Abstract:
A gate valve includes a valve plate located in a movable manner within a holder, a sealing for sealing off of the valve plate relative to the holder, and a wedge arrangement with several first wedge elements located on the valve plate in its direction of movement at a distance from one another, and second wedge elements belonging to the first wedge elements, by means of which the valve plate is pressed transverse to the direction of movement of the valve plate against the sealing with a movement into a closing position. In order to facilitate a low-friction actuation with a reduced actuation force, also in a compact and space-saving manner, the second wedge elements are supported on the holder, so that they can move relative to the holder.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority under 35 U.S.C. §119 to German Patent Application No. 10 2012 010 466.9 filed 26 May 2012, the entire contents of which are incorporated herein by reference. 
     FIELD OF THE INVENTION 
     The invention concerns a gate valve. 
     BACKGROUND OF THE INVENTION 
     A gate valve is known from DE 43 20 185 A1. There, a valve plate is conducted in a movable manner within a rack frame that can be installed on a wall in front of an outlet opening. A sealing arrangement with two ring seals situated on each side of a sealing ring is provided in the area of a passage in a wall plate of the rack frame. By means of a wedge arrangement with several wedge pieces arranged on the gate valve and the rack frame, the gate valve is pressed, transverse to its movement direction against the sealing arrangement, when the valve plate arrives at a closing position covering the passage. 
     With such gate valves with a wedge system, the valve plate is moved, during almost its entire stroke, with a clearance within the rack frame. Only at the end of the closing stroke is the wedging of the wedge pieces that are firmly arranged on the valve plate and the rack frame effective, so that the valve plate is pressed against the sealing only just before the complete shutoff. In this way, the friction and the actuating force can be decreased and the wear and tear, reduced. However, the valve plate lifts off relatively fast from the sealing upon opening, so that a leakage also appears quickly on the entire valve plate. Since the wedge pieces affixed on the valve plate and the rack frame must be moved, collision-free, past one another during the stroke movement, a lateral movement of the wedge pieces is also required. Especially with larger gate valve dimensions with several wedge pieces located above one another, therefore, the side sections of the rack frame must have a corresponding width and stability. For this reason, however, the use of material and the size are increased. 
     Therefore, gate valves are also already known, in which the valve plate, conducted almost free of play in outlining frame profiles, is pressed in a defined manner against the individual sealing profile by means of slide profiles made of plastic as a rule. With such a structure, only the actual gate valve opening is released, whereas the areas on which valve plate and sealing are in contact are tight. Furthermore, the valve plate is conducted free of play during the entire stroke, wherein vibrations can be avoided during operation. However, since the valve plate is pressed during the entire stroke with the sealing, correspondingly higher actuation forces are needed for the movement of the valve plate. As a result of the constant pressing of the valve plate with the sealing, the friction during the actuation is also increased and thus, also the wear and tear of the sealing. If leakage occurs, moreover, the sealing force cannot be increased further. 
     SUMMARY OF THE INVENTION 
     One aspect of the invention relates to a gate valve that, with a compact and space-saving design, makes possible an actuation as low-friction as possible, with a reduced actuation force. 
     With the gate valve in accordance with an embodiment of the invention, only the wedge elements located on the valve plate are firmly connected with the valve plate, whereas the associated second wedge elements are supported on the holder so that they can be moved relative to the holder, and are moved along with a shift of the gate valve plate. In this way, several wedge elements are located, in the direction of movement, in a line one behind the other and need not be moved laterally, with respect to one another. Thus, even larger gate valves can also be conducted on the entire length in relatively narrow side profiles. The entire construction and, in particular, the side guides with the wedge elements to press the gate valve plate against a seal, herein a sealing, can thus be constructed in an extremely compact and space-saving manner. The second wedge elements located in the direction of movement of the gate valve plate in a line behind one another are situated on a common slide rail. In this way, the second wedge elements can be jointly moved. The second wedge elements can, for example, be inserted in recesses within the slide rail. 
     In a particularly advantageous embodiment, the holder is constructed in the form of a frame with two side profiles designed as frame profiles to guide the valve plate on its two longitudinal sides. As a result of the not required lateral displacement of the wedge elements, the side profiles can be constructed extremely compact and with flexural rigidity. 
