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Publication numberUS3863079 A
Publication typeGrant
Publication dateJan 28, 1975
Filing dateFeb 15, 1974
Priority dateFeb 15, 1974
Publication numberUS 3863079 A, US 3863079A, US-A-3863079, US3863079 A, US3863079A
InventorsCalabrese Ronald V
Original AssigneeLumenite Electronic Company
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Automatic sequence control apparatus
US 3863079 A
Abstract
Automatic sequence control apparatus for a sprinkling system having a main electrically activatable valve ahead of a number of individual electrically activatable valves controlling flow to groups of sprinklers. Adjustable timer pins on a 24 hour timing disc determine the sprinkling times and durations. The timer pins engage a trip lever oscillatably journaled about the shaft of a rotary switch which is rotatable continuously in one direction through a series of stable detent positions equally angularly disposed throughout a full 360 DEG turn of the shaft. A pawl carried by the trip lever engages a ratchet wheel on the shaft. The number of teeth on the ratchet wheel is an exact multiple of the number of detent positions for the shaft, and the oscillation amplitude of the trip lever is sufficient to rotate the shaft from one detent position to the next each time a timing pin oscillates the trip lever. The rotary switch has two contact decks, each having an output contact for each group of sprinklers. The output contacts are identically arranged in each deck and the angular spacing between adjacent output contacts is precisely the same as the angular spacing between shaft detent positions. The shaft has a pair of wiper contact members each with one or more wiper contacts arcuately spaced about the shaft and sequentially engageable with the output contacts in their respective decks. The output contacts in one deck are respectively connected to the individual electrically activatable valves to energize and deenergize them in a sequence and for a duration determined by the timing pins. The output contacts in the second deck are all connected to the main electrically activatable valve and the wiper contact or contacts in that second deck are relatively wide enabling them to engage one output contact before disengaging a preceding one to thereby keep the main electrically activatable valve energized during the entire sprinkling cycle. The rotary switch is manually indexed by rotating an index knob on the end of the shaft to override the pawl and ratchet mechanism. Five- and eleven-station controls are illustrated. The basic parameters of 23 different embodiments of the invention are listed, and the parameters are interrelated according to the following formula: S = (N + 1)(360/D) where S = the arcuate spacing of the wiper contacts about the shaft in each deck, in degrees N = the number of output contacts in each deck D = the number of detent positions of the shaft in a full turn.
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United States Patent 11 1 Calabrese 1451 Jan. 28, 1975 AUTOMATIC SEQUENCE CONTROL APPARATUS [75] Inventor: Ronald V. Calabrese, Addison, Ill.

[73] Assignee: Lumenite Electronic Company,

Franklin Park, 111.

22 Filed: Feb. 15, 1974 21 Appl. No.: 442,790

[52] US. Cl. 307/41, 137762416; 200/11 D,

200/17 R, 200/37. A, 239/69, 307/141 [51] Int. Cl H02] 3/00, G05b 19/00 [58] Field of Search 200/11 R, 11 D, 14, 17 R, 200/17 A, 18, 24-27, 33 R, 35 R, 37 A,

[56] References Cited UNITED STATES PATENTS 1,906,943 5/1933 Fisher et al. 200/37 A X 2,594,190 4/1952 Mastney 200/11 D 2,665,964 l/l954 Olah et al. 335/140 X 2,740,056 3/1956 Parker et a1. 200/14 X 3,140,720 7/1964 Griswold 137/78 X 3,309,543 3/1967 Alston et al. 307/41 X 3,440,434 4/1969 Yates ct a|..... 307/41 3,604,943 9/1971 Bayer et 'al 307/41 Primary Examiner-James R. Scott Attorney, Agent, or Firm-Davis, McCaleb & Lucas [5 7] ABSTRACT positions equally angularly disposed throughout a full 360 turn of the shaft. A pawl carried by the trip lever engages a ratchet wheel on the shaft. The number of teeth on the ratchet wheel is an exact multiple of the number of detent positions for the shaft, and the oscillation amplitude of the trip lever is sufficient to rotate the shaft from one detent position to the next each time a timing pin oscillates the trip lever. The rotary switch has two contact decks, each having an output contact for each group of sprinklers. The output contacts are identically arranged in each deck and the angular spacing between adjacent output contacts is precisely the same as the angular spacing between shaft detent positions. The shaft has a pair of wiper contact members each with one or more wiper contacts arcuately spaced about the shaft and sequentially engageable with the output contacts in their respective decks. The output contacts in one deck are respectively connected to the individual electrically activatable valves to energize and deenergize them in a sequence and for a duration determined by the timing pins. The output contacts in the second deck are all connected to the main electrically activatable valve and the wiper contact or contacts in that second deck are relatively wide enabling them to engage one output contact before disengaging a preceding one to thereby keep the main electrically activatable valve energized during the entire sprinkling cycle. The rotary switch is manually indexed by rotating an index knob on the end of the shaft to override the pawl and ratchet mechanism. Fiveand eleven-station controls are illustrated. The basic parameters of 23 different embodiments of the invention are listed, and the parameters are interrelated according to the following formula:

S (N l)(360/D) where S the arcuate spacing of the wiper contacts about the shaft in each deck, in degrees N the number of output contacts in each deck D the number of detent positions of the shaft in a full turn.

15 Claims, 12 Drawing Figures PATENTEB JAN 2 8 I975 SHEET 10F 3 PATENTED JAN? 8 I975 sum 30F 3 1 AUTOMATIC SEQUENCE CONTROL APPARATUS BACKGROUND OF THE INVENTION The field of invention includes automatically timed control apparatus for use in sequentially energizing and deenergizing electrically activatable components such as valves for automatic sprinkler systems and the like.

Timing control apparatus for sequentially activating components such as solenoid-operated sprinkler valves in the system disclosed here, washing and rinsing and drying operations in dishwashing and laundering equipment, automatic mixers, and the like, conventionally employ a relay-actuated stepping switch to deenergize one function and energize the next at selected times determined by timing elements on a constant speed motor-driven disc. If the apparatus is on a daily cycle, as for example a lawn where groups of sprinklers are turned on and off, one group at a time, every night, the disc rotates once in 24 hours. Timing pins or clips are positioned about the periphery of the disc and these sequentially close and open a switch which applies an electrical-impulse to a coil or solenoid in the stepping switch.

