with little or no space
therebetween.
The rows of conveying means can also be stacked
vertically to provide further increase in the density of the
storage system. The conveying means are typically inclined with
the input end of the system being vertically disposed higher than
the output end of the system, thus providing a gravity feed means
of conveying said material.
A multiplicity of wheels typically provide the rolllng
means and the support means for the palleted material. To date,
wheels lncorporating bearings have been used to provide thls
.
rolling and support means. The lncorporatlon of bearlngs lnto
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20297~
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these wheels was thought necessary in order to reduce the inherent
friction associated with the system and to thereby facilitate
movement of the pallets.
The use of bearinged wheels, however, presents certain
problems. In warehousing applications where a high degree of
moisture is present or in applications where routine cleaning of
the conveying means by pressurized water or some other appropriate
method is typically employed, deterioration of these metal wheel
bearings is often encountered. In addition, bearinged wheels are
expensive to manufacture.
It would, therefore, be desirable to have a gravity feed
high density material handling and ætorage system that utilized
bearing free wheels that could be fabricated entirely without
metal components, thereby eliminating the moisture related
problems described, as well as, reducing the entire cost of the
systems.'
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SUMMARY OP THE INVENTION
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It is an ob~ect of the present invention to provide a
bearing free wheel suitable for use in replacing the bearinged
wheel typicallY employed in gravity feed high density material
handling and storage systems.
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It is a further ob~ect of the present invention to
provide a bearing free wheel that provides improved durability
characteristics and reduced maintenance problems in applications
where moisture is encountered.
It is still a further object of the present invention to
provide a bearing free wheel that provides satisfactory rolling
performance in the conveyance of palleted materials.
It is still a further ob;ect of the present invention to
provide a bearing free wheel that is less expensive to manufacture
than the bearinged wheel typically employed in such systems.
Thus, in accordance with the present lnvention, there is
provided a wheel to be used in gravity feed high density material
storage and handling systems that contains no bearings and, which
contains no metal components, and which incorporates means to
adequately reduce frictions between said wheel and ad~acent
components.
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Further features of the invention will be described or
will become apparent in the course of the following detailed
description.
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BRIEF DESCRIPTIO~ OF THE DRAWINGS
In order that the invention may be more clearly
understood, the preferred embodiment thereof will not be described
in detail by way of example, with reference to the accompanying
drawings, in which:
Fig. 1 is an end view of the invention.
Fig. 2 is a typical end view showing configuration of
pallet, track and wheel.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to figure 1, there is shown an end view of the
bearing free wheel 1 and the related support structure consisting
of the track rail 2, axle 3, washers 4 and bottom ties 5.
The bearing free wheel 1 has an appropriately
dimensioned opening at its geometric centre to permit the axle 3
to be inserted. The axle 3 is then inserted into openings on the
parallel track rails 2. The holes in the track rails 2 are
positioned so that the axle 3 and wheel 1 together project a
specified distance above the upper surface of the track rail 2.
Bottom ties 5 are inserted and mechanically secured to each track
rail 2 so as to ensure that a consistent relative distance between
the track rails 2 is maintained. The number and position of these
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20297~9
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bottoms ties 5 is variable and dependent on the specific storage
application.
In the described embodiment of the present invention the
wheel 1 is fabricated from a suitable non-metallic material such
as polypropylene. During fabrication, a suitable lubricant such
as silicone is impregnated into the substrate used to form the
wheels, and in operation this lubricant migrates to the axle 3,
thereby and providing lubrication between the axle 3 and the wheel
1.
Additional or alternative means of reducing system
friction would include adding a suitable material to the axle 2,
by means of a coating or impregnation process. Such sultable
material could be teflon or other suitable material that would
provide reduced friction between the axle 3 and the wheel 1.
Reduced friction between these components could also be
achieved by inserting a sleeve fabricated from a suitable low
friction material into the wheel 1 thereby reducing the friction
between the axle 3 and the wheel 1. Suitable material for this
application would be nylon impregnated molybendeum.
Referring to figure 1 and figure 2 a possible physical
configuration of the wheels and support structure can be seen.
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This configuration involves a staggered wheel pattern consisting
of three inch diameter wheels supported on axles which are spaced
having their centres two inches apart.
Figure 2 shows three parallel tracks configured
underneath a typical pallet. The number of tracks employed and
the relative positions thereof is variable and dependent on the
characteristics of the palleted material, including the overall
dimension of the pallet, the overall weight of pallet and conveyed
materials etc.
The shape and dimensions of the wheel 1 for any
particular application is also variable. Figure 1 shows a wheel 1
having a slightly crowned rolling surface. An alternative
embodiment of the present invention would include a bearing free
wheel 1 with a flatter rolling surface providing additional
surface area in applications requiring increased weight bearing
ability.
