US3170723A

US3170723A - Apparatus for lifting long building elements

Info

Publication number: US3170723A
Application number: US190135A
Authority: US
Inventors: Halvorsen Kjell; Knapp Jonas Oscar
Original assignee: Strangbetong AB
Current assignee: Strangbetong AB
Priority date: 1961-04-29
Filing date: 1962-04-25
Publication date: 1965-02-23
Anticipated expiration: 1982-02-23
Also published as: NL277736A; BE616997A; GB969675A; DE1214848B

Description

Feb. 23, 1965 K. HALVORSEN ETAL 3,170,723

APPARATUS FOR LIFTING LONG BUILDING ELEMENTS Filed April 25, 1962 United States Patent G 3,170,723 APPARATUS FOR LIFTING LONG BUILDING ELEMENTS Kjell Halvorsen, Stuvsta, and Jonas Oscar Knapp, Ektorp,

Sweden, assignors to Aktiebolaget Striingbetong, Stockholm, Sweden, a corporation of Sweden Filed Apr. 25, 1962, Ser. No. 190,135 Claims priority, application Sweden, Apr. 29, 1961, 4,532/ 61 9 Claims. (Cl. 294-67) The invention relates to apparatus for lifting beams and similar building elements, particularly concrete beams.

When concrete beams are to be lifted in connection with their mounting, for instance, it is customary to use a lifting device in the form of a steel beam suspended from a crane by means of two spaced wires and provided at both ends with trailing stirrups or coils which have been placed around the concrete beam. For various reasons it is difficult, in practice, to use longer lifting beams than about 20 feet and if the concrete beams have a greater length, end portions of the beam will project beyond the lifting stirrups. To resist the bending moments produced in these overhanging end portions it is necessary to reinforce the beam by means of a longitudinal top reinforcement, which involves increased costs, particularly since such a reinforcement serves no other purpose than preventing overload of the beam at the time of actual lifting thereof. When a beam is of a length of 100 feet, for instance, each end portion will extend beyond the lifter about 35 feet, the reinforcement mentioned is not sufficient, and two cooperating cranes must be used, which makes the work still more expensive.

The object of the invention is to provide apparatus which makes it possible to lift long concrete beams by one single crane without the necessity of providing the beams with an additional top reinforcement.

In accordance with the invention, it is contemplated that, on either side of and spaced from the central cross section of said beam, two tie members are caused to engage the beam in two points spaced from each other in the longitudinal direction of the beam, whereupon the opposite ends of the tie members are linked to each other, the two links thus obtained being, by means of central tie members, connected to a common lifting means.

By disposing the points of engagement suitably along the beam and by calculating the angles between the tie elements correspondingly, it is possible due to the links to obtain such a distribution of the lifting power that the negative bending moments acting on the beam are reduced considerably. Another essential advantage is that the vertical distance between the crane hook and the upper surface of the beam can be kept small so that the effective lifting height of the crane is increased.

The invention is particularly directed to a device which comprises 'two central tie members adapted to be connected to a common grab hook each at one end and each having its oppositeend linked to two stirrups adapted to be hingedly connected to a beam at different beam sections, all of said hinges extending substantially parallel to each other. In their simplest form the various tie members may consist of lines, ropes or the like, although as a rule rods are to be preferred. In case the two central tie members are rods, said rods are preferably provided with a hinge close to their outer ends, which hinge is arranged perpendicular to the tie members to permit swinging of the stirrups about the last Said hinge in the tie member to thereby permit swinging of the beam.

A suitable embodiment of the device according to the invention is shown in the accompanying drawing.

ice

FIGURE 1 shows a diagrammatic view of the device 1 while lifting a beam.

FIGURE 2 shows a cross section of the beam.

FIGURES 3 and 4 show on a larger scale one half of the lifting device as seen from the side and from above, respectively.

In FIG. 1 is shown a truss arrangement constituted by pivotally inter connected link members 7,.14 and 15 for raising and lowering a beam 20 under the action of a single crane hook.

To the right in FIGS. 3 and 4 are shown two parallel, approximately triangular plates 5 joined by means of a bolt carrying a roll 6 which is adapted to serve as grip for a crane book. The plates 5 form a fastening means for two tie members or links 7. Each of these members 7 consists of two

parallel rods

7a and 7b hingedly coupled each to one plate 5 by means of a bolt 8 (FIG. 4). The opposite ends of the

rods

7a, 7b are secured to a cross head 9.

