US3367513A

US3367513A - Soaking pit crane

Info

Publication number: US3367513A
Application number: US567762A
Authority: US
Inventors: Ross B Mccready; Donald W Schaper
Original assignee: Kerma Corp
Current assignee: Kerma Corp
Priority date: 1966-07-25
Filing date: 1966-07-25
Publication date: 1968-02-06
Anticipated expiration: 1985-02-06
Also published as: GB1146258A; AT279067B; DE1531208B1

Description

Feb. 6, 1968 R. B. MCCREADY ETAL 3,367,513

SOAKING PIT CRANE Filed July 25. 1966 5 Sheets-Sheet 1 IN VENT OR.

R088 5. MCRBIDV DONALD W .SCHAPER AZ'TORNEYJ 1953 R. B. MCCREADY ETAL 3,367,513

3 Sheets-Sheet 2 Wmig Feb. 6, 1968 R. B. MQ A 3,367,513

SOAKING PIT CRANE 'Filed July 25, 1966 5 Sheets-Sheet 5 INVENTOR. R088 8. MCRMDY DONALD M SCMPER ,4 TTORWEYS United States Patent 3,367,513 SHARING PET CRANE Ross B. McCready and Donald W. Schaper, Alliance, Ohio, assiguors to Kenna Corporation, Alliance, Ghio, a corporation of (Ehio Filed July 25, 1966, Ser. No. 567,762 6 Claims. (Cl. 212-11) ABSTRACT OF THE DISCLOSURE A crane having load-engaging tongs supported by a column on a movable support. A cable drum and a first sheave means in the column to move the column vertically. A second sheave means movable vertically in the column by a second cable drum. A member that opens and closes the tongs connected to the first and second sheave means.

The present invention relates to cranes and more particularly to overhead bridge cranes, in which a vertically movable column having load engaging tongs at the lower end is carried by an overhead support, for example, a crane trolley.

An object of the present invention is to provide a new and improved crane having a vertical movable column With load engaging tongs at the lower end thereof, for example, a soaking pit crane, and a cable system for moving the column vertically and/ or opening and closing the tongs, and wherein the tongs may be opened and closed without changing their elevation or that of the column.

A further object of the present invention is the provision of a new and improved crane comprising a vertically movable column having tongs at the lower end thereof and a system of cables to raise and lower the column and to open and close the tongs such that all of the cables normally operate to support and move the column when the ton-gs are closed thereby reducing the number of cables required for a crane of given capacity.

A further object of the present invention is the provision of a new and improved crane having a vertically movable column with load engaging tongs at the lower end, a system of cables to move the column vertically and to open and close the tongs, and two independently driven drums to which the cables are operatively connected such that failure of one of the drum drives permits the column to be supported and moved vertically by the other without the ton-gs opening.

A still further object of the present invention is the provision of a new and improved soaking pit crane having a vertically movable column with load engaging tongs at the lower end thereof, a column hoist mechanism including cable system for raising and lowering the column and a tong operating mechanism including a cable system for opening and closing the tongs, the mechanisms being such that when the tongs grip a load both mechanisms including their cable systems normally operate to support and move the load and failure of the column hoist mechanism permits safe hoisting of the load by the tong actuating mechanism.

Another object of the present invention is the provision of a new and improved soaking pit crane having a vertically movable column with load engaging tongs at the lower end thereof which are pivotable about horizontal axes to open and close and rotate as a unit about a vertical axis, a system of cables arranged to raise and lower the column and for opening and closing the tongs and means providing for manipulation of a load such as by lowering and rotating the load about a vertical axis without the tongs accidentally opening and dropping the load.

3,367,513 Patented Feb. 6, 1968 Another object of the present invention is the provision of a new and improved crane having a vertically extending column with load engaging tongs at the lower end and wherein the tongs are moved between open and closed positions by a tong actuating linkage supported on flexible slings, the slings being moved by vertically shiftable sheave means to operate the tong actuating linkage,

Further objects and advantages of the present invention will be apparent to those skilled in the art to which it relates from the following detailed description of the preferred embodiment thereof made with reference to the accompanying drawings forming a part of this specification and in which:

FIG. 1 is a fragmentary side elevational view with parts broken away, of a abridge-type soaking pit crane embodying the present invention;

FIG. 2 is a plan view of'a portion of the crane shown in FIG. 1;

PEG. 3 is a side elevation view with parts broken away, of the movable column illustrated in FIG. 1.

The crane, according to the present invention, has application in many different environments but is particularly suitable for handling ingots in soaking pits and accordingly the preferred embodiment of the invention will be described in connection with soaking pit operations.

