Abstract:
A diverter valve comprises a body defining a first, a second, and a third orifice, a flipper operably positioned to substantially prohibit flow through one of the first, the second, and the third orifices, and a flipper drive mechanism drivably coupled to the flipper. The flipper drive mechanism comprises a motor, a cam drivably coupled to the motor and including a cam position indicator, a follower drivably coupled to the cam translating rotational motion of the cam into reciprocal motion to drive the flipper, and a motor control circuit in sensory communication with the cam position indicator. The motor control circuit couples an external source of electrical power to the motor to energize the motor to drive the cam to a first and a second predetermined position. The motor control circuit includes a first controllable switch in series with a first position switch. This first position switch opens in response to the cam position indicator indicating that the cam is at the first predetermined position. The motor control circuit further includes a second controllable switch in series with a second position switch and in parallel to the first controllable switch and the first position switch. This the second position switch opens in response to the cam position indicator indicating that the cam is at the second predetermined position.

Description:
FIELD OF THE INVENTION 
     The instant invention is directed generally to the field of diverter valves, and more particularly to drive mechanisms for diverter valves. 
     BACKGROUND OF THE INVENTION 
     Controllable valves for channeling or diverting a flow of fluid from one channel to another are used in many fluid flow control applications. One such application is in the field of consumer home appliances, and more particularly in modern, high efficiency washing machines. Conventional consumer washing machines utilize tremendous amounts of water during the wash and rinse cycle because all water utilized in these cycles was directly dumped overboard by a simple drain valve. However, advances in the washing machine technology and concern for conservation of natural resources has resulted in the incorporation of a controllable diverter valve in place of this simple drain valve in these new, high efficiency washing machines. 
     In such a machine, a solenoid actuated diverter valve is utilized to redirect the flow of water being siphoned from the washing drum so that it may be recirculated to the washing drum for a period during a particular cycle. Once this cycle of recirculation is complete, the solenoid actuated diverter valve is operated to divert or redirect the flow of water from the recirculation circuit to the drain circuit so that the water may be dumped overboard, typically to a standpipe. Such recirculation may be accomplished in either or both the wash cycle and the rinse cycle to conserve the amount of water utilized in the washing process. In a typical application for a rinse cycle, the diverter valve will first be set to a recirculation position directing any water flowing therethrough back to the washer tub. The washing machine will then begin a spin cycle, spraying the clothes with fresh water. The water is pulled through the close by the centrifugal action of the spinning tub where it falls down to the sump and flows to the water pump inlet. The pump forces the water through the diverter valve to a siphon break where it is redistributed on the spinning clothes. This recirculation is allowed to continue for a period of time. Thereafter, the diverter valve solenoid is actuated to place the diverter valve in the drain position to discharge the rinse water to the standpipe. Once all of the water used in that portion of the rinse cycle has been discharged, the solenoid is again actuated to place the diverter valve in the recirculation position so that an additional cycle may begin with fresh water. In a typical application, this process is repeated several times to completed the rinse cycle. In this way superior performance may be achieved with a significantly reduced amount of water being used. 
     While this high efficiency recirculation method of washing and rinsing has been perfected, the performance of the solenoid actuated diverter valves themselves have not met with such success. Because these valves rely upon a solenoid to actuate the diverter valve flipper, the physical size of this solenoid actuated valve is significant. To hold this solenoid drive mechanism in place, a large metal bracket is required. Also because of the significant weight of the solenoid and bracket, the drain bucket onto which this bracket is mounted must be made of metal to support the weight of the solenoid and bracket assembly. This further increases the overall weight of the washing machine and increases the cost per machine. Because actuation of the solenoid pulls on its armature which is connected to a lever that is attached through a shaft to the flipper of the diverter valve, the actual operation of this solenoid actuated diverter valve is also quite noisy. This noise results from the sudden contact of the armature to the housing end wall when it is pulled into position by energization of the solenoid. This loud noise several times during the wash and rinse cycles reduces the customer appeal for these washing machines, therefore adversely impacting the sales of these machines. This despite the obvious advantage of the conservation of water provided by these machines. 
