Patent Abstract:
A cam-operated timer for a household appliance including a housing and a switch wafer mounting in the housing used to receive and locate the wafers to prevent inaccuracies in wafer thickness from accumulating through the stack of wafers. The switch wafer mounting includes first and second locating features for receiving first and second switch arm wafers. The first switch arm wafer rests against the first locating feature, and the second switch arm wafer is stacked atop the first switch arm wafer and rests against the second locating feature.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application is a divisional of U.S. patent application Ser. No. 10/322,999, filed on Dec. 18, 2002 by Daniel K. Amonett, et al., now abandoned which is a divisional of U.S. patent application Ser. No. 10/000,414 filed on Nov. 2, 2001 by Daniel K. Amonett et al., now U.S. Pat. No. 6,613,991, which is a continuation-in-part of U.S. patent application Ser. No. 09/368,284 filed Aug. 3, 1999 by Daniel K. Amonett et al., now U.S. Pat. No. 6,441,326, which is continuation-in-part of U.S. patent application Ser. No. 09/365,561 filed Aug. 2, 1999 by Daniel K, Amonett et al., now U.S. Pat. No. 6,080,943, all of which are hereby incorporated by reference herein in their entireties. 

   FIELD OF THE INVENTION 
   the present invention relates to cam-operated timers for appliances. 
   BACKGROUND OF THE INVENTION 
   Many household appliances are equipped with mechanical timers to control their operation. Examples include dishwashers, icemakers, clotheswashers and dryers, wall and outlet timers, microwave ovens, and various other appliances. 
   While there is thus a diverse variety of applications for timers, most timers have a similar general structure. Typically, the timer includes a wheel or drum outfitted with cam surfaces. Spring metal switch arms are mounted to ride on these cam surfaces to be raised and lowered from the wheel or drum surface in response to the elevation of the cam surfaces. 
   A timing motor is typically coupled to rotate the cam wheel or drum, such that the switch arms are raised or lowered in accordance with a predefined regular pattern that is defined by the elevation of the cam surfaces on the wheel or drum. In some timers, the timing motor moves the wheel or drum by causing drive pawls to oscillate and move the cam wheel or drum forward in a step-by-step fashion. In other timers, the timing motor is connected through a gear train to a toothed surface on the cam wheel or drum to rotate the cam wheel or drum in a continuous manner. In either case, the timing motor and its stator, rotor and windings is typically a separately assembled part, housed in a separate housing from the drive assembly; as a consequence, the combination of the timing motor and gear train are fairly substantial in size, and form a large part of the volume and weight of the timer. 
   The switch arms inside the timer are typically mounted in pairs such that cam-actuated motion of either or both switch arms of a pair causes the pair of arms to make or break an electrical contact therebetween. The switch arms thus form an electrical switch that controls the operation of the appliance. In some timers, switch arms are mounted in groups of three so as to form a single pole, double throw switch or other more complex switching arrangement. 
   The contacting surfaces of the arms are often coated with expensive metals such as silver alloy to facilitate good contact between the arms and minimize the effects of corrosion. To further facilitate contact between the arms, in some timers a contact rivet is included on each arm, extending toward the opposite arm, such that contact is made between the rivets on the switch arms. To avoid the cost of making and assembling this additional contact rivet, in other timers the arms are stamped with a “dimple”, i.e., a raised section of metal that extends toward the opposite arm to form a contact surface. This approach is useful in containing costs where it can be applied; however, where the switch arms are mounted in a group of three, the central switch arm cannot be dimpled to form a contact, since the dimple can only extend in one direction relative to the surface of the central switch arm and the central switch arm must make contact with the arms above and below it. Accordingly, when three switch arms are stacked in this manner, the central switch arm must be outfitted with a contact rivet in order to have surfaces that extend toward both neighboring arms, increasing costs. 
   In a typical timer there are multiple switches and thus multiple groups of two or more switch arms that interact with the cam surfaces on the cam wheel or drum. In such timers, often the switch arms are mounted in “wafers”; that is, the respective upper arms of each switch is mounted in a first wafer, and the respective lower switch arms of each switch is mounted in a second wafer. The wafers are typically formed of plastic molded over the ends of the switch arms opposite their cam-actuated surfaces. To mount the switch arms for actuation by the cams of the wheel or drum, the wafers are stacked atop each other, and affixed to the timer housing, so that the arms are suspended in a specific position relative to the wheel or drum of the timer. 
   To assure proper switch functions, the position of the switch arms relative to the wheel or drum, must be controlled to fairly tight tolerances. This means that the size of the wafers, and the position of the switch arms in the wafers, and the mountings to which the switch wafers are mounted, must also be controlled to tight tolerances. Unfortunately, where two or three wafers are stacked to create switch groups of two or three arms, the necessary tolerances become difficult to satisfy, most particularly because it is difficult to maintain a tight tolerance in the switch mounting surfaces that span a long distance, e.g., the entire height of a stack of three wafers. Manufacturing wafers and mountings to sufficiently tight tolerances is thus difficult and expensive. 
   The switch arms in a wafer are typically made of the same material. Inexpensive metals such as alloy brass are typically used to make switch arms for low current applications. In higher current applications, more expensive, more highly conductive metals such as copper alloy are used to minimize resistance and the resultant heat and energy loss. Unfortunately, even if only one pair of switch arms carries high current, the need for more expensive metals in the switch arms substantially increases the cost of the timer. 
   The terminal ends of the switch arms are operatively connected to various components of an appliance such as a dryer, in order to control the function of that particular component. Individual leads for each of the electrical components are provided by these terminals and each individually fit to one or more of wafers forming part of a switch block made up of the stacked wafers and switch arms. The labor involved in connecting individual connectors to individual terminals is relatively intensive. Further the use of separate individual connectors increases the likeliness of incorrect wiring of the switch into the appliance. Additionally, one may appreciate that the individual fitting of each lead to a terminal is time consuming. 
   The appliance operator typically sets the timer using a knob that extends outside of the timer housing and can be grasped by the operator. In a typical clotheswasher timer, for example, the operator rotates the knob in a forward direction, thereby rotating the cam wheel or drum in a forward direction, until the cam wheel or drum is in an appropriate initial position to begin a timed operation cycle. The user then presses a button, or moves the knob axially to initiate the cycle and also start the timing motor. 
   As is familiar to most users of household appliances, a substantial clatter is generated by the interaction of the cam-operated switches and drive pawls and/or any one-way or ratchet clutch when the timer is advanced to the appropriate position to begin a cycle. For example, the drive pawls click across the pawl-driven surfaces of the cam wheel or drum as the wheel or drum is advanced, and at the same time, the cam operated switch arms click as they are opened and closed by the cam surfaces as the wheel or drum is rotated, and any one-way clutch also clicks. The resulting noise is unpleasant, and is accompanied by substantial irregular tactile feedback. 
   A second difficulty is that the timer must be set by rotation in a single direction. This constraint arises from the fact that the cam surfaces on the drum or wheel typically are formed with sharp drop-offs so that switches are closed or opened rapidly. Reverse rotation of the cam will cause the cam surfaces on the drum or wheel to bind against the switch arms, preventing further reverse rotation and potentially damaging the timer. To prevent damage by reverse rotation timers often include a rachet pawl or other mechanism to block reverse rotation; of course, this structure only enhances the clatter generated during forward rotation of the timer for setting. 
   Recently, so-called “quiet set” drum-type timers have been introduced. In these timers, a mechanism lifts the switch arms and drive pawls from the surface of the drum to disengage the drum from the pawls during setting. This permits the drum to be rotated manually without clatter from the pawls and switch arms, and also permits bi-directional rotation during setting because the pawls and arms are disengaged from the drum surface. 
   Unfortunately, users have become accustomed to receiving tactile feedback when setting a timer, and may prefer to receive such feedback. A “quiet set” timer, therefore, may be perceived as undesirable as compared to a timer that does provide tactile and audible feedback such as a prior non-“quiet set” timer. 
   Additionally, timers, timer functions, and methods for settings and using timers often varies from appliance to appliance. Such differences result in timers which are not user friendly especially for those appliances which are used in concert with one another, such as clotheswashers and dryers. Thus, it would be desirable to include timers on appliances in a manner more friendly to the user. 
   SUMMARY OF THE INVENTION 
   In accordance with the present invention, the drawbacks and difficulties with known cam-operated timers are overcome. In one aspect, the present invention does this is by providing electromechanical timers for various appliances that are nearly identical from the user standpoint. For example, the timer of the present invention may be provided on both a clotheswasher and a dryer in order to facilitate ease of operation between those appliances. Additionally, the concept of equivalent, or matched, timers on a clotheswasher and a dryer is of advantage to those who market such appliances. The matched timers increases the likelihood that a customer who purchases one of the appliances, for example the clotheswasher, will purchase the other (the dryer). 
   Each timer is set in the same or similar manner and the washing or drying action are both started in the same or a similar manner. In the washer a knob attached to a shaft in the timer which is indexed inwardly in order for the shaft to engage a cam-carrying member. The knob can then be rotated to cooperatively rotate the shaft and cam-carrying member to set the washer to a particular cycle. The knob may then be indexed outwardly in order to start the timer and cycle mechanism of the washing machine. The timer provided on the dryer may operate in a manner identical to that of the timer provided on the clotheswasher. The timer on the dryer may also include alternate methods of operation. A first alternate embodiment adds an additional separate start switch which must be actuated to start the dryer. In a second alternate embodiment, the knob traverses a slightly longer distance when indexed outwardly and is held for a period of time in order to start the dryer. In this second alternate embodiment, when released, the knob returns to its original position. Axial movement of the knob and shaft in the opposite direction than that described above is also possible in yet an alternate embodiment. Other combinations of operation of the timer of the present invention are possible depending on the method by which the user turns off the machine or permits the machine to automatically turn off. The timer may also include various combinations of model specific touch, including quiet set features, textured feel features, and a connector with both heavy duty and standard duty terminals. Such features will be described below. 
   In a first aspect, the invention features a cam-operated timer having a setting feedback function. The timer includes an audible and/or tactile feedback member that is not part of the drive mechanism nor part of the cam-actuated switches of the timer (but may include parts of the cam-carrying member). The audible and/or tactile feedback member is positioned within the timer to engage a textured surface that rotates with or in response to rotation of the timer&#39;s cam-carrying member (e.g., the timer&#39;s cam wheel or drum), so that upon rotation of the cam-carrying member, the audible and/or tactile feedback member produces desired audible and/or tactile feedback. 
