BACKGROUND OF INVENTION
Field of Invention
This invention relates to field of housing security. A door with a deadbolt lock or a patio door lock may be closed, but not locked, leading to dangerous safety situations. This issue exists in the currently installed mechanical locks. The invention attaches to the existing lock latch handle and allows detecting the state of the lock using existing lock system and reporting it to a user via Wi-Fi-based message or e-mail.
Description Of Prior Art
There is some prior art that includes monitoring deadbolt lock status, but most of them require replacing the old lock with the new one.
Other prior art has different embodiment and functionalities such as listed below:
- a. It offers the solution that requires installing the sensor in a location different from the sensor processor location.
- b. The presented embodiments do not offer practical steps that would allow realization of their invention. For example, they offer placing the sensor reader inside the lock, which is not a trivial part of a typical user installation.
- c. The presented embodiments use a magnetic sensor. Given the lock's metal housing and metal installation structure, the magnetic sensor will be surrounded by metal. That makes it difficult to detect the sensor magnetic field levels. Also, the magnetic sensor requires close proximity to the processor, which can make the implementation impractical, requiring specific and accurate sensor placement.
Currently this problem is addressed commercially by using electronic locks. However, that means that one has to buy a new lock and replace the existing lock, which may not be feasible for many lock users.
There are hobbyist type solutions, but those are not simple to implement and do not do what the invention proposes.
This invention acts as “add-on” device mounted on the latch handle and allowing using an existing lock; it uses accelerometer type sensor to determine the lock status; it uses single sensor and processor system that allows for a single installation step; it addresses practical issues of low power, position detection accuracy, freedom of sensor placement.
SUMMARY OF INVENTION
The device in the invention consists of two major parts: the lock latch handle attachment and the electronic circuit enclosure with a circuit board. The electronic circuit enclosure is inserted into the latch handle attachment.
Every deadbolt lock or a patio lock have a latch handle that allows to close or open the lock. The invention's lock latch handle attachment fits onto the latch handle. The lock latch handle attachment has a mechanical structure that allows the electronic circuit enclosure to be attached to it.
The electronic circuit, that resides in the electronic enclosure, uses a microcontroller that reads accelerometer sensor data to obtain position of the latch handle to compute whether the latch handle is in a closed or open positions. If the computed latch handle position changes from the previous one, the microcontroller will turn on Wi-Fi processor, which will send out a Wi-Fi message in a form of email or SMS message to a user.
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIG. 1, the device consists of latch handle attachment 4 and PCB case 6. PCB case 6 has a dovetail extrusion 5 that fits into the dovetail 9 in the latch handle attachment 4. This allows easy removal of the PCB case 6 if, for example, batteries need to be replaced. Cavity 8 is used mount the device onto the latch handle 3. FIG. 1 shows dissembled view of the device as not attached to the latch handle yet.
As shown in FIG. 3, in its operational state, the latch handle attachment 4 is inserted onto door handle 3 and secured with set screw 7 shown in FIG. 2. The lock latch handle 3 attaches to the door 1 via some support 2. The door 1 and support 2 are not part of the invention and are shown for clarity of the device installation.
FIG. 4 clarifies the location of dovetail cavity 9 and the latch handle cavity 8 in the latch handle attachment 4. The set screw 7 shown in FIG. 4A is used to secure latch handle attachment 4 on the latch handle 3. It is understood by those skilled in the field, that the latch handle 3 configuration may vary from one lock vendor to another, thus the design of the cavity 8 and location of the set screw 7 may vary.
FIG. 5 shows the latch handle 3 in locked position. This happens when vertical line 601 is collinear with the vertical center line of the latch handle 3 and the installed device and the angle is zero.
FIG. 6 shows the unlocked state when the latch handle 3, the latch handle attachment 4 with the PCB case 6 were moved counterclockwise at the angle greater than 10 degrees with the vertical line 601. It is understood by those skilled in the field, that the position indicating locked state may vary from one lock vendor another and would have to be adjusted if the locked and unlocked state angle changes.
The details of the device electronics operation are shown in FIG. 7. In the shown embodiment the device uses two AAA batteries 101. It is understood by those skilled in the field, that other batteries types can be used.
As shown in FIG. 1, before turning on the device, the latch handle attachment 4 is inserted onto the latch handle 3 via cavity 8 and secured with the set screw 7 shown in FIG. 2. Then, as shown in FIG. 1, PCB case dovetail extrusion 5 slides into the dovetail cavity 9 in the latch handle attachment 4. As shown in FIG. 7, after the on/off switch 102 is turned on, the microcontroller 104 computer program sets its clock to 8 MHz to allow communicating with accelerometer 103 and read the lock position coordinates. Then microcontroller 104 computer program enables DC-DC boost converter 106 and the high side power switch 107 in order to power up Wi-Fi processor 105. Then microcontroller 104 computer program sends the data to Wi-Fi processor 105. Wi-Fi processor 105 own computer program computes whether the lock state is locked or unlocked and then sends that information out as email or SMS message via internet 108 to a user. Then microcontroller 104 computer program puts it into low power mode by disabling DC-DC boost converter 106 and the high side power switch 107 and changing from 8 MHz to 32 KHZ clock. 32 KHZ clock allows the microcontroller 104 to run at low power. The accelerometer 103 runs in low power SLEEP mode.
When the latch handle 3 moves up as shown in FIG. 6 or down as shown in FIG. 5, as shown in FIG. 7, the accelerometer 103 wakes up from SLEEP mode and issues an interrupt signal, which is detected by the microcontroller 104 computer program. Upon receiving the interrupt, the microcontroller 104 computer program switches to 8 MHz clock to be able to run I2C protocol and be able to query the accelerometer 103 about what position it is reading. If the accelerometer 103 reads the position different from the old one, the microcontroller 104 will send this data to Wi-Fi processor 105, otherwise the microcontroller 104 does not send out any data.
As shown in FIG. 7, when Wi-Fi processor 105 computer program receives the data via I2C protocol, it will evaluate whether the lock is locked or unlocked and send that information to user's email or message server via internet 108. This is a known operation for those skilled in email software design and will not be discussed in details here.
Patent Application
20250174062
