U.S. patent application number 15/309089 was filed with the patent office on 2017-03-09 for crumber for trencher.
The applicant listed for this patent is DIGGA AUSTRALIA PTY LTD.. Invention is credited to Stewart James WRIGHT.
Application Number | 20170067225 15/309089 |
Document ID | / |
Family ID | 54391862 |
Filed Date | 2017-03-09 |
United States Patent
Application |
20170067225 |
Kind Code |
A1 |
WRIGHT; Stewart James |
March 9, 2017 |
CRUMBER FOR TRENCHER
Abstract
A crumber for a trencher machine is provided, the crumber
including a crumber mount for mounting to a crumber boom, and a
crumber arm, the crumber arm being mounted to the crumber mount by
a linkage, the linkage having a first linkage arm and a second
linkage arm, the linkage being arranged to allow rotation of at
least one of the linkage arms of at least 75.degree.. The crumber
mount has at least one edge or surface of the crumber arm, wherein
the least one edge or surface of the crumber mount and the
complementary edge or surface of the crumber arm abut on each other
when the crumber arm is in a lowermost position. In this manner,
the crumber arm is supported along an extended length when in the
lowermost position.
Inventors: |
WRIGHT; Stewart James;
(Brisbane, AU) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
DIGGA AUSTRALIA PTY LTD. |
Brisbane, Queensland |
|
AU |
|
|
Family ID: |
54391862 |
Appl. No.: |
15/309089 |
Filed: |
May 6, 2015 |
PCT Filed: |
May 6, 2015 |
PCT NO: |
PCT/AU2015/050217 |
371 Date: |
November 4, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E02F 5/14 20130101; E02F
3/369 20130101; E02F 5/06 20130101 |
International
Class: |
E02F 5/14 20060101
E02F005/14; E02F 5/06 20060101 E02F005/06 |
Foreign Application Data
Date |
Code |
Application Number |
May 7, 2014 |
AU |
2014901684 |
Claims
1. A crumber for a trencher machine, the crumber comprising: a
crumber mount for mounting to a crumber boom, and a crumber arm;
the crumber aim being mounted to the crumber mount by a linkage the
linkage comprising a first linkage arm and a second linkage arm,
the linkage being arranged to allow rotation of at least one of the
linkage arms of at least 75.degree..
2. The crumber for a trencher according to claim 1, wherein at
least one of the linkage arms is rotatable by between 75 to
120.degree., more preferably from 80 to 110.degree., even more
preferably from 85 to 100.degree., even more preferably about
90.degree..
3. The crumber for a trencher according to claim 1, wherein the
linkage comprises a first linkage arm pivotally connected to the
crumber mount and pivotally connected to the crumber arm, and a
second linkage arm pivotally connected to the crumber mount and
pivotally connected to the crumber arm.
4. The crumber for a trencher according to claim 1 wherein the
linkage comprises a pair of first linkage arms each pivotally
connected to the crumber mount and pivotally connected to the
crumber arm, and a pair of second linkage arms each pivotally
connected to the crumber mount and pivotally connected to the
crumber arm.
5. The crumber for a trencher according to claim 1 wherein the
crumber arm comprises a first crumber arm side plate and a second
crumber arm side plate, the first and second crumber arm side
plates being connected to each other.
6. The crumber for a trencher according to claim 5 wherein the two
side plates are connected to each other by one or more intermediate
connectors.
7. The crumber for a trencher claim 5 wherein the linkage comprises
a first proximal linkage arm and a second distal linkage arm, with
the second distal linkage arm having a distal end pivotally
connected to one of the crumber side plates, the distal end of the
second linkage arm being located between the first crumber arm side
plate and the second crumber arm side plate.
8. The crumber for a trencher according to claim 5, wherein the
crumber arm is movable from a first lowermost position to a second
uppermost position, the second distal linkage arm lying
approximately parallel to the crumber boom when the crumber arm is
in a first lowermost most position.
9. The crumber for a trencher according to claim 5, wherein the
first proximal arm is rotatable by at least 75.degree. when the
crumber arm is moving from a first lowermost position to a second
uppermost position.
