US2891405A

US2891405A - Intermittent drive mechanism

Info

Publication number: US2891405A
Application number: US613421A
Authority: US
Inventors: Owen E Elmore
Original assignee: PR Mallory and Co Inc
Current assignee: Duracell Inc USA
Priority date: 1956-10-02
Filing date: 1956-10-02
Publication date: 1959-06-23
Anticipated expiration: 1976-06-23

Description

June 23, 1959 o E. ELMORE INTERMITTENT DRIVE MECHANISM Filed 001:. 2, 1956 Villa/lad I ll INVENTOR 01W Ziggy/M [Zr/Mia ATTORNEY 2,391,405 lNTERMITTENT DRIVE MECHANISM Owen Elmore, Indianapolis, .Ind., assignorto Mallory &.C0.,'.Ine., Indianapolis, Ind., acorpor'ation of Delaware Application Gctober 2, 1956, Serial No'., 6 13,421

12 Claims. (Cl. :74'-1.5)

The present inventionre'lates generally totimers of the type which are. used to timethe, cycleof an apparatus, such as a washing machine and the like and which are operative. to initiate or terminate an operating cycle after a predetermined interval, and has par ticular pertinency to such devices incorporating mechanical escapements.

It is a feature of the present invention to construct a mechanical escapement or intermittentdrive mechanism without requiring the use ofgears, cams, escape wheels and verges. It is common practice to provide in many electric switches used in automatic appliances, such as washing machines, dish-washers, etc., an escapement means which provides periodic, rapid closing and opening of electrical circuits. These escapements usually require a multiplicity of moving parts consisting of cams and trains of gears, They also have a tendency to produce over-travel of the switch cams which they drive and some of them make. use of an escape wheel and verge mechanism with which to reduce or elirninate the over-travel. Also, since these escapements usually provide periodic impulses,.the're may elapse time intervals during which no switching action is required, yet the impulses continue to occur, thus causing unnecessary wear of the escapement and its parts.

i It is an object of the present invention to. provide a simple, eflicient and practical. escapement for power drives and for timing devices.

It is also and'object of the present invention to provide for power drives in general .and' for those used in timing devicesa mechanical escapement providin'gior a simple and sturdy construction and'jone of more efficient and reliable operation.

7 Still another object of the invention-is to pr'ovide a simple escapement "consisting oft'a' minimum of parts;

Another object of the invention'is to provide an escape ment in which each impulse or jumph'as apre'cise amount of travel without any over-travel:

Another object of this invention isto provide an escapement in which-any impulsecan beiprovided for or deleted'as desired, and, if deleted; constant speed; of travel will result.

Another object of this invention-is to provide forthe substantial elimination of backlash -or free play of the cam shaft :of the "switch.

Another object of this invention is to provide an escapementwhichiwill provide. a' positivedriveto its lead in the event. of an overload or. failure ofrthe escapement spring.

Other objects and advantages will appear to those skilled in the art from'the. following, considered in conjunction :with: the accompanying "drawings.

I'n-th'e accompanying drawings, in which .certainmodes of. carrying-out the present invention are .shown for illustrative purposes, andwhereini Fig. .1 is a plan vievhof the novel .escapement of the invention as used, in conjunction with a synchronous typeset Zrnotorand driven thereby;

States atent .Fig. 2 is a. cross-sectional view of the escapement .of the present invention as .taken along line 2-2 of Fig 1;

Fig. 3 is a cross-sectional view of the escapement of the present inventionas taken along line 3*3 of Fig 1;

Fig. 4 is. a viewof a portion of the escapement of the presentinvention useful in depictingthe relationship between the driving: elements therein and its associated toothed restricting plate; and

Fig. 5 is an exploded view of the driving arm, the driven arm and.the driving plates so as to more adequately depict .the cooperative arrangement therebetween.

Generally speaking, the present invention relates to escapements for timing devices through the utilization of which it becomes possible. to control the intermittent operation of cam switches. These cam-operated switches are in turn enabled to activate a series of contacts in a determined sequential pattern. Theescapement is usually operative between a continuously operating motor and the. intermittently operated cam mechanism. Thus, it'is. constructed for a step by step motivation, in determined increments of motion of the cams of a cooperating switch; Such escapements are thus usually of complicated geared relationship, including several components. Moreover, these devices have a tendency to'produce over-travelof switch cams, necessitating the use of braking or confining'means therefor. The present escapement comprises extremely few'moving parts, which accomplishesadded efficiency in that backlash or free play of the cam shaft is practically eliminated. The escapement further provides a" positive drive to its lead an overload or'failu re of the escapement spring. Referring to'the figures, there is depicted a section of a timer switch 9 having a motor 14} so constructed that whenenergized the outputgear'set'for shaft 11 rotates it in a clockwise direction-as viewed from end 8 of shaft 12." This shaft can not be rotated'manually in either direction. This is so because shaft 111, as driven by motor 10; is coupled toan associated inner shaft 12 of switch section9 by means of a one-wayspring clutch mechanism 13. This clutch mechanism is so arranged rotationofthe-inner-shaft-12.= However, if'an attempt is made-to-r'otateinnershaft in a counter clockwise direction, the aforesaid spring clutch mechanism 13' tightens to the l'notor shaft" liJl and -rotation in this direction is prevented.

