US2463070A

US2463070A - Timing mechanism

Info

Publication number: US2463070A
Application number: US766555A
Authority: US
Inventors: Harrison I Turner
Original assignee: Individual
Current assignee: Individual
Priority date: 1947-08-06
Filing date: 1947-08-06
Publication date: 1949-03-01
Anticipated expiration: 1966-03-01

Description

March 1, 1949. H. 1. TURNER TIMING MECHANISM 5 Sheets-Sheet l Filed Aug. 6, 1947 m3 \Q wQ Lg/ MM Ml M His r i z/Tmhevs.

March 1, 1949.

H. l. TURNER TIMING MECHANISM Filed Aug. 6, 1947 BY 1 at 2) IN VEN TOR.

MS M Q /zmrneys.

March 1, 1949'. TURNER 2,463,070

TIMING MECHANISM Filed Aug. 6, 1947 5 Sheets-Sheet 4 March 1, 1949. H. 1. TURNER TIMING MECHANISM 5 Sheets-Sheet 5 Filed Aug. 6, 1947 m a m Patented Mar. 1 1949 UN I TED STA-T E S PATENT OFF] (IE1.

TIMING MECHANISM Harrison I. Turner, Cordova; 11]. Application August 6, 1947, Serial -N0.- 166,555

16 Claims; 1

My inventionrelates to. timing switches and mechanisms and particularly to switches embodying means for accurately fixing a time interval within wide limits.

Timing switches constructed according to my invention are especially adapted to controlling the time cycle of operations of welding devices, motors, heaters, roasters, driers, and'a large variety of machines, devices and processes which are equipped for control b the opening or closingof an electric circuit.

The objects of my invention are to furnish a timing switch capable of accurate and highly'reliable performance with means for the quick and convenient setting and adjusting of time intervals; to furnish a timing switch which, whencnce its time interval has been set or adjusted, will automatically maintain its setting or adjustment' without requiring resetting or themanual tightening of a screw ornut or of other locking means. Other objects will'appear from the description.

Various types of timing switches designed to control industrial machinery have been availablefor years, but in those timers which have provided convenience of adjustment, accuracy, and'flexibility approaching that of the invention disclosed herein, there has been employed asan essential part of the mechanism a nut arranged for travel along a screw, which combination, when exposed to dust and grit or even oil. or grease of high viscosity, has often proved slug gish in operation or has failed entirely to operate when intended. In such timers, there has been no automatic means of locking the adjusting means so that repeated operations of the mechanism could not disturb the setting or adjustment. On the contrary, a clamping screw or nut has been'required for that purpose, and has proved a source of serious trouble due to the ire-- quent failure of an operator to tighten the screw or nut sufliciently or, in certain instances, due to the attempts of an operator to lock the adjustment securely by applying a wrench or pliers to the locking screw or nut and the consequent destruction of the locking mechanism.

My apparatus includes a housing in which the various parts are mounted; a motor with reduction gearing from the motor shaft to a clutch shaft; aclutch having one member rigidly united to the clutch shaft and a movable member carried by a sleeve mounted on the shaft; a driving sleeve rigidly united to the clutch shaft; a plurality of successively co-acting rings mounted uponthe driving sleeve which may be referred to as primary? driving rings and an additional seriesof successively co-actingrings which may be referred to as secondary driving rings mounted upon .a second shaft; a terminal'ringin the secondary series so arranged'thatflwhen the secondary rings are. completely athered;,it will. cause the primary clutch shaft to revolve-and cause the primary rings to start to gather; a tripring in the primary series arrangedto trip, a switch which may'cut ofi the'current'to themotor or which may form a connection for the-electric current to'asolenoid that in turn will-actuate other tripping means toreverse the-movement-of the-machine in which the timer-ismounted-i My apparatus also inc-ludesmeans by which the relative position or setting of boththe -primary-andsecondary-rings may beadjusted at any desired :point and'a dial with-hands -to indicate the set position and thetime required to complete thegatheringoperation-of the-rings so as to effectuate the tripping operation.

Various objects and advantagesof this invention will beapparent upon considerationof the following detailed descriptionof certain il1ustrative embodiments of the invention shown" in the accompanying drawings; in Which,-

Figure 1 isa front elevationormytimershowing onlyportions of the: contact mechanismand adjusting means;

Figure 2 is a' sectional elevation of the-timer taken substantially onthe line 2'- 2- of Figure-i;

Figure 3is asection of. the timer talzen onthe line 3-3 of Figure 5,- but omitting the adjusting dial mechanism shown in Figures' iand 21=;

Figure 4 shows a section of the timertaken on the line 4-4 of Figure 5;

Figure 5 is a plan viewof the timer;

Figure 6 is a detail of themotor andits gearing and mounting;

Figure 7- is a sectional detail of the clutch mechanism onthe center line of the main shaft;

Figure 8 is an enlarged detail of a clutch sleeve;

Figure 9 is an enlarged detail of the sleeve shown in Figure 8, and at a right angle thereto;

Figure 10 is a detail of the face of a clutch member;

Figure 11 is a sectional detail of'a clutch mem her on the line i I-l I of Figure 10;

Figure 12 is a detail of the clutch release mechanism;

Figure. 13 is an axial, sectional detail of a por tion of the main shaft with sleeve and spring mounted thereon;

Figures 14 and 15 are edge and face views respectively of one of the ring-cams;

Figures 16 and 17 are edge and face views respectively of a winged driving ring;

Figure 18 is a sectional detail on the longitudinal center line of the adjusting assembly;

Figures 19 and 20 are side and end views respectively of sleeve 49;

Figure 21 is an enlarged section of the front plate and dial mechanism taken on the line indicated by 2l2l in Figure l, but with indicator arms in vertical position, 88 pointing upward and 66 downward;

Figure 22 shows a detail plan view of the tripping assembly which opens certain contacts at the end of the desired interval of time;

Figure 23 is a sectional detail on line 23-23 of Figure 22;

Figure 24 is a sectional detail on line 2424 of Figure 22;

Figure 25 is a partial plan view of a retaining strip and screws which support certain contacts;

Figure 26 is a sectional detail of the assembly shown in Figure 25, on line 26-25 of Figure 25;

Figure 27 is a top view of an assembly employed in applying the motion of the solenoid plunger to change the conditioning of timer contacts and of the clutch mechanism;

Figure 28 is a front view of the assembly shown in Figure 27;

Figure 29 is a detail of actuating arm ltd;

Figure 30 is a diagram of the circuits of the timer when connected for operation in a typical one of the several ways in which the timer may be applied;

Figure 31 is a partial sectional detail view on line 2-2 of Figure 4 showing the position of the timer contacts and the various driving rings at an intermediate point while a typical timing cycle is in progress;

Figure 32 is a partial section detail view on line 44 of Figure 5 showing the position of various parts at the commencement of a typical timing cycle;

Figure 33 is a partial sectional detail on line 4,-4 of Figure 5 showing the position of various parts at the end of a typical forward rotation of the driving ring assemblies;

Figure 34 is a detail of the link and the solenoid plunger connected thereto with pin I44 in the position it would occupy when the timer is so arranged that the plunger would be held down in the solenoid coil when the timer is at rest.

