US3435388A - Rotary electric current interrupter - Google Patents

Description

KNVENTOR FRANK R. HORMANN 24 FIG. 1.

OFF INTERVAL ATTOR EYS M r 1969 F. R. HORMANN ROTARY ELECTRIC CURRENT INTERRUPTER Filed Dec. 22, 1966 20 REDUCTION GEARING SELF-STARTlNCH SYNCHRONOUS MOTOR United States Patent Oflice 3,435,388 ROTARY ELECTRIC CURRENT INTERRUPTER Frank R. Hormann, 12 Davison Lane W., West Islip, N.Y. 11795 Filed Dec. 22, 1966, Ser. No. 603,913 Int. Cl. H01h 3/26, 3/42 US. Cl. 33568 7 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to a rotary electrical circuit interrupter, particularly adapted for use as a deterrent to burglary, and aims to provide certain improvements therein.

It has long been customary for persons when they leave their home unattended after dark to let certain electric lights illuminated to give the impression, to burglars who may contemplate robbing the home, that the home is occupied. A burglar observing such a condition over a period of time may soon come to the conclusion that no one is at home because the lights are on continuously. Another method of deterring burglars is to connect certain of the lights on the premises to a mechanical timer which alternately turns a light or lights on and off, but the pattern of such timer is repetitious and an astute burglar can readily determine the pattern.

The primary object of my invention is to provide an electric current interrupter to control for several 'hours, in a random nonrepetitive pattern, the on and off intervals of house lights or of a radio in an unattended home as a deterrent to burglary.

A further object of the invention is to provide a device of the character set forth in the preceding paragraph with which the control of the on and off intervals can be readily varied, either automatically or manually without the aid of tools.

A still further object of the invention is to provide a device of the character set forth which can be set in operation by merely plugging it into an electric outlet.

A still further object is to provide a device of the character set forth which is simple in construction and can be sold at a relatively low price.

The foregoing and other objects of my invention, not specifically enumerated, I accomplish by providing a rotary electric circuit interrupter comprising a self-starting synchronous motor associated with reduction gearing to slowly rotate a shaft, a plurality of cams mounted on said shaft in axially spaced relation, one of said cams being fixed to said shaft and at least one other of said cams being loose on said shaft, means for coupling said cams, to move as a unit, means for automatically or manually varying in an unpredictable manner the angular relation of said cams to each other, a resiliently controlled cam follower engageable with the high points of said cams, an electric circuit in which is connected one or more electric lamps, a radio or other electrical instrumentality responsive to an electric current and switch means operable by the cam follower upon rotation of the 3,435,388 Patented Mar. 25, 1969 cams to periodically make and break the iflOW of current in said electrical circuit.

The invention will be more fully understood and appreciated from the detailed description which follows when considered in connection with the accompanying drawing which illustrates a simple embodiment of the device and wherein:

FIG. 1 is a schematic side elevation of the device showing the cams in driving relation to each other.

FIG. 2 is a schematic side elevation of the device showing the cams disengaged, certain parts being shown in diametrical section.

FIG. 3 is a schematic horizontal axial section of the device and means for disengaging the cams, certain parts being shown in elevation.

FIG. 4 is a section taken along the plane of the line 44 on FIG. 2 and showing schematically the electrical circuitry of the device.

FIGS. 5 and 6 show elevations of cams which are loosely mounted on the shaft, as viewed in the directions of the arrows on the planes of the lines 5-5 and 66 respectively on FIG. 2.

FIGS. 6a and 6b show two positions of a gravity activated cam forming part of the device.

Referring first to FIGS. 1 to 4 of the drawing the device may be said to consist of a base 10 upon which is mounted standards 11, 12 and 13 which support an electric motor 14 and bearings 15 and .16 respectively. The said bearing supports a rotatable shaft 17 adapted to be driven through a coupling 18 by a shaft 19 at the output of reduction gearing contained within a casing 20 and driven by the motor 14. Mounted fixedly on the shaft 17 to be driven thereby is a first disc cam 21. Mounted loosely on shaft 17 in axial spaced relation is a first friction disc 22, a second disc cam 23 of generally Y-form, a second friction disc 24 and a third disc cam 25. On shaft 17 between the cam 25 and a fixed collar 26, there is mounted a coil spring 27 'which normally biases the loose cams and the friction discs toward the fixed cam and into frictional engagement with one another to rotate as a unit. Mounted on the base 10 is a cam follower 28 carried by a resilient lever 29, which is biased upwardly by a spring 30 into engagement with the disc cams as they are rotated. Movement of the lever 29 controls switch means 31 connected in series with a light bulb 32 in an electrical circuit to be described hereinafter and which contains a manually operalble double-throw switch 33.

