US2224593A

US2224593A - Time cycle controller

Info

Publication number: US2224593A
Application number: US275172A
Authority: US
Inventors: William J Brown; Paul J Good
Original assignee: Taylor Instrument Co
Current assignee: Taylor Instrument Co
Priority date: 1939-05-23
Filing date: 1939-05-23
Publication date: 1940-12-10
Anticipated expiration: 1957-12-10

Description

Dec. 10, 1940.

W. J. BROWN ETAL TIM E' CYCLE CONTROLLER Filed May 23, 1939 ATTORNEY.

Patented Dec. 10, 1940 PATENT osrics 2,224,593 TIME CYCLE CONTROLLER William J. Brown and Paul J. Good, Rochester,

N. Y., assignors to Taylor Instrument Companics, Rochester, N. X, a corporation of New York Application May as, 1939, Serial No. 275,172

3 Claims.

This invention relates to time cycle controllers. In many industrial processes it is necessary to control the sequence and duration of a series of steps or operations involved therein. In order to effect this result, it is the practice to utilize a device known as a time cycle controller. Since the duration of the various steps or operations vary with different types of products, it is necessary that the controller be readily changeable by a simple adjustment so that the process operations can be quickly varied atwill. Such a controller must be reliable in operation since the failure of the controller to establish the predetermined sequence and to measure accurately the duration of the several operations will result in a defective product. Furthermore, the controllershould be of simple construction so that it can be easily repaired since it is usually employed in connection with an expensive machine which is disabled if the controller fails.

The main feature of the invention relates to,

' a time cycle controller of simple and effective construction which is relatively inexpensive to manufacture and which will be reliable over a long period of service.

Another feature of the invention relates to a time cycle controller in which the time interval or intervals can be readily changed'without disassembling the controller and without the need of adjusting tools.

These and other features of the invention will appear from the detailed description and claims when taken with the drawing in which Fig. 1 is a front elevation of a time cycle controller of the present invention with the enclosing case thereof omitted. and with certain parts broken away in order to disclose more clearly the details of construction; and Fig. 2 is a plan view of the controller of Fig. 1 with portions thereof broken away to illustrate more clearly the arrangement of certain parts, the switch shaft and control switches being omitted for the sake of clarity.

The time cycle controller of the present inven tion includes several operation-determining elements such as circuit-controlling switches SI to S5 actuated by a cam follower 5 in cooper-' ation with a rotatable timing cam G which is driven through a gear train at .a selectively variable rate from a fixed speed motor M.

The motor M, although it may be of the spring type, is preferablya synchronous electrical motor such as is used in time clocks. This motor is mounted on the front of the frame plate -8 and has its driving shaft 9 projecting toward the rear of the controller through the dial bushing ill in the frame plate. On this motor shaft there is secured an arm H which has a pawl l2 pivoted on its upper end. This pawl at its right hand end, as viewed in Fig. 1, engages a ratchet wheel 5 l 3. The ratchet wheel is secured to a stub shaft it having its rear end journaled as at l5 in the rear frame plate Iii, the forward end of this shaft being recessed so that it can rotate on the free end of the motor shaft 9 as a bearing. The 10 left end of the pawl I2 is provided with a notch ll adapted to be engaged by a hook it on the upper end of a latch l9 pivoted at on 2. lug 2i integral with the arm II. This latch is normally urged in a clockwise direction by a coil is spring 22 having one end connected to the upper portion of the latch l9 and having its other end connected to the lower end of an arm 23 integral with and extending downwardly from the pawl 52. The lower end of the latch i9 is provided 20 with an angular extension 24 which travels in a path whereby it periodically engages the pin 25. This pin is fixed on the rear surface of an adjustable dial disk 26 serving to determine the variable rate at which the gear train T is driven by the fixed speed motor M. This dial, which is rotatably mounted at the rear of the frame plate 8 on the dial, bushing H], has its front surface graduated, for observation through the window 21 in the plate 8. The dial is provided with a rearwardly projecting peripheral flange 28. This flange is provided with a series of holes 29 therethrough for engagement with a ball-type lock 30 mounted on the frame plate 8 so that the ball of the lock will enter one of the openings of the flange and thus retain the dial in the position to which it has been rotated during axljustment. It will be understood that the surface of the flange 28 may be knurled, if desired, so that the dial may be manually adjusted. The 4 rear frame'plate l6 has adjustably mounted in an arcuate slot therein a forwardly extending fixed pin 3| projecting in the path of the rounded 'top portion 32 of the pawl I2 so that in the course of the rotation of the pawl, the pin 3| will depress the left hand end of the pawl, that is, move it in a counterclockwise direction until the latch l9 engages the notch ll. In this way the driving pawl will be disengaged from the ratchet wheel l3 during each revolution of the motor shaft and will not be reengaged therewith until the extension 24 on the latch strikes the pin 25 on the adiustable dial .26, whereupon the latch l9 disen- 5s gages the notch I! in the pawl. This permits the helical spring 22 to draw the pawl into reengagement with the ratchet wheel so that it is again driven by the motor during the remainder of a given revolution of the motor shaft.