Similar numerals refer to similar throughout the several views.

In the following description, the term right side indicates the side to the right of a person facing the front or dial side of the timer.

The body or frame of the timer consists of a right side plate I, a left side plate 2, a motor mounting plate 3 attached to side plate 2 by three mounting studs i, a front plate 5 united to and which holds right and left side plates in proper spaced relation and supports the adjusting dial structure, and a back plate 6, which, like front plate 5, serves to keep the right and left side plates in proper spaced relation. Lips or flanges 1 extending from the side plates serve as a means whereby the back and front plates may be fastened to the side plates by screws 5.1 and SJ, rivets or other suitable means.

The timing mechanism is driven by a small motor 8 which must rotate at an accurately controlled speed (as does a synchronous motor) to parts iii right. The left end of spring provide the intended accuracy of operation. This motor is mounted upon the plate 3 and drives the main or clutch shaft 9 of the timer through a train comprising pinion W, idler I l, clutch spur gear i3, sleeve l5 and clutch members Ill and I8. Pinion i9 is rigidly coupled to the output shaft of the motor. Idler H rotates about pivot-stud l2 extending from motor mounting plate 3 and drives gear it which is supported for rotation about and longitudinal movement along the exterior surface of sleeve or axle-bearing l4. Sleeve Hi, to the right end of which gear i3 is rigidly united, slides on the main or clutch shaft 9. Clutch member ll is rigidly installed on the left end of sleeve l6 and may engage clutch member 58 which is rigidly fastened to collar I9 which in turn is rigidly united to shaft 9 by a set screw or other suitable means. Inside of sleeve IS a spring 29 and a collar 2|, (see Figs. 7, 8 and 9) are installed so that spring 253 at its right end forces collar 2i against bearing M. Axle-bearing H3 is rigidly held in place by press fit in mounting plate-bracket 3 (Fig. 2) and holds collar 2! (Fig. 7) against longitudinal movement to the 29 presses against inner face 222 of sleeve l8 and tends to urge clutch member ll into engagement with clutch member 18. Collar 2 l which is shown enlarged in Figures 8 and 9, is held against rotation with respect to sleeve it by set screw 23 which extends into slot 24, but collar 2! is not prevented from translation with respect to sleeve it. The purpose of collar 2! is to form a thrust bearing in connection with sleeve-bearing I l. Accordingly, the right end of collar 25 is free to rotate against the left end of bearing i l and yet is held against rotation with respect to sleeve is.

The gripping surfaces of clutch members I! and i8 may be notched like the teeth of a saw, so that when the two surfaces are engaged the teeth furnish a positive driving coupling between motor 8 and shaft Q. These teeth are so shaped that they provide their positive driving torque when the clutch member H is rotating in a counter-clockwise direction when viewed from the right side of the timer. The accuracy with which the time interval between the start of a cycle of operation of the timer and the end of the cycle agrees with the interval indicated on the timer dial, of which a description is hereinafter provided, depends in large degree upon the number of the saw teeth in the periphery of the clutch surface. It has been found practical to divide a clutch surface of one and one quarter inch diameter into as many as one hundred teeth.

When clutch members IT and I8 are to be disengaged as shown in Figures 2, 5, 7 and 12, the surfaces are separated by the action of clutch release lever 25 which is a bell crank lever pivoted at 25.! in frame or bracket 2% and arranged for actuation by push rod or bar 2?. The operation of separating the clutch faces against the force provided by spring 29 is accomplished by the pressure of arm of clutch release lever 25 against a shoulder of sleeve it, as shown in Figure 12. When no force is exerted by push rod 21, the spring 2i! forces the clutch faces into engagement. Push rod 2?, which in one application of the timer, is connected to operating arm 28 by pin 29 (see Fig. 3), is pushed and pulled as needed for disengaging or engaging the clutch faces and acts by the partial rotation of shaft 3! carrying sleeve 38 united thereto by set screw 32, with operating arm 28 united to sleeve 30. Push rod 21 may beprevented' from slipping off pin 29 by any common type of'spri'ng pin, which fits over the groovejin pin 29.

lt sho'uld' b e' noted' that, as the clutch faces approach or draw away from each other, gear I3 moves"correspondingly and its teeth which engage'the teeth of idler l I (see Fig. 2), must slide back and" forth lengthwise of the teeth of idler l l: Gear I3'is made thicker than idler l I so that in'its different positions substantially the entire length of" the engaging teeth of idler II will be in contact with tooth surfaces of gear 13. It sh'ouldalso be noted that shaft 9 passes through androtates within sleeve-bearing l4 which serves as the left support for shaft 9.

The right end of shaft 9 rotates in bearing 33 which'is pressed'into side plate I. Rigidly fastened to'shaft 9 by set screw 34 is sleeve 35 shown mostclearly in Figure 13. Installed on shaft 9 a'n'dpartly concealed from view by sleeve 35 is resetspring 361' It shouldbe noted that shaft 9 is not of uniform diameter throughout, but is enlarge'd, as shown in Figure 13, in that portion which is encompassed by spring 36. One end of th i's'sp'ring 36 passes through a hole in the extreme right'end of sleeve 35 and terminates there with a bend as shown in Figure 13 sufiicient to prevent the spring from being pulled out through the hole. The other end of spring 39 terminates in a hole 3'! in motor mounting plate 3 with a bend sufficient to prevent the end of the spring from being pulled out of the hole. The spring is wound in such a direction as to cause shaft 9 to'tend at all times to rotate in a clockwise direction when viewed from the right side of the timer. Securely united to sleeve 35 by screw 38 or other'suitable means (see Fig. 2), is driving ring'39f Also, securely fastened by a press fit or sh'rinkagc'to sleeve 35 is pinion 40. Free to rotate on sleeve 35 within limits as will be hereinafter explained, are a series of intermediate drivin'g rings 4| and a tripping ring 42, all of which must be assembled on sleeve 35 before pinion 40 isp'ressed or shrunk on. For convenience, these driving rings may be called cams, as they have an intermittent action, although that term may not be technically accurate. Tripping ring or cam 42 is free to rotate through only a small are limited in one" direction by the tip of screw 43 and in th'e'other by detent or catch 44.2 as best illustrated" in Figure 4.