     An additional problem existing with the usage of these solenoid actuated diverter valves is that the spring reliability within the solenoid assembly is unacceptably low. Specifically, the reliability of the spring which returns the solenoid shaft to its quiescent position when the solenoid is deenergized, returning the diverter valve flipper back to its quiescent position, is too low. As described above, a typical single rinse cycle includes several operations of a solenoid actuated diverter valve. Additionally, a typical wash cycle includes at least two rinse cycles, each of which having several actuations of the diverter valve. Further, the newest high efficiency machines are utilizing this recirculation technique during the actual wash cycles, thereby increasing the number of actuations of the solenoid diverter valve several fold. 
     When the typical number of loads of laundry washed by a typical family over the projected lifetime of a washing machine is multiplied by the number of solenoid actuations of the diverter valve for each complete wash cycle, it will be recognized by one skilled in the art that the reliability of the solenoid diverter valve must be significant. Unfortunately, the reliability of the springs in the typical solenoids simply does not meet these requirements. While higher reliability materials may be used to construct these solenoid springs, the higher reliability provided results in a significantly increased cost beyond which is commercially feasible in the highly competitive consumer appliance industry. 
     Further, the use of a solenoid driven diverter valve introduces electrical inefficiencies which significantly lessens the environmental gains introduced by the water savings. Specifically, the typical solenoid driven diverter valve uses a held type solenoid which requires the flow of electrical current through the solenoid windings during the entire period that the diverter valve is to be in the diverted position. This continuous power flow increases the users cost of ownership through increased power draw, and further introduces an additional design consideration for the product designers. Specifically, the continuous current flow through the solenoid coils introduces a heat rise which must be compensated for in the overall system design. This heat rise may limit the available materials that may be utilized to house the solenoid and its associated circuitry, and may require separate cooling considerations and/or ventilation to be added to the machine. 
     It is therefore a desire in the industry to have a lightweight, quiet, highly reliable diverter valve actuation system which is relatively inexpensive and which is able to control an operating pressure nearly double the deadhead pump pressure of prior designs. It is such a system that is provided by the instant invention. 
     SUMMARY OF THE INVENTION 
     In view of the above problems existing in the art, it is an object of the instant invention to provide a new and improved drive mechanism for a flipper type diverter valve suitable for use in consumer home appliance applications. More specifically, it is an object of the instant invention to provide new and improved flipper valve assembly that has a significantly reduced operating noise level. It is a further object of the instant invention to provide a new and improved drive and flipper valve apparatus having reduced weight, increased reliability, and reduced cost. Further, it is an object of the instant invention to provide a new and improved flipper valve apparatus able to control an increased operating pressure with a reduced power usage. Further, it is an object of the instant invention to provide a new and improved flipper valve apparatus that eliminates heat rise as a design consideration. 
     In view of these objects it is a feature of the instant invention to provide an integrated drive flipper valve apparatus which utilizes a motor drive cam to actuate the flipper valve between each of its respective positions. It is an additional feature of the instant invention to provide a motor controller that senses the position of the flipper valve to control the motor energization. It is an additional feature of the instant invention to provide as a feature of the flipper flexure so as to allow the motor to continue to either of its fully actuated positions without stalling if an object were to impede the movement of the flipper. It is an additional feature of the instant invention that the flipper diverter valve is not dependent on a return spring. Further, it is a feature of the instant invention that, due to the reduced weight of the assembly, the drain bucket of a washing machine in an exemplary embodiment need not be made of metal. Additionally, it is a feature of the instant invention to utilize a motor controller to control motor operation and flipper actuation. It is an additional feature of the instant invention to utilize a single input to the motor drive to minimize complexity and power utilization for the actuation of the apparatus, although separate inputs for the actuation of the motor drive, one for the drain and one for the recirculation actuated position, may also be utilized where appropriate or desired. 