10. The crumber for a trencher according to claim 9, wherein the
first proximal arm is rotatable by between 75 to 120.degree., or
from 80 to 110.degree., or from 85 to 100.degree., or about
90.degree., 0 when the crumber arm is moving from the first
lowermost position to the second uppermost position.
11. The crumber for a trencher according to claim 5, wherein the
first proximal linkage arm is shorter than the second distal
linkage arm.
12. The crumber for a trencher according to claim 1, wherein the
crumber mount has at least one edge or surface that is of
complementary shape to an edge or surface of the crumber arm,
wherein the least one edge or surface of the crumber mount and the
complementary edge or surface of the crumber arm abut on each other
when the crumber arm is in a lowermost position.
13. A crumber for a trencher, the crumber comprising: a crumber
mount for mounting to a crumber boom and a crumber the crumber arm
being mounted to the crumber mount by a linkage; the crumber mount
having at least one edge or surface that is of complementary shape
to an edge or surface of the crumber arm; and wherein the least one
edge or surface of the crumber mount and the complementary edge or
surface of the crumber arm abut on each other when the crumber arm
is in a lowermost position.
14. The crumber for a trencher according to claim 13, wherein the
at least one edge or surface of the crumber arm comes into contact
with and is supported by the complementary edge or surface of the
crumber mount when the crumber arm is in the lowermost position and
the crumber arm is supported by the crumber mount along the length
of the complementary edge or surface of the crumber mount when the
crumber arm is in the lowermost position.
15. The crumber for a trencher according to claim 13, wherein the
crumber mount comprises two spaced mount side plates for mounting
to the crumber boom, the two spaced side plates being connected
together.
16. The crumber for a trencher according to claim 13, wherein the
crumber further comprises a biasing means to bias the crumber arm
to a lowermost position.
17. The crumber for a trencher according to claim 7 wherein, the
second distal linkage arm has a proximal end located between the
two spaced crumber mount side plates and a distal end located
between the two spaced crumber arm side plates.
18. The crumber for a trencher according to claim 5, wherein the
first proximal crumber arm extends at an angle of about 20 to
30.degree., preferably about 25.degree., to the crumber boom when
the crumber arm is in a lower most position, and extends at an
angle of about 95.degree. to 145.degree., more preferably from
105.degree. to 135.degree., even more preferably from 110.degree.
to 125.degree., even more preferably about 115.degree. to the
crumber boom, when the crumber arm is an uppermost position.
Description
TECHNICAL FIELD
[0001] The present invention relates to a crumber for trencher.
BACKGROUND ART
[0002] A conventional trencher machine includes an elongated boom
which is connected to a frame of the trencher machine for vertical
pivotal movement. A digging chain and tooth assembly is supported
by the boom for orbital movement thereabout. The trencher boom can
be lowered to commence digging a trench.
[0003] A crumber is typically arranged in combination with the
chain and tooth assembly of the trencher machine. The crumber
assists in cleaning out the trench. In use, the distal end of the
crumber extends past the distal end of the trencher boom. The
crumber will typically have a crumber foot or a crumber shoe (which
may also called a scraper plate) at the distal end thereof and the
crumber foot or crumber shoe acts to keep rocks and other debris
loosened by digging of the trench in close proximity to the digging
chain and tooth, thereby assisting in the dirt, rocks or other
debris being removed from the trench by the digging chain and tooth
assembly.
[0004] A typical crumber comprises a crumber boom that is mounted
to the trencher machine. A crumber arm is mounted to the crumber
boom in a manner such that the crumber arm can move upwardly and
downwardly in a vertical plane relative to the crumber boom. For
example, the crumber arm may be linked to the crumber boom by a
linkage arrangement in which a first linkage arm is pivotally
mounted at one end to the crumber boom (or to a crumber mount that
is mounted to the crumber boom) and pivotally mounted at a second
end to the crumber arm and a second linkage arm is pivotally
mounted at one end to the crumber boom (or to a crumber mount that
is mounted to the crumber boom) and pivotally mounted at a second
end to the crumber arm.
