US3001812A - Tongs - Google Patents

Description

Sept. 26, 1961 .1. R. ANDERSON TONGS 5 Sheets-Sheet 1 Filed Sept. 23, 1957 m .llw Urlil v Q q Q Q g 3 "u wh x L mm mm 86 v R ow ow 3 mm R km 8w Q Q .(sm b- NM Q Q Q .9 o

INVENTOR John R. Anderson 5/ /-//.s' A7'7OPNEKS Sept. 26, 1961 J. R. ANDERSON 3,001,812

TONGS Filed Sept. 23, 1957 5 Sheets-Sheet 2 INVENTOR John R. An derson 5) HAS ,dffOPA/EYJ,

Sept. 26, 1961 .1. R. ANDERSON TONGS 3 Sheets-Sheet 5 Filed Sept. 25, 1957 INVENTOR John R. Anderson 5/ HA? ATTOPNEyS, W W

United States Patent .3,001,812 TONGS John R. Anderson, Pittsburgh, Pa., 'assignor to Heppenstall Company, Pittsburgh, Pa., a corporation of Pennsylvania Filed Sept. 23, 1957, Ser. No. 685,595 7 Claims. (Cl. 294-437) This invention relates to linkage tongs adapted to handle loads of different sizes and shapes while said tongs maintain a relatively constant over-all height. More particularly, this invention pertains to such tongs constructed for motor operation and having unique features of adjustability, ease of operation and arrangement of forces markedly different from prior practices.

Different tongs of the general kind disclosed herein are described and claimed in United States patent application Serial No. 521,178, filed July 11, 1-955, now Patent No. 2,857,193 owned by the'assignee of the present invention. The present invention includes features, among others, which enable relatively efficient power drives to be readily used and operated from a distance remote from the tongs disclosed herein. Further, a relatively wider range of :the adjustability of lift arms of tongs disclosed herein and somewhat lower headroom are achievable, such being :of significant worth in many industrial plants. Still further, the .tongs of this invention employ new linkage elements which affect the diagram of forces in a manner to safeguard against any change in the position of the tongs when carrying loads. And, in constructions disclosed herein, the diiving forces may be relatively smaller for a given work load and the driving coupling is apportionable to the service in which the ton-gs is to be used. By using a dry coupling, the risk of leakage or overheating of fluid is eliminated and by using a ball screw and nut in certain embodiments the efiiciency of the new construction in the course 1 of operation is materially enhanced. This invention also enables a tongs to be .constructed'with multiple legs for the handling of loads of unusual length.

Other objects, features and advantages of this invention will be apparent from the following description and from the accompanying drawings, which are illustrative only, in which FIGURE 1 is a view of one embodiment of a new tongs of this invention, for carrying coils of'strip or other material, illustrated in front view and, almost fully closed condition;

FIGURE 2 is aside view of the embodiment shown in FIGURE 1 with the linkage in open-condition;

FIGURE 3 is a front view of the embodiment shown in FIGURES .1 and 2 with the linkage in open condi .tion;

FIGURE 4 is a view, .partly in section, taken along line IV-IV ofEIiGURE 3;

FIGURE Sis a side view, partly in section, ofa modified embodiment of this invention in open condition;

FIGURE 6 is a view taken along line W-VI .ofFIG- 'URE 5;

FIGURE 7 is a view taken along line VIIVII of FIGURE 6;

FIGURE 8 is a view of .a further embodimentof this invention having vmultiplelegs and utilizable to handle sheets or plates including those of larger size and FIGURE 9 is a front viewof the further embodiment illustrated in FIGURE 8.

