US2451250A - Elapsed time indicator - Google Patents

Description

Oct. 12, 1948. SPRINGER 2,451,250

I ELAPSED TIME INDICATOR Filed NOV. 22, 1946 29 I IHVQWCQT hams Springer:

His A't'torne g.

Patented Oct. 12, 1948 UNI T ED S TATES PAT EN T OFFICE .1 EL'APSED TIME INDICATOR Application November 22, 1946, Serial No. 711,682

-Claims.

.My invention relates toelapsed timeindicators such as willbe useful intiming'predeterminedad justabletime intervals such, for example, as cooking or photographic developing operations and the ike.

Its object is to .provide a simplegrugged'inexpensive timer of thistype which is adjustable as to the timed interval, including both initial time settings and plus or minus changes-thereof during the time interval, which'gives an accurate indication of the timesetting andthe time remaining in the time intervalat all times during such interval, and which produces an alarm at the end of the time-interval. A further object of the invention is to provide an-interval timer of the character described in which all of the operations incident to setting, timing,alarm-operation and alarm shutoff are performedby'turning asingle shaft in opposite directions either by a timer motor or manually.

The features ofmy invention-Which are believed to be novel and patentable will be-pointed out in the claims appended! hereto. For a better understanding of my invention, reference is made inthe following description to the accompanying-drawing in which Figsl'representsa face view' of my elapsed timer and Fig.2 aside sectional view thereof taken on line '2-2- of Fig. 1. Fig. Sis a front view but with :the glass cover, holding-rim, and most of the front stationary indicator dial removed. Fig. 4 is a View taken on lineZ4-4, -Fig' 1, of an upper portionof thelstructure to help in showing the disposition ofapart 40 usedfor guiding a movable indicator-34 .through'a slot. 36 ina front dial I3. Figs. 5, 6,.and 7 are front viewswith the greater portion of thefront indicator partsbroken away to show the drivingmechanism and an operating cam in differentpositions, Fig.6 represents a full alarm off position Fig..6 atime interval setting position, and Fig. 7 analarmion position.

Referring first primarlylto Fig. 1, :the :device includes a self-starting synchronous clockmotor having a two-polemagnetic field structure I with an energizingcoili .onits yoke and ianarmature, not shown, butcontained within a vreduceddiameter portion 3 ofa casing 14 containing speed reducing gearing between the motorarmatureand a terminal drive shafthavingthereona gear Spinion- 5. The pole pieces-of the field structure e'mbrace the portion? of'the casing and are separated from the rotor onlybythe thin-shell of the nonmagnetic casing. Amotorstructure ofthis character-is shown indet-ail in-United 'states Patent No.'1,495',936. The motor is""riveted or 'otherwise ber 1 to vibrate insynchronism with the flux pulsations when such armature is free to'do'so.

Its right-hand'free'endas best shown in Figs. -2, l,

and 6, may then strikeagainst amagnetic-bu shing 9 secured to-the fieldcore 2 to produce an audible alarm. however, be held'against vibration and thus re- The armature member 1 may,

main silent by-reason of an extension 10 thereof resting against the-high parts of a cam II as shown in Figs. 5 and 6 and as-will be explained more in detail later.

Spaced'tothe front of -andsecured to-platefi is another plate-l2 which forms the rear-housing portion of the-elapsed timer dial structurewhich includes a stationaryindicator dial l'3,a=glass front cover H and an outer-'bezel-ring -l5-which secures-the glass cover and'dial plate -l3'to housing plate l2. 'Thedial l3 is space'd to the front of housing-plate-ll-by reason'of spacing lugs l6 pressed out to the=frontfrom plate [2. Likewise theglass cover! 4- is spaced slightly tothe-front of stationary dial-plate l-3 by reason of -a-spacing ring ll preferably made of'a slightly compressible gasket material. Lugs -I8 extending forwardfrom plate 12 embrace dial= plate -'l-3 at two-or more points about its periphery to help position and hold it in-place, andlugs -l-9 extending tothe-rear from the outer bezel-ring are bent-around to the rear of--spacing lugs l6 of plate 42 m secure the bezel ring H5 in place,--therebyholdingthelglass cover against gasket 11 and the-gasket against dial plate 43.

