Self-propelled road milling machine

Abstract

A road milling machine includes a mechanical frame having a longitudinal axis. A plurality of ground engagement units support the mechanical frame from a ground surface. A milling drum is supported from the mechanical frame. An operator's workbench is supported from the mechanical frame by a support linkage mechanism configured such that the operator's workbench can move laterally relative to the mechanical frame between an inner position and an outer position. The support linkage mechanism includes at least one pivot link extending between the mechanical frame and the operator's workbench and oriented to pivot about a pivot axis extending parallel to the longitudinal axis of the mechanical frame. In the outer position, the operator's workbench extends laterally partially beyond the mechanical frame on one of its left and right edges, and is at a higher height relative to the mechanical frame than in the inner position.

Description

Technical Field

[0001] This disclosure relates to an improvement in mounting an operator's station on a road milling machine, such that the operator's station can be laterally moved to extend beyond the edge of the milling machine's mechanical frame. Background Technology

[0002] Road milling machines are typically designed with at least one zero-clearance side, allowing the milling machine to mill close to obstacles. It is desirable for the milling machine operator to have direct observation of the cutting action of the milling drum, particularly on the zero-clearance side. To this end, various arrangements have been provided to laterally and outwardly shift the cab or operator's workbench toward the zero-clearance side, thereby providing the operator with improved observation of the milling operation.

[0003] An example of this arrangement is found in U.S. Patent 10,960,938. A specific drawback of this arrangement is that, in order to achieve lateral displacement of the operator's workbench, the operator's workbench moves in an arc within its horizontal plane, resulting in not only lateral displacement but also forward and backward movement of the operator relative to the machine frame. This movement occupies valuable floor space on the machine frame and all the volume above that floor space, which cannot be used for other purposes because unimpeded movement of the operator's workbench must be maintained.

[0004] Therefore, there is a continued need for improved layouts of offset operator workbenches or cockpits on such construction machinery. Summary of the Invention

[0005] In one embodiment, the self-propelled road milling machine includes a mechanical frame having a longitudinal axis extending between a front and a rear portion of the frame, the frame including a left edge and a right edge. A plurality of ground engagement units support the mechanical frame from a ground surface. A milling drum is supported by the mechanical frame. An operator's workbench is supported from the mechanical frame by a support linkage mechanism configured to laterally move the operator's workbench relative to the mechanical frame between an inward position and an outward position. The support linkage mechanism includes at least one pivoting link extending between the mechanical frame and the operator's workbench, the pivoting link being oriented to pivot about a pivot axis extending parallel to the longitudinal axis of the mechanical frame. In the outward position, the operator's workbench laterally extends partially beyond one of the left and right edges of the mechanical frame. The outward position is at a higher height relative to the mechanical frame than the inward position.

[0006] In another embodiment, the milling machine may include a hydraulic lifting cylinder connected to at least one of a support linkage mechanism and an operator's workbench, the hydraulic lifting cylinder being configured to move the operator's workbench between an inner position and an outer position.

[0007] In any of the above embodiments, the milling machine may include a hydraulic accumulator that is hydraulically connected to a hydraulic lifting cylinder and configured to provide hydraulic spring support for the operator's workbench at least when the operator's workbench is in the outer position.

[0008] In any of the above embodiments, the milling machine may include a hydraulic flow limiter disposed between the hydraulic lifting cylinder and the hydraulic accumulator, and configured to limit the flow of hydraulic fluid between the hydraulic lifting cylinder and the hydraulic accumulator in at least one direction to dampen the hydraulic spring support of the operator's workbench.

[0009] In any of the above embodiments, the milling machine may include a stretch sensor configured to provide a stretch signal corresponding to the stretch of the hydraulic lifting cylinder.

[0010] Any of the above embodiments may include a proximity sensor configured to detect the presence of the operator's workbench in an outer position relative to the mechanical frame.

[0011] In any of the above embodiments, the hydraulic lifting cylinder can be a smart cylinder, and the extension sensor can be integrated into the hydraulic lifting cylinder.

[0012] In any of the above embodiments, the support linkage mechanism can be configured to allow the operator workbench to move laterally between an inner position and an outer position, without any forward or backward movement of the operator workbench relative to the mechanical frame, so that the footprint of the operator workbench on the mechanical frame is minimized when moving between the inner and outer positions.

[0013] In any of the above embodiments, the milling machine may include a lifting actuator connected to at least one of a support linkage mechanism and an operator's workbench.

[0014] In any of the above embodiments, the lifting actuator can be connected between the mechanical frame and the operator's workbench.

[0015] In any of the above embodiments, compared to the inner position, the outer position of the operator's workbench can provide the human operator on the operator's workbench with an improved view of the ground surface area adjacent to the milling drum due to the lateral outward movement, and provide an improved overall view of the area around the self-propelled road milling machine due to the higher height of the outer position.

[0016] In any of the above embodiments, when the operator workbench is in the inner position, the stationary footprint of the operator workbench can fall entirely between the left and right edges of the mechanical frame.

[0017] In any of the above embodiments, the plurality of ground engagement units may include at least one front ground engagement unit and at least two rear ground engagement units, and at least one of the rear ground engagement units may be a movable rear ground engagement unit capable of moving relative to the mechanical frame between a retracted position and an extended position. The milling drum may be positioned such that when the movable rear ground engagement unit is in the retracted position, the movable rear ground engagement unit is located in front of the milling drum. The outer position of the operator's workbench may extend laterally partially beyond one of the left and right edges of the mechanical frame adjacent to the movable rear ground engagement unit.

[0018] In another embodiment, the two rear ground engagement units may be laterally aligned, and when the movable rear ground engagement units are in the extended position, the milling drum may be laterally positioned between the two rear ground engagement units, and when in the outer position, if the movable rear ground engagement units are in the extended position, the operator's workbench may be at least partially positioned above the location of the movable rear ground engagement units.

[0019] In any of the above embodiments, the milling machine may include at least two lifting columns extending between at least two rear ground engagement units and the machine frame for raising and lowering the machine frame relative to the ground surface, one of which is a movable lifting column attached to a movable rear ground engagement unit. Furthermore, the operator's workbench may include a recess configured to at least partially receive the movable lifting column when the movable rear ground engagement units are in the extended position and the operator's workbench is in the outward position.

[0020] In a first operating mode of any of the above embodiments, the controller may be configured to receive an extension signal from an extension sensor and a pressure signal from a pressure sensor associated with the hydraulic lifting cylinder, and generate a control signal to the hydraulic lifting cylinder. The controller is configured to detect a rise in hydraulic pressure within the hydraulic lifting cylinder and guide the hydraulic lifting cylinder to retract a predetermined distance when the operator workbench moves toward an outward position, provided that the movable ground engagement unit and the movable lifting column are in the extended position and the operator workbench engages the movable lifting column. This provides a predetermined gap between the operator workbench and the movable lifting column in the outward position of the operator workbench.

[0021] In the second operating mode of any of the above embodiments, the controller may be configured to receive a proximity signal from a proximity sensor and generate a control signal to the lifting actuator. The proximity sensor is configured to detect the proximity of the operator's workbench to the movable lifting column. The controller is configured to, when the operator's workbench moves toward an outward position, if the movable ground engagement unit and the movable lifting column are in an extended position and the proximity sensor detects that the operator's workbench is within a predetermined distance of the movable lifting column, instruct the lifting actuator to stop moving to provide a predetermined gap between the operator's workbench and the movable lifting column in the outward position of the operator's workbench.

[0022] In the third operating mode of any of the above embodiments, the pivot mechanism that moves the movable ground engagement unit and the movable lifting column can be configured such that the extended position of the movable lifting column is positioned such that the movable lifting column cannot interfere with the operator's workbench, even if the operator's workbench is in its outermost position.

