US3239614A - Second sub-interval circuit means for escapement devices - Google Patents

Description

March 8, 1966 H. T. SIMMONS SECOND SUB-INTERVAL CIRCUIT MEANS FOR ESGAPEMENT DEVICES Filed Oct. 30, 1963 4 Sheets-Sheet 1 INVENTOR.

HAROLD T SIMMONS ATTORNE March 8, 1966 H. "r. SIMMONS SECOND SUB-INTERVAL CIRCUIT MEANS FOR ESCAPEMENT DEVICES 4 Sheets-Sheet 2 Filed Oct. 30, 1963 S RN 00 M M l W3 T 23% ATTORNEY March 8, 1966 H. T. SIMMONS SECOND SUB-INTERVAL CIRCUIT MEANS FOR ESGAPEMENT DEVICES Filed Oct. 30, 1963 4 Sheets-Sheet 5 6 N a 6 I F w fl. 8 W 0 :7 11W w a 7 5 H 5 2 H o ATTORNEY March 8, 1966 H T, s M N 3,239,614

SECOND SUB-INTERVAL CIRCUIT MEANS FOR ESCAPEMENT DEVICES Filed Oct. 50, 1963 4 Sheets-Sheet 4 P fi Vl/l/ INVENTOR.

HAR LD T. SIMMONS BY ATTORNEY United States Patent 3 239,614 SECOND SUB-INTERVAL CIRCUIT MEANS FOR ESCAPEMENT DEVICES Harold T. Simmons, Indianapolis, Ind., assignor to P. R. Mallory & Co., Inc., Indianapolis, Ind., a corporation of Delaware Filed Oct. 30, 1963, Ser. No. 320,121 Claims. (Cl. 200-38) The present invention relates generally to time switch mechanisms and has specific pertinence to the means and method for providing a second sub-interval circuit in timing devices which employ mechanical escapements.

Numerous variations of mechanical escapement mechanisms are known to the timer art. Single sub-interval circuit actuating means can be found in conjunction with some of these prior art devices, thus offering increased versatility in timer programming. An example of a mechanical escapement device which is readily adaptable to the inclusion of a single sub-interval circuit is found in US. Patent No. 2,916,923, issued to C. S. Smith et al.

In the Smith et al. patent, supra, a tension-spring type mechanical escapement is disclosed. An improvement thereto, prior to the discovery of the instant invention, comprised the addition of a multi-lobed cam adjacent to the main escapement cam and concentrically disposed with respect thereto. Said improvement further included a cam follower and switch actuator assembly adapted to cooperate with the single or first sub-interval cam. Such a mechanism introduces a timed interval substantially smaller in magnitude than the basic impulse time of the escapement itself. In the case of an automatic washing machine, for example, it may be necessary to introduce rinse water into the machine during the spin function for a determined period, e.g., 10 seconds. Since the basic impulse time of the escapement is nominally much greater, e.g., 60 seconds, the single sub-interval circuit would conveniently afford the desired 10 second control function.

Continual advancement and increased complexity of domestic appliance control systems has imposed greater demand for timer flexibility. In the aforementioned washing machine application, for example, it may be desirable to provide another sub-interval activity within a time switch mechanism of the mechanical escapement type. Besides accommodating the 10 second spray period, it may be necessary to limit the off time between motor reversals, for example, to seconds. Again the special interval is considerably less than the escapement impulse time of 60 seconds. Such a requirement, therefore, would necessitate the introduction of a second sub-interval circuit.

Accordingly, in the present invention there is provided the means and method for conveniently introducing a second sub-interval circuit into a timing device of the mechanical escapement type. There are thus provided two sub-interval circuit actuating means within a single escapement mechanism, with no increase in space requirements and with the addition of a minimum number of working parts. By incorporating a suitable cam on an existing idler gear in the escapement mechanism, and by providing a cam follower in cooperation with an existing circuit switch and program'cam, the second subinterval means can be efficiently adapted to conventional escapement-type timers. Flexibility of programming change is also afforded by the present invention since various assemblies of idler gears and sub-interval cam rings may be readily installed and interchanged.

It is an object of the present invention, therefore, to provide means within a mechanical escapement device for actuating a second sub-interval circuit in a time switch assembly.

