Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
AXEL BUSH
FIELD OF INVENTION
This invention relates to an axel bush. More particularly, this invention
relates to an axel bush.
More particularly, this invention relates to an axel bush for attaching to an
axel in situ. Still
more particularly, this invention relates to an axel bush for an industrial
wheel, particularly a
multiple directional wheel.
BACKGROUND ART
The following references to and descriptions of prior proposals or products
are not intended to
be, and are not to be construed as, statements or admissions of common general
knowledge in
the art. In particular, the following prior art discussion does not relate to
what is commonly or
well known by the person skilled in the art, but assists in the understanding
of the inventive
step of the present invention of which the identification of pertinent prior
art proposals is but
one part.
Where it is not practical to form axel bushes in a complete cylindrical form
because the section
on which the axel bush is to be mounted on the axel is smaller in diameter
than the diameter of
the axel beyond the section, axel bushes must necessarily be either moulded on
to the axel
section or formed from longitudinal halves that may be joined together to form
the bush on the
axel. This may also be the case where the axel is non-removably mounted, so
that the axel
bush cannot be slid on to the axel mounting section as there is no access to
the either end of the
zo axel. Accordingly, there is a need for an improved axel bush that can be
mounted to an axel
where it is not possible to slide the axel bush on to the axel mounting
section via either end of
the axel. Prior art proposals have included forming the axel bush from two
halves that can be
joined together in situ. However, such prior art bushes tend to fail along the
join line, the so-
called coin-purse split or separation of the components along the join line
under pressure.
In discussing the word -axel" or -axel", it will be appreciated that the bush
of the invention is
adapted to attach to other shafts and rods for useful purposes
An object of the present invention is to ameliorate the aforementioned
disadvantages of the
prior art or to at least provide a useful alternative thereto.
STATEMENT OF INVENTION
The invention according to one or more aspects is as defined in the
independent claims. Some
optional and/or preferred features of the invention are defined in the
dependent claims.
1
Date Recue/Date Received 2020-04-17
Accordingly, in one aspect of the invention there is provided:
an axel bush formed by joining edges of component parts together to form a
generally
cylindrical bush by joining the component parts along the joinable edges, the
joinable edges
following a line that is at least partially non-parallel to the longitudinal
axis of the generally
cylindrical bush.
In another aspect, the invention provides:
an axel bush for mounting on a mounting section of an axel, the axel bush
formed from
multiple parts that are adapted to join along at least one longitudinal edge
to form the axel
bush, wherein the longitudinal edge is at least partially non-parallel to the
longitudinal axis of
the axel.
In another aspect, the invention provides:
Complementary component parts of a bush for an axel that fit together around
the axel, the
component parts each having at least one opposing joining edge following a
substantially
curved path.
Preferably, the component parts slide into engagement and are trapped together
against radial
parting, provided that the respective ends of the assembled bush are axially
retarded to resist
axial movement of the component parts relative to each other.
In another aspect, the invention provides:
a split bush formed by joining component parts along at least one join line,
characterised in that
zo the join line follows a curved path.
The longitudinal edge of the parts of the axel bush may follow a curved or
irregular line or a
combination of both. The curved line may be helical, spiral, S-shaped, wavy
and/or radiused.
The irregular line may comprise straight sections connected by sharp angle
transitions. The
irregular line may be jagged, including having a Z- or V-shape, in which the
sharp angle
transitions are at least 90 .
Typically, the bush may be retained on an axel and trapped against
longitudinal displacement
of the component parts relative to each other.
Preferably, the join line is spiral or helically shaped. The curved join line
is effective to resist
splitting of the bush under pressure.
The present invention may be used where the axel configuration does not allow
a bush to be
placed on the axel, except where the bush is a split bush. The curved joining
edges of the
2
Date Recue/Date Received 2020-04-17
component parts may follow a spiral pathway so that the component part
partially wraps
around the axel. The semi-circular end wall of the component part at a first
end may be offset
by about 60 - 110 compared to a second opposed end. The component parts may
comprise
two joining walls. When viewed in end elevation, the extremity of a first
joining wall at the
first end may be close to the extremity of a second joining wall at the second
end, so that the
spacing between the extremities from an axial end view is smaller than the
diameter of the
axel. The spiral path of the joining walls may be sufficiently acute that each
component part is
adapted to wrap around the axel, so that the component cannot easily be
removed from the axel
by laterally moving the component part away from the axel but maintaining the
component part
in coaxial relationship to the axel. The component part may only be removed by
extricating one
component part end, shifting the component part on an angle to allow the mouth
defining the
second end to release the axel from the second end mouth.
