[0001] The present invention relates to a keypad for safes for entering the opening combination.
[0002] Normally, a safe is installed in dark and concealed areas and the user therefore
needs to have a light source located in the vicinity of the safe. If the safe is installed
after the electrical system has been provided in the room, it can be impossible to
have dedicated lighting.
[0003] This problem can be obviated by installing a safe provided with an illuminated screen,
with the drawback that the constant lighting of the screen entails a waste of electric
power.
[0004] For safes in which opening is controlled by a keypad (on which the combination is
to be entered) and in which the screen is not present, the only currently possible
situation is to install a light source in a portion of said safe, by means of which
the keypad can be lit.
[0005] The aim of the present invention is to obviate the above-cited drawbacks, and meet
the mentioned requirements, by providing a keypad for safes that is provided with
a lighting device that allows to use it even in the dark.
[0006] An object of the present invention is to ensure that the device is switched when
one of the keys of the keypad is pressed, without said key having to be one of the
keys related to the opening combination.
[0007] Within this aim, another object of the present invention is to provide a keypad that
is simple, relatively easy to provide in practice, safe in use, effective in operation,
and has a relatively low cost.
[0008] This aim and these and other objects that will become better apparent hereinafter
are achieved by the present keypad for a safe lacking a display screen and with an
electric power supply, of the type that comprises an external film on which reference
symbols for the user are imprinted, a board for supporting an electronic circuit that
is provided with a plurality of buttons, each of which is aligned with a respective
symbol of said film when the keypad is assembled, characterized in that it comprises
an electroluminescent laminar element, which is arranged proximate to said film and
said board, parallel to them, the lighting of said laminar element occurring as a
consequence of the pressing of one of said buttons.
[0009] Further characteristics and advantages of the present invention will become better
apparent from the following detailed description of a preferred but not exclusive
embodiment of a keypad for a safe, illustrated by way of non-limiting example in the
accompanying drawings, wherein:
Figure 1 is a perspective view of a safe on which a keypad according to the invention
is installed, with the keypad in darkness;
Figure 2 is a perspective view of a safe on which a keypad according to the invention
is installed, with the keypad lit;
Figure 3 is an exploded perspective view of the elements that constitute a keypad
according to the invention;
Figure 4 is a flowchart of the process for selecting the combination from the plurality
of keys pressed sequentially.
[0010] With reference to the figures, the reference numeral 1 generally designates a keypad
for a safe 2.
[0011] The safe 2 is generally installed so that its rear portion 3 is inserted within a
wall (and retained therein by means of masonry work or fastening elements) and so
that only its front panel 4 is visible from the outside. The door 5 is arranged centrally
with respect to the panel 4, and the keypad 1 for entering the opening combination
is installed at the center of said door.
[0012] The keypad 1 is substantially constituted by three parts that have respective functions:
an external film 6, on which keys 7 are formed which bear reference symbols for the
user imprinted thereon, an electroluminescent laminar element 8, which is powered
and actuated electrically by means of a cable 9, a board 10 for supporting an electronic
circuit 11, which is provided with a plurality of buttons 12, each of which is aligned
with a respective key 7 (symbol) of the film 6, which in turn is supplied with electric
power by means of a cable 13. The power supply cables 9 and 13 may have a connection
to a battery or to the electric mains or to a more complex apparatus that is capable
of switching the power supply from the electric mains to a backup battery in case
of blackout.
[0013] The electroluminescent laminar element 8 is substantially a capacitive light emitter,
which is capable of converting electricity directly into light without generating
heat in the process. The light source consists of a layer of phosphorescent-emission
substances 14, which is comprised between two electrodes 15 and 16: the upper electrode
15 is transparent and therefore allows light to pass. When an alternating current
is applied to the electrodes 15 and 16, the electric field that is generated causes
rapid charging and discharging of the phosphor during each period (which is linked
to the frequency of the electric power supply), with a consequent emission of light.
The frequency and intensity of the light pulses depend on the intensity and frequency
of the applied voltage and therefore the brightness of the source can be adjusted
by adjusting appropriately the voltage and frequency of the power supply.
[0014] The cycle for analyzing the information keyed in by the user is shown in the flowchart
of Figure 4: the initial block 17 corresponds to the idle configuration of the keypad
1, with the laminar element 8 off.
[0015] Pressing any of the keys 7 entails the lighting of the element 8 (block 18) and,
as a consequence of the partial or total transparency of the film 6, the keys 7 are
also backlit.
[0016] The block 19 performs a comparison: if the pressed key 7 corresponds to one of the
possible symbols of the combination, it is stored (block 20) in a memory unit while
waiting for the other symbols to be keyed in, otherwise the signal is sent to the
block 21.
[0017] The block 21 also performs a comparison: if the pressed key 7 corresponds to the
deletion symbol, all or some of the symbols previously stored in the memory unit are
deleted (block 22); if it corresponds to the confirmation symbol, it is sent to the
block 23, which is constituted by a comparator.
[0018] The comparator 23 selects the last "n" symbols stored within the memory unit and
compares them with the symbols related to the combination set as reference in the
comparator 23: if the symbols do not match, the logic signal is transferred to the
block 24, which does not allow to open the door 5 of the safe 2; if the symbols match,
the logic signal is sent to the block 25, which sends the clearance to open. The block
26 indicates the end of the operations of a cycle of the diagram of Figure 4.
