US3028458A - Sequence timer - Google Patents

Description

April 3, 1962 D. M. STRATHEARN ET AL 3,

SEQUENCE TIMER Filed June 24, 1959 3 Sheets-Sheet 1 INVENTORS DONALD M. STRATHEARN James M.THORNBERY ATTORNEY April 3, 1962 D. M. STRATHEARN ETAL 3,023,458

SEQUENCE TIMER Filed June 24, 1959 3 Sheets-Sheet 2 50 50 F 6. 2 Fuel. 4 mmvroxs DONALD M. STRATHEARN James M.THORNBE.RY

BY KW A'r-roauex April 3, 1962 D. M. STRATHEARN ETAL 3,028,458

' SEQUENCE TIMER Filed June 24, 1959 s Sheets-Sheet 5 INVENTORS' DONALD M. STRHTHEARN JAMES M.THQRNBERY ATTORNEY SEQUENCE TIMER Donald M. Strathearn, Arlington Heights, andJames v Thornbery, Morton Grove, Ill.,'assignors to Controls Company of America, County of Cook, 111., a corpo-.

ration of Delaware Filed June 24, 1959, Ser. No. 822,658 14 Claims. (Cl. 200--38) This invention relatesgto a sequence timer. Disc typetimers have presented certain problems with "respect to the allowable tolerances betweenthe cam' surface and the switch actuators and to the introduction of reverse forces to the cam-discs.- The location of the cam disc in the housing depended primarily on the position of the shaft in. the housing. Any axial movement ofthe shaft would move the disc thus affecting the tolerance on one side of the cam to such an extent that the contacts would be varied. It has been further found that the cams had to be manufactured to withstand a considerable force if they were inadvertently reversed due to the direct connection of the cams and the manual .reverse mechanism.

'The present invention overcomes these objections by splitting the cam and positively locating the resulting two cams inthe housing so that they are not affected by any axial movement of the shaft. Thecams are then driven by'a separate wheel that is biased to absorb any reverse A further object is to provide a timer that eliminates the efiect of axialmotion of the drive shaft on the cam discs to insure proper contact pressures.

Another object of this invention is to prevent the transmission of manual reverse force to the cam discs to eliminate damage to the cams.

Other objects and advantages will be pointedout in or be apparent from'the specification and claims, as will obvious modifications of the single embodiment shown in the drawings in which: v

' FIGURE 1 is a side elevation of the present invention with part of the housing removed.

FIGURE 2 is an end view'of the timer partly in section.

FIGURE 3 is a side elevation with parrot thehousing and one of the timer cams removed. q

FIGURE 4 is an enlarged view taken on line 44 of FIGURE 3 showing the hub mountinglarrange'rnent.

Referring to the drawings, the timer is contained in a split housing including members and 12 having a shaft 14 journaled in integral bearings 16 and 18. A key 20 is provided on, the shaft and a hub 22 is positioned thereon so that it is free to move axially on the shaft. A pair of timer cams 24 and 26 are positioned on the hub and held thereon by a flange 28 and a keeper 30. A ratchet wheel 32 is forced onto spline 34 on the hub'between the cams and has a thrust spring 36 on each side to force the cams outwardly towards the flange and keeper. The cams are interlocked with the ratchet wheel by the drive stud 38 on each cam projecting into a cutout 40 and are biased by a spring 42 against the generally radial drive surface 44 of the cut-out. If the wheel is turned in a clockwise direction, FIGURE 3, the cams will also be turned. The cams are locked from counterclockwise rotation by cam pawl 46 secured to the housing and acting on ratchet teeth 48 on the periphery of the cams. The position of the hub and cams with respect to the housing is maintained by a plurality of housing pads 49abutting the outward faces of the cams so that the shaft can be moved axially without moving the hub. i V

The thrust springs act to hold the cams in contactwith :wheel.

' Patented Apr.3, 1962 ice 2 the pads and the cams may or may not be in contact with .the flange and keeper, thus maintaining the tolerance between the .cams and contacts constant. a

An annular wheel 50 is carried on bearing surfaces 52 on teeth 54 of the ratchet wheel so that'the wheel can be rotated on and maintained concentric with the ratchet A drive pawl 56 having a circular end 57 which fits in an opening 58 in the annular wheel to give a pivotal action to the pawl is biased into engagement with teeth 54 by a spring 60. The drive pawl will slide across the top of the teeth 54 when the drive wheel is turned counterclockwise (FIGURE 3), and will engage the teeth when the drive wheel is turned clockwise thus advancing the ratchet wheel and cam. Any counterclockwise force induced in the ratchet wheel by the counterclockwise move ment of the drive wheel will be prevented by cam pawl 46. The spring 42 acts against the drivestud 38 to prevent the ratchet wheel from turning counterclockwise during counterclockwise rotation of the drive wheel.

