US2670794A - Dual speed interval timer - Google Patents

Description

March 2, 1954 w. P. GALLAGHER DUAL SPEED INTERVAL TIMER 2 sheets-sheet 1 Filed Feb. 26, 1951 w m m m ATTURNEYE March 2, 1954 w. P. GALLAGHER DUAL SPEED INTERVAL TIMER 2 Sheets-Sheet 2 Filed Feb. 25, 1951 INVENTOR.' W6%yd2 M W, X; 1'0" #W ATTORNEYE Patented Mar. 2, 1954 DUAL SPEED INTERVAL TIMER William P. Gallagher, Chicago, 111., assignor to International Register Company, Chicago, 111., a corporation of Illinois Application February 26, 1951, Serial No. 212,737

23 Claims. 1

This invention relates to timing mechanisms, more particularly to the kind for actuating an alarm and/ or a switch after a predetermined interval of time.

In the laboratory, factory, shop, and home there are many operations that have to be carefully timed; that is, they have to be terminated after a predetermined period. Some have to run for a few minutes, others for many minutes. For many such operations the duration has to be reasonably exact regardless of whether the period of operation be very brief or fairly long. Moreover, for some operations the starting and stopping has to be automatic, or the starting effected manually and the stopping automatically. In many such instances, mechanisms such as switches can be operated to initiate and terminate the operation or to merely terminate the operation. For other operations, the starting and stopping has to be effected manually. In the latter instance, the one in charge of the operation may find it necessary to be busy with other matters. Some of these perhaps might be related to the timed operation, others possibly not so related. In any case, attention momentarily may become so completely absorbed in the other matter as to make the attendant oblivious of the passing of the time for terminating the main operation, unless there is some kind of signal actuated to indicate the expiration of the timed operation.

Present practice involves the use of timing devices generally known as interval timers which usually are manually set in motion when initiating a certain operation. These interval timers, upon the completion of the timed period, operate or actuate a signal-visual or audible-after the elapse of the predetermined time for which the device is manually set. When such devices have heretofore been constructed for accurate operation for short intervals, they could not be used effectively for measuring comparatively long intervals of time. On the other hand, devices heretofore constructed for general use in measuring a fairly long interval of time as a rule could not be used for accurately measuring a comparatively short time interval.

The main objects of this invention, are to provide an improved form of interval timer which may be set for accurately measuring time periods of comparatively short duration, as well as time periods of comparatively long duration; to provide improved means for connecting a rotatable time-measuring indicator to a motor so as to vary the relative speed of rotation of said indicator during predetermined portions of its revolution; to provide an improved arrangement of a dial associated with such a time-measuring indicator having within its circumference the markings of both the short and long time periods; to provide manually-actuatable means for setting said time-measuring indicator in operative relationship with a constantly operating motor; to provide improved means for holding said time-measuring indicator from operative relationship with said motor during the setting of the time indicator; to provide an improved signal means associated with said time-measuring indicator; and to provide an improved dual-speed interval timer of this kind which has the minimum of parts, hence economical to manufacture, simple to operate, and accurate in functioning.

In the accompanying drawings:

Fig. 1 is a front elevational of a presently preferred form of interval timer embodying this invention, to which is juxtaposed a positioning pointer on a surrounding housing;

Fig. 2 is an exploded view of the working parts of this improved device;

Fig. 3 is a rear elevation of the embodiment shown in Fig. 1;

Fig. 4 is a side elevation of the same, as viewed in the direction of the arrow shown in Fig. 3, the housing for the dual-speed gearing being shown in section;

Fig. 5 is a front elevation, as viewed from the plane of the line 5-5 of Fig. 4, the uppermost driven gear being broken away to more clearly r indicate the one point of common meshing of the two driven gears;

Fig. 6 is an opposed side elevation of the same, the dual-speed gear housing being in section;

Fig. '7 is a rear view of the same taken on the line 1'! of Fig. 6;

Fig. 8 is a face view of the two integrated driven gears, the view being just the reverse of that shown in Fig. 5;

Fig. 9 is a cross sectional view of the integrated driven gears and the vibrator-control cam as mounted on the time-indicator shaft;

Fig. 10 is an exploded perspective of the two driven gears; and

Figs. 11, 12 and 13 are enlarged fragmentary details illustrative of the gear tooth formation of the two driving gears and the two driven gears, respectively.