Locating protrusions may extend tangentially from each of the facing edges.
The protrusions
may form part of the wall of the bush components. The protrusions may have
facing and
.. abutting surfaces that are aligned parallel to one another. Each end of the
bush component may
be a semi-circular shape. Each semi-circular end may be adapted to engage with
an opposed
component part to form a complete circular end wall of a cylinder. The
protrusions may extend
towards the direction of approach of a complementary component part.
At least one section of the joining or longitudinal line may be an angled
section set at an angle,
preferably a sharp angle, relative to the curved joining edge. The angled
section may be a flat
section that may extend parallel to the longitudinal axis of the formed bush.
The flat section of
each component part may be effective to prevent counter-rotation of the
component parts about
the longitudinal axis, so that when the bush is assembled on an axel and is
axially trapped, the
component parts do not slide along the join line relative to each other and do
not rotate relative
to each other.
Preferably the flat section is at the end of the join line. Advantageously,
each component part
includes a flat section adapted to oppose and abut a corresponding,
complementary flat section
of a complementary component part. The flat section may form part of the join
line.
Alternatively, the join line may be wholly curved. Preferably, the flat
section is adjacent to the
curved join line.
The join line is preferably formed by opposing curved surfaces. The opposing
surfaces
preferably comprise laterally flat seats that follow the curved path. The
opposing laterally flat,
longitudinally curved, seats of each component part are adapted to abut to
form complementary
seats for each other.
The component parts may each include an engagement section. The engagement
sections may
3
Date Recue/Date Received 2020-04-17
be complementary and adapted to engage an opposing engagement section of
another
component part. The engagement section may include a ramp section. The ramp
section may
comprise opposing and abutting surfaces that lie in planes between 0 and 110
relative to the
direction of approach of the opposing component part. In this way the ramp
sections may slide
passed each other as cam surfaces into abutment. The ramp sections may form
part of head
portions that are adapted to be trapped behind an opposing head in a recess of
the other
component part. The ramp sectons therefore engage each other with minimal
distortion. The
ramp sections do not snap into engagement but slide into abutment to create a
resistant catch.
However, due to the relative geometry of the spiral component part body that
may be adapted
to partially wrap around the axel, the engagement sections trap the component
parts in
engagement because the parts cannot be pulled laterally or radially away from
each other as the
angle of removal and the planes of the ramp sections are offset from the angle
of withdrawal
that would be necessary to separate the component parts.
The flat or ramp section may permit movement of the component parts of an
assembled bush
relative to each other under load. Permitting relative movement of the
component parts whilst
securely maintaining their engagement enables the bush to distort under load
without the
component parts separating or the bush otherwise failing. If the component
parts were
positively engaged so that distortion of the engagement means and potential
disengagement
would result on application of heavy loads, the bush might fail or the
engagement means might
zo snap in and out of engagement under load, thereby causing an unwanted
clicking noise.
Preferred embodiments of present invention may overcome this problem by
allowing the bush
to distort and shift slightly along the joining line without the component
parts separating.
The ramp section may be effective to hold the component parts together at the
join line against
compression forces that would otherwise cause the component parts to split or
separate. This is
.. achieved by providing opposing surfaces that resist counter- rotation of
the component parts
about the longitudinal axis of the bush. The flat or ramp sections also act as
a catch to hold the
bush together by axially restriction of the bush at either end, so that the
component parts cannot
axially slide and rotate relative to each other.
A wheel member or tyre may be molded on to the bush after the bush has been
assembled on
an axel. The tyre may be a roller tyre. The roller may form part of a multiple
directional wheel.
However, other applications are envisaged as being within the scope of the
invention. The
generally cylindrical bush may include external surface features to assist in
gripping the
interior surface of a roller or other component to be molded thereto. The
surface features may
include undulations, protrusions, grooves, knobs or ridges. The ridges or
grooves may follow a
curved or irregular line or a combination of both. The curved line may be
helical, spiral, S-
shaped, wavy and/or radiused. The irregular line may comprise straight
sections connected by
sharp angle transitions. The irregular line may be jagged, including having a
Z- or V-shape.
