Abstract:
A device for distributing materials in bulk includes a suspension rotor and a chute located below the suspension rotor. The chute is provided with two lateral suspension arms which are connected to the suspension rotor. A driving mechanism produces a pivoting torque capable of pivoting the chute, while a cylindrical suspension pin is associated with each suspension arm for pivotably connecting it to the suspension rotor. A control lever is connected to the suspension rotor, the driving mechanism being connected to the control lever so as to transmit to the latter the pivoting torque. A stop on the control lever and a counterstop on a suspension arm engage with each other to transmit the pivoting torque to the suspension arm. The stop and the counterstop are disengagable by a translation movement of the two suspension arms after withdrawal of the cylindrical suspension pins for removal of the chute.

Description:
FIELD OF THE INVENTION 
   The present invention relates to a device for distributing materials in bulk with a rotary chute having a variable angle of inclination. It relates more particularly to such a device comprising a suspension rotor, a chute provided with two suspension arms, each of which is connected to the suspension rotor by means of a suspension pin in such a way as to define on the suspension rotor a pivoting axis for the chute, and a driving mechanism to produce a pivoting torque capable of pivoting the chute about its pivoting axis. 
   BACKGROUND OF THE INVENTION 
   Such devices for distributing materials in bulk are for example used in installations for charging shaft furnaces, particularly blast furnaces, in which the rotary chute with a variable angle of inclination provides for the distribution of the charge inside the shaft furnace. It should be appreciated that, in such a device, the chute is an element subject to wear, which must be replaced from time to time. Hence the necessity of suspending the chute in an easily removable way in its suspension rotor while ensuring a reliable transmission of a large pivoting torque to the chute. 
   Devices for distributing materials in bulk with a rotary chute having a variable angle of inclination are described, for example, in U.S. Pat. No. 3,814,403, U.S. Pat. No. 5,022,806 and patent application DE 3342572. 
   The chute in the device described in U.S. Pat. No. 3,814,403 is provided with lateral suspension journals. On one side it comprises two separated suspension journals, which are received in two separated housings of a suspension flange driven in rotation by the pivoting mechanism so that this suspension flange can transmit the pivoting torque to the chute. On the opposite side, it comprises a single suspension journal, which can rotate in a housing of a fixed flange. The journals are fixed in the two flanges by means of transverse wedges. 
   The chute in the device described in U.S. Pat. No. 5,022,806 is also provided with lateral suspension journals. On one side it comprises two separated suspension journals, which are received in a housing of a suspension flange driven in rotation by the pivoting mechanism, so that this suspension flange can transmit the pivoting torque to the chute. On the opposite side, it comprises a single journal, which is received in the housing of a flange free to rotate on a pivot. 
   The chute of the device described in the patent application DE 3342572 is provided with two suspension arms of special shape. Each of these suspension arms is received in the housing of a suspension flange driven in rotation by the pivoting mechanism. The shape of the suspension arm provides for the housing of the suspension flange to be locked while allowing the chute to be easily withdrawn after it is raised. The two suspension flanges transmit the pivoting torque to the chute. 
   The charging device described in the patent application FR 882167 comprises an oscillating charging tube, which is suspended by means of two long horizontal arms like a pendulum in a rotary cylinder. The extremities of the suspension arms are mounted on bearings in the rotary cylinder. One of these extremities carries an actuation lever. A knee-shaped control lever is fixed to the cylinder by means of a bearing. A first extremity of the control lever is connected by a connecting rod to an oscillation mechanism. A second extremity of the control lever bears a slide, which is guided in a closed runner of the activating lever. It is not described how to remove the charging tube. 
   SUMMARY OF THE INVENTION 
   An objective of the present invention is to propose a device for distributing materials in bulk provided with a simpler and more compact suspension for the chute, which nevertheless allows large pivoting torques to be transmitted to the chute while providing for easy removal and installation of the chute. In conformity with the invention, this objective is achieved by a device according to Claim  1 . 