It will be noted that driving cam 39 has united thereto an extension or short bar 45 at the top thereof (Fig. 2). This bar 45 extends to the right sufficiently when cam 39 revolves, to collide with'a'nd engage a similar extension or bar 46 on the adjacent intermediate ring, but not sufiici'ently to contact the second intermediate ring to the right. The result of this arrangement is that driving ring 39 is free to rotate without drivingits adjace'ntcam 4| until its extension 45 collideswith extension 46 of the adjacent ring and any further rotation of driving ring 39 in the same direction will compel the next adjacent ring to rotate withdriving ring 39. Similarly, the projection 46 of any one of the intermediate cams 4-! willengage the projection on the next adjacent rin'gto its right and cause the adjacent ring to revolve. The projection 46 of intermediate ring 41 at the extreme right end of the series will, if rotated sufficiently far, collide with projection 41 on tripping ring 42 and further rotation will cause ring 42 'to rotate within fixed limits.

From the foregoing, it will be apparent that drivingring39 can rotate several turns from one extreme rotative position to thebpposite extreme before the engagement of the projections-on-the various cams with theprojections on theirrespective adjacent cams will finally transmit "-motion of driving cam or ring 39 to tripping ring 42. Assuming that each projectionoccupies /40 f the periphery of its ring, each ring would'befree to rotate a maximum amount of /4oofone complete revolution from one extreme rotative position where one side of its projection striks' one side of the projection on the adacent cam or ring to the opposite extreme position wherethe' other side ofits projection strikes the other side of the projection on the adjacent ring and anyadditional rotation of the first ring will thereafter compel the adjacent cam to rotate with it.-

Thus a series of such cams consisting of one driv ing cam, one tripping cam, and ten intermediate cams would, if the cams of the series at the start were positioned in one extreme position, permitdriving cam 39 to rotate 11 (1- /4o) or 10.45 turns before'all slack in the series would be taken up and tripping cam 42 forced to rotate;

The cam or driving ring assembly just described is one of the novel features of this invention. For a given time interval between the starting:of'the timer and the forced rotation of tripping cam- 42, shaft 9 may rotate as much as'ten times as fast with the series of cams interposed between shaft 9 and cam 42 as if shaft 9 were coupled directly to cam 42. Depending upon how little or'how much slack exists in the series of rings When in set position, that is, at the start of rotation, driving ring 39 may have to rotate any amount between zero turns and 10.45 turns before tripping ring 42 will be forced to rotate and to accompiish its purpose as hereinafter explained.

Rotation of tripping ring 42 starts a successionof events which brings the timing period to an end. It is essential, for the highest degree ofaccuracy of the timer, that'rotation of'ring 42, when it once commences, shall proceed relatively: fast. If ring 42 were to turn only one tenth as fastas is provided for by this invention, then the magnitude of the errors in timing th'at'could result'from imperfections in the shaping or fitting of various parts of'the timer or from'vibration or impact during the final interval while ring 42 wasrotating would be materially increased. Likewise, any

9 were coupled directly" totripping cam 42 aswhen a series of ten intermediate rings is employed. The operation of'such a series of cams as just described is far less subject to interfer ence from dust, grit, dried lubricants, etc-., than is that of the relatively. tigh'tfitting threaded device employed in many timersat present wherein threads of an externally threaded member a distance roughly equal to the circumference of the threaded member times the number of turns it makes in determining the time interval.

As previously stated, spring 36 is wound and soarranged at its ends as to tend to rotate shaft 9' in a clockwise direction when viewed from'theright side of the timer.

tion'; and cohsequentlythe amount of timeduring an internally threaded member must travel along' The number of turns against the torque exerted by spring 36 which shaft 9 must make-from any given startingposi-' which shaft 9 must turn after it starts into motion before tripping cam 42 will be forced to turn, will depend upon how far spring 36 is permitted to rotate shaft 9 in a clockwise direction to reach stopping position. In other words, the amount of slack that is arranged. for in the assembly of rings above described at the time shaft 9 commences to rotate will determine the interval of time between the start of rotation of shaft 9 and the forced rotation of tripping ring &2. To stop the spridriv'en clockwise rotation of shaft 9 at selected positions corresponding to definite time markings on an indicating dial, pinion ii: drives gear 4.8 through the center of which sleeve 59 extends, the gear and sleeve it being rigidly united by press fit, key, or pin. Sleeve 89 and consequently gear it are rigidly fastened to shaft 5% set screw 5! (Fig. 18). Shaft fill is s p-ported for rotation at its right end by bearing 52 which is pressed into side plate I and at its left end by bearing 53 formed in axle 54, which axle may united rigidly to motor mounting plate 3 by screws 55 or other suitable means (Fig. 13) Supported for rotation as a unit about axle member 54 are sleeve 55 and crown gear ill rigidly united by press fit or otherwise.

Between sleeve 69 and sleeve a plurality identical cams or rings 53 are installed on daft 553 on which they are free to rotate within Cei tain limits. Each of these rings is similar in construc tion to ring ll shown in Figures l i l5, havin a projection or finger 59 (Fig. 2) which corresponds in design and purpose to projection or finger 46 on cam or ring ii. Sleeve it also has a projection M; which extends outward from shaft 58 so far that projection 52 of cam or ring adjacent to sleeve t9, if rotated, will eventually strike projection til and either be held against further rotation or will force sleeve l9 and gear 48 to rotate with rin' 58. Sleeve 55 has a projec tion 6| (Fig. 2) which extends over the rim of its adjacent cam or ring 58 far enough so that projection 59 of adjacent ring 5% cannot pass projection 51 and yet projection ti does not extend far enough to engage projection til of the second cam to the right of sleeve 56. From the earlier descrip tion of the functioning of the series of cams or rings carried by shaft 9 it will be apparent that an assembly consisting of sleeve four intermediate cams 58 and sleeve 59 all installed on a single shaft 56 will permit a corresponding number of rotations of sleeve ill from one extreme rotative position where one side of the projection of each element in the assembly engages one side of the projection of its adjacent element to the other extreme rotative position where the other side of the projection of each element engages the other side of the projection of its adjacent element. In the case of a series of elements consisting of sleeve 55, four cams or rings 58, and one sleeve 49 the projections on each of which span of the periphery, sleeve 49 and consequently gear 48 are free to rotate X (l% =4.75 turns from one extreme position to the other, where further rotation of sleeve 49 would be impossible unless sleeve 56 were rotated with sleeve 49. The number of turns pinion is can rotate under such conditions before the maximum possible slack in the series of cams or rings on shaft 50 will be eliminated depends upon the ratio of the number of teeth in gear dB to the number in pinion All. For example, if gear id has 2 times as many teeth as pinion M, then pinion 4b is free to rotate 2 l.75 or 11.8'75 turns.

