US3040921A

US3040921A - Plate handling apparatus

Info

Publication number: US3040921A
Application number: US742767A
Authority: US
Inventors: Floyd E Davis
Original assignee: United States Steel Corp
Current assignee: United States Steel Corp
Priority date: 1958-06-18
Filing date: 1958-06-18
Publication date: 1962-06-26
Anticipated expiration: 1979-06-26

Description

June 26, 1962 Filed June 18, 1958 F. E. DAVIS PLATE HANDLING APPARATUS 2 Sheets-Sheet l from/EY June 26, 1962 F, E, DAVIS 3,040,921

PLATE HANDLING APPARATUS Filed June 18, 1958 2 Shee's-Sheei'I 2 /4 2 f 4 G i o INVENTOR.

1.19 f-zayo f. @4V/s BY -6 f 2 mig@ Wrap/Vey United States Patent 3,040,921 PLATE HANDLENG APPARATUS Floyd E. Davis, Gary, Indi, assigner to United States Steel QQrporation, a corporation of NewI Jersey Filed .lune 18, 1958, Ser. No. 742,767 6 Claims. (Cl. 214-4558) This invention relates to an apparatus for handling plates and, in particular, to an apparatus that can be used to turn plates in addition to lifting them for transporting movement by a travelling crane. ln a preferred embodiment such apparatus is especially adapted for lifting and turning steel plates and uses electromagnets as plate gripping members for this purpose.

Electromagnets supported from 'the hooks of travelling cranes are commonly employed for transporting heavy steel plates, such as armor-plate and the like, in mills and in yards or other storage facilities. However, `conventional arrangements of lifting magnets of this character are not suitable for turning plates when it is necessary to inspect the bottom surfaces thereof. In such case the usual practice is to wrap or loop a chain about the plate to be turned in such manner that it will tilt the plate to a vertical position when the free end of the chain is pulled upwardly by the hook of a travelling crane. Plate turning operations of this character are not only time consuming and costly, but in addition subject operators to hazardous working conditions.

One of the objects of this invention is to provide au apparatus that will eliminate danger to operators and which will expedite and reduce the cost of plate turning operations. A further object is to provide an improved arrangement lof electro-magnetic handling apparatus that can be safely operated by the hook of a travelling crane to both transport and turn heavy steel plates. To these and related ends, the apparatus of this invention, generally stated, comprises a pair of magnets that are mounted for rotational movement about parallel and horizontal aXes, a linkage system interconnecting the magnets for simultaneous movement in opposite rotational directions, and a supporting frame adapted for suspension from the hook of a travelling crane. In a manner to be described, both magnets may have initial engagement with the saine side of a plate in a central area thereof for a plate transporting operation, or a single magnet may be initially engaged with one side of a plate adjacent an edge thereof to begin a turning operation, which is thereafter con tinued by engagement of the other magnet with an opposite side of the plate after it Ihas been lifted and turned to a vertical position, and then completed by lowering the plate to a `horizontal position.

Other objects and advantages of the invention will becorne apparent from the following description.

In the drawings, there is shown a preferred embodiment of the apparatus of this invention. In this showing:

FIGURE l is a side elevational view showing a pair of plate gripping magnets and an interconnecting linkage system therefor in the relative positions which they occupy after operation to tuin a plate to an intermediate turning position in which it is arranged in a vertical plane;

`FIGURE 2 is an elevational View taken in a `direction looking from the right of FIGURE l;

FIGURE 3 shows the apparatus suspended from a crane hook and in an unloaded condition;

FIGURE 4 shows the apparatus in an initial or iinal plate engaging position; and

FIGURE 5 is a fragmentary view showing the lifting magnets in an intermediate position during lowering movement from the position shown in FIGURE l to complete a plate turning operation.

