US2367016A - Timing apparatus - Google Patents

Description

1945. w. P. GALLAGHER TIMING APPARATUS 3 Sheets-Sheet 1 Filed Aug. 14, 1941 Jam 1945. w. P. GALLAGHER 2,357,016

TIMING APPARATUS Filed Aug. 14, 1941 3 Sheets-Sheet 2 Jail. 9, 1945. w. P. GALLAGHER 2,367,016

TIMING APPARATUS Filed Aug. 14, 1941 5 Sheets-Sheet 3 V aZhgfier 4 fl w, r (Yum roastsa maists 2 um'rap s'rA'rss PATENT OFFICE 2,867,016 memo arrsns'rus William r. oslla nm'clu o. nl., sensor to International Register-Company, 11.corporation'ofjl llineisv Application august 14, 1941, Serial No. 400,118" 22 Claims. (a. 161-23) present invention relates to timin appaand' more particularly to interval timerscan range or the a like for automatically controlling thestarting and stopping of a cooking operation. The invention is concerned primarily with providing improved means for minimizing or avoiding the drag load which most of these interval timers impose upon the alternating; current synchronous motor and the time train/driven therefrom. The majority of the interval timers of the prior art utilize a friction clutch to transmit the driving torque from the, time driven meansto the manually settable device which determines the length of the desired time interval. This friction clutch affords a slippage connection which. enables the manually settable device to be turned back counter .to the rotation of the time. driven means when setting up thedesired time interval. It also afiords a s1iDlIe8. 'connection which enables the manually settable device to stop mtg.

tion in a predetermined normal position: after signalling the lapse of the v val, without stopping the continuous operation or the electric motor or other time: driven In the months or years of" continuous operation of the electric motor, the frictionclutch is under going a slipl s operation practically all of the time. This imposes .a on the electric motor and on the time trainiof re duction gearing extending from the. motor to'the friction clutch. Such continuous H I causes increased current consumption. the electric motor, results in a more rapid wear of the motor and ofthe' ing. Furthermore, such continuous results in muflzwm 01 the 'cliitiilni":

impairing itslife andthe ldiustmentiofzthe springloadthemon. i

set to actuate a signal device or My improved construction avoids each of the foregoing objections and limitations present in these prior friction clutch arrangements.

My improved construction serves to free the time actuated driving element from substantially all torque or friction drag during the normal condition of the apparatus when the manually settable element is not being driven.

Diflerent preferred embodiments of my invention are illustrated in the accompanying draw- 18s in which:

Figure 1 is a fragmentary front view of an electric clock embodying my improved timing apparatus, different portions being broken away at diflerent-levels to illustrate various details of the construction;

Figure 2 is a fragmentary perspective view showingthe driving relation between the time actuated driving element and the manually settable interval timer;

l 'igureaisafragmentaryaxialsectionalview taken approximately on the plane of the line 3-3 of Figure 2:

'Flgureiisasimilarsectionalviewshowingthe driving and driven elements in their free-wheeling or idling relation;-

Figure5isasideviewandligures6and7are fragmentary front elevational views showing one preferred embodiment of gong striking mechanism adapted to be actuated bythe interval timer' 'Flgl lre 8 is a similar view on a'large scale showing a circuit controlling switch arranged to by the-interval timer: 35 Figure 9 is a fragmentary view illustrating anpreselected "soapproximately on the plane of the line Ill-ll 'ofFigure' 9, and showing other arrangement of circuit controlling switch adapted to be actuated by the mechanism illustrated in Figures 5 and 6. v -Figure '10 is atransverse sectional view taken a typical switch and buzzer.

-,' Figure 1 illustrates the left hand portion of a typical electrical timing apparatus fol-electric and the like. This general form of electrical timing apparatus is disclosed in the prior patent of myself and Mr. Alfred W. Gardes, No. 2,802,625; issued November 17, 1942, and in my prior Patent No. 2,301,942, issued November 17, 1101942. A housing through which appears the dial 22 of the clock,- this'dial having the usual hour and 2| has a large central opening fractional, hour markings, and the hour and sninutehands 24 and 2| respectively. A resetting knob 2| extends forwardly from the front side of the cover glass 21, this knob being operativfetoresetthehands ofthe clockiftheclock motor should step by reason of current failure or any other cause.

