US2754460A

US2754460A - Water responsive control circuit

Info

Publication number: US2754460A
Application number: US432108A
Authority: US
Inventors: Robert B Goldman
Original assignee: Individual
Current assignee: Individual
Priority date: 1954-05-25
Filing date: 1954-05-25
Publication date: 1956-07-10
Anticipated expiration: 1973-07-10

Description

July 10, 1956 R. B. GOLDMAN 2,754,460

WATER RESPONSIVE CONTROL CIRCUIT Filed May 25, 1954 Kg ;,4; 1 .LE

FT X JE "M I E E INVENTOR.

1905527- B. GOLD/WW L ilnited States Patent lt-ice 2,754,460 Patented July 10-, 1955 WATER RESPONSIVE CONTROL CIRCUIT Robert B. Goldman, Forest Hills, N. Y.

Application May 25, 1954, Serial No. 432,108

7 Claims. (Cl. 318-102) My invention relates to a water responsive control circuit and more particularly to a control circuit for use in automotive vehicles of the convertible type for first raising the windows and then erecting the top in event of rain.

There are a number of water operated circuits known to the art for controlling the erection of the tops of convertible automobiles. The operation of such devices is initiated by a water sensitive relay and the cycle is completed by a limit switch. If it were attempted to apply this principle to the raising of the windows of a convertible, a plurality of limit switches would be required to act when the windows were in raised position. The installation of such limit switches is awkward and expensive. There is another difficulty which is more serious, however. In an automotive vehicle, the power for the operation of the motors must come from the storage battery of the car. The operation of four window motors simultaneously when the generator is not running would draw a higher current than the battery is designed to deliver. I have found, accordingly, that it is necessary to operate the window motors in succession.

One object of my invention is to provide a water re sponsive control circuit in which the windows of an automotive vehicle will be raised in succession followed by the erection of the top in response to water from raindrops acting upon a water sensitive switch.

Another object or my invention is to provide a water sensitive control circuit in which the operation of a motor is initiated by a water sensitive switch and in which the motor is de-energized in response to an increased load of predetermined proportions.

Another object of my invention is to provide a water responsive control circuit in which the operation of a plurality of motors in succession is initiated by a water sensitive switch and the successive operation of the motors is controlled by successive increases in load upon the motors.

Other and further objects of my invention will appear from the following description.

In general my invention contemplates the provision of a plurality of motors, one for raising each of the windows and one for erecting the top. A first relay is adapted to be energized in response to a water sensitive switch. The energization of the first relay initiates the operation of the first motor and raises one of the windows. The motor circuit is completed by a normally closed switch adapted to be opened by a series connected relay winding. An increase in current owing to an increased load upon the motor, created by the window reaching its limit of travel or otherwise, energizes the relay sufliciently to open the normally closed switch. The opening of the normally closed switch interrupts the motor circuit but permits current to flow through a parallel high resistance relay winding, first, to hold the first motor circuit in open position and simultaneously to hold a normally open switch of a successive motor in closed position. In this manner each of the motors are successively energized and de-energized at the limit of travel of the member operated by the motor until the final motor is operated. The final motor usually erects the top and this motor is tie-energized by a mechanically opened, normally closed limit switch. The entire arrangement is adapted to be rendered inoperative by closing the ignition switch of the automotive vehicle. In this manner the normal operating controls for the windows and top may be employed while the operator is in the car. The instant control circuit is intended to operate only in the absence of the owner. It is to be under stood, of course, that while I have described my invention with respect to the control of a plurality of motors for the operation of automotive vehicle windows and top that my invention may be employed to control any other appropriate device. For example, my arrangement can be employed to close the windows of a house in the absence of an owner. I consider a salient feature of my invention the arrangement whereby the action of the motor, having been initiated, is automatically stopped by an increase in load in a manner to hold the motor circuit in an inoperative condition and at the same time maintain another switch in a closed position.

In the accompanying drawings which form part of the instant specification and which are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts in the various views:

Figure l is a diagrammatic view of a control circuit containing one embodiment of my invention.

Figure 2 is a perspective view showing one form of water sensitive switch which may be used in carrying out my invention.

