Patent Publication Number: US-3880302-A

Title: Drive and support mechanism for rotary and angularly adjustable member

Description:
United States Patent [1 1 1 3,880,302 Legille 1 Apr. 29., 1975 [54] DRIVE AND SUPPORT MECHANISM FOR 3.693.812 9/1972 Mahr 214/17 CB ROTARY AND ANGULARLY ADJUSTABLE MEMBER Primur E.\&#39;uminerAlbert .l. Makay Assistant E.\&#39;aminerGary Auton [75] Inventor: Edouard Legille, Luxembourg. Luxembourg [73] Assignee: S.A. Des Aneiens Establissements 1 1 ABSTRACT Paul Wurth Luxembourg A rotary and angularly adjustable member, disclosed Luxembourg in the form of a charge distribution chute mounted [22] Filed: June 11, 1973 within a furnace, may have its angle of inclination adjusted independently of the rotation. The drive and [21] Appl support mechanism includes a rotary housing and a pair of oppositely disposed gear boxes carried by the [30] F i A li i P i i D rotary housing The adjustable member is supported June 16 1972 Luxembourg 65537 drive shafts extending from the gear boxes and is thus rotatable with the housing and angularly adjust- [52] CL 214/35 214/17 266/27 able about the axis of rotation of the housing; angular [51 int. Cl. .7. Fi7b 1/20 adjustment being achieved by means of rotating the [58] Field of Search 214/17 CB 35 R 37 36 drive shafts. The angular adjustment producing por- 2l4/35 5 6 tion of the drive mechanism may include elastic gear means for dividing applied torque between the two [56] References Cited boxes 7 UNITED STATES PATENTS 7 Claims, 5 Drawing Figures 1.710.544 4/1929 Lyth 114/17 CB zaflfi 12/2 A2424 221% 2/6 +2/2 Z5? ll Z- 264 252[ j 22 24 226 I 2 0&#34; 242 I 2 52 2 256 I j 260 254 3 27 2% 256 296 24 2m 37! I 55a 5/2 37? ;I Zifl 50 5 50! 254 :2 3:96 585&#34;: 564 .ili j 5556 56X 35 592 2 59 255 355 400 aw 292 535 pmgminmzsms 3,880,302  
 SHEET 5 or s III I/ DRIVE AND SUPPORT MECHANISM FOR ROTARY AND ANGULARLY ADJUSTABLE MEMBER BACKGROUND OF THE INVENTION l. Field of the Invention The present invention relates to the delivery of material to the interior of a furnace and particularly to the charging of shaft furnaces. More specifically, the present invention is directed to charge distribution devices for controlling the placement of raw material on the hearth of a blast furnace. Accordingly, the general objects of the present invention are to provide novel and improved methods and apparatus of such character.  
 2. Description of the Prior Art Concomitant with the development of modern high output blast furnaces, and the desire to increase the usable yield from blast furnace installations, present furnace design efforts are directed to eliminating or minimizing factors which impede increases in economy of operation. A furnace operating condition or parameter of particular importance from the standpoint of economic operation is the charging or burdening step wherein the raw material is delivered from storage to the interior of the furnace.  
  The conventional prior art furnace charging installation was of the bell-type which included compensation chambers and and bells. Although considerable design effort has been directed to improving bell-type charging installations, the improvements in operation obtained have not been commensurate in degree with other furnace improvements. Also, the trend in furance design in recent years has been toward large high output furnaces. Bell-type charging installations for modern large furnaces would have to be such a size that their manufacturing limits would be exceeded. Also, modern furnaces operate with high throat pressures and it is difficult to achieve sealing of the furnace throat relative to the ambient atmosphere when employing a bell-type charging installation; particularly on large size furnaces. A further deficiency of bell-type charging installations is that such apparatus permits only a single charge configuration; namely the so-called characteristic M-curve. Irregular furnace throughgassing and corresponding difficulty in controlling and regulating the operation of the furnace are unavoidable results of the inability to control charge distribution to achieve charge profiles other than the aforementioned M-curve characteristic of bell-type installations.  
