US3679951A

US3679951A - Electric timing device

Info

Publication number: US3679951A
Authority: US
Inventors: Robert A Whitlock
Original assignee: Aquamatic Inc
Current assignee: Aquamatic Inc
Priority date: 1971-08-02
Filing date: 1971-08-02
Publication date: 1972-07-25
Anticipated expiration: 1989-07-25
Also published as: CA946885A; DE2236571A1; FR2148161A1; FR2148161B1

Abstract

A drum and a rotary switch are driven by an electric motor which indexes them to various circumferential positions. A lead screw is mounted parallel to the drum and is driven by a reversible electric motor. A follower on the lead screw moves therealong until it engages a stop which is adjustably mounted on the drum, whereupon the reversible motor stalls and reverses its direction of rotation to return the follower to the point of beginning. A shoulder on the drum is engaged by the returning follower to again stall the motor and start the next cycle. The returning follower engages a switch to start the indexing of the drum. Thus a sequence of switching operations are timed and the duration of each is readily adjustable.

Description

United States'Patent 151 3,679,951 -Whitlock 1451 July 25, 1972 [54] ELECTRIC TIMING DEVICE 3,368,042 2 1 968 Lace .318/282 x [72] Inventor: Robert A. Whitlock, Rockford, Ill. Primary Examiner Bemard A Gilheany [73] Assignee: Aquamatic lnc., Rockford, Ill. A 'I x a [211 Appl 168329 A drum and a rotary switch are driven by an electric motor which indexes them to various circumferential positions. A 52 us. (:1 ..318/102, 318/444, 307/141 lead Screw is mwmed Pmllel the drum and is (mm by a 51 Im. c1. .110111 43/12 reversible elem A the lead screw [58] Field of Search ..307/139 141' 318/39 101 hmahng it engages a whid is adjusably 318/102 1 on the drum, whereupon the reversible motor stalls and reverses its direction of rotation to return the follower to the point I 56] References Cited of beginning. A shoulder on the drum is engaged by the returning follower to again stall the motor and start the next UNITED STATES PATENTS cycle. The returning follower engages a switch to start the indexing of the drum. Thus a sequence of switching operations 2,991,403 7/1961 Groft ..3 18/467 X are timed and the duration ofeach is readily adjustable 3,198,966 8/1965 Roberts. .318/444 X 3,304,478 2/1967 Hunter ..3 1 8/102 18 Claims, 6 Drawing Figures ELECTRIC TIMING DEVICE BACKGROUND The invention pertains generally to electrical circuit controls, and more particularly to an electric timing device.

Drum type electricaltimers are well known; however most of them time by rotation of the drum. When one desires to vary the timing duration, it is often necessary to change-the position of many of the stops on the drum. It is desirable to have an electrical'timing device in whichthe timing duration can be readily varied and/or inwhich onetiming durationcan be varied without affecting other timing durations. Timers using followers on lead screws are also known; however the problem, of varying the position of one stop necessitates changing other stops. Additionally such timers are limited in capacity because of length, and returning the follower to the point of beginning is a problem. It is desirable to have a timing device which alleviates the problems described above.

SUMMARY The present invention relates to an electric timing device.

It is a generalobject of the present invention to provide a reliable electric timing device for controlling the duration of a plurality of operations.

Another object is to provide an electric timing device in which the timing duration can be readily varied.

Still another object is to provide an electric timing device in accordance with the foregoing object in which one timing duration can be varied without effecting the duration of adjacent functions.

Another object of the present invention is to provide an electric timing device of the drum type which times by movement axially of the drum rather than by rotation of the drum.

Yet another object of the present invention is to provide an electric timing device including a drum with stops thereon, a lead screw with a follower, and a reversible electric motor of the type which reverses when stalled and which drives the follower between stops on the drum.

These, together with other objects and advantages of the present invention, will become apparent as the same becomes better understood from the following detailed description when taken in conjunction with the drawings.

DRAWINGS FIG. 1 is a perspective view of a preferred embodiment of the present invention;

FIGS. 2 and 3 are, respectively, top and front elevations of the embodiment ofFlG. 1;

FIG. 4 is an end view as seen from the right of FIG. 3;

FIG. Sis a view taken along line 5-5 of FIG. 3; and

FIG. 6 is a diagrammatic view showing a portion of the circuitry ofthe embodiment of FIG. 1.

DESCRIPTION Reference is now made more particularly to the drawings which illustrate the best presently known mode of carrying out the invention and wherein similar reference characters indicate the same parts throughout the several views.