Each time a conventional stepper coil is impulsed, it drives a pawl-like plunger or armature to advance a ratchet wheel which is part of the stepping switch. This opens one set of contacts and closes another set to deenergize one electrically activatable component and energize another. The plunger or armature is biased, as by a spring, so that when the stepper coil disengages at the end of the electrical impulse, it returns to cocked position, ready to advance the ratchet wheel in response to the next impulse.

In the conventional stepping switch used in this kind of apparatus, the ratchet wheel rotates forward during an operating cycle and then backward to reset. It does not rotate continuously in the same direction as it goes through repeated cycles. The ratchet wheel is generally rotatably biased by a torsion spring in the direction opposite that which it is rotated by the stepper coil and a pawl normally holds it against backward rotation by the spring. At the end of the operating cycle, a reset coil lifts the pawl, releases the ratchet wheel, and enablesthe torsion spring to rotate it back against a stop to its starting position ready for the next cycle.

Because of the relatively slow movement ofa 24 hour timing disc, the switch energizing the stepper coil is held closed for longer than necessary to produce the impulse needed to advance the stepper switch. To avoid large, expensive, continous-duty stepper coils, small intermittent-duty coils or solenoids may be used with means for limiting current to it. One example is described in applicant's co-pending application Ser. No. 169,924 filed Aug. 9, I971 on Automatic Control Apparatus With Thermistor Protected Stepper Coil" where a positive thermal coefficient thermistor is placed in series with the stepper coil. Because attempts to use smaller stepper coils have required current limiting controls, this has simply resulted in trading off one problem for another. Ifa smaller coil is used, something has to be added to protect it.

Many -attempts have been made to produce electrically activated stepping switches for sequence controls but none has been entirely satisfactory from the standpoint of low first cost and reliability. The requirement of stepper and reset coils and all the associated mechanical parts and control circuitry makes a complex,

BRIEF SUMMARY OF THE INVENTION Broadly the object of this invention is to provide apparatus for automatically controlling the sequence and duration of a plurality of electrically activatable components, one example being opening and closing electrically activatable valves which control groups of sprinklers, in predetermined time sequence, each for a predetermined duration.

A primary object is to provide in such apparatus a unidirectional rotary switch which is mechanically operated by a timing disc through a trip level and a pawl and ratchet mechanism, thereby eliminating completely the need for an electrically activatable stepping switch previously used in conventional sequence control apparatus. 7

Another object is to provide such apparatus having a multideck rotary switch in which one deck has a wiper contact sequentially engageable with output contacts connected respectively to individual electrically activatable components, and a second substantially similar deck with output contacts all connected to a main electrically activatable component, and in which incremental advance of the rotary switch through successive rotated positions by a timing member successively energizes and deenergizes the individual components through an operating cycle, while maintaining the main component energized for the entire duration of that operating cycle.

Another object is to provide such apparatus which can be manually indexed to a desired portion of a sequencing cycle by merely rotating an index knob without repeatedly depressing levers or buttons.

A specific object is to provide an automatic sprinkler sequence control apparatus having a two-deck rotary switch with a shaft incrementally rotated through pawl and ratchet mechanism by a timing member, the first deck of the rotary switch having a wiper member with one or more relatively narrow contacts each of which is sequentially engageable with output contacts connected respectively to individual sprinkler solenoid control valves, the rotary valve having a second deck similar to the first deck except that the wiper contacts are relatively wider and the output contacts are all connected to a main sprinkler solenoid valve controlling flow through the individual valves, thereby maintaining the main valve open during an entire operating cycle while the individual valves open and close in response to incremental advance of the rotary switch.

Other objects and advantages will be apparent from the following description in connection with the drawings in which:

FIG. 1 is a schematic view of an automatic lawn sprinkler control system illustrating the present invention with some parts fragmentarily shown and a mechanically actuated rotary switch shown in greatly enlarged, exploded perspective;

FIG. 1A is a fragmentary cross section of FIG. 1 taken along line 1A1A;

FIG. 2 is a side view, partly in vertical cross section, of the rotary switch shown in FIG. 1, in assembled condition;

FIG. 2A is a fragmentary cross sectional view of FIG. 2 taken along line 2A-2A;

FIG. 3 is a cross-sectional view of FIG. 2 taken along line 3-3;

FIG. 4 is a fragmentary enlarged cross-sectional view of FIG. 3 taken along line 4-4; 7

FIGS. -9 are views of the mechanism shown in FIG. 3 in different portions of an operating cycle; and

FIG. 10 is a view similar to FIG. 3 of a modified form of the invention.

Like parts are designated by like reference characters throughout the figures.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now in detail to the drawings, a piping system is illustrated as it would be provided for watering a lawn, golf course, or agricultural field using an automatic sequence control apparatus employing the principlesof the present invention. A main supply conduit 24 is connected with a water source P under pressure. A main electrically activatable valve MV controls the flow of water from the conduit 24. This valve is of the normally closed type and opens when energized or activated as will be described.

Alternatively, supply conduit 24 may be connected to an unpressurized or low pressure source such as a well or standpipe. In such case an electrically activatable pump may be substituted for the valve MV. However, whether the main electrically activatable component MV is a valve or-a pump, it is referred to herein as a main electrically activatable component and it controls the flow of water through conduits 28, 29, 31 and 32 to sprinkling conduits 33, 34, 36, 37 and 38. Be-

a tween each of these sprinklingconduits and main valve MV, there is an individual electrically activatable component in the form of a solenoid valve. Five of these individual solenoid valves are shown, being designated V1, V2, V3, V4 and V5. These individual valves control flow into groups of sprinklersdesignated S1, S2, S3, S4 and S5, respectively. Each group of sprinklers may comprise any number of sprinklers, only one of which is shown as representative to each group in the present case. The main valve MV and each individual valve Vl-V5 has a solenoid actuator 39 which holds the valve open as long as it is energized and enables it to close when deenergized.

A multi-deck rotary switch means is generally designated 41. It has a shaft 42 rotatably journaled in a support frame which includes a journal bushing 43 having external threads 44. The bushing 43 extends through an opening 46 in a panel 47 which is fragmentarily shown in FIG. 2. Lock nuts 48, 49 are screwed onto the threads 44 on opposite sides of the panel 47 and hold the switch firmly inplace. The shaft 42 has a C-ring 51 recessed in a groove 52. The C-ring is seated on the end of the bushing 43 and may either rotate with the shaft or may be stationary on the bushing while the shaft rotates within it.