Concentric with the clock dial are the two rotatable adjusting members 2! and 20 which are settable to different positions to predetermine the starting and stopping of the cooking operation. The adjustable member 21 is prefer: ably in the form of a continuous ring surrounding the clockdial and bearing the notation Stop cooking. The ring is formed with an outwardly projecting actuating knob 28, preferably located adjacent to the above notation. Extending inwardly from the ring in registration with this knob is a pointer formation 28" which is adapted to register with the hour and fractional hour markings 23 on the clock dial in the different angular positions to which the adjusting ring is moved. The other adjusting member 28 may likewise be in the form of a continuous ring, surrounding the ring 28, although in the preferred construction the member 29 is in the form of an arm having a knob or handle extremity 2! which is of substantially the same size and shape as the knob ll on the ring 28. An inwardly extending pointed formation ll" on the adjustable member I! overlies a portion of the adjusting ring 28, and is adapted to register with a second series of hour and fractional hour markings 3| provided on the adjusting ring 26. These latter marks designate the Cooking hours" i. e. the length of time that the cooking operation is to continue, the adjusting member 20 being movable to different ones of these marks for adjusting the length of the cooking time period. The manner in which these two adjusting members 28 and 29 are set, and the particular mechanism through which these settings automatically control the starting and stopping of a cooking operation, are clearly set forth in the aforementioned copending applications identified above, and hence there is no need of duplicating that portion of the disclosure here.

The electric clock and other time driven elements of the apparatus are driven by the electric motor Bl (Figure 9) which, in almost all instances, will be a synchronous alternating current motor of any preferred construction, such as are commonly employed in electric clocks and the like. The interval timer constituting the present invention is illustrated as being disposed to the left of the clock 22 (Figure 1), and is arranged to be driven from the time train of the electric motor and electric clock through a large gear Ill which meshes with pinion I12 rotatably mounted on a suitable supporting shaft I11. As shown in Figure 3, the upper end of said shaft I13 is supported in a frame plate I14, and below the pinion I12 the shaft is supported in a frame plate 49. Rotating with the pinion I1: is a time driven frictional driving wheel I15. This driving wheel has a wedge-shaped periphery which is adapted to effect peripheral driving engagement with a cooperating frictional driven wheel I11. The latter is mounted on a spindle I" which carries a manually rotatable knob 44 through which different time settings can be given to the driven wheel I11. The knob 44 is mounted on the spindle l1! exteriorly of the casing 2i, and has a flanged inner portion which is marked with minute graduations 44, ranging say from to 60. These marks are adapted to be brought into registration with an index pointer 45 on the casing II when it is desired that the interval timer shall sound an audible alarm uponthelapoeofaselectedtimeinterval. Rigidlyanchoredtothelower portionof thespindle I10, soastorotatedirectlywiththe settingknob 44, is a time settable tripping arm I. A hub IN securedtothearmlllhasadrive fltover the splined portion of the spindle I". Rotary motion is transmitted from the large frictional drive wheel ill to the time settable arm I through the instrumentality of a drive stud I". This stud is rigidly anchored to the arm Ill and projects forwardly therefrom through apertures I" formed in the friction wheel I11. The apertures Ill are elongated radially of the wheel or made sufliciently larger than the drive stud I that the friction wheel is capable of axial mm ing movement relatively to the stud, and is also capable of a limited amount of wabble motion relatively to the stud.

The friction wheel I11 is compoaed'of two thin cup-shaped washers or disks III preferably composed of spring tempered stainless steel. The two disks are duplicates, each comprising a cupped central portion Ill and a flat peripheral flange portion In. The opposin cupped portions I82 of the two disks are staked over a hub Ill. Also secured to said hub, over the outer sides of the diaphragms, are washers or backing disks Ill. The hub Ill is capable of sliding axially along the spindle Ill, and is also capable of a slight wabble motion relatively thereto, in order to accommodate the freedom of movement referred to in connection with the driving stud I" and driving slots Ill.

The peripheral flanges I" of the two disks or diaphragms are normally held pressed together under substantial resilient pressure. The frictional driving pinion Ill transmits a drive peripherally to the friction driven wheel ill by spreading the peripheral flanges III, III apart and establishing a frictional grip with the driven wheel between these flanges, as clearly shown in Figure 3. The beveled periphery'of the driving pinion I15 functions in the manner of a rolling wedge for spreading the flanges I, III apart in the progressive rotary motion of the driven wheel. It will be understood that there is a flexure of each disk substantially at the point of frictional engagement, so that the two disks are not bodily separated from each other but only a limited area of the material in each disk is rolled or flexed away'from the other disk in the general region of the driving pinion Ill. This establishes line'contact between these two friction wheels at the opposite shoulders ill of the beveled pinion. These two lines or circles of contact insure an accurate, closely maintained pitch ratio between the driving wheel and the driven wheel so that there is no objectionable .variation in the gear ratios between these two wheels in the manufacture and operation of the device.

