Abstract:
A timer has a dial, a captured tripper, and/or a retainer. The captured tripper has active and inactive positions on the dial. In the inactive position, the captured tripper is captured to the dial but is free to move independently of the dial. Alternatively or additionally, in the inactive position, the captured tripper is not positioned to operate a switch. In the active position, the captured tripper is captured to the dial and is prevented from moving independently of the dial. Alternatively or additionally, in the active position, the captured tripper is positioned to operate the switch. The retainer maintains a predetermined orientation between the captured tripper and the dial when the captured tripper is in both the active and inactive positions.

Description:
TECHNICAL FIELD 
       [0001]    The technical field of the present disclosure relates to a user interface for a timer such as an electromechanical timer. 
       BACKGROUND 
       [0002]    Timer switches, whether mechanical, electrical, or electromechanical, have been used in a wide variety of indoor and outdoor applications. For example, one popular use of such timers is to switch lights on and off. Typical timers permit the on and off times to be independently controlled so that a load, such as the above mentioned lights, is switched on at a first independently set time and is switched off at a later second independently set time. 
         [0003]    In order to select desired on and off times, it is known to equip timers with pins or trippers whose positions are individually selectable so to trip one or more switches on and off at the desired times. Unfortunately, these known timers have a number of drawbacks. 
         [0004]    For example, if a timer is provided with multiple on pins or trippers and multiple off pins or trippers so that more than one on time and more than one off time may be set, and if a user desires to set only one on time and only one off time, the user must remove from the timer the pins or trippers that are not being used. Not only is the removal of these excess pins or trippers an unnecessary nuisance, but these removed pins or trippers can be mislaid so that they are not readily available should the user later desire to set additional on and off times. 
         [0005]    Furthermore, the pins or trippers of known timers must be removed from and reattached to the timer whenever a user chooses to adjust the on and off times. Pins or trippers can be dropped during their removal and reattachment, which at a minimum is a nuisance. Worse, dropped pins or trippers can be lost, especially when timers are used outdoors. 
         [0006]    The timer described below overcomes one or more of these or other problems. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    Features and advantages of the timer described herein will become apparent from the detailed description below when taken in conjunction with the drawings in which: 
           [0008]      FIG. 1  is an exploded view of the timer described below; 
           [0009]      FIG. 2  is a front view of a relevant portion of the timer of  FIG. 1 ; 
           [0010]      FIG. 3  is a cross-section of the timer of  FIG. 1  taken along section lines  3 - 3  of  FIG. 2 ; 
           [0011]      FIG. 4  shows a portion of the timer of  FIGS. 1-3 ; and, 
           [0012]      FIGS. 5-7  illustrate a cam and switch arrangement that can be used in connection with the timer of  FIGS. 1-5 . 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    A timer  10  as shown in  FIGS. 1-5  includes first and second dials  12  and  14 , first and second captured trippers  16  and  18 , and first and second retainers  20  and  22 . The first and second dials  12  and  14  may be keyed together so that a timer movement moves the first and second dials  12  and  14  in unison. The movement of the timer  10  may be a mechanical, electrical, or electromechanical movement that is arranged to rotate the first and second dials  12  and  14  in the direction of the arrow shown in  FIG. 2 . 
         [0014]    The first dial  12  has first and second sides  24  and  26 . The first side  24  includes an annular outer ring  28 , an annular inner ring  30 , an annular ramp shaped ring  32 , and an annular groove  34 . The annular outer ring  28  and the annular inner ring  30  are disposed in planes that are parallel to and offset from one another. The annular ramp shaped ring  32  is between the annular outer ring  28  and the annular groove  34 . The annular groove  34  is between the annular ramp shaped ring  32  and the annular inner ring  30 . 
         [0015]    The first dial  12  has an annular peripheral edge  36  extending between the first and second sides  24  and  26  and that overhangs the second side  26  by a small amount. Teeth  38  are disposed annularly around the second side  26  near the annular peripheral edge  36 . The first dial  12  also has a hub  42  and a central hole  44  extending through the hub  42 . 