[0005] The crumber arm is typically spring-loaded such that it is
biased to a lowermost position. When a new trench is to be dug, the
trencher boom is lowered until the distal end comes to contact with
the ground stop the chain and tooth arrangement is operated to
commence digging a trench. Continue lowering of the boom causes the
trench to become deeper. Once the trencher boom has been lowered to
be desired depth of the trench, the trencher machine is then moved
along the line along which the trench is to be dug.
[0006] It will be appreciated that the distal end of the crumber
extends past the distal end of the trencher boom. As a result, at
the commencement of excavation of a new trench, the distal end of
the crumber arm will contact the earth beyond the distal end of the
trencher boom. As the trencher boom is continued to be lowering
during the initial stages of excavation of the trench, the distal
end of the crumber arm will remain in contact with the essentially
undisturbed soil that is beyond the extent of the trench being dug.
This causes the crumber arm to pivot upwardly relative to the
trencher boom (it being appreciated that the crumber arm remains
essentially at ground level whilst the trencher boom is
progressively lowered into the ground). Unfortunately, it is a
common occurrence that the crumber arm is pivoted upwardly relative
to the trencher boom to an extent such that the maximum travel of
the crumber arm is reached. In these circumstances, further
lowering of the trencher boom will cause damage to the crumber
arm.
[0007] To avoid this problem, in practice the operator of the
trencher machine will remove the crumber arm from the crumber boom
prior to commencing excavation of a new trench. Once the full depth
of the trench has been dumped, the operator must then reattach the
crumber arm to the crumber boom. Although this protects the crumber
arm from damage, these steps lengthen the time required to excavate
a trench. They also have the potential to cause is some
occupational health and safety issues during removal and
reattachment of the crumber arm to the crumber boom.
[0008] It has also been found that the linkage arms used to connect
the crumber arm to the crumber boom (or to the crumber mount that
is attached to the crumber boom) may be damaged during use of the
crumber. Further, wear can occur in regions where the crumber arm
comes into contact with the crumber mount. This wear can be
accentuated during transport of the trenching machine because the
crumber arm will be typically in its down position due to the
action of the biasing spring during transport of the trenching
machine.
[0009] It will be clearly understood that, if a prior art
publication is referred to herein, this reference does not
constitute an admission that the publication forms part of the
common general knowledge in the art in Australia or in any other
country.
SUMMARY OF INVENTION
[0010] The present invention is directed to crumber, which may at
least partially overcome at least one of the abovementioned
disadvantages or provide the consumer with a useful or commercial
choice.
[0011] With the foregoing in view, the present invention in one
form, resides broadly in a crumber for a trencher machine, the
crumber comprising a crumber mount for mounting to a crumber boom,
and a crumber arm, the crumber arm being mounted to the crumber
mount by a linkage, the linkage comprising a first linkage arm and
a second linkage arm, the linkage being arranged to allow rotation
of at least one of the linkage arms of at least 75.degree..
[0012] In one embodiment, at least one of the linkage arms can
rotate by between 75 to 120.degree., more preferably from 80 to
110.degree., even more preferably from 85 to 100.degree., even more
preferably about 90.degree..
[0013] In one embodiment, the linkage comprises a first linkage arm
pivotally connected to the crumber mount and pivotally connected to
the crumber arm, and a second linkage arm pivotally connected to
the crumber mount and pivotally connected to the crumber arm.
[0014] In another embodiment, the linkage comprises a pair of first
linkage arms each pivotally connected to the crumber mount and
pivotally connected to the crumber arm, and a pair of second
linkage arms each pivotally connected to the crumber mount and
pivotally connected to the crumber arm.
[0015] In one embodiment, the crumber arm comprises a first crumber
arm side plate and a second crumber arm side plate, the first and
second crumber arm side plates being connected to each other. The
two side plates maybe connected to each other by one or more
intermediate connectors. The intermediate connectors may be welded
to the first and second crumber arm side plates.