The distinctive concept of this invention involves an arrangement of gears between a motor and a rotatable, time-measuring indicator which gears may be selectively set in driving relationship so as to cause the rotation of said timemeasuring indicator at different speeds for successive portions of a nearly 360 degree revolution of the indicator.

Referring first to Figure 2, the preferred embodiment of this invention comprises a manuallyadjustable time-measuring indicator A; andtwospeed drivengearing B which may beselectively meshed with motor-driven driving gearing C so as to cause the time-measuring indicator to re'-- setting in meshing engagement the gearing'B and C, whereupon said shaft will be revolved in the reverse direction by themotor- I71 The-journaled: mounting of this inner endof. the-shaft l5 intthemounting flange 38' has sufficient loose ness ortolerance to permit theouter portionzof the shaft to be cooked or tilted laterall-yaavery smallamount to'facilitate'the speed change from one gear diameter. to another gear diameter, as willlaterappear. The time-measuring indicator A2 also comprises a finger knob l8 and a dial L9 associated'with the shaft I5 to permit an' indicated. amount of; rotation. required. to effect; the operation of:the signal means E aftera predetermined lapse of time.

The shaft i5=has secured thereto a bushing 2e (seeiFig; .9). grooved at 21 for'seating in the bottom of;a slot or recess, 33 inthe plate. 2'! as will bezlateridescribed. The bushing 20 also affords a support for the gearing B Also fixedonthe shaft i5 is the'carn D'axiallyspaced.from; the bushing: 26; At its; outer end the shaft i5: is formed; with an enlargement 22 which is .cut; away at zscandslotted at 2 ito form .a resilientorcompressible hub 25zoyerrwhieh the dial! 9 is-adapted to'be'pushedin asnug push fittto secure the dial to the shaft in proper angular" relationship to correspond with the angular position-of lthe gearing B. The dial has a non-circular;borerhavin'g a fiatspot engagingwith the flat spot 23.

The mounting l li'comprises a-pair of oppositely depressed plates: 26: and. 21' secured togetherby fastening means 28 to provide enclosures .respecs tively for the gearing B- and G. and the gearing (not. herein shown) which connects; the gearing Cfwith. themotor I 7 The plate 25 mounts a threaded'hub--29=whereon is adapted to be screwed a nut: 29a for the' purpose-of attachingthe device to'a suitable-partfof a supporting frame 39 (see Fig. 4"); Lugs: or shoulders: 30, SI and 32: are punched: laterally from the face of the depressedpart of. the plate 25;. Theformer' of these twolugs 3i) and-.3-l;are punched outwardly to. coaet' with slots. inthe aforesaid frame part to insure proper'positioning ofthe, device on the-frame; The latter-f these lugs, namely,- 32, ispunched inwardly tolcoact with a similar lugor shoulder 4.9on the -gearing; Brto limit thez-opposite rotationofthe shaft" l5.

As previously described, the plate 21 is formed with a slot or recess 33- for receivingsthe journal bushing 220 011 the shaft l; topermita-sidewise or. radial deflection. of, this I intermediate: portion of the shaft with respect to the-mounting plate 27. Theshaft has a sufficient-looseness inithe hub. 29. ofouter cover plate. 26. to. permit: the slightangular. cockingof the shaft Aspring 34 secured on and between lugs 35 and 36, struck out from the plate 21, normally urges th bushing 20 against the bottom of the recess 33 whereby the shaft l 5 is properly positioned to normally mesh the gearing B with the gearing C to effect the proper limited rotation of the shaft !5, as will be explained more fully presently. The plate 2.7 alsorprovidessuppofififorftlie motor I? which is=a conventional; synchronous typ'e motor suitably geared to a shaft 31 (see Fig. 2) whereto is attached the gearing C. The plate 2'? also has secured-thereto, at one side of the motor I! and adjacent the cam D, a bracket 38 which forms a part-oi the .signal zmeans E, to be explained presentlyr The finger-knob l8 and the time dial it] may besecuredtogetherin any suitable manner so that they turn as a unit. When the shaft I5 is in: its neutral or starting position, the O on the dial l9 registers with the pointer 39 suitably formedonsome surrounding part of the-supporting frame all Whereon this-interval timer is tobemounted;

