Patent Application
20180298639
This invention relates to electronic smart locks and particularly relates to expedients for permitting operation of the lock even when the powering batteries no longer provide requisite energy to operate the lock.
Electronic smart locks, defined herein as battery controlled locks for latching and unlatching, are sometimes configured to be controlled remotely to perform valuable functions, including the basic function of locking and unlocking a door, assigning or deleting access combination codes, testing the lock's battery level, receiving notifications when an access code opening a door and receiving alerts when the lock battery is low. With such basic functions, no mechanical keys are required. While these are all valuable functions, the basic one of unlocking the door is of utmost importance, with the requirement of certainty that the door lock will function 100% of the time.
Thus, with rental units (a common utilization of electronic locks to provide the security without mechanical key operation and the possibility of keys being inappropriately retained or copied) if a vacation rental guest arrives in the middle of the night, from 1,000 miles away or even from another continent, and the lock fails to open; that is a nightmare of huge proportions. Yet, a tired or failed battery can and will disable a smart lock. Estimates of battery life vary extensively, making periodic maintenance uncertain.
In recognition of this, electronic lock manufacturers have tried to use various expedients including advance warning of battery failure (which is usually unreliable and also problematic particularly if the rental site is remote from the owner for effecting timely maintenance); and configuring the locks with complicating manual mechanical overrides (requiring a separate key or emergency mechanical combination lock). These expedients however, obviate the reasons for using the electronic locks in the first instance.
Smart locks are battery powered and batteries can drain unexpectedly, resulting in a lockout. Accordingly, it is an object herein to provide a self-contained 100% reliable hybrid mechanical/electronic emergency backup, for entry in case of lock malfunctions, which will enable unlocking of an electronic lock having a “dead” battery but without external and separate mechanical lock expedients such as keys and spare batteries.
Generally the present invention comprises the inclusion, within or in direct conjunction with a smart electronic lock, of a hand crank generator or dynamo configured to permit the mechanical generation of sufficient electrical energy for a short period of time to enable activation of the electronic lock for opening and entry. It is understood that the term “hand crank” is not limited to a hand operation but encompasses any cranking activation. Hand crank generators or dynamos are commonly found in emergency lighting such as flashlights or for the emergency powering of radios. Typically the cranking of the small generator for about a minute provides up to about one half hour of one watt drain powering. Accordingly, powering of the electronic lock, which requires energy for a small fraction of time used for flashlights and radios, effectively requires minimal effort and cranking time (often as little as two or three seconds) for the backup lock activation.
The mechanical dynamo or electrical power generator is electrically looped into the activation circuit whereby electrical energy generated is directed into the battery control circuit as an effective battery backup. Hand cranked dynamos are generally of three types, with the first involving an energy storage device such as a rechargeable battery (usually a button cell having a lithium anode), or a capacitor which store mechanically generated energy for short term use.
The other two types of dynamos involve immediate electrical generation with either a loaded spring or a continuously operating flywheel. Though the first type is generally included in the present invention (with operational lives greater than those of standard batteries used with smart locks), the latter embodiments have the additional advantage of long term use and effectiveness without the possible degradation of a battery or a capacitor.
The present invention comprises a battery powered smart lock comprising a locking mechanism with an interface element for entry of an unlocking code for controlling the locking mechanism, the interface element is in an electrical circuit with the battery which provides power for the operation of the interface element and unlatching operation of the locking mechanism. The smart lock further comprises a mechanically operated dynamo in an electrical circuit with the interface element wherein the dynamo is configured to be externally mechanically operated to provide sufficient electrical energy to power operation of the interface element and unlatching operation of the locking mechanism, in the event that the battery becomes incapable of providing a requisite power operation to unlatch the locking mechanism.
Common battery powered electronic locks are powered with a single nine volt alkaline battery, two AA or four AAA alkaline batteries all of which provide maximum milliamp capacities for numerous lock activations over a period of time. With the typical batteries and arrangements described, voltages (in series) range from about 3 volts to 9 volts with small milliamp drain. A single or small number of cranks of a typical hand crank generator provides up to about 12 seconds of electrical generation at about one watt drainage which is generally sufficient to permit emergency activation of an electronic lock. It is understood that additional activation time and energy requirements may be provided on an emergency basis with continued “cranking”. The manually powered dynamo generates sufficient electrical energy to analyze an entered key code, and if correct, engage the latch bolt to open a door. This emergency expedient does not require a battery, a key or any tools and is always available for use and is failure proof and lockout proof.
The above objective and other details, features and objectives of the invention will become more evident from the following discussion and drawings in which:
With specific reference to the drawings, in
In the event of the battery power failing, and in the absence of a key for mechanical override of the lock, a person is able to rotate wheel 13 of dynamo 30, with the winding handle 14, to spring load it. Release button 15 is then pressed to release stored spring energy to drive the internal structure of dynamo (not shown but with an internal energy generating structure commonly found in wind up spring loaded emergency lights and/or radios), which in turn provides sufficient electrical energy to the activation circuit of the latching mechanism while the user enters the numerical access code with the key pad 11. If the circuitry determines that it is a correct key code, the latching mechanism is engaged with a latch bolt to the lock lever 12, so that the door can be opened manually. In addition, the electrical energy may also concurrently trigger a notification to an off-site location sent to the proper person advising about the entry and the battery failure.
In the embodiment shown in
It is understood that the above description and illustrative drawings are merely exemplary of the invention, with changes in components, electrical requirements and structure being possible without departing from the scope of the present invention as defined by the following claims.
| Number | Date | Country | |
|---|---|---|---|
| 62485940 | Apr 2017 | US |
