US2605833A

US2605833A - Timer

Info

Publication number: US2605833A
Application number: US207707A
Authority: US
Inventors: Harvey N Bliss
Original assignee: Veeder Root Inc
Current assignee: Veeder Industries Inc
Priority date: 1951-01-25
Filing date: 1951-01-25
Publication date: 1952-08-05
Anticipated expiration: 1969-08-05
Also published as: DE948261C

Description

"Aug. 5, 1952 H. N. uss 2,605,833

TIMER Fi ld Jan. 25, 1951 4 sheets-sheen n HUURS MINUTES OGLOCK cooK PERIQD FINISH TIME 1 Monitor HARVEY N BLISS M g aw 0 5, 1952 H. N. BLISS 2,605,833

TIMER Filed Jan. 25, 1951 4' Sheefi-Sheet 3 I42 as /27 A75 /33 60 54 5 32 Snventor 3/ 37 36 HAR EY N BLIJS attorney Patented Aug. 5, 1952 UNITED STATES PATENT OFFICE TIMER Harvey N. Bliss, Windsor, Conn, assignor to Veeder-Root Incorporated, Hartford, Conn, a. corporation of Connecticut Application January 25, 1951, Serial No. 207,707

2i Claims.

This invention relates to timers, and more particularl to time responsive control mechanism which may be preset to sequentially perform a plurality of operations at preselected future times.

Although timers constructed in accordance with thi invention may be utilized in many installations to perform various operations, the timer of this invention is particularly i well adapted for use with kitchen ranges so as 'to enable the housewife to preset her range to automatically commence and complete a cooking operation at chosen future times, it being highly desirable that timers for kitchen ranges be provided with simplified control devices so that the housewife can set the range for automatic operation, under the control of the timer, without becoming involved in a series of complicated calculations or operations to arrive'at the particularsetting she desires.

It is a general object of the present invention to provide a timer for kitchen ranges and the like which may be preset to automatically control a cooking operation of preselected duration to be completed at a preselected time.

It is a more particular object of this invention to provide a timer for kitchen ranges and the like which has separate indicators and independent setting means therefor for directly indicating a selected finish time and for directly and separately indicating a cookingfperiod thereby requiring no calculations in presetting.

It is another object of this invention to provide a timer for cooking ranges or the like with direct readin indicators showing a cooking period and a selected finish time with independent setting means for each indicator which may be preset simultaneously or in any desired sequence.

Still another object of this invention is to provide a timer for cooking ranges or the like which may be preset with facility to visibly, indicate a selected automatic cooking period and to visibly indicate a selected fihishtime for the cooking period and which will indicate during the cooking period the time remaining'to run.

A further object ofthe invention is to provide a new and improved system of combining and correlating a clock mechanism, a switch con trol mechanism, and manually settable devices having indicating means to show the selected positions of the clock mechanism at which the switch contro1 mechanism will be functioned in terms of operating time and finish time, whereby the combined apparatus is rendered completely the correlation and cooperation of the said mechanisms and devices is fully automatic.

Another object of the present invention is to provide in a device of the character described an improved switch control mechanism which permits sensitive and accurate functioning of the switch and which is particularly. adapted for use in the new and improved system of the invention.

Other objects will be in part obvious, and in part pointed out more in detail hereinafter.

The invention accordingly consists in the features of construction, combination of elements and arrangementof parts which will be exemplified in the construction hereafter set forth and the scope of'theapplication of which will be indicated in the appended claims.

In the drawings--- I Fig. l is a front elevational view of a timer constructed in accordancewith this invention and which is particularly adapted for use with an electric kitchenrange for automatically controllin a cooking operation of the range at preselected future times.

Fig. 2 is atop plan view of the timer shown in Fig. 1.

Fig. 3 is a rear elevational view of the timer shown in the first two figures.

Fig. 4.1 a vertical cross-sectional view taken as indicated generally by the line 4-4 of Fig. 2 and viewedin the direction of the arrows there- Fig. 5 is a transverse sectional view taken generally as indicated by the line 55 of Fig. 3 and viewed as indicated by the arrows thereon.

Fig. 6 is a fragmentary horizontal sectional View taken as indicated generally by the line E-J of-Fig. 3 and viewed in the direction of the arrow thereon.

Fig. 7 is also a fragmentary horizontal crosssectional view taken a indicated generally by the line f!'l of Fig.3 and viewed in the direction of the arrows thereon.

Fig. 8 is a diagrammatic view of the operating mechanism of the timer shown in'oblique projection.

In the various views of the drawings, there is illustrated a specific embodiment of a timer constructed in accordance with the present invention which is particularly adapted for use in H connection with an electric kitchen range for controlling the automatic operation of the range.

It will be apparent, however, that timers con structed in accordance with the present invention are not limited for use with kitchen ranges and may be advantageously utilized in many other installations for time responsive control of the various operations. For instance, the timer of the present invention may be utilized to open or close valves at preselected future times in any desired sequence or may be used to open or close electric switches to circuits which may incorporate various electrical appliances.

Referring now to the drawings in detail, the time controlled mechanism of this invention is disposed within a case indicated generally by the reference numeral suitable for mountin in any desired manner upon an electric kitchen range (not shown). The case ID has a front wall H provided with a face plate l9 and supporting a clock face l2 having conventional minute and hour hands I3 and I4, respectively, the clock being settable by means of a conventional knob id. The clock operating mechanism shown in the drawings is of conventional construction driven by a synchronous electric motor M having conventional field elements I 5 and [6 (Fig. 3) and a coil H. The gear train 4| of the clock mechanism is also conventional and will be described in more detail later in connection with other operating parts of the timer mechanism.