A drive arm 62, integral with the drive wheel and including a cam follower 63 is actuated by a motor driven cam 64 having a slow rise-fast drop cam surface. When the drive arm reaches the drop of the cam, spring 68 snaps the drive arm against stop 70 advancing the drive wheel in a clockwise direction. The drive pawl will engage the ratchet teeth on the ratchet wheel advancing the cam discs one step. The motor cam is driven through reduction gearing by a motor 72 secured to the housing and for each revolution of the motor cam, the timer spray every half cycle when the spray circuit is closed.

Each cam disc has a series of radially spaced concentric These grooves represent on and off times for the particular circuit with which they are connected. Grooves were selected flexible blade 78 is secured to the housing adjacent each stationary contact and has a finger 80 which rides on the timer cam toactuate that particular circuit. As the timer is advanced step by step fingers 80 follow one track and drop into the grooves as the disc moves. actuating the particular circuit with which they are connected. The contacts are connected to spade terminals by rivets 81 which hold the contacts on the housing.

Since these cams are always held against the housing pads there is no possibility of any variation in the cam contact tolerance hence the switch contact pressures Will remain constant thus eliminating a serious objection in previous timers. The split disc construction shown here has a further advantage in that the basic washing machine program can be provided on one disc and the other disc can be provided with suitable cam surfaces for obtaining various custom features found in manufacturers different machines from the-bottom to the'top of the line. This permits a lower tooling or mold cost to be realized. 1

Turning knob 82 in a clockwise direction (FIGURES 1 and 3) transmits clockwise rotation through the ratchet wheel and drive studs to cams 2.4 and 26 to advance the timer. Reverse rotation of. the knob will not affect the timer since the force cannot be transmitted to the cams. Reverse rotation acts through'the shaft and hub to the ratchet wheel and drive pawl to the arm and drive wheel to rotate the arm to the dotted line position shown in FIGURE 3 where the drive arm is shown against stop 84 molded in the housing. During the time that the ratchet wheel moves toits dotted line position, the cams are prevented by pawl 46. The angular displacement of the aoeasss I return to their original position thus relieving spring 42.

It will be understood that axial motion of the shaft can be utilized to operate a line switch in a conventional manner if desired. V

In operation the timer is manually set by turning the a timed relation comprising tioned on the shaft normal thereto, a ratchet wheel mounted on the shaft, said shaft being free to'move axially with respect to the wheel, means for connecting the discs and ratchet wheel, means for supporting a plu rality of switches in a plane parallel, to each disc, means on the discs for opening and closing the switches, means knob 82tothe desired starting point. The motor cam is rotated at a constant speed actuating the drive arm at a constant rate. Each rotation of the motor cam will index the ratchet wheel and cams one step. The ratchetwheel is positively connected to the timer cams in the forward direction so that the cams will be rotated one step in the sequence for each movement of the wheel.

Although but one embodiment of the present invention has been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

We claim: l. A timer comprising a housing, a plurality of switches secured to the housing, a shaft journaled in the housing, a hub mounted on the shaft, said shaft being free to move axially with respect to the hub, a pair of discs freely mounted on the hub and including means for operating the switches when the discs rotate about the shaft axis, a ratchetwheel secured to the hub between the discs and operatively connected to'each disc, means for advancing the ratchet wheel in a step by step manner so 7 that the discs actuate the switches in a timed relation.

2. A timer comprising a housing, a plurality of in the housing, a shaft journaled in the housing, a hub keyed tothe shaft, said shaft being free to move axially therein, a ratchet wheel secured to the hub, a pair of discs positioned on opposite sides of and operatively engaging the ratchet wheel, said discs being free to rotate on the hub and actuating the switches, a thrust spring positioned on each side of the wheel and biasing the discs against the pads, said pads maintaining the position of the discs with respect to the switches, and means for advancing the discs in a step by step relationship.

3-. A timer comprising a housing, having a plurality of switches secured therein, a shaft journaled in the housing, a hub keyed to the shaft, said shaft being free to move axially therein, a ratchet wheel secured to the hub, a pair of discs positioned on opposite sides of and operatively engaging the ratchet whel, said discs being free to rotate on the hub and operatively engaging the switches, means within the housing aligning the discs with respect to the switches, a drive wheel concentrically mounted on the ratchet wheel, means carried by the drive wheel for operatively engaging the ratchet wheel, and means for imparting an oscillatory motion to the drive wheel to advance the ratchet wheel and discs in a step by step manner.

4. An apparatus for actuating a plurality of switches ina timed relation comprising a shaft, a pair of discs positioned on the shaft normal thereto, a plurality of switches located in planes adjacent the discs, means on thediscs for actuating the switches in a timed sequence, a ratchet wheel mounted on the shaft to rotate therewith, said shaft being free to move axially withrespect to the 'wheel and discs, means connecting the wheel to the discs,

for holding the discs in the same position with respect to.

the switches regardless of axial movement of the shaft, and means for advancing theratchet wheel in a step by step relation.

