US 3043444 A
Description (OCR text may contain errors)
July 10, 1962 D. F. MELTON CONTROLLED MOTION CRANE 4 Sheets-Sheet 1 Filed Oct. 9, 1958 N m R. a MM WEI.
D L A N O D *ATTORNEVY July 10, 1962 D. F. MELTQN 4 4 CONTROLLED MOTION CRANE 1 Filed Oct. 9, 1958 4 Sheets-Sheet 2 IOI TO MOTOR 7 INVENTOR.
DONALD E MELTON ATTORNEY July 10, 1962 D. F. MELTON 3,043,444
CONTROLLED MOTION CRANE Filed Oct. 9, 1958 4 Sheets-Sheet 3 IRREVERSIBLE SPEED REDUCER 4 llilllll JRREVERSIBLE SPEED REggCER l9 8O IRREVERSIBLE 54 SPEED REDUCER INVENTOR. DONALD E MELTON WW/VAN ATTORNEY July 10, 1962 D. F. MELTON 3,043,444
CONTROLLED MOTION CRANE Filed Oct. 9, 1958 4 Sheets-Sheet 4 INVEN TOR.
DONALD E MELTON Wwf/L ATTORNEY nited States atent o sea-3,444
, Patented July 10, 1962 This invention relates to controllable overhead cranes and more particularly to cranes having a plurality of load cables for positioning a load and more specifically to a cable drum means co-acting with said cables to provide versatility of positioning.
Prior art cranes, particularly overhead cranes, generally show the use of single cables or multiple cables whose center line is parallel to a central axis of the crane for raising and lowering loads with the positioning primarily dependent upon the location of the overhead crane body. Generally, the suspenison of such cables from these cranes is central of the crane body thereby making it difficult to locate or pick up loads which are off-center from the crane body, for example when the load is desired or placed near overhead crane supporting side walls and the like.
In the preferred embodiment of my invention I provide a plurality of driven cable drums, one drum for each cable, wherein the cables can be separately raised or lowered or the cables can be simultaneously moved in the same direction. The individual cables are each secured to a load supporting hook or the like for the positioning of a load attached thereto.
By providing individual cable drums for each cable, and there are four cables, the cables are brought at their lower extremity to a single load bearing unit, and by their cable connections from a plurality of drums to a single point, or load bearing unit, an inverted pyramid is formed of the cable configuration. Such pyramidal configuration is advantageous in maintaining stability at the load bearing unit, in that the overhead structure on which the drums are mounted, when moved, creates a tendency in a suspended load to swing or twist, and the pyramidal configuration of the cables substantially prevents this swinging and twisting at the load bearing unit. Further by having individual drums for each cable, each separately actuatable, I provide structure which facilitates positioning the load bearing unit in any location beneath the overhead crane, and particularly it allows for positioning or pick up of a load at or near the side walls supporting the overhead crane structure. In other words, I provide for flexibility in positioning the load bearing unit under the crane without having to move the overhead bridge or carriage of an overhead crane. It might also be said that the movement of the bridge and carriage affords a coarse adjustment of the load bearing unit, and the operation of the individual cable drums affords a fine or Vernier adjustment of the load bearing unit within the volume below the carriage or crane unit.
It is therefore an object of my invention to provide a driven crane unit having a plurality of cables converging to a single load carrying means with each said cable being moved by a separate cable drum drive.
It is a further object of my invention to provide a novel means for paying out cable from a rotatable cable drum provided with a tangent sheave means for guiding the pay-out of the cable from each of the drums.
It is another object of my invention to provide at each cable drum a pivotal sheave to permit the proper positioning of the cable at each drum to effectuate load positions in a variety of positions.