3,239,614 Patented Mar. 8, 1966 A further object of the present invention is to provide a second sub-interval circuit actuating device which cooperates with a conventional program cam to produce a timed interval less than that of the basic escapement impulse.

Another object of the present invention is to permit the use of two sub-interval circuit systems Within a single escapement device.

Still another object of the present invention is to provide a second sub-interval circuit actuating means requiring only two additional parts, viZ., a cam and a cam follower, when incorporated in a conventional escapement-type timer.

Yet another object of the present invention is to provide a second sub-interval circuit actuating device having inherent timing accuracy because it cooperates with the time-driven gear train which powers the escapement device.

Still another object of the present invention is to provide a second sub-interval circuit actuating device wherein each cycle is faithfully repeated and pulse durations are not affected by any escapement adjustments.

Yet another object of the present invention is to afford flexibility of programming within the second sub-interval actuating means by providing easy interchangeability of the associated cam and gear assembly.

Still another object of the present invention is to provide a second sub-interval circuit actuating device which is efiiciently and economically adaptable to existing time switch assemblies without increasing the size thereof.

The present invention, in another of its aspects, relates to novel features of the instrumentalities described herein for teaching the principal object of the invention and to the novel principles employed in the instrumentalities whether or not these features and principles may be used in the said object and/or in the said field.

Other objects of the present invention and the nature thereof will become apparent from the following description considered in connection with the accompanying figures of the drawing wherein like reference characters describe elements of similar function therein, and wherein the scope of the invention is determined rather from the dependent claims.

In the drawings:

FIGURE 1 is a perspective view of a typical electromechanical time switch assembly to which the present invention is adaptable.

FIGURE 2 is a perspective view, partially exploded, of a mechanical escapement mechanism incorporating the features of the present invention.

FIGURE 3 is a vertical sectional view of the time switch assembly of FIGURE 1, taken along line 33 of FIG- UR-E 1.

FIGURE 4 is an enlarged perspective view of the second sub-interval cam and follower parts of the present inventi-on.

FIGURE 5 is a sectional view taken along line 5-5 of FIGURE 3 showing the escapement position with the first and second sub-interval switches open.

FIGURE 6 is a sectional view taken along line 5-5 of FIGURE 3 showing the escapement position with the first sub-interval switch closed and the second sub-interval switch held open by the second sub-interval cam.

FIGURE 7 is a sectional view taken along line 5-5 of FIGURE 3 showing the escapement position with the first sub-interval switch open and the second sub-interval switch closed.

Generally speaking, the present invention permits the use of two sub-interval circuit systems within a single escapement-type timer. -By adapting a suitable cam member to an existing idler gear within the escapement drive train, there is provided a means of controlling one subinterval switch. Another sub-interval circuit switch is actuated in response to rotation of a muli-lobed cam afiixed in juxtaposition with the main escapement cam. Both sub-interval systems are susceptible to broad varia- 'tions in time period selection, and it thus becomes possible to introduce program flexibility heretofore unattainable in an escapement-type device.

Referring now to FIGURE 1 of the drawings, there is illustrated a typical electromechanical time switch assembly incorporating the features of the present invention. This timer is composed of two principal sub-assemblies, viz., the motor and escapement on stepping mechanism indicated by reference numeral 10, and the cam and switch mechanism indicated by reference numeral 11. Rear plate 12 serves as the baseplate for the mechanical escapement parts as well as affording mounting means for cam and switch assembly 11. Motor adapter plate 13 is affixed to one end of rear plate 12 and facilitates attachment of drive motor 14. A plurality of electrical switches, indicated typically by reference numeral 15, respond to the action of respective program cams on totatable camshaft 16. Front plate 17 provides forward support and piloting for camshaft 16.

Also visible in FIGURE 1 is the actuating portion of the first sub-interval mechanism of the mechanical escapement to be described herein. Pin 18, which is integral wit-h cam follower link 19, pivots with respect to stud 20 while sliding upon the surface of rear plate 12. Said movement of pin 18 causes actuation of first sub-interval switch member 54 through urging of actuator clip 21.