The preferred embodiment of the present invention shown in the drawings includes a generally cylindrical drum, generally designated 10, and a lead screw 11, both rotatably mounted on a frame which includes a base plate 12 and end plates I3 and 14. The drum l0 and lead screw 11 are mounted with their axes parallel and, preferably, the lead screw is parallel to the adjacent drum surface even if the drum is not a cylinder. A follower 15 is mounted on the lead screw and is provided with a flat side adjacent a member 16 which prevents rotation of the follower 15 as the lead screw 11 is rotated. It is contemplated that other arrangements may be utilized to assure that the follower travels along the lead screw as the latter is rotated.

A motor 21 is mounted on end plate [3 for driving the lead screw 11. Motor 21' is an electric motor of the type which reverses direction of rotation when stalled. One suitable motor is apermanent magnet synchronous motor sold by Giannini Controls Corp., Cramer Division, Old Saybrook. Conn. and designatedCramer l 17 with dual rotation. Motor 21 rotates the lead screw 11 to move the follower 15 from a point of beginning such as shown in FIGS. 2 and 3 toward the left. The follower moves until it engages a stop (hereinafter described) whereupon it stalls themotor 21. The motor then reverses and returns the follower to the point of beginning where it engages another stop to start the cycle over again.

The drum 10 includes a cylindrical sleeve 31 having

end members

32 and 33. End member 33 has a circumferential shoulder 34. which serves as the stop at the point of beginning for engagement by the follower 15. A plurality of openings 35 arearranged in the sleeve 31 for selectively receiving elements 36 therein. As can be seen, a plurality of openings 35 are arranged longitudinally of the sleeve 31 and parallel to the axis. The stop 36 can be placed into any one of these aligned openings to vary the position where the follower 15 engages the stop. In this manner, the duration of the cycle can be varied by moving the stop 36 from opening to opening. Other arrangements for adjustably locating the stop 36 can be utilized, if desired. A row of these openings is found at each of a number of circumferential positions on the drum. As hereafter described, the drum I0 is indexed to its various circumferential positions by a second electric motor 38, which is also mounted on end plate 13.

A disk 42 is mounted for rotation with the drum and is conveniently located outwardly of the end plate 14. Disk 42 has a plurality of indentations, each one corresponding to one of the circumferential positions of the drum. A plurality of rotary switches 44-47 are mounted on the disk 42 for rotation therewith. One suitable utility of the rotary switches will hereinafter be explained;

Three

switches

51, 52, and 53 are mounted on end plate 14, as best seen in FIG. 3. The function of these switches is best seen by reference to the circuit diagram shown in FIG. 6. As shown, power is supplied across

leads

61 and 62. An on-off switch 63 is conveniently provided in lead 61. Lead screw motor 21 is connected to the leads by a line 64 which has branches 64a and 64b. Interposed in branch 64a is a start switch 65, while switch 51 is shown as a two-way switch which alternately connects branches 64a and 64b to line 64. When switch 63 is closed, the start switch 65 can be closed to provide power to the lead screw motor 21. The lead screw starts to rotate and advance the follower 15 to the left as seen in FIGS. 2 or 3. It can be seen that the follower 15 is initially in engagement with switch 53, and the switch 53 has been thrown to the position shown in phantom lines in FIG. 6, thereby completing a circuit through line 68 to drum motor 38. As soon as the drum starts to rotate, a single indentation (not shown) in shoulder 34 throws switch 51 to its second position, shown in phantom lines, and thereby completes a holding circuit to lead screw motor 21. In this manner, the drum will be rotated through a full 360 to perform a plurality of sequential timed operations. Simultaneously with the throwing of switch 51, switch 52 has its detent moved out of the indentation in disk 42 and is also thrown to its second position shown in phantom lines in FIG. 6. This breaks the circuit to the drum motor momentarily until the follower 15 passes switch 53 and allows it to return to its normal position shown in full lines in FIG. 6. At this point, the circuit is again completed to the drum motor and it rotates the drum until the detent of switch 52 falls into the next successive indentation.

At this point assume that the drum l0, disk 42 and the corresponding rotary switch 44 have been moved to the circumferential position indicated by the numeral 1 in FIG. 6.

Meantime, the follower 15 is being moved by the lead screw until it engages the stop 36 at its selective position on the first circumferential position of the drum. As explained above, the follower will engage the stop and stall the motor. This causes the motor to reverse and return the follower to the follower to the point of beginning. As the follower 15 approaches the point of beginning, it engages the switch 53 and again completes a circuit to the drum motor 38. The abovedescribed operation is then repeated and the drum is advanced to the position indicated by the numeral 2. This sequence of operations continues until the drum has been rotated its full 360. 1t is contemplated, however, that the drum can be rotated through only a portion of its circumference if desired. In this manner, a sequential number of operations are performed and the time of each operation is selectively adjustable without varying the time of the adjacent operation.

