US3297838A - Program timer - Google Patents

Description

Jan. 10, 1967 R. o. RULSEH 3,297,333

' PROGRAM TIMER Filed April 15, 1964 6 Sheets-Sheet 1 AUTOMATIC OFF INVENTOR Roger D. Rulseh FIG.I. W

ATTORNEY R. D. RULSEH Jafi. 10, 1967 PROGRAM TIMER 6 Sheets-Sheet 2 Filed April 13, 1964 INVENTOR Roger D.Rulseh ATTOR N E Y Jan. 10, 1967 R. D. RULSEH 3,297,338

PROGRAM TIMER Filed April 13, 1964 6 Sheets-Sheet 3 INVENTOR. Roger D.Rulseh ATT RNEY Jan. 10, 1967 R D, RULSEH 3,297,838

PROGRAM TIMER Filed April 13. 1964 6 Sheets-Sheet 4 R zmgswlToRh 0 er D. u se FIG. 8. g

ATTORNEY Jan. 10, 1967 R. D. RULSEH 3,297,838

PROGRAM TIMER Filed April 13. 1964 6 Sheets-Sheet 5 Y INVENTOR Roger D. Rulseh BYW77% ATTT )RI'IFIY Jan. 10, 1967 R. D. RULSEH 3,297,833

' PROGRAM TIMER Filed April 13. 1964 6 Sheets-Sheet 6 INDICATOR DISC CAM 24 CAM 23 CAM 25 INDEX CYCLE CAM ROTATION TIM E 3:25 3 26 3227 3 2B 3229 3130 3131 3:32

5 INVENTOR Roger D. Ruiseh ATTORNEY I United States PatentO 3,297,838 PROGRAM TIMER Roger D. Rulseh, Two Rivers, Wis., assignor to American Machine & Foundry Company, a corporation of New Jersey Filed Apr. 13, 1964, Ser. No. 359,045 18 Claims. (Cl. 20038) This invention relates to timer devices for controlling the occurrence of an event and particularly to such devices in which the event is the operation of an electrical switch.

More particularly, the timer of the present invention is specifically adapted to precisely control the occurrence of an event, or several events of extremely short duration which occur at prolonged intervals of time.

The problem of developing a timer to precisely control the initiation and termination of an event which takes place at prolonged intervals of time has long plagued the timer industry. The basis of the problem is the difiiculty of precisely controlling an event that is to take place after long elapsed intervals of time. A mechanism which runs slowly enough to provide the long elapsed time intervals moves too slowly to accurately control the initiation and termination of a short interval event. For example, a dial which rotates once in twenty-four hours can be used to control the occurrence of an event several times during a twenty-four period. However, a dial that rotates only once in twenty-four hours moves so slowly that it cannot precisely control an event with an accuracy within sever-a1 seconds, of the desired time for the initiation and termination of the event. The difliculty is in part attributable to the mechanical drive systems for the well known commercially available timers. Obviously, to be economically priced the drive train and operating mechanisms for such timers must be produced by mass production methods, and hence, extremely close tolerances are not commercially feasible. With presently available timers, if it is desired to accurately control the occurrence of an event which takes place at prolonged intervals of time it is necessary to precisely construct within extremely close tolerances, the entire drive train and tripping mechanism of a slowly moving dial. A slight variation in the thickness or position of a trip member of the slight misalignment of a switch could easily cause an inaccuracy of as much as a minute.

The timer of the present invention accurately controls initiation and termination of a short interval event which takes place after a long elapsed period of time. In operation a switch actuator is conditioned for operation .during a short interval of time (preferably five minutes) by a slowly moving dial that makes one revolution in twenty-four hours. The switch actuator is then operated by a more rapidly moving cam that is rotated at the rate of one revolution in five minutes. The dial, cam, and actuator, are so arranged that the switch actuator can only be operated by the cam during the preselected short intervals of time when the actuator is in condition for operation. To compensate for inaccuracies caused by normal manufacturing tolerances of the dial and drive train, the dial and cam are so arranged, and their movement so interrelated, that the cam operates the actuator during a time interval beginning slightly after the actuator is in condition and terminating slightly before the end of the conditioning cycle. For example, the cam is so arranged relative to the dial that operation of the actuator by the cam can only take place during the time interval beginning for example, one minute after conditioning of the actuator and terminating for example, one minute before the end of the conditioning of the cycle. Thus, an inaccuracy of one minute in the commencement "ice or termination of the conditioning operation does not affect the exact instant that the rapidly moving cam operates the switch actuator. By so arranging the dial and cam applicant has devised a timer which operates a switch with an accuracy of several seconds and in which the inaccuracies resulting from normal manufacturing tolerances are avoided.

In the preferred embodiment, the dial is driven periodfcally in response to rotation of the cam. In essence, the dial is indexed in a step by step manner to intermittently advance the dial. Advancement of the dial occurs during only a portion of a single revolution of the cam and the cam is arranged to operate the switch actuator only during the time interval commencing with the termination of a dial driving cycle and ending with the commencement of the next succeeding dial driving cycle.

Trip lugs are selectively positioned on the dial to condition the switch actuator for operation when the lugs move into engagement with the actuator. In addition, the timer has an intermittently driven day omit mechanism to which suitable lugs can be secured to prevent operation of the actuator during any twelve hour period of time. The day omit mechanism overrides the operation of the operating cam, and is operable to prevent operation of the switch automatically during any twelve hour period of a week.

Another feature of the present invention is the control of several events which take place within extremely brief intervals of time, after a prolonged interval of time. For example, in a school bell system it is desirable to provide a warning bell of several seconds duration a short while, say one to three minutes, prior to a main second bell of several seconds duration. The warning bell indicates that a class period is about over, and the later bell signilies that the class period is ended. With this timer the exact time for operation of the warning bell and the main bell can be accurately set, and the duration of operation can also be precisely set. For example, the timer can be set to ring the warning bell at exactly 3:28 oclock for precisely 15 seconds. The main bells can be set to ring for 30 seconds at exactly 3:30. When so set the same operation is repeated every twenty-four hours.

On Saturday and Sunday or any other day when school is not in session operation of the switch actuator can be prevented by the day omit mechanism. The day omit mechanism is indexed by the hour dial to move a disabling trip lug to a position to prevent operation of the actuator during a 12 hour period of time. By using four disablingtrip fingers properly arranged, operation of the actuator can be prevented for any 48 hour time period for example that beginning at 6:00 p.111. Friday, and ending 6:00 pm. Sunday. When once set, the day omit mechanism is effective to prevent operation of the switch for the same 12 hour period of successive weeks.

.It is also desirable to manually operate the bells in the event of an emergency, for example, a fire, and for fire drills and air raid drills. With the timer of this invention such operation is easily controlled manually without disturbing the normal operation of the timer.

During vacation the switch actuator can easily be disabled manually to prevent operation of the switch and hence, the bells. The timer continues to run when the actuator is disabled so that normal operation is resumed when the actuator is again activated.

correspondingly, an object of the present invention is to provide a timer for accurately controlling the occurrence of an event which is to take place after a long elapsed period of time.

Another object is to provide a timer for accurately controlling the occurrence of a brief interval event which is to take place after a long elapsed period of time.

Another object is to provide a timer for accurately controlling several short interval events which are to occur each day.

