Note: Descriptions are shown in the official language in which they were submitted.
CA 02530079 2005-12-14
APPARATUS DRIVEN BY A PRESSURIZED MEDIUM
BACKGROUND
1. Field of Invention
The invention relates to an apparatus driven by a pressurized medium. The
apparatus is comprised of an actuator, which is articulately mounted to be
swingable
around a swing axis, a line segment, and a connecting element, which is
connectable to the actuator. The invention further relates to a loading
machine such
as an agricultural, forestry machine, or a construction machine.
2. Related Technology
German Patent specification DE 14 81 066 discloses a pressurized-medium-
driven apparatus, specifically a hydraulic apparatus employed for swinging,
raising or
lowering extension arms or front-end loaders on loader vehicles. Ordinarily,
such
hydraulic apparatuses have a hydraulic cylinder which is swingably mounted
between the extension arm or swing arm assembly and a frame of the vehicle.
When
the hydraulic cylinder is expanded or contracted, the extension arm or swing
arm
assembly is raised or lowered. Typically, pressurized hydraulic fluid is
supplied to the
hydraulic cylinder via a rigid hydraulic line comprised of metal, which is
connected to
flexible hydraulic tubes comprised of plastic or rubber. The metal hydraulic
lines are
usually mounted on the swingable component parts and are fixed by a suitable
holding means. The flexible hydraulic tubes are particularly used for
connection
between the supply line and the hydraulic cylinder because they are flexibly
deformable. The flexible hydraulic tubes can accommodate the relative
movements
which occur between the hydraulic cylinder and the supply line during a
swinging
movement.
Flexible hydraulic tubes, when used, are susceptible to potential leakage, and
cracking and bursting. Flexible tubes are less robust than metallic lines and
thus are
more susceptible to damage from articles and obstacles that can come into the
range of movement of the hydraulic cylinder. Further, the materials used for
flexible
hydraulic tubes are more apt to crack or burst than the materials of rigid
metal lines.
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In the light of these risks, a safety means can be provided that provides
protection in the event of failure of the flexible hydraulic tubes and to
prevent a
sudden loss of pressure in the hydraulic cylinder as a result of such failure.
Parts of
the hydraulic system that are exposed to the machine load, a loss in pressure
would
be accompanied by sudden lowering of the extension arm or swing arm assembly.
To provide a protective means for the hydraulic cylinders against bursting
tubes,
loader vehicles, such as telescope loaders, are provided with safety valves,
in the
form of load-retaining valves, pressure-retaining valves, or tube break
protectors,
disposed in a part of the hydraulic system exposed to the machine load, namely
between the flexible hydraulic tube and the inlet of the hydraulic cylinder.
These
safety valve arrangements can lead to disadvantageous limitations concerning
the
engineering design and compactness of the hydraulic system, because the safety
valves must be mounted directly on the hydraulic cylinder or integrated into
the
cylinder housing.
SUMMARY
The present invention relates to a pressurized-medium-driven apparatus that
completely eliminates the use of flexible hydraulic tubes in parts of the
hydraulic
system that are exposed to the machine load. According to the present
invention,
the pressurized-medium-driven apparatus has a line segment and a connecting
element that are connected so as to be mutually swingable with respect to each
other around the swing axis. As a result of the fact that the line segment and
the
connecting element can be arranged so as to be mutually swingable around the
swing axis of the actuator, the connecting element, which provides the link
from the
line segment to a pressurized-medium chamber of the actuator, can follow the
swinging movement of the actuator, and thus there is no relative movement
between
the actuator and the connecting element. Preferably, the line segment is
mounted to
or disposed along a component which is to be swung by the actuator. The
component can be an extension arm or swing arm assembly. Consequently, the
relative movement that occurs between the line segment and the connecting
element
is the same as the relative movement that occurs between the actuator and the
component swung by the actuator. The pressurized-medium-driven apparatus can
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be a pneumatic or hydraulic apparatus, wherein a hydraulic or pneumatic
cylinder
can be controlled and operated. The supply of pressurized medium can be from
customary sources such as hydraulic pumps or air compressors, with suitable
valve
means interposed between the source and the line segment for supplying the
cylinder. Thus, the line segment is a part of the connection of the actuator
with the
source of pressurized medium, and can serve both to supply pressurized medium
to
the pressurized-medium chamber of the actuator and to withdraw pressurized
medium from said chamber.