  A novel bell-less charging installation which overcomes the deficiencies of bell-type charging installations has recently been devised. This bell-less charging installation is described in U.S. Pat. No. 3,693,812, which is assigned to the assignee of the present invention, and said US. Pat. No. 3,693,812 is hereby incorporated herein by reference. The patented device is a novel bell-less charging installation which permits the charging configuration or profile to be randomly predetermined and also enables the sealing of the counterpressures at the furnace throat relative to the ambient atmosphere to be successfully achieved. In accordance with US. Pat. No. 3,693.812 a rotary distribution chute, adjustable in pitch angle relative to the blast furnace central axis, is arranged in the blast furnace port or throat. The raw material with which the furnace is to be charged is supplied to the distribution chute in metered quantities and is deposited on the furnace hearth by the chute in accordance with a predetermined configuration.  
  An improvement to the drive means of the apparatus of U.S. Pat No. 3.693.812, by which rotary movement and pitch angle adjustment of the charge distribution chute is obtained, is disclosed in US. Pat. No. 3.814.403. While the mechanisms for maneuvering the distribution chute of US. Pat. No. 3,693,812 and U.S. Pat. No. 3,814,403 have been proven to be exceedingly useful and successful, it has nevertheless been desired to provide a further improved distribution chute drive mechanism which is characterized by ease of replacement of the distribution chute itself.  
 SUMMARY OF THE INVENTION In accordance with the present invention a distribution chute is suspended, in a pitch angle-adjustable manner, from a rotary housing arranged concentrically with the axial charge inlet spout and positioned above the throat of a shaft furnace. The rotary housing is driven via a rotary sleeve and, on the side of the rotary housing positioned remote from the furnace, a pair of oppositely disposed gear boxes are provided. The gear boxes house portions of the drive mechanism for achieving the pitch angle adjustment of the chute. The pitch angle adjustment gear boxes each drive a shaft which passes horizontally through the rotary housing and the distribution chute is fixed. at its two oppositely disposed longitudinal sides, to the ends of these drive shafts. The present invention also contemplates means for rotating the housing and for driving the gear boxes in such a manner that the rotation may be achieved independently of the pitch angle adjustment of the chute.  
 BRIEF DESCRIPTION OF THE DRAWING The present invention may be better understood and its numerous objects and advantages will become apparent to those skilled in the art by reference to the accompanying drawing wherein like reference numerals refer to like elements in the several figures and in which:  
  FIG. 1 is a perspective view of the improved drive mechanism of U5. Pat. No. 3,814,403, FIG. 1 being included in the present application in the interest of relating the drive mechanism of the present invention to the other components of a charging installation;  
  FIG. 2 is a cross-sectional sidc&#39;elevation view of a portion of a charging installation in accordance with a first embodiment of the present invention;  
  FIG. 3 is an enlarged cross-sectional view of a portion of the drive mechanism of FIG. 2;  
  FIG. 4 is an exploded view of the mechanism of FIG. 3; and  
 FIG. 5 is a partial cross-sectional view of a second I embodiment of a drive mechanism in accordance with the present invention.  
 DESCRIPTION OF THE PREFERRED EMBODIMENTS feed spout 62. The drive mechanism of FIG. 1 includes a main drive motor 1 which is coupled, via gears 4 and 6, to a main drive shaft 8; the coupling mechanism also including a coupling 2 and brake 3. The main drive shaft 8 has affixed thereto, in addition to drive gear 6, gears 10 and 12. The gear 12, via drive means indicated generally at 11, causes rotation of a disc 24 which is concentric with feed spout 62. The drive means 11 comprises a ring gear 14 having a rotary cylinder 16 affixed thereto. The drive means further comprises a further ring gear 18 which is also attached to cylinder 16. The ring gear 18 engages a ring gear 20 affixed to a rotary sleeve 22 mounted coaxially of the central feed spout 62. The rotary sleeve 22 is rigidly connected to the rotary disc 24. The distribution chute is connected, by means not shown, directly to disc 24 at a point opposite to the coupling to drive shaft 60 and thus a desired rotary movement about the blast furnace axis A is imparted to the distribution chute by the main drive motor 1.  