Because of the variable speeds at which the shaft I5 is tooperate-bythe meshing of the gearing B and:C. presently to. be. described, the circumferential portion; of the dial.- l9 is divided by; markings and numerals. intotwo. portions. For a, substantialpart of its: circumferencaq the dial; is scored. and. numbered: to represent equal time units.- each of. 15.1-minutes: duration. Another portionof the-dial. eircumferenceis scored to. represent 15? equal, units of; tirne '-each:of;1 minute duratiomrthe-firstiten of these one? minuteintervals,beingmumberemLtolO; Itof course will be: understoodthatithepoint of dividing the dial i9 into the-:respectivapartsland the length of the. timing;periods-.are not critical to thisdisclosure;- The arrangement of these: will be. dependent uponthe requirements. for. which the timer, is: constructed:

The gearing B. comprises: sector-shaped gears ii and 4! ofdifierent diametersconcentrically attached to thebus-hingtwon the shaft 15. These gears are adapted-.to.-:successively mesh" withthe gear 42 andpinienMi-which'constitutethe gearing to. eifectthefast. and slow rotation respectively of-a'thershaft .lfidwith its attached-knob and dial, l 8 and'gle) for the-predetermined portions of its; rotationi.

The gear 40, as herein shown (see Fig, 8) ,,is of a; circumference? slightly more than 18.0. degrees whereas the gearrel 'iS JOfLZ: circumference slightly less than: degrees: Each gear. 49 and-:41 is formed witlraniaxial recess d late-fit overa hub 45:0:1 thebushingifi and 'permit the required disposition thereof in: the proper; angular relationshipto insuretheir successive. and proper meshing with the-gearingifl. Inthergear M the-recess is nonecircular to"fitthenonecircular; hub 45; The gearsj iii andzl are preferably spa'ced'apart axially a; short-.distancecby punching a. spacingicup formation: 43' rearwardly from the web of the largegeari' 50; or by; providingspacing washers between'zthe gears. To. securerthesetwo gears 40 and 41* in their proper angularrelationship, the gear 4!! is formed with a tongue it-which fits in a recess-41in the-gear; 4! when the-gearsare superimposed :upon each-other. These-gears arestaked to the. bushing; 20 :inthe-conventional manner in mechanism a of; thiss k-indu ASzWiH. beenoted. fromaEigs-L 5: andl8, the relative angular. disposition-of;thelgears lfl and 4 I .isgsuch that. one radial; terminus. of thegear 40 slightly overlaps: theadjacentt or: corresponding; radial terminus of the gear 4| whereas there is a circumferential gap between the other radial termini of these gears. This radial overlapping insures a successive meshing of the gear with the gear 42 as the gear 4| passes out of meshing engagement with the pinion 43 during the normal rotation of these gears by the motor H. The radial gap between the termini of these gears 40 and 4| constitutes an angularly extending idling gap indicated at g in Figure 8 to provide for an idling freedom of continued rotation of the motordriven gear 42 and pinion 43 when the shaft |5 has returned to its starting position. The gear 4| has 2. lug 49 struck out from the face thereof to coact with the lug 32 on the mounting plate 26 for limiting the opposite rotation of the shaft l5.

The motor driven gearing C, as already noted, is in the form of a coaxially-arran'ged, integral gear 42 and pinion 43 connected to the motordriven shaft 3! so as to rotate at the predetermined speed.

It will be seen from the foregoing that the motor I? is geared to produce almost a complete revolution of the shaft l5 in approximately 85 minutes, and because of this extremely slow speed of rotation it is desirable that the teeth on the gearing B and C, be of very small tooth size, as shown in magnified form Figs. 11, 12 and 13. Moreover, the very small tooth size and the form of the teeth is important for securing an effective continuity of operation of the shaft l5 as the driving transfer is made from the gear 4| to the gear 40. For the motor-driven gears 42 and 43 and the gear 4| the teeth are preferably sharp or disk is formed with an internal annular cam track 5| terminating in adjacent, oppositelydisposed, radial offsets 52 and 53, which offsets coact with a cam track follower 54 for effecting the desired operation of the signal means E. As most clearly shown in Fig. 8, the offset 52 is in the nature of an outwardly-extending depression or recess, Whereas the offset 53 is in the form of an inwardly-extending shoulder.

The signal means E herein-shown comprises the bracket 38 whereon is formed a vibrator 55 to which is attached an armature 56. The action of this vibrator is controlled by an arm 5"! on which is mounted the cam-track follower 54,

The bracket 38, somewhat in the form of a broad U-shaped member, is suitably welded, soldered or otherwise secured to the mounting plate 21, at one side of the motor so as to dispose the vibrator 55 with the attached armature projecting into the field of the motor I! so as to be acted upon magnetically by the motor field. As previously described the lateral flange 38 of bracket 38 provides a bearing for the inner end of the shaft I5.