The rotary switch 41 has a detent deck 53 and first and second contact decks 54 and 56, respectively.

The detent deck consists of a stationary plate 57 and a rotatable blade 58. The inner end portion of the shaft 42 has a flat 59 on each side. This is engaged within a rectangular opening 61 at the center of the blade to hold them against relative rotational movement. The blade 58 is staked tightly to the shaft 42 by indentations 62 (FIG. 2) which upset portions 63 of the shaft into engagement with the underside of the blade. The blade has two diammetrically spaced through-holes 64, each witha detent ball 66 loosely held therein and pressed upward by an elongated leaf spring member 67 held against the underside of the blade by rivets 68. The detent plate 57 is formed with a plurality of dimples having downwardly concave detent recesses 69 for engaging the detent balls 68 as shown in FIG. IA. In the embodiment shown, there are precisely 24 detent recesses 69 evenly arcuately spaced exactly 15 apart in a circular track around the shaft 42. Thus, the detent means acting between the shaft 42 and the frame 40 sequentially retains the shaft in a plurality of evenly arcuately spaced stable detent positions, in this case the arcuate spacing being 15. As will be described, other embodiments may employ different total numbers of these detent positions and different arcuate spacings between adjacent detent positions, but in all cases they will be evenly arcuately spaced about the shaft.

The first or upper contact deck 54 comprises an outer stationary plate 71 with a circular opening 72 (FIG. 4), and an inner, circular plate 73 with a central rectangular opening 74 engaged with the flatted inner end portion of the shaft 42. Both the plates 71 and 73 are made of material having good electrical insulating characteristics and good mechanical strength such as an electrical grade laminated phenol formaldehyde plastic sheet. As shown in FIG. 4, the inner rotatable plate 73 has, along its outer periphery, an annular flange 76 staked in place and held by tines 77x extending through the plate 73. The flange 76 underlies the plate 71 and with the wiper contact means to be described keeps the plate 73 coplanar with the place 71 while enabling it to rotate freely within the opening 72.

Wiper contact means generally designated 77 consist of an annular wiper ring 78 held firmly in place by tines 79 staked into the plate 73. The outer portion of ring 78 overhangs and engages the top surface of the plate 71 to help retain the plate 73 coplanar with the plate 71. In the embodiment illustrated, there are four wiper contacts 81 comprising integral tabs extending radially from the wiper ring 78 and evenly arcuately spaced about the shaft 42, at intervals. The wiper ring and wiper contacts, of course, will be electrically conductive, preferably metal.

Deck 54 has five output contacts, C1, C2, C3, C4 and C5 sequentially engageable, one at a time, by the wiper contacts 81. These contacts are arranged in precisely 15 increments about the shaft 42, the same as the detent recesses 69, and as will be described, each is connectible to a particular one of the individual solenoid valves Vl-VS. The output contacts C1-C5 are circumferentially positioned to match the detent positions of the wiper contact means so that when any of the wiper contacts 81 is engaged with one of the output contacts, the wiper contact means 77 is in one of its 24 stable detent positions. Furthermore, the five output contacts are all spaced 15 apart so any of the wiper contacts 81 successively engages all of the output contacts C1-C5 as the wiper contact means is moved through succes' sive detent positions. In addition to the output contacts just described, stationary plate 71 has a longer contact 82 engaging the main annulus of the wiper ring 78 at all times. As will be described, this is a common contact, bringing one side of an electrical power source direct to the wiper contact means.

The second, lower contact deck 56 is shown as identical in all respects with the above described deck 54 except for one important inventive feature, namely that the wiper contacts 81a are wider (circumferentially) than contacts 81. Because of this identity between parts, the parts in deck 56 will be identified by the same reference indicia followed by the letter For example, the five output contacts corresponding to C1, C2, C3, C4 and C5 are identified Cla, C2a, C311, C4a and C5a.

The circumferential width of the wiper contacts 81 in deck 54 is such that the wiper contact 81 disengages from each of the output contacts before engaging the next. As will be seen, this enables each individual valve V1-V5 to close before the next is opened, avoiding concurrent operation of two groups of sprinklers when the system is in straight automatic mode.

As will also be seen when the circuit connections are described, the second deck 56 controls operation of the main valve MV. By making the wiper contacts 81a wider as shown, they will span the distance between adjacent contacts and engage one output contact before disengaging an adjacent preceding one. This keeps the main valve MV open for the entire sprinkling cycle, opening concurrently with individual valve V1 and closing concurrently with closing of individual valve V5. This avoids starting and stopping of flow through the main valve MV during change-over from one group of sprinklers to another. Among other advantages, this minimizes destructive water hammer when the water flow stops.

The rotary switch 41 is assembled by a pair of bolts 83 and 84 extending through openings 86 in plates 57, 71 and 71a. The bolts are held by nuts 87 and washers 88 and the parts are held in proper spaced relation by spacer bushings 89.

The mechanism for actuating the rotary switch to cause the first and second wiper contact means 77 and 77a successively to engage corresponding pairs of first and second output contacts C1-C5 and C1a-C5a will now be described.

A ratchet wheel 91 is mounted on and rotatable with the shaft 42 by a set screw 92. At the outer end of the shaft, a manual advance knob 93 is fastened by a pin 94. A trip lever 96 is positioned between the knob and ratchet wheel and is oscillatably journaled for back and forth swinging movement about the shaft. A pawl 97 is pivoted on a pin 98 at one end of the trip lever. As shown in FIGS. 1 and 2A, the pawl is urged counterclockwise about the pin 98 and the trip lever is urged clockwise about the shaft against a stop 99 by a tension spring 101 which is fastened between pin 102 on the pawl and a fixed pin 103 fastened to the frame. Note in FIG. 2A that the line of action of the spring 101 is to the right of the pin 98.

There are precisely 24 teeth 104 on the ratchet wheel 91, corresponding to the 24 detent positions 69 of the shaft so that one back and'forth oscillation of the trip lever engages one of the teeth 104 and advances the shaft 15 from one detent position to the next. Alternatively, the ratchet wheel'may have 48 teeth in which case the pawl will advance it two teeth per oscillation of the trip lever; or the ratchet wheel may have 72 teeth in which case the pawl will advance it three teeth at a time; etc. The general rule is that the number of teeth on the ratchet wheel is an even multiple of the number of detent positions of the shaft.

