US3244824A - Astronomic dial for time switch - Google Patents

Description

April 5, 1966 R NNNNN NG 3,244,824

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ASTRONOMIC DIAL FOR TIME SWITCH Filed Dec. 25, 1963 :3 Sheets-Sheet 2 FIGZ INVENTOR.

RALPH M. MANNING ATTORNFY April 5, 1966 R. N. MANNING 3,244,824

ASTRONOMIC DIAL FOR TIME SWITCH Filed Dec. 23, 1963 5 Sheets-Sheet 5 FIG. 5

FIG. 5c

INVENTOR.

RALPH M. MANNING ATTO RN EY United States Patent 3,244,824 ASTRONQMFC DiAL 1 0R TIME SWITCH Ralph M. Manning, Winchester, Mass, assignor to General Electric Company, a corporation of New York Filed Dec. 23, 1963, Ser. No. 332,676 14 Qlaims. (1. 20ti38) This invention relates to time switches, and more particularly to astronomic dials for time switches.

Astronomic dials for time switches generally comprise a timing dial which is suitably rotated once every twentyfour hours so that each switch actuating arm, supported to rotate with the timing dial, will actuate a stationary switching device which is suitably placed at the periphery of the timing dial to be actuated by the arm as the timing dial revolves.

As is well known in the art, the movement of each switch actuating arm with respect to the rotating timing dial is controlled in accordance with a predetermined program so that the switch actuating arm may be utilized to perform switching functions throughout the year at times coinciding with sunrise and sunset. This is generally accomplished by providing cams individual to each arm for controlling the motion of the corresponding arm with respect to the timing dial. These cams are caused to rotate with the calendar dial which is suitably geared to the timing dial so that it will rotate once for every 365 revolutions of the timing dial. In this way, each cam rotates through one complete revolution each year and thus provides the desired program for its corresponding arm.

It is also recognized that the time of sunrise and sun set varies not only with variations in the season but also with variations in latitude. For this reason, the cams utilized in the prior art devices would only be suitable a few degrees either side of the particular latitude for which the arms were designed. Thus, in order to cover a range of latitudes, a compromise had to be made between accuracy and the number of cams necessary to cover the desired range. Consequently, a plurality of pairs of cams had to be manufactured so that the proper number of pairs of cams would be available to cover all desired latitudes. Furthermore, once one of these prior art astronomic dials was installed at a particular location, it could not be moved to a different latitude without necessitating the purchase and installation of a new set of cams designed for the new latitude. This type of astronomic dial thus lacked the desired flexibility which would permit its use at different latitudes. it also created manufacturing and distributing problems due to the necessity for manufacturing and stocking a plurality of sets of cams. In addition, these dials were found to be quite costly due to the inclusion of the speed-reducing gear train utilized to drive the calendar dial.

Accordingly, it is an object of this invention to provide an astronomic dial which avoids the previously-noted limitations of the prior devices.

It is another object of this invention to provide an astronomic dial which has a single cam for controlling the a.m. and pin. switch-actuating arms.

It is another object of this invention to provide an astronomic dial which has a single cam that is capable of controlling the a.m. and p.m. switch-actuating arms over a Wide range of latitudes.

It is yet another object of this invention to provide a low cost astronomic dial by simplifying its construction, reducing the number of parts and eliminating the necessity for a costly speed-reducing gear train previously used to drive the calendar dial.

It is still another object of this invention to provide an improved and simplified system for rotatably driving one member at a speed with respect to a rotating timing member which is a submultiple of the speed of rotation of the timing member.

An astronomic dial embodying the present invention suitable for actuating a switching device in accordance with the seasonal variations in sunrise and sunset comprises a timing disk carrying on its periphery a spiral cam which is rotated a given amount for each revolution of the timing disk so as to rotate the associated calendar dial a corresponding amount with respect to the timing dial through its cooperation with the plurality of pin-shaped projections arranged in a circular configuration upon the calendar dial. It is another important feature of this invention that integral with the calendar dial a single cam surface is provided for controlling both the a.m. and p.m. actuating arms.

