Abstract:
A connector for pouring concrete into concrete formworks includes a piston tube and a filling port tube interconnected with each other and extending at an acute angle with respect to each other. The piston tube is mounted on the formwork or on a flange mountable on the formwork whereby a stopper piston axially movable in the piston tube may form a flush seal on an inside surface of a formwork element. A control unit including a spindle moves the stopper piston to close off a passage between the filling port tube and the piston tube. A quick connect coupling is supported on the filling port tube for connection to a concrete feed line.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    In the production of concrete parts, especially outer walls of buildings, formwork systems are known which comprise two formwork elements running parallel. For filling such formworks, various methods are known. For example, conventional concrete is introduced from above into the formwork, so that the concrete falls in free fall into the interior of the formwork. The concrete then fills the formwork until it reaches the top edge of the formwork elements. Such filling is preferably performed for vertically oriented building walls. 
         [0002]    Alternatively, the concrete is pumped into the formwork through filling connections in a side formwork element. The filling connections are usually located in the bottom area of the formwork. A connecting port, on which a filling tube can be connected in a pressure tight way, is provided on the formwork, so that the concrete can be pumped with pressure through the port into the formwork. As soon as the concrete in the formwork has hardened, the filling tube is removed from the connecting port. If the concrete has hardened both in the formwork and also in the filling connection, then removal of the formwork is very difficult because an interfering hardened concrete plug remains. 
       SUMMARY OF THE INVENTION 
       [0003]    The present invention provides an improved connector for filling concrete formworks. 
         [0004]    A connector in accordance with the invention for pouring concrete into a formwork comprises a piston tube and a filling port tube which is connected to the piston tube. The piston tube and the filling port tube together form, essentially, a V-shaped filling connector. The piston tube of the filling connector is arranged flush with the formwork at one end of the piston tube. The piston tube includes a movable stopper piston, which has an end wall oriented in the direction of the formwork and which is moved within the interior of the piston tube by a control unit. The stopper piston can be moved in the piston tube so that its end wall closes flush with the formwork on which the piston tube is arranged. The filling port tube is fixed in the area of the formwork at an acute angle to the wall of the piston tube. The connection between the piston tube and the filling port tube is provided such that concrete, which is introduced into the filling port tube, flows into the piston tube in order to be led finally into the formwork. 
         [0005]    After the formwork has been filled completely with concrete, that is, the concrete has been pumped through the filling port tube and the piston tube into the formwork, the stopper piston is moved in the direction of the formwork. The concrete in the piston tube is pressed into the formwork until the end wall of the stopper piston forms a flush seal with the formwork. Thus, no concrete remains in the piston tube of the filling connector. Therefore, after the concrete is dried, no plug is formed on the formwork wall which would prevent removal of the formwork. 
         [0006]    In accordance with another aspect of the invention, a concrete formwork filling connector includes a stopper piston which closes off the filling port tube with its side wall when the stopper piston forms a smooth seal with its end wall with the formwork. In this position, the end wall of the stopper piston is essentially flush with the end of the piston tube of the filling connector. Depending on the size of the piston tube and the opening provided in the formwork for connecting the piston tube of the filling connector, the piston tube either stands on the formwork element of the formwork or projects so far into the formwork element of the formwork until it is flush with the inside surface of the formwork element. As a function of the arrangement of the piston tube on or in the formwork element of the formwork, the end position of the stopper piston is also to be fixed in the piston tube as well as the cross section of the opening in the formwork. According to a preferred arrangement, the stopper piston reaches, in its end position, past the end of the piston tube of the connector. The opening cross section in the formwork is adapted to the inner cross section of the piston tube or to the outer cross section of the piston tube. 
         [0007]    In accordance with a further aspect of the invention, if the stopper piston is to be moved within the piston tube from its starting position in the direction towards the formwork, then the stopper piston extends with its side wall advancing increasingly into the connection point between the filling port tube and the piston tube, so that the size or cross section of a passage formed at the connection between the piston tube and filling port tube is reduced. In this way, through suitable positioning of the stopper piston within the piston tube, the flow of concrete into the formwork can be controlled to provide a predetermined amount or dose. In this way, it is possible also to control the pour rate of concrete into the formwork. The stopper piston can be moved so far in the direction towards the formwork that it completely closes the connection passage cross section or size between the filling port tube and the piston tube. Further inflow of concrete into the piston tube may then be prevented. 
