Abstract:
A general purpose molding and casting machine which will run unmanned to receive a casting assemblage and then separate the runners and sprue from the casting. Once the separation has taken place the casting is carried to the finished parts area and runners and sprue remnants are delivered to the scrap area for reuse.

Description:
RELATED APPLICATIONS 
     This application is related to Disclosure Document Number 416964, filed Mar. 19, 1997. 
    
    
     FIELD OF THE INVENTION 
     The invention finds applicability in the field of molding and casting. 
     Terms Used Herein: 
     DIE CASTING MACHINE is a machine that injects molten metal into a die (mold) to form a casting, or castings. 
     ROBOT is a programmable, automated device that is adapted to unload die casting machines and set the casting assemblage (Gate) down in an organized, predictable fashion. 
     GATE is the casting assemblage, consisting of the casting or castings, with the runners and the sprue, all tied together. 
     DEGATING is a process for removing the waste portion or gate remnant from the casting. 
     DEGATE-AND-TRIM MACHINE is a machine that utilizes a complex punch and die set to separate the good casting or castings from the gate, and then trim away the flash and/or overflow. 
     CASTING is the desired product resulting after degating. 
     GATE REMNANT is the portion of the gate that is separated from the castings by the degating and trim process. 
     BACKGROUND OF THE INVENTION 
     Modern die casting plants employ a number of die casting machines with a degate-and-trim machine alongside each casting machine. The die casting machines, in the larger sizes, are usually attended by a robot, and can thus run unmanned. The degate-and-trim machines are rarely automated as to loading and unloading, and thus require labor to operate. 
     In rare, high volume instances where degate-and-trim machines have been automated, the buildup of scrap (broken-off pieces of the gate, flash and overflows) inevitably hinders the proper working of the machine. This is the main reason that most degate-and-trim machines were never automated. 
     Objects of the Invention 
     A main object of this invention is to produce a machine which will automatically and efficiently separate the casting from waste material. 
     A significant object of this invention is to produce a machine for separating castings from scrap requiring a minimum amount of manpower. 
     Another object of this invention is to produce an efficient means for determining imperfections in different sets of castings. 
     A still further object is to produce a machine which will efficiently return scrap separated from the casting for recycling. 
     These and other objects of the present invention will become apparent from a reading of the following specification taken in conjunction with the enclosed drawings. 
     Problem Solved By This Invention 
     This invention completely solves the problem of scrap buildup, and permits easy interface with the robot that unloads the die casting machine. This permits seamless, unmanned operation between the two machines, namely, the mold and the degate and trim machine. Additionally, this invention provides a means for progressively removing parts from the gate while the die casting machine is making its next shot, thus the degate-and-trim machine does not have to be as big or expensive as that of the prior art. 
     BRIEF SUMMARY OF THE INVENTION 
     The invention covers a general purpose machine which will run unmanned to automatically remove die castings from their gates, trim the castings and send the trimmed castings to a parts container or bin. The scrap remnants and trim are automatically removed for remelting and use to manufacture additional castings. 
     The automated degate-and-trim machine works in the following manner. First, the robot grabs the gate while the gate is still hot and in the casting machine. A typical gate, and the robot&#39;s grippers might grab the casting around the sprue. The robot then brings the gate to the automated degate-and-trim machine (A.D. &amp; T.M.) and sets the castings onto lower male fixtures positioned on the degating plate or platform. The A.D. &amp; T.M.&#39;s press then actuates, trimming and separating the castings from the gate. The press then opens, lifting the castings with a female die, and an unloading plate or parts catcher slides in from below to receive the castings released onto it. The unloading plate containing the castings slides and ejects the casting into parts chutes, from whence they slide into the parts bins. After this process the robot picks up a gate again and moves the gate ahead so that the second castings set is degated and trimmed. The process can be repeated until all castings are removed and trimmed. After the castings have been degated and trimmed, the gate plate slides back and tips up, dumping all scrap, i.e., the gate remnant, flash and overflows, into the scrap conveyor, thus leaving the machine clean and clear for the next shot. 