4
Date Recue/Date Received 2020-04-17
Preferably the surface features comprise one or more longitudinal ridges. The
longitudinal
surface features may extend parallel to the longitudinal axis of the completed
or generally
cylindrical bush. The longitudinal surface features may be regularly
circumferentially spaced
from each other around the outer surface of the axel bush.
The external surface features may be in the form of protrusions or
indentations. The external
surface features may be effective to facilitate adherence of a mold material
thereto. The
protrusions are preferably longitudinal ribs. The longitudinal ribs may be
circumferentially
spaced around outer surface of the barrel of the assembled bush. The component
parts may
comprise separate portions of the external surface features that align and are
completed on
joining the component parts. Thus each component part may include portions of
a rib that is
only completed on joining the component parts.
The contour of the longitudinal ribs preferably provide longitudinal
structural strength. The
longitudinal ribs are preferably configured to displace roller material so
that less roller material
is required to fill the space between the outer bush surface and the outer
roller surface. The
external surface features also permits careful control of the thickness of the
roller wall molded
onto the bush. This may be important with regard to performance
characteristics, such as
structural integrity during repeated, possibly high load, use, ride quality
and/or noise
minimisation of a wheel incorporating the bush.
Where one or more separate internal bearing are required, these may be in the
form of split
zo bearings. The split bearings may comprise two or more bearing parts,
such as a pair of halves,
that together form the bearing. The internal surface of the bush may
accommodate the bearings
as a housing. The bush housing may provide means for permitting overmolding of
the split
bearings. The bearing may be accommodated by internal surface features, such
as an annular
seat groove formed in the internal wall of the bush. The internal surface
features may be
completed on assembly of the component parts. Portions of the internal surface
features may be
located on separate component parts which align to complete the internal
surface features when
the bush is assembled. The internal surface features may be longitudinally
spaced to
effectively trap the bearings and ensure that they remain properly spaced
along the length of
the axel and the bush.
The bush may be formed from component parts that are hinged or connected along
one or more
permanent longitudinal joins, and are joinable together at another pair of
opposed longitudinal
edges circumferentially spaced from the permanent longitudinal joins. The
component parts
may comprise two parts. The two parts may be permanently hingedly connected,
and have
mating longitudinal edges circumferentially spaced from the permanent
longitudinal
connections. The component parts may comprise two separate parts mateable or
joinable
together to form the generally cylindrical bush. The component parts may be
identical and
5
Date Recue/Date Received 2020-04-17
include mutually engageable complementary parts.
The joinable or mateable edges may form the mutually complementary engageable
parts, such
as male-female tongue and groove parts, protrusions and recesses for trapping
the protruding
parts. The engageable or joinable parts may include, in profile and extending
longitudinally
along the respective edges, a head, or bayonet or arrow head-shaped male
mating or protruding
portion having a protruding edge that transitions into a ramp surface of the
ramp section. The
ramp surface may be inclined at an angle to a radial line extending from the
longitudinal axis
of the completed bush cylinder. The ramp section may terminate with a detent
wall in the form
of a flat broad structure behind the head, bayonet or arrow head ramp section
that directly faces
io an opposing broad flat surface on an opposing component part. The bayonet
or arrow head or
ramp section may be connected to a semi-cylindrical wall of a component part
by a narrow
neck, whereby a recess is defined by the flat broad detent wall, the internal
surface of the bush
facing towards the radial centre of the semi-cylindrical wall and forming part
of the neck, and a
broad face of the end wall of the cylindrical wall facing axially. These
structural and surface
features together define a recess for receiving and/or trapping a head
portion, in profile, formed
at the terminal edge of the joining edge of the opposed component part.
Other male-female engageable or complementary, friction fit parts are
envisaged as falling
within the scope of the invention.
The axel bush may comprise an internal bore that includes internal surface
features that are
zo adapted to either engage with an axel for a driven roller or wheel, or may
comprise a smooth
bore to permit rotation of the bush relative to the axel.
