US3555214A

US3555214A - Timing device

Info

Publication number: US3555214A
Application number: US805122A
Authority: US
Inventors: Art Lee; Ralph M Manning
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1969-03-07
Filing date: 1969-03-07
Publication date: 1971-01-12
Anticipated expiration: 1988-01-12

Abstract

A timing device for performing a switching function at dusk and at a specific time during the night. A synchronous motor drives a time dial at a first speed during the daylight hours and a double that speed after dusk through a power train including a lever arm driven by an eccentric to engage the teeth of a ratchet gear to rotate a cam assembly which actuates movable contacts through which the motor and a load controlled by the timing device are energized. Projections carried by the time dial engage cam portions formed on a star wheel to rotate the star wheel and the cam assembly to actuate the movable contacts to deenergize the load and the motor.

Description

United States Patent Arthur A. Fournier, Jr., David Att0rneysJon Carl Gealow,

M. Schiller, Joseph B. Foreman, Frank L. Neuhauser and Oscar B. Waddell [21] Appl. No.

[ S4] TIMING DEVICE 8Claims, 10Drawing Figs. I i

ABSTRACT: A timing device for performing a switching function at dusk and at a specific time du synchronous motor drives a time dial at a the daylight hours and a double that s 2 9O 8 8 3 0H 3 3 0/7 04 27 h m H I. C C 5 L U .m l l 2 1 5 5 l l a power train including a lever arm d 50 Field 74/352; 38(D2). 38(all) engage the teeth of a ratchet gear to rotate a cam assembly tacts through which the motor and a load controlled by the timing devi ZOO/38(D3) which actuates movable con ce are energized. Projections carried by the time dial engage cam portions formed on a star wheel to rotate the star wheel and the cam assembly to actuate the movable contacts to deenergize the load and th motor.

S T N m m A 3 mm MA m R w w.. N U Q U 2,076,371 4/1937 Hottenroth,.lr.,etal..... 200/38(D3) 2,922,853 1/1960 Truesdelletal 200/38(D2) PATENTEDJAM 2 I97! SHEET 3 BF 3 y e MW m M w A -0 HQ a P 5 1 TIMING nizvIca BACKGROUND or THE INVENTION This invention relates-to an improved timing device and more particularly to a timing device which performs a switching function at dusk and at a specific time during the night.

With the advent of highways located remote from cities and more particularly Iemote from the businesses in the cities, it has been found desirable to locate signs in remote areas visible from these highways to call attentionto the businesses in the cities. Since these highways are generally heavily traveled throughout the daylight hours and late into the evening, it is desirable that the signs visible therefrom be illuminated in the evening. While numerous time switches are available which could be utilized to control the electrical illumination of such signs, these switches generally require the attention of a serviceman to adjust them to the seasonal changes in the time of sunset if wasteful power consumption by the sign illumination devices during daylight hours is to be avoided. Further, these time switches normally include a continuously operating 24- hour timer driven by a synchronous motor. In the case ofa failure of power to the timer, its operation of the sign illuminathan the latest time at which it is desirable to accomplish the switching function, but preferably not much later than that time so as to provide as long a period as possible during the dark hours during which the motor driving the time dial is unenergized.

In accordance with a preferred embodiment of this inven tion a time dial is driven by a synchronous motor through a powertrain including a lever arm which is driven by an eccentric on a shaft to engage the teeth of a f rst ratchet gear and rotate the first ratchet gear. The lever arm also drives a second ratchet gear which in turn drives a cam assembly which actuates a set of movable contacts. An electromagnetically actuated means cooperates with the lever arm such that when it is energized the lever arm drives the ratchet gears one'tooth per revolution of the eccentric, and when it is deenergized the lever arm drives the ratchet gears two teeth per revolution of the eccentric. The electromagnetically actuated means also affects energization of the motor when it is energized. The electromagnetically actuated means is energized at sunrise so as to effect energization of the motor such that the lever arm drives the ratchet gears at the rate of one tooth per revolution tion devices will be in error by the duration of the power OBJECTS OF THE INVENTION It is therefore a primary object of this invention to provide a timing device which will perform a switching function at dusk and at a predetermined time during the night and which is self correcting in case of power failure and adjusts automatically to seasonal variations in the time of sunset.