In accordance with this invention, cam followers, individual to each switch actuating arm, are simultaneously in cooperative engaging relationship with different portions of the single cam that is provided to control their movement. The cam and cam followers in turn cooperate with individual slots in the timing disk and the switch actuating arms to provide the desired relative motion between the switch actuating arms and the timing disk. Adjustments for variations in the latitude are accomplished by providing for the selective adjustment of the axis of the slots in the switch actuating arms relative to the axis of the slots in the timing disk.

The features of this invention which are believed to be novel are set forth in the appended claims while further important aspects and features, as well as objects and advantages, will be more readily understood by a reference to the following detailed description and drawings in which:

FIG. 1 is a front elevation showing a time switch assembly with the astronomic dial of the invention mounted in position;

FIG. 2 is an exploded perspective view of the astronomic dial of my invention;

FIG. 3 is a cross-sectional view of the astronomic dial taken along lines 33 in FIG. 1;

FIG. 4 is an elevational view partially in section of a portion of the astronomic dial which illustrates the cooperation between the spiral cam and the calendar dial, and

FIGS. Sa-Sc are elevational views showing the manner in which the spiral cam and pin-shaped projections in the calendar dial cooperate in accordance with the invention.

This invention is disclosed in relation to a time switch of the type disclosed in US. Patent 2,900,463 of William I. Schultz and Carl F. Van Benekom, issued August 18, 1959, and assigned to the same assignee as the present application. However, it should be recognized that the astronomic dial of this invention is not limited it use with time switches of the type disclosed in the aforementioned patent but is equally applicable to other and different types of time switches.

Referring to the drawings, there will be seen in FIG. 1 a time switch assembly of the type disclosed in the aforementioned patent which comprises a support plate 1 having an enlarged opening 3 permitting through access to the front and rear sides of the plate. Spanning the opening 3 on the front side of plate 1 is a bridge member 4 preferably integral with the plate. Extending rearwardly through opening 3 and substantially centrally disposed therewith is a stationary shaft (not shown) which in cantilever fashion has one end fixed to bridge member 4 while the opposite end freely extends beyond the rear side of plate member 1.

Mounted on support plate 1 and extending along the rear surface thereof is a switch and a switch operator 5 which in its preferred form is cylindrical in shape and has an axial opening therethrough for mounting on the stationary shaft support previously mentioned. The outer peripheral surface of operator is provided with sets of longitudinally disposed .actuator cams '6 and '7 and switch operator cams 8. As is more clearly explained in the Schultz et al. patent, the plurality of opera-tor cams '8 extending longitudinally along the surface of operator 5 are adapted to engage and actuate the switch assembly upon rotation of operator 5. This rotation is provided when trippers 11 and 12 sequentially engage, as they rotate with timing dial 13, in a manner which will hereinafter be explained. Rotation of timing dial 13 at a constant speed is provided in a manner well known in the art through suitable gears to a synchronous drive motor. It can thus be seen that the positioning of the trippers 11 and 12 with respect to timing dial 13 will determine the scheduling of the sequential operation of the switch asse'mbly.

Referring now to FIG. 2, the components that make up the astronomic dial assembly of my invention are illustrated in an exploded perspective fashion to facilitate an understanding of the invention. Timing dial 13 which is secured to timing member 14 by screw 15 is not illustrated in FIG. 2 to permit a clear representation of the remaining components of the dial. However, it will be recognized that annular shoulder 16 on timing member 14 provides means for concentrically locating timing dial '13 with respect to timing member 14.

A depending bushing 17 (see FIG. 3) is provided to mount the dial assembly on the shaft of the timing motor to which it is keyed while at the same time providing means for supporting actuator arm 18 and 19, cam follower holders 20 and 21, and calendar dial 22 so that these elements can rotate with respect to timing member 14. Arms 18 and 19 which carry trippers 12 and 11 also serve to support latitude compensating members 23 and 24- so that they can rotate with respect to the arms. Means are provided by locking screws 25 and 2a to lock the position of latitude compensator members 23 and 24 with respect to arms 18 and 19, respectively.