         [0016]    The second dial  14  has first and second sides  50  and  52 . The first side  50  of the second dial  14  faces the second side  26  of the first dial  12  when the timer  10  is assembled. The first side  50  is formed with an annular well  54  surrounded by an annular rim  56  at the peripheral edge of the second dial  14 . Teeth  58  are provided around the outer perimeter of the annular rim  56 . The second dial  14  also has a hub  60  and a hole  62  through the hub  60 . The hole  62  of the second dial  14  aligns with the hole  42  of the first dial  12  when the timer  10  is assembled as shown in  FIG. 3 . 
         [0017]    The first captured tripper  16  is formed as an on tripper since it cooperates with a first cam portion to close a pair of switch contacts, and the second captured tripper  18  is formed as an off tripper since it cooperates with a second cam portion to open the pair of switch contacts. 
         [0018]    The first captured tripper  16  has a head  70  joined to a barrel  72  by a neck  74 . A recess  76  is formed at the neck  74  between the head  70  and the barrel  72 . The end of the head  70  is formed with a protrusion  78  that engages the annular groove  34  when the first captured tripper  16  is in its active position. A horseshoe shaped bracket  80  is attached to an arm  82  that depends from the barrel  72  near the neck  74  of the first captured tripper  16 . The arm  82  is L-shaped having first and second arm portions  82   a  and  82   b . The first arm portion  82   a  is formed at a right angle to the barrel  72 , and the second arm portion  82   b  is formed at a right angle to the first arm portion  82   a  so that the second arm portion  82   b  is parallel to the barrel  72 . 
         [0019]    The first captured tripper  16  further includes a first tooth  84  attached to the barrel  72  on one side of the arm  82 , a second tooth  86  attached to the barrel  72  on the opposite side of the arm  82 , and a switch operator  88  at the end of the barrel  72 . The first tooth  84  meshes with the teeth  38  of the first dial  12  when the first captured tripper  16  is in its active position, the second tooth  86  meshes with the teeth  58  of the second dial  14  when the first captured tripper  16  is in its active position, and the switch operator  88  cooperates with the first cam portion to close the switch contacts when the first captured tripper  16  is in its active position and the first and second dials  12  and  14  are rotated sufficiently for the switch operator  88  to engage an appropriate lobe on the first cam portion. 
         [0020]    The first retainer  20  has a hole  92  that aligns with the hole  42  of the first dial  12  and the hole  62  of the second dial  14  when the timer  10  is assembled as shown in  FIG. 3 . A tab  94  extends from the outer periphery of the first retainer  20  away from the hole  92 . The tab  94  has a slot  96  that receives an arm  98  of the bracket  80  of the first captured tripper  16  and that permits the first captured tripper  16  to move between its active and inactive positions. 
         [0021]    The first captured tripper  16  is captured to the timer  10  when the first and second dials  12  and  14  are mated as shown in  FIG. 3 . The horseshoe shaped bracket  80  and the second arm portion  82   b  ensure that the first captured tripper  16  is captured to the timer  10  when the first and second dials  12  and  14  are mated so that the first captured tripper cannot become separated from the timer  10 , even when the first captured tripper  16  is in its inactive position. 
         [0022]    The second captured tripper  18  is formed similarly to the first captured tripper  16 , differing only in that the barrel  721  of the second captured tripper  18  is longer than the barrel  72  of the first captured tripper  16 . Therefore, the switch operator  88  of the first captured tripper  16  but not the switch operator  88 ′ of the second captured tripper  18  cooperates with the first cam portion to close the switch contacts, and the switch operator  88 ′ of the second captured tripper  15  but not the switch operator  88  of the first captured tripper  16  cooperates with the second cam portion to open the switch contacts. 
         [0023]    During assembly, the second captured tripper  18  is snapped onto the first dial  12  so that its protrusion  78 ′ is against the annular ramp shaped ring  32 , so that its recess  76 ′ receives the annular edge  36  of the first dial  12 , and so that its arm  82 ′ snugly engages the second side  26  of the first dial  12 . This position of the second captured tripper  18  is the inactive position. The second retainer  22  is then inserted onto the first dial  12  so that its hole  92 ′ receives the hub  42  of the first dial  12  and so that its slot  96 ′ receives the arm  98 ′ of the bracket  80 ′ of the second captured tripper  18 . 
         [0024]    The first captured tripper  16  and the first retainer  20  are similarly applied to the first dial  12 . 
