US3804262A - Telescopic boom - Google Patents

Telescopic boom Download PDF

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Publication number
US3804262A
US3804262A US00289986A US28998672A US3804262A US 3804262 A US3804262 A US 3804262A US 00289986 A US00289986 A US 00289986A US 28998672 A US28998672 A US 28998672A US 3804262 A US3804262 A US 3804262A
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United States
Prior art keywords
boom
cylinder
sections
cylinders
section
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 - Lifetime
Application number
US00289986A
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English (en)
Inventor
D Wiencek
J Jones
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
CENTURY II Inc A CORP OF
CENTURY II Inc A DE CORP
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Harnischfeger Corp
Priority date (The priority date 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 date listed.)
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Publication date
Application filed by Harnischfeger Corp filed Critical Harnischfeger Corp
Priority to US00289986A priority Critical patent/US3804262A/en
Priority to CA179,972A priority patent/CA976917A/en
Priority to ZA737240A priority patent/ZA737240B/xx
Priority to DE19732346004 priority patent/DE2346004A1/de
Priority to GB4300773A priority patent/GB1405387A/en
Priority to SE7312566A priority patent/SE394102B/xx
Priority to CH1326673A priority patent/CH560648A5/xx
Priority to IT52557/73A priority patent/IT994275B/it
Priority to ES418852A priority patent/ES418852A1/es
Priority to BR7240/73A priority patent/BR7307240D0/pt
Priority to NL7312853A priority patent/NL7312853A/xx
Priority to FR7333436A priority patent/FR2200184B3/fr
Priority to DD173620A priority patent/DD106613A5/xx
Priority to JP10460673A priority patent/JPS4970359A/ja
Application granted granted Critical
Publication of US3804262A publication Critical patent/US3804262A/en
Assigned to CENTURY II, INC., A CORP. OF DE reassignment CENTURY II, INC., A CORP. OF DE ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: HARNISCHFEGER CORPORATION, A CORP. OF DE
Assigned to CENTURY II INC., A DE CORP. reassignment CENTURY II INC., A DE CORP. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: HARNISCHFEGER CORPORATION, A DE CORP.
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66C—CRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
    • B66C13/00—Other constructional features or details
    • B66C13/12—Arrangements of means for transmitting pneumatic, hydraulic, or electric power to movable parts of devices
    • 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
    • B66C23/64—Jibs
    • B66C23/70—Jibs constructed of sections adapted to be assembled to form jibs or various lengths
    • B66C23/701—Jibs constructed of sections adapted to be assembled to form jibs or various lengths telescopic
    • B66C23/705—Jibs constructed of sections adapted to be assembled to form jibs or various lengths telescopic telescoped by hydraulic jacks