As explained above, spring 36 exerts a torque 8 on pinion 4i! urging said pinion clockwise when viewed from the right side of the timer. Pinion 4%) then tends to cause gear 48 to rotate in a counterclockwise direction. Obviously, sprin 36 by this means, if sleeve Eli is held against rotation, can rotate pinion iil only until all slack between sleeve ill, cams 58, and sleeve 56 has been taken up. So, if motor 8 has been driving shaft 9 for a predetermined period of time at the end of which tripping ring cam :22 has been forced to rotate enough degrees to accomplish a function to be later explained, then, when clutch members I! and i8 disengage, spring 36 will act to reset shaft 9 to the desired starting reset position determined solely by the rotative position in which sleeve 56 may have been placed. The number of turns the motor must make and consequently the time interval that must expire while shaft 9 is rotating from its starting or reset position to a rotative position where tripping cam e2 will accomplish its tripping action is adjustable and can be fixed by merely rotatin sleeve 56 on pivot member 54. With a ratio of 2 to one between the number of teeth on gear and the number on pinion 4i], "ith sufiicient slack in the assembly on shaft to permit gear id to rotate in excess of 4 turns from a reset position before collision of the projections on the elements of the assembly with each other can arrest rotation of gear 48, it is possible to adjust sleeve 56 to any rotative position permitting shaft 9 to rotate from a minimum of Zero turns to a maximum of at least ten turns before tripping ring or cam i2 is forced to turn.

To rotate sleeve 56 and to fix it in set or reset position (Figs. 2, 4 and 21), pinion $2 is united to a dial shaft 63 in driving engagement with crown gear 5's. Shaft (33 passes through and is united to a collar 6d which in turn is mounted for rotation in a bore through the approximate center of front plate 5, and its inner end is supported for rotation by hearing bore iii in motor mountin plate 3 (Fig. 5). Pinned to collar ti on the inner side of front plate 5 is gear fit. On the outer side of collar 6 1 are pinned minutes indicator arm 65 washer 6i. Collar 6 acts as a bearing for dial shaft and also serves to transmit rotation of gear 65 to minutes indicator arm The position of minutes indicator arm E35 is clearly indicated by the 20 minutes scale (58 on the face of dial Dial (it is enclosed within a cover ii having transparent material '52 covering a circular hole in the cover through which the dial may be observed. ihe cover and transparent material are clamped to front plate 5 by screws it. The transparent material may be cemented or riveted to the inner surface of cover ii to hold it secure to said surface.

On the outer end of shaft 63 is installed sleeve it at the inner end of which and integral therewith is cup disk 15 having saw teeth out into its rim. These teeth normally engage a flat side of pin 75 extending from front plate 5 and by this engagement cup disk 15 is prevented from rotating in a clockwise direction when viewed from the front of the timer. The effect of spring 3% acting through pinion lfl, gear 5-8, and the assembly of rings on shaft 59 traced to crown gear 57, will be that spring 35 tends to rotate crown gear 51 in a counter clockwise direction when viewed from the right side. To resist such rotation of crown gear 57, dial shaft 63 which carries pinion 62 must be held against rotation in a clockwise direction. Accordingly, the saw teeth of cup disk 75 are cut so that when cup disk 75 is urged to rotate in a clockwise direction the direction thereby.

the timer is set.

,9 surfaces ofits teeth which lie in the plane of shaft 63 are forced against a surface of pin '56 ,which lies in substantially the same plane, and .cup disk 15 and consequently shaft 63 are prevented from rotating.

When it is desired to rotate shaft 63 for the purpose of adjusting the interval for which the timer is set, cup disk 15 is readily brought out of engagement with pin 16 by merely pulling forward knob l'l which is securely fastened to shaft 63 by set screw 58. Pulling out on knob 11 and shaft 63 compresses spring 19 but when the knob is released cup disk 15 is automatically forced back into engagement with pin 16 and held against rotation in a clockwise It is held against rotation in the opposite direction by a torque exerted by spring 36.

Pinned directly to the outer surface of cup disk 15 is seconds indicator arm 88, the position of which is indicated by the markings on seconds scale 8| which is divided into 60 equal divisions representing seconds. In one preferred form of this invention, main shaft 9 is geared to motor 8 so that shaft 9 turns at the rate of one half revolution per minute and, if the numbers of teeth on

gears

40 and 48 are 20 and 50 respectively, then of .94 Or of a turn of crown gear 51 will change by 60 seconds the interval between the time of starting of the timer into operation and the time when tripping cam 42 will be forced to rotate. Therefore, if the number p of teeth in crown gear 51 is 55 and the number in pinion 62 is 11, one full turn of shaft 63 will rotate crown gear 51 one fifth of a turn and will change by 60 seconds the interval for which Correspondingly, one sixtieth of a turn of shaft 63 will vary the time interval by one second. Scale Bl which indicates the position of dial indicator arm 88 is divided into centric thereto for rotation on pivot 83 is pinion 84 which engages gear 65. Consequently, rotation of pinion 62 with shaft 63 through any arc will cause minutes indicator arm 66 to rotate through an are determined by the ratio of the gearing just described between pinion 62 and gear 65. If this ratio is 25:1 for example, 20 full turns of knob 1! and seconds indicator arm 88, .will cause minutes indicator arm 65 to turn %5 .of one turn. Therefore, if scale 68 is constructed to cover 9. 25 of 360 degrees and is divid d into-20 equal divisions, the movement of minutes indicator arm fifi from one division to another will correspond to a one minute change in the interval for vwhich the timer is set. Accordingly, the dial mechanism as just described will indicate the number of whole minutes of timing interval by ,theposition of minutes indicator arm 66. relative to scale 68 and the number of additionaluseconds bythe position of seconds indi- CatOnarm 8!! relative to seconds scale 8!.

.Aniinportant,advantage of this dial mechanism over other indicating mechanisms of timers ossessing flexibllity and accuracvmore or less rn1lar.j to-, that of my inventionis the means whereby the dial mechanism automatically locks itself in whatever adjusted position it may have been manually placed by an operator.

The means provided to control and adjust the time interval between the starting of the motor and the tripping by cam 42 has been explained. The effect of rotating tripping cam 42 will now be explained. A bell crank

lever having arms

44 and 44 .l is mounted on pivot pin 88 upon the side plate I and held by nut 81. The arm 44 has a detent catch united to the lower end thereof and the arm 4% urged downward by a tension spring 85. Projection 47 of cam 42 is of such length and so positioned that when it rotates in a counterclockwise direction as viewed from the right side of the timer it will strike the detent catch M2 and carry it backward against the tension of spring 85. A detent arm 88 is united to collar 39 and rigidly secured to shaft 90 at the right side of the timer by set screw 9| in collar 89 (Fig. 22). United to collar 92 is a tripping bar supporting arm 93 which is rigidly united to shaft 98 by set screw 94. Pinned to detent arm 88 at the right and pinned to tripping bar supporting arm 93 at the left is tripping bar 95. Shaft 98 is pivoted in a bearing at its right end in right side plate I and in a bearing at its left end in left side plate 2. Detent arm 88, tripping bar arm 93, tripping bar 95, and shaft 90 are constructed to partially revolve as a unit through a small arc with the axis of shaft 90 as a center. Suitable spacer collars on shaft 90 prevent lateral motion of said shaft.