Formed at one point in the periphery of the large friction wheel I11 is a clearance pocket I where the driving pinion Ill loses frictional driving engagement with the large wheel, resulting in the driving pinion rotating idly within the clearance pocket without imparting rotary motion to the large wheel. This clearance pocket is formed by punching outwardly projecting humps or indentations I" in the flange portions I of the two disks Ill, and arranging these humps in oppositely facing relation to form the clearance pocket. Figure 4 illustrates the position of the parts when the clearance pocket Ill hammer 201 is carried on one end of has revolved around into registration with the small driving wheel- I10, this being the normal position of the at which time the driving wheel rotates idly in the clearance pocket withoutimpartingrotarymotiontothelargewh'eel I11. However, as soon as the large wheel "1 is rotated through a manual setting operation performed by turning the knob 00, the frictional driving relation is reestablished between the small friction wheel I10 and the large friction wheel I 11, so that the small wheel begins to drive the large wheel back in the reverse direcv tion for restoring the large wheel to its original position, i. e., with the clearance pocket I04 registering with the small wheel I10. The driving ratio between the small wheel 'and the large wheel is such that the large wheel isqotated through one complete revolution in substantially 60 minutes, corresponding to the markings on the knob 04.

The tripping arm I03 which rotates concurrently with the knob 00 and friction wheel I" may be arranged to trip a striking hammer for soundingia gong, or it may be arranged to close switch contacts for energizing a buzzer, or it may be arranged to perform other signal functions. In the embodiment illustrated in Figures 5 and 6 this tripping arm is arranged to trip a striking hammer for sounding a gong. In this embodiment, the outer end of the arm I03 carries a pin 203 on which are mounted a large roller 200 and a smaller roller 200. The large roller is adapted to cock a striking hammer 201 to cocked position in the operation of manually setting the device for signalling the lapse of a predetermined time interval, and the small roller 00 is adapted to trip a retaining latch 200 hich releases the gong hammer at the lapse of the predetermined time interval. The striking hammer 201 is adapted to strike a gong 200 which is shown as surrounding the electric motor 0|, such arrangement enabl n a more compact construction to be obtained. The gong a flexible reed or leaf spring 2|0 which has its other end secured to a rocking plate 2. This plate, together with a companion plate 2|2 spaced laterally therefrom, form a rocking frame which is mounted for rocking movement on the rearwardly projecting portion of the shaft I13. A spacing post 2|: has its ends riveted to the plates 2| I and 2|2 for joining said plates into a rigid frame. A tension spring 2 has one end hooked to a. frame post 2|0 and has its other end hooked to an apertured arm 2|0 extending from the plate 2| I, this spring tending constantly to rock the frame 2| |-2|2 in a direction to swing the hammer 201 against the gong 200. A stop lug 2|1 projecting rearwardly from the plate 2|2 is adapted to strike a stationary stop shoulder 2|0 on the supporting frame at an instant just before the hammer 201 strikes the gong 200, whereby the actual striking of the gong occurs by spring fiexure of the leaf spring 2|0 when the stop shoulders 2|1, 2|0 come into engagement, The rocker frame plate 2|2 is formed with a laterally and downwardly bent arm 22|, at the extremity of which is formed a cam slope 222 ending in a raised cam dwell 223. The roller 204 on the manually settable tripping arm |03 is 'adapted to roll under the cam hump 223 for swinging the hammer carrying frame 2, 2| 2 upwardly to a latched position, as shown in Figure 7. Upon the tripping of this hammer carrying frame from said latched the hammer is swung downwardly to striketho gong 200.

' constantly to urge the latch latching in a counterclockwise'direction, as viewed in Figure 6. A shouldel- 220 on the latch is adapted to snap under the arm 22| of the hammervframe when the hammer frame has been raised to cocked position by the action of the roller 200 cam h'ump 223. A finger 22| rojecting upwardly from the rear end of the shoulder 220 is adapted to strike the edge of the arm 22| for limiting the swinging movement of the latch 200 when the shoulder 220 assumes its latching position under the arm 22|. A circular recess 23| in the forward edge of the latch 200 is adapted to be engaged by the small roller 200 on the tripping arm I03 when this tripping arm has been time-driven back to its zero or normal position. Such engagement of the small roller against the circular recess serves to oscillate the latch 200 in a clockwise direction, thereby withdrawing the latch shoulder 220 from the arm 22| and permitting the hammer frame and hammer to snap downwardly fo'r sounding the gong.

