Abstract:
A pneumatic mail delivery system includes a carrier having first and second open ends and corresponding hinged covers for selectably covering the open ends. The system includes first and second carrier terminals each having front openings selectively covered by hinged doors. The terminals may be positioned at a mail deposit location and a residential location. A pneumatic conduit connects the terminals through which the carrier may be guided therebetween. The conduit is connected to a blower for conveying the carrier. Spring-biased buttons attached to respective terminals are electrically connected to the blower for actuating the blower upon detecting a closure of a respective door. A photoelectric light sensor is attached to each terminal and is electrically connected to a light source mounted on the front of each terminal. Respective lights are energized when a respective light sensor detects mail in the carrier.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates generally to pneumatic tube systems and, more particularly, to a pneumatic mail delivery system that automatically delivers mail to a residence through a pneumatic conduit upon closure of a mailbox door. 
     Pneumatic tube systems have been used particularly in the banking industry for carrying objects between a customer&#39;s vehicle and the main bank building in order to facilitate banking transactions, such as in U.S. Pat. No. 4,343,574 to Anders. Other pneumatic tube systems have been utilized for carrying parts between locations, such as the system proposed in U.S. Pat. No. 5,518,545 to Miyano. Although assumably effective for their intended purposes, the existing systems are not particularly suited for the rapid delivery of mail between a delivery location and a residence. 
     Therefore, it is desirable to have a pneumatic mail delivery system in which a carrier is automatically conveyed between carrier terminals upon closure of a carrier terminal door. Further, it is desirable to have a pneumatic mail delivery system in which a mail delivery person or a residential occupant is visually alerted as to the presence of mail at a carrier terminal. 
     SUMMARY OF THE INVENTION 
     A pneumatic mail delivery system according to the present invention includes at least one carrier having a cylindrical configuration and constructed generally of a transparent material. The system includes at least first and second carrier terminals, the first carrier terminal operating as a mail delivery location displaced from a residence and the second carrier terminal positioned in the residence proper. A pneumatic conduit interconnects the first and second terminals through which the carrier may be guided between the terminals. A blower connected to the conduit provides the air differential needed to convey the carrier. It is understood that a plurality of first carrier terminals may be positioned together within a mailbox delivery cabinet, as in the case of an apartment complex. A corresponding second carrier terminal would be positioned in each apartment with corresponding terminals being interconnected by respective pneumatic conduits. 
     Each carrier terminal includes a front panel defining an opening in communication with the conduit. A spring-biased button is positioned within each opening and is electrically connected to the blower. A momentary depression of the button closes a circuit to enable the blower to be energized so as to convey the carrier between carrier terminals. Obviously, whether the blower actuates a pushing force or a pulling force (a vacuum) depends on which button was momentarily depressed. It is also understood that the activation buttons are also electrically connected to an electrical power source. 
     Automatic delivery of the carrier upon closure of the mailbox door enables a mail delivery person to quickly deliver mail to one or more residences without having to perform the additional step of pressing a send button. This is especially advantageous when delivering mail to a plurality of mailbox terminals housed in a single mailbox cabinet at an apartment complex. In that case, all of the mailbox terminal doors may be opened, mail may be appropriately inserted into each carrier, and then all the doors may be closed so as to cause delivery of each carrier to respective apartments. 
     Each carrier terminal further includes a photoelectric light sensor electrically connected to a light source that is mounted to the front panel of the carrier terminal. The light sensor is positioned so as to reflect a light across the conduit and through the transparent carrier when the carrier is positioned at that carrier terminal. If the light is broken, such as by mail within the carrier, the light sensor energizes the corresponding light source to indicate the presence of mail in the carrier. 
     Therefore, a general object of this invention is to provide a pneumatic mail delivery system which automatically conveys mail from a mail depository terminal to a residential terminal through a pneumatic conduit upon closure of a mailbox door. 
     Another object of this invention is to provide a pneumatic mail delivery system, as aforesaid, that is more convenient for both mail delivery and receipt. 
     Still another object of this invention is to provide a pneumatic mail delivery system, as aforesaid, which visually indicates the presence of mail in a carrier. 
     Yet another object of this invention is to provide a pneumatic mail delivery system, as aforesaid, which enables the carrier door to be closed simultaneously with closure of the mailbox door. 