The completed and assembled bush formed from the component parts may comprise
a
generally cylindrical core, pipe or tube and external surface features in the
form of longitudinal
ridges or ribs. The external surface features may have a greater radial height
towards their
middle centre and may taper towards the outer surface of the generally
cylindrical core, pipe or
tube. Accordingly, in side elevation the outline of the axel bush may be
generally fusiform in
silhouette.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may be better understood from the following non-limiting
description of
preferred embodiments, in which:
Figures la-lb are perspective views of a first embodiment of an axel bush
according to
one aspect of the invention comprising a tongue and recess locating system, 16
outer
ribs and a helical joining edge;
6
Date Recue/Date Received 2020-04-17
Figures 2a-2b are perspective exploded views of the embodiment shown in
Figures la-
lb;
Figure 3 is a perspective view of an axel bush made according to a third
embodiment,
comprising a bayonet catch, 16 outer ribs and a helical joining edge, that is
mounted to
an axel of a wheel frame of a multiple directional wheel;
Figures 4a-4b are end perspective views of the axel bush shown in Figure 3;
Figure 5a is a perspective view of the axel bush shown in Figure 3, removed
from an
axel;
Figure 5b is a perspective view of the axel bush shown in Figure 3 partially
mounted on
the axel shown in Figure 5a;
Figure 6 is a perspective view of the axel bush shown in Figure 3-5b mounted
on an
axel;
Figure 7 is an end perspective view of the axel bush shown in Figures 3 - 6
with its
component parts separated;
Figure 8 is an end perspective view of the axel bush shown in Figures 3 - 7;
Figure 9 is an end perspective view of one component part of the axel bush
shown in
Figures 3 - 8;
Figure 10 is a perspective view of a part of a wheel frame on which are
mounted axel
bushes made according to a third embodiment comprising a smooth outer surface
and a
Z-shaped joining edge;
Figures 1 la-lid are perspective views of a component part of an axel bush
made
according to a fourth embodiment comprising 8 ribs and a helical joining edge;
Figure 12 is a perspective view of two component halves of an axel bush made
according to a fifth embodiment comprising a bayonet catch, 10 outer ribs and
a Z-
shaped joining edges;
Figure 13 is a side elevation of a component part of the axel bush shown in
Fig. 12;
Figure 14a is a side elevation of the component part of the axel bush shown in
Figure
13 mated to an identical part;
Figure 14b is an end elevation of the assembled axel bush shown in Figure 14a;
7
Date Recue/Date Received 2020-04-17
Figure 15 is an end elevation of a component part of an axel bush according to
a sixth
embodiment comprising a bayonet catch, 10 outer ribs and a helical joining
edge;
Figure 16 is a side elevation of the component part shown in Figure 15;
Figure 17 is a perspective view of the component part shown in Figures 13;
Figure 18 is a second perspective view of the component parts of the
unassembled axel
bush shown in Figure 12;
Figure 19 is a perspective view of an assembled axel bush formed from the
component
parts shown in Figures 12 and 18;
Figure 20 is a side view of the completed axel bush shown in Figure 19an
assembled
axel bush according to an eighth embodiment similar to that shown in Figure
19, but
comprising ribs having flat ends;
Figure 21 is a perspective view of an assembled axel bush according to an
seventh
embodiment similar to that shown in Figure 19, but having ridges terminating
in
straight rather than angular ends;
Figure 22 is an end view of the completed axel bush shown in Figure 21;
Figure 23 is a side view of the completed axel bush shown in Figures 21 ¨ 22;
Figure 24 is a side view of a completed axel bush according to an eighth
embodiment
featuring a bayonet catch, 8 longitudinal ridge outer surface features having
straight
edged terminal ends and Z-shaped joining edges;
Figure 25 is a perspective view of the axel bush shown in Figure 24;
Figure 26 is a perspective view of an unassembled pair of component parts of
the axel
bush shown in Figures 21 - 23;
Figure 27 is an end view of the completed axel bush shown in Figures 24 - 25;
Figure 28 is a perspective view of an unassembled pair of component parts of
the axel
bush shown in Figure 24;
Figure 29 is a perspective view of an assembled axel bush made according to a
ninth
embodiment comprising a bayonet catch,16 longitudinal ridge or rib portions on
its
outer surface, with the rib portions alternating between raised and lower
profile rib
portions and Z-shaped joining edges;
8
Date Recue/Date Received 2020-04-17
Figure 30 is an end view of the completed axel bush shown in Figure 29;
Figure 31 is a side view of the axel bush shown in Figures 29 and 30;
Figure 32 is a perspective view of the unassembled component parts of the axel
bush
shown in Figures 29 - 31;
Figure 33 is a perspective view of a bush according to a preferred embodiment;
Figure 34a is a perspective view of a cylindrical bush according to one
embodiment;
Fure 34b is a perspective view of a component part of the bush embodiment
shown in
Figure 34a from two different perspectives, emphasising that identical
component
halves form the bush of Figure 34a;
Figure 35a is a perspective view of a cylindrical bush according to another
embodiment
in which end flats and catches have been added to the embodiment shown in Fig.
