GB2257203A

GB2257203A - Letter box flap indicating system.

Info

Publication number: GB2257203A
Application number: GB9113885A
Authority: GB
Inventors: David Bryan Green
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-06-27
Filing date: 1991-06-27
Publication date: 1993-01-06
Also published as: GB9113885D0

Abstract

A letter box located at the entrance of a building enables persons remote from, or not with a line of sight to the entrance, to ascertain when mail and the like has been delivered through the letter box. A signalling means (12) (13), which may be electrically or mechanically operated, is provided and operates automatically in response to the movement of a closure (5) for the letter box. The movement actuates a switch which activates an audible and/or visible alarm. The letter box may be provided on an outer door of a porch and the main door may have a peep-through viewer. <IMAGE>

Description

This invention relates to letter boxes and is concerned with letter boxes of the type incorporated in the door of a building to enable mail, newspapers and the like to be delivered to the building.

It is quite common for houses and other domestic buildings to have a porch erected externally of the main door of the building and for the porch also to be provided with a door. Thus, the main door serves as an inner door and the porch door serves as an outer door.

The outer door will ordinarily include a letter box comprising portions defining an opening to receive mail and the like and a closure for the opening which is movable between a first position in which it closes the opening and a second position in which it enables mail and the like to pass through the opening. However, when mail and the like is posted through the letter box in the outer door so that it enters the porch, it is not always apparent that the mail and the like has been delivered since this fact cannot readily be ascertained by a person in a second area of the building located beyond the inner door unless the inner door includes panes of glass through which it is possible to see the mail and the like.In such circumstances, it is necessary to open the inner door (which, since it is the main door of the building, will generally be equipped with security locks and the like) in order to see if the mail or the like has been delivered. This is time consuming and irritating (particularly if the mail and the like has not in fact arrived) and also results in heat loss from the interior of the building.

It is an object of the present invention to enable a person beyond the inner door to be able to ascertain that mail and the like has been delivered without having to open the inner door.

According to one aspect of the present invention there is provided an entrance for a building comprising: (a) an outer door providing access to a first area of the building, (b) an inner door in the first area to provide access to a second area beyond the first area, (c) a letter box in the outer door, and (d) means enabling a person located in said second area to determine when mail and the like has been delivered through the letter box.

The means enabling the person to determine if mail has been delivered may be a spy hole in the inner door and, if desired, this hole may operate in conjunction with a periscope to enable mail and the like lying on the floor in the first area to be more readily seen by a person standing beyond the inner door in the second area. Alternatively, said enabling means may be a signal generating means actuated by the postman or other person delivering the mail and the like to the building. In this case, a signalling means may be provided externally of the outer door to be actuated by said person once he has delivered the mail and the like, this signalling means being linked to a visual and/or aural alarm to alert persons inside the building that mail and the like has been delivered.

However, it is particularly preferred for said enabling means to be a signal generating means which is automatically actuated when mail and the like is passed through the letter box opening.

Accordingly, a second aspect of the present invention provides a letter box comprising: (a) portions defining an opening to receive mail and the like, (b) a closure for the opening and movable between a first position in which it closes the opening and a second position in which it enables mail and the like to pass through the opening, and (c) means of generating a signal when the closure moves from its first position to its second position.

The signal produced may be a visual and/or aural signal In one embodiment, the signal generating means may be a bell attached to the closure so that as the closure moves the bell rings.

Alternatively, a vibration or tilt switch may be operably connected to the closure so that, as the closure moves, the switch causes illumination of a lamp in the second area beyond the inner door.

In a particularly preferred embodiment, the signal generating means includes a magnet and a reed switch arranged so that, as the closure moves from its first to its second position, the magnet and the reed switch move relatively to one another so that the reed switch closes and completes an electrical connection which actuates a visible and/or audible alarm. Preferably as a consequence of this electrical connection, an aural alarm is sounded for a predetermined period of time and also a lamp illuminates. It is preferred for the lamp to remain illuminated until such time as the circuit is reset by a person in the second area. This system has the advantage that both an audible and a visual signal are given and hence it is of use to persons who are deaf or blind.

The visible alarm and, preferably, the audible alarm is located in the second area and may be mounted on the inner side of the inner door adjacent, for example, to the letter box in the inner door.

For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings which: Figure 1 is a diagrammatic view of an entrance incorporating a letter box in accordance with the present invention, Figure 2 is a front view of the letter box fitted to the outer door of the entrance of Figure 1, Figure 3 is a rear view of the letter box of Figure 2, Figure 4 is a rear view of the letter box fitted to the inner door of the entrance of Figure 1, and Figure 5 is a diagram of the electrical circuit of the arrangement of Figures 1 to 4.

Referring to the drawings, there is shown an entrance for a building comprising an outer door 1 giving access to a first area in the form of a porch 2 including an inner door 3 which is the main door giving access to a second area ie the main part of the building.

The outer door 1 includes a letter box comprising portions 4 defining an opening closed by a closure in the form of a flap 5 pivoted at its upper edge so as to normally occupy a first position in which it closes the opening. The flap 5 can be pivoted to a second position in which it enables the mail and the like to pass through the opening. A bracket 6 is provided on the rear face of the flap 5 via a prit pad and the bracket carries a magnet 7. The bracket 6 is located adjacent to a part of the portion defining the opening and said part carries a reed switch 8. The arrangement is such that as the flap 5 is pivoted to its second position to enable mail to pass through the opening, the magnet 7 moves with respect to the reed switch 8.

The reed switch 8 is connected in an electrical circuit as shown in Figure 5. The circuit includes a reset button 9 which is conveniently mounted in a console 10 on the rear face of a letter box 11 in the inner door (Figure 4). The circuit includes a lamp 12 and buzzer 13 which are also mounted on the console 10.