[0023] In the fourth operating mode of any of the above embodiments, the lifting mechanism of the movable operator's workbench can be configured such that lateral outward movement from the inner position always terminates at an intermediate position, which is selected to provide a gap between the operator's workbench and the movable lifting column if the lifting column is in its extended position. By thus limiting the outer position of the operator's workbench, it is ensured that the movable lifting column does not interfere with the operator's workbench, even if the movable lifting column is in its fully extended position.

[0024] In the fifth operating mode of any of the above embodiments, a human operator is provided with an operating interface that allows the operator to select between the third and fourth modes.

[0025] In a sixth operating mode of any of the above embodiments, the controller may be configured to receive a proximity signal from a proximity sensor configured to detect the proximity of the movable lifting column to the operator's workbench and generate a control signal to the extension actuator. The controller is configured to instruct the extension actuator to stop when the operator's workbench is in the outward position and the proximity sensor detects that the operator's workbench is within a predetermined distance of the movable lifting column, so as to provide a predetermined gap between the operator's workbench and the movable lifting column in the extended position of the movable rear ground engagement unit and the movable lifting column.

[0026] Many objects, features and advantages of the present invention will readily become apparent to those skilled in the art upon reading the following description in conjunction with the accompanying drawings. Attached Figure Description

[0027] Figure 1 This is a schematic right-side front view of a road milling machine.

[0028] Figure 2 yes Figure 1 A schematic top view of a road milling machine.

[0029] Figure 3 yes Figure 1 The right rear perspective view of the road milling machine shows the operator's workbench in the inner position.

[0030] Figure 4 yes Figure 1 The right rear perspective view of the road milling machine shows the operator's workbench in the outer position.

[0031] Figure 5 yes Figure 1 A schematic plan view of the rear section of a road milling machine, showing the right rear track in the fully extended position with solid lines, and the right rear track in the retracted position and intermediate extended position with dashed lines.

[0032] Figure 6 It is similar to Figure 5 A schematic plan view of the rear section of the road milling machine, further illustrating the operator's workbench in the inner position (shown by solid lines), and in the outermost and middle outer positions (shown by dashed lines).

[0033] Figure 7 This is a schematic rear front view of the support linkage mechanism supporting the operator's workbench from the mechanical frame of a road milling machine. The operator's workbench is shown in the outermost position (shown by solid lines), and in the inner and middle outer positions (shown by dashed lines). A hydraulic lifting cylinder is shown for moving the support linkage mechanism and the operator's workbench between different positions.

[0034] Figure 8A This is a schematic diagram of a hydraulic power source associated with a lifting cylinder. The hydraulic power source is in a first position, in which the lifting cylinder is locked in the extended position and provides a hydraulic spring feature.

[0035] Figure 8B It is similar to Figure 8A The diagram shows the hydraulic power source in the second position, where the lifting cylinder is retracting to lower the operator's workbench and move it inward. The hydraulic spring action is interrupted during the extension or retraction of the lifting cylinder.

[0036] Figure 9 yes Figure 1A plan view of the movable right rear track and lifting column of a road milling machine, further illustrating its use in... Figure 5 The extension actuator that moves the right rear track and lifting column between different positions is sometimes referred to as a swing cylinder.

[0037] Figure 10 This is a schematic diagram of the controller of a road milling machine and the various sensor inputs and control outputs associated with the controller.

[0038] Figure 11 This is a schematic diagram of a hydraulic smart cylinder with an integrated extension sensor.

[0039] Figure 12 This is a perspective view of the lower right front side of the operator's workbench, as well as an embodiment of the support linkage mechanism and lifting actuator.

[0040] Figure 13 yes Figure 12 Enlarged 3D view of the support linkage mechanism and lifting actuator.

[0041] Figure 14 This is a schematic diagram of another embodiment of the support linkage mechanism and lifting actuator.

[0042] Figure 15 This is a schematic diagram of another embodiment of the support linkage mechanism and lifting actuator.

[0043] Figure 16 This is a schematic diagram of another embodiment of the support linkage mechanism and lifting actuator.

[0044] Figure 17A This is a schematic diagram of another embodiment where the support linkage mechanism and the lifting actuator are in the raised position.

[0045] Figure 17B yes Figure 17A A schematic diagram of the support linkage mechanism and the lifting actuator in the lowered position.

[0046] Figure 18 This is a schematic right-side front view of a road milling machine in the form of a "large" milling machine with two front tracks and two rear tracks, according to some aspects of this disclosure, and incorporating a movable cab.

[0047] Figure 19 yes Figure 18 A schematic plan view of a road milling machine. Detailed Implementation

[0048] Figure 1 and Figure 2The diagram shows a construction machine, generally designated 10, in the form of a self-propelled road milling machine. The road milling machine 10 includes a mechanical frame 12 with a longitudinal axis 14 extending between a front portion 16 and a rear portion 18 of the mechanical frame 12. The road milling machine 10 shown is of a type sometimes referred to as a compact milling machine, characterized by a milling drum located between a rear wheel or track and a pivotable right rear wheel or track.

[0049] It will be understood that many aspects of the invention are also applicable to other types of construction machinery, including so-called “large” or “half-lane” milling machines, characterized by two front tracks and two rear tracks and a milling drum located between the front and rear tracks, such as shown, for example, in US10,968,576, the details of which are incorporated herein by reference. Figure 18 and Figure 19 An example of a "large" milling machine similar to U.S. Patent 10,968,576, incorporated into the present invention, is shown. Furthermore, some aspects of the present invention can be used with a "half-lane" milling machine that uses two front ground engagement units and one rear ground engagement unit.

[0050] Multiple ground-mounted units 20A, 20B, 20C, and 20D support the mechanical frame 12 from the ground surface 22. Figure 1 and 2 In the illustrated embodiment, there are two front ground engagement units 20B and 20D and two rear ground engagement units 20A and 20C. Generally, the milling machine 10 may have at least one front ground engagement unit and at least two rear ground engagement units. The ground engagement units are shown as tracked units, but wheeled units may also be used. One or more ground engagement units may be powered, for example, by a hydraulic motor to drive the milling machine 10. One or more ground engagement units may be steerable.

[0051] At least one of the rear ground engagement units, in the illustrated embodiment being the right rear ground engagement unit 20A, may be a movable rear ground engagement unit 20A that is movable relative to the mechanical frame 12 between a retracted position 20A' and a fully extended position 20A'''. The movable ground engagement unit may also be moved to one or more intermediate extended positions, such as 20A''. Both the fully extended position 20A''' and the intermediate extended position 20A'' can be referred to as extended positions. Figure 1 and Figure 2 In the middle, the right rear ground engagement unit 20A is shown in the fully extended position 20A'''. The retracted position 20A' and the intermediate extended position 20A'' are schematically shown in the discussion below. Figure 5 middle.

[0052] like Figure 5As schematically shown, when the movable right rear ground engagement unit 20A is in the fully extended position 20A''', the milling drum 24 of the milling machine 10 is laterally positioned between the rear ground engagement units 20A and 20C. When the movable right rear ground engagement unit 20A is in the retracted position 20A', the movable right rear ground engagement unit 20A is positioned in front of the milling drum 24.

[0053] At least two rear ground engagement units 20A and 20C are connected to the mechanical frame 12 via lifting columns such as 26A and 26C. The lifting columns raise and lower the mechanical frame 12 and the attached milling drum 24 relative to the ground surface 22. At least the right rear lifting column 26A is a movable lifting column 26A attached to a movable rear ground engagement unit 20A.