   In the disclosed specific embodiment, the audible and/or tactile feedback member is a shaped spring member, e.g., a “V”-shaped or “U”-shaped member, which engages to a textured surface comprising a series of ridges or teeth. The textured surface may be carried on the cam-carrying member itself, and the audible and/or tactile feedback member is mounted to the housing so as to engage the textured surface of the cam-carrying member at all times. In other contemplated embodiments, the audible and/or tactile feedback member may be engaged to other members that rotate with the cam-carrying member, rather than to the cam-carrying member itself. Furthermore, the audible and/or tactile feedback member need not always engage to the associated textured surface, but may only engage the associated textured surface when an operator places the timer in a manual setting mode (by, e.g., axially displacing a shaft that serves as the axis of rotation for the cam-carrying member). 
   In the disclosed specific embodiment, the timer further includes an actuator for engaging the cam-actuated switches and moving the cam-actuated switches away from the cam surfaces of the cam-carrying member when the operator places the timer in a manual setting mode. Further, a clutch is included in the drive mechanism for permitting slip in the drive train between the timing motor and cam-carrying member when the operator places the timer in a manual setting mode. When these elements are utilized, the sole source of audible and/or tactile feedback to the operator when manually setting the timer is the audible and/or tactile feedback member, so that the “feel” of the timer during setting can be tightly controlled and customized. In particular, different models of an appliance line can be distinguished by the audible and/or tactile feel provided by the timer during manual setting. A timer used in the top of the line appliance model can be provided with a feel that is found to be most desirable to typical customers. Gradations of feel can be provided to different timers on lower end models. 
   The textured surface of the cam-carrying member, and the surface of the audible and/or tactile feedback member that engages to the textured surface, can be configured in various ways to provide the desired audible and/or tactile feedback. Specifically, the ridges on the textured surface and on the engaging surface of the audible and/or tactile feedback member can be made relatively smooth and rounded, or relatively sharp-edged, to change the audible and/or tactile feedback. Furthermore, the spacing between the ridges or teeth on the audible and/or tactile feedback member can be made wider or narrower, regular or irregular, intermittent or random, to change the audible and/or tactile feedback. 
   Another aspect of the invention relates to the clutch included in the drive mechanism. As noted above, the clutch permits slip in the drive train between the timing motor and cam-carrying member when the operator places the timer in a manual setting mode. When the timer is in its run mode, the clutch also permits forward rotation of the cam-carrying member independently of the timing motor, but prevents independent reverse rotation of the cam-carrying member. 
   In the disclosed embodiment, the clutch is in the form of a first rotating member and a second rotating member that are included in the drive train between the timing motor and cam-carrying member. The first and second rotating members each include a plurality of protrusions about their surface. When the first and second rotating members are axially aligned, the protrusions of the first rotating member mesh with the protrusions of the second rotating member so as to engage the second rotating member and force reverse rotation of the second rotating member upon reverse rotation of the first rotating member, but permit slip between the second rotating member and first rotating member upon forward rotation of the first rotating member. When the first and second rotating members are not axially aligned, there is no engagement between the protrusions of the first and second rotating members. 
   In the specific embodiment that is disclosed, the first and second rotating members are gears in the drive train between the timing motor and cam-carrying member. The first rotating member has a plurality of clutch teeth positioned about an inside periphery thereof, and the second rotating member has a plurality of clutch prongs sized to engage the clutch teeth. The first rotating member is annular and defines an orifice about its axis of symmetry. The second rotating member is placed through the orifice so that the clutch prongs of the second rotating member can be axially aligned with the clutch teeth of the first rotating member. 
   The clutch prongs are circumferentially spaced so that the prongs do not simultaneously align with the clutch teeth. Specifically, there are m prongs circumferentially spaced about the second rotating member, and n teeth circumferentially spaced about the first rotating member; the prongs and teeth are arranged such that exactly one prong aligns with exactly one tooth every 360/m·n degrees of relative rotation of the first and second rotating members. In the disclosed specific embodiment, there are five prongs (m=5) and twenty-four teeth (n=24), so that a prong aligns with a tooth every three degrees of relative rotation of the first and second rotating members. Furthermore, the prongs are spaced so that, from a position where a prong on the second rotating member is aligned with a tooth on the first rotating member, three degrees of relative rotation will bring a prong on approximately the opposite side of the second rotating member into alignment with a tooth on the first rotating member. 
   A third aspect of the present invention relates to structures of the switch arms in the timer. Specifically, the contacting surfaces of one or several switch arms are lanced, that is, there is a tear in the surface of the switch arm, and adjacent the tear a first portion of the contact surface of the arm is deflected away from the surface of the switch arm in a first direction. This structure provides a sharp contact edge that permits the switch arm to make good contact with adjacent switch arm(s) while reducing the effects of corrosion, without resorting to the use of expensive contact metal coatings. 
   In the illustrated specific embodiment of the invention, a second portion of the contact surface adjacent to the tear in the switch arm, extends away from the surface of the switch arm in a second direction opposite to the first direction. Thus, there are two lanced portions in the contact area of the switch arm extending in opposite directions, so that a switch arm mounted between two other switch arms will have extending portions suitable for making contact with both other switch arms. 
   A fourth aspect of the present invention relates to the mounting of the switch arms to the timer housing. The housing includes first and second locating areas for receiving first and second switch arm wafers. A first switch arm wafer is mounted to the housing and rests against the first locating area, and a second switch arm wafer is stacked atop the first switch arm wafer and rests against the second locating area. In this manner, the variation in the position of each switch arm wafer is reduced. The effect of inaccuracies in the molding of the wafer or of the housing can be minimized since each switch arm wafer is separately located within the housing. 
   In the disclosed specific embodiment of this aspect, the first and second locating areas comprise first and second steps, and the first and second switch arm wafers are sized such that the first switch wafer fits to the first step and inside of the second step, and the second switch arm wafer fits to the second step and overlaps the first. In addition, the first and second locating areas comprise sections of one or more posts, each post having a first section with a first larger diameter and a second section with a second smaller diameter. The first switch wafer defines a locating hole with a diameter larger than the first diameter, and the second switch wafer defines a locating hole with a diameter smaller than the first diameter but larger than the second diameter, so that the first switch wafer fits over the first section of each post whereas the second switch wafer fits over the second section of each post. In embodiments with three or more switch wafers (such as is illustrated below), additional steps may be included to accurately locate those wafers as well. 
   In alternative embodiments, in place of steps, there may be a continuous ramp, such that the first switch wafer is sized to intersect the ramp in a first locating area, but the second switch wafer is sized to intersect the ramp in a second locating area. Furthermore, in place of stepped posts, there may be one or more continuously tapering posts, such that the first switch wafer&#39;s locating hole causes the first switch wafer to engage the continuously tapering post in a first locating area, and the second switch wafer&#39;s locating hole causes the second switch waver to engage the continuously tapering post in a second locating area. 
   A further aspect of the invention relates to the arrangement of switch arms in the wafers. Specifically, at least one of the switch arm wafers includes switch arms made of different metals. This allows high current and low current switches to be mixed in a single set of arms, where the high current switches are formed with wider and/or more expensive metal arms, and/or with a more heavy-duty contact, and the lower current arms are made with narrower and/or less expensive metal arms, and/or with a less heavy-duty contact. 
   Along with the differing switch arm materials and widths for handling various current capacities, the timer of the present invention also includes alternate embodiments of the structure and location of the switch arms. In one embodiment, the timer includes a configuration of two or more arrangements of switch arms, each arrangement capable of carrying a different current. These arrangements are located on either side of an axial center line of the program cam with the tips of at least one set of the switch arms overlaying a semicircular area of the cam. The tips of at least the other set overlie the semicircular area of the cam, on the opposite side of the axial center line relative to the first semicircular area. Alternatively, the arrangement of switch arms may be entirely located on one side of the axial centerline of the program cam, with the tips of those switch arms overlaying the corresponding semicircular area of the cam. 
   The timer of the present invention also includes single point connections for electric dryer timers wherein the switch arms, as discussed above, form a connector or a plurality of connectors which are connected to the clothesdryer by a single connector block. The block including this plurality of individual connectors is mounted and/or molded in an insulating structure with each individual connector attached to a wire or wires connected to various functions of the dryer. 
   Alternatively, in those embodiments of the timer of the present invention including arrangements of switch arms located on either side of an axial center line or on the same side of an axial center line, the timer may include a plurality of connector blocks. Each of these connector blocks is connected to at least two of the switch arms and includes a plurality of individual connectors mounted or molded in an insulating structure with each individual connector attached to a wire. A wire is connected to various components and/or functions of the dryer. 
   An additional aspect of the invention relates to the arrangement of the geartrain and timing motor. The timing motor comprises a stator plate and a rotor mounted for rotation in the stator plate. The geartrain comprises meshing gears positioned on both opposite sides of the stator plate for providing a gear reduction of the rotation of the timing motor. By mounting the geartrain directly to the timing motor stator and including meshing gears on both opposite sides of the stator plate, the size of the timing motor and geartrain assembly can be substantially reduced as compared to prior systems in which the timing motor is contained within a separate housing and the geartrain is positioned entirely outside of this housing. 
   Another aspect of the timer of the present invention is the ability of the timer to provide a three-contact switch in which all three contacts may simultaneously be connected together. This capability can have useful application in some environments, and potentially reduce the number of switches that are needed. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an exploded view of the cam-operated timer of the present invention. 
       FIG. 2A  is an exploded view of the flat motor and split geartrain assembly of the timer. 
       FIG. 2B  is a perspective view of the flat motor and split geartrain assembly of  FIG. 2A , particularly depicting the geartrain sub-assembly journalled in the front housing of the timer. 
       FIG. 2C  is a perspective view of the flat motor and split geartrain assembly of  FIG. 2A , particularly depicting the geartrain sub-assembly and main cam as they would be arranged when journalled in the rear housing. 
       FIG. 2D  is a perspective view of the clutch mechanism, geartrain and main cam of the timer. 
       FIG. 2E  is an exploded view of the clutch mechanism, geartrain and main cam of the timer. 
       FIG. 2F  is a view of the outline of the clutch teeth of the fifth stage gear superimposed on the outline of the clutch prongs of the fifth stage pinion when the prongs are in their relaxed position. 
       FIG. 3  is a perspective view of the rear housing of the timer containing the flat motor and geartrain sub-assembly. 
       FIG. 4A  is a perspective view of a switch arm wafer having a plurality of switch arms including electrical contacts and cam followers. 
       FIG. 4B  is an enlarged view of the switch wafer mounting area of the rear housing shown in FIG.  3 . 
       FIG. 4C  is a perspective view of the rear housing of  FIG. 4B  containing a plurality of switch arm wafers in a stacked configuration. 
       FIG. 5A  is a perspective view of lanced contact faces on switch arms of the timer. 
       FIG. 5B  is a perspective view of insert molded cam followers attached to switch arms of the timer. 
