US3388223A - Resettable electric clock timer mechanism - Google Patents

Description

June 11, 1968 J. F. MAR-CHAND 3,388,223

RESETTABLE ELECTRIC CLOCK TIMER MECHANISM Filed March 31, 1966 2 Sheets-Sheet l INVENTOR. JOHN E MARCH/1ND A TTORNEY 1968 J. F. MARCHAND RESETTABLE ELECTRIC CLOCK TIMER MECHANISM June 11 2 Sheets-Sheet 3 Filed March 51, 1966 A M II.

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INVENTOR. JOHN E MARC/ AND ATTORNEY United States Patent Ofiice Patented June 11, 1968 3,388,223 RESETTABLE ELECTRIC CLGCK TIMER MECHANISM John F. Marchand, 445 E. 65th St, New York, NY. 10021 Filed Mar. 31, 1966, Ser. No. 540,476 Claims. ((11. 200-38) This invention relates to an electric clock timer system which controls load circuits for predetermined intervals,

and which resets itself after a certain operating time.

In the past electric clock timers have been used to control various load circuits at predetermined intervals, a good example being the interval timers on the ovens of electric ranges and the like. This timing effect is normally by contacts on a disc or other element of the timer which is rotated. The start up mechanism of such a timing system may be fairly fast, for example, a manually operated pushbutton or dial which starts the clock timer motor running and which acts over a fraction of a second of operating time.

However, there are also situations in which the timing interval must be initiated by a faster pulse, for example, one which may have a duration best measured in the milliseconds. A problem then arises for some timing problems by reason of the fact that the rotating member, such as the disc of an electric timing mechanism, is one that turns slowly.

The present invention is one that permits a reliable, quick actuation with relatively slower actuator systems, such as manual buttons, without any further element. On the other hand, the new operating principle which will be described below also provides for reliable operation with very short action of the initiating pulse, but in such a case an additional element in the form of a fast acting latch relay is necessary in order to start and continue the movement of the timer motor for its predetermined cycle.

The present invention functions by making use of a characteristic of electric clock timers which normally is considered an unavoidable evil, namely the fact that any rotating mechanism builds up a rotary momentum and so tends to overshoot when the driving torque ceases, unless elaborate or expensive damping mechanisms are used. This inherent characteristic, which has previously been considered a drawback, is put to use in the present invention to provide a reliable resetting arrangement. In some cases it is even desirable to increase this natural overshoot tendency a little by adding predetermined weight to the moving parts, thus producing an additional flywheel effect of just the extent needed. Thus by making use of a motor timer characteristic which was only a drawback the present invention achieves an important new effect that works reliably and permits a simpler and cheaper type of interval timer construction. In fact, expensively damped constructions are not even useful in the present invention. Instead, satisfactory reliability is obtained by a new way of utilizing the rotor momentum of a shaded pole motor and this improvement permits economies by simple constructions. The present invention is thus an electric clock system that includes a timer of particular design in combination with particular start up systems that are appropriately fast or very fast depending on their role in the operation of the timer, and it is the whole of the combination that constitutes the invention rather than any one element thereof.

The present invention is a simplified timing mechanism that can be used for a useful series of timing intervals suitable to its capabilities, and one that can be used with a wide range of electrical loads either directly or else with suitable ordinary relays where the power demands of the control load are beyond the current carrying capacity of the timer mechanism itself.

In my prior application, Ser. No. 338,235, filed I an. 16, 1964, I described and claimed fixed delay commercial squelch circuits for television and radio receivers which shut off sound during the time when a commercial announcement is being broadcast. This is one field in which the new timing mechanism of the present invention may be used and, in fact, in the specific description in conjunction with some of the drawings such a use will be described as a typical illustration. However, the invention is not limited to this use. Also it should be pointed out that in my prior application modifications of electric timers were described. However, none of these involved a momentum overshoot effect for resettability. The initiation of timing was by a manually operated pushbutton or by a quick remote control pulse. Where a very simple fast initiation by a manual pushbutton is wanted, the present invention eliminates the need of a latching relay to get quick enough action, and where this type of actuation is practical the elimination of a hitherto needed relay makes this modification an attractive one.

