EP0221578B1 - Hydraulic circuit for self-undecking crane - Google Patents
Hydraulic circuit for self-undecking crane Download PDFInfo
- Publication number
- EP0221578B1 EP0221578B1 EP19860115927 EP86115927A EP0221578B1 EP 0221578 B1 EP0221578 B1 EP 0221578B1 EP 19860115927 EP19860115927 EP 19860115927 EP 86115927 A EP86115927 A EP 86115927A EP 0221578 B1 EP0221578 B1 EP 0221578B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- cylinder
- valve
- jack
- pressure
- legs
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B66—HOISTING; LIFTING; HAULING
- B66C—CRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
- B66C23/00—Cranes comprising essentially a beam, boom, or triangular structure acting as a cantilever and mounted for translatory of swinging movements in vertical or horizontal planes or a combination of such movements, e.g. jib-cranes, derricks, tower cranes
- B66C23/62—Constructional features or details
- B66C23/72—Counterweights or supports for balancing lifting couples
- B66C23/78—Supports, e.g. outriggers, for mobile cranes
- B66C23/80—Supports, e.g. outriggers, for mobile cranes hydraulically actuated
Definitions
- This invention relates to a hydraulic circuit for self-undecking cranes, and more particularly, to a hydraulic circuit for such cranes which utilize swingably deployable legs to support the upper during the self-undecking procedure.
- each of the four legs incorporates an hydraulic jack and the specification discloses an hydraulic circuit having a pump on the upper for generating pressurized hydraulic fluid for supply to each of the four jacks; and also for supply to an hydraulic cylinder for swinging the front legs from their inoperative position at the front of the crane to the operative position one on each side of the crane and vice versa.
- the hydraulic circuit also includes means whereby the pressurized fluid operates an hydraulic cylinder to extend or retract the outrigger arms from the box.
- each of the jacks serving to extend or retract one of the four legs incorporates a locking valve and relief circuit as is standard with such jacks in case the hydraulic supply source fails whilst the jacks are supporting the upper and to allow for temperature changes.
- the present invention is a.
- the self-undecking crane provides means whereby whilst the hydraulic jacks of the four legs are pressurized to cause said legs to support the upper, it is not possible to swing the four supporting legs of the upper from their operative setting to a non-operative setting.
- the self-undecking crane indicated generally at 10 in Figures 1 and 2, includes an upper works 12 rotatably mounted by means of a turntable bearing 14 on a lower works or carrier 16.
- a ring 18 mounted on the upper 12 is releaseably secured to the inner rance of the turntable bearing 14, such as, for example, shown in U.S. patent 3 923 407, issued Dec. 2, 1975 to L. B. Jensen and R. E. Thune, wherein a locking ring, actuated by a hydraulic cylinder, is expanded to lock the ring to the inner race and contracted to unlock the same.
- This hydraulic cylinder while not shown in Figures 1 and 2, is shown in Figure 3 at 20. With the cylinder 20 contracted the turntable bearing 14 is released from the ring 18 and the upper 12 may be separated from and elevated above the carrier 16, as shown in Figure 1.
- a pair of legs 22 are mounted to a cross tube 24 and are manually pivotable about a vertical axis between a stowed position, as shown by the solid line position in Figure 2 and an outward position, as shown in phantom line in Figure 2.
- the legs 22 are pinned or otherwise secured in these two positions.
- a hydraulic cylinder 26 is connected through a crank arm to the cross tube 24. Retraction of the hydraulic cylinder 26 will rotate the cross tube 24 and the attached legs 22 from their outward, rearward (relative to the upper 12) extending position shown in phantom line in Figure 2 to a vertical position as shown in Figure 1. Extension of the cylinder 26 will return the legs 22 from vertical orientation to a substantially horizontal position. Hydraulic jacks 27 and 29 are incorporated into and extend from the free end of the front legs 22.