These and other objects of my invention will be apparent from the following specification and drawings, of which- FIGURE 1 is a diagrammatic perspective view of the overall crane unit with a plurality of load bearing cables;
FIG. 2 is an elevation view of a load carrying means to which the cables are attached;
FIG. 3 is an elevation view of the crane of FIG. 1;
FIG. 4 is a perspective view of another load carrying means;
FIG. 5 is a detailed plan view of the crane of FIGS. 1 and 3 showing the means for driving the drums;
FIG. 6 is a detailed elevation view of one of the plural- 0 ity of cable drum means;
FIG. 7 is an end view of the cable drum means of FIG. 6 showing the tangent sheave inclined from the vertical;
FIG. 8 is an enlarged perspective view of the cable drum means and the tangent sheave guide means.
Referring now to FIG. 1, a crane unit 10 is shown mounted on guide tracks 11 for longitudinal movement as when said crane unit is moved by a motor 12 (FIG. 3). The tracks 11 are mounted on beams 13 which form the crane unit carrying means. The beams 13 are mounted for movement normal to tracks 11 by rollers 1106 running on tracks 15 mounted on Walls 14 and 14a. A control unit 16 is connected to a power supply 17 and provided with a plurality of switches 72, 71, 69, 61, 62, 63 and 64 to enable an operator to selectively energize the operating motors 12 and 70 of the crane unit, to be hereinafter described in detail, and to energize the cable drum drives of crane unit 10 to position the load bearing means 18.
Thus I have set out the basic structure of an overhead crane which provides the positioning of the crane unit 16.
For accurate positioning of the load carrying means 18, to which a load may be attached, I provide a plurality of cable drums 19, 20, 21, and 22 mounted for rotation on shafts 77, 24, 25, and 26, respectively. These shafts are supported on crane unit main frame 27 by shaft bearing housings 76 at one end, and by irreversible speed reducers 53, 54, 55, and 56 at the other end asshown in FIG. 5. Cables 30, 31, 32, and 33 are attached to the cable drums 20, 19, 21, and 22, respectively, by means of cable clamps 35. To the other end of the cables, load carrying means 18 is attached.
Specifically, the load carrying means 18, disclosed in FIG. 4, includes a main supporting cylinder 36 which is secured to a cable hook plate 37 provided with openings 38. Each of the cables 30, 31, 32, 33 has a hook 39 at the end thereof for engagement with openings 38. Secured to main supporting cylinder 36 is a pivotal load bearing means 40 to which a universal unit 41 is pivotally attached by means of pin 42. Load hook 43 is pivotally attached to universal unit 41 by means of a pin 44. Such arrangement allows for a pivoting of the hook at both pin 42 and at pin 44, and loads may be attached to hook 43.
To raise or lower or position load bearing unit 18, it is necessary to rotate cable drums 19, 20, 21, and 22. The cable drums, when driven, cause the respective cables attached thereto to wind or unwind on the drums. To drive said cable drums, I provide a reversible drive motor 45, which when energized drives shafts 46, 47, 48, and 49 through appropriate gearing housed in gear units 50 and 51 (FIG. 5). Said shafts are additionally supported as by hearing blocks 52. Also mounted on crane unit frame 27 are four irreversible speed reducers 53, 54, 55, and 56. By rotating shafts 46, 47, 48, and 49, irreversible speed reducers 53, 54, 55, and 56 are driven through electrically actuated clutch-brake units 57, 58, 59, and 60, mounted on shafts 47, 48, 49, and 46, which are energized or deenergized by switches 61, 62, 63, 64 on control box 16. Cable drum shafts 77, 24, 25, and 26 are driven from the output shafts 65, 68, 67, and 66 of the irreversible speed reducers 54, 56, 55, and 53. Thus deenergization of drive motor 45 by switch 69 on control box 16 in one direction or the other with all clutch brake units example, cables 32 and 33 alone may be raised by the deenergization of the clutch brake units 57 and 58 to stop the rotation of drums 19 and 20.
Thus by separately controlling the clutch brake units it is possible to position the load bearing unit at a plurality of points within an imaginary rectangle or square emanating downwardly from crane unit 10.
The control box 16 is connected to a power supply 17 for the energization of motors 45, 12, and 7t) and the energization of brake-clutches 57, 58, 59, 60 through switches 69, 71, 72', 61, 62, 63, 64, respectively. A cable 73 contains the necessary wires for connecting the power supply through said switches to the motors and the clutchbrakes to be energized or deenergized as the case may be. Such electric clutch brakes are well known in the art and will not be described further.