[0054] Figure 9 Details of one embodiment of a mechanism for moving a movable ground engagement unit 20A and a movable lifting column 26A between different positions relative to a mechanical frame are shown. A swing arm 28 is pivotally attached to the mechanical frame 12 at a pivot connection 30 and pivotally attached to the movable ground engagement unit 20A via the movable lifting column 26A. An extension actuator 32 is pivotally connected to the mechanical frame 12 at one end 34 and to the swing arm 28 at the other end 36, such that extension and retraction of the extension actuator 32 pivots the swing arm 28, the attached lifting column 26A, and the ground engagement unit 20A between their different positions. A steering actuator 38 is pivotally connected to the mechanical frame 12 at one end 40 and to a steering arm 44 attached to the movable ground engagement unit 20A at the other end 42. Extension and retraction of the steering actuator 38 pivots the movable ground engagement unit 20A about a steering axis 46 relative to the movable lifting column 26A. In one embodiment, one or both of actuators 32 and 38 may be hydraulic cylinders and may be “smart” hydraulic cylinders including an integrated extension sensor, as referenced below. Figure 11 As explained further.

[0055] When the movable ground engagement unit 20A is in the retracted position 20A', the movable lifting column is in its corresponding retracted position 26A'. When the movable ground engagement unit 20A is in its intermediate extended position 20A'', the movable lifting column is in its corresponding intermediate extended position 26A''. When the movable ground engagement unit 20A is in its fully extended position 20A''', the movable lifting column is in its corresponding fully extended position 26A'''. Both the intermediate extended position 26A'' and the fully extended position 26A''' can be referred to as the extended positions of the movable lifting column 26A.

[0056] As will be understood by those skilled in the art by reference to a compact road milling machine of the type shown, the movable right rear ground engagement unit 20A can be positioned in the fully extended position 20A''', as Figure 1 and Figure 2 As seen in the diagram, the movable right rear ground engagement unit 20A is located laterally outside the milling drum 24 to increase stability during normal milling operations. Furthermore, the movable right rear ground engagement unit 20A can be moved to a retracted position 20A', in which the movable right rear ground engagement unit 20A does not extend laterally outside the machine frame 12, thereby allowing the milling machine 10 to approach obstacles such as curbs or walls for milling.

[0057] In one embodiment, when the movable right rear ground engagement unit 20A is in the fully extended position 20A''', the two rear ground engagement units are laterally aligned, and the milling drum is laterally positioned between the two rear ground engagement units such that the rotation axis of the milling drum is substantially laterally aligned with the rotation axes of the two rear ground engagement units. When aligned in this way, when the milling machine 10 is configured to turn under so-called Ackermann turning conditions, the rotation axes of the milling drum and the two rear ground engagement units can intersect with the turning center of the milling machine 10.

[0058] like Figure 3 and Figure 4 As best viewed from the center, the milling machine 10 may include a movable operator's workbench 48, which may be an enclosed cab or an open operator's workbench. Figure 7 As schematically shown, the support linkage 50 is configured to allow the operator's workbench 48 to move laterally relative to the mechanical frame 12 between an inner position 48A, a middle outer position 48B, and an outermost position 48C. In the inner position 48A, the operator's workbench 48, including its floor 52, is located... Figure 7 The lowest height 60 is schematically shown, and it has a footprint entirely within the left edge 54 and right edge 56 of the mechanical frame 12. In the outermost position 48C, the operator's workbench 48 extends laterally and partially beyond the right edge 56 of the mechanical frame 12 by a distance 58 (see [reference]). Figure 6 ), and floor 52 is in Figure 7 The diagram schematically shows a higher height of 62. Both the middle outer position 48B and the outermost position 48C can be referred to as the outer positions of the operator's workbench 48.

[0059] like Figure 6As best shown in the schematic diagram, when the operator workbench 48 is in its outermost position 48C, it is at least partially located above the fully extended position 20A''' of the movable rear ground engagement unit 20A. To allow this positional overlap, the operator workbench 48 may include a recess 64 configured to at least partially receive the movable lifting column 26A when the movable rear ground engagement unit 20A is in its fully extended position 20A''' and the operator workbench 48 is in its outermost position 48C.

[0060] A hydraulic lifting cylinder 66 may be connected between the mechanical frame 12 and at least one of the support linkage mechanism 50 and the operator's workbench 48. The hydraulic lifting cylinder 66 may be configured to move the operator's workbench between an inner position 48A and an outermost position 48C. The hydraulic lifting cylinder 66 may be a "smart" hydraulic cylinder, including an integrated extension sensor 66S configured to provide an extension signal corresponding to the extension of the hydraulic lifting cylinder 66, as shown below. Figure 11 As further explained below, the extension signal also corresponds to the position of the operator's workbench 48 relative to the mechanical frame 12. The hydraulic lifting cylinder 66 can also be referred to as a lifting actuator. More generally, as further explained below, the hydraulic lifting cylinder 66 can be described as being connected to at least one of the support linkage mechanism 50 and the operator's workbench 48.

[0061] In one embodiment, the support linkage 50 can be configured to move the operator workbench 48 laterally between the inner position 48A and the outermost position 48C, without any forward or backward movement of the operator workbench 48 relative to the mechanical frame 12, so that the footprint of the operator workbench 48 above the mechanical frame 12 is minimized when moving between the inner position 48A and the outermost position 48C.

[0062] This configuration of the support linkage 50 can be provided by configuring the support linkage 50 as including two pivoting linkages 50A and 50B extending between the machine frame 12 and the operator workbench 48. Pivoting linkage 50A is pivotally connected to the machine frame 12 to pivot about pivot axis 68 and pivotally connected to the operator workbench 48 to pivot about pivot axis 70. Pivoting linkage 50B is pivotally connected to the machine frame 12 to pivot about pivot axis 72 and connected to the operator workbench 48 to pivot about pivot axis 74. Pivoting axes 68, 70, 72, and 74 can all extend parallel to the longitudinal axis 14 of the machine frame 12. In one embodiment, pivoting linkages 50A and 50B may have equal lengths.

[0063] It will be understood that pivot linkages 50A and 50B can be directly attached to the mechanical frame 12 or can be directly attached to a separate component fixedly attached to the mechanical frame 12. Furthermore, pivot linkages 50A and 50B can be directly attached to the operator workbench 48 or can be directly attached to a separate component fixedly connected to the operator workbench 48.

[0064] In such Figure 7 In the schematically illustrated embodiment, the hydraulic lifting cylinder 66 can be pivotally connected to the mechanical frame 12 at pivot point 76 and pivotally connected to the operator's workbench 48 at pivot point 78. In such a case... Figure 4 In another embodiment shown, the hydraulic lifting cylinder 66 has its upper end pivotally connected to one of the pivot links, such as pivot link mechanism 50B.

[0065] Figure 12 and Figure 13 Showing more details Figure 4 The structure of the support linkage mechanism 50 and the hydraulic lifting cylinder 66 shown in the embodiment is illustrated. In this embodiment, the lower mounting platform 100 has flanges 102' and 104', which are configured to be bolted to the mechanical frame 12, thereby effectively making the mounting platform 100 part of the mechanical frame 12. The aforementioned pivot point 76 of the hydraulic lifting cylinder 66 to the mechanical frame 12, and the pivotal connections of the pivot linkage mechanisms 50A and 50B to the mechanical frame 12 are formed on the lower mounting platform 100. The upper ends of the pivot linkage mechanisms 50A and 50B are joined together by support rods 106 and 108, which are configured to be bolted to the lower surface of the operator's workbench 48, thereby effectively making the support rods 106 and 108 part of the operator's workbench 48. The pivotal connections of the upper ends of the pivot linkage mechanisms 50A and 50B to the operator's workbench 48 are formed by the support rods 106 and 108. The upper end of the hydraulic lifting cylinder 66 and its pivot point 78 are attached to the mounting bracket 110, which is separately bolted to the operator's workbench 48. Therefore, the entire assembly of the support linkage mechanism 50 and the hydraulic lifting cylinder 66 can be removed by detaching the lower mounting platform 100 from the mechanical frame 12 and removing the support rods 106 and 108 and the mounting bracket 110 from the bottom of the operator's workbench 48.