- a pair of rear legs 28 are pivotably mounted on the rear of the upper 12.
- a pair of cylinders (not shown in Figures 1 and 2, but identified in Figure 3 at 40 and 42) are operatively connected to each leg 28 and rotate the legs through 180 degrees between an upright stowed position, as shown in Figure 2, and an outward operative position, as shown in Figure 1.
- Each of the pair of cylinders 40 and 42 has one cylinder positioned inside the horizontal portion of the L-shaped leg and pinned between that position and a link member pivotably secured to the hinge connection of the leg to a hollow beam on the upper 12.
- the other cylinder of each pair is positioned inside the hollow beam and is pinned between the link member and the beam.
- a pair of jacks 31 and 33 are incorporated into and extend from the free end of each of the rear legs 28.
- the valve 36 provides power-beyond capability through conduit 38 and controls the raising and lowering of the cranes' counterweight through conduit 44 and 46.
- a conduit 48 connects the valve 36 with the reservoir 32.
- the conduit 38 connects with a two-position valve 50 to which conduits 52 and 54 are also connected. With the valve 50 in its upward position, as shown in Figure 3, conduit 54 is blocked and conduit 52 is in communication with conduit 38 to supply hydraulic fluid pressure from the pump 30 to other hydraulic components on the upper 12, such as for example, the hydraulic disk brake circuit for the draw works as disclosed in U. S.
- the conduit 54 connects with the power-beyond port of control valve 56 and branches into parallel pressure passage 58.
- the control valve 56 is in a valve bank including valves 60, 62, 64, and 66.
- a power-beyond passage 68 connects between these valves and the parallel pressure passage 58 connects with each valve through a check valve.
- a return conduit 70 is also connected to each of these valves.
- the valve 56 is also connected through conduits 72 and 74 with the rod and head ends respectively of the jack 31.
- a pair of pilot-operated check valves 76 and 78 are interposed in conduits 76 and 78 respectively with each check valve piloted off the other conduit.
- the conduits 72 and 74 are connected with the reservoir 32 through conduit 70 and the check valves 76 and 78 are seated to hydraulically lock the jack 31. Shifting the valve 56 to the left will connect the rod end of jack 31 with pump pressure through conduit 72. This pressure will unseat check valve 76 and will be directed as a pilot pressure to unseat check valve 78; the heat end of jack 31 thereby being connected to the reservoir 32.
- the jack 31 will therefore be contracted.
- valve 56 Shifting the valve 56 to the right will connect conduit 74 with pump pressure and open the pilot check valve 76.
- the jack 31 will thereby be extended.
- a thermal expansion, pressure relief valve 80 is connected across the check valve 76 to permit the exhaust of hydraulic fluid due to fluid expansion from heat, such as exposure to the sun, through conduit 72 and the open center valve 56 to the reservoir 32 through conduit 70.
- the pilot check valves 76 and 78 and the relief valve 80 are preferably incorporated into a valve block 82 physically attached to the jack 31.
- the valve 60 is connected through conduits 84 and 86 to the rod and head ends respectively of jack 27, with a valve block 88 interposed therein.
- the valve 60 controls the extension and retraction of jack 27 in the same way as valve 56 controls jack 31.
- control valves 64 and 66 are arranged to control the extension and retraction of jacks 33 and 29 respectively with similar valve blocks 90 and 92 attached to the associated jacks and interposed between the valves and the jacks.
- the control valve 62 is connected via conduit 94 to the rod end of each of the cylinders 26, 42, and 40, while conduit 96 connects this valve with a two position valve 98.
- a pair of pilot-operated check valves 100 and 102 are interposed in conduits 94 and 96 respectively and are piloted off the pressure in the other conduit.
- the valve 98 is spring biased toward the right, as viewed in Figure 3, wherein conduit 96 connects with a conduit 104, which connects with the head end of each of the cylinders 26, 42, and 40, and a conduit 106 leading to reservoir 32 is blocked. When shifted to the left, i.e.
