Abstract:
An air amplifier apparatus and method for transferring or filling sand particles into a flask of a molding machine. A plurality of nozzles are each mounted with respect to the molding machine. A pressurized fluid, such as discharged from an air compressor or other pressure forming device, delivers pressurized fluid into each nozzle. The pressurized fluid flows through a passageway of each nozzle and can follow a Coanda profile as it accelerates the particles through the passageways. The accelerated particles are then discharged into a void formed by the flask of and pattern in the molding machine.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    This invention provides an air amplifier for use as an apparatus and in a method for filling a flask of a molding machine, whereby sand particles originally falling into the flask only by gravity are now accelerated upon exiting amplifier nozzles. The accelerated sand particles are directed or slung (as in sand slinger) toward a pattern plate and flask mounted within a molding machine. 
         [0003]    2. Discussion of Related Art 
         [0004]    Some conventional molding machines use gravity feed systems to fill a cope flask and a drag flask with sand. During the fill procedure, green sand is loaded into a measuring hopper. The hopper is then opened and the sand falls by gravity into and fills a space defined by the flask and a pattern plate. 
         [0005]    In other conventional molding machines, sand is pneumatically blown into a void/space defined by a flask and a pattern plate. In some, if not all, pneumatically blown fill processes, a seal is formed between the flask and the device that feeds the pneumatically blown sand. Flasks used with a pneumatically blown filling device require a vented structure, such as one or more screens or vents, so that air can discharge from the flask without carrying the sand outside of the flask. The seals and also the vented flasks require undesirable maintenance, for example to keep the vents open and properly operating. Machines of this closed fill design also do not provide the flexibility or access that is desired in the production of many castings, such as, for example, the use of chaplets, ram up cores, exothermic risers, etc. 
       SUMMARY OF THE INVENTION 
       [0006]    It is one object of this invention to provide an apparatus for filling a cope flask and/or a drag flask of a molding machine by using nozzles to accelerate and direct sand particles into a void formed by a flask structure. 
         [0007]    It is another object of this invention to provide a method for filling the cope flask and/or the drag flask in a timely manner, to achieve better time and motion efficiency of the molding machine. 
         [0008]    The above and other objects of this invention are accomplished with a distribution apparatus mounted upstream with respect to a flask to be filled. The distribution apparatus has a plurality of nozzles, such as, for example, air amplifier nozzles, that can receive sand, for example gravity fed sand, and distribute the sand into the different nozzles. The nozzles can be arranged in any suitable pattern or array, depending upon the intended use or the type of pattern mounted within the corresponding flask. 
         [0009]    Each nozzle can have a pressurized fluid, such as air, flowing through a passageway of the nozzle. The pressurized fluid passes through openings within the nozzle and increases the velocity of fluid flowing through the nozzle. In one embodiment, the nozzles include a pressurized fluid inlet, a Coanda profile, and/or a mixed fluid outlet. 
         [0010]    As the sand falls by gravity from a hopper, the sand enters an inlet of each nozzle. The pressurized fluid flowing through the nozzle draws the sand into and through the passageway of the nozzle and accelerates the sand as it travels through the passageway of the nozzle. The sand discharges through an outlet of the nozzle and is directed toward a void formed by the flask. 
         [0011]    Any nozzle can be adjustably mounted with respect to the mold or the flask, so that the flow of accelerated sand can be directed or aimed into the void of the flask. For example, any one or more of the nozzles can be aimed at or near a pattern mounted within the void of the flask. 
         [0012]    The accelerated sand particles can provide denser compaction and/or more uniform compaction of the sand about the pattern, and can desirably reduce or eliminate, for example, the need for conventional hand ramming to achieve the desired mold quality. 
         [0013]    A computer, controller or other calculating device can be programmed and used to achieve different flow parameters of the sand through the nozzle, and also to change the position of each nozzle with respect to the flask. 