.clevis space 12,:the upper endseof --which are joined by a spool vl3 .adap-tedtobe engaged, for example, by the :hook of a .crane of other .materials handling item of equipment. -A platform 14 is affixed to the side of head 11 and adjustable relative thereto toward and away from said head. A reversible electric motor 15 is fixed to platform 14 and adapted to drive belts 16 through a dry coupling 17, which may be one of the Flexidyne type, whenever motor 15 is energized. In such a Flexidyne coupling, the motor shaft spins a housing 18 having a predetermined quantity of steel shot therein which effects coupling with a rotor having a shaft keyed to a driving pulley 19 for the belts 16. The lower end of head 11 is drilled and fits around the top of a columnguide 20 to which it is secured by keys 21. An opening 22 in the side of head 11 enables the belt 16 to engage a driven pulley 23 fixed to the top of a vertical threaded operating shaft 24. The threads on shaft 24 are shaped to cooperate with a ball bearing nut 25 of the Saginaw type with the result that rotation of shaft 24 is performed in a relatively frictionless manner relative to its nut 25 and the power efiiciency of the new construction is correspondingly advanced.

Nut 25 is fixedly held by a crosshead 26 extending across the interior of hollow column 20. Column 20 is rovided with slots 27 in registry, which slots are slidably engaged by runners 28 of the crosshead 25. An upper yoke 29 surrounding column 20 is keyed to crosshead 26 by keys 30. The keys 30 also constitute the pivots for the linkage elements of the tongs 10. A lower frame or yoke member 31 is fastened to the bottom of column 20 by keys 32 which also serve as the central pivots for the lower end of such new linkage. A thrust bearing 33 is mounted in the lower end of column 20 and serves as a bearing for the lower stub shaft end of shaft 24, the screw thread and stub shaft parts of which are provided with a coupling 34. A magnetic brake 35 is positioned at the lower end of shaft 24 within the sides of a depending work rest 36 secured to yoke 31 and column 20. Brake 35 preferably is electrically released and spring applied and in the circuit of motor 15 so that upon ,energization of motor 15 brake 3511's released, and, vice versa.

The new linkage in tongs 10 is duplicated in mirror fashion on the front side and on the back side. Further, the new linkage is symmetrical to the left and right side, in mirror fashion, of the median longitudinal plane through the axis'of column 20 perpendicular to the plane of the paper on which FIGURE 3 appears. The linkage elements to each side of such median plane are suitably connected by longitudinally extending spacers and bars to provide the desired rigidity of structure in the course of operation. Such linkage includes, on the front and back, a pair of outwardly and downwardly extending main levers 37, the upper ends of which are pivoted in registry about the axis of the pivots 30 and the lower ends of which are pivoted to lift arms 38 at 39. Strut members 40 are upwardly and outwardly extending and are pivoted at their lower ends in registry about the axis of the pivots 32. The upper ends of the respective struts 40 are pivoted at 41 to the levers 37. Each strut to each side and on the front and back comprises two parallel portions spaced by spacers 42 a distance sufficient to span the particular lever 37 to which they are pivotally connected. The inner strut element 40a in each such pair is provided with a projecting end 4%. Such projecting ends 40b are pivotally connected by links 43 to the upper extension 380 of the lift arms 38. In this way, the forces operative upon tongs It in the course of carrying or handling a load inhibit the tendency for the load to try to spring such arms apart by a wedging action against the opposed load supporting steps 44 on opposite sides of the tongs. Further, such new linkage enables the lift arms 38 to come closer to column 20, as indicated in FIGURE 1, Where the tongs is shown in almost fully closed position. Fully closed position would occur when the arm plates 4-5 abut the sides 46 of rest 36. It should be noted too that the linkage elements are straight from the central pivots thereof to the pivotal connections with the lift arms.

In operation, when a load of 47 is to be engaged, the tongs may be opened by rotating shaft 24 to drive yoke 29 toward yoke 31 until the tongs can be lowered to span the load, as shown in FIGURE 3, and, if desired, may be allowed to rest on the load to be supported in part through the engagement of rest 36 with the top of coil 47. Thereupon, the motor 15 is energized releasing brake 35 so as to turn shaft 24 in a direction which will raise yoke 29 on column 20 until the plates 45 come against the ends of coil 47, whereupon motor 15 is deenergized and brake 35 automatically reapplied so that upon the lifting of head 11, tongs 10 will transport coil 47 to any location desired. In the closing movement of tongs 1t), moreover, even if motor 15 should not be shut off, the setting of the Flexidyne coupling 17 can be made such that upon a predetermined overload the rotor therein will slip and stop turning the belt 16 although it will continue to keep the closing pressure of the lift arms 38 against the load 47 and constitute a safe tongs even though the brake 35 has not been reapplied because the power to motor 15 has not been shut off. After coil 47 is transported to its new location, the tongs 10 are opened and are then ready for a new materials handling operation.