Another object is to provide a timer for accurately controlling several successive events which are to take place during a short predetermined interval of time following a long elapsed period of time.

A further object is to provide a timer having a slowly driven dial which conditions a switch actuator for operation, and a more rapidly driven cam which operates the actuator only when it is conditioned.

A further object is to provide a timer, for accurately controlling the operation of a switch for a brief interval of time after a long elapsed period of time, having a unique operating mechanism.

A further object is to provide a timer, for precisely controlling short interval events, having an improved manually operable mechanism to override the operation of the timer without affecting its setting.

A further object is to provide a timer having a switch actuator, the operation of which can be automatically prevented, during a preselected period of time on selected days, and not prevented on other days, without affecting the setting of the timer.

A further object is to provide a timer having an intermittently driven dial to condition a switch actuator for operation for a predetermined interval of time, and a continuously driven cam to operate said actuator only during a brief time period after the commencement of but prior to the termination of the predetermined interval of time.

Another and further object is to provide a timer in' which the timer mechanism is adjustable to initiate and terminate operation of a switch with an accuracy of several seconds.

A still further object is to provide a timer that is relatively easy for the user to operate, and that can be manufactured by mass production methods with accompanying tolerances while maintaining extreme accuracy of operation.

The following specification, of which the accompanying drawings form a part, explains the manner in which the foregoing objects are attained in accordance with this invention. In the drawings:

FIG. 1 is a top plan view of a timer made in accordance with this invention;

FIG. 2 is an elevational view in section of the timer line of FIG. 1, showing the gear train and driving mechanism thereof;

FIG. 3 is an elevational view in partial section of the timer of FIG. 1, showing the details of the switch actuator thereof;

FIG. 4 is a view in exploded perspective showing the relationship of the various elements of the cam assembly for operating the switch actuator;

FIG. 5 is a plan view, partially in section, more clearly showing the Geneva drive mechanism for indexing the driven dial of the timer of FIG. 1;

FIG. 6 is a partial bottom view showing the electrical switch and several of its operating elements;

FIGS. 7 through 11 show the functional operations of the various elements of the timer during a cycle of operation of the switch actuator with:

FIG. 7 showing the timer just prior to conditioning of the switch actuator;

FIG. 8 showing the timer with the switch actuator in its conditioned state;

FIG. 9 showing the timer with the first switch actuator operated by the cam assembly;

FIG. 10 showing the second switch actuator operated by the cam assembly;

FIG. 11 showing the position of the operating elements after the termination of a cycle of operations;

FIG. 12 is a schematic drawing showing the electrical wiring of the timer; and

FIG. 13 is a graphical representation of the sequence of operations of FIGS. 7-11 for a complete conditioning and operating cycle of the actuators, and shows the interrelationship of the various cam edges and their limits of adjustment, as well as the time interval that the actuators are conditioned for operation.

Referring now to the drawings and particularly to FIGS. 1 and 2, the timer of this invention is seen to comprise a support 1 in the form of a flat plate, a dial assembly 2, a first switch actuator 33, a second switch actuator 4 and a driven cam assembly 5.

Dial assembly 2 includes a circular hour indicating disc 6 driven at the rate of one revolution in twenty-four hours, a stationary minute indicating disc 7, and a minute pointer 8 that makes one revolution each hour. An hour pointer 9 is fixed to minute disc 7 and is so aligned with the actuators 3 and 4 as to indicate the time at which a trip lug 10 on the periphery of hour disc 6 conditions the actuators for operation.

Cam assembly 5 is driven by a motor '11 its pinion gear 12 and a spur gear 13 fixed to a, shaft 14 of the .cam assembly. Motor 11, which is mounted on a support plate 15,is effective to drive cam assembly 5 at the rate of one revolution in five minutes. Hour disc 6 is intermittently driven via a gear train 16 made up of all the gears above support 1, as seen in FIG. 2, and which includes a Geneva wheel 17. The gear train is so arranged that hour disc 6 is indexed of a revolution during each complete revolution of cam assembly 5. Minute pointer 8 is continuously driven by cam assembly 5 via a gear train 18, located between the support plates 1 and 15. Gear train 18 is so arranged that minute pointer 8 makes A revolution for each complete revolution of cam assembly 5. The details of the gear trains 16 and 18 will be subsequently described.

As seen in FIGS. 7 through 11 a projecting tip of actuators 3 and 4 is disposed in the path of travel of trip lug 10. Trip lug 10 engages the projecting tip and moves same toward driven cam assembly 5 against the action of a spring carried by each actuator, as seen in FIG. 8. Such motion stresses the spring to condition the actuators for operation. When merely conditioned, actuators 3 and 4 do not operate switch 9. Operation of the actuators is effected by cam assembly 5 which permits the actuators to pivot a sufficient distance to operate switch 19 via a lever system, as shown in FIG. 9. Thus, hour disc 6 conditions actuator assembly 3 to operate switch 19 and cam assembly 5 then operates actuator assembly 3 to operate switch 19. The above general description has been set forth to simplify an understanding of the basic operation of this timer. The elements of this timer will now be described in detail. 7

Structure of timer Referring now to FIG. 2 it is seen that the various elements of the timer are mounted on flat parallel spaced apart support plates 1 and 15 adapted to be mounted in a housing (not shown) of well known suitable design to protect the elements of the timer. Motor 11 is mounted on support plate 15 on the side opposite from support 1. The motor is a standard timer motor having a selfcontained reduction gear unit 20 to rotate pinion 12 at the rate of one r.p.m.

Driven cam assembly As best seen in FIGS. 2 and 4 cam assembly 5 is comprised of a plurality of elements mounted on shaft 14 to rotate with the shaft. Fixed to shaft 14 intermediate its ends and above support 1 is a supporting disc 21 provided with a pin 22 parallel with shaft 14, the pin extending through disc 21 to project beyond each side of the disc. Above disc 21 is a first set of cams 23 and 24, and a second set of cams 25 and 26, the first and second sets of cams being maintained in spaced apart parallel relation by a spacer 27. Each cam is formed from flat sheet metal and is provided with a centrally located circular opening for mounting on shaft 14 by slipping the cams over the shaft.

Cam 23 has an arcuate peripheral face 28 concentric with shaft 14, a gradually sloping lifting edge 29 that merges with the peripheral face, and a radial edge 30 at the end of peripheral face 28 opposite edge 29. In the flat part of cam 23 midway between lift edge 29 and radial edge 30 is a deformed projection 31 that projects toward cam 24 from a point spaced between shaft 14 and peripheral face 28.

Cam 24 has an arcuate peripheral face 32 provided with a recess 33 that has a gradually curved lift edge 34 which merges with peripheral face 32 at one side of the recess and a radial edge 35 that connects with peripheral face 32 at the other side of the recess. A relatively wide arcuate slot 36 is cut in cam 24, the slot originating at an edge 37 slightly spaced angularly from radial edge 35 and terminating at an edge 38 approximately 180 from edge 35. At the side of cam 24 opposite slot 36 is a narrow arcuate slot 33 having end edges 40 and 41;

Slot 39 is the same distance from shaft 14 as projection 31 so that projection 31 fits into the slot and movement of cam 23 relative to cam 24 is restricted to the angular sector of the slot, which is approximately 80.

