KEYANDADAPTERFORAKEY FIELD OFTHEINVENTION

The present invention relates to keys, in general and, in particular, to keys which indicate whether an associated lock is locked or unlocked

BACKGROUND OF THE INVENTION

When leaving a house or car, it is important to know whether or not the door is locked. At present, the user must rely on his or her memory, which is generally not reliable, especially in older people. Keys are known on which the user can provide an indication manually after having locked or unlocked the door. However, these keys also rely on the user's memory in that the user must remember to change the indicator on the key. Furthermore, there is no certainly that the lock has actually changed its state, but rather that the user thinks it has. Accordingly, there is a long felt need for a key which provides an indication automatically that the action of locking has actually taken place, and it would be very desirable to have such a key which does not depend on the memory of the user to select the correct indication.

SUMMARY OF THE INVENTION

There is provided according to one embodiment of the present invention a lock state indicator including a key head adapted and configured to transform the force of rotating the key to move the lock to an indication of the state of the lock.

The key head may be integrally formed with a shank of a key, or can be mounted on the head of a conventional key to convert the conventional key to a lock state indicator.

According to one embodiment of the invention, the key head includes a frame defining at least two recesses, and an indicator element mounted on the frame and

arranged to pivot between the two recesses only under sufficient force to cause a change in the state of the lock.

There is provided according to the present invention a lock state indicator for a lock having as associated key, the lock state indicator including a key head, a lock state indicator element coupled to the key head, and an element coupled to the lock state indicator element for automatically causing the lock state indicator element to indicate a changed state of the lock, the lock state indicator element being capable of indicating a changed state only upon actual physical change of state of the lock.

According to a preferred embodiment of the invention, the key includes a shank and a manipulable portion adapted and configured to be held by a user, the manipulable portion including the lock state indicator, the lock state indicator being configured and adapted to change from one orientation to another upon application of force required to lock to physically lock or unlock the lock.

According to another embodiment of the invention, the key head includes a wireless receiver, and the lock includes a latch and an electrical switch. The electrical switch is arranged to be contacted by the latch in a locked state, and released by the latch in an unlocked state, and to provide a signal corresponding thereto to the receiver in the key to cause the lock state indicator element to indicate a state of the latch. There is further provided according to the invention, a key head adapter a substantially hollow head engaging portion, and a shank engaging portion including a closure portion configured and adapted to seat in and close hollow head engaging portion about a key, wherein the shank engaging portion is adapted and configured to move between two positions when the lock is locked or unlocked and serves as an indicator element to indicate whether the lock is locked or unlocked.

There is also provided according to the invention a method for forming a lock state indicator, the method including providing a key head coupled to a key shank for locking and unlocking a lock, the key head including a manually manipulable portion, coupling a lock state indicator member to the key head, and coupling an

element to the lock state indicator element for automatically causing the lock state indicator element to indicate a changed state of the lock, the lock state indicator element being capable of indicating a changed state only upon actual physical change of state of the lock.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be further understood and appreciated from the following detailed description taken in conjunction with the drawings in which:

Figure 1 is a plan view of a key constructed and operative in accordance with one embodiment of the present invention;

Figure 2 is a plan view of a key constructed and operative in accordance with one embodiment of the present invention;

Figure 3 is an exploded view of the key of Figure 2;

Figures 4a and 4b are respective perspective and end views of the key of Figure 2 in a locked orientation;

Figures 4c and 4d are respective perspective and end views of the key of Figure 2 in a locked orientation; and

Figure 5 is a schematic illustration of a key head adapter, according to one embodiment of the invention; and Figure 6 is a schematic illustration of a key and associated lock according to one embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a key for a lock, which provides an automatic indication on the key when the lock is actually locked or unlocked. This is accomplished by utilizing the mechanical locking or unlocking of the lock to cause a change in the indicator on the key, while other kinds of manipulation of the key are unable to cause the change. Thus, the action of locking or unlocking requires use of force which does two things at once - turn the lock and, at same time, move the indicator element from one position to the other when the locking action has been accomplished, in reality. The key may include an integrally formed shank and indicator head, or a special head may be provided for mounting on a conventional key. This special head includes recesses and a rocking indicator member which can be switched between two positions indicating, in each position, a different state of the lock.