The space between plates =6 and 42 is occupied lay-reduction gearing between the terminal pinion '5 of the motorunit' and ashaft ZShaVing bearings in plates'G andl'Z and extending forward through openings at the centers of dial .plate-ls'and glass cover- M and having an operating thumb-piece -2 l securedon its front end and accessible at the front of the timer. "The-gear reduction just referred=to includes theygears 22, 23, 24, 2-5 and a mutilated gear26 on shaft 2:? best shown'iniFigffi This geartrain also includes aslipfriction. clutch indicatedjatii 1,1Figfl 5,",between; gears 24 and"215.

Secured on the rear "of "shaffiflisthe "cam "I l which cooperates with the alarm armature as previously mentioned. The cam H with its cam follower l9 not only has the usual cam actions but also acts as a two-way stop to limit the travel of the cam in opposite directions. This is by reason of the short radial projection 28 on the cam periphery. The greater length of the came periphery is occupied by the raised surface 23 on which the cam follower l rides to hold the alarm armature! raised and prevents the same from vibration during a timing interval. The relatively short depression 33 in the cam when opposite the cam follower In as represented in Fig. 7 allows the armature l to Vibrate freely and the alarm to sound at the end of a timing interval, The notch 3| in the cam surface is for the purpose of receiving the cam follower at the termination of a timing interval after the alarm has been silenced manually, as shown in Fig. 5. In this position the cam follower vibrator is raised sufficiently to prevent alarm operation, and the notch 31 prevents easy accidental turning of the cam clockwise from this position, while the stop prevents counterclockwise rotation of the cam beyond this position.

Also secured to shaft 20 is an indicator member having a hub part 32, a radial spider part 33, and a C-shaped sector part 34, which extends around to the right from the radial spider part 33 nearly during the remainder of the timing interval to show the time remaining in the interval. The indicator sector 34 and its spider 33 are of relatively thin, somewhat flexible, material to permit the greater portion of the sector 34 to pass through a radial slit 36 in the dial plate l3 so that the greater portion of sector 34 may lie in front or all completely behind the dial plate depending on the rotary position of the indicator 34. That portion which is in front of the dial plate lies loosely in a track or depression 31 in the front of dial plate 13. This depression begins at the slit 36 andextends around the dial plate in a clockwise direction about 310 degrees to the point 33 opposite the upper end of the time graduated scale 35. The depression gradually becomes shallower from the slit 36 to point 38, is concentric with shaft 20, and is of a radial width slightly greater than the radial width of indicator sector 34 so as to accommodate that portion of sector 34 which is exposed in front of the dial plate with the front surface of the sector approximately flush with the raised or time graduated portion of the dial plate. Also the front surface of the indicator member or at least the sector 34 part thereof has a color which contrasts with the front surface of the dial plate. Thus the dial plate may be polished abrass with black time graduations, and the front surface of the indicator may be enameled in red.