Referring to the operation of this embodiment, the normal position of the parts is illustrated in Figure l. The knob 44 normally'stands with the 0 marking 00' in registry with the index pointer 00, thus showing that the interval timer is in a normal, non-set condition. At this time. the tripping arm I03 with its rollers 234 and 200 occupies a position which holds the small roller 200 pressed into the circular recess 23| of the latch 200, with the latch pressed to an extreme right hand position abutting against the hub I12 Joining gear l12'and friction wheel I10 (Figure 1). Such abutment of the pawl finger 223 against the hub I12 establishes a limi stop which determines when the knob 00 is in its normal or 0 position. In this position of the knob and of the tripping arm I03, the clearance gap I in the large friction wheel I11 is in direct istration with the small friction wheel I'll. Thus, there is no appreciable friction. contact between the peripheries of these two wheels.

The small driving wheel nil revolves idly or in a free-wheeling relation to the stationary large wheel, so that friction load or torque drag is imposed on the driving wheel I10 in the normal position of the interval timer. Assume now that the housewife desires to set up the interval timer for sounding the lapse of an interval of say twenty minutes. She revolves the knob 04 in a counterclockwise direction to bring the 20 marking on the knob into registraiton with the index pointer 00. This rotates the knob 40, large friction wheel "1 and tripping arm I03 concurrently through approximately one-third of a revolution. As the tripping arm starts this movement toward the left, the latch pawl 200 swings directly therewith until the forward hammer supportdrop the arm 22| down over the latch shoulder 22! in the operation of latching the hammer carrying member in its cocked osition, as shown in Figure '1. In setting the device for a twenty minute interval, the tripping arm I" is carried beyond the cam hump 228 down to approximately the dotted line osition shown in Figure 7.

This setting rotation of the parts also interrupted the free-wheeling relation between the friction wheels I15, I11 by revolving the clearanoe gap I in a counterclockwise direction away from the driving wheel I". In such mtation the peripheral flanges I" of the large friction wheel are yieldingly spread apart with a progressive rolling motion which maintains both peripheral flanges pressed with a tight frictionai pressure against the circles of contact "I on the driving wheel I12. "This setting motion is counter to the direction of driving influence of the driving wheel I", the latter tending to rotate the driven wheel I11 in a clockwise direction, as indicated by the arrows in Figure 1. Hence, as soon as the counterclockwise setting motion has been stopped at the 20 minute marking, the driving action of the wheel I'll immediately starts rotating the large friction wheel in a reverse or clockwise direction for slowly rotating the parts back to their normal position. shortly before the lapse of the 20 minute interval, the small roller 20! moves into engagement with the circulan recess Ill in the latch Ill, thereby swinging this latch to its releasing position (Figure 6) at the lapse of the 20 minute interval. It will be evident that a relatively close degree of secure: can be obtained with respect to the time that the latch shoulder 22. releases the arm 22i of the hammer carrying member. Upon this tripping of the latch, the gong 209 is sounded for indicating the end of the twenty minute interval. The friction wheel I11 continues to revolve through a short additional distance for bringing the clearance pocket I" into registration with the driving friction wheel H5, thereby interrupting the peripheral driving engagement between these two wheels. This small additional motion also carries the finger 229 of latch 20! back against the hub I12 of gear I12 for establishing a limiting stop in such direction of motion.

The ability of the driven friction wheel lll to shift axially and to wobble slightly, as a resuit-of its floating mounting and the loose fit between the pin I88 and slots "1, enables this driven wheel to adapt itself to any inaccuracies of assembly ormotion of the parts, and to maintain the proper free-wheeling relation and the proper clutching relation without any binding or abnormal wear of the two friction wheels or their mountings.

Figure 8 illustrates a modified construction in which the manually settable tripping arm I" is arranged to actuate electrical contact apparatus for controlling an electrically energized signal or other electric circuit. In this embodiment the construction is the same as that described above except that the end of the spring arm 2 Ill carries movable contacts 224 and 2" instead of the clapper or hammer 201. Contact 234 is adapted to cooperate with stationary contact 234', and contact 225 is adapted to cooperate with stationary contact 235'. The circuit 224' would only be closed when the rocker frame 2, M2 was maintained in the raised position illustrated in Figure '1. Where such a circuit is intended to give audible sounding upon the lapse through contacts 234,

