U.S. patent application number 13/084090 was filed with the patent office on 2011-11-03 for apparatus for processing ground surfaces.
This patent application is currently assigned to BOMAG GMBH. Invention is credited to Robert Laux, Marco Reuter.
Application Number | 20110266858 13/084090 |
Document ID | / |
Family ID | 44730485 |
Filed Date | 2011-11-03 |
United States Patent
Application |
20110266858 |
Kind Code |
A1 |
Laux; Robert ; et
al. |
November 3, 2011 |
Apparatus For Processing Ground Surfaces
Abstract
An apparatus for processing ground surfaces comprises a moving
device, a working device, especially a milling device for milling
the ground surface, and a drive device for driving the moving
device and the working device, wherein the working device is
movable between a working position, in which it is in operative
engagement with the ground surface, and a maneuvering position, in
which it is not in operative engagement with the ground surface,
wherein a sensor device is provided which detects the maneuvering
position and/or at least one working parameter of the working
device, namely its power consumption, working speed, rotational
speed or its inclination, and/or at least one load parameter of the
moving device, and a control device which reduces the frictional
connection between the drive device and the working device and/or
the drive power transmitted by the drive device to the working
device in the maneuvering position and/or in case of the detection
of a deviation of the at least one detected working parameter or
load parameter from a set parameter value.
Inventors: |
Laux; Robert; (Neuwied,
DE) ; Reuter; Marco; (Emmelshausen, DE) |
Assignee: |
BOMAG GMBH
Boppard
DE
|
Family ID: |
44730485 |
Appl. No.: |
13/084090 |
Filed: |
April 11, 2011 |
Current U.S.
Class: |
299/1.5 |
Current CPC
Class: |
A01B 79/005 20130101;
E01C 19/004 20130101; B28D 7/005 20130101; B28D 1/18 20130101; E01C
23/088 20130101; A01B 33/02 20130101 |
Class at
Publication: |
299/1.5 |
International
Class: |
E01C 23/12 20060101
E01C023/12; E21C 35/24 20060101 E21C035/24 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 14, 2010 |
DE |
10 2010 014 893.8 |
Claims
1. An apparatus for processing ground surfaces, comprising: a
moving device; a working device; and a drive device for driving the
moving device and the working device, wherein the working device is
movable between a working position, in which it is in operative
engagement with the ground surface, and a maneuvering position, in
which it is not in operative engagement with the ground surface; a
sensor device which detects the maneuvering position and/or at
least one working parameter of the working device and/or at least
one load parameter of the moving device; and a control device which
reduces a frictional connection between the drive device and the
working device and/or a drive power transmitted by the drive device
to the working device in the maneuvering position and/or in case of
detection of a deviation of the at least one detected working
parameter or load parameter from a set parameter value.
2. An apparatus according to claim 1, wherein the working device
(4) is in operative connection with the drive device (6) via a
coupling device (16; 19), wherein the frictional connection and/or
a coupling slip of the coupling device (16) is controllable by the
control device (14).
3. An apparatus according to claim 2, wherein the frictional
connection and/or the coupling slip of the coupling device is
adjustable in such a way that essentially no coupling slip results
in the maneuvering position and that coupling slip results in the
working position.
4. An apparatus according to claim 1, wherein the sensor device
comprises at least one load sensor which is in operative connection
with the moving device in order to detect load parameters acting on
the moving device comprising at least one of weight loads and/or
acceleration loads and/or changes in the latter.
5. An apparatus according to claim 1, wherein the sensor device
comprises at least one inclination sensor for detecting an
inclination and/or a change in the inclination of the
apparatus.
6. An apparatus according to claim 1, wherein the sensor device
comprises at least one workload sensor for detecting a power
consumption and/or a working speed and/or a rotational speed of the
working device and/or changes in the latter.
7. An apparatus according to claim 6, wherein the workload sensor
is in operative connection with a coupling device for detecting
drive power acting on the coupling device and/or drive speed and/or
coupling slip and/or changes in the latter.
8. An apparatus according to claim 1, wherein the drive device
comprises an auxiliary drive device and a main drive device,
wherein the working device is in operative connection with the
auxiliary drive device in maneuvering operation and with the main
drive device in working operation, and wherein the auxiliary drive
device provides a lower working power than the main drive
device.
9. An apparatus according to claim 8, wherein the auxiliary drive
device is configured to synchronize a working speed of the working
device with a drive speed of the main drive device in the
maneuvering position.
