US2751460A

US2751460A - Remote controlled electric switch

Info

Publication number: US2751460A
Application number: US361241A
Authority: US
Inventors: Clifford W Petersen
Original assignee: McGraw Electric Co
Current assignee: McGraw Electric Co
Priority date: 1953-06-12
Filing date: 1953-06-12
Publication date: 1956-06-19
Anticipated expiration: 1973-06-19

Description

June 19, 1956 c. w. PETERSEN 2,751,46Q

REMOTE CONTROLLED ELECTRIC SWITCH Filed June 12, 1953 3 SheetsSheet 1 INVENTOR. cm i, CUFFQEDWPETERSEH A-y-reeauav June 19, 1956 c. w. PETERSEN REMOTE CONTROLLED ELECTRIC swmca 3 Sheets-Sheet 2 Filed June 12, 1953 INVENTOR. CuFFoRD W. PETERSEN a KFW\ June 19, 1956 c. w. PETERSEN 2,751,460

REMOTE CONTROLLED ELECTRIC SWITCH Filed June 12, 1953 3 Sheets-Sheet 3 SYNcHRoNouS SELF-STARTING q /-9 Mo-roR MAGNEHC.

CLUTCH AND REOuc-rloN GEAIMNG INVENTOR. Curr-om: W. Pe-ranseu A-r-roaNE United States REMOTE CONTROLLED ELECTRIC SWITCH Application June 12, 1953, Serial No. 361,241

Claims. (Cl. 200-92) This invention relates to a remote controlled electric switch.

In greater detail, this invention relates to a remote controlled electric switch of the wired radio type which provides for the remote control by carrier current of a predetermined frequency superimposed on the power lines and controlling the energization of the switch, the switch in turn controlling any desired type of apparatus operated by electric power, such for example, as motors, power relays, switches, lamps, electric heaters, lighting systems or any other electrically operated apparatus.

This invention is an improvement over that disclosed in the copending application, W. G. Coe, United States application Serial Number 125,589, filed November 4, 1949, now Patent No. 2,698,916, dated January 4, 1955, for Control System and Receiver Therefor, assigned to the same assignee as the present invention.

Objects of this invention are to provide an apparatus which allows for the remote control of a single or a plurality of electrically operated devices when a selected frequency is superimposed on the power lines and is maintained for any one of several preselected periods of time.

In greater detail, further objects of this invention are to provide a remote controlled electric switch which may be set to close when an electric impulse such as a carrier current of a predetermined frequency is maintained for ten seconds, fifteen seconds, or twenty seconds for one position of the switch and which is maintained for a greater length of time, for example, forty seconds for another position of the switch, it being understood that these figures are not given as limiting data but are merely given as illustrative.

In the prior manufacture of switches of this general type a high degree of accuracy has to be maintained in the machining, assembling or positioning of the many component parts all of which coact in the normal functioning of the switch. If the tolerance is exceeded for any one of the several parts the switch is rendered inoperative for the purpose intended.

This invention is designed to overcome the above noted defects and objects of this invention are to provide a novel form of construction of a remote controlled switch in which there is a minimum of accuracy required in its manufacture, assembling or positioning of the parts and in which substantially all of the parts requiring accuracy are assembled about a single center of rotation and in which the other parts of the switch which are operated from the hereinabove described portions do not require the high degree of tolerance heretofore necessary.

Further objects are to provide a remote controlled elecfric switch responsive to carrier current of a predetermined frequency which may be set to selectively operate for one position of the switch when the carrier current is maintained for any one of the preselected periods of time thereby making it possible to remotely control different apparatus or different groups of apparatus by means of carrier current of a single frequency.

Further objects are to provide a remote controlled electric switch of the above identified type which will reset itself at the start position with the switch in open position for all of the remote controlled switches irrespective of the position that any of the remote controlled switches may have, to thereby bring all of the remote controlled switches back to the same starting point.

An embodiment of the invention is shown in the accompanying drawings, in which:

Figure 1 is a vertical, sectional view through one of the receivers, such view showing one side of the panel.

Figure 2 is a view showing the other side of the panel with the casing removed.

Figure 3 is a view, partly diagrammatic, showing the manner in which the device is connected to the line and load.

Figure 4 is a side elevation of the cam and pawl.

Figure 5 is a view taken on line 55 of Figure 4.

Figure 6 is an enlarged face view of the cam.