-It is another object of this invention to provide a novel and improved timing construction.-

SUMMARY or THE INVENTION The foregoing objects are accomplished in accordance with this invention by providing a timing device the operation of device which is of inexpensive and reliable of the eccentric. Rotation of the second ratchet gear rotates the arm assembly to actuate the movable contacts to provide a second circuit for energizing the motor. The first ratchet gear is driven throughout the day at the rate of one tooth per revolution of the eccentric.

' At dusk the electromagnetically actuated means is deenergized, whereby the lever arm drives the ratchet gears at the rate of two teeth per revolution of the eccentric. Rotation of the second ratchet gear rotates the cam assembly to actuate which is based upon the recognition of a particular general relationship of sunrise and sunset to noon. More particularly,

sunrise and sunset occur before and after noon by approxi-' mately the same time period. That is, the time period from sunrise until noon approximately equals the time period from noon until sunset. Similarly, the time period from midnight until sunriseis approximately equal to the time period from sunset ut until midnight. If a time dial starts turning at one revolution per day at sunrise and stops at sunset, the remaining angle represents the hours of darkness from sunset to sunrise. Since the times of sunrise and sunset vary, it is not possible to locate a fixed position for midnight in the angle representing the dark or night hours. However, the dark angle may be effectively divided in half by doubling the speed of the dial starting at sunset. Thus a given point on the time dial will make one complete revolution between sunrise and midnight regardless of the time of sunrise and sunset. By adjusting the rate of rotation of a time dial while maintaining the ratio of the rate of rotation during daylight to that at night of one to two, the time for completing one rotation may be shifted from midnight to another predetermined time. If the time dial is driven by a motor which is started at sunrise and stopped at the completion of one rotation of the time dial, the motor driving the time dial will remain energized from the predetermined time until sunrise. The time dial may be calibrated to indicate the correct time between sunset and the predetermined time. The predetermined time must be chosen during the dark hours between sunset and sunrise. It must be chosen at a time later the movable contacts to energize. the load on illuminating devices controlled by the timing device. An adjustable tab ,carried by the timing gear is positioned to engage a first cam portion of a star wheel to rotate the cam assembly to actuate the movable contacts to deenergize the load at a preset time. At completion of one revolution of the time gear, a projection or pin carried by the time gear engages a second cam portion of the star wheel to rotate the cam assembly to actuate the movable contacts to deenergize the motor.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view with a portion broken away of the timing device of the present invention;

FIG. 2 is an exploded view of portion of the timing device of FIG. 1;

FIG. 3 is a view in rear elevation of the timing device of FIG.

FIG. 4 is a circuit diagram of the timing device of FIG. 1; FIGS. 5a through 5d are enlarged front plan views with some portions removed and others broken away to better show the several operating positions of the cam assembly and the set of movable contacts;

FIGS. 6a and 6b are enlarged front plan views with some portions removed and others brokenaway to better show the several operating positions of the lever arm.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1, a timing device constructed in accordance with the present invention including a housing 10 which contains all the operating components of the timing device will be described. Wherein it will be generally desirable to mount the timing device in close proximity to the electrical device being controlled thereby, the housing 10 is preferably weatherproof. Accordingly, the housing includes a formed sheet metal base 12 and a formed sheet metal cover 14 attached to each other along one edge by hinges (not shown). The open end of base 12 is provided with a flange 16 which is received within a cupped flange 18 provided on the open end of cover 14. The cover 14 when closed is pulled against the base 12 to compress a sealing member 20 secured in cupped flange 18 by engagement of the lever 22 on the cover 14 with the pin 24 on the base 12.