On the shaft l4 of the ratchet wheel l3 there is secured a pinion 33 which is a part of the gear the pinion 31.

train including the

gears

34, 36, 36, 31 and 36. It

should be mentioned that a friction brake is provided to prevent the gear train from coasting when the pawl l2 disengages the ratchet wheel [3. Although this brake can be made in various forms it preferably consists of a spring washer B which continuously engages a surface ofthe gear 34, as best illustrated in Fig. 2. The gear 33 is secured on the rear end of a shaft 39, to the front end of which the timing earn 6 is secured as by a nut 46. This shaft is mounted both for longitudinal and rotary movement in a cylindrical bearing 4| secured on the frame plate 6. A spiral spring 42 surrounding the forward portion of this bearin its front end engaging the rear of the timing earn 6 and has its other end engaging the front of the frame plate 3. By this construction the cam may be forced rearwardly against the action of the spring 42 to disengage the gear 36 from sired part of the cycle. However, when the manual pressure is withdrawn from the cam, the spring 42 will return the gear 36 into mesh with It will be understood that the size of the teeth on the gear 36 and pinion 31 troller than can be eflected by the adjusting dial 26,

sector plates

43 and 44 are adjustably secured to the cam, to change its contour at will. The sector plate 43, the outline of which is shown partially in full and partially in dotted lines in .Fig. 1,-is rotatably mounted on the shaft 39,

being secured to the cam in various positions by any suitable means. However, the present securing arrangement includes an arcuate slot 46 concentric with the shaft 39, through which slot there extends an adjusting screw 46 engaging a threaded opening in the sector plate, so that the plate can be clamped against the rear face of the main cam 6.

In order to indicate at what time in the cycle the high spot of the sector 43 becomes effective,

' there is provided on the sector an index 41 which projects through an arcuate slot 48 in the timing cam 6 which slot, like the slot 46, is concentric with the shaft 39. The surface of the cam in the path of the index 41 may be provided with suitable graduations indicating units of time or other units of measure, to assist the operator in determining the adjustment of the sector 43.

A sector 44 of the outline indicated in Fig. l, is also rotatably mounted on the shaft 39 and is clamped to the rear surface of the cam by means of the clamping screw 49 passing through the arcuate slot 60 in cam 6 into the sector. Similar- 1y, an index 5| secured on the front of sector 44 projects through the arcuate slot 62, which slot,

' like slot 56, is concentric with the shaft 39. It

The composite periphery of the cam 6 and the

sectors

43 and 44 is engaged by the angular portion 63 of the follower arm 6' which is pivoted at 64 on the frame. As herein illustrated, the rear arm 66 of the follower operates through a link 66 to rock a switch or control shaft 61. This shaft which is supported for rocking motion in the brackets 63 and 69 carried by the frame plate 3, has mounted thereon a series of electrical switches SI and S6 inclusive, preferably of the mercury bottle type. Since these switches have their principal axes arranged at different inclinations with respect to the axis of the rocking shaft, they operate at different times as this shaft is rocked. These switches may, for example, control the operations of various types of processing machines. It will be understood, however, that instead of using mercury type switches, the follower may actuate a series of pilot or air relay valves, as disclosed in the patent to Foote No.

