Note: Descriptions are shown in the official language in which they were submitted.
SOUND DAMPENING CONVEYOR CHAIN FLIGHT
FIELD
[0002] The present invention relates to a chain and flight conveyor for use
in conveying
material in the mining industry and, in particular, to an improved design of a
chain and flight
conveyor. Still more particularly, this invention relates to conveyor chains
for continuous miners
and chain haulage units.
SUMMARY
[0003] Conveyor flights with various coatings have been attempted in the
past. The primary
reason for these coatings was for noise control. While the coatings have been
shown to reduce
conveyor noise by 5-10 dBA, these materials wore off of the flights relatively
quickly and were
determined not to be of sufficient value for commercial use on continuous
miners or longwall
equipment. The coatings compressed beyond their working limit and began to
tear and chuck
out. One of the reasons for this failure is that the coating was too thin.
There is a limited amount
of space available on the conveyor for the flight bars, so in order to make
the coating thicker, the
integrity of the existing flight is compromised.
[0004] Urethane coating on conveyor chain flights has proven effective in
reducing the noise
exposure of continuous miner operators. Problems preventing widespread
acceptance of this
solution include the cost of implementation and maintenance of the chain, the
durability of the
urethane coating, etc.
[0005] The most successful urethane-coated flight design to date is a
standard forged steel
conveyor flight, which is machined down to reduce its thickness and thus allow
room for the
urethane coating. The machined-down flight is then used as a flight core,
which is encapsulated
in the urethane coating. However, the coating is thinner than desired, and the
corners of the steel
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flight cause stress concentration on the urethane coating. The end of the
flight nearest the chain
is currently enlarged and has holes to fit the chain pins. The urethane
coating is undesirably thin
due to the enlarged end of the flight.
[0006] The flight core is welded integrally to the chain flight section,
which is a part of the
chain assembly. Replacing a flight due to loss of the urethane coating is
expensive and difficult.
If more than a few flights have lost their urethane coating, it is not
economical to repair the
chain, and the entire chain must be replaced.
[0007] An independent object of this disclosure is to provide a conveyor
chain having
replaceable urethane-coated flights. With a conveyor chain having replaceable
urethane-coated
flights, it is then possible to replace damaged urethane coated flights in a
few minutes with
minimum downtime of the continuous miner.
[0008] In one independent embodiment, a conveyor flight for a chain
includes at least two
spaced apart links, and two side plates that connect the links, with each side
plate including two
spaced apart extension pins extending from the side plate. The flight may
include a metal
support, and the metal support may include two spaced apart cylindrical
portions adapted to
receive the two spaced apart extension pins. The flight may also include a
flexible casing
surrounding the metal support.
[0009] In another independent embodiment, a flight is provided for a chain
flight assembly
of a conveyor chain, the chain flight assembly including a pair of parallel
flight pins spaced apart
by a distance, each pin having a length, a pair of spaced apart, parallel side
plates mounted on the
pins, and at least one flight. The flight may generally include a flight core
including an arm and
a pair of parallel tubes spaced apart by the distance, the arm being between
and coupled to each
tube, each tube having a first end and a second end, and a flight coating
encapsulating and
secured to the core, the coating including a first end and a second end, the
first end including a
pair of openings. The core and the coating may form a unitary flight, the
unitary flight being
connectable to the pins, the first end of each tube being adapted to receive a
portion of the length
of an associated pin, each opening in the coating being adapted to receive
therethrough a portion
of the associated pin.
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[0010] In a further independent embodiment, a chain flight assembly of a
conveyor chain is
provided. The assembly may generally include a pair of parallel flight pins
spaced apart by a
distance, each pin having a length, a pair of spaced apart, parallel side
plates mounted on the
pins, and at least one removable flight. The flight may include a flight core
including an arm and
a pair of parallel tubes spaced apart by the distance, the arm being between
and coupled to each
tube, each tube having a first end and a second end, and a flight coating
encapsulating and
secured to the core, the coating including a first end and a second end, the
first end including a
pair of openings. The core and the coating may form a unitary flight, the
unitary flight being
removably connectable to the pins, the first end of each tube removably
receiving a portion of
the length of an associated pin, each opening in the coating receiving
therethrough a portion of
the associated pin.