It is also possible in a more elaborate modification of the present invention to operate with timing intervals that vary widely, for example timing of a few minutes, as is illustrated for commercial squelching, photographic timing and the like, and longer intervals, such as for example intervals of some hours, by means of the same timer. The long intervals require a latching relay, but it is an advantage that the overshoot principle of the present invention may be used for the shorter time intervals coupled with what might be considered a mechanical overshoot for the longer timing intervals by the addition of a suitable type of switch. The possibility of handling several different timing problems permits a flexibility and versatility which is a practical advantage of the present invention for certain uses. This additional flexibility is obtained without compromising the reliability and simplicity which are basic features of the present invention.

The invention will be described in greater detail in conjunction with the drawings in which:

FIGURE 1 is an isometric illustration of one mod fication;

FIG. 2 is a detailed view on a larger scale of a different and preferred modification;

FIG. 3 is a diagrammatic illustration of the basic principles of the present invention, and

FIG. 4 is an isometric view of a modified mechanism permitting very long as well as very short intervals from the same timer.

FIG. 3 is a diagrammatic illustration of the principles under which the present invention operates. For this purpose a conductive path, which may be on a switch disc, is shown drawn out in a straight line at 32. A contact 33 moves over the path when the latter is turned, as on a timer driven disc. 34 shows the distance through which the timer mechanism moves after power has been shut off from the timer motor. That is to say, this is the momentum overshoot for the particlar mechanism. Two different kinds of interrupting, insulating segments 35 and 36 are shown, the former being much narrower than the overshoot 34 and being useful with modifications employing a locking relay or similar mechanism. The broader segment 36 can be used where a locking relay is to be eliminated. In FIG. 3 the relative size of the overshoot distance and insulating segments is very greatly exaggerated for clarity. In actual construction the insulating segment 35 can be of the width of a human hair or still narrow, with of course the other dimensions of overshoot and wider segment 36 in proportion.

If We assume that the timer was running with the path 32 moving under the switch blade 33 and if we assume that there is a locking relay in series between the blade 33 and the motor circuit, as will be illustrated and described in connection with FIG. 4, when the blade reaches the extremely narrow insulating segment 35, the locking relay becomes unlocked or unlatched, but the momentum carries the switch blade past the insulating segment. However, the timer does not continue to operate because the latching relay is in series in the motor circuit and it has become unlatched. Now when a starting pulse, even a very short one, initiates another cycle, the relay is locked, and as the blade 33 has moved to a further part of conducting segment, the timer will start up again. In other words, the overshoot has put the blade 33 in a position where the timer is reset and ready to be started on command.

Where a slower actuation, such as a manual pushbutton, is present, bypassing the blade 33 while the button is depressed, the wider insulating segment 36 is employed. It will be noted that this segment is a little wider than the distance 34 of overshoot. Thus, when the blade 33 strikes the insulating segment and the motor power is shut off, the timer mechanism coasts or overshoots a distance somewhat less than the width of the segment 36. Now when the pushbutton is actuated to start another timing cycle and bypasses the insulation, the motor starts turning immediately, and before the button can be released the blade 33 has moved off the far edge of the segment 36 onto conducting path once more and the motor continues to turn through a full revolution. In both cases the overshoot has resulted in resetting the timing mechanism, so that when a new actuation is started the timing mechanism will go through a whole cycle.

FIG. 1 shows anoverall isometric of a typical electric clock timer with discs in which timing is effected on the disc periphery. This makes illustration of a typical simple circuit easier, but the construction is less compact for the same degree of versatility than that of FIG. 2 and so, for many purposes, is not preferred.

The electric timer motor, of the standard self-starting synchronous type, is shown as connected to a 110 volt AC line with a grounded wire and a hot wire 2 using a polarized plug 3. The timer motor rotates a grounded shaft 31 on which are fastened two conducting discs 4 and 5. The first disc controls the motor circuit and is provided with a narrow insulating segment 9. As has been described above, this may be of the order of width of segment 36 in FIG. 3 but in the drawing is shown exaggerated for clarity. A leaf contact 6 rides on the disc 4 and is connected to the motor, completing its circuit. In other words, when the leaf 6 is in contact with the conducting portions of the periphery of the disc 4, the motor will turn.