It is only necessary to relate that the electric brakeclutch units '57, 58, 59, and 61} when energized release the brake and engage the clutch, and when deenergized the brake is engaged and the clutch released. Thus by moving any or all of switches 61, 62, 63, 64 to on the clutches are engaged to transmit power from motor 45 to the respective cable drums. Likewise the motor switches 72, 71, 69 are such that they may drive their respective motors in one direction or the other, with a mid-position for o Referrin now to FIGS. 6, 7, and 8 for a detailed description of one of the plurality of cable drums 19 and the drive therefor in conjunction with the manner of cable pay-off. With the rotation of output shaft 65 of irreversible speed reducer 54, shaft 75 keyed thereto is rotated, said shaft being supported by hearing housing 76 mounted on main crane frame 27. Secured to shaft 75 and coaxial therewith is a grooved cylinder 77 provided with grooves 78 longitudinal thereof. Cable drum 19 is provided with a ball spline unit 79 slidably engageable with grooves 78. The ball spline unit 79 allows drum 19 to be rotated with shafts '75 and 77 by means of the engaging relation of ball spline unit 79 and the grooves 78, and, in addition the ball spline unit of the cable drum 19 allows the drum to slide longitudinally along shaft 77 in grooves 78 as will be hereinafter described.
The cable 31 is secured to drum 19 by means of a clamp 35, and as the drum is rotated by shaft 77, the cable is wound or unwound on drum 19.
Rotatably or pivotally mounted on shaft 75 is a tangent sheave unit 81 said sheave unit 80 pivoting or rotating on bearings 81 and 82. The tangent sheave unit 80 consists of two parallel plates 83 and 84, secured to end plates 85 and 86. are housings S7 and 88 for bearings 81 and 82. Thus plates 83 and 34 connected to end plates 85 and 86 are rotatable or pivotal about shaft 77, and are undisturbed by the rotation of shaft 75 as hereinbefore described.
Mounted between plates 83 and 84 is a tangent sheave 91D which is free to rotate about pin 89. Sheave 9b is provided with a groove 92 to receive cable 31 therein. in addition, two rollers 93 and 94 are mounted between plates 83 and 84 adjacent the periphery of sheave 90 is maintain cable 31 within groove 92.
The cable 31 always acts in groove 92 tangent sheave 9t), and with the sheave 90 in a fixed position laterally Integral with end plates 85 and 36' of shaft 77 the cable 31 always runs on tangent to the periphery of groove 92 of sheave 91?.
With a load applied to load bearing unit 1%, and with shaft 77 rotating, there is suificient force acting through the cable to cause drum 19 'to move longitudinally along shaft 77 in grooves 78 so that the cable 31 at all times is substantially vertical from the tangent sheave 90 to the cable drum 19 as viewed 'in FIG. 6.
Thus it is seen that the cable drums are moved longitudinally along their rotating shafts by the application of a load 23 to the load bearing unit 18, and that this is made possible by the fixed longitudinal position of the tangent sheave and the ball spline .unit on each of the cable drums.
Further, because there are four cable drums, and the cables running from them converge to a point at the load bearing unit 18, the cables are not in a true vertical from the tangent sheaves 9t} downward. Rather, with the cables converging toward load unit 18, the cables are inclined inwardly from the tangent sheaves 99. Thus the importance of the rotatable or pivotal tangent sheave unit 81 is seen. The force exerted on the cables by a load at 18 tends to pull all cables inwardly and to positionthe tangent sheave unit 18 at substantially the same inclination as the cables. The inclination of the tangent sheave unit 811 is best seen in FIGS. 7 and 8. The fact that tangent sheave unit 8i) is mounted on bearings 81 and 82-makes unit readily positionable in an inclined direction about shaft 75. The incline from vertical X is illustrated in FIG. 8.