A junction means can be provided between the line segment and the
connecting element to connect the line segment to the connecting element.
Preferably such junction means has a connecting axis that coincides with or
can be
brought into alignment with the swing axis of the actuator. In particular, the
junction
means can comprise a union connector, and an overlapping telescoping pipe ends
having seal means.
Because the junction axis is coaxial with the swing axis, there are no
relative
movements between the connecting element, the hydraulic cylinder or the line
segment. The segment can be a robust rigid piece. The connecting element can
be
directly connected to the cylinder by a flange connection and can serve as a
support
or holding means for the junction means. The additional support provides
assurance
that the junction axis will be maintained in alignment with the swing axis of
the
hydraulic cylinder.
In an alternative configuration, the connecting element can be a rigid
hydraulic
tube or a pipe comprised of steel or brass. The rigid pipe can be directly
connected
to the wall of the hydraulic cylinder by a customary hydraulic fitting means.
The pipe
can also be configured such that it opens out directly on the swing axis
means.
Further, the connecting element can be configured as a metal block connected
to the
hydraulic cylinder by a flange connection, and has a rigid connecting line in
the form
of a bore, which leads form the pressure-medium chamber to the swing axis or
junction axis.
By appropriate robust engineering design of the connecting element the
junction means and the line segment ensure ample rigidity is achieved while
providing for and maintaining the appropriate degrees of freedom around the
swing
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axis or the junction axis. The junction means can also be firmly installed to
have its
axis maintained in alignment with the swing axis.
It is also possible to have the connecting element configured as a piece which
is rigidly connected to the actuator, such as a pivot bolt connected to the
housing of
the actuator, where the actuator is swingable around the longitudinal axis of
the pivot
bolt. Preferably, the junction means is fixed to the pivot bolt to ensure
affixation of
the junction axis coaxially with the swing axis of the actuator. The junction
means
can be connected to the pressurized-medium chamber of the actuator by means of
one or more bores interior to the pivot bolt. The swing articulation is
preferably
configured such that the actuator is swingably mounted on the pivot bolt and
the
pivot bolt is rigidly connected to the swing arm assembly. In this
configuration, it is
also conceivable for the actuator and pivot bolt to include a rigidly
connected unit,
with the pivot bolt swingably mounted on the swing arm assembly.
A rigid holding means can also be provided, which are anchored in the region
of the swing bearing on the actuator or on the component that is to be swung.
The
holding means extends into the region of the swing axis or junction axis,
where the
holding means secures the connecting element, the junction means and the line
segment, to ensure that the junction axis permanently coincides with the swing
axis.
Preferably, the line segment is also in a hydraulic tube, which is rigidly
constructed
and configured. In the alternative, the hydraulic tube is fixed to the
component which
is to be swung such that the junction axis is fixed wherein the rigid line
segment at
least facilitates this reliable axis alignment.
The junction means can include a swiveling hydraulic or pneumatic fitting,
screw-connected swivel joints, and can have, a straight, angled, or S-shaped
form.
Swivel joints serve to join components such as pipes or tubes and have at
least two
connecting sides which are mutually swingable around a fixed junction axis. At
the
same time, the swivel joint allows passage of a pressurized medium and
transmission of the pressure of the medium of the components thereby joined.
Such
screw-connected swivel joints for hydraulic applications and are commercially
available.
To protect an actuator against tube failure, a safety valve, particularly a
load-
retaining, a pressure-retaining valve, or tube failure protection valve, can
be
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provided. It is advantageous that neither the connecting element nor the line
segment, nor any of the commercially available junction means, employs or
requires
flexible hydraulic tubes, and thus it is unnecessary to dispose the safety
valve
directly at the actuator.