Definitions

  • a mobile crane has a boom comprising a plurality of telescopic hollow boom sections.
  • Hydraulic operating which is that of an inverted A-frame or trapezoid to increase boom strength, to provide the maximum ratio between internal component space and weight, and to enable a more compact physical arrangement of the boom and boom hoist cylinders on the crane when the boom is in lowered position.
  • the hydraulic cylinders are progressively smaller in size (proceeding from the base end of the boom to its remote end) to provide a balanced hydraulic system and pressure compensating valve means located between the source of fluid and the first (lowest) cylinder respond to pressure differentials thereat to dump or unload excess fluid as is required to maintain a predetermined pressure differential.
  • This invention relates generally to booms having a plurality of telescopic boom sections, such as are used on mobile cranes or the like.
  • booms having boom sections of improved structural design and having improved means for extending and retracting the same.
  • a mobile crane which has a boom comprising a plurality of telescopic boom sections.
  • Each boom section is fabricated of solid steel plates with the top plate being wider than the bottom plate and the side plates welded therebetween and sloped inwardly.
  • Sideplate stiffeners welded between the bottom plate and the side plates run the length of the boomsection. This configuration results in a boom section of minimum weight with a bottom plate of relatively increased buckling strength and maximum interior space for boom operating components.
  • Hydraulic operating cylinders for the boom sections are housed within the boom and each is provided with its own remotely operable electrically controlled main valve physically located thereon.
  • Hydraulic fluid is supplied to the valves by flexible hydraulic fluid hoses disposed between the side plates of adjacent boom sections and the hoses uncoil or coil in a frictionless manner as the sections are extended or retracted.
  • a pair of hoses in looped arrangement connect each pair of adjacent valves.
  • Electric control wires for operating the electric valves are wrapped about the hoses and held in place thereon by heat-shrunk plastic tubing.
  • a boom inaccordance with the present invention is relatively stronger than conventional booms of comparable weight and size, while at the same time enabling a more compact arrangement of boom operating components therewithin.
  • the hoses for supplying hydraulic fluid to the cylinders within the boom are more simply and compactly arranged.
  • the cross-sectional configuration of the boom sections is that of an inverted A-frame or trapezoid, and this enables the boom, when lowered, to assume a relatively low position on the crane carrier without the need for wider spacing between the pair of boom hoist cylinders on the carrier which raise and lower the boom.
  • FIG. 1 is a side view of a mobile crane having a telescopic boom in accordance with the invention
  • FIG. 2 is an enlarged view of the interior of the boom shown in FIG. 1 with the boom sections shown in partially extended position;
  • FIG. 3 is another even further enlarged view of the interior of the boom shown in FIGS. 1 and 2 with the boom sections shown in fully retracted position;
  • FIG. 4 is an enlarged view of the base of the boom shown in FIG. 1;
  • FIG. 5 is an enlarged view, with some portions broken away, of one of the boom sections shown in FIGS. 1, 2 and 3;
  • FIG. 6 is a view of the boom section shown in FIG. 5, showing a portion of the rear end thereof and a portion in section on line 6-6 of FIG. 5;
  • FIG. 7 is an enlarged view of the boom shown in FIG. 3, showing a portion of the rear end thereof and a portion in section on line 77 of FIG. 3;
  • FIG. 8 is an enlarged view. partly in cross section, of one of the hydraulic cylinders shown in FIGS. 2, 3, 7 and 9;
  • FIG. 9 is a schematic diagram of the hydraulic control system for a boom in accordance with the invention.
  • FIG. 10 is an enlarged cross section view of an electrically operated hydraulic control valve shown in FIG- URE 8;
  • FIG. 11 is a top plan view of taken on line 11-11 of FIG. 7 showing the hose connections to the control valve for one of the cylinders;
  • FIG. 12 is an enlarged cross section view of one of the hydraulic hoses in the boom showing electrical wires. for the control valves secured thereto.
  • FIG. 1 shows a mobile crane 10 comprising a chassis ll, ground wheels 12, an operator's cab 13, a horizontally rotatable crane upper 14 mounted on the chassis. a telescopic boom 15 in accordance with the invention pivotably mounted on the crane upper. and a pair of boom hoist cylinders 16 (only one visible in FIG. 1) connected between the crane upper and the boom.
  • FIGS. 1, 2, 3 and 7 show that boom 15 comprises a plurality of telescopic boom sections, namely: a base section 20, an inner mid section 21, an intermediate mid section 22, an outer mid section 23, a fly section 24, and a manual section 25.
  • the rear end of base section 20 has trunion mounts 26 on opposite sides which receive pins 27 that pivotably mount the base section on crane upper 14.
  • the boom hoist cylinders 16 are located on opposite sides of base section 20 and are pivotably connected by pins 28 to support brackets 29 on crane upper 14.
  • the rod ends of the boom hoist cylinders 16 are pivotably connected by pins 30 to connecting brackets 31 on opposite sides of base section 20.
  • the forward end of manual section 25 has a working head 32 thereon which, for example, is provided with a pulley 33.
  • the boom also comprises a plurality of hydraulic cylinders for extending and retracting the boom sections, namely: an inner mid section cylinder 41, an intermediate mid section cylin der 42, an outer mid section cylinder 43, a fly section cylinder 44 and a manual section cylinder 45.
  • the cylinders operate the boom sections bearing the same name.
  • FIG. 8 is an enlarged view, partly in cross section, of outer mid section cylinder 43 and a description thereof will suffice for the cylinders 41, 42, 44 and 45 which are identical thereto except as regards size.
  • Cylinder 43 comprises a hollow tubular housing 50 closed at one'end by an end plate 51 within which a hollow tubular cylinder rod 52 is slideably mounted.
  • the inner end of rod 52 is provided with a piston 53 having piston rings 54. Housing 50 and rod 52 cooperate to define a cylinder retract chamber'55 and the end of this chamber is closed off by sealing means 56 secured to housing 50 and having sealing rings 57.
  • Cylinder rod 52 is provided with a cylinder extend chamber 58. Cylinder rod 52 is also provided with an internal passage 59 which is connected by a tube 60 to retract chamber 55. Cylinder rod 52 is further provided with an internal passage 61 which is connected to extend chamber 58.
  • the ports of the passages 59 and 61 are connected by passages 62 and 63, respectively, in an adapter plate 64 on the end of rod 52 to ports 75 and 76, respectively,of an electri cally operated cylinder control valve 67 attached to plate 64.