The operating components of the timing device are assent bled on a base structure including a pair of flat

sheet metal plates

26 and 28. The front plate 26 is spaced apart from'the back plate 28 by three cylindrical spacers, one of which Elli is shown in FIG. 1. The cylindrical spacers may be attached to the back plate 28 in a permanent manner, such as by riveting, and the front plate 26 is secured to the spacers by

screws

32, 34, and 36 which are received in threaded apertures in the spacers.

The base structure including plates 26 and 293 is readily mounted in and removable from the housing lltl. A rectangular aperture 38 is formed in a rearwardly extending flange d ll at the top of front plate 26 for receiving a rectangular tab l2 which is mounted upon and spaced from the top of base l2 of the housing. An aperture is provided in the rectangular tab l2 for receiving a cotter pin 44 which prevents flange dtl from sliding off of the tab 42. A pair of brackets, one of which is shown, are secured to a rearwardly extending flange 4d at the bottom of front plate 26 by a pair of screws 50, which screws also secure an insulating terminal block 52 to the flange 48. The brackets are each provided with a tab portion (not shown) which is secured by a screw (not shown) to the back wall of the base 12.

The operating components of the timing device are best shown in FIG. 2 with their relationship to the front plate 26 and back plate 28 being further shown in FIGS. 1 and 3.

The operating mechanism includes a gear, lever, and cam power train 54 through which a synchronous gear motor 56 operates a set of movable contacts 58 as is best seen in FIGS. 2 and 3. The synchronous gear motor 56, only the rotor and gear portion of which is shown in FIG. 2, provides an output at gear 60. Gear 60 drives a larger diameter gear 62 which is secured on a shaft 64. The shaft 64, which is supported at one end by the front plate 26 and at the opposite end by the back plate 28, is provided with an eccentric portion 66 which is received in an aperture 68 formed in a lever arm 70.

A first portion 72 and a second portion 74 of the lever 70 extend in diametrically opposite directions with respect to the shaft 64. The ends of the lever portions '72 and "7d are provided with tabs '76 and 78 respectively.

Tabs

76 and 78 extend in planes perpendicular to each other, and are formed in planes perpendicular to the body of the lever arm 7b. The end of tab 78 is formed as a tooth which is biased into engagement with ratchet gears 80 and 82, which are supported on a shaft 84, by a spring 86. Shaft 84, like shaft 64, is supported by

plates

26 and 28. The shaft 84 not only supports the ratchet gears 80 and 82 of the power train, but also a cam assembly lid and a star wheel 90. In addition, a pinion 92 is provided with a bore to freely receive shaft 84, for rotation thereon. Pinion 92 is press fit within a bushing 94 and ratchet gear fill is press fit over bushing 94 such that they freely rotate together with respect to shaft 84.

The power train 54 further includes a time gear assembly it? which is supported for rotation on the front plate 26 in a position wherein it engages pinion star wheel 9! which is lteyed by pin @b for rotation with the shaft 84 includes a pair of cam portions MW and W2, one of which 100 is engaged by a tab lllld provided on a plate which is adjustably secured to a time gear lltltl, and the other of which 102 is engaged by a pin lttl mounted on the time gear 108.

Having thus described the principal elements of the power train 54 and the housing in which they are contained, the electrical circuit of the timing device which controls the power train 54 will be described by making reference to FlG. 4. The electrical components or" the timing device, and an electrical load, the energization of which is controlled by the timing device, are both energized from an alternating current supply represented by the lines Lil and L2. A photocell M2 which is mounted in a sidewall of the base 1.2 to be exposed to the ambient light level, is connected in series with a current limiting resistor I14 a diode llti, and the actuating coil lid of a relay 120 between lines Ll. L2. A capacitor ll22 confor rotation thereby. The