       FIG. 6  is a perspective view of the front housing of the timer, depicting the hub extension for testing of the timer following assembly.  FIGS. 7A-7F  are partial cut-away views along line  7  in FIG.  6 . 
       FIG. 7A  is an exploded view of the setting feedback system of the timer of the present invention. 
       FIG. 7B  is a partially cut-away view of the timer of the present invention depicting the setting feedback system in the setting mode. 
       FIG. 7C  is a partially cut-away view of the timer of the present invention as shown in  FIG. 7B  wherein components of the setting feedback system have been sectioned in half to display the interaction of the latch and key mechanisms of the setting feedback system. 
       FIG. 7D  is a partially cut-away view of the timer of the present invention depicting the positioning of the setting feedback system during the operational mode of the timer. 
       FIG. 7E  is a partially cut-away view of the timer of the present invention depicting the positioning of the setting feedback system during the operational mode of the timer, wherein components of the setting feedback system have been sectioned in half to display the interaction of the latch and key mechanisms of the setting feedback system. 
       FIG. 7F  is a partially cut-away view of the timer of the present invention depicting the travel limiting boss and the setting feedback system in the setting mode. 
       FIG. 7G  is a perspective view of the main cam of the timer of the present invention, depicting the custom feel profile of the cam with a “V”-shaped follower providing tactile and/or audible feedback. 
       FIG. 8  is a perspective view of the timer of the present invention, including switch arms mounted in switch wafers and a connector block for attachment to the terminals of the switch arms. 
       FIG. 9  is a perspective view of the timer of the present invention depicting an alternate embodiment having two switch blocks located on one side of an axial center line of the cam carrying member. 
       FIG. 10  is a perspective view of the timer of the present invention depicting an alternate embodiment of the two switch block configuration, having switch blocks located on opposite sides of the axial center line of the cam carrying member. 
       FIG. 11  is a perspective view of the timer of the present invention depicting the alternate embodiment having two switch blocks, with each switch block located on opposite sides of an axial center line of the cam carrying member. 
       FIG. 12  is a perspective view of a connector block in accordance with the principles of the present invention, depicting connecting points for the terminals of the switch arms. 
       FIG. 13  is a perspective view of the connector block of  FIG. 12  in accordance with the principles of the present invention, depicting the opposite face of the connector block. 
   

   DETAILED DESCRIPTION 
   The present invention avoids the drawbacks and solves the problems discussed in the background of the invention above. As shown in  FIG. 1 , the present invention provides a cam-operated timer  10  including a flat timing motor  12  and split geartrain  14  assembly, a one-way clutch mechanism  16 , switch arms  18  for handling both standard and heavy duty electrical operations, a method of locating switch arm wafers  20  in the timer  10 , electrical contacts  22  having lanced faces  24 , insert molded arm cam followers  26  attached to the switch arms  18 , a cam hub extension  28  for testing the operation of the timer  10  following assembly, and a setting feedback system  30 . 
   More particularly, depicted in  FIG. 1  is the illustrated embodiment of the cam-operated timer  10  of the present invention. As can be seen, the timer  10  includes a front housing  34  and a rear housing  36 . Contained within the front housing  34  and rear housing  36  are the various components of the timer  10 , including the flat timing motor  12  and split geartrain  14  assembly. A Westclox motor, including a flat stator plate with a rotor is known in the prior art. 
   The timing motor  12  and geartrain  14  drive the main cam  38  of the timer  10 . A plurality of program cam surfaces  40  are continuous about and integral with the face of the main cam  38  and provide a geometry to be contacted by the cam followers  26  of the switch arms  18 . As the main cam  38  rotates, the varying contours of these program cam surfaces  40  move the switch arms  18  of the timer  10  between neutral and offset positions. A plurality of these switch arms  18  are housed in a common wafer  20 . 
   The movement of the switch arms  18  relative to one another results in the activation and deactivation of electrical circuits which operate the cycles of the appliance (not shown) to which the timer  10  is associated. The wafers  20  containing switch arms  18  are located in the rear housing  36  of the timer  10  over molded stepped plastic posts  128  in order to increase accuracy in the timer  10  of the present invention. The switch arms  18  include insert molded cam followers  26  which actively contact and follow the geometry of the program cam surfaces  40  of the main cam  38 . The switch arms  18  may be constructed of various materials depending on their use. 
   The cam-operated timer  10  of the present invention further includes a hub extension  28  protruding outside the front housing  34  of the timer  10 . This hub extension  28  is integral with the main cam  38 . Following assembly of the timer  10 , the hub extension  28  is used for testing the operation of the switch arms  18  of the timer  10 . By the particular configuration of the components of the hub extension  28 , all timers produced may be tested by the same testing device following assembly. 
   The cam-operated timer  10  of the present invention also includes a setting feedback (SF) system  30 . By this SF system  30 , cam followers  26  are lifted off the program cam surfaces  40  so that a single shaped leaf spring, e.g., a “V”-shaped (or alternatively “U”-shaped) follower  238  remains in contact with a custom feel profile  236  on the side of the main cam  38  proximal the front housing  34 . This “V”-shaped follower  238  acts as a tactile and/or audible feedback member, by engaging the textured surface of the custom feel profile  236  to impart such tactile feel to the user during rotation of the main cam  38 . Each of the above-described features of the cam-operated timer  10  of the present invention will be discussed in greater detail below. 
   As shown in  FIGS. 2A through 2C , the illustrated embodiment of timer  10  of the present invention includes a timing motor  12  and geartrain  14  assembly to drive the main cam  38  of the timer  10 . The timing motor  12  includes a stator plate  42  and an L-bracket  44 . The stator plate  42  is formed from a flat steel stamping, and includes an orifice  46 , the circumference of which is bounded by a plurality of stator poles  48 . The timing motor  12  of the present invention also includes a rectangular bobbin coil  50  having square wire terminals  52  that plug into buss bars  53  in the timer  10 . The stator plate  42 , L-bracket  44  and bobbin coil  50  are located in the rear housing  36  of the timer  10  over molded plastic posts  54  (see FIG.  3 ). A locating hole and plurality of details  56  are formed through the flat steel stamping of the stator plate  42 . In assembling the stator plate  42  into the rear housing  36  of the timer  10 , the molded plastic posts  54  (see  FIG. 3 ) integral with the rear housing  36  are disposed through the locating hole and details  56  in the stator plate  42 . 
   The timing motor sub-assembly also includes a rotor  58 , which is disposed within the orifice  46  in the flat steel stamping of the stator plate  42 . The rotor  58  includes a steel rotor post  60  extending through the body of the rotor  58  in a direction substantially perpendicular to the plane of the stator plate  42 . This rotor post  60  is journalled in a socket  72  (see  FIG. 3 ) molded in and integral with the rotor holding clip  68  of the timer  10 . The opposite end of the rotor post  60  includes a rotor pinion  62  operatively connected to a first stage gear  64  of the geartrain  14 . The rotor  58  is free to rotate on rotor post  60  within the housing of the timer  10 . The rotor  58  additionally includes a plurality of rotor poles  66  along its outer circumference. 
   The rotor  58  is held in place by a rotor holding clip  68  which spans the orifice  46  in the stator plate  42 . The rotor holding clip  68  is disposed through air gaps  70  in the stator plate  42  formed in orifice  46  between stator poles  48 . The section of the rotor holding clip  68  spanning orifice  46  includes a socket  72  (see  FIG. 3 ) in which rotor post  60  is disposed to provide an axis of rotation for rotor  58 . The rotor holding clip  68  also prevents the rotor  58  from falling out during final assembly. 
   The operation of the timing motor occurs by a magnetic field flowing around and through the stator poles  48  and rotor poles  66 . The rotor  58  has a single permanent magnet (not shown) within its body producing flux along the direction of the axis of rotation. Electrical current is applied to the winding of the bobbin coil  50  attached to the stator plate  42 , producing alternating flux passing through the stator plate  42 . This causes the rotor  58  to move in synchrony with the flux in the stator plate  42 . The stator poles  48  in the surface of the stator plate  42  adjacent to the position of the rotor  58  help to focus the flux. Since there is no forming required, rotor  58  to stator pole  48  air gaps can be controlled much more accurately than in the traditional round cup style timing motor where the poles are formed and susceptible to bending. The bobbin coil  50  is also much more efficient in this flat timing motor  12  than in a round timing motor. Since the magnet wire is wrapped around only the steel instead of around the rotor  58 , much less wire is required to achieve magnetic saturation of the stator plate  42 . 
   The geartrain  14  driven by the timing motor sub-assembly provides a constant speed of rotation to the main cam  38  and is split on both sides of the stator plate  42 . As a result, all gear and pinion meshes are completed during sub-assembly operations and the only blind assembly is mating a splined shaft  74  on a third stage pinion  76  with a splined socket  78  on a third stage gear  80 . The rotor pinion  62 , first stage gear  64 , a first stage pinion  82 , a second stage gear  84 , a second stage pinion  86  (shown in  FIG. 2C ) and the third stage gear  80  are located over molded posts  54  (see  FIG. 3 ) or sockets (not shown) integral with the rear housing  36  of the timer  10 . These components are assembled and the timing motor sub-assemblies positioned over them and staked in place. The third stage pinion  76 , a fourth stage gear  88 , a fourth stage pinion  90 , a fifth stage gear  92  and a fifth stage pinion  94  and the main cam  38  are assembled over molded posts or sockets (not shown) in the front housing  34  of the timer  10 . The rear housing  36  is then inverted and snapped in place over the front housing  34 , capturing the entire timing motor  12  and geartrain  14 . During the final assembly operation, the splined shaft  74  on the third stage pinion  76  mates with a splined socket  78  on the third stage gear  80  completing the geartrain  14 . 
   In operation, as the rotor  58  is driven by magnetic flux across stator poles  48  and rotor poles  66 , the rotor pinion  62  rotates, thereby rotating the first stage gear  64  to which rotor pinion  62  is operatively connected. First stage pinion  82  (see  FIG. 2A ) rotates cooperatively with first stage gear  64  and in turn, rotates second stage gear  84 , to which first stage pinion  82  is operatively connected. Second stage pinion  86  rotates cooperatively with second stage gear  84  and in turn, rotates third stage gear  80 , to which second stage pinion  86  is operatively connected. Third stage pinion  76  rotates cooperatively with third stage gear  80  and in turn, rotates fourth stage gear  88 , to which third stage pinion  76  is operatively connected. Fourth stage pinion  90  rotates cooperatively with fourth stage gear  88  and in turn, rotates fifth stage gear  92 , to which fourth stage pinion  90  is operatively connected. Fifth stage pinion  94  rotates cooperatively with fifth stage gear  92  and in turn, drives the main cam  38  of the timer  10  to which fifth stage pinion  94  is operatively connected. At the same time, square wire terminals  52  of the bobbin coil  50  mate with buss bars  53  located in the front housing  34  of the timer  10 , providing two isolated electrical terminals for the timing motor under the standard switch block terminals. In this manner, assembly of the timer  10  is effected with the connection of the splined shaft  74  of the third stage pinion  76  to the socket  78  of the third stage gear  80  being the only blind assembly. This enhances the ease of assembly, thereby reducing error in assembly and subsequent failure of the timer  10 . 