  The gear 10 on main drive shaft 8 also drives, via a planetary gear means indicated generally at 13, an auxiliary drive shaft 42. The auxiliary drive shaft 42 is employed, in the manner to be described below, to achieve independent pitch angle adjustment of the rotating distribution chute. The planetary gear means 13 comprises a planet wheel 13 which is directly engaged by gear 10 on main drive shaft 8. The planetary gear means also includes a pair of intermediate gear wheels 34 and 36 and an inner gear 32. The two intermediate gears 34 and 36 of planetary gear means 13 directly drive a rotary disc 40 via respective intermediate shafts 35 and 37. Rotary disc 40 is rigidly connected to auxiliary drive shaft 42. Auxiliary drive shaft 42 passes through the. intermediate gear means 11 and is provided, at its lower end, with a further gear 44. Gear 44 drives a ring gear 46 which is mounted on rotary disc 24 by means of bearings 48; ring gear 46 being independently rotatable relative to disc 24.  
  The ring gear 46 on rotary disc 24 drives, via pinion gear 50, a shaft 56 which passes through disc 24 and is rotatably mounted therein. Shaft 56 is provided, at its lower end, with a worm thread 54. The worm gear 54 on shaft 56 drives, via an intermediate gear 57, a partial ring gear 58. Partial ring gear 58 is affixed to one end of a shaft 60 and, as noted above. the other end of shaft 60 is connected to the distribution chute by means which permits the pitch angle of the chute to be adheat and flue dust, the worm gear 54 and the gears 57 and 58 are housed in a gear box 52 which is fixed to the underside of disc 24. v  
  Further considering the means by which the angular position of the distribution chute maybe adjusted independently of the rotation thereof, the inner gear 32 of planet gear means 13 is connected to an auxiliary drive motor 25 via a drive shaft 33, gears 28 and 30, a brake device 27 and a coupling means 26.  
  To summarize operation of the drive mechanismof FIG. 1, the main drive motor 1 rotates disc 24 and, with a correctly selected transmission ratio of the various intermediate gears, the-ring gear 46 mounted on rotary disc 24 will rotate at the same speed as disc 24. With no relative speed between disc 24 andring gear 46 the position of pinion gear 50 will remain unchanged relative to its rotary axis. The distribution chute will there-.  
 fore be rotated about the furnace axis A without its angular position relative to this axis being changed.  
  When it is desired to change the angular position of the distribution chute, the auxiliary drive motor 25 is employed, via planet gear means 13, to impart a speed increase or decrease relative to the speed of movement of disc 24 to ring gear 46. Any relative speed between ring gear 46 and rotary disc 24 will cause pinion 50 to be rotated and thereby causing a change in the angle of inclination of the distribution chute. A variation in relative speed between ring gear 46 and rotary disc 24 may be achieved by employing an auxiliary drive motor 25 which can be reversed or through the selection of gear ratios whereby synchronous speed between rotary disc 24 and gear ring 46 exists only at a particular ratio between the rotational speeds of main drive motor 1 and auxiliary motor 25.  
  The inclusion of the protective gear box 52 affixed to the underside of rotary disc 24 may not, under some conditions, provide adequate protection from furnace internal conditions for the components of the drive mechanism positioned therein. Heat surges within the furnace can briefly reach temperatures of 1,000C and, due to thermal expansion, could conceivably lead to locking of gears 54, 57 and 58 located in gear box 52. Of perhaps more significance, the position of gears 54, 57 and 58 precludes their being cooled by the throughflow of inert gas or purified and cooled blast furnace gas.  