[0066] In one embodiment, the hydraulic lifting cylinder 66 can be a conventional or "dumb" hydraulic cylinder. When using such a conventional hydraulic lifting cylinder 66, the position of the operator's workbench 48 relative to the mechanical frame 12 can be detected by various position sensor arrangements. In one embodiment, a proximity sensor 67 can be arranged to detect when the pivot linkage 50B has reached a position corresponding to the outer position 48C or the intermediate outer position 48B. In another embodiment, a rotary position sensor 69 can be placed on one of the pivot axes 68, 70, 72, or 74 to detect relative rotation between the components supporting the linkage 50 and / or the mechanical frame 12, the angle of which can be correlated with the position of the operator's workbench 48 relative to the mechanical frame 12.

[0067] Figure 8A and Figure 8B A hydraulic power supply system 80, which can be used with a hydraulic lifting cylinder 66, is schematically shown. Pressurized hydraulic fluid can be supplied from a source 82 (also labeled P) to the cylinder end 86 or piston end 88 of the hydraulic lifting cylinder 66 via a three-way electro-hydraulic control valve 84 and supply lines 85 and 87. Returning hydraulic fluid is directed by control valve 84 to a tank 90, also labeled T. A pressure sensor 83 can be connected to supply line 85 and configured to provide a pressure signal 81 corresponding to the hydraulic pressure within the cylinder end 86 of the hydraulic lifting cylinder 66 (see [reference]). Figure 10 The second pressure sensor can be connected to supply line 87.

[0068] like Figure 7 The hydraulic lifting cylinder 66 shown is configured to resist gravity and support the weight of the operator's workbench 48, conveniently allowing hydraulic spring support to be provided by connecting the hydraulic accumulator 92 to supply lines 85 and 87. The accumulator 92 can be connected to the supply lines 85 and 87 via a connecting line 94. The connecting line 94 can also connect the supply lines 85 and 87 to each other.

[0069] A bidirectional flow limiter 96 and a control valve 97 can be installed in the connecting line 94 between supply lines 85 and 87.

[0070] A one-way flow limiter 98 and a control valve 99 may be disposed in the portion of the connection line 94 connected to the accumulator 92. The one-way flow limiter 98 includes a check valve 103 that allows free flow to the accumulator 92 but prevents free flow from the accumulator 92. A bypass 102 in the one-way flow limiter 98 includes a flow limiter 104 that allows restricted flow of hydraulic fluid from the accumulator 92 back to the supply lines 85, 87.

[0071] Figure 8AThe system 80 is shown in a first position, which is, for example, the position it would be in if the hydraulic lifting cylinder 66 had been extended to move the operator's workbench 48 to position 48C. Control valve 84 is in a position that blocks further hydraulic flow to and from the hydraulic lifting cylinder 66, preventing further adjustment of the hydraulic lifting cylinder 66. Control valves 97 and 99 are in the open position to allow the accumulator 92 to provide hydraulic spring function.

[0072] With this arrangement, when the operator's workbench 48 is in the outermost position 48C or the middle outer position 48B, the impact load that would normally be transmitted between the mechanical frame 12 and the operator's workbench 48 can be hydraulically damped. The unidirectional flow limiter 98 can be described as a hydraulic flow limiter disposed between the hydraulic lifting cylinder 66 and the hydraulic accumulator 92, and configured to restrict the flow of hydraulic fluid between the hydraulic lifting cylinder 66 and the hydraulic accumulator 92 in at least one direction, to cushion the hydraulic spring support of the operator's workbench 48.

[0073] Figure 8B The system 80 is shown in a second position, which is the position the system would be in if the hydraulic lifting cylinder 66 were retracting to move the operator's workbench toward the inward position 48A. Control valve 84 is in the left-hand operating position to control the flow to and from the hydraulic lifting cylinder 66. Control valves 97 and 99 are in their closed positions to block flow to and from the accumulator 92 and between supply lines 85 and 87. A similar arrangement for extending the lifting cylinder would move control valve 84 to the right-hand operating position, and control valves 97 and 99 would remain closed.

[0074] The dashed box 101 surrounding control valves 97 and 99, as well as flow limiters 96 and 104, indicates that those components can optionally be constructed as an integral block of hydraulic components, in which case the connecting lines, such as 94, are integrally formed within the block. Those components can also be separate hydraulic components connected via individual hydraulic lines.

[0075] Alternatively, flow limiters 96 and 104 can be fixed flow limiters with a fixed-size flow path therethrough, or they can be variable flow limiters with a variable-size flow path therethrough. Variable limits allow for adjustment of damping functionality.

[0076] As mentioned earlier, the hydraulic lifting cylinder 66 and the extension actuator 32 can be "smart" hydraulic cylinders, each equipped with an integrated extension sensor 66S and 32S, respectively. A representative structure of such a "smart" hydraulic cylinder is as follows: Figure 11 As shown, the details of the "intelligent" hydraulic lifting cylinder 66 will be described by way of example. When other actuators described herein are implemented as "intelligent" cylinders, Figure 11This can also represent the internal structure of those actuators. In the illustrated embodiment, the hydraulic lifting cylinder 66 is of the type sometimes referred to as a "smart cylinder," which includes an integrated sensor 66S configured to provide a signal corresponding to the extension of the piston member 300 relative to the cylinder member 302 of the hydraulic lifting cylinder 66.

[0077] The sensor 66S includes a position sensor electronic housing 304 and a position sensor coil element 306.

[0078] The piston portion of the hydraulic lifting cylinder 66 includes a piston 1108 and a rod 1110. The piston 1108 and the rod 1110 have a hole 1112 defined therein, in which the position sensor coil element 306 is received.

[0079] The hydraulic lifting cylinder 66 is configured such that a signal representing the position of the piston 1108 relative to the position sensor coil element 306 is provided at the connector 1114.

[0080] Such intelligent cylinders can operate on several different physical principles. Examples of such intelligent cylinders include, but are not limited to, magnetostrictive sensing, magnetoresistive sensing, resistance (potential) sensing, Hall effect sensing, sensing using linearly variable differential transformers, and sensing using linearly variable inductor transducers.

[0081] Figure 10 The sensors associated with each of the hydraulic lifting cylinder 66 and the extension actuator 32 are schematically shown, bearing the same designations as those used for the actuators but with the suffix "S". Thus, the hydraulic lifting cylinder 66 may include an integrated extension sensor 66S and the extension actuator 32 may include an integrated extension sensor 32S. The extension sensor 66S provides a signal 222 corresponding to the extension of the hydraulic lifting cylinder 66 and the position of the operator's workbench 48. The extension sensor 32S provides a signal 221 corresponding to the extension of the extension actuator 32 and the position of the movable ground engagement unit 20A and the movable lifting column 26A.

[0082] Alternative embodiments of the support linkage mechanism and lifting actuator:

[0083] Figures 14 to 17B Several alternative embodiments of the support linkage mechanism and / or lifting actuator are shown. (Reference) Figure 1 and Figure 2 The layout of the milling machine 10 seen in the image. Figures 14 to 17B This is a schematic front view of an alternative embodiment. This is different from the schematic view showing the support linkage 50. Figure 6 To create a contrast, Figure 6 This is a rear front view. Therefore, the left edge 54 and right edge 56 of the mechanical frame 12 are... Figure 7 As can be seen in the text, but now in Figures 14-17B The middle part is turned upside down.

[0084] The support linkage 50 discussed above includes two pivot links, each extending between the machine frame 12 and the operator workbench 48, with each pivot link oriented to pivot about a corresponding pivot axis extending parallel to the longitudinal axis of the machine frame 12. Figures 14-17B Each of the alternative embodiments includes only one such pivot link. Therefore, all embodiments can generally be described as including at least one pivot link extending between the machine frame 12 and the operator workbench 48, the at least one pivot link being oriented to pivot relative to the machine frame 12 about a pivot axis extending parallel to the longitudinal axis of the machine frame 12.