As representing the preferred embodiment of the invention, the drawings show part of an overhead bridge crane indicated generally as A. The crane A comprises a bridge B which is only partially illustrated in the drawings and includes a pair of horizontally spaced interconnected girders 9, 1t) supported at their end by trucks (not shown) for movement along elevated rails or trackways provided in a soaking pit area. The bridge girders 9, 10 have rails 11 and 13 upon which a trolley C is supported for movement transversely of the direction of movement of the bridge. The trolley C includes a frame 14 having a downwardly projecting section of column guide frame 15 providing an opening within which a column D, rectangular in cross section, is supported for vertical movement. The column D is provided with load gripping tongs E at the lower end thereof. The tongs E grip the load which in the preferred embodiment is an ingot and the ingot is raised and lowered by moving the column D vertically relative to the trolley C.

The crane A is spotted, for example, in the course of removing an ingot from a soaking pit, over the appropriate ingot by moving the bridge B and trolley C to align the column D with the ingot to be removed. A system of cables is operatively connected between the trolley, column and tongs and operable to lower the column to position the tongs at an elevation to grip the upper end of the selected ingot, close the tongs to grip the ingot, and raise the loaded column to remove the ingot from the pit. The cable system operates in reverse to load an ingot into a soaking pit.

The trolley C is supported for movement along the bridge B by two pairs of

wheels

16 and 17 connected to

axles

18 and 19, respectively, which in turn are connected to the trolley frame 14. Trolley C is driven in opposite directions along bridge B by a reversible electric motor 20 supported on a deck 22 of the trolley framework 14. The electric motor 20 drives the axle 18 through a speed reducer 24 and a suitable gear train 26. A suitable braking mechanism (not shown) is provided to brake the motor 20 and trolley to hold the trolley C in a selected position on the bridge B.

The trolley C supports the column D for vertical movement relative thereto in the guide frame 15 which is generally rectangular in cross section and open at the bottom to permit the column to move relative to the frame in telescoping relationship. The guide frame 15 is connected to the trolley framework 34 in any suitable manner and extends downwardly therefrom between the spaced bridge girders 9 and it The guide frame 35 has four vertically extending angles 3%, one at each corner, provided with hearing strips 31 which engage the respective corners of the rectangular column D and guide the column during movement. By this arrangement the column D is continually guided in the frame 15 and is movable therein between a retracted position which is the position illustrated in FIG. 1 and an extended position wherein the upper end of column D is located near but within the lower end of guide frame 15. The lower end of guide frame 15 supports an operators station 32 where the controls for the crane are located. A walkway 34 extending around the lower end of guide frame 15 provides the operator with a good view of the tongs and the soaking pit area.

The column D is moved vertically and the tongs E open and close by main or column hoist and

tong operating mechanisms

38 and 39, respectively, located on the trolley deck 22. The column hoist mechanism 38 includes a motor driven cable drum 4% and the tong operating mechanism 39 includes a motor driven cable drum &2. The drums 40 and 41 are connected with the column and the tongs carried thereby by a system of cables. The cable system comprises at least four cables which may be referred to as two pairs of two cables each.

Cables

42 and 43 of one of the pairs of cables have one of their ends connected to the drum 40 of the column hoist mechanism 38. From the drum 40

cables

42 and 43 extend down and around a pair of

sheaves

44 and 45, respectively, rotatably supported in vertically movable members connected by means including an equalizing lever 46 to a member 47 in the column D. The

sheaves

44 and 45 are located substantially centrally of the column D and the member 47 is supported in the column for limited vertical bodily movement in a guideway 48 which is integral with the framework of column D. From the

sheaves

44 and 45 the cables extend upward toward the trolley and the ends thereof are connected to a pair of stabilizers 49 secured to the trolley frame 14. Rotation of the drum 40 either lengthens or shortens the vertical reaches of the

cables

42 and 43 and moves the column D upwardly or permits downward movement thereof in guide frame 15 depending upon the direction of rotation of the drum 49. it should be noted that the

cables

42 and 43 always support the column D.

The drum 40 is rotated in opposite directions by a reversible electric motor t supported on trolley deck. The motor 50 is drivingly connected to the drum through a suitable transmission 51 including a drive comprising a worm 5111 which drives a meshing worm gear 52. The worm gear 52 is secured on and drives a shaft 53 which has a gear 54 secured at the end thereof remote from the worm gear 52. The gear 54 meshes with a gear 55 secured to the shaft of drum 49. A suitable conventional braking mechanism (not shown) is provided to lock the drum against rotation upon de-energization of the motor 50.

