US3436116A - Tiltable lifting tongs - Google Patents

Description

April 1, 1969 J. R. ANDERSON 3,436,116

TILTABLE LIFTING TONGS Filed July 12, 1967 Sheet of 2 INVENTOR I John R. Anderson April 1, 1969 .1. R. ANDERSON TILTABLE LIFTING TONGS Sheet of2 Filed July 12, 1967 Fig.4.

INVENI'OR John R; Anderson Fig.3.

Unite States US. Cl. 294103 7 Claims ABSTRACT OF THE DISCLOSURE Lifting tongs of the type having opposed grappling jaws for grasping and releasing a load and having a power driven sling for tilting the tongs while suspending them above ground level. The sling is in the form of parallel pairs of roller chains and wire ropes arranged on either side of the tongs and reaved between idler and drive pulleys supported in a housing disposed above the tongs and adapted at its upper portion to be engaged with a crane hook. The sling can be selectively driven to tilt the tongs from a downward position to a sideward position, such tilting occurring with the center of gravity of the tongs remaining at all times substantially in the same vertical plane.

This invention relates to a selectively tiltable lifting tongs.

Coils of strip are produced at various stages in various of the metal-forming industries, such as steel, aluminum, etc. The coils are sometimes produced as an intermediate mill product and are sometimes produced as a final product for shipment to a customer. In the steel industry, for example, strip material in the form of hot band and cold rolled strip is delivered from rolling mills, processing lines, etc. and must be coiled to enable material to be handled and transferred to another point either for further processing or for shipment to the customer. By reason of the orientation of strip mills and processing lines, the strip is necessarily coiled on a horizontal axis to form a coil which is ordinarily banded to hold it in the form of a coil. Such coils are of varying weights, but they may weight as much as one hundred thousand pounds in some cases.

Although such coils are wound on a horizontal axis because of mill designs, and are unwound on a horizontal axis for the same reason, it is preferable to store such coils with their axis vertical. In this manner they are stable and may be stacked. When coils are stored with their axes horizontal, they are subject to rolling, and stacking in that position increases the possibility of rolling or of breaking the bands which hold the coils in shape.

It has been common to provide tilters to tilt newly formed coils from a horizontal to a vertical axis after coiling and then form a vertical to a horizontal axis for further processing. Such tilters have the disadvantage of being heavy and expensive; and they are ordinarily placed in a fixed position opposite the exit or entry end of a mill which eliminates flexibility of operation.

I avoid the drawbacks inherent in such tilters by providing lifting tongs which are movable between a position in which the coil axis is horizontal and in which the coil axis is vertical. I provide a tilting mechanism for tilting tongs, such mechanism, preferably, comprising a tilting mechanism having a housing adapted to be engaged at 4 its upper portion by a crane hook; and a power driven flexible elongated suspending means supported by the housing and connected at its ends to support member means forming part of a lifting tongs assembly for supporting tongs above ground level and for selectively tilting suspended tongs through a pre-determined angular displacement.

atent O Patented Apr. 1, 1969 Other details, objects and advantages of the invention will become apparent as the following description of a present preferred embodiment thereof proceeds.

In the accompanying drawings I have shown a presentpreferred embodiment of the invention in which:

FIGURE 1 is an elevation view of lifting tongs embodying the present invention showing the lifting tongs suspended from a crane hook in a downward position;

FIGURE 2 is an elevation View of the same lifting tongs of FIGURE 1 showing the suspended lifting tongs tilted in a sideward position;

FIGURE 3 is an elevation view partly in section of the grappling arm portion of the present invention showing further details of construction;

FIGURE 4 is an elevation view partly in section of another portion of the present invention showing still further details of construction;

FIGURE 5 is another view of the portion of FIGURE 4.

Referring now the drawings wherein like reference numerals refer to like parts throughout the various views, generally designates lifting tongs including a grappling arm portion 12 shown in detail in FIGURE 3. Grappling arm portion 12 is similar in many respects to the lifting tongs described in US. Patent 3,076,674. The particular features of grappling arm portion 12 will be described as illustrative only and, as such, does not form part of the present invention. Grappling arm portion 12 includes an elongated, horizontal rigid base member 14 formed of laterally spaced parallel angle plates 15, one of which is shown. Hereinafter, directional references will be made and will be designated as left or outer, right or inner, and upward and downward as viewed in the FIGURES 1, 3, and 4 of the drawings. It is emphasized that these directional references are not to be construed as limiting the invention but, rather, are merely used for convenience of description.