nected in parallel with the actuating coil M8 serves to maintain a continuouseurrent in coil-llld even though current flows through diode lllltli only during alternate half cycle of the alternately current supply. A second series circuit connected between lines Ll and L2 includes normally open contacts of a snap switch 124 and the field winding l26 of synchronous gear motor $6; A third series circuitconne'cted between lines Li and L2 includes the extemal' load to be cbiitrolled by the timing device, which load-is shown asa'lariip llZil, and a pair of movable contacts llEltl and i352 of theset of movable contacts Through a third movable contact 1346f the set of movable contacts and movable contact 1'32 aci'rci'iit inparallel with the normally open contacts of snap "124 may be established between line L2 and the fieldwinding 126 of the gearmotor56- in operation of the timing device, movable contacts 130 and i3 1 are-displaced by rotation of cam assembly 88 to engage with and disengage from' movable contact 132 in a predetermined sequence. ln order to move movable contacts 130 and H4 to engage movable contact 132, movable contact 134 is provided with a cam follower tab 136 which is positioned to be engageable with a first cam surface 138 of cam assembly 88. Similarly, movable contact 130 is provided with a cam follower tab 140 which is positioned to be engaged by a second cam surface 142 of cam assembly 88. The cam surfaces 138 and 142 each includes six identical camsegments with the cam assembly rotating one-sixth of a revol i tion or one cam segment per day. Each of the cam segments of cam surface 138 is formed with a sloping portion 144 rising from a lowest arcuate portion 146 to a highest arcuate'portion 148, with an intermediate arcuate portion 150 located between the lowest arcuate portion 146 and the highest arcuate portion 148. Each segment of the cam surface 142 includes a sloping portion 152 interposed between a higherarcuate portion 154 and a lower arcuate portion 156 as are best seen in FIG. 3.

The operation of the timing device'will'now bedescribed by making reference first to FIGS. 2,3 and 5, wherein'the positions of the components of the power train 54'during the period preceding sunrise are shown. During this time interval the movable contacts lllll and i132 and ll3l are all spaced apart from each other, with the movable contact l32 being in its natural or free position. As detailed in FIG. 5a, the movable contacts i130 and are spaced from movable contact 1132 when the cam follower tab 136 of movable contact 134 rests on the lowest arcuate portion 146 of (38.111 surface liltl and cam follower tab M ll of movable contact 130 rests on the lower arcuate surface 156 ofcam surface 140. With the set of movable contacts 58 in their open position, and with the photoelectric cellllil in its high resistance state such that relayfactuating coil M8 is not energized sufficientlyto actuate its armature and thereby close the contacts of snap switch I24, both the inotorfield winding 326 and the lamp lllb controlled by the timing device are deenergized. I

At or immediately following sunrise, sufficient light will fall on photocell i112 to-lower its resistance to the point wherein sufficient current flows through relay actuating coil M8 to cause its armature i158 tobe attracted tothe core within the relay actuating coil; This downward movement of the armature Md as viewed in FIG. 2 will permit downward movement of the free end of actuating lever 1168 of the snap switch 12 The downward movement of the free end of actuating lever w ll permits the operator B62 of snap switch 124 to move downward, whereby its normally open contacts are closed, thereby energizing the field winding 126 of synchronous gear motor 56.

Referring now to H6. 2, the manner in which the synchronous gear motor '56 drives theratchet gears 80 and 82 through the portion of the power train 54 including the lever arm Ill, shaft 64 and gear 62 secured thereto will be described. Rotation of the motor output gear 60 in the direction of the arrow A will cause rotation of the gear 62 and the shaft 6 5 in the direction of the arrow B. Rotation of the eccentric portion of the shaft 64 will cause a rotary motion to ment imparted to the first portion 72 of the lever arm is shown by the arrow C. v

The motion of thelever arm 70 will be further understood by making reference to FIG. 6a; Upon initial energization of the motor 56 the lever arm 70 will be in the position shown by the solid line 164 in FIG. 6a.- Further rotation of the shaft 64 in the direction shown by the arrow B will cause the tab 78 to be drawn upward over two teeth of the ratchet gears 80 and 82 to the position shown by dashed line 166. Due to the energization of relay actuating coil 118 its armature 158 has moved downward, thereby moving an extended arm 168 attached to the armature from the position shown by the solid line 170 in FIG. 6a to the position shown by the dashed line 172.

