Abstract:
A concrete dispensing apparatus is used in a manufacturing process for producing pre-cast concrete structures, which are conventionally used to form a foundation for a residential or commercial building. The dispensing apparatus includes a hopper that funnels to a discharge opening extending along the entire transverse length of the dispensing apparatus. A plurality of individually controlled gates cover the entire discharge opening for selectively controlling the length and location of the discharge opening through which concrete is dispensed. The dispensing apparatus also includes a finishing mechanism including a vibratory screed and a rotational finishing roller. The form can be moved relative to the dispensing apparatus or vice versa. A form vibrator induces a vibratory motion into the form to remove air from the dispensed concrete mixture. Operative control is accomplished through an operator control panel operable to control a hydraulic system powering the operative functions of the dispensing apparatus.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to the formation of pre-cast concrete structures, and, more particularly, to a dispensing apparatus for distributing concrete mixture into a form corresponding to the pre-cast concrete structure. 
     BACKGROUND OF THE INVENTION 
     Pre-cast concrete structures, such as the type disclosed in U.S. Pat. No. 4,751,803, issued to Melvin M. Zimmerman on Jun. 21, 1988, are commonly utilized in the construction of foundation walls for residential and commercial buildings. Improvements to the basic pre-cast process have been made over the years, as are represented in U.S. Pat. No. 5,055,252, issued to Melvin M. Zimmerman on Oct. 8, 1991; in U.S. Pat. No. 5,656,194, granted on Aug. 12, 1997, to Melvin M. Zimmerman; and in U.S. Pat. No. 6,494,004, issued on Dec. 17, 2002, to Melvin M. Zimmerman. In generally terms, the process involves setting up the form with a polystyrene foam bottom and reinforcing members appropriately positioned, then pouring a concrete mixture into the form. After hardening, the side members of the form are stripped away from the now hardened concrete structure and the concrete structure is loaded onto a truck for delivery to the job site to be assembled into a foundation wall with other similar pre-cast structures. 
     In some instances, openings, such as for windows and doors to be added to the pre-cast concrete structure, are formed as part of the pre-cast concrete form. Concrete mixture is not to be added to the part of the form corresponding to the window or door openings. Similarly, two or more pre-cast concrete structures can be set-up into a single form into which the concrete mixture is to be added. In such situations, a transverse divider is provided between the concrete structures so that the side members and the dividers can be stripped away from the independent hardened concrete structures before shipping. 
     Once the form is set-up, a concrete mixture is dispensed into the form to fill the form. This process is typically accomplished through conventional chutes or tubular concrete dispensing devices during which the dispensing device is moved back and forth across the form until the form is filled appropriately with concrete mixture, working around any openings that are established within the form. Dispensing the concrete mixture into the form presents an opportunity to improve the process, reduce manufacturing time, decrease costs and improve profits. 
     Accordingly, it would be desirable to provide an apparatus that would be capable of dispensing concrete mixture into forms corresponding to pre-cast concrete structures. 
     SUMMARY OF THE INVENTION 
     It is an object of this invention to provide a dispenser apparatus that is operable to dispense concrete mixture into a pre-cast concrete structure form. 
     It is a feature of this invention that the concrete dispensing apparatus moves relative to the pre-cast structure form to dispense concrete mixture into the form from one side thereof to the other. 
     It is an advantage of this invention that the concrete dispensing apparatus dispenses concrete mixture into the pre-cast structure form along the entire transverse length simultaneously as the concrete dispensing apparatus moves from one side of the form to the other side. 
     It is another feature of this invention that the concrete dispensing apparatus includes a plurality of gates along the transverse length thereof. 
     It is still another advantage of this invention that each gate can be independently opened or closed to control the dispensing of concrete mixture within the form. 
     It is yet another advantage of this invention that the portions of the concrete dispensing apparatus overlying openings formed in the pre-cast structure form can be closed by shutting the corresponding gates until the dispensing apparatus has moved past the formed opening. 
     It is still another feature of this invention that the concrete dispensing apparatus incorporates a finishing mechanism behind the hopper containing a supply of concrete mixture to be dispensed. 
     It is still another advantage of this invention that the top surface of the concrete poured into the filled pre-cast structure form will be finished as the concrete dispensing apparatus is moved relative to the form from one side to the other. 
     It is yet another feature of this invention that the finishing mechanism includes a vibratory screed and a rotated finishing roller. 
     It is still another feature of this invention that the concrete dispensing apparatus includes a form vibrator engagable with the ends of the form to induce a vibratory motion into the form to settle the concrete mixture and remove air therefrom. 
