US2737236A - Timing mechanism - Google Patents

Description

March 6, 1956 Q ESTES 2,737,236

TIMING MECHANISM Filed Jan. 15, 1953 ZEHN C. 27155,

IN V EN TOR.

United States Patent TIMING MECHANISM John C. Estes, Richland, Wash., assiguor to Febco, Inc, Los Angelcs, Califi, a. corporation of California Application January 13, 1953, Serial No. 331,650

1 Claim; (Cl.-161---1) This invention relates generally to electrical timing equipment. and more particularly describes circuits and devices. for sequentially energizing a plurality of electrical service circuits.

It; is well known that many applications, industrial and otherwise, include mechanisms which are energized or a Although the present invention is particularly useful in controlling the valves of an irrigation system as just dis cussed, nevertheless it will be readily understood that the invention is not restricted to such use and other uses and applications are within my contemplation. The invention has for its principal object the provision of a novel electrical control and timing system.

Another object is to disclose such a system having easily adjustable means for controlling the length of time of energization of the controlled units.

A further object is to provide means in a system of the above character for conveniently doubling or having the amount of time during which each controlled unit or circuit is energized.

Another object is todisclose a system of the above character'including means for automatically starting the sequential cycle of the controlled apparatus at a predetermined time.

It is another object to provide a system of the above character including means for stopping the energization of service contacts after one cycle of operation.

Another object is to provide a system of the above character including manually actuable means for initiating a cycle at any desired time.

Yet another object is to disclose a novel electrical timing system having the above advantages in operation which is: reliable and foolproof in use but relatively economical to construct.

A- further object is to provide a timingsystem of the above character including means for re-energizing a selected service contact or contacts a plurality of times during a cycle of operation.

These and other and allied purposes and objects of the invention will be understood from a study of the following description of a preferred embodiment thereof taken in connection with the accompanying drawing in which:

Fig. 1 is a diagrammatic layout showing a time clock, a timing controller and selector and a stepping switch together=with interconnecting circuitry constituting. a preferredembodiment of, my invention.

Fig. 2 is; a detailed schematic view of a preferred embodiment of, thetime controller and selector of my invention.

2 Fig. 3 is a view of a terminal board and connectors which may be used in combination with the apparatus of Fig. 1.

Generally speaking the present invention makes use-of a number of contact switches which may desirably be in the form of conventional micro-switches although other suitable make and break switches, normally open, may

be employed. In the present illustrative embodiment of the invention. four such switches are circumferentially disposed about a rotatable contact member arranged. to sequentially close each of said four switches for a'short time during a revolution of the rotatable member. A selector is provided and is connected to the circumferentially disposed switches by suitable. leads whereby the closing of one, two or four of the switchestdepending upon the setting of the selector) allows current to flow through the controller proper. The selector includes a manually actuable selection switch by which the operator or user may select the number of effective electric contacts madeby the switches during each revolution of the rotatable contact member. Means may be included in the controller to decrease the time interval during which current flows therethrough, such means being here shown as an additional micro switch actuated at the same time as is any of the first named micro-switches, but for a shorter length of time.

The output of the controller just described is in'the form of a seriesof electric impulses which are fed to the energizing means of a stepping switch. The latter-named switch is conventional in construction and includes a plurality of service contacts, each such contact being adapted to be connected to a particular one of the tlevices to be controlled. Typically in an irrigation system each such service: contact is connected to a normally closed valve controlling flow of liquid in a certain portion of the system, and energization of' a service contact corresponding to a given valve serves to hold that valve open. Each actuation of the stepping switch by an electric impulse from the timing controller causes the stepping switch to cease energizing one of its-service contacts and to commence energization of the successive service contact. The last of such contacts in a cycle, instead of being connectedto one of the controlled devices, is connected to a relay for stopping the system, whereby the stepping switch sequentially energizes each of the controlled devices and then stops itself.

Referring nowtothe drawing and in particular to Fig. 1 thereof, there is indicated generally at 10 a timing controller which includes suitable driving means such as a small electrical motor indicated generally at-l2. A selector is indicated generally at'14 and is electrically connected to controller 10 by conductors 16, 18, and 20.