- valve 98 connects conduits 96 and 104, and blocks conduit 106.
- the pressure to actuator 99 is provided from the one of jacks 27, 31, 29 and 33 having the highest pressure in its head end, in which end pressure is created when resistance to extension is encountered.
- a pilot line 107 sensing the pressure in the head end of jack 31 and a pilot line 108 sensing the pressure in the head end of jack 27 are connected to opposite ends of a shuttle valve 110.
- pilot lines 112 and 114 sensing the pressure in the head end of jacks 33 and 29 respectively are connected to opposite ends of shuttle valve 116.
- shuttle valves 110 and 116 are connected through pilot lines 118 and 120 respectively to a third shuttle valve 122, the central connection of which connects with actuator 99 through pilot line 124.
- the shuttle valve 110 transmits the higher of the two pressures in the head end of jacks 31 and 27 to the shuttle valve 122, while the shuttle valve 116 transmits the higher pressure in jacks 33 and 29 to the shuttle valve 122.
- the latter valve transmits to the actuator 99 the higher of the pressures in pilot lines 118 and 120.
- the actuator 99 then shifts the valve 98, against its spring bias, to the left when the pressure received thereby exceeds a predetermined pressure. When so shifted, pressure communication between the control valve 62 and the head end of cylinders 2, 42 and 40 is precluded.
- a closed-center, power-beyond, control valve 126 receives fluid pressure from the power-beyond port of valve 66 through conduit 128 and is connected to the head and rod ends of cylinder 20 through conduits 130 and 132 respectively.
- the locking ring, to which cylinder 20 is connected, is released or unlocked from the turntable bearing 14 by shifting the valve 126 upward to pressurize conduit 132 and the rod end of cylinder 20. Shifting valve 126 downward will pressurize the head end of cylinder 20 through conduit 130 extending the cylinder and causing the locking ring to latch or lock the ring 18 to the turntable 14.
- the present invention provides a circuit which minimizes the possibility of imposing the weight of the upper on supporting legs when the legs are oriented in other than a vertical orientation. Consequently, the invention precludes damaging the upper legs through imposition of bending loads thereon. In addition, the upper when supported on the legs is maintained in a stable configuration and the possibility of accidentally dropping the upper onto the ground or the carrier is minimized.
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Jib Cranes (AREA)
Description
- This invention relates to a hydraulic circuit for self-undecking cranes, and more particularly, to a hydraulic circuit for such cranes which utilize swingably deployable legs to support the upper during the self-undecking procedure.
- Already known from US-A 4 273 244 is a self-undecking crane having an upper separable from a carrier. This crane has a pair of vertical, downwardly extending front legs that can be swung in this setting from an inoperative position forward of the crane to an operative position one of each side of the crane. At the rear of the crane is a dismountable transversely extending box into which two side- by-side outrigger arms are slidably received, one on each side of the crane so that these outrigger arms can be extended from or retracted into the box. Each outrigger arm has at its outer end a downwardly extending leg. Each of the four legs incorporates an hydraulic jack for extending and retracting its associated leg.
- In this prior art each of the four legs incorporates an hydraulic jack and the specification discloses an hydraulic circuit having a pump on the upper for generating pressurized hydraulic fluid for supply to each of the four jacks; and also for supply to an hydraulic cylinder for swinging the front legs from their inoperative position at the front of the crane to the operative position one on each side of the crane and vice versa. The hydraulic circuit also includes means whereby the pressurized fluid operates an hydraulic cylinder to extend or retract the outrigger arms from the box.
- The hydraulic circuit to each of the jacks serving to extend or retract one of the four legs incorporates a locking valve and relief circuit as is standard with such jacks in case the hydraulic supply source fails whilst the jacks are supporting the upper and to allow for temperature changes.
