Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B66—HOISTING; LIFTING; HAULING
  • B66C—CRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
  • B66C1/00—Load-engaging elements or devices attached to lifting or lowering gear of cranes or adapted for connection therewith for transmitting lifting forces to articles or groups of articles
  • B66C1/10—Load-engaging elements or devices attached to lifting or lowering gear of cranes or adapted for connection therewith for transmitting lifting forces to articles or groups of articles by mechanical means
  • B66C1/42—Gripping members engaging only the external or internal surfaces of the articles
  • B66C1/44—Gripping members engaging only the external or internal surfaces of the articles and applying frictional forces
  • B66C1/442—Gripping members engaging only the external or internal surfaces of the articles and applying frictional forces actuated by lifting force

Definitions

• This invention relates to a lifting device for gripping and lifting a concrete pipe or any other similar large and heavy object.
• Such prior art lifting device typically utilise the common principle of the construction tong, wherein a pair of pipe clamping jaws are provided on a scissor mechanism for gripping either side of the exterior surface of a section of pipe, the mechanism being supported from a lifting means, such as a crane, such that the clamping force applied by the jaws upon the pipe increases with its weight.
• a lifting means such as a crane
• An example of such known lifting device is shown in US5842729.
• a problem with such known lifting devices is that the pipe may slip out from between the jaws, leading to a risk of injury to adjacent workers. Also such devices require access to the sides of the pipe and thus may not be suitable to locating a pipe into a trench having sides no wider that the diameter of the pipe.
• Such known lifting devices can only handle pipes of a specific diameter and therefore a number of different sized lifting devices would be required for pipes of differing diameters.
• a lifting device for a concrete pipe comprising first and second opposing load engaging members arranged for movement towards and away from each other to grip a portion of said pipe therebetween, wherein said first and second load engaging members are adapted to be urged towards one another under the weight a pipe held therebetween.
• said first and second load engaging members are adapted to be located on either side of a wall section of the pipe at or adjacent an end of the pipe.
• said lifting device comprises a base member attachable to a lifting means, such as an arm of an excavator, said first load engaging member being provided on an arm member coupled to the base member by means of at least two vertically spaced linkage members to permit vertical displacement of said arm member with respect to said base member, each linkage member being pivotally connected to said base member at a first end of the respective linkage member and being pivotally connected to said arm a location spaced from said first end, said second load engaging member being provided at or adjacent a distal end of one of said linkage members opposite said first end to be located above said first load engaging member, such that said second load engaging member is displaced downwardly and towards said first load supporting member when said arm member is displaced downwardly with respect to said base member, for example under the weight of a pipe gripped between said first and second load supporting members.
• a lifting means such as an arm of an excavator
• said arm member comprises a substantially L shaped member having a substantially vertical upper arm portion, to which said at least two linkage members are pivotally connected, and a substantially horizontal lower arm portion, an upper surface of said lower arm portion defining said first load engaging member, whereby said lower arm portion may extend into the end of a pipe to be lifted.
• said at least two linkage members comprise first and second linkage members, each of said first and second linkage members comprising a substantially horizontally disposed arm extending between said base member and said upper arm portion of the arm member.
• said first and second linkage members are arranged substantially parallel to one another.
• the first and second linkage members, upper arm portion of the arm member and portion of the base member to which the first and second linkage members are connected may define a parallelogram arrangement.
• said second load engaging member may be mounted on, or be provided on, a distal end of the lowermost of said linkage members.
• the second load engaging member comprises a load engaging plate or shoe pivotally connected to the end of said lowermost linkage member for rotation about a horizontal axis extending transverse to the linkage member.
• the load engaging plate or shoe may be curved, V shaped or otherwise profiled to conform to the outer curvature or shape of the pipe to be engaged thereby.
• a stop means may be provided for limiting the maximum upward displacement of the arm member with respect to said base member.
• Said stop member may comprise an abutment against which one of said linkage members abuts when the arm member is in its uppermost position with respect to the base member.