The relationship and cooperation of controller 10-and selector 14 with other circuit elements of Fig. 1 will'be better understood by consideration first of the internal construction and circuitry of Fig. 2 where is shown a preferred construction of controller 10 and selector. 14. A rotatable member 22 is carried upon shaft 24 which is driven through suitable gearing by motor 12 of the controller. Member 22' is desirably in the form of a gear wheel for reasonsappearing hereinafter and for purposes of the present description'it will be assumed torotate clockwisewhen motor 12' is energized. Near the periphery of gear wheel 22 is a contacting member 26* which may take the form of a stud extending'parallel to shaft 24 or upwardly from the face of gear wheel 22 as'seen-in Fig. 2.

Circumferentially' disposed around gear wheel 22 are a number of micro-switches 30, 40, 50 and 60. Each ot theswitches includes a contact arm 32, 42, 52 and 62 so disposed as to-extend inwardly toward the center of gear wheel 22 and in the path of stud 26. The contact arms terminate in members 34, 44, 54 and 64 arranged to be sequentially contacted by pin 26 during rotation of the gear wheel 22 by camming action between the pin 26 and the members 34, 44, 54 and 64. Each such contact, as will be readily understood, closes the normally open contacts of the micro-switch. Each of the four switches 30, 40, 50 and 60 includes two electrical terrni nals 31,33, 41, 43, 51, 53, 61 and 63. One terminal, as 31, 41, 51 and 61, of each of the switches is connected to input terminal 70 of controller by bus 71.

A fifth switch may be included in the electrical controller and is indicated at 80. Switch 80 is similar to normally open switches 30, 40, 50 and 60 and is provided with arm 82 terminating in the member 84, and has terminals 81 and 83, the latter being connected to the controller output terminals 72 by lead 73. An auxiliary rotatable member 90 in the present illustration takes the form of a geared wheel rotatable about shaft 92 and meshing with gear 22 and 94. The gearing of the two members 22 and 90 is so chosen that the smaller gear 90 rotates more rapidly than gear 22 in the ratio of the number of switches circumferentially disposed about the larger gear 22. In the present instance, therefore, gear 90 totates at four times the speed of gear 22 and is provided with a contact member or stud 96 extending, as seen in the drawing, upwardly from the face of the wheel 90. Stud 96 is arranged to depress arm 82 of switch 80 by camming abutment against the member 84 once in each revolution of the gear 90. Gear 90, as indicated by the arrow thereon, of course, rotates in a direction opposite to that of gear 22, and the gears are assembled so that switch 80 is closed during the time when any of the switches 30, 40, 50 or 60 is closed.

It will be seen that switch 80 and gear 90 constitute means to minimize the duration of a timing pulse or signals produced by the timing controller. In the normal use of my invention it may be necessary that gear 22 be made to rotate at a very slow speed, of the order of one-tenth to one-quarter revolution per minute. Under such circumstances each of the switches 30, 40, 50 and 60 is closed for a substantial period of time. As will be understood as the description progresses, it is desirable that the electrical signal or pulse produced by the controller be of relatively short duration, and this is conveniently accomplished by the switch 80 and gear 90. It

will be noted that a pulse or signal can be produced at the output terminal 72 of controller 10 only when switch 80 is closed by stud 96, and since gear 90 rotates at four times the speed of gear 22, the duration of a pulse is only one-fourth as long as if switch 80 were not in the circuit.

Means are provided for selecting which of the switches 30, 40, 50 and 60 will effectively provide a path of current flow through controller 10 from the input terminal 70 to the output terminal 72, such means in the present illustration taking the form of selector 14. A three-position switch includes a contact arm 102 pivotable about a central point 106. A knob 108 (see Fig. l) is provided to facilitate rotation of the arm into positions as desired, and the knob may carry an indicating pointer 110. Suitable indicia 112 are provided so that the operator may adjust knob 108 (and thereby contact arm 102) to a desired position by reference to the indicia 112, as will be later described in detail.

With further reference to the schematic diagram of Fig. 2, it will be seen that contact arm 102 is connected through conductor 16 to terminal 81 of switch 80, and terminal 33 of switch is also connected to terminal 81 through lead 115. Terminal 53 of switch 50 is connected by lead 18 to contact 117 of selector 14 and also by jumper 118 to contact 119 of the selector. Terminals 43 and 63 of switches and 60 respectively are connected together and, through lead 20, to contact 120 of selector 14.