Cam 25 is quite similar to cam 24, cam 25 having a peripheral face 42, a recess 43, a gradually sloped lift edge 44 that merges with peripheral face 42 at one side of recess 43 and a radial edge 45 at the other side of the recess. Cam 25 has an arcuate slot 46 with side edges 47 and 48, and inwardly projecting gear teeth 49 formed ,on the inwardly facing circumferential edge of the slot.

Cam 26 has a peripheral face 50 concentric with shaft 14, a recess 51, a gradually sloped lift edge 52, and a radial edge 53. A small circular opening 54 is provided in cam 26 at a point spaced from the axis of shaft 14 the same distance as pin 22, opening 54 having a diameter to freely receive pin 22.

The various parts of cam assembly 5 are assembled as shown in FIGS. 2 and 4. Cam 26 is first placed over shaft 14 and opening 54 aligned with pin 22 so that pin 22 projects through opening 54 when cam 26 abuts support disc 21, Cam 25 is then placed on shaft 12 so pin 22 projects through slot 46. An adjusting member 55 having a knurled end 56, a cylindrical portion 57, a gear .58 at the end of the cylindrical portion, and a cylindrical bore 59 extending partially into cylindrical portion 57 from the gear end, is slipped over pin 22. Bore 5? is of sufficient length to permit gear 58, which has a diameter slightly less than the width of slot 46, to mesh with gear teeth 49. Bore 59 is of sufiicient diameter to permit adjusting member 55 to be rotated on pin 22.

Spacer 27 is then placed over shaft 14. The spacer has a diameter slightly greater than the radial distance to the inner edge of slot 46 so that the spacer extends beyond the outer edges of the teeth of gear 58 to prevent axial movement of adjusting member 55 in a direction away from cam 25. Cam 24 is then mounted on shaft 14 so that adjusting member 55 projects through slot 36. Projection 31 of cam 23 is aligned with slot 39 and cam 23 is placed on shaft 14 against cam 24.

A graduated indicator disc 60 is then placed on shaft 14 with adjusting member 55 projecting through a circular opening 61 in disc 60. A knurled nut 62 having a threaded bore 63 is then screwed on threaded end 64 of shaft 14 to secure cams 23 through 26 to shaft 14. The lower end of nut 62 is also counter bored to provide an annular end 65 that presses against the top surface of indicator disc 60.

opening 61 is at an angle of 116 from pointer 66. The "angle between the axis ofopening 61 and graduation C 28. It therefore follows that the angle between graduations A and B measured in a counterclockwise direction is 144. Since cam assembly 5 makes one revolution in five minutes, and since 144 is two-fifths of the circumference of disc 60 it follows that the time necessary for a point on the disc to traverse the angle between graduations A and C is exactly two minutes. Correspondingly, the time required for disc 60 to rotate through the angle from C to B or from B to A is exactly one minute. The sector between main graduations A and B, and main graduations B and C is divided into twelve equal parts so that each graduation represents five seconds.

Dial assembly and drive train Drive train 16 for hour disc 6 includes Geneva wheel 17 fixed to gear 70 that rotates on shaft 71. Gear 76 drives gear 72 that is fixed to a gear 73 which rotates on shaft 74. Gear 73 drives a much larger diameter gear 75 which is fixed to a stepped bushing 76 that rotates about a sleeve 77 fixed to support 1. Hour disc 6 is in turn secured to bushing 76, and hence bushing 76, gear 75 and hour disc 6 rotate as a unit.

Since Geneva wheel 17 is fixed to gear 70, the wheel and gear rotate in unison. As best seen in FIGS. 1 and 5, Geneva wheel 17 has five radially extending slots 77 and five arcuately scalloped sides 78 to form a five point Geneva wheel. Each slot 77 has a width slightly greater than the diameter of pin 22. A bushing 79 fixed to shaft 14 between support disc 21 and support plate 1 has a vcut away side 80 that faces pin 22 to provide clearance when the Geneva wheel is rotated. The radius of bushing 79 is compatible with that of arcuate side 78 of Geneva wheel 17. Pin 22 and bushing 79 cooperate to drive Geneva wheel 17 one-fifth of a revolution during each complete revolution of cam assembly 5. During the interval when pin 22 does not engage one of slots 77, the Geneva wheel is prevented from further movement by the circumferential portion of bushing 79 which moves into arcuate cutout 78. Hence, it is apparent that hour disc 6 is intermittently driven by cam assembly 5 via Geneva Wheel 17 and reduction gear train 16. The gear arrangement is such that hour disc 6 is driven revolution every five minutes. The outer periphery of disc 6 is provided with 288 equally spaced slots 81 for mounting of trip lugs 10. The indicia of disc 6 includes graduations 82 radially aligned with slots 81; the graduations represent five minute intervals and provide indicia for indicating the approximate time of day.

Minute pointer 8 is continuously driven via reduction gear train 18 by gear 83 secured to shaft 14 of cam assembly 5. Gear train 18 includes a gear 84 fixed to shaft 71. Gear 84 drives gear 85, fixed to shaft 74, which in turn drives gear 86 which also is fixed to shaft '74. Gear 86 drives gear 87 that is fixed to one end of a shaft 88 that rotates in bushing 77. The other end of shaft 88 has a reduced diameter threaded end 89 to receive a knob 91 having threaded bore 91, minute pointer 8 being secured to the knob for rotation with the knob and shaft 88.

Minute disc 7 is fixed to a bushing 92 that is secured to bushing 77 and hour pointer 9 is fixed to disc 7. Hence, it is apparent that minute disc 7 and pointer 9 never move but maintain the position shown in FIG. 1. It is to b particularly noted that minute pointer 8 makes one complete revolution in one hour. Since cam assembly 5 rotates once in five minutes, it is apparent that the cam assembly must rotate twelve revolutions for each revolution of minute pointer 8. Minute pointer 8 and minute disc 7 combine to provide a visual indication of the exact time during any hour so that the timer can be accurately set.

Switch actuator assembly As previously set forth, the switch actuator assembly includes a first switch actuator 3 and a second switch actuator 4. First actuator 3 is comprised of an elongated operating arm 93 secured to a collar 94, and a trip arm 95 pivotally mounted on the collar in superposed engaging relation with operating arm 93. The first actuator further includes a switch operating lever 96 secured to a bushing 97 that is connected to a shaft 98. Collar 94 is fixed to the upper end of shaft 98, and hence operating arm 93 and operating lever 96 are connected together for movement in unison about the axis of shaft 98.

Second actuator 4 is comprised of an operating arm 99 secured to one end of an elongated sleeve 100, and a trip arm 101 mounted for pivotal movement relative to elongated sleeve 100. An operating lever 102 is secured to a collar 103 that is fixed to the lower end of elongated sleeve 100. Elongated sleeve 100 is mounted in a bearing in the form of a bushing 104 secured to support plate 1.

Operating arm 93 is formed from flat sheet metal, is substantially straight as viewed in plan, and is provided with a central opening for mounting the operating arm on bushing 94 so that the arm projects substantially the same distance on each side of bushing 94.

The end of operating arm 93 that extends between cam assembly and hour disc 6 is provided with a generally rectangular cutout 105 and is bent at right angles to the plane of the arm so that a tip 106 projects upwardly in a direction away from support plate 1. Between tip 106 and collar 94, operating arm 93 is provided with an L-shaped tab 107 formed by slitting the material of the arm and deforming same downwardly so that the open portion of the L faces disc 6. Between tab 107 and bushing 94 is a small circular opening 108. Tab 107 and opening 108 cooperate to retain a spring 109 having a reversely bent end 110 that extends through opening 108 and a straight end 111 that projects past tip 106 of the operating arm.