While an electric clock mechanism has been shown in the drawings, it will be apparent from the following description that the clock mechanism may be of the hand wound spring type or any other type which might be preferred in a particular installation.

The wall I journals three setting shafts which are associated with manually operable control knobs 20, 2| and 22. y The righthand control knob 25 is connected to a setting shaft 23 for setting a minutes number wheel 24 and an hours number wheel 25 visible through windows 26 in the wall I and plate I9 adjacent the control knob 29. The visible indication on the

number wheels

24 and 25 indicates the time at which the desired cooking operation will be completed. This may be identified by suitable indicia such as oclock-Finish Time imprinted on the face plate l9 adjacent and below the windows 26. When the knob is manipulated to set the number wheels 24 and to the desired indication other elements of the timer mechanism are also set in a manner to be described later.

The lefthand control knob 2| is connected to a setting shaft 2'! for setting a minutes number wheel 28 and an hours number wheel 29 readily visible through windows 30 in the wall I] and plate l9 adjacent the control knob 2|. The

number wheels

23 and 29 indicate the cook period in hours and minutes, which, in the specific embodiment, is shown by the indicia Hours-Minutes-Cook Period imprinted on the plate I8 adjacent and below the windows 30. When the control knob 2| is manipulated to indicate the desired cook period in the windows 30 other devices of the timer mechanism are set in a manner to be described later.

The centrally disposed control knob 22 is connected to a switch actuator shaft 3| (Fig. 5) which may be set in one position to place the electric range under the control of the timer mechanism for automatic operation and in another position to place the range in condition for manual operation. The shaft 3| carries a disk segment 32 which bears the indicia Set On Off Man which are separately visible, dependin upon the rotated position of the switch actuator shaft 3|, through a window 33 located in the clock face |2 adjacent and above the numeral 5. For normal operation of the range, the indicia Man is visible in the window 33 to indicatev that the range may be manually operated. To set the range for-automatic operation, the shaft 3| and control knob 22 is rotated until the indicia Set is visible in the window 33. Thereafter, the range is automatically controlled by the timing mechanism and is sequentially operated to the On and "Off conditions which are indicated by the corresponding indicia visible in'the window 33. As will be described more particularly hereinafter, all that the operator need do to set the timing mechanism for automatic operation of the range is to manipulate the control knobs 20 and 2| simultaneously or in any desired sequence to place the selected indications of the finish time and cook period in the

windows

26 and 30, respectively, and then set the switch actuator shaft 3| by means of the control knob 22 to Set position as indicated in the window 33.

By way of illustration, there has been shown in Fig. 1 of the drawings a desired finish time of twelve oclock and a cook period of 1 hr. 40 min. with the actuator shaft Set. This means that at 10:20 the automatic cook period will commence and the actuator shaft 3| will rotate counterclockwise (as viewed in Fig. 1) so that the indicia On will be visible in the window 33. At twelve oclock the 1 hr. 40 min. cook period will have been completed and the actuator shaft 3| will again rotate counterclockwise so that the Off indicia will be visible in the window 33.

A general description of the timing mechanism and its operation may be best understood with respect to Fig. 8 wherein the elements are diagrammatically illustrated. The synchronous motor M has a pinion drive shaft 40 driving the conventional-gear train indicated generally by the reference numeral 4| which, in turn, drives a minute gear 42 having a minute hand shaft 43 and a drive pinion 44. The drive pinion 44 drives a gear 45 and associated pinion 46 which, in turn, drives an hour gear 41 and its associated hour hand shaft 48. It will be understood that the various gears and other elements of the timing mechanism are supported or journaled by the case or frame H) in the manner shown in the various figures.

In accordance with the present invention the pinion 46, in addition to driving the hour gear 41 drives a power take-off gear 49 which carries a bevel gear 50 for rotation therewith. The bevel gear 50 meshes with a second bevel gear 5| which is freely rotatable on a shaft 58 secured by the frame or case ID. The gear 5| is provided with a sleevelike hub 52 which has fixed thereto a pawl-like pickup element or finger 53 for rotation therewith. As a result, the finger 53 is driven one complete rotation by the clock mechanism every twelve hours. Also disposed on the shaft 56 and therefore concentric with the hub 52 is a gear 54 hereinafter referred to as the timing gear. The timing gear 54 is freely rotatable and axially slidable on the shaft 55. Ex-- tending outwardly from one side of the timing gear 54 is a pin 55 which may be engaged by the finger 53 whereby the timing gear 54 may be rotated by the clock mechanism. The timing gear 54 is urged in an axial direction toward the finger 53 by a spring I34 extending between the frame I0 and an annular hub member I33 fixed to the gear 54. As a result, the gear 54 is normally disposed so that the finger 55 is disposed in the path of rotation of the finger 53 and will be rotated by the finger 53 when the finger 53 is brought into contact with the pin 55 by the clock mechanism. On the other hand, the timing gear 54 may be slid axially away from the finger 53 to remove the pin 55 from the path of rotation of the finger 53.

The timing gear 54 is in mesh wi-th'a wide gear 60 which comprises one element of a differential indicated generally by the reference numeral 6|. The gear 56 is made sufficiently wide so that the timing gear 54 remains in mesh therewith in either shifted position.