         [0025]    The second dial  14  is then applied to the first dial  12  so that the hub  42  of the first dial  12  is received within the hub  60  of the second dial  14 . The first and second dials  12  and  14  are keyed together so that the teeth  38  of the first dial  12  are aligned with the teeth  58  of the second dial  14 . For example, the inside perimeter of the hub  60  of the second dial  14  may have a ridge, and the outside perimeter of the hub  42  of the first dial  12  may have a slot. The ridge and slot extend along an axis that is parallel to the center axis of the holes  44  and  62 . Accordingly, when the second dial  14  is applied to the first dial  12  so that the hub  42  of the first dial  12  is received within the hub  60  of the second dial  14 , the ridge slides into and mates with the slot. 
         [0026]      FIG. 3  shows the first captured tripper  16  in its active position and the second captured tripper  18  in its inactive position. When the first captured tripper  16  is in its active position, its protrusion  78  is received in the annular groove  34  of the first dial  12 , its first tooth  84  meshes with the teeth  38  of the first dial  12 , and its second tooth  86  meshes with the teeth  58  of the second dial  14 . 
         [0027]    Because the protrusion  78  of the first captured tripper  16  is engaged within the annular groove  34  of the first dial  12 , because the first tooth  84  of the first captured tripper  16  meshes with the teeth  38  of the first dial  12 , because the second tooth  86  of the first captured tripper  16  meshes with the teeth  58  of the second dial  14 , and because the first and second dials  12  and  14  are keyed together and thereby cannot rotate independently of one another, the first captured tripper  16  is locked into position on the first dial  12  and cannot rotate independently of the first dial  12 . In its active position, the first captured tripper  16  is in position to close the switch when the first and second dials  12  rotate sufficiently that the switch operator  88  engages the first cam portion. 
         [0028]    To move the first captured tripper  16  to its active position on the first dial  12 , the user simply pushes the first captured tripper  16  in a direction perpendicularly toward the hubs  42  and  60 . Doing so causes the protrusion  78  of the first captured tripper  16  to ride along the annular ramp shaped ring  32  and engage the annular groove  34  of the first dial  12 , causes the first tooth  84  of the first captured tripper  16  to mesh with the teeth  38  of the first dial  12 , and causes the second tooth  86  of the first captured tripper  16  to mesh with the teeth  58  of the second dial  14 . The first captured tripper  16  would then have the active position with respect to the first dial  12  exemplified by the position of the first captured tripper  16  as shown in  FIG. 3 . 
         [0029]    To move the first captured tripper  16  to its inactive position on the first dial  12 , the user simply pulls the first captured tripper  16  in a direction perpendicularly away from the hubs  42  and  60 . Doing so causes the protrusion  78  of the first captured tripper  16  to disengage from the annular groove  34  of the first dial  12  and ride along the annular ramp shaped ring  32 , causes the first tooth  84  of the first captured tripper  16  to move out of the teeth  38  of the first dial  12 , and causes the second tooth  86  of the first captured tripper  16  to move out of the teeth  58  of the second dial  14 . The first captured tripper  16  would then have the inactive position with respect to the first dial  12  exemplified by the position of the second captured tripper  18  as shown in  FIG. 3 . 
         [0030]    Because the first and second teeth  84  and  86  no longer mesh with the teeth  38  and  58 , the first captured tripper  16  is free to move around the periphery of the first dial  12  even though the first dial  12  is stationary. As the first captured tripper  16  moves around the periphery of the first dial  12 , the retainer  20  rotates about the hubs  42  and  60 . Thus, the first captured tripper  16  may be moved to a new position relative to the first dial  12 . Moreover, even though the first captured tripper  16  is free to move around the periphery of the first dial  12 , the first captured tripper  16  is still captured to the timer  10  as discussed above. Furthermore, when the first captured tripper  16  is in its inactive position, the first captured tripper  16  is not in position to engage the first cam portion. 
         [0031]    Accordingly, the first and second captured trippers  16  and  18  when not in their active positions are allowed to move freely relative to the first dial  12  and yet are captured to the timer  10  as explained above so that the first and second captured trippers  16  and  18  cannot be separated from the timer  10  without disassembling the timer  10 . Therefore, the first and second captured trippers  16  and  18  when not in use to control the switch cannot be accidentally lost from the timer  10 . 
