Note: Descriptions are shown in the official language in which they were submitted.
CA 02206313 1997-OS-28
WO 96/16884 PCT/AU95/OOT58
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TITLE
"END CAP ASSEMBLY FOR A ROLLER TUBE OF A CONVEYOR ROLLER"
FIELD OF THE INVENTION
THIS INVENTION relates to an end cap assembly for a roller tube of a conveyor
roller. More particularly, the end cap assembly is of the form incorporating
bearings for rotatably mounting the end cap and a roller tube on a shaft.
DISCUSSION OF THE PRIOR ART
At present, end cap assemblies for idler rollers comprise a large number of
component parts, possibly 24 separate parts in some instances. Typical end cap
assemblies also have problems associated with vibration or conveyor rattle
which
can be transferred by the steel casing of the roller bearings in the end cap
assembly and in turn to a shaft held therein. Such vibration is known to have
a
peeving effect on the shaft which is undesirable.
A further consequence of the vibration or conveyor rattle is noisy operation.
A
still further problem associated with the prior art is the need for
establishing and
maintaining an effective seal in the end cap assembly against dust entering
the
bearing or the roller.
The end cap assembly for a roller tube of a conveyor roller has as one object
thereof to substantially overcome the above problems associated with the prior
art.
BRIEF DESCRIPTION OF THE INVENTION
In accordance with the present invention there is provided an end cap assembly
for a roller tube of a conveyor roller characterised by comprising an end cap
body
proportioned to press fit within an end of the roller tube, a bearing means
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retained between the end cap body and a shaft of the conveyor roller and a
seal
means provided about the shaft and abutting an outer surtace of the end cap
body so as to restrict the passage of dust and other materials into the
bearing
means, the end cap body having an inner collar portion arranged so as to abut
in
a flexible and resilient manner the shaft of the conveyor roller projecting
therethrough, the bearing means further being retained between the end cap
body and the shaft of the conveyor roller at least in part by way of an
annular
retaining means that is fitted to the end cap body to hold the bearing means
between it and the inner collar portion of the end cap body.
Preferably, the seal means is press fitted about the shaft whereby upon
rotation
thereof the seal means rotates with respect to the end cap body.
In accordance with another aspect of the present invention there is provided a
method for the refurbishment of an existing roller tube of a conveyor roller
characterised by comprising the steps of cutting the existing roller tube
around its
circumference adjacent an end cap thereof, removing the end cap assembly and
replacing same with an end cap assembly comprising an end cap body
proportioned to press fit within the cut end of the roller tube, a bearing
means
retained between the end cap body and a shaft of the conveyor roller tube such
that an outer race thereof moves with the end cap body and its inner race
moves
with the shaft and a seal means press fitted about the shaft and abutting an
outer
surface of the end cap body.
Preferably, the seal means rotates with the shaft and abuts flexibly and
resiliently
the outer surface of the end cap body in a sliding manner.
Still preferably, the end cap body contains at least one aperture therein
allowing
passage of fluid from within the roller tube through the end cap body.
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In accordance with an aspect of the invention an end cap assembly for
a roller tube of a conveyor roller comprises an end cap body proportioned to
press fit within an end of the roller tube, a bearing means retained between
the end cap body and a shaft of the conveyor roller and a seal means
provided about the shaft and abutting an outer surface of the end cap body so
as to restrict the passage of dust and other materials into the bearing means,
the end cap body having an inner collar portion arranged so as to abut in a
flexible and resilient manner the shaft of the conveyor roller projecting
therethrough, the bearing means further being retained between the end cap
body and the shaft of the conveyor roller at least in part by way of an
annular
retaining means that is fitted to the end cap body to hold the bearing means
between it and the inner collar portion of the end cap body.
In accordance with another aspect of the invention a method for the
refurbishment of an existing roller tube of a conveyor roller comprises the
~5 steps of cutting the existing roller tube around its circumference adjacent
an
end cap thereof, removing the end cap assembly and replacing same with an
end cap assembly comprising an end cap body proportioned to press fit within
the cut end of the roller tube, a bearing means retained between the end cap
body and a shaft of the conveyor roller tube such that an outer race thereof
2o moves with the end cap body and its inner race moves with the shaft and a
seal means press fitted about the shaft and abutting an outer surface of the
end cap body, the end cap body having an inner collar portion arranged so as
to abut in a flexible and resilient manner the shaft of the conveyor roller
projecting therethrough, the bearing means further being retained between
25 the end cap body and the shaft of the conveyor roller at least in part by
way of
an annular retaining means that is fitted to the end cap body to hold the
bearing means between it and the inner collar portion of the end cap body.