   A device for distributing materials in bulk according to the invention comprises a suspension rotor and a chute located below the suspension rotor. This chute is provided with two lateral suspension arms extending upwards where they are connected to the suspension rotor so as to define a roughly horizontal pivoting axis for the chute on the suspension rotor. The device also comprises a driving mechanism for producing a pivoting torque capable of pivoting the chute about its pivoting axis. A cylindrical suspension pin is associated with each suspension arm for pivotably connecting it to the suspension rotor. Each of these two cylindrical suspension pins is arranged in a retractable manner in a bearing of the suspension rotor. A control lever is connected to the suspension rotor by means of an articulated joint. The driving mechanism is connected to this control lever to transmit to the latter the pivoting torque. In order to transmit this pivoting torque to a suspension arm, the control lever is provided with a stop, which comes into contact with a counterstop provided on the respective suspension arm. The stop and counterstop are moreover designed in such a way that they can be disengaged by a translation movement of the two suspension arms after withdrawing the cylindrical suspension pins for removal of the chute. It should be appreciated that this device is distinguished by a very simple and very compact suspension of the chute, which enables large pivoting torques to be transmitted to the chute, while ensuring easy removal and installation of the chute. 
   The pivoting torque may be transmitted to the chute through only one of the two suspension arms. However, a symmetrical transmission of the pivoting torque to the two suspension arms is more advantageous. For this purpose, a control lever is associated with each of the two suspension arms and connected by means of an articulated joint to the suspension rotor. The driving mechanism is then connected to the two control levers to transmit the pivoting torque symmetrically to said levers. In this device, in order to transmit the pivoting torque to the two suspension arms of the chute, a stop on each of the two control levers cooperates with a counterstop on the suspension arm with which the respective control lever is associated. 
   It is of course possible to devise different driving mechanisms to transmit a pivoting torque to the control lever or levers. In a preferred embodiment, this driving mechanism comprises a control rotor having a rotation axis coaxial with the suspension rotor, and an angular drive carried by the suspension rotor. The input shaft of this angular drive is provided with a pinion, which meshes with an annular gear carried by the control rotor. Its output shaft is parallel to the pivoting axis of the chute and is driven in rotation when the input shaft is driven in rotation by the control rotor. A mechanism consisting of a crank and connecting rod connects the output shaft to the control lever or levers. It should be noted that a rotation of the input pinion of the angular drive takes place if there is a difference in angular speed between the suspension rotor and the control rotor. This rotation of the input shaft produces a rotation of the output shaft of the angular drive which is converted by the crank and connecting rod mechanism into a pivoting of the control lever or levers about their articulated joint or joints on the suspension rotor. 
   It is also possible to devise different embodiments of the stop and the counterstop. In a preferred embodiment, the stop is for example formed by a driving pivot carried by the control lever. The counterstop is then advantageously formed by a guiding slot made in said suspension arm of the chute. This guiding slot advantageously has an entrance in the free end of the arm so as to be able to introduce into it the driving pivot by a translation of the suspension arm in a direction perpendicular to the driving pivot. 
   In order to facilitate the installation and removal of the suspension pins, each of the two suspension arms of the chute advantageously comprises an oblong hole for the passage of its suspension pin, so that the two suspension pins can be freed by raising the chute. 
   In order to optimise the transmission of the pivoting torques from the control lever to the suspension arm, it is advantageous to have the suspension pin of the suspension arm and the articulated joint of the control lever substantially coaxial. 
   With the same objective, it is also advantageous to form the control lever from an assemblage of two symmetrical half-levers between which is then housed a free end of the suspension arm. 
   In a preferred embodiment, the device comprises an outer casing in which the suspension rotor is suspended. This casing is equipped with a lower screen, which is provided with a circular opening. The lower end of the suspension rotor carries a flange that is set into this circular opening. In this flange are positioned two elongated holes for the passage of the two suspension arms of the chute. Two supporting flanges flank each of the elongated holes for the support of the suspension pins at their two ends. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other special features and characteristics of the invention will emerge from the detailed description of an advantageous embodiment given below as an illustrative example with reference to the appended drawings. The latter show: 
     FIG.  1 : a vertical cross-section through a device for distributing materials in bulk with a rotary chute having a variable angle of inclination; 
     FIG.  2 : a horizontal cross-section through the device in  FIG. 1 ; 
     FIG.  3 : a vertical cross-section similar to that of  FIG. 1 , illustrating the removal of the chute; 
     FIG.  4 : a vertical cross-section showing details of the suspension of the chute of the device in  FIG. 1 ; 
     FIG.  5 : a vertical cross-section similar to that in  FIG. 4 , illustrating the removal of the chute. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The device for distributing materials in bulk  10  shown in  FIGS. 1 and 2  is more particularly intended to form part of a device for charging a shaft furnace, such as a blast furnace for example, represented schematically by its upper end  12 . 
