U.S. patent application number 13/695077 was filed with the patent office on 2014-05-01 for asphalt pavement constructing machine and method of operation.
This patent application is currently assigned to VOLVO CONSTRUCTION EQUIPMENT AB. The applicant listed for this patent is John R. Haupt, Michael P. MacDonald. Invention is credited to John R. Haupt, Michael P. MacDonald.
Application Number | 20140119827 13/695077 |
Document ID | / |
Family ID | 47041843 |
Filed Date | 2014-05-01 |
United States Patent
Application |
20140119827 |
Kind Code |
A1 |
Haupt; John R. ; et
al. |
May 1, 2014 |
ASPHALT PAVEMENT CONSTRUCTING MACHINE AND METHOD OF OPERATION
Abstract
The present invention relates to an asphalt pavement
constructing machine and a method for operating an asphalt pavement
constructing machine provided with an asphalt compacting surface
for compacting asphalt mix on a paving surface during an asphalt
pavement formation operation. At least one exciter is provided that
vibrates the compacting surface at one or more frequencies selected
to prevent the asphalt mix from adhering to the compacting
surface.
Inventors: |
Haupt; John R.;
(Shippensburg, PA) ; MacDonald; Michael P.;
(Chambersburg, PA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Haupt; John R.
MacDonald; Michael P. |
Shippensburg
Chambersburg |
PA
PA |
US
US |
|
|
Assignee: |
VOLVO CONSTRUCTION EQUIPMENT
AB
ESKILSTUNA
SE
|
Family ID: |
47041843 |
Appl. No.: |
13/695077 |
Filed: |
October 26, 2012 |
PCT Filed: |
October 26, 2012 |
PCT NO: |
PCT/US2011/032970 |
371 Date: |
October 29, 2012 |
Current U.S.
Class: |
404/75 ;
404/117 |
Current CPC
Class: |
E01C 19/286 20130101;
E01C 19/238 20130101; E01C 19/38 20130101; E01C 19/4853
20130101 |
Class at
Publication: |
404/75 ;
404/117 |
International
Class: |
E01C 19/38 20060101
E01C019/38 |
Claims
1. An asphalt pavement constructing machine, comprising: an asphalt
compacting surface; and at least one exciter that vibrates the
compacting surface at one or more frequencies selected to prevent
asphalt adhering to the compacting surface.
2. The asphalt pavement constructing machine according to claim 1,
wherein: the asphalt compacting machine is a rolling compactor
provided with the asphalt compacting surface and another asphalt
compacting surface; at least one other exciter vibrates the another
compacting surface at an frequency that prevents asphalt mix
adhering to the another compacting surface; and the asphalt
compacting surfaces are cylindrical and located on first and second
rollers that propel the rolling compactor.
3. The asphalt pavement constructing machine according to claim 1,
wherein: the asphalt compacting machine is an asphalt paver
provided with an asphalt hopper, an asphalt conveyor, an asphalt
spreader, and a screed; and the asphalt compacting surface is a
generally flat surface located on the underside of the screed.
4. The asphalt pavement constructing machine according to claim 1,
wherein the at least one exciter is a piezoelectric exciter.
5. The asphalt pavement constructing machine according to claim 1,
wherein the at least one exciter is an electromagnetic exciter.
6. The asphalt pavement constructing machine according to claim 1,
wherein the at least one exciter is a hydraulic exciter.
7. A method for operating an asphalt pavement constructing machine
provided with a compacting surface, the method comprising the steps
of: using the compacting surface to compact asphalt mix on a paving
surface during an asphalt pavement formation operation; and using
at least one exciter to vibrate the compacting surface at one or
more frequencies selected to prevent the asphalt mix from adhering
to the compacting surface.
8. The method according to claim 7, wherein: the asphalt compacting
machine is a rolling compactor provided with the asphalt compacting
surface and another asphalt compacting surface; the asphalt
compacting surfaces are cylindrical and located on first and second
rollers that propel the rolling compactor; and the method further
comprising the step of using at least one other exciter to vibrate
the another compacting surface at one or more frequencies selected
to prevent asphalt mix adhering to the another compacting
surface.
9. The method according to claim 7, wherein the asphalt compacting
machine is a paver provided with an asphalt hopper, an asphalt
conveyor, an asphalt spreader, and a screed and the asphalt
compacting surface is a generally flat surface located on the
underside of the screed, the method further comprising the steps
of: using the asphalt hopper to receive asphalt mix; using the
conveyor to deliver the asphalt mix to the auger; using the auger
to spread the asphalt mix on a paving surface; and using the
compacting surface to compact the asphalt mix, whereby an asphalt
pavement is provided on the paving surface.
