WO1998032296A1

WO1998032296A1 - Remote control keyless padlock

Info

Publication number: WO1998032296A1
Application number: PCT/US1998/000068
Authority: WO
Inventors: Dennis Rowan
Original assignee: Dennis Rowan
Priority date: 1997-01-16
Filing date: 1998-01-08
Publication date: 1998-07-23
Also published as: AU5906998A

Abstract

A remotely controlled padlock apparatus wherein the padlock will release its shackle upon activation when a code signal is received (10) from a remote transmitter device. The padlock apparatus invention uses micropower technology (12) to provide a padlock that can run one or more years on a set of AA batteries or indefinitely with rechargeable cells supported by solar batteries (Solar cells) (12). The padlock apparatus incroporates an illumination feature for use in time of darkenss. A user only needs to point the transmitter in the general direction of the padlock and press the transmit button. At that point the padlock will open and illuminate the local area for a predetermined amount of time, indicating the exact location of the padlock.

Description

REMOTE CONTROL KEYLESS PADLOCK

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a remotely controlled lock mechanism, and more particularly to a remote control padlock apparatus having a power efficient lock control mechanism.

Prior Art

Apparatus for unlocking a door lock by a signal from a remote transmitter is well known in the art.

References relating to systems for vehicle door locks include the following U.S. Patents No. 4,663,626 issued May 5, 1987 to Smith entitled REMOTE CONTROL VEHICLE UNLOCKING DEVICE No. 4,859,009 issued January 23, 1990 to Kleefeldt et al. entitled DOOR-LOCKING SYSTEM FOR A MOTOR VEHICLE, U.S. Patent 4,827,744 issued May 9, 1989 to Namazue et al . entitled VEHICLE USE LOCK SYSTEM, No. 4,719,460 issued January 12, 1988 to Takeuchi et al . entitled KEYLESS ENTRY SYSTEM FOR AUTOMOTIVE VEHICLE DEVICES WITH THEFT-PREVENTION FEATURE, No. 5,181,403 issued January 26, 1993 to Lii entitled REMOTE-CONTROLLED AUTOMOBILE AND MOTORCYCLE LOCK, No. 4,825,210 issued April 25, 1989 to Buchhuber et al . entitled ELECTRONIC LOCKING SYSTEM HAVING A LOCK AND A METHOD FOR RESYNCHRONIZATION.

References that relate to electronically opening locks having shackles include the following U.S. Patents.

U.S. Patent No. 5,090,222 issued February 25, 1992 to Imran entitled ELECTRONIC LOCK BOX AND RETENTION MECHANISM FOR USE THEREIN, U.S. Patent No. 3,901,057 issued August 26, 1975 to Coley, Sr. entitled PADLOCK; U.S. Patent No. 4,727,368 issued February 23, 1988 to Larson et al . entitled ELECTRONIC REAL ESTATE LOCKBOX SYSTEM; U.S. Patent No. 4,914,732 issued April 3, 1990 to Henderson et al . entitled ELECTRONIC KEY WITH INTERACTIVE GRAPHIC USER INTERFACE .

SUMMARY OF THE INVENTION

An object of this invention to provide a remote control padlock apparatus having a power efficient lock control mechanism.

Another object of the present invention is to provide a power efficient padlock apparatus that can operate from standard batteries for over one year.

A further object of the present invention to provide a remotely controlled padlock apparatus utilizing a passive power source that derives energy from ambient sources, such as light.

Still another object of the present invention is to provide a remotely controlled padlock including a power source wherein energy provided by the power source that is not used to power the padlock mechanism is stored in internal rechargeable cells for use during periods of darkness.

A further object of the present invention is to provide a remotely controlled padlock apparatus having a power source and power efficient circuitry, wherein the padlock has no need of periodic battery replacement.

A still further object of the present invention to provide a remotely controlled lock system having an illumination feature that provides safety and convenience to the user during darkness.

Still another object of the present invention is to provide a remotely controlled lock system that will learn the code of an existing transmitter device.

Further objects and advantages will become apparent from consideration of the drawings and ensuing descriptions.

DESCRIPTION OF DRAWINGS

Figure 1 is a comprehensive block diagram of the invention.