     It is yet another feature of this invention that the operative functions of the concrete dispensing apparatus are independently controlled through a control mechanism cooperable with a hydraulic system. 
     It is another object of this invention to provide a concrete dispensing apparatus that would be operable to dispense a concrete mixture into a pre-cast concrete structure form that is moved beneath the dispensing apparatus, as well as a concrete dispensing apparatus that is movable over top of a stationary pre-cast structure form. 
     It is a further feature of this invention that the concrete dispending apparatus incorporates a hopper for holding a supply of concrete mixture. 
     It is still a further feature of this invention that the hopper has a larger opening at the top thereof for the receipt of concrete mixture into the hopper, than the discharge opening controlled by the plurality of gates. 
     It is a yet another feature of this invention that the hopper incorporates an auger that prevents bridging of the concrete mixture and provides uniform dispersion of the concrete mixture along the transverse length of the hopper. 
     It is a further advantage of this invention that the concrete mixture is uniformly spread across the bottom of the hopper for substantially equal dispensing of the concrete mixture through the open gates at the discharge opening of the hopper. 
     It is still a further feature of this invention that the operative control of the concrete dispensing apparatus is provided by an operator stationed adjacent the control panel for the dispensing apparatus. 
     It is yet another object of this invention to provide a concrete dispensing apparatus for use with a pre-cast concrete structure form, which is durable in construction, inexpensive of manufacture, carefree of maintenance, facile in assemblage, and simple and effective in use. 
     These and other objects, features and advantages are accomplished according to the instant invention by providing a concrete dispensing apparatus for use in a manufacturing process for producing pre-cast concrete structures that are conventionally used to form a foundation for a residential or commercial building. The dispensing apparatus includes a hopper that funnels to a discharge opening extending along the entire transverse length of the dispensing apparatus. A plurality of individually controlled gates cover the entire discharge opening to selectively control the length and location of the discharge opening. The dispensing apparatus also includes a finishing mechanism including a vibratory screed and a rotational finishing roller, which can be powered or unpowered. The form can be moved relative to the dispensing apparatus or vice versa. A form vibrator induces a vibratory motion into the form to remove air from the dispensed concrete mixture. Operative control is accomplished through an operator control panel operable to control a hydraulic system powering the operative functions of the dispensing apparatus. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The advantages of this invention will be apparent upon consideration of the following detailed disclosure of the invention, especially when taken in conjunction with the accompanying drawings wherein: 
         FIG. 1  is a front elevational view of a concrete dispensing apparatus incorporating the principles of the instant invention; 
         FIG. 2  is a side elevational view of the concrete dispensing apparatus shown in  FIG. 1 ; 
         FIG. 3  is a rear elevational view of the concrete dispensing apparatus depicted in  FIG. 1 ; 
         FIG. 4  is a top plan view of the concrete dispensing apparatus depicted in  FIG. 1 ; 
         FIG. 5  is a front perspective view of the concrete dispensing apparatus shown in  FIGS. 1-4 ; 
         FIG. 6  is a rear perspective view of the concrete dispensing apparatus depicted in  FIGS. 1-4 ; 
         FIG. 7  is a rear perspective view of the concrete dispensing apparatus similar to that of  FIG. 6 , but having a portion thereof broken away to better view the auger mechanism located within the hopper; 
         FIG. 8  is a perspective detail view of a discharge gate mounted at the bottom of the hopper to control the size and location of the discharge opening; 
         FIG. 9  is an enlarged, exploded detail view of the discharge gate shown in  FIG. 8 ; 
         FIG. 10  is a schematic diagram of the hydraulic system powering the operation of the concrete dispensing apparatus; 
         FIG. 11  is a perspective view of the control panel operatively connected to the hydraulic system for controlling the operation thereof; 
         FIG. 12  is an elevational view of the control panel shown in  FIG. 11 ; and 
         FIG. 13  is a front elevational view of the concrete dispensing apparatus in operation dispensing concrete mixture around a formed opening in the wall panel form. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to  FIGS. 1-6 , an apparatus for dispensing a concrete mixture into a form can best be seen. The apparatus is intended for use in conjunction with forms for making pre-cast concrete structures, such as foundation wall sections that can be transported to a building site and assembled to create a foundation for the residential or commercial building to be constructed. In the forms that are assembled for creating such modular concrete foundation wall panels, openings for doors or windows are required. While the concrete mixture is to be poured generally into the wall panel form, the concrete mixture is not to be poured into the openings that are also configured into the form. The concrete dispenser  10  to be described below is intended to be moved relative to the modular foundation wall panel form to be filled with concrete mixture. The concrete dispenser  10  can be moved relative to the form, or the form can be moved relative to a fixed position concrete dispenser  10 . This later configuration is deemed preferable and is the configuration of the invention shown in the drawings. 