A modified embodiment of this invention is illustrated in FIGURES to 7 and parts thereof corresponding generally in construction and functioning to parts in the embodiment shown in FIGURES l to 4, inclusive, are marked with the same reference numerals with the addition of a prime accent thereto. In such modified embodiment of FIGURES 5 to 7, a pair of longitudinally spaced columns 20 are provided so that shaft 24' may be centrally positioned between such columns. Further, motor 15 is mounted adjacent the lower portion of shaft 24 with a saving in headroom, which is of importance in many industrial plants. The crosshead 26' in the case of the FIGURE 5 embodiment is fixed to and extends between the respective front and back parts of such yoke 29'. The coupling 34 is, however, made flexible in order to accommodate any tendency for the axis of the shaft to be subjected to bending forces in the course of the operation of tongs Still further, provision is made in the modified embodiment of FIGURES 5 to 7 for the counterweighting of the linkage and upper yoke 29', which upper yoke 29 is guided by both columns 20' extending through spaced vertical openings in yoke 29'. Cables 43 extend over respective pulley 49 pivotally mounted in head 11 and are connected at their other ends to counterweights 50 within the hollow interior of the respective columns 20. The effective weight and the steadiness of such counterweights 50 may be increased by springs 51 in compression and extending between the tops of the interiors of the columns 20 and the upper portions of the counterweights 50, as shown in FIGURE 5. The linkage of the modified embodiment of FIGURES 5 to 7 and the operation thereof is essentially the same as that hereinabove described in connection with the embodiment of FIGURES l to 4.

By means of this invention, a multi-legged tongs may be provided as illustrated by the further embodiment 52 of FIGURES 8 and 9 suitable for the handling and lifting of strips, sheets and plates including those of relatively long and wide character. Such further embodiment 52 is also a tongs of relatively lower headroom and the application of its gripping upon a load to be carried is uniform and effective. It employs the unique linkage hereinabove described in connection with the prior embodiments set forth in this application. In tongs 52, a longitudinally extending upper box beam 53 and a longitudinally extending lower box beam 54 are provided in vertical registry. Main columns 55 at the front and back ends extend between such beams and are rigidly connected thereto. Auxiliary columns 56 are provided between the columns 55 and the columns 56 are also rigidly connected top and bottom to the beams 53 and 54 re spectively. A clevis 57 is afiixed centrally to the upper portion of beam 53 and straps 58 may extend from clevis 57 to the respective ends of beam 53 to aid in load support distribution when a loaded tongs 52 is being moved. Main sleeves 59 are adapted to travel up and down in horizontal and vertical registry with one another on the respective columns 55, as are the auxiliary sleeves 60 on the respective auxiliary columns 56.

As shown in FIGURE 9, an outwardly facing set of links 62 to each side is provided in pivotal connection between the sleeves 59 which correspond to the movable upper yoke of the previously described embodiments and the fixed members 61 at the ends of beam 54. Members 61 in turn correspond to the lower yoke members previously described in connection with the other illustrated embodiments. Inwardly facing sets of links 63 are connected between upper yoke members in the form of auxiliary sleeves 60 and lower yoke members 64 connected to the bottom of columns 56 and beam 54 as shown. The respective linkages at each of the columns are in horizontal registry as shown in FIGURE 9 and operate together when tongs 52 is operated.

