Abstract:
A ceramic fiber band that can fulfill a plurality of functions in connection with the injection and/or extrusion process of an injection molding or extrusion apparatus (i.e. heat, cool, and insulate), thereby reducing overall energy costs and creating a safer working environment. The ceramic band, being an insulator and having heating and/or cooling elements with a faster response contained therein, exert the desired heating/cooling effect upon the barrel portion of the injection/extrusion machine thereby raising, lowering, or maintaining the temperature of the fluid plastic compound passing through the barrel.

Description:
REFERENCE TO PENDING APPLICATIONS 
   This application claims the benefit of U.S. patent application Ser. No. 09/704,130, filed on Nov. 1, 2000 Now U.S. Pat. No. 6,486,445 and entitled A VACUUM CAST CERAMIC FIBER INSULATED BAND HAVING HEATING AND COOLING ELEMENTS. 

   REFERENCE TO MICROFICHE APPENDIX 
   This application is not referenced in any microfiche appendix. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates generally to vacuum cast ceramic fiber insulators, specifically those having the ability to raise, lower or maintain temperature by utilizing heating and/or cooling controls in a low temperature apparatus. 
   2. Prior Art 
   The use of injection/extrusion machines to create plastic parts is well known. Plastic compounds are subjected to heat in order to render it into a fluid state. After it reaches a fluid state, the compound is then forced under pressure into mold cavities or through dies. It is well known in the art that the fluid resin compounds are directed into the mold cavities or dies by way of injection or extrusion barrels. In order to insure the optimum flow characteristics of the compound, the barrels are equipped with heating mechanisms in order to control the temperature of the compound. Multiple types of heating bands have been disclosed in the prior art. The most common is the heating coil that surrounds the barrel and conducts heat to the compound as it flows through the barrel. 
   The optimization of the flow characteristics of the fluid compound is dependent upon the ability to control the amount of heat applied to the barrel as the fluid compound passes through it. Therefore, an improved heating and cooling mechanism is needed to improve the efficiency in the attempt to achieve the optimal flow characteristics for the fluid compound. 
   The present invention is directed to a ceramic insulating and heating/cooling band. The prior art does not demonstrate the use of such bands with low temperature apparatus, in the range of less than 1000° C./1600° F. Thus, there is a need for a temperature control mechanism for use in low temperature apparatus, such as injection/extrusion machines. 
   BRIEF SUMMARY OF THE INVENTION 
   The present invention is generally directed toward a device for effectively insulating while heating and/or cooling a fluid plastic compound more efficiently. Specifically, the present invention is directed toward a device having the ability to maximize the controllability of the temperature of a fluid plastic compound in connection with the injection/extrusion process of low temperature apparatus, such injection molding and extrusion machines 
   A discussion concerning specific terms used herein is in order. The term “ceramic band” is synonymously referred to as a vacuum cast ceramic fiber heater band, machinable ceramic fiber board or other materials of the ceramic genre. While extrusion machines can be different from injection molding machines, the present invention can be utilized in connection with both types of machines. Therefore, reference to one type of machine should be viewed as reference to both types of machines. The use of the terms “low temperature” and “low temperature apparatus” herein refers to those apparatus which cannot obtain temperatures of 1000° C./1600° F. and higher. 
   The present invention utilizes a ceramic band which surrounds the barrel of the injection/extrusion machine. The ceramic band acts as an insulator for the heat contained on and within the barrel. Further, the ceramic band incorporates heating elements and vacuum precipitated cooling mechanisms to provide the ability to accurately and quickly change the temperature of the barrel. 
   The heating/cooling mechanisms can be, but not necessarily, cast within the ceramic band providing an efficient temperature control unit. 
   The ceramic band can take a plurality of different forms, including but not limited to a half-section configuration or individual block configuration. In any configuration, the band fits around the exterior portion of the barrel and provides a heating and/or cooling effect to such barrel, thereby heating or cooling the fluid plastic compound flowing through such barrel. 