.To assure that the free end 39 of the colored indicator sector 34 will always pass through slit 33 when the sector is turned clockwise from the completely unexposed position to a partially exposed position, a guide member 40 is preferably provided. This guide member is secured to the front side of plate [2 and has a short sector spaced from plate [2 on the same radius as sector 34 and which extends in a clockwise direction a short distance through the slit 36 as best shown in Figs. 1, 2, 3, and 4. It is to be noted that the slit 36 is out in dial plate l2 at the counterclockwise end of the depressed sector portion 3'! thereof or between a raised and depressed portion of plate [2 so that the slit in efiec't faces in a clockwise direction from behind to the front of dial plate 12. The guide 40 rests tight against the depressed surface portion of this slit and has the effect of continuing the depressed track portion 3! through the slit in a counterclockwise direction. When the colored indicator sector 34 is rotated clockwise from the fully concealed position, such as represented in Fig. 3, the free end 39 thereof is guided through the slot 36 by the guide 40. The spider end of sect-or 34 moves behind the guide 46 when the sector is rotated counterclockwise to its extreme counterclockwise po-- sition and that portion of guide 40 which extends through slit 36 hides any portion of the colored sector 34 behind the guide which might otherwise be seen through the slit (see Fig. 4). There is a slight spiral shape to the sector 34 so that its free end 39 is displacedslightly toward the front of the device as compared to the spider end thereof. This spiral shape conforms generally to the corresponding change in depth of the depressed track 31 in the dial plate. The design is such that the shaft 23 with the cam I l and indicator 34 thereon may be easily rotated by the timer motor I through th gear train and friction clutch 21, or manually by the thumb-piece 2| with clutch 21 slipping when gears 25 and 26 are in mesh. The construction is such as to provide a compact, closely spaced, and relatively thin dial assembly such as is shown in Fig. 2.

The relative rotary positions of the cam H, the mutilated gear 26, and the indicator sector 34 on shaft 20, and the relative rotary positions of these parts with respect to the parts with which they cooperate are such as to insure their proper sequence of opera-tion in accomplishing the results desired.

InFig. 5 the cam follower ID is shown in the notch 3| and against stop projection 28 of cam II. This is the full or manually oif position of the device. The vibrator arm 1 is lifted and does not vibrate. The mutilated portion of gear 26 is opposite gear 25 and there is no driving connection between the timer motor and cam shaft 20. The colored indicator sector 34' is completely hidden behind the time indicating dial with its free end 39 in an upper center position as represented in Fig. 5. Thus in this position the alarm is turned off, the timer indicator is disconnected from the motor and the time indication is zero. This is the normal condition of the apparatus when not in use. The motor may be energized or not as desired.

To make use of the device to time an interval, the motor is energized. if deenergized. The thumb-piece 2| is turned clockwise, rotating the parts attached thereto accordingly. Cam follower l0 rides out of notch 3| into the depression 30. This may cause the alarm to sound momentarily if "the manual setting operation is slow and cor responds to the positioniiofl the parts shown in Fig. 7. However, it is assumed that insuch a setting operation the manual clockwise rotation will be sufficiently rapid that the sounding of the alarm will hardly be noticeable, if it is noticeable at all. The cam follower'is then pushed up as it rides out of the depression 30 onto the raised the free end of indicator sector 34 appears through slot-36, andthe'counterclockwise end of the toothed portionof mutilated gear 26 meshes with its driving gear 25. This manual clockwise setting operation is continued until'the free'end 2c of colored sector 84 is opposite the timegradua'ti'on desired, say for example 40 on the graduated scale '35. In such portion of the setting operation the gear 25 is'driven manually 'by gear '26 in the opposite direction-to thatwhich it-is driven by the timing motor, and the clutchat Z'Islips.

The device is now set for a timing interval of 40 which may be seconds or minutes or any othertime units, depending onthe gearreduction ratio used. The gearing represented assumes that the terminal pinion'fi of the motor operatesat 316 revolutionsper minute and that the time dial of the device'is graduated-in minutes. The thumb-piece 2| is nowreleased and the timer motor drives the colored sector 34 counterclockwise at a rate such that it will disappear through slot 35 in exactly 40 minutes. It is to'be noted that if at any time during the 40-minute time interval it is desired to reset the device for a shorter or longer timing interval, it can be done. Also, that the free end of the colored sector 34 at all times indicates on the graduated scale the time remaining in the time interval and'that'the exposed length of the sector is likewiseameasure of the time remaining in the time interval and can be seen from a considerable distance.