Turning .now to the differential 5|, gear 60 is freely rotatable about a shaft 62 and journals one end of a plurality of pinion shafts 63 equally radially spaced from the shaft 62. The other ends of the pinion shaft 63 are journaled in a disk 64 rotatably mounted on a shaft 65. The shafts 63 carry intermeshing pairs of pinion gears .65 arranged so that the outer extremities of the pinions of each pair in mesh respectively with concentric pinions 6'! and 58 integrally formed on

shafts

62 and 65, respectively. The pinions 61 and 68 are formed on the opposed inner ends of the

shafts

62 and 65 which carry gears 69 and 10, respectively at their outer ends. As will be apparent, gear 60 may be driven through differential 6| by either

drive gear

69 or 10, or both, and this may be accomplished either simultaneously or sequentially, a desired. Conversely,

drive gear

69 or 19 may be driven by rotation of gear 60. As previously mentioned, gear 66 is in mesh with timing gear 54 and therefore the relative rotated position of timing gear 54 with respect to finger 53 can be varied by rotating either gear 69 or In, or both. Since finger 53 is operated by the clock mechanism, the rotational distance between finger 53 and pin 55 on timing gear determines the amount of time which will elapse before the differential is actuated by the clock mechanism. When finger 53 engages with pin 55, the clock mechanism drives the differential through gear 66.

Differential driving gear 69 is connected with the finish time setting mechanism by a gear mounted for rotation with and on one end of a shaft 16 which supports the finish time minutes number wheel 24 and hours number whee1 25. The other end of the shaft I6 secures a bevel gear 11 which is in mesh with a bevel gear 18 secured to the inner end of the finish time setting shaft 23. Thus, manipulation of the control knob 20 and finish time setting shaft 23 will drive the differential gearing 6| through the drive gear 69. At the same time the

number wheels

24 and 25 are set to the selected position within the windows 26 in the timer face II, this for the reason that the minutes number wheel 24 is fixed to the shaft 16 while the hours number Wheel 25 is driven through conventional transfer mechanism by the minutes number wheel 24. In the embodiment shown, the minutes number wheel 24 bears two consecutive sets of indicia running from 00 to 50 in multiples of 19 consecutively. The hours number wheel 25 is provided with indicia running from numbers 1 to 12, inclusive. Also in the embodiment shown, the transfer mechanism comprises a mutilated pinion 89 rotatably mounted on a transfer pinion shaft 8| secured in the frame or case In. The mutilated pinion B9 is engaged by a locking disk 82 having suitable transfer teeth 32' on the minutes wheel 24 and, in turn, drives the gear 83 on the hours wheel 25. The arrangement is such that one complete revolution of the minutes number wheel 24 will rotate the hours number wheel 25 by two hours as represented by two digits on the hours number wheel 25.

The gear ratios employed, including those in the differential 6|, are such that when the shaft 16 is rotated one revolution corresponding to a period of two hours, as above mentioned, the time gear 154 will be rotated revolution which is the distance traveled by finger 53 in the same period, 1. e. two hours. The indicia on the

number wheels

24 and 25 are arranged so that the finish time appearing in the windows 26 increases, i. e., indicate a later time when the shaft 16 is rotated clockwise, as viewed in Fig. 8 of the drawings. When the shaft 16 is rotated clockwise the time gear 54 also is rotated in av clockwisedirection by the differential 6 I. Clockwise rotation of time gear 54 serves'to advance the pin 55 ahead of the finger 53 thereby causing the differential 6| to be driven in a reverse direction by the clock mechanism commencing at a later time, depending upon the extent to which the number wheels, 24 and 25 are advanced. I

The finish time setting mechanism is provided with a .detent comprising a spring arm 84 carried by the frame or caseifl and engageable in a plurality of cavities 85 in the outer side wall of the minutes number wheel 24. There is one cavity 85 provided for each of the digits appearing on the number wheel 24 so that the finish time indicator can be accurately set in selected ten-minute increments. The .detent also serves to hold the differential drive gear 69 while the differential is being driven in either direction by the differential drive gear 10 or by the timing gear 54. I 2

Differential drive gear 19 is connected with the cook period setting mechanism by a gear 99 which is secured to one end of a shaft 9| for rotation therewith. The other end of the shaft 9| secures a bevel gear 92 which is in mesh for setting purposes with a bevel gear 93 secured to the inner end of the cook period setting shaft 21. The shaft 9| is axially shiftably supported by the frame or case IO so that the

gears

92 and 93 may be brought into mesh when the selected cook period is beingset, and may be disengaged after being set for purposes and by means to bedescribed later. Spring I46 dis I posed between the frame and gear 96 normally urges the shaft 9| in a, righthand direction (as viewed in Fig. 6) to intermesh gears 92 and 93'. The gear is sufiiciently wide to remain in mesh with gear '10 regardless of the shifted position of shaft 9|. Detent means comprising a ball 98 engageable inthe teeth of the bevel gear 93 and a spring 99 disposed within a cavity I90 (Fig. 6) in the frame In provides for accurate setting of the Cook Period indicator in ten-minute increments.