  • Fluid pressure in passage 61 of rod 52 caused by. extend operation of valve 67 causes fluid flow into extend chamber 58 and effects extend operation of cylinder 43.
  • fluid pressure in passage 59 of rod 52 caused by retract operation of valve 67 causes fluid flow into retract chamber 55 and effects retract operation of cylinder 43.
  • Housing 50 of cylinder 43 is provided on its exterior with a trunnion 68 by which it is connected to a trunnion mount 69 on outer mid boom section 23.
  • Cylinder rod 52 of cylinder 43 is provided on its exterior with a trunnion 70, by which it is connected to a trunnion mount 71 on boom section 22.
  • the trunnion 68 on the housing of each cylinder 41, 42, 43, 44 and -45 is connected to the trunnion mount 69 of that boom sectionwhich it operates.
  • the other trunnion 70 on the rod end of the cylinders 41, 42, 43, 44 and 45 is connected to the trunnion mount 71 of the next adjacent boom section.
  • a hydraulic cylinder such as cylinder 43 offers several advantages over conventional hydraulic actuators or cylinders used in prior art cranes.
  • a conventional cylinder is normally connected and supported at each of its extreme ends (the outer rod end and the base end of the cylinder) to the boom sections I associated therewith. Consequently, in extremely large cranes, as the cylinder is operated to extend the boom section, the two connection points of the cylinder move very far apart and the cylinder is subjected to buckling and bending forces which tend to increase the risk of mechanical failure of the cylinder'and impose greater wear forces on internal moving components of the cyl inder.
  • cylinder 43 is provided with a conventional h'olding valve 72 which is mounted on plate 64 and operates to prevent undesired retraction of the extended cylinder until the holding valve is released (opened) in response to retract operation of the main control valve 67.
  • cylinder 41, 42, 43, 44 and 45 is provided with a similar holding valve.
  • the electrically operated main control valve 67 shown in FIG. 10 is an electrohydraulic proportional metering valve comprising a valve housing 73 containing a four-way sliding spool 74, two fluid control ports 75 and 76 which are connected through plate 64 to the passages 59 and 61, respectively, in rod 52 of cylinder 43.
  • Valve 67 further comprises an electrical torque motor 80 and a nozzle flapper pilot stage for operating spool 74.
  • the torque motor 80 includes coils 81, polepieces 82, magnets 83 and-an armature 84.
  • the armature 84 is supported for limited movement by a flexureitube 85.
  • the flexure tube 85 also provides a fluid seal between the hydraulic and electromagnetic portions of the valve.
  • a flapper 86 attaches to the center of the armature 84 and extends down, inside the flexure tube 85.
  • a nozzle 87 is located on each side of the flapper 86 so that flapper motion varies the nozzle openings. Pressurized hydraulic fluid is supplied to each nozzle through a filter 88 and inlet orifice 89. Differential pressures caused by flapper movement between the nozzles 87 are applied to the ends of the valve spool 74.
  • the four-way valve spool 74 directs flow from pressure supply chamber 92 to either control port 75 or 76 in an amount proportional to spool displacement.
  • the spool 74 contains flow metering slots 90 in the control lands that are uncovered by spool motion. Spool movement deflects a feedback wire 91 that applies a torque to the armature/flappenSpool detent springs 92 are provided to center the spool whenever hydraulic driving pressures are absent.
  • valve spool position is proportional to the electrical signal. The actual flow from the valve to the load will depend upon the load pressure.
  • valve 67 is commercially available from Moog, Inc., Controls Division, Proner Airport, East Aurora, NY. 14052 and is disclosed in that companys Catalog 602.
  • FIGS. 5 and 6 show in detail the physical construction and configuration of intermediate mid boom section 22 which will now be described in detail; it being understood that the other boom sections 20, 21, 23, 24 and 25 are similar thereto.
  • Section 22 comprises a top plate 100, a bottom plate 101, a right side plate 102, and a left side plate 103. Each of these four plates is fabricated of a solid plate or sheet of steel. The upper edges of the side plates 102 and 103 are joined by a continuous weld to the undersurface of the top plate 100. The lower edges of the side plate 102 and 103 are similarly joined by a continuous weld to the upper surface of the bottom plate 101.
  • Side plate stiffeners 105 and 106 are edge-welded between the side plates 102 and 103, respectively, and the edges of the bottom plate 101.
  • the side plate stiffeners 105 and 106 serve to increase the buckling strength of the side plates 102 and 103, respectively, by about a factor of five in the embodiment shown.
  • the bottom plate 101 is substantially narrower than the top plate 100 (in a ratio of about 5 units to -3 units) and the angle a defined between a side plate and the bottom plate is an angle greater than 90, but less, for example, than 120.
  • Each side plate 102 and 103 is wider than the bottom plate 101 in a'ratio of about 6 units to 3 units.
  • the general cross-sectional configuration of section 22 is that of a trapezoid or an inverted A-frame.
  • top plate 100 is about 24.6 inches wide, 0.375 inches thick, and 383 inches long.
  • Bottom plate 101 is about 13 inches wide, 0.500 inches thick, and 376 inches long.
  • Each side plate 102 and 103 is about 33 inches wide, 0.l50 inches thick, and 380 inches long.
  • Each side plate stiffener 105 and 106 runs the length of section 22 and is about 6.375 inches wide and 0.250 inches thick. It has been discovered through testing that boom section 22 affords the following advantages. First, the internal height of boom section 22 is increased without an increase in other cross section properties, such as additional weight.
  • the stiffener plates 105 and 106 change the end condition of the side plates 1 02 and 103 from simply supported to semi-fixed and thereby allow thinner side plates to be used in view of buckling considerations.
  • the relatively narrower bottom plate 101 allows a thinner bottom plate to be used in view of buckling considerations.
  • the relative narrowness of the bottom of aboom section such as 22 (particularly boom base section 20) allows the storage position of boom to be lower between the boom hoist cylinders 16 thereby affording lower overall height without increasing boom section width and'without reducing'the moment arm of the boom hoist cylinders.
  • the width of the top plate 100 of boom section 22 can be varied for desired side strength purposes without affecting any of the above-listed advantages.
  • boom section 22 further comprises a slide pad support plate 110 welded to the side plates 102 and 103 at the top rear end of the boom section.