         [0014]    Upstream of the nozzles, funnels or funnel inlets can be used to distribute the gravity fed sand into corresponding nozzles. Each funnel or funnel inlet can have a shape of a truncated cone, for example that converges in a direction toward the corresponding nozzle. The funnels or funnel inlets can be positioned next to each other to reduce or eliminate horizontal surfaces that would otherwise catch or collect sand and interfere with distribution and/or flow of the sand. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    The above and other features and objects of this invention are better understood from the following detailed description taken in view of the drawings, wherein: 
           [0016]      FIG. 1  is a schematic partial sectional view of certain elements of a molding machine, according to one embodiment of this invention; 
           [0017]      FIG. 2  is a longitudinal sectional view of a nozzle, taken along a centerline, according to one embodiment of this invention; 
           [0018]      FIG. 3  is a top view of the nozzle, as shown in  FIG. 2 ; 
           [0019]      FIG. 4  is a top view of an upstream plate, according to one embodiment of this invention; 
           [0020]      FIG. 5  is a sectional view, taken along line  5 - 5 , as shown in  FIG. 4 ; 
           [0021]      FIG. 6  is a sectional view, taken along line  6 - 6 , as shown in  FIG. 4 ; 
           [0022]      FIG. 7  is a top view of a downstream plate, according to one embodiment of this invention; 
           [0023]      FIG. 8  is a sectional view, taken along line  8 - 8 , as shown in  FIG. 7 ; 
           [0024]      FIG. 9  is a sectional view, taken along line  9 - 9 , as shown in  FIG. 7 ; 
           [0025]      FIG. 10  is a sectional view of a funnel, according to one embodiment of this invention; 
           [0026]      FIG. 11  is a top view of the funnel, as shown in  FIG. 10 ; and 
           [0027]      FIG. 12  is a sectional view of the nozzle shown in  FIG. 2 , but with diagrammatic arrows showing how pressurized air enters the nozzle and accelerates the particles through the nozzle. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0028]    Molding machine  20  of this invention can be used in connection with molding technology, including molds that use green sand. U.S. Pat. No. 6,622,772, the entire disclosure of which is incorporated into this specification by reference, describes background technology that could be applied to this invention. 
         [0029]      FIG. 1  shows certain elements of molding machine  20 , according to one embodiment of this invention. Particles  21  are delivered, such as through source or supply  22 , to any suitable hopper  23 , such as a variable volume hopper, or any other suitable feed or supply device for delivering particles  21 . Supply  22  can be manually and/or automatically opened and/or volume controlled, to permit particles  21  to flow in a downstream direction. As used throughout the specification and in the claims, the terms upstream and downstream relate to a direction of normal flow of particles  21  entering supply  22 , passing through hopper  23  and entering nozzles  40 . For example, the downstream direction is from the top to the bottom, as shown in  FIG. 1 . 
         [0030]    Particles  21  may comprise green sand normally used with molding machines, or any other suitable sand or other particulate substance that can be used in molding machine  20 . 
         [0031]    As shown in  FIG. 1 , molding machine  20  comprises mold  30  having cope flask  31  and drag flask  33 , which can be connected or mounted with respect to each other using matchplate  35  or any other suitable connector known to those skilled in the art of molding machines. Cope flask  31  forms void  32  in which pattern  36  can be mounted or otherwise positioned. Drag flask  33  forms void  34  in which pattern  37  can be mounted or otherwise positioned. Void  32  and  34  can have any suitable shape and/or dimensions that accommodates the corresponding pattern  36  or  37 . 
         [0032]    In certain embodiments of this invention, distributor  39 , which receives and discharges particles  21 , comprises nozzles  40  and/or structural elements directly or indirectly connected or attached to nozzles  40 . As shown in  FIG. 1 , four nozzles  40  are mounted with respect to molding machine  20  and/or mold  30 .  FIGS. 4 and 7  illustrate a 5×6 array or thirty positions for corresponding nozzles  40 . Any other number, shape and/or arrangement of nozzles  40  can be used, according to this invention. 
         [0033]      FIG. 2  shows each nozzle  40  having inlet  42  and outlet  44 . Inlet  42  is positioned with respect to or is in communication with supply  22  of particles  21 , for receiving or allowing particles  21  to enter passageway  48  of nozzle  40 . Inlet  42  can be positioned at upstream end  41  of distributor  39 . Outlet  44  can be positioned at downstream end  43  of distributor  39 , so that particles  21  discharge through outlet  44  and travel into void  32  or  34 . 
         [0034]    Pressurized fluid  25  can comprise any suitable gas or liquid used to carry particles  21 . For example, pressurized fluid  25  can be pressurized air or any other pressurized gas. 
         [0035]    Pressurized fluid  25 , such as shown in  FIG. 2 , passes through passageway  48  and discharges through outlet  44 . As illustrated in  FIG. 12 , pressurized fluid  25  draws particles  21  into the flow field established within passageway  48 , and accelerates particles  21 , such as indicated by the increasing length of flow arrows, within or through passageway  48 . The flow stream established by pressurized fluid  25  can be directed or aimed so that discharged particles  21  are transferred into void  32  or  34 , for example at or near pattern  36  or  37 . 