Referring now to FIGURE 2 of the drawings, the entire escapement and cooperating sub-interval mechanism 10 is seen in perspective view, partially exploded. Aperture 22 in motor adapter plate 13 permits engagement of the drive motor output pinion with second sub-interval gear 23, a constant speed member herein. Concentrically disposed with respect to gear 23 and rigidly afiixed thereto, is second sub-interval cam ring 24. Integral with cam ring 24, and projecting upward therefrom, is second subinterval cam lobe 25. The action of cam lobe 25 comprises the novelty of the present invention, viz., by affording a second sub-interval circuit activity within a conventional mechanical escapement mechanism. Retaining ring 26 locates second sub-interval gear 23 on its pivot post. A semicircular relief 27 in motor adapter plate 13 permits easy interchangeability of gear 23 for substitution of alternate cam ring configurations.

With continued reference to FIGURE 2, the mechanical advancement action of escapement 10 is described as follows. Second sub-interval gear 23 meshes with idler gear 28 which has idler pinion 29 coaxially disposed thereupon. Idler pinion 29, in turn, engages main gear 30 which is located on the camshaft centerline and journalled by post 31. Post 31 is cantilever-mounted in rear plate 12. Rigidly attached to main gear 30 on a common axis of rotation is a three-lobed escapement cam 32. This cam rotates in the direction of the arrow, either constantly or intermittently, depending upon the type of power supply, at one-third the desired impulse rate. As ma in gear 30 and escapement cam 32 rotate, the peripheral surface of one of the lobes, such as 33, comes in contact with a tolling arm 34. As rotation continues, tolling arm 34 is lifted by lobe 33, but is held against the cam periphery by means of a drive spring 35 having one end affixed to stationary arm 36 and the other end attached to the free end of tolling arm 34. The other end of tolling arm 34 turns angularly about stud 20. Also, on tolling arm 34 is disposed a drive pawl 37 pivotally attached thereto by means of stud 38.

With further reference to FIGURE 2 of the drawings, drive pawl 37 contains a finger 39 adapted to engage peripheral serrations in ratchet wheel 40. The finger portion of drive pawl 37 is adapted to overlap into a pocket or seat formed in stop pawl 41. Stud 42 serves as a pivot post for stop pawl 41 and holding pawl 43,

and torsion spring 44 urges both pawls toward ratchet wheel 40. Stop pawl 41 thus urges finger 39 of drive pawl 37 to accurately follow the individual serrations of ratchet wheel 40.

Referring still to FIGURE 2 of the drawings, the escapement action is described as follows. As tolling arm 34 swings outward in an are through urging of escapement cam 32, finger 39 of drive pawl 37 rises along a serration of ratchet wheel toward the tip thereof. Although drive pawl 37 is tightly held against the serration profile by means of stop pawl 41, ratchet wheel 40 does not rotate or back up while the drive pawl is being lifted because holding pawl 43 prevents such action. As drive pawl 37 cams upward and outward while tolling arm 34 rises, stop pawl 41 also cams outward away from the ratchet due to the outward motion of the drive pawl. Stop pawl 41, however, owing to the force of torsion spring 44, always presses against the extended tip of the drive pawl, thus holding it securely but lightly against the ratchet surface. The inclined surface of lobe 33 on escapement cam 32 is of such a height that tolling arm 34 is sufficiently raised so that drive pawl finger 39 drops in behind the next serration located counter-clockwise on ratchet wheel 40.

An escapement cam 32 completes one-third of its total rotation, or 120 degrees, the inclined surface of the cam abruptly ends and a straight drop-off surface is encountered. Thus, tolling arm 34, which is so constructed as to permit a free falling drop-01f from the cam lobe, reaches the end of the inclined surface thereof and instantaneously drops due to the force of drive spring 35. When tolling arm 34 forcefully drops, drive pawl finger 39 engages the face of a ratchet serration and forces ratchet wheel 40 to rotate instantaneously in a clockwise direction. At the completion of one serrations travel, the end of drive pawl 37 buts tangentially against the seat of stop pawl 41, thus limiting the return travel of both the drive pawl and the tolling arm. This constitutes the stopping action of stop pawl 41.