         [0032]    The retainers  20  and  22  rotate about the hubs  42  and  60  as their corresponding first and second captured trippers  16  and  18  move about the first dial  12 . At the same time, the retainers  20  and  22  maintain the orientation of the first and second captured trippers  16  and  18  on the first dial  12  so that the first and second teeth  84  can properly mate with the corresponding teeth  38  and  58  on the first and second dials  12  and  14 . Thus, the retainers  16  and  18  insure that the axes along the length of the heads  70  and  70 ′ of the respective retainers  16  and  18  as viewed in  FIG. 2  always intersect the center axis of the hole  42 . In this manner, the retainers  16  and  18  prevent the first and second captured trippers  16  and  18  from becoming canted on the first dial  12  so that the teeth  84  and  86  are improperly oriented with respect to the corresponding teeth  38  and  58 . 
         [0033]    The timer  10  can be easily provided with more than two captured trippers. In this case, a retainer is added for each of the additional captured trippers. If the user desires to use only one pair of on and off captured trippers to operate the switch so as to control a load, the user simply moves the unused on and off captured trippers to the inactive position shown by the position of the second captured tripper  18  in  FIG. 3 . For example, if the timer  10  is provided with two on captured trippers and two off captured trippers, and if the user desires to use only one pair of on and off captured trippers to operate the switch so as to control a load, the user moves one on captured tripper and one off captured tripper to the active position shown by the position of the first captured tripper  16  in  FIG. 3 , and moves the unused on captured tripper and the unused off captured tripper to the inactive position shown by the position of the second captured tripper  18  in  FIG. 3 . 
         [0034]    As shown in  FIGS. 5 ,  6 , and  7 , a cam  100  has first and second cam portions  102  and  104  at one end thereof. The first and second cam portions  102  and  104  rotate in unison under action of the first and second captured trippers  16  and  18  to control the position of a movable switch blade  106  with respect to a stationary switch blade  108 . As shown by the top view of  FIG. 6  (with the first and second dials  12  and  14  removed for clarity) and the bottom view of  FIG. 7 , the first cam portion  102  has lobes  110 , and the second cam portion  104  has lobes  112 . 
         [0035]    When the first dial  12  has sufficiently rotated, and with the captured tripper  16  in its active position, the switch operator  88  of the captured tripper  16  moves into contact with the lobes  110  and rotates the first and second cam portions  102  and  104  and the cam  100 . similarly, when the first dial  12  has sufficiently rotated, and with the captured tripper  18  in its active position, the switch operator  88 ′ of the captured tripper  18  moves into contact with the lobes  112  and rotates the first and second cam portions  102  and  104  and the cam  100 . 
         [0036]    As shown in  FIG. 7 , rotation of the cam  100  moves the switch blade  106 . Specifically, the end of the cam  100  opposite to first and second cam portions  102  and  104  has four switch controllers  114 , although a different number of switch controllers may be used.  FIG. 7  illustrates the position of the cam  100  and switch controllers  114  when the first captured tripper  16  has rotated the cam  100  to the switch on position. In the switch on position, the movable switch blade  106  is allowed to fall into the gap between two adjacent switch controllers  114  so that the movable switch blade  106  engages the stationary switch blade  108 . When the cam  100  is next rotated by the second captured tripper  18 , the cam  100  assumes the switch off position. In the switch off position, the movable switch blade  106  rides up on one of the switch controllers  114  so that the movable switch blade  106  disengages from the stationary switch blade  108 . 
         [0037]    Certain modifications of the timer  10  have been discussed above. Other modifications of the timer  10  will occur to those practicing in the art of the timer  10 . For example, as described above, the first captured tripper  16  drives the switch contacts  106  and  108  to their closed position, and the second captured tripper  18  drives the switch contacts  106  and  108  to their open position. Alternatively, the first captured tripper  16  may be arranged to drive the switch contacts  106  and  108  to their open position, and the second captured tripper  18  may be arranged to drive the switch contacts  106  and  108  to their closed position. 
         [0038]    Moreover, the timer  10  may be provided with a cover  120  ( FIG. 5 ) that provides hour or actual time marks so that the first and second captured trippers  16  and  1  may be positioned on the first dial  12  relative to one another based on time. 
         [0039]    Accordingly, the description of the present invention is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the best mode of carrying out the invention. The details may be varied substantially without departing from the spirit of the invention, and the exclusive use of all modifications which are within the scope of the appended claims is reserved.