The lift arms 65 to each side of the tongs 52 comprise a lattice structural frame having a load supporting step and lip 66 extendingfor the full length of the tongs and projecting beyond the ends thereof in the illustrated further embodiment. Such lattice is longitudinally bound together at the top, also on each side, by an angle 73 and in like manner a spacing bar 74 is provided along the axis of the pivot between the connecting links 75 and the extensions 76 of the lift arms 65 to each side of tongs 52. The headroom of tongs 52 may be made lower by mounting the power operator on an adjustable height platform 67 on beam 54 and between the columns 56. Such power operator may comprise an electric motor 68 having a Flexidyne coupling 69 to a speed reducer 70 and a drive sprocket 71. A magnetic brake 72 is also mounted on platform 67 and operate upon the rotor or driven shaft of the Flexidyne coupling. In that way the motor can come up to speed with relatively light loading and when the power is cut off, the motor can lose speed and decelerate in a normal manner since the spring applied brake of brake mechanism 72 is on the driven side of such coupling.

A longitudinal shaft 77 is mounted in pillow block bearings 78 within the interior of box beam 54. A driven sprocket 79 is driven by driving sprocket 71 through a roller chain connection 80. Rotation of shaft 77 by sprocket 79 will correspondingly rotate the sprockets 81 at the respective ends of shaft 77. Each of the sprockets 81 is in vertical alignment with an upper sprocket 82 pivotally mounted on a countershaft within upper beam 53. A roller chain 83 engages the respective sets of sprockets 81 and 82 at each of the respective ends of tongs 52 with the free ends of each chain being adjustably anchored in the lugs 84 and 85 respectively on each of the sleeves 59. Hence, each sleeve 59 becomes a link to complete an endless chain 83 so that as the shaft 77 is rotated in counterclockwise direction, as viewed in FIGURE 9, the upper sprockets 82 will also be rotated in counterclockwise direction and the sleeves 59 will be raised in synchronism. Such raising of the sleeves 59 will raise the passive auxiliary sleeves 60 in synchronism therewith because of the linkage registry connections thereto respectively until the tongs has been closed to the desired extent upon a load or for other purpose. When the tongs 52 is in closed or partially closed condition, rotation of the shaft 77 in a clockwise direction will move the tongs in an opening direction. Such movement is occasioned by the energization of motor 68 and when such motor is energized, as described above, the brake 72 is released until spring applied 'upon the de-energization of such motor. 'Beams 53 and54 are provided with appropriate openings for the passage of the roller chains 83.

Various modifications may be made in aspects of the illustrated embodiment of my invention and in other embodiments without departing from the spirit thereof or the scope of the appended claims.

I claim:

1. In a tongs, apparatus comprising, in combination, a head, a guide column connected to said head and extending below the same, an operating shaft having ball receiving threads extending parallel to said column, an upper yoke movable by said shaft vertically along said column in guided relation thereto, a ball nut engaging said threads and connected to said yoke to move it when said operating shaft is rotated, an electric motor mounted on said tongs, a dry fluid flexible coupling connected between said motor and said shaft, a magnetic brake on the driven side of said coupling operatively connected to said shaft to hold it in unmovable position when said motor is de-energized, a lower yoke member connected to said column, symmetrical linkage extending to each side of said tongs and pivotally connected at the upper and lower central portions thereof to said upper and lower yoke members respectively, two laterally downwardly and outwardly extending levers in said linkage pivotally connected together at the upper ends thereof to the center of said upper yoke, generally vertical lift arms pivotally connected to the lower portions of said levers respectively, strut members extending laterally outwardly and upwardly and pivotally connected at the lower ends thereof to the center of said lower yoke member, the upper ends of said struts being pivotally connected to the-central portions of said levers respectively, said lift arms having extensions above the pivotal connections with said levers respectively, said struts having projecting ends above the pivotal connections with said levers respectively, and links pivotally connecting said projections of said struts and said extensions on said lift arms respectively, said links extending generally in the direction of said levers respectively.