Through the constant rising and falling of tolling arm 34, as activated by escapement cam 32, ratchet wheel 40 is rotated intermittently in instantaneous advancements. The time duration of advancement cycles can be arranged predeterminedly by varying the speed of cam 32. Furthermore, the degree of angular advancement of ratchet wheel 40 can be set and determined :by varying the number of ratchet teeth. Camshaft 16, which has typical program cam 45 afiixed thereon, is piloted and supported on one end by a hole in post 31, the latter post being anchored in rear plate 12. Ratchet wheel 40, in turn, is radially piloted by the outside diameter of post 31 and torque is imparted from the ratchet wheel to the camshaft by virtue of tangs 46 engaging slots 47.

The basic escapement action having been heretofore described, the components of the first sub-interval circuit mechanism can now be discussed. Referring again to FIGURE 2 of the drawings, first sub-interval cam 48 is disposed in juxtaposition with escapement cam 32 and is adapted to rotate therewith about a common centerline. It can be observed, therefore, that main gear 30, escapement cam 32, and first subinterval cam 48 are all connected together for uniform rotation. Cam follower link 19, which pivots about stud 20, is responsive to the action of cam 48. Each rise and fall of follower link 19 causes pin 18 to actuate first sub-interval switch member 54 seen in FIGURE 1. Depending upon the number of lobes on cam 48, therefore, the periodicity of actuation of the first subinterval circuit may be selected in conformity to particular timing requirements.

By applying typical numerical values to the system illustrated in FIGURE 2, the relationship between the escapement impulse period and the first sub-interval period can be more clearly visualized. Assume, for example, that the time period between escapements or advancements of camshaft 16 is 1 minute. Since there are 3 lobes onescapement cam 32, one complete revolution of that cam would require 3 minutes or 180 seconds. Since first sub-interval cam 48 has the same angular velocity as cam 32, and since cam 48 contains 12 lobes in the configuration shown, actuator pin 18 would cycle every seconds, or four times during each escapement period. Quite often, howeven'the lobes on cam 48 will not be uniform and evenly spaced because of particular sequencing requirements. But in each instance, the first sub-interval period will be less than the escapement impulse period, and the versatility of the escapement is thus improved.

As herein-before mentioned, however, the purpose of the present invention is to afford even greater versatility to existing mechanical escapement devices. By the addition of second sub-interval cam ring 24, as illustrated in FIGURE 2, a second means of triggering a sub-interval circuit switch is provided. Placement of second sub-interval cam ring 24 within the time-driven gear train affords inherent accuracy such that each cycle of operation is faithfully repeated. Pulse durations are not affected by adjustments in the related escapement mechanism. Cam lobe 25 may feature a narrow or broad dwell surface in accordance with the particular interruption period required in the second sub-interval circuit switch. A plurality of cam lobes may be employed in lieu of single lobe 25 used for illustration in FIGURE 2. As hereinbefore cited, the introduction of various cam configurations is made relatively simple by means of removable ring 26 and access relief 27. Thus, the second sub-interval program is susceptible to broad variation herein.

Referring now to FIGURE 3 of the drawings, a sectional view of the time switch assembly of FIGURE 1 serves to illustrate the first and second sub-interval circuit actuating mechanisms. With attention to the second subinterval components, drive motor pinion 49 is shown in mesh with second subinterval gear 23. Second subinterval cam lobe 25 is adapted to strike nylon follower 50, the latter being rigidly attached by adapter 51 to movable sw-i-tch member 52. Tab 53 on switch member 52 rides the peripheral contour of program cam 45. With reference now to the first sub-interval circuit actuating components, follower link 19 is shown with actuator pin 18 affixed thereto. Adapter plate 21 is fixedly attached to movable switch member 54, and tab 55 is adapted to follow the peripheral contour of program cam 56.

FIGURE 4 presents an enlarged fragmentary perspective view of the second sub-interval cam and follower parts to emphasize the details of the present invention. It will be recognized that numerous variations in the cam and follower geometry may be made without departing from the intended scope of the inventive concept.

With reference now to FIGURE 5, escapement and subinterval mechanism 10 is seen in plan view, while terminal boards 57 and 58 have been sectioned to expose the first and second sub-interval switch assemblies. In this view the escapement mechanism is shown in a condition .just prior to the occurrence of an advancement impulse. Referring now to the first sub-interval actuating mechanism, it is seen that tab 55 of movable switch member 54 is prevented from following the recessed portion of program cam 56 because the end of follower link 19 is displaced by the rise section of cam 48. Hence, first sub-interval switch assembly 59 remains in the neutral position.