The vibrator 55 is herein-shown integral with the bracket 38, being formed by cutting out bordering portions of the base of the U-shaped bracket. The end of the armature 56 is riveted to the vibrator 55 adjacent its outer end. A tempered steel spring extension 58 is secured to the end of the vibrator 55 to dispose the end of the 6 extension for engagement by the control arm 51.

The control arm 5! has one end recessed at 59 and shouldered at 60 (see Fig. 2) to permit the arm to be releasably set in the slot 6| in one of the transverse legs of the U-shaped part of the bracket 38. Such a mounting permits a limited rocking of the arm 51 under the oppositely acting forces of a spring 62 and the cam track follower 54 as the latter is influenced by the cam track 5| of the cam D.

When the aforesaid recessed and shouldered end of the arm 57 is seated in the bracket slot 6|, the arm 51 is positioned to shiftably set the outer free end thereof in a slot 63 (see Fig. 3) in the other transverse leg of the U-shaped bracket 38. A longitudinally-spaced tongue 64 and lug 65 on the arm 5'! are thereby located on opposite sides of the aforesaid bracket leg. The tongue 64 is positioned to engage and depress the spring extension 58 of the vibrator 55 and immobilize the vibrator when the cam-track follower 54 is engaged by the cam track 5| on the cam D." The lug 65 is positioned to retain the spring 62 in position to normally retract the arm 51 to hold the cam-track follower 54 in constant contact with the aforesaid cam track 5|.

This arrangement of the arm 51, so as to be depressed by the coaction of the cam track 5| and the follower 54, thereby forces and holds the tongue 64 against the spring extension 58 and insures an effective silencing of the vibrator 55. so long as the cam-track follower 54 is in contact with the cam track 5|.

It should be understood that although the camactuated arm 5! is herein used to immobilize a magnetic vibrator, the arm 51 could be employed with equal facility to actuate a switch that would close a circuit to some other type of signal-visual or audible-or for still some other purpose.

The operation of the herein-shown embodiment of this invention is substantially as follows:

The motor I1 is connected in an electric circuit and normally is running constantly, unless a switch in that circuit is open.

The dial I9 is normally set at the 01? position when the timer is not in use. The dial is so positioned for the reason that, in order to maintain the tongue 64 on the arm 51 of the signal control means E in position to silence the vibrator 55, the dial I!) has to be turned to shift the cam-track follower 54 out of the offset depression 52 and over the offset shoulder 53 into contact with the cam track 5|. No further counterclockwise movement of the dial I9 is permissible by reason of the contact of the lug 49 on the gear 4| with the lug 32 on the mounting plate 26. In such position the driven gears 4!] and 4| are free of contact with the motor-driven driving gears 42 and 43.

When one desires to make use of this timer to operate a signal (or close a switch or actuate some other device) at the end of a given period of time within the range of the dial Hi, the knob I8 is grasped by the fingers and thumb and turned clockwise. This moves the cam D to disengage the follower 54 from behind the offset shoulder 53 and into the offset depression 52. Instantly, the spring '65 thereupon shifts the arm 51 to re tract the tongue 64 and momentarily frees the action of the vibrator 55 under the influence of the armature 56. The sounding of the vibrator at that moment is assurance that it is in operative condition to effect the desired warning at the end of the time period for which the device is to be set.

Im thiss preliminar g turning of: the: dial? cloolewise, and.-. im the. continuing; turning thereof for itsrsetting; thethumb and finger-engagement; on the. knob. iz8 .ztends=.t r depressathashaft l slightly ra-diallyinithe. recessa33 -againstthe action of the spring; 3.4. This;- will :sufiiciently enlarge; the normalradial.- distance betweenrthe-shaftz l5. andthe axis. of thegearing C to. maintain the-gearingB and C .out. of.- mesh anditherebyavoid any'grating or chattering of the gearing duringthis clockwise rotationiof the. dial l-9. However; the. sloping-.and roundedjorm.oitheextremely fine gear. teethton the.diivinggand.driven.gearspermitsrelative slippage v therebetween. imthis preliminarygsetting. op".- eration. by: the action of the teeth camming; the shaft] 5rsidewisezeven-if theknob- I8 is :not pushed downwardly;

The-.dialz i9 issturnedclockwiseto aposition' to register. with. the. pointer 39. the. dial mar-king corresponding with. the number of minuteszfollowing, which it. is:- desiredz. to. have. the signal sound,.