     The concrete dispenser  10  is formed with a frame  11  supporting a hopper  15  having upright walls that define a cavity  16  for receiving and storing on a temporary basis a supply of hydrated concrete mixture for dispensing into a form or mold. The upright walls of the hopper  12  converge toward the bottom of the hopper  12  to form a discharge opening  17  that is significantly narrower than the inlet opening  18  at the top of the hopper  12  into which the hydrated concrete mixture is delivered. The frame  11  can be adapted for movement along a form, such as by having wheels (not shown) that will travel on tracks or the like along a stationary form. In the drawings, the frame  11  is provided with legs  12  that are configured to support the hopper  15  in a stationary manner above the form so that the form can be moved beneath the hopper  15 . Preferably, the legs  12  have adjustable feet  14  that can be positionally adjusted, such as by threading into the legs  12 , to level the frame  11  at the job site. 
     The hopper  15  has a gate mechanism  20  mounted thereon at the discharge opening  17  so that the discharge of hydrated concrete mixture from the hopper  15  can be selectively controlled. The discharge opening  17  is subdivided into multiple ports  21  and the gate mechanism  20  includes a control gate  22  mounted at each port  21  to be operated independently from each other control gate  22  mounted on the hopper  15 . As best seen in  FIGS. 8 and 9 , each control gate  22  includes a door  23  pivotally mounted on a pivot rod  24  carried by the hopper  15  and a hydraulic actuator mounted on the outside of the hopper  15  and connected to the door  23  to cause pivotal movement thereof in response to extension and contraction of the hydraulic actuator  25 . The number, spacing and sizes of the control gates  22  can be configured to the typical pre-cast foundation wall panel that is made during the manufacturing process. As depicted in the drawings, the preferred embodiment is to provide  9  control gates  22  spanning the transverse width of the hopper  15 . Preferably, as best seen in  FIG. 1 , the control gates  22  located near the center and at the one end of the hopper  15  have a smaller size to permit flexibility in the delivery of concrete mixture around blocked out openings in the wall panel. 
     Referring now to  FIG. 13 , a representative form  1  for a wall panel having an opening  5  formed into the structure of the wall panel is shown positioned below the hopper  15  to receive hydrated concrete mixture therefrom. Counting from the bottom of the form  1  at the left side of the drawing, the first four control gates  22  are opened to dispense the hydrated concrete mixture into the form. The fifth through eighth control gates  22  are closed as each of these control gates  22  fully or partially overlap the opening  5 . The ninth control gate  22  is opened to deliver hydrated concrete mixture into the form  1  above the opening  5 . Once the form  1  has moved such that the hopper no longer overlies the opening  5 , the fifth through eighth control gates  22  will be opened to dispense concrete mixture across the entire transverse width of the form  1 . 
     As can be seen in  FIGS. 1-7  and  13 , extending forwardly from the transverse ends of the hopper  15  are form vibrators  27  that are positioned to engaged the top and bottom form members  2 ,  3 , respectively, and transfer thereto a vibratory motion. Preferably, each of the vibrators  27  are extended forwardly of the discharge opening  17  by an arm  28 . The purpose of the form vibrators  27  is to induce vibration into the wall panel form to induce air trapped in the concrete mixture being dispensed from the hopper  15  to be released and to slump the concrete mixture within the wall panel form to evenly distribute the hydrated concrete mixtures throughout the confines of the form. 
     Preferably, the hopper  15  also supports rearwardly thereof a surface finishing apparatus  30  to work the top surface of the concrete mixture once poured into and distributed within the wall panel form. The finishing apparatus  30  preferably includes a vibratory screed  32  that levels and smoothes the top surface of the concrete mixture. The screed  32  preferably has at least two vibrators  33  mounted thereon for the same purposes as the form vibrators  27 , i.e. to encourage trapped air to leave the concrete mixture and to distribute the concrete mixture across the transverse width of the vibratory screed  32 . In general structural terms, the screed  32  is a flat panel extending rearwardly of the hopper  15  to engage, level and smooth the concrete mixture dispensed through the discharge opening  17 . 
