Note: Descriptions are shown in the official language in which they were submitted.
CA 02486050 2005-02-24
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BRAKE DRUM STACKING METHOD
AND BRAKE DRUM WITH DRUM STACKING STRUCTURE
Back round
S The present invention relates to a method of stacking brake drums for
storage or shipment
and to brake drums with a drum stacking structure.
With reference to Fig. 1, a plurality of brake drums, some of which have been
numbered
as 10, are shown strapped by metal straps, one strap being indicated at 12, to
a pallet 14 for
shipment. In. Fig. 1, there are five layers of brake drums respectively
indicated at 16, 18, 20, 22
and 24. Each layer or level of brake drums in Fig. 1 is comprised of five
brake drums, one on
each corner of the layer with one brake drum positioned in the center of the
four corner drums.
The bottom layer 16 of brake drums rest on an upper surface of pallet 1. The
other layers 18, 20,
22 and 24 of brake drums each rest on a respective sheet of plywood (26, 28,
30 and 32)
positioned between the respective brake drum layers. A top plywood sheet 34
rests on the upper
surfaces of the brake drums of the upper layer 24. The straps typically pass
over the top of upper
sheet 34. Given the dimensions of bake drums in certain applications, such as
for heavy duty
trucks, each of the plywood sheets 26, 28, 30, 32 and 34 typically is
approximately one half sheet
of plywood. Although in theory the plywood could be returned to the brake drum
shipper for
reuse, this would involve shipping costs. In addition, often times the plywood
is simply not
returned and new plywood must be obtained for subsequent shipments of brake
drums. This
involves significant costs.
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In another common approach, each layer has four drums with one drum being
positioned at each corner of the layer.
Therefore, a need exists for improved brake drums with stacking features and
for an improved method of stacking brake drums. The present invention is
directed
toward new and unobvious aspects of a brake drum with stacking features and
brake
drum stacking method acts, both alone and in various combinations and
subcombinations with one another and as set forth in the claims below.
Summary
I 0 One embodiment of a brake drum comprises: an annular body having a first
longitudinal axis and comprising an exterior surface and an interior surface,
the body
having an annular wall portion with a right cylindrical interior brake
engaging first
wall surface, the first wall surface having a longitudinal axis which is
coaxial with the
first longitudinal axis, the first wall surface having a first diameter, the
wall portion
I 5 comprising an exterior second wall surface which is opposed to the
interior first wall
surface, the body also comprising an annular-first rim portion extending
between the-
first and second wall surfaces and in a plane which is perpendicular to the
first
longitudinal axis; a plurality of rim supporting lands at the exterior surface
of the
body, the lands defining segments of a rim-supporting shelf which is spaced
from the
20 first rim portion, a respective lateral motion limiting wall surface
associated with each
land and projecting in a direction away from the rim portion, the lateral
motion
limiting wall surface being positioned inwardly of the associated land, the
maximum
cross-sectional dimension between the lateral motion limiting wall surfaces in
a lateral
direction perpendicular to the first longitudinal axis being less than the
first diameter,
25 whereby the rim portion of a first brake drum may be positioned on the
lands of a
second like brake drum with the lateral motion limiting wall surfaces of the
second
brake drum being inserted into the interior space defined by the first wall
surface of
the first brake drum; and the lands extending radially outwardly from the
first
longitudinal axis such that lateral shifting of the first brake drum relative
to the second
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drum in a lateral direction is limited by the lateral motion limiting wall
surfaces of the
second brake drum and prevents the rim portion of the first brake drum from
shifting
laterally off the lands of the second brake drum.
As another aspect of an embodiment, there may be three of said lands and the
lands may be spaced 120 degrees apart about the first longitudinal axis.
The lateral motion limiting wall surfaces may each project upwardly from the
associated land. In addition, at least a portion of each of the lateral motion
limiting
wall surfaces may angle inwardly moving in a direction away from the
respective
lands and away from the rim portion.
More specifically, each of the lateral motion limiting wall surfaces may each
angle inwardly along its entire height.
