FIELD

[0001] The invention relates to the field of overhead cranes.

BACKGROUND

[0002] The handling of products in warehouses has been highly automated. However, for whatever reason, one area wherein automation has made limited inroads is in the handling of heavy steel plates and palleted coils.

SUMMARY OF THE INVENTION

[0003] Forming one aspect of the invention is apparatus for use with an overhead crane.

[0004] The overhead crane is of the type having: a pair of runway beams each having an end truck mounted thereto for translational movement; a bridge frame connecting the end trucks; a trolley mounted to the bridge frame for movement therealong; a winch arrangement connected to the trolley; and a wire rope arrangement extending from the winch arrangement.

[0005] The apparatus comprises a pair of stabilizing bars, a sheave arrangement, a frame, a pair of sleeves, a pair of lifting arms and a pair of guide arms.

[0006] The stabilizing bars project downwardly from the trolley.

[0007] The sheave arrangement, in use, has the wire rope arrangement passing therethough use and is suspended thereby.

[0008] The frame is suspended from the sheave arrangement.

[0009] The sleeves project upwardly from the frame and are adapted such that, upon retraction of the wire rope, the sleeves are engaged by the stabilizing bars. [0010] The lifting arms project downwardly from the frame, are spaced apart from one another along a principal axis that is horizontal and are mounted for movement along the principal axis between: an extended position whereat the lifting arms are relatively distal to one another; and a retracted position whereat the lifting arms are relatively proximal to one another.

[0011] The guide arms project downwardly from the frame, are spaced apart from one another along a secondary axis that is horizontal and perpendicular to the principal axis and are mounted for movement therealong between: an extended position whereat the guide arms are relatively distal to one another; and a retracted position whereat the guide arms are relatively proximal to one another.

[0011] According to another aspect of the invention, the lifting arms can terminate in a pair of reentrant lips.

[0012] According to another aspect of the invention: the lifting arms can project downwardly beyond the guide arms; the lifting arms can be adapted to support the underside of a pallet for transport by the crane; and the guide arms can be adapted to support a product borne by the pallet against tipping during transport.

[0013] According to another aspect of the invention, the sleeves can be spaced apart from one another in the direction of the secondary axis.

[0014] According to another aspect of the invention, each guide arm can terminate in a lip, the lips of the guide arms being adapted to assume a reentrant position. [0015] According to another aspect of the invention: the lifting arms can be adapted to support the underside of a plate for transport by the crane; and the lips of the guide arms, when in the reentrant position, can be adapted to support the edges of the plate against flexure during transport.

[0016] According to another aspect of the invention, the sheave arrangement can comprises a sheave block disposed between the sleeves.

[0017] According to another aspect of the invention, the sheave arrangement can comprise two pairs of sheave blocks, the pairs of sheave blocks being spaced apart from one another in the direction of the secondary axis, the blocks of the pair being spaced apart from one another in the direction of the primary axis.

[0018] According to another aspect of the invention, each guide arm can have a limit switch positioned proximal to the reentrant lip, the limit switches of the guide arms being orientated towards one another and adapted to arrest inward movement of the guide arms when a load is operatively centered therebetween.

[0019] According to another aspect of the invention, each lifting arm can have a limit switch positioned proximal to the reentrant lip, the limit switches of the lifting arms being orientated towards one another and adapted to arrest inward movement of the lifting arms when a load is operatively captured therebetween.

[0020] According to another aspect of the invention, the apparatus can further comprise a principal rack and pinion mechanism providing for said movement of the lifting arms between the extended and retracted position, the principal rack and pinion mechanism comprising a pinion and, for each lifting arm, a rack.

[0021] According to another aspect of the invention, the apparatus can further comprise a secondary rack and pinion mechanism providing for said movement of the guide arms between the extended and retracted position, the secondary rack and pinion mechanism comprising a pinion and, for each guide arm, a rack. [0022] Advantages, features and characteristics of the invention will become apparent from the following detailed description, with reference to the appended drawings, described briefly below.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In the drawings:

FIG 1 is apparatus according to an example embodiment of the invention;

FIG. 2 is an end view of the apparatus of FIG. 1;

FIG. 3 is a bottom view of the apparatus of FIG. 1, with some parts removed for clarity;

FIG. 4 is an enlarged partial x-ray view of encircled area 4 of FIG. 3;

FIG. 5 is an enlarged partial x-ray view of a portion of encircled area 5 of FIG. 1;

FIG. 6 is a side view of the apparatus of FIG 1. positioned to grasp a plate and spacers positioned thereupon;

FIG. 7 is an end view of the apparatus of FIG. 1 in gripping receipt of a plate and spacers positioned thereupon;

FIG. 8 is a view similar to FIG. 6 showing the load suspended;

FIG. 9 is a view similar to FIG. 7, showing the load fully elevated and the stabilizer bars received by the sleeves;

FIG. 10 is a side view of the structure of FIG. 9;

FIG. 11 is a side view of apparatus 20' according to another example embodiment of the invention; FIG. 12 is an end view of the apparatus of FIG. 11;

FIG. 13A is an end view of the apparatus of FIG. Il in use and positioned about a palletized load to be lifted.