Astronomic dial assembly 10 may be assembled as follows: Switch actuating arms 18 and 19 are first mounted upon bushing 17 inan order dicta-ted by the design of operator 5. The order indicated in FIG. 3 is based upon the assumption that the actuator cam to be operated by tripper 11 is adjacent the top end of operator 5. For this reason, tripper 11 is mounted on top of .arm 19 and tripper 12 is shaped and positioned to actuate a longitudinally offset actuator cam. Cam follower holder 20 is then placed so as to straddle bushing 17 and pin 28 is advanced into slot 29 of latitude compensating member 23 until one end of spring 27 can be placed over pin 28 before it is advanced into slot 36 of timing member 14. Next, pin 31 is passed through the opposite end of spring 27 and is then placed in slots 32 and 33. At this point, calendar dial 22 is mounted upon the bushing 17 and is rotated until the cam follower portions of pins 28 and 31 drop into slot 36 where they are brought into engagement with cam surface 37 by the action of spring 27. After this assembly operation is complete, calendar dial 22 is secured on bushing 17 by washer 34 and fastener 35.

The astronomic dial assembly may now be mounted upon the shaft of the timing motor assembly to which it is keyed in any well known manner. The assembly may then be fastened to the shaft by screw 38.

As was previously indicated, astronomic dial assembly 11 is ro-tated'one revolution per day so that star wheel 50 will come into contact with projection 41 of bridge 4 once each day. Referring now to FIG. 4, star wheel it) is staked to a shaft which passes through bushing 39 in the periphery of timing member 14. The other end of this shaft is attached to spiral cam 42 to rotate it one fifth of a revolution for every revolution of timing member 14.

Suficient clearance is provided between timing member 14 .and calendar dial 22 so that spiral cam 42 may be raised so that it will be disengaged from pins 43 on the periphery of calendar dial 22. This is an important feature of my invention since it readily permits the calibration of the astronomic dial, when it is being placed in service, by merely grasping star wheel and pulling it upwardly so that calendar dial 22 is free to rotate until indexing projection 45 is made to coincide with the proper calendar date around the periphery of calendar dial 22. This is to be contrasted with the difiiculty faced in disconnecting the calendar dial from the gear train in the prior art devices.

Referring now to FIG. 4, it may be seen that the axis of the star Wheel-spiral cam assembly is til-ted with respect to the plane of calendar dial 22 so that only one portion of the lower edge of spiral cam 42 is in contact with the upper surface of calendar dial 22. It will be noted that in the preferred embodiment of this invention there are five points on star wheel 40 so that it will revolve one fifth of a revolution each day in response to one of its projections coming in contact with projection 41. Bearing in mind that calendar dial 22 should make one complete revolution with respect to timing dial 13 1 every 365 days, there are provided around the periphery of calendar dial 22 seventy-three equally spaced pins. These pins cooperate with the spiral cam 22 to bring about the required movement of the calendar dial with respect to the timing dial without requiring the bulk and expense associated with a gear train.

Referring now to FIGS. Szz-Sc, it can be seen that each complete revolution of spiral cam 42 will result in moving calendar dial 22 clockwise, with respect to timing dial 1-3, a distance proportional to the spacing between corresponding points on two adjacent pins. FIGS. Sa-Sc illustrate the relationship between cam 42 and the pins on calendar dial 22 when the cam is being rotated in the direction indicated by arrow 50. FIG. 5a illustrates the beginning of a cycle of operation when cam 42is picking up pin 43a while dropping pin 43. FIGS. 5 b and 5c indicate the progressive positions of the pins with respect to spiral cam 42 as the cam rotates, it being recognized that the cam will complete this cycle of operation after the passage of five days at which time spiral cam 42 will drop pin 43a and pick up pin 4-31) to start a new cycle.

To summarize then, timing dial 13 which is revolved one complete revolution every 24 hours carries star wheel 44) so as to come into contact with projection 41 to thereby cause the rotation of star wheel through one complete revolution every five days. Spiral cam 4-2 in turn cooperates with pins 43 upon calendar dial 22 to rotate it one complete revolution with respect to timing dial 13 every 365 days. This motion will cause the cam follower portions of pins 28 and 31 to make one complete revolution with respect to cam surface 37. Thus, for each day of the year the radial distance separating pins 28 and 3 1 from the axis of rotation of calendar dial 22 will be under control of cam surface 37. This motion in conjunction with the angles between slots 32 and 33 and slots 29 and 30 will determine the program of motion of arms 1-9 and 18 in a manner now to be described.