The limit-of suchclockwiseturning of the dial I 9; .and of coursefthe .shaf-tl5-,,is-the engagement at the. lug, 49,. on-. the gear. 44' withithe lug, 32. on the mounting plate 26... Theiengagement of these lugs; is. by; opposite'faces from. those. which limit thecounterclockwise movement of. the dial-J9 previously: noted..

'llhetinstantithe cametrackzfollower 54 ismoved out of.the oamrtracledepression: 52 the. arm 5] is shifted.totimmobilizethevibrator 55.

When the desired marking onthe dial I9 is brought-: into.:registrationwiththe.pointer 39, the knob: [it isreleased.-. Thereupon the spring 34 pressesthe shaft bushing. 2&1: into. the :base of. the recess 33: and; meshesrone. or the other. of' the sector-shaped driven gears: ML and. 4| with the driving: gear-4% orrthedriv-ing pinion 43-. If the setting, has. been: withini the lit-minute. period shown on the: dial-i lil thev gear 40 meshes with the gean'42, It the. settingghasibeen beyond the-15- minute-marking, on. the. dial. I9; the. gear 4| is meshed with the pinion 43. During. thereverse counterclockwise;rotationrfromthis latter setting, thegear; 40. comes"=into. mesh.. with. the gear 42 as the: gear 4| moves outot meshing. engagement withithepinienA-t (see:1 !ig..5)

Once theknohl8 hasibeen thusiturned to mesh the gearingB-andG, ther-motor l1 beginstozdrive the shaft. I5; in; ai counterclockwise direction. During; the .timethat. the gear. 4.! is inmesh with the. pinion.43 the shaft.- I5 is. rotating; comparatively slow, at the-rate. of. approximately. '70 minutes. for a. little: less. than. 18.0. degrees. However, during; thei-timethe. gear. 40. is.in mesh; with the gear-.42 the shaftvl5l-is rotatinggat. a much faster speed, approximately 180. degrees: in-.15. minutes, i. e., several times as fast as when the gear. 4| meshes with the. pinion. 43...

Itshould. be explained, that the sum. of. the radii.of the-gear 4fltand..the.gear. 42-. isabout. .011 of an inch. less. than. the... sum. of. the radii of the gear. 4Lancl the pinion. Therefore, when the'shaft l5-.- isturned..to set?- thetimer. for v more than. arnfteen minute run, the entering or retreating: engagementonthe gear 41 withthe pinion 43 (duringqth'e :oppositerotationsof theshaft l5) spaoes1the.-- axis; ofr the sha-ft l5 from the axis-of: the-'- moton-drivem shaft. 3-1 sufiicientlyto avoid; any; m'omentarsrscraping of the; gears 40 andzlizaas. thagearekiiandpiniomw?moyzrintmand out oftmeshi.

During: thee revolutiom off; the: shaft; I 5;? by: the motor I1, the cam-track follower 54, contacting the. cam: track. 511,. depresses;- the arm: 51. to; hold the: tongue; 64; against: the: spring extension. 58 so.- as to: prevent; the. operation: of thevibrator 55; ASTSOEJII; as the; follower 5.4- drops: into-the ofiset depression 52 on the camD (see Fig; 89;; the O- on the dial: Hi? meanwhile reaching. the pointer. 39, the'spring; 66 shifts the" arm': 51 to retract.- the: tongue: 64- and; free. the: vibrator 55 to: sound:. The vibrator wills continue: to sound until the dial. I9 is; turned. for: a resetting: or is shifted (counterclockwiseh so as to move the cam; track follower 54. up. oven the shoulder; 53: onto theicamtrack 5k.

Variationsaandimodificationsiin the details of the-structurehnd arrangement of theparts -may be resorted-tmwithin:the-spirit and coverage of the appended claims.

1-. An intervaltimer comprising, a; motor, a time-measuring device.- having, rotary movement, multiple: speed: means. for connecting: said; timemeasuring device with said motor comprising driving? gearing,- connected with said motor; a plurality ofa circular. sectoresha-ped. drivengears of different diameters connected to said time measuring device; and; means for establishing different. meshing; relations between saidv driven gearsand said-driving, gearing for operating; said device at variable: speeds duringpredetermined portions of. its rotary-movement.

