The disclosure of the following priority application is herein incorporated by reference: Japanese Patent Application No. 2001-339287 filed Nov. 5, 2001
The present invention relates to an operating lever device for a construction machine, having an operating member that is used to control a prime mover rotation rate and is mounted at a grip attached to the front end of an operating lever, and a construction machine having the operating lever device.
Operating levers having an engine rotation rate control member in the related art include the operating lever disclosed in Japanese Patent Registration No. 2752820. This operating lever includes an operating member that is used to control an engine speed and is mounted a grip main body of a swing lever, which is not allowed to rotate, in such a manner that the operating member can rotate relative to the grip main body. This structure prevents the operating member from being inadvertently operated during an operation for swinging performed by the operator gripping the grip main body and also prevents the operating lever from being inadvertently rotated while the operating member is being operated.
The operator of a crane work machine mounted with a boom hoist drum, a main hoist drum, an auxiliary hoist drum and the like sometimes drives a plurality of drums simultaneously through a combined control of the operating lever. For instance, he may drive the boom hoist drum while also driving the main hoist drum or may drive the auxiliary hoist drum while driving the main hoist drum. It is desirable to ensure that the engine speed can be freely adjusted when controlling the drive of a plurality of drums as described above. However, it is difficult to adjust the engine speed while controlling the drive of a plurality of drums with the operating lever disclosed in the above-identified publication since the operating member is disposed at the grip main body of the swing lever. In addition, if the operating member is inadvertently operated, an undesirable fluctuation of the engine speed will result.
The present invention provides an operating lever device for a construction machine, which adjusts the prime mover rotation rate with ease while commanding the drive of a plurality of actuators and a construction machine having the operating lever device.
The present invention also provides an operating lever device for a construction machine, which does not allow any undesirable fluctuation of the prime mover rotation rate once the prime mover rotation rate has been adjusted and a construction machine having the operating lever device.
An operating lever device for a construction machine according to the present invention comprises a joystick lever used to issue drive commands to a plurality of driving bodies; a grip main body that is mounted at a front end of the joystick lever in such a manner that the grip main body does not rotate relative to the joystick lever; and an operating member that is allowed to rotate relative to the grip main body and is rotated to adjust a prime mover rotation speed.
It is preferable that the operating lever device having the operating member is provided on one of a left side and a right side in an operator's cab of the construction machine. It is preferable that the plurality of driving bodies include a swinging device which supports a revolving superstructure of the construction machine so as to allow the revolving superstructure to swing relative to a traveling structure of the construction machine; and that the operating lever device having the operating member is an operating lever device which controls drive of the swinging device.
The operating lever having the operating member may be provided on each of a left side and a right side in an operator's cab of the construction machine. It is preferable that the plurality of driving bodies include a swinging device which supports a revolving superstructure of the construction machine so as to allow the revolving superstructure to swing relative to a traveling structure of the construction machine; and that one of the operating lever devices located on the left side and the right side in the operator's cab is an operating lever device that controls drive of the swinging device.
It is preferable that the operating member is provided at a top of the grip main body. A collar portion maybe provided at a bottom of the grip main body. It is preferable that the operating member is allowed to rotate around a central axis extending along a longitudinal direction of the grip main body. The grip main body may be a substantially cylindrical shape, and the operating member may be formed as a lid that is a substantially cylindrical shape.
A rotation of the operating member may be limited to a predetermined operating extent, and the predetermined operating extent corresponds to a predetermined maximum prime mover rotation speed. It is preferable to further comprise an operating extent detector that detects an operating extent of the operating member and outputs the detected operating extent to a control device which adjusts the prime mover rotation speed. It is possible that the operating lever device having the operating member further comprises a swing brake switch through which a command for engaging a swing braking device that disallows a swinging motion of the revolving superstructure is issued.
It is possible that a selector switch that switches a prime mover rotation speed command signal from the operating member between a valid state and an invalid state is further provided, and that the prime mover rotation speed command signal from the operating member provided at one of the operating lever devices disposed on the left side and the right side in the operator's cab is set to a valid state in response to a command issued through the selector switch.
It is possible that an altering device that alters characteristics of a prime mover rotation speed command value corresponding to a prime mover rotation speed command signal in conformance to a rotating operation of the operating member is further provided, and that the altering device alters the characteristics of the prime mover rotation speed command value so as to increase the prime mover rotation speed when the operating member located on the left side in the operator's cab is rotated along one direction and also increase the prime mover rotation speed when the operating member located on the right side in the operator's cab is rotated along another direction.