[0011] In yet another independent embodiment, a chain flight assembly of a
conveyor chain
is provided. The assembly may generally include a pair of parallel flight pins
spaced apart by a
distance, each pin having an outer surface and a length, a pair of spaced
apart, parallel side plates
mounted on the pins, at least one removable flight including a pair of
openings spaced apart by
the distance, each opening having an inner surface and removably receiving an
associated pin,
and adhesive between the inner surface of each opening and the outer surface
of the associated
pin to removably connect the flight to the pins.
[0012] In another independent embodiment, a method of assembling a chain
flight assembly
of a conveyor chain is provided. The method may generally include providing a
pair of parallel
flight pins spaced apart by a distance, each pin having a length, mounting a
pair of spaced apart,
parallel side plates mounted on the pins, providing at least one flight, the
flight including a flight
core including an arm and a pair of parallel tubes spaced apart by the
distance, the arm being
between and coupled to each tube, each tube having a first end and a second
end, and a flight
coating including a first end and a second end, the first end including a pair
of openings,
providing including encapsulating the core in the coating to form a unitary
flight, and after
encapsulating, removably connecting the unitary flight to the pins including
removably receiving
a portion of the length of an associated pin in the first end of each tube,
and removably receiving
a portion of the associated pin through each opening in the coating.
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BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a partial perspective view of a conveyor including a chain
and flights.
[0014] FIG. 2 is a perspective view of one flight including an internal
core and an external
urethane coating.
[0015] FIG. 3 is a perspective view of the internal core shown in FIG. 2.
[0016] FIG. 4 is a perspective view of an alternate embodiment of the
internal core shown in
FIG. 3.
[0017] FIG. 5 is a partial perspective view of an alternate embodiment of a
conveyor
including a chain and flights.
[0018] FIG. 6 is a perspective view of an alternative embodiment of a chain
flight assembly.
[0019] FIG. 7 is an exploded perspective view of the chain flight assembly
shown in FIG. 6.
[0020] FIG. 8 is a perspective view of a core of the chain flight assembly
shown in FIG. 6.
[0021] FIG. 9 is a perspective view of an external coating for the chain
flight assembly
shown in FIG. 6.
[0022] FIG. 10 is a perspective view of another alternative embodiment of
the chain flight
assembly.
[0023] Before any independent embodiments of the disclosure is explained in
detail, it is to
be understood that the disclosure is not limited in its application to the
details of the construction
and the arrangements of components set forth in the following description or
illustrated in the
drawings. The disclosure is capable of other independent embodiments and of
being practiced or
being carried out in various ways. Also, it is to be understood that the
phraseology and
terminology used herein is for the purpose of description and should not be
regarded as limiting.
Use of "including" and "comprising" and variations thereof as used herein is
meant to
encompass the items listed thereafter and equivalents thereof as well as
additional items.
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Further, it is to be understood that such terms as "forward", "rearward",
"left", "right", "upward"
and "downward", etc., are words of convenience and are not to be construed as
limiting terms.
DETAILED DESCRIPTION
[0024] A conveyor 10 including a chain 14 and flights 18 is shown in FIG.
1. The flight 18
includes sound dampening material in the form of a urethane coating 20, and a
metal support 22,
in the form of an embedded steel plate core, is shown in Figure 2. In other
embodiments, other
less preferred forms of a metal support, such as a block (not shown), can be
used.
[0025] More particularly, the chain 14, as illustrated in FIG. I, includes
two swivel links 26
connected by two side plates 30. Although only two swivel links 26 connected
by two side
plates 30 are shown, the chain 14 usually is an endless chain (not shown), and
flights 18 are
attached at spaced apart locations along the chain 14.