2. In a tongs, apparatus comprising, in combination, a head, a guide column connected to said head and extending below the same, an operating shaft having threads extending parallel to said column, an upper yoke movable by said shaft vertically along said column in guided relation thereto, a nut engaging said threads and connected to said yoke to move it when said operating shaft is rotated, an electric motor mounted on said tongs, a friction coupling connected between said motor and said shaft and adapted to engage fully substantially at operating speeds of said motor, a brake operatively connected to said shaft to hold it in unmovable position when said motor is de-energized, a lower yoke member connected to said column, symmetrical linkage extending to each side of said tongs and pivotally connected at the upper and lower central portions thereof to said upper and lower yoke members respectively, two laterally downwardly and outwardly extending levers in said linkage pivotally connected together at the upper ends thereof to the center of said upper yoke, generally vertical lift arms pivotally connected to the lower portions of said levers respectively, strut members extending laterally outwardly and upwardly and pivotally connected at the lower ends thereof to the center of said lower yoke member, the upper ends of said struts being pivotally connected to the central portions of said levers respectively, said lift arms having extensions above the pivotal connections with said levers respectively, said struts having projecting ends above the pivotal connections with said levers respectively, and links pivotally connecting said projections of said struts and said extensions on said lift arms respectively.

3, In a tongs, apparatus comprising, in combination,

arframe including a vertically extending column, a-screw shaft extending parallel tosaid column, amotor mounted on said tongs in fixed relation to said column, a low starting torque and fast releasing coupling operatively connected between said motor and said shaft, a brake on the driven side of said coupling operatively connected to .saidtshaft to hold it unmoved when said motor is stopped, a sleeve member operatively connected to said shaft andtmovable up and down on said column by the rotation of'said shaft, symmetrical linkage extending to each side of said tongs and pivotally connected at the upper and lower central portions thereof to said sleeve member 'and lower portion of said frame respectively, two laterallydownwardly and outwardly extending levers in said linkage'pivotally connected at the upper portions thereof to said sleeve, lift arms pivotally connected to the lower'portions of said levers respectively, two laterally upwardly and outwardly extending strut members pivotally connected at the lower portions thereof to said frame below said sleeve, the upper portions of said strut members being pivotally connected to intermediate potrions of said levers respectively, said strut members having projecting ends extending above the pivotal connection with said levers respectively, said lift arms having extensions extending above the pivotal connections with said levers respectively, and links pivotally connecting said projecting ends and said extensions respectively.

4. In a tongs, apparatus comprising, in combination, a plurality of vertically extending horizontally aligned and spaced columns connected together at the tops and bottoms thereof, sleeve mechanism extending between said columns for guidance thereby and movable up and down thereon, a shaft operatively connected to said sleeve mechanism and adapted to be rotated to move said sleeve mechanism, sets of symmetrical linkage extending to .each side of a plane defined'by the axes of said columns, said set of linkage being in horizontal alignment and connected together for synchronous movement, laterally downwardly and outwardly extending levers insaid linkage pivotally connected at the upper ends thereof'to said sleeve mechanism, .latera'lly'upwardly .and outwardly extending struts pivotally connected at the lower ends thereof to the lower ends of said columns and pivotally connected at the upper ends thereof respectively to intermediate portions of said levers, lift members pivotally connected to the lower ends of said levers and extending downwardly therefrom, said struts having upwardly projecting ends, said lift members having upwardly projecting extensions, and compression links pivotally connecting the projecting ends of said struts and lift members above said levers to each side of said plane respectively.

5. In a tongs, apparatus comprising, in combination, a pair of vertically extending horizontally spaced columns connected together at the top and bottom thereof, a yoke member extending between said columns for guidance thereby and movable up and down thereon, a screw shaft positioned between said columns, operatively connected to said yoke member and adapted to be rotated to move said yoke member, an electric motor adjustably mounted and fixedly connected to the side of said columns and adjacent the lower ends thereof and of said shaft, symmetrical linkage extending to each side of a plane defined by the axes of said columns, laterally downwardly and outwardly extending levers in said linkage pivotally connected at the upper ends thereof about a common axis to said yoke member, laterally upwardly and outwardly extending struts pivotally connected at the lower ends thereof to the lower ends of said columns about a common axis and pivotally connected at the upper ends thereof respectively to intermediate portions of said levers, lift members pivotally connected to the lower ends of said levers and depending therefrom, said struts having upwardly projecting ends, said lift members having upwardly projecting extensions, and co pression links pivotally connecting the projecting ends 7 of said struts and lift members above said levers to each side of said plane respectively.

