US2346442A - Door operating mechanism for tilting furnaces - Google Patents

Description

April 1944- .H. M FEATERS DOOR OPERATING MECHANISM FOR TILTING FURNACES Filed Aug. 28," 1943 4 Sheets-Sheet l INVENTORV Kwm. Q ew y WW.

April- 11, 1944. H. L. M FEATERS 2,346,442 DOOR OPERATING MECHANISM FOR TILTING FURNACES Filed Aug. 28, 1943 4 Sheets-Sheet 2 INVE N'IOR April 1 1, 1944. H, MCFEATERS 2,346,442

DOOR OPERATINGMEQHANISM FOR TILTING 'FURNACES Filed Aug. 28, 194;)' 4 4 Sheets-Sheet 5 April 11, 1944. 1.. MOFEATERS DOOR OPERATING MECHANISM FOR, Ig-LTING FURNACES 7 Filed Aug. 28, 1945 4 Sheets-Sheet 4 LNVEN'IOR M 77 M 6 szwm Patented Apr. 11, 1944 UNITED STATES; PATENT oFncr.

DOOR OPERATING MECHANISM FOR TILTING FURNACES Harry L. McFeaters, New, Castle, Pa., assignor to Pennsylvania Engineering Works, a corporation of Pennsylvania Application August 28, 1943,.Serial N0. 500.33%

Claims. 01. 266-24) i This invention relates to tilting furnaces suchas open hearth furnaces and more particularly to mechanism for operating the charging doors of such furnaces.

The charging doors of tilting open hearth furwith tilting open hearth furnaces.

These and other objects which will be apparent to those skilled in this particular art, I attain by means of the mechanism described in the,

specification and illustrated in the drawings accompanying and forming part of this application. In the drawings:

Figure 1 is a more or less diagrammatic side elevational view of a tilting open hearth furnace equipped with a door operating mechanism embodying this invention and Which is more or less diagrammatically illustrated in this view;

Fig. 2 is an enlarged view in side elevation of the door operating mechanism disclosed in Fig. 1. This View by dottedlines illustrates the operation of the hoisting line tension maintaining mechanism during tilting of the furnace to pouring and slagging positions. 1

Fig. 3 is a somewhat ,diagrammaticperspective view of the door operating mechanism of Figs. 1 an 2;

Fig. 4 is an elevational view looking toward the charging side of a tilting furnace equipped with the door operating mechanism of Figs. 1, 2 and 3. In this View which is also more or less diagrammatic, three only of a series of charging doors are shown, it being understood that such seriesmay include as many doors as desired; and

Fig. 5 is an enlarged sectional view in elevation of the hoisting line tension maintaining mechanism of this invention. In this View, the mechanism, while it embodies the same principle as the mechanism of Figs. 1 to 4 inclusive, has a somewhat different arrangement of the elements of the mechanism.

Theopen hearth furnace which is more or less diagrammatically disclosed in the drawings is of the tilting type. It has an under frame 5 provided with arcuate rail-like portions 6 (one only being shown), whichare supported on anti-friction rollers I. These rollers are held in spaced relation by an 'arcuate retainer 8 and are sup-- ported on arcuate tracks 9 (one only being shown) on the top of the base member [0. The furnace is adapted to be tilted about its longitudinal center line I I by means of suitable power operated tilting mechanism through the agency of a connecting rod 12 as is usual.

Along its front or charging side, the furnace is provided with a number of vertically movable doors I3; there being one door for each charging opening; the number of such openings depending upon the size of the furnace.

-Referring to Figs. 2 to 4 inclusive, a hoisting unit It is provided for each door and these units are mounted on some suitable support such as member l5 located a sumcientdistance abovethe top of the furnace to provide space for installation of the hoisting line tension maintaining device of this invention.

.Each hoisting unit, may comprise an electric motor, a reduction gear, a crank or a winding drum, a suitable limit switch and a brake.

disclosed in Fig. 5 maybe utilized instead, if desired. The hoisting line may be a steel cable or' a chain, or part may be cable and another part.

chain. i

The hoisting line disclosed in Figs. 2 to 4 inelusive, throughout the major part of its length, comprises a steel cable ll while throughout the remainder of its length a chain I8 i utilized. The cable and chain portions are connected together by means of a turnbuckle device I 9 which isused as a connector and as means for adjusting the length of the line as a whole.

At its upper end, the hoisting line is connected to the crank of a hoisting unit as at 20, while at its lower end, a at 2|, it is connected to a yokelike member attached to the furnace door.

The pouring spout 22 of the furnace is located at the side of the furnace opposite doors l3. In order to pour, the furnace is tilted toward the pouring spout side about its longitudinal center line H through an arc of about 35. For the slagging operation, the furnace is tilted in the opposite direction through an arc of about 15.

During charging, melting down and refining, the furnace is held in its normal horizontal position.