A prime mover rotation speed control system according to the present invention, wherein a prime mover rotation speed command value from an operating lever device for a construction machine, a prime mover rotation speed command value originating from an accelerator pedal and a prime mover rotation speed command value originating from a fuel lever are compared; a largest value among the command values is selected, and prime mover rotation speed is controlled in conformance to the largest value.
An operating lever device for a construction machine according to the present invention comprises: a lever used to issue a drive command for a driving body; a grip main body provided at a front end of the lever in such a manner that the grip main body does not rotate relative to the lever; an operating member that is provided at a top of the grip main body and is operated to adjust a prime mover rotation speed; and a locking member that locks the prime mover rotation speed at the prime mover rotation speed having been set with the operating member.
It is preferable that the operating member and the locking member are formed as an integrated dial and the prime mover rotation speed is set by rotating the dial and the prime mover rotation speed thus set is locked by pressing the dial.
The lever may be a joystick lever through which drive commands are issued to a plurality of driving bodies.
A prime mover rotation speed control system according to the present invention comprises any one of the operating lever devices described above, a prime mover provided in a construction machine; and a control device that controls a rotation speed of the prime mover so as to achieve a rotation speed having been set based upon a prime mover rotation speed command signal set with the operating member provided at the operating lever device.
A construction machine according to the present invention comprises any one of the operating lever devices described above; at least one driving body on which drive control is implemented with the operating lever device; a prime mover; and a control device that adjusts a rotation speed of the prime mover in correspondence to an extent to which the operating member is operated.
a) is a side elevation of an upper portion of the operating lever achieved in the embodiment of the present invention,
a) is a top view of an operating lever and
a) is a top view of an operating lever and
The first embodiment of the present invention is now explained in reference to
At the bottom of the lever 10, spools 3a to 3d respectively supported by pilot valves 4a to 4d (see
As shown in
For instance, if the operating lever 10L is operated frontward, the spool 3a is pressed down and, as a result, the pilot valve 4a is driven, whereas if the operating lever 10L is operated rearward, the spool 3b is pressed down and the pilot valve 4b is driven. If the operating lever 10L is operated to the left, the spool 3c is pressed down and, as a result, the pilot valve 4c is driven, whereas if the operating lever 10L is operated to the right, the spool 3d is pressed down and the pilot valve 4d is driven. In addition if the operating lever 10L is operated frontward by a 45° angle to the right, i.e., along direction B in
The grip 11 is clamped at the lower portion of its external circumferential surface by a pair of split ring members 14a and 14b (see
The following is an explanation of the internal structure of the grip 11, given in reference to
A potentio-shaft (a shaft of the potentiometer) 23a at the front end, i.e., at the upper end, of the potentiometer 23 is inserted at a coupling 27 having a longitudinal notch 27a. A pin 33, to be detailed later, is inserted at the notch 27a. The coupling 27 and the potentio-shaft 23a are locked to each other to form an integrated unit via a bolt 28. Gaps are created between the external circumferential surface of the coupling 27 and the base member 21 and between the front end of the potentio-shaft 23a and the cover 25. As a result, the potentio-shaft 23a and the coupling 27 are allowed to rotate around an axis X of the grip 11, i.e., around the central axis of the grip extending along the longitudinal direction.
A pipe 31 is attached to the base member 21 via a ball plunger 29 so as to be allowed to rotate around the axis X. The rotary operating member 30 is fitted on the outside of the pipe 31, and the rotary operating member 30 and the pipe 31 are coupled as one via a screw 32. The pin 33 passes through the pipe 31 along the radius of the pipe 31. The front end of the pin 33 passes through a groove hole 21b ranging along the circumferential direction over approximately 90° at the side surface of the base member 21 and is inserted at the notch 27a at the coupling 27. Thus, the potentio-shaft 23a is allowed to rotate together with the coupling 27, the pipe 31 and the rotary operating member 30 via the pin 33. Since the pin 33 moves inside the groove hole 21b formed at the side surface of the base member 21, the potentio-shaft 23a, the coupling 27, the pipe 31 and the rotary operating member 30 are allowed to rotate only within the 90° range around the axis X and cannot rotate beyond this range.
The potentiometer 23 detects the rotating quantity of the potentio-shaft 23a representing the operating quantity of the rotary operating member 30 and outputs a signal corresponding to the detection value. It is to be noted that the rotary operating member 30 is made to stop at the position at which the rotating operation thereof has stopped due to the resistance between the base member 21 and the pipe 31. It is desirable to constitute the rotary operating member 30, which is normally operated by the operator using his fingers, with a non-slippery material.
