Patent Abstract:
The press for fusing beads heats the tops of beads to fuse the beads together, fixing them in a pattern. The press includes an enclosure having a slot defined in the front face. A heating plate having a heating element is mounted within the enclosure. A tray, which holds the beads to be fused, is placed on a tray support that slides within the open slot to a position under the heating plate. A control circuit senses the position of the tray support, and when the tray is in position beneath the heating plate, allows an operator to initiate a timed heating cycle and locks the tray in place. When the heating cycle is initiated, the heating plate is brought into close proximity with the tray, placing the tops of the beads into contact with the heating plate and energizing the heating element to heat the heating plate to a predetermined temperature.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims the benefit of U.S. Provisional Patent Application 60/721,973 filed on Sep. 30, 2005. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT  
       [0002]     Not Applicable.  
       FIELD OF THE INVENTION  
       [0003]     The present invention relates to a heating appliance, and in particular, to a heated press for fusing plastic materials such as plastic beads.  
       DISCUSSION OF RELATED ART  
       [0004]     Many children enjoy crafts and hobbies that allow them to form artistic or useful shapes from plastic. These types of hobbies are beneficial to young children as the hobbies are opportunities for the child to practice attention to detail, to develop manual dexterity, and to express creativity.  
         [0005]     One such hobby is the making of artistic shapes by fusing plastic beads. Bead fusing uses small cylindrically shaped beads. The beads are available in a wide range of colors and sizes. To produce a shape or object, the beads are placed in a mold with pegs for holding the beads. The cylindrically shaped beads are slid over the pegs in the mold. The hobbyist selects the colors of beads appropriate for his or her design and chooses the peg for each bead in order to create the desired design. To finish the project, the bead tops are fused. Fusing uses a heat source to melt the tops of the beads together to fuse the beads into the desired pattern. Conventionally, a clothing iron is used as the heat source for melting the beads. The tops of the beads are covered with a thin, non-stick material so that the melted beads do not adhere to the surface of the iron. A typical material used to protect the iron is a wax-coated paper.  
         [0006]     After the tops of the beads are fused and the beads have cooled, the project can be removed from the mold. Many hobbyists repeat the fusing process on the back of their projects to make the finished product sturdier.  
         [0007]     A first concern associated with the practice of bead fusing by small children is the risk of burn injuries. A type of bead typically fused has a melting temperature of approximately 200° F.-220° F. Children four years of age and older enjoy bead fusing. Younger children in particular may not appreciate the hazard associated with the high temperatures, placing them at risk of receiving burns when handling the hot iron or when handling heated beads. As a result, adults must closely supervise children when they are fusing beads. For very young children, adults must perform the fusing operation for the child. When an adult performs the fusing for the child, the child misses out on some of the enjoyment and benefits of participating in the hobby. It would be beneficial if young children could safely apply the fusing heat source themselves without exposure to a risk of receiving a burn injury.  
         [0008]     A second concern is controlling the relevant process variables to achieve a reliable fusing of the bead tops. When the beads are excessively melted, the appearance of the bead project is degraded, while incompletely fused bead projects are similarly unattractive and less sturdy than a properly fused project. The important variables to control during fusing are the temperature of the iron and the duration of the application of iron&#39;s heat to the beads. Unfortunately, the temperature controls on irons are only roughly calibrated. Generally, irons do not indicate a temperature setting in degrees, but rather display temperature adjustment ranges labeled like “cotton” or “permanent press,” indicating the types of fabric to be ironed at that setting. Because the fabric settings are not standardized, there can be wide variation in temperature of an iron adjusted to the “cotton” setting. It would be advantageous if the temperature of the heat source were reliably adjusted to a known value so that ideal fusing of beads may be reliably accomplished.  