10. An apparatus according to claim 2, wherein the coupling device
comprises a belt drive having a belt tension which is adjustable
for controlling the frictional connection and/or the coupling slip
by means of the control device.
11. An apparatus according to claim 1, wherein the working device
comprises a milling device for milling the ground surface.
12. An apparatus according to claim 1, wherein the at least one
working parameter of the working device comprises at least one of a
power consumption, working speed rotational speed and/or
inclination of the working device.
13. An apparatus according to claim 9, wherein the working speed of
working device comprises a rotational speed of the working
device.
14. An apparatus according to claim 10, wherein the belt drive
comprises a belt tightener.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to an apparatus for processing
ground surfaces.
BACKGROUND OF THE INVENTION
[0002] Such automotive construction machines for processing
surfaces are known from EP 1 408 158 B1.
[0003] The road milling machine which is described therein
comprises a machine frame with a drive motor for driving moving
devices and for driving working devices. The moving devices can
consist of wheels or track assemblies which are connected with the
machine frame via lifting columns.
[0004] As a roller drive, the drive device especially drives a
milling drum for milling ground surfaces, preferably in
counter-rotating operation. The milling drum can be uncoupled from
the drive train by means of a coupling device. A scraper blade is
disposed in a height-adjustable manner in the direction of travel
behind the milling drum, which scraper blade slides over the
surface that has been milled or is to be milled by the milling
drum. The bottom edge of the scraper blade is always disposed at
the lowest plane of the cutting circle of the milling drum in
milling operation.
[0005] Such construction machines work in a strip-like manner
according to the width of the milling drum. This means that, after
completion of a predetermined section of milled ground surface, the
construction machine needs to travel back in order to mill off an
adjacent strip. This reverse travelling is known as maneuvering
operation. In maneuvering operation, the working device is in the
so-called maneuvering position, while it is in the so-called
working position in working operation.
[0006] What is relevant here is that, in contrast to working
operation, the milling drum has the same rotational direction in
maneuvering operation as the moving devices. This is also known as
synchronized operation.
[0007] In order to prevent any inadvertent collision of the tools
of the milling drum with the ground surface in synchronized
operation, it is necessary according to the state of the art that
the milling drum stands still during reverse travel because the
construction machine can be accelerated in an uncontrolled and
sudden manner in case of an inadvertent engagement of the milling
drum with the ground surface. Since the circumferential speed of
the milling drum, especially at operating speed, can be many times,
e.g., three times, the travelling speed, a strong and uncontrolled
acceleration of the road construction machine can occur in case of
a sudden engagement of the milling drum. Moreover, there is a
danger that the milling drum will be damaged in the event of an
inadvertent engagement with the ground surface.
[0008] According to the aforementioned EP 1 408 158 B1, the milling
drum is decoupled from the drive train after it has been moved
upward from the milling cut at the end of a strip of ground surface
to be processed. The construction machine can now be moved back
without any danger in maneuvering operation to the beginning of the
section to be processed, wherein the drive motor at first needs to
be throttled to idle speed for the renewed coupling of the milling
drum. Both the lowering of the drive motor, which consists of an
internal combustion engine, to idle speed and also the renewed
acceleration to operating speed requires a considerable waiting
period, unlike a conventional passenger car engine.
[0009] Before processing the next strip, the drive motor needs to
be brought back again to operating speed. These processes are very
time-consuming and very onerous for the vehicle operator,
especially in cases where short sections are to be processed.
Moreover, the continual engagement of the clutch and the resulting
frequent load changes of the engine lead to increased wear and tear
on the coupling device, the engine and all components involved in
the drive train.
[0010] An automotive construction machine developed for remedying
these disadvantages and a method for processing ground surfaces is
known from DE 10 2006 024 123 A1.
[0011] The road milling machine described therein provides that the
milling drum can be removed from the milling cut by pivoting or
lifting by means of lifting columns of the moving devices. The
distance of the lifted milling drum from the ground surface is
monitored by a monitoring device. If this monitoring device detects
a shortfall in a predetermined distance, either the lifted milling
drum which continues to rotate at this point is decoupled from the
drive motor or the moving devices are decoupled from the drive
motor, the machine frame is lifted or an alarm signal is generated.
If the milling drum actually has ground contact, it is merely
necessary to destroy the current rotational energy. The mass of the
construction machine is sufficient in order to prevent a jump of
the construction machine in the direction of travel.