  • a pair of external slide plate 111 and 112 are welded to plate 110 and serve as bearing surfaces for the undersurface of the top plate 100 of the boom section 21 into which boom section 22 telescopes.
  • Support plate 110 is braced by welded external braces 113 and 114 and by a welded horizontal inner brace 115 to which spaced apart vertical braces 116 are welded.
  • Rear stiffener plates such as 117 are provided at the rear end of boom section 22 and are welded to support plate 110 and an associated side plate 102 or 103.
  • a cylinder attachment assembly 71 and a trunnion mount 69, both hereinbefore referred to in connection with the description of cylinder 43, are provided at the outer rear end of boom section 22.
  • Boom section supports such as support 120, are welded on the inner surface of the side plates 102 and 103-near the rear end of boom section 22.
  • Each support 120 is rigidified and stabilized by a brace 121.
  • a pair of internal slide pads such as pad 122, are
  • Support 123 which iswelded to the inner surfaces of the side plates 102 and 103 near the forward end of boom section 22.
  • Support 123 is rigidified and strengthened by a welded horizontal brace 124 and welded vertical braces 125.
  • Polyethyle slide pads such as 130 are mounted on steel backup plates, such as 131,” and extend through openings, such as 132, in the side plates 102 and 103 into the interior of boom section 22 where they frictionally engage the sides of boom section 23 which telescopes into boom section 22.
  • the manual sectioncylinder 45, the fly section cylinder 44, and the outer mid section cylinder 43 fit within manual boom section 25 when boom 15 is in retracted condition.
  • Intermediate mid section cylinder 42 and inner mid section cylinder 41 fit within intermediate mid boom section 22 and inner mid boom section 21, respectively.
  • the main control valves 67A, 67B, 67 67C and 67D for the cylinders 41, 42, 43, 44 and 45, respectively, ' are supplied with hydraulic operating fluid from a pressurized fluid source, such as pumps 136 and 137 shown in FIG. 9, which is understood to be located on crane 10.
  • FIG. 11 is a top plan view of valve 67 on outer mid cylinder 43 and shows thathydraulic fluid T-fittings 140 and 141 are provided on opposite sides thereof. It is to be understood, for example, that fittings 140 and 141 are located on the extend sideand the retract side, respectively, of valve 67. Furthermore, valve 67 is provided internally with a pressure compensated flow control device 142 into which T-fitting 140 discharges.
  • fittings 140 and 141 on valve 67 are connected by flexible hoses 1498 and 1508, respectively, to the pumps 136 and 137 and to a fluid reservoir 147.
  • hose 149B is for fluid supply and hose 150B for fluid return.
  • the fittings 140 and 141 are also connected to fluid supply and fluid return hoses 149C and 150C, respectively, which are connected to the control valve 67C for the next cylinder 44.
  • the main control valves 67A, 67B, 67C and 67D for the other cylinders are each provided with fluid supply and return T-fittings designated respectively: 140A and 141A; 1403 and 1418; 140C and 141C; 140D and 141D.
  • fittings are interconnected by flexible fluid supply and return hoses designated, respectively: 149A and 150A; 1498 and 150B;- 149C and 150C; 149D and 150D.
  • main control valves are connected in parallel arrangement to the fluid supply and fluid return systems.
  • the valves 67A, 67B, 67C, and 67D are provided with pressure compensated flow control devices 142A, 1428, 142C and 142D, respectively.
  • the hydrauliccontrol system shown in FIG. 9 also includes a pressure responsive valve 156 for automatically connecting pump 137 to the system if system pressure indicates that more than one cylinder is being extended and additional fluid is required.
  • the pumps 136 and 137 are understood to be engine-driven and operating continuously when crane 10 is in use.
  • the hydraulic control system also includes a pressure compensated flow control valve 157, a pressure switch 158, a relief valve 159, and solenoid controlled pressure relief valves 160 and 161.
  • the flexible fluid supply and fluid return hoses such as 149C and 150C are physically located between the side plates of adjacent boom sections in a looped or coiled arrangement which enables the hoses to pay out or coil back upon themselves as the boom sections are extended or retracted, respectively.
  • FIG. 12 shows, the lower portion of each hose loop is supported or rests in support clips 155 which are secured at intervals on the outer surfaces of the boom side plates. It isto be noted that, although each hose flexes at the curved portion as the boom 15 is operated, the straight upper and lower segments of the hose do not slide on, rub or frictionally engage the sides of the adjacent boom sections but are stationary with respect thereto. Consequently, the hoses are not subjected to damaging abrasion or wear from this source but only to flexing action.
  • each of the four electrically controlled main valves is connected by electrical conductors, generally designated 165, which extend from an electrical controller 166 on crane 10 to the valves.
  • electrical conductors 165 extend from an electrical controller 166 on crane 10 to the valves.
  • controller 166 is designed to enable actuation of each valve separately to allow any single boom section to be operated individually or to enable actuation of all valves simultaneously to allow all boom sections to be operated simultaneously and proportionately.
  • the electrical conductors 165 for the valves are connected to a terminal block 167 provided on each valve. Between each valve. as FIG. 12 shows. the conductors I65 are twisted around a hydraulic hose. such as hose 149C, and secured in place thereon by means of a flexible heat-shrunk plastic sleeve or tube 168.
  • the conductors 165 take the form of braided insulated wires. This arrangement is advantageous'in that the wires are securely held in place. not liable to damage as the boom sections move, and like the hoses, are not subject to frictional wear but only flexure.
  • the boom extension cylinders 45, 44, 43, 42 and 41 are sized progressively larger from top to bottom so that, although the working pressure required is least at the uppermost cylinder 45, the combined effect of required working pressure, induced load pressure and line pressure drops is such that pressure requirements as measured at the pump 136 or 137, or even at the boom base cylinder 41, are approximately equal for any given load, regardless of which cylinder or combination of cylinders are in use.
  • valve 67A there is only one pressure compensated valve 67A, with auxiliary valves, such as 157, for providing unloading and main relief capabilities near the boom base, for directly controlling inner mid section cylinder 41.
  • auxiliary valves such as 157
  • the other four valves 67B, 67, 67C and 67D are remote controlled electro hydraulic proportional metering valves mounted on cylinders in the boom.