In tripping bar 85 there are five threaded holes number 95 (Fig. 22). These holes are provided to accommodate, in any desirable combination for purposes which will later be explained, I pins threaded at their lower ends of the type numbered 91 shown in Figures 2, 3 and 4. In detent arm 88 there are two threaded

holes

98 and 99, either one of which, depending upon the performance desired of the timer as will hereinafter be clarified, will accommodate a screw I00 as shown in Figures 3 and 4.

A panel liil made of insulating material is mounted at the lower front of the housing and has passing through it a plurality of screw terminals leg with nuts M18 as shown in Figures 1, 3 and i. Panel fill may be secured to lips I04 extending from side plates i and 2'. by screws I05 or other suitable means. Flexible wires Hi8 (Figs. 3 and 4), lead from terminals 292 to contact members E82, 588, H8 and ii! and are united to said members by screws H2. Contact members Ml, E88, N39, lit and lil all are tipped with silver tips 5 E3 or other metal of high conductivity and are united to insulating supporting members or bars lid by screws IE2 and H5 which pass through the insulating members and screw into threaded bores in plates I Hi. Insulating members or bars 5 I4 are pivoted freely on shaft H! which is supported at its right end by side plate I and at its left end by side plate 2. Spacer sleeve l l8 and set screw H8 together with other spacer sleeves M8! on shaft it! serve to prevent sideways motion of the insulating members and of shaft ill. Wires H35 pass freely through bores I28 in insulating members ll i (Fig. 5). Tension springs liil have their upper ends hooked to insulating members H4 and their lower ends to brackets 122 extending outward from and united to back plate 8 and act to rotate insulating members H4 a few degrees about shaft II! in a clockwise direction when viewed from the right side of the timer.

In order that insulatin members lit may be held in various angular so about shaft ill, the purposes of which will be clear from explanations hereinafter provided, a retaining strip containing threaded bores 22% is riveted. or united to back plate as shown in Figures 3, i and 5 and in greater detail in Figures 25 and 26, and screws I25 are inserted in the threaded bores as necessary to hold insulating members in the required positions. For example, with insulating members positioned as in Figures 1 and 2, screws are required in bores A and B 26) to support against the pull of springs I23 the rear ends of insulating members I M carrying contacts Hill and I08. If desired that contacts it? and N38 be normally closed, instead of normally open as shown in Figures 1 and 2, then the screw in bore A could be removed and spring 524 could force contact 588 into engagement with contact till. Similarly, with contacts I99, H8 and l.l in the positions shown in Figures 1 and 2, screws are required in bores C and E (Figs 26), but none is required in bore D because it is desired that spring I2I be allowed to hold contact lie against contact III. If desired that contacts llll and Ill as well as contacts I09 and Ill] be normally open, screws could be inserted in bores E; F, and G instead of in bores C and E. Experience has proved that various different relationships of contacts in the non-operating condition of the timer may be found necessary to meet the needs of the Various uses made of a timer of this type and accordingly screws may be inserted in bores its in the required combinations or additional bores may easily be provided if found desirable.

At the left end of actuating plate 25 and united to or integral with it, shaft 3! (Figs. 27 and 28) is pivoted in left side plate 2. Also at this end is a clutch operating arm 28 in which there is bore I21 for attaching one end of a tension sprim. At the right end of actuating plate I26 and also united to or integral with it is shaft I 28 which is pivoted in right side plate I. Figures 2'7 and 28 show the actuating plate I26 with a clutch operating arm 28 assembled to shaft 35, and also show a plunger lever arm l29 and a short arm I30, which is riveted to sleeve LEI, assembled to shaft I28. Sleeve E32 serves as a spacer to prevent sideways motion of the assembly shown in Figures 27 and 28 between side plates I and 2 and as a convenient anchorage for one end of a tension spring 533. Set screw I34 fastens plunger lever arm iZS rigidly to shaft I28 and set screw I35 fastens arm I3ll rigidly to shaft I28 (Fig. 5).

A solenoid I of conventional type is securely fastened to right side plate I by studs i3l, nuts I38, and screws I39. A plunger Iii. for the solenoid is movable upward by the force of spring I4! acting through clutch operating arm 28, shaft 3!, actuating plate I26, shaft E28, plunger lever arm I29, pin I42, connecting link Hi3, and pin M4. Plunger I40 is movable downward by the magnetic attraction of solenoid coil when sui able electric power is applied to the terminals of sai coil. Wires M5 connect the solenoid coil with terminal screws 502 on panel till.

The power exerted by the solenoid coi. may be augmented by surrounding the coil by a laminated series of iron plates secured by nouunag netic frames H36 and bolts I31.

Whenever plunger I lil moves downward, actuating plate H6 is tilted counter clockwise when viewed from the right of the timer. A screw I41, with head of suitable height is driven into the bore at I; in actua. 25, as shown in Figures 27 and 2e, and when plate tilted counter clockwise, will strike ce insulating member H l on which contact it is mounted a i: together so current can flow from one to the other. l'jontacts it' l and 535 may be so connected to a source of electric power that their closing, one upon the other, will close a circuit to the coil of solenoid M5 through wi es i ifi, downward motion of plunger Hill will then cause the circuit to the coil to be closed and plunger held by magnetic force in the down ocsition until the connection to the source of power is broken, either by the separation of contacts it? and i% or by a manually operable switcl'i, or other-- wise as desired. 01', the leads is to motor 8 may also be connected through "ruin ls so that the closure of contacts lid and is?) serves to conduct power to the motor, and the downward motion of plunger Hill will not only serve to lock itself down by the action described above, but will likewise start and keep motor running until the contacts open or until the connection to the source of power otherwise broken. Further-more, since clutch operating arm 223 rotates with actuating plate I25 as a unit, downward motion of plunger Hi5} will cause clutch member ll to engage member is and rotation of motor 8 will cause shaft 9 to rotate.