     In view of the above-described problems existing in the art, and in accordance with the objects and features of the instant invention, the preferred embodiment of the instant invention includes a valve body preferably molded from a flame retardant talc filled polypropylene or other appropriate material. The body provides the internal valve geometry, flipper seal surfaces, shaft pivot points, recirculation hose connection, and inlet spin weld interface. Further, the body in accordance with a preferred embodiment of the instant invention provides the receptacle for the drive mechanism, locates and retains the circuit board and motor, and interfaces with the protective cover enclosing the motor and its control circuitry. The motor is preferably a standard leaded timer type motor that will operate preferably at approximately 4 rpm and deliver, in a preferred implementation, approximately 15 inch ounces of torque. In a preferred implementation the motor will have a square output shaft and will turn only in a given direction. The motor may be mounted by mounting ears to two stand off posts on the body which will locate the motor in relationship to the body. 
     A preferred embodiment of the instant invention will also utilize a cam that is preferably injection molded from a plastic type material. This cam may be pressed fit on the motor output shaft and has a center post that extends inside the motor output shaft to provide retention and lateral stability. An offset post on the face of the cam transmits the motor torque to the cam follower. The periphery of the cam has a notch that allows a microswitch lever to actuate when the mechanism is in each fill closed position. In this preferred embodiment, the follower will also be injected molded from a plastic type material and will include a slot that interfaces with and contains the cam follower at one end. The follower will also preferably include a double D feature at the other end that interfaces with and rotates the shaft. The follower is preferably sandwiched between the circuit board and the cam in this preferred embodiment. Also in this preferred embodiment the follower will contain a narrowed section that is designed to flex t absorb the over travel of the mechanism or allow motor travel to continue if an object becomes caught preventing movement of the flipper mechanism. The shaft driven by the follower will also preferably be injection molded from a plastic type material, and may be incorporated as a single piece with the follower itself. In either event, the shaft includes a groove molded to accept a quad ring type seal. The shaft also includes another double D feature molded in to interface and transmit motion to the flipper. The quad ring is assembled into the grove on the shaft and interfaces with the shaft and the shaft hole in the body to provide a watertight seal between the shaft and the body. The flipper body will also preferably be injected molded from a plastic type material and will be over molded with rubber to form a double-sided circular seal with a raised ring around each surface. 
     A further aspect of a preferred embodiment of the instant invention will include an inlet that is injection molded from the same material as the body, and will provide the connection for the hose that brings water into the valve. This inlet will preferably be spin welded onto the body, although other attachment methods may be utilized as appropriate. The cover will also preferably be injection molded from the same material as the body and the inlet. This cover interfaces with the body and protects the electrical components from splashed water. It preferably has latches that will retain it to the body and may include a vertical rib along the top of the cover over the electrical connector to channel water runoff away from the connector. The cover may also have vertical posts extending down to the top of the shaft, the top of the microswitches, and the top of the customer electrical connector to provide additional vertical stability. 
     The circuit board will preferably be a single sided printed circuit board assembly that includes microswitches mounted on the circuit board to provide the correct positioning for proper actuation via operation of the follower and cam. An electrical connector customized for a particular application is mounted to the board which positions it properly in relation to the access window provided in the body. All electrical inner connections are provided by the board with the exception of the wire leads that connect to the motor coil. A motor control circuit provides the logic necessary to allow the motor to be controlled by a single control line from the timer. In a preferred embodiment a 120-volt AC single on the control input sends the valve to the drain position. The absence of the signal on the control input sends the valve to the recirculation position. Alternatively, the motor may be controlled by separate control lines from the timer as desired or appropriate. This circuit board may be supported by standoffs mounted into the body, and will be horizontally located by the same posts to which the motor mounts. 
     In a preferred embodiment, a diverter valve in accordance with the teachings of the instant invention comprises a valve body having a fluid inlet and a first and a second fluid outlet, and a flipper body operably positioned within the valve body providing selectable sealing engagement with the first and the second fluid outlets. The valve further preferably includes a motor, a cam drivably coupled to the motor, and a cam follower operably coupled to the cam for translating motion to the flipper body to operably position the flipper body in sealing engagement with the first and the second fluid outlets. The cam follower may be one piece or may comprise an assembly of a follower body and a shaft. 