     A further object of this invention is to provide a pneumatic mail delivery system, as aforesaid, in which mail may be inserted or removed from a carrier without having to remove the carrier from the pneumatic conduit. 
     Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example, an embodiment of this invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a pneumatic mail delivery system according to the present invention installed at an apartment complex; 
     FIG. 2 is a fragmentary perspective view of the system as in FIG. 1 showing a carrier terminal with a carrier positioned therein; 
     FIG. 3 a  is a perspective view as in FIG. 2 with a portion of the pneumatic conduit removed; 
     FIG. 3 b  is an isolated perspective view on an enlarged scale of the spring-biased button as in FIG. 3 a;  and 
     FIG. 4 is a perspective view of a carrier as in FIG. 3 a  removed from the carrier terminal. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A pneumatic mail delivery system  10  according to a preferred embodiment of the present invention will now be described in detail with reference to FIGS. 1 through 4 of the accompanying drawings. The pneumatic mail delivery system  10  includes at least one carrier  20  having a generally cylindrical configuration and substantially constructed of a transparent material (FIG.  4 ). The carrier  20  includes a body portion  22  intermediate a pair of opposed sealing rings  24 ,  26  (FIG.  4 ). Each sealing ring  24 ,  26  forms a peripheral rim about first  28  and second  30  open ends. 
     The carrier  20  further includes first  32  and second  34  covers hingedly coupled to respective sealing rings  24 ,  26  for pivotal movement between open and closed configurations. Preferably, the covers  32 ,  34  are attached with a spring hinge  36  such that the covers are spring-biased toward respective open configurations (FIGS.  2  and  3 ). Each sealing ring  24 ,  26  includes a diameter larger than a diameter of the intermediate body portion  22 . Further, each sealing ring  24 ,  26  defines a pair of oppositely positioned grooves  48 , their function being further described below. 
     A latch  38  is positioned within each open end  28 ,  30  of the carrier  20  (FIG.  4 ). Each latch  38  includes a base  40  fixedly attached to an inner surface/rim of a respective sealing ring with a magnetic pin  42  reciprocatively positioned within the base  40 . Each pin  42  is fastened within the base  40  with a compression spring (not shown) such that is biased to push the pin  42  outward. Each cover  32 ,  34  includes a metal disk  46  positioned to contact the tip of a magnetic pin  42  upon closure of the cover. The latch  38  is constructed to operate like a push button of a ball-point pen in that it may be depressed to magnetically hold a respective cover in a closed configuration or depressed again to release the cover via a spring action. 
     The pneumatic mail system  10  further includes a first carrier terminal  50  (FIG. 2) positioned at a mail delivery location, such as the location of a traditional mailbox. This invention is especially advantageous where mailboxes are located at a street or road located some distance from a residence. The pneumatic mail system  10  further includes a second carrier terminal  70  located inside or adjacent to a residence, as shown in dashed lines in FIG.  1 . The first  50  and second  70  carrier terminals are interconnected by a tubular pneumatic conduit  72  (FIG.  1 ). The conduit  72  defines an interior space through which the carrier  20  may be guided between the terminals. The first  50  and second  70  carrier terminals are integrally connected to the conduit  72 . A pair of guide tracks  74  extend longitudinally along an inner surface of the conduit  72  and carrier terminals  50 ,  70  and are oppositely positioned 180° from one another therein (FIG.  3 ). Each sealing ring  24 ,  26  includes a diameter that is substantial equal to a diameter of the conduit  72  and carrier terminals so as to provide an air seal between the carrier  20  and conduit  72 . The guide tracks  74  and sealing ring grooves  48  have complementary configurations that mate with one another so that the carrier  20  may be guided along the guide tracks  74  between terminals. 
     The pneumatic mail system  10  includes a blower  80  connected to the conduit  72  for transmitting an air stream thereto or receiving an air stream therefrom. In other words, the blower  80  is capable of blowing air or creating a vacuum and this air differential causes the carrier  20  to be conveyed between carrier terminals by exerting either a pushing or pulling force. The mechanics of conveying a carrier between carrier terminals using a blower is known in the art. 