The safety valve can be disposed at a structurally advantageous location
inside the pressurized-medium-driven apparatus. In an embodiment in which more
than one actuator is provided, this allows a plurality of actuators to be
protected with
a single safety valve, which can yield appreciable cost savings. The single
safety
valve can be disposed in a main line, ahead of branches to the individual line
segments for the respective actuators. According to another embodiment of the
invention, a pressurized- medium reservoir can be provided, which facilitates
pressurized-medium-driven spring-loading. It is particularly advantageous if
the
reservoir can be arranged in combination with a safety valve, where it is
unnecessary to connect the reservoir directly to the actuator. The safety
valve can
be disposed at almost any desired location in the pressurized-medium-driven
apparatus and the design advantages to allow the freedom to locate the
pressured-
medium reservoir or a plurality of such reservoirs.
An inventive hydraulic apparatus is suitable for raising and lowering an
extension arm of a loading vehicle, such as a telescoping loader. For safety
reasons,
telescoping loaders, in particular, must have protective means for instances
of tube
failure. The use of such protective means has restrictive consequences
concerning
the layout and disposition of hydraulic components. Because the connecting
element
for the hydraulic cylinder, the supply line segment, and junction means can be
constructed as rigid robust components, the protective means against tube
failure
does not need to be disposed directly on or at the hydraulic cylinder.
An inventive pressurized-medium-driven apparatus can be employed in a
loader such as a front-end loader, telescoping loader or wheel loader. The
loader
can include one or more actuators used to raise and lower a loading arm,
extension
arm, or swing arm assembly. In particular, when a plurality of actuators are
used,
appreciable cost savings can be achieved by eliminating one or more safety
valves.
It is also possible to install a spring-loading means; the necessary
adaptations for
this are facilitated by the fact of the advantageous and simplified
positioning
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possibilities for the safety valve(s) and pressure-medium reservoir(s)
according to
the present invention.
The loaders can include pressurized-medium-d riven apparatuses for
positioning assemblies and devices capable of receiving a loader implement.
The
robustness and stability of the apparatus is enhanced by the possibility of
eliminating
the use of flexible hydraulic tubes in the hydraulic supply lines for one or
more
actuators in the region of said receiving devices.
The pressurized-medium-driven apparatus can be employed in agricultural or
forestry machines, such as tractors, soil cultivating machines, harvesting
machines,
uprooting machines, etc., and construction machines, such as excavators or
cranes.
Such machines can have a plurality of actuators, which can be operated. The
apparatus can also be used in agriculture tasks on a device towed by a
tractor.
Such towed devices can operate under arduous conditions. They commonly have
lifting mechanisms with actuators having flexible pressurized-medium tubes
which
while in operation are threatened by projecting three branches, shrubbery, or
other
items. The stability and robustness of the system can be improved, by
minimization
or elimination of flexible pressurized-medium tubes.
BRIEF DESCRIPTION OF THE DRAWINGS
The inventive and additional advantages, advantageous refinements, and
advantageous configurations thereof will be described further herein below,
with
reference to the accompanying drawings which illustrate some exemplary
embodiments of the invention.
Figure 1 is a schematic representation of a loading machine with an
apparatus driven by a pressurized medium according to the invention;
Figure 2 is a partial perspective view of the pressurized-medium-driven
apparatus according to in Fig. 1 with the swinging mechanism;
Figure 3 is a detail perspective view of the swinging mechanism in Figure 2;
Figure 4 is a schematic hydraulic circuit diagram for a pressurized-medium-
driven apparatus of the present invention;
Figure 5 is a partial perspective view of the pressurized-medium-driven
apparatus according to Fig. 1 with a reservoir for the pressurized medium;
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Figure 6 is a perspective detail view of a second embodiment of the swinging
mechanism;
Figure 7 is a perspective detail view of a second exemplary to Fig. 6; and
Figure 8 is a cross section of a third embodiment of the swinging mechanism.
DETAILED DESCRIPTION
Fig. 1 shows a loading machine 10 which has a front end loader implement
mechanism 14 mounted on a tractor 12. The loader implement mechanism 14 is
attached to the tractor 12 on both sides by means of connecting brackets 16,
17
mounted on a support bracket 20 which is connected to a frame 18 of the
tractor 12.