   With respect to the heating mechanisms, standard heating elements are cast within the ceramic band. With respect to the cooling mechanisms, air or fluid can be utilized to decrease the temperature of the barrel. Suitable apparatus for providing air or fluid cooling ability is provided through a manifold apparatus either in the interior or on the exterior of the ceramic band. 
   In addition, monitoring devices such as LED lights, can be utilized to monitor the present invention and advise the operator its current operational condition. 
   The primary objective of the present invention is to provide a self-insulated heating and cooling unit used in connection with low temperature plastics injection/extrusion machines. 
   Another object of the present invention is to provide a device which insulates and provides improved temperature controllability for the barrel portion of injection and extrusion machines. 
   Another object of the present invention is to provide a faster responding device utilizing insulation, heating elements, forced air, vacuum or liquid coolant devices to alter the controlled temperature of the barrel portion of injection and extrusion machines. 
   A further object of the present invention is to effectuate rapid reduction of temperature of a barrel portion of an injection and extrusion machine precipitating a vacuum induced air flow between blocks comprising the band of the invention and said barrel&#39;s exterior surface. 
   Other objects and further scope of the applicability of the present invention will become apparent from the detailed description to follow, taken in conjunction with the accompanying drawings wherein like parts are designated by like reference numerals. 

   
     DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of the present invention in connection with an injection machine. 
       FIG. 2  is a perspective view of the present invention in a block configuration. 
       FIG. 3  is a perspective view of an individual block of the present invention. 
       FIG. 4  is a cross-sectional view of the present invention as shown in  FIG. 3  along line A—A. 
       FIG. 5  is a cross-sectional view of the present invention as shown in  FIG. 3  along line B—B. 
       FIG. 6  is a cross-sectional view of the present invention, having a rectangular cross-section. 
       FIG. 7  is a perspective view of the present invention, having a circular cross-section. 
       FIG. 8  is a perspective view of the instant invention in connection with an injection machine wherein a plurality of interconnecting conduit blocks circumferentially surround the perimeter of an injection machine&#39;s barrel to form an individually addressable heating/cooling zone. 
       FIG. 9  is an alternative embodiment wherein a plurality of two or more adjacent conduit blocks circumferentially surround the perimeter of an injection machine&#39;s barrel to form an individually addressable heating/cooling zone. 
       FIG. 10  is an illustration of front, rear and bottom views of individual conduit block absent any cooling tube. 
       FIG. 11  is a front, rear and bottom views illustrating the presence of a cooling tube for effectuating a vacuum induced air flow via an imbedded cooling tube. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring now to the figures, a preferred embodiment of the present invention is generally shown. As generally shown in the figures, a band  10  encases the barrel  22  portion of a liquid resin machine  20  in order to provide an insulation effect as well as efficiently controlling the temperature of liquid plastic flowing through the barrel  22 . Machine  20  can be any type of machine that prepares resin for molding or otherwise shaping. Such machines include, but are not limited to, plastic injection mold or extrusion machine. 
   In the formation of plastic parts, the raw materials which make up plastic are mixed and prepared within a machine  20 . During the mixing process, the components are heated into a flowable state. The flowable plastic material travels through the barrel  22  portion of machine  20  into a desired mold or through a desired extrusion die. 
   During this process, in order to maintain a highest level of quality with respect to the flowable plastic material, the ability to maintain control over material&#39;s temperature is critical. The preferred embodiment of the present invention utilizes a band  10  to encase barrel  22 , wherein band  10  is made of a an insulating material along with heating and cooling elements cast within the band  10 . The heating/cooling elements provide the ability to accurately and quickly change the temperature of barrel  22  which in turn modifies the temperature of material as it travels through passageway  24  of barrel  22 . Passageway  24  is sometimes known as the “screw” cavity portion of barrel  22 . Typically band  10  is made of a vacuum cast ceramic fiber material, however, it is understood that other compatible material is within the scope and spirit of this invention. 