Base member 14 supports an inner grappling jaw 16 suitably fixed intermediate the ends of base member 14. An outer grappling jaw 17 is supported by base member 14 adjacent the left end thereof and is suitably spaced from inner jaw 16 and is reciprocally movable with respect thereto for gripping material such as coiled sheet steel 18. Outer jaw 17 is suitably fixed to one end of a generally L-shaped grappling arm 20 formed of identically shaped laterally spaced plates 21, one of which is shown. One leg 20a of grappling arm 20 is disposed between plates of base member 14 and is suitably slidably arranged with respect thereto. The other leg b of grappling arm 20 extends outwardly beyond the left end of base member 12 where it is connected with outer grappling jaw 17.

An elongated ball screw type nut 23 is suitably fixed between the plates 21 forming grappling arm 20 and specifically intermediate the ends of leg 20a of grappling arm 20. An elongated partially threaded shaft extends through not 23 with an intermediate portion of the threads of shaft 25 engaging the threads of nut 23. The right end of shaft 25 has a smooth surface and is suitably keyed to a sleeve member 26 and is longitudinally slidable a fixed distance with respect thereto. Sleeve member 26 is supported by a roller bearing 27, supported by and retained in bearing housing 28. Bearing housing 28 is suitably fixed between plates 15 of base member 14. A toothed drive sprocket 30 is suitably fixed to sleeve member 26 to the left of bearing 27. A collar 31 fixed about an outer peripheral left end portion of sleeve member 26 serves to fix sleeve member 26 with respect to sprocket 30, bearing 27 and bearing housing 28. Another collar 32 fixed about a right end portion of shaft 25 fixes the limit of leftward longitudinal movement of shaft 25 in sleeve member 26.

A power drive assembly 34 for drive shaft is suitably arranged on an upper portion of base member 14 and includes a reversible electric motor 35. The drive shaft 36 of motor is suitably fixed to a coupling 37, which in turn is suitably fixed to a speed reducer 38. A toothed sprocket 39 is suitably fixed to the output shaft of reducer 38 and is generally coplanar with sprocket 38. Sprockets 39 and 30 are operatively connected by suitable means such as roller chain 40. A hollow housing 41 detachably fixed to an upper portion of base member 14 encloses the power drive assembly 34.

Shaft 25 has a generally smooth surfaced left end portion 42 terminating in a generally convex surfaced end 43 which extends leftwardly beyond nut 23 into a portion of a thrust block 45. Thrust block 45 has a right or inner end portion 46 having an opening 47 shaped for receiving left end portion 42 of shaft 25. Thrust block 45 also includes an outer bifuracted portion 49 with a slightly concave shaped inner end 48 communicating with opening 47. The concave shape of inner end 48 is complementary to the convex shape of end 43 of shaft 25. End 43 of shaft 25 engages inner end 48 of bifurcated portion 49 to function together as a brake for preventing rotation of shaft 25. This is fully explained in the aforementioned US. Patent 3,076,674.

Thrust block 45 is suitably slidably supported inbetween the plates 21 of grappling arm 20 as by means of lands on the outer surface of the legs of bifurcated portion 49 engaging corresponding slots formed in plates 21 along leg 20a of grappling arm 20.

A generally L-shaped lever arm 50 formed from laterally spaced identical plates 51, one of which is shown, has the long leg 50a thereof extending longitudinally of base member 14 and disposed above the power drive assembly 34. The short leg 50b of lever arm 50 extends downwardly with the end thereof being suitably pivotally connected to the bifurcated portion 49 of thrust block 45. The right hand end portion of long leg 50a of lever arm 50 has a pair of diametrically opposed, laterally extending bosses 52, one of which is shown, fixed thereto. The bosses 52 serve to support the ends of cables and chains and will be described more fully hereinafter. A pair of identical elongated links 54 is suitably pivotally fixed at one end portion 54a thereof to intermediate laterally diametrically opposed portions of base member 14. The other end portion 54b of each link 54 has a longitudinally extending closed slot 55 surrounding a pin 56 fixed to an intermediate portion of the long leg 50a of lever arm 50. Slots 55 of the links 54 serve to define the upward and downward limits of movement of lever arm 50.