By manually rotating the knob 93 in a counterclockwise direction, the shaft 42 will override the pawl and ratchet mechanism enabling the wiper contact means 77 and 77a to be manually indexed quickly and easily to set the rotary switch in the proper portion of the control cycle.

Timing means which oscillate the trip lever 96 at selected times to determine the operating time and duration for each of the individual valves V1-V5 will now be described.

A timing disc 106 is rotated once in 24 hours by motor 107 through speed reducing gearing illustrated by the pinion 108 and gear 109. The motor drives the pinion through shaft 111 and the gear drives the timing disc through a shaft 112. It will be understood that this is merely a schematic representation of any suitable arrangement for driving the timing disc 106 at constant speed which, depending upon the application, rotates the timing disc completely during some suitable time period. 7

About the periphery of the timing disc, there is a series of evenly arcuately spaced openings 113 for the selective placement of timing pins P1, P2, P3, P4, P5 and P6. As one specific example, the timing holes 113 may be spaced fifteen minutes apart and the timing pins P1-P6 may be placed in suitable holes to turn the sprinklers S1-S5 on and off late at night when loss of water by evaporation is minimized.

In practical application of this invention, the components described above, except for the piping valves and sprinklers, will be housed in a control case (not shown) at a control station or some protected, accessible location. In addition, the housing will contain a source of electrical power, here shown as a l 10 volt/24 volt stepdown transformer 114; and indicator lamp 116; station mode selector switches K1, K2, K3, K4 and K5 for selecting automatic, manual and off" positions or modes for each of the individual sprinkler control valves Vl-VS; and a main switch KM.

A common output terminal TC is connected to one input terminal of each solenoid valve MV and V1-V5 through conductors 117, 118, 119, 121, 122, 123 and 124.

A main output terminal TV is connected through conductor 126 to another input terminal of main valve MV.

Output terminals T1, T2, T3, T4 and T5 are connected respectively to another input terminal of each individual solenoid valve Vl-VS through conductors 127, 128, 129, 131 and 132.

Two main power input terminals L1 and L2 are connected to an external 1 10 volt alternating current power source.

Main switch KM and mode selector switches Kl-KS are preferably slide switches having a slide button with right and left closed positions and a center open position. More specifically, these are illustrated as double pole, double throw switches. Each is illustrated with a pair of movable contacts 1 and 2, right-hand stationary contacts 3 and 4, and left-hand stationary contacts 5 g and 6.

7 In the embodiment illustrated, the timing motor 107 is powered by the 110 volt inputs Isl-L2. L1 is connected directly to timing motor 107, and to the primary of transformer 114, through conductors 133 and 134,

timing motor 107. In the rain position, L2 is connected through conductor 139 and fuse 137 to the transformer and again through conductor 138 to the timing motor.

When main switch KM is in the on position, one power output terminal 141 of the transformer 114 secondary is connected through conductor 142, contact 5, and output terminal TC to one input terminal of each of the valves MV and V1-V5; and power output terminal 141 is also connected to one side of indicator lamp 116 through conductor 143. The other power output terminal 144 of transformer 114 is connected in common through conductors 146, 147 and 148 to all of the contacts and 6 of switches Kl-KS and to the wiper contact means 77 and 77a through common output contacts 82 and 82a. In the individual switches K1-K5 each contact 1 is connected to a corresponding output terminal T1-T5 through conductors 149, 151,152, 153 and 154, respectively. All of the movable contacts 2 are connected through a common conductor 156 and conductors 157 and 158 to the lamp 116 and main output terminal TV. The stationary contacts 3 are connected to the first deck output contacts C1-C5 through conductors 159, 161, 162, 163 and 164, respectively. Sta-- tionary contacts 4 are connected to the second deck output contacts C1aC5a through conductors 166, I67, 168, 169 and 161, respectively.

An important feature of the present invention is that the rotary switch rotates in one direction only and never reverses direction to reset as in the case with conventional relay actuated stepping switches commonly used in sequencing apparatus.

Before describing other embodiments including the eleven-sprinkler embodiment partly shown in FIG. 10, use and operation of the system shown in FIGS. 1-9 will be described for both manual and automatic modes.

Assume the following positions of the components at the beginning of the operating cycle:

a. Main switch KM is in on position with movable contacts 1 and 2 engaging contacts 5 and 6, respectively;

b. All selector switches K1-K5 are in their automatic positions, with movable contacts 1 and 2 of each engaging contacts 3 and 4, respectively;

0. Timing pins P1-P6 are in 2:00 A.M., 2:15 A.M., 2:30 A.M., 2:45 A.M., 3:00 AM. and 3:l5 A.M. positions, respectively, around the periphery of timing disc 106 which is positioned so the next pin to engage trip lever 96 will be P1;

d. The shaft 42 is indexed to the of position shown in FIG. 5 where two of the four wiper contacts 81 an away, clockwise and counterclockwise, respectively, from the output contacts C1 and C5. As stated, the shaft 42 may be advanced manually, counterclockwise, by turning knob 93 to index the wiper contacts to this particular position.

The four wiper contacts 81 in the first deck 54 are at 90 arcuately spaced positions. It will be understood that the corresponding wiper contacts 81a in the second deck 56 will be in exactly corresponding positions 5 below wiper contacts 81. With the components in the positions assumed in a through "d" above, the timing motor 107 will be energized from L1 to L2 through conductors 133, 138, 139 and 136, and contacts 6 and 2. This rotates the timing disc 106. Pin P1 engages trip lever 96 and oscillates it about the axis of shaft 42. Pawl 97 and ratchet wheel 91 rotate counterclockwise. Detent balls 66 are moved out of one diametrically opposed pair of detent recesses 69 (FIG. 1A) toward an adjacent pair of recesses 69. Intermediate the two adjacent detent recesses, the balls move across overcenter high points 172 (FIG. 1A). Slightly beyond there, the upward pressure of the leaf spring member 67 against the balls, and the sloping surface 137 into the next detent recess causes the shaft and wiper contact assemblies to move ahead to the next detent position by snap action. In other words, just beyond the high point 172 there is an overcenter action which tends to snap the shaft forward to the next stable detent position in which the balls 66 are seated in corresponding recesses 69. As will be described, for some of these detent positions the wiper contacts 81 and 81a will be engaged with output contacts C1-C5 and Cla-C5a to energize the sprinkler control valves. Following the snap action movement described, the pin P1 continues to move against the hook end of the trip lever 96. When it passes that end, the spring 101 pulls the trip lever back, clockwise, against stop 99 to a starting or cocked position ready to advance the ratchet wheel one more tooth when the trip lever is again moved by the next timing pin.