In accordance with this invention, the basic program controlling the motion of arms 13 and 19 is obtained from cam 37. This is possible since the curves of the sunrise and sunset are out of phase approximately six months; i.e., the shape of the sunset'curve between September 22 and March 21 is basically the same as the sunrise curve between March 21 and September 22. In like manner, the sunrise curve between September 22 and March 21 is similar in shape to the sunset curve between March 21 and September 22. However, since the curves are not identical in shape, the basic program provided by cam 37 is compensated for by controlling the position and shapes of the slots which cooperate with pins 2 8 and 3 1. Slots 30 and 33 are at slightly different angles on timing member 14 and, in addition, they are not located 180 apart, thus compensating for the differences in the characteristic curves of sunrise and sunset. Compensation is completed by arranging the scale indicia on arms 18 and 19, which are otherwise identical, so that slots 29 and 32 will be at slightly different angles with respect to their corresponding arm for the same latitude setting.

Since the change in the total number of daylight hours between the winter solstice and the summer solstice is a function of the latitude, it can be seen that the range of motion of arms 18 and 19 must correspondingly increase as the latitude increases. For example, at 50 north latitude there is a change of about eight hours in the length of daylight between the Winter solstice and the summer solstice, Whereas at 20 north latitude there is a change of a little less than four hours. This means that, as the latitude setting increases, the angle between the slots of the compensating members and the slots in timing member 14 will have to be increased since the angle between these slots is directly related to the magnitude of movement of the arms which is generated as the cam followers make one revolution with respect to cam 37.

It is another feature of the invention that compensators 213 and 24 have a sufiicient range of rotation to permit the alignment of their slots with the corresponding slots in timing member 14. This would correspond with zero degrees latitude which results in immobilizing arms 18 and 19 with respect to timing member 14, thus permitting, if desired, a fixed location for switch actuating trippers 11 and 12. Slot 51, in timing member 14, is also provided to adjustably accommodate a switch actuating tripper to permit a fixed tripper location within a span of approximately 1% hours either side of midnight, assuming that timing dial 13 is located in the position illustrated in FIG. 1.

When operation of the switch is to occur at sunset and sunrise, the range of adjustment provided by arms 18 and L9 is adequate for most locations within any given time zone. 'Due to state boundaries influencing the limits for the various time zones, there are a few areas which, practically speaking, should have been in the next time zone. Under these conditions, the time indicated by the clock is drastically displaced with respect to sun time. One purpose in making dial 1-3 adjustable is to provide an easy means of compensating for the above-mentioned offset in time.

In addition, when the switch is used to turn on at sunset and oif at a fixed time of night, the fixed position of slot 511 offers only a limited range of adjustment. This range of adjustment may be extended, either earlier or later, by moving the trlpper to one extreme of its adjustment and then lining the dial 13 up with the tripper to obtain the correct reading for sunset. This automatically changes the relationship between dial 13 and slot 51, thus resulting in an extension of its normal range of adjustment.

Even though this invention has been described with reference to adjusting the angle of the slots carried in switch actuating arms 18 and 19, it will be recognized that these slots may the fixed, while slots 30 and 33 in timing member 14 may be adjusted to permit its use at any desired latitude.

In accordance with the invention, the shape ,of cam 37, as well as the angle of slots 30 and 33 and the location of the latitude markings on arms 18 and 19, may be determined in the following manner: First, assuming that it is desired to adjust for latitude variations within the range from 20 north to 50 north, the character istic curves for 40 north latitude will be utilized since this will result in minimizing the errors that might be generated at the extremities of the range. Next, the maximum and minimum radial distances of cam surface 37 from the center of timing dial 22 will be determined. It can be seen that this is a function of the size of calendar dial 22 since this determines the size of its center portion which is available for groove 36. These radial distances will then determine the radial distances of both ends of slots 30 and 33. Next, the angle of slot 30 is chosen relative to the angle of slot 29 so that the angles of the two slots result in each slot contributing approximately half of the total motion of arm 18 with respect to timing member 14. Compensator 23 is then locked in this position which will correspond to 40 north latitude. It can be seen that the length of slot 30 Will be determined not only by angle selected by the previous operation but also by the previously selected radial distances which determine its ends. This is necessary to accommodate the motion of pin 28 when moved over these radial distances by cam 37. Slot 29 is also selected to accommodate such motion in all positions necessary to cover the desired range of latitudes. The shape of cam 37 is determined so that tripper 12 will follow the sunrise curve for 40 north latitude. Having once determined the shape of cam 37, compensator 24 is rotated in arm 19 so that slot 32 bears the same angle to the axis of arm 19 that slot 29 bears to the axis of arm 28. Slot. 33 is then located relative to slot 32 such that each contributes approximately half the total motion of arm 19. A plot is then made of the motion of tripper 11 with respect to timing dial 13 for one complete revolution of calendar dial 22. This curve is then compared with the desired sunset curve for 40 north latitude and the position of slot 33 is adjusted while holding compensating member 24 in a fixed position until its optimum placement is determined. Thereafter, the latitude markings on arms 18 and 19 may be similarly developed by comparing the motion with the desired characteristic curves for each latitude.