Lever arm 50 also has a main pivot pin 53 extending between the plates 51 and suitably connected to a portion of a support arm 57. Support arm 57 includes a pair of laterally spaced L-shaped plates 58, one of which is shown, each of the plates 58 having an elongated arm 59 suitably longitudinally, coextensively fixed to each inner face of the plates 15 forming base member 14. Each plate 58 also includes an elongated leg 60 extending transversely of arm 59 and disposed leftwardly of outer grappling jaw 17. Leg 60 of support arm 57 has an upper portion 61 disposed above arm 59 and a lower portion 62 disposed below arm 59. Short leg 50b of lever arm 50 has a lower portion thereof disposed between the upper portions 61 of the plates 58 forming support arm 57 with pivot pin 53 of lever arm 50 extending through coaxial openings through parts of the short leg 50b and upper portion 61 respectively. Each lower portion 62 of leg 60 has a longitudinal slot 63 formed in the inner surface thereof and extending upwardly into a lower region of the upper portion 61 of leg 60. Diametrically opposed coaxial openings 64 extend through a lower region of lower portion 62 of leg 60. A flat elongated shaft 66 having a plurality of longitudinally spaced openings 67 therethrough is slidably received in the opening between lower portions 62 of leg 60 in the opening defined by the opposed slots 63.

Openings 67 in shaft 66 are substantially the same diameter as openings 64 in lower portion 62, with the openings registering with each other. A different opening 67 in shaft 66 can be registered with openings 64 by sliding shaft 66 upwardly or downwardly as desired. Shaft 66 is held fixed in relationship with leg 60 by a pin 68 extending through openings 67 and 64.

A pair of diametrically opposed generally cylindrical bosses 70 are suitably fixed to a lower end portion of shaft 66. Bosses 70 are similar in shape to bosses 52 fixed to the right end portions of lever arm 50 and are used, like wise, for supporting the ends of chains and cables. The upper portion 61 and leg 60 has a generally cylindrical rod 71 fixedly extending through and outwardly of the upper end region thereof. The centerpoint of bosses 70 and the extreme left portions of rod 71 lie generally in the same vertical plane. Rod 71 serves as a guide for chains and cable as will be clearly shown hereinafter.

Disposed above grappling arm portion 12 of the lifting tongs assembly 10 is a suspending means 74 in the form of a power driven sling arrangement. Suspending means 74 includes an elongated hollow housing 76 having an upper portion 77 formed of a pair of laterally spaced generally triangular plates 78 having a pair of diametrically opposed coaxial openings 79 through upper portions thereof. A tubular generally cylindrically shaped spool 80 is supported coaxialy with the opening 79 and is fixed with respect to housing 76 by suitable means such as with stud 81 and nuts 82. Spool 80 accommodates a crane hook 83 and to this end is smoothly curvalinearly undercut at the center portion 84 thereof. A reversible electric motor 85 is suitably rigidly mounted in housing 76 with its output shaft 86 oriented in a downward direction. A toothed sprocket 87 is fixed to output shaft 86. A speed reducer 89 is centrally located in housing 76 and suitably fixed therein with its input shaft 90 extending downwardly and lying substantially in the same vertical plane as output shaft 86 of motor 85. A toothed sprocket wheel 92 having twice the number of teeth as sprocket 87 is suitably fixed to input shaft 90 and lies in substantially the same plane as sprocket 87. A roller chain 93 operatively connects sprocket 87 and sprocket wheel 92. An output shaft 94 extends outwardly from an intermediate portion of speed reducer 89 and is transverse with respect to input shaft 90 and is suitably coupled thereto by a bevel gear arrangement, not shown, but of any well-known type. Output shaft 94 extends laterally outwardly of speed reducer 89 and has opposite outward portions 94a and 94b identically shaped and partially disposed externally of housing 76.

The following description pertains to arrangements of elements on the outward portions 94a and 94b of output shaft 94. The arrangement of elements is essentially identical for each portion 941: and 9412. Only one arrangement of elements will be described with the understanding that it pertains to both portions 94a and 94b. The drawings will clearly reflect this. Toothed drive sprockets 96 are suitably keyed to portions of output portion 94a of shaft 94 immediately adjacent speed reducer 89. Sheaves 97 in abutment with and outwardly of sprockets 96 are suitably rotatably mounted on outward portion 94a. Roller bearings 98 provide additional support for output shaft 94 and are supported on outward portion 94a outwardly of sheaves 97. Bearing housings fixed to portions of the walls of housing 76 suitably hold bearings 98. End covers 99 are bolted to the outer surface of bearing housings 95.