         [0009]     Several devices have been developed for heating and shaping plastic materials. German Patent No. 3,919,164, published Dec. 13, 1990, describes a device with a movable upper plate that presses against the contour of plastic materials to weld or cut the materials. German Patent No. 3,938,380, published May 23, 1991, describes an apparatus with a movable press plate and a non-stick slip film for extruding plastic material. German Patent No. 19,858,152, published Jun. 21, 2000, describes an apparatus for the production of plastic boards, including a press with heated and cooled sections for stretching plastic materials. Japanese Patent No. 57-155,255, published Sep. 25, 1982, describes a press-molding apparatus for producing a molded article from thermosetting resin containing glass beads.  
         [0010]     None of the above inventions and patents describes the present invention as claimed. Thus, a press for fusing beads solving the aforementioned problems is desired.  
       SUMMARY OF THE INVENTION  
       [0011]     The press for fusing beads heats the tops of beads to fuse the beads together, fixing them in a pattern. The press preferably includes a control circuit that ensures a consistent, repeatable heating cycle used in the fusing process, and that operates the press to achieve an enhanced degree of safety for a user. The press includes an enclosure having an open slot at the front face. A heating plate having a heating element is mounted within the enclosure. A tray, which holds the beads to be fused, is placed on a tray support that slides within the open slot to a position under the heating plate. A control circuit senses the position of the tray support, and when the tray is in position beneath the heating plate, allows an operator to initiate a timed heating cycle. When the heating cycle is initiated, the control circuit either activates an actuator within the enclosure to move the tray upward, placing the tops of the beads into contact with the heating plate, and energizes the heating element to heat the heating plate to a predetermined temperature; or the user uses a manual vertical actuator mechanism to lower the heating element onto the beads in the tray manually.  
         [0012]     At the completion of the heating cycle, the heating element is de-energized, and the control circuit either controls the positioning actuator to lower the tray back upon the tray support, or indicates to the user that the melting cycle is complete and that the user should raise the heating element back into its elevated position.  
         [0013]     The press may provide a number of additional actuators and sensors to detect conditions associated with the press and to control the operation of the press. The press may include a fan in electrical connection with the control circuit. The control circuit operates the fan to cool beads and the internal components of the press at the end of a heating cycle. An electrically operated latch for holding the tray support plate within the press may be provided, or a locking post on the lowerable heating assembly may mechanically engage a locking post receiving means of the tray to prevent the tray from being slid out of the slot of the enclosure. The latch is electrically connected to the control circuit, which operates the latch to prevent the tray from being removed from the press during and after the heating cycle, while the beads are still hot. The press may be provided with indicator lights and a display that provide information to the user concerning the state of operation of the press, allowing the user to understand when it is safe to start the press and when to remove the bead tray from the press. The display can further provide an indication of abnormal or potentially unsafe conditions monitored by sensors within the enclosure.  
         [0014]     These and other features of the present invention will become readily apparent upon further review of the following specification and drawings. 
     
    
     DESCRIPTION OF THE DRAWINGS  
       [0015]      FIG. 1A  is a perspective view of a press for fusing beads according to the present invention as seen from the front.  
         [0016]      FIG. 1B  is a perspective view of the press of  FIG. 1A  as seen from the rear.  
         [0017]      FIG. 1C  is a perspective view of the press of  FIG. 1A  as seen from the bottom.  
         [0018]      FIG. 2  is a perspective view of a press for fusing beads according to the present invention, broken away and partially in section to show details of the tray holder assembly.  
         [0019]      FIG. 3  is a perspective view of a press for fusing beads according to the present invention, broken away and partially in section to show details of the heating element assembly.  
         [0020]      FIG. 4  is a block diagram of a computer-based safety control circuit for the press of the present invention.  
         [0021]      FIG. 5  is a process diagram showing operations implemented by the safety control circuit of  FIG. 4 .  
         [0022]      FIG. 6  is a top plan view of the preferred embodiment of the invention, illustrating a tray support plate in an extend position.  
         [0023]      FIG. 7A  is a left-side elevational view of the preferred embodiment of the invention, partially broken away, illustrating the tray support plate in the extended position.  