ammo

ofaselecte timeintervahtheeimliteouldbe arranged to energl a solenoid operated bell strikerwhichwoulddropandmndthebellupal the opening of contacts 2M, 2" at the lapse of theselectedtimeinterval. Theotherccntactl "I, ll! may be adjusted for effecting a momentarycloeureonlyatthe instantthattheroeker frame snaps inwardly to the position shown in Figure 6 (corresponding to the inertia impulse of the hammer 201 striking the gong 2), or they may be adjusted for maintaining continuous closure during the entire time that the rocker frame occupies its normal position (Figure 6). In the first instance, the momentary closure of the contacts may be arranged to energize a single-stroke bell. In the latter instance, the contacts may be arranged to govern arelay or perform any desired signaling or control nmction Figures 9 and 10 illustrate another modified embodiment using a different form of signal control mechanism. The driving relation to the manually settable tripping arm I" is identical with that described in connection with the first embodiment, but the tripping arm has a pointed extremity 228 instead of carrying the rollers 2, 2". This pointed extremity is arranged to actuate a simplified form of signal operating mechanism. Such latter mechanism is substantially identical with that disclosed in the aforementioned prior patent of myself and Alfred W. Gardes, No. 2,302,625. Said operating mechanism comprises an operating lever I which is pivoted on a pin 2 extending upwardly from the frame plate ll, this lever member being yieldingly held in the normal position illustrated by a tension spring 242 which has one end hooked to an apertured arm 2 extending from said lever, and which has its other end hooked to'a lug 2" projecting up from the plate ll. The pointed exso tremity of the time settable tripping arm I" is adapted to cooperate with a corresponding wedgeshaped formation 2" on the operating lever I, this occurring just before the settable arm I arrives back in its normal position in engagement with the lug or strop 2" projecting outwardly from the frame plate 49. When the time settable arm is restored to this normal position the clearance pocket I is in registration with the driving friction wheel I", as previously described. The outwardly extending arm of the operating lever 2H carries a projecting roller 2|! composed of insulating material. This roller is adapted to actuate a snap switch 252, best shown in Figure 10. The switch is mounted on an insulating base 2", and comprises a stationary contact Ill and movable contact 2 adapted to snap into and out of engagement with the stationary contact. This switch may be of special construction for securing a snap action between the contacts, but the details thereof are fully described in the aforementioned prior patent and need not be repeated here.

The snap switch 252 controls the circuit of a signal buzzer 201 which is shown as comprising a core 202 and a winding 2" mounted thereon, this core and winding constituting the movable element of the buzzer. The core is composed of a magnetic metal, and formed in the lower end thereof is a guide bore 264 which has a sliding fit over a stud 2" projecting laterally from the frame plate 40. The stud 2" is preferably composed of brass or other non-magnetic metal. The frame plate II is composed of a magnetic metal so that when the core 262 is energized it tends to move axially toward the plate ii. A compression spring 26 interposed between the inner end of the stud 265 and the end of the bore normally holds the core and winding in a retracted position as shown. The other end of the core 202 is formed with a guide pin 2 which has a slidable fit in a guide bore 269 formed in an adjustable guide screw 21 I. Said screw threads through a tapped hole in the upper frame plate 41 and is adapted to be locked in any vertical position of adjustment by a lock nut 212. The screw 2'" is preferably composed of brass or other non-magnetic metal. The pressure of the spring 268 normally holds the shouldered end of the core against the adjacent end of the guide screw. It will be understood that the winding 263 is energized by the alternating current which operates the synchronous electric motor 6|. Hence, the movable buzzer unit 262-283 tends to vibrate wtih the same frequency as the alternating current.

In this latter embodiment, when the tripping arm I" arrives in proximity to the stop 2" the wedge-shaped outer end 283 of said arm engages the wedge-shaped formation 246 on the lever 2, thereby rocking said lever in a counterclockwise direction with the continuous motion of the tripping arm I 83. Such rocking movement of the lever 2 operates through the insulating roller 25l to close the snap switch 252, as described above. The snap switch is only held in its closed position for a brief time, say from 10 to 30 seconds or so, because of the small area of contact between the wedge-shaped end 283 of the arm Ill and the wedge-shaped formation 246 on the lever 2", and also because of the adiusted position of the snap switch 252 relatively to the path of travel of the roller l. During this closed condition of the snap switch, the buzzer device 26l sounds its signal by a continuous vibration. When the wedge-shaped, outer end of the tripping arm I83 slips past the wedgeshaped portion 216 of the lever 2, the lever 2 is immediately restored to normal position, and the tripping arm I83 is thereafter brought to a stop against the shoulder 24! with the clearance gap I94 of the driven wheel lTl registering with the driving wheel I15. The general construction and operation of the signal and signal operating means illustrated in Figures 9 and 10 are described in greater detail in the aforementioned prior Patent No. 2,302,625.

While I have illustrated and described what I regard to be the preferred embodiments of my invention, nevertheless it will be understood that such are merely exemplary and that numerous modifications and rearrangements may be made therein without departing from the essence of the invention.

I claim:

1. In timing apparatus for governing the operation of a device at a preselected time, the combination of time-selecting means movable from a normal position to different time-selecting solely by said clearance pocket I selecting means has been restored to its normal positions and operable to govern said device, v

time-driven means for driving said time-selecting means from said different time-selecting positions back to said normal position, mechanism for transmitting driving motion from said time-driven means to said time-selecting means comprising driving and driven members rotating on separate fixed axes and adapted to have direct driving engagement, and means for substantially interrupting said direct driving engagement when said time-selecting means has been restored to its normal position.