Thus, it may be seen that in accordance with the invention, a single cam is utilized to achieve both am. and p.m. programs for a wide range of latitude instead of requiring one set of cams for sunrise and a diiferent set of cams for sunset in order to cover the same range of latitudes. This is rendered possible in accordance with the invention through the novel cooperation of cam 37 with the two pairs of slots, one slot of each pair being adjustable with respect to the angle of the other slot to control the range of motion of the switch actuating arms in accordance with the characteristic curve for the particular latitude. The novel cooperation between these elements also results in providing an astronomic dial of great simplicity by minimizing the number of parts thus lowering the cost of the resulting assembly. Furthermore, the two switch actuating arms utilized are identical, thus permitting the use of the same part for each arm by merely placing the arms in the assembly with the appropriate latitude markings on top. It is also readily apparent that cam follower holders 20 and 21 are also identical permitting the stocking of one part for both members. Thus, in accordance with this invention, an extremely simple, inexpensive and versatile astronomic dial is provided which is compact enough to be directly substituted for a normal timer dial with all of the attendant advantages inherent in this arrangement in the distribution of time switches with both conventional and astronomic dials. While this invention has been described with reference to a range of latitudes from 20 north to 50 north, it will be recognized that it can be utilized for the southern latitudes by merely shifting the calendar dial markings approximately Furthermore, if it were desired to cover a wider range than that indicated without sacrificing accuracy, the slots could assume different shapes; i.e., the slots could be curved in such a manner as to permit the utilization of this astronomic dial over a Wider range of latitudes.

While there has been described What is at present considered to be a preferred embodiment of the invention, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit or scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. An automatic timing device comprising:

(a) support means having an axis of rotation therethrough,

(b) a timing member rotatable about the axis and having a slot formed therethrough,

(c) first means mounted on said support means and connected to said timing member to rotate said timing member about the axis,

((1) a switch actuating arm mounted to said timing member for rotation about the axis having a second slot formed therein,

(e) a cam mounted to said timing member for rotation about the axis,

(f) means mounted to said timing member engaging the slot in said timing member, said cam and said switch actuating arm to control the rotational position of said actuating arm with respect to said timing member in response to the relative position of said cam with respect to said timing member, and

(g) second means connected between said cam and said timing member rotating said cam with respect to said timing member.

2. An automatic timing device comprising:

(a) support means having an axis of rotation therethrough,

(b) a timing member rotatable about the axis having a first slot, elongated along a second axis, and formed therethrough,

(c) driving means mounted on said support means and connected to said timing member to rotate said timing member about the axis of rotation,

(d) a switch actuating arm mounted to said timing member for rotation about the axis of rotation and having a second slot, elongated along a third axis, and formed therethrough,

(e) a second member mounted to said timing member for rotation about the axis of rotation and having a cam surface thereon,

(f) means connected to said second member and said timing member rotating said second member with respect to said timing member,

(g) means supported by said timing member engaging said cam surface and the first and second slots through said timing member and said switch actuating arm to control the rotational position of said switch actuating arm with respect to said timing member in response to the relative rotation of said second member with respect to said timing member, and

(h) means for adjusting the position of the second axis with respect to the third axis so that the relative magnitude of motion of said actuating arms with respect to said timing member may be adjusted.