The shaft 9| carries the minutes number wheel 28 and the hours number wheel 29 for indicating the selected cook period in the windows 39 of the face The minutes number wheel is splined to the shaft 9| for rotation therewith and in the embodiment shown is provided with two consecutive sets of indicia ranging from 00 to 50 in steps of 10. The hours number wheel ,29 of the cook period bears the hours indicia numbered from 1 to 5 and is driven by the minutes number wheel 28 through a mutilated transfer pinion 94 rotatably mounted, on

a transfer pinion shaft 95 secured to the frame or case I9. The transfer pinion 94 is engaged by a locking disk 96 having suitable transfer teeth 96' carried by the minutes number wheel and by a driven gear 9'! carried by'the hours number wheel. The arrangement is such that the hours number wheel 29' is turned through two digits (hours) upon each complete revolution of the minutes numberwheel 28. The desired cooking time can thus be preset on the

number wheels

28 and 29 and. be visible through the windows 30 by manipulation of the control knob 2|. The side of the number wheel 29"is provided with a lug IOI which is adapted to engage stops I02 and I03 supported by the casing I9. The stops I02 and'l03 are so located that the wheel 29 can be turned freely. to display the numerals through 5 but cannot be turned directly from 0 to 5 or vice versa. In other words, rotation of wheel 29 is limited to less than a full revolution in either direction.

The gear ratios employed between the cook period setting mechanism and the time gear 54 including the gear ratios of the differential BI, in the embodiment shown, are exactly the same as those between the finished time setting mechanism, i. e. for each revolution of the shaft 9| the time gear 54 is rotated of a revolution which corresponds to a period of two hours in both cases.

The indicia on the

number wheels

28 and 29 are arranged oppositely to that of the

number wheels

24 and 25 with the result that the cook period is increased by rotating the shaft 9I in a counterclockwise direction, as viewed in Fig. 8 of the drawings. Counterclockwise rotation of shaft 9I drives the time gear 54 through differential 6| also in a counterclockwise direction. The result is that when the cook period is increased, as shown by a higher set of numbers appearing in the window 39, the time gear 54 is rotated so as to bring the pin 55 closer to the finger 53, thus conditioning the apparatus for operation in a reverse direction by the clock mechanism commencing at an earlier time depending upon the extent to which the

number wheels

28 and 29 are advanced.

When the timer is assembled, the cook time setting mechanism, finish time setting mechanism, differential 6| and time gear 54 are connected so that, with the cook period indicators at zero and the pin 55 in engagement with the finger 53, the reading on the finished time indicators is the same as the setting of the clock hands I3 and I4. Thereafter, these devices remain fully coordinated and complete accuracy of the timer is assured.

As will be apparent from the above description, the rotated position of the time gear 55 will always depend upon the algebraic sum of the settings of the cook period setting mechanism and the finish time setting mechanism, i. e. the distance of the pin 55 from the finger 53 will always be equal (from a time standpoint) to the difference between the time indicated by the clock hands I4 and I3 which fixes the position of finger 53 and the finish time indicated by

number wheels

24 and 25 minus the cook period indicated by

number wheels

28 and 29.

When the device is set in operation for automatic control of the range or other instrumentality, the first operation which takes place is the advancement of the finger 53 by the clock mechanism until it engages the pin 55 on the time gear 54. Thereafter, the clock mechanism drives the time gear 54 which, in turn, drives the gear 60 of the differential GI. Inasmuch as the shaft I6 is retained against rotation by the detent 84, the output of the differential is directed to shaft 9| of the cook time setting mechanism with the result that the

number wheels

28 and 29 are returned to zero position in time with the clock mechanism. At the end of the operation, when the cook time period has been reduced to zero, the time gear 54 is shifted by mechanism to be described hereinafter so as to disengage the pin 55 from the finger 53.

Coming now to the manner in which the aforesaid relationship of the cook period setting mechanism, finish time setting mechanism, time gear 54, and finger 53 is utilized in accordance with the invention to control an associated mechanism such as an electric range, it will be observed that a notched control disk I05 is fixed to shaft 65 for rotation therewith. The ratio of gears '19 and 99 is such that the shaft 95 makes one-third of a revolution for each complete revolution of the shaft 9|. In other words, the control disk I95 will make one complete revolution every six hours, this being also the maximum setting of the cook period indicating

number wheels

28 and 29. The control disk I95 has thirty-six notches I99 cut in its outer periphery with the result that the disk I95 is rotated one notch for each ten-minute period shown on the cook

time indicating wheels

28 and 29. One of the notches I99 which is indicated at I95 is cut relatively deep compared with the remaining notches I96 for the purpose hereinafter described.

As previously mentioned, the rotated position of the actuating shaft 3| is utilized to determine the condition of operation of the associated apparatus, such as a kitchen range. The shaft 3| is biased in a counterclockwise direction by the spring 34, which is secured at one end to the frame I0 and at the other end to a collar 35 fixed to the shaft 3|. The spring 34 also serves to urge the shaft 3| outwardly, i. e. to the right as viewed in Fig. 5 of the drawings, to the axial position shown. The collar 35 is slotted at 36 to slidably receive a key 3? on the segment dial 32 to permit the shaft 3| to move axially without displacing the dial 32. The dial 32 is rotatably received in a recess 38 in the wall I I which is covered by the face plate I8 and is thus restrained against movement in a direction axially of shaft 3I.