More particularly referring now to the drawings, the conductor it) is connected to a positive terminal 12 of a potential source, such a battery. The conductor 14 is adapted to be connected to the terminal 16 which is the ground or index terminal of the battery. I will describe my invention with respect to an automotive vehicle in which the potential source is a storage battery. It is to be understood, of course, that any suitable potential source may be employed when my control circuit is employed for other uses. Inasmuch as I desire to render my control circuit inoperative when the car is being driven, I arrange my water sensitive switch W across the potential source in series with a normally closed manual switch 18, a mechanically operated limit switch LS, a normally closed relay operated switch 1R1 and a relay winding R2. It will be observed that the relay winding R2 will be energized whenever the circuit is closed across water sensitive switch W, provided the manual switch 18, the limit switch LS and the relay switch 1R1 are in their closed positions. The water sensitive switch W is shown in Figure 2. It comprises an insulating base 22 upon which is mounted a pair of

grids

24 and 25 formed of respective interdigitating fingers 26 and 23. Binding post 30 connects with grid 24 and its fingers 26 while binding post 32 connects with grid 25 and its fingers 28. The space between the pair of adjacent fingers 26 and 23 is quite small and suflicient to be bridged by a single small drop of water. The grid may be formed in any appropriate manner, as for example, by electrodepositing a conductive metal upon the insulating back 22. The metal is then covered with a wax or other protective coating. The grids may be formed by scribing the outlines of the interdigitating fingers through the protective coating and then etching through the conductive metal by means of acid. Any appropriate means for mounting the grid (not shown) in an exposed position upon the car may be provided. Distilled water is not a conductor. The first drops of rainfall, however, dissolve sufficient impurities in the atmosphere so that the initial drops of rain form an electrolytic solution adapted readily to conduct current. Furthermore, the grid itself will be coated with deposited salts and other soluble matter. The relay R2, controlled by the water sensitive switch W, is a sensitive one owing to the fact that the current density through a drop of water must necessarily be low.

In order to render the control circuit inoperative when the ignition is energized, an ignition key operated switch K is adapted to energize relay winding R1. The energization of winding R1 opens its normally closed relay operated switch 1R1 to interrupt the circuit which would 'be completed through relay winding R2 by water sensitive switch W. It will also be observed that the operation of my control can be stopped at any point by interrupting the circuit through relay winding R2 by means of a normally closed manual switch 13. The circuit through relay winding R2 can also be interrupted by opening a normally closed limit switch LS. This switch may be of any appropriate design and is adapted to be opened by movement of the top to its erected position.

Relay winding R2 controls a normally open switch 1R2. Whenever winding R2 is energized, switch 1R2 closes thus energizing relay winding R3. Relay winding R3 controls two switches, namely 1R3 and 2R3. Switch 1R3 is adapted to hold the relay winding R3 in energized condition after the circuit through relay winding R2 is broken, as would be the case if a drop of water evaporated or ran from the water sensitive switch W. Motor 40 controls the first window and is adapted to be connected across the line by normally open relay switch 2R3. This switch is connected in series with a normally closed switch 1R4 and a low impedance relay winding R4L. The winding 41 is the shunt field winding for the motor 40. The core of relay winding R4L has wound around it a high impedance relay winding R il-i. The winding Ri-I is connected in parallel with the circuit segment formed by the low impedance winding R4L and the normally closed relay switch 1R4, as can readily be seen by reference to Figure 1. Upon the closing or" switch 2R3 the transient reactance prevents the current passing through winding R4L from reaching a point high enough to actuate the armature of the relay. This armature, when actuated, opens the normally closed switch 1R4 and simultaneously closes the normally open switch 2R4. Upon the closing of theswitch 2R3, the current will begin to build up through winding R tL causing the armature of motor 40 to rottae. The counter electromotive force generated by the armature of the motor 40 continues to prevent the current through winding RdL from reaching a level high enough to actuate the relay armature after the transient reactance has subsided and the current has reached a steady state. actance, which is equivalent of electrical inertia, the physical inertia of the armature assists in preventing the immediate opening of the switch 1R4 when the current transiently exceeds its normal actuating level. With the steady state achieved, the motor continues to run raising the number one window of the automotive vehicle. When the window reaches the limit of its travel, there is an increased load upon the motor slowing down its armature and reducing the counter e. m. f. The reduction in the counter e. m. f. raises the current flowing through relay winding R4L sufliciently over its steady state level to move the relay armature to open switch 1R4 and close switch 2R4. While switch 1R4 was closed, the resistance through winding R4L was so low that very little current flowed through winding R4H. When switch 1R4 opens, however, increased current will flow through high impedance winding R4H. The high resistance of the winding is such that there is insuflicient current to operate the motor 49 or to produce any substantial current drain upon the battery. The current, however, is sufficient to maintain the armature of the relay R4 in its actuated position, that is, with switch 1R4- open and switch 2R4 closed.