2. In timing apparatus for governing the operation of a device at a preselected time, the combination of.time-selectlng means movable from a normal position to different time-selectin! positions and operable to govern said device, time-driven means for driving said timeselecting means from said diflerent time-selecting positions back to said normal. position, mechanism for transmitting driving motion from said time-driven means to said time-selecting means comprising driving and driven members rotating about fixed axes and adapted to have peripheral driving engagement, and a clearance gap in the periphery of one of said members for substantially interrupting said driving engagement when said time-selecting means has been restored to its normal position. 1

3. In timing apparatus for governing the operation of a device at a preselected time, the com ination of time-selecting means movable from a normal position to diil'erent time-selecting positions and operable to govern said device, continuously rotating time-driven means for driving said. time-selecting means from said different time-selecting positions back to said normal position, mechanism for transmitting driving motion from said time-driven means to said time-selecting means comprising driving and driven wheels rotating about spaced fixed axes and adapted to have frictional driving engagement substantially at their peripheries, and a clearance pocket in said driven friction wheel for substantially interrupting said driving engagement when said time-selecting means has been restored to its normal position.

4. In an interval timer for governing the operation of a device after a selected time interval, the combination of time-selecting means manually settable from a normal position to different time-selecting positions and operable to govern said device, continuously rotating timedriven means for driving said time-selecting means from said different time-selecting positions back to said normal position, mechanism for transmitting driving motion from said timedriven means to said time-selecting means comprising driving and driven wheels rotating on separate fixed axes and adapted to have frictional driving engagement substantially at their peripheries for transmitting a speed reducing drive, one of said wheels comprising spring pressed gripping surfaces adapted to establish resilient frictional engagement with the other wheel, and a clearance pocket in said driven friction wheel in which said driving friction wheel is adapted to idle during the non-operating intervals of said timer, the driving engagement between said wheels being interrupted when said timeposition.

5. In an interval timer, the combination of a time-selecting member, time driven means, and a driving connection therebetween comprising driving and driven friction wheels having peripheral driving engagement, one of said wheels comprising a pair of resilient discs, and the'other of said wheels engaging between said discs and causing flexure of said resilient discs substantially at the point of peripheral engagement between said wheels.

6. In an interval timer, the combination of a manually actuated time selecting member, time driven means for driving the latter, and a driving connection therebetween comprising driving and driven friction wheels having peripheral driving engagement, prising a contact with each other substantially at their edges, and the other of said wheels having a wedge-shaped periphery producing a rolling spreading action between the peripheral edges of said resilient discs by outward fiexure of the metal in said resilient discs substantially at the point of peripheral motion transmitting engagement between said wheels.

'7. In an interval timer, the combination of a manually actuated time selecting member, time driven means for driving the latter back to a normal position, and a driving connection therebetween comprising driving and driven friction wheels rotating about eral driving engagement, one of said wheels comprising a pair of resilient discs, the other of said wheels engaging between said discs, and a clearance pocket in said driven wheel in which said driving wheel is adapted to idle during the nonoperating intervals of said timer the driving engagement between said wheels being interrupted solely by said clearance pocket when said time selecting member has been restored to its normal position.

8. In an interval timer of the class described, the combination of a manually actuated time selecting member movable from a normal position to different time selecting positions, time driven means for driving said time selecting member back to said normal position, a driving connection between said time driven means and said time selecting member comprising driving and driven friction wheels adapted to have peripheral driving engagement, said driven friction wheel comprising a pair of resilient discs having abutting contact with each other substantially at their edges, said driving friction wheel comprising a wedge-shaped periphery having a rolling spreading action between the peripheral edges of said resilient discs, and a clearance gap cut out of the periphery of said driven wheel of suflicient size to receive said driving wheel and in which gap said driving wheel is enabled to rotate idly during the non-operating intervals of said timer, whereby the driving engagement between said wheels is interrupted when said time selecting member has been restored to its normal position.

9. In an interval timer, the combination of a manually settable member, time driven means, and a friction slippage connection therebetween comprising driving and driven friction wheels adapted to have peripheral driving engagement, a clearance gap in said driven wheel for interrupting the driving engagement between said wheels when said driven wheel is in a predetermined position, and a floating mounting for said driven section wheel permitting the latter to wobble or adopt different axially inclined positions and different axially displaced positions in maintaining effective frictional engagement with said driving friction wheel.