The radius of tangent sheave is such that a sharp bend in'the cable 31 is prevented, particularly when the cable is inclined to position D shown in MG. 6. It is seen that in effect each cable from the tangent sheave 99 circumscribes a volume of an imaginary quarter cone with the apex at the junction of the cable at the tangent sheave, and yet the cable pay-off is not disturbed in that portion of the cable from the tangent sheave to the cable rum, thus avoiding any pulling away of the cable from the grooves 36 in the cable drums.
In operation, then, the operator positions the crane unit 10 first by energization of motors 7t} and 12 through switches '71 and 72. Motor 12 turns belt 95 through pulley 96 to drive roller97 on tracks 11. This moves crane unit 10 along tracks 11 toward or away from wall 14. To move the crane unit 1t) along wall 14, motor 71) is energized through switch 71, and belt 98 is driven by pulley 99 of motor 70 to turn roller 101) through pulley 101. Having established the coarse position of crane unit 119 in this manner, and with the load bearing unit 18 in position A of FIG. 3, unit 18 is lowered by rotating all the cable drums 19, 20, 21, and 22 to unwind the cables 31, 30, 32, and 33 therefrom. This is done by energizing motor 45 through switch 69 and brakeclutch units 57, '58, 59, and 60 through switches 61, 62, 63, and 64. The cable drums 19, 2t), 21, and 22 are rotated in a manner hereinabove described, with all cables being unwound at the same rate until the load unit 18 is in, say, position B of FIG. 3.
The load 23 may then be secured to load unit 18, and the operator is now ready to move the load unit 18 and attached load to a new position. This may necessitate positioning the entire crane unit 11 which would be done by energizing motors 45 and 12, as hereinabove described.
However, assuming that crane unit 19 is in a desired position, further positioning of the load unit 18 is accomplished by movement of switches 61, 62, 63, 64, and 69. These switches provide the actuation or deactuation of clutch-brakes 57, 58, 59, and 60 and motor 45. For example, to move load unit 18 from position B of FIG. 3 to position C, the operator may energize all clutch brakes by switches 61, 62, 63, and 64, and reverse motor 45 to rotate cable drums 19, 20, 21, and 22 to wind up cables 30, 31, 32, and 33. Thus by simulto the desired position C.
taneously winding up cables 30, 31, 32, and 33 the load unit 18 is brought first to a position substantially in the same horizontal plane as position C. At this point the switches 62 and 63'may be switched off to deenergize brake clutch units 58 and 59, to stop drums 20 and 21.. The wind-up of cables 31 and 33 on drums 19 and 22 continues and moves unit 18 nearer to wall 14 and Any slack in cables 30' and 32 may be removed by winding up on drums 2i) and 21. I
One drum does not rotate to play out cable while another takes in cable. The drums are either all playing out cable or all taking it in, unless the clutch brake unit for a particular drum or drums has been deenergized in which case that particular drum or drums does nothing in regard to lengthening or shortening the cable.
Thus the drums may 'be rotated singly, or in pairs, or simultaneously, to position load unit 18, as hereinbefore described.
Of course, individual motors could be used to drive each cable drum, but in my preferred embodiment I use only one motor 45, thus economizing on the number of motors required for the construction of crane unit 16.
A load bearing unit 118 of FIG. 2 is a modification of unit 18, and is provided with a motor 119 mounted on cylindrical support 120. Cable hook support plate 121 is provided with openings 122 to receive hooks 39 of cables 30, 31, 3'2, and 33.
A pivotal load bearing means 40 is supported for rotation in bearing assembly 123 mounted in cylinder support 120. To means 40 is attached universal unit 41 and load hook 43 as hereinabove described.
The motor 11? turns shaft 124, and through speed reducer 125 shaft 126 is rotated. Shaft 126 is secured to means 40 so that means 40 is rotated with shaft 126 to position hook 43 about a central axis passing through load bearing unit 118. Either load bearing unit 18 or 118 will operate satisfactorily with cables 30, 31, 32, and 33.