     The slide rail expediently has at least one contact surface for the carrying of the slide rail by a first wedge element with the shifting of the valve plate into an open position. In this way, with a shifting of the valve plate into an open position by the first wedge elements via the slide rail, the second wedge elements can be carried along. 
     In another advantageous embodiment, the second wedge elements can contain elevated side walls. In this way, the first wedge elements can be conducted laterally within the second wedge elements. 
     In a particularly advantageous manner, the valve plate is conducted in a movable manner within the side profiles of the holder designed as a frame by the second element and a guide element that is located on the valve plate. By means of these two parts, a slide bearing function with little play and a defined minimum pressing between the valve plate and sealing can be guaranteed over the entire stroke. The second wedge elements and the guide elements can be made of plastic, so that low frictional torques and reduced actuation forces are produced during the stroke. In this way, the advantages of known sliding and wedge gate valve systems are combined without restrictions. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Additional special features and advantages of the invention can be deduced from the following description of a preferred embodiment example with the aid of the drawing. The figures show the following: 
         FIG. 1 , a part of a gate valve in accordance with the invention in a cross-section; 
         FIG. 2 , a part of the gate valve shown in  FIG. 1  in a longitudinal section; 
         FIG. 3 , a guide of the gate valve in a perspective; and 
         FIG. 4 , the guide of the gate valve in an exploded view. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows a part of a gate valve, which can be used, for example, to shut off waste water in basins. The gate valve contains a rectangular, square, or round gate valve  1 , which is located in a movable manner within a holder  2 , which is constructed here as a frame. In the embodiment shown, the frame-shaped holder  2  comprises a lower closing profile  3  shown in  FIGS. 2 to 4 , and two parallel side profiles  4 , which can be seen in  FIG. 1 , in which the valve plate  1  is conducted laterally. The frame-like holder  2  with the horizontal, lower closing profile  3  and the vertical side profiles  4  provided with retainer pieces  5  can be sealed off, for example, with a sealing  6  and fastened on the outside of a wall of a basin, or the like, provided with a passage. On the valve plate  1 , the water pressure can then act in the direction of the arrow P shown in  FIG. 1 . The valve plate  1 , however, can also be located in a movable manner as a gate in a corresponding holder of a channel or a groove or in a suitable guide of a housing. 
     In the depicted housing-free embodiment, the valve plate  1  is conducted in a movable manner on its two longitudinal sides  7  via guide elements  8  into the two side profiles  4 , parallel relative to one another, of the holder  2 , which is constructed as a frame, and in a lower closing position, is on a bottom gasket  9  situated on the lower closing profile  3 . The bottom gasket  9  shown in  FIGS. 2 and 3  is located on an upper leg  10  of the lower closing profile  3 , constructed as an angular profile, between a front and back retaining strip  11  and  12 . By means of a spindle drive, which is in fact known and therefore not depicted, the valve plate  1  can be moved upwards into an opening position for the clearance of a passage from the lower closing position shown in  FIGS. 2 and 3 . 
     The side profiles  4  are constructed in accordance with  FIG. 1  as open frame profiles with an inside leg  13  and an outside leg  14 . Between the inside leg  13  and the outside leg  14  of the two side profiles  4 , the valve plate  1  is conducted in a movable manner via the guide elements  8 , shown also in  FIGS. 2 to 3 . In accordance with  FIG. 4 , the guide elements  8 , which are preferably made of plastic, can be stuck on the longitudinal sides  7  of the valve plate  1  via a slot  15 , and held within a recess  16 . 