Assume now that gear 22 and meshing gear 90 are rotating in the directions indicated by their respective arrows, gear 22 rotating at one-quarter R. P. M. and gear 90 at 1 R. P. M. When stud 26 carried on gear 22 is in the position shown in Fig. 2, it abuts member 54, thus depressing switch arm 52 and closing switch 50. At the same time stud 96 of gear 90 also depresses switch arm 82 so that the switch is closed. Contact arm 102 of selector 14 is in the position shown in solid line of Fig. 2. In this way an electrical path is provided through controller 10 and selector 14 from the controller input terminal 70 to controller output terminal 72, the path including bus 71, switch 50, lead 18, contact arm 102, lead 16, switch 80 and lead 73. This path through the controller will exist only so long as switches 50 and 80 are closed. In practical operation, as before noted, gear 22 rotates relatively slowly and switch arm 52 is therefore depressed for a relatively long time. Gear rotates at four times the speed of gear 22, and hence switch 80 is held closed only one-fourth as long as any one of the switches 30, 40, 50 or 60. Accordingly, as the parts continue their movement from their positions shown in Fig. 2, switch 80 is the first to open, thus breaking the electrical path between terminals 70 and 72 of the controller.

Consider now the situation one minute later. Gear 22 will have rotated one-quarter revolution and stud 26 will have moved into abutting contact with the member 64, thus depressing arm 62 and closing switch 60. Gear 90 will have rotated one complete revolution so that stud 96 is again in the position shown in Fig. 2, closing switch 80. No electrical path is provided, however, between terminals 70 and 72 of controller 10 since, in selector 14, contact arm 102 is not in contact with the point 120.

Another minute later finds switch 30 closed by reason of its arm 32 being depressed by stud 26, and of course stud 96 and switch 80 are again in the positions shown, switch 80 being closed. In this situation, and regardless of the position of contact arm 102 of selector 14, a path is established from terminal 70 to terminal 72, such path including bus 71, switch 30, lead 115, switch 80 and lead 73.

At the expiration of another minute, i. e. three minutes after the position shown in Fig. 2, gear 22 will have retated so that its stud 26 depresses arm 42, thus closing switch 40. As was the case with switch 60, no electrical path is established through controller 10 because contact of selector 14 is open when contact arm 102 is in the position shown in solid line in Fig. 2.

Accordingly, a complete revolution of gear 22 provides two separate times when contact is established between terminals 70 and 72 of the controller. Such a complete revolution lasts four minutes, and the controller therefore establishes contact once every two minutes. This results, it will be understood, when contact arm 102 of selector 14 is positioned as shown in the solid line of Fig. 2.

When contact arm 102 is moved to position A, as indicated by the dotted line of Fig. 2, it will be seen that lead 18 is no longer in contact therewith. Consequently the position of the elements shown in Fig. 2 does not establish contact between terminals 70 and 72, and as a further consequence only one such contact is established during each complete revolution of gear 22. This single occasion occurs when switch 30 is closed by stud 26, since it will be observed that contact established by switch 30 is independent of connections or contacts afforded by selector 14.

When contact arm 102 is moved to position B shown by the dotted line of Fig. 2, the ends of the arm are in contact with points 119 and 120. It will now be seen that closing of either switch 40 or switch 60 by stud 26 prw videsan electrical path between terminals 70 and 72 of the controller, such path including bus 71, switch 40 (or 60), lead 20, contact arm 102, lead 16, switch 80 and lead 73. Closing of switch 50 likewise provides such a path because of jumper 118 connecting points 117 and 119. Under such conditions four successive contacts will be established during each revolution of gear 22, or one contact per minute under the assumed conditions whereby gear 22 rotates at one quarter'R. P. M.

ImFig. 1. conductors-130 and 131 are adapted to be. con.

nected to a suitable source of A. C. power. A. time clock is indicated generally at 133 and is driven by a synchronouselectric motor 134 connected to conductors 130 and 131 by leads 132 and 136. Clock 133 is arranged to make contact at 135 between lead 136 and lead 137 connected to the input terminal 70 of controller 10. The moment of making such contact may be set to any desired.- time as by adjusting pointer 138'on. dial 139, the dial preferablyv bearing 24 hour indicia. Clock 133 is well known in the-art, is conventional in construction: and. is hence: not described in detail herein. It constitutes a preferrcd means. for automatically initiating a cycle of operation: of'thev timing controller and stepping switch as now to be. described. A stepping switch, indicated generally at 140 includes a plurality of service contacts 141 and a contact arm 142 mounted for pivotal movement at 143. Point 143 is con- 'nect'ed by lead 144 to conductor 130. One of the service contacts141, as 145, may be designated a. stop contact and is connected to lead 146. A normally closed stop relayindicatedl generally at 1.47 includes-a coil 148 having one endconnected to lead 146, an electromagnetic core 149'and a" movable armature 150 having at its outer end a: contact point 151. A lead 152 extends from supply conductor I31, and the other end of coil148 is connected theret'oand' to contact point 151 of armature 150. A fixed contact point 153 is connected through lead 154. to one side of the winding of motor 12, the other side of the motor winding being connected to supply conductor 130 through lead 155.