The closing of switch 2R4 energizes the motor 5v), which is provided with a field winding 51, through the normally closed relay switch 1R5 and the low impedance In addition to the transient rcrelay winding RSL. The high resistance relay winding RSI-I is connected across the normally closed switch 1R5 and the winding RSL. The relay R5, of which windings R5L and RSH form part, controls normally closed relay switch 1R5 and normally open relay switch 2R5. The motor may drive the mechanism for raising the second window. When this window reaches its limit of travel, the armature of motor 5-3 will carry an increased load and will reduce its speed of rotation. This reduces the counter emf and raises the current flowing through the winding R5L a suflicient amount to actuate the armature associated with the relay windings and to open switch 1R5 and to close switch 2R5. The opening of switch 1R5 interrupts the circuit through the motor 59 by way of the low resistance winding REL. This permits a holding current of a small amount to flow through the auxiliary high resistance winding RSI-I in a manner analogous to the action of the holding of relay contact 1R4 in open position by current flowing through the holding high resistance winding PAH. It will be seen that at this point in the cycle of operations current is flowing through the holding winding R3 maintaining contacts 1R3 and 2R3 closed, current is flowing through holding winding R4H holding relay contact 1R4 open and relay contact 2R4 closed, and current is flowing through holding winding RSI-I maintaining contact 1R5 open and contact 2R5 closed.

The closing of relay contact 2R5 will complete the circuit through motor 60, which is provided with a field winding 61, by way of the low impedance relay winding R6L. The motor 60 actuates the third window and raises it. When this window reaches the limit of its travel, the increased load upon the motor 6% reduces the counter emf and increases the armature current. This increase in armature current is suthcient to produce an increase of magnetic flux in Winding R6L to operate the armature of the relay. The actuation of the armature opens normally closed relay contact 1R6 and closes normally open relay contact 2R6. The opening of switch 1R6 permits an energization of the high impedance winding RdH which will maintain the relay R6 in its actuated position, that is, with switch 1R6 open and switch 2R6 closed in a manner analogous to the action of holding windings RdI-I and R5H.

The closing of switch 2R6 will energize the motor 7%, which is provided with a shunt field winding 71. Motor '70 will raise the fourth window of the automotive vehicle. When this window reaches its raised position, the increased load upon the motor 7% will cause the relay winding R7L to actuate the relay armature to open normally closed switch 1R7 and to close normally open switch 2R7. The opening of the normally closed relay switch 1R7 will permit the energization of the high resistance holding winding R7H.

The closing of switch 2R7 will energize the motor 80, which is provided with a field winding iii. The motor 30 will drive the mechanism which erects the top of the convertible car. When the automotive top reaches its erected position, it will mechanically open limit switch LS. When this occurs, the circuit through holding winding R3 is broken and switches 1R3 and 2R3 will return to their normally open positions. The opening of switch 2R3 will interrupt the current through the holding winding RdH. When this occurs, switch 2R4 will move to its open position, thus interrupting the current through holding winding RSI-I. When this occurs, switch 2R5 will open, interrupting the current through holding winding RfiI-i, thus permitting the switch 2R6 to resume its normally open position. This causes an interruption of current flow through the holding winding RiH and permits the switch 2R7 to open stopping the top motor 30. When the top 7 is up, the water sensitive switch W can no longer energize the relay winding R2 because the limit switch LS now interrupts the circuit.

The cycle of operations initiated by the water sensitive switch can be stopped at any time by opening the normally closed manual switch 18. When the manual switch 18 is open or the ignition switch K is closed, the water sensitive control circuit is rendered inoperative and the Windows and top may be controlled by the normal controls with which the automotive vehicle may be fitted.

It will be understood, of course, that the sequential operation of the motors 4t), 5t), 6t 7t? and 80 are employed in an automotive vehicle owing to the lack of capacity of the normal storage battery of a car.

It will be seen that I have accomplished the objects of my invention. I have provided a water responsive control circuit enabling the windows of an automotive vehicle to be raised in succession followed by the erection of the collapsible top in response to water from raindrops or snow acting upon a water sensitive sw' ch. The window raising motor is adapted to be de-energized upon the interposition in an increased load from any cause. Thus, if a child were in the vehicle and thrust an arm or its head in the path of the window travel, the window raising motor would be de-energized before the child could be injured. The cycling of the control circuit is completed upon the raising of the top and the entire circuit automatically de-energized.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is Within the scope of my claims. It is further obvious that various changes may be made in details within the scope of my claims without departing from the spirit of my invention. It is therefore to be understood that my invention is not to be limited to the specific details shown and described.