   The geartrain  14  of the present invention also includes an anti-backup clip  98 . The anti-backup clip  98  is formed from plastic and is disposed about the axis of rotation of the second stage gear  84 . The anti-backup clip  98  includes an arm  100  split on opposite sides of the base  102  of the rotor pinion  62 . The base  102  of the rotor pinion  62  includes a finger  104  which protrudes from the base. The anti-backup clip  98  includes a clip finger  106  which follows the circumferential geometry of the base  102  of the rotor pinion  62  as it rotates cooperatively with the rotor  58 . The interaction of finger  104  and clip finger  106  will only permit rotation of the rotor  58  in one direction (counter-clockwise as shown in FIG.  2 C). In this manner, the proper direction of rotation of the rotor  58  is insured upon the start of the timing motor  12 . 
   In another embodiment of the cam-operated timer  10  of the present invention, the geartrain  14  may include a run indicator (not shown). Since appliances tend to make noise during operation, it is desirable to have a run indicator to determine whether the timer  10  is running. To this end, the tip of the splined third stage pinion  76  shaft has an arrow (not shown) molded on the end of it and extends through a hole (not shown) in the rear housing  36 . When viewed from the rear of the timer  10 , if the arrow is rotating (approximately one r.p.m.), the timing motor is running. 
   As depicted in  FIGS. 2A through 2E  and most particularly in  FIGS. 2D and 2E , the geartrain  14  assembly of the present invention includes a clutch mechanism  16  which allows manual rotation of the main cam  38 , only in a forward direction. During manual operation of the main cam  38 , any unchecked rotation of the cam  38  in a reverse direction may result in damage to various components of the timer  10 , particularly the switch arms  18 . To eliminate the possibility of such damage and to allow the timer  10  to be manually set by advancing the cam  38  in a forward direction, the geartrain  14  will not slip relative to the main cam  38  during attempted manual reverse rotation of the cam, thus preventing any such reverse rotation. However, the clutch mechanism  16  allows slip between the geartrain  14  and the cam  38  when the main cam  38  is manually advanced. 
   The clutch mechanism  16  for the constant speed drive system of the timer  10  of the present invention includes the fifth stage gear  92  and fifth stage pinion  94 . The fifth stage gear  92  has a series of protrusions, hereinafter referred to as clutch teeth  110 , about the inside circumference of the gear ring  112  of the fifth stage gear  92  on the face of the gear  92  most proximal to the front housing  34  of the timer  10 . The outer periphery of this gear ring  112  includes the teeth of the fifth stage gear  92  that mesh with the teeth of the fourth stage pinion  90 . The fifth stage pinion  94  includes a plurality of pinion teeth  116  disposed about the outer periphery of the fifth stage pinion  94 . These pinion teeth  116  engage teeth on a gear ring  117  disposed about the outer periphery of the main cam  38 . The fifth stage pinion  94  includes a plurality of clutch prongs  118  extending from the outer circumference of the fifth stage pinion  94  on the end distal to the pinion teeth  116 . When the fifth stage pinion  94  is placed through an orifice  120  located through the center of the fifth stage gear  92 , the pinion teeth  116  nest with the teeth on the gear ring  117  on the main cam  38  on the side of the fifth stage gear  92  distal to the front housing  34  of the timer  10 . The end of the fifth stage pinion  94  including the clutch prongs  118  is thus disposed on the side of the fifth stage gear  92  most proximal to the front housing  34  of the timer  10 . During this engagement, the clutch prongs  118  of the fifth stage pinion  94  abut the clutch teeth  110  located about the inner circumference of the fifth stage gear  92 . In this relationship, each clutch tooth  110  includes a flat side  122  that is substantially perpendicular to the longitudinal axis of the clutch prong  118  to which it is associated and a ramped side  124  that is substantially parallel to the longitudinal axis of the clutch prong  118  to which it is associated. 
   Referring to  FIGS. 2D and 2E , the clutch mechanism  16  of the timer  10  of the present invention functions as follows: During normal operation of the timer  10 , as the fourth stage pinion  90  rotates (clockwise in  FIG. 2D ) and drives the fifth stage gear  92  (counter-clockwise), the clutch teeth  110  move cooperatively with the fifth stage gear  92  such that the flat sides  122  of the clutch teeth  110  abut the distal tips  126  of the clutch prongs  118  of the fifth stage pinion  94 . As discussed, these flat sides  122  are substantially perpendicular to the longitudinal axis of the clutch prongs  118  such that the prongs  118  cannot slip past the clutch teeth  110 . This causes the fifth stage pinion  94  to rotate cooperatively (counter-clockwise) with the fifth stage gear  92 . The fifth stage pinion  94  in turn is operatively connected to a gear ring  117  on the periphery of the main cam  38 , thereby resulting in the forward rotation of the main cam  38  (clockwise). Thus, during normal operation of the timer  10 , the geartrain  14  and main cam  38  of the timer  10  are engaged. 
   In the situation in which the main cam  38  is advanced manually in order to set the timer  10 , the progression of rotation proceeds from main cam  38 , to fifth stage pinion  94 , to fifth stage gear  92 , and so on back down the geartrain  14 . Thus, the fifth stage pinion  94 , being operatively connected to the main cam  38 , will rotate (counter-clockwise in  FIG. 2D ) as the main cam  38  is advanced (clockwise). As the fifth stage pinion  94  rotates, the clutch prongs  118  of the fifth stage pinion  94  abut and slide over the ramped side  124  of the clutch teeth  110 . As discussed, these ramped sides  124  are substantially parallel to the longitudinal axis of the clutch prongs  118  to which they are associated, thus offering little resistance to the movement of the prongs  118  with respect to the clutch teeth  110 . This action causes the clutch  16  to slip and allows the timer  10  to be manually set due to slip permitted by the geartrain  14  relative to the main cam  38 . 
   In the situation in which the main cam  38  is attempted to be reversed manually, the clutch mechanism  16  will prevent any such reverse rotation of the main cam  38 . Upon attempted reverse rotation of the main cam  38  (counter-clockwise in FIG.  2 D), the fifth stage pinion  94  will rotate (clockwise) cooperatively with the main cam  38  so that the distal tips  126  of the clutch prongs  118  abut the flat sides  122  of the clutch teeth  110  that are substantially perpendicular to the longitudinal axes of the prongs  118 . In this position, the clutch prongs  118  cannot slide over the clutch teeth  110 . Thus, the clutch  16  does not slip, and the geartrain  14  does not permit slip relative to the main cam  38 . The forces applied due to friction and the gear ratio of the geartrain  14  thus prevent reverse manual rotation of the main cam  38 . 
   Referring now to  FIG. 2F , details of the interaction of the clutch teeth  110  on the fifth stage gear  92  and clutch prongs  118  on the fifth stage pinion  94  can be explored.  FIG. 2F  shows the outline of the teeth of fifth stage gear  92  superimposed on the outline of the prongs  118  of fifth stage pinion  94  in its relaxed position. This shows the relative sizes of these parts. It will be appreciated that when the prongs  118  of the fifth stage pinion  94  are meshed with the teeth  110  of fifth stage gear, the prongs will be flexed (with the exception of the single prong that may be aligned as is the case with prong  118   a  in FIG.  2 F). 
   The clutch prongs  118  are circumferentially spaced so that the prongs  118  do not simultaneously align with the clutch teeth. Specifically, there are five prongs circumferentially spaced about the fifth stage pinion  94 , and twenty-four teeth  110  circumferentially spaced about the fifth stage gear  92 ; the prongs  118  and teeth  110  are arranged such that exactly one prong  118  aligns with exactly one tooth  110 , and drops into engagement with the tooth in the manner of prong  118   a  and tooth  110   a , every three (360/24·5) degrees of relative rotation of the fifth stage pinion  94  and fifth stage gear  92 . 
   Furthermore, the prongs  118  are spaced so that, from a position where a tooth and prong are aligned, three degrees of relative rotation will bring another prong  118  and tooth  110 , on approximately the opposite side of the fifth stage pinion  94  and fifth stage gear  92 , into alignment. As seen in  FIG. 2F , prong  118   a  on the fifth stage pinion  94  is aligned with a tooth  110   a  on the fifth stage gear  92 . Three degrees of relative counterclockwise motion of fifth stage pinion  94  relative to fifth stage gear  92  will bring prong  118   b  into alignment with tooth  110   b . A further three degrees of relative motion will bring prong  118   c  into alignment with tooth  110   c . Another three degrees will bring prong  118   d  into alignment with tooth  110   d . A final three degrees of motion will bring prong  118   e  into alignment with tooth  110   e . This allows for a maximum of three degrees of backlash in the clutch, which is desirable to prevent damage from reverse motion of the cam. Furthermore, if a heavy load is placed on the clutch such that the currently engaged prong is flexed, after only three degrees of reverse rotation, a second prong  118  will engage with its corresponding tooth  110  on the opposite side of the pinion  94  and gear  92 , causing the torque load to be shared between two prongs on opposite sides. 
   Referring now to  FIG. 3 , the flat stator plate  42 , L-bracket  44  and rotor  58  of the timing motor sub-assembly  12  are depicted as mounted in the rear housing  36  of the timer  10  over molded plastic posts  54 . Additionally, stepped locating posts  128  and stepped walls  130  are shown. These posts  128  and walls  130  are used to locate wafers  20  containing a plurality of switch arms  18  in the rear housing  36  of the timer  10 . During normal operation of the timer  10 , as the main cam  38  advances, the program cam surfaces  40  on the face of the main cam  38  result in movement of the switch arms  18 . The movement of the switch arms  18  causes electrical contacts  22  (see  FIGS. 4A ,  5 A) to be made, thereby operating the cycle of the appliance to which the timer  10  is associated. 