At the end of each cycle of the controller, the end portion 63 of the follower is resting on the low point 66 of the cam, as indicated in dotted lines in Fig. 1. When the operator starts the timer in operation by means not shown, the motor M rotates the shaft 9 continuously. Since this shaft carries the arm ll together withthe pawl l2 and the latch l9 mounted thereon, in a clockwise direction, during a part of each revolution of the shaft 9 and the arm II, the pawl 12 is in engagement with the teeth of the ratchet wheel l3 so that the gear train operates to drive the cam 6. As the rounded part 32 of the pawl passes under the fixed pin 3|, the pawl is disengaged. from the ratchet wheel and is held disengaged by the latch l9 which engages the notch I6 on the pawl. When this takes place, the gear train T stops. However, in the course of the rotation of the arm II, the pin 25 on the adjustable dial 26 engages the extension 24 on the latch l9 so that this latch is forced to disengage the notch in the pawl. Thereupon the spring 22 causes the pawl to reengage the ratchet wheel.

Thus, during each revolution of the motor shaft, the ratchet wheel and consequently the gear train driven thereby, stops for a period of adjustable duration. It will be understood that by rotating the dial 26, the length of the stopping period in each cycle can be varied at will within the limits of adjustment.

As the motor M drives the cam 6, the end portion 53 of the follower arm 5 travelsup the inclined portion 6| of the cam and up the inclined portion 62 of the sector 43. At it does so, the follower 5 rocks the shaft 51 forward thereby completing the operation of certain of the mercury switches Si and S6. As the follower drops down to the main periphery 63 of the cam, certain of the switches are completely operated to effect their control in the cycle. Toward the con clusion of the cycle,'the end portion 53 of the follower drops to the portion 64 of the periphery of the cam and then eventually to its dotted line position in engagement with the low portion 60 to effect operation of certain others of these until its index 41 is opposite the graduation on uation indicating the desired setting.

From the foregoing it will be seen that there has been provided a time cycle controller in which a substantially fixed speed motor operates through adjustable means to drive a cam at any desired rate, without the need of change gears or the like.

We claim:

1. A timing mechanism comprising elements to be operated in a predetermined sequence and for predetermined periods, means including a rotatable cam and a follower actuated thereby for operating said elements, means for driving said cam at a predetermined rate, said cam including a disk having an outline of predetermined contour and having an arcuate slot therein concentric with the axis of rotation thereof, -a sectoran index on said sector projecting through saidsecond slot. 7

-2. In a device of the class described, control mechanism, including a cam and follower cooperating therewith for operating said mechanism, means including a ratchet wheel for driving said cam at any one of several selected rates, an arm mounted for rotation about the axisof rotation of said ratchet wheel, a pawl mounted on said arm in a position to engage said ratchet wheel, means for normally holding said pawl in engagement with said ratchet wheel, a latch on said arm for holding said pawl out of engagement with,

said ratchet when disengaged therefrom, means mounted in a position to disengage said pawl from said ratchet wheel during each rotation of said arm, means adjustable in an arcuate path and serving to unlatch said latch whereby said mounted for rotation about the axis of rotation of said ratchet wheel, a pawl mounted on said arm in a position to engage said ratchet wheel, spring means for normally holding said pawl in engagement with said ratchet wheel, a latch on said arm for holding said pawl out of engagement with said ratchet when disengaged therefrom, a pin mounted in a position to disengage said pawl from said ratchet wheel during each rotation of saidrarm, a second pin adjustable in an arcuate path and serving to unlatch said latch whereby said pawl reengages said ratchet wheel.

WILLIAM J. BROWN. PAUL J. GOOD.