Figure 2 is a schematic block diagram of an embodiment of a signal receiver and conditioner shown in Figure 1.

Figure 3 is a schematic diagram of an embodiment of a microcontroller circuit shown in Figure 1.

Figure 4 is a schematic block diagram of an embodiment of a shackle control element shown in Figure 1 including an elastic transmission element.

Figure 5 shows a schematic representation of the embodiment of Figure 4 in a locked state.

Figure 6 shows a schematic representation of the embodiment of Figure 4 in a state following the reception of the proper code signal .

Figure 7 shows a schematic representation of the embodiment of Figure 4 in the state following shackle ejection.

Figure 8 shows a schematic representation of the embodiment of Figure 4 following shackle ejection and demonstrating the strength of the elastic transmission element.

Figure 9 shows a flowchart of shackle operation after the activation signal has been received.

Figure 10 shows the power control circuit for a dual^" powered device . Figure 11 shows the illumination feature for the embodiment of the present invention.

Figure 12 shows a circuit used to drive the lamp of the illumination feature of Figure 11.

DETAILED DESCRIPTION OF THE INVENTION:

A remotely controlled padlock embodiment is described wherein the padlock will release its shackle upon activation. Activation occurs when a code signal is received from a transmitter device such as those used for auto lock systems. An important feature of the invention over other types of remotely controlled lock systems is the utilization of micropower technology to provide a padlock that can run one or more years on a set of AA batteries or indefinitely with rechargeable cells supported by solar batteries (solar cells) .

Another important feature of the padlock of the present invention is the incorporation of an illumination feature or use in times of darkness . A user only needs to point the transmitter in the general direction of the padlock and press the transmit button. At that point the padlock will open and illuminate the local area for a predetermined amount of time, indicating the exact location of the padlock.

Figure 1 is a comprehensive block diagram of the invention. The power consumption of the components is a major factor and a significant feature in the design of the invention. Referring to Figure 1, the component blocks of the invention that are contained in the padlock housing will be described individually starting with the signal receiver and conditioner means 10.

A coded signal is received by the signal receiver and conditioner means 10 and applied to micro controller 12. Microcontrollers that can be used as element 12 in Figure 1 are available in the art, one example being a PIC 1 5654LP microcontroller. A power supply and controlling circuit 20 and a frequency reference means 22 are provided for microcontroller 12.

Other components of the embodiment of the invention in

Figure 1 include a shackle driver, holding mechanism and sensor means 14, a non-volatile random access memory (NV RAM) means 16, a user interface 18 and a security means 24.

Figure 2 illustrates the circuit elements of signal receiver and conditioner 10 of the padlock. The signal receiver and conditioner component can be a radio receiver, an infrared pickup, ultrasound receiver, etc. It is the intent of the present invention to use known signal transmitter devices if possible. The signal receiver and conditioning circuit of Fig. 2 is designed to receive such an existing transmitter signal. Figure 2 shows an infrared (IR) photodiode 10-1, as the receiving element connected to a series of amplifiers 10-3, 10-5 and filters 10-2, 10-4. The output of IR photodiode 10-1 is first sent to high pass filter 10-2 to remove the effects of any ambient room light and any 60 hz frequency of fluorescent lights. The filtering must precede the amplifiers especially if transistor stages are used in the amplifier because if a large amplitude 60 Hz fluorescent light signal and the received transmitter signal are both present at the base of a transistor amplifier, the voltage swing on the base of the transistor will cause the two signals to amplify non- linearly (mix) rather than amplify linearly.

The first amplification stage 10-3 is a low level amplifier that amplifies signals that are two weak to be detected by ordinary operational amplifiers. Low-level amplifier 10-3 amplifies the signal in such a manner that micropower operational amplifiers can be used for the final two stages consisting of bandpass filter 10-4 and limiting amplifier 10-5. The output of amplifier 10-3 is filtered by a band pass filter 10-4. Filter 10-4 isolates the desired frequency band to include desired harmonics. The output of filter 10-4 is then amplified and limited to logic levels through limiting amplifier 10-5 to produce a digital pulse train readable by the microcontroller 10. The overall gain of this circuit must be over 80 db.