     Rearwardly of the vibratory screed  32  is a roller trowel  35  to give a final finish to the top surface of the concrete mixture after the screed  32  has performed its respective function. The roller trowel  35  is to further smooth the top surface of the concrete mixture to provide a watery layer, sometimes called the cream, to appear evenly across the surface of the concrete mixture. Preferably, the roller trowel  35  is powered in rotation in opposition to the direction of movement of the forms beneath the concrete dispenser  10 , although the finishing roller  35  could also be powered to rotate in the same direction as the movement of the forms. Alternatively, the finishing roller  35  can be unpowered and will rotate in the same direction as the movement of the forms due to frictional contact with the forms and the surface of the concrete mixture. The driving of the rotation of the roller trowel  35  is preferably accomplished through a hydraulic system to be described in greater detail below; however, the outboard end of the roller trowel  35  has a sprocket  37  mounted thereon for operative connection to a drive chain. Alternatively, the powered rotation of the finishing roller  35  can be accomplished in other conventional ways, such as a direct coupling of a hydraulic motor on the end of the roller  35 . The finishing apparatus  30  can be mounted at an angle to the path of travel of the form, or perpendicular thereto as is depicted in the drawings. 
     As best seen in  FIGS. 4 and 7 , an auger  40  is mounted internally of the cavity  16  of the hopper  15  extending from one transverse end of the hopper  15  to the other. The auger  40  serves to prevent bridging of the hydrated concrete mixture within the narrowing cavity  16  of the hopper  15 , and to evenly distribute the concrete mixture across the transverse width of the discharge opening, which is particularly important as the cavity  16  is emptied of concrete mixture to be dispensed. The auger  40  includes a central rotatable shaft  43  and interrupted auger flighting  44  welded to the central auger shaft  43  to convey concrete mixture within the hopper  15 . The central shaft  43  is rotatably supported by two outer end bearings  42  mounted on the end walls of the hopper  15  and by at least one interior sealed bearing  45  mounted in the interior of the hopper  15 . Preferably, the flighting  44  is arranged to convey the concrete mixture toward or away from the center of the hopper  15 , depending on the direction of rotation of the auger shaft  43 . 
     The operative functions of the concrete dispenser  10  are preferably coupled in an operative manner to a hydraulic system  50  depicted schematically in  FIG. 10 . Hydraulic fluid is supplied under pressure from a tank (not shown) to a bank of electric solenoid valves  52  that is operable to control the flow of hydraulic fluid to each hydraulic cylinder  25  associated with the gate mechanism  20 . The solenoid valves  52  are controlled through switches  62  mounted at the top of a control box  60 , best seen in  FIGS. 14 and 15 . The hydraulic system  50  further includes a bank of solenoid valves  53  that are coupled with flow control valves  54  to control the operation of drive motors associated with the roller trowel  35 , the auger  40  and the movable forms. 
     Hydraulic fluid circulated to the hydraulic motor  55  drives the rotation of the roller trowel  35  through a chain drive (not shown) coupled to the sprocket  37  in a known manner. Similarly, the auger  40  is driven from the hydraulic motor  56 , which is separately controlled from the other hydraulic components. Since the wall panel form (or in the alternative the concrete dispenser  10 ) has to be moved underneath the hopper  15 , the drive mechanism (not shown) for moving the form (or in the alternative, moving the concrete dispenser  10  relative to the form) is powered through a hydraulic motor  57  controlled through the control box  60  so that the operation of the entire process can be effectively controlled by the operator from a single location. The form vibrators  27  and the screed vibrators  33  are preferably conventional vibratory drives powered through compressed air, although the vibrators  27 ,  33  could be hydraulically driven as well. 
     As seen in  FIGS. 11 and 12 , the control box  60  is provided with an array of toggle switches  62  at the top of the control box  62 , with each respective switch being operable to control the extension and contraction of each respective hydraulic cylinder  25  associated with the gate mechanism  20 . A pair of override switches  63   a ,  63   b  is preferably associated with the gate mechanism to cause all hydraulic cylinders  25  to extend to close all gates simultaneously (switch  63   a ) or to contract and open all gates simultaneously (switch  63   b ), regardless of the settings of the individual switches  62 . The control box  60  is also provided with a main power switch  61  to activate or deactivate the control system. Separate switches are provided to control the forward and reverse functions of the auger (through toggle switch  64 ), the roller trowel (through toggle switch  65 ) and the track drive mechanism of the form (through toggle switch  66 ). An emergency stop button  67  is also provided to provide an instantaneous halt to all operations of the concrete dispenser  10  and associated mechanisms. 