The tongs E are pivoted to a member 56 connected to and forming the lower portion of the column D. The member 56 is connnected to the column framework for rotation about a vertical axis so that the tongs may be located in various angular positions. The tongs E comprise a pair of spaced

bell crank members

57 and 53.

Members

57 and 58 are connected intermediate their ends to the lower portion of the member 56 by

pins

60 and 62 which provide for pivotal movement of

members

57 and 58 about generally horizontal axes. The crank members may have opposed tines 63 at their lower ends adapted to engage and penetrate the ingot or load to be gripped by the tongs to provide better gripping engagement therebetween.

The tongs E are moved between open and closed positions represented by the full line and broken line showings, respectively, in FIG. 3 by a tong actuating mechanism 64. The tong actuating mechanism 64 is arranged to move relative to the column framework under the control of the tong operating mechanism 39. The tong actuating mechanism 64 includes a pair of

links

65 and 65 pivotally connected at one of their respective ends by a pin 67 on the lower end of an actuator rod 68 and having their other ends pivotally connected by pins as, 70 to the upper ends of the bell crank

members

57 and 58, respectively. The actuator rod 68 is connected to a crosshead or truss member 71 by a suitable thrust bearing 72. The bearing 72 is carried by a member 73 located between and pivoted to spaced plates 74 of crosshead 71 by bosses 75 on opposite sides of the member 73. The construction provides for movement of the rod 68 vertically with the crosshead 71., rotation of rod 68 about its vertical axis relative to the crosshead 71 and pivotal movement of the crosshcad 71 about the axis of the bosses 75 for a purpose hereinafter mentioned.

The crosshead 71 rotatably supports a pair of

sheaves

76 and 77 at its opposite ends. The sheaves are supported in a pair of slings ,3 and 8d. The slings 7S and 89 com prise flexible members, preferably cables, which are connected at one end to slidable sheave blocks 32 and which rotatably suppport sheaves 86 and 38, respectively. The sheave blocks and 84 are movable vertically relative to the column frame in suitable guideways and 9% provided therein. Downward movement of the sheave blocks 82 and 84 are limited by the framework of the column. The other ends of slings 7t are connected to the sliding frame 47 at 91 and 5G, respectively. Upward movement of the sheave blocks and 84 relative to the column framework will elevate the connected ends of the cables 78 and 8t lifting the crosshead 71 and attached actuator rod 68 to effect pivoting of

members

57 and 58 to their closed position. Lowering of sheave blocks 82 and 84 relative to the column framework lowers the connected ends of cables 78 and 8t] permitting the crosshead 71 and actuator rod 68 to lower by gravity and open the

tong members

57 and 58.

The sheave blocks 82 and 84 are moved vertically relative to the column framework by the tong operating mechanism 39. The tong operating mechanism 39 includes a pair of cables 94 and having their one ends wound on cable drum 4. From the drum 41 the cables extend clown and pass under and around sheaves 85 and 88., and have their opposite ends wound on and connected to the drum 40 of the column hoist mechanism 38. The ability of the crosshead 71 to pivot about the axis of the bosses '75 provides for equalizing the loads on the cables 78 and The tong actuator drum ,1 is rotated in opposite directions by a reversible electric motor 98 supported on trolley deck 22. The motor 98 is connected to drive drum 41 through a speed reducer Hit}. A suitable braking mechanism is provided for the drum 41 and motor 98 so that upon de-energization or failure of the motor 98 the drum is prevented from unwinding and paying out

cables

94 and 95.

Rotation of tong actuator drum 41 in one direction shortens the cable reaches between the drums 4t), 41 moving the sheave blocks 82 and 84, member 71 and rod 68 upwardly relative to the column frame which closes the tongs. Rotating the drum 41 in the opposite direction lengthens the cable reaches and permits the sheave blocks 82 and 84 to move downwardly with respect to the column frame which causes the slings 78, St? to slack. This slack is taken up by the crosshead 71 and actuator rod 68 moving downward under the inlluence of gravity and pivots the bell crank

members

57 and 58 about

pivots

60 and 62 to open the tongs. The

cables

94 and 95 contribute to the support of column D when the sheave blocks 32, 84 have moved to close the tongs E which would be the situation when the column is loaded by an ingot.

The rotation of the member 56 about a vertical axis and, in turn, the tongs E is accomplished by a reversible electric motor 102 supported on a platform 104 provided in the upper section of the column D. The motor is drivingly connected to the lower column portion 53 through a speed reducer 106 which drives a vertically disposed shaft 108 extending downwardly from the platform 104. The shaft 108 has a pinion gear 110 on the lower end thereof which meshes with a bull gear 112 fixed to the member 56. The bull gear 112 is supported for rotation relative to the column frame by a suitable bearing 114, for example, a bronze bushing. The actuator rod 68 extends through an opening provided in the center of the bull gear and is connected to the bull gear for rotation thereby and can slide vertically relative thereto.