Regeneration of an industrial mixed-bed de-ionizer is one example of a plurality of sequential operations which may be controlled by the above-described electric timing device. As well known-in the art, such regeneration includes the operations of blow down, backwash, settling, acid-caustic, caustic, slow rinse, fast rinse, second blow down, first air mix, second air mix, fill, fast rinse, and service position. With the device of the present invention, each of these operations can be varied in duration without upsetting the duration of any of the other operations.

The circuit diagram of FIG. 6 has been described as relating to rotary switch 44. In the regeneration of the industrial, mixed-bed de-ionizer, rotary switch 44 controls circuitry to a plurality of indicator lights, for example lights 7-9 in FIG. 6, each of which indicates the operation in progress. Rotary switch 45 controls the regenerant pump for acid, and rotary switch 46 controls the regenerant pump for caustic. Rotary switch 47 is utilized as a stand-by switch.

It is now deemed obvious that there has been described a unique electric timing device which includes a reversing motor 21 which drives the lead screw 11 to advance a follower 15 in a reciprocating manner. When energized, the reversing motor 21 advances the follower 15 until it engages the stop 36 selectively positioned longitudinally of the drum. This stalls the motor 21 and causes it to reverse; whereupon the follower 1S reverses direction until it engages shoulder 34. During its travel, the follower 15 engages switch 53 which energizes drum motor 38 to advance or index the drum a portion of a revolution. The follower, when engaging the shoulder 34, stalls the reversing motor and the next portion of the cycle is started, but the drum has been rotated to the next control position. The stops 36 on the drum can be easily adjusted longitudinally of the drum without affecting the stop of either the preceding or succeeding position.

While a preferred embodiment of the invention has herein been illustrated and described, this has been done by way of iilustration and not limitation, and the'invention should not be limited except as required by the scope of the appended claims.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. An electric timing device including a support, a lead screw rotatably mounted on the support, a reversible electric motor operatively connected to the lead screw for rotating the I same, said motor being of the type which reverses when stalled so that it alternately rotates the lead screw in opposite directions, a follower engaged with the lead screw for movement therealong, a first stop, a second stop, mounting means for mounting the stops on the support spaced from each other and each in position for engagement by the follower to stall the electric motor and reverse the same, and a switch positioned in the path of the follower to be thrown by the same, whereby the follower moves from the first stop to the second stop and engages the same to stall the motor, the motor reverses and the follower returns to the first stop to complete a cycle, the switch being thrown by the follower during travel through the cycle.

2. An electric timing device as set forth in claim 1 in which themounting means adjustably mounts one of the stops at any one of a plurality of positions parallel to the lead screw, and the switch is positioned adjacent the other stop.

3. An electric timing device as set forth in claim 1 wherein the mountingmeans includes a drum rotatably mounted on the support adjacent the lead screw, the drum having an outer surface with a portion adjacent the lead screw and parallel thereto.

4. An electric timing device as set forth in claim 3 including a second electric motor operatively connected to the drum to rotate the same under control of the switch.

5. An electric timing device as set forth in claim 1 wherein the mounting means includes a drum rotatably mounted on the support adjacent the lead screw and coaxial therewith, the first stop is on the surface of the drum; and including a plurality of other stops on the surface of the drum spaced circumferentially from the first stop, a second electric motor operatively connected to the drum to rotate the same under control of the switch and arranged to advance the drum to successively position each of said other stops for engagement by said follower, whereby the follower is moved through successive timed cycles between the second stop and said stops on the surface of the drum.

6. An electric timing device as set forth in claim 5 including a rotary switch mounted for rotation with the drum.

7. An electric timing device as set forth in claim 5 wherein each of said stops on the surface of the drum is adjustably mountable thereon along a line parallel to the axis of the lead screw.

8. An electric timer including a support, a drum rotatably mounted on the support, a lead screw rotatably mounted on the support adjacent the drum and parallel to the adjacent drum surface, a follower engaged with the lead screw for movement therealong as the lead screw is rotated, a reversible electric timing motor for rotating the lead screw to advance the follower and for returning the follower to a point of beginning, means for indexing the drum to a plurality of circumferential positions where a different part of the drum surface is adjacent the screw shaft, and means on the drum surface at each of said circumferential positions for engagement by the follower to limit advancement thereof and cause the follower to be returned to the point of beginning, whereby a separate timing function is performed at each of said circumferential positions on the drum surface.

9. A timer as set forth in claim 8 wherein the means on the drum surface are adjustable in a direction parallel to the axis of the lead screw, whereby each timing function is adjustable without affecting the adjacent timing function.

10. A timer as set forth in claim 8 wherein the reversible electric timing motor is of the type that reverses when stalled, and the means on the drum surface is a stop at each of said'circumferential positions to be engaged by the follower and stall the motor; and including a stop at the point of beginning to be engaged by the follower and again stall and reverse the motor.