         [0008]    If the stopper piston is moved even farther in the direction of the formwork, for a closed filling port, the residual concrete still in the piston tube is pressed into the formwork. Only when the stopper piston has reached its end position, that is, forming a flush seal with an inside surface of the formwork element of the formwork, is the movement of the stopper piston complete. 
         [0009]    Accordingly, not only can the concrete flow be controlled to provide a finite dose by the filling connector according to the invention, the filling connector is simultaneously blocked flush with the formwork element, which is formed in the formwork, after stopping the flow. In this way, a residual concrete connecting piece, also called a plug, does not remain on the hardened concrete element, or part and which would make removing the formwork more difficult, especially for the production of exposed concrete surfaces. In the scope of the invention the filling connector according to the invention has proven to be very advantageous. Due to the formwork filling provided by the stopper piston to be flush with the inside surface of the formwork element, only barely visible traces of the connector are to be detected on the hardened concrete. 
         [0010]    In accordance with yet another aspect of the invention, a connector for filling concrete formwork is provided with a stopper piston movable past the free end of the piston tube, in order to intentionally leave, for example, a shape in the concrete body to be created. This is advantageous especially when the end wall of the stopper piston has an exchangeable end surface that comprises, for example, a punch or a die plate, on which indicia, such as for example, the production date of the concrete part, can be stamped. Other information can also be stamped into the concrete part, such as the name of the manufacturing company or the composition of the concrete. 
         [0011]    In one preferred embodiment of the invention, a control unit is provided for moving the stopper piston within the piston tube comprising a spindle which can be driven rotatably either by hand, in that a hand crank is attached at the free end of the spindle, or by a motor, in that such motor is connected directly or via gearing to the spindle. The movement of the stopper piston in the piston tube can then be automated, so that the flow rate of concrete can be regulated automatically. Several filling connectors in one formwork can be controlled centrally. For a motive drive of the spindle, adjustments of the position of the stopper piston can also be regulated by means of a central control, for example, in the form of software. For a mechanical adjustment of the stopper piston, catches can be provided on the spindle, which can be fixed such that further rotation past the catch is not possible. 
         [0012]    In another preferred embodiment, the filling port tube of the filling connector has a coupling on its free end. The coupling is used for connecting concrete feed lines, or hoses, through which concrete is pumped to the filling connector. Preferably, these couplings are provided as quick connect couplings in order to allow quick coupling and decoupling of the feed lines. The quick connect couplings can be exchangeable, so that they always correspond to coupling pieces of various manufacturers and different systems. In this way, the filling connector can be adapted to the available quick connect coupling of the appropriate feed line. A coupling which is constructed as a quarter turn fastener, has proven to be advantageous whereby the feed line can be coupled very easily to the filling connector. 
         [0013]    The filling connector according to the invention has the additional advantage that it is possible, due to the closure of the filling port and the quick removal of the feed line from the filling connector through the quick connect coupling, to clean the filling port tube after filling the formwork. For this purpose, the filling port tube is flushed with water until all of the concrete in the filling port tube is removed. This process is usually performed when the non hardened fresh concrete has converted into young concrete, that is, it has hardened far enough that, for example, the formwork can be removed, but the young concrete has not hardened completely. Because the cleaning of the filling connector is simple, the handling of the connector as a whole is significantly improved. Of course, the stopper piston must seal the filling port during the cleaning to the extent that the injected water does not reach into the formwork. 
         [0014]    In another preferred embodiment of the invention, a seal is provided between the stopper piston and the piston tube, so that no concrete can flow between the stopper piston and the piston tube, which would lead to damage to the filling connector. Preferably, the seal between the stopper piston and the piston tube is constructed as an amorphous seal. For a piston which is fit into the piston tube with very tight tolerances, the amorphous seal can be realized by providing a grease film. The grease film also supports the sliding movement of the piston in the piston tube, so that the piston is supported and seizing is prevented. In addition, thanks to the sealing grease film, it is guaranteed that the concrete flowing through the piston tube does not remain adhered to the inner wall of the piston tube. 