The device is mounted on a vertical panel 1 of insulating material and is housed within a casing 2 provided with a removable bottom 3. Preferably a centering disk 4 is also provided. Terminals 5 are secured to the panel 1 and pass through the disk 4.

A self-starting synchronous motor 6 is provided with a magnetic clutch and reduction gear mechanism indicated generally at 7 in Figure 3 and the clutch is so arranged that it closes when the motor is energized and opens when the motor is deenergized, in the usual and well-known manner.

The motor is directly connected to one side of the line 3 and is connected automatically to the other side 9 of the line when the sensitive relay, indicated generally at 10, closes. A tuned circuit consisting of the blocking condenser 31 and inductance 12 are connected across the line and are tuned to the selected frequency. The winding 13 of the relay 10 is energized with direct current from the output terminals of the bridge rectifier 14 whose input terminals are connected across the inductance 12, a protective resistor 15 being connected in series.

The motor, through the reduction gearing and the clutch drives a driving member or arm 16 which is biased by means of the spring 17 to zero position against an adjustable zero stop or pin 18. This stop can be positioned in any one of a plurality of holes 19 corresponding, for instance to a setting for a ten, fifteen or twenty second signal. The motion of the arm or driving member 16 is counter-clockwise when the motor is driving, and clockwise when it is quickly returned by the spring 17 to zero position. A limit stop 20 is provided to limit the travel of the arm when driven by the motor. If the arm hits the stop 20, the motor merely stalls and no damage is done.

A sleeve or hub 21 is rigid with the arm 16 and has an enlarged portion 21' upon which an insulating cam 22 loosely rides, the cam being held against removal by the split washer 23. The arm 16 or driving member carries a spring pressed pawl 24 which rides in the slots 25 in the cam 22 and drives the cam when the pawl engages an end of a slot while the arm or driving member to is driven by the motor. The pawl freely rides over the solid portions of the cam between the slots on return motion of the arm when the pawl encounters such portions.

The cam is divided into two similar portions, which may be called complete cycles of the cam and each portion includes a slot 25 and a short face 26, corresponding to open position of the switch, and a long face 27, corresponding to closed position of the switch. The short portion 26 of the cam is at a greater radial distance than the long portion 27.

A cam follower 28 rides on the cam and is rigid with the movable, conducting portion 29 of the switch, such portion being biased closed by the spring 30 see Figure 3. The switch controls the connection of the load 30 to the line.

The spring pressed pawl plays a further part in the operation of the apparatus. It not only drives the cam in a positive manner in a counter-clockwise direction when driven by the motor, but also provides a drag or friction against the cam when the driving arm 16 is being returned to zero position by the spring 17. This causes the cam to move in a clockwise direction until it is arrested by the cam follower abutting one of the

shoulders

31 or 32 of the cam which correspond, respectively, to full open starting position or the full closed starting position.

The different positions of the zero pin 18 determines whether the receiver will close its switch for a ten, fifteen or twenty second signal for instance. In this way, selective control of many different receivers can be had. All of the receivers will open their switches when a forty second signal is received since this is much longer than any of the closing periods. Thus all of the receivers can be brought to open position simultaneously and may thus be synchronized no matter what position their cams may have occupied. The driving member, though it only executes partial revolutions, rotates at such a rate as would correspond to a complete revolution in sixty seconds.

It is to be noted particularly that all of the parts which require accurate relative adjustment, such as the driving member and the cam are mounted about a single center of rotation. The other parts of the switch which coact with the cam do not have to be so accurately related. The result of this is that the receiver does not require a high degree of tolerance as heretofore necessary, for instance, in the device disclosed in the copending application.

It will be seen also that very few parts are required and that the number of moving parts has been reduced to a minimum.

Although this invention has been described in considerable detail, it is to be understood that such descrip tion is intended as illustrative rather than limiting, as the invention may be variously embodied and is to be interpreted as claimed.

I claim:

1. A remote controlled electric switch designed for use in a system where controlling impulses are furnished for two different lengths of time, said remote controlled electric switch comprising a self-starting synchronous motor designed to rotate in one direction only, a switch, a driving member driven from said motor and arranged to move from a zero position to a first or second position in the same direction without completing a full revolution, a normally open clutch between said motor and said driving member arranged to magnetically close when said motor is energized, biasing means for returning said driving member to zero position from either said first or second position, a cam follower for operating said switch, a cam driven from said driving member and having its face divided into at least one series of portions including a shorter portion and a longer portion coacting with said cam follower to respectively open and close said switch, a first stop located at the zero position of said driving member, a second stop located at the second position of said driving member, and pawl means for positively connecting said cam and driving member While said driving member is executing driving action.