A bolt 10 extending parallel to the roll 6 carries a rotatably journalled sleeve 11 having a radially protruding lug 12 which is connected to the cross head 9 by means of a pin 13 perpendicular to the bolt 10. The ends of the bolt 10 extend beyond the sleeve 11 and through holes in the ends of two links or

stirrups

14 and 15 which thus are hingedly connected end to end to each other and to the tie member 7 in substantially coplanar arrangement for pivotal movement about a common axis passing through bolt 19. The stirrup 14 mounted next to the,

sleeve is adapted to be directed vertically downwards to form a support for the bottom of the beam. Said stirrup 14 is composed of two

parallel rods

14a, 14b, the lower ends of which have corresponding bores for insertion of a transverse, preferably tubular member 16. The stirrup 15 which is to be secured to a point located closer to the outer end of the beam, is likewise composed of two

parallel rods

15a, 15b, the outer ends of which are disconnectably joined by a transverse rod or bolt 17.

To facilitate the adaption of the lifting device to beams of different sizes, the coupling ends of the stirrups 14 and the beam engaging ends of the stirrups 15 may be provided with

bores

18 and 19 respectively, as shown in FIG. 4, for insertion of the bolt 10 and the rod 17, as desired. Although not shown, it may'moreover be suitable, with regard to varying widths of the beams, to make the bolt 10 long enough so that the distance between the legs of the stirrups may be varied. In such case, any clearance along the bolt may be filled with washers.

As shown in FIG. 2, the upper flange of the beam 20 is provided with transverse holes 21 formedduring the casting by the insertion of tubes having a length equal to the Width of the beam. Such a hole has been provided at a desired distancefrom each end of the beam to serve as an attachment for one of the stirrups 15.

To support a concrete beam with the device described, the legs of the two vertical stirrups 14 are lowered over the middle portion of the beam at equal distances fromthe middle section of the beam (see FIG. 1), and the lower ends of the

legs

14a, 14b are joined below the beam by insertion of the tubes 16; The tube 16 has protruding tube ends which are locked by means of pins 22 (see FIG. 3). Additionally, the bolts 17 associated with the outer stirrups 15 are inserted through the holes 21 in the beams and are connected to the

legs

15a, 15b of the stirrups. FIG. 1 shows the device ready for a'lifting operation.

Due to the links 10 provided between the tie members, it is possible to transmit to the two outer tie elements forces great enough to compensate entirely or almost entirely for the large bending moments caused by the tare weight of the brackets and occurring between the vertical sections through the points of engagement of the

tie members

14 and 15 on the beam. The angle between the two central tie members 7 is of course of decisive importance, in that the tensile forces in the members 15 increase as said angle increases. In most cases the most advantageous distribution of forces is obtained if the tensile force in each outer stirrup 15 is approximately equal to the total weight of the beam. As a specific example the angle between the central tie members 7 may be between 90 and 150, whereas the angle between one of the outer stirrups 15 and the longitudinal axis of the beam may vary between and about 15.

Due to the links 13 the suspended beam becomes swingable around a line parallel to its longitudinal axis approximately on a level with the links 10, which inter alia contributes to the distribution of the lifting force on the various stirrup legs.

What we claim is:

1. Apparatus for lifting a beam comprising a pair of tie members having opposite ends, means connecting said tie members together at one of the respective ends thereof in inverted V-shape arrangement with the tie members inclined at a determinable angle with the horizontal, a pair of link members connected in pivotal fashion to each of the tie members at the other of the ends thereof, one of each of said pairs of link members extending substantially vertically downwards from the other of the ends of the tie members, the other of each of the pairs of link members extending from the other of the ends of the corresponding tie member at an angle to the horizontal which is less than the angle of the tie member, and means at each of the ends of the link members remote from the other of the ends of the tie members for supporting the beam thereat, said means connecting the tie members being effective to receive a force for moving the tie members and link members and the beam therewith while said link members are effective to support the beam at a plurality of spaced locations.

2. Apparatus as claimed in claim 1 wherein each said tie member is constituted by a pair of parallel rods, said means connecting each of said tie members including a pair of plates and bolts hingeably connecting each of the rods to a respective plate, and a roll supported from each of the plates and adapted for being engaged by a hook for raising and lowering the beam.

3. Apparatus as claimed in claim 1 wherein each of the link members is constituted by two parallel rods.

4. Apparatus as claimed in claim 3 wherein the parallel rods of each of the link members are provided at common ends thereof with a succession of openings, and pivots connecting the rods of the link members together by being accommodated in corresponding openings, said openings providing adjustment of the position of the link members with respect to the beam.