- The present invention is as defined in the accompanying Claim 1. As will be apparent from this claim the self-undecking crane provides means whereby whilst the hydraulic jacks of the four legs are pressurized to cause said legs to support the upper, it is not possible to swing the four supporting legs of the upper from their operative setting to a non-operative setting.
- In the drawings:
- Figure 1 is a side elevational view of a self-undecking crane incorporating the present invention.
- Figure 2 is a top plan view of the crane shown in Figure 1 with portions thereof broken away and eliminated, and
- Figure 3 is a schematic diagram of a hydraulic circuit according to the present invention.
- The self-undecking crane, indicated generally at 10 in Figures 1 and 2, includes an
upper works 12 rotatably mounted by means of a turntable bearing 14 on a lower works orcarrier 16. Aring 18 mounted on the upper 12 is releaseably secured to the inner rance of the turntable bearing 14, such as, for example, shown in U.S. patent 3 923 407, issued Dec. 2, 1975 to L. B. Jensen and R. E. Thune, wherein a locking ring, actuated by a hydraulic cylinder, is expanded to lock the ring to the inner race and contracted to unlock the same. This hydraulic cylinder, while not shown in Figures 1 and 2, is shown in Figure 3 at 20. With the cylinder 20 contracted the turntable bearing 14 is released from thering 18 and the upper 12 may be separated from and elevated above thecarrier 16, as shown in Figure 1. - A pair of
legs 22 are mounted to across tube 24 and are manually pivotable about a vertical axis between a stowed position, as shown by the solid line position in Figure 2 and an outward position, as shown in phantom line in Figure 2. Thelegs 22 are pinned or otherwise secured in these two positions. Ahydraulic cylinder 26 is connected through a crank arm to thecross tube 24. Retraction of thehydraulic cylinder 26 will rotate thecross tube 24 and the attachedlegs 22 from their outward, rearward (relative to the upper 12) extending position shown in phantom line in Figure 2 to a vertical position as shown in Figure 1. Extension of thecylinder 26 will return thelegs 22 from vertical orientation to a substantially horizontal position.Hydraulic jacks front legs 22. - A pair of
rear legs 28 are pivotably mounted on the rear of the upper 12. A pair of cylinders (not shown in Figures 1 and 2, but identified in Figure 3 at 40 and 42) are operatively connected to eachleg 28 and rotate the legs through 180 degrees between an upright stowed position, as shown in Figure 2, and an outward operative position, as shown in Figure 1. Each of the pair ofcylinders cylinders leg 28 with which they are associated to rotate to the outward, operative position, and extension of both will rotate that leg to its inward, stowed position. A pair ofjacks rear legs 28. - A
pump 30, driven by an engine on the upper 12, draws hydraulic fluid from areservoir 32 and discharges fluid under pressure through aconduit 34 to a closed-center, power-beyond,control valve 36. Thevalve 36 provides power-beyond capability throughconduit 38 and controls the raising and lowering of the cranes' counterweight throughconduit conduit 48 connects thevalve 36 with thereservoir 32. Theconduit 38 connects with a two-position valve 50 to whichconduits valve 50 in its upward position, as shown in Figure 3,conduit 54 is blocked andconduit 52 is in communication withconduit 38 to supply hydraulic fluid pressure from thepump 30 to other hydraulic components on the upper 12, such as for example, the hydraulic disk brake circuit for the draw works as disclosed in U. S. Patent Application, Serial Number (Docket 10120). Theconduit 54 connects with the power-beyond port ofcontrol valve 56 and branches intoparallel pressure passage 58. Thecontrol valve 56 is in a valvebank including valves passage 68 connects between these valves and theparallel pressure passage 58 connects with each valve through a check valve. Areturn conduit 70 is also connected to each of these valves. - The