  As may best be seen by reference to copending Application Ser. No. 355,730, the pitch angle adjusting forces provided by the drive mechanism disclosed in the copending application are applied only at one longitudinal side of the distribution chute; i.e., by means of the shaft 60. This manner of angular drive imposes extremely stringent strength requirements on the chute material. Additionally, angular adjusting forces must be absorbed by the chute and must be transferred at the second longitudinal side thereof to a mounting. The previous arrangement thus leads to torsional stresses in the distribution chute which are increased during the charging process when the chute is loaded with raw material being delivered to the furnace.  
  FIG. 2 is a cross-sectional view of a first embodiment of an improved distribution chute drive device in accordance with the present invention. in FIG. 2, the distribution chute is indicated at 208 in a horizontal position. The opposite disposed longitudinal sides of chute 208 are connected, by means of respective guide memebers 390 and 392, to rotatable shafts 322 and 324. Shafts 322 and 324 are rotatable about a horizontal axis to vary the inclination ofdistribution chute 208.  
  The shafts 322 and 324 are supported in respective gear boxes, indicated generally at 270 and 27 2, and the gear boxes are in turn rigidly mounted within a rotary housing defined by elements 228, 234 and 236. Accordingly, the distribution chute 208 is directly connected to the rotary housing and, in the manner to be explained below, is rotated therewith by means of a suitable drive.  
  v In order to impart rotational movement to the rotary housing and thus to the distribution chute 208, a rotary cylinder 200 penetrates the upper wall 202 of a drive chamber indicated generally at 204. The drive chamber 204 is in the form of a superstructure mounted on the blast furnace top or throat. Referring again briefly to FIG. 1, rotary cylinder 200 is drived by main drive motor 1 via gears 4, 6 and 12. The end of rotary cylinder 200 which projects into drive chamber 204 is provided with a gear 206. Gear 206 engages a ring gear 212 located concentrically relative to the central feed spout 210: ring gear 212 being supported by a bearing bracket 214. The bearing bracket 214 is fixed rigidly to the underside of the upper wall 202 of drive chamber 204 and comprises a bearing such as, for example, a &#34;roller rotary connection with groups of rollers 216, 218. 220 for the axial and radial support of ring gear 212. The roller rotary connection is continually supplied with lubricant under pressure from outside the drive chamber 204 by means of conduits 222 and 224.  
  The ring gear 212 is provided, at its underside, with an integral adapting ring 226 which serves to extend the ring gear inwardly toward the central feed spout 210. As previously noted, the rotary housing includes elements 228, 234 and 236; these elements respectively comprising a conical rotary sleeve, a vertical casing and a horizontal rotary disc. The conical rotary sleeve portion 228 of the rotary housing is attached to the adapting ring 226 by means of bolts 230 and 232.  
  As previously described, the means for achieving pitch angle adjustment of distribution chute 208 are mounted within gear boxes 270 and 272. The gear boxes 270 and 272 are positioned on the side of the rotary housing which is remote from the furnace in the interest of minimizing the influence of the blast furnace environment on the components located in gear boxes 270 and 272. The gear boxes 270 and 272, as well the gears located therein. are designed so as to be homologous to one another with reference to a plane passing through the blast furnace logitudinal axis A.  
  The means by which rotation of shafts 322 and 324 is achieved comprises. referring again to FIG. 1, the planetary gear means 13, auxiliary motor 25, gear 10 and rotary disc 40. The pitch angle adjustment drive further comprises a drive shaft 238 coaxial with rotary cylinder 200, a gear 240 attached to shaft 238 and a pair of ring gears 242 and 246 which are interconnected via an intermediate gear 244. The two ring gears 242 and 246 are mounted by means of a further roller rotary connection on a bearing support ring 254. The bearing support ring 254 is arranged concentrically with the central feed spout 210 and is attached to the underside of the upper wall 202 of drive chamber 204 via a thick-walled circular sheet metal casing 252. The roller rotary connection between ring gears 242 and 246 and bearing support ring 254 comprises three groups of rollers 256, 258 and 260 for absorbing the axial and radial forces of ring gears 242 and 246. A continuous supply of a suitable lubricant is delivered to the rotary roller connection&#34; defined by bearings 256, 258 and 260 via channels 262 and 264 provided in the bearing support ring 254 and in casing 252 whereby the lubricant can be supplied to the roller bearings under an appropriate pressure from outside of drive chamber 204. It is to be noted that the circular sheet&#39;metal casing 252 is provided with recesses in the area of the gears 206 and 240 which partially intersect casing 252.  