     The first carrier terminal  50  will now be described in detail although it is understood that the first  50  and second  70  carrier terminals have a substantially similar construction. The first carrier terminal  50  includes a first front panel  52  defining an opening  54  in communication with the interior space of the first carrier terminal  50  and conduit  72  (FIG.  2 ). A first door  56  is pivotally coupled to the first front panel  52  with a spring hinge (not shown) such that the first door  56  may selectably close the opening  54  although the first door  56  is spring-biased to an open configuration. Another spring-loaded button  58  is mounted to the front panel  52  along the edge of the opening  54  (FIG. 3 a ). The button  58  includes a pin  60  having a magnetic tip  62  that is biased outwardly by an internally positioned compression spring (not shown). The first door  56  also includes a metal disk  66  mounted to its inner surface and positioned to contact the magnetic tip  62  when pivoted to its closed configuration. This button  58  also operates like that of a ball-point pen wherein a first depression of the button  58  (by a user depression of the first door) causes the pin  60  to retract and magnetically hold the first door  56  in a closed configuration. A second depression of the first door  56  and button  58  actuates a spring action strong enough to release the first door  56  to its normally open configuration. The pin  60  is electrically connected to the blower  80  with a wire  68 . Obviously, the button  58  is also electrically connected to an electrical power source, such as traditional AC current or a battery (not shown). 
     When the button  58  is momentarily depressed in a manner indicative of closure of the first door  56 , a circuit is closed (not shown) so as to enable the blower  80  to be energized. When energized, the blower  80  creates the appropriate air differential within the conduit  72  to convey the carrier  20  between carrier terminals. The blower  80  will cause the carrier  20  to be conveyed from the second to the first terminal or from the first to the second terminal depending on which button was pressed (i.e. indicating which door was closed). 
     A first photoelectric light sensor  90  is mounted to the first carrier terminal  50  and is positioned for directing a light beam across the tubular part of the first carrier terminal and against a reflector plate  92  (FIG.  3 ). The sensor  90  is held within a housing  94 . When the carrier  20  is positioned at the first carrier terminal  50 , the light beam shines and is reflected through the transparent material thereof. The sensor  90  is electrically connected to a light source  96  mounted to the first front panel  52 . Preferably, the light source  96  is a red bulb. If the light beam of the sensor  90  is not reflected back to the sensor  90 , the light source  96  is energized to indicate the presence of mail within the carrier  20 . The light on the first front panel  52  is useful to notify a postal carrier that a resident has left mail to be picked up. It is understood that another light sensor, reflector plate, and light are mounted to the second carrier terminal in substantially the same manner as described above. 
     In use, the carrier  20  is initially positioned at the first carrier terminal  50  as a result of a resident having retrieved the previous day&#39;s mail and causing the carrier  20  to be returned upon closure of the second carrier terminal door. If outgoing mail was placed in the carrier  20  by the resident prior to closing the second carrier terminal door, this mail will be detected by the first photoelectric light sensor  90  and the first light source  96  will be energized so as to alert a postal carrier. The postal carrier may access the carrier  20  by depressing the first carrier terminal door  56  which causes both that door  56  and the first carrier cover  32  to spring open. Outgoing mail may then be removed through the open end of the carrier and first front panel opening and new mail may be delivered therethrough. A closure of the first carrier terminal door  56  simultaneously closes the corresponding carrier cover  32  and depresses a respective is spring-loaded blower activation button  58 . Activation of the blower  80  causes an appropriate air differential within the conduit  72  to convey the carrier either from the first to the second carrier terminal or vice versa. The light source  96  is de-energized when the carrier  20  is sent as the reflection of the light beam of the sensor  90  is restored. 
     Although the pneumatic mail system  10  has been described hereto as including a single first carrier terminal  50 , second carrier terminal  70 , with a single conduit  72  extending therebetween, it should be appreciated that a plurality of first carrier terminals may be housed within a mailbox cabinet  100  as shown in FIG.  1 . Each of these plurality of first carrier terminals corresponds to a second carrier terminal with a corresponding conduit extending therebetween and with a corresponding carrier within the conduit. Each conduit is connected to a common blower  80  as described above. Thus, mail to a plurality of residences, such as in an apartment complex, may be delivered quickly from a single depository location. 
     It is understood that while certain forms of this invention have been illustrated and described, it is not limited thereto except insofar as such limitations are included in the following claims and allowable functional equivalents thereof.