valve 56 is also connected throughconduits 72 and 74 with the rod and head ends respectively of thejack 31. A pair of pilot-operatedcheck valves 76 and 78 are interposed inconduits 76 and 78 respectively with each check valve piloted off the other conduit. With thevalve 56 positioned as shown in Figure 3, theconduits 72 and 74 are connected with thereservoir 32 throughconduit 70 and thecheck valves 76 and 78 are seated to hydraulically lock thejack 31. Shifting thevalve 56 to the left will connect the rod end ofjack 31 with pump pressure throughconduit 72. This pressure will unseat check valve 76 and will be directed as a pilot pressure tounseat check valve 78; the heat end ofjack 31 thereby being connected to thereservoir 32. Thejack 31 will therefore be contracted. Shifting thevalve 56 to the right will connect conduit 74 with pump pressure and open the pilot check valve 76. Thejack 31 will thereby be extended. A thermal expansion, pressure relief valve 80 is connected across the check valve 76 to permit the exhaust of hydraulic fluid due to fluid expansion from heat, such as exposure to the sun, throughconduit 72 and theopen center valve 56 to thereservoir 32 throughconduit 70. Thepilot check valves 76 and 78 and the relief valve 80 are preferably incorporated into avalve block 82 physically attached to thejack 31. - The
valve 60 is connected throughconduits jack 27, with a valve block 88 interposed therein. Thevalve 60 controls the extension and retraction ofjack 27 in the same way asvalve 56controls jack 31. Similarly, control valves 64 and 66 are arranged to control the extension and retraction ofjacks similar valve blocks - The
control valve 62 is connected viaconduit 94 to the rod end of each of thecylinders conduit 96 connects this valve with a twoposition valve 98. A pair of pilot-operatedcheck valves conduits valve 98 is spring biased toward the right, as viewed in Figure 3, whereinconduit 96 connects with aconduit 104, which connects with the head end of each of thecylinders conduit 106 leading toreservoir 32 is blocked. When shifted to the left, i.e. the position shown in Figure 3, under the influence of pressure acting through actuator 99, thevalve 98 connectsconduits blocks conduit 106. The pressure to actuator 99 is provided from the one ofjacks jack 31 and apilot line 108 sensing the pressure in the head end ofjack 27 are connected to opposite ends of a shuttle valve 110. Similarly,pilot lines jacks pilot lines pilot line 124. The shuttle valve 110 transmits the higher of the two pressures in the head end ofjacks jacks pilot lines valve 98, against its spring bias, to the left when the pressure received thereby exceeds a predetermined pressure. When so shifted, pressure communication between thecontrol valve 62 and the head end ofcylinders valve 62 is shifted to the right, when the pressure in the head end of any one of the jacks exceeds a predetermined pressure. The importance of this arrangement is that an inadvertant retraction of thelegs jacks - A closed-center, power-beyond,
control valve 126 receives fluid pressure from the power-beyond port of valve 66 throughconduit 128 and is connected to the head and rod ends of cylinder 20 throughconduits valve 126 upward to pressurizeconduit 132 and the rod end of cylinder 20. Shiftingvalve 126 downward will pressurize the head end of cylinder 20 throughconduit 130 extending the cylinder and causing the locking ring to latch or lock thering 18 to theturntable 14. - The present invention provides a circuit which minimizes the possibility of imposing the weight of the upper on supporting legs when the legs are oriented in other than a vertical orientation. Consequently, the invention precludes damaging the upper legs through imposition of bending loads thereon. In addition, the upper when supported on the legs is maintained in a stable configuration and the possibility of accidentally dropping the upper onto the ground or the carrier is minimized.