The angle may be at least 3 degrees relative to a plane parallel to the first
longitudinal axis and which intersects the location where the lateral motion
limiting
wall surface projects from the associated land. Desirably, the angle is from 3
degrees
to 45 degrees. A particularly desirable range of angles is from 25 degrees to
35
degrees, with 30 degrees being a specific exemplary angle. .The lateral motion
limiting wall surfaces may each angle continuously .in a radially inward
direction from
the associated land. The lateral motion limiting walls may also be arcuate.
In accordance with an embodiment, a first brake drum comprises an annular
body having a longitudinal axis and comprising an exterior surface and an
interior
surface, the body having a wall portion with a machined annular interior brake
engaging first wall surface of a first radius about the longitudinal axis and
being of a
first diameter, the body comprising an exterior secozad wall surface which is
opposed
to the interior first wall surface, the body conr~prising an acmular rim
portion e~aending
between the first anal second ~~ali s~.zrfaces9 the body fi.art.her comprising
a ~sim
supporting shelFat the e~te.rioe s~xrfaee cf'th~: body which is spaced from
the riz~a
portion and which is lsositione:d a.rvu~ ~.~ix~vensioned to receive;
ar°xd support a rim p~Wio~~
of a second brake dr~arzv ~~rhich is like thF. first i~ral~e drum ~r~hen the
second brake dr~rr~
is stacked onto the first brake drm; and the exterior surface comprising a
stop which
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is operable to limit shifting of the stacked second brake drum in a direction
perpendicular to the longitudinal axis so as to prevent the rim portion of the
second
brake drum from falling off the shelf of the f rst brake drum.
As another aspect, the shelf may comprise a plurality of spaced apart shelf
segments. The shelf segments may be spaced apart an equal distance about the
first
longitudinal axis.
As a further aspect, the stop comprises a plurality of stop surfaces each
associated with a shelf segment, the stop surfaces being located tangent to a
circle
having a second diameter which is less than the first diameter; and the shelf
segments
being located tangent to a circle having a third diameter which is greater
than the first
diameter.
The difference between the third and second diameter is desirably greater than
the difference between the first and second diameter such that the brake drum
rim
portion remains on the shelf when shifted the maximum allowable extent in any
lateral
1 S direction perpendicular to the first longitudinal axis.
A brake drum may comprise: an annular -body; the body comprising a rim
portion; brake drum rim portion supporting means for receiving and supporting
the
rim portion of another like brake drum when said brake drum and said another
like
brake drum are stacked; and said support means further comprising means for
limiting
the Lateral shifting of the stacked brake drums to maintain the rim portion of
the
another brake drum on said support mEans of said brake drum.
In accordance with an embodiment, a pallet of brake drums comprises: a
plurality of stacks of brake drums at least three brake drums high positioned
one on
top of another with no plywood sheets or other layering material between the
adjacent
2~ layers of brake drums. The pallet may fuzther comprise a top layer
overlaying the top
of the brake drums of the stacks a~~d ~~t least one coupler suc h as a strap
tying the top
layer to the pallet tc ~°etair~~ tire top laye~° r~ position.
A method of stacking brake cl~~~a~r~s fnr storage or shipment in oxaa~,
embo~.lin~ent
comprises: positionic-sg a lower ri.rr~ potaao~ c~~'~b fig°st crake
drurr~ onto apt upwardly
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facing supporting shelf of a second brake drum with the first brake drum being
stacked
onto the second brake drum; and limiting lateral shifting of the first brake
drum
relative to the second brake drum to prevent the rim portion of the first
brake drum
from laterally shifting off of the supporting shelf of the second brake drum.
The
limiting act may further comprise the act of engaging the interior of the
first brake
drum upon lateral shifting of the first brake drum to limit the lateral
shifting of the first
brake drum.
The first and second brake drums are desirably nested together with the
interior
of the first brake drum receiving a portion of the exterior of the second
brake drum
when the rim portion of the first brake drum is supported on the shelf of the
second
brake drum.
At least three brake drums may be stacked in accordance with the method into
a stack of brake drums.
As an aspect of a method, at least four stacks of at Least three brake drums
per
stack may be on a pallet, a protective layer may be placed on top of the at
least four
stacks with the stacks sandwiched between-the pallet and the protective layer,
and the
protective layer may be coupled, such as by strapping, to the pallet.