6. In a tongs, apparatus comprising, in combination, a plurality of horizontally aligned vertically extending guides, upper and lower longitudinally extending beams rigidly connected to the tops and bottoms of said guides respectively, slidable members on each of said guides adapted to move up and down thereon in synchronism, downwardly and laterally outwardly extending levers pivoted to each of said slidable members and extending to each side of said tongs respectively, upwardly and lateral- 1y outwardly extending struts pivotally connected to said lower beam adjacent the bottoms of said guides respectively and extending to each side of said tongs respectively, said struts having their upper ends generally in the plane of and connected to the central portion of said levers respectively, load carrying arms pivotally connected to the outer ends of said levers on each side of said tongs, all of said load carrying arms being rigidly horizontally connected on each of said sides respectively, said struts and load carrying anms having portions projecting above their respective pivotal connections with said respective levers, and compression links extending generally in the direction of the adjacent levers pivotally connecting said projections respectively, said levers, struts and links adjacent each of said guides comprising a set of linkage, said sets of linkage being in horizontal registry, a motor and brake assembly mounted on said lower beam adjacent the center thereof and in longitudinally extending fashion, a longitudinally extending sprocket shaft mounted on said lower beam and adapted to be rotated in a predetermined direction by said assembly when said motor is energized and to be held against movement by said brake when said motor is not energized, sprockets mounted in said upper beam adjacent certain of said slidable members and in vertical registry with said sprocket shaft, endless chains engaging said sprockets in vertical registry respectively, said slidable members adjacent to said chains comprising the closing links for said chains respectively, whereby when said sprocket shaft is rotated said load carrying arms will open and close without significant change in vertical position in accordance with movements of said slidable members and said registering linkages.

7. In a tongs, apparatus comprising, in combination, at least one vertically extending column, sleeve mechanism guidedly connected to said column and relatively movable up and down thereon, drive means operatively connected between said column and sleeve mechanism for such relative movement, a set of symmetrical linkage extending at right angles to a vertical plane passing through the axis of said column, laterally downwardly and outwardly extending levers in said linkage pivotally connected at the upper portion thereof to said sleeve mechanism, laterally upwardly and outwardly extending struts pivotally connected at the lower portions thereof to the lower portion of said column and pivotally connected at the upper portions thereof to intermediate portions of said levers respectively, lift members pivotally connected to the lower portions of said levers and extending downwardly therefrom, said struts having upwardly projecting portions, said lift members having upwardly projecting portions, and links pivotally connecting the projecting portions of said struts and lift members above said levers respectively, each said link in operation being under compression.

References Cited in the file of this patent UNITED STATES PATENTS 1,652,013 Jones et a1. Dec. 6, 1927 1,733,084 Schmidt Oct. 22, 1929 1,990,673 Shaughnessy Feb. 12, 1935 2,063,684 Kloos Dec. 8, 1936 2,229,800 Dean Ian. 28, 1941 2,579,539 Blaire Dec. 25, 1951 2,821,317 Locke Jan. 28, 1958 2,857,193 Heppenstall Oct. 21, 1958 FOREIGN PATENTS 938,985 Germany Feb. 9, 1956 Attesting Officer UNITED STATES PATENT. OFFICE CERTIFICATE OF CORRECTION Patent No. 3,001,812 September 26 1961 I John R. Anderson It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 3, line 6 strike out "of"; column 4. line 43,

for "operate" read operative column 6, line 22, for "potrions" read portions column 7, lines 36 and 37 for "sprocket shaft," read sprockets on said sprocket shaft,

Signed and sealed this 6th day of March 1962,

(SEAL) Attest:

ERNEST W. SWIDER DAVID L. LADD Commissioner of Patents

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