Abstract:
A mold having a piezoelectric power generating arrangement, includes first and second die halves having a molding cavity therein for forming a molded product when a molding material is poured therein, piezoelectric elements positioned beneath at least one die half for generating electrical power when a load is applied on the piezoelectric elements from the molding material poured into the molding cavity and in response to removal of a load of the molded product from the molding cavity, and a first arrangement for retrieving the generated electrical power and for supplying the retrieved electrical power output to an electrical storage device and/or using the retrieved electrical power output to power an external powered device.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates generally to energy generating devices, and more particularly, is directed to a mold including a piezoelectric power generating arrangement for generating electrical power in response to pouring of molding material into the mold and removal of the molded product from the mold. 
     Numerous industrial processes have in common the pouring of a molding material into a mold, and which include, without limitation, fluids, grains, powders, slurries and resins, and from which a finished product is later ejected. These molds are used in the field of, for example, metallurgy, plastics, masonry, baking, confectionary and terra cotta, and are all intended to be covered by the present invention. 
     Some of these processes involve the pouring of very hot molten material into the molds. In the United States, much of the production of 80 million tons or so of steel begins as molten metal poured about twenty feet from huge ladles into the molds. 
     It would therefore be desirable to tap this large volume of mechanical energy, as well as the large amount of heat energy generated in these molding operations. 
     OBJECTS AND SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide a mold including a piezoelectric power generating arrangement that takes advantage of wasted mechanical energy in molds. 
     It is another object of the present invention to provide a mold including a piezoelectric power generating arrangement to tap the large volume of mechanical energy from a molding operation and convert this to electrical power. 
     It is still another object of the present invention to provide a mold including a piezoelectric power generating arrangement to tap the large volume of heat energy from a molding operation and convert this to electrical power. 
     It is yet another object of the present invention to provide a mold including a piezoelectric power generating arrangement that is relatively inexpensive to manufacture and easy to use. 
     In accordance with an aspect of the present invention, a mold having a piezoelectric power generating arrangement, includes first and second die halves having a molding cavity therein for forming a molded product when a molding material is poured therein. A plurality of piezoelectric elements are positioned beneath at least one die half for generating electrical power when a load is applied on the piezoelectric elements from the molding material poured into the molding cavity, and there is a first arrangement for retrieving the generated electrical power and for supplying the retrieved electrical power output to an electrical storage device and/or using the retrieved electrical power output to power an external powered device. 
     The mold includes a base on which the piezoelectric elements are positioned such that the piezoelectric elements protrude slightly above an upper surface of the base, and a bottom wall is positioned on the base and on the piezoelectric elements. The bottom wall can be flexible and can be connected on the base for pivoting movement between a first position on the piezoelectric elements and a second position off of the piezoelectric elements. 
     Optionally, the base includes at least one recess therein, and the bottom wall includes at least one bracket for fitting in the at least one recess when the bottom wall is positioned on the piezoelectric elements. 
     The mold further includes a side wall with an opening, an L-shaped ejection gate comprised of a closing side wall and the bottom wall connected to one end of the closing side wall. A pivoting arrangement pivotally connects the L-shaped ejection gate to the base for pivoting movement between a first closed position in which the closing side wall closes the opening in the side wall and the bottom wall is positioned on the base and on the piezoelectric elements, and a second open position in which the bottom wall is pivoted to a position off of the base and the piezoelectric elements. There is further a latching arrangement connected to the side wall for securing the L-shaped ejection gate in the closed position. 
     There is also a top wall movable between a closed position and an open position, and wherein the first die half is mounted on the bottom wall and the second die half is mounted on the top wall. 
     In addition, the plurality of piezoelectric elements generate a further electrical power output in response to removal of a load of the molded product from the molding cavity. In this regard, there is a second arrangement for retrieving the further generated electrical power output and for supplying the retrieved further electrical power output to an electrical storage device and/or using the retrieved further electrical power output to power an external powered device. 
     To take advantage of the heat energy in a hot product, there can also be at least one bi-metallic strip secured in a cantilevered manner to a wall surface of the mold, with at least one piezoelectric element connected at a free end of the bi-metallic strip, as well as a third arrangement for retrieving still further generated electrical power output from the at least one piezoelectric element which is connected to the bi-metallic strip and for supplying the retrieved still further electrical power output to an electrical storage device and/or using the retrieved still further electrical power output to power an external powered device. 
     There are also electrical contact elements mounted to the base, and wires for connecting the electrical contact elements to the piezoelectric elements for retrieving the generated electrical power. 
     In one embodiment, there is also a conveyor on which a plurality of the molds are positioned for movement between a pouring station at which the molding material is poured into the mold to form the molded product, and a discharge station at which the molded product is removed from the mold. The wires include first probe wires at the pouring station for connection to the electrical contact elements for retrieving the generated electrical power, and second probe wires at the discharge station for connection to the electrical contact elements for retrieving the further generated electrical power. 