     In a further preferred embodiment, the motor includes an output shaft in driving engagement with the cam, and rotates the cam in a given direction. The cam follower is operably coupled to the cam such that the cam follower translates the rotational motion of the cam to reciprocal motion to drive the flipper body. Additionally, the cam preferably includes an offset post and the follower defines a slot therein for accommodating the offset post. This slot is configured to allow lateral translation of the offset post therein, and the lateral translation being transverse to the reciprocal motion. Preferably, the cam includes a center post extending inside the output shaft of the motor. In a highly preferred embodiment, the follower accommodates continued rotation of the cam after motion of the flipper body has ceased. This may be accomplished by the follower through the inclusion of a neck down region. 
     The diverter valve further preferably comprises a motor controller circuit operably connected to the motor to operate the motor to drive the flipper body between engagement with the first and the second fluid outlets. The motor controller circuit is in sensory communication with the cam to sense its position thereof, the sensed position of the cam utilized to deenergize the motor when the flipper body has engaged one of the first and the second fluid outlets. Preferably, the cam includes a notch in an outer periphery thereof, the motor controller circuit comprises at least one microswitch having an actuatable lever in communication with the outer periphery, and the position of the cam is sensed when the lever communicates with the notch indicating that the flipper body has engaged one of the first and the second fluid outlets. Preferably, the motor controller circuit comprises a second microswitch having an actuatable lever in communication with the outer periphery, and the position of the cam is sensed when the lever communicates with the notch. The microswitches are each positioned to indicate that the flipper body has engaged one of the first and the second fluid outlets. 
     In a further preferred embodiment of the instant invention, the motor controller comprises a first and a second controllable switch coupled in parallel with each other and in series with a first and a second position switch to provide energization to the motor to rotate the cam. The first and the second position switches are preferably in sensory communication with the cam to open at a given rotary position of the cam. The controllable switches are preferably TRIACs gated in response to an external command to transition the flipper body. Alternatively, the controllable switches may be separate normally open and normally closed contacts of a latching type control relay operated in response to external commands to transition the flipper body. 
     In an alternate embodiment of the instant invention, a drive circuit for a diverter valve having a valve body defining an inlet and a first and a second outlet, fluid flow being directed from the inlet to one of the first and the second outlets by a flipper body translatable between sealing engagement with the first and the second valve outlets, comprises a motor, a cam drivably coupled to the motor, and a cam follower operably coupled to the cam. The cam follower operates to convert rotary motion of the cam into reciprocal motion to drive the flipper body between sealing engagement with the first and the second valve outlets. The drive circuit preferably further comprises a motor control circuit operable in response to an external command to energize the motor to drive the flipper body between sealing engagement with the first and the second valve outlets. This motor control circuit is in sensory communication with the cam to deenergize the motor at a predetermined position of the cam. 
     In a further preferred embodiment, the cam defines a notch in its outer periphery. The motor control circuit includes at least one position sensing element in sensory communication with the outer periphery of the cam to indicate the predetermined position of the cam. Preferably, the motor continues to drive the cam to the predetermined position despite a lack of motion of the flipper body. 
     The motor control circuit preferably comprises at least one gateable switch in series with at least one switch controlled by the position sensing element to energize the motor until the predetermined position of the cam is reached. The motor control circuit further includes a second position sensing element in sensory communication with the outer periphery of the cam indicating a second predetermined position of the cam, and a second gateable switch in series with a second switch controlled by the second position sensing element. This second gateable switch and the second switch are coupled in parallel to the at least one gateable switch and the at least one switch. In this way, the motor control circuit is operable to energize the motor to rotate the cam from the predetermined position to the second predetermined position, and from the second predetermined position to the predetermined position. 