     In its broadest aspect, the herein disclosed invention involves an automatic degate and trim machine comprising a means for receiving and positioning a gate, for example a male fixture. Said gate comprising a casting and gate remnant. With the gate positioned in registry with a female die having ejecting means disposed therein, said female die along with a ram descend with force onto the gate to yieldably engage the casting, as well as, separate the gate remnant from the casting while leaving the gate remnant on a gate plate. Once the gate remnant is separated from the casting, the ram and the female die yieldably engaging the casting are raised to allow a parts catcher to come into position under the female die. With the parts catcher in position said ejecting means is actuated causing the casting to be ejected from the female die onto said parts catcher which delivers the casting into a parts bin for receiving said casting. With the casting out of the way of said gate remnant, a gate plate containing said gate remnant is tilted causing the gate remnant to fall into a scrap bin. The automatic degate and trim machine can have the casting deposited onto a chute prior to delivery to said parts bin and the gate remnant can be deposited onto a chute or conveyor prior to deposit into said scrap bin. Once the cycle is complete the machine can repeat the cycle. 
     Viewed another way, the invention encompasses an automatic degate and trim machine having as its main components: 
     a ram, 
     a female die with ejecting means disposed therein, 
     a male die or fixture for receiving a gate comprising a casting, 
     a gate plate and 
     a parts catcher, 
     wherein said gate plate has disposed thereon said with male fixture for receiving a gate, said ram and female die with ejecting means positioned in a raised position over the male fixture being powered and operating reciprocally such that the ram and female die can be lowered with force to cut and separate the casting from said gate leaving a gate remnant and with the female die yieldably retaining said casting within the female portion of the die. With the female die raised the female die can release the casting into a parts catcher and then into a parts bin, 
     the gate plate having received the gate remnant delivers the gate remnant to a scrap bin for recycling. Once the cycle is complete the machine can repeat the cycle. 
     In its broadest aspect, this invention involves an automated method for removing and separating castings from a gate containing the same comprising placing a gate onto a gate plate wherein a ram and a female die with ejecting means disposed therein descends with force onto the casting of said gate to yieldable engage the castings to separate and trim away gate remnant form the casting, leaving the gate remnant on said gate plate, with the gate remnant separated from the castings, the castings are separated and deposited into individual groups for deposit into separate bins and the gate remnant is removed from the gate plate for placement into scrap. This method allows for ready determination of imperfections in the different castings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a pictorial view of the automated degate and trim machine displaying a greatly enlarged gate (casting assemblage). 
     FIG. 2 is a plan view showing the gate received on the gate plate. The gate plate is supported on a gate plate support or lower platen shown in dashed lines. 
     FIG. 3 is an exploded view showing the components making up the gate plate and male projections, gate plate support and their relationship to the gate, female dies and punch. 
     FIGS. 4-8 is a series of views showing the casting being severed and received into the female die and at a proper time released therefrom. The end of the female die and the end of the casting have been removed to show the inner mechanism of the female die and how the casting sits on the male fixture. 
     FIG. 9 is a view of the female dies having released the castings into the parts catcher. 
     FIG. 10 is a view showing the parts shunted onto a parts chute. 
     FIG. 11 is a schematic view of the castings being released from the dies and then shunted onto a parts chute. 
     FIG. 12 is a view of a finished casting. 
     FIG. 13 is a view of the casting received on the gate plate, with the chain in a relaxed position. 
     FIG. 14 is a view of the gate plate translating and depositing the gate remnant into a scrap bin after the casting has been separated. The chain is in a taut position. 
     FIG. 15 is a front view schematic representation of an automatic degate and trim machine disposing of gate remnant and shunting the finished castings into a chute and then to the parts bin. 
     FIGS. 16-20 are a series of views describing the procedural steps by which the machine operates. 
    