         [0024]      FIG. 7B  is a left-side elevational view of the preferred embodiment of the invention, partially broken away, illustrating the tray support plate, and a tray thereon, under a heating plate of the present invention.  
         [0025]      FIG. 7C  is a left-side elevational view of the preferred embodiment of the invention, partially broken away, illustrating the heating plate in a lowered position and in contact with beads on the tray.  
         [0026]      FIG. 7D  is a left-side elevational view of the preferred embodiment of the invention, partially broken away, illustrating a scraper being introduced into a second slot of invention, the scraper dislodging fused beads from the heating plate.  
         [0027]      FIG. 8  is a perspective illustration of the preferred embodiment of the invention. Similar reference characters denote corresponding features consistently throughout the attached drawings. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0028]     The present invention is a press for fusing beads, designated generally as  20  in the drawings. As shown in  FIGS. 1A, 1B , and  1 C, the press is shown to include an enclosure  21  with user interface components  230  on the exterior of the enclosure  21 . The user interface components  230  may include an alphanumeric display  40 , indicator lights  44 ,  46 ,  48 , and a start button  42 . A control circuit  200 , described below, controls the operation of the press  20 , sensing the pressing of the start button  42  to start a bead fusing cycle and indicating, via the indicating lights  44 ,  46 , and  48  and the alphanumeric display  40 , the operating state of the press  20 . The control circuit  200  also monitors sensors  224  within the press  20  to detect conditions that might potentially result in unsafe operation.  
         [0029]     Electrical power for controlling and operating the press  20  is provided via an electrical power cord  50  terminating in an electrical plug  52 . The plug  52  is adapted for connection to a source of electrical power from a conventional AC receptacle, such as 110V AC in North America and 220V AC in Europe, for example.  
         [0030]     The press  20  further comprises a tray support plate  94 . The tray support plate  94  slidably engages a tray guide  30  so that the tray support plate  94  can be slid within the enclosure  21  of the press  20 . The drawer guide  119  ( FIG. 7A ) may be further included to support the tray support plate  94  between its extended and retracted positions. A handle or knob  26  attached to the front of the tray support plate  94  provides a purchase that allows a user to slide the tray support plate  94  in or out of the press  20 . The upper surface of the tray support plate  94  is adapted to hold a tray  22 . A recessed area  24  of the tray  22  is adapted to hold a bead mold  17  containing beads  25  to be fused by the press  20 .  
         [0031]     The enclosure  21  is comprised of an upper portion  36  and a lower portion  34  that are assembled to form the enclosure  21  with a front opening  32  for inserting the tray  22 . The assembled enclosure  21  defines a substantially hollow interior  19  within the upper portion  36  and the lower portion  34 . The enclosure  21  may be made of any suitably strong, temperature-resistant material, such as metal or heat-resistant plastic.  
         [0032]     Referring now to  FIG. 1B , details of the rear of the press  20  may be appreciated. The rear of the enclosure  21  is provided with ventilation openings  60 . An internal fan  80  exhausts warm air from within the enclosure  21  during a cooling cycle described below. The power supply cord  50  is preferably retractable within the enclosure  21  of the press  20 .  
         [0033]     Referring to  FIG. 1C , one of the safety features of the press  20  may be appreciated. A child resistant latching mechanism  54  is provided. The child resistant latch  54  comprises one or more screw fasteners. The heads of the fasteners are preferably recessed below the surface of the enclosure  21  when fully latched, making the screws difficult for young children to operate without the assistance of a tool. Because the latch mechanism  54  is located on the bottom of the enclosure and requires a tool to operate, the latch mechanism  54  is not readily operable by underage children. By limiting the ability of children to open the enclosure  21 , the risk of a burn or an electrical shock to a child by accessing energized elements within the press  20  is reduced. Other appropriate child proof latching mechanisms that may be known in the art may also be used.  