     In a further alternate embodiment, a valve comprises a body defining a first, a second, and a third orifice, a flipper operably positioned to substantially prohibit flow through one of the first, the second, and the third orifices, a flipper drive mechanism drivably coupled to the flipper. The flipper drive mechanism comprises a motor, a cam drivably coupled to the motor and including a cam position indicator, a follower drivably coupled to the cam translating rotational motion of the cam into reciprocal motion to drive the flipper, and a motor control circuit in sensory communication with the cam position indicator. The motor control circuit couples an external source of electrical power to the motor to energize the motor to drive the cam to a first and a second predetermined position. The motor control circuit includes a first gateable switch in series with a first controllable switch. This first controllable switch opens in response to the cam position indicator indicating that the cam is at the first predetermined position. The motor control circuit further includes a second gateable switch in series with a second controllable switch and in parallel to the first gateable switch and the first controllable switch. This second controllable switch opens in response to the cam position indicator indicating that the cam is at the second predetermined position. 
     Other objects and advantages of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an exploded isometric view of a flipper valve assembly constructed in accordance with the teachings of the instant invention; 
     FIG. 2 illustrates details of the body of the flipper valve assembly of FIG. 1; 
     FIG. 3 illustrates a simplified cross sectional view of the motor cam interface of the assembly of FIG. 1; 
     FIG. 4 illustrates a bottom view of the motor cam assembly of FIG. 3 illustrating additional aspects of the instant invention; 
     FIG. 5 illustrates an isometric view of the follower of the flipper valve assembly of FIG. 1; 
     FIG. 6 illustrates a side view of the follower of FIG. 5 illustrating additional aspects thereof; 
     FIG. 7 illustrates a simplified electrical schematic of a control circuit of an embodiment of the instant invention; 
     FIG. 8 is a system operation diagram illustrating system operation versus mechanical degrees; and 
     FIG. 9 is a system operation diagram illustrating operation of the system versus time. 
     While the invention will be described in connection with certain preferred embodiments, there is no intent to limit it to those embodiments. On the contrary, the intent is to cover all alternatives, modifications and equivalents as included within the spirit and scope of the invention as defined by the appended claims. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With an understanding of the prior designs and the problems existing therewith, direction is now focused on the drawings of the application, and in particular first to FIG.  1 . It should be noted that the embodiments illustrated in the figures are presented by way of example, and not be way of limitation. As will become apparent to one skilled in the art from the following description, numerous modifications to the embodiments presented are available and within the scope of the instant invention. Therefore, explicit reservation of all such modifications within the scope of the appended claims is made. To aid in the understanding of the instant invention, like reference numerals will be used throughout the figures for like elements. 
     As may be seen from the exploded isometric view of FIG. 1, a flipper valve assembly  10  constructed in accordance with the teachings of the instant invention preferably includes a molded valve body  12  which defines therein the internal plumbing routing from the single inlet  16  to the recirculation outlet  14  and the discharge outlet (not shown). Additionally, the valve body  12  may also include a unitary molded drain bucket portion  18  which includes a mounting cowel  20  which will allow attachment of the body  12  to the feature panel of a conventional washing machine from the inside out. An inlet  22  provides connection for a hose that brings water into the valve inlet  16 . This inlet  22  is preferably an injected molded part and will preferably be spin welded onto the body  12  within the molded inlet  24 . 
     Prior to such attachment process of the inlet  22 , a flipper body  26  is inserted within the valve body through inlet  16  to provide directional control of the water entering through inlet  22 . The flipper body  26  is preferably injected molded from a plastic type material, although other materials may be utilized as appropriate. It is contemplated within the instant invention that the flipper valve mechanism of the instant invention may be utilized in applications other than consumer home appliances, in which case different materials may be required. In the instant embodiment, the flipper body  26  is preferably over molded with a rubber material to form a double side circular seal  28  having a raised ring around each surface. The flipper body  26  also includes a female shaft channel  30  designed to mate with the flipper valve drive shaft  32  once assembly. This mounting channel  30  preferably includes a double D configuration, although other mounting drive configurations may be utilized as desired. 