[0019] Advantageously, the user can enter a string of symbols of any length at will (press
an unlimited number of keys 7), so long as the last "n" selected symbols are the ones
that correspond to the opening combination of the safe 2: pressing the confirmation
key after this keying entails that only the last "n" pressed keys 7 (and the corresponding
string of "n" symbols) are sent to the comparator 23, which checks their match with
the set combination. The combination can of course be changed in the comparator 23
so that the user can choose the combination that he prefers.
[0020] Positively, the user, after pressing a key 7 at random to light up the keypad 1,
is not forced to press the key 7 related to the delete symbol (to clear from memory
the symbol related to the key 7 that had been pressed indeed to achieve lighting),
and can press immediately the sequence of keys 7 related to the "n" symbols of the
combination as soon as the keypad 1 lights up.
[0021] It has thus been shown that the invention achieves the intended aim and objects.
[0022] The invention thus conceived is susceptible of numerous modifications and variations,
all of which are within the scope of the appended claims.
[0023] All the details may further be replaced with other technically equivalent ones.
[0024] In the embodiments shown, individual characteristics, given in relation to specific
examples, may actually be interchanged with other different characteristics that exist
in other embodiments.
[0025] Moreover, it is noted that anything found to be already known during the patenting
process is understood not to be claimed and to be the subject of a disclaimer.
[0026] In practice, the materials used, as well as the shapes and the dimensions, may be
any according to requirements without thereby abandoning the scope of the protection
of the appended claims.
[0027] The disclosures in Italian Patent Application No. BO2004A000048, from which this
application claims priority, are incorporated herein by reference.
[0028] Where technical features mentioned in any claim are followed by reference signs,
those reference signs have been included for the sole purpose of increasing the intelligibility
of the claims and accordingly such reference signs do not have any limiting effect
on the interpretation of each element identified by way of example by such reference
signs.
1. A keypad for a safe (2) lacking a display screen and with an electric power supply,
of the type that comprises an external film (6) on which reference symbols for the
user are imprinted, a board (10) for supporting an electronic circuit (11) that is
provided with a plurality of buttons (12), each of which is aligned with a respective
symbol of said film (6) when the keypad (1) is assembled, characterized in that it comprises an electroluminescent laminar element (8), which is arranged proximate
to said film (6) and said board (10), parallel to them, the lighting of said laminar
element (8) occurring as a consequence of the pressing of one of said buttons (12).
2. The keypad according to claim 1, characterized in that said laminar element (8) is interposed between the film (6) and the board (10).
3. The keypad according to claim 1, characterized in that the light emitted by said laminar element (8) filters through the film (6) outside
the safe (2), clearly revealing the symbols applied to said film (6) even if the safe
(2) is installed in a dark room.
4. The keypad according to one or more of the preceding claims, characterized in that said film (6) is at least partially transparent and allows the light radiation emitted
by said laminar element (8) to escape.
5. The keypad according to one or more of the preceding claims, characterized in that said laminar element (8) remains lit for a programmable period of time starting from
the last pressing action applied by the user to one of the buttons (12).
6. The keypad according to one or more of the preceding claims, characterized in that said board (10) for supporting an electronic circuit (11) comprises a memory unit,
which is suitable to store a sequence of symbols related to the sequence of keys (12)
pressed, and a comparator (23), which is suitable to compare a string of stored symbols
with all or part of the sequence stored in said unit.
7. The keypad according to claim 6, characterized in that said comparator (23) is programmable, the set combination being changeable.
8. A method for using a keypad (1) according to one or more of the preceding claims,
characterized in that it comprises the steps of pressing (18) at least one button (12) by placing the finger
on at least one of the symbols present on the film (6), causing the lighting of the
electroluminescent laminar element (8) and making the keypad (1) clearly visible,
keying in the correct sequence the "n" symbols related to the combination, and pressing
(22) the symbol related to confirmation of the combination.
9. The method according to claim 8, characterized in that the string of symbols that constitutes the combination is constituted by "n" positions
and in that said string stores only the last "n" entered symbols, the at least one button (12)
pressed before keying the sequence of symbols of the combination not being included
in said string.
10. The method according to claim 8, characterized in that the sequence of all the symbols related to the buttons (12) pressed by the user,
starting from the button keyed to light up the electroluminescent laminar element
(8), is stored within a unit that has "n" memory cells, the last "n" keyed symbols
being progressively stored.
11. The method according to claim 10, characterized in that keying the symbol that confirms said "n" stored symbols, i.e., the last "n" keyed
symbols, entails sending said "n" symbols to a comparator (23), which compares them
with the set combination and allows opening when they match said set combination (25).
12. The method according to claim 8 and as an alternative to claim 10, characterized in that the sequence of all the symbols related to the keys pressed by the user is stored
within a unit that has a large number of memory cells that are suitable to store all
the keyed symbols.
13. The method according to claim 12, characterized in that keying the symbol that confirms said stored symbols entails sending the last "n"
symbols stored in the unit, ignoring the preceding ones, to a comparator (23), which
compares them with the the set combination and allows opening when they match said
set combination (25).