Thus I have described a crane unit having a plurality of cable drums, one for each cable, with each cable from each drum acting through a tangent sheave to form a pyramidal configuration of the cables which positions a load bearing unit in a variety of positions beneath the crane unit upon actuation of the cable drums in the manner hereinabove described.
Since many variations of the exact details of construction shown in the drawings will occur to persons skilled in the art in view of the teachings of this application, it is intended that this invention should not be limited to the exact structure shown but only by the scope and spirit of the attached claims.
Now, therefore l claim:
1. A crane unit mounted for positioning a load bearing unit, at least three rotatable cable drums mounted on said crane unit, means for driving each of said cable drums, a cable connected at one end to each of said three rotatable cable drums, a load bearing unit connected at substantially one point thereof to the other end of said cables, whereby said cables converge from said cable drums to the load bearing unit and rotation of said drums in one direction raises said load bearing unit and rotation of said drums in the opposite direction lowers said load bearing unit.
2. in an overhead crane unit for positioning a load, the combination including, at least three cable drums each mounted for rotation on said crane unit, a means for driving said three cable drums, at least three cables each one of which is secured at one end to each one of the three cable drums, said three cables converging to substantially a single point at the other end thereof, a load bearing unit attached to said cables at said other end for supporting a load, whereby energization of said driving means simultaneously rotates said cable drums to 6 wind or unwind the cables thereon to position said load bearing unit.
3. In an overhead crane unit, the combination including, at least. three rotatable cable drums mounted on said crane unit, a single means for separately and simultaneously driving any member of said cable drums mounted on said crane unit, three cables, one of said cables attached at one end thereof to one of said drums, a second of said cables attached at one end thereof to a second of said drums, a third of said cables attached at one end thereof to a third of said drums, and a load bearing unit attached at substantially a single point to the other end of each said cable, said cables converging to form an inverted pyramid configuration, whereby actuation of the driving means in one direction raises said load bearing unit and actuation of the driving means in the other direction lowers said load bearing unit.
4. In an overhead crane unit, the combination including, a drive means mounted on said crane unit, at least three shafts driven by said drive means and mounted on said crane unit, a cable drum means connected to each shaft and rotatable therewith, a cable connected to each said cable drum means, and a single load bearing unit mounted on the otherend of said cables, said cables converging from said cable drum means to substantially a single point on said load bearing unit to form an inverted pyramid configuration.
5. The combination of claim 4 wherein said cable drum means includes a pivotally mounted tangent sheave for guiding the cable at each said drum means between the cable drum means and said single load bearing unit.
6. In an overhead crane unit, the combination including, motor drive means mounted on said crane unit, at least three shafts driven by said motor means, irreversible speed reducer means connected to each of said three shafts, brake clutch means interposed between each said shaft means and each said irreversible speed reducers, at
least three cable drum means each one driven by one of said irreversible speed reducers, at least three cables each one of which is attached to one of said cable drum means, a load bearing unit connected to the extremity of said cables, means to energize said brake clutch means, and said motor drive means, whereby energization of said drive means and said brake clutch means raises said load bearing unit.
7. In an overhead crane unit the combination including at least three cable drums mounted for rotation on said crane unit, a tangent sheave means pivotally mounted at each said cable drum, at least three cables each of which is attached to one of said cable drums, said cables each passing over said tangent sheave means at each said cable drum, a load bearing unit connected at substantially a single point to the extremity of said cables, said cables converging from said tangent sheave means to form an inverted pyramid configuration, whereby rotation of said drums in one direction or the other raises or lowers the load bearing unit dependent upon the direction of rotation.
8. In a cable drum means the combination including a rotatable shaft means, a cable drum, means for slidably connecting said cable drum to said rotatable shaft so said cable drum can freely move along the axis of said shaft, tangent sheave means pivotally mounted on said rotatable shaft adjacent said cable drum, a cable secured to said drum and being wound or unwound thereon, said cable passing through said pivotally mounted tangent sheave means for guidance of the cable while being wound or unwound on said drum regardless of cable pay off angle from said sheave.