10. The method according to claim 7, wherein the at least one
exciter is a piezoelectric exciter.
11. The method according to claim 7, wherein the at least one
exciter is an electro-magnetic exciter.
12. The method according to claim 7, wherein the at least one
exciter is a hydraulic exciter
Description
FIELD OF THE INVENTION
[0001] The present invention relates to asphalt pavement
constructing machines provided with at least one compacting surface
vibrated at one or more frequencies selected to prevent asphalt
adhering to the compacting surface.
BACKGROUND OF THE INVENTION
[0002] The formation of asphalt pavement typically involves a
number of asphalt pavement constructing machines. An asphalt paver
typically receives, deposits, and performs at least a partial
compaction of the asphalt mix to form a freshly laid asphalt
pavement. After initial compaction by the asphalt paver, a
compactor, such as, a roller or drum compactor, is typically used
for final compaction and finishing of the freshly laid asphalt
pavement. During both laying and compaction, adherence of asphalt
to the compacting surfaces of the paver and/or compactor may damage
the asphalt pavement and generate surface impressions in the top
surface of the pavement as the asphalt is compacted, thus, leading
to costly repair and delays for the paving contractor. Accordingly,
systems have been devised to prevent this occurrence.
[0003] With respect to pavers, the current practice for preventing
adherence of asphalt involves heating the compacting surface(s),
which is typically located on the underside of a screed (or screed
plate), to several hundred degrees Fahrenheit. Since it is
difficult to heat the screed uniformly, often times the uneven
heating will cause the compacting surface to deform, which, in
turn, results in an uneven contour of the asphalt pavement and a
top surface that has slight depressions. Additionally, large
amounts of energy are required for the screed to be preheated,
which can take as long as 20 minutes before work can be performed.
Furthermore, since the top of the screed typically functions as a
working platform for workers, the thermal radiation generated
during this process produces an uncomfortably hot working
environment.
[0004] With respect to compactors, the current practice for
preventing adherence of asphalt involves water spray systems.
Scrapers are also used, but only to remove asphalt after it adheres
to the compacting surfaces of the roller and, accordingly, after
impressions have already been left in the top surface of the
pavement. In addition to generating undesirable cooling of the
asphalt pavement, water spray systems are large and bulky. In order
to be effective, the water must coat the entire compacting surface
of the roller, which may be difficult for a number of reasons,
including wind and clogged nozzles. This system also requires
numerous components, including large tanks of water that must
constantly be refilled, filters that must be checked, and pumps
that must operate correctly at all times. In order to ensure
complete water coverage frequent inspection and repair is
common.
[0005] The present invention relates to asphalt pavement
constructing machines provided with a compacting surface vibrated
at one or more frequencies selected to prevent asphalt mix adhering
to the compacting surface.
SUMMARY OF THE INVENTION
[0006] According to one aspect of the present invention, an asphalt
pavement constructing machine comprises an asphalt compacting
surface and at least one exciter that vibrates the compacting
surface at one or more frequencies selected to prevent asphalt
adhering to the compacting surface.
[0007] According to another aspect of the present invention, a
method for operating an asphalt pavement constructing machine
provided with a compacting surface comprises the steps of using the
compacting surface to compact asphalt mix on a paving surface
during an asphalt pavement formation operation and using at least
one exciter to vibrate the compacting surface at one or more
frequencies selected to prevent the asphalt mix from adhering to
the compacting surface.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 illustrates a side view of an asphalt pavement
constructing machine according to one embodiment.
[0009] FIG. 2 illustrates a compacting surface according to one
embodiment.
[0010] FIG. 3 illustrates a side view of an asphalt pavement
constructing machine according to another embodiment.
[0011] FIG. 4 illustrates compacting surfaces according to one
embodiment.
DETAILED DESCRIPTON OF THE INVENTION
[0012] Turning now to FIG. 1, an asphalt pavement constructing
machine according to one embodiment is depicted. As shown, the
asphalt pavement constructing machine is a paver 15 configured to
receive, deposit, and partially compact asphalt mix 5 and form an
asphalt pavement 7 on top of a paving surface 6. As shown therein
the paver 15 may be provided with an asphalt hopper 20, an asphalt
conveyor 25, an asphalt spreader 30, a screed 40 supported by tow
arms, as at 43, and an asphalt compacting surface 45.