  • valve 67A, valve 157, valve 159 and all necessary interconnecting tubing are housed in acommon valve housing (not shown).
  • the pressure compensating valve 157 functions by constantly measuring the difference between pump and cylinder pressure and dumping or unloading the excess pump flow as required to maintain the desirable differential. This would normally be impossible in conventional hydraulic control circuits for cranes when the most remote cylinderis 125 feetaway, but if the system balance is such as is possible in the present invention so that the nearest cylinder pressure reading is the same as the furthest, then it is only necessary to measure and respond to the nearest pressure condition, and the unloading function of valve 157 serves the furthest cylinder equally as well as the nearest cylinder.
  • a mobile crane 10 has a boom l5 comprising a plurality of telescopic boom sections 20, 21, 22, 23, 24
  • Each boom section is fabricated of solid steel plates with the top plate being wider than the bottom plate 101 and the side plates 102 and 103 welded therebetween and sloped inwardly.
  • Side plate stiffeners 105 and 106 welded between the bottom plate 101 and the side plates 102 and 103, respectively, run the length of the boom section.
  • This configuration results in a boom section of minimum weight with a bottom plate 101 of relatively increased buckling strength and maximum interior space for boom operating components.
  • Hydraulic operating cylinders 41, 42, 43, 44 and 45 for the boom sections 21, 22, 23, 24 and 25, respectively, are housed within the boom and each is provided with its own remotely operable electrically controlled main valve such as valve 67.
  • Hydraulic fluid is supplied to and returned from the valves by flexible hydraulic fluid hoses such as hoses 149C and 150C disposed between the side plates of adjacent boom sections and the hoses uncoil or coil in a frictionless manner as the boom sections are extended or retracted.
  • Electric control wires, such as 165, for operating the electric valves are wrapped about the hoses and held in place thereon by heat-shrunk plastic tubing 168.
  • Boom 15 in accordance with the present invention is relatively stronger than conventional booms of comparable weight and size. while at the same time enabling a more compact arrangement of boom operating components, such as cylinders and hoses, therewithin. Furthermore. the hose means for supplying hydraulic fluid to the cylinders within the boom are simpler and more compact than known hose arrangements.
  • each pair of adjacent boom sections defining a space therebetween when telescoped
  • a plurality of hydraulic cylinders mounted within said boom to effect movement of said boom sections, one cylinder being provided for each movable boom section and each cylinder having a portion which is relatively movable with respect to a portion of a cylinder for an adjacent boom section,
  • each control valve being mounted on the relatively movable portion of its associated cylinder
  • a plurality of flexible hydraulic fluid hoses for supplying fluid from said source directly to each cylinder, at least one of said hoses being connected between the control valves for the cylinders of adjacent boom sections and arranged in a loop located within the space between adjacent boom sections when the latter are telescoped,
  • control valves for remotely operating said control valves.
  • control means comprises a plurality of flexible members for effecting operation of said control valves, at least one flexible member being coextensive with each hose connected between a pair of control valves, and means for securing said flexible member to a coextensive hose.
  • a boom according to claim 2 wherein said means for securing said 'flexible'member to said coextensive hose comprises a heat-shrinkable tubular member around said hose and said flexible member.
  • a boom according to claim 4 including a reservoir and at least two hoses connected between the control valves on cylinders of adjacent boom sections, one hose being a fluid supply hose connected to said source and the other hose being a fluid return hose connected to said reservoir.
  • each hose is disposed in a looped arrangement in the space between the sides of two adjacent boom sections, and including a support clip mounted on a side of at least one of said boom sections for supporting said hose.
  • a mobile crane comprising:
  • said boom comprising a base section and a plurality of linearly movable sections telescopable therein, each of said sections being wider at its top side than at its bottom side. each pair of adjacent sections defining a space therebetween when telescoped,
  • said base section being pivotably connected to said upper portion of said crane for vertical movement
  • each boom hoist cylinder being connected between said upper portion of said crane and the base section of said boom, said boom hoist cylinders spaced apart a distance greater than the width of the bottom side of said base section and less than the width of the top side of said base section.
  • each said hydraulic cylinder being located within said boom and connected between that section which it moves and an adjacent section, each said hydraulic cylinder having a portion which is relatively movable with respect to a portion of a hydraulic cylinder for an adjacent section,
  • each control valve being mounted on the said portion of the cylinder which it operates,
  • a telescopic boom having a base end and a remote end:
  • each cylinder being provided for each movable boom section, each cylinder having a portion which is relatively movable with respect to a portion of a cylinder for an adjacent boom section,
  • said cylinders being progressively smaller in size in proceeding from those sections near the base end toward the remote end to provide a balanced pressure system
  • said means for supplying fluid from said source directly to i the control valve for eachof said cylinders, said means comprising a plurality of hydraulic fluid hoses, at least one of said hoses being connected between the control valves on the cylinders for adjacent boom sections and disposed in looped arrangement in the space between adjacent boom sections when the latter are telescoped,
  • control means including pressure compensating relief valve means located near the base end of said boom, responsive to the differential between fluid pressure at said source and fluid pressure of fluid for the cylinder of the boom section closest to the base of said boom and operable to unload excess fluid to maintain a predetermined pressure differential for said system.
  • a boom according to claim 9 wherein said pressure compensating valve means is connected between the source of hydraulic fluid and the remotely operable valve for the cylinder of the boom section closest to the base of said boom.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Jib Cranes (AREA)
US00289986A 1972-09-18 1972-09-18 Telescopic boom Expired - Lifetime US3804262A (en)