A pair of identically shaped idler shafts 100 extend transversely of input shaft 90 of speed reducer 89 and are disposed on either side of a lower portion of speed reducer 89 and lie in a common horizontal plane. The idler shafts 100 are fixed with respect to housing 76 by suitable means such as nuts 101 screwed into threaded end portions of the idler shafts 100. Identical toothed idler sprockets 102 are suitably rotatably mounted on portions of each of the idler shafts 100 on opposite sides of speed reducer 89. (i.e. there are four identical sprockets 102, two on each side of idler shaft 100). Identical idler sheaves 103 are rotatably mounted on portions of idler shafts 100 outwardly of idler sprockets 102. Idler sprockets 102 are identical in form with drive sprockets 96 and lie in substantially the same vertical plane therewith. Idler sheaves 103 are identical in form with drive sheaves 97 and also lie in substantially the same vertical plane therewith.

As shown in FIGURE 1, and partially in FIGURES 4 and 5 a pair of identical wire ropes 105 each having one end thereof suitably attached to each boss 70 on lower portion 60a of leg 60 extends upwardly of leg 60 to engage shaft 71 at the upper portion 61 of leg 60. Each wire rope 105 further extends from shaft 71 into housing 76 where it is reaved about the inner surface of one idler sheave 103, then around the upper surface of a drive sheave 97 and then downwardly about the inner surface of the other idler sheave 103 to outwardly of housing 76 to a boss 52 on a plate 51 of lever arm 50 where the other end of wire rope 105 is suitably connected with boss 52.

A pair of identical roller chains 107 follow the same path just described for wire ropes 105. That is, a chain 107 is suitably connected at one of its ends to boss 70, extends upwardly of leg 60, around shaft 71, into housing 76, reaved upwardly of an idler sprocket 102 and over a drive sprocket 96 to inwardly of another idler sprocket 102, then downwardly outwardly of housing 76 to a boss 52 where the other end of the roller chain 107 is suitably connected with a boss 52.

It should be noted that the above description with respect to the path followed by wire ropes 105 and roller chains 107 was made with reference to FIGURE 1 where the lifting tongs are oriented in a downward direction preparatory to grasping the coil of sheet steel 18.

The elements comprising the grappling arm portion 12 of lifting tongs are so arranged that the center of gravity of the mass of the assembly of these elements lies in a substantially vertical plane which passes through the center line of spool 80 in housing 76. Thus, the crane supports the lifting tongs 10 on its center of gravity line to thereby insure stability. This type of center of gravity arrangement, it might be added, is standard practice in the lifting tongs art.

In operation of the lifting tongs 10 shown in FIGURES l and 3 the tongs 10 are positioned over coil 18 with the grappling jaws 16 and 17 in an open position. The inner grappling jaw 16 is positioned to engage an inner portion of coil 18. Electric motor 35 is energized to rotate shaft 25 for moving outer grappling jaw 17 into engagement with an outer portion of coil 18. When the coil 18 is engaged by the grappling jaws 16 and 17 the lifting tongs 10 are raised by the crane to pivot arm 50 to mechanically apply the necessary gripping pressure on coil 18. The crane is then raised to elevate coil 18 above the floor level. The lifting tongs 10 can then be transported by the crane to a place where it is desired to tilt the coil 18. At this place motor 85 is energized to thereby drive sprockets 96 and drive sheaves 97. As viewed in FIGURE 1 the drive sprockets 96 and sheaves 97 are rotated clockwise. The wire ropes 105 and roller chains 107 are drawn upwardly along leg 60 of support arm 57 and into housing 76 and at the same time, the ropes 105 and chains 107 are paid out from housing 76 toward lever arm 50. The grappling arm portion 12 is thus tilted clockwise to the position shown in FIGURE 2 at which time the grappling jaws 16 and 17 can be opened and the coil 18 removed. The center of gravity of the grappling arm portion 12 remains substantially in the same vertical plane through all positions thereof between the positions shown in FIGURES 1 and 2, thereby insuring stability of the loaded tongs.