The device of this invention comprises means or mechanism for maintaining a substantially constant tension in the hoisting line during tilting of the furnace to pouring and slagging positions. This device is located above the furnace and engages the hoisting line between the hoisting unit and the furnace door. When the furnace is being tilted to pouring and slagging positions the hoisting unit is not operating and the device of this invention maintains a substantially Figs. 2 to 4' inclusive, a crank I6 is shown, but it will be understood that a winding drum 42 as.

constant tension in the hoisting line during tilting of the furnace to such positions.

The tension maintaining device comprises three sheaves which engage the hoisting line at three spaced positions between the hoisting unit and the furnace door. The position of one of these sheaves is fixed. Another of the sheaves is mounted on the top of the furnace and therefore, its position is changed as the furnace is tilted. The third sheave is supported out of line with the other two by a pair of support arms. These support arms are pivotally connected together by means which is coaxial with the shaft of the of line with the other twov by the two support arms, a loop is. formed in the hoisting. line between the fixedposition sheave and the sheave mounted on the furnace.

sheave 2.3, the fixed position sheave, ismounted for rotation within a support bracket or meme ber 24 attached to the horizontal beam-like member 25 which is carried by vertical supports 26 and 21. Support bracket 24 as shown in Fig. 3 comprises spaced plate-like portions 28 which have aligned holes. for receiving shaft 29 of sheave 23. v

A sheave 30, which is the second sheaveof the tension maintaining deviceis mounted on a shaft 3! carried by. a bracket 32 secured tothe top of. the furnace at a position which, in this case, is immediately above its longitudinal center line. A sheave 33, the third sheave of thedevice,

issupported out of line with sheaves 23 and 30 by. means of support arms 34 and 35. These arms are pivotally connected together-by shaft 33, the shaft of sheave 33. Support arm 34 has its end remote from shaft 36 pivotally connected at 34a,

to the support member or bracket 24 adjacentabove the charging door 13 supports the chain i portion-of the hoisting line which extends vertically downward from thesheave tothe furnace door. While bracket 32 for sheave 33 is located directly above the longitudinal center.line..of the furnace, it may be located at some. other suitable position on top ofthe furnace structure, if desired;

W e st u t is opera ed. to i e. and;

lowerthe furnace door, which isonly while the. furnace is in horizontal position, sheave. 33 is held in the position shown in Figs. 1 and 2 by support arms 34 and 35.

As the furnace is tilted to pouring and slagging positions, the position of the loop formed'in the hoisting line is changed. When moved to pour-- ing position, sheave 33 is moved to the dotted" line position 38 and sheave 30 is moved tothe When the furnace is tilted to the slagging position, sheave 30 is moved dotted line position 39.

to dotted line position 40 and sheave 33 to dotted line position 4|. If \thepivot points fortheendsof support arms 34,:and35, the ends remote. from shaft 36,; co-,v

incided with the axes of rotation of sheaves 23 and 30, the change in the sum of the lengths of the arcs of contact between the hoisting line and sheaves 23, 30 and 33occasioned by tilting of the furnace-would either so increase the tension in the hoisting line as to cause the furnace door to be raised from closed position or would decrease the tension in the hoisting line sufficiently to permit disengagement of the sheaves by the oisting line.

I have found that it is possible to maintain the tension in the hoisting line substantially constant during tilting of the furnace in both directions, or so nearly constant that the furnace door is not raised from closed position nor is sufficient slack occasioned in the hoisting line topermit disengagement of the sheaves by such I accomplish this by locating the pivot line. point 34a for arm 34 and pivot point 35a for arm 35 at points removed from the axes of rotation of sheaves 23 and 30.

Inan installation in which the tension main taining device of this invention arranged in accordance with the disclosure of Fig. 2 is used in connection with a tilting open hearth furnace of 200- tons capacity, certain-of the elements of the: deviceare arranged as follows so far as sizes and'locations are concerned.

The distance between pivot point 34a and the center of shaft 36 is '7 feet 7 /2 inches. Pivot point 34a is located 11 inches to the left of the center ofshaft 29 of sheave'23, and is dropped 3% inches below the center of such shaft. distance between the center of shaft 35 and pivot point 35a is 7 feet 4 inches.- Pivot point 35a is located 12 and inches to the left of the center of shaft 3l-and is dropped 1 inch below thecenter of such shaft.

In this installation, th sheaves 23, 30 and 33 are all 15 inches in diameter and are provided with a 2 inch deep hoisting'line groove.

The distances between the center of shaft 36 and pivot points 34a and 35a depend upon the available space between the top of the furnace structure and the center of shaft 29 of sheave 23. It is important in laying out the device to makesure that support arms 34 and 35 do not-become aligned or in other words, straighten out-during tilting of the furnace.

Now referring-to Fig. 5, it will be seen that a slightly different arrangement of sheaves and support arms is utilized in the tension maintaining device.

The hoisting unit 42 is here shown of the winding drum type. This unit is mounted on a horizontal platform carried by one of the main rail support beams.

Inthis form, a chainis usedas the hoisting.

line. Between the hoisting unit and thefixed position sheave 43 over. which the chain passes, it passes underguide sheaves42a and 42b. The shaft of sheave 43 is numbered 44. and is car ried by a pair of horizontal channel members 45. (only one being shown) secured to the main.

rail beams.

