US3591738A

US3591738A - Mechanism for the time control of electric switches

Info

Publication number: US3591738A
Application number: US881434A
Authority: US
Inventors: Edward Wilkinson
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-12-02
Filing date: 1969-12-02
Publication date: 1971-07-06
Anticipated expiration: 1988-07-06

Abstract

A controlling or programming mechanism in which switches are controlled by the movement of feeler pins, this movement being controlled both by perforations through a moving tape, and also by depressions in cams, the arrangement being such that a switch is actuated only when its pin passes through a perforation and into a cam depression.

Description

United States Patent lnventor Edward Wilkinson Pavement Pocklington, York, Yorkshire, England Appl. No. 881,434

Filed Dec. 2, 1969 Patented July 6, 1971 MECHANISM FOR THE TIME CONTROL OF ELECTRIC SWITCHES 6 Claims, 4 Drawing Figs.

US. Cl 200/46 Int. Cl 1101143/08 Field of Search 200/46, 61.13, 61.15

References Cited UNITED STATES PATENTS 8/1937 Plym et a1. 200/46 X 2,824,182 2/1958 Lambert 200/46 3,049,598 8/1962 Lannan et a1. 200/46 3,321,590 5/1967 Hooper 200/46 3,414,716 12/1968 Jones 200/46 3,480,726 11/1969 Walker 200/46 X Primary ExaminerRobert K, Schaefer Assistant Examiner-William J. Smith Attorneys Emory L. Grotf and Emory l... Groff, Jr.

ABSTRACT: A controlling or programming mechanism in which switches are controlled by the movement of feeler pins, this movement being controlled both by perforations through a moving tape, and also by depressions in earns, the arrangement being such that a switch is actuated only when its pin passes through a perforation and into a cam depression.

PATENTEUJUL SIB/i 3 m1 738 SHEET 2 [1F 2 MECHANISM FOR THE TIME CONTROL OF ELECTRIC SWITCHES CROSS-REFERENCE TO RELATED APPLICATIONS BACKGROUND OF THE INVENTION This invention concerns a mechanism for controlling or programming one or more circuits, that is to say a mechanism which will control the opening and closing of one or more switches accurately in desired time sequence.

An object of the invention is to provide a mechanism with a switching program in which the program can be altered easily, and can run for a long period of time if desired. Another object of the invention is to provide a mechanism which can have more than one channel of switching, and in which precise and controlled operation of electric circuits in relation to time is obtained.

The mechanism according to the invention can be used to program the operation of machinery for factory control or the like.

SUMMARY OF THE INVENTION The mechanism according to the invention comprises an endlessly spooled tape, means for driving said tape out from and back into the spool, a plurality of control feeler pins mounted across an exposed tape part and each pressed onto the tape surface, tracks of perforations along and through the tape, one track aligning with each pin, a plurality of rotatable cams, one such cam below each track, means for driving said earns, a switch associated with each pin which switch is actuated only when a pin drops through a perforation and into a depression in a cam, one of said cams and pins controlling the operation of the driving means, means for maintaining said drive to complete at least one cycle of operations, at least one other pin and cam effecting the control of a circuit of an apparatus or mechanism.

It will be understood that the tape, which term includes any strip such as a film, can be of substantial length and that accurate control by the tape is unnecessary, the control cams, when turning, causing accurate opening and closing of their associated switches. Perforations need not necessarily coincide with cam control, the tape providing the main program, the cams ensuring accuracy.

Preferably the one feeler pin initiates the closing of a motor circuit through one cam switch, and a holding on cam closes a second switch to maintain the motor circuit closed until at least one cycle is complete. Thus, the holding on cam may have a depression therein in which a pin of a microswitch engages before the initiation of the cam movement. As soon as the cams commence to turn, the pin is lifted from the depression to close the said switch which is held closed until the cam has made one revolution, the control cams turning with the holding on cam.

The switch controlling pins can each be connected directly to a switch, each of which is in series with a switch associated with a cam. With this arrangement, where a pin passes through a perforation its switch can close, but the control of the electric circuit is finally dependent upon the operation of the series connected switch by its cam.

Preferably, the control switches are electric switches, each carrying a feeler pin mounted above the controlling cams, and the tape passes between the pins and controlling cams said cams having cutouts or depressions, the or each switch operating only when a perforation and cutout or depression coincide, which cutouts or depressions are formed with the rear or trailing end ofa cutout or depression being shaped to lift a pin therein to the undersurface of the tape or film the movement of which, when the end of a perforation is reached, lifting the pin further to the upper tape surface.

The switches conveniently are microswitches with feeler pins of standard form.

The tape preferably has a plurality of perforated tracks, one through its associated pin for initiating the movement of the cams, and two or more each for initiating the operation of a switch controlling an electric or like circuit of an apparatus to be controlled.

It will be understood that a switch is not operated unless a pin passes through a perforation and also into a cutout or depression.

BRIEF DESCRIPTION OF THE DRAWINGS.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown, the mechanism is mounted on plates 10 supported in a casing 11. A film or tape F (as shown, a 35 mm. film) is coiled around four rollers 12-12, the film or tape being drawn ofi from the inside of the coil by a sprocket wheel 13 and a sprocket wheel 14 takes the tape or film through a signal pickup assembly 15. Suitable friction or slip drives can be incorporated.

