Abstract:
The invention relates to a slidable closure element for slide closures of metallurgical vessels, composed of a one-piece plate of heat resistant material which is engaged at its two opposite narrow edges by frame members that are drawn together by screws serving to tension them and hold them in contact with the edges of the plate.

Description:
This is a continuation of application Ser. No. 263,714 filed May 14, 1981, now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates to a slidable closure for slide closure of metallic vessels. 
     Closure elements of this type are for example known from German Allowed Application No. 2,620,423. In this construction the closure element is a plate of heat resistant material which is provided with an opening through which molten metal can pass out of the metallurgical vessel. The plate is inserted into a frame of approximately C-shaped configuration and thereafter the open side of the C is closed by placing a retaining member across it and connecting the retaining member to the frame by means of screws. The plate is guided in the frame by having its longitudinal edges bevelled and by having the frame itself provided with correspondingly configurated grooves in its longitudinal sides. 
     A problem with this prior art is that the manufacture of the frame is relatively expensive because it is complicated. Bevelling of the longitudinal edges of the plate themselves also requires additional operating steps and, moreover, brings with it the danger that when the plates are inserted or removed from the frame the edges may break. It is to be understood that because of the particular configuration of the known frame, it is not possible to insert or remove the plate in the plane of the frame. Rather, after the retaining member is removed from the frame the plate must first be shifted relative to the frame in the plane of the frame until the bevel longitudinal edge of the plate moves out of engagement with the corresponding groove of the frame. Thereafter, the plate must be lifted up at the opposite edge and must be removed from the frame in the direction normal to the plane of the frame. This handling during mounting or dismounting of the plate is relatively complicated and runs a considerable risk of danger to the plate which is already of rather brittle material. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to overcome the disadvantages of the prior art. 
     A more particular object of the invention is to provide an improved slidable closure element with a slide closures of metallurgical vessels in which the frame holding the plate is of simple construction and can readily be secured to and removed from the plate without any danger of damage to the plate. 
     Another object is to provide a slide closure for use with such a closure element. 
     In keeping with these objects, and with still others which will become apparent hereafter, one feature of the invention resides in a slidable closure element for slide closures of metallurgical vessels which, briefly stated, may comprise a heat-resistant plate having two transversely spaced edges, a pair of frame members engaging the respective edges, and tensioning screws releasably connecting the frame members and drawing them into tight engagement with the edges. 
     Such a construction according to the present invention has a variety of advantages. First of all, the frame members are all of identical configuration. Furthermore, they can be in form of cut-offs made from commercially available profiled members, for example U-shaped profile members, and therefore can be produced simply and inexpensively. The frame accommodates itself to the configuration of the longitudinal narrow edges of the plate, i.e. engages the entire edge uniformly, so that the force with which it is pressed against the plate is to all intents and purposes uniformly distributed over the entire circumference of the plate. This means that local pressure peaks acting upon the plate are avoided. The plate itself does not require special treatment steps, such as bevelling of its edges. The mounting and dismounting are extremely simple and touching of the plate is not necessary since after the screws are released the frame members can be simply pulled away from the two sides of the plate and a new plate can be placed between them. 
     The invention will hereafter be described with reference to exemplary embodiments. It should be understood, however, that this is by way of example only and not to be considered limiting. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     FIG. 1 is a front perspective view illustrating a slidable closure element according to the invention; and 
     FIG. 2 is a partially exploded perspective view, showing a slide closure for use with the closure element of FIG. 1 to cover opening 10. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     As shown in FIGS. 1 and 2 the head plate 1 and the slide closure plate 1a both are of octagonal configuration. Each plate 1, 1a has an opening 2 through which in the installed condition the molten metal can escape from the metallurgical vessel. Plate 1 or 1a has two opposite narrow sides which, since the plate here is of octagonal configuration, each have three mutually inclined facets. Each of these sides composed of the three facets is engaged by a frame member 3 configurated to tightly engage the three facets. At the opposite ends these frame members are connected by tensioning screws or bolts 4 which extend between them and secure them to each other so that they are drawn in towards one another into tight engagement with the edges of the plate 1 or 1a. Adjacent these opposite ends the frame members are provided with recesses 5 which will be explained subsequently. 
     The plate 1 or 1a is of refractory material, as will be evident from the fact that it is to be used in connection with metallurgical vessels. 
     The plate in FIG. 1 is to be used with a slide closure as shown in FIG. 2 which includes a mounting plate 6 that is connectable to the bottom of the metallurgical vessel 11. Mounted on the mounting plate 6, so that it can be pivoted to open position via a pivot arrangement 13, is the slide closure housing 9. The open position of opening 10 is shown in FIG. 2 and in this position the plates 1 or 1a are mounted or dismounted. When the housing 9 is moved to closed position the mounting screws 14 provided on the plate 6 extend into the associated slots 15 of the housing 9 so that the housing 9 is then held in closed position. 
     Mounted on the mounting plate 6 is the head plate 1, by means of locating pins 8 which extend into the recesses or slots 5 of the frame members 3. A slide carriage 7 is provided which is slidable in not illustrated guides in the housing 9 with the aid of a hydraulic cylinder 16, is also provided with locating pins 8 which extend into the slots or recesses 5 in the frame members 3 of the slide closure plate 1a. 
     The locating pins 8 provided on the mounting plate 6 and on the carriage 7 and the cooperating slots or recesses 5 on the frame members 3 of the head plate 1 and the slide closure plate 1a are of slightly conical configuration so that the plates 1, 1a can be secured without difficulty to the mounting plate 6, respectively, the carriage 7 and will be firmly seated after they are pressed in place. Moreover, the inventive slots 5 (which could be replaced by bores) together with the locating pins 8 also permit a correspondingly simple dismounting of plates 1 or 1a which are worn and must be replaced with new ones. 
     If the inventive plates 1 or 1a with their frame members are used in a three-plate slide closure, then a further advantage is obtained in the fact that the coupling of the hydraulic cylinder 16 which moves the center plate for opening and closing of the slide closure, can directly engage a screw bolt 4 of the slide closure plate. 
     It will be appreciated that the plate 1 or 1a could have a configuration other than octagonal, i.e. any polygonal shape, or else could be of circular or oval configuration. It is then merely necessary to accommodate the shape of the frame members 3 to the different shape of the plate so as to obtain a uniform engagement between the frame members and the plate, which is a condition for the ability to do without any sealing material (e.g. mortar) for closing the various gaps between the associated components. 
     The invention as hereinbefore been described with reference to particular embodiments. However, it is not to be considered limiting thereto and is defined authoritatively only in the appended claims.