Continued rotation of the shaft 64 will cause the tab 76 of first portion 72 of the lever arm to move into contact with the edge of extending arm 168, whereby continued rotation of the eccentric portion 66 of the shaft 64 will cause the lifting of tab 78 from the teeth of ratchet gears 80 and 82, as shown by the solid line 174 in FIG. 65. Further rotation of the shaft 64 will result in the tab 76 moving downward, so as to be freed from the edge of extending arm 168, such that the tab 78 may again move into contact with the teeth of ratchet gears 80 and 82 as shown by the dashed line 176 in FIG. 6b. It should be observed that the tab 78 moves into contact with the teeth of the ratchet gears 80 and 82 located between the teeth engaged by the tab 78 in its two positions shown inFIG. 6a. Continued rotation of the shaft 64 will cause the second portion 74 of the lever arm 70 to be moved downward-whereby the tab 78 which is in en-. gagement with a tooth of each of the ratchet gears 80 and 82 will cause the teeth to be moved downward the spacing of one tooth, thereby rotating ratchet gears 80 and 82 through the angle occupied by one tooth. Additional rotation of shaft 64 will cause tab 78-to again move upward over a pair of teeth. However, again, the interference of the edge of extending arm 168 with the tab 76 causes the lifting of tab 78 over the first teeth on ratchet gears 80 and 82 such that it again engages the second teeth to again rotate the ratchet gears 80 and 82 through the angle occupied by a single tooth.

Thus, after two revolutions of the shaft 64 the ratchet gears 80 and 82 are rotated through an angle occupiedby two teeth.

Further rotation of the shaft 64 and oscillation of the lever arm 70 does not further advance ratchet gear 82 wherein. a-

tooth is not provided in the next succeeding tooth position.

The just described rotation ofthe ratchet gear 82 through an angle occupied by two teeth is effective to actuate movable contact 130 to engage movable contact 132 to provide a circuit in parallel with that'formed by the closed contacts of snap switch 124 for connecting the field winding 126 to Line L2. Ratchet gear 82 and the cam assembly 88 are keyed for rotation with the shaft 84. This may be accomplished by providing a flat on the shaft 84 and mating flats both within the bushing upon which is mounted the ratchet gear 82 and within the cam assembly 88. Upon rotation of the ratchet gear 82 through the angle occupied by two successive teeth, the cam assembly 88 is rotated to a position wherein cam follower tab 136 of the movable contact 134 rises on the sloping portion 144 of the first cam surface 138 to close movable contact 134 on movable contact 132, as shown in FIG. 5b.

Wherein the

cam follower tabs

136 and 140 are riding on the

sloped portions

144 and 152 respectively of the

cam surface

138 and 142, respectively, the spring forces of the

movable contacts

130 and 134 would tend to rotate the cam assembly 88 in the clockwise direction as viewed in FIG. 5b. In order to prevent this backward rotation of the cam assembly 88, the ratchet gear 82 and the shaft 84 to which they are keyed, a spring biased pawl 178 is provided to engage the teeth of the ratchet gears 80 and 82 to prevent their backward rotation.

Referring now to FIG. 4, it will be seen that the closing of contacts 132and 134 provides a circuit in parallel with thatmotor 56. Thus, the motor 56 will continue to run during the daylight period with the tab 78 of lever arm 70 advancing ratchet gear 80 one tooth space for each revolution of shaft 64. Pinion 92 being pressfit to the same bushing 94 as is ratchet gear 80, will drive time gear 108 in a clockwise direction as viewed in FIG. 2.

At dusk'the resistivity of the photocell 112 will increase to a level wherein sufficient current will no longer flow through the relay actuating coil 118 to maintain the armature 158 attracted to the relay core. The release of the armature 158 will move actuating lever 160 upward to open the normally closed contacts of snap switch 124. The opening of the contacts of snap switch 124 at this time does not cause deenergization of the motor field winding 126, wherein it continues to be energized through the now closed

movable contacts

132 and 134.