The front end loader implement mechanism 14 has an extension arm or swing
arm assembly 22 comprised of two parallel swing arms 24, 25, each of which
swing
arms is swingably connected to the respective connecting bracket 16, 17. To
stabilize the swing arm assembly 22, a crossbeam 26 is provided as shown in
Fig. 2
which interconnects the two swing arms 24, 25. At the front end region of the
front
end loader implement mechanism 14, a device 28 for receiving the loader
implement
30 is provided. The loading machine 10 shown as shown in Fig. 1 has a loading
shovel as the loader implement 30. Other loader implements, such as forks or
grippers, can be mounted on the receiving device 28. The front end loader
implement mechanism is provided with a device 32 which is driven by a
pressurized
medium, which device 32 serves to swing or raise and lower the swing arm
assembly 22. The device 32 is illustrated in detail in Figs. 2-6. The front
end loader
implement mechanism 14 also has parallel guide rods 34, 35 which hold the
loader
implement 30 in a constant position with respect to the ground beneath the
loading
machine 10.
The pressurized-medium-driven device 32 as illustrated in Fig. 2, has on both
sides of the swing arm assembly 22 a respective actuator 36, 37 in the form of
a
hydraulically driven positioning cylinder. To accomplish a swinging movement
of the
swing arm assembly 22, the swing arms 24, 25, parallel guide rods 34, 35, and
actuators 36, 37 are swingably connected to the connecting brackets 16, 17 via
pivot
bolts 38, 39, 40, 41, 42, 43 where only the bolts 38, 40, and 42 for one side
of the
swing arm assembly 22 are visible in Fig. 2. The actuators 36, 37 are
connected to
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the swing arms 24, 25 via additional pivot bolts 44, 45 which define a swing
axis 46
around which the respective actuators 36, 37 execute swinging movements with
respect to the swing arm assembly 22.
In one embodiment, the actuators 36, 37 can be positioning cylinders which
are connected on their plunger side to the connecting brackets 16, 17 and on
their
piston side to the swing arms 24, 25. Pressure can be applied to the piston
side in
order to raise the swing arm assembly 22, and to the plunger side in order to
lower
the swing arm assembly 22. Alternatively, the actuators 36, 37 can be mounted
in
the opposite direction of orientation from that shown.
Pressurized medium is fed to the actuators 36, 37 via a line 48 leading to the
plunger side and second line 50 leading to the piston side. A safety valve 52
in the
form of a pressure retaining valve is disposed in the lines 48, 50, in order
to protect
the actuators 36, 37 against an abrupt drop in pressure.
The line 48 on the plunger side has a first flexible line segment 54, a rigid
line
segment 56, and a second flexible line segment 58. The first flexible line
segment 54
opens out into the safety valve 52. The rigid line segment 56 leads from the
safety
valve 52 and extends to the opposite side of the swing arm assembly 22 in
order to
supply pressurized medium to the second actuator 37. The second flexible line
58
leading to the contraction side or the lowering side of the actuator 36
branches off
from the rigid line segment 56. The flexible line segments 54, 58 can
accommodate
relative movements between the plunger side of the actuator 36 and the swing
arm
24, and between the swing arm 24 and the connecting bracket 16, resulting from
swinging movements.
The line 50 leading to the piston side has a flexible line segment 60, first
rigid
line segment 62, a second rigid line segment 64, and a connecting element 66
which
is also rigid. The flexible line segment 60 opens out into the safety valve
52. the first
rigid line segment 62 leads from the safety valve 52 to the pressurized media
supply
of the second actuator 37 on the opposite side of the swing arm assembly 22.
The
second rigid line segment 64 braches outward from the first rigid line segment
62
and opens out into a swiveling junction connection 68 for pressurized-medium
lines.
A connecting element 66 extends from the junction connection 68 to the piston
side
or the thrust side of the actuator 36.
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The junction connection 68 can be a swiveling junction connection for
pressurized-medium lines configured such that the second rigid line segment 64
of
the piston-side line 50 is swingably connected to the connecting element 66.
The
latter is rigid. Such swiveling junction connections are available, by the
company
PARKER, a manufacturer of pressurized-medium-driven components and
accessories.