         [0036]    The acceleration and thus the increased velocity of particles  21  can provide better or denser compaction and/or more uniform compaction of particles  21  about, at or near pattern  36  or  37 . 
         [0037]    In certain embodiments according to this invention, each nozzle  40  is attached to plate  50 .  FIGS. 1-3  and  6  illustrate how an upstream end portion of nozzle  40  is mounted within bore  51  of plate  50 . Bore  51  forms fluidic communication with inlet  42  of nozzle  40 . 
         [0038]    A downstream end portion of nozzle  40  can be attached to plate  55 . Downstream end  43  can be mounted within bore  56  of plate  55 , such as shown in  FIGS. 1-3  and  9 , to form fluidic communication between outlet  44  and bore  56 . The assembled structure formed by nozzle  40 , plate  50  and plate  55  forms space  58 , or another suitable void, between plates  50  and  55 . In certain embodiments of this invention, space  58  can be used to provide pressurized fluid  25  to passageway  48  of nozzle  40 . Nozzle  40  can be attached, secured, connected or otherwise mounted with respect to plate  50  and/or plate  55 , using any other suitable mechanical connection or integral material. In some embodiments according to this invention, nozzle  40  and plates  50  and  55  are sealably attached with respect to each other, to prevent pressurized fluid  25  from leaking through the formed structure of distributor  39 . 
         [0039]    One common space  58  can be used to provide pressurized fluid  25  to each nozzle  40 . In other embodiments according to this invention, space  58  can be divided into two or more separate portions, such as by using one or more baffle structures or any other suitable valving arrangement. Manifold  60 , such as shown in  FIG. 12 , can be used in addition to or in lieu of space  58 , to deliver pressurized fluid  25  to each nozzle  40 . Two or more manifolds  60  can be used to independently control flow parameters of pressurized fluid  25  through nozzle  40 . The different portions and/or different manifolds  60  can be used to provide different flow parameters of pressurized fluid  25  to at least two of nozzles  40 . 
         [0040]    Controller  70  can be programmed or otherwise used to determine at least one flow parameter at which pressurized fluid  25  is delivered to each of nozzles  40 . Controller  70  can emit a signal to a control device, such as a control valve shown in  FIG. 12  or another suitable regulator, to manage or change any flow parameter of pressurized fluid  25 . The flow parameters can be changed simultaneously to the different nozzles  40 . In addition to or in lieu of the simultaneous flow control to each nozzle  40 , controller  70  can also change flow conditions over a given time period while maintaining the same flow conditions at two or more of nozzles  40 . 
         [0041]    As shown in  FIG. 2 , nozzle  40  comprises at least one opening  46  which is exposed to or in fluidic communication with passageway  48  of nozzle  40 . Opening  46  forms communication with pressurized fluid  25 , for example within space  58  and/or within manifold  60 . As shown in  FIG. 2 , each opening  46  is a through bore. However, opening  46  may comprise any other suitable void, tube, pipe or other communication device that can form fluidic communication between passageway  48  and a source of pressurized fluid  25 . The number of openings  46 , and the size and orientation of each opening  46  can be varied or designed to accomplish one or more different flow conditions, flow parameters and/or flow patterns within passageway  48 . Opening  46  can also be positioned or directed to create a swirling flow within and/or downstream of nozzle  40 . 
         [0042]    One or more nozzles  40  can be adjustably mounted with respect to mold  30 , including cope flask  31  and/or drag flask  33 . For example, nozzle  40  can have a gimbal mount adjustably positionable with respect to cope flask  31  and/or drag flask  33 , that provides rotational movement about one or more of three different axes. A gimbal mount can be used to position or aim nozzle  40 , for example at or near pattern  36  or  37  positioned within void  32  or  34 . 
         [0043]    In certain embodiments according to this invention, in addition to or in lieu of the gimbal mount, at least one nozzle  40  can be moveably mounted or positionable with respect to cope flask  31  and/or drag flask  33 . For example, nozzle  40  can be manually and/or automatically, such as through a programmed robotic control, moved in any one or more of three dimensions. Each nozzle  40  can be moved and/or repositioned by using any suitable programmed controller and a positioning device. 