FIG. 13B is a side view of the structure of FIG. 13A;

FIG. 14A is a view similar to FIG. 13B, positioned at an elevation to grasp the load;

FIG. 14B is an end view of the structure of FIG. 14A;

FIG. 15A is a view similar to FIG. 14A, wherein the guide arms have been retracted against the load (coil);

FIG. 15B is an end view of the structure of FIG. 15A;

FIG. 16A is a view similar to FIG. 15A, wherein the lifting arms have been retracted against the pallet;

FIG. 16B is an end view of the structure of FIG. 16A;

FIG. 16C is an enlarged view of encircled area 16C of FIG. 16B;

FIG. 17A is a view similar to FIG 16B, in receipt of the load;

FIG. 17B is a side view of the structure of FIG. 17A;

FIG. 17C is an enlarged view of encircled area 17C of FIG. 17A;

FIG. 18A is a view similar to FIG. 17A, with the load above the floor;

FIG. 18B is a side view of the structure of FIG. 18A;

FIG. 19A is a view similar to FIG. 18A, with the load fully elevated such that the stabilizing bars are received by the sleeves; and

FIG. 19B is a side view of the structure of FIG. 19A. DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0024] Two example embodiments of the invention 20, 20' are described below.

[0025] As an initial matter, each example embodiment is for use by an overhead crane having:

• a pair of runway beams each having an end truck mounted thereto for translational movement;

• a bridge frame connecting the end trucks;

• a trolley mounted to the bridge frame for movement therealong;

• a winch arrangement connected to the trolley; and

• a wire rope arrangement extending from the winch arrangement.

[0026] Cranes of this type come in many forms and as such further description of the crane is neither provided nor required.

[0027] The first embodiment is shown in FIG 1 and the second embodiment is shown in FIG 11.

[0028] Each embodiment will be understood to comprise:

• a pair of stabilizing bars 22;

• a sheave arrangement 24;

• a frame 26;

• a pair of sleeves 28;

• a pair of lifting arms 30;

• a pair of guide arms 32;

• a principal rack and pinion mechanism 34; and

• a secondary rack and pinion mechanism 36.

[0029] The stabilizing bars are elongate and terminate in tapered, conical ends

38. [0030] The sheave arrangement will be understood to be adapted to receive and be suspended by the wire rope arrangement of the crane used.

[0031] The frame is connected to the sheave arrangement and thereby adapted to be suspended thereby and defines a principal axis X-X and a secondary axis Y-Y. Laser distance measurement sensors 40 are disposed beneath the main frame to detect the free space beneath. The frame also carries an inclinometer 41. This information can, of course, be used to assist in positioning of the frame.

[0032] The sleeves project upwardly from the frame, each including a lower cylindrical portion 42 having an inner diameter adapted for a clearance fit with a stabilizing bar and upper, outwardly flared portion 44.

[0033] The lifting arms are spaced apart from one another along the principal axis, extend downwardly from the frame and terminate in a pair of reentrant lips 46. Each lifting arm has a limit switch 48 positioned proximal to the reentrant lip, the limit switches of the lifting arms being orientated towards one another. Each lifting arm also has a load detector 50 positioned proximal to the reentrant lip and presenting towards the frame. Each lifting arm also has a pair of photo eyes 52 disposed above and below the reentrant lip, which again provides information useful when positioning the crane at the correct elevation.

[0034] The guide arms are spaced apart from one another along the secondary axis, each extending downwardly from the frame to a free end 54. Each guide arm has a limit switch 57 positioned disposed adjacent the free end, the limit switches of the guide arms being orientated towards one another.

[0035] The principal rack and pinion mechanism comprises a pair of pinions (not shown) and, for and associated with each lifting arm, a pair of racks 56. The pinion is driven by a brake motor, gear reducer, sprocket and chain and toque limiter clutch and includes an encoder and travel limit sensors, all not shown. [0036] The secondary rack and pinion mechanism comprises (not shown) a pinion and, for and associated with each guide arm, a rack. The pinion is driven by a brake motor, gear reducer, sprocket and chain and toque limiter clutch.