A swing brake switch 35 is provided at the external circumferential surface of the grip 11. As the swing brake switch 35 is turned on, a swing brake device (not shown) is activated to prevent an undesirable swing of the revolving superstructure 63 which may be caused by its own weight on a slope or the like. A signal line extending from the potentiometer 23 and the like passes through the centers of the grip 11 and the operating lever 10, is taken out through the base end of the operating lever 10 and is connected to a controller 50 (see
Next, the operations which characterize the embodiment of the present invention, executed when operating the crawler crane to hoist the boom, take up/down the hooks 68 and 69 and the like are explained. These crane operations are performed while the operator holds the grips 11 of the operating levers 10L and 10R with his left hand and right hand respectively. It is to be noted that the rotary operating member 30 is provided at each of the left and right levers 10L and 10R.
First, the boom hoisting operation and the take up/down operation of the main hook 68 are explained. As the operator moves the lever 10R frontward or rearward with his right hand, the main hoist drum 66 is driven to take up/down the main hook 68, whereas as the operator moves the lever 10R to the left or to the right, the boom hoist drum 65 is driven to hoist up/down the boom 64, as explained earlier. In addition, if the lever 10R is operated along a diagonal direction, the main hoist drum 66 and the boom hoist drum 65 are driven at the same time.
Since the rotary operating member 30 is located at the front end of the grip 11, as described earlier, the operator operating the lever 10R by holding the grip 11 is not allowed to inadvertently rotate the rotary operating member 30. In particular, if the operator holds the grip 11 while keeping the side of the little finger of his right hand in contact with the split ring members 14a and 14b, the right hand is settled in a stable manner to prevent an erroneous operation of the rotary operating member 30 and to facilitate the operation of the lever 10R. As a result, any undesirable change in the engine speed is prevented and, at the same time, the crane operation can be performed smoothly.
It is to be noted that if the lever 10L is moved to the left or to the right with the left hand while the operator is operating the lever 10R with his right hand, the swinging device 62 is driven causing the revolving superstructure 63 to swing. Thus, a swinging operation can be performed concurrently during the boom hoisting operation and the take up/down operation of the main hook 68.
If the rotary operating member 30 provided at, for instance, the lever 10L is rotated with the left hand when hoisting the boom and taking up/down the main hook 68, the engine speed is controlled in correspondence to the operating quantity of the rotary operating member 30, as described above. In this situation, the grip 11 itself does not rotate relative to the lever 10L, and thus, the operator can operate the rotary operating member 30 with, for instance, his thumb and index finger with ease while holding the grip 11. Especially, by holding the grip 11 while keeping the side of the little finger of his left hand in contact with the split ring members 14a and 14b, the operator's left hand can be held in a stable manner to allow the operator to operate the rotary operating member 30 with the fingers of his left hand with ease. This eliminates the need for the operator to twist his wrist to operate the rotary operating member 30, and since an inadvertent rotation of the lever 10L is prevented, no undesirable swinging operation or take up/down operation of the auxiliary hook 69 is performed against the operator's wishes.
Since the rotary operating member 30 is allowed to rotate only over the 90° range and the control is implemented to set the engine speed to the predetermined maximum rotation rate when the potentio-shaft 23a is rotated by 90°, the operator can control the engine speed up to the maximum rotation rate without having to adjust his hold on the grip 11. It is to be noted that the rotary operating member 30 provided at the lever 10R may be rotated with a finger of his right hand. In such a case, the boom hoist drum 65 and the main hoist drum 66 can be driven and the engine speed can be adjusted at the same time with the right hand alone.
Next, a situation in which the operator performs an auxiliary hook take up operation in combination with the crane operations described above is explained. As the operator moves the lever 10L frontward or rearward with his left hand, the auxiliary hoist drum 67 is driven and the auxiliary hook 69 is taken up/down. In addition, if the operator operates the lever 10L diagonally, the revolving superstructure 63 is made to swing concurrently while the auxiliary hook 69 is taken up/down. By moving the right lever 10R and also rotating the rotary operating member 30 with one finger of the right hand or the left hand at this time, the drive of the individual drums 65 to 67 and the drive of the swinging device 62 and the adjustment of the engine speed can be achieved all at once.
It is to be noted that the engine speed can be also controlled through a pedal operation or a fuel lever operation. If the rotary operating members 30 provided at the left and right levers 10L and 10R, the accelerator pedal and the fuel lever are operated all at once, the engine speed control is executed as explained below.