In Figure 2, Rb is a pull-up resistor for the photodiode 10-1 having a value that depends upon the photodiode being used and the photodiode manufacturer's bias recommendation. Semiconductor manufacturers produce modules for IR reception that are directly substitutable for the entire signal receiver and conditioner circuit of Fig. 2. These prefabricated modules contain circuits to detect amplitude modulated or frequency modulated signals as well as simple ^ogic detection. The major consideration for the circuit for the signal receiver and conditioner 10 is power consumption.

Figure 3 shows a preferred embodiment for microcontroller 12 of Figure 1 for the present invention. This particular microcontroller may be a state of the art device that draws a mere 15 micro amperes of current at 3 volts with a clock frequency of 32 kHz. The clock frequency is set by an oscillator in frequency reference means 22 including crystal XTAL 12-1 and capacitors Cl and C2. The values for these capacitors are dependent upon the desired clock frequency. Extremely low power consumption is realized with clock frequencies in the kHz range with the network of 12-2 comprising resistor RI , diode D, resistor Rt and capacitor C3.

The network 12-2 extends the desertion of reset to allow the low frequency oscillator to stabilize. The twelve 1/0 lines are general purpose digital lines that used to control the lock mechanism and monitor the sensors. Figure 4 is a block diagram showing more detail of the shackle driver, holding mechanism and sensors means 14 of Figure 1. The motor driver circuit 14-1 applies power to the windings of the low voltage DC motor (MOTOR) 14-2 with polarity and magnitude responsive to the input from one or more of the twelve microcontroller 1/0 lines. Because the power drawn by the low voltage DC motor 14-2 may cause power drops in the lock power system, possibly causing the microcontroller to misfunction, the motor driver circuit 14-1 may contain extra circuitry to force the operation to completion. This will require feedback from a displacement transducer 14-3. The motor 14-2 output is connected to a gear assembly 14-4 that transforms the motor energy efficiently into a mechanical displacement (x) . The accumulated displacement is monitored by the displacement transducer 14-3. The displacement transducer 14-3 can simply be a set of limit switches. The purpose of the displacement transducer 14-3 is to give the microcontroller 12 and/or the motor driver circuit an indication of how far the motor 14-2 has displaced the gear assembly 14-4. The displacement (x) of gear assembly 14-4 is transmitted to shackle holding mechanism 14-5 through an elastic transmission medium 14-6. The shackle holding mechanism 14-5 may be a pin or other mechanical device that holds the shackle when the padlock is in a secure state. A shackle sensor 14-7 is provided to indicate that the shackle is secure.

The purpose of the elastic transmission medium 14-6 is to prevent excessive power drain and/or damage to the padlock should the shackle holding mechanism 14-5 become bound. The shackle holding mechanism can become bound against the shackle as a result of friction due to excessive force applied to the shackle. If the gear assembly 14-4 were to be connected directly to the shackle holding mechanism 14-5 while bound, then an attempt to open the lock would result in a tremendous amount of torque being applied to shackle holding mechanism H 14-5. This would either pry the shackle holding mechanism 14-5 loose or damage the internal mechanism of the padlock. In either case, it would cause a tremendous power drain on the battery because one skilled in the use of electric motors knows a motor with its armature- frozen is essentially a short circuit.

The elastic transmission medium 14-6 allows the motor 14-2 and gear assembly 14-4 to impart a predetermined amount of energy regardless of the condition of the shackle holding mechanism 14-5. Furthermore, this energy is conserved because it is stored in the elastic transmission medium 14- 16 which may be a spring or torsion rod.

Figures 5, 6, 7 and 8 illustrate the importance of the elastic transmission medium 14-6.