   As shown more particularly in  FIGS. 4A through 4C , the switch arms  18  of the timer  10  are contained in a common switch arm wafer  20 , which is disposed over plastic posts  128  in the rear housing  36  of the timer  10 . The wafer  20  is injection molded from a suitable thermoplastic material, and carries a plurality of switch arms  18 . The wafer  20  of the illustrated embodiment of the present invention is of a generally rectangular shape, having an end face  140 , a terminal face  142  and two slides  132 ,  134  which abut walls  136 ,  138  integral with the rear housing  36 . The switch arms  18  are molded into the wafer  20  with distal ends  144  (see  FIG. 4A ) projecting as cantilevers from the end face  140  of the wafer  20 . Terminals  146  of the switch arms  18  project oppositely from the terminal face  142  of the wafer  20 . The switch arm wafer  20  additionally includes a locating hole  148  and a locating notch  150 , through which the plastic locating posts  128  are disposed. The wafer  20  also includes wafer arms  152  which extend from the end face  140  of the wafer parallel to and in the same direction as the distal ends  144  of the switch arms  18 . In the illustrated embodiment of the timer  10  of the present invention, three switch arm wafers  154 ,  156 ,  158  are located in the rear housing  36  of the timer  10  in a stacked configuration. Each switch arm  18  molded into a wafer  20  may be made of the same material as or different materials from the other switch arms  18 . 
   Referring to  FIG. 4A , the structure of switch arms  18  contained within a wafer  20 , is shown. In the illustrated embodiment of the timer  10  of the present invention, at least one of the switch arms  18  is made of a different size and material than the remainder of the switch arms  18 . The switch arm wafer  20  shown includes a plurality of standard switch arms  160  and one heavy duty switch arm  162 . As developed in the background of the invention, the switch arms  18  of quick connect appliance timers  10  are generally all made of the same material and have terminals that are 0.125 inches wide by 0.020 inches thick. Such switch arms  18  operate well for applications where the electrical loads are handled well by standard alloy brass material and a ⅛ inch terminal size. In certain appliances however, such as an electric dryer, switch arm materials and terminals capable of handling greater heater loads in addition to the more typical loads of other appliances, may be necessary. In order to handle such increased current requirements, the timer  10  of the present invention includes at least one heavy duty switch arm  162 . This heavy duty switch arm  162  is made of a material with better electrical properties than standard alloy brass. An example of such a material would be copper alloy  194  or  197 . The heavy duty switch arm  162  of the present invention is also greater in width than the standard switch arms  18 . In the illustrated embodiment of the present invention, the heavy duty switch arm  162  is about ¼ inch wide. Since copper alloy is more expensive than brass alloy, the copper alloy is used only for the heavy duty switch arms  162  required to control the greater current requirements, while using less expensive brass alloys for the remainder of applications of the standard switch arms  160 . 
   In the illustrated embodiment of the timer  10  of the present invention one heavy duty switch arm  162  is inserted molded with a plurality of standard switch arms  160  in a common wafer  20 . Three wafers  154 ,  156 ,  158  will then be stacked one on top of another together to provide the switching functions required for the application of the device to which the timer  10  is associated. By providing only one heavy duty switch arm  162  with the more expensive copper alloy the costs of the timer  10  are reduced and a timer  10  which can handle increased 25 amp circuit requirements is provided. 
   Referring now to  FIGS. 8-13 , along with the heavy duty switch arm  162  having differing switch arms materials and/or different switch arm widths for handling various current capacities, the timer  10  of the present invention also includes alternate embodiments regarding the structure and location of the switch arms  18 . In the timer  10  as described above, the switch arms  18  are attached in wafers  154 ,  156 ,  158 , and, as can be seen in  FIG. 8 , are amenable to connection to a single connector block  300 . However, referring to  FIGS. 10 and 11  in particular, in a first alternate embodiment of the present invention, the timer  10  includes a configuration including two or more switchblock arrangements of switch arms  18  in wafers  20 . Each of these arrangements includes at least one heavy duty switch arm  162 , and therefore is capable of carrying greater electrical currents. These switchblock arrangements are located on opposite sides of an axial center line  314  of the program cam  38  with the distal ends of at least a first set  316  of the switch arms  18  overlaying a first semicircular area  320  of the cam-carrying member  38 . The distal ends of the second set  318  of switch arms  18  will overlie a second semicircular area  322  of the cam  38 , located on the opposite side of the axial center line  314  from the first semicircular area  318 . 
   In particular, in this first alternate embodiment of the timer  10  of the present invention, the timer  10  includes a plurality of cam-actuated switches  18 , with each switch having at least a first and second metal arm. A plurality of these arms  18  are then mounted in a first switch arm wafer  154  and a plurality of the arms  18  are mounted in a second switch arm wafer  156 . As can be seen from the Figures, these first and second switch wafers  154 ,  156  are then mounted in the timer  10  as stacked atop one another. Additionally, the timer  10  of the first alternate embodiment may include a plurality of switch arms  18  mounted in a third wafer  324  and a plurality of switch arms  18  mounted in a fourth wafer  326 . These third and fourth wafers  324 ,  326  are also stacked atop one another. The first and second wafers  154 ,  156  are then located on a first side  320  of the axial center line  314  of the cam-carrying member  38  and the third and fourth wafers  324 ,  326  are located on a second side  322  of the axial center line  314  of the cam-carrying member  38 . As a result of the respective locations of the first and second, and third and fourth wafers  154 ,  156 ,  324 ,  326 , the switch arms  18  of the first and second wafers  154 ,  156  overlie a first semicircular area  320  defined by the outer periphery of the cam-carrying member  38  and the axial center line  314 . Likewise, the switch arms  18  mounted in the third and fourth wafers  334 ,  336  overlie a second semicircular area  322  of the cam-carrying member  38  on the opposite side of that axial center line  314  from the first and second wafers  154 ,  156 . Additionally, as will be appreciated by those having skill in the art, the timer  10  may include any number of wafers. 
   In a second alternative embodiment, two or more arrangements of switch arms  18  may be located entirely on one side of the axial centerline  314  of the program cam  38 . In such a configuration, the distal ends of those switch arms  18  will overlie a corresponding semicircular area, such as  320 , of the cam  38  (as depicted in FIG.  9 ). 
   As described previously, the timer  10  of the present invention also includes single point connections for electric dryer timers wherein the switch arms  18 , as discussed above, form a connector or a plurality of connectors which are connected to the clothesdryer by a single connector block  300 . The block  300  including this plurality of individual connectors  310  is mounted and/or molded in an insulating structure  312  with each individual connector  310  attached to a wire or wires (not shown) connected to various components of the dryer. 
   Referring now to  FIGS. 8 ,  12 , and  13 , views of the connector block  300  in accordance with the principles of the present invention are shown. As can be seen, the connector block  300  is operatively connected to the terminal ends of the switch arms  18  mounted in the switch wafers  20 . The use of the connector block  300  eliminates the need for individual leads from each of the terminals to various components of the appliance, such as a dryer. In alternate embodiments of the present invention including two or more arrangements of switch blocks  316 ,  318 , as discussed above, two or more connectors may be used with each connector attaching to a respective switch block. It will be appreciated by those skilled in the art that one connector block  300  may include terminals of different widths, materials, and/or current carrying capacities, or each of the plurality of connector blocks may include terminals having switch arms of different widths, materials, and/or current carrying capacities. 
   The connector switch block of the present invention replaces the individual wiring harness connections on standard dryer timers with one connector block containing both low and high amperage circuits. The present invention eliminates the need for high amperage connectors in dryer timers and minimizes connections which need to be made. An oversized connector within the plug is used for high amperage circuits and a regular sized connector in the plug is used for low amperage circuits, thereby creating a configuration by which the connector plug may only be attached to the circuits in the correct manner. 
   In one embodiment of the invention, the quick connector block  300  includes connectors having a capacity of at least 20 amps. In an alternate embodiment of the present invention, the quick connector block  300  of the present invention has a capacity in the range of about 15 amps to about 25 amps. 
   Referring now to  FIGS. 4B and 4C , a method for locating switch arm wafers  20  in the rear housing  36  of the timer  10  of the present invention is depicted. As developed in the background of the invention, location of each switch arm  20  with respect to its counterparts in adjacent wafers  20  is critical for timing accuracy. Thus, the spacing and location of switch arm wafers  20  in their stacked configuration is integral to this accuracy. The wafer locating method of the timer  10  of the present invention eliminates the problem of maintaining tolerances over large surfaces in the switch mounting, and results in extremely accurate switch arm placement and thus, increased accuracy in the functionality of the timer  10 . 
   As shown in  FIG. 4B , plastic posts  128  are molded integral to the rear housing  36  of the timer  10 . These posts  128  include steps  164  so that each section of post  128  of equal diameter to each successive step  164  corresponds to a particular switch arm wafer  20 . In the illustrated embodiment of the present invention, each post  128  includes three sections of varying diameter to correspond to the three switch wafers  154 ,  156 ,  158  of the timer  10 . Additionally, steps  168  operating as functional contours are molded into the wall  130  of the rear housing  36  of the timer  10  defining the boundary of location of the switch arm wafers  154 ,  156 ,  158 . 
     FIG. 4C  shows the three switch arm wafers  154 ,  156 ,  158  of the illustrated embodiment of the present invention disposed over the stepped posts  128  in a stacked configuration. The stepped posts  128  have a length of 0.600 inches in the illustrated embodiment of the present invention. Since the location of all three wafers  154 ,  156 ,  158  with respect to the cam  38  is critical for timing accuracy, the posts  128  are stepped  126  to eliminate the need for draft over the 0.600 inch length. Each wafer  20  is 0.200 inches thick, so every 0.200 inch length of the locating posts  128 , the diameter of the post  128  is reduced by 0.010 inches. Thus, the locating hole  148  and locating notch  150  in the lower wafer  154  are 0.010 inches smaller in diameter than the locating hole  148  and notch  150  in the center wafer  156 . In like manner, the locating hole  148  and notch  150  in the center wafer  156  are 0.010 inches smaller in diameter than the locating hole  148  and notch  150  in the upper wafer  158 . Since only a small surface determines the position of the wafer in a direction orthogonal to the axis of rotation of the cam, a tight tolerance can be held for the location of each wafer  154 ,  156 ,  158 . 
   As discussed, each wafer  20  also includes an arm  152  on each side of the wafer  20  extending from the end face  140  of the wafer  20  in the same direction as and substantially parallel to the distal end  144  of the switch arms  18 . The end of each arm  152  is held in close relationship with the steps  168  of the wall  130  molded in the rear housing  36 . This helps to resist the force exerted on the switch arm assembly  18  during mating of a connector plug. These wafer arms  152  are of varying lengths for the upper, center and lower wafers  158 ,  156 ,  154  of the present invention in order to correspond to the walls  130  in the rear housing  36  of the timer  10 . Thus the wafer arm  152  of the lower wafer  154  is 0.020 inches longer than the wafer arm  152  of the center wafer  156 . In like manner, the wafer arm  152  of the center wafer  156  is 0.020 inches longer than the wafer arm  152  of the upper wafer  158 . As with the locating posts  128 , the steps  168  of the walls  130  facilitate holding tight tolerances over relatively long vertical distances. 