[0016] In some embodiments, the linkage comprises a first proximal
linkage arm and a second distal linkage arm, with the second distal
linkage arm having a distal end pivotally connected to a crumber
side plate, the distal end of the second linkage arm being located
between the first crumber arm side plate and the second crumber arm
side plate. In this manner, the distal end of the second linkage
arm is located inside a volume defined by the first crumber arm
side plate and the second crumber arm side plate. Thus, the crumber
arm side plates act to protect the distal end of the second linkage
arm from damage that may otherwise be caused by contact with dirt
or debris.
[0017] In one embodiment, the crumber arm is movable from a first
lowermost position to a second uppermost position, the second
proximal linkage arm lying approximately parallel to the crumber
boom when the crumber arm is in the first lowermost most
position.
[0018] In one embodiment, the first proximal, arm can rotate by at
least 75.degree. when the crumber arm is moving from the first
downward most position to the second uppermost position.
Preferably, the first proximal, arm can rotate can rotate by
between 75 to 120.degree., more preferably from 80 to 110.degree.,
even more preferably from 85 to 100.degree., even more preferably
about 90.degree., .degree. when the crumber arm is moving from the
first lowermost position to the second uppermost position.
[0019] In some embodiments, the first proximal linkage arm is
shorter than the second distal linkage arm.
[0020] In some embodiments, the crumber mount has at least one edge
or surface that is of complementary shape to an edge or surface of
the crumber arm, wherein the least one edge or surface of the
crumber mount and the complementary edge or surface of the crumber
arm abut on each other when the crumber arm is in a lower most
position.
[0021] In a second aspect, the present invention provides a crumber
for a trencher machine, the crumber comprising a crumber mount for
mounting to a crumber boom, and a crumber arm, the crumber arm
being mounted to the crumber mount by a linkage, the crumber mount
having at least one edge or surface that is of complementary shape
to an edge or surface of the crumber arm, wherein the least one
edge or surface of the crumber mount and the complementary edge or
surface of the crumber arm abut on each other when the crumber arm
is in a lowermost position.
[0022] In this embodiment, the at least one edge or surface of
crumber arm comes into contact with and is supported by the
complementary edge or surface of the crumber mount when the crumber
arm is in the lowermost position. Thus, the crumber arm is
supported by the crumber mount along an extended length (being the
length of the complementary edge or surface of the crumber mount)
when in the lowermost position. This is in contrast to prior art
crumbers where the crumber arm would often just come into contact
with a point of the crumber mount when the crumber arm was in the
lowermost position, thereby increasing wear.
[0023] The crumber mount may be provided with two or more apertures
to enable the crumber mount to be fixed to the crumber boom. The
crumber mount may be fixed to the crumber boom by use of
appropriate fastening pins, bolts, screws or any other suitable
fasteners.
[0024] The crumber mount may comprise two spaced mount side plates.
The two side plates may be mounted to the crumber boom. The two
spaced side plates may be connected together.
[0025] The crumber may further comprise a biasing means to bias the
crumber arm to a lowermost position. The biasing means may comprise
a spring. The spring may be mounted within the crumber mount. The
spring may have an end that bears against the crumber arm in order
to bias in the crumber arm to a lower most position.
[0026] In some embodiments, the second distal linkage arm has a
proximal end located between the two spaced crumber mount side
plates and a distal end located between the two spaced crumber arm
side plates.
[0027] In some embodiments, the first proximal crumber arm extends
at an angle of about 20 to 30.degree., preferably about 25.degree.,
to the crumber boom when the crumber arm is in a lower most
position, and extends at an angle of about 95.degree. to
145.degree., more preferably from 105.degree. to 135.degree., even
more preferably from 110.degree. to 125.degree., even more
preferably about 115.degree. to the crumber boom, when the crumber
arm is an uppermost position.
[0028] Any of the features described herein can be combined in any
combination with any one or more of the other features described
herein within the scope of the invention.
[0029] The reference to any prior art in this specification is not,
and should not be taken as an acknowledgement or any form of
suggestion that the prior art forms part of the common general
knowledge.