     In operation, the concrete dispenser  10  is coupled operatively to an apparatus (not shown) for mixing and conveying an appropriate hydrated concrete mixture into the cavity  16  of the hopper  15 . Such apparatus for mixing and conveying the hydrated concrete mixture is usually more efficiently operated when the concrete dispenser  10  is stationary. Thus, as reflected in  FIG. 13 , the preferred embodiment is to have the form  1  move underneath a stationary concrete dispenser  10 . The forms  1  require a track mechanism  7  that is operable to move the form in a linear manner relative to the concrete dispenser  10 . The track mechanism  7  is operatively coupled to the drive motor  66  controlled through the control box  60 . 
     The transverse length of the hopper  15  and the discharge opening  17  at the bottom portion of the hopper  15  is substantially the same width as the wall panel form to be filled with the concrete mixture. The form vibrators  27  are positioned on the end members  2 ,  3  of the forms  1  to induce a vibrational movement into the forms  1  to be transferred to the concrete mixture to be dispensed therein. Once the concrete dispenser  10  passes over the first side wall of the empty wall panel form  1  to be positioned over the empty form, the operator hits the “All Open” override switch  63   b  to contract all of the hydraulic cylinders  25  and open all ports covering the entire discharge opening  17 . The concrete mixture is then dispensed from the hopper  15  through all ports into the form  1 . Assuming that this particular foundation wall panel is a solid panel with no window or door openings to be formed therein, the operator hits the “All Close” override switch  63   a  to extend all hydraulic cylinders and close each port of the discharge opening  17  when the concrete dispenser  10  reaches the opposing side wall of the form  1 . 
     As the concrete dispenser  10  dispenses the concrete mixture into the wall panel form from one side wall to the other, the trailing finishing apparatus  30  works the top surface of the concrete mixture to level off the concrete mixture with the vibratory screed  32  and then smooth the top surface of the concrete mixture by the rotating roller trowel  35  trailing the screed  32 . Since the concrete dispenser  10  is preferably stationary, the movement of the form below the hopper  15  allows the finishing apparatus  30  to provide a smooth, level surface from one end member of the form to the other and from one side wall of the form to the other. 
     In situations where a window or door opening  5 , or some other wall feature in which no concrete is desired, is blocked out within the wall panel form  1 , the operator will hit the “All Open” override switch  63   b  to initiate the flow of concrete mixture through all ports of the discharge opening  17 , assuming that the respective opening  5  is not positioned at the initial side wall of the wall panel form  1 . When the discharge opening  17  approaches the opening  5  in which no concrete mixture is desired, the operator flips the switch or switches  62  corresponding to the ports that overlie in whole or in part the opening  5  to close the control gates  22  for those particular ports. Even ports that only partially overlie the opening  5  are closed as no concrete mixture into the blocked out opening  5  is desired. The operator may have to slow down the speed of operation of the track mechanism  7  moving the form  1  relative to the concrete dispenser  10 , such as by momentarily halting the movement while the concrete mixture continues to flow into the form  1 , depending on the number of open ports through which concrete mixture is being delivered. 
     When the operator sees that the discharge opening  17  has cleared the blocked out opening  5 , he can either hit the “All Open” override switch  63   b  again to open all control gates  22  or re-open each individual gates by manipulation of the switches  62  corresponding to the closed control gates  22 . Where two openings  5  in the form transversely overlap each other, the operator has the control to open and close each appropriate control gate  22  to continue the flow of concrete mixture into the form  1 , except into the blocked out openings  5 . With appropriate manipulation of the switches  64 ,  65  on the control box  60 , the operator can also control the direction of operation of the internal auger  40  and the roller trowel  35 . Rotational speed control can also be provided either through an appropriate control device (not shown) on the control box  60  or by manually changing the settings on the corresponding flow control valve  54 . Forward and reverse operation of the auger  40  can dislodge an obstruction or help break up bridging, or to change the direction of flow of concrete mixture toward or away from the center of the hopper  15  so that the even distribution of the concrete mixture across the entire discharge opening can be maintained. 
     It will be understood that changes in the details, materials, steps and arrangements of parts which have been described and illustrated to explain the nature of the invention will occur to and may be made by those skilled in the art upon a reading of this disclosure within the principles and scope of the invention. The foregoing description illustrates the preferred embodiment of the invention; however, concepts, as based upon the description, may be employed in other embodiments without departing from the scope of the invention.