At the end of the 40 minute'interval cam follower ill drops into depression 31],so11nding the alarm, and simultaneouslythe clockwise end of the gear sector ofgear 26 is disengaged'with. gear 25. The device will stay in this condition'until reset or turned full oif by hand. The alarm can be silenced by turning thumb-piece 2| counterclockwise to raise cam follower ifi'intonotch 3!. The stop projection 23 in cooperationwith the cam follower prevents the manual turning of the shaft 28 too far in either direction and can have a peripheral length as long as desired :for this purpose. Figs. 1 and 2 indicatethe colored sector 3 to be in approximately the full off'position. Fig. 6 represents approximately a 54-minute time time setting with the free end 29 of colored sector 34 exposed opposite the 54-minute graduation. On the front of the time dial just to the inside of the indicatortrack fl there are preferably arrows with the notations On and Off to indicate the directions in which the knob 2! should be turned for turning the timer on as in a time setting operation and for turningthe timer off to silence the alarm at the end of a timing operation. It is noted thatthe teeth of gear 26 are omitted over that section which is opposite rdrivinggear 25 when the cam I l is between thepositions shown in Figs. and 7 where only manual operation of the timer shaft 20 is desired.

If desired, a remote electrically actuated alarm maybe sounded at the end of'a time interval and an arrangementthe motor is shut off by -knob 2 l with the shutting oif-ofthe alarm'and-is' turned on again when the timer issetfor a timingoperation. This assures that the motor will be energized only during timing andalarm sounding operations, without the necessity of-any attention by the user of the device exceptthat incident to the manual turningofknobz l 'for theother purposes described.

'What I claim as new and desire tosecure by Letters Patent of the'UnitedSta-tes is:

tween said motor and shaftlincluding aslip friction clutch and a mutilated gear through which said shaft may be driven in one direction an amount limited'to less than one-complete'revolution by reason of the mutilated gear, manual means for turning Jsaid shaftin either dir-ection, such'manualturning being permitted when -the shaft is in driving relation with-the timermotor byreason of the slipping of .saidclutch, an alarm, a cam on said shaft, .a cam follower bearing against said cam for controlling the operation of said alarm, anindicator on :said shaft, agraduated time dial on which said indicator indicates to show the rotary position of said shaft, thecam surface of saidrcam having along raised surface, a short depressedisurface. and-a short-raised surface extending about the "cam-in the'order named in the direction opposite to that in which the cam is adapted to bedriven by the timer motor,and a'stop projection on the cam between the long and short raisedsurfaces whichprevents movement of such stop projection past the cam follower in either-direction, saidttimer motor being-in driving connection with said'ro'tar'y shaft'onlywhen the cam follower-is resting on the long raised portion of said cam, said indicator indicatingat the-zero 'end ofsaid scale whenthe cam follower is in the-short depressed-portion of said cam and at the other end of the graduated scale when the cam follower is on thelong raised portion of said cam and'adjacent the stop projection and said cam'follower' permitting the alarm to sound only whenin the short depressed-portion of said cam.

2. An internal timer com prising'a timer motor, an alarm, a cam follower for controlling said alarm, a graduated time dial, a rotaryshaft, 'a driving connection between. said-timer motor and shaft including a'mutilatedgear on said shaft and a slip friction clutchga cam on said shaft for controlling the operation of the "alarm through the camfollower, an indicatoron said shaft cooperating with said time dial to indicate the time setting of said timer, a man'ual thumbpiece for rotating said :shaft for the purpose of setting the timer and shutting off the-alarm, and

stop means for limiting the rotation 'of said shaft to slightly less than a complete revolution, the arrangement and relative :ro'taryrelation of the parts secured to'therotary shaft'being suchthat the timermotor may drive the shaft onl'y-in'one directionfrom astopp'edmosition where the indicator gives a maximum timeindication on said scale to an alarm sounding position Where the indicator indicates zero on said scale whereat the motor is disconnected from driving relation with said shaft by reason of the mutilated gear and the cam allows the cam follower to move to the alarm sounding position to sound the alarm only in such rotary position, said shaft having a further limited range of rotary movement between the alarm sounding position and the other stop- 7 ped position during which it is disconnected from the timer motor and over which it may be moved manually from alarm sounding position to shut off the alarm.