As shown in
Only the signal from one of the rotary operating members 30L and 30R at the left lever 10L and the right lever 10R may be used as a valid signal. For instance, either the lever 10L or the lever 10R may be selected in accordance with the operator's preference to implement the engine speed control by using the rotation speed command value reflecting the operation of the rotary operating member at the selected lever.
As shown in
As described above, either one of the left rotary operating member 30L and the right rotary operating member 30R can be selected. As a result, the rotary operating member better suiting the preference of the operator or ergonomic consideration can be selected to improve the operability.
The direction along which the left rotary operating member 30L is operated to increase the engine speed may be reversed from the direction along which the right rotary operating member 30R is operated to increase the engine speed.
As shown in
If the rotary operating member 30 is located on the left side in the operator's cab, the switching circuit 50C is switched to the contact point A with the selector switch 103. As the rotary operating member 30 is operated counterclockwise, i.e., along the direction in which the thumb of the left hand holding the grip 11 is pushed outward, at this setting, the engine speed increases. If the rotary operating member 30 is located on the right side in the operator's cab, the switching circuit 50C is switched to the contact point B with the selector switch 103. As the rotary operating member 30 is operated clockwise, i.e., along the direction in which the thumb of the right hand holding the grip 11 is pushed outward, at this setting, the engine speed increases.
When the direction along which the left rotary operating member 30L is operated to increase the engine speed and the direction along which the right rotary operating member 30R is operated to increase the engine speed are set opposite from each other as described above, the operator can operate the left and right rotary operating members 30L and 30R in a natural manner. In addition, since the characteristics of the rotation speed command value corresponding to the output voltage from a rotary operating member 30 are switched by the switching circuit 103, the left and right levers 10L and 10R can be constituted by using identical parts. As a result, advantages such as a cost reduction and simplification of the assembly process can be achieved.
It is to be noted that the engine speed may be made to increase by operating the left rotary operating member 30L clockwise and operating the right rotary operating member 30R counterclockwise, instead. The operating direction of each rotary operating member 30 should be set when assembling the operating lever 10. However, the operating direction may be later switched by the operator to better suit his preference by operating the selector switch 103.
The rotary operating member 30 provided at a given operating lever 10 can be also used to control the tilting amount of a hydraulic pump as well as to control the engine speed.
As shown in
For instance, as the switching circuit 50F is switched to the terminal C via the selector switch 104, the switching circuit 50G is switched to the terminal E. As a result, the engine speed control is implemented in response to the operation of the left lever rotary operating member 30L and the regulator 105 is controlled in response to the operation of the right lever rotary operating member 30R to control the tilting amount of the hydraulic pump. If, on the other hand, the switching circuit 50F is switched to the terminal D via the selector switch 104, the switching circuit 50G is switched to the terminal F. As a result, the engine speed control is implemented in response to the operation of the right lever rotary operating member 30R and the regulator 105 is controlled in response to the operation of the left lever rotary operating member 30L to control the tilting amount of the hydraulic pump.
As described above, the tilting amount of the hydraulic pump can be adjusted by using the rotary operating member 30 provided at an operating lever 10. As a result, it becomes possible to adjust with ease the tilting amount as well as to control the engine speed while operating a plurality of actuators, which is particularly useful when, for instance, the construction machine is running at very low speed.
It is to be noted that the rotary operating members may be set in advance so as to control the engine speed with the left lever rotary operating member 30L and control the tilting amount with the right lever rotary operating member 30R or vice versa.
While the rotary operating member 30 is provided at each of the left and right operating levers 10L and 10R in the first embodiment explained above, the rotary operating member 30 may be provided only at one of the operating levers. In such a case, the number of required parts is reduced. It is to be noted that since the engine speed does not need to be adjusted very often during a swinging operation, the rotary operating member 30 is provided preferably at the left lever 10L through which a command for the swinging operation is issued. Since this allows the engine speed to be adjusted by the operator operating the rotary operating member 30 at the left lever 10L with his left hand while driving the main hoist drum 66 and the boom hoist drum 65 through an operation of the right lever 10R, good operability is assured.
It is to be noted that the number of operating levers 10 does not need to be two. In addition, the operating levers 10 may be positioned to the front of the operator's seat 5 instead of on the left and right sides of the operator's seat 5. Furthermore, as long as the operating levers 10 are each constituted of a single joystick lever capable of outputting drive commands to a plurality of driving bodies, the shape and the internal structure of the operating levers 10 are not limited to those explained in reference to the embodiment.