With continued reference to FIGURE 5, and particularly to the second sub-interval actuating mechanism, it is observed that tab 53 of movable switch member 52 is riding on the normal or neutral surface of program cam 45. Hence, second sub-interval switch assembly 60 remains in the neutral position. Second sub-interval cam lobe 25, which is advancing in the direction of its arrow with time-driven rotation of motor pinion 49, approaches follower 50.

As cam lobe 25 passes under follower 50, the escapement mechanism has actuated sufiiciently to cause an impulse or advancement of ratchet wheel 40 in the direction of its arrow. The amount of angular displacement is predetermined by the number of ratchet teeth and may be, for example, 6 degrees. Program cams 45 and 56 rotate the same amount. The resulting relationship of parts is illustrated in FIGURE 6. With reference again to the first sub-interval circuit actuating components, as now seen in FIGURE 6, tab of movable switch member 54 has lodged on the recessed portion of program cam 56. This occurred by virtue of the time-driven rotation of first sub-interval cam 48 which allowed the end of follower link 19 to reach the fall portion thereof. In turn, the contacts of first sub-interval switch assembly 59 were allowed to close, thus initiating that circuit activity.

While still referring to FIGURE 6, and particularly to the second sub-interval circuit actuating components, if is observed that recessed portion 61 of program cam 45 is located beneath tab 53. Although biased toward program cam 45, movable switch member 52 does not react because it is connected to cam follower 50 which, in turn, is restrained by the action of cam lobe 25. Second subinterval switch assembly 6%, therefore, is caused to remain in the neutral position. The duration of time for this delayed closing action is dependent upon the length of cam lobe 25.

When cam lobe 25 finally passes from under follower 50, as illustrated in FIGURE 7, the contacts of second sub-interval switch assembly 64 are caused to close through biasing of movable switch member 52, thus initiating that circuit activity. Electrical continuity through switch assembly will be maintained until the leading edge of cam lobe 25 once again strikes follower 50, thereby opening the contacts. In the embodiment herein illustrated, this opening action will occur just prior to the occurrence of the next escapement impulse. This is because the escapement time interval and the rotational period of gear 23 are equal, viz., 60 seconds, and it will be recalled that cam lobe 25 had previously struck follower 5% just prior to an escapement impulse. In this manner, therefore, the second sub-interval duration cannot only be made significantly shorter than the established escapement interval, but can be staggered with respect thereto. As hereinbefore mentioned, the second sub-interval cam configuration is susceptible to many variations. Besides varying the length of cam lobe 25, it may be desirable to employ a plurality of cam lobes such that switch assembly 60 would be cycled several times for determined periods during one revolution of gear 23.

With reference again to FIGURE 5 of the drawings, it is important to observe that second sub-interval cam lobe 25 is functional only when tab 53 is in registry with a recess in program cam 45, such as typified by reference numeral 61. When tab 53 is riding either the neutral surface or a raised portion of program cam 45, cam lobe 25 does not come in contact with follower 50. Hence, there is no resultant activity within the second sub-interval circuit and gear 23 serves merely as an idler gear for the escapement drive. In the illustrated embodiment, therefore, the second sub-interval circuit activity is intermittent and entirely responsive to the configuration of program cam 45. Extremely versatile sub-interval programming is thus afforded herein since the width and frequency of recessed portion at is capable of wide variation in the design of program cam 45. v

The second sub-interval device of the present invention as hereinbefore described in one of its embodiments, is merely illustrative and not exhaustive in scope. Since many widely different embodiments of the invention may be made without departing from the scope thereof, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interposed as illustrative and not in a limiting sense.

What is claimed is:

1. A mechanism for actuating a switch-operating cam assembly at determined intervals, said mechanism comprising a driving means, a stepping means physically coupled to and driven by said driving means, a plurality of sub-interval circuit actuating means cooperating with said mechanism, one sub-interval cam means disposed within said driving means, follower and switch means cooperating with said cam means to actuate one sub-interval circuit, another sub-interval cam means cooperating with said stepping means, and follower and switch means adapted to actuate a sub-interval circuit in response to rotation of said other sub-interval cam.