It should be also noted that when the grappling arm portion 12 is tilted to the position shown in FIGURE 2 the wire ropes and roller chains 107 engage the guide shaft 71 and are guided thereby downwardly along the leg 50a of lever arm 50. In both orientations of the grappling arm portions illustrated in FIGURES l and 2 the suspension provided by the wire ropes 105 and roller chains 107 are in a spread pattern with the center of gravity of the elements comprising the grappling arm portion 12 lying in a vertical plane disposed relatively midway of the spread pattern. Although the downward position of the lifting tongs 10 was described as the loading position, those skilled in this art will recognize that the sideward position can also be the loading position.

While I have shown and described a present preferred embodiment of the invention it is to be distinctly understood that the invention is not limited thereto but may otherwise be variously embodied.

I claim:

1. Lifting tongs comprising, a housing having an upper crane hook engaging portion; an elongated base member disposed below said housing and having its longitudinal axis lying in a substantially horizontal plane; a pair of opposed grappling jaw members supportedby said base member and extending downwardly therefrom, one of said jaw members being fixed intermediate the ends of said base member, the other of said jaw members being slidable with respect to said base member and disposed adjacent one end thereof; a reversible actuating means supported by said base member and operative with said slidable jaw member for selectively moving said slidable jaw member toward and away from said fixed jaw member for grasping and releasing material, respectively; a first support arm member supported by said base member and having at least an elongated first portion selectively adjustable in length and disposed outwardly of said one end of said base member; a second support arm member supported by said base member pivotedly connected at one part thereof to said slidable jaw member and having a second portion thereof disposed above said base member and adjacent the other end thereof; said members being arranged such that the center of gravity of the mass of the assembly of said members lies in a substan ially vertical plane passing through said hook engaging portion of said housing member; flexible elongated sling means supported in part in said housing and connected at its ends to said portions of said support arm members, respectively, for supporting said assembly above ground level; and power drive means supported in said housing and operatively arranged with said sling means for driving said sling means along the longitudinal axis thereof to tilt said assembly when suspended above ground level through a predetermined angular displacement such that said center of gravity remains substantially in said vertical plane at all positions of said assembly.

2. Lifting tongs as set forth in claim 1 wherein said first portion of said first support arm member is disposed in a generally vertical plane outwardly of said base member.

3. Lifting tongs as set forth in claim 1 wherein said first portion includes an upper section slidably arranged with respect to a lower section for adjusting the relative longitudinal position with respect to each other.

4. Lifting tongs as set forth in claim 3- including locking means for locking said lower and upper sections to each other.

5. Lifting tongs comprising, a housing having an upper crane hook engaging portion; an elongated base member disposed below said housing and having its longitudinal axis lying in a substantially horizontal plane; a pair of opposed grappling jaw members supported by said base member and extending downwardly therefrom, at least one of said jaw members being selectively movable toward and away from the other of said jaw members for grasping and releasing material, respectively; a support arm member supported by said base member and having an elongated first section selectively adjustable in length and disposed in a generally vertical plane adjacent one end of said base member, and an elongated second section disposed above said base member with one end thereof being adjacent the other end of said base member; said members being arranged such that the center of gravity of the mass of the assembly of said members lies in a substantially vertical plane passing through said hook engaging portion of said housing member; flexible elongated suspending means supported in part in said housing and connected at its ends to the ends of said first and second sections, respectively, for supporting said assembly above ground level; and power drive means supported above said housing and operatively arranged with said suspending means for driving said suspending means along the longitudinal axis thereof to tilt said assembly when suspended above ground level through a predetermined angular displacement such that said center of gravity remains substantially in said vertical plane at all positions of said assembly.

6. Lifting tongs as set forth in claim 5 wherein said first section includes an upper portion slidably arranged with References Cited UNITED STATES PATENTS 3,076,674 2/1963 Anderson 294l03 FOREIGN PATENTS 657,669 2/1963 Canada.

952,746 11/1956 Germany.

OTHER REFERENCES L. Bonnhoff: German printed application No, 1,169,- 632, May 1964.

EVON C. BLUNK, Primary Examiner.

ROBERT D. GUIOD, Assistant Examiner.

U.S. Cl. X.R.

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