  As an alternative to the rigid attachment of the support ring 254 for the roller rotary connection to the upper wall 202 of drive chamber 204, the roller rotary connection for ring gears 242 and 246 may be attached to the rotary housing 228 and carried along thereby.  
 The drive for ring gears 242 and 246 will, in either event, be integrally maintained in the same manner as the remaining gear for pitch angle adjustment of the distribution chute 208.  
  The gear box 270 comprises supporting members 282 and 286, walls 274 and 278 and a closure plate 290; the closure plate being welded to the lower ends of support members 282 and 286. Similarly. gear box 272 comprises supporting members 284 and 288, walls 276 and 280 and closure plate 292 welded to support members 284 and 288. The gear boxes 270 and 272 are liquid inpervious whereby an oil bath for the gears may be provided within each of the gear boxes. The gear boxes 270 and 272 may, as desired, be permanently or detachably connected to the rotary housing defined by elements 228, 234 and 236. in the embodiment of FIG. 2 the support members 286 and 288, respectively of gear boxes 270 and 272 are attached by suitable fasteners to respective supports 370 and 372 welded to the conical rotary sleeve 228.  
  Drive wheels 298 and 300 are positioned immediately above the upper walls 272 and 276 of respective gear boxes 270 and 272. The drive wheels 298 and 300 are engaged by ring gear 246. Drive and support shafts 294 and 296, respectively for drive wheels 298 and 300, pass into the respective gear boxes and are supported in the top walls of the gear boxes by means of bearings, not shown. A worm drive 302, 306 within gear box 270 transfers the torque of the drive wheel 298 to a shaft 310 and thus to a spur gear 316. The spur gear 316 drives a partial ring gear 319. The partial ring gear 319 has a hollow shaft 326 which is rigidly connected with a hollow spline shaft 330. Spline shaft 330 is rotatably mounted by means of bearings 338, 342 in the supporting members 282, 286 of gear box 270. The inclination angle adjustment drive shaft 332 is inserted in spline shaft 330 and passes through the vertical casing 234 of the rotary housing and partially projects into the blast furnace port. in the same manner. gear box 272 houses a worm drive 304, 308, shaft 312, spur gear 318, partial ring gear 320, hollow ring gear shaft 328 and hollow spline shaft 332. The spline shaft 332 of gear box 272 is rotatably mounted by means of bearings 340, 344 in supporting members 284 and 288. R0- tatable shaft 324 is inserted in spline shaft 332 of gear box 272 and also passes through the vertical casing 234 of the rotary housing and partially projects into the blast furnace port. The portions of shafts 322 and 324 which project into the blast furnace port support respective connecting arms 390 and 392 and, as previously noted, the distribution chute 208 is fixed to these connecting arms via respective bolted joints 394, 396 and 398, 400. The connecting arms 390 and 392 are provided with spline shaft recesses through which the arms are pushed onto respective shafts 322 and 324.  
  The spline shafts 330 and 332 are provided with respective annular projections 346 and 348 which locate the front ends of respective hollow ring gear shafts 326 and 328 relative to ball bearings 342 and 344 in the interest of preventing displacement of the partial ring gears with respect to the spline shafts. Additional spacers 350 and 352 are placed between respective hollow ring gear shafts 326 and 328 and associated bearings 338 and 340. The bearing mountings 354, 358 and 356, 360 are placed on the outside of supporting members 282, 286 and 284, 288. The bearing mountings 354, 358 and 356, 360 serve simultaneously as flanges for the attachment of sealing rings 362, 366 and 364, 368. The drive shafts 322 and 324 are themselves provided, on the ends opposite to the central feed spout 210, with end plates 378 and 380 which serve as stop members; the end plates and thus the drive shafts being held in the proper position by respective clamps 382, 384 and 386, 388.  