         [0015]    The present invention also provides a filling connector which is detachable from or fixed to the formwork. Preferably, for a detachable connection, the filling connector is flanged to the formwork. A flange is provided at the end of the piston tube which is guided or inserted into a receptacle in the formwork, so that the filling connector is held securely and reliably on the formwork. This embodiment offers the advantage that the filling connector can be completely removed from the formwork. Moreover, if there is a defect in the filling connector, it can simply be replaced by a new one. In addition, the formwork element can be more easily moved about and stored if the filling connector can be removed after the production of the concrete parts. However, care must be taken in attaching the filling connector that the flange of the filling connector is held securely in its receptacle. Still further, it is important to adjust the stopper piston so that the piston assumes the desired position flush with the formwork in its maximum excursion. According to the arrangement of the piston tube on the formwork (sealed with the inside or the outside of the formwork element of the formwork), the stopper piston must be moved so far that it projects past the end of the piston tube or forms a flush seal with it. 
         [0016]    The filling connector may also be welded to the formwork, which represents a durable, reliable, and robust connection. The proper connection of the filling connector and formwork can be realized in advance in the manufacturing plant, just like the fixing of the end position of the stopper piston. For on site assembly, no additional work is necessary. Readjustment of the motion path of the stopper piston can usually be eliminated. Thus, only the feed line must be connected to the filling port tube. 
         [0017]    In a preferred embodiment of the invention, the piston tube and the stopper piston have a cylindrical construction. The terms tube (piston tube and filling port tube) and piston (stopper piston) are understood in the sense of the application as general terms, so that they are not limited to cylindrical constructions. Instead, both the tubes and also the piston may have nearly arbitrary cross sections. However, they must be fitted to each other. It is also possible to use square cross section tubes, in which a square stopper piston can move, for example. 
         [0018]    At least part of the filling port tube preferably can have a cylindrical cross section, so that the feed lines usually constructed with a round cross section can be connected in a simple way and without additional adapters. 
         [0019]    Preferred embodiments are described further in detail herein with reference to the drawing figures. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]      FIGS. 1A through 1C  are cutaway perspective views illustrating a concrete filling connector in accordance with the invention; 
           [0021]      FIGS. 2A through 2C  are longitudinal central section views of the connector shown in  FIGS. 1A through 1C  with the stopper piston in various positions corresponding to the positions in  FIGS. 1A through 1C , respectively; 
           [0022]      FIG. 3  is a cutaway perspective view of an alternate embodiment of the invention; and 
           [0023]      FIGS. 4A and 4B  are cutaway perspective views illustrating a modified stopper piston of the filling connector including an exchangeable end face insert for the stopper piston. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0024]      FIGS. 1A through 1C  show a filling connector  1 , which is connected rigidly to a formwork  2 . The essentially V shaped filling connector  1  comprises a piston tube  3  and a filling port tube  4  fixed to the piston tube so that a one piece outer structure of the filling connector  1  is formed. The piston tube  3  is welded to a formwork element  5  of the formwork  2 , so that a durable connection between the piston tube and formwork is formed. The piston tube  3  is positioned at an angle of ninety degrees, that is, perpendicular to the formwork  2 . The piston tube  3  is connected with the formwork element  5  such that the open end  3   a  of the piston tube  3  is flush with and forms a flush seal with the inside surface  5   a  of the formwork element  5 . The formwork element  5  has an opening  6 , whose diameter corresponds to the outer diameter of the piston tube  3 . The filling port tube  4  is fixed to the piston tube  3  at an acute angle adjacent to or in the area of the formwork  2 . In the example shown, the filling port tube  4  is arranged at the side of the piston tube  3  at an angle of about thirty degrees. 