Trip arm 95 is formed of flat sheet metal and has an opening at one end to mount the trip arm for pivotal movement relative to collar 94 and operating arm 93. Trip arm 95 is superposed on the end of operating arm 93 that extends between cam assembly 5 and hour disc 6. Adjacent its end, trip arm 95 is provided with a trip finger 112 that projects generally radially toward the axis of disc 6. At its extreme end, trip arm 95 is bent in a direction toward support plate 1 to provide an end 113 that has a tab 114 projecting in a direction opposite to trip finger 112, the tab being in a plane below the plane of operating arm 93. End 113 extends through cutout 105 of operating arm 93. With this arrangement, the straight end 109 of spring 108 can be moved into engagement with end 113 by stressing the spring and lifting same over tab 114. Spring 109 is then efiective to bias trip arm 95 toward the periphery of disc 6 so that trip finger 112 is in the path of travel of trip lug 10. The movement of trip arm 95, in a direction toward hour disc 6, under the action of spring 109 is limited by the engagement of edge 115 of the trip arm with a side edge 116 of cutout 105 that faces cam assembly 5, side edge 116 providing a stop surface. As best seen in FIG. 1, tip 106 of operating arm 93 is wider than the adjacent portion of arm 93 to provide an edge 117 spaced from the adjacent end of the arm in a direction toward the cam assembly.

Operating arm 99 and trip arm 101 of second switch actuator 4 are substantially identical to operating arm 93 and trip arm 95 of first switch actuator 3.

Operating arm 99 is fixed to bushing 100 and trip arm 101 is pivotally mounted on the bushing in a manner similar to the mounting trip arm 95. Trip arm 101 has a trip finger 118 that is vertically aligned with trip finger 112 of trip arm 95. Trip arm 101 also has an end 119 which is engaged by a spring 120 that is identical to spring 109. Operating arm 99 has a tip 121 that is cut out to receive the end of trip arm 101 in a manner similar to that described for trip arm 95 and operating arm 93. Tip 121 projects tranversely of the end of operating arm 99 and terminates at an edge 122 spaced from the side edge of the operating arm, edge 122 facing toward cam assembly 5.

As best seen in FIG. 6, operating lever 96 extends generally toward switch 19. The switch has an actuating member 123 in the form of a lever, that is engaged by a nose 124 of lever 96 to operate switch 19. Lever 96 is also provided with a curved end that projects beyond nose 124, the end having inner and outer arcuate edges 126 and 127. In the FIG. 6 position with the switch 011, arcuate edges 126 and 127 curve circumferentially relative to the axis of a shift 128. A slot 129 is cut in end 125, the sides of the slot curving about the axis of shaft 128.

It is to be noted that, as seen in FIG. 7, inner arcuate edge 126 of lever 96 is spaced from shaft 128 when operating arm 93 is in its normal position. However, when operating arm 93 is operated by the action of cam assembly 5, inner arcuate edge 126 of operating lever 96 moves to the position seen in FIG. 9, whereupon inner arcuate edge 126 engages shaft 128, such engagement serving to prevent further movement of operating lever 96 toward switch 19, after operating the switch.

Operating lever 102 moves in response to movement of operating arm 99. Operating lever 102 is identical with operating lever 96, and is disposed in aligned spaced relation to operating lever 96. Operating lever 102 has a nose 129' for movement into engagement with actuating member 123 of switch 19. Operating lever 102 also has an arcuately curved end with an inner arcuate edge 130 and a slot 131. As seen in FIG. 3, operating levers 96 and 102 are spaced apart only slightly in superposed relation and project across actuating member 123. Hence, counterclockwise pivotal motion of either operating lever is effective to operate switch 19, by moving actuating member 123, as seen in FIGS. 9 and 10.

Since both operating arms 93 and 99 are secured respectively to operating levers 96 and 102, it is apparent that counterclockwise pivotal movement of either operating arm is effective to move the operating lever, to which the operating arm is connected, to operate switch 19.

Manual operating mechanism The timer is also provided with a manual operating lever 132 pivoted to shaft 128. At the end of manual operating lever 132 opposite shaft 128 is an operating knob 133 that extends through a slot 134 in support plate 1. The side edges of slot 134 are arcu-ately curved about the axis of shaft 128 so that manual operating lever 132 can be manually moved toward end 135 of the slot or toward end 136 of the slot. The end of manual operating lever 132 which pivots on shaft 128 is enlarged and has a tab 137 that projects across switch actuating member 123, tab 137 engaging actuating member 123 and moving same to operate switch 19 when knob 133 is moved toward end 135 of slot 134. Angularly spaced from tab 137 relative to shaft 128 is a pin 138 fixed to manual operating lever 132, the pin projecting across the open end of slots 129 and 131 when the timer is set for automatic operation. Pin 138 is disposed at the same radial distance from the axis of shaft 128 as the center line of slots 129 and 131, when the operating levers are in their normal position. Movement of operating knob 133 toward end 136 of slot 134 causes pin 138 to move laterally into slots 129 and 131 to lock operating levers 96 and 102 against movement. When pin 138 is so disposed in slots 129 and 131, both actuators '3 and 4 are effectively disabled since any movement of operating levers 96 and 102 to operate the switch is prevented. It is to be noted that end 136 of slot 134 is slightly enlarged to retain operating knob 133 when the operating knob is manually moved to that end. By this arrangement, once the operating knob is moved into end 136, the knob and manual operating lever 132 remain in a locked position until manual operating lever 132 is manually moved again to either the automatic or manual easiest;

9 positions as indicated by the indicia adjacent slot 134 in FIG. 1. Movement of operating knob 133 to the manual position causes tab 137 to move actuating member 123 to operate switch 19 manually, and thus override the operation of the actuators.

Day omit mechanism As best seen in FIGS. 1 and 3, day omit mechanism 140 is mounted on that portion of shaft 128 that projects above support plate 1. Day omit mechanism 140 includes an arm 141 that pivots on shaft 128, a spool 142 mounted for rotation on shaft 128, and a one-way clutch (not shown) of well-known design which permits arm 141 to pivot in a counterclockwise direction without rotating spool 142 but which rotates spool 142 when the arm pivots in a clockwise direction as seen in FIG. 1. One side of arm 141 has a flat later-ally projecting face 143 disposed under hour disc 6 in the path of travel of pins 144 that project from the underside of disc 6. Arm 141 is normally biased in a clockwise direction by a spring 145 which has several convolution-s around the narrow center portion of spool 142 and has straight ends, one of '.'which is disposed behind face 143 and the other of which is disposed on the opposite side of pin 146, the pin 146 also functioning to limit clockwise movement of arm 141 under the action of spring 145. Top flange 147 of spool 142 is provided with fourteen equally spaced radially extending slots 148. Each slot is adapted to receive a trip lug similar to trip lug which is manually positioned in desired slots on flange 147. It is to be noted that the trailing ends 148 and 149 of operating arms 93 and'99 have flat side edges 150 and 151, respectively, adjacent their ends which act as stop surfaces. Day omit mechanism 140, trip lug 10' and actuators 3 and 4 are so arranged and disposed that movement of a trip lug adjacent stop faces 150 and 151 is effective to prevent movement of arms 93 and 99, and hence the actuators are disabled so long as the trip lug remains in that position.

