Abstract:
A tiltable-converter supporting mechanism with drawing hooks which engage with bearing bushing bolting pieces and are actuated by pressure medium cylinder means has self-locking bracing means holding the engaging drawing hooks in a locked position.

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to a tiltable crucible or converter with supporting trunnions fixed to the converter shell and a bearing structure surrounding at least half of the circumference of the converter shell, wherein the supporting trunnions are arranged in bearing bushings that are releasably connected to the bearing structure. 
     According to U.S. Pat. No. 3,652,071 it has been known to attach bearing bushings to a bearing structure by means of drawing hooks which are pivotable into and out of an engagement position. The drawing anchor connection between the converter and the bearing structure is made releasable and connectable, respectively, by hand. For releasing and making the connection, a number of service men are necessary in the immediate vicinity of the converter. For safety purposes, however, work at the converter or at its bearing structure ought to be prevented, if possible. Furthermore, the time necessary for releasing or actuating the drawing hooks as well as for tightening and loosening the turnbuckles securing these drawing hooks, constitutes a period of standstill of the converter. Summary of The Invention 
     The invention aims at preventing these disadvantages and has as its object to create a converter connection which can be actuated without manipulation in the converter vicinity and which can be completely secured in the engagement position. 
     This object is achieved by improving the construction described in U.S. Pat. No. 3,652,071 in that for actuating the drawing hooks in and out of the engagement position with a bearing bushing bolting piece, a pressure medium cylinder is provided. On the one hand the pressure medium cylinder is hinged to the bearing structure and, on the other hand, it is connected directly or hinged via a linkage to the drawing hooks. The drawing hooks, when in the engagement position, are maintained in a locked position by self-locking bracing means attached to the bearing structure. Because of the self-locking bracing means, it is possible to maintain the pressure medium cylinders, which pivot the drawing hooks into and out of engagement position, free from pressure during operation of the converter. 
     Suitably the bearing bushing bolting piece is pivotably arranged at the bearing structure and by means of a pressure medium cylinder it can be brought into and out of an engagement position with the bearing bushings. 
     Advantageously, the drawing hook is arranged to be pivoted around an axis located on the bearing structure between its hook end and its shaft end. The hook end can be brought into engagement with the bearing bushing bolting piece and the shaft end is hinged to one end of a push rod. The other end of the push rod is guided in a guide and is movable into a locked position along this guide by means of a pressure medium cylinder. 
     According to another embodiment of the invention drawing hooks are arranged on both sides of the supporting trunnions. The shaft ends of the two opposing drawing hooks are articulately connected with each other by two push rods and the push rods are movable with their common joint along a guide into a locked position by means of pressure medium cylinder means. 
     With this arrangement it has proved to be especially advantageous for the push rod to be supplied with springs that act in the direction of pressure and, when the drawing hooks are in the engagement position, for the push rod to be movable beyond its dead position into a locked position which automatically prevents the movement of the drawing hooks. 
     According to a further preferred embodiment, the hook end of a drawing hook is adjustable by means of a pressure medium cylinder toward a bracket (console) of the bearing housing bolting piece and the shaft end of the drawing hook is movable along a guide into the locked position by means of a self-locking mechanical drive, such as a turnbuckle or a knuckle lever. The advantage of this embodiment is that the drawing hooks are exposed to tensile stresses only and not to bending stresses. 
     In a modified embodiment of the invention, instead of the supporting trunnions and the bearing bushings, claw-like consoles, that are connected to the converter wall and have fitting surfaces, are provided as bearing elements of the converter, and the drawing hooks are brought into and out of engagement by them. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In order that the invention may be more fully understood, a few embodiments thereof shall now be described by way of examples and with reference to the accompanying drawings in which: 
     FIG. 1 is a front view of a converter that is releasably connected to its bearing structure; 
     FIG. 2 is a ground plan thereof; 
     FIGS. 3 to 5 show details of the connection between the converter and the bearing structure of the first embodiment shown in FIG. 1 on a larger scale, i.e., FIG. 3 is a section along line III--III of FIG. 2, 
     FIG. 4 is a section along line IV--IV of FIG. 1, and 
     FIG. 5 is a longitudinal section of a push rod; and 
     FIGS. 6 to 9 show a section analogous to FIG. 3, but each one for another embodiment of the invention. 
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     In FIGS. 1 and 2 the converter is denoted with 1, its bearing structure with 2. The bearing structure 2 is horseshoe-shaped, but it can also be closed, and it is connected to the converter tilting trunnion 3. At the converter shell, supporting trunnions 4 are attached so as to convey the weight of the converter onto the bearing structure 2. Three supporting trunnions are provided and the radial planes extending through them enclose angles of about 120° ; thus the converter is mounted in a statically defined manner at three points. 
     The supporting trunnions 4 are surrounded by bearing bushings 5 which are releasably connected to the bearing structure 2. The bearing bushings 5 comprise an inner sleeve 6 and an outer sleeve 7 and that rests on the bearing structure 2 along a fitting surface on the top thereof. This fitting surface is formed by the inner face of a bearing half-shell 8 which is inserted into a recess in the bearing structure 2 having a semi-circular cross-section 2. 