[0012] In such a construction machine, the milling drum can remain
coupled with the drive motor permanently, in particular in a
synchronous maneuvering operation. The time lost when making the
necessary adjustments, e.g., by throttling and accelerating the
drive motor, is reduced to a considerable extent.
[0013] Such a monitoring device, however, does not offer any
guarantee for a reliable and flawless monitoring with respect to
the detection of the distance of the rotating, lifted milling drum
from the ground surface. There is a danger, for example in case of
flaws in the ground surface or suddenly rising or falling ground
surfaces, that a secure reaction of the monitoring device does not
occur or only occurs too late. This can have serious consequences
because the rotating milling drum might engage the ground surface
and accelerate the construction machine in a sudden and
uncontrolled manner.
[0014] The invention is therefore based on the object of providing
an apparatus for processing ground surfaces, with which the
processing of ground surfaces can be reliably streamlined and with
which in particular the time required for changing between a
working operation and a maneuvering operation can be shortened and
corresponding waiting periods reduced.
SUMMARY OF THE INVENTION
[0015] According to one embodiment of the present invention, an
apparatus for processing ground surfaces comprises a moving device,
a working device and especially a milling device for milling the
ground surface, and a drive device for driving the moving device
and the working device which can be moved to a working position, in
which it is in operative engagement with the ground surface, and to
a maneuvering position, in which it is not in operative engagement
with the ground surface, wherein a sensor device is provided which
detects the maneuvering position and/or at least one working
parameter of the working device, namely its power consumption,
working speed, rotational speed or its inclination, and/or at least
one load parameter of the moving device, and a control device which
reduces the frictional connection between the drive device and the
working device and/or the drive power transmitted by the drive
device to the working device in the maneuvering position and/or in
case of detection of a deviation of the at least one detected
working parameter or load parameter from a set parameter value.
[0016] Preferably, the working device comprises at least one
milling device for milling the ground surface, wherein the term
milling device means any tools and devices for processing the
ground surface such as grinding, compacting, milling or leveling
tools. In relation to the rotational direction of the milling
device, the moving device preferably has the same direction of
rotation in maneuvering operation and an opposite direction of
rotation in working operation.
[0017] It is principally possible in the apparatus in accordance
with the present invention to adapt the drive device as one drive
or a plurality of drives. Accordingly, the working devices and the
moving devices can be driven either by a common drive or also by
their own drives. This will be described below in greater
detail.
[0018] One aspect of the invention is that, inter alia, the working
device can remain permanently coupled with the drive device, i.e.
in working operation as well as in maneuvering operation, by the
use of the above sensors specific in particular to the working
parameters.
[0019] The control device is adapted so as to monitor the
frictional connection at work between the drive device and the
working device and reduce such frictional connection when a
maneuvering operation and/or a deviation of a detected parameter
from a set parameter is determined. These detected parameters are
working parameters of the working device or the entire apparatus,
namely their power consumption, working speed, rotational speed or
inclination, and/or load parameter of the moving device or
apparatus, such as the weight acting on the moving device or
acceleration.
[0020] It is possible, for example, to reduce the drive power
transferred to the drive device during the detection of the
maneuvering operation via the control device in such a way that, in
case of malfunction, i.e. the unintended contact of the drive
device with the ground surface, it is merely necessary to brake the
machine's reduced drive power. Although the drive device in this
state is still operating at a (reduced) working speed from which
working operation can be resumed quickly again after maneuvering,
this speed is no longer sufficient to accelerate the machine in an
uncontrolled manner in case of a sudden inadvertent engagement.
[0021] Furthermore, unintended action of the drive device on the
apparatus, e.g., in the case of an unintended contact of the
working device with the ground surface during maneuvering
operation, can be prevented by a selective controlling of the
frictional connection between the drive device and the working
device; in particular the safety of processing ground surfaces can
thus be improved with such an apparatus. A frictional connection
can thus be reduced in such a way that although the drive device is
further driven in the maneuvering position at a set speed,
preferably the working speed, a frictional connection threshold is
exceeded upon contact with the ground surface so that no further
drive power that can drive the apparatus in an uncontrolled manner
is transmitted.
[0022] In contrast to the detection of the distance between the
working device and the ground surface and the reaction to the
detection of a shortfall in this distance, the apparatus in
accordance with the present invention offers a much more precise
and secure possibility for checking whether or not there is a
trouble-free maneuvering operation. In particular the detection of
the working parameters acting on the apparatus, especially the
working device, is an essential aspect here. Thus, e.g., the speed
of the working device can be detected by using corresponding
sensors. Since the rotational speed will change suddenly upon a
sudden engagement of the working device with the ground surface or
any other impediment, a malfunction can thus be inferred directly
and effectively. The same applies to the monitoring of the required
drive power, the consumption of which will also rise suddenly in
case of a malfunction as described above. The same applies to a
change in inclination of the working device or the apparatus
itself.