     A sealing  17 , which is shown in  FIG. 1 , is located within the side profiles  4 ; it contains sealing lips  18  adjacent to the valve plate  2 . In the embodiment shown, the sealing  17  lies close to the inside leg  13  of the side profile  4  and is held by a retaining crosslink  19  welded onto the inside of the inside leg  13 . Furthermore, inside the side profiles  4  is a wedge arrangement with several first wedge elements  20  located on the two longitudinal sides  7  of the valve plate  1  in its direction of movement in a line one behind the other, and second wedge elements  21 , which engage with the first wedge elements. The first wedge elements  20 , which are preferably made of metal and are welded to the valve plate  2 , have a wedge surface  22  that faces the second wedge elements  21 . The second wedge elements  21  are located on a movable slide rail  23 . On the side pointing to the first wedge elements  20 , they have a second wedge surface  24  corresponding to the first wedge surface  22 , and on the side opposite the second wedge surface  24 , a straight contact surface  25  for contact on the inside of the outside leg  14  of the side profile  4 . 
     As can be seen in  FIG. 4 , the second wedge elements  21  have a quadrangular outer contour with elevated side walls  26 . The first wedge elements  20  are conducted in a movable manner between the two side walls  26  of the second wedge elements  21 . The second wedge elements  21  are inserted into rectangular recesses  27  of the slide rail  23  and have on the outsides of the two side walls  26  a step  28  for retention within the recesses  27 . Corresponding to the first wedge elements  20 , the associated second wedge elements  21  are located in the direction of movement of the valve plate  1  in a line one behind the other and not staggered laterally relative to one another. 
     From  FIGS. 2 and 3 , one can see that the second wedge surface  24  of the second wedge element  21  inserted into the recess  27  of the slide rail  23  runs in such a way that at the transition to the slide rail  23  on the upper end of the recess  27 , a contact surface  29  is formed for the carrying along of the slide rail  23  by the first wedge elements  20  during the movement of the valve plate  1  into the opening position. The first and second wedge elements  20  and  21  are situated in such a way that with the movement of the valve plate  1  into the opening direction, the first wedge element  20 , pressed by the water pressure against the second wedge element  21 , reaches with the upper end surface  30  the contact surface  29  on the recess  27  in the slide rail. On the lower closing profile  3 , adjustable contacts  31  are located as a lower contact for the two slide rails  23  on the two longitudinal sides  7  of the valve plate  1 . In the embodiment shown, the adjustable contacts are constructed as adjusting screws with lock nuts. 
     Below, the mode of functioning of the shutoff valve in accordance with the invention is explained with the aid of  FIGS. 2 and 3 . 
     If the valve plate  1  is moved upwards from the closing position shown in  FIGS. 2 and 3 , the first wedge elements  20  fastened on the valve plate  1  slide with their wedge surfaces  22  past the wedge surfaces  24  of the second wedge elements  21  located on the slide rail until the upper end surfaces  30  of the first wedge elements  20  acting as carrying surfaces arrive at the contact surfaces  29  of the slide rails  23 . The pressing between the slide plate  1  and the sealing  17  shown in  FIG. 1  is thereby reduced. In another upward movement, the first wedge elements  20  carry along the second wedge elements  21  upwards via the slide rail  23  for the rest of the stroke. The valve plate  1  is conducted by the quadrangular guide elements  8 , which are preferably made of plastic, and the second wedge elements  21 , which are likewise preferably made of plastic, in a sliding manner almost free of play within the side profiles  4 . 
     If, on the other hand, the valve plate  1  is moved downwards from an upper open position, then the second wedge elements  21  are carried along by means of the first wedge elements  20  until the slide rails  23 , shortly before arriving at the valve plate  1  at the bottom gasket  9 , reach with their lower end the contacts  31  constructed as adjusting screws. In the further downward movement of the valve plate  1  with the welded first wedge elements  20 , the latter move further on the wedge surfaces  24  of the second wedge elements  21 , which are likewise preferably made of plastic. The valve plate  1  is thereby pressed in the direction of the sealing lips  18  of the sealing  17 , whereby the sealing effect is increased. 
     All references cited herein are expressly incorporated by reference in their entirety. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. There are many different features to the present invention and it is contemplated that these features may be used together or separately. Thus, the invention should not be limited to any particular combination of features or to a particular application of the invention. Further, it should be understood that variations and modifications within the spirit and scope of the invention might occur to those skilled in the art to which the invention pertains. Accordingly, all expedient modifications readily attainable by one versed in the art from the disclosure set forth herein that are within the scope and spirit of the present invention are to be included as further embodiments of the present invention.