9. In a cable drum means the combination including a rotatable shaft means, a cable drum, means for slidably mounting said cable drum on said rotatable shaft so said drum is rotatable therewith and freely movable longitudinally along the aXis thereof, pivotal means including a rotatable tangent sheave mounted thereon piv .otally mounted on said rotatable shaft, 21 cable secured to said drum and passing over said tangent sheave, a load bearing unit connected to said cable whereby rotation of said cable drum in one direction winds said cable on said drum and rotation in the other direction unwinds said cable on said drum and during the winding or unwinding the drum moves longitudinally on said rotatable shaft.
10. In a crane unit the combination including three rotatable shafts mounted on said crane unit, three cable drums, each cable drum slidably mounted for free longitudinal movement on each one of the three rotating shafts respectively, three tangent sheave means each one of which is pivotally mounted on one of said three shafts respectively adjacent each onerof said cable drums mounted on each one of said shafts, three cables each of which is attached to one of said cable drums, said cables passing individually from each of said drums over one of said tangent sheaves associated with each said drum, said three cables converging from said tangent sheaves to a single point at the extremities of said cables, a load bearing unit mounted at the extremities of said cables, whereby rotation of the drums in one direction raises said load bearing unit and rotation in the other direction lowers said load bearing unit.
11. In an overhead crane unit the combination including, three rotatable shafts mounted on said crane unit, three cable drum means driven by said rotatable shafts, three cables each of which is attached to a separate one of said cable drum means, a tangent sheave means pivotally mounted on each of said cable drum means, said cables individually passing from each cable drum means in contact with said pivotally mounted tangent sheave means, said cables converging to a point at their lower extremities to form a pyramid like configuration, a load bearing unit connected to said cables at said lower extremities, whereby the tangent sheave means at each cable drum means pivots freely to remain in contact with the cable attached at each cable drum means.
12. In a crane unit the combination including four rotatable shafts mounted on said crane unit, four cable drums, each cable drum slidably mounted for free longitu-dinal movement on each one of the four rotating shafts respectively, four tangent sheave means each one of which is pivotally mounted on one of said four shsafts respectively adjacent each one of said cable drums mounted oneach one of said shafts, four cables each of which is attached to one of said cable drums, said cables passing individually from each of said drums over one of said tangent sheaves associated with each said drum, said four cables converging from said tangent sheaves, to sub: stantially a single point at the extremities of said cables, a load bearing unit mounted at said extremities of said cables, whereby rotation of the drums in one direction raises said load bearing unit and rotation in the other direction lowers said load bearing unit.
13. In an overhead crane unit the combination including, four rotatable shafts mounted on said crane unit, four cable drum means driven by said rotatable shafts, four cables each of which is attached to a separate one of said cable drum means, a tangent sheave means pivotally mounted on each of said cable drum means, said cables individually passing from each cable drum means in contact with said pivotally mounted tangent sheave means, said cables converging to a point at their lower extremities to form an inverted pyramid like 1 configuration, a load bearing unit connected to said cables at said lower extremities, whereby the tangent sheave means at each cable drum means pivots freely to remain in connection with the cable attached at each cable drum means.
References Cited in the file of this patent UNITED STATES PATENTS 1,685,724 Roseuthal Sept. 25, 1928 1,811,623 Ferguson June 23, 1931 2,178,280 Hutchins Oct. 31, 1939 2,593,494 Seward Apr. 22, 1952 FOREIGN PATENTS 763,897 France Feb. 19, 1934 992,069 France June 27, 1951 "am f UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,043,444 July 10, 1962 Donald F. Melton 1: error appears in the above numbered pat- It is hereby certified the d Letters Patent should read as ent requiring correction and that the sad. corrected below.
Column 1, line 18, for "suspenison" read suspension column 2, lines 71 and 72, for "deenergization" read energization column 3', line 72, for "is" read to Signed and sealed this 15th day of January 1963.
DAVID L. LADD ERNEST W. SWIDER Commissioner of Patents Attesting Officer