     In accordance with another aspect of the present invention, a method of generating electrical power during a molding operation, includes the steps of arranging a plurality of piezoelectric elements on a base beneath a mold such that the piezoelectric elements protrude slightly above an upper surface of the base, pouring molding material into the mold to form a molded product, generating an electrical power output from the piezoelectric elements in response to a load from the poured molding material, retrieving the generated electrical power output, and supplying the retrieved electrical power output to an electrical storage device and/or using the retrieved electrical power output to power an external powered device. 
     The method also includes the steps of permitting the molding material to solidify into a molded product, removing the molded product, generating a further electrical power output from the piezoelectric elements in response to removal of a load of the molded product, retrieving the further generating electrical power output, and supplying the retrieved further electrical power output to an electrical storage device and/or using the retrieved further electrical power output to power an external powered device. 
     The method also includes the step of moving a plurality of the molds along a conveyor between a pouring station at which the molding material is poured into the mold to form the molded product, and a discharge station at which the molded product is removed from the mold. 
     The first recited step of retrieving the generated electrical power output occurs at the pouring station, and the step of retrieving the further generating electrical power output occurs at the discharge station. 
     The method also includes the steps of securing a bi-metallic strip in a cantilevered manner to a wall surface of the mold, with at least one piezoelectric element connected at a free end of the bi-metallic strip, retrieving still further generated electrical power output from the at least one piezoelectric element which is connected to the bi-metallic strip, and supplying the retrieved still further electrical power output to an electrical storage device and/or using the retrieved still further electrical power output to power an external powered device. 
     The above and other objects, features and advantages of the invention will become readily apparent from the following detailed description thereof which is to be read in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a mold including a piezoelectric power generating arrangement according to the present invention; 
         FIG. 2  is a cross-sectional view of the mold of  FIG. 1 , taken along line  2 - 2  thereof; 
         FIG. 3  is a cross-sectional view of the mold of  FIG. 1 , taken along line  3 - 3  thereof; 
         FIG. 4  is a top plan view of the mold, with the pivoting side door removed, and showing the piezoelectric elements; 
         FIG. 5  is a top plan view of the pivoting door; 
         FIG. 6  is a front elevational view of the pivoting door; 
         FIG. 7  is a partially exploded, perspective view of the mold in an open configuration; 
         FIG. 8  is a top plan view of an automated conveyor assembly including a plurality of molds; 
         FIG. 9  is an enlarged perspective view showing the latching arrangement; and 
         FIG. 10  is a flow chart diagram of the method of operation of the mold according to the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to the drawings in detail, and initially to  FIG. 1  thereof, a mold  10 , for example, a plastic mold, a steel mold, etc. according to the present invention includes a base plate  12  having a generally square configuration, although the specific shapes and dimensions in the present application are not important. A U-shaped vertical wall  14  sits on base plate  12  and extends upwardly therefrom with one side  14   a  being open. 
     As shown best in  FIGS. 3 and 4 , a plurality of piezoelectric elements  16  are positioned in recesses  17  at the upper surface of base plate  12  and protrude slightly above the upper surface  12   a  thereof. The particular spatial arrangement of piezoelectric elements  16  is not important, as long as there are a sufficient number of piezoelectric elements  16  to generate a useful electrical output. Interspersed between the rows of piezoelectric elements  16  are elongated grooves  18  in base plate  12 . 
     To close open end  14   a  of U-shaped vertical wall  14 , and as best shown in  FIGS. 1 ,  2  and  5 - 7 , there is an L-shaped ejection gate  20  that is hingedly connected by hinges  22  or any other pivoting means, such as a pivot rod, etc. to base plate  12  at open side  14   a  of U-shaped vertical wall  14 . L-shaped ejection gate  20  includes a closing wall  24  for closing open side  14   a  of U-shaped vertical wall  14  and a horizontal bottom wall  26  extending transversely from the lower end of closing wall  24 . When closing wall  24  closes open side  14   a , bottom wall  26  sits on top of base plate  12 , and in particular, on top of piezoelectric elements  16  which protrude slightly above the upper surface  12   a  of base plate  12 . Optionally, the lower end of bottom wall  26  is preferably provided with brackets  26   a  which fit within grooves  18  for alignment of bottom wall  26 . 
     In a preferred embodiment of the present invention, bottom wall  26  is a pan that has some flexibility so that it can bend or flex in a resilient manner when the molding material is added to mold  10 , as will be described hereafter. However, the present invention is not limited thereto. 