As long as the rotary operating member 30 can be rotated around the axis X of the grip with ease by the operator, it does not need to be formed as a lid assuming a substantially cylindrical shape. For instance, instead of a lid shape, the rotary operating member 30 may assume a simple substantially cylindrical shape and, in such a case, a lid may be fitted at the top of the rotary operating member 30. In addition, the angular range over which the rotary operating member 30 is allowed to rotate may be set to a value other than 90°. In this case, too, it is desirable to set a predetermined maximum value of the engine speed in correspondence to the maximum operating angle over which the rotary operating member 30 can be operated.
Moreover, the engine speed may also be controlled by using an operating member that does not rotate around the axis X of the grip 11.
Instead of the rotary operating member 30, a dial 30B may be provided at the upper circumferential surface of the grip 11, as shown in
Alternatively, a slide switch 30C may be provided at an upper portion of the grip 11 instead of the rotary operating member 30, as shown in
Or, a slide switch 30D may be provided at an upper portion of the grip 11 instead of the rotary operating member 30, as shown in
As explained above, a grip 11 is provided at the front end of the joystick lever 10, through which drive commands for a plurality of driving bodies such as the boom hoist drum 65, the main hoist drum 66, the auxiliary hoist drum 67 and the swinging device 62 are issued in such a manner that the grip 11 is not allowed to rotate relative to the joystick lever 10 and a rotary operating member 30 is provided so as to be allowed to rotate relative to the grip 11 in the first embodiment of the present invention. By rotating the rotary operating member 30, the engine speed can be adjusted with ease while issuing commands for driving the plurality of driving bodies.
By providing the joystick lever 10 having the rotary operating member 30 on either the left side or the right side in the operator's cab of a construction machine, the number of required parts can be reduced. If the rotary operating member 30 is provided at the operating lever used to operate the swinging device 62 which drives the revolving superstructure 62 for a swinging operation, the operability is improved. The operability can also be improved by providing the joystick lever 10 having the rotary operating member 30 on each of the two sides, i.e., the left side and the right side, in the operator's cab.
By disposing the rotary operating member 30 at the top of the grip 11, an undesirable change in the engine speed resulting from an erroneous operation of the rotary operating member 30 during a crane operation can be prevented. In addition, the presence of the collar portions 14a and 14b at the bottom of the grip 11 allows the operator to hold the grip 11 in a stable manner and ultimately to operate the lever 10 with great ease.
The rotary operating member 30, which is allowed to rotate around the axis X at the center of the operating lever 10 along the longitudinal direction, can easily be operated with operator's fingers. In addition, since the grip 11 itself does not rotate relative to the operating lever 10, the rotary operating member 30 can be operated without inadvertently operating the lever 10. Since the grip 11 and the rotary operating member 30 are both formed in a substantially cylindrical shape, good operability is assured. By restricting the rotation of the rotary operating member 30 so that the rotary operating member 30 can never be turned beyond a predetermined operating quantity, e.g. , 90°, corresponding to a predetermined maximum engine speed, the engine speed can be controlled up to the maximum value without having to adjust the hold on the grip 11.
The rotation speed command value from the rotary operating member 30, the rotation speed command value from the fuel lever 100 and the rotation speed command value from the accelerator pedal 101 are compared with one another, the largest value among them is selected and the engine speed control is implemented in correspondence to the selected value. By adopting this method, it is ensured that the engine speed control is implemented smoothly even when engine speed commands are output via a plurality of operating members.
The operating lever 10 constituted of a joystick lever is installed in the construction machine, drive commands are output to a plurality of actuators via the operating lever 10 and a command for an engine speed adjustment is issued via the rotary operating member 30 provided at the operating lever 10. The controller 50 then controls the engine speed in conformance to the command from the rotary operating member 30, i.e., in conformance to the operating quantity of the rotary operating member 30. As a result, the construction machine can be operated smoothly.
It goes without saying that a rotary operating member 30 such as that described above may be provided at a standard operating lever which is not a joystick lever to control the engine speed and/or the pump tilting amount. However, by providing the rotary operating member 30 described above at a joystick lever that can be operated along various directions, the engine speed control can be implemented even more effectively while preventing any erroneous operation of the rotary operating member 30.
Since the engine speed is controlled to achieve the rotation rate having been set based upon the prime mover rotation speed command signal set with the operating member 30, the construction machine can be operated smoothly.