34a;
Fure 35b is a perspective view of a component part of the bush embodiment
shown in
Figure 35a noting that identical component halves form the bush of Figure 35a;
Figure 36a is a perspective view of a cylindrical bushwith an overmolded
roller
according to another embodiment in which ribs have been added to the
embodiment
shown in Fig. 35a;
Fure 36b is a perspective view of a component part of the bush embodiment
shown in
Figure 36a noting that identical component halves form the bush of Figure 36a;
Figure 37a is a perspective view of a cylindrical bush including axially
spaced bearings
according to another embodiment; and
Fure 37b is an exploded perspective view of the parts of the bush embodiment
shown in
Figure 37a noting that identical component halves form the bush of Figure 37a
and
provide a housing for the axally spaced split bearings.
DETAILED DESCRIPTION OF THE DRAWINGS
Preferred features of the present invention will now be described with
particular reference to
the accompanying drawings. However, it is to be understood that the features
illustrated in and
described with reference to the drawings are not to be construed as limiting
on the scope of the
invention.
Figures la - 2b show a first embodiment of the invention in the form of an
axel bush 10
9
Date Recue/Date Received 2020-04-17
comprising a cylindrical core 12, a pair of identical component parts 14a,b
mated or joined to
each other along a pair of helically curved edges 16. The curved edges 16
comprise tongue and
groove interconnecting parts 18a,b. An outer surface 13 of the cylindrical
core 12 has sixteen
longitudinally aligned ribs 19.
Each component part 14a, 14b comprises a pair of helically curving side edges
16 that are
perfectly complementary to opposing helically curved edges on the other mating
or joining
component part 14a, 14b. Each component part 14a, 14b is identical. At one end
of the
component part 14a, 14b, adjacent the helically curved edge 16, there is a
male protruding
tongue 18b that extends beyond the flush surface of the helically curved edge
16. At the
opposed end of the component part 14a,b, the respective helically curved walls
16 terminate
with a recess 18a that is complimentary to the protrusion 18b. Both the
protrusion 18b and the
complementary recess 18a are adjacent the inner surface of the cylindrical
core 12. The
component parts 14a, 14b are held together in situ in an engaging or joining
position by the
male and female engagement means, the tongue and recess parts 18a, b. The
radial
compressive forces caused by molding a roller thereon or thereabout the bush,
so that the
inward radial compressive force urges the component parts 14a, 14b to counter
rotate relative
to each other along their helical join lines, is resisted by the flat sections
adjacent the tongue
and recess parts that ensure that the component parts 14a,b the axel bush 10
does not counter
rotate and remains assembled. The curved walls 16 of the respective component
parts 14a, 14b
zo therefore remain joined together whilst compressive forces are applied
to the bush. These
forces may be deflected and disseminated along the curved join line of the
edges 16, so that
localisation of loading at any one point along the edges 16 is reduced and
failure of the axel
bush 10 is minimized.
Figure 3 shows an axel bush 30 made according to a second embodiment mounted
to a wheel
frame manufactured and supplied by Rotacaster Wheel Limited. Prior to
assembly, the bush 30
is comprised of two identical halves. The component halves are placed around a
cylindrical
axel 32 mounted and extending between wheel frame head posts 34. A roller (not
shown) may
then be moulded around the axel bush 30 as described in WO 2004014667, the
entire contents
of which are hereby imported herein.