The apparatus of this invention comprises a pair of 3,ll4ll,921 Patented .lune Z6, 1962 ICC electromagnets 1 and 2 which are respectively supported on a frame 3 for rotational movement about parallel horizontal axes that are defined by pivot pins 4. A linkage system 5 interconnects the magnets 1 and 2 `for simultaneous rotational movement in opposite rotational directions about the pivots 4 in a manner' and for a purpose to be described. The magnets 1 and 2 are adapted to be energized independently of cach other by suitable controls not shown in the cab of the travelling crane from which the apparatus is suspended and, for this purpose, are provided with separate energizing cables 6.

Asbest shown in FIGURES l and 2, the frame 3 comprises a pair of laterally spaced T-shaped side members 7 which are arranged in inverted positions in which they respectively provide a horizontal base member 8 and a vertical member 9 projecting upwardly from the center of the base member 8. The side members 7 are held in rigidly spaced relation by a cross-'bar 1li which has opposite ends thereof rigidly secured to the upper ends 11 of the vertical members 9. A clevis 12 pivotally connected to the center of the cross-bar 10 provides for suspension of the apparatus from the crane hook 13` of a travelling crane (not shown). The magnets 1 and 2 are each suspended from the frame 3 by two pairs of links 14 that are respectively arranged on opposite sides of the base member 3 and have pivot connections 15 at their upper ends to the outer ends 16 of the horizontal base member 8, the lower ends of the links 14 being connected with the magnets 1 and 2 by the pivots 4 mentioned above. The base member outer ends 16 have additional pivot openings 17 `for the pivots 15 which provide an adjustment for a puipose to be described.

The linkage system 5 comprises a pair of identical motion controlling and transmitting linkages, which are respectively in the nature of and provide the action of a pantogra'ph or quadric-crank linkage, at opposite ends of the magnets 1 and 2. Each of these linkages comprises a pair of motion transmitting links 20 and a pair of motion controlling links 21. The links 20 have their outer ends connected by pivots 22 to the magnets 1 and 2 respectively, which are located at points outwardly with respect to the supporting pivots 4 about which the magnets 1 and 2 have rotational movement. The inner ends of the links 2t) are connected by a common pivot 23 which is mounted for guided rectilinear movement in a slot 24 extending vertically and centrally of the side member leg 9. The motion controlling links 21 have their inner ends connected by a common pivot Z5 which is mounted for guided rectilinear movement in a vertical slot 26 in the leg 9 at a point below the slot 2li. The outer ends of the links 21 are connected by pivots 27 to the levers 20 at points that are equally spaced with respect to the common pivot 23. The linkage S, as described above, provides the action of a pantograph and operates to impart equal angular movement to the magnets 1 and 2, but in opposite directions.

FIGURE 3 shows the parts of the apparatus in the positions which they occupy when it is not supporting a plate and is suspended from a crane hook 13. Under this condition, the common pivot 23 is at the lower end of the guide slot 24 and the pivot 2Sl is arranged between the ends of the guided slot 26. The magnets 1 and 2 as shown in FIGURE 3 occupy positions inclined at equal angles with respect to a vertical center plane containing the axes of the

common pivots

23 and 25.

When a plate handling operation is to be performed, the apparatus is lowered to engage the magnets with a plate to be moved thereby. If the plate is to |be lifted and transported by the crane hook 13, each of the magnets 1 and 2 is engaged with the plate in a central area thereof. In the event that the apparatus is to be used to turn a plate, then only one of the magnets is engaged with the plate to `be turned, and such engagement is made in an area adjacent an edge of the plate. FIGURE 4 of the drawings shows the manner in which the magnet 2 is engaged with a plate P preliminary to a plate turning operation.

When the apparatus is lowered from the position shown in FIGURE 3 to engage a plate P, either or both of the magnets engage 'with the upper surface of the plate and are rotated into the horizontal position shown in FIG- URE 4 upon continued lowering movement of the crane hook 13. If only one of the magnets is engaged with the plate, as in the case of the magnet 2 in FIGURE 4, then the linkage system S operates to pivot the other mag. net to horizontal position. As 'both magnets move to their horizontal position, the

common pivots

23 and 25 move to the upper ends of

ti e slots

24 and 26 as shown in FIGURE 4.