The crane A operates to remove an ingot from a selected soaking pit by energizing the drive for the bridge (not shown) and the motor 20 which moves the bridge B and-trolley C along the bridge rails 11 and 13 until the column D is spotted over a selected ingot in a soaking pit. Assuming the tongs E are open, the sheave blocks 82, 84 will be at or near their limit of vertical downward movement in the column frame and the upper end of the member 47 will be at its upper limit of travel in the column frame and in engagement with the framework of the column. The column will then be supported by the

cables

42, 43 of the column hoist mechanism. With the column in position over the ingot, the motor 50 is energized to rotate the drum 40 to pay out

cables

42, 43, 94, 95 and permit the column D to descend until the open tongs E are in position to engage the upper end of the ingot. Motor 98 is then energized to drive the drum 41 to shorten the reaches of

cables

94, 95 between the drums 40 and 41 causing an upward movement of the sheave blocks 82 and 84, crosshead 71 and actuator rod 68 relative to the column frame. Upward movement of rod 68 pivots the bell crank

lever

57 and 58 about

pivots

60 and 62 causing the tines 63 to grip the ingot. This tong closing is accomplished without changing the elevation of the column D providing for more accurate alignment of the ingot in the tongs.

Continued winding of

cables

94, 95 onto drum 41 transfers part of the column weight onto

cables

94, 95. The load is thus supported by all the cables. In the

event cables

94, 95 lift the load off its support, the frame 47 and

sheaves

44, 45 would be pulled downward by

slings

78, 80 insuring that all the cables are taut and share in support of the column. Preferably, a suitable limit control is provided for preventing the operation of the tong actuating motor 98 beyond the length of time required for the member 47 to reach its allowed limit of travel and thus, preventing the

cables

42, 43 from becoming slack. Alternatively, the operator can observe the position of the member 47 in the column framework.

In the

event cables

42, 43 should break, the member 47 would move downwardly until the lower end thereof engaged the framework of the column whereupon the entire weight of the load would be transferred to the

cables

94, 95 of the tong operating mechanism. The transfer would occur without the tongs opening and dropping the load.

After the ingot has been engaged, the motor 50 is energized to rotate the drum 40 in the direction to wind

cables

42, 43, 94, 95 onto the drum 40 and move the column D upwardly in the guide frame 15 lifting the ingot out of its soaking pit. When the ingot has attained a clearance elevation, the bridge and trolley drives can then be actuated to move the ingot to a desired location. When the ingot has arrived at its desired location, the main column hoist drum 40 is rotated to permit the column to descend and lower the ingot upon a support. If the ingot is to be positioned on a particular side, for example, the column member 56 including the tongs can be rotated about the vertical axis of the bull gear 112 by the motor 102. It will be apparent that the present construction permits manipulation of the ingot and the manipulation is accomplished without releasing the grip on the ingot. The ingot is released from the tongs E by rotation of drum 41 in a direction to lengthen cables 94, which permits downward movement of sheave blocks 82, 84, crosshead 71 and actuator rod 68 which pivot the bell crank levers 57 and 58 to their open position. A limit switch of conventional construction may be supported on the column frame to be tripped by either sheave block 82 or 84 during tong opening movement to limit the extent of downward travel of the blocks.

It should be apparent from the foregoing that the number of support cables required to support and move the column vertically can be substantially reduced in number since all cables are utilized to support and move the column D vertically when the tongs are closed such as when the column is supporting an ingot. Also, this cable reeving arrangement provides a safety feature so that in the event the drive for the drum 40 becomes inoperative during hoisting, the tong operating mechanism 39 would support the column and motor 98 could then effect vertical movement of the column by rotation of drum 41 without releasing the ingot from tongs E. Moreover, the flexible sling connection between the sheave blocks 82, 84 and the crosshead 71 provide for even application of force on the ends of the crosshead and provides a mechanical advantage for closing the tongs.

Although the preferred embodiment of the present invention has been described in detail, it should be apparent that various changes, modifications and adaptations could be made therein without departing from the scope of the invention as defined in the appended claims.