[0023] In accordance with the present invention, the tedious
deactivation of the drive train of the working device and, in turn,
the tedious reactivation of the subsequent working operation are no
longer necessary when initiating the maneuvering operation. This
allows the operator to execute the tasks to be performed with the
apparatus much more efficiently.
[0024] As already explained above, the working device and
especially the milling device of the apparatus are preferably in
operative connection with a drive device via a coupling device. The
control device controls the frictional connection and/or the slip
(clutch slip) of this coupling device. This way, the working device
is still driven especially in maneuvering operation, while the
reduced frictional connection ensures that no acceleration of the
apparatus is initiated via its drive in case of inadvertent contact
of the working device with the ground surface.
[0025] The frictional connection and especially the clutch slip of
the clutch device are adjustable in such a way that there is
essentially no clutch slip in maneuvering operation while there is
clutch slip in working operation. This can preferably be set
individually for any apparatus, any drive device and for further
ambient parameters, for example the working speed, the type of
ground surface to be processed, etc.
[0026] The apparatus is further characterized in that the sensor
device of the apparatus preferably comprises at least one load
sensor which is in operative connection with the moving device.
This detects the load parameters acting on the moving device such
as weight loads, acceleration loads and/or changes in the latter.
Accordingly, any unexpected change in force or alleviation not
initiated by the operator and caused by an unintentional engagement
of the drive device with the ground surface or any other impediment
can be identified. In response, the frictional connection between
the drive device and the working device and/or the drive power
transmitted to the drive device can be reduced rapidly and
effectively or corresponding safeguards taken.
[0027] Preferably, the sensor device of the apparatus comprises at
least one inclination sensor which detects an inclination and/or a
change in inclination of the apparatus. An unplanned engagement of
the drive device or a similar disturbance which inevitably leads to
an especially abrupt change in the inclination of the apparatus can
thus be detected quickly and reliably.
[0028] The sensor device preferably comprises at least one workload
sensor which detects the power consumption and/or the working speed
and/or the rotational speed of the working device and/or changes in
the latter. This way, the frictional connection or the drive power
between the drive device and the working device can be reduced or
corresponding safeguards taken in case of deviations of one of
these parameters from a set parameter value.
[0029] In one embodiment, this workload sensor is in operative
connection with the coupling device. Accordingly, the drive power,
the drive speed, the coupling slip and/or changes in the latter can
be detected for the coupling device and one of the above
"safeguards" can be taken in case of a deviation of one of these
parameters from a set parameter value.
[0030] A further advantage of the sensors and monitoring device
described above is the possibility of monitoring the machine also
in terms of its operability, especially in normal working
operation. Disturbances in operation, which can be inferred from
e.g. defective clutch elements, worn-out tools etc., can thus be
detected with the same sensors in a secure and cost-effective
way.
[0031] In a further embodiment, the drive device preferably
comprises an auxiliary drive device and a main drive device. The
working device is or can be connected with the auxiliary drive
device in maneuvering operation and with the main drive device or
with both of these drive devices in working operation. Here, the
auxiliary drive device provides less working power than the main
drive device. It is thus ensured that the working device of the
construction machine can be accelerated to its working speed or
placed in a working mode rapidly after a maneuvering operation,
while working operation is not possible by the drive of the
auxiliary drive device. The security function thus remains reliably
intact. It is noted here that such an embodiment with an auxiliary
drive device and a main drive device can also be applied to
conventional apparatuses for processing ground surfaces. It
principally offers the possibility of switching an apparatus
quickly between maneuvering and working operation.
[0032] In one embodiment, the drive device is adapted in such a way
that, as a result of the auxiliary drive device, a synchronization
of the working speed of the working device, especially its
rotational speed, with the drive speed of the main drive device is
possible, especially in maneuvering operation. A "switching"
between the main drive device and the auxiliary drive device and
especially a reactivation of the connection between the main drive
device and the working device can thus be ensured rapidly, while
the processing time for a given ground surface and in particular
the time required for switching are reduced.