A pushbutton switch 7 is shown which momentarily bypasses the switch 6 and when depressed starts the motor. As has been described above, the insulating segment 9 is so narrow that the momentum of the timer when it is shut off moves the disc 4 for a distance such that while it stops with the blade 6 still in contact with the insulating segment, it is near enough to the edge so that when the pushbutton 7 is depressed and the timer motor starts turning the disc 4 will move to a point where the blade 6 is in contact with the conducting portion of the disc. It should be noted that we are dealing with finite times, the timer not stopping instantaneously when power is shut off as the blade 6 strikes the segment 9; and also the actuation of the pushbutton 7 is likewise not instantaneous and may take from a substantial fraction of a second to a second or more, depending on how fast the button is manually actuated. The simple form of the present invention which has been described in connection with FIGS. 1 and 2 is not suitable for operation where initiation time is extremely short. For this purpose a locking relay or its electronic equivalent is still needed, and the cornbination of the present invention with such an element will be described below in conjunction with FIG. 1, which also illustrates the combination of short intervals and very long intervals on ditferent discs.

When the pushbutton 7 has been momentarily depressed the timer starts, the blade 6 reaches the conducting portion of the disc 4 and the timer continues throughout its cycle until the blade 6 again strikes the segment 9. A second disc 5 cooperates with a second blade 3 which grounds the load 28 and starts whatever operation the load circuit controls. As the present invention is not limited in its broader aspects to any particular type of load, such as a commercial squelch device, it is shown diagrammatically. When the motor starts the disc 5 moves until the blade 8 has left the wider insulating segment 10. This segment is not quite as greatly exaggerated as is segment 9 and provides a maximum reliability so that when the timer has turned through a full cycle the load is disconnected by the insulating segment 10 when the motor stops. The greater width of the segment 10 assures that the load is cut off reliably at the end of the cycle.

Unless polarizing sockets are used with a polarizing plug 3 the modification of FIG. 1 is not suitable for muting the audio systems of television sets and radios because if there is not polarization of the incoming wires, the switch blade 8 could put the hot lead of the 110 volt circuit on the voice coil of a loudspeaker or other portions of the audio circuit, With undesirable, and in some cases disastrous, results. Also, for many purposes it is desirable to isolate completely the audio system of a television or radio receiver from the 110 volt line in order not to pick up stray signals. In such a case, even with a polarizing socket and a polarizing plug 3 the modification is not desirable. However, for other operations, such as for example a coffee percolator or toaster, it is a matter of complete indifference to the applicance which wires connect it to the ungrounded side of the AC line, and for such uses the modification shown in FIG. 1 is suitable, of course using a relay, but not a locking relay, in the load 28 if the power consumption is such as to require it. If there is no provision for polarization of the power line coming in, there is the possibility that the shaft 31 will be connected to the hot side of the AC line, and in such cases the timer mechanism should be reliably enclosed,if necessary providing for power cord interlock if the timer is open, to eliminate shock hazard. These are conventional precautions with electric appliances and are, therefore, not illustrated.

FIG. 2 represents a construction which, for many purposes, is preferable to the simple one of FIG. 1. Only the switch disc is shown with switch blades, the motor shaft 31 of course being turned in the same way as in FIG. 1. The disc, which is shown as insulating, is provided with a continuous conductive ring 14 which is connected to one end of the load circuit through the blade switch 13. In the drawing this is illustrated as a muting loud speaker 26 for squelching of commercial circuits, the voice coil 27 of the speaker being shorted during the squelching intervals, as will be described below. The disc carries two additional conducting paths 23 and 24 on which ride blade switches 15 and 16. Both conducting paths are connected to the path 14 through the connector 25. The two blades 15 and 16 are connected to two contacts of a single pole double throw switch 17, the movable contact 18 of which is connected to the other end of the voice coil 27. It will be noted that the connecting path 24 extends for almost a complete circle with an insulating gap 20 which corresponds to the insulating segment 10 in FIG. 1. The conducting path 23, however, extends only half way around the disc, the remainder of the distance being an insulating path which is indicated at 21 and which in effect performs for this path the same functions as does the insulating gap 28 for the path 24.

On the periphery of the disc there is a wide conducting circle 22 which extends all the way around the disc except for a very narrow insulating segment 19, which is of the same dimensions and performs the same function as does the corresponding segment 9 in FIG. 1. It, too, is exaggerated for clarity. Two blades 11 and 12 ride on the path 22, and of course the insulating segment 19 when they reach it, and are connected to the timer motor and to ground respectively, as is indicated schematically. A starting pushbutton, (not shown), is provided as in FIG. 1.