A lead 156" extends from the output terminal 72 of controller to one side of the winding of an actuating solenoid. 157, the other'side being connected by lead 158 to conductor 130. Energization of solenoid 157 causes contact arm142' to advance in a clockwise direction. from .one contact 141 or 145 to the next contact where it remains until" a subsequent de-energization and energization.

Means are p'rovidedfor manually initiating a cycle of operation at any desired time, such means being here shown as including a normally open switch, indicated generally at 159 and serving, when closed, to connect lead 156 to conductor 131. Switch 159 desirably may be a conventional push button.

Movement of contact arm 102 into one of its three positions corresponds to rotation of knob 108 (see Fig. l). The indicia 112 previously mentioned desirably are 2N /2 as shown, where N indicates normal adjustment of the system, 2 indicates that stepping switch 140 energizes each of its service contacts 141 for twice as long a period as normal and /2 indicates that each of the service contacts 141 is energized for one half the normal period. Thus the position of indicator 110 of selector 14 as shown in Fig. 1 corresponds to the position of contact arm 102 as shown in solid line in Fig. 2; when indicator 110 points to "2 in Fig. 1, contact arm 102 is in position A of Fig. 2; and when indicator 110 points to /z in Fig. 1, contact arm 102 is in position B of Fig. 2.

The operation of the timing system is as follows. Time clock 133 is set to close contacts 135 at any desired time. When that time arrives, closing of the contacts energizes the driving motor 12 of timing controller 10, and gear 22 (together with gear 90, if used) rotates. As soon as an electrical path is established between the terminals 70 and 72 of controller 10, the solenoid 157 of stepping switch 140 is thereby energized and contact arm 142 is moved one step to the contact 141 next in clockwise sequence following stop contact 145. With the breaking of contact 145, power is no longer supplied through conductor 146 and consequently relay coil 148 is deenergized. Relay 147 being normally closed, points 151 and 153 are brought together and power is now supplied to motor 12 of timing controller 10 through lead 152,. closed relay 147 and lead 154. Thereafter continued operation of the system. through a complete cycle is independent of time clock 133 and the clock is desirably arranged to break the contacts at a short predetermined time after initially closing the. contacts so that. later actuation of the stop relay 147 after a complete cycle of operation of the system will be effective to stop the system.

In the above described manner stepping switch will successively energize the service contacts 141 and the conductors 160 connected thereto. It will be understood that each of the conductors160 is: adapted to be connected to an individual controlleddevice such. as a valve or the like, the. other side of such. controlledv devices being con nectedxto conductor 131. When'contact arm 142- again energizes stop contact 145 andv thereby opens contact points 151 and 153, power is removed from the driving motor 12 of timing. controller 10 and thus the system comes to rest. The cycle of operation may then; be reinitiated by depressing push button. 159, whereby power is momentarily applied to winding 157 of the stepping switch and contact arm 142 is moved to the next. contact following stop contact 145. Of course, if push button.

159 is not actuated, the system will be automatically restarted by time clock 133 at the selected time.

Means for rte-energizing selected service contacts during a single cycle may be provided, such means desirably taking the form of a terminal board as shown in Fig. 3 and indicated generally at 170. Terminal board includes contacts 172, each contact being connected to a corresponding. one of. the contacts 141.in accordance with the letters A, B, C and so forth. connecting leads for this purpose being omitted in the interest of clarity. Means are provided for facilitating the connection. together of selected ones of the contacts 172 on the terminal board, such. means inthepresent illustration taking the form of links 174 made of. conductive material, preferably brass or other suitable metal... Each of the links 174 may include a. pair of spaced openings 176 adapted. to encircle and make electrical contact with two adjacent. contacts: 172, such. as between A and B as shown. Moreover, the contacts 172 are desirably spaced so that a link 1.74 may connect two of the contacts which are not in sequence, as illustrated by the connecting link 174 extending between contacts H and N, and when the contacts 172 are arranged in a plurality of rows I prefer to stagger successive rows as shown for maximum fiexibility in use. It will be seen, for example, that a single link may connect contact H with any one of the contacts C, D, G, I, N or P, and in a preferred form of terminal board 170 each of the contacts 172 takes the shape of a cylindrical pin projecting outwardly from the board 170 a suflicient length to permit a plurality of links 174 to be connected thereto.