   Referring now to  FIGS. 5A and 5B , two additional aspects of the switch arms  18  of the cam-operated timer  10  of the present invention are depicted: electrical contacts  22  having lanced faces  24  and cam followers  26  molded onto the distal ends  144  of switch arms  18 . 
   As shown in  FIG. 5A , electrical contacts  22  are located on the surfaces of each of the switch arms  18  at their distal end  144 . These contacts  22  make and break electrical circuits that drive the various cycles of an appliance. As previously discussed and as shown in  FIG. 4C , the illustrated embodiment of the present invention includes three switch arm wafers  154 ,  156 ,  158  in a stacked configuration and located in the rear housing  36  of the timer  10 . Thus, three switch arms  170 ,  172 ,  174  will be disposed adjacent over one another in the illustrated embodiment of the present inception. Contacts  22  will be located on an upper switch arm  170 , a center switch arm  172  and a lower switch arm  174 . Generally, upper and lower switch arms  170 ,  174  will include contacts  22  on the surface proximal to the center switch arm  172 , and the center switch arm  172  will include contacts  22  on both its upper and lower surfaces. Thus, circuits may be made between upper and center switch arms  170 ,  172  and between center and lower switch arms  172 ,  174 . Additionally, circuits may be made between upper, center and lower switch arms  170 ,  172 ,  174  by having all three contact one another simultaneously. 
   The faces  24  of the electrical contacts  22  are lanced. Due to these lanced faces  24 , the timer  10  of the present invention may be operated, and electrical circuits completed, even though corrosion may be present on the contacts  22  of the switch arms  18  and without using expensive silver alloy as a component of the contacts  22 . 
   As developed in the background of the invention, contacts  22  used to switch low current devices often are comprised of precious metals. In such applications, the presence of any corrosion on the contacts  22  may prevent the electrical circuit from being completed. This problem is ameliorated by the high conductivity of precious metals. However, such metals are very expensive, thereby raising the cost of the product. To obviate the need for precious metals, other switches use dimpled switch arms. However, the dimpled switch arm material does not provide the corrosion resistance of a precious metal, and the dimple may only be formed on one side of the switch arm making it necessary to use a contact rivet for the center arm. 
   Lanced contacts solve the above-discussed problems. As shown in  FIG. 5A , the lower contact  176  of the center switch arm  172  is provided with a lanced face  24  having a knife edge  178 . The lanced face  24  of the opposing upper contact  180  of the lower switch arm  174  includes a similar knife edge  178  formed to contact the lower contact  176  of the center switch arm  172 . 
   By providing a knife edge  178  on the lanced face  24  of the contact  22 , an extremely high force is generated at the point of contact when the switch arms  172 ,  174  are moved as a result of the geometry of the program cam surfaces  40  to complete an electrical circuit. This high contact force on the sharp knife edges  178  of the lanced faces of contacts  176 ,  180  will cut through any corrosion or contamination that may be on the switch arms  172 ,  174 , thereby reliably completing the electrical circuit. Second, the switch arm  18  can be lanced in both directions in the same location providing a raised lanced contact face  24  for both sides of the center switch arm  172 . This eliminates the need to rivet a contact on one side of the center switch arm  172 . 
   Although all of the contacts are shown as having lanced faces, it will be appreciated that only some of the contacts may be lanced, as desired, while obtaining the benefits described above. 
   Referring now to  FIG. 5B , each switch arm  18  of the timer  10  of the present invention has an insert molded plastic cam follower  26  attached to the distal end  144  of the switch arm  18 . The cam followers  26  are molded to the upper, center and lower switch arms  170 ,  172 ,  174  and move the switch arms  18  between neutral and offset positions as a result of the geometry of the program cam surfaces  40 . Each cam follower  26  for a set of upper, center and lower switch arms  170 ,  172 ,  174  is associated with a single program surface  40  on the main cam  38 . Thus, for each trio of switch arms  18  there are three dedicated program surfaces  40  on the main cam  38 . The cam followers  26  molded to the upper arms  170  also provide an arc shield between each set of contacts  22 . This type of molded tip design allows precise control of the location of each contact  22 , improving contact air gap control and timing accuracy. 
   Since each switch arm  18  has its own molded plastic cam follower  26 , the position of each switch arm  18  is controlled independently by the program cam surface  40  on the main cam  38  to which the cam follower  26  is associated. As such, the numerous possible configurations of switch arms  18  increases the variety of types of electrical contacts that can be made in the timer  10  of the present invention. For example, a set of switch arms (upper  170 , center  172  and lower  174 ) can be operated as a conventional single-pole double-throw switch by allowing the upper and lower cam followers  182 ,  186 , associated with the upper and lower switch arms  170 ,  174  respectively to ride on a constant cam level while the center switch follower  184 , associated with the center switch arm  172 , rides on neutral level for an off position, an upper offset position to complete the electrical circuit between the upper and center switch arms  170 ,  172 , or a lower offset position to complete the circuit between the center and lower switch arms  172 ,  174 . This configuration provides slow-make fast-break circuits at the upper and center switch arms  170 ,  172  and fast-make slow-break circuits at the center and lower switch arms  172 ,  174 . 
   The set of switch arms  18  can also operate as a double-pole single-throw switch by allowing the center switch follower  184  to ride on a neutral cam level while the lower switch follower  186  rides on an upper offset position to make the circuit between the lower and center switch arms  174 ,  172 , and the upper switch follower  182  rides on a lower offset position to make the circuit between the upper and center switch arms  170 ,  172 . This configuration provides fast-make slow-break for circuits at the upper and center switch arms  170 ,  172  and slow-make fast-break for circuits at the center and lower switch arms  172 ,  174 . 
   By combining these two different types of switch actions and allowing all three switch arms  170 ,  172 ,  174  to ride on various neutral or offset cam levels, it is also possible to provide fast-make fast-break and slow-make slow-break for both top and bottom circuits as well. Fast-make and break results in improved accuracy since a dropping switch arm action is well defined. Another advantage of fast-make and break is a reduced contact erosion and heating which results in increased switch life. Yet another advantage of a fast make and break is a reduction in duration of radio frequency interference due to the fact that the circuit is closed and opened instantaneously, providing instant contact force and instant air gap. 
   It will be noted that the independent control of the three switch arms  18  also permits the three switch arms of a group to be simultaneously connected together, e.g. by maintaining the center switch arm in a neutral position while driving the lower switch arm up into the center switch arm and allowing the upper switch arm to drop into contact with the center switch arm. The resulting three-way connection allows for switching possibilities that under some circumstances may be advantageous, and potentially reduces the number of switches needed for a particular application. 
   The cam followers  26  also provide geometry for a setting feedback (SF) actuator  208  to raise the followers  26  off the program cam surface  40 . When the cam followers  26  are raised, the main cam  38  can be rotated in either direction to set the timer  10  to a particular cycle. As shown in  FIG. 5B , the front edge of each cam follower  26  includes an arcuate face  188  curving from the tip  190  of the cam follower  26  which contacts the main cam  38  at a direction substantially perpendicular to the program cam surfaces  40  of the main cam  38 . This leading edge  192  extends from the distal end  144  of the switch arm  18  along the longitudinal axis of the switch arm  18 . The arcuate surface  188  then curves 90° from that tip  190  to a leading edge  192  of the cam follower  26  that is substantially parallel to the program cam surface  40  of the main cam  38 . The arcuate face  188  and leading edge  192  are engaged by the SF actuator  208  of the SF system  30  to lift the cam followers  26  off the program cam surface  40 . The interaction of the SF actuator  208  and cam followers  26  will be explained in greater detail below. 
   Referring now to  FIG. 6 , the structure of the timer  10  of the present invention involved during testing of the timer  10  is shown. Cam-operated timer  10  testing takes place after assembly has been completed. The purpose of the cam-operated timer  10  test is to test the operation of cam-operated timer  10  components, including the switch arms  18 . This test verifies operation of the switch arms  18  by the program cam surfaces  40  of the main cam  38  and determines whether all electrical contacts  22  are properly made. The components of the timer  10  used during this test procedure include a hub extension  28  of the main cam  38  which extends outside the front housing  34  of the timer  10  and three “key” slots  194 ,  196 ,  198  located in the base  200  of the hub extension  28 . During testing the cam-operated timer  10  is operatively connected to a test fixture that has a rotator (not shown) for rotating the main cam  38 , and a data recorder (not shown) for verifying the response of the switch arms  18  to the program cam surfaces  40 . The rotator is operatively connected to the hub extension  28  of the main cam  38  protruding from the front housing  34  of the timer  10 . The data recorder is connected to the switch arms  18  for recording operation of the switch arms  18 . Operation of switch arms  18  is determined by applying electrical voltage to selected contact terminals. The data recorder then measures whether a particular switch arm is opened or closed by measuring whether a voltage is present on the switch arm  18 . 
   As developed in the background of the invention, the hub extension  28  protruding from the face of the front housing  34  of the timer  10  may be of a different shape and configuration for every model of timer  10 . This makes it difficult for one piece of test equipment to test every timer  10  that is built. The timer  10  of the present invention incorporates a cam test hub  28  having features to facilitate testing of each timer  10  with a single piece of test equipment. 
   The hub extension  28 , base  200  and a cam ring  204  are integral with the main cam  38  and extend through an orifice  206  in the front housing  34  of the timer  10 . When the timer  10  is fully assembled, the hub extension  28 , base  200  and cam ring  204  are disposed outside the front housing  34  of the timer  10 . The cam ring  204  includes three unequally spaced slots  194 ,  196 ,  198  and is located at the base  200  of the hub extension  28 , below the front face of the timer  10  but disposed on the outside of the front timer housing  34 . The cam ring  204  and slots  194 ,  196 ,  198  are integral with the hub extension  28  of the main cam  38 . The isolated slot  194  operates as a zero tooling position of the cam  38  and the other two slots  196 ,  198  are provided for engagement by the test fixture to drive the cam  38 . Since these three slots  194 ,  196 ,  198  will always be of the same configuration and in the same location with respect to the zero tooling location, the test equipment can use the same encoding and driving head for all models of timer  10 . 
   During testing, the hub extension  28  of the main cam  38  is rotated by the rotator to which it is operatively connected. As the main cam  38  rotates the switch arms  18  operate in accordance with the main cam  38  by moving between neutral and offset positions as determined by the geometry of the program carried on the program cam surfaces  40 . The hub extension  28  is rotated at a rate to rotate the main cam  38  360° in about e.g. two to ten minutes. This rate of rotation of the main cam  38  is greatly accelerated over the rate of rotation of the cam  38  during normal operation of the timer  10 . The rate of rotation during testing is accelerated about e.g. ten to twenty times. Some cam-operated timer  10  configurations may require more time to rotate the main cam  38  and some may require less time to rotate the main cam  38 . As the main cam  38  rotates, the data recorder collects data from the switch arms  18  during operation according to the program cam surfaces  40  of the main cam  38 . The collected data from the data recorder is then used to determine whether the switch arms  18  are functioning properly. 