Also, the single-pole double-throw switch 17 is adjusted to choose the timing intervals desired. Let use assume that it connects the moving contact with blade 15. Also let us assume that the timer is in the reset position, i.e., the motor shut off but ready to start, which is illustrated on the drawing. Now, the initiating pushbutton is depressed, the timer motor starts, the disc moves slightly so that the blades 11 and 12 ride on thewide conducting path 22, and the timer continues because there is a completion of the circuit to the motor. As the path 24 extends all the way around the disc except for the insulating segment 20, the loudspeaker will be muted for a full turn of the timer disc; in other words, the timing will be the same as shown in FIG. 1, and if the timer shaft 31 turns at 1 r.p.m., this will squelch the loudspeaker 26 for one minute.

If a shorter interval is desired, the switch 17 is thrown connecting the loudspeaker coil to switch blade 16 and now when another cycle is initiated it will only last for half a minute, as the circular conducting path 23 extends for only half way around the disc. The timer continues to turn through its full cycle but as the path traversed by the blade 16 is over insulation, the loudspeaker remains unmuted until the timer has gone through its cycle and another squelch cycle is initiated by voluntary actuation of the initiating button.

It will be noted that there is an extremely simple switch construction, requiring only a' single disc, the conducting portions of which can readily be applied by printed circuit techniques, using, of course, conductors sufficiently thick so that they will not be worn through. The blades 11, 12, 13, 15 and 16 are shown perfectly tangential. It is necessary that they be somewhere near tangential to avoid unnecessary wear on the conductive paths. However, they do not have to be perfectly tangential, as if they make a small angle no significant wear results.

FIG. 2 shows a system in which the motor actuation is completely isolate-d from the switching of the load circuit for the intervals chosen. This is quite suitable for squelching of the audio in a television and radio receiver during commercials, and so this particular type of load circuit is illustrated as being typical of one for which the complete isolation of motor control and load circuits is suitable or required. Obviously, of course, any other load circuit may be used.

When a single disc of small size is used as in FIG. 2, it is generally undersirable to provide for more than twotiming intervals on the same disc, through of course with sufiiciently narrow blades more can be accommodated, with a selecting switch having more than two poles. With small discs it is generally preferable to connect a second disc, or more in an extreme case, where there are a larger number of timing intervals to be selected. The operation of course proceeds in exactly the same manner, and a conductive path 14 must of course be present on the second disc. It is also practical to use both sides of the disc, in which case the path 14 need not be repeated but the paths 23 and 24 can be connected through the disc to the conducting paths on the other side. It is also possible to have the contact path 22 appear on bothv sides of the disc and have one blade 11 on one side and the other blade 12 on the other side. A path of narrower width is thus made possible. It is not necessary to duplicate the insulating segment 19, as of course the circuit is broken if either blade 11 or blade 12 strikes an insulating segment.

For certain purposes it is desired to interrupt connection to a load for the particular timing interval. This is simply done by interchanging the conductive andnonconductive portions of the paths 23 and 24 with gaps 20 and 21 and, of course, connecting the path 14 to the gaps. In such a case when the timer is at rest the load is connected, but it is disconnected as soon as the timer is started and the blades 15 or 16 have reached an insulating portion for the time interval chosen. Thereafter the connection is not remade until another cycle is initiated.

FIG. 2 shows a mechanism which is quite versatile, as the load is completely isolated from the timer motor. However, for certain purposes, such as electrical appliances, this isolation is not needed. In such a case a simpler load circuit arrangement with a common ground, as is illustrated in FIG. 1, can be employed. Of course in such a case the blade 13 and paths 14, 22 and 23 are all connected together. The load, as in FIG. 1 is permanently connected to one side of the AC line and the other side is grounded. In this case, of course, a single narrow connecting path 22 can be used, as it is not necessary to have two separate blade switches 11 and 12, which are shown in FIG. 2, to permit the stopping the motor.

FIG. 4 illustrates a combination of switching for short intervals and long intervals. As in FIG. 2, where the disc 5 is used for shorter time intervals, the conducting paths and switches bear the same reference numerals except that only one switch 11 is used for the motor circuit. Disc 5 turns on a hollow shaft 37, whereas the solid shaft 39 turns a disc 38. Both shafts are grounded and are connected to the conducting paths of disc 5 and a conducting path 40 of disc 38-. Blade 41 moves over the latter, and the insulating segment 42 can be quite broad. Through conventional gearing, disc 38 may be made to turn much more slowly than disc 5. For example, if the latter makes one revolution in two minutes, the former may make one revolution in an hour or two hours.