Disposed on the internal end of the actuating shaft 3I are a pair of spaced apart arms I98 and I99 having ears I01 and III, respectively, at the outer ends thereof and extending therefrom at an angle of approximately As best shown in Fig. 2 of the drawings, the arms I99 and I99 are so located when shaft BI is in its normal axial position that the arms will have a path of rotation at right angles to the plane of disk I and just outside the periphery thereof. However, the ears I91 and I I I, being turned inwardly toward the disk I05, will normally engage against the side of the timing disk I05 adjacent the periphery thereof. The arms I98 and I99 are preferably made of light spring material whereby they are relatively flexible in a plane axially of the shaft 3|. Since the righthand edges of the ears I91 and HI are beveled as indicated at IIO, the engagement of the ear I97 or III with the disk I95 will not prevent turning of the shaft in a clockwise direction, this for the reason that the arm I08 or I99, as the case may be, will be cammed and thus flexed outwardly to cause dis- 9 engagement. However, upon the reverse rotation of shaft 3|, the flat'edges of the ears I01 and III are brought into engagement with the disk I and thus remain in holding engagement. In'the Set position of shaft 3| the arms I08 and I09 are moved, to the position shown in Figs. 2 and 6 of the drawing, i. e. with the ear I01 of arm I08 engaged against disk I05. Engagement of ear |01 with disk I05 retains shaft 3| in the Set position against the bias of spring 34. a

The length of theear I01 is such that, when it is brought into engagement with the edge of disk I05 and'disk I05 is rotated to bring one of the notches I06 into registry therewith, the ear I01 will pass through the notch thereby releasing shaft 3| for rotary movement under the influence of spring 34.

The effective length of the arm I08 is such that the ear I01 will engage the disk I5 slightly in advance of oneof the notches I03 when the

cook time indicators

28 and 29, are accurately set in one of the selective ten-minute settings thereof. Accurate positioning of the

number Wheels

28 and 29 is insured, as previously mentioned, by the detent 9B.

As'soon as any driving force is transmitted to the differentialtl by reason of the pickup of the pin 55 by the finger 53 the disk I05 will begin to rotate; Slight movement of the control disk I05 causes a notch I06 to be brought into registry with the ear I01 on the arm I08 permitting the ear I01 to pass through the notch, thus permitting counterclockwise rotation of the actuating shaft 3| to the On position.

The ear I on the arm I09 is made somewhat longer than. the ear I01 so that it cannot pass through any of the notches I06 except the deep notch I06. Accordingly, when shaft 3| is released for counterclockwise movement by reason of. ear I01 passing through one of the notches I06, rotation is, thereafterhalted by, engagement of ear I'II withthe side of disk I05, thus. fixing the On? position of shaft 3|. The axial position of disk I05 on the shaft 65 is such that the deep notchltlfi is brought into registry with the ear III when the cook

time indicating wheels

28 and 29 have been returned to the zero position. When this condition occurs the ear III is free to pass through the notch I06, thus releasing the actuating shaft 3| for further rotation to the Off position. The Oil position of shaft 3| is fixed by the engagement of finger I I2 on stationary lug II3.

It thus will be seen that when the selected cook period is set on the

number wheels

28 and 29 the relatively deep notch I06 will be rotated away from registry with the path of movement of the ear I I I byan amount which is equal from a time standpoint to the desired cook time. At the same time, as previously mentioned, the time gear 54 is rotated relative to the'finger 53 in an amount depending upon the selected cook time and selected finish time. [As a result, the pin 55 of the time gear 54 is picked up by the finger 53 to cause reverse driving of the differential 6| by the clock mechanism at the position of the clock which difiers from the 'finish time by the amount of the cook. period selected. Almost immediately upon engagement of the pin 55 by the finger 53 resulting in rotation of the disk I05, a notch I0 is brought. into registry with the finger I01 permitting the actuating shaft to move to the On position. Then, as thedifierential 6| is further driven by the "clock mechanism and 10 the number wheels 28 and'29 are returned to zero, the deep notch I06 is brought into registry with the ear III, thus releasing the shaft 3| for movement to the "Off position. At this moment, of course, the finishtime appearing on the

number wheels

24 and,25 corresponds exactly with the clocktime. In order to utilize the movements of shaft 3| to control an'associated apparatus, the shaft 3| has fixed thereto a cam I25. In the specific embodiment shown in the drawings, cam I25 is utilized to operate a switch I connected by means of terminals I2| forfcontrolling the heating elements of the range with which the timer is being employed. The switch I20 is of conventional construction and may be provided, by way of example, with a pivotal contact arm I21 fulcrumed by a pin I28 intermediate its ends and adapted to cooperate with stationary contacts I29. A spring I26 is utilized to bias the arm I21 to closed. position. The outer end of the terminal arm I21 engages one arm of a bell crank I22 which, in turn, engagesthe cam I25.

The cam I25 is so designed that the switch I25 is held in open position at all times except when the shaft 3| is in the On orManual positions.

The cam I25 also operates a second bell crank I which is pivotally mounted on a shaft |3| secured, bythe frame IOand which has a bifurcated arm I32 embracing the hub I33 on the timing gear 54. The arrangement is such that upon rotation of the actuator shaft 3| to the Off or Manual positions the cam I25 will rotate the .bell crank I30-to shift the timing gear 54 axiallyaway from the finger 53 whereupon the pin 55 is removed from the path of rotation of the finger 53. This insures that there will be no interference of the finger 53 with the positioning of the time gear 54 in either rotated direction by the Finish Time and Cook Time setting mechanisms, nor will the position of the time gear 54 be operated by the finger 53 when the device is not in use.