The circuit further comprises a monostable multivibrator which consists of an integrated circuit 20, a capacitor 21, a resistor 22 and a second resistor 23. The capacitor 21 and resistor 22 are rated so as to provide an appropriate time delay for the circuit.

A transistor 24, which may advantageously but not necessarily be a bipolar junction transistor, is provided as a switch for the buzzer, such that, as its gate is high the buzzer will be on. The buzzer is further provided with a freewheeling diode 25 to enable it to discharge safely. An SCR (silicon controlled rectifier) thyristor 14 is provided as a switch for the lamp 12. The SCR thyristor has the characteristic that it begins to conduct when a high voltage is received at its gate. It will continue to conduct after that voltage has been removed and will only cease to conduct when there is no voltage between its anode and its cathode. Hence the manual switch 9, which serves to connect the anode to the cathode, is able to switch it off.

In use, when mail or the like is passed through the opening defined by portions 4 of the letter box in the outer door, the magnet 7 on the closure flap 5 moves past the reed switch and activates it connecting the positive rail to earth through resistor 26. Pin 2 of IC 20 is earthed by virtue of its being connected to the output side of resistor 26 and pin 23 of IC 20 is consequently latched to a high voltage. Pin 3 is connected to both the gate of transistor 24 and thyristor 14 through resistor 23, and it switches both of these on, which in turn switch on the lamp 12 and the buzzer 13. Pin 3 remains high as long as pin 2 is high or pin 6 is low. Prior to operation of the reed switch, pin 7 of the IC is low and capacitor 21 to which it is connected, is discharged. As pin 3 goes high, pin 7, which follows it, goes high and allows capacitor 21 to charge itself up through resistor 22.

By this time the reed switch has reset itself and pin 2 is high again. A time delay ensues (set by the product of the values of capacitor 21 and resistor 22) as the voltage at pin 6 of the IC gradually rises. When it reaches the lowest voltage recognised as high by the IC, typically two thirds of the supply voltage, it causes pin 3 to go low. This cuts off the supply to the gates of transistor 24 and thyristor 14. The transistor 14 is hence switched off and the buzzer 13 discharges through freewheeling diode 25 and ceases to operate. The SCR thyristor 14 however remains conducting in view of its characteristics discussed briefly above and the lamp remains on until manually reset by switch 9 which shorts the anode to the cathode of thyristor 14.

The integrated circuit used in this embodiment of the invention is the 555 chip as designated in electronics companies' catalogues and is interchangeable between different manufacturers' versions of the chip.

It can be seen that, as mail and the like is delivered, the buzzer 13 sounds for a short period (eg 5 seconds) and the lamp 12 comes on. Thus, persons in the main part of the building are made aware that mail and the like has been delivered and is awaiting collection. As they collect the mail, they can actuate reset button 9 to reset the circuit and turn out the lamp 12.

Claims

CLAIMS:

1. An entrance to a building comprising: a) an outer door including an opening which allows mail and the like to be delivered through the door, and b) a means for signalling the delivery of mail and the like through the door.

2. An entrance to a building as claimed in claim 1 wherein an inner door defines a first enclosed area within the building, and provides access to a second area beyond the first area.

3. An entrance to a building as claimed in claim 1 or 2 wherein the opening is provided with a closure moveable between a first position in which it closes the opening and a second position in which it enables mail and the like to pass through said opening.

4. An entrance to a building as claimed in claim 3 wherein the signalling means is activated by the movement of the closure between its first and second positions.

5. An entrance to a building as claimed in claim 4 wherein the signalling means is electrically operated by means of a switching device sensitive to the motion of the closure.

6. An entrance to a building as claimed in claim 5 wherein the switching device is a magnetically controlled reed switch.

7. An entrance to a building as claimed in claim 5 wherein the motion of the closure actuates an audible signal.

8. An entrance to a building as claimed in any one of claims 1 to 6 wherein the signalling means is audible and/or visible.

9. An entrance to a building as claimed in claim 8 wherein the visible signalling means is one or more lamps.

10. An entrance to a building as claimed in any one of claims 1 to 4 wherein the signalling means is actuatable externally of the building.

11. An entrance to a building as claimed in claim 2, or any one of claims 3 to 10 when appendant to claim 2 wherein the second door possesses a hole enabling viewing of the first area.

12. A letter box comprising: (a) portions defining an opening to receive mail and the like, (b) a closure for the opening and movable between a first position in which it closes the opening and a second position in which it enables mail and the like to pass through the opening, and (c) means of generating a signal when the closure moves from its first position to its second position.

13. A letter box as claimed in claim 12 wherein the signal generating means is a bell attached to the closure so that as the closure moves the bell rings.

14. A letter box as claimed in claim 12 wherein the signal generating means is a vibration or tilt switch operably connected to the closure so that, as the closure moves, the switch causes illumination of a lamp.

15. A letter box as claimed in claim 12,13 or 14 wherein the signal generating means includes a magnet and a reed switch arrangement so that, as the closure moves from its first to its second position, the magnet and the reed switch move relatively to one another so that the reed switch closes and completes an electrical circuit which actuates a visible and/or audible alarm.

16. A letter box as claimed in claim 15 wherein, as a consequence of said electrical circuit, an aural alarm is sounded for a predetermined period of time and also a lamp illuminates.

17. A letter box as claimed in claim 16 wherein said lamp remains illuminated until such time as the circuit is reset by a person in the second area.

18. An entrance to a building substantially as hereinbefore described in Figures 1 to 5 of the accompanying drawings.

19. A letter box substantially as hereinbefore described in Figures 1 to 5 of the accompanying drawings.