    
     DESCRIPTION 
     With reference to FIG. 1 the automated degate and trim machine  10  for receiving a gate  12  onto a degate plate  14  (arrow) has disposed thereon a set of male fixtures or lower dies  16  for positioning the gate  12 . Above the male fixtures is a set of female dies  18 . The female dies  18  function in cooperation with a parts catcher  20  and a chute  22  (explained below). The degate plate  14  functions with a chain  26  to drop gate remnant  34  into a chute or recycling bin  28  (explained below). The gate  12  is composed of castings  28 , a sprue or biscuit  30  and runners  32 . The sprue  30  is the opening through which molten metal is poured into the mold. As used herein the sprue is a waste piece of metal which the robot (not shown) can grasp and hold onto. The runners  32  are composed of metal which was poured into the mold. 
     Referring to FIGS. 1 and 2 in operation a robot (not shown) brings the gate  12  and places the castings  28  within the gate  12  onto lower die or male positioning means  16  which are attached to a lower platen, explained below. Once the gate castings  28  are positioned on the male positioning means  16  the castings will be in registry with female dies  18  mounted above the castings  28 . As shown in FIGS. 4-8, the female dies  18  descend onto the castings  28 , and with the sharp edges of the die, as well as with pressure exerted by ram or punch  36  through the hydraulic system sever the castings  28  from the gate leaving gate remnant  34  on the degate plate  14 . The ram or punch  36 , as well as the female dies, are attached to an upper platen  37  which, in turn, is driven by a fluid or air cylinder (not shown). 
     With reference to FIG. 3, there is shown an exploded view of the ram  36  and female dies  18 , the gate  12 , the degate plate  14  and the gate plate support or lower platen  46 . The degate plate support or platen  46  is stationary while the degate plate is able to translate from right to left to dump the gate remnant and return to its original position (explained below). The degate plate support or lower platen  46  is shown with male fixtures or lower dies  16  disposed thereon, as well as guide slot  48  for receiving projection  50  under the degate plate. Guide slot  48  in conjunction with projection  50  may help stabilize the translation and return of the degate plate or stabilization can be attained by separate ways, guide rods or guide rails. Projection  50  also retains the chain. Open cut-outs  52  in the gate plate accommodate the male fixtures  16 . In addition, the cut-out access  52  allows for the degate plate  14  to translate while the degate plate support or platen remains stationary. The male fixtures or male dies are placed on the stationary degate plate or platen support and receive a major amount of force from the thrust of the ram and female dies. As an alternative embodiment, the male and female dies can be, and sometimes are, reversed in position. 
     More specifically, referring to FIGS. 4-8, a female die  18  shown with its end removed has disposed in the top compartment  45  of the die  18 , a pad  39  on the first end of a shaft  41  with the second end the shaft joined to a pad lift cylinder guide  42 . A spring  43  is positioned around the shaft  41  with the ends of the spring  43  abutting the pad  39  and the top of the die compartment  45 . As shown in FIG. 4 prior to the descent of the die  18 , the pad lift cylinder (not shown) is relaxed, the spring  43  is extended in a relaxed position. Once the ram cylinder (not shown) is actuated, the female die  18  descends (arrow) upon the gate  12  with the casting  28  shown with end removed in the gate  12  (FIG.  5 ). In FIG. 5 the casting is trimmed. During this step the pad  39  has remained in contact with the descent of the upper platen  37 . This holds the casting firmly on the lower male die or fixture. Note particularly that in FIGS. 4-8 the male die or fixture  16  is shown with a square shoulder  17  which is able to more securely position the casting  28  for severing and trimming. The male die  28  with the square shoulder is a preferred embodiment of this invention. After the casting has been severed (FIG. 6) the pad  39  is lifted leaving a gap  47 . This gap is brought about by the hydraulic cylinder raising the pad off of the casting. This release of the pad (gap) is necessary; otherwise, the spring would push the casting out of the female die as soon as the ascent began. With ascent (arrow) of the die (FIG. 7) the casting is wedged in the female die so that the die lifts the casting as the upper platen  37  ascends. The pad lift cylinder (not shown) is retracted, holding the spring  43  back. Note that in FIGS. 5-7 spring  43  is compressed. As a final step (FIG. 8) the pad lift cylinder relaxes causing the spring  43  and pad to push the casting  28  out of the upper die  18  (arrow). However, in operation, prior to the casting being ejected from the female die, parts catcher  20  moves under the female die to catch the casting  28  being ejected as explained below. 
     As described by FIGS. 9-11, the female dies  18 , employed to sever the casting  28  from the gate  12 , are made so as to yieldably grasp and retain the casting  28 . This is normally effected in that the castings once trimmed will naturally fit snuggly inside the female die. Once castings are severed the female dies retaining the castings therein are raised through means of the hydraulic press (ram) which opens lifting the castings with the female die. Referring specifically to FIG. 11, an unloading plate or parts catcher  20  slides in below the castings held in the female dies to receive the castings which are released onto the parts catcher  20 . The arrows in FIGS. 9-11 show direction of movement of the castings  28 . 