Figure 5 shows details of the shackle mechanism. In Figure 5, the gear assembly 14-4 is composed of a gearbox 14-4A, a worm screw 14-4B and a carriage 14 -4C that displaces proportionally to the rotational angle of the worm screw 14-14B. The elastic transmission medium 14-6 is a spring 14-6A. The displacement transducer 14-3 is comprised of limit switches SWI and SW2 spaced along the worm screw 14- 4B that are closed by contact with the carriage 14-4C. The shackle sensor 14-7 is comprised of switch SW3 , and the shackle holding mechanism 14-5 is a simple shackle pin 14- 5A. Figure 5 shows the padlock in its locked state. Spring 14-6A is in compression thus forcing the shackle pin 14-5A into the shackle and holding it securely. When switch is plosed by carriage 14-4C, it indicates that there is the proper amount of compression energy produced as the displacement of the carriage 14-4C against spring 14-6A and tored in the spring 14-6A. The depression of shackle sensor switch SW3 by the shackle indicates that the shackle is secure.

In the system operation, when the microcontroller 12 (Figure 1) receives the proper coded signal transmitted from the transmitter, the activation process begins. The first function of the microcontroller 12 is to drive the DC motor 14-2 via motor driver circuit 14-1 in such a direction (i.e. to the right) to store tensile energy in spring 14-6A. Switch SW2 is depressed by carriage 14-4C when the correct amount of energy is stored in spring 14- 6A. This af er-activation state is shown in Figure 6. Figure 7 shows the mechanism after shackle ejection. If desired, the shackle could be spring loaded to eject however the weight of the padlock should be sufficient to allow it to open without the use of a spring.

Referring to Figures 4 and 7, the shackle sensor means 14-7 (switch SW3 of Figure 4) signals the microcontroller 12 when the shackle ejects. At this point, the microcontroller signal recompresses the spring 14-6A

(Figure 7) and the entire activation process is complete.

Any time later the user can reinsert the shackle without any signal from the microcontroller 12.

Figure 8 shows the mechanism in a state, after activation, where the shackle pin 14-5A is frozen or bound. In this state, spring 14-6A is in tension without the corresponding deflection of the shackle pin 14-5A. Figure 8 represents pictorially the manner in which the elastic transmission medium 14-6 (spring 14-6A) alleviates the failure conditions stated previously. The. amount of force applied to the shackle holding mechanism 14-5 is F=Kx, where x is the linear displacement of the carriage and K is the spring constant. The amount of a energy stored in the spring is Kx²/2.

It should be noted that Figures 5 to 8 show only one embodiment for the elastic transmission medium 14-6. Other embodiments could include the use of torsion rods or twistable shafts to hold the energy.

Figure 9 is a flow chart showing the general operation of the padlock.

Initially, in block 50, power is applied to microcontroller 12 when a transmitted signal is received which then (block 52) scans the transmitter signal for the proper code. If the received code (block 54) is not the proper code the process ends (block 72) . If the code is correct, a check is made (block 56) to determine if the shackle sensor 14-7 (switch SW3) indicates that the switch SW3 is depressed. If switch SW3 is not depressed (i.e. the padlock is already open), the process ends. If switch SW3 is depressed, the padlock opening sequence is activated (block 58) . The DC motor 14-2 is actuated (block 60) to drive carriage 14-4C toward the unlock state, i.e. carriage 14-4C is driven toward switch SW-2 motor 14-2 as long as switch SW-2 is open. When switch SWZ is depressed (block 62) and closed, the motor is 'turned off (block 64) . The next step (block 66) , if the shackle sensor 14-7 (switch SW3) is depressed, the motor 14-2 stays off. If switch SW3 is not depressed, indicating the shackle is open, the motor 14-2 drives carriage 14 -4C (block 68) toward the "lock" direction (toward switch SW1) . As long as switch SW1 is not depressed (block 70) the motor 14-2 continues to drive carriage 14-4C until switch SW1 is closed, at which point the process ends (block 72) .

The power requirements for the described microcontroller 12 embodiment is in the order of 15 microamperes and 3 volts. The quiescent power for the lock (i.e. everything less than the power needed to operate the motor) is less than 50 microamperes) . A typical small DC motor will draw 25 milliamperes and will need a maximum of four seconds to operate the charge the elastic medium transmission 14-6. Assuming that the padlock will be used on average of 4 times a day and since there are 86400 seconds in a day, then the average power drawn by the motor is: 25*4*4/86400= 4.6 microamperes (average). Therefore, the total current drawn by the lock is 50 + 4.6 = 55 microamperes. The simplest configuration for the padlock power supply is a set of long life disposable batteries contained in a battery compartment in the padlock. This battery compartment would further include a mechanical interlock to allow access to the batteries only when the shackle is open. Should the batteries fail, an auxiliary port to power the lock can be provided. This auxiliary port can be a connector accessible to the exterior of the padlock such as a set of 9 volt type nipples where a 9 volt battery may be attached temporarily.