The load 28 and one side of the motor is connected to the hot wire 2 of the AC line, as in FIG. 1. One pole of a double-pole, double-throw switch 43 can switch the load either onto the blade switch 41 for slow timing or to one or other of the switches 15 and 16 of the fast timer, the latter two being selected as described in FIG. 2 by the single-pole, double-throw switch 17, the movable pole 18 of which is connected to one of the contacts of the double-pole switch 43. A locking relay 44 is provided in the motor circuit and is connected to movable contact on the double-pole switch 43. When this switch is in the lower position the connection .is through the blade 11 to the grounded path 13 on disc 5. In the upper position the connection is to a normally closed microswitch 45 which is actuated by a smallbump 46 in the disc 38. This disc is provided with a small amount of play so that when the disc 38 lifts the switch 45 by the bump 46, thus momentarily opening the circuit to the locking relay 44 and unlocking it, the play permits the switch 45 to slide down the bump, thus producing an operation analogous to a toggle switch. The locking relay has been unlocked, how ever, and as it is in series with the switch 45 the motor does not continue to turn until another sequence of operation is initiated by a starting button or starting pulse. When such a pulse is received, and it can be very short comparted to the time it takes to operate a manual pushbutton, the relay 44 locks and stays looked through the switch 45 until a full revolution of the disc 38 has taken place. Since a locking relay is necessary for actuation from the slow turning disc 38, the gap 19 on disc 5 is very narrow, corresponding in relative dimensions to a narrow segment 35 in FIG. 3. If the switch 43 is in its lower position the overshoot on the disc 5 when it has completed a revolution causes the blade 11 to pass over the narrow insulating segment 19, and now when the latching relay is once more actuated the motor will continue to turn, while the blade 11 runs along the conducting path 22 on disc 5.

FIG. 4 illustrates at the same time the provision for long and short intervals and the use of a locking relay with a narrow insulating segment. A narrow segment and locking relay may be incorporated in the construction of FIGS. 1 and 2 where this is desirable, as for example with a very fast, remote control instead of a manual pushbutton.

It will be seen that the present invention is a versatile one that can be used with or without a latching relay, depending on the conditions required. As pointed out above, a latching relay is required where there is a very slow interval or where the actuation is much faster than by manual pushbutton, as for example in a device in which a remote control with a short electrical pulse is used to start a timing cycle. In each case the same principle of timer overshoot is used. The slight play in the disc 38 described in FIG. 4 together with the toggle eifect of the bump 46 and the switch 45 in effect produce an overshoot. Even though the disc turns slowly, this overshoot is magnified by the fact that there is enough play so that once the switch 45 has passed over the highest point of the bump 46, it can snap down again on the other side to its normally closed position.

I claim:

1. In a synchronous electric clock timer of the selfstarting variety provided with slow turning switching elements and switching conducting paths thereon, said clock timer having a finite but definite overshoot when power to the timer motor is shut oif, the improvement which comprises,

(a) at least one rotatable switching element connected to be rotated by the timer,

(b) a motor controlling conductive path on at least one rotatable switching element, said path having an insulating segment of size relative to the overshoot of the motor, at least one blade switch contacting said path and connected to motor switching means for the clock motor, whereby when the rotating element causes the blade switch to contact the insulating segment the motor stops after a predetermined distance of overshoot,

(c) means for momentarily starting the timer motor for a sufficient period of time so that the blade switch comes in contact with a conducting portion of the path whereby the motor continues to turn,

(d) switching elements rotated by the timer having at least one conducting path and blade switches cooperating therewith to change electrical connections of a load circuit, said conducting paths being interrupted with insulating segments longer than the distance of overshoot of the timer motor whereby on momentarily starting the timing motor a load switching cycle is initiated and takes place through at least one predetermined interval determined by the relative lengths of the conducting path and non-conductive segment, and on completion of the timing cycle the timer is reset to initiate a new cycle when the momentary motor actuating means is energized.

2. A timer mechanism according to claim 1 in which the rotating element contains a conductive path and at least one blade switch in circuit with the motor, and the insulating segment in the conducting path is slightly longer than the distance of timer motor overshoot, and the momentary means for starting the timer motor have an actuation time constant longer than the time required to move the rotating element through the remaining portion of the insulating segment, whereby on momentary starting of the timer motor the blade switch again contacts a conductive portion of the path and thus maintains the motor in operation for another cycle.

3. A timer mechanism according to claim 2 in which two blade switches contact the conductive path for maintaining motor operation and means for isolating the load circuit from the motor circuit during operation.