6. An apparatus for actuating a plurality of switches in a timed relation comprising ashaft, a hub mounted, on

" thev shaft, a ratchet wheel'having a pluralityof teeth'on the periphery thereof secured to the hub, each tooth having a bearing surface thereon, a drive'wheel mounted on" a A the teeth and" rotatable thereon, means carried by the drive wheel for engaging the ratchet wheel to rotate the ratchet whcel'with the drive wheel in one direction and V disengaging the teeth so that the drive wheel rotates on the bearing surfaces of the teeth in the other direction, means rotatable with the ratchet wheel and actuating the switches when the drive wheel rotates in one direction, andmeans for preventing rotation of the switch actuating means and ratchet wheel when the drive wheel. rotates in the other direction.

7. A sequence timing mechanism for'a plurality of switches, comprising a shaft, a hub secured to the shaft, a ratchet wheel mounted on the hub and having'a bearing surface around its outer periphery, a drive wheel ro,-, tatable on the bearing surface of the 'ratchet wheel, a;

pawl mounted. in the drive wheel and operatively engaging the ratchet wheel, means for reciprocally actuating the drive wheel to advance the ratchet wheel in a step by step manner, a disc positioned on each side of the ratchet wheel and rotatably mounted on the hub, said discs operatively engaging the ratchet wheel, means for forcing the discs outward from the ratchet wheel, means for supporting a plurality of switches adjacent the discs, said 8. A timer for'actuating a plurality of switches comprising, a housing, a shaft journaled in the housing, a ratchet wheel operatively connected to the shaft, said shaft being free tomove axially with respect to the discs, motor means for driving the wheel, a disc on each side of and operatively' engagingthe wheel, said discs having cam tracks on their outwardly facing faces, a plurality of bosses secured to the housing and means for forcing the disc faces against the bosses to maintain the alignment of the cam tracks and switches.

9. A device as set forth in claim 8 wherein the driving means comprises an annular wheel journaled on and concentric with the ratchet wheel and operatively engaging the ratchet wheel to advance the discs.

10. A timing device for actuating a plurality of switches comprising, a housing, a shaft journaled in the housing, a hub mounted to rotate with the shaft, said shaft being free to moxe axially within the hub, a ratchet'wheel secured to the hub, an annular wheel journaled on and operatively engaging the ratchet wheel to advancethe,

faces into contact with the bosses to maintain the position of the discs with respect to the switches.

11. A timer comprising, a shaft, a ratchet wheel keyed to the shaft, a pair of discs rotatably mounted on the shaft,

one on each side of the wheel, means for driving the wheel in a step-by-step manner, a stud on each disc engageable withthe wheel for transmitting the step by step a shaft, a pair of discs posi- 5 motion to the discs, means for preventing reverse rotation of thediscs, the engagement of the studs with the wheel including a lost motion connection whereby reverse rotation of the shaft transmitted to the Wheel allows the wheel to move in a reverse direction while the discs remain stationary.

12. A- timer according to claim 11 in which the driving means includes a drive wheel journale'd on the periphery of the ratchet wheel, the drive wheel including a cam follower receiving the step by step motion, a drive pawl carried by the drive wheel whereby reverse rotation of the ratchet wheel received from the shaft is transmitted to the drive wheel, and stop means for limiting reverse motion of the drive wheel.

13. A timer comprising, a housing, a plurality of switches secured to the housing, a shaft journalcd in the housing, a hub mounted to rotate with the shaft, 21 pair of cam discs mounted to rotate on the hub and free to move axially with respect to the hub, a ratchet wheel secured to the hub between the cam discs, means between the wheel and the disc to axially bias the discs into operative engage ment with the switches, means for advancing the ratchet wheel in a step-by-step manner, and means for transferring the motion of the ratchet wheel to the discs to sequentially actuate the switches.

14. A timer according to claim 13 wherein the transferring means includes a lost motion means ailowing limited reverse rotation of the shaft without moving the discs.

References Cited in the file of this patent UNITED STATES PATENTS 2,204,532 Erbguth et al. June 11, 1940 2,469,341 Pearson May 3, 1949 2,619,557 lllian Nov. 25, 1952 2,703,347 Constantine Mar. 1, 1955 2,717,286 Bales -2 Sept. 6, 1955 2,758,166 Aus't et al. Aug. 7, 1956 2,782,271 Jordan Feb. 19, 1957 2,788,850 Leunenberger Apr. 16, 19 57 2,877,317 Euler et al Mar. 10, 1959 2,917,933

Harris Dec. 22, 1959

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