In the embodiment shown, pins 144 are secured in the underside of disc 6 along the same diameter of disc 6.

The length of arm 141 and the position of pins 144 is such that the arm is moved in a counterclockwise direction equal to the angle between adjacent slots each time pin 144 engages face 143. When the arm has moved this distance, the pin slides off the end of face 143 and arm 141, then snaps back against pin 146 under the action of spring 145. During this return motion, spool 142 travels with the arm and hence is indexed V of a revolution.

Since pins 144 are disposed diametrically opposite, such indexing occurs every twelve hours, and it is merely necessary to position trip lugs in selected ones of slots 148 to prevent operation of the actuators for any twelvehour period of any day, Monday through Sunday. In

the embodiment shown and described, pins 144 are so arranged that indexing occurs at 6:00 pm. and at 6:00 am. Hence, in the embodiment shown, it is possible to disable the actuators during any twelve-hour period beginning at 6:00 am. and ending at 6:00 pm, or beginning at 6:00 pm. and ending at 6:00 am. It is to be understood, however, that pins 144 could be disposed in different diametrically opposite positions relative to the indicia on dial 6 so that the twelve-hour periods begin at any desired time.

Electrical system load power supply and to either terminal 154 or terminal 10 156. When the other side of the load power supply is connected to the remaining one of the terminal the connection is completed. Terminals 152, 153, 154 and 156 are provided as part of the timer assembly to facilitate making the necessary connections. While the timer has been described using a volt 60 cycle motor it is to be understood that different voltages could be used, it being only necessary to provide a motor 20 capable of operating at such other voltages. It is also to be understood that the load power supply could in some instances be 120 volts.

Operation in general In operation cam assembly 5 continuously drives minute pointer 8 via gear train 18 and periodically indexes hour disc 6 via Geneva wheel 17 and gear train 16.

The instant of operation of operating arm 93 is controlled by cams 23 and 24 whereas the instant of operation of arm 99 is controlled by cams 25 and 26. However, the ca'ms only operate the operating arm when actuators 3 and 4 are conditioned for operation which happens when a trip lug 10 carried by dial 6 engages trip fingers 112 and 118 to bias ends 106 and 121 toward cam assembly 5. When so conditioned for operation trip lug 10 engages the short flat extreme tip of trip finger 112 and 118. It is to be noted that the angled face 161 of trip fingers 112 and 118 provides a cam surface which slides relative to trip lug 10 when the trip lug moves trip arms 95 and 101 against the bias of springs 109 and 120. With the trip arms so conditioned cam assembly 5 functions, to first release operating arm 93 to operate switch 19 to an on position; then to return arm 93 to its conditioned position in which the switch is off; then to release operating arm 99 to against turn the switch on and then to move operating arm 99 back to its conditioned position in which the switch is off.

Setting the timer As seen in FIG. 7 when main signal pointer 66 is aligned with tips 106 and 121 of actuators 3 and 4 minute pointer 8 is exactly aligned with the 25 minute graduation of minute disc 7. Since ca'm assembly 5 makes exactly one revolution in five minutes and drives minute pointer 8 for exactly of a revolution for each revoluthe initiation and termination of a warning signal, switch 19 being turned on at the initiation of the warning signal and turned off at the termination of the warning signal.

When actuator 3 is conditioned for operation face 117 of end 106 is biased into engagement with peripheral face 32 of cam 24. When drop ofi edge 35 of the cam moves past end 106 of the actuator, end 106 is free to move inwardly against the edge of recess 33 thereby pivoting operating arm 93 and operating lever 96 to turn switch 19 on, as seen in FIG. 9. Switch 19 then remains on until lift edge 29 of cam 23 moves end 106 of the actuator outwardly so face 117 rides on peripheral face 28 of cam 23. Since cam faces 32 and 28 have the same radius, face 117 rides on face 32 of cam 24 after edge 30 of cam 23 passes tip 106.

Since, in the preferred embodiment disclosed the warning signal is to take place between one and three minutes prior to the main signal, slot 36 (FIG. 4) of cam 24 is formed so that edge 37 of the slot abuts cylindrical portion 57 of adjusting member 55 when drop off edge 35 of cam 24 is aligned with graduation C of indicator disc of adjusting member 55 to prevent movement of edge 35 beyond graduation A. In this extreme position initiation of the warning signal occurs exactly one minute prior to the initiation of the main signal.

The circumferential position of lift edge 29 of cam 23 controls the termination of the warning signal. Cam 23 cooperates with cam 24 in such a manner that the termination of the warning signal occurs between 4 and 60 seconds after the initiation of the warning signal. These limits arise because of the interaction of projection 31 of cam 23 with slot 39 of cam 24. Rotating cam 23 in a counterclockwise direction relative to cam 24 causes projection 31 to abut edge 41 of slot 39. In this position termination of the warning signal occurs 4 seconds after its initiation. On the other hand, if cam 23 is rotated to its extreme clockwise position relative to cam 24 so that projection 31 abuts edge 40 of slot 39 the termination of the warning signal occurs exactly 60 seconds after its initiation. Hence, if the user of the timer wishes to set the timer to provide a warning signal that is initiated two minutes prior to the main signal and lasts for a duration of 15 seconds knob 62 is turned counterclockwise a sufficient amount to loosen cams 23 and 24 and the cams are rotated so that edge 35 of cam 24 is aligned with graduation B of indicator disc 60, and the innermost portion of lift edge 29 of cam 23 is aligned with the third graduation from mark B, (see FIG. 8). Knob 62 is then tightened to lock the cams in these positions.

Although the initiation of the warning signal is adjustable, the time of initiation of the main signal is fixed and hence can only occur on the hour, and at five minute intervals thereafter. Cam 26 controls the initiation of the main signal, whereas cam 25 controls the termination of the main signal. When cam 26 (FIG. 4) is mounted on shaft 14 so that pin 22 extends through opening 54 of the cam, the cam is secured against rotation relative to the cam assembly. Drop off edge 53 of cam 26 is spaced the same distance angularly from the axis of opening 54 as main signal pointer 66 is spaced angularly from the axis of opening 61. Hence, when cam assembly is assembled edge 53 and pointer 66 lie in the same vertical plane passing through the axis of shaft 14. Since cylindrical portion 57 of adjusting member 55 extends through opening 61 in indicator disc 60, disc 60 is also seen to be secured against rotation relative to the cam assembly. Hence, drop oif edge 53 is effective to initiate the main signal whenever actuator 4 is conditioned for operation by permitting end 121 of operating arm 99 to move radially into recess 51 when edge 53 passes the end of the operating arm. Although the time of initiation of the main signal is fixed to occuronly at 5 minute intervals the time of termination of the main signal is adjustable between 4 and 60 seconds after its initiation. Such adjustment is elfected by loosening knob 62 and then rotating the knurled end 56 of adjusting member 55 to rotate cam 25 relative to cam 26 by virtue of the driving connection between gear teeth 58 of the adjusting member, and gear teeth 49 of cam 25. Turning knurled knob 56 in a clockwise direction is effective to increase the duration of the main signal by moving lift edge 44 of cam 25 circumferentially away from drop off edge 53 of cam 26. The circumferential distance between edges 47 and 48 of slot 46 is such that the maximum clockwise adjustment of cam 25 relative to cam 26 provides a main signal of 60 seconds duration, and maximum counterclockwise adjustment of cam 25 relative to cam 26 provides a main signal of only 4 seconds duration. Obviously, cam 25 can be set at any desired point between these to extremes to adjust the duration of the main signal for any length of time between 4 and 60 seconds.