• Biasing means such as one or more springs, may be provided for biasing said linkage member into contact with said abutment to retain the first and second load engaging members in a fully spaced apart configuration when no load is support therebetween to enable the lifting device to be applied to and removed from a pipe.
• biasing means may act between the base member and the arm member or between the base member and one of the linkage members.
• the base member may include an attachment means for attachment to a conventional excavator coupler.
• Such attachment means may comprise a pair of spaced apart parallel pins or bars.
• the base member is formed such that the attachment means is substantially vertically aligned with the first and second load engaging members.
• Figure 1 is a side view of a lifting device according to an embodiment of the present invention.
• Figure 2 is an end view of the lifting device of Figure 1.
• a lifting device 10 for gripping and lifting concrete pipe sections in accordance with an embodiment of the present invention is illustrated in Figures 1 and 2.
• the lifting device 10 comprises an elongate base member 12 having a coupling means 14 at an upper end for fitment to the arm of an excavator, the base member 12 having a downwardly depending substantially vertical arm section 16 to which is connected an L shaped arm 18 via a pair of vertically spaced parallel linkage members 26,28, each linkage member 26,28 being pivotally connected at a first end to the vertical arm section 16 of the base member and being pivotally connected at a second location, spaced from said first end, to a vertical upper section 22 of the L shaped arm 18 to provide a parallelogram arrangement allowing limited vertical movement of the L shaped arm 18 relative to the base member 12.
• the lowermost linkage member 26 extends beyond its pivot axis on the vertical section 22 of the L shaped arm 18 and a load engaging shoe 24 is pivotally mounted on a distal end of said lowermost linkage member 26 such that the load engaging shoe 24 and an upper surface of a horizontally extending lower section 20 of the L shaped arm 18 define between them opposing load engaging members between which an end region of a concrete pipe may be gripped.
• the coupling means 14 of the base member of the lifting device is vertically aligned with the load engaging shoe 24.
• a stop member 30 is located on the vertical arm section 16 of the base member 12 such that the uppermost linkage member 28 abuts the stop member 30 to delimit the upward travel of the L shaped arm 18.
• a return spring (not shown) may be provided, acting between the base member 12 and the L shaped arm 18 or one of the linkage members 26,28, to bias the L shaped arm 18 to its uppermost position as defined by the abutment of the uppermost linkage member 28 with stop member 30.
• the pipe engaging face of the upper face of the lower section 20 of the L shaped arm 18 and the pipe engaging faces of the load engaging shoe 24 may be provided with profiled gripping surfaces and/or resilient gripping pads to grip the pipe and/or cushion the contact between the lifting device 10 and the pipe.
• the base member 12 is connected to the end of the arm of an excavator and the lifting device 10 is manoeuvred such that the horizontal lower section 20 of the L shaped arm 18 enters into the end of a pipe section to be lifted with the load engaging shoe 24 located on the outside of the pipe such that the opposing load engaging members defined by the L shaped arm 18 and the load engaging show are located on either side of an end region of the pipe.
• the lifting device 10 is then raised to bring the upper surface of the lower section 20 of the L shaped arm 18 in to contact with the inner surface of the pipe. Subsequently the weight of the pipe arrests continued upward movement of the L shaped member 18.
• the base member 12 continues to rise relative to the L shaped arm 18, the linkage members 26 and 28 rotating about their pivot axes to allow relative vertical displacement between the base member 12 and the L shaped member 18, until the load engaging shoe 24 engages the outer surface of the pipe, whereupon further relative displacement between the L shaped arm 18 and the base member 12 is arrested.
• Subsequent lifting of the lifting device causes the pipe to be lifted with the lifting device, the weight of the pipe increasing the gripping force of the opposing load engaging members of the lifting device 10 on the pipe.
• the lifting device 10 can lift and release a pipe without requiring access to the sides of the pipe and without requiring any manual user intervention to attach the lifting device 10 to the pipe.
• the L shaped arm 18 supports the inside of the end of the pipe such that the weight of the pipe is borne directly by the elongate horizontal lower section of the L shaped arm 18, such that the pipe is much less likely to slip out of the gripping device than with known devices whereby the outer sides of the pipe are gripped between opposing tongs.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Load-Engaging Elements For Cranes (AREA)

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• 2010
  • 2010-03-04 GB GBGB1003597.0A patent/GB201003597D0/en not_active Ceased
• 2011
  • 2011-03-03 EP EP11708439A patent/EP2542494A1/de not_active Withdrawn
  • 2011-03-03 WO PCT/EP2011/053173 patent/WO2011107539A1/en active Application Filing

Non-Patent Citations (1)

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