U.S. patent application number 09/753621 was filed with the patent office on 2001-07-26 for elastic crawler shoe.
This patent application is currently assigned to KOMATSU LTD.. Invention is credited to Hori, Kazutoshi.
Application Number | 20010009336 09/753621 |
Document ID | / |
Family ID | 18543743 |
Filed Date | 2001-07-26 |
United States Patent
Application |
20010009336 |
Kind Code |
A1 |
Hori, Kazutoshi |
July 26, 2001 |
Elastic crawler shoe
Abstract
With the objective of providing an elastic crawler shoe which is
capable of discharging snow which gets into a space between crawler
belt links before a packing phenomenon occurs, a projection which
is made of an elastic material is provided so as to protrude into
the space which is enclosed by the right and left crawler belt
links and front and rear connecting pins.
Inventors: |
Hori, Kazutoshi;
(Komatsu-shi, JP) |
Correspondence
Address: |
ARMSTRONG, WESTERMAN, HATTORI,
McLELAND & NAUGTON
1725 K Street, N.W., Suite 1000
Washington
DC
20006
US
|
Assignee: |
KOMATSU LTD.
Tokyo
JP
|
Family ID: |
18543743 |
Appl. No.: |
09/753621 |
Filed: |
January 4, 2001 |
Current U.S.
Class: |
305/189 |
Current CPC
Class: |
B62D 55/26 20130101 |
Class at
Publication: |
305/189 |
International
Class: |
B62D 055/26 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 26, 2000 |
JP |
2000-016635 |
Claims
What is claimed is:
1. An elastic crawler shoe comprising a core bar fixed to crawler
belt links, each of which is endlessly coupled by means of
connecting pins, and an elastic body bonded to the core bar so as
to cover the core bar, the elastic crawler shoe further comprising
a projection which is made of an elastic material, the projection
being provided so as to protrude into a space which is enclosed by
the right and left crawler belt links and the front and rear
connecting pins.
2. The elastic crawler shoe as defined in claim 1, wherein a
covering member which is made of either iron or resin is bonded to
the surface of the projection.
3. The elastic crawler shoe as defined in claim 1, wherein the
surface of the projection is formed out of an elastic material
whose hardness is higher than that of the main body of the
projection.
4. The elastic crawler shoe as defined in any one of claims 1 to 3,
wherein the core bar has a hole, so that the elastic body is
unitarily formed with the projection.
5. The elastic crawler shoe as defined in any one of claims 1 to 3,
wherein the projection is mounted on the core bar so as to be
detachable.
6. The elastic crawler shoe as defined in claim 5, wherein a
projection core bar is embedded in the projection and is bolted to
the core bar.
Description
TECHNICAL FIELD
[0001] The present invention relates to an elastic crawler shoe
which is suitable for use in a tracklaying vehicle such as a
construction machine, an agricultural machine or the like.
BACKGROUND ART
[0002] In a conventional tracklaying vehicle such as a bulldozer, a
crawler belt which is made of iron is wound around a plurality of
rolling wheels arranged on the upper and lower parts of a track
frame and is driven by driven drive sprockets so as to make the
vehicle travel. However, the vehicle equipped with such an iron
crawler belt damages the surface of a paved public road during
traveling. For this reason, recently, what is called a rubber
crawler belt system in which many core bars which are made of metal
are embedded in an endless rubber belt at regular intervals and are
engaged with the drive sprockets, thereby to drive the belt is
often adopted.
[0003] However, in the case of this rubber crawler belt, since many
core bars are embedded in the endless rubber belt, when the rubber
belt is damaged resulting from cracks, exfoliation and the others,
the rubber crawler belt as a whole needs to be replaced with a new
one, and therefore there were problems that running costs on a user
side run up and time-consuming maintenance is required.
[0004] To overcome the foregoing problems, a crawler belt formed in
such a manner that many elastic crawler shoes, each of which is
comprised of one core bar and an elastic body bonded to the core
bar so as to cover the core bar, are arranged in a longitudinal
direction of a crawler is disclosed, for instance, in Japanese
Patent Laid-Open Publication No. 8-48269 (1996), International
Publication No. WO99/12799 and the others. In the case of this
proposed elastic crawler shoe, even when the elastic body of one of
the elastic crawler shoes is damaged, only the damaged shoe can be
replaced, and therefore this elastic crawler shoe is advantageous
in that running costs and time required for maintenance can be cut
down.
[0005] However, when the above-mentioned conventional elastic
crawler shoe is used, for instance, on a pressed snow road in
winter, snow covering the road surface gets into a space between
right and left crawler belt links, and a phenomenon (which is
called "a packing phenomenon" ) in which the sprocket or the like
repeatedly packs down the snow which has gotten into the space
problematically occurs. When such a packing phenomenon occurs, the
sprocket or an idler cannot engage with the crawler belt links, and
the crawler belt comes off as a result.