Figure 10 shows an embodiment of a circuit to provide dual power control to the padlock mechanism. A solar cell, or external auxiliary power 36 via a connector can be employed as the power source in Figure 10. The circuit of Figure 10 further includes transistors Tl and T2 in combination with resistors 30 (Ri) and 32 (R2) and rechargeable battery 34. The circuit of Figure 10 may include a rectifier diode (not shown) in series with the battery power source to prevent damage to transistor Tl in the event that the contacts brush against the battery in reverse polarity. Because current through transistor Tl is limited by base resistor 30, the external contacts could be used in conjunction with a transformer (not shown) to charge the batteries (assuming that rechargeable cells are installed) .

Standard alkaline AA batteries are rated (worst case) at 170 hrs at 9 mA. The power consumption of the present invention is under 55 microampere. Thus typical battery life would be 15 * 170/0.055 = 27,800 hrs = 1159 days or 3.2 years .

Instead of disposable batteries, an alternative power system can be provided by using rechargeable batteries and one or more solar cells. A 3.25 inch square of ceramic solar cell material yields 3.1 volts at 72uA under 200 lux fluorescent roomlight conditions. This would be enough to power the lock independently of the batteries. Under better conditions (incandescent or day light) there would be sufficient power to operate the padlock and charge the batteries. Figure 10 shows a power system comprising both rechargeable cells 34 and solar cells 36. The transistor Tl allows the solar cells to take over the powering the circuit when solar power is greater than battery power. It also prevents the backward driving of the solar cells by the battery in times of darkness.

Figure 10 is an illustration of the preferred dual power control circuit including transistors Tl and T2. This circuit is similar in operation to a diode. Current will flow from the node VI to the node V2 only if the voltage at VI is higher than V2. The major difference being that a diode will drop the voltage from VI to V2 by approximately 0.6 volts; whereas this circuit will drop less than 0.2 volts. It should be noted that there are two states in which this circuit of Figure 10 can operate. The first state is V1>V2. The second state is V1<=V2.

In the first state, the transistor T2 is reverse biased and the transistor is forward biased and current flows from the VI to V2. The amount of current transferred from VI to V2 is given by the relationship: 1= (Vl-0.6) *HFe/Ri . This effectively allows the current from the source attached to VI to be limited. In the second state, the transistor T2 saturates and effectively raises the voltage at the base of Tl to the voltage V2. Raising this voltage prevents the transistor Tl from operating in reverse. Tl and T2 should be 2N3906 or other devices with high H_£e at low collector current and low V_ce(SAT). The value of resistor 32 (R2) should be about 10 microohms and the value of resistor 30 (Ri) Ri is selectable from the equation given above. The amount of current drained by the circuit of Figure 10 is given by the following expression:

I_d= (VI-0.G)/Ri {for VI>V2} or (V2-V1-0.6) /R2 + V2/Ri {for V1<=V2} . Figure 1 also shows a non-volatile random access memory (NV RAM) component 16. This is a memory chip connected to the microcontroller 12 and is an optional feature of the invention allowing the padlock to learn and remember a custom code. This custom code feature allows the user the convenience using his/her already existing transmitter (such as for an auto alarm) to operate the padlock as well. Without this feature, the user would have to carry a separate transmitter for the padlock. To facilitate this feature, a user interface 18 comprising at least one button and one indicator (such as LED or audio speaker) is added. The interface 18 is employed to set the padlock into "a learn mode", to learn the code of the transmitter being used. User interface 18 is only active when the shackle is open. To change the code of the padlock, the user unlocks the padlock with the existing transmitter. The user then presses a learn button, then points the new transmitter at the lock and presses the transmit button until the indicator on the lock glows or sounds. While the padlock is open, the indicator on the lock will always indicate when the correct code is being received; this is a good way to check that the "learn" occurred correctly . This feature is also useful to determine which transmitter is the correct one, in the event it gets confused with others.