BRIEF DESCRIPTION OF DRAWINGS
[0030] Preferred features, embodiments and variations of the
invention may be discerned from the following Detailed Description
which provides sufficient information for those skilled in the art
to perform the invention. The Detailed Description is not to be
regarded as limiting the scope of the preceding Summary of the
Invention in any way. The Detailed Description will make reference
to a number of drawings as follows:
[0031] FIG. 1 shows a side view of a crumber for a trencher in
accordance with an embodiment of the present invention. In FIG. 1,
the crumber arm is in a lowermost position;
[0032] FIG. 2 shows a side view of the crumber shown in FIG. 1,
with the crumber arm shown in an uppermost position;
[0033] FIG. 3 shows a perspective view of the crumber shown in FIG.
1, with the crumber being shown apart and in line for assembly;
[0034] FIG. 4 shows a side cross-sectional view of the crumber
mount of the crumber shown in FIGS. 1 to 3;
[0035] FIG. 5 shows an end view of the crumber mount shown in FIG.
4;
[0036] FIG. 6 shows a side view of the crumber arm of the crumber
shown in FIG. 1;
[0037] FIG. 7 shows a perspective view of the crumber arm shown in
FIG. 6;
[0038] FIGS. 8 and 9 show side views of the crumber shown in FIGS.
1 and 2, respectively, with angles of rotation added thereto;
and
[0039] FIGS. 10 and 11 show side views of a prior art crumber, with
the crumber arm shown in a lowermost position in FIG. 10 and the
crumber arm shown in an uppermost position in FIG. 11.
DESCRIPTION OF EMBODIMENTS
[0040] The crumber 10 shown in FIGS. 1 to 3 comprises a crumber
mount 12 and a crumber arm 14. The crumber mount 12 has apertures
16, 18 formed therein. The apertures 16, 18 can be placed in line
with similar apertures formed in a crumber boom and fasteners, such
as fastening pins or bolts, can be passed through the aligned
apertures to fix or mount the crumber mount to the crumber boom.
The crumber boom 11 is shown in dashed outline in FIG. 1.
[0041] The crumber arm 14 is connected to the crumber mount 12 by
means of a linkage. The linkage comprises a first linkage arm 20
and a second linkage arm 22. The first linkage arm 20 comprises a
proximal linkage arm and the second linkage and 22 comprises a
distal linkage arm. In this regard, the trencher machine is located
proximal to end 24 of the crumber mount 12.
[0042] Turning now to FIG. 3, the crumber mount 12 comprises a
first crumber mount side plate 26 and a second crumber mount side
plate 28. Side plate 26 is spaced from side plate 28. An
intermediate support plate 30 is positioned between the side plates
26 and 28. The side plates are provided with openings 32, 34 (see
FIG. 1) that receive tabs on the intermediate support plate 32
thereby holding the intermediate support plate 30 in position.
Intermediate support plate 30 may be welded to the side plates 26,
28.
[0043] The crumber arm 14 includes first crumber arm side plate 36
and second crumber arm side plate 38. Crumber arm side plates 36
and 38 are spaced from each other. A stiffener 40 is located
between the crumber arm side plates 36 and 38 and welded thereto. A
scraper plate 42 is welded to the lower end of the crumber arm 14
and acts to rigidly fix the lower end of the crumber arm side
plates 36 and 38 together. In use, the lower end of the scraper
plate 42 contacts the bottom of the trench and acts to move dirt
and debris into close proximity with the trencher boom, thereby
facilitating removal of dirt and debris from the trench by the
chain and teeth rotating around the trencher boom. In practice, the
scraper plate 42 may be fitted with removable feet. The removable
feet may be replaced when they are worn. Alternatively, the scraper
plate 42 may be hard-faced in order to increase its useful working
life. The scraper plate may have one or more points or intensifiers
formed at its lower end. The improves operation of the crumber.