[0033] According to one embodiment, the drive device and especially
the auxiliary drive device are adapted in such a way that the drive
device can be accelerated by the auxiliary drive device in
particular to the working speed of the main drive device during a
decoupling of the main drive device from the working device as well
as in maneuvering operation. This way, it is possible to accelerate
the working device back to the speed of the main drive device,
especially shortly before the conversion of the machine from
maneuvering operation back to working operation, so that a
switching and the renewed commencement of working operation are
possible in a simple manner without interruptions.
[0034] The auxiliary drive device preferably comprises an electric
or hydraulic drive so that rapid response characteristics are
guaranteed. Preferably, the "charging" of the auxiliary drive
device occurs by means of the main drive device and in particular
in the working state in which the main drive device is alleviated,
i.e., for example, in maneuvering operation.
[0035] In one embodiment, the coupling device preferably comprises
a belt drive. Its belt tension is preferably adjustable by means of
the control device, especially by way of a belt tightener, for
controlling the frictional connection and/or the coupling slip. The
belt drive preferably comprises a hydraulic or similarly modifiable
belt tightener. The above safeguards during maneuvering operation
can thus be easily ensured.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] The invention will be described below with reference to
examples which will be explained below in greater detail with
reference to the drawings.
[0037] FIG. 1 shows an apparatus for processing ground surfaces in
working operation;
[0038] FIG. 2 shows a schematic depiction of a second embodiment of
the apparatus and in particular its drive diagram; and
[0039] FIG. 3 shows a schematic depiction of a third embodiment of
the apparatus and in particular its coupling diagram.
[0040] The same reference numerals will be used in the description
below for the same and functionally equivalent parts.
DETAILED DESCRIPTION OF THE INVENTION
[0041] The apparatus or construction machine 1 as shown in FIG. 1
for processing ground surfaces comprises a machine frame 3 and a
drive device 6. The drive device 6 is used for driving moving
devices 2 and a working device, which is a milling device 4 in this
case. The moving devices 2 consist of wheels in this embodiment.
The milling device 4 can be decoupled from the drive device 6 by
means of a coupling device (not shown) and can be brought into a
lifted position by means of lifting devices 5 on the machine frame
3 (not shown).
[0042] The lowered position shown here corresponds to the working
position or working operation in which the illustrated ground
surface 13 is milled off. As shown, the rotational direction of the
working device 4 runs opposite to the direction of movement of the
apparatus 1 or the direction of rotation of the wheels 2 in working
operation. In the lifted or maneuvering position (not shown), the
working device 4 is no longer engaged with the ground surface 13 to
be milled. In this position, the apparatus is moved "backwards" to
the starting point of a new milling strip. During this changeover,
the rotational movement of the working device 4 and the direction
of movement of the apparatus 1 are synchronous. If an uncontrolled
engagement of the working device 4 with the ground surface 13 or
another impediment occurs, the apparatus 1 is accelerated in an
abrupt and uncontrolled manner. It is this "malfunction" that shall
be avoided.
[0043] This is possible in particular by means of a reduction of
the drive power transferred to the working device 4 in maneuvering
operation. For this purpose, working parameters and load parameters
of the apparatus 1 are detected by way of corresponding sensors,
the detected parameters are compared with existing set reference
parameters and corresponding safeguards remedying the "malfunction"
outlined above are initiated by way of a suitable control device. A
sensor device with different sensors for detecting a deviation of
at least one working parameter or load parameter from the set
parameter value is provided. In this regard, the apparatus 1 can
principally be provided with individual sensors or a combination of
these sensors. The apparatus 1 according to FIG. 1 thus comprises
at least one load sensor 8, at least one workload sensor 10 and at
least one inclination sensor 12, the function of which will be
explained below in greater detail.
[0044] The load sensor 8 detects the load parameters acting on the
moving device 2 such as weight loads, acceleration loads or changes
in the latter in order to detect any unexpected changes in force or
alleviation not initiated by the operator. If, for example, there
is a sudden engagement of the working device 4 with the ground
surface 13 in maneuvering operation because, e.g., the wheels 2 of
the apparatus 1 pass through a depression, this engagement would
lift the apparatus 1, leading to a brief alleviation of the lifting
devices 5 and to a corresponding detection at the load sensors 8. A
"malfunction" thus detected in maneuvering operation leads to a
direct reaction in the drive system 6 of the working device 4,
while the frictional connection between the drive device 6 and the
working device 4 and/or the power provided or made available by the
drive device 6 to the working device 4 is reduced.