The clutch -mechanism-13, as shown particularly in Figs. 2: and :3:: comprises-two shaft-sections 8t and 81 connectedltoeach'other:via'- a rod82 projecting into a bore'83-andadapted to fittherein in a substantially-tight manner so i as :toform a .friction clutch having a helical tension. springi- 24 tightly wound thereabout.

Driving plate 14". is securely fastened. to and rotates withsinner shaft 12. Driving arm ldis supported by driving plate .14 andzpivots'zabout tab'17; which is part of driving plate 14. Driven plate 18 is securely fastened to and. drives outerl shaft 19'i which is concentric with innershaft 12 Outerashaftf19 whendriven, drives'conf ventional circuit camsswhichare attached to it, but are not shown. 7 Driven. plate 18: contains two guide: tabs 20, turned inwardlyas viewed from the shaft end, straddlingldrivingarm 16. These serveto allow driving-arm lztoslide. freely. in a direction. approximately perpendicular'with'trespectstothe direction of'r'o'tational increments," but which serve to. transmit the. incremental :rotational.

driving; force. imparted *by driving. arm 16 to the driven plate v18. .One 'extremity-oratongue. 21 of. driving arm 16 normally 'engageswithtone. of theinternalv teeth' 22:

Further,

of restricting ring 23. Helical tension spring 24 is attached between the opposite extremity 25 of driving arm 16 and an appropriate arm 27 forming a part of driving plate 14.

Driven plate 18, arm 16, and driving plate 14 are adapted to fit over each other and to cooperate as shown in Figs. 1-4. In Fig. the structure of each of these components is specifically shown. The driving plate of the escapement 14 comprises an especially configured and integrally formed thin plate having an angulated, arrow shaped head portion 40 having

sides

41 and 42. Tab 43 is vertically joined to side 42. Extending therefrom is a horizontal dependency having finger-

like projections

44 and 45 separated by means of vertical tab 17. A circular aperture 50 adapted to fit over shaft 12 is centrally formed in the main portion 51 of the plate. Extending substantially at right angles thereto is an arm 27 having a side 52 joined to side 41 and a side 53 joined to extension 45. Arm 27 further has a cut-out 55 for purposes of anchoring and coupling one end of spring 24 to arm 16 which also has a cut-out 56 formed therein for anchoring the aforesaid spring 24 thereto.

Arm 16 comprises a unitarily formed plate having opposing

sections

21 and 25, the

sides

60 and 61 of which are slightly angulated with respect to each other. Side 62 of arm 16 joins angulated side 63 and side 64 thereof by means of a bowed portion. A rhomboidally configured cut-out 67 is adapted to fit over tab 17.

Driven plate 18 comprises a unitarily formed thin cross-sectioned plate having a substantially rectangular top section 70, a bottom semi-circular section 71 through which a circular aperture 72 is cut for purposes of circumscribing the shafts of the switch. A finger

extension comprising sides

74, 75, and 76 is joined thereto and vertical dependencies extend therefrom as adapted to contain tip 21 of arm 16 therebetween as described in the operation of the switch.

In the operation hereof, assume driving arm 16 to be completely engaged with one internal tooth of restricting plate 23. As a constant speed rotational force is supplied by the motor, driving plate 14 is rotated clockwise and driving arm 16 is moved by tab 17 on driving plate 14 towards the tip of internal tooth 28 to which it is engaged. Driving arm 16 can only slide in a direction which is approximately tangential to the outer shaft due to its being retained against internal tooth 28 on restricting ring 23, with a positive loading from helical spring 24. Since the spring retaining arm 27 of driving plate 14 continues to rotate, spring 24 is extended, thus applying and transmitting a similar force to the spring retaining end of driving arm 16.