A clock mechanism 16 is provided, this being driven by an electric motor 17, and incorporates appropriate gearing and indicators to show days and time of day on a face 16a. The motor 17 also drives the sprocket wheels l3, 14, through appropriate gearing. Means, such as a knob on the shaft of the wheel 14, can be provided so that the tape can be moved manually.

The pickup assembly consists of a microswitch S, which cooperates with a second microswitch S and three programming microswitches 8,, S, and S The switch S, is controlled by a hold on cam C, having a single detent D,, the

switch being held open when its pin P is in the detent. Each.

switch 5 -8,, also has an actuating pin P,, these pins cooperating respectively with cams C -C and each cam has at least one depression or detent such as D,, FIG. 3. The film or tape is perforated and the pins bear on the upper surface thereof unless aligning with a perforation.

The length of the film F is such that the desired program time is obtained, and it may be such as to give a week's run.

It will be seen from FIG. 4 that in the example illustrated the switches S S and S, are connected in parallel, although other arrangements can be resorted to, for example these switches could control independent circuits. As shown, the switches 8 -8,, control a relay 21 which in turn controls an electric device.

The switches S, and S are connected in parallel, the switch 8, being a master switch, in that until its actuator pin is allowed to pass through a tape perforation into the depression in the cam C, the circuit to an electric motor 18 is open, when the cam C, is in the position shown.

When the pin of the switch 8, passes through a tape perforation, and into the depression of its cam C the motor 18 is energized, so that all of the cams C,---C are turned by the motor. The actuating pin of the switch S, moves out from the detent D, when the cams commence to turn, holding the switch S, on, until the cams make one complete revolution, when the pin of the switch 5, moves into the detent D, to open the circuit to the motor 18. Thus, the switch S, maintains the power supply to the motor, even if the switch S is open.

Every perforation in the track controlling the switch 8, must have a corresponding perforation through one of the tracks controlling the switches 8 -8,, before there is a circuit closed by any one of these switches 8 -8,.

Two pushbutton controls 19, 20, are provided in the circuit to the relay 21. The control 19 can be operated by its button to open the circuit of the relay and the control 20 can be operated by its button to close the said circuit independently of operation by the switches 8 -8 The cutouts or depressions on the cam peripheries C -C are brought under their respective pins only when the motor 18 is turning, and the circuit associated with the switches S S is made only when a perforation is below a switch pin and the pin drops into a depression. The depressions are formed so that the rear end lifts the associated pin to the undersurface of the tape or film, and the movement of the said film or tape, when the end ofa perforation is reached, lifts the pin so that it then rides on the upper tape surface until the next perforation has moved to below the pin.

The circuitry can be complex, and in the example shown is arranged simply to control a single relay circuit, which is closed for different time periods depending on which track is used. Thus a program can be set which is different for different time periods (say one-day periods).

In another arrangement (not illustrated) the feeler pins are separate from the cam switches. In this arrangement each pin can pass through a perforation, and this action closes contacts in series with the contacts of a microswitch associated with a cam. Thus, the turning of the cams is initiated by a first pin which passes through a perforation to complete the circuit to the motor through a series connected microswitch associated with the cam C The holdon cam C operates its switch as above described, and further pins each with contacts inseries with a microswitch (S-S) controlled by a cam (C-C) control the electric circuit or circuits.

The switches need not necessarily be electric switches. They could be pneumatic or hydraulic switches.

lclaim:

l. Controlling or programming mechanism comprising an endlessly spooled tape, means for driving said tape out from and back into the spool, a plurality of control feeler pins mounted across an exposed tape part and each pressed onto the tape surface, tracks of perforations along and through the tape, one track aligning with each pin, a plurality of rotatable cams, one such cam below each track, means for driving said cams, a switch associated with each pin, which switch is actuated only when a pin drops through a perforation and into a depression in a cam, one of said cams and its related pin controlling the operation of said cam driving means, means for maintaining the operation of said cam driving means to complete at least one cycle of operations, at least one other related pair of said pins and cams effecting the control of a circuit of an apparatus or mechanism.

2. Controlling mechanism as claimed in claim 1, wherein the cam drive maintaining means comprises an additional holdon cam and an associated feeler pin which operates independently of the tape.

3. Controlling mechanism as claimed in claim 2, wherein 'the'trailing ends of the cam depressions below the tape are shaped to lift the pins onto the tape surface.

4. Controlling mechanism as claimed in claim 3, wherein the switch means of the control pins comprise electric microswitches.

5. Controlling mechanism as claimed in claim 3, wherein the tape drive means comprises an electric motor which also drives a clock mechanism.

6. Controlling mechanism as claimed in claim 4, wherein the tape drive means comprises an electric motor which also drives a clock mechanism.

Claims

1. Controlling or programming mechanism comprising an endlessly spooled tape, means for driving said tape out from and back into the spool, a plurality of control feeler pins mounted across an exposed tape part and each pressed onto the tape surface, tracks of perforations along and through the tape, one track aligning with each pin, a plurality of rotatable cams, one such cam below each track, means for driving said cams, a switch associated with each pin, which switch is actuated only when a pin drops through a perforation and into a depression in a cam, one of said cams and its related pin controlling the operation of said cam driving means, means for maintaining the operation of said cam driving means to complete at least one cycle of operations, at least one other related pair of said pins and cams effecting the control of a circuit of an apparatus or mechanism.

3. Controlling mechanism as claimed in claim 2, wherein the trailing ends of the cam depressions below the tape are shaped to lift the pins onto the tape surface.