[0026] Extending perpendicular to the direction of chain travel are two
spaced apart pins 34
that extend outwardly from each of the side plates 30. Each of the flights 18
is attached to the
spaced apart pins 34, as further explained below. As illustrated in FIG. 1,
one set of the two
spaced apart pins 34 extend to the left of the chain 14 and one set of the two
spaced apart pins 34
extend to the right of the chain 14.
[0027] Each flight 18 has the thin-walled steel core 22, leaving space for
adequate thickness
of the sound-dampening coating 20. The core 22, as shown in Figure 3, is a
flat steel plate
having a first end 40 and a second end 44, and a left edge 48 and a right edge
52, as shown in
Figure 3. Each of the left and right edges of the core 22 has a cylindrical
portion 50 that defines
a cylindrical opening 54 that extends the length of the core 22. The
cylindrical openings 54
receive the elongated chain pins 34. The core 22 is clamped onto the flight
pins 34 by clamping
means in the form of rivets or threaded fasteners 56 (see FIG. I) that pass
through openings 58
that extend only through the metal support 22. The core 22, together with the
elongated pins 34,
provides strength and rigidity to support the urethane outer shell 20 of the
flight 18.
[0028] In order to permit access to the rivets or threaded fasteners 56, so
that the flight 18
can be removed from the conveyor 10, or so a new flight 18 can replace a
damaged one,
openings 60 are present in the urethane coating 20 above the openings 58
through the metal
support 22.
[0029] In one embodiment, not shown, the sound-dampening flight 18 can be
made in
multiple pieces that are glued together and onto the cores 22 at the same
time. In the preferred
embodiment, the flight 18 is molded directly onto the core 22. More
particularly, the core 22 is
inserted into a mold, and then the sound-dampening material 20 is poured over
the core. The core
can be one piece or two piece. Shown in FIG. 3 is a one-piece core 22 and
shown in FIG. 4 is a
core 72 made of two identical pieces 74 and 76, arranged symmetrically. The
core can also be
made into a single piece by welding two pieces along the edges. The one-piece
core provides
more reliable clamping onto the chain pins 34, but the two-piece core is be
less expensive to
manufacture.
[0030] As shown in FIG. 5, the length of the cylindrical openings 54 need
not be the entire
length of the core 22. When pins 34 that do not extend the entire length of
the core 22 are used
for economical reasons, the length of the cylindrical openings 54 can be
suited to the length of pin
extension 34. This also allows various widths of chain assembly to be easily
made by simply
selecting the flights of the desired width, and keeping the pin length common.
[0031] A dual-sprocket conveyor chain from U.S. Patent 6,662,932, is shown
in the
illustrations. The concept could also be applied to standard single-sprocket
conveyor chain. In
the illustrations, the urethane flight is shown partially transparent to
reveal the flight pins and core
within.
[0032] FIGS. 6-9 show a chain flight assembly 400 according to another
embodiment of the
invention. The chain flight assembly 400 shown in FIGS. 6-7 is similar to the
chain flight
assembly described above in regard to FIGS. 1-5, and only differences will be
discussed herein.
Common elements have the same reference number, plus "400".
[0033] The chain flight assembly 400 includes chain flights 418, swivel
links 426, side
plates 430, and flight pins 434. As shown in FIGS. 7-8, the chain flight 418
includes a flight
coating 420, made from a sound dampening material, such as urethane, and an
inner flight core
422 made from a rigid material, such as steel.
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100341 FIG. 8 shows the core 422 in greater detail. The illustrated core
422 includes two
parallel tubes 438 and an arm 442 coupled to the tubes 438. Each tube 438
includes a first end
446 and a second end 464, and the tubes 438 are spaced apart by a distance
equal to the pitch
length of the chain 14. The tubes 438 have an inner surface 466 defining an
inner diameter. The
inner diameter is slightly larger than the diameter of the pins 434 to permit
a clearance fit
between the tubes 438 and an outer surface of the pins 434.