[0013] Those of ordinary skill in the art will appreciate that
during a paving operation, asphalt mix 5 is typically loaded onto
the paver 15 and temporarily held in an asphalt hopper, such as
asphalt hopper 20. Those of ordinary skilled in the art will also
appreciate that during a paving operation, one or more asphalt
conveyors, such as asphalt conveyor 25, typically transport the
asphalt mix 5 from the asphalt hopper 20 and deposit it on a paving
surface, such as paving surface 6, whereat one or more asphalt
spreaders, such as asphalt spreader 30, which may be in the form of
one or more augers, as shown, spread the asphalt mix 5 on the
paving surface 6 in a direction that is lateral with respect to a
direction of travel of the paver 15. Those of ordinary skill in the
art will appreciate that the asphalt mix 5 is compacted after the
asphalt mix 5 is deposited on the paving surface 6 and laterally
distributed on the paving surface 6 by the asphalt spreader 30.
[0014] As shown in FIG. 1, the paver 15 is provided with at least
one asphalt compacting surface, such as for example, asphalt
compacting surface 45, which compacts the asphalt mix 5 to form an
asphalt pavement 7 on the paving surface 6. As shown in the present
embodiment, the asphalt compacting surface 45 is a generally flat
surface located on the underside 41 of a screed 40, which may be
provided with a work platform 42 whereupon workers may stand. Those
of ordinary skill in the art will appreciate that as the paver 15
travels along the paving surface 6, for example by a track assembly
or wheels, as at 16, the asphalt compacting surface 45 exerts a
compressive force on the deposited asphalt mix 5 to smooth and at
least partially compact the asphalt mix 5, whereby a freshly laid
asphalt pavement 7 is formed on the paving surface 6.
[0015] According to one aspect of the present embodiment, the
asphalt compacting surface 45 is vibrated at one or more
frequencies. According to another aspect of the present embodiment,
the asphalt compacting surface 40 is vibrated at one or more
frequencies to prevent asphalt adhering to the asphalt compacting
surface 45 as the asphalt mix 5 is compacted by the asphalt
compacting surface 45.
[0016] Turning now to FIGS. 1 and 2, as shown, the paver 15
includes one or more exciters 50, including, for example
electromagnetic, as at 50a (FIG. 2) piezoelectric, as at 50a' (FIG.
4), or hydraulic exciters, as at 50a'' (FIG. 4), that vibrate the
asphalt compacting surface 45 at one or more frequencies selected
to prevent asphalt adhering to the asphalt compacting surface 45 as
the asphalt mix 5 is contacted by the asphalt compacting surface
45. Those of ordinary skill in the art will appreciate that it is
within the scope of the present invention to utilize any number of
exciters 50 and to distribute the exciters with respect to the
asphalt compacting surface 45 in any manner that excites the
asphalt compacting surface 45 in a manner that prevents asphalt
from adhering to the asphalt compacting surface 45. In FIGS. 1 and
2, for example, a plurality of exciters 50 are shown located within
the screed 40, whereby the asphalt compacting surface 45 is
vibrated indirectly by the exciters 50. As shown in FIG. 2, one or
more electronics 100 may be used to drive the exciters 50 and
control the frequency of vibration(s) generated by the exciters
50.
[0017] Turning now to FIG. 3, an asphalt pavement constructing
machine according to another embodiment is depicted. As shown
therein, the asphalt pavement constructing machine is a rolling
compactor 60 that may be used for final compaction of pavement 7.
As shown in FIG. 3, the rolling compactor 60 is provided with first
and second rollers 61, 62. According to one aspect of the present
invention, the rollers 61, 62 propel the rolling compactor 60 along
the pavement 7. According to another aspect of the present
embodiment, the rollers 61, 62 are configured to perform a final
compaction of the pavement 7. According to yet another aspect of
the present embodiment, the rollers 61, 62 may be used to provide
the pavement 7 with a generally smooth finished top surface 7a.