[0085] In addition, Figure 3 , Figure 4 , Figure 12 and Figure 13 In the embodiments shown, the lifting actuator is a hydraulic cylinder, while alternative embodiments show that other types of actuators can be used, such as rotary threaded shafts and nuts. Also as shown in these embodiments, the lifting actuator does not necessarily need to be connected to the mechanical frame 12 or the operator's workbench 48, but can be connected between the various links of the supporting linkage mechanism. In general, the lifting actuator can be any suitable actuator.

[0086] exist Figure 14 In one embodiment, the support linkage 120 includes a pivot link 122 pivotally connected to the mechanical frame 12 at 124 and pivotally connected to the operator workbench 48 at 126. A support link 128 is pivotally attached to the pivot link 122 at 130. The support link 128 has a lower roller 132 that rolls on the upper surface of the mechanical frame 12 and an upper roller 134 that rolls to support the lower surface of the operator workbench 48. A lifting actuator 136 includes a threaded shaft 138 received in a threaded nut 140 held at the upper end of the pivot link 122, so that rotation of the threaded shaft 138 causes the upper ends of the links 122 and 128 to move closer together or further apart, thereby raising or lowering the operator workbench 48 relative to the mechanical frame 12. When the operator workbench is raised, it also moves laterally. Figure 14 It is located on the left side, and when it is lowered, it moves laterally to the right side. The threaded shaft 138 can be manually actuated by the handle 142', or rotated by a hydraulic or electric rotary actuator.

[0087] exist Figure 15In one embodiment, the support linkage 142 includes a pivot link 144 pivotally connected to the mechanical frame 12 at 146 and pivotally connected to the operator workbench 48 at 148. A support link 150 is pivotally attached to the pivot link 144 at 152. The support link 150 has a lower roller 154 that rolls along a groove 156 of a guide rail 158 attached to the mechanical frame 12, and an upper roller 160 that rolls along a groove 162 of a guide rail 164 attached to the operator workbench 48. A lifting actuator 166 includes an electric motor 168 that drives a threaded shaft 170, which is received in a nut 172 held between scissor links 174 and 176, such that rotation of the threaded shaft 170 causes the upper ends of links 144 and 150 to move closer to or further away from each other, thereby raising or lowering the operator workbench 48 relative to the mechanical frame 12. It also moves laterally when the operator's workbench is raised. Figure 15 On the left side, and as it lowers, it moves laterally to the right. The threaded shaft 170 can also be moved as follows: Figure 14 The handle can be manually actuated, or rotated by any other suitable rotary actuator.

[0088] exist Figure 16 In one embodiment, the support linkage 178 includes a pivot link pivotally connected to the mechanical frame 12 at 182 and pivotally connected to the operator workbench 48 at 184. A support link 186 is pivotally attached to the pivot link at 188. The support link 186 has a lower roller 190 that rolls in the upper surface or track of the mechanical frame 12, and an upper roller 192 that rollably supports the lower surface or track of the operator workbench 48. A lifting actuator 194, shown as a hydraulic cylinder, is pivotally connected to the mechanical frame 12 and the pivot connection 188 at 196. Extension or retraction of the hydraulic cylinder causes the pivot link to pivot about the lower pivot connection 182 to raise or lower the operator workbench 48 relative to the mechanical frame 12. When the operator workbench is raised, it also moves laterally. Figure 1 It moves to the left side when lowered, and laterally to the right when lowered. The hydraulic cylinder lifting actuator 194 can be replaced by any suitable linear actuator.

[0089] exist Figure 17A and Figure 17BIn one embodiment, the support linkage 400 includes a pivot link 402 pivotally connected to the machine frame 12 at 404 and pivotally connected to the operator workbench 48 at 406. A support link 408 is pivotally attached to the pivot link 402 at 410. The support link 408 has a lower roller 412 that rolls on the upper surface of the machine frame 12 or in a track 414, and an upper roller 416 that rollably supports the lower surface of the operator workbench 48 or the track 418. A lifting actuator 420, schematically shown as a winch, is mounted on the machine frame 12 and includes a winch drum, with one end of a winch belt or cable 424 wound around the winch drum. The other end of the winch belt or cable 424 is attached to a roller, schematically shown as 426. The roller 426 is supported by tension in the winch belt or cable 424. Figure 17A and Figure 17B It was constantly being pulled to the left.

[0090] exist Figure 17A In the diagram, roller 426 is shown straddling the top of the arched protrusion of support link 408. Roller 426 is always engaged between the lower surface of pivot link 402 and the upper surface of support link 408.

[0091] exist Figure 17B In, with Figure 17A In contrast, roller 426 is displaced to the right and remains locked between connecting rods 402 and 408. This is to allow the operator's workbench 48 to be moved from... Figure 17B The lower position rises to Figure 17A The elevated position, through, as by Figure 17A As indicated by arrow 430, the winch drum 422 is rotated counterclockwise, and the winch belt or cable 424 is wound around the winch drum 422. This will cause the roller 426 to... Figure 17B Pull the position to the left Figure 17A Position. As pivot link 402 moves from Figure 17B Position upward facing Figure 17A The position pivots, the operator's workbench rises and moves laterally to the left in the figure. The lower roller 412 of the support link 408 moves to the left within the track 414, while the upper track 418 moves to the left relative to the upper roller 416. To move from... Figure 17A The operator's workbench 48 is raised and lowered, and the winch drum 422 is raised and lowered as follows: Figure 17B As indicated by arrow 432, the machine rotates clockwise, and when roller 426 is pressed between connecting rods 402 and 408, the weight of the operator's workbench, acting downwards due to gravity, pushes the operator's workbench downwards toward the machine frame 12. Figure 17B Return to the location.

[0092] Operational advantages:

[0093] The above-described arrangement provides a movable operator workbench that offers numerous advantages over existing technology systems, such as those shown in U.S. Patent 10,960,938.

[0094] The first advantage is that, because the support linkage 50 is configured to pivot about pivot axes 68 and 72 parallel to the longitudinal axis 14 of the mechanical frame 12, the operator table 48 moves laterally between the inner position 48A and the outermost position 48C without any forward or backward movement of the operator table relative to the mechanical frame 12. This reduces the use of valuable floor space on the mechanical frame 12 and the volume above that floor space compared to systems like those in US10,960,938, where the operator table also moves forward and backward when moving between its inner and outer positions.

[0095] A second advantage of the support linkage 50 being configured to pivot about pivot axes 68 and 72, which are parallel to the longitudinal axis 14 of the machine frame 12, is that, in addition to providing lateral movement of the operator's worktable 48, the support linkage 50 raises and lowers the operator's worktable 48 such that, in the middle outer position 48B or the outermost position 48C, the operator's worktable 48 is raised in height, thus providing an improved overall view around the milling machine 10 due to the increased height.

[0096] A third advantage of the support linkage 50 being configured to pivot about pivot axes 68 and 72, which are parallel to the longitudinal axis 14 of the mechanical frame 12, is that this allows the hydraulic lifting cylinder 66 to be arranged together with the hydraulic accumulator 92 to provide hydraulic spring support to the operator's workbench, thereby providing improved comfort and safety for the operator.

[0097] Control system:

[0098] Now for reference Figure 10 The diagram schematically illustrates an automatic control system 200 for a road milling machine 10. The automatic control system 200 includes a controller 202. The controller 202 receives input signals from various sensors described herein. The controller 202 may also receive additional signals indicative of various operational functions of the road milling machine 10. Communication of control signals from the controller 202 to various actuators (such as 66 and 32) of the road milling machine 10 is... Figure 10 The diagram is schematically shown via communication lines 204 and 206. It will be understood that the flow of hydraulic fluid to the hydraulic lifting cylinder 66 is controlled by an electro-hydraulic control valve 84, which receives an electrical control signal transmitted from the controller 202 via communication line 204 in a known manner. Similarly, the extension actuator 32 will be directly controlled by another electro-hydraulic control valve (not shown), which receives an electrical control signal transmitted via communication line 206.