Having thus described my invention, what I claim is:

1. In a water responsive control circuit of the character described a first relay winding, a first normally open first relay switch, a second normally open first relay switch, water sensitive means for energizing the first relay winding, circuit means completed by the closing of the first normally open first relay switch for holding the first relay winding in energized condition, a motor, a low impedance second relay Winding, a normally closed second relay switch, circuit means including said second normally open first relay switch and said normally closed second relay switch and said low impedance second relay winding connected in series for energizing said motor, an auxiliary high impedance winding shunted across said low impedance second relay winding and said normally closed second relay switch, the construction being such that the energization of said low impedance second relay winding will open said normally closed second relay switch and permit the energization of said high impedance second relay winding to hold the normally closed second relay switch in open position thereby maintaining the motor in de-energized condition.

2. In a water responsive control circuit of the character described a first relay winding, a first normally open first relay switch, a second normally open first relay switch, water sensitive means for energizing the first relay winding, circuit means completed by the closing of the first normally open first relay switch for holding the first relay winding in energized condition, a first motor, a low impedance second relay winding, a normally closed second relay switch, a normally open second relay switch, circuit means including said second normally open first relay switch and said normally closed second relay switch and said low impedance second relay winding connected in series for energizing said first motor, an auxiliary high impedance second relay winding shunted across said low impedance second relay winding and said normally closed second relay switch, a second motor, a circuit for energizing said second motor including said normally open second relay switch, the construction being such that the energization of said low impedance second relay winding will open said normally closed second relay switch and close said normally open second relay switch whereby to de-energize said first motor and initiate the circuit through said second motor.

3. A water responsive control circuit as in claim 2 including means responsive to a predetermined movement of said second motor for interrupting the circuit through said first relay winding.

4. A water responsive control circuit as in claim 2 including a key controlled relay winding, a normally closed key controlled relay switch and circuit means for connecting said normally closed key controlled switch in series with said first relay winding whereby to prevent the energization of said first relay winding whenever said key controlled relay winding is energized.

5. In a water responsive control circuit of the character described a first relay winding, a first normally open first relay switch, a second normally open first relay switch, water sensitive means for energizing the first relay winding, circuit means completed by the closing of the first normally open first relay switch for holding the first relay winding in energized condition, a first motor, a low impedance second relay winding, a normally closed second relay switch, a normally open second relay switch, circuit means including said second normally open first relay switch and said normally closed second relay switch and said low impedance second relay winding connected in series for energizing said first motor, an auxiliary high impedance second relay winding shunted across said low impedance second relay winding and said normally closed second relay switch, a second motor, a low impedance third relay winding, a normally closed third relay switch, a normally open third relay switch, circuit means including said normally open second relay switch, said normally closed third relay switch and said low impedance third relay winding connected in series for energizing said second motor, an auxiliary high impedance third relay winding shunted across said low impedance third relay winding and said normally closed third relay switch, a third motor, a circuit for energizing said third motor including said normally open third relay switch, the construction being such that the energization of said low impedance third relay winding will open said normally closed third relay switch and close said normally open third relay switch whereby to de-energize said second motor and initiate the circuit through said third motor.

6. A water responsive control circuit as in claim 5 including means responsive to a predetermined movement of said third motor for interrupting the circuit through said first relay winding whereby to interrupt the circuit through said holding high impedance second relay winding and thus interrupt the circuit through said holding high impedance third relay winding to permit the normally open third relay switch to resume its open position and interrupt the circuit through said third motor.

7. In a water responsive control circuit of the character described a motor, a low impedance relay winding, a normally closed relay operated switch and a normally open switch, a circuit for energizing said motor including said low impedance relay winding, said normally closed relay switch and said normally open switch connected in series, an auxiliary high impedance winding shunted across said low impedance relay winding and said normally closed relay switch, the construction being such that upon the energization of said motor by the closing of said normally open switch the motor will be energized and upon the energization of said low impedance winding owing to an increase in armature current through the motor said motor circuit will be interrupted by the opening of said normally closed relay operated switch maintained in such opened condition by current flowing through the shunted high impedance relay winding.

References Cited in the file of this patent UNITED STATES PATENTS