     A bearing bushing bolting piece 9, shown in more detail in FIG. 3, is arranged to pivot around a bolt 10 in the carrying structure and in the engagement position encloses the half of the bearing bushings 5 extending from the bearing structure. The bearing bushing bolting piece 9 comprises two lever-like extensions 11, at whose ends the piston rod of a pressure medium cylinder 12 engages. With the help of this pressure medium cylinder the bearing bushing bolting piece is pivotable, so that the bearing bushings are open towards their upper side and the converter can be lifted from the bearing structure. The open position of the bearing bushing bolting piece is shown in FIG. 3 in broken lines. The bearing bushing bolting piece further comprises at its upper side a fitting surface 13. The hook end 15 of a drawing hook 14 that is arranged to pivot about a bolt 17 at the bearing structure can engage with this fitting surface 13. The shaft end 16 of the drawing hook 14 which is opposite the hook end, is hinged to one end of a push rod 18, which has its other end guided in a track guide 19 and is movable along this guide by means of a pressure medium cylinder 20. 
     The push rod 18 in FIG. 5 comprises two telescope-type parts, 21 and 22, that are movable with respect to each other and which are pressed away from each other toward their stop surfaces 24 by means of saucer springs 23. As a result the push rod, when subjected to tensile forces, has an unchangeable length, while when subjected to compressive forces, the saucer springs become active. When the drawing hook 14 is in the engagement position -- i.e. the position, in which the hook end of the drawing hook is well set on the bearing bushing bolting piece to then the push rod 18 is at a point shortly before its dead position, i.e. shortly before that position in which the axis of the push rod forms a right angle with the axis of the guide 19. If the push rod 18 is now moved into the dead position and a bit further to the end position of the pressure medium cylinder 20, the push rod shortens, and its saucer springs 23 become active. In this locked position, which is illustrated in FIG. 3 in full lines, the drawing hook 14 is pressed by the saucer springs of the push rod 18 against the bearing bushing bolting piece 9 and cannot be disengaged from the bolting piece 9 by any force directly acting upon it. The pressure medium cylinder 20 thus need not be pressure-actuated in this locked position. 
     As can be seen from FIGS. 1 and 4, two adjacent drawing hooks are provided per bearing bushing bolting piece. Each of the drawing hooks is provided with a separate pressure medium cylinder 20 and can be brought into the engagement position by its cylinder. The bearing structure 2 is a box construction within which the shaft parts 16 of the drawing hooks 14 and their axes 17, as well as the push rods 18, the guides 19, the pressure medium cylinders 20 and the pressure medium cylinders 12, are housed and well protected. 
     FIG. 6 constitutes an embodiment in which the drawing hooks 14 and 14&#39; are arranged symmetrically on both sides of the supporting trunnion. The shaft ends 16 and 16&#39; of the two opposing drawing hooks 14 and 14&#39;, respectively, are articulately connected with one another by two push rods 18 and 18&#39;, respectively. The push rods are movable with their common joint along the track guide 19 by the pressure medium cylinder 20. In this embodiment, the bearing bushing bolting piece 25, which is also of symmetrical design, is not mounted on the bearing structure 2, but is connected with the bearing bushing 5 by a screw 26 so that the bearing bushing bolting piece 25 is detached together with the converter 1 from the bearing structure 2. The locked position is obtained in the same way as in the embodiment shown in FIG. 3. 
     A preferred embodiment of the invention is shown in FIGS. 7 and 8. The bearing bushing bolting piece 27 is pivotally mounted on the bearing structure in the same way as the bearing bushing bolting piece 9 shown in FIG. 3. It has a bracket or console 28, to which the hook end 30 of a drawing hook 29 is movable by a pressure medium cylinder 32. The shaft-end 31 of the drawing hook 29 is guided in a guide 33 formed by two parallel faces, and the shaft end can be moved along the guide by means of a self-locking mechanical drive, 34 or 35. The converter is connected to the bearing structure by pivoting the drawing hook 29 into an engagement position with the console of the bearing bushing bolting piece by means of the pressure medium cylinder 32, which position is shown in FIGS. 7 and 8 in dot-and-dash lines. Whereupon the mechanical drive 34 or 35 moves the shaft end 31 of the drawing hook 29 along the guide 33 into a locked position which is shown in FIGS. 7 and 8 in full line. The locked position is reached only when the drawing hook is braced with its hook end 30 against the console 28. The mechanical drive 34 or 35 is dimensioned to be self-locking. In FIG. 7 a turnbuckle is shown as drive 34. The ends of the turnbuckle are articulately connected with the shaft end on the one hand and with the bearing structure on the other hand. FIG. 8 shows a knuckle joint movable beyond its straightened position and provided with springs as drive 35. The drives 34 and 35 are suitably hydraulically actuated. 
     FIG. 9 is a modified embodiment of the invention in which the converter has claw-like consoles 36 connected to the converter wall as supporting elements, instead of the supporting trunnions and the bearing bushings. These consoles have inclined faces 37 and 37&#39; with which the hook ends of the drawing hooks can be brought into and out of engagement. The configuration of the drawing hooks whose bearing as well as drive are suitably effected according to the embodiment shown in FIG. 6, can also be effected according to the modifications shown in FIGS. 7 and 8.