Priority Applications (14)

Application Number Priority Date Filing Date Title
US00289986A US3804262A (en) 1972-09-18 1972-09-18 Telescopic boom
CA179,972A CA976917A (en) 1972-09-18 1973-08-30 Telescopic boom
ZA737240A ZA737240B (en) 1972-09-18 1973-09-11 Telescopic boom
DE19732346004 DE2346004A1 (de) 1972-09-18 1973-09-12 Teleskopausleger
GB4300773A GB1405387A (en) 1972-09-18 1973-09-13 Telescopic boom
SE7312566A SE394102B (sv) 1972-09-18 1973-09-14 Teleskopisk kranarm vid mobilkran.
CH1326673A CH560648A5 (xx) 1972-09-18 1973-09-14
IT52557/73A IT994275B (it) 1972-09-18 1973-09-17 Perfezionamento nei bracci telescopiei in particolare per gru e simili
ES418852A ES418852A1 (es) 1972-09-18 1973-09-18 Perfeccionamientos en los brazos telescopicos para gruas moviles o similares.
BR7240/73A BR7307240D0 (pt) 1972-09-18 1973-09-18 Lanca de guindaste telescopica
NL7312853A NL7312853A (xx) 1972-09-18 1973-09-18
FR7333436A FR2200184B3 (xx) 1972-09-18 1973-09-18
DD173620A DD106613A5 (xx) 1972-09-18 1973-09-18
JP10460673A JPS4970359A (xx) 1972-09-18 1973-09-18