2. A remote controlled electric switch designed for use in a system where controlling impulses are furnished for two different lengths of time, said remote controlled electric switch comprising a self-starting synchronous motor designed to rotate in one direction only, a switch, a driving member driven from said motor and arranged to move from a zero position to a first or second position in the same direction without completing a full revolution, a normally open clutch between said motor and said driving member arranged to magnetically close when said motor is energized, biasing means for returning said driving member to zero position from either said first or second position, a cam follower for operating said switch, a cam driven from said driving member and having its face divided into at least one series of portions including a shorter portion and a longer portion coacting with said cam follower to respectively open and close said switch, said cam and said driving member being revolubly mounted and rotatable about a common axis, and detachable connecting means between said cam and driving member for positively driving said cam when said driving member is driven from said motor and releasing said driving member on return motion of said driving member, a first stop located at the zero position of said driving member, and a second stop located at the second position of said driving member, said first stop being adjustable to any of several positions to determine the distance traveled by said driving member for the duration of the shorter of said impulses.

3. A remote controlled electric switch designed for use in a system where controlling impulses are furnished for two different lengths of time, said remote controlled electric switch comprising a self-starting synchronous motor designed to rotate in one direction only, a switch, a driving member driven from said motor and arranged to move from a zero position to a first or second position in the same direction without completing a full revolution, a normally open clutch between said motor and said driving member arranged to magnetically close when said motor is energized, biasing means for returning said driving member to zero position from either said first or second position, a cam follower for operating said switch, a cam driven from said driving member and having its face divided into at least one series of portions including a shorter portion and a longer portion coacting with said cam follower to respectively open and close said switch, a stop located at the zero position of said driving memher, said cam having a cutout portion corresponding to one of said series of portions, and a pawl carried by said driving member and arranged to travel in the cut-out portion of said cam and to engage the cam at one end of said cut-out portion, said cam being arranged to execute complete revolutions in one direction only due to partial revolutions of said driving member.

4. A remote controlled electric switch designed for use in a system where controlling impulses are furnished for two different lengths of time, said remote controlled electric switch comprising a self-starting synchronous motor designed to rotate in one direction only, a switch, a driving member driven from said motor and arranged to move from a zero position to a first or second position in the same direction without completing a full revolution, a normally open clutch between said motor and said driving member arranged to magnetically close when said motor is energized, biasing means for returning said driving member to zero position from either said first or second position, a cam follower for operating said switch, a cam driven from said driving member and having its face divided into at least one series of portions including a shorter portion and a longer portion coacting with said cam follower to respectively open and close said switch, a stop located at the zero position of said driving member, said cam having a cut-out portion corresponding to one of said series of portions and a pawl carried by said driving member and arranged to travel in the cut-out portion of said cam and to engage the cam at one end of said cut-out portion, said cam being arranged to execute complete revolutions in one direction only due to partial revolutions of said driving member, said pawl being spring pressed and being arranged to ride over the unbroken portion of said cam.

5. A remote controlled electric switch designed for use in a system where controlling impulses are furnished for two different lengths of time, said remote controlled electric switch comprising a self-starting synchronous motor designed to rotate in one direction only, a switch, a driving member driven from said motor and arranged to move from a zero position to a first or second position in the same direction without completing a full revolution, a normally opened clutch between said motor and said driving member arranged to magnetically close when said motor is energized, biasing means for returning said driving member to zero position from either said first or second position, a cam follower for operating said switch, a cam driven from said driving member and having its face divided into a plurality of series of portions with each series including a short portion and a longer portion coacting with said cam follower to respectively open and close said switch, a stop located at the zero position of said driving member, said cam having a cut-out portion for each of said series of portions, and a pawl carried by said driving member and arranged to travel in the cut-out portions of said cam and to engage the cam at one end of each of said cut-out portions, said cam being arranged to execute complete revolutions in one direction only due to partial revolutions of said driving member, said pawl being spring pressed and being arranged to ride over the unbroken portions of said cam.

References Cited in the file of this patent UNITED STATES PATENTS 1,041,716 Burnham Oct. 15, 1912 1,483,433 Hall Feb. 12, 1924 1,575,010 Scheer Mar. 2, 1926 1,941,377 Woodworth Dec. 26, 1933 1,986,032 Townsend Jan. 1, 1935