3. An automatic timing device comprising:

(a) support means having an axis of rotation therethrough,

(b) a timing member rotatable about the axis of rotation at a fixed speed having a first slot elongated along a second axis formed therethrough,

(c) means mounted on said support means and connected to said timing member to support said timing member and to rotate said timing member about the axis of rotation,

(d) a switch actuating arm mounted to said timing member for rotation about the axis of rotation, said switch actuating arm including an element having a second slot therein elongated along a third axis and supported by said arm, said element being rotatable in said actuating arm so that the third axis can be rotated with respect to said switch actuating arm,

(e) a second member mounted to said timing member for rotation about the axis of rotation having a cam surface,

(f) means connected between said second member and said timing member rotating said second member with respect to said timing member, and

(g) means engaging said cam surface and the slots through said timing member and said element in switch actuating arm to rotate said actuating arm with respect to said timing member in response to the relative rotation of said second member with respect to said timing member.

4. An automatic timing device comprising:

(a) support means having an axis of rotation therethrough,

(b) a timing member rotatable about the axis of rotation at a fixed speed and having first and second slots formed therethrough, the first and second slots being elongated along second and third axes respectively,

(c) means mounted on said support means and connected to said timing member to rotate said timing member about the axis of rotation at the fixed speed,

((1) a first switch actuating arm mounted to said timing member for rotation about the axis of rotation, said first switch actuating arm having a first rotatable element with a third slot formed therethrough elongated along a fourth axis, said rotatable element supported by said first switch actuating arm so that the fourth axis can be rotated with respect to said first switch actuating arm through a predetermined range of angles,

(e) a second switch actuating arm mounted to said timing member for rotation about the axis of rotation, said second switch actuating arm having a second rotatable element with a fourth slot therethrough elongated along a fifth axis, said rotatable element supported by said second switch actuating arm so that the fifth axis can be rotated with respect to said second switch actuating arm through a predetermined range of angles,

(f) a second member mounted to said timing member for rotation about the axis of rotation, said second member having a cam surface formed thereon,

(g) first means mounted to said timing member engaging said cam surface, the first slot in said timing member, and the third slot in said first movable element to rotate said first switch actuating arm with respect to said timing member in response to the relative rotation of said second member with respect to said timing member,

(h) second means engaging said cam surface, the second slot in said timing member and the fourth slot in said second movable element to rotate said second switch actuating arm with respect to said timing member in response to the relative rotation of said second member with respect to said timing member, and

(i) third means connecting said second member and said timing member and rotating said second membeer with respect to said timing member.

5. The combination of claim 4 in which said third means comprises a plurality of equally spaced projections arranged in a circular configuration upon a surface of said second member and a spiral cam rotatably supported by said timing member to cooperate with said projections so as to rotate said second member through an angle equal to the angle subtended by an are drawn between corresponding points on adjacent projections in response to one revolution of said spiral cam.

6. The combination of claim 4 in which said third means further comprises a Wheel secured to rotate said spiral cam and having projections thereon, said spiral cam and said Wheel being supported by said timing member so that one of said projections on said wheel will sequentially contact a fixed stop on said support means once each revolution of said timing member to rotate said spiral cam a fixed amount for each revolution of said timing member.

7. The combination of claim 6 in which said projections on said second member are pin-shaped projections arranged upon a planar surface of said second member, said spiral cam being supported to rotate about a sixth axis inclined with respect to said planar surface so that said spiral cam is in cooperative relationship with only one of said pin-shaped projections at a time.

8. The combination of claim 7 in which said timing member rotates one revolution each day, the product of the number of projections on said second member and said wheel being equal to three hundred and sixty-five so that said second member rotates once for every three hundred and sixty-five revolutions of said timing member, said cam surface and the first slot in said timing member being shaped and located relative to each other so that said first switch actuating arm moves relative to said timing member to actuate an associated switch at the time of sunrise when located at a latitude corresponding to the rotational position of the slot in said first rotatable element.

9. The combination of claim 8 in which the second slot in said timing member is shaped and located relative to said cam so that said second switch actuating arm moves relative to said timing member to actuate an associated switch at the time of sunset when located at a latitude corresponding to the rotational position of the fourth slot in said second rotatable element.

10. The combination of claim 9 in which said second member is a calendar dial having the twelve months spaced around its periphery adjacent to seventy-three pinshaped projections, said wheel having five projections thereon whereby said calendar dial advances one pin with respect to said timing member exery five days.