Referring to Figure 1, there is shown a plan view of a key 10 constructed and operative in accordance with one embodiment of the present invention. Key 10 includes a shank 12 and a head 14. Shank 12 generally includes a series of notches 16 or dimples which correspond to the lock that key 10 is designed to open, as known. A lock state indicator 18 is mounted in key 10. Preferably, the head includes a manipulable portion 19 adapted and configured to be held by a user, the manipulable portion including lock state indicator 18. When the key is inserted in the lock, a certain force is required to rotate the key, so as to mechanically move portions of the lock, thereby to cause the lock to physically lock or unlock. According to the invention, this force or mechanical movement causes a change in indicator 18 on the key, which thereafter indicates whether the lock is locked or unlocked. According to the present invention, the lock state indicator is adapted and configured to change from one orientation to another upon application of the force required to physically lock or unlock the lock. This may be the force required to overcome the resistance provided by the lock or the latch, or may be the force that is transmitted by the latch

element. The force used to rotate the key, in turn, causes the locking mechanism in the lock to move until the latch is engaged or until the latch can move no further.

In another embodiment, the force required to move the indicator to the "locked" indication can be different from that required to move the indicator to the "unlocked indication". For example, the locked indication can be "turned on" when the latch can move no further, while, in order to turn the "unlocked" indication on, a lighter force could be required that will come from the minimal friction in the beginning of the action of opening the lock.

In each of these embodiments, the lock state indicator will only react to force coming from the lock system, and will not be able to change its position upon random force or manipulation of the key itself.

One embodiment of a key 20 according to the invention is illustrated in respective perspective, exploded and end views in Figures 2, 3 and 4. Key 20 includes a conventional shank 22 with a special head 24, manipulable by the user to lock a lock, which includes a lock state indicator 26. Head 24 includes a frame 30 having a pivot 31 which divides frame 30 into two recesses 32, and a rocking indicator member 34, here shown as having two parts configured be affixed to one another about pivot 31. Indicator member 34 can be switched between two positions, each position indicating a different state of the lock. For example, in Figures 4a and 4b, the indicator is shown indicating that the lock is locked, while in Figures 4c and 4d, the indicator is shown indicating that the lock is unlocked. It is a particular feature of the invention that the required force originating in the lock system to switch indicator member 34 can be provided substantially only by actually locking or unlocking the lock, and not by manipulating head 24 when the key is not in the lock. According to an alternative embodiment of the invention, shown in Figure 5, the lock state indicator is a key head adapter 40 mountable on the head of a conventional key. Key head adapter 40 is adapted and configured to be affixed, preferably permanently, to the key head of the conventional key to permit indication of the state of the lock on the adapter 40 when, and only when, the key on which it is ό

mounted is inserted into the associated lock and, in fact, either locks or unlocks the lock. In the illustrated embodiment, key head adapter 40 is formed of two parts, a substantially hollow head engaging portion 42 and a shank engaging portion 44. Shank engaging portion 44 includes a closure portion 46 which is configured and adapted to seat in and close hollow head engaging portion 42 about the key. Closure portion 46 includes two locking teeth 48 designed to engage complementary pairs of grooves 50 and 52 in head engaging portion 42. In operation, rotation of the key inside the lock to lock or unlock the lock provides sufficient resistance to cause locking teeth 48 to move between grooves 50 and grooves 50. In this way, shank engaging portion 44 serves as an indicator element to indicate whether the lock is locked or unlocked.

In another embodiment, the mountable adaptor will include an electronic indication (LED, etc.) that will indicate electronically the status of the lock.

Referring now to Figure 6, there is shown a schematic illustration of a key 60 and associated lock 70 according to one embodiment of the invention. Key 60 includes a shank 62 and a head 64. Head 64 includes a wireless signal receiver 65 coupled to a dual status indicator 66. Status indicator 66 is adapted to indicate one of two states of lock 70. Status indicator 66 may be, for example, a LED, which is green when the lock is locked and red when the lock is unlocked. Buttons 68 may be provided to permit the user to check the state of the lock by viewing the indicator (e.g., an activation switch for lighting up the LED), while saving battery power. Lock 70 includes a latch 72 which is arranged to enter a recess 74 inside the door frame so as to lock the door to the frame, as known. Seated in recess 74 is an electrical switch 76 having a protruding electrical switch pin 78. Switch pin 78 is coupled to a lock status transmitter 80 having an antenna 82. When key 60 is inserted into lock 70 and rotated to move latch 72, the latch presses (or releases) pin 74. Pin 74 closes (or opens) a circuit in electrical switch 76, which, in turn, causes lock status transmitter 80 to transmit an indication of the new state of the latch. Wireless receiver 65 receives the signal and causes lock status indicator 66 to indicate the new status.

It will be appreciated that the present invention can be utilized with any lock and key wherein the force require to create mechanical movement of a part of the lock can be employed to automatically mechanically change the indication on the key, merely by the application of this force.

While the invention has been described with respect to a limited number of embodiments, it will be appreciated that many variations, modifications and other applications of the invention may be made. It will further be appreciated that the invention is not limited to what has been described hereinabove merely by way of example. Rather, the invention is limited solely by the claims which follow.