Similarly to the action of screw ml is forcing contact l8? against contact M28, other screws may be driven into the other bores in actuating plate 26 and cause contacts ace, tit and iii to engage or disengage each other as may be needed for various timing processes. For @l'i ample, a screw Hil of suitable driven into bore L of plate E25 will, when actuating plate 526 is tilted counter clockwise by the action of solenoid M5, cause contact H53 to break connection with contact ill and to make connection with contact His and that will continue to be the horizontal posititon or until a pin 3? carried by tripping bar moves upward, and by raising the tail of an insulating member iii, caur s a change in the positioning of the contacts. That the use of one or more contact screws t ll in other bores of plate 526 may serve to provide diiierent action of the contacts will be plain to anyone acquainted with electrical control devices accordingly need not be explained further. It should be noted, however, that if contact screws i l'i are mounted in bores M and N in the forward side of actuating plate 525, the upward movement of plunger i iii, instead of its ownward movement, and the resultant clockwise tilting of actuating plate i22 may be employed to close circuits through the contacts as above explained. She cycle of operation of the timer may be started by either closing a circuit to solenoid or by opening the circuit, depending upon selected changes in the arrangement of the timer parts.

With the timer parts assembled as shown in Figure 4, downward motion of plunger Hit will cause short arm 538 to rotate counter clockwise with actuating plate 26 as a unit. Such rotation will rais arm I38 from its position as shown in Figure 4 so that a considerable space will exist between it and the tip of screw 5% which is screwed into bore 93 of detent lever arm 83 and, for security, may be locked in place by a locknut on the under side of the detent lever arm.

- spring 36 to reset tion.

'two bores, one above the other, are .the lower end of connecting link- I43 50 that plunger M6, when connected to link I63 with :pin M4 in the lower of the two bores instead of in the'upper one as illustrated, may in its'normal :-.non'-oneratins; condition beheld in.- a downward Prior to' such rotation of arm I30, the pressure exerted against screw 1 traced to the action of Isl by it, *whichmay be spring MI, serves to over- "come the tension spring I33 and to cause the forward point ofdetent arm 88 to be raised slightly above the point of detent 44.2 as shown in Figures 3 and 4. As soon as the short arm 'I30 'is =-rotated counter clockwise, the forward point of detent lever arm 88 will beheld by the 'cletentl4.2 against counter clockwise. rotation,

and clockwise rotation of detent 44.2'as viewed from the right side of the timer; will serve to release the forward point of detent lever 88. and

'to allow spring I33 to rotate detent lever arm 1 88 and tripping bar 95 in a counter clockwise.di-.

rection. The required clockwise rotation of *detent 44.22 will be forced by the action of projection ll of tripping cam 42 at the end of the intervalfor which the timer has been set. The

tripping bar 95; 20

counter clockwise rotation of of shaft 90 as a center will tact against another to close a circuit or to draw =.one.contact away from another to open a circuit, nasimay be required to utilize the timer in the accomplishment of a given function. For example, if plunger MI! has been locked in a down positionby electric current passing through contacts)? and W8, then the release of detent lever arm.88 by detent 44.2 and the resultant pressure of screw Ill against the insulating mom- ,ber IM. which carries contact Hi8 will force con- ..tact I08 to separate from contact I III, the circuit to solenoid I45 and motor 8 will be bro-ken,

.-;and.-.plunger I All will then rise under the action of spring I-II to its non-operating position ready for another. cycle of operation. At the same time arm I3!) will force screw I09 and tripping bar. 95. to rotate in a clockwise direction as viewed from the right side of the timer until the forward point of detent lever arm .88 has risen slightly.

above thepoint of detent 44.2 to permit spring 65 to rotate bell crank arm counter clockwise until I detent 44.2 is beneath the point of-detent-lever arm 83. Since, as already explained, the rotation of clutch lever arm 28 in a counter clockwise direction, as viewed from the left of the timer, will 1 cause push rod- 2'! to rotate clutch-release lever 25 and thereby separate clutch member I I from member I8, the upward motion of plunger I49 following the opening of the circuit through con--v 4 tacts IQ? and IE8 will open the clutchand disconnect motor 8 from main shaft 9 andallow said shaft to=its starting posi- In practice, needs arise for the accomplishment of numerous different operations by timers of this class. It is for that reason that bores-9b,

.one for each contact, have beenprovided for screws 9'! in tripping bar 95; that onebore for screws I41 for each contact has been provided on each side of actuating plate I26; and that a terminal screw I02 has been provided for the wire to each contact member and for each wire lead ing" from motor 8 and solenoid I 45. In addition, provided in by loosening set screw drive the timer mechanism.

position by electric current and allowed to, rise to an operative condition by the action of spring MI upon the breaking of the electric circuit. /Wth the plunger so connected, upward motion or plunger must be utilized to cause .arm- I30 to draw away from screw It!) instead of pushing a minst it, sov as to permit detent lever arm 88 to rotate counter clockwise when viewed from the right side of the timer when released by detent To provide for such a condition, screw IIIII may be shifted to bore $9 in detent arm 88 and,

I35, arm I30 may be rotated 189 degrees so as to extend forward instead of backward from shaft I28. Also, in order that clutch members I! and I8 maybe brought into engagement by upward motion of plunger M9 instead. of by downward motion of said plunger, push rod 27 may be connected between pin I 49 on clutch operating arm and clutch operating lever 25 as shown in Figure I2 instead of between pin 29 and clutch operating lever as shown in Figure 3. In order that motor may operate when plunger I 48 is in the raised position, screw I l"! in actuating plate may be sh fted from bore K to bore M.

Figi e 30 shows a diagram of the circuits of the timer connected in one of the several possible ways. Leads marked P have voltage impressed upon them from any suitable source. Momentary pressure on push button B will cause plunger MID of solenoid I i-5 to be pulled downward by the action of the solenoid coil whereupon contact MI by action of screw I41 will close against contact I88, thereby electrically locking plunger It?) in the down position and at the same time applying power to motor 8 causing it to Also power which has been applied to lead LI through contacts H0 and H II will be disconnected by the action of another screw It? in bore L forcing contact Ill] away from contact H I and power will be applied to lead L2 through contacts we and III! by the movement of contact I It into engagement with contact m9. Motor 8 will accordinglydrive the time mechanism with all contacts in the condition just described until the expiration of the time interval indicated by dial indicator arms t8 and M. At the end of said interval, contacts Ill? and H28 will open by pressure of screw 91 against the insulating member I I4. which carries contact Iilll and will allow plunger MB to be pulled upward by spring MI, stopping motor 8, and restoring contacts I09, H8 and III to the condition illustrated in Figure 30.

In a characteristic operation of my timer, the timer is assembled in starting position. with the secondary rings in their extreme released position. That is, they are gathered together by the action of the spring 36 as far as possible by the spring action, thelimit being fixed byvdetent or lugEiI on sleeve 56, and a predetermined amount of slack is left in the primary rings.

The knob TI is then turned. manually to set the seconds and minutes hands at the points on the dial indicating the desired time selected to have elapsed from the starting of the motor until the current is cut off therefrom.