3. An elapsed time indicator comprising a stationary dial having a circular time graduated scale thereon extending over a substantial portion of a circle and having a radial slit therein in radial alignment with the zero time graduation of such scale, an indicator rotatively mounted behind the dial on an axis concentric with the circular time scale, said indicator having a radial spider portion and a sector-shaped indicator portion of a color contrasting with said dial, the sector portion being secured to the spider portion at one end only and with its free end extending in an upscale direction concentric with the axis of rotation on a radius to permit it to pass through said radial slit when the indicator is rotated, said indicator having a range of rotation from a position where it is completely hidden behind the dial to a position where it is largely exposed with its free end in radial alignment with the upper end of said time scale, means for guiding said sector through the slit when rotated, a timer motor, a

drive connection between said motor and indicator including a slip friction clutch and a mutilated gear by means of which said motor may drive said sector in a downscale direction only between maximum and zero time indication at a rate corresponding to the time graduations, manual means for rotating said sector in either direction over the same range and over an additional range of movement where the sector is hidden behind the dial, and an alarm actuated in response to the arrival of said indicator at a zero time indicating position and cut off by move ment of said indicator in either direction from said last-mentioned position.

4. An elapsed time indicator comprising a stationary dial having a circular time graduated scale thereon extending over a substantial portion of a circle and having a radial slit therein in radial alignment with the zero time graduation of such scale, an indicator rotatively mounted behind the dial on an axis concentric with the circular time scale, said indicator having a radial spider portion and a sector-shaped indicator portion of a color contrasting with said dial, the sector portion being secured to the spider portion at one end only and with its free end extending in an upscale direction concentric with the axis of rota tion on a radius to permit it to pass through said radial slit when the indicator is rotated, said indicator having a range of rotation from a position where it is completely hidden behind the dial to aposition where it is largely exposed with its free end in radial alignment with the upper end of said time scale, means for guiding said sector through the slit when rotated, an alternating current timer motor, a driving connection between said motor and indicator including a slip friction clutch and a mutilated gear whereby the indicator may be driven in a downscale direction at a rate corresponding to said time graduated scale only over the exposed range of movement of the indicator, manual means for rotating said indicator in either direction over its exposed range and over an additional completely hidden range, an alarm device energized by said motor, a cam follower for controlling the operation of said alarm, and a cam rotated with said indicator for actuating said cam follower to permit the operation of said alarm only when the indicator is in approximately a zero time indicating position.

5. An elapsed time indicator comprising a stationary dial having a circular time graduated scale thereon extending over a substantial portion of a circle, and having a radial slit therein in radial alignment with the zero time graduation of such scale, an indicator rotatively mounted behind the dial on an axis concentric with the circular time scale, said indicator having a radial spider portion and a sector-shaped indicator portion of a color contrasting with said dial, the sector portion being secured to the spider portion at one end only and with its free end extending in an upscale direction concentric with the axis of rotation on a radius to permit it to pass through said radial slit when the indicator is rotated, said indicator having a range of rotation from a position Where it is completely hidden behind the dial to a position where its free end is in radial alignment with the upper end of said time scale, means for guiding said sector through the slit when rotated, an alternating current timer motor, a driving connection between said motor and indicator including a slip friction clutch and a mutilated gear whereby the indicator may be driven in a downscale direction at a rate corresponding to said time graduated scale only over the exposed range of movement of the indicator, manual means for rotating said indicator in either direction over its exposed range and over an additional completely hidden range, an alarm device energized by said motor, a cam follower for controlling the operation of said alarm, a cam rotated with said indicator for actuating said cam follower to permit the operation of said alarm only when the indicator is in approximately a zero time indicating position, and means operated in response to the manual rotation of said indicator in a downscale direction beyond its zero time indicating position for deenergizing said timer motor.

HANS SPRINGER.

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

UNITED STATES PATENTS Number Name Date 1,797,072 Caraba Mar. 17, 1931 2,389,908 Hickey Nov. 27, 1945 2,398,015 Leathers Apr. 9, 1946 FOREIGN PATENTS Number Country Date 592,442 Germany Mar. 26, 1932

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