     In a preferred embodiment of the instant invention, the unitary molded body  12  also includes an electronics drive housing  34  integrated therewith. An electrical connector port  36 , as well as the circuit board mounting posts  38  are also integrally molded therein. The electrical connector port  36  may be of a standard configuration, or of a configuration defined by customer requirements to accept an electrical connector  40  utilized for a particular application. In addition to the mounting posts  38 , positioning stumps  42  hold the controller circuit board  44  in a proper position therein. This ensures that the customer electrical connector  40  may properly mount to the controller electrical connector  46  when inserted through the connector port  36 . The housing  34  also includes a hole in the bottom thereof (not shown) to allow the flipper drive shaft  32  to mate with the flipper body  26  outside of housing  34  while also mating with the follower  48  within the housing  34 . A liquid seal is provided by a quad ring  50  contained within a notch of drive shaft  32  to prevent water from entering housing  34 . 
     Within housing  34  the flipper drive shaft  32  mates with cam follower  48  in a drivable relationship. This drivable relationship may be accommodated via a double D configuration, or other configurations known in the art. Additionally, the follower  48  and the flipper drive shaft  32  may be molded as a single part if desired. The follower  48  operates in conjunction with cam  52  which is driven by motor  54 . In the exemplary implementation of a consumer home washing machine, the motor  54  may be of a standard timer type motor providing as little as 15 inch ounces of torque and turning at a rate of approximately 4 RPM. Different sizes and speed motors may be utilized based upon the requirements of the installation into which this flipper valve assembly is to be utilized. 
     The housing  34  preferably mates with an enclosure cover  56  which is preferably injection molded from the same material as the enclosure  34 . This cover  56  interfaces with the enclosure  34  to protect the electrical components contained therein from splashed water. Preferably, the cover  56  includes latches  58  that will retain the cover  56  to the enclosure  34 , mating with mounting ribs  60 . While not specifically illustrated in this FIG. 1, the cover  56  may include a vertical rib along the top of the cover  56  to channel water runoff away from the connector  36 . The cover may also include vertical posts (not shown) extending down to the top of shaft  32 , the top of the microswitches  62 ,  64 , and the top of the electrical connector  46  to provide additional vertical stability. 
     As may be appreciated by the exploded isometric view of FIG. 1, the cam  52  is positioned between microswitches  62 ,  64 . The periphery of cam  52  includes a notch  66  that allows the lever  68 ,  70  of microswitches  62 ,  64 , respectively, to actuate when the mechanism is in each fully closed position. That is to say, as motor  54  rotates cam  52 , the notch  66  allows one of the levers  68 ,  70  of cams  62 ,  64  to drop into the notch  66  thereby actuating the microswitch for the control mechanism. The lever  68 ,  70  of the other microswitch is held in a non-actuate position by the outer periphery of cam  52 . Alternatively, the cam may include a detent to actuate microswitches of a different configuration. The actual control circuitry will be described in greater detail below with reference to FIG.  7 . 
     During operation of the valve of the instant invention, the motor  54  rotates cam  52  which translates follower  48  to drive shaft  32  to move flipper  26  between its two fully actuated positions. As illustrated in FIG. 2, the flipper  26  may block either the recirculation outlet  14  or the discharge outlet  72 . When the flipper is actuated to block the discharge outlet  72 , water entering through inlet  16  will be diverted to flow through the recirculation outlet  14 . Likewise, when the flipper  26  is actuated to close off the recirculation outlet  14 , water entering through inlet  16  is diverted to flow to the discharge outlet  72 . In between each of these two fully actuated positions, both the recirculation outlet  14  and the discharge outlet  72  are open to water flow. However, system operation in the exemplary implementation of a consumer home washing machine is not particularly concerned with the momentary transition and dual output water flow between actuation positions. System operation may also be controlled to transition the flipper body  26  only during periods of no water flow into inlet  16 . Additionally, this system may be operated with a motor  54  having a relatively high speed output so that the transition of the flipper body  26  from one actuated position to the other takes place within a very short time period. It is also contemplated that a third actuated position may be included, that position being midway between each of the other two actuated positions whereby both outlets  14  and  72  are fully open. This third position may be controlled by various methods, including the inclusion of a third and fourth microswitch (not shown) on the controller circuit board  44 . 