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DESCRIPTION OF THE DRAWINGS
The present invention will now be described, by way of example only, with
reference to one embodiment thereof and the accompanying drawings, in which:
Fig. 1 is a perspective view of an unmodified conveyor roller having a prior
art end cap assembly fitted thereto;
Fig. 2 is a perspective view of the conveyor roller of Fig. 1 after having the
roller tube thereof cut about its circumference and having the end cap
assembly removed from about the shaft;
Fig. 3 is an exploded perspective view of the conveyor roller of Fig. 2 to
which an end cap assembly in accordance with the present invention is
being fitted;
Figure 4 is a perspective view of the conveyor roller of Fig. 2 to which an
end cap assembly of the present invention has been fitted;
Fig. 5 is a cross-sectional view of an end cap-assembly of the present
invention fitted to an end of a conveyor roller; and
Fig. 6 is an exploded cross-sectional view of the end cap assembly of Fig.
5, having the bearing means removed therefrom.
DESCRIPTION
In Figs. 5 and 6 there is shown an end cap assembly 10 comprising an end cap
body 12 of generally annular configuration, a bearing means 14 and an annular
seal means, for example an annular seal ring 16.
. The end cap body 12 comprises an outer surface 18, a recessed peripheral
surface 20, an inner surface 22 and an inner collar portion 24. The outer
surface
18 has a smooth outer edge 26 and a central annular channel 28. The peripheral
surface 20 has a shoulder 30 provided therein between the smooth edge 26 and
a substantially flat face 32.
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The inner surface 22 is substantially flat but has provided therein a recess
34.
The recess 34 forms two sealing portions 36 and 38 in which a retaining means
40 and the bearing means 14 respectively are located, as best seen in Fig. 6.
The retaining means 40 is provided in the form of an annular ring and having
provided thereon a raised rib 42 to provide positive location thereof in a
complimentary recess 44 of the sealing portion 36. A pair of annular arms 46
extend outwardly from the retaining means 40. The seating portions 36 and 38
are separated by a shoulder 48 against which the retaining means 40 is held
but
over which the bearing means 14 may pass.
The bearing means 14 comprises an outer race 50, an inner race 52 and a single
row of baCl bearings 54 held therebetween in known manner. The arms 46 of the
retaining means 40 abut resiliently and flexibly the inner race 52 and the
outer
race 50.
The inner collar portion 24 of the end cap body 12 comprises an inner shoulder
56 and a neck portion 58 projecting therefrom and in part defined by the
channel
28. The neck portion 58 has a pair of arms 60 and 62 projecting therefrom. The
arm 60 projects inwardly and abuts the inner race 52 of the bearing means 14.
The outer race 50 abuts the inner shoulder 56. The arm 62 projects outwardly
but away from the neck portion 58. The arm 62 defines the narrowest aperture
64 of the substantially annular end cap body 12.
The annular seal ring 16 has an aperture 66 described by a central surface 67.
A
recessed inner surface describes an angled shoulder 68. A peripheral flange 70
extends from a peripheral face 72 of the ring 16. The flange 70 flexibly abuts
the ,
channel 28. The central surface 67 is press fitted over a shaft 74 whereas the
flat
face 32 of the peripheral surface 20 is press fitted within a roller tube 76.
The
shoulder ~0 of the peripheral surface 20 abuts an outer end of the roller tube
76.
The space defined between the arms 60 and 62 and the shaft 74 contains a
quantity of grease for lubrication. A further quantity of grease is provided
in the
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space defined by the arm 60, the bearing means 14 and the neck portion 58,
also
for lubrication purposes. A still further quantity of grease is provided in
the space
defined by the angled shoulder 68 and the neck portion 58. In addition to the
lubrication of the bearing means 14 and the various seals created by the arms
60
and 62 and the angled shoulder 68 the grease acts to trap and prevent the
ingress of dust.
The inner race 52 of the bearing means 14 is held in position on the shaft 74
through the use of an industrial adhesive in combination with a pair of
circlips 88
provided adjacent thereto. The circlips 88 are located in a pair of channels
90
about the shaft 74. It is envisaged that the pair of circlips 88 be provided
at one
end only of the shaft 74
An inner surface 84 of the conveyor roller 78 has provided thereabout a number
of annular barbs 86. The flat face 32 of the peripheral surface 20 is able to
deform and be held in position on the roller 78. The barbs 86 are oriented to
prevent the end cap body 12 pulling free of the roller 78.