Figure 11 shows the addition lamp 40 on the padlock housing 41 to provide an illumination safety feature in the padlock. As described before, this feature is intended to aid the user in discovering the padlock in low visibility. Figure 12 illustrates the circuit added to implement this feature. The lamp 40 may be a miniature high brightness type lamp used in small flashlights. The transistor 42 may be an enhancement type MOSFET. The gate of transistor 42 (T3) is connected to any one of the I/O pins of the microcontroller 12. The resistor 44 is used to limit the current through lamp 40 in order to reduce power drops when the bulb is initially turned on. This illumination feature can double as the indicator in user interface 18 if the previously described learn feature is also incorporated into the padlock.

It should be noted that certain of the blocks of illustrated in the Figures have no specifically illustrated and described circuit, for example, the motor driver circuit 14-1 of figure 4. It is understood that these blocks are realizable by one skilled in the art. It should be further understood that the design of a component such as the motor driver circuit 14-1 depends upon the particular DC motor that it will drive. Since there are a wide variety of DC motors available that will fulfill the low power requirement of this invention, the details of the motor driver circuit will correspondingly vary.

It should be understood that the foregoing description is only illustrative of the invention. Various alternatives and modifications can be devised by those skilled in the art without departing from the invention. Accordingly, the present invention is intended to embrace all such alternatives, modifications and variances which fall within the scope of the appended claims .

Claims

CLAIMSWhat is claimed is:

1. A remotely controlled padlock apparatus comprising :

a padlock structure including a shackle holding mechanism and a shackle that can be held by and released from said shackle holding mechanism;

a signal receiving means for receiving means and responsive to said transmitted coded signal to provide control signals;

a shackle driver means connected to said shackle holding mechanism and responsive to a control signal from said controller means to operate said shackle holding means to hold and to release said shackle.

2. A remotely controlled padlock apparatus according to claim 1 further including shackle sensor means for sensing and providing a fast signal when said shackle is held by said shackle holding means, and a second signal when said shackle is released from said shackle holding means .

3. A remotely controlled padlock apparatus according to claim 2 further including a power supply means connected to said controller means.

4. A remotely controlled padlock apparatus according to claim 3 wherein said power supply means includes chemical power cells.

5. A remotely controlled padlock apparatus according to claim 3 wherein said power supply means includes rechargeable batteries .

6. A remotely controlled padlock apparatus according to claim 3 wherein aid power supply means includes solar cells.

7. A remotely controlled padlock apparatus according to claim 3 wherein said power supply means includes first power producing means including at least one chemical power cell connected via a rectifying means to a second power producing means including at least one solar cell .

8. A remotely controlled padlock apparatus according to claim 3 wherein said signal receiving means includes a light responsive means.

9. A remotely controlled padlock apparatus according to claim 3 wherein said signal receiving means includes a sound responsive means.

10. A remotely controlled padlock apparatus according to claim 3 wherein said signal receiving means includes means responsive to radio frequency signals.

11. A remotely controlled padlock apparatus according to claim 3 wherein said shackle driver means includes a motor, a movable element driven by said motor between first and second locations and means for connecting said movable element to said shackle holding means to operate said shackle holding means wherein said shackle is held when said movable element is in said first location and said shackle is released when said movable element is in said second location.

12. A remotely controlled padlock apparatus according to claim 11 wherein said sensor means includes a first sense signal generating means at said first location to provide signal when said shackle is held and a second sense generating means at said second location when said shackle is released.

13. A remotely controlled padlock apparatus according to claim 3 wherein said padlock structure housing includes a lamp that is actuated in response to a control signal from said controller means.

14. A remotely controlled padlock apparatus according to claim 11 wherein said shackle holding means includes a pivot pin that engages a notch in said shackle, and wherein said means for connecting said movable element to said shackle includes a tension means connected to said pivot pin and said movable element wherein when said movable element is driven between said first and second locations said tension means is placed under tension and said pivot pin is pulled from said notch.