   Referring now to  FIGS. 7A-7G , a set of switch arms (upper  170 , center  172  and lower  174 ) are shown with their molded cam followers  26 , and the operation of the SF system  30  is depicted. The SF actuator  208 , which lifts the switch arms  18  off of the surface of the cam  38 , is shown interacting with the followers  26 . In the figures, the shaft  210  is shown in both the “in” and “out” positions. A latch  212 , which holds the SF actuator  208  in a setting mode, is shown, along with a key  214 , which releases the latch  212  to allow the SF actuator  208  to drop. When the shaft  210  is indexed “in”, in a direction along the longitudinal axis of the shaft  210  and toward the rear housing  36  of the timer  10 , the timer  10  is in a setting mode. In this setting mode, the latch  212  holds the SF actuator  208  in a raised position. In turn, the SF actuator  208  engages the cam followers  26  and holds the cam followers  26  out of engagement with the program cam surfaces  40  of the main cam. When the shaft is extended “out”, in a direction along the longitudinal axis of the shaft  210  and away from the rear housing  36  of the timer  10 , the key  214  displaces the latch  212  away from the SF actuator  208 , which falls from its raised position and out of engagement with the cam followers  26 . Thus, the cam followers  26  contact and follow the geometry of the program cam surfaces  40  as the main cam  38  rotates. 
   During setting of the timer  10 , the main cam  38  can be rotated in either a forward or a reverse direction. Referring to  FIG. 7A , the SF system additionally includes a manual setting clutch plate  240 . The clutch plate  240  includes a plurality of apertures  242  circumferentially disposed through the face of the clutch plate  240 . These apertures  242  mesh with a plurality of protrusions  244  disposed on the face of the cam  38 , and located about the circumference of an orifice  246  through the main cam  38 . When the apertures  242  mesh with protrusions  244 , the clutch plate  240  and main cam  38  rotate cooperatively. The clutch plate  240  also includes an orifice  241  disposed through its center. The outer circumference of this orifice  241  is defined by a plurality of notches  248 . These notches may be engaged by a clutch pin  250  located on the shaft  210 . When the timer  10  is in its operating position, the clutch pin  250  is not engaged with a notch  248  of clutch plate  240 . Thus, the shaft  210  may be rotated without cooperative rotation of the main cam  38 . However, when the shaft  210  is indexed into its setting position, the clutch pin  250  engages a notch  248  on the clutch plate  240 . In this position, rotation of shaft  210  results in cooperative rotation of clutch plate  240  and main cam  38 , thereby allowing the operator of the timer  10  to set the main cam  38  to a desired position. 
   Referring to  FIG. 7B , all of the components of the SF system  30  are shown in the setting position. The shaft  210  is axially movable in a longitudinal direction and has been indexed toward the rear housing  36  of the timer  10 . In this position, the latch  212  holds the SF actuator  208  in a setting mode. When the latch  212  is released, the SF actuator  208  drops, allowing the switch arms  18  to contact the surface of the main cam  38 . The shaft  210  and key  214 , which are attached to the shaft  210  and shown as a cross-section, are also indexed in this setting position. In this position, the latch  212  of the SF system  30  engages the SF actuator  208 . The latch  212  includes two latch arms  216 , each having latch fingers  218  disposed at the distal ends of the arms  216 . These latch fingers  218  include flat sections  220  and a latch ramp  222 . The flat sections  220  operatively engage the SF actuator  208  and the latch ramp  222  engages the key  214 . In particular, the flat sections  220  of the latch fingers  218  integral to the latch  212  support flat sections  226  of latching tabs  224  integral to the SF actuator  208 . 
   As the shaft  210  is indexed toward the rear housing  36  of the timer  10 , the latching tabs  224  of the SF actuator  208  slide past the latch fingers  218  of the latch  212 . As the tabs  224  slide past the latch fingers  218 , the fingers  218  are forced to move in a direction away from and substantially perpendicular to the longitudinal axis of the shaft  210 . Once the tabs  224  have moved past the latch fingers  218 , the fingers  218  and latch arms  216  return to their original position. In this position, the flat sections  220  of the latch fingers  218  engage the flat sections  226  of the latching tabs  224  to hold the SF actuator  208  in a raised position. 
   When the SF actuator  208  is held in a raised position, the tips of the cam followers  26  of the upper, center and lower switch arms  170 ,  172 ,  174  rest on the SF actuator  208 , preventing the cam followers  26  from contacting the program cam surface  40  of the main cam  38 . As the shaft  210  is indexed to move axially in a longitudinal fashion, the arcuate edge  228  of the SF actuator  208  engages the arcuate face  188  of the cam followers  26  attached to each switch arm  140 . The arcuate face  188  of the cam followers  26  is inverted as compared to the arcuate edge  228  of the SF actuator  208 . As the SF actuator  208  is raised cooperatively with the axial movement of the shaft  210  toward the rear housing  36  of the timer  10 , the SF actuator  208  lifts up against the lower side of the leading edge  192  of the cam follower  170 . As the shaft  210  is moved to its fully indexed position, the cam followers  26  are lifted out of contact with the program cam surfaces  40  of the main cam  38 . 
   Referring now to  FIG. 7C , the SF actuator  208 , shaft  210  and latch  212  as shown in  FIG. 7B  have been sectioned in half to show ramp details of the key  214  and latch  212 . These key ramps  230  operate to disengage the SF actuator  208  from a setting mode as follows: As the shaft  210  and attached key  214  are extended in a direction along the longitudinal axis of the shaft  210  and away from the rear housing  36  of the timer  10 , the key ramp  230  applies force on the latch ramp  222  to force the latch fingers  218  away from the shaft  210 . The arms  216  of the latch  212  are substantially parallel to the shaft  210  and have limited movement in a direction substantially perpendicular to the shaft  210  when a force is applied. As the key ramp  230  applies an outwardly directed force on the arms  216  of the latch  212  upon movement of the key  214 , the latch fingers  218  will move away from the shaft  210 . As the latch fingers  218  move away from the shaft  210 , the flat sections  220  of the latch fingers  218  and the flat section  216  of the SF actuator  208  latching tabs  224  (shown in  FIG. 7B ) will become disengaged. At the point of disengagement, force from the switch arms  18  will cause the SF actuator  208  to move toward the main cam  38 , allowing the switch arm cam followers  26  to contact the program cam surface  40 . As the operator continues to extend the shaft  210  away from the rear housing  36  of the timer  10 , the key ramps  230  and latch ramps  222  will help to force the shaft  210  to a fully extended position. 
     FIGS. 7D and 7E  show the SF actuator  208 , shaft  210  and attached key  214  in the fully extended position away from the rear housing  36  of the timer  10 . The switch arms  18  are still shown in a lifted position in  FIGS. 7D and 7E  to demonstrate the distance the SF actuator  208  moves from the setting position once released from the latch  212 .  FIG. 7E  depicts the SF actuator  208 , shaft  210  and latch  212  of  FIG. 7D  sectioned in half to show the ramp details of the key  214  and latch  212  in the setting position. As the shaft  210  is indexed toward the rear housing  36  of the timer  10 , a flange  232  disposed about and integral with the circumference of and integral with the shaft  210  engages the SF actuator  208  to lift the actuator  208  away from the cam  38 , thereby operatively lifting the cam followers  26  away from the program surfaces  40  of main cam  38 . The ramped surfaces  222 ,  220  of the latch tabs  224  and the key  214  force the latch fingers  218  away from the shaft  210  as previously described until the latch tabs  224  of the SF actuator  208  slide past the flat sections  220  of the latch fingers  218 . Once the latch tabs  224  of the SF actuator  208  have moved from the side of the latch fingers  218  proximal to the front housing  34  of the timer  10  to a position on the side of the latch fingers  218  distal to the front housing  34  of the timer  10 , the latch fingers  218  will “snap” back toward the shaft  210 , locking the SF actuator  208  in the setting position (as in FIG.  7 B). 
   Referring now to  FIG. 7F , it is shown that the SF actuator  208  spans across the full diameter of the main cam  38  and is parallel to the cam  38 . As the SF actuator  208  is raised all the switch arms  18  to be lifted are on one side of the main cam  38 . Thus, since the force of the switch arms  18 , as they engage the SF actuator  208 , is localized on one side of the shaft  210 , a travel limiting boss  234  is disposed on the inside of the rear housing  36  over the SF actuator  208  and opposite the switch arms  18  of the timer  10 . As the SF actuator  208  is raised, the travel limiting boss  234  forces the SF actuator  208  to level as the shaft  210  is being indexed toward the rear housing  36  of the timer  10 . Specifically, as the shaft  210  is being indexed in, force from the switch arms  18  applied to the SF actuator  208  will tend to hold down the side of the SF actuator  208  engaging the switch arms  18 . This results in the raising of the opposite side of the SF actuator  208 , such that the actuator  208  is no longer parallel to the main cam  38 . Once the side of the SF actuator  208  not engaging the switch arms  18  contacts the boss  234  on the rear housing  36 , that side of the SF actuator  208  is prevented from moving and the side of the actuator  208  engaging the switch arms  18  will lift the switch arms  18 . The boss  234  is designed so that when the SF actuator  208  is latched in place, it is parallel to the surface of the main cam  38 . 
   Another aspect of the SF system  30  of the timer  10  of the present invention, shown in  FIGS. 2D and 2E  and previously discussed is the clutch mechanism  16 , which is part of the geartrain  14  between the timing motor  12  and main cam  38 . This clutch mechanism  16  provides a one-way coupling between the timing motor  12  and the main cam  38 . 
   Specifically, the fifth stage pinion  94  in the geartrain  14 , meshes with the outer gear ring  117  of the main cam  38 , and is engaged to the fifth stage gear  92  in the geartrain  14  via the clutch mechanism  16 . This clutch  16 , as described above, permits manual forward rotation of the main cam  38 , by allowing the main cam  38  and fifth stage pinion  94  of the drive train to rotate in a forward direction without rotating the remainder of the geartrain  14  or the timing motor  12 . However, the clutch  16  prevents manual reverse rotation of the timer  10 . During attempted reverse rotation of the cam  38 , the fifth stage pinion  94  is coupled to the timing motor  12 , which due to friction and the gear ratio of the geartrain  14 , blocks rotation of the main cam  38 . 