[0099] Similarly, the controller 202 can control the direction of the road milling machine 10 via the ground engagement units 20A, 20B, 20C, 20D through the steering of their respective steering cylinders such as 38.

[0100] The controller 202 can control the extension of the lifting columns 26A and 26C in a similar manner.

[0101] Controller 202 includes or may be associated with processor 208, computer-readable medium 210, database 212, and input / output module or control panel 214 having display 216. Input / output device 218, such as a keyboard or other user interface, is provided so that a human operator can input instructions to the controller. It is understood that the controller 202 described herein may be a single controller having all the described functions, or it may include multiple controllers, wherein the functions are distributed across multiple controllers.

[0102] The various operations, steps, or algorithms described in conjunction with controller 202 can be directly embodied in hardware, computer program product 220, such as software modules executed by processor 208, or a combination of both. Computer program product 220 can reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, removable disk, or any other form of computer-readable medium 210 known in the art. Exemplary computer-readable medium 210 can be coupled to processor 208, allowing the processor to read information from and write information to the memory / storage medium. Alternatively, the medium can be integrated into the processor. The processor and medium can reside in an application-specific integrated circuit (ASIC). The ASIC can reside in the user terminal. Alternatively, the processor and medium can reside as discrete components in the user terminal.

[0103] As will be understood by those skilled in the art, the term "processor" as used herein can refer to a processing device and / or logic for at least general or special purposes, including but not limited to microprocessors, microcontrollers, state machines, etc. A processor can also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors combined with a DSP core, or any other such configuration.

[0104] In addition to providing the various control features discussed above, the control system 200 may also provide several operating modes to prevent interference between the operator workbench 48 and the movable lifting column 26A due to the overlap of the outer position 48C of the operator workbench 48 and the extended position of the movable lifting column 26A.

[0105] It will be understood that, due to the overlap between the outermost position 48C of the operator's workbench 48 and the fully extended position 26A''' of the movable lifting column 26A, it is desirable to provide a system for preventing these components from interfering with each other. This can be achieved in any of the several operating modes described further below.

[0106] First mode:

[0107] In the first operating mode, the controller 202 can receive an extension signal 222 from the integrated extension sensor 66S of the "smart" hydraulic lifting cylinder 66 and a pressure signal 81 from the pressure sensor 83 associated with the cylinder end 86 of the hydraulic lifting cylinder 66. The extension signal 222 corresponds to the extension amount of the hydraulic lifting cylinder 66. The pressure signal 81 corresponds to the hydraulic pressure within the cylinder end 86 of the hydraulic lifting cylinder 66.

[0108] Controller 202 can be configured to receive extension signal 222 and pressure signal 81 and generate control signal to hydraulic lifting cylinder 66 so that when operator workbench 48 moves to the outermost position 48C, if movable ground engagement unit 20A and movable lifting column 26A are in fully extended positions 20A''' and 26A''' and operator workbench 48 engages movable lifting column 26A, controller 202 detects a rise in hydraulic pressure within hydraulic lifting cylinder 66 and directs hydraulic lifting cylinder 66 to retract a predetermined distance to intermediate outer position 48B to provide a predetermined gap 223 between operator workbench 48 and movable lifting column 26A (see [link to relevant documentation]). Figure 6 (e.g., 20 mm).

[0109] The second mode:

[0110] In the second operating mode, proximity sensor 224 (see Figure 6 and Figure 10 The recess 64 can be mounted on the operator workbench 48 or optionally on the movable lifting column 26A, and configured to provide a proximity signal 226 corresponding to the proximity of the operator workbench 48 to the movable lifting column 26A. In this case, the problem may be the possible interference between the inner edge 65 of the recess 64 and the movable lifting column 26A.

[0111] The controller 202 can be configured to receive a proximity signal 226 and generate a control signal to the hydraulic lifting cylinder 66. The controller 202 is configured such that when the operator workbench 48 moves toward the outermost position 48C, if the movable ground engagement unit 20A and the movable lifting column 26A are in the fully extended positions 20A''' and 26A''', and the proximity sensor 224 detects the operator workbench 48 within a predetermined distance of the movable lifting column 26C, the controller 202 instructs the hydraulic lifting cylinder 66 to stop extending, so as to provide a predetermined gap 223 (e.g., 20 mm) between the operator workbench 48 and the movable lifting column 26A, and once again leave the operator workbench 48 in the intermediate outer position 48B.

[0112] The third model:

[0113] A third operating mode can be provided by configuring a pivoting mechanism that allows the movable ground engagement unit 20A and the movable lifting column 26A to move, such that the extended position of the movable lifting column 26A is positioned so that the movable lifting column 26A does not interfere with the operator workbench 48, even when the operator workbench 48 is in its outermost position 48C. This extended position of the movable lifting column 26A can also be in the intermediate extended position 26A'' in front of the operator workbench 48, such as... Figure 6 As illustrated schematically. Alternatively, the extended position of the movable lifting column can be located laterally outside the outermost position 48C of the operator's workbench. By thus limiting the extension position of the movable lifting column 26A, it is ensured that the movable lifting column 26A will not interfere with the operator's workbench 48, even when the operator's workbench 48 is in the outermost position 48C.

[0114] The movement limit of the movable lifting column 26A can be provided by the physical geometry of the swing arm 28 and the extension actuator 32 and the various physical structures associated therewith, or the movement limit can be provided by the controller 202 by controlling the extension actuator 32.

[0115] However, in this embodiment, the extension actuator 32 need not be a "smart" cylinder or have an associated extension sensor 32S. The extension actuator 32 can be a conventional or "dumb" hydraulic cylinder. In embodiments using a conventional hydraulic cylinder for the extension actuator 32, the limitation of movement of the swing arm 28 can be provided by the physical geometry of the swing arm 28 and the extension actuator 32, and the various physical structures associated therewith. In another embodiment using a conventional hydraulic cylinder for the extension actuator 32, the limitation of movement of the swing arm 28 can be provided by the controller 202 using additional position sensors that detect the position of the movable rear ground engagement unit relative to the mechanical frame 12.

[0116] Furthermore, in this embodiment, the hydraulic lifting cylinder 66 need not be a "smart" cylinder or have an associated extension sensor 66S. The hydraulic lifting cylinder 66 can be a conventional hydraulic cylinder. In embodiments using a conventional hydraulic cylinder for the hydraulic lifting cylinder 66, the limitation of movement of the operator's workbench 48 can be provided by the physical geometry of the support linkage 50 and the various physical structures associated with it. In another embodiment using a conventional hydraulic cylinder for the hydraulic lifting cylinder 66, the limitation of movement of the operator's workbench 48 can be provided by the controller 202 using other position sensors, such as a proximity sensor 67 or a rotary position sensor 69, that detect the position of the operator's workbench 48 relative to the mechanical frame 12.

[0117] The third operating mode can be described as a mode in which the outer position of the operator workbench 48 and the extended position of the movable ground engagement unit 20A are defined such that when the movable ground engagement unit 20A is in the extended position, the operator workbench 48 can move between an inner position and an outer position without interference between the movable lifting column 26A and the operator workbench 48, and when the operator workbench 48 is in the outer position, the movable ground engagement unit 20A can move between a retracted position and an extended position without interference between the movable lifting column 26A and the operator workbench 48A.

[0118] The fourth mode:

[0119] A fourth operating mode can be provided by configuring a lifting mechanism that moves the operator's worktable 48 such that lateral movement from the inner position 48A always terminates at the intermediate outer position 48B. This intermediate outer position is selected such that if the lifting column 26A is in its fully extended position 26A''', a gap 223 is provided between the inner edge 65 of the recess 64 of the operator's worktable 48 and the movable lifting column 26A (see...). Figure 6 By restricting the outer position of the operator's workbench 48 in this way, it is ensured that the movable lifting column 26A will not interfere with the operator's workbench 48, even when the movable lifting column 26A is in the fully extended position 26A'''.