         [0025]    A stopper piston  7  is supported so that it can move in the piston tube  3 . The stopper piston  7  can be moved in a linear motion from the rear end  8  of the piston tube  3  in the direction towards the formwork  2 , that is, in the direction of the piston tube end  3   a . The linear motion of the stopper piston  7  is realized by a control unit  10  comprising a rotatable spindle  9 . The spindle  9  is connected on one end to a hand crank  11 , with which an operator can activate the spindle by hand. Alternatively, a motor can also be attached directly or via gearing to the free end of the spindle  9 , so that the spindle  9  is turned by such motor. 
         [0026]    At the free end  8  of the piston tube  3  there is a spindle holder  12 , at which a stop  13  is formed. The stop  13  is part of an adjustment device  14 , which also includes two nuts  15   a ,  15   b  that are threaded onto the spindle  9  and act as locknuts opposite each other, in order to fix their positions on the spindle. The spindle  9 , is supported in and cooperates with the spindle holder  12  so that it can rotate, and advance and retract the stopper piston  7 . The spindle  9  is turned until the nut  15   a  lying opposite the piston tube  3  engages the stop  13 . In this way, the motion path of the spindle  9  and thus the motion path of the stopper piston  7  in the piston tube  3  may be limited. The end position of the stopper piston  7 ,  FIG. 1C , relative to the formwork  2  can be fixed in a simple and uncomplicated way by positioning the nuts  15   a ,  15   b  on the spindle  9 . 
         [0027]    The filling port tube  4  comprises on its free end a coupling  16  constructed as a quick connect coupling, to which a concrete feed line or hose, not shown, can be attached for introducing flowable concrete into the filling connector  1 .  FIG. 1A  illustrates the stopper piston  7  arranged in its starting position on the free end  8  of the piston tube  3 . Flow of concrete through the filling port tube  4  is introduced into the formwork  2  in an unimpaired way through the piston tube  3  and the opening  6  of the formwork element  5 . The direction of flow of concrete is represented by the arrows  17  in the filling port tube  4 . A passage or opening  18  formed at the intersection of tubes  3  and  4  is at a maximum size in the position of stopper piston  7  in  FIG. 1A  whereby the greatest possible concrete flow is guaranteed. 
         [0028]      FIG. 1B  illustrates the stopper piston  7  moved in the direction towards the formwork  2 . In this position, the opening  18  formed between the piston tube  3  and the filling port tube  4  is partially closed by the stopper piston  7 . Stopper piston sidewall  19  projects into the opening  18 , so that concrete flow is reduced. Because the stopper piston  7  is longer than the greatest extent of the opening  18 , flow of concrete in the piston tube  3  in the direction of the free end  8  can be prevented, but concrete may still be forced into the formwork  2 . 
         [0029]      FIG. 1C  illustrates the completion of the process of filling the formwork  2 . The stopper piston  7  has been moved in the piston tube  3  so far forward that its end wall  20  forms a flush seal with the inside surface  5   a  of the formwork element  5 . The passage or opening  18  between the piston tube  3  and the filling port tube  4  is now completely closed so that concrete cannot flow through the filling connector  1  into the formwork  2 . Simultaneously, with the movement of the stopper piston  7  in the direction of the piston tube end  3   a , any concrete remaining in the piston tube  3  is pressed into the formwork  2 . 
         [0030]      FIG. 1C  also illustrates that the nut  15   a  presses against or is in contact with the stop  13  of the adjustment device  14 . In this way, the motion path of the stopper piston  7  is limited and its end position is defined uniquely so that the end wall  20  of the stopper piston  7  forms a flush seal with the inside surface  5   a  of the formwork element  5 . In this way also, a continuous concrete surface flush with the formwork is created within the formwork element  5 . Therefore, in the concrete part to be produced, there are no visible traces of the stopper piston  7  or the point of introduction of the concrete. 
         [0031]    In the section views of  FIGS. 2A through 2C , the passage or opening  18 , which is formed between the piston tube  3  and the filling port tube  4 , can be seen clearly. The farther the stopper piston  7  is moved in the piston tube  3  in the direction of the formwork element  5 , the smaller the opening  18 . Accordingly, a simple way of controlling flow of concrete is provided without having to provide additional devices. 