With the upward movement of armature 158, extending arm 168 will also move upward wherein tab 78 will no longer be lifted from the ratchet gears 80 and 82 so as to miss the first tooth on the downward stroke, and will now begin to drive the ratchet gears at the rate of two teeth per revolution of the shaft 64. The ratchet gear 80 will now be driven at twice the speed it was driven throughout the daylight hours. Also, the ratchet gear 82 will now be driven wherein the tab 78 will engage the first tooth of the group of three teeth which are spaced from the two teeth which were driven at sunrise by an angle occupied by one tooth. Thus, on the first revolution of the shaft 64 after sunset the ratchet gears 80 and 82 will be rotated through an angle occupied by twoteeth. The rotation of ratchet gear 82 will rotate cam assembly 88, with

cam follower tabs

136 and 140 rising further on sloping

portions

144 and 152 of the cam surfaces. However, the movable contact 130 will remain spaced from movable contact 132 and movable contact 134 will remain in engagement with movable contact 132 as shown in FIG. 5b. On the second revolution of the shaft 64 after sunset the ratchet gears 80 and 82 will be again rotated through an angle occupied by two teeth. As this is happening, the cam assembly will be rotated to the position shown in FIG. 5c wherein the cam follower tab 140 of movable contact 130 has dropped off of the higher arcuate portion 154 of the cam surface 142 to cause the engagement of

movable contacts

130 and 132 to energize the load 128. Cam follower 136 v of the movable contact 134 is engaged with the highest arcua pointer 180 indicates the time at which the load 128 is to be deenergized. At this predetermined time the tab 104 on the adjustable plate 106 will engage tooth 182 on star wheel to rotate it and the shaft 84 to which it is keyed in the counterclockwise direction. Cam assembly 88 will be rotated by the shaft 84 to the position shown in FIG. 5d. Cam follower tab 136 has dropped from the highest arcuate portion 148 of the cam surface 138 to the intermediate arcuate portion 159, as a result of which

movable contacts

132 and 134 drop away from movable contact 130, to deenergize the lamp or load 128.

Movable contacts

134 and 132 still being closed, the motor 56 remains energized to continue to drive the time gear assembly 96 in the clockwise direction. At approximately 2:30 a.m. the time gear assembly will have been rotated to the position wherein pin will engage one of the radials 184 of cam and cam assembly 88 in the counterclockwise direction. The cam assembly 88 will be rotated to the position shown in FIG. 5a, wherein cam follower tab 136 has dropped to the lowest arcuate portion 146 of the cam surface 138, thereby separating or opening

movable contacts

132 and 134 to deenergize the motor field winding 126. The motor will remain deenergized until sunrise the following morning.

described may be disturbed by a failure of the alternating current supply. at lines L1 and L2. A power failure between approximately 2:30 am. and sunrise, during which period the motor 56 is not energized, does not of course have any affect on the operation of the timing device. However, a power failure during the daylight hours when the rachet gear 30 is being driven at the rate of one tooth per revolution of shaft 34,

or during the period following sunset to 2:30 a.m. when the ratchet gear 80 is being driven at the rate of two teeth per revolution of shaft 64, will temporarily disturb the desired operation of the lamp or load 3.28. The timing device will automatically reset itself within no more than 2 days and 4 hours.

For power failures during the day'the timing device will develop an error in its timing functions equal to one-half of the total time of the power failure. Similarly, for power failures during the period from dusk until 2:30 am. it will develop an error in its timing functions equal the total time of the power failure. in each case these errors are in the direction of causing the load or lamp 128 and the motor 56 to be deenergized later than the desired time. If the error is less than the total time from 2:30 am. to sunrise, the load 128 and the motor 56 will deenergize before sunrise, such that normal operations will start at sunrise.