         [0034]     By referring now to  FIG. 2 , internal details of the press  20  may be understood. The tray support plate  94  described above is shown fully inserted within the lower housing  34  of the enclosure  21 . A pair of tray guides  30  are supported by side frames  82  disposed within the lower housing  34 . Each tray guide  30  defines an elongated guide slot. The tray support plate  94  slidably engages the tray guide slots, allowing the tray support plate  94  carrying a tray  22  to slide into or out of the press  20 . Preferably, a drawer guide  119  may also be used to support the tray support plate  94  ( FIG. 7A ).  
         [0035]     When the tray support plate  94  is fully inserted within the enclosure  21  of the press  20 , leaf springs  92  mounted to a fixed support within the hollow interior  119  are biased to hold the tray  22  in a lowered position on the tray support plate  94 . In the lowered position, the tops of fuser beads  25  disposed in a mold  17  placed in the bead mold holder  24  of the tray  22  are held away from contact with a heating plate  120 , described below.  
         [0036]     A linear actuator mechanism  90  may be provided in one embodiment to lift the tray  22  to a raised position above the tray support plate  94 . In the raised position, the tops of fuser  25  beads disposed in a mold  17  supported by the tray  22  are placed in contact with the heating plate  120 , described below. The linear actuator mechanism  90  may be comprised of a plurality of solenoids  90  disposed within the lower housing  34 . When energized, the solenoids  90  lift the tray the tray  22  away from the tray support plate  94  against the force of the tray springs  92  to the raised position. When the solenoids  90  are de-energized, the springs  92  return the tray  22  to the lowered position.  
         [0037]     An electrically operated latching mechanism  100  may be provided in one embodiment for holding the tray  22  in position. The latching mechanism  100  can be electrically energized to hold the tray support plate  94  in position within the press  20  during a heating operation and released to allow the tray support plate  94  to be withdrawn from or inserted into the press  20 . In the illustrated embodiment, the latching mechanism  100  comprises a solenoid-operated latch  100 . When the solenoid  100  is energized, the plunger of the latching solenoid  100  rises to engage an opening in the tray support plate  94 , holding the tray  22  in place while the solenoid  100  is energized. De-energizing the latching solenoid  100  lowers the plunger, unlatching the tray support plate  94 . Alternatively, a solenoid  100  with the opposite operating sense may be employed, so that the tray support plate  94  is latched by de-energizing the solenoid  100  and unlatched by energizing the solenoid  100 .  
         [0038]     The ventilation fan  80  disposed within the housing of the press  20  draws ambient air within the enclosure  21  through ventilation openings  60  in order to cool the fused beads  25  after a heating cycle. The fan  80  exhausts the heated air outside of the enclosure  21 . Preferably the fan  80  is positioned and operated to exhaust the air away from the front opening  32  at the front of the press  20  so that the heated air is not directed towards a user operating the press  20 .  
         [0039]     Sensors  224  disposed within the housing are provided to detect conditions that indicate a safe or unsafe condition for operating the press  20 . One or more position detecting sensors  28  are located at the ends of a tray guide slot to detect whether or not the tray support plate  94  is fully inserted within the press  20 . The sensors may include photoelectric sensors comprising a light emitter element and a photo detector element separated by a gap positioned at the end of the tray guide slot. When the tray support plate  94  is not fully inserted, the light from the light emitter is detected by the photo detector element. When the tray support plate  94  is fully inserted, the plate  94  shadows the photo detector, interrupting the light from the light emitter element. Monitoring the output response of the photo detector provides an indication of whether the tray support plate  94  is fully inserted.  
         [0040]     A proximity detector sensor  112  detects whether the upper enclosure housing  36  is in place, sealing off access to the internal components of the device from users during operation. The proximity sensor may be a microswitch  112  mounted on a portion of the lower housing  34  or a lower housing component, such as the tray guide support frame  82 . The proximity switch condition, closed or open, may be monitored to detect the state of assembly of the housing for the press  20 .  
         [0041]     Referring now to  FIG. 3 , the details of the heating plate assembly  115  in one embodiment may be appreciated. Preferably the components of the heating plate assembly  115  are installed within the upper housing  36 , allowing access to the region between the heating plate  120  and the lower assembly when the enclosure  21  is opened. Alternatively, the components of the heating assembly  115  may be mounted from supports fixed in the lower housing  34 .  