         [0032]      FIGS. 2A through 2C  also illustrate that the piston tube  3  forms a seal that is flush with the inside surface  5   a  of the formwork element  5 . The opening  6  of the formwork element  5  has a diameter that corresponds substantially to the outer diameter of the piston tube  3 . The piston tube  3  is connected essentially at a right angle to the formwork element  5  and, preferably, welded to the formwork element. It is also important that the filling port tube  4  be fixed to the piston tube  3  adjacent to or in the area of the formwork  2 . The filling port tube  4  is arranged so that, between the side of the filling port tube  4  close to the formwork  5  and the end  3   a  of the piston tube  3  there is enough projecting length of the piston tube  3  so that the piston tube  3  can be pushed flush with the formwork into the opening  6  of the formwork element  5  and a seam or weld bead can be formed on the piston tube  3  between the outside surface of the formwork element  5  and the filling port tube  4 . 
         [0033]      FIG. 2C  illustrates that the adjustment device  14  can be adjusted such that the end wall  20  of the stopper piston  7  projects somewhat past the end  3   a  of the piston tube  3  and the formwork surface  5   a , so that the stopper piston  7  is pressed into still fluid concrete in the formwork  2 . This may be useful under certain conditions, for example, when indicia related to the concrete filling is to be intentionally provided in the final concrete part. 
         [0034]      FIG. 3  shows an embodiment of the filling connector  1 , which is not welded to the formwork  2 . Instead, a flange  21  is provided on the end of the piston tube  3  close to the formwork and is held in a receptacle or connector holder  22  on the outside of the formwork element  5 . The holder  22 , which is realized in the example shown by spaced apart pins  23 , guarantees a reliable and precisely fitting positioning of the filling connector  1  on the formwork  2 . The holder  22  including the pins  23  and the flange  21  must be suitably adapted to each other. 
         [0035]    In general, two modifications to the connector  1  are possible. In the first modification, the end of the piston tube  3  projects beyond the flange  21 . In this case, the opening  6  of the formwork element  5  may be slightly larger than the outer diameter of the piston tube  3 . The piston tube  3  is inserted into the opening  6  of the formwork element  5  which produces good fixing and exact positioning of the filling connector  1  on the formwork  2 . The length of the piston tube  3  which projects past the flange  21  corresponds in this case to the thickness of the formwork element  5 . 
         [0036]    In a second modification, the flange  21  may be arranged flush with the end of the piston tube  3 . The inner diameter of the piston tube  3  then corresponds exactly to the diameter of the opening  6  of the formwork element  5 . Here, the additional support by the piston tube in the positioning of the filling connection is eliminated. This disadvantage, however, is prevented by exact fixing of the filling connector  1  on the formwork  2 , especially by robust and precise attachment of the flange  21  in the holder or receptacle  22 . 
         [0037]      FIGS. 4A And 4B  show a filling connector  1  from the inside surface  5   a  of the formwork element  5 . The filling connector  1  includes a stopper piston  7  that has a modified wall  20  constructed, for example, to receive a die plate or punch  24  The die plate  24  can also include, as in the shown example in  FIG. 4B , a number code in addition to the manufacturing date, for example. In this way, it is possible to characterize the final concrete part to be created, for example, with suitable indicia, such as the production year or the production date. The die plate  24  is preferably disposed on piston  7  by insertion into a recess in the end wall  20  and is arranged so that it is flush with an edge  25  of the end wall  20 ,  FIG. 4B . Through such an arrangement, the die plate  24  does not effect or require adjustment of the stopper piston  7 , because the outer dimensions of the piston do not change. 
         [0038]    The filling connector  1  described hereinbefore is believed to be understood by those of ordinary skill in the art based on the foregoing description and viewing the accompanying drawings. Conventional engineering materials and practices may be used to fabricate the connector  1  and carry out its intended use. 
         [0039]    Although preferred embodiments of the invention have been described in detail herein, those skilled in the art will recognize that various substitutions and modifications may be made without departing from the scope and spirit of the appended claims.