2. An interval timer comprising; a: motor, a time-measuring device-having; rotary movement, multiple. speedmeansgfor connecting; said timemeasuring, device. with saidmotor. comprising driving gears.- connectedf with-said motor, a; p1u.- rality: of; concentrically mounted circularseotorshapeddrivengears. of "different diameters cone nected to said. time measuring device, andxmane ually operated meansv for. establishing different meshing? relations: between said driving. and driven gears for operating said device at: variable speeds during predetermined portions of; a 360 degree revolution;

3. An interval timer comprising, motor-driven gearing; a time-m'easuring, indicator, a pair of concentrically mounted circular sector-shaped driven gears of; diifering diameters movable: into and out. of mesh with. said motor driven gearing to rotatesaidiindicator, and-manual means for meshing either oner'of; said: circular driven gears with: said. motor-driven gearing so as to: effect the operationiofsaidrin'dicatbr rat variableispeeds during predetermmedmortions? of? its revolution.

4'. An interval timercomprising,.a' mounting, motor-driven continuously rotating gearing1jour= naled on' said mounting; a time-measuring indircator journaled" on isaidmounting; a" pair of con-.- centrically mounted"circularsector shaped driven gears: of differing diameters movable into? and out of. mesh withasaid motor driven gearing; for rotatably" connecting said: indicatorwith: said gearing,manuallmeansforimeshing either one of said gears-With saidrgearingf so as to effect the operation of said indicator" at variable speeds during predetermined" portions' of its; revolution, and coacting shoulders: associated with said mounting and saidrindicator for limiting the op posite rotation of said indicator torapproidmately 360: degrees.

51 An intervaltimerrcomprising', motor driven continuously rotating; drivin'ggearing, a" timee measuring; indicator;v pair: of: circumferentially spaced. concentrica'lly arranged sector-shaped gearsa'oftdifferingdiametersfrconnectablezto rotate said}: indicator; the circumferential '& spacing he'- 9 tween adjacent ends of said sector-shaped gears defining an idling gap in which said driving gearing is adapted to have idling rotation, and manual means for meshing said gears with said motor-driven gearing so as to effect the operation of said indicator at variable speeds during prediameters for rotatably connecting said indicator to said gearing, the circumferential spacing between two adjacent ends of said sector-shaped driven gears defining an angular idling gap in which said driving gearing normally has idling rotation, manual means for meshing said gears with said gearing so as to effect the operation of said indicator at variable speeds during predetermined portions of its revolution, and coasting shoulders on said mounting and one of said gears adapted to limit the opposite rotation of said indicator to approximately 360 degrees.

'7. An interval timer comprising, a mounting, a plurality of concentrically mounted motor operated driving gears journaled on said mounting, a radially-deflectable shaft journaled on said mounting, a plurality of concentrically mounted driven gears of differing diameters on said shaft adapted to successively mesh with said motor operated driving gears, and means for manually effecting a radial deflection of said shaft to momentarily disengage said driving and driven gears to permit a rotation of said shaft to so set the engagement of one of said gears with said gearing as to predetermine the degree and speed of rotation of said shaft by said motor-driven gearing, certain of said gears having rounded teeth to permit forced slippage of said gears.

8. An interval timer comprising, a mounting, motor-driven continuously rotating driving gearing journaled on said mounting, a radially-deflectable shaft journaled on said mounting, a pair of circumferentially-spaced concentricallyarranged sector-shaped driven gears of differing diameters fixed on said shaft and adapted to.successively mesh with said motor-driven gearing,

the circumferential spacing between adjacent ends of said sector-shaped driven gears defining an angularly extending idling gap in which said continuously rotating driving gearing normally has idling rotation and means for manually effecting a radial deflection of said shaft to momentarily hold said sector-shaped driven gears from engaging with said driving gearing while effecting a reverse rotation of said shaft to so set the engagement of one of said gears with said motor-driven gearing as to predetermine the degree and speed of rotation of said shaft by said motor-driven gearing.

' 9. An interval timer comprising, a mounting, motor-driven gearing journaled on said mounting, a shaft journaled on said mounting, said mounting being recessed adjacent the journal of said shaft to permit said shaft to be radially deflected, gears of differing diameters on said shaft adapted to successively mesh with said motor-driven gearing, and means for manually effecting a radial deflection of said shaft to momentarily disengage said gears to permit a rotation of said shaft to so set the engagement of one of said gears-with said gearing as to pre- 10 determine the degree and speed of rotation of said shaft by said motor-driven gearing.