10. In an interval timer, the combination of a manually settable member, time driven means, and a friction slippage connection therebetween comprising a driving friction wheel, a driven friction wheel comprising a pair of resilient friction discs between which said driving friction wheel is adapted to have peripheral driving engagement, and a floating mounting for said driven wheel comprising a driven shaft and a hub for said driven wheel capable of wobble motion on said driven shaft to enable said driven wheel to one of said wheels compair of resilient discs having abuttingfixed axes having periph-.

adopt different axially inclined positions relatively to said driving wheel during the frictional driving engagement ii. In combination. a driving friction wheel and a driven friction wheel rotating about substantially fixed axes and arranged for peripheral driving engagement, said driven friction wheel comprising a pair of aligned discs, said driving friction wheel having rolling frictional engagement between said discs, and a clearance gap in said driven wheel for interrupting the driving engagement between said wheels when said driven wheel is in a predetermined position, said driven friction wheel and clearance gap being so constructed as to enable said driving engagement to be reestablished by rotating said driven wheel relatively to said driving wheel.

12. In combination, a driving friction wheel and a driven friction wheel arranged for peripheral driving engagement, said driven friction wheel comprising a pair of cupped resilient discs mounted in opposed relation with their peripheral portions resiliently pressed together, said drivin friction wheel comprising -a wedge-shaped periphery having a rolling spreading action between said peripheral portions of the driven wheel and having line contact with each disc at the side edges of said wedge-shaped periphery, a floating mounting for said driven wheel enabling it to shift axially and to wobble laterally for maintaining accurate frictional engagement with said driving wheel, and a clearance gap cut out of the peripheral portions of said resilient discs in said driven wheel, said clearance gap being of larger radius than said driving wheel and automatically interrupting driving engagement between said wheels when said driven wheel .is in a predetermined angular position.

13. In timing apparatus of the class described, the combination of a continuously rotating timedriven member, motion transmitting mechanism driven thereby comprising driving and driven wheels adapted to have cooperating engagement substantially at their peripheries, a clearance pocket in the periphery of said driven wheel for interrupting the drive to said driven wheel in one angular position of the latter, an adjustable arm adapted to have driving energy transmitted thereto from said time driven member through said motion transmitting mechanism, a stop, said driving energy tending to rotate said arm toward said stop and to maintain it in engagement therewith, means for manually adjusting said arm in a reverse direction to different positions away from said stop corresponding to different time intervals, a signal, a striker for said signal, means responsive to manual rotation of said adjustable arm in the manual setting operation for moving said striker to operative position, and means responsive to time driven rotation of said adjustable arm in the opposite direction for causing said striker to strike said signal.

14. I an interval timer of the class described, the combination of a continuously rotating timedriven member, motion transmitting mechanism driven thereby comprising driving and driven friction wheels adapted to have cooperating frictional engagement substantially at their peripheries, a clearance pocket in the periphery of said driven wheel for interrupting the drive to said driven wheel in one angular position of the latter, a tripping arm adapted to have driving energy transmitted thereto from said time driven member through said friction clutch, a stop, said driving energy tending to rotate said arm toward operation for corresponding to diflerent time intervals, a song.

a striker for said gong, a latch cooperating with said striker, means responsive to manual rotation of said tripping arm in the manual setting moving said striker to cocked position, said latch thereupon holding said striker in cocked position, and means responsive to the time driven rotation of said tripping arm in the opposite direction for tripping said latch so as to cause said striker to strike said gong.

15. In an interval timer of the class described,

. the combination of an electric clock, a continuously rotating member driven by said clock at a timed rate, a friction clutch cooperating therewith, an adjustable tripping arm adapted to have driving energy transmitted thereto from said continuously rotating member through the medium of said friction clutch, a stop, said driving energy tending to rotate said arm toward said stop, means for manually adjusting said arm in a reverse direction to diilerent positions away from said step corresponding to different time intervals, a gong, a striker for said gong, a latch cooperating with said striker, means responsive to such manual rotation of said tripping arm in the manual setting operation for moving said striker to cocked position, means for causing said latch to thereupon hold said striker in cocked position, and means responsive to the time driven rotation of said tripping arm in the opposite direction for tripping said latch so as to cause said striker to strike said gong.

16. In an interval timer of the class described, the combination of a continuously rotating time driven member, a friction clutch, a tripping arm adapted to have driving energy transmitted thereto from said time driven member through said friction clutch, a stop, said driving'energy tending to rotate said arm toward said stop, means for manually adjusting said arm in a reverse direction to different positions away from said'stop corresponding to different time intervals, an operating member, contacts responsive to the actuation of said operating member to different positions, a latch for holding said operating member in one position, means responsive to such manual rotation of said tripping arm in the manual setting operation for moving said operating member to said latter position, and means respohsive to the time driven rotation of said tripping arm in the opposite direction for tripping said latch so as to permit said operating member to move to another position.