[0120] Movement restrictions on the operator workbench 48 can be provided by the physical geometry of the support linkage 50 and the hydraulic lifting cylinder 66 and the various physical structures associated therewith, or if the hydraulic lifting cylinder 66 has an associated extension sensor 66S, movement restrictions can be provided via the controller 202 by controlling the extension of the hydraulic lifting cylinder 66.

[0121] However, in this embodiment, the hydraulic lifting cylinder 66 need not be a "smart" cylinder or have an associated extension sensor 66S. The hydraulic lifting cylinder 66 can be a conventional hydraulic cylinder.

[0122] In embodiments using a conventional hydraulic cylinder for the hydraulic lifting cylinder 66, movement limitation of the operator's workbench 48 can be provided by the physical geometry of the supporting linkage 50 and the various physical structures associated therewith. In another embodiment using a conventional hydraulic cylinder for the hydraulic lifting cylinder 66, movement limitation of the operator's workbench 48 can be provided by the controller 202 using other position sensors, such as a proximity sensor 67 or a rotary position sensor 69, that detect the position of the operator's workbench 48 relative to the mechanical frame 12.

[0123] Furthermore, in this embodiment, the extension actuator 32 need not be a "smart" cylinder or have an associated extension sensor 32S.

[0124] The fourth operating mode can also be described as a mode in which the outer position of the operator workbench 48 and the extended position of the movable ground engagement unit 20A are defined such that when the movable ground engagement unit 20A is in the extended position, the operator workbench 48 can move between the inner and outer positions without interference between the movable lifting column 26A and the operator workbench 48, and when the operator workbench 48 is in the outer position, the movable ground engagement unit 20A can move between the retracted and extended positions without interference between the movable lifting column 26A and the operator workbench 48A.

[0125] The fifth mode:

[0126] In the fifth operating mode, an operator interface can be provided to the operator, which can be configured to allow the operator to choose between the third and fourth modes mentioned above.

[0127] In this fifth operating mode, the hydraulic lifting cylinder 66 can be associated with a lifting cylinder extension sensor 66S, which is configured to provide a cylinder extension signal 222 corresponding to the extension of the hydraulic lifting cylinder 66. This allows the hydraulic lifting cylinder to selectively limit the outer position of the operator's workbench 48 to either the outermost position 48C or the middle outer position 48B.

[0128] In this fifth operating mode, the controller 202 can be configured to receive the cylinder extension signal 222 and the position signal 221 of the movable rear ground engagement unit, and generate control signals to the hydraulic lifting cylinder 66 and the extension actuator 32. The controller is configured such that:

[0129] In one operating mode (the third mode mentioned above), the extension actuator 32 is restricted to the movement of the movable rear ground engagement unit 20A between the retracted position 20A' and the intermediate extended position 20A'', and allows the hydraulic lifting cylinder 66 to move the operator workbench 48 to the outermost position 48C.

[0130] In another operating mode (the fourth mode described above), the extension actuator 32 is allowed to move the movable ground engagement unit 20A to the fully extended position 20A''', and the hydraulic lifting cylinder 66 is restricted to the movement of the operator's workbench 48 between the inner position 48A and the intermediate outer position 48B; and

[0131] The controller 202 includes an operator interface configured to allow a human operator to select between one operating mode and another.

[0132] The sixth model:

[0133] In the sixth operating mode, proximity sensor 228 (see...) Figure 6 and Figure 10 The device can be mounted on the operator workbench 48 or optionally on the movable lifting column 26A, and configured to provide a proximity signal 230 corresponding to the proximity of the operator workbench 48 to the movable lifting column 26A. This can also be described as the proximity of the movable lifting column 26A to the operator workbench 48. In this case, the problem is that if the operator workbench 48 is already in the outermost position 48C, and the operator then attempts to move the movable lifting column 26A from the retracted position 26A' to the fully extended position 26A'''', the moving lifting column 26A will collide with the operator workbench 48.

[0134] The controller 202 can be configured to receive a proximity signal 230 and generate a control signal to the extension actuator 32. The controller 202 is configured such that when the operator workbench 48 is in its outermost position 48C and the proximity sensor 228 detects that the operator workbench 48 is within a predetermined distance (e.g., 20 mm) of the movable lifting column 26A, the controller 202 directs the extension actuator 32 to stop to provide a predetermined gap 232 (e.g., 20 mm) between the operator workbench 48 and the movable lifting column 26A in an intermediate extension position 26A'' of the movable lifting column 26A (see [link to documentation]). Figure 6 ).

[0135] Figures 18-19 Alternative embodiments:

[0136] Figure 18 and Figure 19A “large” milling machine similar to that in U.S. Patent 10,968,576 is schematically presented and certain aspects of this disclosure are incorporated herein by reference. Milling machines are generally designated as 500. These components are similar to Figure 1 and Figure 2 The embodiments are illustrated with the same reference numerals. In the milling machine 500, the operator's workbench 48 is longitudinally located between the front and rear tracks.

[0137] In this milling machine 500, there is no interference problem between the movable operator's workbench 48 and any lifting columns. However, there is still a need for an efficient mechanism for lifting and laterally moving the operator's workbench to give the operator a better view of the engagement between the milling drum 502 and the milled ground surface. Therefore, in Figure 19 In the middle, the operator's workbench 48 is shown in dashed lines, schematically offset beyond the right edge of the mechanical frame 12.

[0138] Therefore, it can be seen that the apparatus and methods of this disclosure readily achieve the mentioned and inherent objects and advantages. Although certain preferred embodiments of this disclosure have been described and illustrated for the purposes of this invention, many changes can be made by those skilled in the art to the arrangement and structure of components and steps, and these changes are covered within the scope and spirit of this disclosure as defined by the appended claims. Each feature or embodiment of the disclosure may be combined with any other feature or embodiment of the disclosure.

Claims

1. A self-propelled road milling machine, comprising: A mechanical frame having a longitudinal axis extending between a front and a rear portion of the mechanical frame, the mechanical frame including a left edge and a right edge; Multiple ground-jointing units are used to support the mechanical frame from the ground surface; The milling drum is supported by a mechanical frame. as well as Operator workbench; The feature is that it further includes a support linkage mechanism comprising at least one pivoting link extending between the machine frame and the operator's workbench, the at least one pivoting link being oriented to pivot about a pivot axis extending parallel to a longitudinal axis of the machine frame. The support linkage mechanism is configured such that the operator's workbench can move laterally relative to the machine frame between an inner position and an outer position, the outer position extending laterally beyond one of the left and right edges of the machine frame, and the outer position being at a higher height relative to the machine frame than the inner position. The plurality of ground engagement units include at least one front ground engagement unit and at least two rear ground engagement units, and at least one of the rear ground engagement units is a movable rear ground engagement unit capable of moving relative to the mechanical frame between a retracted position and an extended position. The milling drum is positioned such that when the movable rear ground engagement unit is in the retracted position, the movable rear ground engagement unit is located in front of the milling drum; and The outer part of the operator's workbench extends laterally beyond one of the left and right edges of the mechanical frame adjacent to the movable rear ground engagement unit; The self-propelled road milling machine further includes at least two lifting columns extending between at least two rear ground engagement units and the mechanical frame for raising and lowering the mechanical frame relative to the ground surface, wherein one of the lifting columns is a movable lifting column attached to a movable rear ground engagement unit; and The operator workbench includes a recess configured to at least partially receive the movable lifting column when the movable rear ground engagement unit is in the extended position and the operator workbench is in the outward position.

2. The self-propelled road milling machine according to claim 1, characterized in that, It also includes a hydraulic lifting cylinder connected to at least one of the support linkage mechanism and the operator's workbench, the hydraulic lifting cylinder being configured to move the operator's workbench between an inner position and an outer position.