2. A mechanism for actuating a switch-operating cam assembly comprising a time-driven gear train, an escapement means physically coupled to and driven by said gear train, said escapement for advancing said cam assembly in a step-by-step manner at determined intervals, a plurality of sub-interval circuit actuating means, one sub-interval cam means affixed to a gear within said gear train, follower and switch means cooperating with said cam means to actuate one sub-interval circuit, another sub-interval cam means cooperating with said escapement, and follower and switch means adapted to actuate a sub-interval circuit in response to rotation of said other sub-interval cam.

3. A mechanism for actuating a switch-operating cam assembly comprising, a time-driven gear train, a stepping means physically coupled to said gear train, said stepping means for advancing said cam assembly in a stepby-step manner at determined intervals, a plurality of sub-interval circuit actuating means provided therein, one sub-interval cam means concentrically disposed with respect to an idler gear within said gear train and adapted to rotate therewith, follower and switch means cooperating with said cam means to actuate one sub-interval circuit, another sub-interval cam means cooperating with said stepping means, and follower and switch means adapted to actuate a sub-interval circuit in response to rotation of said other sub-interval cam.

4-. A mechanism for actuating a switch-operating program cam assembly comprising, a time-driven gear train a stepping means coupled to said gear train, said stepping means for advancing said cam assembly in a step-by-step manner at determined intervals, a plurality of sub-interval circuit actuating means provided therewithin, one subinterval cam mean concentrically disposed with respect to an idler gear within said gear train and adapted to rotate therewith, follower and switch means cooperating with said cam means to actuate one sub-interval circuit when scheduled by an adjacent program cam, another sub-interval cam means cooperating with said stepping drive mechanism, and follower and switch means adapted to actuate a sub-interval circuit in response to rotation of said other sub-interval carn when scheduled by an adjacent program cam.

5. A mechanism for indexing a switch-operating program cam assembly comprising, a time-driven gear train, an escapement means coupled to and driven by said gear train, said escapement means for advancing said cam assembly in a step-by-step manner at determined intervals, a plurality of sub-interval circuit actuating means, a sub-interval cam ring concentrically disposed with respect to an idler gear within said gear train and adapted to rotate therewith, said cam ring having a cam lobe of determined dimensions projecting upward therefrom, said cam lobe being adapted to cause delayed closure and subsequent reopening of one sub-interval circuit switch when scheduled by a cooperating program cam, another sub-interval cam means cooperating with said escapement means, and follower and switch means adapted to actuate a sub-interval circuit in response to rotation of said other sub-interval cam when scheduled by a cooperating program cam.

to index said cam assembly in a step-bystep manner at determined intervals, two sub-interval circuit actuating means, a sub-interval cam ring concentrically aflixed to a gear within said train, said cam ring having a plurality of cam lobes of determined dimensions projecting therefrom, said cam lobes cooperating with a follower to cause delayed closure and subsequent reopening of one sub-interval circuit switch, said switch being biased to ward the closed position, a multi-lobed cam cooperating with said stepping means, and follower and switch means adapted to actuate a sub-interval circuit in response to rotation of said multi-lobed cam.

'7. A mechanism for advancing a switch-operating cam assembly comprising, a time-driven gear train, an escapement means coupled to and driven by said gear train, said escapement means for advancing said cam assembly in a step-by-step manner at determined intervals, two sub-interval circuit actuating means provided therein, a plurality of sub-interval cam lobes of determined dimensions affixed to an idler gear within said gear train, said cam lobes cooperating with a follower to cause delayed closure and subsequent reopening of one sub-interval circuit switch, said switch being biased toward the closed position, a ratchet wheel rotatable about a fixed axis, a driving pawl having a wheel engaging portion for imparting movement thereto in a predetermined direction, tolling bar means on which and driving pawl is mounted, escapement cam means for angularly displacing said bar to move same and said driving pawl, a second pawl mounted on a pivot and having wheel engaging means for preventing movement of the wheel in the opposite direction, piv-otable locking means having a pocket formed therein cooperating with said driving pawl for accepting a portion thereof and guiding the movement of said driving pawl against said wheel so as to prevent over-driving the same, said pivotable locking means being concentrically mounted on the pivot of said second pawl, a multi-lobed cam fixedly disposed in juxtaposition with said escapement cam, and a pivotable follower responsive to rotation of said multi-lobed cam and adapted to actuate another sub-interval circuit switch.