10. An interval timer comprising, a mounting, motor-driven gearing journaled on said mounting, a shaft journaled on said mounting, said mounting being recessed adjacent the journal of said shaft to permit said shaft to be radially deflected, gears of differing diameters on said shaft adapted to successively mesh with said motor-driven gearing, resilient means normally urging said shaft into an axial position to maintain the meshing of said gears and gearing, and means for manually effecting a radial deflection of said shaft to momentarily disengage said gears to permit a rotation of said shaft to so set the engagement of one of said gears with said gearing as to predetermine the degree and speed of rotation of said shaft by said motor-driven gearing.

11. An interval timer comprising, a mounting, a motor, a time-measuring indicator journaled on said mounting for rotation through nearly a complete revolution from a starting position, multiple-speed gearing for connecting said indicator to said motor for operating said indicator at variable speeds for predetermined portions of its revolution, manual means for turning said indicator away from said starting position to set said gearing for effecting the desired operation of said indicator, a device controlling arm, and a cam rotatively synchronized with said indicator to hold said arm in a retracted position when said indicator is rotated away from its starting position but release said arm when said indicator is in its starting position.

12. An interval timer comprising, a mounting, a motor, a time-measuring indicator journaled on said mounting for rotation through nearly a complete revolution from a starting position, multiple-speed gearing for connecting said indicator to said motor for operating said indicator at variable speeds for predetermined portions of its revolution, manual means for turning said indicator away from said starting position to set said gearing for effecting the desired operation of said indicator, a device controlling arm, a cam rotatively synchronized with said indicator to hold said arm in a retracted position when said indicator is rotated away from its starting position but release said arm when said indicator is in its starting position, and means for rendering said arm inoperative when said indicator is rotated slightly opposite the direction for setting the same.

13. An interval timer comprising, a mounting, a motor, a time-measuring indicator journaled on said mounting for rotation through nearly a complete revolution from a starting position, multiple-speed gearing for connecting said indicator to said motor for operating said indicator at variable speeds for predetermined portions of its revolution, manual means for turning said indicator away from said starting position to set said gearing for effecting the desired operation of said indicator, a cam connected to rotate with said indicator and having an annular track of nearly 360 degrees terminating in a startingpoint recess, a device controlling arm positioned adjacent said cam, and a cam-track follower on said arm engageable with said track when said indicator is rotated away from its starting point whereby said arm is held inoperative during the rotation of said indicator toward or away from said starting position but is released by the seating of said follower in said cam track recess when driven gears being sufiiciently greater than the sum of the radii of the other said sector-shaped gear and the other motor-driven gear to effect a radially tilting of said device when said one sector-shaped gear and the respective motordriven gear enter into or recede from meshing engagement and thereby avoid scraping of said other sector-shaped gear and its respective motordriven gear.

22. In an interval timer, the combination of a synchronous electric motor, driving gearing connected to said electric motor to rotate continuously therewith, a time measuring device, and a driven gear set connected with said time measuring device comprising gears of different diameters adapted to be meshed with said driving gears, said driven gear set comprising an idling gap in which said driving gearing normally has idling rotation.

23. In an interval timer, the combination of a synchronous electric motor, driving gearing connected to said electric motor to rotate continuously therewith, a time measuring device, a driven gear set connected with said time measuring device comprising driven gears of different diameters and an idling gap between two of such gears in which said driving gearing normally has idling rotation, and means for meshing said driven gears with said driving gearing for driving said time measuring device at diflerent constant, uniform rates of speed, certain of said gears having rounded teeth to permit forced slippage of said gears.

WILLIAM P. GALLAGHER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,498,174 Kennedy June 17, 1924 1,902,508 Kearsley Mar. 21, 1933 1,926,190 Borden Sept. 12, 1933 1,961,417 Gains June 5, 1934 2,050,614 Kerr Aug. 11, 1936 2,122,057 Gains June 28, 1938 2,261,723 Hofiman Nov. 4, 1941 2,281,553 Bennett May 5, 1942 2,525,440 Akeley Oct. 10, 1950 2,543,032 Lavianna Feb. 27, 1951 2,547,634 Faustini Apr. 3, 1951 2,565,017 Brown Aug. 21, 1951

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