I As the. knob isturned, the primary and secondary rings are successively rotated out of their starting or released positions by the action of the gears 625l and are set or spaced to positions quired for the i-motor to drive the primary and secondary rings to the end of the travelnecessary to cause them to actuate the tripping mechanism and throw the switches which will out out the motor and also cause the desired changes in the current running the machine or process to which the timer is attached or connected. At the same time, gears 628284-65 will set the minutes hand the shaft 63 and sleeve 7 3 will set the seconds hand at the desired points on the dial. The starting button is then pushed and the motor started which will run until stopped by a switch as heretofore described.

When the motor stops and the clutch releases, the spring 36 carries the driving rings back. to their predetermined set or starting position where the rings 58 have been carried back as far as permitted by lug or finger ii! on sleeve 56. The cycle can then be repeated by pushing the starting button manually or by arranging means connected with the machine to which the timer is attached to push the starter button.

When my machine is assembled, all of the driving rings are put in so-called chock-a-block position. that is, all of them are turned until each of the fingers is in contact with the rear of the finger on the preceding ring, and I refer to this position as the assembled position.

When the knob is used manually to withdraw the detent 6! from the finger on the adjoining driving ring, the action of the spring 35 will cause the driving rings to follow until all of the fingers of the rings 58 are in contact either with the detent B1 or with the finger on the next preceding driving ring, and I refer to this position as the set or reset position. In this position, the dog 16 bearing against the teeth of the crown or cup disk 15 will prevent any farther rearward movement of the sleeve and the detent 5i thereon. But when the driving effect of the motor has forced all of the fingers on the driving rings into contact with their next preceding ring, the position may be called the tripping or final position and as soon as the rings reach this position, the switch is tripped, thus throwing out the clutch, stopping the motor, and allowing the restoring spring 36 to reassemble the rings in their set or reset position.

Many modifications in the form and arrangement of parts may be made and such may be applied to the control of electric circuits in many ways other than those specifically mentioned here without departing from the spirit of my invention and I do not limit my claims to the particular forms shown in the drawings. Many circuits and sequences of contact operation for timing devices have been devised to meet the needs in that field, but they constitute no part of my invention and need not be explained here.

I claim:

1. A timer of the class described comprising a housing, an electric motor, a clutch shaft rotatably mounted in the housing, a motor shaft operatively connected to the clutch shaft by gearing, a clutch having one member mounted upon a sleeve rigidly united to the clutch shaft, and its coacting member united to a sleeve slidable lengthwise upon said shaft and rotatable on the shaft, a fixed driving ring as described rigidly united to a second sleeve united to the shaft and spaced apart from the clutch sleeve, a primary series of successively coacting intermediate driving rings rotatably mounted upon the second sleeve and arranged to actuate a tripping ring at the end of their limits of travel in one direction having linkage to throw a switch arranged to 16 out off the current from the motor after a predetermined period of operation of the motor.

2. A timer as set out in claim 1, and a manually operable knob and shaft mounted in the housing with intermediate gearing operatively connecting the knob shaft to the second sleeve on the clutch shaft whereby the driving rings be manually set in various positions of adjustment by the knob.

3. A timer as set out in claim .1, and a manually operable knob and knob shaft mounted in the housing with intermediate gearing connecting it to the second sleeve on the clutch shaft whereby the driving rings may be manually set in various positions of adjustment, a graduated dial mounted upon the housing adjacent the knob and a hand united to the knob shaft to indicate on the dial the time required for the motor to operate a sufficient time to drive the driving rings far enough to actuate the tripping mechanism.

4. A timer as set out in claim 1, a manually operable knob and knob shaft mounted in the housing with gearing operatively connecting the knob shaft to the second sleeve on the clutch shaft whereby the driving rings may be manually set in various positions of adjustment by the knob, a graduated dial mounted upon the housing, and minute and second hands arranged to be set by the knob to indicate given periods of time in minutes and seconds.

5. A timer as set out in claim 1, a manually operable knob and knob shaft mounted in the housing with gearing operatively connecting the knob shaft to the second sleeve on the clutch shaft whereby the driving rings may be manually set in various positions of adjustment by the knob, a graduated dial mounted upon the housing, and minute and second hands arranged to be set by the knob to indicate given periods of time in minutes and seconds, the seconds hand being united to a sleeve fixed to the knob shaft, and the minutes hand being carried by a sleeve geared to the knob shaft by reduction gearing.

6. A timer of the class described, comprising a housing, an electric motor, a clutch shaft rotatably mounted in the housing, the motor shaft being operatively connected to the clutch shaft by reduction gearing, a clutch having one member mounted upon a sleeve rigidly united to the clutch shaft, and its coacting member united to a sleeve slidable lengthwise upon said shaft and rotatable on the shaft, a fixed driving ring rigidly united to a second sleeve united to the shaft and spaced apart from the clutch sleeve, a primary series of successively coacting intermediate driving rings rotatably mounted upon the second sleeve arranged to actuate a tripping ring at the end of their limits of travel in one direction, a solenoid mounted in the housing and having a movable core, an electric circuit to supply current to the solenoid and t0 the motor, adjustable switches to cut in or cut out the current to or from either the motor or the solenoid, a lever pivoted in the housing having one end pivoted to the core of the solenoid and its opposite end operatively connected to one end of a spring arranged to urge the movable core out of the solenoid coil, and a spring-held switch-actuating lever mounted in the housing having one end united to a tiltable switch plate carrying one or more pusher studs and its opposite end arranged to be engaged by a detent formed integral with one arm of a bell crank lever pivoted in the housing the opposite end of which is spring-held in set position, the tripping ring having an arm projecting there- 17 from arranged to contact and carry the detent out of contact with the switch-actuating lever and allowing the switch-actuating lever to rock on its pivot and to tilt the switch plate as necessary to open or close the circuit to the motor or the solenoid.

'7. A timer as described in claim 6, and a coiled compression spring mounted upon the clutch sleeve arranged to urge the slidable clutch member along the sleeve and into engagement with the fixed clutch member.

8. A timer as described in claim 1, and a secondary shaft parallel to the clutch shaft and having its outer end journaled in a side plate of the housing and its inner end enlarged and journaled in a tubular bearing mounted in a supporting plate united to the housing, said secondary shaft being geared to the clutch shaft and having rigidly united thereto a sleeve with a projecting detent, and a sleeve rotatably mounted on said bearing with a lug or finger projecting laterally therefrom arranged to contact a similar lug or finger formed on the periphery of the first of a secondary series of successively coacting driving rings or cams rotatably mounted on the secondary shaft between said bearing and the fixed sleeve.