. The relationship of the various elements of the cam assembly can best be visualized by reference to FIG. 13

-which shows an unrolled view of the outline of the various cams and induction disc and the relationship of the various actuating edges. FIG. 13 shows that cam 24 can be set to initiate the warning signal at any time between 2 and 4 minutes after main signal pointer 66 passes tip 106, which corresponds to 1 to 3 minutes prior to initiation of the main signal. Cam 23 can be adjusted to terminate the warning signal between 4 and 60 seconds after the initiation of the warning signal. It is to be noted that when drop off edge 35 of cam 24 is aligned with mark A on indicator disc 60 and cam 23 is set to its maximum warning signal time of 60 seconds, the warning signal and main signal overlap and hence, switch 19 remains on continuously from one minute before the main signal normally occurs until the switch is turned off by the operation of lift edge 44 of cam 25. Cam 25 is seen to be adjustable to terminate the main signal at any time between 4 and 60 seconds after its initiation.

The timer is easily set to the proper time of day. Turning knob manually drives the various elements of the timer at a rapid rate. The timer is properly set to the time of day when the appropriate hour of day on hour disc 6 is approximately aligned with or slightly past hour pointer 9, and minute pointer 8 is aligned with the proper minutes after the hour on minute disc 7. For example, as shown in FIG. 7, the timer is set at 3:25 oclock since numeral three on hour disc 6 is slightly past hour pointer 9, and minute pointer 8 is aligned with numeral 25 on minute disc 7.

The timer provides warning and main signals only during a five minute interval when the actuators are conditioned for operation. Hence, to set the timer to provide these signals it is only necessary to place a trip lug 10 in a slot 88 aligned with the appropriate five minute graduation of hour disc 6. The duration of the warning signal, and the main signal during each such five minute interval is easily set by loosening knob 62 and setting the cams, as previously described. If it is desired to omit the programmed signals during any 12 hour period of time of any week, trip lugs 10' are inserted in the slots 148 of day omit mechanism corresponding to the 12 hour intervals beginning at 6:00 am. or 6:00 pm. of the day when no signal is wanted. FIG. 1 shows a trip lug 10 placed in a slot 148 to omit the signal program between 6:00 pm. Friday and 6:00 am. Saturday of each week.

By inserting a trip lug 10" in the appropriate slot 81 of hour disc 6, as shown at the right hand side of FIG. 2, only one actuator is conditioned for operation, rather than both, at the selected time. If trip lug 10" is placed on disc 6 with blade extending above disc 6, (as shown in FIG. 2) only actuator 3 is conditioned for operation, and hence, only a warning signal is provided during the selected time interval. On the other hand, if trip lug 10" is placed on disc 6 with blade 170 extending below disc 6 (which is easily done by removing trip lug 10" and inverting same) only actuator 4 is conditioned for operation and hence, only a main signal occurs during the selected time interval. By similarly using trip lugs 10" in the slots of day omit mechanism 140, either signal can be eliminated during a 12 hour interval beginning at 6:00 am. or 6:00 pm. of a day of each week.

Operation assembly 5, to operate switch 19. For the purpose of explanation assume that the timer is to provide a 15 second warning signal 2 minutes prior to a 30 second main signal, and that the main signal is to occur at 3 :30 pm. The positions of the elements of the timer at various 13 times during such an interval, (knob 133 being set for automatic operation), are shown in FIGS. 7-l1. With the timer motor connected the timer is set to provide the main signal at 3:30 pm. by placing a trip lug 10 in the slot 81 aligned With the 3 :30 pm. graduation on disc 6. As shown in FIG. 7, a trip lug 10 is so mounted on disc 6; the time of day is 3 :25 pm; and thus main signal pointer 66 is aligned with tips 106 and 121 of actuators 3 and 4 respectively. (Tip 121 is hidden from view in FIG. 7 since actuator 3 is identical with actuator 4 and is disposed in superposed relation to actuator 4 thereby obscuring tip 121 in FIG. 7. However, the fact that tips 106 and 121 are coplanar at this time is apparent from reference to FIG 2.) Operating cams 23 and 24 have been set, inthe manner previously described, so that drop off edge 35 is aligned with mark B on indicator disc 60, and the radially innermost portion of lift edge 29 of cam 23 is aligned with the third graduation in a direction toward mark A. This setting corresponds to that required for a 15 second warning signal. Cam 26 is fixed and hence, initiates a main signal at exactly 3:30 pm. Cam 25 is set by rotating adjusting member 55 to position lift face 44 to terminate the main signal 30 seconds after it is initiated. Even though in FIG. 7 drop off edge 53 of cam. 26 is slightly past the tips 106 and 121 of the actuators, the switch is not operated because the actuators are not conditioned for operation by trip lug 10.

As is apparent from FIG. 2, cams 23 and 24 are between the planes. defined by the upper and lower edges of tip 106 of actuator 3, and hence, these cams operate actuator 3 only, to provide a warning signal, when the actuator is conditioned for operation. Similarly, cams 25. and 26 are between the planes defined by the upper and lower edges of tip 121 of actuator 4, and these cams operate actuator 4 only, to provide a main signal. FIG. 2 also. shows that trip lug 10 extends a sufiicient distance beyond each of trip finger 112 and 118 to engage both trip fingers to condition actuators 3 and 4. Since trip lug 10 engages only one of the trip fingers only one actuator is conditioned for operation by a trip lug 10". FIG. 8 shows the position of the timer elements at a time 2 minutes after that of FIG. 7. As shown in FIG. 8 cam assembly has rotated 144 from the FIG. 7 position, minute pointer 8 has advanced to the 27 minute graduation on disc 7 and the Geneva wheel has been operated to index hour disc 6. This indexing has moved trip lug '10 a suflicient distance clockwise to cam the trip fingers 112 and 118 toward cam'assembly 5, thereby stressing springs 109 and 120 (FIG. 3), to condition actuators 3 and 4 for operation. As shown in FIG. 8, the actuators do not operate the switch but are merely conditioned for operation.

FIG. 9 shows the position of the timer elements at a time one minute after that of FIG. 8. As shown in FIG. 9 cam assembly 5 has rotated 72 from the FIG. 8 position, and minute pointer B has advanced 'to 28 minutes after the hour. The drop off edge of cam 24 has advanced slightly past tip 106 of actuator 3 thus permitting spring 109 to snap tip 106 into recess 33 of cam 24, to thereby pivot operating arm 93 in a counterclockwise direction. Since operating arm 93 and switch operating 1 ver 96 are each fixed to shaft 93, operating lever 96 similarly pivots in a counterclockwise direction to operate switch 19 to an on position by virtue of the engagement of nose 124 with switch actuating member 123. Such actuation of switch 19 provides a warning signal. Actuator 4. is not actuated at this time but remains in its conditioned position since tip 121 is in engagement with peripheral faces 42 and 50 of cams 25 and 26 respectively. Switch 19 remains on until lift edge 29 of cam 23 lifts tip 106 out of recess 33 to return operating arm 93 to its conditioned position, in which the switch is again turned off.