.. Referring to Figures 4a-9, the second embodiment of the axel bush 30
comprises a pair of
identical halves 44a, b that are adapted to engage together by allowing the
engagement of
bayonet or arrowhead, or abutting ramp members 38b that comprise an inner
inclined ramp
surface 41 and a narrow neck 42 that connects the arrowhead or ramp member 38b
to the wall
of the semi-cylindrical core structure 43. The arrowhead structure or ramp
member 38b is
.. provided at the end of each component part 44a, b adjacent one longitudinal
side or edge 45a of
each component part. An opposed edge 45b to the edge 45a comprises
complimentary
engagement or joining structures 38a in the form of a substantially square
shaped (in profile)
Date Recue/Date Received 2020-04-17
head behind which extends an outwardly inclined recess surface 47 that is
adapted to slidingly
receive and trap the arrowhead ramp member 41, whilst the neck recess 48
defined by the
arrowhead ramp member41, neck 42 and the end surface of the semi-cylindrical
core wall 43,
respectively receive and trap the square head 38a for an exceptionally strong,
friction resistant
engagement at both adjoining edges 45a, b of each of the component parts.
Preferably, the
material used to form the respective component parts 44a, b is typically
acetal. Taking into
consideration the wall thickness and rib structures 39 and the rigidity to the
bush structure
imparted by the ribs 39 in the longitudinal direction, because the mating
parts 18a,b are not
positively engaged but merely form a resistance fit, the component parts 44a,
b may be
io mounted on the axel 32 by hand. It is envisaged that the component parts
44a, b are made from
extremely rigid material, such as steel, so that the mating of the component
parts with a cam or
ramp surface engagement allows the bush to be assembled without the need for a
radially
compressive tool to achieve the assembly of the axel bush 30 on the axel 32.
It is noted that
the rib structures 19 extend longitudinally along the outer surface of the
axel bush 30 and
provide reinforcement to the overall structure of the core 43. To remove the
bush from an axel,
wherein the component parts 14a,b are axially trapped against counter rotation
relative to each
other, a tool may be helpful to urge the ramp sections 18a,b out of
engagement, although this
may be advantageously done by hand.
Referring to Figure 10, there is shown a third embodiment of an axel bush 50
that comprises a
zo substantially cylindrical structure 52 formed of identical component
parts 54a, b in which the
joining line 56 therebetween is formed from a continuous curved edge. The
exterior surface of
the component parts shows the appearance of the end flat sections that
transition between an
intermediate angular section with shallow angled corners s 58.
It is noted that the third embodiment does not feature ribs longitudinally on
the outer surface of
the axel bush 50.
Figures ha-llb show a fourth embodiment in the form of component parts 64 of a
axel bush
60. The component part 64 is adapted to engage with an identical component
part 64 along
curved side walls 66 which together located and join into abutting
relationship by tongue and
recess guides 68a-b.
In Figures 12 ¨ 14b there is shown a fifth embodiment in the form of an axel
bush 70
comprising a pair of identical half component parts 74a, b that are adapted to
mate together by
engagement of bayonet engagement means or ramp sections 78a, b. The z-shaped
outer side
edges 76 comprise a middle inclined section 76b extending between outer
straight edges 70a,c
running substantially parallel to the longitudinal axis 71. However,
preferably these straight
edges obscure the curved joining edges or seats against which the component
halves rest and
abut when the bush is assembled.
11
Date Recue/Date Received 2020-04-17
The longitudinal ribs 79 feature a shallow arc shape in which the intermediate
portion 71a
shallowly rises relative to the respective end portion 3 lb and this follows
the truncated
fusiform shape of the rollers moulded thereon. The respective rib ends 72
comprise an
inwardly inclined wall to form small, sharp angled protrusions whereby to
better secure the
roller molded thereon and thereabouts, so that some of the molded roller
material extends
radially inwardly relative to the outer most extent of the longitudinal rib
79.
Turning to Figures 15 and 16, there is shown a sixth embodiment in the form of
an axel bush
80 in which only one component part 84 of a pair of component parts 84 is
shown and
demonstrates graphically the arrowhead or ramp engagement portion 88a and
bulbous head
portion 88b. In Fig. 15, the end elevation view illustrates that the opposed
end portions
88a,88b almost completes a full wrap around an axel that has the same diameter
as the internal
diameter 81 of the part 84. A small opening 89 is provided that permits the
single component
part 84 to be mounted on to the axel. The component part 84 must be tilted at
an angle offset to
the axel axis to permit the part 84 to be mounted onto the axel. Once mounted,
the part 84
hangs on to the axel in a lose resistance fit, but does require a small amount
of force to be
dislodged. However, if the part 84 is made sufficiently rigidly, it is not
possible to remove the
part 84 from an axel without tilting same relative to the axel axis.