         [0042]     A flat heating plate  120  made of a thermally conductive material, such as stainless steel or other metal, is disposed within the upper housing  36  and supported by a plurality of insulated mounts  124  from the upper housing  36 . The insulated mounts  124  may be resilient mounts that yield under a vertical pressing force to allow the press  20  to accommodate beads  25  of varying heights being pressed against the heater by the tray actuators described above. Alternatively, larger beads  25  may be accommodated by providing resilient supports for the tray positioning actuators.  
         [0043]     The heating plate  120  is provided with a heating element  130 . The heating element  130  may be a resistive heating element  130  that converts electrical energy to heat when a current is passed through the element  130 . The heating element  130  may be embedded in the heating plate  120 , or alternatively, may be disposed on a surface of the heating plate  120 .  
         [0044]     The lower surface of the heating plate  120  may be provided with a non-stick coating to prevent melted bead material from sticking to the surface of the heating plate  120 . Preferable the non-stick coating is a thin layer of a polymeric material, such as polytetrafluoroethylene (PTFE). Other materials may be used provided that they are stable under the anticipated temperatures for the heating plate  120 , have non-stick properties so that they do not adhere to the material of the beads  25 , and which do not chemically interact with the bead material.  
         [0045]     A temperature sensor  132  may be provided on the heating plate  120  for monitoring the temperature of the heating plate  120 . The temperature sensor  132  may be a component whose electrical properties very with temperature, such as a temperature sensitive resistor or thermister. Alternatively, a temperature sensitive switch (not shown) that opens or closes at a fixed or preset temperature set point can provide an indication of whether the heating plate temperature is above or below a given point. Alternatively, the heating element  130  may be comprised of a material whose resistance varies with temperature so that measuring the voltage and current associated with the heating element  130  provides an indication of the heating plate  120  temperature. For example, the heating element  130  may be made of an alloy, such as nichrome, that has a positive temperature coefficient of resistance.  
         [0046]     An insulating barrier  122  may be disposed between the inner surface of the upper housing  36  and the heating plate  120 . The insulating barrier  122  is preferably composed of a thermally insulating material able to withstand the anticipated temperatures attained by the heating element  130 . Such materials as thermosetting plastics, mica or other suitable materials may be used. The insulating barrier  122  serves to keep the external surfaces of the enclosure  21  cool to the touch to prevent the development of hot spots on the enclosure  21  that may present a burn hazard to users.  
         [0047]     By referring to  FIGS. 1A and 4 , details of the safety control circuit  200  for the press  20  may be understood. The safety control circuit  200  comprises a memory  204 , a central processing unit (CPU)  202  and control interfaces  210 . A control bus  212  couples the memory  204  and control interfaces to the CPU  202 . The memory  204  may be comprised of random access memory (RAM)  206  and read only memory (ROM)  208 . The random access memory  206  may store instructions from an executing program and data, such as information read by the CPU  202  or generated as the result of calculations performed by the CPU  202 . The ROM  208  is a non-volatile storage area that stores fixed data and operating instructions to be executed by the CPU  202 . The CPU  202  reads program instructions stored by the memory  204  and executes the instructions to provide the functionality required by the control circuit  200 . The control interfaces  210  facilitate communications between the CPU  202  and components external to the control circuit  200 . The external components include the user interface components  230  and the device control components  220 . The user interface components  230  comprise the operator controls  232  that include the start button  42  used to initiate the electrically controlled operations of the press  20 . The indicator lights  234  are controlled by the central processing unit  202  to indicate the current state of the press  20 . The indicator lights may include a illuminator for the start button  42  to indicate that a heating cycle may be safely started, a red light  44  indicating that a heating cycle is in progress, a yellow light  46  indicating that the press  20  is executing a cooling cycle, and a green ready light  48  to indicate that the cooling is complete and that beads may be safely removed from the machine. The user interface  230  may also include an alphanumeric display  236  providing a descriptive indication of the operating state of the press  20 . The display  40  may provide an indication of the time remaining in a cooling cycle.  
