US 3749437 A
Lifting tongs are a device to firmly grasp a structural beam, etc., without marring it, as a crane is operated, with its cable attached to the lifting tongs directly or to a spreader bar that spaces and holds two or more lifting tongs, to lift the beam to its overhead installation locale. Thereafter, a slight lowering and a slight raising of the lifting tongs readjusts their grasping members to clear the structural beam, without crane operating personnel and/or riggers going above to the installed beam to remove the lifting tongs. Essentially, this is done as the top transverse member of the lifting tongs is readjusted relative to the bottom transverse member. The top of the installed beam maintains the elevation of the top transverse member as the remainder of the lifting tong components are slightly lowered until a latch grasps the top transverse member in a greater spaced apart position of the lifting tong components.
Description (OCR text may contain errors)
United States Patent [19.1
[ 1 July 31, 1973 BEAM SUPPORTING DEVICE AS LIFTING TONGS, FOR ATTACHMENT TO CABLES OF CRANES  Inventor: Buddy E. Lynn, 4208 N. 35th,
Tacoma, Wash. 98407 22 Filed: Aug. 19, 1911  Appl.No.: 173,147
Primary Examiner-Evon C. Blunk Assistant Examiner-Johnny D. Cherry Attorney-Roy E. Mattem [5 7 1 ABSTRACT Lifting tongs are a device to firmly grasp a structural beam, etc., without marring it, as a crane is operated, with its cable attached to the lifting tongs directly or to a spreader bar that spaces and holds two or more lifting tongs, to lift the beam to its overhead installation 10- cale. Thereafter, a slight lowering and a slight raising of the lifting tongs readjusts their grasping members to clear the structural beam, without crane operating personnel and/or riggers going above to the installed beam to remove the lifting tongs. Essentially, this is done as the top transverse member of the lifting tongs is readjusted relative to the bottom transverse member. The top of the installed beam maintains the elevation of the top transverse member as the remainder of the lifting tong components are slightly lowered until a latch grasps the top transverse member in a greater spaced apart position of the lifting tong components.
5 Claims, 6 Drawing Figures PAIENIEU JUL 3 1 I975 INVEN'I'OJQ, BUDDY E. LYNN ATTORNEY BEAM SUPPORTING DEVICE AS LIFTING TONGS, FOR ATTACHMENT TO CABLES OF CRANES BACKGROUND OF THE INVENTION During the construction of many homes, churches, office buildings, etc., wood laminated beams are erected overhead on columns. Generally, they remain exposed becoming interior components to be observed. Therefore, care must be taken to avoid their damage, even avoiding marring their surfaces.
Present lifting devices such as chain wrappings and grappling hooks, etc., often cause marring and many times cause more severe damage. Therefore, to reduce and to avoid damage, laminated wood beams are often wrapped with a protective covering.
A lifting device has therefore been needed to firmly support such beams without marring or damaging them. In addition to avoidance of any need for protective wrappings at this installation time is desirable so men need not be sent aloft at dangerous heights to unwrap them. Moreover, any need for sending men aloft to remove grappling hooks, chains, wraps, etc., is hopefully to be eliminated.
Utilization of the lifting tongs of this invention completely protects any beam lifted while eliminating a requirement for wrapping based solely on protection during lifting functions. Moreover, when all beams are lifted into place, no erection crew members ever go above to the installed beam to release the lifting tongs. By reversing direction of the cable movements and also using the positioned beam to support parts of the lifting tongs, they have their respective portions adjusted relative to one another to clear the installed beam.
SUMMARY Beams being installed in homes and commercial buildings and in ships and bridges, are, when at flat car or truck bed or ground level, first immediately supported by the device of this invention referred to as lifting tongs, in lieu of a hook and/or chain, which upon adjustment partially surrounds each beam about its cross section at or near its center of gravity. A selected hole located above in this device receives a cable hook to also balance the beam load transversely, without tilting during lifting, as a crane is operated to shorten the cable during beam placement operations.
Then after the beam is installed, reverse operation of a crane lowers most of this beam supporting device, except for its transverse slider member. This above transverse beam holding member continues to rest on the top of the located beam while the other components move relative to their vertical guide bar that is moving down. This guide bar is connected below or is integral with a transverse underlying bottom arm beam support. Above, this guide bar connects or is integral with a shorter transverse top arm that has selective spaced holes to receive lifting cable attachments.
When this transverse slider member reaches a position near its transverse top arm, it is supported there by a grasping pivotal catch or hook. Thereafter, as the crane cable is again reversed, this time the entire beam supporting device is raised a short distance, so both the transverse slider member and the transverse underlying bottom arm support are at positions to clear the installed beam. Subsequently, the swinging away or withdrawing of the crane components thoroughly clears all portions of the lifting tongs from the installed beam. In
so doing, all these maneuvers are undertaken by a crane operator and/or rigging personnel always working at or near ground level. There is no requirement for anyone to go above on the located beam to detach the supporting device or lifting tongs from the beam then resting in its erected location in an overall structure.