When the error due to power failure is greater than the total time from 2:30 a.m. to sunrise, the motor will run until sunrise driving the ratchet gear 80 at the rate of two teeth per revolution of shaft 64, thus reducing the total error by the time period from 2:30 a.m. until sunrise.Energization of the relay actuating coil 118 at sunrise will cause actuation of armature 158 and movement of extending arm 168 to be engaged by tap 76 of lever arm 70, wherein as previously described, ratchet gear 80 will be rotated at the rate of one tooth per revolution of shaft 64. Upon the deenergization of actuating coil 113, the ratchet gear 80 will again be driven at the rate of two teeth per revolution of shaft 64. Further correction of the error will be made between 2:30 am. and sunrise of the next day. Under the worst conditions of power failure, which is one of l2 hours duration ending at midnight on the longest day of the year, the timing device will have corrected itself within 2 days and 4- days when installed at a location of 40 N. Latitude.

While a particular embodiment of this invention has been shown and described, it will be obvious to those skilled in the art that various changes and modifications may be made without departing from this invention in its broader aspects and, therefore, it is intended that the appended claims cover all such changes and modifications as fall within the true spirit and scope of this invention.

We claim:

1. A timing device for energizing a load at sunset and deenergizing the load at a later predetermined time comprismg:

a. a synchronous motor for rotating a drive gear at a fixed speed when energized;

b. a shaft having an eccentric portion and a gear secured thereto to be driven by said drive gear;

. a lever arm driven by said eccentric portion of said shaft,

said lever arm having first and second portions;

. first and second-ratchet gears positioned to be engaged and driven by said second portion of said lever arm;

e. a time ear gear assembly driven by said first ratchet gear, and being provided with at least two cam engaging means;

f. a cam assembly adapted to be rotated by said second ratchet gear;

g. a star wheel connected to rotate said cam assembly and having cam portions adapted to be engaged and. driven by said cam engaging means of said time assembly;

h. a set of movable contacts adapted to be operated by said cam assembly;

. an electromagnetic actuating means, adapted to be energized at sunrise and decnergized at dusk, the cnergization of said actuating means at sunrise causing the energization ofsaidmotor; and H J. an arm actuated from a first position when said electromagnetic actuating means is deenergized to a second position when said electromagnetic actuating means is energized, said arm in said second position being engaged by said first portion of said lever arm whereinsaid ratchet gears are advanced one tooth for, each revolution of said eccentric portion, in said first positiorrsaid arm not being engaged by said first portion of said, lever arm wherein said ratchet gears are advanced two teeth foreach revolution of said eccentric portion, said cam assembly being rotated by said second ratchet gear to actuate said set of movable contacts to provide a second circuit for maintaining energization of said motor, at dusk said earn assembly being rotated by saidsecond ratchet gear to actuate said set of movable contacts to energize the load, rotation of said time gear assembly by said first ratchet gear after dusk causing one of said cam engaging means to engage said cam portion of said star wheel to rotate said star wheel and said cam assembly to actuate said set of movable contacts to deenergize the load, further rotation of said time gear assembly by said first ratchet gear causing a second one of said cam engagingmeans to engage said cam portion of said star wheel to rotate said star wheel and said cam assembly to actuate said set of movable contacts to deenergize the motor.

2. The timing device defined in claim 1 wherein said cam assembly is provided with first and secondcam surfaces, and said set of movable contacts comprises three movable contacts, a first one of said movable contacts being provided with a cam follower to engage said first cam surface and a second one of said'movable contacts being provided with a cam follower to engage said secondcarn surface, whereby rotating of said cam assembly'actuates said first and second contacts to engage and disengage said third movable contact.

3. The timing device defined in claim 1 wherein said star wheel is provided with first and second cam portions, and said first cam engaging means of said time gear assembly is a tab adjustably secured to said time gear and positioned to engage said first cam portion of said star wheel to rotate said star wheel and said cam assembly to actuate said set of movable contacts to deenergize the load, and said second cam engaging means of said time gear assembly is a pin secured to said time gear and positioned to engage said second cam portion of said star wheel to rotate said star wheel and said cam assembly to actuate said set of movable contacts to deenergize the motor.

4. The timing device defined in claim ll wherein the men gization of said electromagnetic actuating means is controlled by a photocell.