In Fig. 1 there is shown the roller tube 76 of a conveyor roller 78 having a
prior
art end cap assembly 80 fitted about the shaft 74. In Fig. 2 there is shown
the
end cap assembly 80 exploded into its various components. Further, a portion
82
of the roller tube 76 adjacent the end cap assembly is shown cut away about
the
circumference of the roller tube 76.
In Figs. 3 and 4 there is shown the fitting of the end cap assembly 10 of the
present invention to the conveyor roller 78.
In use, the end cap assembly 10 of the present invention operates by allowing
the end cap body 12 to rotate with relation to the shaft 74 through the action
of
the bearing means 14. The inner race 52 of the bearing means 14 is fitted to
the
shaft 74 and held by an appropriate industrial adhesive. As such, the roller
tube
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76 to which the end cap body 12 is fitted may rotate with respect to the shaft
74
as is required in the normal operation of the conveyor roller 78.
As has been noted above, the retaining means is held within the seating
portion
36 thereby positively locating the bearing means 14 within the seating portion
38
against the shoulder 56 and arm 60 of the end cap body 12. The annular seal
ring 16 is press fitted through central surface 67 to the shaft 74 whereby the
angled shoulder 68 and the peripheral flange 70 thereof form a flexible and
rotatable seal against the channel 28 of the outer surface 18 of the end cap
body
12.
The arm 62 of the neck portion 58 of the end cap body 12 forms a flexible
rotatable seal against the shaft 74, as can be best seen in Figure 6. This
feature
in combination with the action of the seal ring 16 and the action of the arm
60 of
the neck portion 58 serves to prevent dust and other foreign material entering
into the bearing means 14. In addition, the retaining means 40 and its
positive
location of the bearing means 14 through the action of arms 46 serves also to
prevent material entering the bearing means 14 from the inside of the conveyor
roller 78.
It is envisaged that each of the end cap body 12, the seal ring 16 and the
retaining means 40 may be formed of a polyurethane thereby making the end cap
assembly 10 particularly light but also providing the arms 46, the arms 60 and
62,
and the flange 70 with a particular degree of resilience and flexibility
allowing a
degree of resilience to be exercised in the creation of the various sealing
effects
within the end cap assembly 10 of the present invention.
The refurbishment of an existing conveyor roller 78 is achieved by the cutting
of
the roller tube 76 at a point along its circumference adjacent the existing
end cap ,
assembly 80, as can be seen in Figures 1 and 2. Once this laser cutting step
has
been completed the end cap assembly 80 is removed from the shaft 74, as is
seen specifically in Fig. 2. The end cap assembly 10 of the present invention
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may then be fitted about the shaft 74 and the end cap body 12 press fitted
within
the roller tube 76, as is shown in Fig. 5.
The bearings and the shaft of a conveyor roller 78 are consequently able to be
serviced. Further, the polyurethane material used in the construction of the
end
cap assembly 10 absorbs a large proportion of the vibration or conveyor rattle
which may be transferred from the roller tube 76 to the bearing means 14 and
the
shaft 74 thereby causing a peeving effect. There is also a consequent
reduction
in the level of sound or noise produced during normal operation of the roller
conveyor 78.
The provision of the smooth edge 26 to the end cap body 12 and effectively to
the roller tube 76 is advantageous in that it prevents unnecessary wear on a
conveyor belt running on the roller tube 76. It is envisaged that a breather
hole
or aperture (not shown) may be provided in the end cap body 12 passing from
the
inner surface 22 to the outer surface 18 thereof. This breather hole will
allow the
passage of condensed fluid from within the conveyor roller 78 to drain
therefrom.
It is further envisaged that the two end cap assemblies 10 required on each
conveyor roller 78 may be coloured differently to indicate which thereof has
provided therein the breather hole. Only that situated at the lower end of the
conveyor roller 78 will require the breather hole.
The end cap assembly 10 of the present invention provides an end cap assembly
comprising far less components than that of the prior art with a number of
integral
dust seals and which further allows refurbishment of existing conveyor rollers
78.
Modifications and variations such as would be apparent to the skilled
addressee
w
upon a reading of the specification are considered to fall within the scope of
the
present invention.