In the second embodiment, the engine speed having been adjusted by using a rotary operating member such as that described above is then locked to sustain the rotation speed. The following is an explanation of the second embodiment of the present invention, given in reference to the drawings.
As the swing lever 110 is operated, a pilot valve 114c or 114d is driven via a spool 113c or 113d in correspondence to the operating direction and the operating quantity. As the auxiliary hoist lever 111 is operated, a pilot valve 114a or 114b is driven via a spool 113a or 113b in correspondence to the operating direction and the operating quantity. In response to the drive of the pilot valves 114a to 114d, the direction control valves 42 and 43 are switched to supply the pressure oil to the hydraulic motors 45 and 46 and thus, the auxiliary hoist drum 67 and the swinging device 62 are driven.
As shown in
As the lock on signal is input to the hold circuit 501, the hold circuit 501 holds the current rotation speed command value Ni and outputs that rotation speed command value Ni to the motor driver 51. When the lock off signal is input to the hold circuit 501, the hold circuit 501 immediately outputs the current rotation speed command value Ni input from the function generator 50H to the motor driver 51.
As described above, the jog dial 30E is used to select an engine speed setting and then lock the setting so as to not allow the rotation speed to change in the second embodiment. Since the engine speed is locked, the engine speed cannot be altered inadvertently even if the operator operates the jog dial 30E by mistake while operating the swing lever 110. As a result, the operability improves.
While an explanation is given above on an example in which the rotary operating member 30E is provided at the swing lever 110, the rotary operating member 30E may be instead provided at a lever used to issue a command to drive another actuator, e.g. , the auxiliary hoist lever 111. However, the engine speed does not need to be adjusted frequently during a swinging operation and, for this reason, greater convenience is afforded by providing the rotary operating member 30E at the swing lever 110 located on the left side of operator's seat so as to allow the operator to operate the main hoist drum 66 and the boom hoist drum 65 with his right hand while controlling the engine speed with his left hand.
It is to be noted that the jog dial 30E may be provided at a joystick lever used to issue commands to drive a plurality of actuators as well. For instance, the jog dial 30E may be provided in place of the rotary operating member 30 at the left lever 10L explained in reference to the first embodiment. Since the joystick lever is operated along a plurality of directions, a rotary operating member provided at the top of the grip 11 is more likely to be operated inadvertently, compared to a standard lever such as the swing lever 110. However, the engine speed setting can be locked by pressing the jog dial 30E and thus, any undesirable change in the engine speed is prevented to further improve the operability in the embodiment.
It is also to be noted that instead of the jog dial 30E, a jog dial 30F shown in
Alternatively, as shown in
Advantages similar to those explained earlier can be achieved in conjunction with a jog dial 30F shown in
While an explanation is given above in reference to the embodiments on an example in which the operating levers 10L and 10R and the swing lever 110 are provided to operate a crawler crane, these levers may be adopted in another type of construction machine such as a hydraulic excavator.
Actuators to which drive commands are issued via the operating levers 10L and 10R are not limited to hydraulic actuators, and they maybe, for instance, electrically driven actuators, instead. The operation quantity of the rotary operating member 30 may be detected with an operating quantity detector other than the potentiometer 23.
In addition, while an engine is used as a prime mover for the construction machine, an electric motor may be used instead of the engine.
While an explanation has been given above on an example in which the operating lever is adopted in a crawler crane, the present invention may be adopted with equal effectiveness in a construction machine other than a crawler crane.
Number | Date | Country | Kind |
---|---|---|---|
2001-339287 | Nov 2001 | JP | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/JP02/11504 | 11/5/2002 | WO | 00 | 4/27/2004 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO03/040015 | 5/15/2003 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
4314619 | Tsuji | Feb 1982 | A |
4489805 | Okabe | Dec 1984 | A |
4955344 | Tatsumi et al. | Sep 1990 | A |
5002454 | Hadank et al. | Mar 1991 | A |
5517967 | Nakayama | May 1996 | A |
6328127 | Hori et al. | Dec 2001 | B1 |
6571902 | Heyne et al. | Jun 2003 | B2 |
20030000327 | Mototani et al. | Jan 2003 | A1 |
Number | Date | Country |
---|---|---|
A 5-116884 | May 1993 | JP |
B2 2752820 | Feb 1998 | JP |
A 10-338051 | Dec 1998 | JP |
A 2000-238990 | Sep 2000 | JP |
A 2001-107908 | Apr 2001 | JP |
A-2001-240373 | Sep 2001 | JP |
Number | Date | Country | |
---|---|---|---|
20050034915 A1 | Feb 2005 | US |