   As further shown in the figures, heating element  40  which is embedded within band  10  and produces a heating effect directed toward barrel  22 . Typically, heating element  40  is a standard heating element having electrical connection means  42  which are capable of producing desired levels of heat. However, it is understood that other compatible heating means capable of producing desired levels of heat are within the scope and spirit of this invention. 
   The preferred embodiment of the present invention incorporates a band  10  which utilizes a band of blocks  70  which completely encases barrel  22  as shown in the figures. The band of blocks  70  is made of a plurality of conduit blocks  72  and is secured by a securing means  74 . Securing means  74  can be a rope made out of a high temperature resistant material or similar type of securing means and connects each block  70  through a connection conduit  76 . Conduit block  72  contains heating elements  40  and coolant elements  50 . In the preferred embodiment of this type of band, conduit block has an exterior surface  80  and an interior surface  82  with interior surface  82  having recess  84  and which rests against barrel  22 . 
   Heating elements  40  are located below the surface of recess  84 . This positioning protects the elements from damage and excessive wear while allowing the element to provide heat to barrel  22 . 
   In the preferred embodiment, two cooling elements are utilized. In  FIGS. 4 and 5 , they are referred to as a first cooling element  52  and a second cooling element  54 . The number of cooling elements is, however, not limited to two as this number is for illustrative purposes. 
   Both elements  52  and  54  create a passage from the exterior of block  72  to the recess  84  of the block  72 . In operation, air and/or liquid is inserted through element  52  into recess  84  the air and/or liquid fill the cavity created by recess  84 . The air and/or liquid then exits through element  54 . The process is a continuous one causing a cooling effect to be exerted upon barrel  22 . 
   Cooling element  50  is cast within heater band  10  and provides a cooling effect along barrel  22 . Cooling element  50  can utilize air or liquid to reduce the temperature of barrel  22 , thus reducing the temperature of the flowable plastic material flowing there through. A manifold apparatus, which can be cast within heater band  10  or positioned along the exterior of heater band  10 , provide air or liquid to cooling element  50 . 
   Around heater band  10  is placed a protective covering which can be placed to encase the entire apparatus. Further, since the temperatures can be extremely high, heater band  10  acts as an insulator in order to absorb most of the temperature being emitted from barrel  22  as flowable plastic material passes there through. 
   In operation, a control device (not shown) is in communication with band  10  which is capable of determining if the temperature of material is at an acceptable level, and if not, whether material should be heated or cooled. If heating or cooling is to take place, this control signally communicates a command to band  10  in order to increase or decrease the heat on barrel  22 . Once band  10  receives this command, it either heats or cools barrel  22  by initiating either heating element  40  or cooling element  50 . 
   A monitoring device (not shown) can be attached to the present invention which determines if the flowable plastic material is maintaining a desired temperature. This device is capable of alerting the present invention of an increase or decrease in material temperature in order for the present invention to activate either heating element  40  or cooling element  50 . When used in a manual operational setting, monitoring lights, such as LED lights, can be utilized to advise the operator of the injection/extrusion machine of the status of the present invention. When used in an automatic operational setting, the device can be in communication with a computer system which can automatically activate either hearing element  40  or cooling element  50 , if necessary. 
   The preferred embodiment is shown in operation as follows. The band of blocks  70  of band  10  are positioned along the outer perimeter of barrel  22 . It is assumed the length of barrel  22  is encased by one unit of band  10 . It is understood that multiple units can be utilized in order to completely encase the barrel. As flowable plastic material passes through the passageway  24  of barrel  22 , it is monitored for desired temperature. In the event the temperature needs to be increased, heating element  40  is activated which provides a heating effect directed toward barrel  22 . In the event the temperature of flowable plastic material needs to be decreased, the cooling element  50  is engaged. In the event cooling element  50  utilized air, band  10  would be equipped with an air coolant entrance  56  and an air coolant exit  58 . Heat from barrel  22  is removed from barrel  22  through common thermodynamic principles. 