9. A timer of the class described, comprising a housing, a motor, a clutch shaft rotably mounted in the housing, the motor shaft being operatively connected to the clutch shaft by reduction gearing, a clutch having one member mounted upon a sleeve rigidly united to the clutch shaft, and its coacting member united to a sleeve slidable lengthwise upon said shaft and rotatable on the shaft, a fixed driving ring rigidly united to a second sleeve united to the shaft and spaced apart from the clutch sleeve, a primary series of successively coacting intermediate driving rings rotatably mounted upon the second sleeve arranged to actuate at the end of their limits of travel in one direction a tripping ring with linkage arranged to cause said tripping ring to throw a switch to cut off the current from the motor after a predetermined period of operation of the motor, a secondary shaft having one end mounted in the housing and its opposite end enlarged and journaled in a tubular bearing mounted in a supporting plate, said secondary shaft being geared to the clutch shaft and having rigidly united thereto a sleeve with a projecting detent, a sleeve rotatably mounted on said bearing with a lug or finger projecting laterally therefrom arranged to contact a similar lug or finger formed on the periphery of the first of a secondary series of driving rings or cams rotatably mounted on the secondary shaft between said bearing and the fixed sleeve, and a helical spring mounted upon the clutch shaft to urge the slidable clutch member along the sleeve and into engagement with the fixed driving ring and arranged to rotate said driving ring and through it the intermediate driving rings to return them into their starting or set position when the current is cut off from the motor.

10. A timer as described in claim 9, and a manually operable knob and knob shaft mounted in the housing with gearing connecting it to the movable sleeve on the clutch shaft whereby the driving rings may be manually set in various positions of adjustment, a graduated dial mounted upon the housing adjacent the knob and a hand united to the knob shaft to indicate on the dial the time required for the motor to operate a suificient time to cause the driving rings to actuate the tripping mechanism.

11. In a timing mechanism, the combination with a shaft, of series of successive oo-axial, co acting rings mounted thereon, each rotatable freely in one direction with relation to its next succeeding ring through a predetermined arc only and thereafter in driving engagement with such succeeding ring, a plurality of circuit controllers, an electric motor, magnetically actuated clutching means providing a substantial driving engagement between said motor, said shaft and the initial ring of said series, a helical torsion spring installed co-axial with said series of rings upon a common shaft and connected to the initial ring of the series arranged to restore said rings to a predetermined starting position upon disengagement of said clutch, an indicator manually movable in relation to a stationary scale providing at all times an indication corresponding to the adjustable starting position of said ring, electrical connections between a source of power and both said motor and said magnetically operated connection means through said circuit controller, means responsive to one of said rings at the opposite end of the series for actuating said circuit controller, and means for disengaging said magnetically operated connecting means upon actuation of said circuit controller.

12. In a timing mechanism, the combination with a plurality of adjacent successively coacting co-axial rings, each rotatable through a definite arc with respect to its successive adjacent ring and thereafter in driving engagement therewith, a circuit controller, a motor, a magnetically operated clutch providing driving engagement between said motor and one of said rings, a spring connected to said ring for restoration of said ring to an adjustable startin position upon disengagement of said magnetically operated connecting means, means responsive to another one of said rings for actuating said circuit controller, and means for disengaging said magnetically operated connecting means upon actuation of said circuit controller.

13. In timing mechanism, a housing, a plurality of pairs of circuit controllers, an electric motor, a restoring spring, a magnetically actuated clutch, means for windin said restoring spring, driven at a substantially uniform speed by said motor between a starting and actuating position through the connection provided by said clutch, means responsive to said driven means for altering the relationship of at least one of the pairs of circuit controllers upon the attainment of said actuating position by said driven means whereby to break said clutch connection and allow restoration of said driven means to said starting position by said restoring spring, adjusting means including a disk with a toothed periphery for changing the starting position of said driven means to vary the time of travel of said driven means between its startin and terminating positions, an indicator rigidly connected to said adjusting means and movable therewith in close relation to a stationary time units scale carried by the housing, a dog rigidly installed in the housing structure and positioned for normal holding engagement with a tooth of the disk, means for manually forcing the disk out of engagement with said dog, and automatic spring-actuated means for restoring holding engagement between said dog and disk upon release of manual force.

14. In a timer of the class described, the com- 1 9 bination with a housing, of a clutch shaft mount.- ed therein, a fixed clutch member rigidly united to theclutch shaft, a movable clutch member united to a clutch sleeve secured upon and slidable along said clutch shaft, a spur gear wheel united tosaid sleeve and having a central bore journaled upon an axle-bearing upon which said sleeve member and gear revolve and in whichthe clutch shaft may rotate, said axle-bearing being supported by a supportingplate insaid housing, a collar rotatablymounted upon said shaft in said bore and slidably united to said sleeve, a compression helical spring mounted upon the shaft arranged to exert pressure in opposite directions upon the axle-bearing and the sleeve whereby the movable clutch member may be urged toward and into engagement with the fixed clutch member, an outer sleeve rigidly mounted upon the clutch shaft spaced from the clutch sleeve, having a fixed driving ring at one end thereof and a tripping ring at the opposite end thereof, with a series of intermediate driving rings revolvably mounted on the sleeve between the fixed ring and the tripping ring, a helical spring mounted upon the clutch shaft arranged to tighten as the clutch shaft is driven by the motor and to unwind when the clutch is released, and having its opposite ends united to the supporting plate and the outer sleeve respectively, a second shaft parallel to the clutch shaft and having one end journaled in the housing and the other end journaled in a bearingsleeve rigidly supported in the supporting plate, a sleeve with a crown gear united thereto revolvably mounted on the bearing-sleeve and carwine a finger or lug arranged to contact and actuate a similar lug, on fingeron the first oi? a series of coaxialsuccessively: eoacting rings on said shaft, a sleeve secured on said shaftand spaced from the sleeve-bearing. carrying a spur geararranged to mesh with a correspondinggear mounted upon the outer sleeve on the clutch shaft, a manually operable shaft with a gearthereon in mesh with said crow-n gear whereby the relative positions of the drivingrings may be adjusted in various set positions, and a motor geared to the clutch shaft by suit-' able reduction gearing;

1 5. in a timerof; the class described, the combination with a motor, of; a cutout switch to out offthe current therefrom, switch operating mechanism, a trippin ring to actuate saidmechanis-m, a clutch shaft carrying. a fixed and a slidable clutch me mber-, a plurality ofadjustable co-axial successivelycqacting driving rings arranged to revolve around the clutch shaft and to be actuated by the slidable clutch member when driven by the motor for a predetermined inter-val to actuate the tripping ring.

l6. A combination as described in claim 15, and manually operable means to adjust the relative position of the driving rings so as to vary the time interval necessary to actuate the switch.

HARRISON I. TURN-ER.

REFERENCES CITED UNITED STATES P TENTS Name Date Sehwartz Oct, 29, 1940 Number