3. The self-propelled road milling machine according to claim 2, characterized in that, It also includes a hydraulic accumulator that is hydraulically connected to the hydraulic lifting cylinder and configured to provide hydraulic spring support for the operator's workbench at least when the operator's workbench is in the outer position.

4. The self-propelled road milling machine according to claim 3, characterized in that, It also includes a hydraulic flow limiter disposed between the hydraulic lifting cylinder and the hydraulic accumulator, and configured to limit the flow of hydraulic fluid between the hydraulic lifting cylinder and the hydraulic accumulator in at least one direction to dampen the hydraulic spring support of the operator's workbench.

5. The self-propelled road milling machine according to claim 2, characterized in that, The hydraulic lifting cylinder is an intelligent cylinder, which includes an integrated extension sensor configured to provide extension signals corresponding to the extension of the hydraulic lifting cylinder and the corresponding position of the operator's workbench.

6. The self-propelled road milling machine according to claim 1, characterized in that, It also includes a lifting actuator connected to at least one of the support linkage mechanism and the operator's workbench.

7. The self-propelled road milling machine according to claim 6, characterized in that, The lifting actuator is connected between the mechanical frame and the operator's workbench.

8. The self-propelled road milling machine according to claim 6, characterized in that, It also includes a proximity sensor configured to detect the presence of the operator's workbench in a position relative to the outside of the mechanical frame.

9. The self-propelled road milling machine according to claim 1, characterized in that, The support linkage is configured to allow the operator's workbench to move laterally between an inner and outer position, without any forward or backward movement relative to the mechanical frame, thereby minimizing the footprint of the operator's workbench above the mechanical frame when moving between the inner and outer positions.

10. The self-propelled road milling machine according to claim 1, characterized in that, Compared to the inner position, the outer position of the operator's workbench provides the operator on the workbench with an improved view of the ground surface area adjacent to the milling drum due to the lateral outward movement, as well as an improved overall view of the area around the self-propelled road milling machine due to the higher height of the outer position.

11. The self-propelled road milling machine according to claim 1, characterized in that, When the operator's workbench is in the inner position, the fixed floor space of the operator's workbench lies entirely between the left and right edges of the mechanical frame.

12. The self-propelled road milling machine according to claim 1, characterized in that: When the movable rear ground engagement unit is in the extended position, the two rear ground engagement units are laterally aligned, and the milling drum is laterally positioned between the two rear ground engagement units. as well as When in the outer position, if the movable rear ground engagement unit is in the extended position, the operator's workbench is at least partially above the position of the movable rear ground engagement unit.

13. The self-propelled road milling machine of claim 1, wherein, Also includes: A hydraulic lifting cylinder is connected to at least one of a support linkage mechanism and an operator's workbench, the hydraulic lifting cylinder being configured to move the operator's workbench between an inner position and an outer position; An extension sensor configured to provide an extension signal corresponding to the extension of the hydraulic lifting cylinder; A pressure sensor configured to provide a pressure signal corresponding to the hydraulic pressure within the hydraulic lifting cylinder; A movable lifting column extends between a movable rear ground engagement unit and a mechanical frame for raising and lowering the mechanical frame relative to the ground surface. as well as A controller configured to receive extension and pressure signals and generate control signals to the hydraulic lifting cylinder, the controller being configured to detect a hydraulic rise in the hydraulic lifting cylinder and direct the hydraulic lifting cylinder to retract a predetermined distance when the operator's workbench moves toward an outward position, provided that the movable ground engagement unit and the movable lifting column are in the extended position and the operator's workbench engages the movable lifting column, so as to provide a predetermined gap between the operator's workbench and the movable lifting column in the outward position of the operator's workbench.

14. The self-propelled road milling machine of claim 1, wherein, Also includes: A lifting actuator connected to at least one of a support linkage mechanism and an operator's workbench, the lifting actuator being configured to move the operator's workbench between an inner position and an outer position; A movable lifting column extends between a movable rear ground engagement unit and a mechanical frame for raising and lowering the mechanical frame relative to the ground surface. A proximity sensor configured to provide a proximity signal corresponding to the proximity of the operator's workbench to a movable lifting column; as well as A controller configured to receive a proximity signal and generate a control signal to a lifting actuator is configured such that when the operator workbench moves toward an outward position, if the movable ground engagement unit and the movable lifting column are in the extended position and the proximity sensor detects that the operator workbench is within a predetermined distance of the movable lifting column, the controller instructs the lifting actuator to stop moving, so as to provide a predetermined gap between the operator workbench and the movable lifting column in the outward position of the operator workbench.

15. The self-propelled road milling machine of claim 1, wherein, Also includes: A movable lifting column extends between a movable rear ground engagement unit and a mechanical frame for raising and lowering the mechanical frame relative to the ground surface. as well as The outer position of the operator's workbench and the extended position of the movable ground engagement unit are defined such that when the movable ground engagement unit is in the extended position, the operator's workbench can move between the inner and outer positions without interference between the movable lifting column and the operator's workbench; and when the operator's workbench is in the outer position, the movable ground engagement unit can move between the retracted and extended positions without interference between the movable lifting column and the operator's workbench.

16. The self-propelled road milling machine according to claim 15, characterized in that: When the movable rear ground engagement unit is in the extended position, the movable rear ground engagement unit is positioned in front of another rear ground engagement unit.

17. The self-propelled road milling machine according to claim 15, characterized in that: When the movable rear ground engagement unit is in the extended position, the two rear ground engagement units are laterally aligned, and the milling drum is laterally positioned between the two rear ground engagement units. as well as When the operator workbench is in the outer position and the movable rear ground engagement unit is in the extended position, the movable lifting column is located laterally outside the operator workbench, so that the movable lifting column does not interfere with the operator workbench.

18. The self-propelled road milling machine of claim 1, wherein, Also includes: A lifting actuator connected to at least one of a support linkage structure and an operator workbench, the lifting actuator being configured to move the operator workbench between an inner position, an outer position, and a middle outer position. A lifting actuator extension sensor is configured to provide a lifting actuator extension signal corresponding to the extension of the lifting actuator; A movable lifting column extends between a movable rear ground engagement unit and a mechanical frame for raising and lowering the mechanical frame relative to the ground surface. An extension actuator configured to allow a movable rear ground engagement unit and a movable lifting column to move between a retracted position, an extended position, and an intermediate extended position. The extension actuator extension sensor is configured to provide a position signal of the movable rear ground engagement unit corresponding to the position of the movable rear ground engagement unit relative to the mechanical frame. as well as A controller configured to receive extension signals from the lifting actuator and position signals from a movable rear ground engagement unit, and to generate control signals to the lifting actuator and the extension actuator, the controller being configured such that: In one operating mode, the extension actuator is restricted to the movement of the movable rear ground engagement unit between a retracted position and an intermediate extended position, and the lifting actuator is allowed to move the operator's workbench to an outward position. In another operating mode, the extension actuator is allowed to move the movable ground engagement unit to the extension position, and the lifting actuator is restricted to the movement of the operator's workbench between the inner position and the middle outer position. as well as The controller includes an operator interface configured to allow operators to select between one operating mode and another.

19. The self-propelled road milling machine of claim 1, wherein, Also includes: A movable lifting column extends between a movable rear ground engagement unit and a mechanical frame for raising and lowering the mechanical frame relative to the ground surface. An extension actuator configured to move a movable rear ground engagement unit and a movable lifting column between a retracted position and an extended position. A proximity sensor configured to provide a proximity signal corresponding to the proximity of the operator's workbench to a movable lifting column; as well as A controller configured to receive a proximity signal and generate a control signal to an extension actuator, the controller being configured such that when the operator workbench is in the outward position and the proximity sensor detects that the operator workbench is within a predetermined distance of the movable lifting column, the controller directs the extension actuator to stop, so as to provide a predetermined gap between the operator workbench and the movable lifting column in the extended position of the movable rear ground engagement unit and the movable lifting column.

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