Detailed Description of the Drawings
Fig. 1 is illustrates a plurality of brake drums stacked for shipment on a
pallet
with sheets of plywood used to separate layers of brake drums.
Fig. 2 is a top exterior ~~iew of one embodiment of a brake drum with drum
stacking features.
Fig. 3 is a vertical sectional view of the brake drurr~ of Fig. 2 taken along
lines
3-3 of Fig. 2.
Fig. 4 is an enlarged view of a portion of the brake drum of Fig. 3, the
portion
having been labelLd in Fig. :1 with the designa~:ior~ Fig. ~.
Fig. 5 is an enlarged mirror ir~mge vieva of ~ porti~~~~ of she brake drum of
Fig,
3, the portion having been labeled in Fig. 3 with the designatiorf Fig. ~.
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Fig. 6 illustrates an embodiment of a method of stacking of three brake drums.
Fig. 7 illustrates a plurality of brake drums stacked fiJr shipment in
accordance
with an embodiment of a method disclosed herein.
Detailed Description
Fig. 1 illustrates an embodiment of a brake drum 40 provided with one form of
stacking structure which allows a plurality of brake drums to be stacked one
on top of
another. The brake drum 40 is described by way of example only, as the
invention is
not limited to this particular embodiment of a brake drum or to the specif c
forms of
stacking structures shown and described herein. Body 40 typically comprises a
monolithic one-piece body formed, for example, by casting. Body 40 rnay be of
any
suitable material which is used for brake drums, such as materials used in
brake drums
currently available from Consolidated Metco, Inc., of Portland, Oregon, with
cast iron
being a specific example.
1 S Brake drum 40 comprises an annular body 42 having an exterior s~uface 44
and an interior surface 46 (see Fig. 3)Body 42 has a longituadinal axis:4$ and
a
central circular opening 50 centered on the longitudinal axis.
The body 42 further comprises a sidewall portion 52 and a top or end portion
54. A transition portion 56 extends between the end portion 54 and side wall
portion
52.
The side wall portion 52, following machining of a casting to provide a brake
drum engaging surface, comprises a right cylindrical interior first wall
surface 60
having a longitudinal axis which is coaxial with axis 4$. 'Wall portion 52
also
comprises an exterior wall surface 62 which is opposed tc~ the wall surface
60. In this
case, opposed siwply means that wall surface 62 is outside of the drum and is
generally across the wall 52 from surface f0. The body 4? else comprises an
annular
rim portion 7U extendi~-ug between wall surfaces 60 and 62 pat a lowe~°
po;~ir~za x>f the
brake drum sh3wn in Fig. 3. IZim portion 70 is desirably planar and, in Fig.
3, is
shown located in a g~lar~e ~72. Desirably, rim portioa~ 70 is continuous
abot~.t the entire
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periphery of the wall. Therefore, in this example, the brake drums do not have
to be
rotated to a particular relative orientation prior to stacking as explained
below.
The diameter D2 of annular surface 60 is variable and depends upon the
specific configuration of the brake drum being manufactured. As one specific
example, the interior diameter of the side wall of the casting, prior to final
machining,
may be 16.32 inches plus or minus 60 thousandths. Thus, the range of the
interior
diameter of the unfinished casting would be from 16.26 to 16.38 inches.
Following
machining to provide the brake engaging surface 60, an exemplary dimension of
diameter DZ for this example is 16.5 inches in diameter plus or minus 10
thousandths
(from 16.49 to 16.51 inches). It should be noted that references to terms such
as
parallel and perpendicular in this description allows for some variation, such
as
permitted by tolerances associated with brake drum manufacture.
With reference to Fig. 2, a brake drum stacking structure is provided in the
exterior surface 44 of the brake drum and particularly in the; end surface of
the brake
drum. This brake drum stacking structure desirably provides support for the
rim
portion 70 of one brake drum when stacked onto ahe .stacking structure of a
second
similar brake drum.