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US00289986A US3804262A (en) 1972-09-18 1972-09-18 Telescopic boom

Publications (1)

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US3804262A true US3804262A (en) 1974-04-16

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Application Number Title Priority Date Filing Date
US00289986A Expired - Lifetime US3804262A (en) 1972-09-18 1972-09-18 Telescopic boom

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US (1) US3804262A (xx)
JP (1) JPS4970359A (xx)
BR (1) BR7307240D0 (xx)
CA (1) CA976917A (xx)
CH (1) CH560648A5 (xx)
DD (1) DD106613A5 (xx)
DE (1) DE2346004A1 (xx)
ES (1) ES418852A1 (xx)
FR (1) FR2200184B3 (xx)
GB (1) GB1405387A (xx)
IT (1) IT994275B (xx)
NL (1) NL7312853A (xx)
SE (1) SE394102B (xx)
ZA (1) ZA737240B (xx)

Cited By (12)

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Publication number Priority date Publication date Assignee Title
GB2263270A (en) * 1992-01-20 1993-07-21 D J Ind Ltd Load handling apparatus
US5678708A (en) * 1993-04-26 1997-10-21 Hiab Ab Extendible crane boom
US5695082A (en) * 1996-04-08 1997-12-09 Pioneer Engineering Crane having a readily removable outer boom section
US20050218101A1 (en) * 2003-11-28 2005-10-06 Giampaolo Montineri Telescopic boom arm
US20100146873A1 (en) * 2007-04-16 2010-06-17 Falck Schmidt Defence Systems A/S Telescoping mast
US9452913B2 (en) * 2012-12-20 2016-09-27 Cnh Industrial America Llc Telescopic boom
US20180273352A1 (en) * 2017-03-22 2018-09-27 Wetherell Mfg Co. Sequential piggyback cylinders for extendable boom crane
CN109368512A (zh) * 2018-12-25 2019-02-22 西京学院 一种滑轮组增程式三级电动缸
US20190315612A1 (en) * 2018-04-16 2019-10-17 Hinowa S.P.A. Aerial work platform
US10533585B2 (en) 2015-11-16 2020-01-14 Saab Ab Telescopic device and method for operating a telescopic device
US10889473B2 (en) * 2016-12-09 2021-01-12 Fassi Gru S.P.A. Load crane main boom
US11802028B2 (en) 2017-11-27 2023-10-31 Liebherr-Werk Ehingen Gmbh Telescopic boom for a crane and crane having a corresponding telescopic boom

Families Citing this family (2)

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Publication number Priority date Publication date Assignee Title
SE402003C (sv) * 1976-06-23 1982-02-11 Jonsereds Fabrikers Ab Anordning vid lastapparat med teleskopiskt forlengbar kranarm och med hydraulledningar uppburna av kranarmen
DE10003058A1 (de) * 2000-01-25 2001-07-26 Macmoter Spa Rohrverleger