8. A mechanism for advancing a switch-operating program cam assembly comprising, a timedriven gear train, an escapement means coupled to and driven by said gear train, said escapement for advancing said cam assembly in a step-by-step manner at determined intervals, two sub-interval circuit actuating means provided therein, a sub-interval cam ring concentrically disposed with respect to an idler gear within said train and adapted to rotate therewith, said cam ring having a cam lobe of determined circumferential length projecting upward therefrom, a follower cooperating with said cam lobe to cause delayed closure and subsequent reopening of one sub-interval circuit switch when scheduled by an adjacent program cam, said switch being biased toward the closed position, a main escapement cam for angularly moving a tolling bar about a fixed pivot point, a spring connected to the free end of said bar to maintain the same against said escapement cam, a driving pawl pivotably mounted on said bar having a tip portion and a finger portion, said finger portion being unitarily joined behind said tip portion, said finger portion adapted to bear against the teeth of a ratchet wheel, a second piv-otable pawl having a side adapted to limit the movement of said driving pawl against said wheel so as to prevent over-driving the same, a multi-lobed cam aifixed in juxtaposition with said escapement cam and adapted to rotate therewith, and a pivotable follower responsive to rotation of said multilobed cam for actuating another sub-interval circuit switch when scheduled by a cooperating program cam.

9. A mechanism for advancing a switch-operating program cam assembly comprising, a time-driven gear train, a stepping means coupled to said gear train, said stepping means for indexing said cam assembly in a step-by-step manner at determined intervals, two sub-interval circuit actuating means rovided therewithin, a sub-interval cam aflixed to a gear within said gear train, a follower attached to a movable switch arm biased toward the closed position, said follower cooperating with said cam to cause delayed closure of one sub-interval circuit switch when scheduled by an adjacent program cam, a multi-lobed cam cooperating with said stepping means, a pivotable follower responsive to rotation of said multi-lobed cam and having an actuator pin disposed thereon, said actuator pin cooperating with a movable switch member to operate another sub-interval circuit when scheduled by an adjacent program cam.

10. A mechanism for indexing a switch-operating program cam assembly comprising, a time-driven gear train, a stepping means coupled to said gear train, said stepping means for advancing said ca-m assembly in a step-by-step manner at determined intervals, a plurality of sub-interval circuit actuating means, a sub-interval cam affixed to a gear within said gear train, a follower attached to a movable switch arm biased toward the closed position,

said follower cooperating with said cam to cause delayed closure and subsequent reopening of one sub-interval circuit switch when scheduled by an adjacent program cam, the delay period of said closure being proportional to the circumferential length of said sub-interval cam, another sub-interval cam means cooperating with said stepping means, and follower and switch means adapted to actuate a sub-interval circuit in response to rotation of said other sub-interval cam when scheduled by a cooperating program cam.

References Cited by the Examiner UNITED STATES PATENTS 6/1965 Linn 200-38 6/1965 Anderson 307-141

Claims (1)

1. A MECHANISM FOR ACTUATING A SWITCH-OPERATING CAM ASSEMBLY AT DETERMINED INTERVALS, SAID MECHANISM COMPRISING A DRIVING MEANS, A STEPPING MEANS PHYSICALLY COUPLED TO AND DRIVEN BY SAID DRIVING MEANS, A PLURALITY OF SUB-INTERVAL CIRCUIT ACTUATING MEANS COOPERATING WITH SAID MECHANISM, ONE SUB-INTERVAL CAM MEANS DISPOSED WITHIN SAID DRIVING MEANS, FOLLOWER AND SWITCH MEANS COOPERATING WITH SAID CAM MEANS TO ACTUATE ONE SUB-INTERVAL CIRCUIT, ANOTHER SUB-INTERVAL CAM MEANS COOPERATING WITH SAID STEPPING MEANS, AND FOLLOWER AND SWITCH MEANS ADAPTED TO ACTUATE A SUB-INTERVAL CIRCUIT IN RESPONSE TO ROTATION OF SAID OTHER SUB-INTERVAL CAM.

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