The junction connection 68 can be positioned such that its swing axis
coincides with the swing axis 46 of the actuators 36 and 37. To fix this
position,
holding means 70 are provided as shown in detail in Fig. 3. The holding means
70
includes an angle profile piece 72 at one end of which is rigidly fixed to the
swing
arm 24, by welding. At the other end, a holding member 74 is provided which is
rigidly attached to the angle profile piece 72. The holding member 74 extends
around and holds the junction connection 68. Such holding means can have
myriad
other configurations and the form of such holding means is not limited to that
illustrated in Figs. 2 and 3. The holding means 70 can be excluded if provided
the
necessary holding of the junction connection 68 by means of an appropriately
robust
construction of the rigid line segments 62, 64 and the connecting element 66
is
provided.
One embodiment of control means for the pressurized-medium-driven device
32 will now be described, with reference to the schematic hydraulic circuit
diagram is
shown presented in Fig. 4. Hydraulic fluid from a hydraulic tank 75 is pumped
by a
hydraulic pump 76 to operate the actuators 36, 37. A control valve 77
controlled by
the operator of the loading machine 10 controls the back and forth flow of
hydraulic
fluid in the line segments 54; 60 for the plunger-side and piston-side lines
48, 50.
The control valve 77 is preferably in the form of an electrically actuatable
slide valve
having three switching positions, namely, "raise", "lower" and "neutral".
In the "raise" position, the hydraulic pump 76 is connected with the piston-
side
line 50 and the hydraulic tank 75 is connected with the plunger-side line 48.
In the
"lower" position the hydraulic pump 76 is connected with the plunger-side line
48 and
the hydraulic tank 75 is connected with the piston-side line 50. In the
"neutral"
position, the connections of the hydraulic pump 76 and hydraulic tank 75 to
the lines
48, 50 are interrupted. The line segments 54, 60 are connected to the
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safety valve 52. Safety valve 52 comprises a controllable pressure limiting
valve 78
and a bypass line 82 provided with a check valve 80.
The pressure limiting valve 78 in its normal position closes the piston-side
line
50, as illustrated in Fig. 4, but a bypass of the pressure limiting valve 78
is provided
by the bypass line 82 in combination with the check valve 80, acting in the
direction
toward the actuators. When a preset "control pressure" is reached, the
pressure
limiting valve 78 is opened in the direction of the hydraulic tank 75, by
means of a
first pressure control line segment 84 which can be connected to the piston-
side rigid
line segment 62, or by means of a second pressure control line segment 86
which is
connected to the plunger-side line 50. Thereby the first pressure control line
serves
for overload protection for the actuator 36 or 37, wherewith when a critical
operating
pressure is reached the pressure limiting valve 78 is opened. Beyond the
safety
valve 52, toward the actuators 36, 37, the rigid line segments 56, 62 of the
plunger-
side line 48 and the piston-side line 50, respectively, are connected; from
these, the
plunger-side flexible lines 58, 58 lead to the actuators 36, 37, and the
piston-side
rigid lines 64, 64 lead to the junction connections 68, 68. Beyond the
junction
connections 68, 68 toward the actuators 36, 37 the connecting line segments
66, 66
are connected, which are in the form of rigid line segments leading to the
piston-side
chambers 88, 90 of the actuators 36, 37.
In another embodiment, a hydraulic fluid reservoir 92 can be connected to the
first rigid line segment 62 of the piston-side line 50 via a third rigid line
segment 94
and a shutoff valve 96 having a closed and an open position.
The hydraulic fluid reservoir 92 is disposed on the crossbeam 26 of the swing
arm assembly 22 as shown in Fig. 5. It is also conceivable that the hydraulic
fluid
reservoir 92 to be disposed inside a hollow crossbeam 26, which has an
interior
cavity to accommodate it. Alternatively, the hydraulic fluid reservoir 92 can
be
disposed elsewhere on the swing arm assembly 22. The shutoff valve 96 can be
actuated by an electric line 98, to connect or disconnect the hydraulic fluid
reservoir
92 from the circuit. The hydraulic fluid reservoir 92 provides an element of
spring-
loading of and mediated by the pressurized hydraulic fluid, whereby an impulse
acting on the swing arm assembly 22 can be accommodated and dampened. In
order to ensure that when the control valve 77 is closed or in the "neutral"
position
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the actuators 36, 37 can undergo a spring-loaded movement, a spring-loaded
valve
100 is provided, in the form of a shutoff valve; valve 100 enables plunger-
side flow of
hydraulic fluid into the tank. When the spring-loading function is activated,
preferably
the shutoff valve 96 and the shutoff valve 100 are both open.