DRAWINGS OF A PREFERRED EMBODIMENT FIG. 1 is a perspective view indicating the lifting tongs positioned to securely hold a structural beam indicated by dotted lines;
FIG. 2 is a perspective view of the opposite side of the lifting tongs indicating how the lifting tongs are lowered in part after the beam is in place overhead;
FIG. 3 is a detailed perspective view of portions of the lifting tongs, as viewed in FIG. 2, to illustrate how components are first repositioned in preparation to clear the lifting tongs from the structural beam;
FIG. 4 is a perspective view showing how the lifting tongs are cleared above and below the installed structural beam and therefore the assembly is ready to be swung clear and, lowered to lift another beam into place;
FIG. 5 is a partial and detailed perspective view of portions of the lifting tongs which are smooth and often padded to make firm but unmarn'ng contact with a structural beam being lifted into place; and
FIG. 6 is a perspective view on a smaller scale to indicate how a spreader may be used to position two lifting tongs.
DESCRIPTION OF PREFERRED EMBODIMENT In FIG. 1, lifting tongs 10, comprising an assembly of components, taking the place of hooks, chain wraps, grappling hooks, etc., are shown in their lifting configuration with respect to handling of a structural beam 12. Such a beam 12 is often a laminated wood beam or full wood beam to be placed overhead in a structure where it remains visible as part of the interior of a building. Therefore marring and/or more serious damage to the beam is to be avoided.
At ground level, on a truck bed, or on a railroad car, a beam 12 is generally supported at each end on temporary timbers, not shown. Utilizing this lower clearance under beam 12, a lower transverse support sub assembly 14 of lifting tongs 10 is insertedunder beam 12.
Secured to this sub' assembly 14 is an upstanding guide body 16 of a height substantially greater than the depth of any beam 12 to be lifted. The cross section of guide body 16 remains uniform during its substantially free length or height. l
Slidably installed on this upstanding guide body 16, is an upper transverse holding sub assembly 20. It is moved, either to rest on top 22 of beam 12, or to be po- 7 sitioned well above beam 12.
In its cleared high position, transverse holding sub assembly 20 is itself held, as its own cammed latching plate or guide 24 contacts and guides a latching hook or retainer 26 into a locking position beneath it. Latching hook 26 is in turn pivotally mounted in anchoring or bearing structure 28 that is secured to upstanding buide body 16, as shown in FIGS. 2 and 3.
Above this retention location for upper transverse holding sub assembly 20, upstanding guide body 16 is fitted with a cable hook receiver 30. It is a component of an attachment receiver sub assembly 32 which is a shorter transverse structure having receiving holes 34,
36. Through one of these holes, a cable, a crane cable hook 88, or shackle, etc., is passed and secured in preparation for and during a lift of a structural beam 12 into place in an overall building structure, not shown. Multiple holes 34, 36, and others to be provided, if necessary, serve as selective places of attachment so beam 12, when lifted, will be transversely balanced with its top or bottom remaining parallel both to level ground and also to level receiving locations on structural columns, not shown.
In preparation for a lift, once lower transverse support sub assembly 14 and upper transverse holding sub assembly are positioned in engagement with a beam 12, there may be on occasions, such as during a time of high velocity winds, :1 need for more fully encompassing beam 12. This is done by installing a slidable and securable beam edge retainer 40 on upper horizontal guide 42 of sub assembly 20. A penetrating set screw 44 is used during securement. Also an overall keeper 46 for retainer 40 is secured by a screw 48 to the end of horizontal guide 42. A similar additional encompassing structure is added to lower transverse support sub assembly 14, not shown, except for its overall keeper 52 and screw 54. Keeper 52 may be rotated to a clearing position.
As illustrated in FIG. 5, all surfaces in a position to contact a structural beam to be left exposed in a building are preferably smooth, without ridges or projections. Moreover, often padding 56 is placed over these surfaces to further insure against damage upon contact of these surfaces with, for example, a laminated wood beam 12.
Throughout, FIGS. 1 through 5, the embodiment shown is preferred when the lifting tongs 10 are to be made by utilizing components derived originally from standard structural shapes of steel plate, bar, angles, tubes, channels, beams, etc. where cutting, burning and welding operations are undertaken during its fabrication. In addition, the embodiment shown is well braced with brackets and fillers to adjust the lifting stresses throughout lifting tongs 10.
For example, lower transverse support sub-assembly 14 extends to the other side of upstanding guide body 16 where it is further positioned by corner brace 58. This opposite side continuation of lower transverse support sub-assembly l4 aids in stabilizing lifting tongs 10 when they are resting on the ground before a lift is undertaken. Also with its brace 58, it adds to the overall strength of the lifting tongs.
In the direction ofa beam 12 to be lifted, lower transverse sub assembly 14 has matching surface longitudinal supporting guides 60, 62 on either side of this lower horizontal guide 64. Each of these guides 60, 62 are stabilized by triangular braces 66, 68.