   This device  10  comprises an outer casing  14 , which is connected in an impervious manner to the upper end  12  of the shaft furnace. This outer casing  14  is provided with a fixed charging duct  16 , which is substantially coaxial with the vertical axis  18  of the shaft furnace and which emerges imperviously from the upper end (not shown) of the outer casing  14 . A suspension rotor  20  is suspended in the outer casing  14 , for example by means of a large diameter roller ring (not shown). This suspension rotor  20  comprises a vertical suspension sleeve  24  surrounding the fixed charging duct  16  and provided with a horizontal flange  26  at its lower end. This flange  26  is set into a circular opening of a lower screen  28  which separates the inside of the casing  14  from the inside of the furnace. 
   In  FIG. 1 , the reference number  30  denotes a second rotor, also called a control rotor  30 . This control rotor  30  surrounds the suspension rotor  20  and is suspended in the outer casing  14 , for example using a large diameter roller ring (not shown), so as to have its rotation axis substantially coaxial with the rotation axis of the suspension rotor  20 . The two rotors  20  and  30  are driven in rotation by a driving device  110 . This driving device comprises  110 , in a way known per se, a first pinion  112 , which meshes with an annular gear  114  of the suspension rotor  20 , and a second pinion  116 , which meshes with an annular gear  118  of the control rotor  30 . With the help of two motors  120 ,  122  and a differential mechanism  124 , which are installed outside the casing  14 , this driving device is suitable for driving in rotation the two rotors  20 ,  30 , either with perfectly synchronised rotational speeds or with different rotational speeds. 
   The reference number  32  denotes a chute for distributing, materials in bulk through the charging duct  16 . This chute  32  comprises two lateral suspension arms  34 ,  34 ′. On both sides of the suspension sleeve  24 , the flange  26  is provided with two elongated holes  35 ,  35 ′ through which the free ends of the two suspension arms  34 ,  34 ′ penetrate into the inside of the outer casing  14 . Above the flange  26 , the two suspension arms  34 ,  34 ′ are connected to the suspension rotor  20  by means of two suspension pins  36 ,  36 ′. The latter are housed in bearings  37 ,  37 ′ which are provided on the flange  26  on both sides of the suspension sleeve  24  so as to define on the suspension rotor  20  a substantially horizontal pivoting axis for the chute  32 . 
   The reference number  38  denotes in a general way an angular drive carried by the flange  26  of the suspension rotor  20 . This angular drive  38  comprises a vertical input shaft  40 , which is parallel to the rotation axis of the two rotors  20 ,  30  and which is fitted with a pinion  42  meshing with an annular gear  44  on the control rotor  30 . It also comprises a horizontal output shaft  46 , which is parallel to the pivoting axis of the chute  32  and which has two free ends, each provided with a crank  48 ,  48 ′. A system of gears interconnects the input shaft  40  and the output shaft  46  in such a way as to convert a rotation of the vertical input shaft  40  into a rotation of the horizontal output shaft  46 . 
   Two connecting rods  50 ,  50 ′ connect the two cranks  48 ,  48 ′ symmetrically to two control levers  52 ,  52 ′, each of which has roughly the shape of a right-angle bracket with two arms. For each of these two control levers  52 ,  52 ′, the end of one of these arms is connected by an articulated joint to its connecting rod  50 ,  50 ′, while the end of the other arm is connected by means of an articulated joint  54 ,  54 ′ to the suspension rotor  20 . These articulated joints  54 ,  54 ′ define for each control lever  52 ,  52 ′ on the suspension rotor  20  a pivoting axis substantially coaxial with the pivoting axis of the chute  32 . 
   It was seen above that a rotation of the input pinion  42  of the angular drive  38  produces a rotation of the cranks  48 ,  48 ′. This is converted by the connecting rods  50 ,  50 ′ into a symmetrical pivoting of the two control levers  52 ,  52 ′ about their articulated joints  54 ,  54 ′. Now, a rotation of the input pinion  42  occurs if there is a difference in angular speed between the suspension rotor  20  and the control rotor  30 . In other words, to cause the two control levers  52 ,  52 ′ to pivot symmetrically about their articulated joints  54 ,  54 ′, it is sufficient to drive the control rotor  30  at an angular speed different from that of the suspension rotor  20 . 