Operation of the apparatus to turn `a plate P over is effected by lowering the crane hook 13 to engage one of the magnets adjacent an outer edge of the plate P as shown in connection with the magnet 2 in FIGURE 4. The magnet Z is then energized and the crane hook 13 is pulled upwardly to raise the frame 3. As the frame 3 moves upwardly in this manner, the parts of the linkage system and the magnets 1 and 2 move to the relative positions shown in FIGURE 3 and finally to the position shown in FIGURE 1 in which the plate P is suspended in the vertical plane containing the axes of the

common pivot pins

23 and 25 of the link system 5. In this position, the

pins

23 and 25 are respectively positioned at the bottoms of the

guide slots

24 and 26, and the magnets l and 2 are each arranged in ventical planes in which they face each other and engage opposite sides of the plate P. When this position is reached, the magnet is energized to hold it in engagement with the plate P and the magnet 2 is deenergized. The crane hook i3 is then lowered and during this lowering movement the plate P adheres to the magnet 1 so that when it is lowered into contact with the surface of the ground the bottom edge of the plate P will engage the ground surface with a rolling action that will cause the magnet `1 and the plate P to swing out to the position shown in `FIGURE 5. As this lowering movement is continued, the magnet ll will pivot to a horizontal position as shown in FIGURE 4 in which the position of the plate P is reversed and has an opposite surface thereof facing upwardly. As this lowering movement takes place, the magnet 1 and plate P move through the relative positions shown in 4FIGURE 5.

When the apparatus is to be used for handling plates P of greater thickness, the pivot pins 15 are inserted in the openings 17 to provide a greater spacing of the links 14 and of the magnets i and 2 upon pivotal movement to the vertical plate holding position shown in FIGURE 1.

yFrom the foregoing, it will be apparent that the apparatus of this invention may be readily operated/ to lift and transport a plate or to turn it over `for inspection of both sides thereof. Attention is particularly directed to the fact that the rotational movement of the magnets 1 and 2 that takes place during turning a plate over are effected entirely by gravitational force due to the weight of the magnets and the plate yP. Attention is further directed to the fact that all par-ts of the `apparatus are arranged symmetrically with respect to a vertical center plane of the frame 3 which contains the axes of the

pantograph pivots

23 and 25. In this respect, it will be further noted that the action of the common linkage 5 in connecting the magnets 1 and 2 is essentially that of a pantograph and insures simultaneous rotation of the magnets 1 and 2 in opposite rotational directions during movement between the intermediate Vertical position thereof shown in FIG- URE v1 and the iinal or initial horizontal lift positions shown in FIGURE 4.

While one embodiment of my invention has been shown and described it will be apparent that other adaptations and modifications may be made without departing from the scope of the following claims.

I claim:

l. In an apparatus for lifting and turning plates, a supporting frame comprising a pair of laterally spaced T-shaped side members arranged in inverted positions respectively providing `a horizontal base member and a vertical member projecting upwardly from the center of said base member, a cross-bar extending between the upper ends of said vertical members, and a clevis at the center of said cross-bar for suspension from a crane hook, a pair of plate gripping members respectively arranged in positions extending between the outer ends of said base members and parallel to each other and to said cross-bar, supporting links at opposite ends of each of said gripping members respectively having pivotal connections at their upper ends with one of said base member ends and pivotal connections at their lower ends with one of said gripping members, and an identical linkage system associated with each of said side members comprising a pair of motion transmitting links having pivotal con* nections at their outer ends with said gripping members and a common pivotal connection at their inner ends, a second pair of motion transmitting links respectively having pivotal connections at their outer ends with one of said rst pair of links and a common pivotal connection at their inner ends, said common pivotal connections being spaced vertically relative to each other and having axes lying in a vertical plane with respect to which the links in each of said pairs `and said gripping members have a symmetric arrangement, and means mounting each of said common pivotal connections on said vertical members for guided rectilinear movement in said vertical plane.