     L-shaped ejection gate  20  can be tilted about hinges  22 , as shown by the change from the closed position of  FIG. 1  and the open position of  FIG. 7 . Preferably, there is some means for releasably securing L-shaped ejection gate  20  in the closed position of  FIG. 1 . For example, as shown in  FIG. 9 , the releasing means may be formed by a latching arrangement  28  provided at the upper end of U-shaped vertical wall  14  at open end  14   a  thereof which can include an L-shaped pivoting latch  28   a  on the upper end of U-shaped vertical wall  14  that can be pivoted into engagement with an L-shaped catch  28   b  on the upper outer surface of vertical closing wall  24  to secure L-shaped ejection gate  20  in the closed position. However, any other suitable latching arrangement can be provided, such as a solenoid actuated rod, etc., and latching arrangement  28  can be pneumatically or hydraulically driven. Latching arrangement is not shown in the other figures. 
     A top wall  30  is provided to close the upper open end of mold  10 . In this regard, top wall  30  fits within U-shaped vertical wall  14  and closing wall  24 , and can be moved reciprocally therein by a rod  32  secured thereto, which is connected to a hydraulic or pneumatic drive  34  for driving the same. 
     A lower die half  36  is fixed to the upper surface of bottom wall  26  and includes a recessed area  36   a  corresponding to the shape of the object to be molded. In like manner, an upper die half  38  is fixed to the underside of top wall  30  and includes a recessed area  38   a  corresponding to the shape of the object to be molded. When top wall  30  is moved downwardly to close the upper open end of mold  10 , die halves  36  and  38  engage each other, as shown in  FIGS. 2 and 3 , whereby recessed areas  36   a  and  38   a  form a cavity  40  which is in the shape of the object to be molded. Cavity  40  is shown as a simple spherical shape for explanation purposes only, but the present invention is not limited thereby. A molding material is then provided into cavity  40  through, for example, a pouring opening  42  in U-shaped vertical wall  14  and through respective channels (not shown) in die halves  36  and  38 . Pouring opening  42  can be formed through any other wall, including top wall  30 . 
     It will be appreciated that the present invention is not limited to this particular arrangement of die halves  36  and  38 . For example, die halves  36  and  38  can be arranged side to side. 
     As shown in  FIG. 4 , wires  44  connect piezoelectric elements  16  to an electrical storage device  46  such as a battery or the like. Alternatively, wires  48  can connect piezoelectric elements  16  to electrical contact elements  50  on base plate  12  and which can be electrically connected with an external electrical storage  52  device and/or an external mechanical or electrical powered devices  54 , for example, lights, a motor, etc. that is powered for operation thereby. The electrical contact elements can alternatively be electrical contact strips  50 ′ as shown in  FIG. 7  that laterally run along base  12  so that an electrical probe can contact and slide along the contact strips  50 ′ as the mold is moving. In such case, the electrical probe can have a roller or bearing surface at the end for rolling along the contact strips. 
     In operation, and referring to  FIG. 10 , in a first step  100 , mold  10  is closed by lowering top wall  30  and pivoting L-shaped ejection gate  20  to the position shown in  FIGS. 1-3  where bottom wall  26  rests on piezoelectric elements  16 . Then, in step  102 , molding material is poured into cavity  40  through opening  42  which is then sealed. When the molding material is added thereto, the weight thereof causes bottom wall  26  to flex a small amount as a result of the additional weight, which increases the pressure on piezoelectric elements  16 . This activates piezoelectric elements  16  to cause them to output electrical power. In step  104 , the electrical power from piezoelectric elements  16  is either stored in electrical storage devices  46  or  52 , or used to power external mechanical or electrical powered devices  54 . As a result, mechanical energy of the weight of the molding material is converted to electrical energy by the load, which electrical power can then be withdrawn and used for powering external devices. In step  106 , the molding material then solidifies into the molded object. Thereafter, in step  108 , the mold is opened by raising top wall  30 . In step  110 , the molded object is removed by pivoting L-shaped ejection gate  20  about hinges  22  to the position shown in  FIG. 7 . At this time, because the weight of the molded object and bottom wall  26  are removed from piezoelectric elements  16 , this reduction of weight thereon again activates piezoelectric elements  16  to cause them to output electrical power. In step  112 , the electrical power from piezoelectric elements  16  is again either stored in electrical storage devices  46  or  52 , or used to power external mechanical or electrical powered devices  54 . As a result, mechanical energy from the removal of the weight of the molding material is converted to electrical energy by the load, which electrical power can then be withdrawn and used for other purposes. 
     It will therefore be appreciated that, in view of the large number of molding operations throughout the world, the present invention provides a simple and inexpensive way to generate electrical power during such molding operations. 