FIG. shows the position of the timer elements at a time two minutes after that of FIG. 9. The time is now 3 :30 pm. as shown by the position of minute pointer relative to the indicia of minute disc 7. Cam assembly 5 has rotated 144 from the FIG. 9 position. Since drop off edge 53 of cam 26 has just moved past tip 121 of operating arm 99, operating arm 99 pivots in a counterclockwise direction under the action of spring 120. Since operating arm 99 and switch operating lever 102 are each secured to sleeve 100, operating lever 102 correspond ingly pivots in a counterclockwise direction so that nose 129' engages switch actuating member 123 to again turn the switch on to initiate the main signal. Since lift edge 44 is set to lift tip 121 30 seconds after initiation of the main signal, lift edge 44 will then be effective to pivot operating arm 99 in a clockwise direction to turn switch 19 off by moving nose 129' away from switch actuating member 123.

The position of the parts of the timer after lift edge 44 operates to return actuator 4 to its conditioned position, where the switch is off, is shown in FIG. 11. In FIG. 11 one minute has elapsed since the initiation of the main signal. Cam assembly 5 has thus rotated 72 from the FIG. 10 position and the indexing cycle of disc 6 has already started. However, this indexing cycle although started, has not yet moved trip lug 10 beyond fiat tips 160 of trip fingers and 101. Therefore, lift edge 44 of cam 25 could have been set to terminate the main signal at a time as late as one minute after the initiation of the main signal, without the danger of the conditioning cycle ending before lift edge 44 engages tip 121 to operate switch 19 to its off position. About 10- second after the time shown in FIG. 11, the position of the various elements of the timer is again the same as that shown in FIG. 7, save that trip lug 10 is to the left of, rather than to the right of trip fingers 112 and 118. To simplify the above description of the operation of the timer during a five minute interval of operation a detailed explanation of the timed relationship of the indexing cycle relative to the limits of adjustment of the various cams was purposely omitted but will now be explained in detail.

During each revolution of cam assembly 5 pin 22 engages a slot 77 of the Geneva wheel to index hour disc 6 of a revolution. Referring now to FIG. 13, it is shown that the initiation of the indexing cycle occurs at 62 of rotation of the main signal indicator 66 past tip 106. The driving cycle continues for another 108 of rotation of the cam assembly. However, even though the Geneva wheel is continuously driven during the 108 of rotation, trip lug 10 and trip fingers 112 and 118 are so arranged with regard to the driving mechanism that the trip lug 10 is always driven a suffi-cient distance by disc 6 to be on fiat surface of the tip of each trip finger at least 10 of rotation before mark C on the indicator disc reaches tip 106. This is due to the velocity driving characteristic of the Geneva wheel, which is initially slow, proceeds very rapidly to a maximum as pin 22 crosses the line joining the centers of the Geneva wheel and the cam assembly, and then decreases in velocity until the pin 22 leaves the slot of the Geneva wheel. By virtue of this indexing arrangement actuators 3 and 4 are always conditioned at least 5 to 10 seconds before the earliest possible time that the warning signal can be initiated by cam 24. Hence, it is assured that the actuators are conditioned for operation prior to operation of actuator 3 by cam 24.

It is also to be noted that the range of adjustment of cam 25 overlaps the start of the Geneva wheel driving cycle by approximately 10 to 12 degrees. This slight overlap again has no effect on the precise time of termination of the main signal by cam 25 since both actuators remain conditioned until the Geneva mechanism drives trip lug 10 completely off the tips 160 of the trip fingers. Hence, it is also assured that termination of the main signal will never be caused by indexing hour disc 6 to move trip lug 10 but will always be caused by cam 25. By virtue of this arrangement it is apparent that actuators 3 15 and 4 are always fully conditioned for operation before the earliest possible time that cam 24 can be set to operator actuator 3 to turn the switch on, and the actuators remain conditioned until after the latest possible time that the cam 25 can be set to operate the actuator 4 to turn the switch oit. Of course, the actuators remain conditioned during the entire interval commencing prior to the initiation of the warning signal, and terminating after the termination of the main signal.

The fact that the actuators are only operated by the rapidly rotating cam assembly 5 contributes significantly to the extreme accuracy of the timer program. If such operation was effected by disc 6 and trip lug 10 errors in the timing of the various signals would invariably result because of the very slow speed of travel of the trip lug when disc 6 is indexed.

Thus, by virtue of the operation of trip lug 10 driven by disc 6 actuators 3 and 4 areconditioned for operation during a preselected time interval; cam assembly 5 driven by motor 11 is effective to operate switch actuators 3 and 4 at certain times after the commencement of the preselected time intervals, and that the certain times during which cam assembly 5 can operate actuators 3 and 4 terminate prior to the termination of the preselected time interval during which the actuators are conditioned.

If it is desired to override the automatic operation of the timer, this can be done manually at any time irrespective of the operation the timer is then performing. To manually operate switch 19 to an on position it is merely necessary to manipulate knob 133 to its manual position (FIG. 1) in which the knob engages end 135 of slot 134. So long as knob 133 is manually held in this position tab 137 of manual operating lever 132 presses against actuating member 123 of the switch and the switch remains on. This is quite an advantageous feature especially when the timer is used in a school bell system where it is frequently necessary to sound bells in a particular sequence during fire drills, and for other emergency purposes. To provide for automatic return of manual operating lever 132 to its automatic position a switch 19 is selected that has a spring (not shown) with sufficient resiliency to return both actuating member 123 and lever 132 to their normal positions so that the switch is again off.

To manually override the automatic operation of the timer when the actuators are conditioned and one of the actuators is operated by cam assembly 5 to turn the switch on requires a little more manual manipulation but can also easily be accomplished. When the switch is automatically operated to an on position either operating arm 93 or operating arm 99 is pivoted in a counterclockwise direction. To turn the switch oif is merely necessary to move the appropriate operating arm back to its normal position manually, for example, by pushing on the arm with a finger to pivot the arm in a clockwise direction. Then, if it is desired to disable automatic operation for an extended period of time knob 133 need only be moved to its oit position in which the knob engages end 136 of slot 134 (FIG. 1). Operating arm 93 and 99 can then be released without again operating switch 19 because pin 138 is now disposed in slots 129 and 131 of levers 96 and 102 respectively, and movement of either of these levers is thus prevented. When manual operating lever 132 is moved to the off position the lever remains in the ofi position until manually returned to the automatic position. When manual operating lever 132 is in the ofi position the preset program of the timer is overridden, and switch 19 is not operated although cam assembly 5 and dial assembly 2 are rotated in the normal manner. When a trip lug 10 engages trip fingers 112 and 118 and lever 132 is in the ofi position, trip fingers 95 and 101 pivot in the normal Way to stress the springs 109 and 120 of the actuators. However, when cam assembly 5 presents a recess which would normally allow the operating arms to pivot, no such pivotal motion takes place because operating levers 96 and 192 are locked against movement by pin 138. When manual operating lever is again returned to its automatic position by manipulating knob'133 the entire preset program of the timer is again in effect and normal operation is resumed.