     Referring specifically to FIG. 11, upon release from the dies  18  the castings  28  drop into the parts catcher  20  shown on the left in slashed lines (FIG.  11 ). The parts catcher is made to move rapidly to the right (shown by arrow) striking into its stops  49  and coming to an abrupt halt. At the end of the guide rails or rods is a rubber sleeve or bumper which takes up shock when the guide rail comes to the end of its travel. The parts catcher  20  is attached to a rod  21  which, in turn, is attached to the hydraulic system (not shown). Since the castings  28  cannot stop as fast as the parts catcher  20  stops the castings are thrown by their momentum to the right and onto receiving chutes  22  shown by arrows for delivery to a parts bin. The motion of the parts catcher is controlled by guide rods and sleeves shown in FIGS.  1  and  9 - 11 . The motive force is produced through hydraulic or air cylinders. Attention is directed to the fact that the castings are delivered to two separate baskets on the parts catcher  20 . Two separate chutes  22  and two separate parts bins for receiving parts are employed. The advantage of two separate chutes is that the parts can be separately examined for flaws based on the individual parts in the bin and adjustments can be made for each individual line run. This segregation is particularly useful where multiple, and particularly more than two, castings are being dealt with. While the invention has been described as the finished castings being deposited into a chute and then a parts bin, the finished product could have been deposited directly into the parts bin. 
     With reference to FIG. 12, there is shown the finished casting  28 . The casting shown is a cast part of a door closer. It is obvious that the automated degate and trim machine could handle castings of unlimited shapes and sizes and the invention is not limited to any particular casting configuration. 
     With reference to FIGS. 13-15, once the casting is separated from the gate  12  there remains a gate remnant  34  on the degate plate  14 . The gate remnant is removed from the degate plate by the degate plate  14  translating to the left in a straight line until a slack chain  26  (shown in FIGS. 13-15) becomes taut causing the degate plate  14  which is hinged (not shown) to tilt dropping the gate remnant onto a scrap bin  44  where the remnant can be recycled. Instead of the scrap being placed in bin  44 , it can be placed onto a conveyor  53  as shown in FIGS. 16-18. With degate plate unloaded it is returned to its original position and the cycle can be repeated. Detail of the degate plate  14  and degate plate support are shown in FIGS. 2 and 3. In FIGS. 13-15 a chain  26  is shown, however, the chain could be substituted with a cable or like device. 
     Referring more specifically to FIGS. 13-15, the gate plate  14  is able to translate from right to left and dump gate remnant  34  onto scrap bin  44 . The mechanism by which translation and dumping takes place is that the hydraulic system drives shaft attached to brace  55  which, in turn, is attached to guide shaft  56 . The left end of the gate plate  14  is hinged at the juncture of brace  55  and guide shaft  56 . As previously pointed out, the scrap placed onto a conveyor is more convenient since the conveyor can facilitate recycling. 
     Referring to FIG. 15 there are shown auxiliary gate remnant deflectors  51  which direct stray pieces of remnant onto a chute, conveyor or scrap bin. For ease of recycling, a conveyor is preferred because with a conveyor the process will be more continuous. The conveyor can lead directly to the furnace. 
     FIGS. 16-20 briefly describe the steps of the machine process. FIG. 16 shows the machine with the gate  12  on the lower dies  16 . Scrap conveyor  53  carries scrap to the scrap bin  44 . With reference to FIG. 17 the female die  18  grasp the castings after the gate  12  is broken. The castings  28  are shown in dashed lines and arrow shows direction of the die. The dies are raised (arrow) with the castings and the castings are released into a parts catcher (not shown) (FIG.  18 ). Referring to FIG. 19, the gate remnant  34  is deposited into a scrap bin  44  and the castings into the parts bin. Arrows show the reciprocal action of the parts catcher. The tilt of the gate plate and its translation are shown by arrows. With the cycle complete the machine is ready for the next gate (FIG.  20 ). 
     An alternative embodiment of this invention is the combination of a gate plate support and a gate plate comprising said gate plate support having male fixtures on the top surface of the gate plate support, said gate plate having slots through which said male fixtures protrude and also allow the gate plate to translate, said gate plate being able to translate and tilt to dispose of gate remnant on the gate plate, said male fixtures being able to receive a casting in a gate. The mechanism to cause the gate plate to translate is a chain and sprocket arrangement. The gate plate can be made to tilt by a hinge and tension on a chain attached to the gate plate. With the slack taken out of the chain, the gate plate will tilt, dumping the gate remnant as herein disclosed. 
     As an alternative embodiment, the gate plate could be cleared of gate remnants by a wiper, such as a windshield wiper, or the scraps could be removed by magnetic attraction. 
     The female dies and ram are actuated by hydraulic means, however, other motive forces known to those skilled in the art could be used to operate the dies and ram. 
     The invention has been described in the context of twin castings. It is obvious that the machine could be fashioned to accept a greater number of castings, or could be fashioned to accept a single casting. 
     CONTROL SEQUENCE 
     The control is an ordinary action-reaction type control, using an ordinary Programmable Logic Controller. The program is basically the same for all castings being run. All program-initiated actuation are via solenoid valves, to cause motion in hydraulic or air cylinders. 
     The machine cycle starts as a robot brings the gate over from the die casting machine and sets it (the gate) onto the lower (male) fixtures. At this point, a spring-loaded pin is depressed, actuating a part-present sensor that is an input to the control: 
     
