Patent Publication Number: US-2019193145-A1

Title: Air set sand molding apparatus

Description:
BACKGROUND 
     The present invention relates to an air set sand molding apparatus. 
     Mold patterns are used to for making sand molds, which include sand mold patterns, sand mold parts, and sand mold cores used in the metal casting process. A pattern is formed in the sand mold and casting fluid is poured into the sand mold. The sand mold can be formed using a method referred to as air set molding. In air set molding, a mixture of sand, a resin, and a catalyst is poured into a molding flask that includes a pattern. The pattern is at least a portion of the cast tooling or part. The mixture cures in the molding flask to create the sand mold. The cured sand mold must be removed from the molding flask, which presents many challenges. To remove the sand mold, the molding flask is turned over or upside down so that the sand mold drops out of the molding flask by gravity. However, this often times damages the sand mold or the sand mold does not fall out of the molding flask by gravity. If the sand mold does not fall out of the molding flask, the user often times hits the molding flask to urge the sand mold out of the molding flask. Hitting the molding flask (e.g., with a hammer) can damage the molding flask and/or the sand mold. The molding flask is intended to be used multiple times. Dropping the sand mold by gravity can damage the sand mold. 
     SUMMARY 
     In one embodiment, the invention provides an air set molding apparatus configured to form a sand mold, the apparatus includes a pattern mounting plate including an ejection pin aperture, a molding flask on the pattern mounting plate, the molding flask having a closed lower end and an open upper end. The molding flask including an ejection pin aperture in the closed lower end, an ejection pin movable relative to the pattern mounting plate and the molding flask, the ejection pin movable through the ejection pin aperture of the pattern mounting plate and the ejection pin aperture of the molding flask between a lowered position and a raised position. As the ejection pin moves from the lowered position to the raised position, the ejection pin lifts the sand mold through the open upper end of the molding flask. 
     In another embodiment the invention provides an air set molding apparatus configured to form a sand mold, the apparatus includes a pattern mounting plate including an ejection pin aperture, an ejection plate movable relative to the pattern mounting plate between a lowered position and a raised position, and an ejection pin coupled to the ejection plate for movement with the ejection plate between the lowered position and the raised position. The ejection pin is movable through the ejection pin aperture of the pattern mounting plate as the ejection plate moves from the lowered position to the raised position to lift the sand mold away from the pattern mounting plate. 
     Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an air set molding apparatus according to one embodiment of the invention. 
         FIG. 2  is a top view of the air set molding apparatus of  FIG. 1 . 
         FIG. 3  is a perspective view of the air set molding apparatus of  FIG. 1  with a molding flask removed and ejection pins in a raised position. 
         FIG. 4  is a perspective view of the air set molding apparatus with side panels removed and the ejection pins in a lowered position. 
         FIG. 5  is a perspective view of the air set molding machine of  FIG. 4  but with the ejection pins in the raised position. 
         FIG. 6  is a perspective view of the air set molding machine of  FIG. 1  with a sand mold in a raised position. 
         FIG. 7  is a perspective view of a portion of the air set molding machine of  FIG. 1 . 
     
    
    
     Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. 
     DETAILED DESCRIPTION 
       FIG. 1  illustrates an air set sand molding apparatus  10  that is used to create or form a sand mold  14  ( FIG. 6 ) of a pattern  12 . Air set sand molding is also referred to as and includes pepset sand molding, all-core sand molding, dry sand molding, no-bake sand molding, chemically bonded sand molding, and the like. 
     As will be discussed below, the air set molding apparatus  10  automatically and easily removes a cured sand mold  14  ( FIG. 6 ) from a molding flask  16  with very low risk of damage to the mold  14  and the molding flask  16 . The sand mold  14  can include sand mold pattern, sand mold part, sand mold core, and the like. 
     Referring to  FIG. 1 , the air set sand molding apparatus  10  includes a pattern mounting plate  18 , a frame  20 , and the molding flask  16 . The pattern mounting plate  18  has a top side and a bottom side. The molding flask  16  is supported on the top side of the plate  18 . As best seen in  FIG. 3 , the pattern mounting plate  18  includes several ejection pin apertures  22 . The ejection pin apertures  22  extend all the way through the plate  18 , that is through the top and bottom sides of the plate  18 . The apertures  22  are arranged in rows  24  and columns  26  to form a grid like pattern on the plate  18 . 
     The frame  20  supports the pattern mounting plate  18  above the floor at a convenient working height for the user. For example, in some embodiments, the frame  20  holds the plate  18  about 30 to 40 inches above the floor. The frame  20  includes supports  30  and panels  32 . The panels  32  are removably coupled to the supports  30  to that the user can access components within the frame  20  and hidden by the panels  32 . 
     Referring to  FIGS. 1 and 2 , the molding flask  16  includes a lower end or bottom wall  36  and sidewalls  38  that extend up from the lower end  36 . Upper ends of the sidewalls  38  define and open upper end  40  of the molding flask  16 . Molding flask ejection pin apertures  42  extend through the bottom wall or lower end  36  of the molding flask  16 . In the illustrated embodiment, four apertures  42  extend through the bottom wall  36  of the molding flask  16 . In other embodiments, fewer or more than four apertures  42  extend through the wall  36 . The apertures  42  of the molding flask each align with one of the ejection pin apertures  22  of the plate  18  to form a generally continuous through hole or through aperture. 
     The pattern  12  is located inside the molding flask  16  below the open upper end  40  of the molding flask  16 . In the illustrated embodiment, the pattern  12  is formed in the bottom wall  36  of the flask  16  and then the sidewalls  38  are attached to the bottom wall  36 . In other embodiments, the sidewalls  38  can be already or permanently attached to the bottom wall  36 . In other embodiments, the pattern  12  can be separate component that is set on the bottom wall  36  rather than being integrally formed in the bottom wall  36 . The ejection pin apertures  42  of the molding flask  16  are located outside the part pattern  12 . That is, the apertures  42  form no part of the part pattern  12  and do not interfere with the part pattern  12 . Rather, the apertures  42  are located through the flat area of the bottom wall  36 . 
     Referring to  FIGS. 4, 5, and 7 , the air set sand molding apparatus  10  further includes an ejection plate  50  and ejection pins  52  that are raised and lowered by the ejection plate  50 . The ejection plate  50  is underneath or adjacent the bottom side of the pattern mounting plate  18 . The ejection plate  50  is located inside the frame  20  and panels  32  ( FIG. 1 ). The ejection plate  50  is movable up and down relative to the plate  18  and frame  20  between a lowered position ( FIG. 4 ) and a raised position ( FIG. 5 ). It should be understood that the lowered position illustrated in  FIG. 4  is just one possible lowered position of the ejection plate  50 . The ejection plate  50  may be further lowered so that the ejection pins  52  do not extend at all beyond the top of the mounting plate  18 . However, in one embodiment, the lowered position is set so that upper ends  54  of pins  52  are flush with the top of the bottom wall  36  of the molding flask  16 . Therefore, the upper ends  54  of the pins  52  extend slightly beyond the top of the mounting plate  18  (e.g., the thickness of bottom wall  36 ). 
     The ejection plate  50  includes several ejection pin apertures  58 . The ejection pin apertures  58  are arranged in columns and rows similar to the pattern mounting plate  18 . The location of the apertures  58  of the ejection plate  50  relate or match up with the location of the apertures  22  of the mounting plate  18 . That is, each of the apertures  58  of the ejection plate  50  lines up with one of the apertures  22  of the mounting plate  18 . The pin apertures  58  of the ejection plate  50  are sized to receive an ejection pin  52  to couple the ejection pin  52  for movement up and down with the ejection plate  50  related to the pattern mounting plate  18 . For example, in one embodiment, the pin apertures  58  are blind bores, not through bores, in the plate  50  to support the pins  52  for movement with the plate  50 . In other embodiments, the pins  52  have an interference fit with the apertures  58 . 
     The air set sand molding apparatus  10  further includes a drive  62  that moves the ejection plate  50  between the raised and lowered position. The illustrated drive  62  includes hydraulic cylinders  64  that raise the plate  50  and allow the plate  50  to be lowered when desired. A double rack and pinion system  66  is utilized to ensure that plate  50  is raised and lowered in a level and even manner and so that one part of the plate  50  does not raise or lower at a different rate. It should be understood that the drive  62  is just one of many possible drive devices that could be used to raise and lower the ejection plate  50 . In other embodiments, other suitable drives can be used, such as electric motors, pneumatic or pressurized air, etc. 
     In operation, the ejection plate  50  starts in the lowered position so that the upper ends  54  of the ejection pins  52  are about flush with the bottom wall  36  of the molding flask  16 . The user fills the molding flask  16  with a mixture of sand, catalyst, resin, and an activator. The mixture fills in around the part pattern  12  while the user typically strikes the mixture off using the sidewalls  38  of the flask  16  as a guide to create a level surface  70  (see  FIG. 6 ) on top of the mold. The mixture is given time to cure and harden. Then, the user moves the ejection plate  50  toward the raised position (see  FIGS. 3 and 6 ) using the drive  62  and associate control system. As the ejection plate  50  moves to the raised position, the ejection pins  50  pass through the apertures  22  of the plate  18  and the apertures  42  of the flask  16  and move to a raised position. The pins  50  raise or lift the sand mold  14  out of the flask  16  as shown in  FIG. 6 . That is, the sand mold  14  is raised above the open upper end  40  of the molding flask  16 . As discussed above, the ejection pins  52  that lift the sand mold  14  are outside the perimeter of the pattern  12 . Therefore, the pins  52  lift and press against a flat part  76  of the sand mold  14 , which is a waste portion, and the pins  52  do not press against the cavity created by the pattern  12  in the mold pattern  14 . The pins  52  pressing against the cavity created by the pattern  12  may damage the sand mold  14  or otherwise create undesirable surface features on the final product created by the mold. The user can then easily lift or otherwise move the sand mold  14  to another location because the mold has be lifted out of the flask  16 . 
     The air set sand molding apparatus  10  and ejection system can easily be reconfigured for use with a different molding flasks and patterns simply by moving the location of the ejection pins  52  on the ejection plate  50 . The pins  52  are uncoupled or removed from the ejection plate pin apertures  58  and repositioned into different apertures  58  depending on the shape and size of the new pattern and molding flask. The pattern mounting plate  18  also has several pin apertures  22 , as discussed above, so that the pins  52  can pass through the plate  18  to lift the sand mold as discussed above. 
     Thus, the invention provides, among other things, an air set molding apparatus that automatically and easily removes the sand mold from the molding flask with very low risk of damage to the sand mold and the molding flask. Various features and advantages of the invention are set forth in the following claims.