  Should it be desired to remove distribution chute 208 from the furnace throat for any reason, the chute is manipulated into the position where it projects horizontally into a hatch, not shown. provided in the blast furnace throat. The chute is thereupon fixed to a crane yoke. Subsequently, manholes or service ports 434 and 436 provided on drive chamber 204 are opened thereby affording maintenance personnel with access to drive shafts 322 and 324. The clamps 382, 384 and 386, 388 are thereafter removed thus permitting shafts 322 and 324 to be withdrawn to an extent such that the connecting arms 390 and 396 are free. To facilitate this withdrawal process, threaded holes 430 and 432 are provided on respective shafts 322 and 324; threaded holes 430 and 432 receiving a withdrawal tool.  
  To facilitate reassembly, the ends of the shafts 322 and 324 which engage respective connecting arms 390 and 392 are provided with a conieally shaped lead portion as shown in FIG. 2.  
  The drive mechanism of FIG. 2 is, in the embodiment described, located in the vicinity of the throat of a blast furnace and thus is potentially exposed to blast furnace flue dust and high temperatures. For the purposes of cleaning and cooling the drive mechanism, inert gas or purified and cooled blast furnace gas is fed into the drive chamber via a port 438. The supply pressure for this cleaning and cooling gas is selected to be higher than the counter-pressure at the blast furnace throat so that gas from drive chamber 204 flows into the blast furnace top or throat. In FIG. 2 the gas discharge points from the drive chamber into the furnace throat are indicated by means of arrows 385.  
  In operation, synchronous rotational speed of ring gear 212 and the interconnected ring gears 242, 246 result in the distribution chute 208 being rotated with an unchanged pitch angle. In the case of a relative speed difference between ring gear 212 and gears 242, 246, the pitch angle of the distribution chute 208 will be changed.  
  When a distribution chute inclination angle change is commanded, the total force necessary to produce the desired angular movement of the chute will be divided between ring gears 242 and 246. In the optimum case each of gears 242 and 246 will transmit half of the requisite power to the chute. Due to manufacturing tolerances, as well as lack of precision workmanship during construction of the gears, the relationship between the power transmitted by the two gears deviates from the optimum 50-50 division in actual practice. It would, in the least favorable situation, be possible for all the power to be transmitted by a single gear as is the case in the apparatus of referenced US. Pat. No. 3,814,403. As previously noted, the application of the total angular drive torque to one side of the distribution chute may impart substantial stress to the various components of the drive and the chute.  
  In order to approach, to the degree possible, an equal division of power between the ring gears 242 and 246, the drive wheels 298 and 300 will, in the preferred embodiment, possess a degree of elasticity. An example of such an adjustable and elastic drive wheel is depicted in FIG. 3 FIG. 3 represents a partial cross-section through one of the drive wheel means 298 and 300 whereas FIG. 4 shows the drive wheel means of FIG. 3 in an exploded view. Referring jointly to FIGS. 3 and 4, each of drive wheels 298 and 300 includes a shaft 294, a drive disc 410, a counter-disc 402 and a ring gear 408. The drive disc 410 is keyed to shaft 294 as indicated at 414. The counter-disc 402 is provided, on its underside. with projections 424, 424 and 424&#34;; projection 424&#34; not being shown in FIG. 4. The counter-disc 402 is rigidly connected to drive disc 410 by means of bolts 412, 412&#39; and 412&#34;; the disc 402 and ring gear 408 being provided with elongated slots whereby a limited degree of adjustment of disc 402 relative to disc 410 is permitted. The ring gear 408 is provided with three radially inwardly projecting members 422, 422 and 422&#34;. With the gear means assembled, the projections 424 on disc 402 loosely mesh with the projections 422 of ring gear 408. The projecting members 422 and the projections 424 are separated from one another by means of helical springs 416, 416&#39;, 416&#34;, 416&#39;, 416, and 416&#34;. As a result of the aforementioned elongated slots in gear 408, the ring gear is capable of a limited degree of elastic rotary movement relative to drive disc 410 and counter-disc 402. To further aid this relative movement of ring gear 408, thrust bearings 404 and 406 are respectively inserted between disc 402 and gear 408 and between gear 410 and gear 408. In operation, torque resulting from the driving of ring gear 408 is transmitted, by means of the helical springs 416, to disc 402 and thus to drive disc 410. The helical springs 416 thus permit an elastic transfer of torque from ring gear 242 to worm gears 302 and 304. The torque is transferred approximately uniformly through the helical springs so that a uniform elastic force is exerted on shafts 322 and 324 and the substantially evenly divided force is transmitted to both sides of the distribution chute for adjusting the angle of inclination thereof.  