As described above, timing pin P1 rotatably advanced shaft 42 one detent position, that is 15, from the off position of FIG. 5 to the FIG. 6 position. One of the wiper contacts 81 engages output contact CI. Similarly, one of the wiper contacts 81a engages output contact Cla. This energizes and opens main valve MV and individual valve V1 directing flow through sprinkler group S1 by activating the circuit as follows.

One power input terminal of each of main valve MV and individual valve V1 is connected to output terminal 141 of transformer 114 through conductors 117, 119 and 118, common outputterminal TC, contacts 5 and 1 of main switch KM, and conductor 142. The other power input terminal of main valve MV is connected to the other output terminal 144 of transformer 114 through conductor 126, output terminal TV, conductor 156, contacts 2 and 4 of switch K1, conductor 166, output contact Cla, wiper ring 78a and common contact 82a in the second contact deck, and conductors 147 and 146. And the other power input terminal of individual valve V1 is connected to the other power input terminal 144 of transformer 114 through conductor 127, output terminal Tl, conductor 149, contacts 1 and 3 of switch K1, conductor 159, output contact C1 and wiper ring 78 and common contact 82 in the first contact deck, and conductors 148 and 146.

At the same time, the indicator lamp 116 is lighted. One side is connected to transformer output terminal 141 through conductor 143. The other side is connected to the other transformer output terminal 144 through conductors 157 and 156, contacts 2 and 4 of switch K1, conductor 166, output contact Cla and wiper ring 78a and common contact 82a in the second contact deck, and conductors 148 and 146.

Thus, summarizing the above, as timing pin P1 moves trip lever 96 at 2:00 A.M. in the example given, main valve MV and individual valve V1 open simultaneously, directing water to the group of sprinklers S1. Lamp 116 lights to show that sprinkling is in progress.

At 2:15, 2:30, 2:45, 3:00 and 3:15, respectively, timing pins P2, P3, P4, P5 and P6 engage the trip lever 96 and successively index the rotary switch to the FIG. 7, FIG. 3, FIG. 8, FIG. 9 positions, and finally to a new off position identical to FIG. 5 except that the wiper rings 81 and 81a have been rotated 90 counterclockwise. In other words, wiper contacts 81 (and corresponding wiper contacts 81a) are again at the A and B positions indicated in FIG. 5. This successive automatic indexing of the shaft and wiper contact means 77 and 77a resultts in the following specific activation sequence for the individual valves Vl-VS at 15 minute intervals:

Deenergizes valve V1 and energizes valve V2 at 2:15

Deenergizes valve V2 and energizes valve V3 at 2:30

Deenergizes valve V3 and energizes valve V4 at 2:45

Deenergizes valve V4 and energizes valve V5 at 3:00

and finally simultaneously deenergizes valves V5 and MV at 3:15 A.M.

By moving any mode selector switch Kl through K5 to manual position, that is, by engaging movable contacts 1 and 2 with contacts 5 and 6, respectively, the corresponding valve V1 through V5 will be activated simultaneously with the main valve Mv, and lamp 116 will be lighted. For example, by moving switch Kl to manual position, the main valve MV is connected to the output terminal 144 of transformer 114 through conductors 126, 158 and 156, contacts 2 and 6 of switch K1, and conductor 146.

By placing main switch KM in rain position, that is, engaging contacts 3 and 4, the timing motor 107 will continue to drive disc 106 and keep it properly timed,

but none of the sprinkler valves will be energized.

As explained above, the first deck wiper contacts 81 are relatively narrow and disengage each output contact C1-C5 before engaging the next, while the second deck wiper contacts 81a are relatively wider and disengaged one output contact only after engaging the next. This results in an operating cycle in which each sprinkler group Sl-SS is shut off at least momentarily before water is directed to the next group, while valve MV stays open for the entire operating cycle beginning with the opening of valve V1 until the closing of valve V5.

During each operating cycle, operating at 2:00 A.M. and ending at 3:15 A.M. in the example given, with the timer pin settings shown, the shaft 42 rotates the wiper rings 90 per cycle, from the off position shown in FIG.

5 to a next position which is just the same except that each wiper contact means is rotated 90 counterclockwise. In each operating cycle the active wiper contact 81 (and 81a) moves counterclockwise 90 from position A to position B.

As illustrated in FIG. 5, the five output contacts C1-C5 span an arc of 60 enabling the wiper contacts 81 to flank the end contacts C1 and C5, 15 away from either, in the off position. Likewise, the live output contacts C1a-C5a span the same 60 arc and two wiper contacts 81a flank end contacts Cla and C5a away from either. There are four such positions, of course,

one for each of the wiper contacts when in position A. 5 Thus, with one operating cycle per rotation of the 24 hour timing disc 106, it takes 4 days for the shaft 42 to rotate the wiper rings one full turn. By using each wiper contact 81, and 81a, only one-fourth of the time, and with a single off position as shown in FIG. 5 between operating cycles, the wiper rings can rotate continuously in the same direction without reversal for reset. At the end of each sprinkling cycle, at 3: l 5 A.M. in the example given, the wiper ring asembly stops with one of the four wiper contacts 81 in position A, only 15", one detent position, away from the restart position for a new cycle shown in FIG. 6.

FIG. 10 shows how the wiper contact assembly of FIG. 3 may be modified for use with an elevensprinkler system. Eleven wiper contacts C101 through C111, in the first deck, are spaced 15 apart, making a total span of 150. The wiper ring 178 has in this case only two wiper contacts 181 spaced 180 apart. The second deck is not shown, because it would be identical except that the wiper contacts would be somewhat wider for th purpose described in connection with wiper contacts 81a, namely, to keep the main valve open during the entire sprinkling cycle. The elevensprinkler wiper arrangement of FIG. 10 has two off positions in which the contacts 181 are in positions AA and BB, each being 15, one detent position, away from an end output contact C 101 or C111. Thus, each wiper assembly would rotate 180 per operating cycle, taking two days to rotate a full turn.

An eleven-sprinkler system controlled by a rotary switch as shown in FIG. 10 would be exactly the same as the five-sprinkler embodiment in FIG. 5 except, of course, there would be more individual valves, sprinklers and manual/automatic mode selector switches.