Driving arm 16 continues to slide until the end or tongue 21 which was previously engaged with an internal tooth 28 of restricting plate 23 clears the tip of that tooth. By virtue of the force applied to its opposite end by spring 24, arm 16 now travels in an arc pivoted about tab 17 until it strikes and is retained by the next internal tooth 29 of restricting plate or ring. Thus, this motion of driving arm 16 is transformed into a rotary motion of driven plate 18 by the restricting tabs 20 which straddle driving arm 16 and thus an impulse or jump advancement of driven plate 18 and its outer shaft 19 is accomplished.

It is to be noted that any tooth, or series of teeth, can be deleted as desired from the restricting plate, which will then allow for constant speed rotation without impulses over the portion so deleted. If spring 24 should fail, such as by breaking or by not having sufficient force to overcome the load attached to shaft 19, tab 17 of driving plate 14 will continue to rotate until it engages the nearest edge of tab of driven plate 18, thereby driving plate 18 and the attached load at constant speed.

The amount of backlash or free play of the cam shaft 19 is strictly dependent of the fit between straddling tabs 20 on driven plate 18 and the width of driving arm 16.

.4 There is no other source for play and this amount is thus completely controlled or eliminated.

From the foregoing, it is apparent that the present novel escapement embodies improvements and features which substantially lessen the number of component parts needed, with, of course, consequent savings in cost of fabrication, yet provides an escapement of great efi'iciency capable of driving relatively heavy switch mechanisms.

What is claimed is:

1 l. A mechanism for converting rotation from a continuous source to a step by step incremental movement at predetermined intervals to associated cyclic and timing devices utilizing means for activating a series of associated electrical circuits, comprising a continuously operating motor, a shaft coupled thereto and turned thereby, said shaft having a plurality of sections one of which has a bore to receive a pin from its adjacent section and being adapted to be interlocked with respect to each other, clutch mechanism for locking said sections so as to provide unitary movement only in one rotational direction, one of said shaft sections adapted to motivate an intermittent drive placed between said motor and said utilizing means for activating electrical circuits, said intermittent drive including a driving plate connected to said section including the bore and having a pair of finger extensions separated by a tab, a driving arm coupled thereto by said tab, a spring connected therebetween, and a driven plate having a pair of guides moveable about the circumference of a toothed ring, said driven plate being moved thereabout at predetermined intervals by force exerted thereon by said driving arm on said guides, and an output shaft attached to said driven plate adapted to be moved incrementally by said driven plate.

2. A mechanism for converting rotation from a continuous source to a step by step incremental movement at predetermined intervals to associated timing and cyclic devices utilizing means for activating a series of associated electrical circuits, comprising a continuously operat ing motor, a shaft coupled thereto and turned thereby, said shaft having a plurality of sections one of which has a bore to receive a pin from its adjacent section and being adapted to be interlocked with respect to each other, clutch mechanism including a pressure spring circumscribing said shaft so as to provide unitary movement between the sections only in one rotational direction, said shaft section having the bore connected to an intermittent drive including a driving plate, a driving arm coupled thereto, a spring connected therebetween, said driving arm having a finger extension, a driven plate coupled to said driving arm, a toothed restricting ring having a multiplicity of individual teeth radially disposed with said escapement, said finger adapted to bear against said individual teeth to be moved in increments thereby, and an outer shaft of said mechanism adapted to be coupled to said driven plate.

3. A mechanism for converting rotation from a continuous source to a step by step incremental movement at predetermined intervals to associated timing and cyclic devices having means for activating a series of associated electrical circuits, comprising a continuously operating motor, a shaft coupled thereto and turned thereby, said shaft having a plurality of sections one of which has a bore to receive a pin from its adjacent section and being adapted to be interlocked with respect to each other, clutch mechanism including a pressure spring circumscribing said shaft so as to provide unitary movement between the aforesaid sections only in one rotational direction, said shaft section having the bore connected to an intermittent drive including a driving plate, a driving arm coupled thereto including a spring connected therebetween, said driving arm having a finger extension, a driven plate coupled to said driving arm, a toothed restricting ring having a multiplicity of individual teeth radially disposed with respect to said arm, said finger adapted to bear against said individual teeth to be restrained thereby,

ascribe i and an outer shaft of said mechanism adapted to be coupled to said driven plate, whereby mechanism coupled to said outer shaft will also be'moved'in accordance with the rotational motion transmitted to said outer shaft.