     Further, it is possible to provide an automated molding operation with a large number of such molds  10 . For example, as shown in  FIG. 8 , there is shown a circular conveyor  60  which is rotated in the direction of arrow  62 . A plurality of molds  10  are positioned on conveyor  60  for movement between a pouring station  64  and a discharge station  66 . At pouring station  64 , there is a pouring spout  67  that supplies the molding material to the mold  10  at pouring station  64 . In this regard, the pouring opening  42  can be provided through top wall  30  and upper die half  38 . Spring loaded probe wires  68  can be in electrical contact with electrical contact elements  50  or  50 ′ at this station such that, when the molding material is poured into mold  10  at pouring station, the additional weight actuates piezoelectric elements  16  of the mold  10  thereat to generate electrical power that is supplied through wires  48 , electrical contact elements  50  and probe wires  68 . Thus, the electrical energy can either be stored in electrical storage devices  46  or  52 , or used to power external mechanical or electrical powered devices  54 . Thereafter, the next mold  10 ′ is rotated by circular conveyor  60  to pouring station  64 . At this time, mold  10  has the molding material therein and the mold material has begun to solidify into the molded product. Since the piezoelectric elements  16  only produce electrical energy in response to a change in the load thereon, there is no further electrical output therefrom after the molding material has been added. This operation continues until mold  10  is moved by conveyor  60  to discharge station  66 . At this time, the molded product is fully formed. At discharge station  66 , top wall  30  is raised up, latching arrangement is released and L-shaped ejection gate  20  is pivoted about hinges  22  to the position shown in  FIG. 7 , whereby the molded product can be removed from lower die half  36  and deposited on a chute  70 . The pivoting of L-shaped ejection gate  20  can occur, for example, by hydraulically actuated arms  71  of a hydraulic actuator  73 . However, when L-shaped ejection gate  20  is pivoted, the load on piezoelectric elements  16  is removed. The removal of this weight again actuates piezoelectric elements  16  of the mold  10  thereat to generate electrical power that is supplied through wires  48 , electrical contact elements  50  and additional probe wires  72  which are in electrical contact with electrical contact elements  50  at this station. Thus, the electrical energy can either be stored in electrical storage devices  46  or  52 , or used to power external mechanical or electrical powered devices  54 . 
     In addition to piezoelectric elements  16  positioned in base plate  12 , additional piezoelectric elements  74  can be provided in association with mold at other locations and which are not responsive to the pouring of molding material or removal of the molded product. For example, as shown in  FIGS. 2 and 4 , a bi-metallic strip  76  formed of two plates  76   a  and  76   b  or different metal with different thermal expansion coefficients and which are bonded together, is mounted to a side wall surface of mold  10  in a cantilevered manner. At least one additional piezoelectric element  74  is secured between plates  76   a  and  76   b  at the free end thereof. Thus, as mold  10  heats up, the different thermal expansion coefficients of plates  76   a  and  76   b  cause one plate to expand more than the other, which results in bending of bi-metallic strip  76 , as shown by the dashed lines in  FIG. 2 . This, in turn, applies a load to piezoelectric elements  74  which, in response thereto, produces an electrical output that can be removed through wires  78  connected thereto. As a result, the heating of mold  10  results in the load being applied by bi-metallic strip  76  to piezoelectric elements  74 . In like manner, the cooling of mold  10  results in bi-metallic strip  76  moving back to the solid line position in  FIG. 2 , which again applies a load to piezoelectric elements  74  which, in response thereto, produces an electrical output that can be removed through wires  78  connected thereto. 
     It will be appreciated that the present invention is not limited to the above embodiments, but encompasses all embodiments within the scope of the present invention. For example, vertical wall  14  can be a square four sided wall, and in such case, ejection gate  20  would not be needed. Instead, bottom wall  26  would sit on top of base plate  12 , and in particular, on top of piezoelectric elements  16  which protrude slightly above the upper surface  12   a  of base plate  12 , and would be formed by a pan that has some flexibility so that it can bend or flex in a resilient manner when the molding material is added to mold  10 . In such case, the molded product can be removed by either tipping the entire mold  10  or by reaching into the mold with mechanical arms to retrieve the molded product. As a further alternative, one side wall could be hinged along a vertical axis to open and thereby remove the molded product. Alternatively, bottom wall  26  need not be flexible, but rather, the pouring of mold material would pivot ejection gate  20  to apply pressure to piezoelectric elements  16 . 
     Further, reference to a mold in the present application and claims encompasses numerous industrial processes which have in common the pouring of a molding material into a mold, and which include, without limitation, fluids, grains, powders, slurries and resins, and from which a finished product is later ejected. These molds are used in the field of, for example, metallurgy, plastics, masonry, baking, confectionary and terra cotta, and are all intended to be covered by the present invention. 
     Having described specific preferred embodiments of the invention with reference to the accompanying drawings, it will be appreciated that the present invention is not limited to those precise embodiments and that various changes and modifications can be effected therein by one of ordinary skill in the art without departing from the scope or spirit of the invention defined by the appended claims.