The invention may be applied to systems having other numbers of sprinklers and electrically activatable components other than the fiveand eleven-sprinkler embodiments specifically described. In each case, and referring to examples of components in FIG. 1, the wiper contacts 81/8 la, and the detent positions corresponding to detent recesses 69, must be equally arcuately spaced about the axis of the shaft 42. The number of teeth in the ratchet wheel 91 must be an even multiple of the number of detent positions. The output contacts CI-CS/Cla-CSa must be arcuately spaced apart in amounts corresponding to the arcuate spacing between adjacent detent positions; in other words, if there are 24 detent positions, 15 apart, the output contacts must be 15 apart. And the number of active output contacts Cl-CS/Cla-CSa must equal the number of individual sprinkler valves Vl-VS.

Within the criteria stated in the paragraph above, the interrelation of basic parameters for an automatic sequence control apparatus according to the present invention may be expressed by the following formula:

'= (N -ll) (360/D) where S the arcuate spacing of the wiper contacts about the shaft in each deck, in degrees, N the number of active output contacts in each deck, and

D the number of detent positions of the shaft evenly arcuately spaced in a full turn.

Using the above formula, the basic parameters for some examples of sprinkler systems having from 2 to 23 and having a plurality of first angularly spaced wiper contacts sequentially engageable, one at at time, with said output contacts on rotation of said shaft, succeeding adjacent engaged positions sprinklers are listed as follows: of said wiper contact means with said output N D S No. of Evenly Angular Spacing No. of Sprinklers No, of Evenly Spacing in Arcuately Between Adjacent & No. of Active Arcuatcly Spaced Degrees Spaced Wiper Detent Positions Output Contacts Detent Positions Between Contacts (Same As Between in Eact Rotary Wipcr Adjacent Output Switch Deck Contacts Contacts). In

Degrees 2 1s 60 6 20.0 3 24 60 6 15.0 4 30 60- 6 12.0 5 30 72 5 12.0 5 24 90 4 15.0 6 27 90 4 13.3 7 24 120 3 15.0 8 27 120 3 13.3 9 30 120 3 12.0 10 22 I80 2 16.3 11 24 I80 2 15.0 12 26 I80 2 I3.8 13 28 180 2 12.8 14 30 180 2 12.0 15 32 I80 2 11.3 16 34 180 2 10.6 17 36 I80 2 10.0 18 38 180 2 9.5 19 40 180 2 9.0 20 42 180 2 8.6 21 44 180 2 8.2 22 46 I80 2 7.11 23 24 360 1 15.0

[n the last example above, the single wiper contact is contacts coinciding with a succession of adjacent sapced 360 with respect to itself, thus demonstrating detent positions of said shaft; that the formula applies even to a single wiper contact means for actuating said rotary switch including in each deck. a trip lever oscillatably supported for swinging While fiveand eleven-sprinkler embodiments have movement about said shaft and biased in one dibeen specifically disclosed and the basic parameters for' rection against a stop, and other systems using from two to twenty-three sprinklers a pawl carried by said lever engageable with teeth have been listed, it will be'understood that various 40 on a ratchet wheel on said shaft to incrementally modifications and applications may be made within the rotatably advance said shaft and wiper contact spirit and scope of the invention which should be limmeans between succeeding adjacent detent posiited only by the appended claims. For example, it tions in response to repeated oscillations of said should be clearly understood that the invention may be trip lever through a predetermined are, applied to sprinkling systems having individual valves the number of teeth on said ratchet wheel being a Vl-VS with no main valve MV, in which case the inwhole multiple of the number of said detent posivention could be practised using a single wiper contact tions; deck 54. timing means including I claim: a timing member and means for rotating said timl. in an automatic sprinkler sequence control appaing member at constant speed past said trip lever, ratus for controlling the operating sequence ofa plurala plurality of timing elements carried by said timing ity of individual electrically activatable sprinkler commember sequentially engageable with said trip ponents, the improvement comprising: lever, each said timing element being effective a rotary switch including when moved past said lever to oscillate said lever a shaft rotatably journaled in a support frame for through said predetermined arc to rotatably adunlimited rotation in one direction, detent means vance said shaft and wiper contact means from acting between said shaft and support frame for one of said detent positions to a next adjacent deholding said shaft in a series of stable detent positent position; and tions which are equally angularly spaced an electrical power source connected between said throughtout a full 360 turn of said shaft, wiper contact means and a common output termia first contact deck having a plurality of first output nal for said individual electrically activatable comcontacts supported in a portion of a circular path ponents; about said shaft connected respectively through whereby sequential actuation of said trip lever by a plurality offirst connecting means to a plurality said timing elements advances said wiper contact' of individual output terminals for said individual electrically activatable components, a first wiper contact means carried by said shaft means to connect said power source successively between said individual output terminals and said common terminal to thereby activate and deactivate the individual electrically activatable components in predetermined sequence determined by the positions of said timing elements on said timing member.

2. In an automatic sprinkler sequence control apparatus according to claim 1 in which the relationship between said wiper contact means, output contacts, and detent positions of the shaft is S=(N+ l) (360/D) where v S the arcuate spacing of the wiper contacts on the wiper contact means about the shaft, in degrees,

N the total number of output contacts connected to said individual output terminals, and

D the total number of said detent positions of said shaft in a full 360 turn.

3. In an automatic sprinkler sequence control apparatus according to claim 1 in which said wiper contact means has a plurality of said wiper contacts equally arcuately spaced about said shaft.

4. In an automatic sprinkler sequence control apparatus according to claim 1 having a second contact deck having a plurality of second output contacts identical in number and position in the deck of said plurality of first output contacts supported in a portion of a circular path about said shaft connected respectively through a plurality of second connecting means to a first common-conductor leading to a main output terminal for a main electrically activatable component connected between said main output terminal and said common output terminal;

a second wiper contact means carried by said shaft having a plurality of second wiper contacts identical in number and orientation on said shaft to said first wiper contacts sequentially engageable, one at a time, with said second output contacts on rotation of said shaft, succeeding adjacent engaged positions ofsaid first and second wiper contact means with corresponding first and second output contacts being coincident with one another;

said electrical power source also being connected between said second wiper contact means and said common output terminal;

whereby said main electrically activatable component is energized by said power source through said second wiper contact means simultaneously with energization of any of said individual electrically activatable components through said first wiper contact means.