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US3300060A (en) * 1965-02-03 1967-01-24 Pettibone Mulliken Corp Booms with sequential hydraulic extension
US3478894A (en) * 1967-11-27 1969-11-18 Jeffrey Galion Inc Extensible and retractable boom construction for cranes
US3481489A (en) * 1967-12-05 1969-12-02 Robert E Stauffer Means for extending and retracting boom sections of a crane
US3489294A (en) * 1968-04-25 1970-01-13 Bucyrus Erie Co Load limit control for hoisting equipment
US3605561A (en) * 1969-12-22 1971-09-20 Pettibone Corp One handle sequence selecting valving for crowd cylinders
US3633460A (en) * 1968-12-13 1972-01-11 Tadano Tekkosho Kk Extension means of a multistage extensible boom
US3658189A (en) * 1970-01-06 1972-04-25 American Hoist & Derrick Co Hydraulic extensible boom structure
US3666125A (en) * 1970-09-10 1972-05-30 Warner Swasey Co Boom assembly
US3708937A (en) * 1970-09-28 1973-01-09 Kidde & Co Walter Trapezoidal telescoping crane boom
US3736710A (en) * 1970-12-03 1973-06-05 Kidde & Co Walter Four-section fully hydraulically operated crane boom having three individually supported single piston rams contained within fly section

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US3478894A (en) * 1967-11-27 1969-11-18 Jeffrey Galion Inc Extensible and retractable boom construction for cranes
US3481489A (en) * 1967-12-05 1969-12-02 Robert E Stauffer Means for extending and retracting boom sections of a crane
US3489294A (en) * 1968-04-25 1970-01-13 Bucyrus Erie Co Load limit control for hoisting equipment
US3633460A (en) * 1968-12-13 1972-01-11 Tadano Tekkosho Kk Extension means of a multistage extensible boom
US3605561A (en) * 1969-12-22 1971-09-20 Pettibone Corp One handle sequence selecting valving for crowd cylinders
US3658189A (en) * 1970-01-06 1972-04-25 American Hoist & Derrick Co Hydraulic extensible boom structure
US3666125A (en) * 1970-09-10 1972-05-30 Warner Swasey Co Boom assembly
US3708937A (en) * 1970-09-28 1973-01-09 Kidde & Co Walter Trapezoidal telescoping crane boom
US3736710A (en) * 1970-12-03 1973-06-05 Kidde & Co Walter Four-section fully hydraulically operated crane boom having three individually supported single piston rams contained within fly section

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Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2263270A (en) * 1992-01-20 1993-07-21 D J Ind Ltd Load handling apparatus
GB2263270B (en) * 1992-01-20 1995-01-11 D J Ind Ltd Load handling apparatus
US5494397A (en) * 1992-01-20 1996-02-27 Caterpillar Inc. Load handling apparatus
US5678708A (en) * 1993-04-26 1997-10-21 Hiab Ab Extendible crane boom
US5695082A (en) * 1996-04-08 1997-12-09 Pioneer Engineering Crane having a readily removable outer boom section
US20050218101A1 (en) * 2003-11-28 2005-10-06 Giampaolo Montineri Telescopic boom arm
US7360662B2 (en) * 2003-11-28 2008-04-22 Cnh America Llc Telescopic boom arm
US8661744B2 (en) * 2007-04-16 2014-03-04 Falck Schmidt Defence Systems A/S Telescoping mast
US20100146873A1 (en) * 2007-04-16 2010-06-17 Falck Schmidt Defence Systems A/S Telescoping mast
US9452913B2 (en) * 2012-12-20 2016-09-27 Cnh Industrial America Llc Telescopic boom
US10533585B2 (en) 2015-11-16 2020-01-14 Saab Ab Telescopic device and method for operating a telescopic device
US10889473B2 (en) * 2016-12-09 2021-01-12 Fassi Gru S.P.A. Load crane main boom
US20180273352A1 (en) * 2017-03-22 2018-09-27 Wetherell Mfg Co. Sequential piggyback cylinders for extendable boom crane
US11802028B2 (en) 2017-11-27 2023-10-31 Liebherr-Werk Ehingen Gmbh Telescopic boom for a crane and crane having a corresponding telescopic boom
US20190315612A1 (en) * 2018-04-16 2019-10-17 Hinowa S.P.A. Aerial work platform
CN109368512A (zh) * 2018-12-25 2019-02-22 西京学院 一种滑轮组增程式三级电动缸
CN109368512B (zh) * 2018-12-25 2024-02-20 西京学院 一种滑轮组增程式三级电动缸

Also Published As

Publication number Publication date
CH560648A5 (xx) 1975-04-15
NL7312853A (xx) 1974-03-20
FR2200184B3 (xx) 1976-08-20
IT994275B (it) 1975-10-20
ZA737240B (en) 1974-10-30
DD106613A5 (xx) 1974-06-20
CA976917A (en) 1975-10-28
ES418852A1 (es) 1976-02-16
FR2200184A1 (xx) 1974-04-19
BR7307240D0 (pt) 1974-06-27
DE2346004A1 (de) 1974-03-28
GB1405387A (en) 1975-09-10
SE394102B (sv) 1977-06-06
JPS4970359A (xx) 1974-07-08

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