[0045] This analogously applies to the inclination sensor which
detects a change in the inclination of the apparatus caused by
similar events. In this case as well, the frictional connection
between the drive device 6 and the working device 4 and/or the
power provided or made available by the drive device 6 to the
working device 4 is reduced via a corresponding control signal.
[0046] The workload sensor 10, on the other hand, detects the power
consumption, the working speed and/or the speed of the working
device or the milling device 4 provided here or changes in the
latter. Once an especially abrupt rise or fall is detected, a
corresponding control signal is generated and the frictional
connection between the drive device 6 and the milling device 4
and/or the power provided or made available by the drive device 6
to the working device 4 is reduced.
[0047] FIG. 2 schematically shows a second embodiment of the
apparatus 1 and especially its drive diagram. In order to reduce
the changeover time of the apparatus 1 during the change between
maneuvering and working operation, the drive device 6 is not
decoupled from the working device 4 while monitoring is carried out
by means of sensors 8, 10. In order to reduce the danger of an
uncontrolled acceleration of the apparatus 1 in the case of an
unintended engagement of the working device 4 with the ground
surface, the drive device 6 comprises a main drive device 15 and an
auxiliary drive device 18. Both devices 15, 18 can be activated and
deactivated by means of independent coupling devices 16 and 19 of
the working device 4, wherein the control of the coupling devices
16, 19 occurs in dependence on the operation at hand, i.e. the
working or maneuvering operation.
[0048] The working device 4 is coupled with the auxiliary drive
device 18 via the coupling device 19 in maneuvering operation,
whereas a connection is made with the main drive device 15 by means
of the coupling device 16 in working operation. The auxiliary drive
device 18 provides the working device 4 in the coupled state with
less working power than the main drive device 15. It is thus
ensured that the working device 4 of the apparatus is kept in
maneuvering operation at an especially continuous rotational speed
so that the operational state can be reached again rapidly at the
beginning of a new working operation. In order to prevent an
uncontrolled acceleration or damage to the apparatus 1 in
maneuvering operation, the drive power provided by the auxiliary
drive device 18 is set in such a way that the "idling operation" of
the working device 4 is ensured but no working operation is
possible. It is also possible in a similar embodiment to lower the
rotational speed of the working device 4 in maneuvering operation
or even to reduce the same to zero and to accelerate to working
speed or a similar speed shortly before the renewed switching to
working operation in which re-coupling with the main drive device
15 is possible. In this regard, a synchronization of the working
speed of the working device 4 with the drive speed of the main
drive device 15 is thus possible by means of the auxiliary drive
device 18 especially in maneuvering operation.
[0049] The sensors 10 and 8 shown here are also load and workload
sensors. They are used inter alia for monitoring the operation of
the drive devices, in particular for detecting and synchronizing
the rotational speeds of the auxiliary drive device 18, the main
drive device 15 and the working device 4. It is further possible to
make inferences via the sensors with respect to the state of the
drive device 6 including the coupling devices 16, 19.
[0050] FIG. 3 shows a schematic illustration of a third embodiment
of the apparatus 1 and in particular its coupling diagram.
[0051] For the improved detection of a malfunction, the performance
of the coupling device 16 for severing the connection 17 (shown
schematically here) between the drive device 6 and the milling
device or working device 4 can be varied. In the case of the
hydraulically actuated coupling 16 shown here, this occurs by way
of a limitation of the transferable torque or the transferable
drive power by a change of the coupling pressure, shown in diagram
9. This pressure can be set individually for the construction
machine by means of an adjusting device 11. The transferable power
of the hydraulically actuated coupling device 16 is ideally set to
a level so that in particular it does not slip and thus does not
produce any increased wear and tear in the coupling device 16. The
diagram shown here also shows an apparatus 1 in which the
frictional connection or the coupling slip of the coupling device
16 is adjustable by means of a control device. This way, the drive
device 4 can be further driven in maneuvering operation, while it
is still ensured that, as a result of the reduced frictional
connection, no acceleration of the apparatus 1 is initiated via its
drive device 6 in case of unintended contact of the working device
4 with the ground surface 13.
[0052] While the present invention has been illustrated by
description of various embodiments and while those embodiments have
been described in considerable detail, it is not the intention of
Applicants to restrict or in any way limit the scope of the
appended claims to such details. Additional advantages and
modifications will readily appear to those skilled in the art. The
invention in its broader aspects is therefore not limited to the
specific details and illustrative examples shown and described.
Accordingly, departures may be made from such details without
departing from the spirit or scope of Applicants' invention.
* * * * *