5. Apparatus as claimed in claim 1 comprising means connecting the tie members to the respective link member for pivotal movement about an axis transverse to the members and about an axis perpendicular to said axis.

6. Apparatus as claimed in claim 5 wherein the first of said axes is substantially horizontal and the other axis is substantially perpendicular to the respective tie member.

7. Apparatus for lifting a beam comprising a symmetrical truss including a pair of tie members having opposite ends, means connecting said tie members together at respective ends in V-shaped arrangement, a pair of downwardly depending links, pivots comiecting one of the downwardly depending 'links to each of the tie members at the other of the ends thereof, a further link connected in pivotal fashion to each of the downwardly depending links and the associated tie member by an associated one of said pivots, said downwardly depending links having ends remote from the pivots, means in the downwardly depending links at the last said ends for supporting the beam thereat, said further links each having ends remote from an associated pivot, means at the last said ends on said further links for engaging the beam to further support the latter thereat, and means for moving said truss and the beam therewith by exerting a force on the truss at the first means which connects the tie members, said tie members and links being dimensioned such that said tie members form a larger angle with respect to the horizontal than the angle formed by the further links.

8. Apparatus as claimed in claim 7 comprising means operatively associated with the tie members and the pivots connecting the same to the downwardly depending links for permitting respective transverse pivotal movement between said tie members and the associated further links and downwardly depending links.

9. Apparatus for lifting a beam having substantial longituidnal extent, said apparatus comprising:

a pair of tie members having opposite ends, means connecting said tie members together at one of the respective ends thereof in V-shaped arrangement,

a pair of link members for each tie member, said link members each having opposite ends,

means connecting the link members of each pair at one of the ends thereof together in end-to-end relation and to the corresponding tie member at the end thereof remote from where the ends of the tie members are connected together, all for respective pivotal movement about a common axis,

the link members and tie members having central longitudinal axes which lie in a common plane, said common axis extending perpendicular to said plane,

said link members of each pair having free ends remote from the associated common axis, and means at each of the free ends of said link members for directly engaging a beam at longitudinally spaced relation whereby a beam may be supported at the free ends of the link members.

References Cited by the Examiner UNITED STATES PATENTS 642,078 5/99 Patriarchie 294--81 2,35 8,767 9/44 Breslav 29467 2,969,102 1/61 Cunningham 29481 X 3,010,751 11/61 Day 294-81 SAMUEL F. COLEMAN, Primary Examiner.

LEO QUACKENBUSH, ANDRES H. NIELSEN,

ERNEST A, FALLER, JR., Examiners.

Claims

1. APPARATUS FOR LIFTING A BEAM COMPRISING A PAIR OF TIE MEMBERS HAVING OPPOSITE ENDS, MEANS CONNECTING SAID TIE MEMBERS TOGETHER AT ONE OF THE RESPECTIVE ENDS THEREOF INVERTED V-SHAPED ARRANGEMENT WITH THE TIE MEMBERS INCLINED AT A DETERMINABLE ANGLE WITH THE HORIZONTAL, A PAIR OF LINK MEMBERS CONNECTED IN PIVOTAL FASHION TO EACH OF THE TIE MEMBERS AT THE OTHER OF THE ENDS THEREOF, ONE OF EACH OF SAID PAIRS OF LINK MEMBERS EXTENDING SUBSTANTIALLY VERTICALLY DOWNWARDS FROM THE OTHER OF THE ENDS OF THE TIE MEMBERS, THE OTHER OF THE ENDS OF LINK MEMBERS EXTENDING FROM THE OTHER OF THE ENDS OF THE CORRESPONDING TIE MEMBER AT AN ANGLE TO THE HORIZONTAL WHICH IS LESS THAN THE ANGLE OF THE TIE MEMBERS FOR SUPMEANS AT EACH OF THE ENDS OF THE LINK MEMBERS REMOTE FROM THE OTHER OF THE ENDS OF THE TIE MEMBERS FOR SUPPORTING THE BEAM THEREAT, SAID MEANS CONNECTING THE TIE MEMBERS BEING EFFECTIVE TO RECEIVE A FORCE FOR MOVING THE TIE MEMBERS AND LINK MEMBERS AND THE BEAM THEREWITH WHILE SAID LINK MEMBERS ARE EFFECTIVE TO SUPPORT THE BEAM AT A PLURALITY OF SPACED LOCATIONS.