The motor 14 is preferably a self-starting synchronous motor, such as used in electric clocks, and the reduction gearing (not shown) in the casing 20 is preferably so chosen as to impart to the shaft .19, one revolution in 4 or 5 hours.

The cam 21, which is fast on shaft 17, has random circumferentially spaced high spots 34, of different circumferential length and the cam 25 also has random circum'ferentially spaced high spots 35 of different circumferential length. The cam 23 is of generally Y-shape, with spaced high spots 36 'with the center of gravity of said cam located well below the axis of the shaft 17 when mounted thereon.

The friction discs 22 and 24 are of smaller diameter than of the cams 2.1, 23 and 25 so as not to be engaged by the cam follower 29 and may be formed of any suitable friction material, such as rubber, cork and the like. Interposed between the friction discs 22 and 24 and the opposite faces of the Y-cam 23, there is disposed a single convolution spiral springs 37 of considerably weaker force than the spring 27 to hold said friction discs free from the cam 23 to permit it to assume a position as shown in either FIG. 6a or 6b when the cam 25 is released from frictional engagement with the cam 23 by being moved to the right against the biasing action of spring 27 for a purpose to be presently described.

The cam 25 has a sleeve-like portion 38 and a flange or knob 39 and provides an annular groove 40, within which is movable a yoke 41 of a right angular link 42, having a horizontal arm 43, slideable in a bearing 44. The link 42 is biased to the left by the spring 27 and the free end of the arm 43 is engageable by a projection or crown cam 45, mounted on the outer face of cam 21 as said cam 45 engages said free end once in each revolution of cam 21 to move the link to the right, the yoke 41 of which will thereby move the cam 25 to disengage the Y-cam 23 and the friction discs from one another and from the fixed cam 21. Upon such disengagement the Y-cam will rotate through an are less than a circle, because of its low center of gravity, to one of its positions shown in FIGS. 6a and 6b and come to rest by engagement with the cam follower 28. During engagement of the link 42 with the crown cam 45, the cam 21 will continue to rotate while the cam 25 will remain stationary whereby the angular relationship between the high spots 34 on came 21, the high spots 35 on cam 25 and the high spots 36 on Y-cam 23 will be automatically changed. When the crown cam 45 in the continued rotation of cam 21 has disengaged the link 42, the spring 27 will again move the cams 23 and 25 and the friction discs 22 and 24 into engagement for rotation as a unit. In this connection it is to be noted that the crown cam 45 is so located as not to be engaged by the cam follower 28. Instead of changing the angularity between the high spots on the cams automatically once during each revolution of the cam 21, a change in such angularity can be accomplished manually by grasping the knob 39, moving it to the right, giving it a slight twist and then releasing it.

All three cams 21, 23 and 25 are adapted to engage the cam follower 28 either individually or simultaneously, depending upon the relationship of the high spots on the cams, to control the flow of current through light bulb 32 or any other electrical instrumentality which it is desired to operate at random sequence and various time intervals.

Referring now to the circuitry shown in FIG. 4, a power source 46 is directly connected across the terminals of the synchronous motor 14 which has two leads 47 and 48 connected respectively with a movable contact 49 of the manually operable double-throw switch 33 and the movable contact 50 of the switch means 31 which may be a micro-switch respectively. The switch 31, which preferably is a micro-switch, has a normally open contact 5.1, and a normally closed contact 52. The double-throw switch has two fixed contacts 53 and 54 adapted to be selectively connected with the movable contact 49.