Referring to Figures 21-23 and 26, there is shown an axel bush 90 comprising
10 outer
longitudinal ribs 99 and a pair of identical component parts 94a, b joined
along a curved
joining surface obscured by the shallow z-shaped line of the outer edges 96a-
c.
In Figures 24, 25, 27 and 28 there is shown an eighth embodiment in the form
on an axel bush
100 comprising eight outer longitudinal ribs 109 and identical component parts
showing a
shallow z-shaped outer longitudinal edge 96 that obscures a spiral-shaped join
line or seat. It is
considered that the straight end walls 97 that extend normally to the
longitudinal axis 101
facilitate the moulding process for the molding of a roller onto the axel bush
100 as all
components, primarily the outer surface 107 of the cylindrical core 103 do not
present any
-cul-de-sacs" into which roller moulded material must be forced or allowed to
move over time.
In relation to Figures 29 - 32, there is shown a ninth embodiment in the form
of an axel bush
110 comprising 8 large and radially tall longitudinal ribs 119, alternatingly
interposed
circumferentially around the axel bush cylindrical core body 112 with low
profile longitudinal
ribs 129. The low profile ribs 129 extend a greater length along the outer
surface 115 of the
core 112 but their shallow height permits the outer profile of the roller to
be tapered towards
each end of the roller. The radially taller and circumferentially wider ribs
119 provide
substantial rigidity and strength for the central region 126 of the core 112.
The ends 132 of the
low profile ribs 129 taper towards the outer surface 115, whereas the ends 134
of the tall ribs
119 end abruptly in an end wall 128 similar to the wall 108 of the eighth
embodiment shown in
12
Date Recue/Date Received 2020-04-17
Fig. 24. The inner surface 134 of the core 112 defines a cylindrical bore and
snugly receives
an axel whilst permitting rotation of the axel bush 110 relative to the axel
32.
The bayonet or arrow head or ramp section 118a extends radially at least two-
thirds of the
thickness of the core wall 112a. The core wall is preferably between 50 and
100%, preferably
60- 80% of the radius of the bore113. The neck136 extending between the arrow
head or ramp
section 118a and the core wall 112a is radially about 30 to 80%, preferably 40
- 60%, of the
thickness of the core wall 112a, and the bulbous head 118b is correspondingly
or
complementarily so dimensioned whereby to be snugly trapped in the recess 117
defined by the
arrowhead or ramp section 118a, the neck 136 and the broad end wall 112b of
the core wall
112a.. The bayonet or arrow head or ramp section 118a includes a ramped
surface that is
inclined at an angle of about 30 - 70 , preferably 40 - 50 relative to a
radial line extending
from the axel bush 110 axis 111.
Each component part 114a,b includes a pair of the Z-shaped joining side edges
116 that extend
longitudinally and parallel to the bush axis 111 from the bayonet head 118a
apex or tip 138
along a straight edge wall 116a at the side of the core wall 112a. The
straight edge extends to a
first corner point 140 past one end 128 of the tall ribs 119. The first corner
point 140 provides
the transition from an axially parallel wall edge 116a to an inclined edge
wall 116b extending
through an intermediate region of the side wall 116. This structure permits
minor relative
movement along the adjoining surfaces 116 and alleviates the focussing or
localisation of such
forces which would otherwise form fatigued and weak structural points. Yet the
bush 110
retains its integrity due to the strong engagement of structures 118a,b.
The inclined intermediate joining edge 116b transitions at a second corner
point 142 at the
other end of the component part 114a,b into another axially straight edge 116c
that is parallel
to the first straight edge 116a.
Turning to Figure 33, there is shown an assembled roller 200 comprising a
cylindrical bush 210
having eight external rib surface features 212 and an over-molded roller 230.
The joining edge
214 of the opposing component parts 216,218 comprises, in axial end profile, a
ramp section
220 comprising a ramp surface 222. The ramp surfaces lie in planes that are
parallel or slightly
offset by 1 - 20 to the direction or angle of approach of the respective
opposed component
part 216,218 immediately prior to engagement, so that the ramp surfaces 222
are adapted to
slidingly engage across ramp surfaces in a resistance, rather than snap, fit.