In the illustrated embodiment, one such brake drum stacking structure
comprises a plurality of spaced apart lands, such as three lands 100, 102 and
104,
positioned adjacent to the perimeter of the brake drum 40. The illustrated
lands 100,
102 and 104 project above the adjacent surface 44 of the brake dnun. For
example,
the dashed line 106 in Fig. 4 illustrates the adjoining surface of the brake
drum
adjacent to land 100 and shows how land 100 projects above such adjacent
surface of
the brake drum. The lands 1fl0, 102 and 104, because three such lands are
provided,
define a three point support for the riza~. portion 70 of a brake drum
stack.e~d onto the
lands. Therefore, a stable suppork is provided inasmuch as three points define
a plane.
It is to be understood that tl~e, provision of a plurality of la~~ds
poitionesl tc~ de~tae
segments of a rirn supporting sl-aelf is a particularly desirable emboc~iment_
However,
the lands 100, 102 and 104 rra.ay be replaced by other rirn suppf~rtir~g
str~xct-~re, s~ac;h as
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a continuous shelf which extends about the entire periphery of the brake drum,
although this would be less desirable. In addition, the Lands 100, 102 and 104
may be
of extended length (e.g., encompass a greater arc about the axis 48). As a
specific
example, and although variable, the lands 100, 102 and 104 may be from 318 to
i inch
Long.
As best seen in Figs. 2 and 3, if one were to position the outer peripheral
edge
of each land inside a circle 110, ( portion of circle 110 is shown in dashed
lines in
Fig. 2), which is tangent to such outer surface of the lands, the diameter of
this circle
may be expressed as D3. In addition, a stop structure is provided radially
inwardly of
the lands 100, 102 and 104. In the embodiment of Figs. 2 and 3, one form of
stop
structure comprises a respective wall or step riser surface 120 associated
with land 100
and spaced radially inwardly from the land 100, a wall or step riser surface
wall 122
associated with land 102 and spaced radially inwardly from land 102, and a
wall or
step riser surface 124 associated with land 104 and spaced radially inwardly
from land
104. If one were to draw a circle, such as indicated in part by dashed lines
130 in
Fig. 2, which is tangent to the location where the respective walls 120; 122
and 124
project upwardly from the associated lands 100, 102 and 104, the diameter of
this
circle may be expressed as D~. The stop or motion limiting surfaces may take
different configurations from those shown in Fig. 2. For example, they may
extend
about the entire periphery of the brake drum, although this is less desired.
In addition,
the step riser surfaces rnay be of the same length as the associated lands
100., 1 U2 or
104, or they may be longer or shorter. In addition, the motion limiting
structures may
be placed intermediate the Lands or at some other location as they need not
be: placed
immediately adjacent to a land, although the positioning shown in Fig. 2 is a
particularly desirable construction.
The height of the stops is desirably sufficient to resist lateral sliding
rnotic~n of
one drum relative to another dram when said one drum is stacked ora the other
dr~i.rrt.
Lateral sliding motion refers to lateral rrzotior~ ira a directi~az~ in a
plane perh°nrlirula~: to
the longitudinal axis 48. T he. height ofthe stops may be varied. Typically,
the height
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is at least 1/8 inch and desirably from 1/4 to 3/8 of an inch, although again
it may be
varied. This height is indicated by the letter H in Fig. 4.
The width of the supporting Lands 100 is also variable. However, the lands
extend radially (in width) a sufficient distance to continuously- support the
rim portion
70 of a stacked drum as one drum shifts the maximum extent in any lateral
direction.
Specifcally, circle 130 is sized smallenough for stacked drums to nest
together with
an interior volume defined by wall surface 60 of an upper drum receiving the
respective walls 120,122 and 124 with wall surface 60 being adjacent to wall
surfaces
120, 122 and 124. Thus, D~ is less than D2 to allow this nesting. In addition,
the
difference between diameters D1 D2 and D3 are such that the maximum lateral
shifting
of a stacked drum as permitted by the respective wails or stops i 20, 122 and
124 does
not allow the rim portion 70 to slip off the supporting ledges 100,102 and
104.