[0018] As shown in FIG. 3, the rolling compactor is provided with
asphalt compacting surfaces 63, 64 that are cylindrical in shape
and located on the outer circumferential surface of the rollers 61,
62 that propel the rolling compactor 60 along the pavement 7. Those
of ordinary skill in the art will appreciate that as the rollers
61, 62 propel the rolling compactor 60 along the pavement 7 that
the asphalt compacting surfaces 63, 64 exert a heavy compacting
force on the pavement 7. Those of ordinary skill in the art will
appreciate that the heavy compacting force exerted by the asphalt
compacting surfaces 63, 64 compacts the pavement 7. Those of
ordinary skill in the art will appreciate that the heavy compacting
force exerted by the asphalt compacting surfaces 63, 64 preferably
provide the pavement 7 with a generally smooth finished top surface
7a.
[0019] According to one aspect of the present embodiment, the
asphalt compacting surfaces 63, 64 are vibrated at one or more
frequencies. According to another aspect of the present embodiment,
the asphalt compacting surfaces 63, 64 are vibrated at one or more
frequencies to prevent asphalt adhering to the asphalt compacting
surfaces 63, 64 as the pavement 7 is compacted by the asphalt
compacting surfaces 63, 64.
[0020] Turning now back to FIG. 3, as shown the rolling compactor
60 includes a plurality of exciters 50', including, for example
electromagnetic, as at 50a (FIG. 2) piezoelectric, as at 50a' (FIG.
4), or hydraulic exciters, as at 50a'' (FIG. 4), that vibrate the
asphalt compacting surfaces 63, 64 at one or more frequencies
selected to prevent asphalt adhering to the asphalt compacting
surfaces 63, 64 as the freshly laid pavement 7' is compacted by the
asphalt compacting surfaces 63, 64. Those of ordinary skill in the
art will appreciate that it is within the scope of the present
invention to utilize any number of exciters 50' and to distribute
the exciters with respect to the asphalt compacting surfaces 63, 64
in any manner that excites the asphalt compacting surfaces 63, 64.
In FIGS. 3 and 4, for example, a plurality of exciters 50' are
shown located within the rollers 61, 62, whereby the asphalt
compacting surfaces 63, 64 are vibrated indirectly by the exciters
50, such as, for example, by placing the exciters 50 in direct
contact with an inner cylindrical surface 61a, 62a of the rollers
61, 62. As shown in FIG. 2, one or more electronics 100' may be
used to drive the exciters 50' and control the frequency of
vibration(s) generated by the exciters 50'.
[0021] Advantageously, by employing vibrations at frequencies in
excess of the frequencies used for compacting efficiency, i.e.
frequencies in excess of about 70 Hz, compaction efficiency will
not be degraded. While those of ordinary skill in the art will
appreciate that an optimal frequency may be deduced from empirical
observation, according to one aspect of the present embodiments the
frequency vibration may be substantially equal to or greater than
about 100 Hz. According to yet another aspect of the present
embodiments, the frequency vibration may be substantially equal to
or greater than about 1 kHz. According to another aspect of the
present embodiments the frequency of vibration may be in the
ultrasonic range and substantially equal to or greater than about
20 kHz.
[0022] Advantageously, the principals of the aforementioned
embodiments may be utilized in conjunction with currently known
systems, i.e. heating, scrapers, as at 80, 81 (FIG. 3), or water
systems, for preventing asphalt adherence or may obviate the use of
one or more currently known systems. Advantageously, by controlling
the frequency of vibration, the adherence of asphalt to the asphalt
compacting surfaces on asphalt pavement constructing machines,
including, for example, the asphalt compacting surface 45 on paver
15 or asphalt compacting surfaces 63, 64 on the rolling compactor
60, may be prevented
[0023] The detailed descriptions of the above embodiments are not
exhaustive descriptions of all embodiments contemplated by the
inventors to be within the scope of the invention. The present
description depicts specific examples to teach those skilled in the
art how to make and use the best mode of the invention. Those
skilled in the art will appreciate variations from these examples
that fall within the scope of the invention. Those of ordinary
skill in the art will also appreciate that some conventional
aspects have been simplified or omitted.
[0024] Persons skilled in the art will recognize that certain
elements of the above-described embodiments and examples may
variously be combined or eliminated to create further embodiments,
and such further embodiments fall within the scope and teachings of
the invention. It will also be apparent to those of ordinary skill
in the art that the above-described embodiments may be combined in
whole or in part to create additional embodiments within the scope
and teachings of the invention. Thus, although specific embodiments
of, and examples for, the invention are described herein for
illustrative purposes, various equivalent modifications are
possible within the scope of the invention, as those skilled in the
relevant art will recognize. Accordingly, the scope of the
invention is determined from the appended claims and equivalents
thereof.
* * * * *