[0037] Turning now to FIGS 1-5 in detail, in this embodiment:

• the sleeves are spaced apart from one another in the direction of the secondary axis

• each guide arm terminates in a lip 60, the lips of the guide arms being adapted to assume a reentrant position

• the lifting arms are adapted to support the underside of a plate

• the lips of the guide arms, when in the reentrant position, are adapted to support the edges of a plate supported by the lifting arms

• the sheave arrangement comprises two pairs of sheave blocks 62, the pairs of sheave blocks being spaced apart from one another in the direction of the secondary axis, the blocks of the pair being spaced apart from one another in the direction of the primary axis. The sheave blocks are directly reeved to the hoists to keep the lifter and lifted load level even if loaded unevenly.

[0038] Figures 6-10 are illustrative of the manner in which this embodiment is used.

[0039] More particularly, this embodiment is used with a crane wherein the rope arrangement includes four lifts. For use, each of the lifts is engaged with a respective one of the sheave blocks and the stabilizing bars are connected to extend downwardly from the trolley.

[0040] In use, that part of the apparatus 20 exclusive of the stabilizing bars is lowered such that the reentrant lips of the lifting arms are below a plate 64 to be lifted and the guide arms flank said plate, all generally in spaced, centered relation. [0041] So positioned, the secondary rack and pinion mechanism is activated to draw the guide arms together until both limit switches have engaged, whereupon the frame will be operatively centered, with reference to the secondary axis, to the plate, as shown in FIG. 6.

[0042] Thereafter, the primary rack and pinion mechanism is activated to draw the lift arms together until both limit switches have engaged, wherein the frame will be operatively centered, with reference to the primary axis to the plate, as shown in FIG. 7.

[0043] Thereafter, the winch arrangement is activated, to draw the plate towards the trolley. When the plate has been elevated to provide sufficient clearance, lips 60 assume the reentrant position to support the edges of the plate against sway, as shown in FIG. 8. The inclinometer coacts with the load detectors to arrest movement of the cable if the conditions are such that it appears the plate is not fully engaged by the lips or is blocked against movement, for example, by an adjacent plate. Absent issues of this sort, the winch draws the frame upwardly, as indicated in FIG. 8, until the stabilizer bars are received by the sleeves, as illustrated in FIGS. 9 and 10, at which point, the load (plate 64 and dunnage/spacers positioned thereon) is horizontally transported by the crane.

[0044] When the plate has been transported above the desired location, the above steps are repeated, to release the plate.

[0045] Turning now to FIGS 11-12, in this embodiment 20':

• the sleeves are spaced apart from one another in a horizontal direction that is 45°to the secondary axis; and

• the lifting arms project downwardly beyond the guide arms; and

• the sheave arrangement comprises a sheave block 66 disposed at the intersection of the principal and secondary axis.

[0046] Figures 13A-19B are illustrative of the manner in which this embodiment is used. [0047] More particularly, this embodiment is used with a crane wherein the rope arrangement includes a single lift.

[0048] For use, the lift is engaged with the sheave block 66 and the stabilizing bars are again mounted to the trolley to extend downwardly therefrom.

[0049] In use, that part of the apparatus 20' exclusive of the stabilizing bars is lowered such that the reentrant lips of the lifting arms are below a pallet 68 and the guide arms flank a product 70 born by said pallet, all generally in spaced, centered relation, as indicated by the sequence of FIGS 13A-14B. So positioned, the secondary rack and pinion mechanism is activated to draw the guide arms together until both limit switches have engaged, whereupon the frame will be operatively centered, with reference to the secondary axis, to the pallet, as shown in the sequence of FIGS 14A-15B.

[0050] Thereafter, the primary rack and pinion mechanism is activated to draw the lifting arms together until both limit switches have engaged, wherein the frame will be operatively centered, with reference to the primary axis to the plate, as shown in FIG. 16A-16B.

[0051] Thereafter, the winch arrangement is activated, to draw the pallet towards the trolley. The inclinometer coacts with the load detectors to arrest movement of the cable if the conditions are such that it appears the pallet is not fully engaged by the lips or is blocked against movement, for example, by an adjacent plate. Absent issues of this sort, the winch draws the frame upwardly until the stabilizer bars are received by the sleeves as indicated by the sequence of FIGS 16A-19B.

[0052] Thereafter, the load can be transported by the crane and deposited by following the foregoing steps in reverse.

[0053] Whereas two specific example embodiments are herein shown and described, variations are possible. Accordingly, the invention should be understood to be limited only by the accompanying claims, purposively construed.