         [0048]     The operating condition of the machine is sensed and controlled by the CPU  202  via the device control components  220 . The device control components  220  include the interlocks  222  that inhibit unsafe operation of the machine, sensors  224  that detect conditions within the press  20 , and the actuators  226  via which conditions of the press  20  are set by the CPU  202 . Referring to  FIGS. 2 and 3 , the interlocks  222  comprise the tray latch  100  that is operated to prevent the tray  22  from being removed from the press  20  during a heating cycle or prior to cooling down after a heating cycle. The actuators include the heating element  130 , which is energized to control the temperature of the heating plate  120  during a heating cycle, and the tray actuators, which are controlled to move the tray  22  towards or away from the heating plate  120  to position the beads into contact with the heating plate  120  for fusing and away from the heating plate  120  during a cooling cycle. The actuators further include the fan  80  used to provide cooling during a cooling cycle.  
         [0049]     The sensors  224  include the tray position sensors  28 , the heater temperature sensor  132 , and the enclosure proximity sensor  112  described above.  
         [0050]     By referring to the process diagram shown in  FIG. 5 , and  FIGS. 1A, 2 ,  3 , and  4 , the control logic implemented by the safety control circuit  200  may be understood. As shown in  FIG. 5 , operation of the control logic begins in the start state  302 . To begin operation from the start state fuser beads are placed in the bead pegboard, which is then placed in the holder  24  in the tray  22 . The tray  22  is placed on the tray support plate  94 . The tray support plate  94  is then pushed into the front slot  32  of the press  20 . While in the start state  302 , the control circuit  200  monitors the condition of the sensors  224  to detect if the device is prepared to enter the ready state  304 . The monitoring includes checks to ensure that the enclosure  21  is closed and that the tray support plate  94  and tray  22  are fully inserted using the sensors described above.  
         [0051]     In the start state  302 , the indicator lights, including the illumination for the start button  42  and the illuminator light, are extinguished. Pressing the start button  42  while in the start state  302  has no effect on circuit operation. Once the initial safety checks are completed, the control circuit  200  enters the ready state  304  via path  322 . In the ready state  304 , the start button illumination is energized, indicating that the user may initiate a bead fusing operation by pressing the start button  42 . While in the ready state  304 , the control logic continues to monitor the sensors  224 , and if a not ready condition is sensed, such as the tray  22  being not fully inserted or the enclosure  2 ] being open, the control logic transitions back to the start state  302  via path  324 . A message may be generated and sent to the display  40  to indicate one or more of the conditions that caused the control logic to transition back to the start state  302 .  
         [0052]     If the start button  42  is pressed while the control logic is in the ready state  304 , the control logic transitions to the heating state  306  via path  326 . In the heating state  306 , a heating cycle is initiated to fuse the tops of beads in the bead tray. The tray latch  100  is engaged to prevent the tray  22  from being retracted during the heating cycle. The tray actuators  90  are energized to raise the tray  22  so that the tops of the beads contact the heating plate  120 , and the heating element is energized and controlled to maintain the heating plate  120  at the desired predetermined temperature for fusing the plastic beads. The value for the predetermined temperature may be read from a storage location in the memory  204 . The state of the press  20  is indicated by illuminating the heating state indicator tight  44  on the press  20 . The display  40  may be driven by the control circuit  200  to indicate the heating state. The display  40  may alternatively provide a time display indicating the remaining duration of the heating cycle. The duration of the heating cycle may be a predetermined time period stored in the memory  204  of the control circuit  200 .  