11. A speed reduction system comprising:

(a) support means having a first axis of rotation,

(b) a timing member rotatable about the first axis of rotation,

(c) means mounted on said support means and connected to said timing member to rotate said timing member about the axis of rotation at a first speed of rotation,

(d) a second member mounted to said timing member for rotation relative to said timing member about the axis of rotation, said second member having a plurality of equally spaced projections arranged on the surface thereof in a circular configuration concentric with the axis of rotation,

(e) a cam having a surface arranged in a spiral configuration with respect to a second axis of rotation,

(f) means for rotatably supporting said cam from said timing member so that said cam surface is in a cooperative relationship with only one of said projections at a time as it is rotated about the second axis, and

(g) beans including a wheel mounted on said support means rotating said cam about the second axis in response to rotation of said timing member about said first axis.

12. The combination of claim 11 in which said wheel has five projections and said second member has seventythree projections to thus cause said second member to rotate once with respect to said timing member every three hunderd and sixty-five revolutions of said timing member.

13. A- speed reduction system comprising:

(a) support means having a first axis of rotation therethrough,

(b) a timing member rotatable about the first axis of rotation,

(c) first means mounted on said support means and connected to said timing member to rotate said timing member about said axis,

((1) a second member mounted to said timing member to rotate relative thereto about the first axis of rotation, said second member having a plurality of equally spaced projections arranged on a planar surface thereof in a circular configuration concentric with said first axis of rotation,

(e) a cam having a surface arranged in a spiral configuration with respect to a second axis of rotation, said cam having a thickness normal to said surface which is less than the spacing between adjacent of said projections,

(f) second means rotatably supporting said cam from said timing member so that the second axis of rotation is tilted with respect to the planar surface of said second member in such a way that said cam surface is in a cooperative relationship with only one of said projections at a time as it is rotated about the second axis of rotation, and

(g) third means on said support means rotating said cam about the second axis in response to rotation of said timing member about the first axis, the cam surface subtending an angle of approximately three hundred sixty degrees so that it comes into cooperative relationship with a new projection once every revolution thereof to thereby rotate said second member in response to one revolution of said cam through an angle equal to the angle subtended by an are between corresponding points on adjacent projections.

14. The combination of claim 13 in which said third means for rotating said second member comprises a wheel secured to said spiral cam to rotate about the second axis and having projections thereon, said cam and said wheel being supported by said timing member so that said wheel projections sequentially contact a fixed stop once each revolution of said timing member to rotate said spiral cam through a fixed angle in response to each revolution of said timing member.

References Cited by the Examiner UNITED STATES PATENTS 2,076,371 4/1937 Hottenroth et al 20038 2,779,829 I/ 1957 Everard 200-35 FOREIGN PATENTS 421,278 12/ 1934 Great Britain.

BERNARD A. GILHEANY, Primary Examiner. H. M. FLECK, Assistant Examiner.

Claims (1)

1. AN AUTOMATIC TIMING DEVICE COMPRISING: (A) SUPPORT MEANS HAVING AN AXIS OF ROTATION THERETHROUGH, (B) A TIMING MEMBER ROTATABLE ABOUT THE AXIS AND HAVING A SLOT FORMED THERETHROUGH, (C) FIRST MEANS MOUNTED ON SAID SUPPORT MEANS AND CONNECTED TO SAID TIMING MEMBER TO ROTATE SAID TIMING MEMBER ABOUT THE AXIS, (D) A SWITCH ACTUATING ARM MOUNTED TO SAID TIMING MEMBER FOR ROTATION ABOUT THE AXIS HAVING A SECOND SLOT FORMED THEREIN, (E) A CAM MOUNTED TO SAID TIMING MEMBER FOR ROTATION ABOUT THE AXIS, (F) MEANS MOUNTED TO SAID TIMING MEMBER ENGAGING THE SLOT IN SAID TIMING MEMBER, SAID CAM AND SAID SWITCH ACTUATING ARM TO CONTROL THE ROTATIONAL POSITION OF SAID ACTUATING ARM WITH RESPECT TO SAID TIMING MEMBER IN RESPONSE TO THE RELATIVE POSITION OF SAID CAM WITH RESPECT TO SAID TIMING MEMBER, AND (G) SECOND MEANS CONNECTED BETWEEN SAID CAM AND SAID TIMING MEMBER ROTATING SAID CAM WITH RESPECT TO SAID TIMING MEMBER.

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