17. In timing apparatus of the class described, the combination of a continuously rotating timedriven member, motion transmitting mechanism driven thereby comprising driving and driven wheels adapted to have cooperating engagement substantially at their peripheries, a clearance pocket in the periphery of said driven wheel for interrupting the drive to said driven wheel in one angular position of the latter, an adjustable arm adapted to have driving energy transmitted thereto from said time-driven member through said motion transmitting mechanism, a stop, said driving energy tending to rotate said arm toward said stop and to maintain it in engagement therewith, means for manually adjusting said arm in a reverse direction to diiferent positions away from said stop corresponding 7 to diderent time intervals, signal means adapted to be operated by said arm when said arm is having driving energy transmitted thereto, means for confining the operation of said signal means to a relatively limited period of signaling.

18. In an interval timer of the class described, the combination of a continuously rotating timedriven member, motion transmitting mechanism driven thereby comprising driving and driven friction wheels adapted to have cooperating frictional engagement substantially at their peripheries, a clearance pocket-in the periphery of said energy transmitted thereto driven wheel for interrupting the drive to said driven wheel in one angular position of the latter, a tripp mzarm adapted to have driving energy transmitted thereto from said time-driven member through said friction clutch, a stop, said driving energy tending to rotate said arm toward said stop and to maintain it in engagement therewith, means for manually adjusting said arm in a reverse direction to different positions away from said stop corresponding to different time intervals, switch means, switch actuating mechanism comprising a lever operative to transmit motion from said tripping arm to said switch means, said switch actuating mechanism comprising means for preventing said switch means remaining in closed circuit position beyond a relatively limited period of time, and an audible signal device adapted to be controlled by said switch means.

19. In an interval times of the class described. the combination of an electric clock, a continuously rotating member-driven by said clock at a timed rate, a friction clutch cooperating therewith, said friction clutch comprising a driving and driven friction wheel adapted to have cooperating engagement substantially at their peri heries, said driven wheel having a, clearance pocket therein at one point of its periphery for interrupting the drive to said driven wheel in one angular position of the latter, an adjustable tripping arm adapted to have driving energy transmitted thereto from said continuously rotating member through the medium of said friction clutch, a stop, said driving energy tending to rotate said arm toward said stop and tending to maintain it in engagement therewith, means for manually adjusting said arm in a reverse direction to diiierent positions away from said stop corresponding to different time intervals, a lever spring-biased to neutral position and oscillatable in either direction from said neutral position, a pointed nose on said lever, a cooperating pointed nose on said adjustable tripping arm adapted to engage with the pointed nose on said lever for oscillating the latter, contacts responsive to said lever, and an audible signal device controlled by said contacts.

20. In timing apparatus of the class described, the combination of an electric clock, a continuously rotating member driven by said electric clock, a friction clutch cooperating therewith,

said friction clutch comprising driving and driven wheels mounted on separate axes and adapted to have cooperating engagement substantially at their peripheries, means for automatically inter rupting the drive between said wheels when said driven wheel is in the predetermined position, an adjustable tripping arm adapted to have driving from said electric clock through said continuousLv rotating member and friction clutch, a stop, said driving energy tending to rotate said arm toward said stop and to maintain it in engagement therewith, means for manually adjusting said arm in a reverse direction to diiferent positions away fromlsaid stop corresponding to diiferent time intervals. and signal means adapted to be operated by said arm for a brief time interval as said am is rotating back into normal position against said stop.

21.1n combination. a driving friction wheel and a driven friction wheel rotating about fixed axes and arranged for peripheral driving engagement, a clearance notch in the periphery of said driven wheel for interrupting the peripheral driv- 8 notch is in registration with the periphery of said driving wheel, and means for restoring the peripheral driving engagement between said wheels by rotating said driven wheel relatively to said driving wheel while still maintaining the same fixed spacing between said fheel axes.

engagement between said wheels when said 22. In combinatiomijrlt friction wheel and a second friction wheel rotaflg about fixed spaced axes and arranged for peripheral driving engagement, aclearance notch in the peuiphery of said second friction wheel for interruptingtke peripheral drivinl enlllement between said wheels when said notch is in registration with the periphery. of said first friction wheel, and a lead-in surface at oneend of said clearance notch for enabling the peripheral driving engagement between said wheels to be restored by rotating said second friction wheel relatively to said first friction wheel while still maintaining the same fixed spacing between said wheel axes, thereby revolving said clearance notch out of registration with the periphery of said first frictim wheel.

WILLIAM P. GALLAGHER.

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