[0006] The present invention addresses the problem discussed above,
and aims to provide an elastic crawler shoe which is capable of
discharging snow which gets into a space between crawler belt links
before a packing phenomenon occurs, thereby circumventing a
situation in which a crawler belt comes off.
SUMMARY OF THE INVENTION
[0007] The above object can be accomplished by an elastic crawler
shoe according to the present invention, the elastic crawler shoe
comprising a core bar fixed to crawler belt links, each of which is
endlessly coupled by means of connecting pins, and an elastic body
bonded to the core bar so as to cover the core bar,
[0008] the elastic crawler shoe further comprising a projection
which is made of an elastic material, the projection being provided
so as to protrude into a space which is enclosed by the right and
left crawler belt links and the front and rear connecting pins.
[0009] According to the present invention, even when snow covering
the road surface gets into the space which is enclosed by the right
and left crawler belt links and the front and rear connecting pins
and is packed down by a sprocket or the like, the projection which
is compressed by the packed snow stretches to its original length
owing to its own resilience in an area where the crawler belt links
become disengaged from the sprocket or the like, thereby
discharging the packed snow from within the abovementioned space.
In this way, the snow which has gotten into the space between the
crawler belt links is discharged before a packing phenomenon
occurs, and a crawler belt can thus be prevented from coming
off.
[0010] In the present invention, a structure in which a covering
member which is made of either iron or resin is bonded to the
surface of the projection can be adopted. Thus, even when pebbles
and the others get caught between the crawler belt links, the
covering member which covers the surface of the projection can
prevent the projection from becoming deformed and can prevent the
surface of the projection from becoming chipped.
[0011] Instead of being covered with the covering member which is
made of either iron or resin, the surface of the projection may be
formed out of an elastic material whose hardness is higher than
that of the main body of the projection.
[0012] Moreover, in the present invention, it is preferable that
the core bar has a hole, so that the elastic body is unitarily
formed with the projection. The elastic crawler shoe the elastic
body of which is unitarily formed with the projection therefore has
the advantage of being easily molded.
[0013] Furthermore, the projection may be detachably mounted on the
core bar. Thus, when the projection is damaged, only the projection
can be replaced, and this replacement can be carried out with ease.
In this case, it is preferable that a core bar for the projection
is embedded in the projection and is bolted to the core bar. Thus,
the projection can be detached with ease.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1(a) is a sectional view of an elastic crawler shoe in
accordance with one embodiment of the present invention, and FIG.
1(b) is a sectional view taken along line A-A of FIG. 1(a).
[0015] FIG. 2 is a plan view of the elastic crawler shoe in
accordance with the embodiment.
[0016] FIG. 3 illustrates a projection being at an engaging part of
a sprocket.
[0017] FIGS. 4(a) to 4(c) are sectional views which respectively
illustrate the respective shapes of projections in accordance with
other embodiments.
[0018] FIGS. 5(a) and 5(b) are sectional views which respectively
illustrate projections, the surfaces of which are respectively
covered with covering members, in accordance with other
embodiments.
[0019] FIG. 6 is a sectional view illustrating a detachable
projection in accordance with the other embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] Preferred embodiments of the present invention are
concretely demonstrated hereinafter with reference to the
accompanying drawings.
[0021] FIG. 1(a) is a sectional view of an elastic crawler shoe in
accordance with one embodiment of the present invention, and FIGURE
1(b) is a sectional view taken along line A-A of FIG. 1(a). FIG. 2
is a plan view of the elastic crawler shoe in accordance with the
embodiment.
[0022] An elastic crawler shoe 1 in accordance with the present
embodiment has a structure in which an elastic body 3 which is made
of rubber or the like is bonded to a core bar 2 so as to cover the
core bar 2. The elastic crawler shoe 1 is directly fixed to crawler
belt links 4 by means of bolts which are respectively inserted in
bolt insertion holes defined in the elastic body 3. A crawler belt
as a whole is constructed in such a manner that a plurality of
elastic crawler shoes 1 are arranged in parallel relation in a
traveling direction of a crawler, and each end of each of the
crawler belt links 4 is rotatably coupled to each end of each of
the next crawler belt links 4 by means of a connecting pin 5. The
crawler belt is rotatively driven by the crawler belt links 4 which
are driven by engaging with a sprocket 12 (see FIG. 3) and the
like, so that a vehicle travels.
[0023] The core bar 2 is made of a material of high rigidity so
that it will not become deformed even when vehicle body weight is
imposed thereon. The examples of such a material include common
core bar materials such as steel, cast steel, cast iron and the
like and materials such as metallic composite materials,
non-metallic composite materials and the others. End portions 2a,
2b of the core bar 2 are each bent at a required angle toward a
non-ground contact face of the elastic crawler shoe 1, and the core
bar 2 has a through hole 2c at its central portion in a
longitudinal direction thereof. The through hole 2c may be either
circular or elliptical. It is preferable that as shown in FIG.