.5. The timing device defined in claim 1 wherein said electromagnetic actuating means is a relay having an actuating coil and an armature, said arm being secured to said armature, for actuation thereby, a snap switch connected to contro. the energization of said motor and positioned to be operated by the armature of said relay.

d. The timing device defined in claim 1 wherein said cam assembly and said cam portions of said star wheel are formed about their circumferences with six identical cam sections,

said cam assembly and said star wheel being rotated one-sixth of a revolution for each day of operation of the timing device.

7. The timing device defined in claim'll wherein the end of the first portion of said lever arm is provided with a tab for engaging said arm, and the end of the second portion of said lever arm is provided with a tab for engaging the teeth of said ratchet gears.

Claims

1. A timing device for energizing a load at sunset and deenergizing the load at a later predetermined time comprising: a. a synchronous motor for rotating a drive gear at a fixed speed when energized; b. a shaft having an eccentric portion and a gear secured thereto to be driven by said drive gear; c. a lever arm driven by said eccentric portion of said shaft, said lever arm having first and second portions; d. first and second ratchet gears positioned to be engaged and driven by said second portion of said lever arm; e. a time ear gear assembly driven by said first ratchet gear, and being provided with at least two cam engaging means; f. a cam assembly adapted to be rotated by said second ratchet gear; g. a star wheel connected to rotate said cam assembly and having cam portions adapted to be engaged and driven by said cam engaging means of said time gear assembly; h. a set of movable contacts adapted to be operated by said cam assembly; i. an electromagnetic actuating means, adapted to be energized at sunrise and deenergized at dusk, the energization of said actuating means at sunrise causing the energization of said motor; and j. an arm actuated from a first position when said electromagnetic actuating means is deenergized to a second position when said electromagnetic actuating means is energized, said arm in said second position being engaged by said first portion of said lever arm wherein said ratchet gears are advanced one tooth for each revolution of said eccentric portion, in said first position said arm not being engaged by said first portion of said lever arm wherein said ratchet gears are advanced two teeth for each revolution of said eccentric portion, said cam assembly being rotated by said second ratchet gear to actuate said set of movable contacts to provide a second circuit for maintaining energization of said motor, at dusk said cam assembly being rotated by said second ratchet gear to actuate said set of movable contacts to energize the load, rotation of said time gear assembly by said first ratchet gear after dusk causing one of said cam engaging means to engage said cam portion of said star wheel to rotate sAid star wheel and said cam assembly to actuate said set of movable contacts to deenergize the load, further rotation of said time gear assembly by said first ratchet gear causing a second one of said cam engaging means to engage said cam portion of said star wheel to rotate said star wheel and said cam assembly to actuate said set of movable contacts to deenergize the motor.

2. The timing device defined in claim 1 wherein said cam assembly is provided with first and second cam surfaces, and said set of movable contacts comprises three movable contacts, a first one of said movable contacts being provided with a cam follower to engage said first cam surface and a second one of said movable contacts being provided with a cam follower to engage said second cam surface, whereby rotating of said cam assembly actuates said first and second contacts to engage and disengage said third movable contact.

4. The timing device defined in claim 1 wherein the energization of said electromagnetic actuating means is controlled by a photocell.

5. The timing device defined in claim 1 wherein said electromagnetic actuating means is a relay having an actuating coil and an armature, said arm being secured to said armature, for actuation thereby, a snap switch connected to control the energization of said motor and positioned to be operated by the armature of said relay.

6. The timing device defined in claim 1 wherein said cam assembly and said cam portions of said star wheel are formed about their circumferences with six identical cam sections, said cam assembly and said star wheel being rotated one-sixth of a revolution for each day of operation of the timing device.

7. The timing device defined in claim 1 wherein the end of the first portion of said lever arm is provided with a tab for engaging said arm, and the end of the second portion of said lever arm is provided with a tab for engaging the teeth of said ratchet gears.

8. The timing device defined in claim 1 wherein said second ratchet gear is formed with missing teeth such that it is driven by said lever arm to rotate said cam assembly only twice at sunrise and twice at sunset.