Having described our invention, we claim:

1. In a crane, a trolley movable along elevated ways, a column extending generally vertically from said trolley and having tongs pivotally supported at the lower end, said column having a frame and first and second sheave means at vertically spaced locations on said frame, said first sheave means comprising a plurality of sheaves mounted for rotation in a guide frame, means mounting said guide frame for vertical movement relative to said column frame, said second sheave means including pairs of sheave-s at horizontally spaced locations on said column frame, each of said pairs of sheaves of said second sheave means being rotatably supported in a guide frame, means supporting said guide frame for vertical movement relative to said column frame, an actuator rod operatively connected at one end to said tongs and having a transversely extending member at the opposite end, a .pair of sheaves rotatably supported at the ends of said members, a pair of flexible cables connected at one end to one of said guide frames of said second sheave means and at their opposite ends to said guide frame of said first sheave means and being reeved about one of said sheaves on said member.

2. In a crane having a movable support, a column movable vertically in said support, load engaging tongs supported in the lower end of said column for opening and closing movements, a first cable drum mounted for rotation on said support, first sheave means movable vertically in said column, first cable means operatively connected to said first drum and said first sheave means and said support and operable to move said column vertically upon rotation of said first cable drum, a second cab-1e drum on said support, second sheave means vertically movable in said column, second cable means operatively connected to said first and second cable drums and said second sheave means, means for rotating said first and second cable drums selectively, and means movable vertically in said column and connected to said first and second sheave means for opening and closing said tongs.

3. In a crane having a movable support, a column movable vertically in said support, load engaging tongs supported in the lower end of said column for opening and closing movements, means movable vertically in said column for opening and closing said tongs, a first cable drum mounted for rotation on said support, first sheave means vertically movable in said column, means for limiting the movement of said first sheave means in the upwardly direction, first cable means operatively connected to said first cable drum and said first sheave means and said support and operable to move said column vertically upon rotation of said first cable drum, a second cable drum on said support, second sheave means vertically movable in said column, second cable means operatively connected to said first and second cable drums and said second sheave means, means for rotating said first and second cable drums selectively, and means for operatively connecting said first named means to said first and second sheave means.

4. In a crane having a movable support, a column movable vertically in said support, load engaging tongs supported in the lower end of said column for opening and closing movements, a member movable vertically in said column for opening and closing said tongs, first sheave means connected to said member, a first cable drum mounted for rotation on said support, second sheave means vertically movable in said column, means for limiting the movement of said second sheave means in the upwardly direction, first cable means operatively connested to said first cable drum and said second sheave means and said support and operable to move said column vertically upon rotation of said first cable drum, a second cable drum on said support, third sheave means vertically movable in said column, second cable means operatively connected to said first and second cable drums and said third sheave means, means for rotating said first and second cable drums selectively, and flexible means reeved about said first sheave means and operatively connected to said second and third sheave means.

5. In a crane having a movable support, a column movable vertically in said support, load engaging tongs supported in the lower end of said column for opening and closing movements, a first member movable vertically in said column for opening and closing said tongs, first sheave means connected to said first member, a first cable drum mounted for rotation on said support, second sheave means including first sheaves rotatably supported in a second member vertically movable in said column, means for limiting the movement of said second member in the upwardly direction, first cable means operatively connected to said first cable drum and said first sheaves and said support and operable to move said column vertically upon rotation of said first cable drum, a second cable drum on said support, third sheave means including second and third sheaves rotatably supported in third and fourth members vertically movable in said column, second and third cable means operatively connected to said first and second cable drums and reeved about said second and third sheaves, means for rotating said first and second cable drums selectively, and fourth cable means reeved about said first sheave means and operatively connected to said third and fourth members.

6. In a crane having a movable trolley, a column movable vertically in said trolley, load engaging tongs supported in the lower end of said column for opening and closing movements, a first cable drum mounted for rotation on said trolley, 21 first sheave support movable vertically in said column, means for limiting the movement of said first sheave support in said column in the upwardly direction, first sheave means rotatably connected to said first sheave support, first cable means operatively connected to said first cable drum and said first sheave means and said support and operable to move said column vertically upon rotation of said first cable drum, a second cable drum on said trolley, second and third sheave supports movable vertically in said column, second and third sheave means rotatably supported in said second and third sheave supports, second and third cable means operatively connected to said first and second cable drums and reeved about said second and third sheave means, means for rotating said first and second cable drums selectively, a member movable vertically in said column for opening and closing said tongs, fourth sheave means connected to said member, and fourth cable means reeved about said fourth sheave means and operatively connected to said second and third sheave supports.

References Cited UNITED STATES PATENTS 909,804 1/1909 Kendall 2l2l1 2,219,479 10/1940 Harry 212-127 2,306,055 12/1942 Harry 212127 2,388,408 11/1945 Harry 2l211 ANDRES H. NIELSEN, Primary Examiner.