         [0053]     When the time period of the heating cycle expires, the control circuit  200  transitions to the cooling state  308  via path  328 . In the cooling state  308 , the control circuit  200  continues to engage the tray latch  100  preventing the tray  22  with the heated beads from being retracted. The heating element  130  is de-energized and a cooling fan  80  may be turned on to accelerate the cooling of the heated beads. The tray actuators  90  are de- energized, allowing the tray springs  92  to lower the tray  22  away from the heating plate  120 . The cooling state  308  may be indicated by using a yellow illuminated indicator  46 . The display  40  may be driven by the control circuit  200  to indicate the cooling state  308 . The display  40  may alternatively provide a time display indicating the remaining duration of the cooling cycle. The duration of the heating cycle may be a predetermined time period stored in the memory  204  of the control circuit  200 . Alternatively, the remaining duration of the cooling cycle may be calculated based on a temperature read from a sensor disposed within the press  20 . In one embodiment, the temperature sensor  132  used to monitor the heating plate temperature may be used to estimate the remaining time required for the cooling cycle. In another embodiment, a temperature sensor in the air stream may be used to estimate the remaining time required for the cooling cycle. In yet another embodiment, the display  40  may indicate an estimated temperature of the beads calculated from the expired duration of the cooling cycle and/or temperature information measured with the press  20 .  
         [0054]     Once the time period for the cooling cycle has expired, the control logic transitions to the cooled state  310  via path  330 . In the cooled state  310 , the tray latch  100  is released allowing the tray support plate  94  to be withdrawn from the press  20 , providing access to the fused and cooled beads. In the cooled state  310 , a green all safe indicator  48  is illuminated to indicate that the beads are cooled to a safe temperature. The cooling fan  80  is turned off. Once the user withdraws the tray support plate  94  to access the tray  22  and the beads, the control logic transitions to back to the start state  302  via path  332 .  
         [0055]     In the described embodiment the control logic is implemented using software stored in a computer readable medium with the device. The control logic (software) is executed by the processor  202  causing the processor  202  to perform the functions of the invention as described herein.  
         [0056]     In another embodiment, the elements are implemented primarily in hardware using, for example, hardware components such as application specific integrated circuits (ASICs). Implementation of the hardware state machine in order to perform the functions described herein wilt be apparent to persons skilled in the relevant art(s).  
         [0057]     In yet another embodiment, elements are implemented using a combination of both hardware and software.  
         [0058]     Additional safety checks may be performed during the states described with the logic control transitioning or remaining in the start state  302  when a safety check fails. For example, an abnormally high current may indicate that a solenoid actuator is restricted from making a full stroke, indicating that the tray path to the heating plate  120  may be blocked. A low or zero current value may indicate that the solenoid coil has failed. The current provided to the heating element  130  may also be monitored, with abnormally high or low currents being indicative of a failed or shorted heating element. The failed conditions may result in a diagnostic message being sent to the display  40 . A level sensor may be included to indicate the orientation of the bead fuser. The control logic may maintain the device in the start state  302  when the level sensor indicates that the bead fuser is not properly oriented. One skilled in the art would appreciate that sensors monitoring additional conditions may be interfaced to the control circuit to detect additional potentially unsafe conditions for operating the press  20 .  
         [0059]     Preferably, the state indicator lights are of the red, green and yellow in color and are arranged in an orientation similar to a traffic signal light. The use of a familiar color scheme and orientation may allow younger users to successfully operate the press  20 . Alternative arrangements of the display may be used. For example, in one embodiment, color and arrangement of the indicators is chosen to provide an aesthetic appearance. The indicator light system may be omitted, with all of the relevant state information being provided via the alphanumeric display. The alphanumeric display provides additional information, which may allow older children and adults to diagnose problems with the press  20  and or to provide them with additional information concerning the operation of the press  20 .  
         [0060]     The tray actuators are described as solenoid actuators in the described embodiment. In another embodiment, any electrically operated or actuated mechanism, which will produce a linear movement of the tray towards the heating plate, may be used. For example, the tray actuator may be a motor driven apparatus using a gearing arrangement to produce a vertical motion of the tray  22 . The operation of the motor may wind a spring, which reverses the direction of the tray when the motor is de-energized. Alternatively, the motor may be operated in the reverse direction to move the tray  22  away from the heating plate  120 .  