Claims (4)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US48763883A | 1983-04-22 | 1983-04-22 | |
US487638 | 1983-04-22 |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP84104407.6 Division | 1984-04-18 |
Publications (3)
Publication Number | Publication Date |
---|---|
EP0221578A2 EP0221578A2 (en) | 1987-05-13 |
EP0221578A3 EP0221578A3 (en) | 1987-09-02 |
EP0221578B1 true EP0221578B1 (en) | 1990-06-13 |
Family
ID=23936549
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP19840104407 Expired EP0124024B1 (en) | 1983-04-22 | 1984-04-18 | Hydraulic circuit for self-undecking crane |
EP19860115927 Expired EP0221578B1 (en) | 1983-04-22 | 1984-04-18 | Hydraulic circuit for self-undecking crane |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP19840104407 Expired EP0124024B1 (en) | 1983-04-22 | 1984-04-18 | Hydraulic circuit for self-undecking crane |
Country Status (3)
Country | Link |
---|---|
EP (2) | EP0124024B1 (en) |
JP (1) | JPS6012495A (en) |
DE (2) | DE3474808D1 (en) |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2559441B1 (en) * | 1984-02-13 | 1988-04-15 | Poclain Sa | MOBILE MACHINE COMPRISING A STABILIZATION DEVICE |
GB2224092B (en) * | 1988-10-21 | 1992-11-25 | British Gas Plc | Apparatus and method for supplying an elongate element |
JP2006298524A (en) * | 2005-04-18 | 2006-11-02 | Nippon Sharyo Seizo Kaisha Ltd | Telescopic boom type crawler crane |
CN101839260B (en) * | 2010-03-21 | 2011-11-23 | 常德中联重科液压有限公司 | Step-down multipath reversing valve with two-position two-way hydraulic control valve |
CN102003423A (en) * | 2010-12-17 | 2011-04-06 | 徐州重型机械有限公司 | Hydraulic bidirectional lock and crane with same |
Family Cites Families (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3550506A (en) * | 1969-05-09 | 1970-12-29 | Grove Mfg Co | Controls for outrigger assemblies of mobile cranes and the like |
JPS5614760B2 (en) * | 1973-07-12 | 1981-04-06 | ||
US3923407A (en) * | 1974-02-06 | 1975-12-02 | Fmc Corp | Mechanism for connecting and disconnecting crane sections |
JPS5549621Y2 (en) * | 1974-10-04 | 1980-11-19 | ||
JPS5434361U (en) * | 1977-08-11 | 1979-03-06 | ||
GB2005752B (en) * | 1977-09-13 | 1982-01-27 | Coal Ind | Haulage apparatus for mining machines |
US4124226A (en) * | 1977-10-06 | 1978-11-07 | Harnischfeger Corporation | Electrohydraulic outrigger control system |
DE2903363C2 (en) * | 1979-01-29 | 1981-02-05 | Mannesmann Demag Ag, 4100 Duisburg | Support device for mobile cranes |
US4273244A (en) * | 1979-01-29 | 1981-06-16 | Fmc Corporation | Crane upperstructure self-transferring system |
FR2507984A1 (en) * | 1981-06-19 | 1982-12-24 | Komatsu Mfg Co Ltd | Laterally movable mobile crane - has double acting hydraulic cylinders to actuate outriggers to lift crane sideways |
-
1984
- 1984-04-18 DE DE8484104407T patent/DE3474808D1/en not_active Expired
- 1984-04-18 DE DE8686115927T patent/DE3482463D1/en not_active Expired - Lifetime
- 1984-04-18 EP EP19840104407 patent/EP0124024B1/en not_active Expired
- 1984-04-18 EP EP19860115927 patent/EP0221578B1/en not_active Expired
- 1984-04-23 JP JP8166084A patent/JPS6012495A/en active Pending
Also Published As
Publication number | Publication date |
---|---|
EP0221578A3 (en) | 1987-09-02 |
EP0124024A2 (en) | 1984-11-07 |
EP0124024A3 (en) | 1985-11-27 |
JPS6012495A (en) | 1985-01-22 |
DE3482463D1 (en) | 1990-07-19 |
EP0124024B1 (en) | 1988-10-26 |
EP0221578A2 (en) | 1987-05-13 |
DE3474808D1 (en) | 1988-12-01 |
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