4. A mechanism for converting rotation from a continuous source to a step by step incremental movement at predetermined intervals to associatedtiming and cyclic devices having means for activatinga series of associated electrical circuits, comprising a continuously operating motor, a shaft coupled thereto and turned thereby, said shaft having a plurality of sections one. of which has a bore to receive a pin from an adjacent sectionand being adapted to be interlocked with respect to each other, a clutch mechanism including a vhelical pressure spring circumscribing said shaft so as to provide unitary movement between the aforesaid sections only in one rotational direction, said shaft section having the bore connected to an intermittent drive including a driving plate having a pair of projectionsseparatedby a tab, a driving arm having a finger portion, a spring connecting said plate and said arm, an aperture formed insaid arm fittable over said tab and adapted to pivot thereon,.a driven plate coupled to said driving arm, a toothed restricting ring having a multiplicity of individual teeth externally concentrically disposed with respect to said arm, said finger adapted to bear against said individual teeth to be restrained thereby, and an outer shaft of said mechanism adapted to be coupled to said driven plate, whereby mechanism coupled to said outershaft will'also bemoved in accordance with the rotational motion transmitted to said outer shaft.

5. A mechanism for converting:rotatiomfrom a continuous source to a step by step incremental movement at predetermined intervals to associated timing and cyclic deviceshaving-meansfor activating aseries of associated electrical circuits, comprisinga continuously operating motor, a shaft coupled thereto and turned thereby, said shaft having apluralityof sections one of which has a bore to receive a pin from an adjacent section and being adapted to be interlocked with respectto each other, a clutch mechanism including a helical pressure spring circumscribing said shaft so as to provide unitary movement between the aforesaid sections only on one rotational direction, said shaft section having a bore connected to an intermittent drive including a driving plate having a pair of projections separated by a tab, a driving arm having a finger portion, a spring connected between said plate and said arm, an aperture formed centrally in said arm fittable over said tab and adapted to pivot thereon, a driven plate coupled to said driving arm by means of a plurality of guiding tabs, a toothed restricting ring having a multiplicity of individual teeth outwardly radially disposed with respect to said arm, said finger adapted to bear against said individual teeth to be restrained thereby, and an outer shaft of said mechanism adapted to be coupled to said driven plate, whereby mechanism coupled to said outer shaft will also be moved in accordance with the rotational motion transmitted to said outer shaft.

6. A mechanism for converting rotation from a continuous source to a step by step incremental movement at predetermined intervals to associated timing and cyclic devices having means for activating a series of associated electrical circuits, comprising a continuously operating motor, a shaft coupled thereto and turned thereby, said shaft having a plurality of sections one of which has a bore to receive a pin from an adjacent section and being adapted to be interlocked with respect to each other, a clutch mechanism including a helical pressure spring circumscribing said shaft so as to provide unitary movement between the aforesaid sections only in one rotational direction, said shaft section having a bore connected to an intermittent drive including a driving plate having a pair of projections separated by a tab, a driving arm coupled thereto by said tab, said driving arm having a finger portion,- a driven plate coupled to said driving finger adapted to bear against said individual teeth to be restrained thereby, and an'outer shaft of said mechanism adapted to be coupled to said driven plate, whereby mechanism coupled tosaid outer shaft will also be moved in accordance with the rotational motion transmitted to said outer shaft.

7. A mechanism for converting rotation from a continuous source to a step by step incremental movement at predetermined intervals to associated timing and cyclic devices utilizing means for activating a series of associated electrical circuits, comprising acontinuously operating motor, a shaft coupled thereto and turned thereby, said shaft having a plurality of separate sections one of which has a bore to receive a pin from an adjacent section and being adapted to be interlocked with respect to each other, a clutch mechanism including a pressure spring circumscribing said shaft so as to provide unitary movement betweenthe sections only in one rotational direction, said shaft section having a bore connected to a notched driving plate having a pair of extensions separated by a tab, a drivingarrn having an aperture fitting over said tab within which said tab may move, said driving arm having a finger extension and an opposing end having anotch therein, a spring connecting the notches ofsaid driving plate and arm, a driven plate coupled to said driving arm, a toothed restricting ring having a multiplicity of individual teeth radially disposed with said escapernent, said finger-adapted to bear against said individual teeth to be moved in increments thereby, and an outer shaft of said mechanism adapted to be coupled to said driven plate, whereby mechanism coupled to said outer shaftwill also be moved in increments in accordance with the motion transmitted to said outer shaft.

8. A mechanism for converting rotation from a continuous source to a step by step incremental movement at predetermined intervals to associated cyclic and timing devices utilizing means for activating a series of associated electrical circuits, comprising a continuously operated motor, a multiple-sectioned shaft coupled thereto and turned thereby, said shaft having a plurality of sections abutting one another, a clutch mechanism for engaging said sections so as to provide unitary movement thereof only in one rotational direction, one of said shaft sections having a bore to accept a cooperating pin from its adjacent section and adapted to motivate an intermittent drive placed between said motor and said utilizing means for activating electrical circuits, said intermittent drive including a driving plate connected to said shaft section having said bore, a driving arm coupled thereto including a spring, and a driven plate moveable thereby, said latter plate having means to guide said arm, said driving arm being moved along a toothed ring at predetermined intervals by force exerted thereon by said driving plate and spring, and an outer shaft connected to and moved incrementally by said driven plate.