5. In an automatic sprinkler sequence control apparatus according to claim 4 in which said first wiper contact means is engageable with only one of the first output contacts at a time enabling it to disengage a first output contact before engaging a succeeding adjacent first output contact; and

said second wiper contact means is simultaneously engageable with a pair of adjacent second output contacts enabling said second wiper means to engage a second output contact before disengaging a preceding adjacent second output contact;

whereby said main electrically activatable component is energized continuously for the entire period between energization of the first and deenergization of the last of said plurality of individual electrically octivatable components.

6. In an automatic sprinkler sequence control apparatus according to claim 5 in which said second wiper contact means has at least one wiper contact wider than the wiper contact of said first wiper contact means.

7. In an automatic sprinkler sequence control apparatus according to claim 4 in which each of the first and second wiper contact means has a plurality of wiper contacts equally arcuately spaced about the shaft.

8. In an automatic sprinkler sequence control apparatus according to claim 4 including a separate mode selector switch for each of said first connecting means and a corresponding second connecting means, and a second common conductor connecting each switch direct to said electrical power source,

each said switch being actuatable between manual and automatic mode positions,

each said switch being effective in the automatic mode position to a. connect the corresponding individual output terminal to said electrical power source through the corresponding first connecting means and a corresponding one of said first output contacts when the latter is engaged by said first wiper contact means,

b. connect said main output terminal to said electrical power source through the corresponding second connecting means and a corresponding one of said second connecting means when the latter is engaged by said second wiper contact means,

each said switch being effective in the manual mode position to connect said corresponding individual output terminal and said main output terminal direct to said electrical power source through said second common conductor and thereby bypass said first and second connecting means and said wiper contact means and output contacts.

9. In an automatic sprinkler sequence control apparatus according to claim 1 including a separate mode selector switch for each of said first connecting means and a common conductor connecting each switch direct to said electrical power source, each switch being actuatable between manual and automatic mode positions, each switch being effective in the automatic mode position to connect the corresponding individual output terminal to said electrical power source through a corresponding one of said output contacts when the latter is engaged by said wiper contact means, and each switch being effective in the manual mode position to connect said corresponding individual output terminal direct to said electrical power source through said common conductor and thereby bypass said first connecting means and said wiper contact means and output contacts.

10. ln an automatic sprinkler sequence control system having:

a plurality of sprinkler means each connected through conduit means to a source of water;

an individual electrically activatable valve in said conduit means controlling flow to each sprinkler means; i

the improvement comprising programming means having a rotary switch including a shaft rotatably journaled in a support frame for unlimited rotation in one direction,

detent means acting between said shaft and support frame for holding said shaft in a series of stable detent positions which are equally angularly spaced throughout a full 360 turn of said shaft,

once contact deck having one plurality of output contacts supported in a portion of a circular path about said shaft connected respectively to said electrically activatable valves,

one wiper contact means carried by said shaft and having a plurality of wiper contacts equally arcuately spaced about said shaft, each being sequentially engageable with said output contacts on rotation of said shaft, succeeding adjacent engaged positions of said wiper contacts with said output contacts coinciding with a succession of adjacent detent positions of said shaft;

means for actuating said rotary switch including a trip lever oscillatably supported for swinging movement about said shaft and biased in one direction against a stop, and

a pawl carried by said lever engageable with teeth on a ratchet wheel on said shaft to incrementally rotatably advance said shaft and wiper contact means between succeeding adjacent detent positions in response to repeated oscillations of said trip lever through a predetermined arc, the number of teeth on said ratchet wheel being a whole multiple of the number of said detent positions; timing means including a timing member and means for rotating said timing member at constant speed past said trip lever, a plurality of timing elements carried by said timing member sequentially engageable with said trip lever, each said timing element being effective when moved past said lever to oscillate said lever through said predetermined arc to rotatably advance said shaft and wiper contact means from one of said detent positions to a next adjacent detent position; an electrical power source connected between said wiper contact means and each of said individual electrically activatable valves; whereby sequential actuation of said trip lever by said timing elements advances said wiper contact means to connect said power source successively to said individual electrically activatable valves to thereby energize and deenergize said valves in predetermined sequence determined by the positions of said timing elements on said timing member. 11. In an automatic sprinkler sequence control system according to claim 10 having a main electrically activatable flow controlling component in said conduit means controlling flow of water from said source to said valves; another contact deck having a plurality of output contacts supported in a portion of a circular path about said shaft and connected to said main electrically activatable flow controlling component; said other contact deck having wiper contact means carried by said shaft and a plurality of wiper contacts identical in number and spacing about said shaft to said plurality of wiper contacts in said one contact deck and sequentially engageable, one

at a time, with the output contacts in said other,

deck on rotation of said shaft, said electrical power source also being connecting between the wiper contact means in said other deck and said main electrically activatable flow controlling component;

whereby said main electrically activatable flow controlling component is energized by said power source through the wiper contact means in said second deck simultaneously with energization of any of said individual electrically activatable valves through the wiper contact means in said one deck.

12. In an automatic sprinkler sequence control system according to claim II in which each of said plurality of wiper contacts in said one deck are engageable one at a time with the output contacts in that deck enabling each wiper contact to disengage an output contact before engaging a succeeding adjacent output contact; and

each of said plurality of wiper contacts in said other deck are simultaneously engageable with a pair or adjacent output contacts in that deck enabling each wiper contact to engage an output contact before disengaging a preceding adjacent output contact;

whereby said main electrically activatable component is energized for the entire period between energization of the first and deenergization of the last of said valves.

13. In an automatic sprinkler sequence control system according to claim 12 in which the wiper contacts 7 in said other deck are wider than the wiper contacts in said one deck.

14. In an automatic sprinkler sequence control system according to claim 10 in which said shaft is rotatably in said one direction to override said ratchet, and there is a manually operable knob on said shaft effective to rotatably index said shaft in said one direction to a selected position.