  FIG. 5 depicts a further embodiment of a distribution chute drive mechanism in accordance with the present invention; only one half of the drive unit being shown in FIG. 5. The principal difference between the embodiments of FIGS. 2 and 5 resides in the replacement, in the FIG. 5 embodiment. of the inclination drive shafts 322 and 324 with hollow spline shafts as indicated at 530. The use of the hollow spline shaft 530, however, requires that the manner of connecting the other members of the drive mechanism and the distribution chute 208 to the drive shafts be changed. Referring jointly to FIGS. 2 and 5, the hollow shaft 326 of partial ring gear 319 is, in the FIG. 5 embodiment, held on the spline shaft 530 by means of spacing and sealing rings 532 and 534. The spacing and sealing rings 532 and 534 are, in turn, mounted relative to the fixed walls 282 and 286 of the gear box by means of bearings 536 and 538. The attachment of distribution chute 208 to spline shaft 530 is achieved through the use vof an adapter disc S42; chute 208 being detachably connected to disc 542 by means of bolts. The distribution chute 208 includes an outer casing 544 of thick-walled heat-resistant steel sheeting and an inner cladding 546 of wear-resistant material. A sealing flange 548 having projections 550 and 552, is attached to outer casing and outer casing 544, adapting disc 542 and spline shaft 530.  
  The sealing flange 548 has a further projection 554 which is located in the continuation of the longitudinal axis of the hollow spline shaft 530. The shaft 530 is supported on the projection 554 of sealing flange 548 shown. In order to prevent the sliding of shaft 530, the spline shaft isprovided, at the end disposed away from the blast furnace feed spout, with a removable plate 564 having openings 566 and 568 therein. A bolt 570 arranged coaxially with shaft 530 connects plate 564 to projection 554 of sealing flange 548. In addition, the spline shaft 530 is provided with an annular slot 572 which will be engaged by a suitable removal tool.  
  The hollow spline shaft 530 is provided, at the end facing the sealing flange 548, with openings 558 and 560. An inert gas flow through shaft 530 between openings 566, 568 and 558, 560, as well as through space 553, will achieve desirable cooling and cleaning of hollow spline shaft 530.  
  While preferred embodiments have ben shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of this invention. Accordingly, it is to be understood that the present invention has been described by way of illustration and not limitation.  
 What is claimed is:  
  l. A drive and support mechanism for a rotary and angularly adjustable material distribution chute positioned internally of a furnace comprising:  
 generally annular rotary support means positioned coaxially ofa port in the furnace wall, and supporting the distribution chute, said support means being located externally of the furnace;  
 means for imparting rotational motion to said support means;  
 first and second gear box means mounted on said support means and movable therewith, said gear box means being oppositely disposed with respect to the distribution chute and each other and supporting drive gear means;  
 drive shaft means extending from each of said gear box means, said drive shaft means being operatively associated with said drive gear means and being disposed in the same plane for rotation about an axis transverse to the axis of rotation of said support means;  
 means rigidly connecting oppositely disposed points on the distribution chute to respective of said drive shaft means whereby the chute will follow the movements of said support means and said drive shaft means; and  
 means including the drive gear means in said gear box means for transmitting rotational motion to said drive shaft means independently of the rotary motion of said support means.  