If it is desired to disable actuators 3 and 4 for any 12 hour period of each week, commencing at 6 am. or 6 pm. it is merely necessary to place trip lugs in appropriate ones of slots 148 at the periphery of member 147 of day omit mechanism 142. Then, as spool 142 is indexed by the driving of arm 141 by pins 144 on disc 6 the actuators are disabled when the trip lug is in a position adjacent portions and 151 of operating arms 93 and 99. The eifect of trip lug 10 when so positioned is to prevent counterclockwise pivoting of both operating arms so that automatic operation of the switch is prevented.

While an advantageous embodiment has been chosen for illustrative purposes, it will be obvious to those skilled in the art that various changes and modifications can be made without departing from the scope and spirit of the present invention. The invention is pointed out with more particularity in the appended claims.

What is claimed is:

1. A timer comprising:

switch means operated during at least part of a short preselected time interval of a predetermined time period; actuator means operating said switch means when said actuator means is conditioned for operation;

first driven means conditioning for operation said actuator means during said short preselected time interval; second driven means controlling operation of said actuator means when conditioned for operation to accurately control operation of said switch means during the short preselected time interval; and

means connected to said first and second driven means driving said second driven means along its full course of travel during said short preselected time interval, and periodically indexing said first driven means a distance of travel equal in time to the short preselected time interval and thereby driving the first driven means along its full course of travel during the predetermined time period.

2. A timer in accordance with claim 1 in which said actuator means comprises;

an elongated arm pivotally mounted in the timer and operating the switch means when the arm is pivoted,

a trip finger movable relative to said arm when said actuator means is conditioned for operation; and

a spring connected between said trip finger and said arm;

and said first driven means engaging said trip finger and moving same against the action of said spring to condition said actuator means for operation.

3. A- timer in accordance with claim 2 in which said spring biases said elongated arm against said second driven means when said actuator means is conditioned for operation.

4. A timer in accordance with claim 1 in which said first driven means comprises:

a disc rotatably mounted about a fixed axis, and

a trip lug carried by said disc;

said trip lug engaging said actuator means at least once during a complete revolution of said disc and conditioning the actuator means for operation when so engaged.

5. A timer in accordance with claim 1 in which; said second driven means is a cam assembly which is engaged by said actuator means and rotates about a fixed axis and controls operation of said actuator means.

6. A timer in accordance with claim 1 in which; said second driven means is continuously driven by said driving means, and drives by said driving means said first driven means and index the first driven means by each complete revolution of the second driven means.

7. A timer in accordance with claim 6 in which: said first driven means rotates about another fixed axis, and said second driven means rotates about a fixed axis parallel with and spaced from the axis of said first driven means.

8. A timer in accordance with claim 7 in which: said actuator is an elongated arm pivotally mounted movable relative to an axis parallel with and spaced from the axes of said first and second driven means.

9. A timer in accordance with claim 1 which further includes: a manually actuable control when actuated operating said switch means independently of said actuator means and said first and second driven means.

10. A timer in accordance with claim 1 which further includes: manual means when operated engaging said actuating means and preventing operation thereby of said switch means without arresting said first and second driven means.

11. A timer in accordance with claim 1 which further includes: third driven means to automatically preventing operation thereby of said switch means during a preselected time period, said driving means being connected to and intermittently driving said third driven means in timed relation with said first and second driven means.

12. A timer in accordance with claim 1 in which: said first driven means is a circular disc having a trip lug engaging said actuator means and conditioning the engaged actuator means for operation, said trip lug being mountable at various positions on the periphery of said disc to preselect the time at which said actuator means is conditioned for operation; and said second driven means includes an adjustable cam for controlling operation of said switch actuator.

13. In a timer, the combination comprising:

a support;

electrical switch means mounted on said support and operated during at least part of a short preselected time interval of a predetermined time period;

first and second actuator means each independent of the other and operating said switch means when conditioned for operation; first driven means engaging both said actuator means and conditioning for operation at least one of said actuator means during short preselected time interval;

second driven means engaging both said actuator means and controlling operation of each of said actuator means when conditioned for operation to accurately control operation of said switch means by the operated actuator means during the short preselected time interval; and

means connected to said first and second driven means driving said second driven means along its full course of travel during the short preselected time interval, and periodically indexing said first driven means a 18 distance of travel equal in time to the short preselected time interval and thereby driving said first driven means along its full course of travel during the predetermined time period.

14. A timer in accordance with claim 13 in which said first driven means includes a trip member engaging only one of said actuator means and condition for operation, said engaged actuator means.

15. A timer in accordance with claim 13 in which said first driven means includes a trip member simultaneously engaging said first and second actuator means for conditioning for operation each of said engaged actuator means.

16. A timer in accordance with claim 13 in which each of said actuator means comprises;

an elongated arm pivotally mounted on said support,

a trip finger mounted movable relative to said arm,

and

a spring connected between said trip finger and said arm;

each of said arms being movable between a first position and a second position to operate said switch;

said first driven means engaging said trip fingers of each of said arms and moving same against the action of said springs and condition said actuator means for operation; and

said second driven means maintaining each of said elongated arms in its first position except during said short preselected interval of time.

17. A timer in accordance with claim 13 in which said second driven means includes:

a first adjustable cam operating said first actuator means and varying the length of time of such operation when adjusted, and

a second adjustable cam operating said second actuator means and varying the length of time of such operation when adjusted; and I said first and second cams being rotatably mounted on said support and continuously rotated in unison about a common axis.

18. A timer in accordance with claim 13 which further includes third driven means engaging both said actuator means and preventing operation thereby of said switch means during certain time intervals, irrespective of the operation of said first and second driven means.

References Cited by the Examiner UNITED STATES PATENTS 2,076,371 4/ 1937 Hottenroth et al 20038 2,918,969 12/1959 Kull 200-38 X 2,921,149 1/ 1960 Klein et al 200-38 BERNARD A. GILHEANY, Primary Examiner. G. MAIER, Assistant Examiner.

Claims (1)

1. A TIMER COMPRISING: SWITCH MEANS OPERATED DURING AT LEAST PART OF A SHORT PRESELECTED TIME INTERVAL OF A PREDETERMINED TIME PERIOD; ACTUATOR MEANS OPERATING SAID SWITCH MEANS WHEN SAID ACTUATOR MEANS IS CONDITIONED FOR OPERATION; FIRST DRIVEN MEANS CONDITIONING FOR OPERATION SAID ACTUATOR MEANS DURING SAID SHORT PRESELECTED TIME INTERVAL; SECOND DRIVEN MEANS CONTROLLING OPERATION OF SAID ACTUATOR MEANS WHEN CONDITIONED FOR OPERATION TO ACCURATELY CONTROL OPERATION OF SAID SWITCH MEANS DURING THE SHORT PRESELECTED TIME INTERVAL; AND MEANS CONNECTED TO SAID FIRST AND SECOND DRIVEN MEANS DRIVING SAID SECOND DRIVEN MEANS ALONG ITS FULL COURSE OF TRAVEL DURING SAID SHORT PRESELECTED TIME INTERVAL, AND PERIODICALLY INDEXING SAID FIRST DRIVEN MEANS A DISTANCE OF TRAVEL EQUAL IN TIME TO THE SHORT PRESELECTED TIME INTERVAL AND THEREBY DRIVING THE FIRST DRIVEN MEANS ALONG ITS FULL COURSE OF TRAVEL DURING THE PREDETERMINED TIME PERIOD.

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