         [0061]     In a preferred embodiment of the invention, illustrated in  FIGS. 6-8 , a spring  92  is disposed within the enclosure  21  that biases the heating element  130  into an elevated position over the tray  22  ( FIGS. 7A and 7B ). At least one knob  27  mechanically connected to the heating element  130  at a forward end is captured in at least one inverted J-shaped slot  29  of the enclosure  21 . An upper end of each J-shaped slot  29  holds the knobs  27  in an elevated position, thereby holding the heating element  130  in the elevated position. The heating assembly  115  is pivoted at a pivot means  116 , such as a bolt  117 , at a rear end thereof ( FIG. 7A ). A lower end of each J-shaped slot  29  allows each knob  27  to fall into a lowered position, thereby allowing the heating element  130  to assume a lowered position such that the heating element  130  achieves close mutual proximity with the tray  22 , and contacts any beads  25  that are resting on the tray  22  in order to fuse the beads  25  together ( FIG. 7C ).  
         [0062]     In such an embodiment, wherein the heating element  130  is movable between an elevated and a lowered position, once the beads  25  are fused they may stick to the heating element  130  when same is raised to the elevated position. As such, a generally horizontal second slot  33  is further included in the face  18  of the enclosure  21  ( FIGS. 7D and 8 ), and a scraper  35  may be introduced therein to pry the fused beads  25  away from the heating element  130 .  
         [0063]     The control circuit  200  in such an embodiment may be altered slightly from that previously detailed. In such an embodiment, the control circuit  200  may, upon depression of a power switch  42 , energize the heating element  130  if the proximity detector sensor  112  indicates that the tray  22  is directly under the heating element  130  and that the tray support means  94  is fully inserted into the slot  32 . Upon actuation of the heating element  130 , the temperature sensor  132  indicates when the heating element  130  has reached a predefined operating temperature sufficient to fuse the beads  25 . At this point, a “ready to melt” indicator light  44  is actuated, signaling to the user that he may use the knobs  27  to lower the heating element  130  onto the beads  25 . A timing means of the control circuit  200  is then initiated, and upon the expiration thereof the heating element  130  is de-energized. At such a time, a “done melting” indicator light  48  is actuated, signaling to the user that the knobs  27  may be lifted and set into the raised position to raise the heating element  130 . A second cooling timing means is at this point initiated, and upon the expiration of same a “finished” indicator light  48  is actuated, alerting the user that sufficient cooling time has elapsed and that the user may remove the beads  25  from the enclosure  21 . If the beads  25  have stuck to the heating element, the scraper  35  may be inserted into the second slot  33  to dislodge the beads  25  from the heating element  130 . Preferably, a portion  23  of the enclosure  21  is transparent ( FIG. 8 ) so that the user may see inside the enclosure  21  to determine if the beads  25  have stuck to the heating element  130 , and in order to direct the scraper  35  accurately between the beads  25  and the heating element  130 .  
         [0064]     To prevent the tray  22  from being removed while the heating element  130  is in the lowered position, the heating assembly  115  may further include a locking post  105  ( FIGS. 7A and 7C ) and the tray support  94  may include a locking post receiving means  106  ( FIG. 6 ). The locking post  105  engages the locking post receiving means  106  when the heating element  130  is not in the raised position ( FIG. 7C ), thereby preventing the tray support means  94  from sliding out of the enclosure interior  19 .  
         [0065]     It is to be understood that the present invention is not limited to the embodiments described above. For example, the exactly type, placement, and state indications of the various indicator lights  44 ,  46 ,  48  may be varied in any number of ways. Further, a different number of such indicator lights may be used, for example, with or without the alphanumeric display  40 . Further, the mechanism used to bring the heating plate  130  into contact with the beads  25  may be varied in a wide variety of ways. As such, the present invention encompasses any and all embodiments within the scope of the following claims.

Technology Classification (CPC): 1