     The driving interface between the cam  52  and the motor  54  is illustrated in cross-sectional view of FIG.  3 . As may be seen from this cross-sectional view, the cam  52  includes a center post  74  that extends inside the motor output shaft  76  to provide retention and lateral stability thereof. Preferably, this interface is a press fit interface. The cam  52  also includes an offset post  78  on the face  80  of the cam  52  to transmit the motor torque to the cam follower  48  (see FIG.  1 ). While not necessarily apparent in this FIG. 3, FIG. 4 directly illustrates that the offset post  78  is indeed offset from the center  82  of cam  52 . As also apparent from this FIG. 4, the notch  66  of cam  52  is placed in relationship to the offset post  78  so that the proper signaling from microswitches  62 ,  64  may indicate the fully actuated position of the flipper body  26  between outlet  14  and outlet  72 . The positioning of this notch  66  in the outer periphery of cam  52  in relation to offset post  78  may be varied depending upon the placement of microswitches  62 ,  64  on the controller circuit board  44 . As will also be apparent to one skilled in the art, notch  66  may be replaced with other cam features such as a detent depending upon the technology of the positioning switches  62 ,  64 . All that is required by the instant invention is that the motor controller be provided some indication that the flipper  26  is in its fully actuated position so that the motor  54  may be deenergized. 
     The cam follower  48  preferably includes a follower slot  84  that interfaces with and contains the offset post  78 . As the follower  48  moves with the rotation of cam  52 , the motion of the cam is translated through the shaft mounting portion  86  of the follower  48 . This shaft mounting portion  86  preferably mates with shaft  32  through a female double D configured channel  88 , although other configurations of this mounting channel may be utilized as appropriate. Further, as indicated briefly above, the follower  48  and shaft  32  may be integrally molded as a single piece as desired and appropriate. The follower  48  also preferably includes notches  90 ,  92  to allow the follower  48  to flex to continue to track the cam motion should the flipper be prevented from further translation due to an object becoming stuck in the valve body. This flexure provided by notches  90 ,  92  allows the motor to continue to operate without becoming stalled to translate the cam to its fully actuated position. While only notches  90 ,  92  are illustrated, one skilled in the art will recognize that this flexure may also be accomplished through providing a neck down region for the follower  48 . Other body configurations which provide follower flexure under these conditions are also included within the scope of the instant invention. 
     As may be seen from FIG. 6, the follower  48  also preferably includes bearing nipples  94  on both the top  96  and bottom  98  surfaces of the follower  48 . These bearing nipples  94  are included in this exemplary embodiment to allow free translation of the follower  48  between the bottom surface  80  of cam  52  and the surface of the controller circuit board  44 . These bearing nipples  94  provide minimum friction for the translation of follower  48  between these two surfaces. However, in an implementation where the follower  48  is in a spaced relationship between these two surfaces, these bearing nipples  94  may be dispensed with. 
     An exemplary embodiment of a motor controller applicable to the valve assembly of the instant invention is illustrated in schematic form in FIG. 7, to which specific reference is now made. In this simplified schematic, a 120-volt AC input  100  is utilized to energize the coils  102  of motor  54  via one of two parallel paths  104 ,  106 . In each of these parallel paths,  104 ,  106 , a controllable switch, such as TRIAC  108 ,  110 , is utilized in series with each of the microswitches  62 ,  64  mounted on the control board  44  (see FIG.  1 ). The TRIACs  108 ,  110  each contain a gate terminal  112 ,  114 , which may be driven individually, or with the addition of an appropriate inverter or selection of TRIAC type, from a single control signal. If a single signal is used, the presence of the signal will gate one of the TRIACs, while the absence of the signal will gate the other. Alternatively, the controllable switches may be implemented through normally open and normally closed contacts of a single relay, or through separately controllable relays. Other embodiments of controllable switches will be apparent to those skilled in the art in view of this discussion and the following description of the exemplary operation of the motor control. 