Also fixed to the shaft 3| is a cam I44 for operating a bell crank having arms MI and I42 and pivoted at I43. The arm MI is adapted to engage against the side of the gear 90. The cam I44 is so designed that when the shaft 3| is turned to the Set or On positions, the shaft 9| is moved axially so as to disengage the gears 92 and 9-3. This removes the Cook Time setting mechanism from control by. the knob 2| so that the knob'2l andits detent 98 will place'no load on the driving mechanism during automatic operation of the range.

In order to move the shaft 3| from Off position to Manual'position, it is necessary for the operator to thrust the shaft 3| inwardly against spring 34 to cause the finger I I2 to clear the lug II3, whereupon the shaft 3| is released for the required additional turning movement to the Manualflposition. The Manual position is fixed by abutment of the finger II 2 against a final stop which, for convenience, in the particular embodiment shown comprises the adjacent end of hell crank I30. As previously mentioned, turning the shaft 3| to Manual position closes the switch I20 and thus places the range under the. sole control of the manually operated switches of the range.

It thus will be seen that there has been provided in accordance with the invention a time responsive control mechanism which is fully automatic in operation, which can be preset with simplicity and ease, which is fully accurate and foolproof in operation, and which clearly and simply identifies the stages and conditions of operation at all times.

As many changes could be made in the above construction and many apparently widely different embodiments of this'invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the language used in the following claims is intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

I claim as my invention:

1. A timer comprising a plurality of setting means, a clock mechanism having a driving element, a driven element adapted to be advanced relative to said driving element, and differential gearing interconnecting said driven element, and said'setting means.

2. A timer comprising a plurality of setting means, a clock mechanism having a rotatable driving element, a rotatable driven element adapted to be driven by the driving element in predetermined relatively rotated positions thereof, and differential gearing interconnecting said driven element and said setting means.

3. A timer comprising a plurality of manually operable setting means, a control member connected to one of said setting means for movement therewith, a clock mechanism having a driving element, a driven element adapted to be driven by the driving element in predetermined relative positions thereof, and differential gearing interconnecting said driven element and said setting means.

4. A timer comprising a plurality of manually operable setting means, a control member connected to one of said setting means for move ment therewith, a clock mechanism having a rotatable driving element,.a driven element rotatably settable relative to, said driving element and adapted to be driven by the driving element in predetermined relatively rotated positions thereof, and differential gearing interconnecting said driven element and said settingmeans.

5. A timer comprising a plurality of manually operable setting means, independent indicating means for each of said setting means to indicate the positions thereof, a control member connected to one of said setting means for movement therewith, a clock mechanism having a driving element, a driven element movable relative to said driving element and adapted to be driven by the driving element in predetermined relative positions thereof, and driving means including a differential between said driven element and said setting means.

6. A timer comprising a pair of aligned shafts, differential gearing connecting said shafts including a sun gear on each of said shafts, a planetary supporting gear, and planetary pinions carried on said supporting gear and meshing with said sun gears, manually operable setting means for said aligned shafts, a clock mechanism having a rotatable driving element, a gear meshing with said planetary supporting gear and rotatable coaxially with said driving element, and means forming a driving connection between the driving element and said coaxial gear in predetermined relatively rotated positions thereof.

7. A timer comprising a first indicator shaft, a second indicator shaft, a settable driven element, a continuously maintained positive driving connection between the indicator shafts and the driven element including a differential, a clock mechanism having a time responsive driving element, and means forming a driving connection between the driving and driven elements at a predetermined relatively rotated position thereof.

8. A timer comprising a plurality of manually operable setting means, independent indicating means for each of said setting means to indicate the positions thereof, a control member connected to one of said setting means for movement therewith, means for actuating an associated mechanism responsive to said control member, a clock mechanism having a rotatable driving element, a driven element rotatably settable relative to said driving element and adapted to be driven by the driving element in predetermined relatively rotated positions thereof, and differential gearing interconnecting said driven element and setting means.

9. In a time responsive switching device, a rotatable control disk, switch actuating means responsive to said rotatable control disk, first setting means for setting said control disk in selected rotated positions, time controlled driving means, a rotatable driven member, means forming a driving connection between said driven member and driving means in one relatively rotated position thereof, second setting means, means for rotating said driven member relative to said drive member selectively by said first and second setting means, and means for preventing movement of said second setting means while said control disk is rotated by said first setting means or said driven member.

10. In a time responsive switching device, a rotatable control disk, switch actuating means responsive to said rotatable control disk, an indicator for showing the position of said control disk, first setting means for setting said control disk in selected rotated positions, time controlled driving means, a rotatable driven member, said driving means having means engageable with said driven member in one rotated position relative to said driven member, second setting means, means for rotating said driven member relative in said drive member selectively by said first and second setting means, a second indicator for showing the'rotated position of said driven member relative to said drive member, and means for preventing movement of said second setting means while said control disk is rotated by said first setting means or said driven member.

11. In a time responsive switching device, a rotatable control disk, switch actuating means responsive to said rotatable control disk, first setting means for setting said control disk in selected positions, time controlled driving means, a rotatable driven member, said driving means having means engageable with said driven member in one rotated position relative to said driven member, second setting means, differential gearing interconnecting said driven member with said first and second setting means whereby said driven member may be rotated relative to said drive member selectively by said first and second setting-means, and means for preventing movement of said second setting means while said control disk is rotated by said first setting means or said driven member.