   Other embodiments of the present invention utilize a semi-circle configuration  90 , as shown in  FIG. 7 , and a rectangular configuration  92 , as shown in FIG.  6 . These configurations would include the same internal heating and cooling elemental controls as set out previously. Turning now to FIG.  8 . 
   In  FIG. 8 , the band of the instant invention is generally referred to as element  10 . Said band is comprised of one or more zones  15 . Said zones  15  are comprised of a plurality of interconnected conduit blocks  18  which circumferentially surround the perimeter of injection or extrusion mold barrel  21 . Gaskets  23  circumferentially surround the barrel and are positioned between adjacent pluralities of interconnected conduit blocks  18 . Vacuum tubes  31  are connected to at least one of said plurality of conduit blocks in response to a temperature sensing mechanism and provide for a vacuum induced air flow which draws air between the exterior surface of said barrel  21  and a recessed area of said blocks (not shown in FIG.  8 ). A vacuuming means  33  is used in conjunction with a vacuum system  35  to introduce and sustain vacuum lines  31  with vacuum inducement means well known to those skilled in the art. It is further disclosed that manifold  38  can be connected in the same manner to segregate sub-manifolds  39 ,  40  and  41  allowing vacuum induced air flow to be drawn through selective zones represented by vacuum lines  31  connected to valves with solenoids  39 ,  40  or  41 . 
     FIG. 9  illustrates an alternative embodiment wherein a plurality of two or more immediately adjacent conduit blocks circumferentially surround the perimeter of an injection machine&#39;s barrel to form a heating/cooling zone  45 . In  FIG. 9  an alternative embodiment of the present invention is disclosed wherein three bands and three zones  45 ,  47  and  49  are shown with each zone comprised of one or more plurality of conduit blocks  18  circumferentially surrounding the external surface of an injection or extrusion mold barrel  21 .  FIG. 9 , however, illustrates the means by which only one vacuum induced air flow is precipitated via vacuum lines  31  which are in turn attached to a temperature regulation and vacuum means (not shown in FIG.  9 ). As  FIG. 9  illustrates a series of circumferentially surrounding conduit blocks  18  per zone  45 ,  47  and  49 ,  FIG. 8  had illustrated each zone as represented by a single plurality of circumferentially surrounding bands.  FIG. 10  illustrates a front, rear and bottom views of individual conduit block absent any cooling tube. Turning now to FIG.  10 . 
   In  FIG. 10  an isolation view of a single conduit block absent a vacuum cooling conduit said block is shown. In  FIG. 10 , detail is provided with respect to air passageways  77  which allow air to be drawn between the bottom of said conduit block  75  and the surface of an extrusion or injection mold barrel (not shown).  FIG. 11  illustrates the conduit block of the instant invention  38  wherein the cooling conduit  79  is shown. The conduit  79  traverses the thickness of said block from its interior surface  81  to its exterior surface  83 . When vacuum tubes  31  (not shown in  FIG. 11 ) are inserted or otherwise connected to said cooling conduit  79  and in response to a temperature controlling means facilitate the passage there through of vacuum induced air flow which via air passageways  77  allow air to be drawn between a plurality of block circumferentially surrounding the barrel of an extrusion or injection mold machine. 
   The claims and the specification describe the invention presented and the terms that are employed in the claims draw their meaning from the use of such terms in the specification. The same terms employed in the prior art may be broader in meaning than specifically employed herein. Whenever there is a question between the broader definition of such terms used in the prior art and the more specific use of the terms herein, the more specific meaning is meant. 
   While the invention has been described with a certain degree of particularity, it is manifest that many changes may be made in the details of construction and the arrangement of components without departing from the spirit and scope of this disclosure. It is understood that the invention is not limited to the embodiments set forth herein for purposes of exemplification, but is to be limited only by the scope of the attached claim or claims, including the full range of equivalency to which each element thereof is entitled.