100351 The arm 442 includes a first end 468 proximate the first ends 446 of
the tubes 438, a
second end 480, an upper surface 484, and a lower surface 488. The arm 442
extends parallel to
the tubes 438 toward the second end 480 that, in the illustrated construction,
is beyond the
second ends 464 of the tubes 438. The arm 442 also includes multiple openings
492 extending
between the upper surface 484 and the lower surface 488. In other embodiments,
the arm 442
may include more or fewer openings 492 having various sizes.
[0036] The flight coating 420 is made from urethane or another sound
dampening material.
As shown in FIG. 9, the illustrated coating 420 substantially encapsulates the
core 422, covering
the upper, lower and outer end surfaces of the core 422. In other
constructions, the coating 420
may cover the inner end surface of the core 422. The coating 420 extends
through and fills the
openings 492 of the arm 442, strengthening the bond between the coating 420
and the arm 442.
100371 Referring again to FIG. 7, the pins 434 have an extended length to
attach to the core
422. The flights 418 are connected to the pins 434, and, in the present
embodiment, adhesive
provides structure to connect the flights 418 and pins 434. To assemble the
flight 418 to the
chain 14, an adhesive or chocking compound is applied to the inside of the
tubes 438 and/or to
the pins 434. The pins 434 may be prepared to enhance the adhesive bond, which
may include
knurling, grooving, or sandblasting the outer surface of the pins 434. The
tubes 438 are slid over
the pins 434, securing the flight 418 with respect to the chain flight
assembly 400. The adhesive
fills the space between the inside of the tube 438 and the pin 434.
100381 Suitable adhesives have a shear strength of 5,000 psi, and the tubes
438 and the pins
434 are designed to have an adequate bonding area to provide the requisite
strength for the chain
flight assembly 400. In addition, the selected adhesive has a melting
temperature such that the
application of heat causes the adhesive to melt and permits the operator to
remove and replace a
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worn or damaged flight 418. After applying additional adhesive to the pins 434
and/or tubes 438
(if necessary), a new, replacement flight 418 is installed on the pins 434.
[0039] The modular design of the flight 418 shown in FIGS. 6-9 simplifies
replacement of a
broken flight without requiring disconnecting the chain 14 and replacing an
entire chain flight
assembly 400. The rigid flight core 422 provides strength and rigidity to the
flight 418, while the
flight coating 420 provides sound dampening to reduce the noise caused by
operation of the
conveyor 10.
[0040] In addition, the flight core 422 and flight coating 420 simplify
the manufacturing
process by eliminating the need to first attach a flight onto a chain flight
assembly and then apply
a coating to each flight. Instead, the flights 418 may be produced
individually by first
manufacturing the flight core 422 and then coating the core 422 in the coating
420. This reduces
the cost of forming a chain flight assembly 400 having sound dampening flights
418.
[0041] The length of the tubes 438 may be adjusted depending on the
desired amount of
contact surface between the pins 434 and the tubes 438. Also, the length and
shape of the arm
442 may be adjusted depending on the desired strength or rigidity of the
flight 418.
[0042] FIG. 10 shows an alternative embodiment of a chain flight assembly
500 including a
flight 518 in which the core 522 is slid over the pins 534, and the ends of
the pins 534 adhere to
the core 522. The core 522 extends nearly the entire length of the flight
coating 520, providing
greater strength to the assembly.
[0043] In yet another independent embodiment (not shown), the flight is
made from a
material having sound dampening properties, such that a separate coating is
not required, and
with sufficient strength, such that a separate core element is not required.
One example of such a
suitable material is ductile iron. Although ductile iron is not easily welded
to steel, such a flight
can be attached to the pins by an adhesive, as described above. Such a flight
may have a
construction similar to the flight 418 (e.g., with openings for the pins 434
and with generally the
same outer shape). Alternatively, the flight may have a construction similar
to that shown in U.S.
Patent Application Publication No. US 2009/0250318 Al, published October 8,
2009.
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[0044] Thus, the invention may generally provide, among other things, a
chain flight
assembly with sound dampening. One or more independent features and advantages
of the
invention may be set forth in the following claims.
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