1(a), the inner edge of the hole is rounded off or chamfered.
[0024] The elastic body 3 is made of a relatively soft material
such as rubber, urethane, resin, an elastomer, a non-metallic
composite material or the like. It should be noted that in cases
where the elastic body 3 is made of rubber, vulcanization-bonding,
which is a common method, or the like is used to embed the core bar
2 in the elastic body 3. The elastic body 3 has a concavity 3a at
its central portion in the longitudinal direction of the crawler
shoe 1 on the ground contact face side, and its end portions on the
non-ground contact face side are each bent at a required angle
toward the non-ground contact face so as to fit the bent shape of
the core bar 2.
[0025] Moreover, the elastic body 3 has a projection 6 at its
central portion on the non-ground contact face side. The projection
6 is provided so as to protrude toward the crawler belt links 4
through the through hole 2c which is defined in the core bar 2. The
head of the projection 6 is substantially semi-circular in vertical
section which is parallel to the crawler belt links 4, while the
apex thereof is positioned beyond 1/2 of the height of the crawler
belt links 4.
[0026] In the present embodiment, it is preferable that rubber
whose hardness falls in the range of 50 to 80 at 0.degree. C. in
terms of JIS A H.sub.s is used as a material of the projection 6,
that is to say, the elastic body 3 so that the projection 6 can
perform its function (will be described later).
[0027] In an area where the crawler belt links 4 do not engage with
the sprocket or an idler, as shown in FIG. 1(b), the projection 6
of the elastic body 3 of the thus-configured elastic crawler shoe 1
in accordance with present embodiment protrudes into a space which
is enclosed by the right and left crawler belt links 4, 4 and the
front and rear connecting pins 5, 5. With the projection 6 being in
this state, when snow covering the road surface gets into the
above-mentioned space as the vehicle travels on a pressed snow
road, the crawler belt links 4, 4 engage with the sprocket 12 (see
FIG. 3) or the like with the snow being in the above-mentioned
space. The sprocket 12 or the like packs down the snow within the
abovementioned space during engagement, and the projection 6 is
thus compressed by the packed snow. When the crawler belt links 4,
4 reach an area where they become disengaged from the sprocket 12
or the like, the projection 6 is freed from pressing force of the
sprocket 12 or the like and stretches to its original length owing
to its own resilience, and the packed snow is thus discharged from
within the above-mentioned space. In this way, the snow which gets
into the space between the crawler belt links 4, 4 is discharged
before a packing phenomenon occurs, and the crawler belt is
prevented from coming off as a result.
[0028] In the present embodiment, the projection 6 which is
substantially semi-circular in section has been explained; however,
other various modified shapes are also available. FIGS. 4(a) to
4(c) are sectional views which illustrate those projections
modified in shape, respectively.
[0029] A projection 6A of FIG. 4(a) is substantially rectangular in
section, while a projection 6B of FIG. 4(b) is shaped into a gentle
chevron. In FIG. 4(c), a cavity 7 which is circular in section is
formed in the center of a substantially semi-circular projection
6C. When the cavity 7 is formed in the projection 6C, the
projection 6C becomes low in rigidity and easily bends when it
experiences pressing force.
[0030] Moreover, as shown in FIGS. 5(a) and 5(b), structures in
which covering members 8A, 8B each of which is made of either iron
or resin are bonded to the respective surfaces of projections 6D,
6E, respectively, can also be adopted. According to these
structures, even when pebbles and the others get caught between the
crawler belt links, since the respective surfaces of the
projections 6D, 6E are covered with the covering members 8A, 8B,
respectively, the projections 6D, 6E can be prevented from becoming
deformed, while their respective surfaces can be prevented from
becoming chipped.
[0031] Instead of being covered with either the covering member 8A
which is made of either iron or resin or the covering member 8B
which is made of either iron or resin, the surface of the
projection can be formed into a hard rubber layer the material of
which is different from the rubber which constitutes the main body
of the projection, so that the two layers constitute the
projection.
[0032] In each of the foregoing embodiments, the projection which
is unitarily formed with the elastic body has been explained.
However, as shown in FIG. 6, a projection 9 can be detached from an
elastic body 3A. In the embodiment shown in this drawing, one side
of a projection core bar 10 is secured to the projection 9, while
the other side thereof is fixed to a core bar 2A of the elastic
body 3A by means of a plurality of bolts 11. Thus, when the
projection 9 is damaged, the projection core bar 10 to which the
projection 9 is secured can be unbolted, so that the projection 9
can be replaced with a new one with ease. It should be noted that
similarly to those of FIGS. 5(a) and 5(b), even the surface of the
projection 9 which is made separately from the elastic body 3A can
be covered with a covering member.
* * * * *