         [0044]    As shown in  FIG. 2 , nozzle  40  has a generally straight passageway  48 , with a central portion that slightly converges in the downstream direction. Each nozzle  40  may comprise a straight nozzle, a converging nozzle, a diverging nozzle and/or a converging-diverging nozzle. Passageway  48  can have any other suitable shape that can be used to accelerate particles  21  through passageway  48 .  FIG. 3  shows a top view of nozzle  40  having a generally circular cross section of passageway  48 . However, in other embodiments of this invention, passageway  48  can have a square or rectangular cross section or any other suitable non-circular cross section. 
         [0045]    Nozzle  40  can also be referred to as an accelerator or an acceleration device. In some embodiments of this invention, each nozzle  40  is an independent structure. In other embodiments of this invention, two or more nozzles  40  are combined to form one structure or housing. For example, two or more nozzles  40  can be formed as bores or passageways  48  through a single or integrated structural element. 
         [0046]    Downstream end  43  of distributor  39  and/or a downstream surface of plate  55  can be spaced at a distance from an upstream surface of mold  30 , including cope flask  31  or drag flask  33 . The distance can be sized to form an opening or a gap that sufficiently allows pressurized fluid  25  to escape from within void  32  or  34 , such as when particles  21  are discharged from nozzle  40 .  FIG. 1  shows gap  59  between bottom or downstream plate  55  and the upstream surface of cope flask  31 . Gap  59  can be used to eliminate the need for a conventional flask body to have a vent structure that allows air but not sand or particles  21  to pass through the flask structure, such as when sand is pneumatically blown through a device that is sealed with respect to the flask body. Gap  59  of this invention can be used to reduce or eliminate spillage or waste sand. 
         [0047]      FIGS. 1 ,  10  and  11  show one embodiment of funnel  65 . Funnel  65  can be mounted to an upstream end of a corresponding nozzle  40 . As shown in  FIG. 10 , funnel  65  has passageway  67  for passing particles  21  from supply  22  to inlet  42  of nozzle  40 . As used throughout this specification and in the claims, the term funnel is intended to be interchangeable with the term funnel inlet and/or collector, and each of these terms is intended to relate to a structural element that has passageway  67  converging in the downstream direction, such as toward the corresponding nozzle  40 . The converging shape can be used to better distribute, evenly or unevenly, particles  21  into passageway  48  of nozzle  40 . 
         [0048]      FIGS. 10 and 11  show collector  65  having four scalloped surfaces  66 . With scalloped surfaces  66 , two or more collectors  65  can be positioned adjacent or next to each other to reduce or eliminate horizontal surfaces which are otherwise exposed to supply  22  of particles  21 . Any horizontal surface that exists can collect or hold particles  21 , which normally is undesirable in manufacturing operations. 
         [0049]    In one embodiment according to this invention, a method for transferring particles  21  into void  32  or  34  includes passing particles  21  through two or more nozzles  40 , each mounted with respect to molding machine  20 , mold  30  and/or cope flask  31  or drag flask  33 . Pressurized fluid  25  is drawn into or passes through each nozzle  40  and thus accelerates particles  21  within or through passageways  48  of nozzles  40 . Particles  21  are then discharged through outlet  44  of each nozzle  40 , and into void  32  or  34 , at or near pattern  36  or  37 . Any flow parameter through nozzle  40  and/or any position of nozzle  40  can be varied, for each particular use or even as a function of time, and can be controlled manually and/or automatically, to accomplish any desired continuous or intermittent transfer of particles  21  into void  32  or  34 . 
         [0050]    In certain embodiments of this invention, pressurized fluid  25  establishes or creates a Coanda effect where a fluid stream follows or attaches to an inner surface of nozzle  40 . For example, as shown in  FIG. 12 , when pressurized fluid  25  exits or discharges from or through opening  46 , one or more fluid streams each is formed and can follow, attach to or hug the inner surface, such as the inner converging surface, of nozzle  40 . The Coanda effect can result in better compaction of particles  21 , at or near pattern  36  or  37 . The size and position of opening  46  can be designed differently to accomplish any desired Coanda effect or other flow parameter effect. 
         [0051]    While in the foregoing specification this invention has been described in relation to certain preferred embodiments thereof, and many details have been set forth for purpose of illustration, it will be apparent to those skilled in the art that the invention is susceptible to additional embodiments and that certain of the details described herein can be varied considerably without departing from the basic principles of the invention.