15. An automatic sprinkler sequence control system comprising:

a plurality of sprinkler means each connected through conduit means to a source of water;

an individual electrically activatable valve in said conduit means controlling flow to each sprinkler means;

a main electrically activatable flow controlling component in said conduit means controlling flow of water from said source to said valves;

rotary switch means including a support frame,

a rotary shaft rotatably journaled in said support frame,

detent means acting between said shaft and frame for sequentially retaining said shaft in a plurality of evenly arcuately spaced stable detent positions.

separate first and second contact decks at axially spaced locations along said shaft, each deck having a series of output contacts corresponding in number to said plurality of valves supported in a portion of a circular path about said shaft,

separate first and second wiper contact means carried at axially spaced locations on said shaft each having at least one wiper contact sequentially engageable on rotation of said shaft with corresponding output contacts in said first and second decks respectively, succeeding engaged positions of said wiper contact means on .said output contacts coinciding with some succeeding detent positions of said shaft,

said wiper contact of said first wiper contact means being engageable with only one of the corresponding output contacts at a time enabling it to disengage an output contact before engaging an adjacent succeeding one, a

said wiper contact of said second wiper contact means being simultaneously engageable with a pair of adjacent ones of the corresponding output contacts enabling it to engage an output contact before disengaging an adjacent preceding one;

means for actuating said rotary switch means to rotate said shaft to cause said first and second wiper contact means successively to engage the corresponding output contacts including a trip lever journaled for forward and backward swinging movement through a predetermined arc about said shaft, means biasing said trip lever in a backward swinging direction, stop means limiting such backward swinging movement, and a pawl carried by said lever engageable with a ratchet wheel on said shaft effective to incrementally rotatably advance said shaft and said first and second wiper contact means in response to repeated forward and backward swinging movement of saidtrip lever, the

number of teeth on said ratchet wheel being a whole multiple of the number of said detent positions; and timing means including a timing disc and means for rotating said disc at constant speed past said trip lever,

a plurality of timing elements carried by said timing disc sequentially engageable with said trip lever, each said timing element being effective when so engaged to swing said trip lever through said pre determined arc to rotatably advance said shaft and said first and second wiper contact means from one of said detent positions tothe next;

the relationship between output contacts, detent means, ratchet teeth, and first and second wiper contacts being S= (N l) (360/D) where S the arcuate spacing of said wiper contacts in each wiper contact means, about the shaft. in degrees N the total number of said output contacts in each deck D the total number of said detent positions of said shaft in a full 360 turn;

an electrical power source having one power output terminal connected in common to one power input terminal of said main electrically activatable flow controlling component and to one power input terminal of each of said electrically activatable vavles, said electrical power source having another power output terminal connected in common to both of saidfirst and second wiper contact means; and

conductor means connecting the output contacts in the first contact deck to another power input terminal of each of said electrically activatable valves, and connecting all of the output contacts in the second contact to another power input terminal of said main electrically activatable flow controlling component;

whereby sequential actuation of said trip lever by ments.

22 g UNITED STATES PATENT OFFICE CERTIFICATE OF CQRRECTION Patent No. 3 18631079 jjp d January 28 1975 201. 7 line 63 "an" should be -are I g Ronald V. Calabrese It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Col. 9, line 18, "resultts" should be results--;,

line 34, "Mv" should be MV'-;

line 49, "disengaged" should be disengageline 51, between "while'Vand "valve" insert -the main. Col. 10, line 25, "'th" should be the-. Col. 11, line 34, -'.'sapced" should be -spaced-. Col. 13, line 68 "octivatable" should be 'activatable-. Col. 16, line 32, "rotatably" should be -J;otatabl e. Col. 18, line 16, vavles" should be --valv'es-' Signed and sealed this 20th day of May 1975.

(SEAL) Attest:

. v C. MARSHALL DANN RUTH C. MASON I Commissioner of Patents Attesting Officer r and Trademarks 3 g UNITED STATES PATENT OFFICE a CERTIFICATE OF CORRECTION Pat t N 3 1 1 "Dated January 28 1975 I Ronald V Calabrese It is certified that error appears in the aboveeidentif ied patent and that said Letters Patent are hereby corrected as shown below:

E301. 7, line 63 "an" should be are- Col. 9, line 18, "resultts" should be results--;

.line 34 "Mv" should be --,MV--; I

line 49, "disengaged" should be -disengage-; line 51, between "while", and "valve" insert --the main.

Col. 10 line 25, "'th" should be --the.

Col. 11, line 34, "sapced" should be spaced--.

Col. 13, line 68,- "octivatable" should be '-activatable--.

Col. 16, line 32, "rotatably" should be --1 :otatable.

Col. 18, line 16, "'vavles" should be -valves- Signed and sealed this 20th day of May 1975.

(SEAL) Attest:

. C. MARSHALL DANN RUTH C. MASON Commissioner of Patents Attesting Officer and Trademarks

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1906943 *Jun 10, 1930May 2, 1933Fisher Flouring Mills CoIntermittently-operating controlling device
US2594190 *Mar 9, 1950Apr 22, 1952Oak Mfg CoElectrical apparatus
US2665964 *May 22, 1951Jan 12, 1954Elliott Brothers London LtdRecording instrument
US2740056 *Apr 5, 1955Mar 27, 1956Stoddart Aircraft Radio Co IncSelective rotary reversing switches
US3140720 *Jan 24, 1961Jul 14, 1964Donald G GriswoldFluid distribution control system
US3309543 *Jul 22, 1963Mar 14, 1967Rain Bird Sprinkler MfgAutomatic control for sprinkler systems
US3440434 *Feb 26, 1968Apr 22, 1969Griswold ControlsApparatus for programming cyclic actuation of valves
US3604943 *Feb 26, 1970Sep 14, 1971Clemar Mfg CorpSprinkler systems and variable timing means
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4006636 *Jul 7, 1975Feb 8, 1977Lehmkuhl A/SMethod and apparatus for exact measurement of pressures by means of level or pressure measuring equipment of the bubble tube type
US4015138 *Oct 18, 1974Mar 29, 1977Coal Industry (Patents) LimitedSequence control circuit
US4108419 *Mar 1, 1976Aug 22, 1978Clifton J. BurwellPilot operated valve
US4236104 *Dec 19, 1978Nov 25, 1980Rockwell International CorporationPosition sensing rotary switch and system
US4295191 *Feb 14, 1980Oct 13, 1981Telemetry Controls, Inc.Programmable control system
US4340789 *Apr 16, 1979Jul 20, 1982Williams Robert AChaff-flare test adapter switching system
Classifications
U.S. Classification307/41, 200/37.00A, 239/69, 200/17.00R, 137/624.16, 200/11.00D, 307/141, 968/620
International ClassificationA01G25/16, G04C23/00, G04C23/30
Cooperative ClassificationA01G25/162, G04C23/30
European ClassificationG04C23/30, A01G25/16B