At the top of these illustrated lifting tongs 10, a filler brace 70 is used between upstanding guide body 16 and the horizontal frame member 72 of the shorter transverse structural sub assembly 32. Included in this sub assembly 32 is, a heavy upstanding formed plate 74 having holes 34, 36, to serve as a cable hook receiver 30. Plate 74 continues on for attachment to anchoring or bearing structure 28 located on upstanding guide body 16. Such continuity of overall structure throughout, insures lifting tongs 10 will remain in their initial configuration without any material distortion occurring, which might otherwise lead to a strain failure caused by an excessive stress, coming from an unwanted bending moment.
As illustrated in FIG. 6, where a beam 13 is longer and/or heavier, more lifting tongs 10 are used. They are secured, for example, to a spreader by connectors 82. The rib 84 of the spreader receives in its hole 86 crane hook 88 that is in turn secured to crane cable 90.
SUMMARY OF OPERATION A structural beam 12 resting on temporary end supports, not shown, such as short timbers is lifted above to column or wall supports, not shown, utilizing a crane having chain or cable load carrying means, all not shown. During this lifting or erection of beam 12, the assembled device, called lifting tongs 10, is used.
In FIG. 1, these tongs 10 are positioned for the lifting operation to commence whenever a cable, cable hook, shackle, etc., is connected at hole 34 or 36 and a crane is operated. Lower transverse support sub assembly 14 is placed under beam 12 with upstanding guide body 16 also adjacent beam 12. Upper transverse holding sub assembly 20 is lowered so its upper horizontal guide 42 rests on beam 12. Then as may be necessary, a beam edge retainer 40 is positioned adjacent beam 12.
Lifting is undertaken and beam 12 is placed overhead on columns or walls, not shown. Lifting tongs 10 remain in place preferably until beam 12 is secured suffrciently by other holding means, not shown, to insure it will remain in place.
Then crane operations are reversed to lower most of the components of lifting tongs 10, except for upper transverse holding sub assembly 20. It, however, is prevented from lowering by beam 12 and therefore upstanding guide body 16 moves downwardly through sub assembly 20.
Reversal of a crane continues until cammed latching plate or guide 24 moves latching hook or retainer 26 into locking engagement with it and consequently into locking engagement with upper transverse holding sub assembly 20, as shown in FIGS. 2 and 3.
Thereafter, crane operations are reversed again, this time to raise, slightly, all the components of lifting tongs 10. They are raised until both upper transverse holding sub assembly 20 and lower transverse holding sub assembly 14 are spaced away from beam 12. After reaching this spaced position, as illustrated in FIG. 4, a swinging motion of a crane clears lifting tongs l0 completely free of beam 12, so another beam may be lifted into place with the lifting tongs 10.
During this sequence of operations, the relative movement capability of respective components and sub assemblies of lifting tongs 10, is always utilized,so a crane operator and/or his rigging assistants will not be required to go above to the beams installed elevation to remove lifting tongs 10 from beam'l2.
Moreover, at all times, especially with the use of padding 56, beam 12 is not marred nor otherwise damaged by lifting tongs 10. Yet during an entire lifting and removal operation, lifting tongs l0 securely hold beam 12 without slippage and tilting ever occurring.
Whenever necessary, more units of lifting tongs 10 may be used to hold the beam or other objects being lifted which because of its weight and/ or length may require more places of attachment as illustrated in FIG. 6. Yet at all times when multiple units are used, safe and convenient operations are still undertaken and the beams are not damaged by the lifting tongs. Moreover,
the lifting tongs are always manipulated together to simultaneously release the beam by the crane operator without sending riggers aloft.
1. A lifting tongs unit each lifting tongs unit for use during crane operations to securely position a member to be lifted, and after the overhead securement of the lifted member by other means to an overall building structure, the lifting tongs unit, solely by utilizing crane operations, has some of its components spaced apart, and then each lifting tongs unit is swung clear of the lifted member, comprising:
a. an upstanding guide body;
b. an attachment receiver sub assembly secured to the top of the upstanding guide body;
c. a lower transverse support sub assembly secured to the bottom of the upstanding guide body;
d. an upper transverse holding sub assembly slidably secured to the upstanding guide body; and
e. an automatically latching sub assembly, having a hook pivotally mounted to the lifting tongs near the top of the upstanding guide body, and having a cammed retainer mounted on the upper transverse holding sub assembly in line with the hook, so as the hook is lowered with the upstanding guide body as the guide body slides down through the upper transverse holding sub assembly, the hook will be first pivoted by the cammed retainer and then retained by the cammed retainer on the upper transverse holding sub assembly, until subsequently released following a lifting operation when the lifting tongs are lowered to the ground for readjustment in preparation for another lift.
2. A lifting tongs unit, as claimed in claim 1, comprising, in addition, stabilizing structures as part of the lifting tongs unit to keep the unit upright until a lift is underway.
3. A lifting tongs unit, as claimed in claim 1, having multiple transverse retaining structures located on both the lower transverse support sub assembly and the upper transverse holding sub assembly to confine a member when a lift is underway.
4. A lifting tongs unit, as claimed in claim 1, having padding to protect a member when a lift if underway.
5. A load lifting assembly of spaced multiple lifting tong units, as claimed in claim 1, and a spreader body adaptable to be connected at its top to attachment means secured intum to a crane and at its bottom to the spaced multiple lifting tongs.