12. In a time controlled switch, switch actuatsaid timing gear in one rotated position relative thereto, second setting means, differential gearing interconnecting said timing gear to said control disk and said second setting means whereby said timing gear may be rotated relative to said drive means selectively by said first and second setting means, and upon engagement of said timing gear by said drive means, said control disk will be rotated to permit movementof said actuating arm to on position, and means for preventing movement of said second setting means while said control disk is rotated by said first setting means or said timing gear.

13. In a time controlled switch, switch actuating means, a rotatable control disk for controlling the switching movements of said actuating means, said control disk having one rotated position relative to said actuating means permitting movement thereof to switch opening position, first setting means for setting said control disk in selected positions relative to said actuating means, an indicator for showing the position of said control disk, clock mechanism, a timing gear, rotatable drive means on said clock mechanism engageable with said timing gear in one rotated position relative thereto, second setting means, differential gearing interconnecting said timing gear to said control disk and said second setting means whereby said timing gear may be rotated relative to said drive means selectively by said first and second setting means and upon engagement of said timing gear by said drive means said control disk will be rotated to one of a plurality of positions relative to said actuating means permitting movement thereof to switch closing position, and meansfor preventing movement of said second setting means while said control disk is rotated by saidfirst setting means or said timing gear,

14. In a timer, the combination comprising a clock mechanism provided with a rotatable driving element, a rotatable driven element mounted coaxially with the driving element, means forming a driving connection between the driven element and the driving element in a predetermined relatively rotated position of the driven and driving elements, a first indicator shaft, indicating means for selectively indicating'a period of operating time operated by the first indicator shaft, 2. second indicator shaft,-indicating means for selectively indicating a finish time operated by the second indicator shaft, and driving means including a differential between said driven element and said indicator shafts whereby the rotated position of the driven element relative to said driving element is determined by the difference between the clock time and the finish time minus the operating time.

15. A timer comprising a first setting means including an indicator shaft, indicating means I on the shaft and a drive shaft, a second setting means including a second indicator shaft, second indicating meanson the second shaft and a second shaft, a differential couplingincluding a sun gear on each of said drive shafts,-and a drive gear on which are mounted planetary pinions in meshwithjsaid sun gearsya clock mechanism provided with a rotatable driving element, a gear mountedcoaxially with the driving element and in mesh with the drive gear of said differential coupling, means forming a drivin'g connection between the last-named gear and the" driving element in one relatively rotated position thereof, a switch operating mechanism and a rotatable control member operatively connected for rotation with the first setting means, having means for functioning the switch operating mechanism at an initial and final rotated position thereof.

16. A timer comprising a clock mechanism provided with a driving element, a driven element mounted coaxially with the driving element, means forming a driving connection between the driving element and the driven element in a predetermined relatively rotated position of the driving and driven elements, a first indicator shaft, indicating means operated by said shaft, gear means between said driven element and said first indicator shaft including a differential arranged so that the indicating means may be operated in a subtracting direction as the driven element is turned in the driving direction of the driving element, a second indicator shaft, indicating means operated by the second indicator shaft, means. connecting the second indicator shaft to the differential whereby the said driven element may be turned in the driving direction of the driving element as the last-named indicating means is advanced, rotatable control means operated in response to turningof the first indicater shaft, and means settable for a first move ment responsive to initial movement of the control means and a second movement responsive to movement of the control means to a position corresponding to zero position of the first indicating means.

17. A timer comprising a clock mechanism provided with a rotatable driving element, a driven element mounted coaxially with the driv ing element, means forming a driving connection betweenthe driven element and the driving element in a predetermined relatively rotated position of the driving and driven elements, a first indicator shaft, indicating means operated by the first indicator shaft for selectively indicating a period of operating time,.a second indicator shaft, indicating means operated by the second indicator shaft for selectively indicating a finish time, driving means including aldifferential between said driven element and said indicator shafts whereby the rotated position of the driven element relative to said driving element is determined by the difference between the clock time and the finish time minus the operating time, rotatable control means operated in responseto turning of the first indicator shaft, and means settable for a first movement responsive to initial movement of the control means and a second movement responsive to movement of the control means to a position corresponding; to zero operating time. i i

i 18. A timer comprising a clock mechanism provided with a rotatable driving element, a driven element mounted coaxially with the driving element, engageable means adapted to engage and form a driving connection between the driven element and the driving element in a predetermined relatively rotated position of the driving and driven elements, a first indicator shaftQindicating means operated by the first indicator shaft for selectively indicating a periodof operating "time, a second indicator shaft, indicating means operated by the second indicator shaft for selectively indicating a finish time, driving means including a differential between said driven element and said indicator shafts whereby the rotated position of the driven element relative to the driving element is determined by the difference between the clock time and the finish time minus the operating time, said operating time being zero when the driven and driving elements are interengaged and the finish time is equal to the clock time, means for preventing turning of thesecond indicator shaft through said differential, means for preventing operation of the first indicator shaft during rotation of the second indicator shaft, means for releasing said engageable means between the driven and driving elements during manual operation of said first and second indicator shafts, rotatable control means operated in response to turning of the first indicator shaft, and means settable for a first movement responsive to initial movement ofthe control means and a second movement responsive to movement of the control means to a position corresponding to zero operating time.