[0044] The side plates of the crumber arm 14 are provided with
apertures 44 and 46. Similarly, the crumber mount side plates 26,
28 are provided with apertures 48. A linkage arm assembly 50 is
connected at its proximal end by a pin that passes through
apertures 48 and aligned apertures 52 formed in the linkage arm
assembly 50. This connects the proximal end of the linkage arm
assembly 50 to the crumber mount side plates 26, 28. Similarly, the
linkage arm assembly 50 is connected at its distal end by a pin
that passes through apertures 44 in the crumber arm side plates 36,
38 and through an aligned aperture 54 in the distal end of the
linkage am assembly 50. This pivotally connects the distal end of
the linkage am assembly 50 to the crumber arm 14. It will be
appreciated that the linkage arm assembly 50 comprises two spaced
second linkage arms 22. In some embodiments, screw button head
sockets 64 may be used to fasten the pivotal connections.
[0045] As best shown in FIGS. 1 and 2, the two spaced distal
linkage arms 22 are located between the two spaced crumber mount
side plates and the two spaced crumber arm side plates. As a
result, the two distal linkage arms 22 are located to the inside of
the side plates of the crumber mount and the crumber arm.
Consequently, the side plates provide a degree of protection to the
linkage arms as the linkage arms are not fully exposed to the
working environment.
[0046] The crumber mount side plates 26, 28 are each provided with
an aperture 56. A screw button head socket 58 passes through an
aperture in the proximal end of the first linkage arm 20 and is
used to pivotally connect the proximal end of the first linkage arm
14 to the crumber mount side plate 26. A similar arrangement
utilising screw button head socket 62 is used to connect another
proximal linkage arm to the other crumber mount side plate 28. The
distal end of the proximal linkage arms 14 are connected in a
similar fashion to the proximal end of the crumber arm side plates
36, 38, with the socket 62 passing through openings in the distal
end of the proximal linkage arms 20 and two proximal apertures 46
in the side plates of the crumber arm. In this manner, the proximal
linkage arms 14 are pivotally connected to both the crumber mount
12 and the crumber arm 14.
[0047] The crumber arm 14 is biased to the lowermost position shown
in FIG. 1. In order to enable this to occur, a biasing spring 64 is
fitted over a spring support 66. Spring support 66 is held in place
by the pin 68 that forms part of the pivotal connection for the
proximal end of the proximal linkage arms 20 to the crumber mount
12. A distal end of a biasing spring 64 extends over the end 70 of
the crumber arm 14. A proximal end of the biasing spring 64 rests
in recess 72 formed in intermediate support plate 30 that is fitted
between the side plates 26, 28 of the crumber mount 14. In this
manner, the spring acts to push downwardly on the crumber arm 14,
thereby biasing the crumber arm 14 to the lowermost position shown
in FIG. 1 in the absence of any external applied force.
[0048] Returning now to FIGS. 1 and 2, the crumber arm 14 can move
between the lowermost position shown in FIG. 1 and an uppermost
position shown in FIG. 2. During movement of the crumber arm, the
linkage arms 20, 22 rotate about the pivotal connections to both
the crumber mount 12 and the crumber arm 14. As shown in FIG. 2,
the second linkage arm 22 is significantly longer than the first
linkage arm 20. Indeed, the second linkage and 22 may be from 1.5
to 2 times longer than the first linkage arm 20, more preferably
from 1.75 to 2 times longer than the first linkage arm.
[0049] Turning now to FIGS. 8 and 9, the arrangement and geometry
of the crumber 10 results in the first linkage arm 20 extending at
an angle of approximately 25.degree. to the longitudinal axis of
the crumber boom 11 when the crumber arm 14 is in the lowermost
position. This is shown in FIG. 8. The crumber arm 14 may move
upwardly to its uppermost position by rotation of both the first
linkage arms 20 and the second linkage arms 22 about their
respective pivotally connected ends. The arrangement and geometry
of the crumber 10 results in the first linkage arms 20 extending an
angle of approximately 115.degree. to the longitudinal axis of the
crumber when in its uppermost position, as shown in FIG. 9.
Therefore, the first linkage arm has rotated by approximately
90.degree..