In the operation and use of the device as a burglary deterrent, one turns on the motor 14 by a suitable switch (not shown) whereupon the motor will be set in operation to rotate cam 21 through the reduction gearing in casing 20 and its output shaft 19 and coupling 18. If the cam follower 28 is not in engagement with the high spot of any of the cams 21, 23 or 25 and the switch 31 is in its normally closed position with contact 52 as indicated by the broken line and if the switch 33 is in engagement with contact 54, electric current will flow through the light bulb 32 to illuminate it. As soon as the cam follower engages the high spot on any of the cams, the normally closed switch will open and the normally open switch contact 51 will close whereupon the circuit through the light bulb will be broken. If, however, when the motor is started and the cam follower is on a high spot of a cam, the current through the light bulb will be open and in order for the device to function, it will be necessary to throw the switch 33 into engagement with contact 53. It will thus be obvious that the device is operative regardless of the position of the high spots of the cam in relation to the cam follower since in the first condition recited above the low spots on the cams provide the on position and in the second condition the high spots on the cam provide the on position of the device.

As hereinbefore mentioned, fixed cam 21 will require 4 or 5 hours to complete one revolution during which period there will be no repetitive sequence of the on and off intervals of illumination of the light bulb. If the device is retained in operation for less than one revolution of the fixed cam, the device would still provide a nonrepetitive on and olf operation of the light bulb. By virtue of the automatic disengagement of the loosely mounted cams for a definite interval or of the manual intentional disengagement of the frictional drive between the fixed and loosely mounted earns, the on and off intervals may be infinitely varied.

Where the device is to be used when house occupants are away for long periods, the device may be hooked up with either a mechanical timer for controlling operation during certain hours of darkness or it may be hooked up with a photoelectric relay to be operative during the hours of darkness. By the same token, the device may be hooked up with both a mechanical timer and photoelectric relay.

While I have shown and described a preferred embodiment of my invention, it will be understood that I do not intend to be limited by the foregoing disclosure since variations and modifications thereof may be made within the range of mechanical and engineering skill without departing from the spirit of the invention as defined in the claims. For example, a simplified version of the invention can be realized and be satisfactorily functional by omitting the intermediate Y-cam 23 and driving the loose cam 25 directly by the fixed cam 21.

What I claim is:

1. A rotary circuit interrupter comprising an electrical motor in association with speed reducing means to rotate a shaft, a plurality of cams mounted on said shaft in axially-spaced relation, one of said cams being fixed on said shaft and another of said cams being loose on said shaft, resilient means normally biasing a cam which is loose on the shaft into random angular coupling relation to the cam which is fixed on the shaft to rotate as a unit, a cam follower means engageable with the cams as they rotate, means operable to overcome the biasing of said resilient means to alter the random angular relation of the cams to one another, an electric circuit in which is connected an electrical instrumentality responsive to an electrical current, and switch means operable by the cam follower means upon rotation of the cams to periodically make and break the flow of current in said electrical circuit.

2. A current interrupter according to claim 1, wherein the means operable to overcome the biasing action of the resilient means is operable automatically as the shaft is rotated.

3. A current interrupter according to claim 1, wherein the means operable to overcome the biasing action of the resilient means is operable manually by engagement of means carried by the cam which is loose on the shaft.

4. A current interrupter according to claim 1, wherein the means operable to overcome the biasing action of the resilient means is operable by engagement of an abutment axially spaced from and carried by the cam which is loose on the shaft.

5. A circuit interrupter according to claim 1, wherein the cams are disk cams and friction means serve to hold the adjacent faces of the cams in coupled engagement when the resilient means is in biasing relation to the cam which is loose on the shaft.

6. A circuit interrupter according to claim 5, wherein the friction means is a disk of friction material loosely mounted on the shaft between adjacent faces of the disk cams.

7. A circuit interrupter according to claim 5, wherein there are two cams which are loose on the shaft, the intermediate cam having a segment the center of gravity of which is below the axis of the shaft and said segment FOREIGN PATENTS having a plurality of spaced high points thereon which 620 813 3/1949 Great Britain will automatically assume a position below the axis of 973814 10/1964 Great Britain the shaft when said cam is in noncoupled relation to the other cams- 5 BERNARD A. GILHEANY, Primary Examiner.

References cued HAROLD BROOME Am: tEx m'n an er. UNITED STATES PATENTS a 1 2,619,560 11/1952 Jepson 3335-68 US. 01. X.R. 3,053,095 10/1962 Reynolds 335-73 2 4 3,221,117 11/1965 Simmons.

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