It will now be seen that great flexibility in use of the present timing mechanism may be attained by arranging links 174 as desired on terminal board 170, and any given arrangement may be easily altered as desired. This feature is of special importance when the timing mechanism is used to control water sprinklers irrigating growing crops. The mechanism can be adapted to changing conditions of weather and to the progressive changes incident to the growth of crops throughout their life from planting to harvesting. Furthermore the mechanism may be adapted to terrain conditions existing in a given installation. For example, it is well known that sloping terrain will permit run-oft if heavily watered, and possible damage to the soil will result. In such a situation it may be desirable to water the sloping portions of the terrain for relatively short periods two, three or more times during each cycle of the operation. This is easily accomplished by connecting together two contacts 172 which are not in sequence, such as contacts H and N illustrated in Fig. 3, either of these being connected to the energizing means (not shown) of the valve controlling irrigation of the sloping terrain.

The opposite requirementwhere water is wanted in a relatively long continuous fiowis easily met by linking together as many sequential contacts as desired. The link 174 connecting contacts A and B is illustrative of such a situation, it being understood that only one of the contacts, such as A, need be connected to the energizing means (not shown) of the particular valve concerned.

Accordingly it will be seen that there is provided a timing mechanism possessing a high degree of flexibility in use. It is obvious that many changes from the spe cific illustrative embodiment herein shown will occur to those skilled in the art. The timing clock may be arranged to start the cycle several times in a single day, and if desired a plurality of contacts 141 may be made to function as stop contacts by connecting them to contact 145. Under such conditions the stepping switch will make only a partial revolution before stopping, this being particularly appropriate where the water used is supplied from a well which might run dry it too much water were taken from it continuously. Moreover, under such conditions a pump may be controlled by the mechanism, the pump motor being controlled by a relay switch connected in parallel with the motor of the timing controller so that the pump is energized, and operated only when the timing controller is moving and the system is hence calling for Water.

In the timing controller proper it will be observed that the contacts of the microswitches 30, 40, 50 and 60 are not caused to make or break while energized when the microswitch 80 is used. Rather, those four microswitches merely establish an electrical path through which current will subsequently fiow, or break an electrical path through which current is no longer flowing. This is so because the microswitch 80 actually controls the starting and stopping of current flow, as previously explained. As a result, I may substitute for the four microswitches 30, 40, 50 and 60 other and less expensive means for establishing and breaking contact. Such means may for example include an arm rotatable about an axis and bearing a brush or similar means for making continuous sliding contact with a circumferential conductor and a second brush or sliding contactor connected to the first and radially spaced therefrom on the arm, the second brush or sliding contactor'being arranged to sequentially establish and break contact with a series of four arcuately spaced conductors disposed circumferentially of the axis.

Additional modifications and changes beyond those above mentioned are within the contemplation of the invention, and all such modifications and changes not departing from the'spirit of the invention are intended to be embraced by the following claim.

I claim:

A timing mechanism comprising: a timing controller consisting of a plurality of normally open switches, an additional normally open switch, means for connecting said additional switch in series with a selected number of said first named switches and a single driving means, including an electric motor and a normally closed switch in series therewith, for repetitively, sequentially and singly closing said first named normally open switches and for closing and opening said additional switch during the time of closure of each of the first named normally open switches; a stepping switch having a plurality of electric contacts including a stop contact and a plurality of service contacts, a movable contactor arranged to repetitively, sequentially and singly energize said electric contacts and electrically actuable means for shifting said contactor from one of said contacts to the next in sequence; means for opening said normally closed switch upon energization of said stop contact; and means including electric leads interconnecting said additional switch and the shifting means for energizing the latter upon closure of said additional switch.

References Cited in the file of this patent UNITED STATES PATENTS 1,064,976 Lundius June 17, 1913 2,250,919 Skelly July 29, 1941 2,359,160 Sauter Sept. 26, 1944 2,400,085 Gent May 14, 1946 2,442,497 Kelk et al. June 1, 1948 2,532,894 Currier, Jr Dec. 5, 1950 2,577,155 Rex Dec. 4, 1951 2,636,981 Benow Apr. 28, 1953

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