[0050] FIGS. 10 and 11 show a prior art crumber having a first
linkage arm 20A that extends any angle of approximately 33.degree.
when the crumber arm 14A is in the lowermost position (see FIG.
10). When the crumber arm 14A is in the uppermost position as shown
in FIG. 11, the first linkage arms 20A extend an angle of
approximately 100.degree. to the longitudinal axis of the crumber
boom. Thus, the first linkage arms have only rotated by
approximately 67.degree., significantly less than the rotation of
the first linkage arms of the crumber 10 shown in FIGS. 8 and 9.
Furthermore, when the crumber arms are in the uppermost position,
the lower end of the scraper plate 42A of the prior art crumber
shown in FIG. 11 is significantly lower than the lower end of the
scraper plate 42 of the crumber 10 shown in FIG. 9.
[0051] By virtue of the crumber arm being able to move to a higher
position, excavation of a new trench may commence without the
requirement to undo or release the crumber 10 from the crumber
boom, as is required with present crumbers. Rather, as the crumber
10 of the present invention can move to a higher uppermost
position, the crumber arm 14 can move sufficiently high relative to
the trencher blade such that the crumber arm 14 can rest on
undisturbed ground whilst the trencher blade moves to the required
depth for the trench and the crumber arm can then move down into
the trench once the trencher starts to move along the length of the
new trench. Thus, it is not necessary to remove the crumber 10 from
the crumber boom when commencing a new trench with the crumber of
the present invention.
[0052] Returning to FIGS. 1 and 2, it can be seen that the crumber
mount side plate 26 is provided with an extended upper edge 74.
Indeed, upper edge 74 includes an extended straight edge portion
74. Crumber mount side plate 28 is similarly shaped. The crumber
arm side plate 36 is provided with a proximal lower edge 76 that
also includes an extended straight portion. When the crumber arm 14
is in its lowermost position, as shown in FIG. 1, the complimentary
edges 74, 70 abut on each other such that the edge 76 of the
crumber arm 14 lies on the edge 74 of the crumber mount 12. In this
manner, the force required to support the crumber arm 14 is
distributed along the length of the complimentary edges 74, 76.
This acts to minimise the load concentrations between the crumber
mount 12 and the crumber arm 14.
[0053] The crumber in accordance with embodiments of the present
invention provides a robust crumber having lower wear at contact
positions between the crumber mount and the crumber arm. The
crumber arm can move upwardly to a significantly larger degree than
in prior art crumbers, thereby avoiding the necessity of having to
undo at least one of the pins holding the crumber to the crumber
boom when excavation of a new trench commences. This, of course,
also obviates the requirement to reattach the crumber to the
crumber boom once a length of the new trench has been excavated.
Thus, the crumber of the present invention provides for significant
ease-of-use and increased efficiency.
[0054] In this specification, the term "proximal" is used to refer
to positions located relatively closer to the trencher machine and
the word "distant" is used to refer to positions located relatively
farther away from the trencher machine. The terms "lowermost" and
"uppermost" are used in the context of a position of the crumber
arm relative to the crumber boom.
[0055] In the present specification and claims (if any), the word
`comprising` and its derivatives including `comprises` and
`comprise` include each of the stated integers but does not exclude
the inclusion of one or more further integers.
[0056] Reference throughout this specification to `one embodiment`
or `an embodiment` means that a particular feature, structure, or
characteristic described in connection with the embodiment is
included in at least one embodiment of the present invention. Thus,
the appearance of the phrases `in one embodiment` or `in an
embodiment` in various places throughout this specification are not
necessarily all referring to the same embodiment. Furthermore, the
particular features, structures, or characteristics may be combined
in any suitable manner in one or more combinations.
[0057] In compliance with the statute, the invention has been
described in language more or less specific to structural or
methodical features. It is to be understood that the invention is
not limited to specific features shown or described since the means
herein described comprises preferred forms of putting the invention
into effect. The invention is, therefore, claimed in any of its
forms or modifications within the proper scope of the appended
claims (if any) appropriately interpreted by those skilled in the
art.
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