11. A timer as set forth in claim 10 wherein the stop at the point of beginning is a circumferential shoulder at one end of the drum.

12. A timer as set forth in claim 10 wherein the means for indexing the drum includes a second electric motor for indexing the drum, and a switch adjacent the screw shaft at the point of beginning for supplying current to the second electric motor.

13. A timer as set forth in claim 8 including a rotary switch mounted for rotation with the drum and having a plurality of switching positions corresponding to the circumferential positions of the drum.

14. A timer as set forth in claim 13 wherein the means for indexing the drum includes a second electric motor for indexing the drum and rotary switch, and a switch adjacent the screw shaft at the point of beginning for supplying current to the second electric motor, whereby the timer sequentially times a plurality of functions under control of the rotary switch.

15. A program timer for controlling the duration of a plurality of operations and including: a support, a drum rotatably mounted on the support, a lead screw rotatably mounted on the support adjacent the drum, a follower engaged with the lead screw for movement therealong as the lead screw is rotated, indexing means for indexing the .drum to a plurality of circumferential positions where a different part of the drum surface is adjacent the lead screw, each circumferential position corresponding to one of said operations, means on the drum at each of the circumferential positions for engagement by the follower, synchronous drive means for rotating the lead screw to drive the follower from a beginning point to engage one of the last-mentioned means and for returning the follower to the beginning point, and a rotary switch mounted for rotation with the drum and having a plurality of switching positions corresponding to the circumferential positions of the drum, whereby the timer sequentially times a plurality of operations under control of the rotary switch.

16. A program timer as set forth in claim wherein the means on the drum at each of the circumferential positions are adjustable in a direction parallel to the axis of the lead screw, whereby each timing function is adjustable without affecting the adjacent timing function.

17. A program timer as set forth in claim 16 wherein the synchronous drive means includes a reversible electric motor. and the indexing means includes a second electric motor.

18. A program timer as set forth in claim 17 wherein the reversible electric motor is of the type that reverses when stalled, the means on the drum at each of the circumferential positions is an adjustable stop for engagement by the follower to stall the motor, and including a stop at the point of beginning for engagement by the follower to again stall the motor and reverse the same.

Claims

1. An electric timing device including a support, a lead screw rotatably mounted on the support, a reversible electric motor operatively connected to the lead screw for rotating the same, said motor being of the type which reverses when stalled so that it alternately rotates the lead screw in opposite directions, a follower engaged with the lead screw for movement therealong, a first stop, a second stop, mounting means for mounting the stops on the support spaced from each other and each in position for engagement by the follower to stall the electric motor and reverse the same, and a switch positioned in the path of the follower to be thrown by the same, whereby the follower moves from the first stop to the second stop and engages the same to stall the motor, the motor reverses and the follower returns to the first stop to complete a cycle, the switch being thrown by the follower during travel through the cycle.

2. An electric timing device as set forth in claim 1 in which the mounting means adjustably mounts one of the stops at any one of a plurality of positions parallel to the lead screw, and the switch is positioned adjacent the other stop.

3. An electric timing device as set forth in claim 1 wherein the mounting means includes a drum rotatably mounted on the support adjacent the lead screw, the drum having an outer surface with a portion adjacent the lead screw and parallel thereto.

10. A timer as set forth in claim 8 wherein the reversible electric timing motor is of the type that reverses when stalled, and the means on the drum surface is a stop at each of said circumferential positions to be engaged by the follower and stall the motor; and including a stop at the point of beginning to be engaged by the follower and again stall and reverse the motor.

15. A program timer for controlling the duration of a plurality of operations and including: a support, a drum rotatably mounted on the support, a lead screw rotatably mounted on the support adjacent the drum, a follower engaged with the lead screw for movement therealong as the lead screw is rotated, indexing means for indexing the drum to a plurality of circumferential positions where a different part of the drum surface is adjacent the lead screw, each circumferential position corresponding to one of said operations, means on the drum at each of the circumferential positions for engagement by the follower, synchronous drive means for rotating the lead screw to drive the follower from a beginning point to engage one of the last-mentioned means and for returning the follower to the beginning point, and a rotary switch mounted for rotation with the drum and having a plurality of switching positions corresponding to the circumferential positions of the drum, whereby the timer sequentially times a plurality of operations under control of the rotary switch.

16. A program timer as set forth in claim 15 wherein the means on the drum at each of the circumferential positions are adjustable in a direction parallel to the axis of the lead screw, whereby each timing function is adjustable without affecting the adjacent timing function.

17. A program timer as set forth in claim 16 wherein the synchronous drive means includes a reversible electric motor, and the indexing means includes a second electric motor.