Sheave 46, corresponding to sheave 3ll, is

mounted on a shaft 41 carried by bracket secured to the top of the furnace at a point-directly above its longitudinal center line 48.

shaft is numbered; 50.

channel members 45 at a point below and to the right of shaft 44 of sheave 63.

A sheave 53 mounted on the top of the furnace directly above door I3 keeps the hoisting line (chain) betweenit and the door vertical when the furnace is in normal or horizontal position, the only position during which the door is operated.

In tilting to the left to pouring position (Fig. sheave 49 moves to dotted line position 4911, while sheave 46 moves to dotted line position 4601.. When the furnace is tilted to slagging position, sheave 49 moves to dotted line position 49b while sheave 46 moves to dotted line position 4%. A sheave 53 located above the furnace door side of the furnace holds the furnace door end of the hoisting line in vertical position directly above the door I3.

In an installation in which the tension maintaining device of this invention arranged in accordance with the disclosure of Fig, 5 is used in connection with a tilting open hearth furnace of 175 tons capacity, the pivot point for the upper end of support arm 5! is located 5 inches to the right of the center of shaft M of sheave 43, and is dropped 5 ,4; inches below the center of such shaft.

In this installation, the distance between pivot point 53 at the upper end of arm 5| and the center of shaft '50 of sheave 49 is 4 feet inches While the distance from the center of shaft 50 of sheave 49 to the center of shaft 41 of sheave 46 is 7 feet. In this installation, the pivot point for the lower end of support arm 52 coincides with the center of shaft 4'! of sheave 45.

In some arrangements, as in this one, it is only necessary to ofiset the pivot point of the outer end of but one of the supporting elements for the out of line sheave in order to maintain a substantially constant tension in the hoisting line during tilting of the furnace, or a tension which is so nearly constant that the furnace door is not raised from closed position during tilting nor is suflicient slack occasioned in the hoistelements for the out of line sheave, as in the arrangement of Fig. 5.

The term sheave as used herein means any rotatable element capable of holding the hoisting line in place, and the hoisting line contact surface of which is concentric with its axis of revolution.

Havin thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. The combination with a tilting furnace having a vertically movable door on one side and a pouring opening on the opposite side, of a hoisting unit mounted independently of the furnace, a hoisting line operated by such unit and extendin therefrom to said door, three spaced hoisting line contact members which are partially encircled by the hoisting line and are arranged at spaced positions between the hoisting unit and said door, with the intermediate support member out of line with the other two to form a loop in the hoisting line, and means constructed and arranged to support such out of line member and compensate for such changes in the lengths of the arcs of contact between the hoisting line and such members as occur during tilting of the furnace to pouring and slagging positions.

2. The combination with a tilting furnace having a vertically movable door on one side and a pouring spout on the opposite side, of a hoisting unit mounted independently of the furnace, a hoistin line operated by such unit and extending therefrom to saiddoor, three sheaves which are partially encircled by the hoisting line and are arranged at spaced positions between the hoisting unit and said door, with the intermediate sheave out of line with the other two to form a loop in the hoisting line, and means constructed and arranged to support such out of line sheave and compensate for such changes in the lengths of the arcs of contact between the hoisting line and said sheaves as occur during tilting of the furnace to pouring and slagging positions.

3. The combination with a tilting furnace having a vertically movable door on one side and a pourin opening on the opposite side, o a hoisting unit, a hoisting line extending from such unit to said door, mechanism located between the hoisting unit and said door for maintainin the tension in the hoisting line substantially constant during tilting of the furnace to pouring and slagging positions; such mechanism comprising three sheaves each partially encircled by the hoisting line and so positioned as to form in such line a loop having taut sides, and means for compensating for the changes in the lengths of the sides of such loop as occur during tilting of the furnace to pouring and slagging positions.

4. The combination with a tilting furnace having a vertically movable door and an opposed pouring spout, of a hoisting unit mounted independently of the furnace, a hoisting line extending from such unit to said door, and a hoisting line tension maintaining device located between the hoistin unit and said door and employing three spaced sheaves each of which is partially encircled by said line; said device including means for supporting one such sheave out of line with the other two and for compensating for changes in the lengths of the arcs of contact between such line and said sheaves as occur during tilting of the furnace to pouring and slagging positions.

5. The combination with a tiltin furnace having a vertically movable door on one side and a pouring opening on the opposite side, of a hoisting unit, a sheave mounted on a fixed support above the furnace, a sheave mounted on the furnace, a hoistin line passing under said sheaves and operated by said unit to open and close said door, a third sheave intermediate the other two, out of line therewith and partially encircled by said hoisting line, thus forming a loop in such line, and means for supporting the out of line sheave and compensating for the changing lengths of the arcs of contact between the hoisting line and such sheaves occasioned during tilting of the furnace to pouring and slagging positions.

HARRY L. McFEA'IERS.

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