In the example being discussed above, with a finished ID of wall 60 being 16.5
inches plus or minus 10 thousandths, an exemplary dimension for circle 130 is
16.36
inches plus or minus 60 thousandths (thus from 16.3 inches to 16.42 inches).
In
addition, an exemplary dimension of circle 110, the outer diameter. of the
shelf, is
17.52 inches minus 60 thousandths (thus 17.46 inches to 17.58 inches). In
addition,
although variable, the width of rim portion 70 may be: about 0_75 inch.
In the illustrated embodiment, it is desirable that D3 minus Di is greater
than
D~ minus DZ. Again, the relative dimensions and configuration of the shelf and
lateral
motion limiting structure may be cha~~ged while still preventing the rim 70
from
slipping off of the supporting shelf when a stacked drum laterally shifts.
With reference to Fig. 4, it is desirable that the lateral motion limiting
wall
surfaces, e.g., wall surfaces 120, 122 and I24, be sloped such as indicated by
the angle
B in Fig. 4. That is, desirably at least a portio~a arid rt~ore desirably the
entixc svarface
of such walls are sloped or angled to shift radiaily inwardly rr3o~>ing ire a
direction
away from the associated land. Desirably, axigle B is at least 3 degrees and
may iange
from 3 to 6 degrees to 45 degrees as a, sp~;ciFr example, alihough,,h this may
be varied.
A particularly desirable range would be ~r~as~ ?~ d~:grees t~c~ 3a degrees
v~~ith 30 degrees
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being a specifically desirable example. By sloping the walls 120, 122 and 124
in this
manner, as the rim portion 70 of one brake drum is stacked onto another brake
drum,
the sloping walls tend to guide the rim portion onto the lands.
In Fig. 4, the land 100, as well as the lands 102 and 104, may be in a common
plane, such as indicated by plane 150 in Fig. 3. Also, plane 150 may be
parallel to
plane 72. Alternatively, lands 100 may slope, for example slightly upwardly or
downwardly in Fig. 4.
Fig. 5 illustrates a portion of the transition region 56 at a location where
no
land 102, 104 or 106 is positioned. This transition region may assume other
configurations.
Fig. 6 illustrates a stack of three drums 40 positioned one on top of the
other
with the rim portion of one drum supported by the supporting shelf portion of
a lower
drum. The illustration of Fig. 6 also shows a method of stacking at least
three drums,
for example for storage.
1 S Fig. 7 illustrates a pallet 160 containing a plurality of stacks of brake
drums.
In the example of Fig. 7, two such stacks are shown with each stack containing
four
brake drums. The stacks may include, for example, three to five drums in each
stack.
The pallet 160 may be sized to contain, for example, one stack of brake drums
at each
corner of the pallet (for a total of four stacks of brake drums). Irr an
alternative
approach, five stacks of brake drums rnay be included on the pallet with one
stack
being in the center and the other four stacks arranged at the comers of the
pallet and
around the center stack of brake drums. As can be seen in I~ ig. 7, the
stacked brake
drums are placed one on top of another with the rim portion of the lowermost
brake
drum of each stack being placed on the pallet 160. A.lthout;l~ nor requixed,
desirably in
the embodiment of Fig. 7, a top protective layer 162, such. as of ljZ~~-wo~cly
overlies ~:he
top surfaces of the uppermost brake drums in the stacks. ~'r~.us, tl~c
sta~;l~s of brake
drums are sandwiched between layer 162 and the pallet I60. '1'l~e layer 162
may be
coupled to the pallet 160 by any suitable coupling approaclx. In ~ ig. 7; a
strap 164 (of
exaggerated thickness) is shown thread~;d l~cneath the upl:~er suprt portion
of the;
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pallet, extending upwardly along the two sides of the stacked brake drums, and
across
the tog of the layer 162. Typically, a plurality of straps are used (e.g., two
straps along
each side of the stacked brake drums).
Having illustrated and described the principles of our invention with
reference
S to several desirable embodiments, it should be apparent to those of ordinary
skill in the
art that these embodiments may be modified in arrangement and detail without
departing from the inventive concepts disclosed herein. We claim all such
embodiments which fall within the scope and spirit of the following claims.