       
         
               
               
               
             
               
               
               
               
             
           
               
                   
                   
               
               
                   
                 Control Input 
                 Subsequent Control Output 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                  Part present 
                   Program   → 
                  Solenoid valve is shifted to 
               
               
                   
                   sensor is made 
                 dictates 
                   send the ram and female 
               
               
                   
                   
                   
                   dies onto its downward 
               
               
                   
                   
                   
                   journey 
               
               
                   
                   
               
             
          
         
       
     
     Mechanical: The ram or punch extends downward until it “bottoms out” at its stall point. Before bottoming out, a pressure pad inside the female die(s) will have firmly pressed the castings onto the male fixture(s), thus locating the casting firmly, and then an instant later the female die trims away all the flash, overflows and gate remnants. The casting is now “stuck” inside the female (upper) die(s). 
     
       
         
               
               
               
             
           
               
                   
               
             
             
               
                  Ram “down” 
                   Program   → 
                  Solenoid is shifted to lift the 
               
               
                   sensor is made 
                 dictates 
                   pressure pad that pushes 
               
               
                   
                   
                   down on the trimmed 
               
               
                   
                   
                   castings. 
               
               
                   
               
             
          
         
       
     
     Mechanical: The pressure pad lifts against the spring. 
     
       
         
               
               
               
               
             
           
               
                   
                   
               
             
             
               
                   
                  Pressure pad lift 
                   Program   → 
                  Solenoid is eneegized to 
               
               
                   
                   sensor is made 
                 dictates 
                   lift the ram. 
               
               
                   
                   
               
             
          
         
       
     
     Mechanical: The ram and female dies ascend, with the castings stuck inside the dies. Ram cylinder bottoms out. 
     
       
         
               
               
               
             
           
               
                   
               
             
             
               
                  Ram “up” sensor is made 
                   Program   → 
                  Solenoid for scrap plate 
               
               
                   
                 dictates. 
                   is energized. 
               
               
                   
                   
                  Solenoid for parts 
               
               
                   
                   
                   catcher is energized. 
               
               
                   
               
             
          
         
       
     
     Mechanical: The scrap plate translates to the left (in a straight line) until the chain slack is taken up, whereupon further leftward motion causes the scrap plate to tip up. Eventually, the actuating cylinder bottoms out. 
     Meanwhile, the parts catcher mechanism has translated in (from right to left) until the parts catchers themselves are directly under the castings. The actuating cylinder bottoms out. 
     
       
         
               
               
               
             
           
               
                   
               
             
             
               
                  Two sensors are 
                   Program   → 
                  Solenoid for scrap plate is 
               
               
                   made, one for each 
                 dictates 
                   reversed. 
               
               
                   of the foregoing 
                   
                  Solenoid for parts, 
               
               
                   motions 
                   
                   catcher is reversed. 
               
               
                   
               
             
          
         
       
     
     Mechanical: scrap plate flops back down and translates back to its original (R.H.) position. 
     And, the parts catcher moves rapidly to the right, striking into its stop and coming to an abrupt halt. The castings cannot stop that fast, so they are thrown to the right and end up going down the chutes. 
     
       
         
               
               
               
             
           
               
                   
               
             
             
               
                  Two sensors are 
                   Program   → 
                  End of program. Await new 
               
               
                   made, one for each 
                   
                   signal from part present 
               
               
                   of the foregoing 
                   
                   sensor to start next sequence. 
               
               
                   motions 
               
               
                   
               
             
          
         
       
     
     Note that all actuating cylinders run to, and are arrested by, stops. These stops are rubber rings that also act as shock absorbers. 
     While the invention employs hydraulic or air cylinders for motive force, other power sources readily apparent to those skilled in the art are envisioned by this invention. 
     ADVANTAGES 
     Many advantages accrue to the automatic degate and trim machine of this invention. 
     The machine will operate with conventional robots of the type that are used in die casting plants. 
     The machine is able to keep itself clean. 
     The machine will trim progressively if desired, so that it does not have to be as big as conventional degate and trim machines presently in use. This permits use of smaller capacity equipment requiring less space. Thus, the machine of this invention will be able to trim and dispose of large pieces of gate remnant, as well as small scrap that ordinarily would build up to impeded the functioning of the machine. 
     The robot does not need to be involved during the processing of the last castings set, nor during gage plate dump, freeing it (the robot) to return to the die casting machine for the next gate. 
     Obviously, many modifications may be made without departing from the basic spirit of the present invention. Accordingly, it will be appreciated by those skilled in the art that within the scope of the appended claims, the invention may be practiced other than has been specifically described herein.