  2. The apparatus of claim 1 wherein said gear box means each comprise:  
 enclosure means supported from said annular support means, said enclosure means being mounted from said annular support means on the side thereof disposed away from the furnace, said enclosure means being adapted to contain a reservoir of lubricant for the drive gear means disposed therein.  
  3. The apparatus of claim 2 wherein said means for imparting rotational motion to said support means comprises:  
 a main drive motor positioned remotely from said support means and having an output shaft;  
 transmission means including a rotary sleeve for coupling said main drive motor output shaft to said support means; and  
 bearing means for supporting said support means for the furnace superstructure.  
  4. The apparatus of claim 3 wherein said means for transmitting rotational motion to said drive shaft means comprises:  
 planetary gear means including a planet gear, intermediate gear means and an inner gear;  
 means coupling said planetary gear means planet gear to said main drive motor;  
 an auxiliary drive motor;  
 means coupling said planetary gear means inner gear to said auxiliary drive motor; and  
 means transmitting motion imparted to said planetary gear means intermediate gear means to the drive gear means supported within each of said gear box means.  
  5. The apparatus of claim 3 wherein said means for transmitting rotational motion to said drive shaft means comprises:  
 means for generating a torque commensurate with desired angular position changes of the material distribution chute; and  
 first and second elastic gear means for dividing and transmitting the torque provided by said generating means to the drive gear means disposed in said first and second gear box means.  
 6. The apparatus of claim 5 wherein said means for generating torque comprises:  
 planetary gear means including a planet gear, intermediate gear means and an inner gear;  
 means coupling said planetary gear means planet gear to said main drive motor;  
 an auxiliary drive motor;  
 means coupling said planetary gear means inner gear to said auxiliary drive motor; and  
 means coupling said planetary gear means intermediate gear means to both of said elastic gear means.  
  7. The apparatus of claim 6 wherein said elastic gear means each comprise:  
 a drive disc;  
 a counter-disc, said counter-disc being provided with projections thereon;  
 a ring gear, said ring gear being coupled to said planetary gear means intermediate gear means and being provided with projections thereon which mesh with said counter-disc projections;  
 means rotatably supporting said ring gear being sandwiched between said driving disc and counter-disc;  
 means for adjustably connecting said drive disc to said counter-disc, said adjustable connecting means permitting a limited relative rotational displacement between said counter-disc and driving disc;  
 spring means coupling the projections on said counter-disc to the projections on said ring gear; and  
 means coupling said interconnected discs to the gear box drive gear means.  
 PATENT M).  
 DATEU Abstract,  
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 [SEAL] 3,880,302 April 29, 1975 Edouard Legille v, in above-identified psi ient and the. said Lette s Patent last line, before &#34;boxes&#34; insert -gearline 36, after &#34;be&#34; insert &#34;of&#34; lines 31 and 32 change &#34;Copending Application Serial NO. 355,730&#34; to U.S. Patent 3,814,403  
 line 2, change &#34;drived to driven-- line 22, change &#34;272&#34; to Z7 line 3, after &#34;FIG. 3&#34; (first occurrence) insert a period lines 32-35 (Claim 1) change generally annular rotary support means positioned coaxially of a port in the furnace wall, and supporting the distribution chute, said support means being located externally of the furnace;&#34; to generally annular rotary support means supporting the distribution chute, said support means being positioned coaxially of a port in the furnace wall and being located externally of the furnace?- Signcd and Scaled this A ttes t:  
  C. MARSHALL DANN Commissioner of Patents and Trademarks RUTH C. MASON Alrzsting Officer