19. A timer comprising a clock mechanism provided with a rotatable driving element, a driven element'mounted coaxially with the driving element, engageable means adapted to engage and form a driving connection between the driven element and the driving element in a predetermined relatively'rotated position of the driving and driven elements, a manually operable first indicator shaft, indicating means operated by the first indicator shaft for selectively indicating a period of operating time, a manually operable second indicator shaft, indicating means operated by the second indicator shaft for selectively indicating a finish time, driving means including a differential between said driven element and said indicator shafts whereby the rotated position of the driven element relative to the driving element is determined by the difference between the clock time and the finish time minus the operating time, said operating time being zero when the driven and driving elements are interengaged and the finish time is equal to the clock time, means for preventing turning of the second indicator shaft through said differential, means for preventing operation of the first indicat-or shaft during rotation of the second indicator shaft, a' rotatable control disk operatively connected to the first indicator shaft, switch actuating means movable in one direction to sequentially perform a plurality of switching operations, means biasing the actuating means in said one direction, a plurality of stops on said actuating means sequentially engageable with said control disk during movement of the actuating means in said one direction, means on said control disk defining a plurality of escapements for the first of said stops and means on said control disk defining an escapement for the second of said stops, said last-named escapement being located for registry with the second of said stops when the operating time is zero. a

20. In a time responsive switching device, switch actuating means-movable in one direction to sequentially perform a plurality of switching operations, means biasing the actuating means in said one direction, a rotatable control disk, a plurality of stops on said actuating means sequentially ,engageable with said control disk during movement of the actuating means in said one direction, means on said control disk defining a plurality of escapements for the first of said stops, means on said control disk defining an escapement for the second of said stops, time controlled driving means for said contol disk, and means for setting the control disk whereby upon initial rotation thereof the first of said stops will escape said control disk to effect one switching operation of said actuating means and upon further rotation of said control disk for a preselected period the second of said stops will escape said control disk to effect another switching operation of said actuating means.

21. In a time responsive switching device, switch actuating means movable in one direction to sequentially perform a plurality of switching operations, means biasing the actuating means in said one direction, a rotatable control disk, a plurality of stops of varying form on said actuating means sequentially engageable with said control disk, means on said control disk defining a plurality of notches to provide escapement for the first of said stops only, means on said control disk defining a notch to provide escapement for the second of said stops, manually operable means for setting the rotated position of sa d control disk, time controlled driving means, and means for having an adjustable time delay for interconnecting said driving means and said control disk whereby upon interconnection thereof the first of said stops will escape said control disk to effect one switching operation and upon further rotation of said control disk for a preselected period the second of said stops will escape said control disk to effect another switching operation of said actuating means.

22. In a time responsive switching device, switch actuating means rotatable in one direction to sequentially perform a plurality of switching operations, means biasing the actuating means in said one direction, a rotatable control disk having an axis of rotation transverse of the axis of rotation of said actuating means, a plurality of radially disposed and angularly related stops on said actuating means sequentially engageable with the peripheral portion of said control disk, said stops being of different length, means on said control disk defining a plurality of relatively shallow notches about the periphery thereof providing an escapement for the first of said stops, means on said control disk defining a relatively deep notch on the periphery thereof providing an escapement for the second of said stops, manually operable means for setting the rotated position of said control disk relative to said actuating means, time controlled driving means, and means for interconnecting said driving means and said control disk at a selected future time whereby upon interconnection at said future time the first of said stops will escape said control disk to effect one switching operation and upon further rotation of said control disk for a preselected period the second of said stops will escape said control disk to effect another switching operation of said actuating means.

23. In a time responsive switching device, switch actuating means movable in one direction to sequentially perform a plurality of switching operations, means biasing the actuating means in said one direction, a rotatable control disk, a plurality of stops on said actuating means sequentially engageable with the peripheral portion of said control disk during movement of the actuating means in said one direction, means on said control disk defining a plurality of escapements about the periphery thereof for the first of said stops, means on said control disk defining an escapement on the periphery thereof for the second of said stops, manually operable means for setting the rotated position of said control disk, time controlled driving means, means having an adjustable time delay for interconnecting said driving means and said control disk, and manually operable means for adjusting the lastnamed means whereby interconnection of said drive means and said control disk may be effected at a preselected future time to immediately release the first of said stops to effect one switching operation of said actuating means and upon further rotation of said control disk for a preselected period the second of said stops will be released to effect another switching operation of said actuating means.

24. A timer for automatically controlling electric ranges or the like comprising a switch, a switch actuator, a rotatable control disk for controlling the movements of said actuator, said control disk having a plurality of rotated positions relative to said actuator permitting switch closing movement thereof and one position permitting switch opening movement, first setting means for setting said control disk in selected positions relative to said actuator, an indicator J means selectively by said first and second setting means, manually operable means for placing said actuator in a set position for sequential movements to switch closing and opening positions under the control of said control disk, whereby upon engagement of said timing gear by said rive means said control disk will permit movement of said actuator to switch closing position, a second indicator operable by said second setting means and showing the time when said actuator will move to switch opening position, and means for preventing movement of said second setting mean while said control disk is rotated by said first setting means or said timing gear.

HARVEY N. BLISS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,130,405 Andrews Sept. 20, 1938 2,166,872 Mayers 1- July 18, 1939 2,209,108 Briggs July 23, 1940 2,217,226 Lux Oct. 8, 1940 2,281,553 Bennett May 5, 1942 r 2,300,950 Lux Nov. 3, 1942 2,310,527 Hutt Feb, 9, 1943 2,361,262 Candor Oct. 24, 1944 2,419,077 Isserstedt Apr. 15, 1947 2,557,464 Rambert June 19, 1951