     The operation of a motor control circuit in accordance with the instant invention will now be described with relation to FIGS. 8 and 9. This discussion utilizes the simplified control circuit of FIG. 7 as an exemplary circuit, although one skilled in the art will recognize that such description is not dependent on the actual implementation of the motor control circuit. Specifically, FIG. 8 illustrates system operation in relation to mechanical angle of cam  52 . At the zero degree point  116 , one skilled in the art will note that microswitch D  64  (see FIG. 7) is in a closed position as indicated by trace  118 , and microswitch C  62  is in an open position as indicated by trace  120 . A gating signal B indicated by trace  124  is provided to TRIAC  110  to energize the motor windings  102  and begin rotation of cam  52 . Alternatively, signal B could be a relay driver signal to close an open contact, etc. Further, this signal could be maintained (held on) during the period of time necessary to transition the flipper, depending on the technology of the controllable switch. As the cam is rotated, the notch  66  also rotates until the microswitch C  62  is closed by the outer periphery of the cam  52  at point  126 . The actual angle at which this transition takes place is dependent upon the physical size of notch  66  of cam  52 . As the cam continues to rotate, a point will be reached at which the notch  66  moves into position to actuate or open microswitch D  64 . This point is illustrated in a preferred embodiment at the 180° point  128 . As may be seen from trace  130 , which indicates the motor winding energization, once the microswitch D has been opened at point  128  the motor energization  130  is removed. Once the motor has been de-energized, the rotation of the cam is stopped and the flipper is maintained in its fully actuated position. 
     At some point in time it may be desired to move the flipper body to its other actuated position. At this point a gate signal is applied to TRIAC  108  as indicated at point  128  of trace  132 . Since the microswitch C  62  is closed, the motor coils  102  are again energized and the cam is rotated. At some point during this rotation, dependent upon the physical size of notch  66 , microswitch D  64  will close as indicated at point  134 . The cam continues to rotate until a point is reached where microswitch C again opens and the motor is again de-energized as indicated at point  136 . As may be seen with this exemplary embodiment, the trigger points for these events  116 ,  128 , and  136  are spaced 180 mechanical degrees one from the other. 
     Further appreciation of this operation may be had with reference to FIG. 9, which illustrates system operation versus time. As may be seem from this FIG. 9, the motor is de-energized as illustrated by trace  130  until time  138  at which point a gate signal  124  is applied to TRIAC  110 . Current then flows through the TRIAC and closed microswitch D as indicated by trace  118  until time  140  when microswitch D opens. As will be recognized by one skilled in the art, at time  142  microswitch C closes as indicated by trace  120  as notch  66  of cam  52  rotates out of position for microswitch C  62 . The amount of time between point  138  and point  142  is dependent upon the motor speed. 
     After the motor has been de-energized at time  140 , it remains deenergized until a gate signal  132  is provided at time  144 . Since microswitch C is already closed, the motor coils are again energized and the cam begins to rotate. At time  146 , the notch  66  of cam  52  has rotated out of position in relation to microswitch D which allows this microswitch to again close. The rotation of the cam continues during motor energization until time  148 . At this point the notch  66  of cam  52  has had sufficient time to rotate into position to allow microswitch C to open, thus de-energizing motor  54 . The motor will stay de-energized, and the flipper body in its actuated position until a gate signal is again applied at terminal B  114  (see FIG.  7 ). 
     Numerous modifications and alternative embodiments of the invention will be apparent to those skilled in the art in view of the foregoing description. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the best mode for carrying out the invention. Details of the structure may be varied substantially without departing from the spirit of the invention, and exclusive use of all modifications that come within the scope of the appended claims is reserved.