2. In an apparatus for lifting and turning plates, a supporting frame comprising a T-shaped side member arranged in an inverted position providing a horizontal base member and a vertical member projecting upwardly from the center of said base member, a pair of plate gripping members, a pair of supporting links having pivotal connections respectively at their upper ends with opposite ends of said base member and pivotal connections at their lower ends with said gripping members, and a linkage system comprising a pair of motion transmitting links having pivotal connections at their outer ends with said gripping members and a common pivotal connection at their inner ends, `a second pair of motion transmitting links respectively having pivotal connections at their outer ends with one of said rst pair of links and a common pivotal connection at their inner ends, said common pivotal connections being spaced vertically relative to each other and having axes lying in a vertical plane with respect to which the links in each of said pairs and said gripping members have a symmetric arrangement, and means mounting each of said common pivotal connections on said vertical member for guided rectilinear movement in said vertical plane.

3. In an apparatus for lifting and turning plates, a supporting frame adapted to be suspended from a crane hook, a pair of plate gripping members, a pair of horizontally spaced pivots mounting said gripping members for swinging movement about parallel axes, means sup porting each of said pivots on said frame for limited movement relative thereto, and a linkage system comprising a pair of motion transmitting links having pivotal connections at their outer ends with said gripping members and a common pivotal connection at their inner ends, a second pair of motion transmitting links respectively having pivotal connections at their outer ends with one of said first pair of links `and a common pivotal connection at their inner ends, said common pivotal connections being spaced vertically relative to each other and having axes lying in a vertical plane with respect to which the links in each of said pairs and said gripping members have a symmetric arrangement, and means mounting each of said common pivotal connections on said frame for glided rectilinear movement in said vertical plane.

4. A lifting and turning `apparatus as defined in claim 3 characterized by said pivot supporting means comprising a pair of mounting links having horizontally spaced pivotal connect-ions at their upper ends with said supporting frame, and by said gripping member mounting pivots being mounted respectively on the lower ends of said mounting links.

5. In an apparatus for lifting and turning s-teel plates, a supporting frame adapted to be suspended from a crane hook, a pair of electromagnets respectively having surfaces for magnetic engagement with steel plate to be handled thereby, and means supporting said electromagnets on said frame for rotational movement about spaced horizontal axes from vertical positions in which their said surfaces are in facing relation and are spaced apart a disstance corresponding to the thickness of said steel plate to horizontal positions in which their said surfaces are arranged in a common horizontal plane, and a linkage system interconnecting said electromagnets Afor simultaneous rotational movement in opposite rotational directions between said vertical and horizontal positions comprising a pair of motion .transmitting links having pivotal connections at their outer ends with said electromagnets and a common pivotal connection at their inner ends, a second pair of motion transmitting links respectively having pivotal connections at .theirouter ends with one of said rst pair of links and a common pivotal connection lat their inner ends, said common pivotal connections being spaced vertically relative to each other and having axes lying in a vertical plane with respect to which the links in each of said pairs and said electromagnets having a symmetric arrangement, and means mounting each of said common pivotal connections on said frame for guided rectilinear movement in said vertical plane.

6. A plate turning and lifting apparatus kas dened in claim 5 characterized by said electromagnet supporting means comprising a pair of mounting links having horizontally spaced pivotal connections at their upper ends with said supporting frame, and by said electromagnets respectively having pivotal supporting connections on the lower ends of said mounting links.

References Cited in the le of this patent UNITED STATES PATENTS 1,333,424 Kirk Mar, 9, 1920 1,792,576 Dryon Feb. 17, 1931 1,941,064 Wendt Dec. 26, 1933 2,131,869 Burrell Oct. 4, 1938 2,616,574 Johanson Nov. 4, 1952 FOREIGN PATENTS 695,420 France Dec. 16, 1930