   According to an important feature of the present invention, the transmission of a pivoting torque from the control levers  52 ,  52 ′ to the suspension arms  34 ,  34 ′ relies on a stop-counterstop system, in which a stop on the control lever  52 ,  52 ′ simply comes into contact with a counterstop on the suspension arm  34 ,  34 ′ in order to transmit the pivoting torque. The stop is for example formed by a driving pivot  56 ,  56 ′ carried by the control lever  52 ,  52 ′, while the counterstop is then formed by a guiding slot  58 ,  58 ′. The latter is advantageously provided in the free end of the suspension arm  34 ,  34 ′ and makes in the latter an entrance, so that the driving pivot  56 ,  56 ′ can be introduced into its slot  58 ,  58 ′ by a simple translation of the suspension arm  34 ,  34 ′ in a direction perpendicular to the driving pivot  56 ,  56 ′. 
     FIG. 4  shows a preferred embodiment of the control lever assembly  52 , the suspension pin and the suspension arm  34 . It can be seen that the control lever  52  is formed by an assembly of two symmetrical half-levers  60 ′,  60 ″, between which the free end of the suspension arm  34  is housed. Said suspension arm passes through the elongated hole  35 , which is provided in the flange  26  of the suspension rotor  20  and which is flanked by two supporting flanges  62 ′,  62 ″. Each supporting flange  62 ′,  62 ″ is provided with a bush  64 ′,  64 ″. Said articulated joint  54  of the lever  52  on the suspension rotor  20  is then formed by mounting a journal  66 ′ of the half-lever  60 ′ in the bush  64 ′ of the supporting flange  62 ′ and a journal  66 ″ of the half-lever  60 ″ in the bush  64 ″ of the supporting flange  62 ″. Each of these two journals  66 ′,  66 ″ is also provided with a central bore  68 ′,  68 ″ against which one end of the suspension pin  36  bears. It should be noted that the central axis of the suspension pin  36  is substantially coaxial with the central axis of the articulated joint  54  of the control lever  52 . Mechanical stops (not shown) provide for the axial blockage of the suspension pin  36 . However, after removal of these mechanical stops, the suspension pin  36  can easily be withdrawn from its housing formed by the two bores  68 ′,  68 ″. 
   In order to facilitate the installation and removal of the suspension pins  36 ,  36 ′, each of the two suspension arms of the chute incorporates an oblong hole  70 ,  70 ′ for the passage of its suspension pin  36 ,  36 ′. This oblong hole  70 ,  70 ′ is located along the extension of the slot  58 ,  58 ′ so that the two suspension pins  36 ,  36 ′ can be freed by raising the chute  32 . This is illustrated by comparing  FIGS. 4 and 5 . In  FIG. 4 , the suspension arm  34  presses on the suspension pin  36  with the upper edge of its oblong hole  70 . In  FIG. 5 , the chute  32  is in a raised position, in which there is a clearance “J” between the upper edge of the oblong hole  70  and the suspension pin  36  so as to free the suspension pin  36 . It remains to note that the reference number  72  in  FIG. 4  denotes a mechanical stop which prevents an unwanted raising of the chute  32 . In  FIG. 5 , this mechanical stop  72  is removed. 
   The procedure for removing the chute is illustrated by FIG.  3 . The reference number  100  denotes a device for handling the chute  32  which is suspended from the cable  102  of lifting gear. This handling device  100  is coupled to the chute  32  through an opening for removal  104  provided in the upper end  12  of the shaft furnace. In a first step, the chute  32  is slightly raised in order to bring the two suspension pins  36 ,  36 ′ into the position shown in  FIG. 5  by a translation of the two suspension arms  34 ,  34 ′. In this position, it is now easy to withdraw the two suspension pins  36 ,  36 ′ from their respective housings. The chute  32  is then allowed to descend in order, by a translation of the two suspension arms  34 ,  34 ′, to free the two driving pivots  56 ,  56 ′ from their respective guiding slots  58 ,  58 ′. It is then possible to withdraw the chute  32  laterally through the opening for removal  104 . A counterweight  106  on the handling device  100  keeps the chute  32  substantially parallel to itself during the whole operation of withdrawal. The operation of installing the chute is carried out in the opposite way.