9. A mechanism for converting rotation from a continuous source to a step by step incremental movement at predetermined intervals to associated cyclic and timing devices utilizing means for activating a series of associated electrical circuits, comprising a continuously operating motor, a multiple-sectioned shaft coupled thereto and turned thereby, said shaft having a plurality of sections abutting one another, a clutch mechanism including a spring circumscribing said sections so as to provide unitary movement of said multiple shaft only in one rotational direction, one of said shaft sections having a bore for accepting a cooperating pin and being adapted to motivate an intermittent drive placed between said motor and said utilizing means for activating electrical circuits, said intermittent drive including a driving plate connected to said section with the bore, a driving arm coupled thereto including a spring, and a driven plate moveable thereby, said latter plate having means to guide said arm, said driving arm being moved along a toothed ring at predetermined intervals by force exerted thereon by said driving plate and spring, and an outer shaft connected to and moved incrementally by said driven plate.

10. A mechanism for converting rotation from a continuous source to a step by step incremental movement at predetermined intervals to associated cyclic and timing devices utilizing means for activating a series of associated electrical circuits, comprising a continuously operating motor, a multiple-sectioned shaft coupled thereto and turned thereby, said shaft having a plurality of sections abutting one another, a clutch mechanism including a spring circumscribing said sections and having a post in one section accepted by a bore in its adjacent section so as to provide unitary movement of said multiple shaft sections only in one rotational direction, said shaft section having a bore adapted to motivate an intermittent drive placed between said motor and said utilizing means for activating electrical circuits, said intermittent drive including a driving plate connected to said shaft section with the bore and having a vertical tab extending therefrom, a driving arm coupled thereto by a cut-out fitted over said tab, a spring connected therebetween, and a driven plate moveable by said arm, said driven plate being moved about said shaft to carry said driving arm along a toothed ring atdesired intervals, and an outer shaft connected to and moved incrementally by said driven plate.

11. A mechanism for converting rotation from a continuous source to a step by step incremental movement at predetermined intervals to associated electrical circuits, comprising a continuously operating motor, a multiplesectioned shaft coupled thereto and turned thereby, said shaft having a plurality of sections abutting one another, a clutch mechanism including a spring circumscribing said sections and having a post in one section accepted by a bore in another so as to provide unitary movement of said multiple-section shaft only in one rotational direc tion, said shaft section having a bore adapted to motivate an intermittent drive placed between said motor and said utilizing means for activating electrical circuits, said intermittent drive including a driving plate having a vertical tab extending therefrom, a driving arm coupled thereto by a cut-out fitted over said tab, a spring connected therebetween, and a driven plate moveable by said arm, said driven plate being moved about said shaft to carry said driving arm along a toothed ring at desired intervals, said plate having dependencies as guides for said arm, an outer shaft connected to and moved incrementally by said driven plate.

12. A mechanism for converting rotation from a continuous source to a step by step incremental movement at predetermined intervals to associated cyclic and timing' devices utilizing means for activating a series of associated electrical circuits, comprising a continuously operating motor, a multiple-sectioned shaft coupled thereto and turned thereby, said shaft having a plurality of sections abutting one another, a clutch mechanism for engaging said sections so as to provide unitary movement of said multiple shaft only in one rotational direction, one of said shaft sections having a bore to receive a cooperating pin and adapted to motivate an intermittent drive placed between said motor and said utilizing means for activating electrical circuits, said intermittent drive including a driving plate connected to said shaft section with the bore, a driving arm having a tip portion coupled thereto by means of a tab, a spring connected therebetween, and a driven plate having a pair of dependencies containing said tip portion of said arm being activated by said spring and adapted to move in and out of the declivities of a toothed refractory ring, and an outer shaft thus adapted to be moved incrementally by said driven plate.

References Cited in the file of this patent UNITED STATES PATENTS 850,981 Tillotson Apr. 23, 1907 1,479,970 Leppert Jan. 8, 1924 2,021,413 Gille Nov. 19, 1935 2,218,726 Scott Oct. 22, 1940 2,678,570 Black et al May 18, 1954 2,733,013 Rogers et al. Nov. 8, 1955 FOREIGN PATENTS 689,942 Great Britain Apr. 8, 1953