Because the line segments 62, 64, 66 beyond the safety valve 52 in the
direction of the actuators 36, 37 are connected to the piston-side chambers
88, 90, in
the form of rigid lines, one safety valve 52 can be used to protect both
actuators 36,
37. Also, the rigid line segments 64, 66 are not subjected to bending stresses
during
the swinging movement of the swing arm assembly 22 or the actuators 36, 37,
because the connection axes of the corresponding junction connections 68, 68
are
coaxial with the swing axis 46 of the actuators 36, 37. It is particularly
advantageous
that with this arrangement the safety valve 52 and the hydraulic fluid
reservoir 92 can
be disposed at structurally favorable locations, at an appreciable distance
from the
actuators 36, 37.
In the following, the functions of the hydraulic system will be described in
more detail with reference to the hydraulic circuit diagram of Fig. 4. In the
"raise"
position, the hydraulic fluid is supplied to the safety valve 52 through a
flexible line
segment 60 which is in the form of a flexible hydraulic pressure line. The
pressure
limiting valve 78 in the safety valve 52 is closed. The fluid passes through
the bypass
line 82 to the output of the safety valve 52 and flows via the rigid line
segment 62
into the rigid line segments 64, 64. The junction connections 68, 68 disposed
on the
swing axis 46 provide connections to the piston-side chambers 88, 90 via the
connecting line segments 66, 66 which here are rigid, whereby the actuators
36, 37
are expanded. At the same time, on the plunger side, hydraulic fluid can flow
into the
hydraulic fluid tank 75. Swinging movements of the actuators 36, 37 and the
associated connecting line segments 66 and rigid line segments 64 occur
exclusively
around the swing axis 46 via the junction connections 68, 68 disposed
coaxially to
the swing axis 46; as a result, in the piston-side line 50 beyond the safety
valve 52
toward the actuators 36, 37 it is unnecessary to have any flexible lines. If
necessary,
the already present hydraulic fluid reservoir 92 can be connected on the
piston side,
wherewith the actuators 36, 37 are connected on the piston side to the
hydraulic fluid
reservoir 75.
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In the "neutral" position, the control valve 77 is closed, so that no
hydraulic
fluid can flow into the hydraulic fluid tank 75. However, when a hydraulic
fluid
reservoir 92 is provided, the shutoff valve 100 can be opened by actuating the
spring
function, wherewith even if the control valve 77 is closed one can have flow
into the
hydraulic tank 75 from the plunger side.
In the "lower" position, hydraulic fluid is passed through the plunger-side
line
48, and a corresponding operating pressure builds up. This increasing pressure
causes the pressure limiting valve 78 to open, via the second pressure control
line
segment 86, whereby at the same time hydraulic fluid can flow out of the
piston-side
line 50. The "lower" position allows the swing arm assembly 22 to be lowered
rapidly,
but still under pressure. When such rapid lowering under pressure occurs, the
shutoff valve 100 must be closed, because otherwise the hydraulic fluid which
is
needed would flow out directly into the hydraulic fluid tank 75.
In an alternate embodiment, the connecting line segment 66 shown in Figs. 2,
3, and 5 is integrated into the pivot bolt connections 44, 45, wherewith a
connecting
line segment 66 in the form of a pivot bolt is employed as shown in Figs. 6
and 7. In
the following, this will be described in more detail for the swing arm 24
disposed
forwardly on the right side of the tractor 12. The arrangement for the
corresponding
left swing arm is analogous.