   Inward motion of the control shaft  210 , however, forces the clutch  16  to a position in which the clutch  16  permits slip between the geartrain and the main cam  38 , so that the main cam  38  and fifth stage pinion  94  of the geartrain  14  can be manually rotated forward and rearward uncoupled from the timing motor  12 . Such inward motion of the control shaft results in a clutch lever (not shown), hinged in the front housing  34  of the timer  10 , to be opened by the SF system  30 , thereby permitting slip. However, the fifth stage pinion  94  of the geartrain  14  remains engaged to the gear ring  117  on the main cam  38 , and rotates with the main cam  38 , regardless of the position of the clutch  16 . In this manner, manual reverse rotation of the main cam  38  is prevented as the geartrain  14  remains engaged. However, when the operator of the timer  10  indexes the shaft  210 , the switch arms  18  are lifted out of contact with the program cam surfaces  40  and the geartrain  14  may slip in either direction, thereby allowing rotation of the main cam  38  in a forward or reverse direction. 
   Referring now to  FIG. 7G , upon lifting all cam followers  26  off the program cam surfaces  40  of the main cam  38 , the main cam  38  can be rotated without restriction in either direction. A custom feel profile  236 , similar to a program cam surface  40 , is molded on the side of the main cam  38  proximal to the front housing  34  of the timer  10 . This custom feel profile  236  includes a textured surface comprising a plurality of teeth or ridges used to impart tactile and/or audible feedback to the operator of the timer  10 . The contours of these teeth may vary dependent upon appliance model, line, or the particular application or cycle for which the appliance is to be set. A “V”-shaped follower  238  is located in the front housing  34  of the timer  10  above and in engagement with the textured surface of the custom feel profile  236 . As the user rotates the main cam  38 , the “V”-shaped follower  238  engages the geometry of the teeth of the custom feel profile  236  thereby providing a tactile and/or audible feedback to the user. Since the restrictions of the geartrain  14  and the switch arm cam followers  26  are removed from the main cam  38 , the textured surface of the custom feel profile  236  can be highly defined for each individual application. Since there is no drag on the main cam  38  from either the cam followers  26  or the geartrain  14 , the total feel experienced by the operator of the timer  10  results from the tactile and/or audible feedback imparted by the “V”-shaped follower  238  riding on the custom feel profile  236  molded onto the main cam  38 . The disengagement of the cam followers  26  and the slip of the geartrain  14  relative to the main cam  38  also allows the main cam  38  to be rotated in a reverse direction, making it easier to set. After the main cam  38  has been set to the desired position, the shaft  210  is extended in a direction away from the rear housing  36  of the timer  10 . 
   As described above, in the illustrated embodiment, the timer  10  of the present invention includes a shaft  210  about which the cam-carrying member  38  rotates. A control knob (not shown) may be operatively connected to or near one end of the shaft  210 . In one particular embodiment, the knob may be operatively connected to the end of the shaft  210  which is situated distally from the timer housing  34 , and extends through to the exterior of the appliance (not shown) to which the timer  10  is operatively connected. Examples of such an appliance include, but are not limited to, a clotheswasher and/or a dryer. The knob is used by an operator to rotate the shaft  210  to a desired setting of the timer  10 . The knob can either be indexed in or indexed out in order to cooperatively index the shaft  210  in and out to place the timer  10  in various modes, examples of which include, but are not limited to, a setting mode, a run mode, and a disengaged mode. In the particular embodiment of the timer  10  described above, when the shaft  210  is indexed “in”, in a direction along the longitudinal axis of the shaft  210  and toward the rear housing  34  of the timer  10 , the timer  10  is placed in a setting mode. However, it will be appreciated that alternate embodiments of the timer  10  may be configured such that the timer  10  is placed in a setting mode by indexing the shaft  210  “out”, in a direction along the longitudinal axis of the shaft  210  and toward the front housing  36  of the timer  10 . 
   In its operation, the illustrated embodiment of the timer of the present invention may be provided on both a first and second appliance, and is operated as follows. Initially, the knob is rotationally in an “off” position. This may be denoted by an indicia mark (not shown) on the knob and a corresponding indicia mark (not shown) on the appliance which, when aligned, place the cam-carrying member  38  in a position such that no function encoded by the cam-carrying member  38  is set to run. In the “off” position the shaft  210  is axially in a neutral first position. In order to place the timer  10  in a setting mode, the knob, and thus the shaft  210 , may be indexed inwardly. In doing so, the knob and shaft  210  travel cooperatively axially from the first neutral position to a second position. This second position is located at a point disposed along the longitudinal axis of the shaft  210  in a direction toward the rear housing  34  of the timer  10 . As a result, the shaft  210  is placed in engagement with the cam-carrying member  38  of the timer  10  such that the cam-carrying member  38  may be rotated cooperatively with the knob and shaft  210  to select a cycle on the timer  10  encoding a desired function of the appliance. 
   After a particular function of the appliance has been selected, the knob is indexed outwardly to return to the first neutral position. In a first embodiment of the timer  10 , this causes the selected function of the first appliance to start. Without interruption, the first appliance will then run automatically until the end of the cycle on the cam-carrying member  38  encoding the specified function which has been selected. At that time, the shaft  210  and knob will have rotated cooperatively with the cam-carrying member  38  and at the end of the cycle the indicia mark indicator on the knob will again have aligned with the indicia mark on the first appliance in the “off” position. This indicates that the cam-carrying member  38  has also rotated completely through the cycle which had been set by the user. 
   Other components of the appliance may include switches (not shown) that are in series with the line supplying power to the timer. These components may act as a line switch to allow for interruption of the power, and thus, the operation of the appliance. In one example of such a component, the lid of a washer, dryer, or other appliance may include a lid switch in series with the line. Thus, if the lid of the appliance is opened during the cycle, the line switch will cause a break in the electrical circuit which causes the washer, dryer, or other appliance, to stop the currently operating function. If the operation of the appliance stops, it may restart once the electrical connection circuit is again completed, such as when the lid of the clotheswasher is closed. 
   Alternatively, at any point during the cycle of a selected function, the appliance may be manually stopped by indexing the knob, and thus the shaft  210 , to the second position. The timer  10  and appliance function may then be restarted by re-indexing the knob and shaft  210  back to the first position. If so desired, the knob may alternatively be rotated to the “off” position to end the selected cycle. 
   Regarding the method of operating the timer  10 , when the appliance on which the timer  10  of the present invention is used is a dryer, there exist alternate embodiments of the method of use. In a second embodiment, initially the knob is rotationally in the “off” position. In the “off”position the shaft  210  is axially in a neutral first position. In order to place the timer  10  in a setting mode, the knob, and thus the shaft  210 , may be indexed inwardly. In doing so, the knob and shaft  210  travel cooperatively axially from the first position to a second position. As a result, the shaft  210  is placed in engagement with the cam-carrying member  38  of the timer  10  such that the cam-carrying member  38  may be rotated to select a cycle on the timer  10  encoding a desired function of the appliance. 
   After a particular function of the appliance has been selected, the knob is indexed outwardly to return to the first position. At this point the cam-carrying member  38  is engaged by the shaft  210  and is positioned to begin operation of the dryer. However, in the second embodiment, the dryer will not start until a separate start switch, operatively connected to the dryer, is actuated for a short time in order to override a centrifugal switch in the dryer and start the dryer. Once the start switch has been activated, the dryer then runs automatically until the end of the cycle. 
   As described above with respect to the first embodiment of the timer  10 , the power to the appliance may be interrupted. For example, if the dryer door is opened during the cycle, the drum will stop rotating due to a break caused by a door switch operating as a line switch in series with the line. To restart the dryer in this second embodiment the user must close the door and then actuate the start switch for a short time in order to override the centrifugal switch of the dryer. To manually shut off the dryer the knob once again may be pushed in to the second position. If so desired the user may then rotate the knob to the “off” position. 
   In a third embodiment of the present invention initially, the knob is rotationally in the “off” position. In the “off” position the shaft  210  is axially in the neutral first position. In order to place the timer  10  in a setting mode, the knob, and thus the shaft  210 , may be indexed inwardly. In doing so, the knob and shaft  210  travel cooperatively axially from the first position to a second position. As a result, the shaft  210  is placed in engagement with the cam-carrying member  38  of the timer  10  such that the cam-carrying member  38  may be rotated to select a cycle on the timer  10  encoding a desired function of the appliance. 
   After a particular function of the appliance has been selected, the knob is indexed outwardly to return to the first position. At this point the cam-carrying member  38  is engaged by the shaft  210  and is positioned to begin operation of the dryer. However, this third embodiment of the present invention uses a pull to start feature in order to start the dryer. To use this function, the knob is pulled axially past the original first position to a third position at a point along the longitudinal axis of the shaft  210  and distal from the front of the timer housing  36  and the first position. The knob is held there for a short time in order to override the centrifugal switch in the dryer and start the dryer. When released the knob and shaft  210  are spring loaded to return automatically to original axially first neutral position. The dryer of the third embodiment runs automatically unless the electrical circuits are interrupted as described above with respect to the second embodiment of the dryer timer. 
   In yet other alternate embodiments of the timer  10  of the present invention, axial operation of the knob and shaft  210  in an opposite direction than that described above is possible. For example, in one alternate embodiment of the timer  10  to be used on a washer or dryer in the present invention, the knob is rotationally in the “off” position and in a first neutral position axially. The user then indexes the knob and shaft  210  outwardly, causing the knob to travel axially from the first position to a second position along the longitudinal axis of the shaft  210  and in a direction away from the rear housing  34  of the timer  10 . By indexing the shaft  210  outwardly, the shaft  210  engages the cam-carrying member  38  of the timer of the present invention. The user then rotates the knob in order to select a cycle encoding a desired appliance function. The knob is then indexed back into original axial first position. At this point the washer or dryer may start. The electrical power to the appliance may be interrupted as described previously. 
   Also as described previously the timer  10  in the dryer may include additional alternate embodiments. A fourth embodiment has the features of the third embodiment, but also includes a separate start switch that needs to be actuated for a short time in order to override the centrifugal switch in the dryer once the knob has been re-indexed in to the first position. In a fifth embodiment, a push-to-start feature is used. Once the knob has been indexed to its original first position from the second position, it is indexed inwardly further to a third position. The knob and shaft  210  are then held in the third position for a short time in order to override the centrifugal switch in the dryer. When released, the shaft  210  is spring loaded to return the shaft  210  and the knob automatically to the original first position. 
   While the present invention has been illustrated by the description of various embodiments thereof, and while these embodiments have been described in considerable detail, it is not the intention of the Applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative system and method, and illustrative example shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of Applicant&#39;s general inventive concept.

Technology Classification (CPC): 7