This arrangement
forms a catch that will hold the part halves 216,218 together during an over-
molding process as
long as the ends of the bush are retarded against axial displacement. This
achieves a resistant
catch that does not have a -hard" snap feature.
The ramp 220 configuration allows the joined halves 216,218 to move when the
bush 210 is
13
Date Recue/Date Received 2020-04-17
under a load that causes distortion that would otherwise fail a -snap" design
(one where mating
parts must deflect or distort to permit engagement). The present embodiment
eliminates the
-clicking" sound that can be characteristic of bushings under load where the
snap engagement
continually fails and resets as the load shifts with transit.
With reference to Figures 34a-b, there is shown a basic bush configuration
210a in which
identical component halves 216a,218a combine to form the bushing 210a. This
demonstrated
by showing that component part 216a may be rotated to face "itself" thereby
presenting
opposing parts that may be combined to form the cylindrical bushing 216a. The
bushing 210a
may be over-molded with roller material to achieve a split bushing 210a that
does not -coin
purse" apart under pressure.
In Figures 35a - 35b, there is shown a more developed bushing 210b that is
formed by the
joining of two identical component halves 216b,218b that include, at their
respective end
joining surfaces, flat segments 224b adjacent the end of each helical seat
226b. The flat
segments 224b are effective to resist counter-rotation of the component parts
216b,218b which
would otherwise allow the parts to move longitudinally on each other. The flat
segment 224b
also contains resistance fit engagement features 228b,229b that temporarily
hold the parts
216b,218b together prior to over-molding of the bushing 210b with roller
material.
Figures 36a-36b show more elaborate bushing 210c over-molded with a roller
230c. The bush
210c has a contoured body featuring longitudinal ribs 232c that provide both
strength as well
zo as systematic displacement of roller material and roll thickness control
of roller 230c material
that is molded over the combined identical bush halves 216c,218c.
Referring now to Figs. 37a - 37b, there is shown a bushing 210d that is used
to provide a
housing 210d where a series of split bearings 240d is required. The combined
bush 210d
comprises internally annular seats for the assembled bearings 240d. Not only
does the bush
210d provide a housing, but also provides longitudinal strength, a means to
keep the bearings
240d properly axially spaced and a means to provide over-molding of the roller
material whilst
keeping the split bearings240d together.
Throughout the specification and claims the word "comprise" and its
derivatives are intended
to have an inclusive rather than exclusive meaning unless the contrary is
expressly stated or the
context requires otherwise. That is, the word "comprise" and its derivatives
will be taken to
indicate the inclusion of not only the listed components, steps or features
that it directly
references, but also other components, steps or features not specifically
listed, unless the
contrary is expressly stated or the context requires otherwise.
In the present specification, terms such as -apparatus", -means", -device" and
"member" may
refer to singular or plural items and are terms intended to refer to a set of
properties, functions
14
Date Recue/Date Received 2020-04-17
or characteristics performed by one or more items or components having one or
more parts. It
is envisaged that where an -apparatus", -means", -device" or -member" or
similar term is
described as being a unitary object, then a functionally equivalent object
having multiple
components is considered to fall within the scope of the term, and similarly,
where an
¶apparatus", "assembly", "means", "device" or "member" is described as having
multiple
components, a functionally equivalent but unitary object is also considered to
fall within the
scope of the term, unless the contrary is expressly stated or the context
requires otherwise.
Orientational terms used in the specification and claims such as vertical,
horizontal, top,
bottom, upper and lower are to be interpreted as relational and are based on
the premise that the
component, item, article, apparatus, device or instrument will usually be
considered in a
particular orientation.
It will be appreciated by those skilled in the art that many modifications and
variations may be
made to the methods of the invention described herein without departing from
the spirit and
scope of the invention.
The invention can be described in terms of provisional claims that can assist
the skilled reader
in understanding the various aspects and preferments of the invention.
However, these
provisional claims are not to be construed as defining statements of the
invention. It will be
appreciated that other forms, aspects and preferred features of the invention
and its
embodiments described herein may ultimately be included in the claims defining
the invention
zo in the specifications of complete, international or national
applications (or their subsequent
corresponding patent grants) that may claim priority from the provisional
application
accompanying this specification. In this context, the following non-limiting
claims assist to
better describe the invention:
Date Recue/Date Received 2020-04-17