The swing arm 24 has opposite lateral walls 102 in which swing bearing bores
104 for swingable support of the connecting line segment 66 are provided. The
connecting line segment 66 is fixed radially on the swing axis 46 by means of
said
swing bearing bores 104. On the piston side, the actuator 36 is disposed
between
the side walls 102. The actuator 36 is connected to the connecting line
segment 66
by a threaded connection 106. The actuator 36 has a bottom plate 108 on the
piston
side and an adjoining threaded nipple 110 which extends perpendicularly to the
swing axis 46 in the direction toward the connecting element 66. The
connecting line
segment 66 connects the junction connection 68 to the actuator. In this
configuration, the pivot bolt 124 is rigidly connected to the swing arm 24,
wherewith
the actuator 36 can execute a swinging movement around the pivot bolt 124 and
the
junction connection 68 accommodates the relative movement, and is fixed
axially in
the direction of the swing axis 46 by means of retaining discs 112. The
connecting
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line segment 66 has an actuator-side connecting configuration 114 and a
junction-
side connecting configuration 116. Between the two connecting configurations
114,
116 a first pressurized-medium bore 118 extends along the pivot axis 46. The
junction-side connecting configuration 116 is connected directly to the
connecting
line segment 66 employed in this embodiment, preferably by screwing. The
parameters specified by the manufacturer(s) of the junction connections, e.g.
the firm
PARKER, should be taken into account for the connection of the junction-side
connecting configuration 116 to the connecting line segment 66.
The actuator-side connecting configuration 114 is preferably disposed
centrally between the lateral walls 102 and has a threaded bore 120 that
matches
the threaded nipple 110. A second pressurized-medium bore 122 extends through
the threaded nipple 110, which bore leads in from the free end of the threaded
nipple
110 to the piston-side chamber 88 of the actuator 36. The first and second
pressurized-medium bores 118, 122 are joined by joining by screwing the
actuator-
side connecting configuration 114 to the threaded nipple 110. The pressurized
medium can be supplied to the actuator 36 and can be swung around the swing
axis
46. The connecting line segment 66 can be a robust pivot bolt and is fixed
both
axially and radially, though swingable, with respect to the swing axis 46, it
is
unnecessary to have holding means 70 for the junction connection 68.
A third embodiment is illustrated in Fig. 8, wherein the connecting element 66
is connected via a swiveling junction connection 68 to a pivot bolt 124 of the
pivot
bolt connection 44, and has a third rigid line segment 126 which connects the
junction connection 68 to the actuator. The junction connection 68 is mounted
directly on the pivot bolt 124. Starting from the junction connection 68 a
first
connecting bore 128 extends longitudinally with respect to the swing axis 46
into the
interior of the pivot bolt 124, and intersects a second connecting bore 130 to
a
connecting configuration 132 on the periphery of the pivot bolt 124, which
connects
to the second rigid line segment 64 of the piston-side line 50. A connection
to the
junction connection 68 is provided inside the pivot bolt 124 by the connecting
bores
128, 130. Because of the fact that the junction connection 68 is mounted
directly on
the pivot bolt 124 coaxially to the swing axis 46, one ensures that the
junction
connection 68 is reliably positioned on the swing axis 46. With this
arrangement, the
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pivot bolt 124 is rigidly connected to the swing arm 24, wherewith the
actuator 36
can execute a swinging movement around the pivot bolt 124, and the junction
connection 68 accommodates the relative swinging movement between the
connecting line segment 66 and the third rigid line segment 126 and the pivot
bolt
124. Analogously, it is conceivable to rigidly connect the pivot bolt 124 to
the
actuator 36, wherewith the pivot bolt 124 will be pivotably mounted on the
swing arm
24. With this arrangement, the junction connection 68 is connected to the
second
rigid line segment 64 of the piston-side line 50, so that the swinging
movements
between the swing arm 24 and the pivot bolt 124 are accommodated by the
junction
connection 68, and the third rigid line segment 126 can lead directly from the
pivot
bolt 124 to the actuator, because now there are no swinging movements between
the pivot bolt 124 and the actuator 36.
It is therefore intended that the foregoing detailed description be regarded
as
illustrative rather than limiting, and that it be understood that it is the
following claims,
including all equivalents, that are intended to define the spirit and scope of
this
invention.