4. A timer mechanism according to claim 2 in which the rotating element is provided with a plurality of conducting paths of different lengths with blade switches in each pathand means for selectively connecting the load circuit to any one of said paths.

5. A timer mechanism according to claim 1 in which the rotating element is provided with a plurality of conducting paths of different lengths with blade switches in each path and means for selectively connecting the load circuit to any one of said paths.

6. A timer mechanism according to claim 1 in which the motor circuit is provided with a latching relay, the latching elements of said relay connected through the conducting path for motor control and the insulating segment is shorter in width than the overshoot of the timer motor, whereby when the segment is encountered, the locking relay is unlocked but the overshoot carries the switch blade past the insulating segment and the momentary motor actuating mechanism momentarily locks the locking elements of 'the locking relay, which remain locked through the conducting path until the insulating segment is again reached.

7. A timer mechanism according to claim 6 in which there are a plurality of conducting paths of different lengths with blade switch in each path and selecting means for connecting the switches of any one path to the load circuit. g

8. A timer mechanism according to claim 7 in which the motor circuit is completely isolated from the load switching circuits.

9. A timer mechanism according to claim 5 comprising a plurality of rotating elements, means for rotating the elements at dilferent rates, at least one of which is very slow, and snap acting switching means on said slow rotating element for unlatching the locking relay at the end of said long time interval.

10. A timer mechanism according to claim 9 in which another of the discs turns rapidly and has a motor control path and cooperating switch with an insulating segment shorter than motor overshoot on the disc in question.

References C'ited UNITED STATES PATENTS 1,244,408 10/1917 Bacon 200-36 X 1,679,781 8/1927 Peyton et a1. 200-36 BERNARD R. GILHEANY, Primary Examiner.

F. E. BELL, Assistant Examiner.

Claims (1)

1. IN A SYNCHRONOUS ELECTRIC CLOCK TIMER OF THE SELFSTARTING VARIETY PROVIDED WITH SLOW TURNING SWITCHING ELEMENTS AND SWITCHING CONDUCTING PATHS THEREON, SAID CLOCK TIMER HAVING A FINITE BUT DEFINITE OVERSHOOT WHEN POWER TO THE TIMER MOTOR IS SHUT OFF, THE IMPROVEMENT WHICH COMPRISES, (A) AT LEAST ONE ROTATABLE SWITCHING ELEMENT CONNECTED TO BE ROTATED BY THE TIMER, (B) A MOTOR CONTROLLING CONDUCTIVE PATH ON AT LEAST ONE ROTATABLE SWITCHING ELEMENT, SAID PATH HAVING AN INSULATING SEGMENT OF SIZE RELATIVE TO THE OVERSHOOT OF THE MOTOR, AT LEAST ONE BLADE SWITCH CONTACTING SAID PATH AND CONNECTED TO MOTOR SWITCHING MEANS FOR THE CLOCK MOTOR, WHEREBY WHEN THE ROTATING ELEMENT CAUSES THE BLADE SWITCH TO CONTACT THE INSULATING SEGMENT THE MOTOR STOPS AFTER A PREDETERMINED DISTANCE OF OVERSHOOT, (C) MEANS FOR MOMENTARILY STARTING THE TIMER MOTOR FOR A SUFFICIENT PERIOD OF TIME SO THAT THE BLADE SWITCH COMES IN CONTACT WITH A CONDUCTING PORTION OF THE PATH WHEREBY THE MOTOR CONTINUES TO TURN, (D) SWITCHING ELEMENTS ROTATED BY THE TIMER HAVING AT LEAST ONE CONDUCTING PATH AND BLADE SWITCHES COOPERATING THEREWITH TO CHANGE ELECTRICAL CONNECTIONS OF A LOAD CIRCUIT, SAID CONDUCTING PATHS BEING INTERRUPTED WITH INSULATING SEGMENTS LONGER THAN THE DISTANCE OF OVERSHOOT OF THE TIMER MOTOR WHEREBY ON MOMENTARILY STARTING THE TIMING MOTOR A LOAD SWITCHING CYCLE IS INITIATED AND TAKES PLACE THROUGH AT LEAST ONE PREDETERMINED INTERVAL DETERMINED BY THE RELATIVE LENGTHS OF THE CONDUCTING PATH AND NON-CONDUCTIVE SEGMENT, AND ON COMPLETION OF THE TIMING CYCLE THE TIMER IS RESET TO INITIATE A NEW CYCLE WHEN THE MOMENTARY MOTOR ACTUATING MEANS IS ENERGIZED.

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