Patent Publication Number: US-4223828-A

Title: Mailbox with improved door opening means and flag operator

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention. 
     This invention relates to new and useful improvements in rural mailboxes which are usually located at the side of a road and are serviced by a mailman who travels by automobile or truck from one box to the next. The boxes have a downwardly swingable door which the mailman has to open in order to place mail into the box and/or remove mail therefrom, and when this has been accomplished the mailman has to close the door. Also, many such boxes have a signal flag which, when raised, notifies the mailman that there is mail in the box to be picked up, and after doing so, the mailman has to lower the flag. 
     2. Description of the Prior Art. 
     Our prior U.S. Pat. No. 3,733,026 issued May 15, 1973 discloses a mailbox and servicing apparatus mounted upon a postal service vehicle which greatly expedites the mailbox servicing procedure by the provision of means whereby the mailbox door is automatically opened as the mail service vehicle approaches the box, and the signal flag, if raised, is automatically lowered by opening of the door. Then, as the vehicle leaves the box, the door is automatically closed. 
     The apparatus disclosed in our U.S. Pat. No. 3,733,026 includes a mailbox having an arm projecting outwardly from the mailbox door, the arm being engageable by a slanted actuating rod mounted on the postal service vehicle so that the door is opened when the vehicle arrives at the box. As the vehicle leaves, the actuating rod is disengaged from the arm and the box door is closed by a spring. A linkage between the door and the signal flag automatically lowers the flag, if raised, as a function of opening of the door. 
     The arm on the mailbox door disclosed in U.S. Pat. No. 3,733,026 is relatively rigid, and therefore it presents the possibility of injury to a person or object passing along the road into the path of the arm. Also the actuating rod which is supported on the postal service vehicle extends outwardly from the side of the vehicle and in doing so, it is possible to inflict injury to a person or object which the rod might encounter. The linkage between the door of the mailbox and the signal flag is located outside of the mailbox where it is exposed to the weather. This is a disadvantage when icy conditions occur because the linkage may become inoperable because of ice. 
     SUMMARY OF THE INVENTION 
     It is an important object of the present invention to provide improvements over the apparatus disclosed in our U.S. Pat. No. 3,733,026 whereby the apparatus can be used with greater safety without the risk of injury to individuals or damage to objects encountered thereby. In order to accomplish the aforesaid object, a new lever arm for the mailbox door has been provided which is made of spring wire. The new arm has substantial resistance to bending in a vertical plane and is substantially more flexible to bend horizontally toward and away from the mailbox. Also a new actuating rod and new means for mounting the actuating rod on a postal service vehicle has been provided. The mounting means is provided with hinged joints which permit the actuating rod to collapse toward the side of the vehicle when an object is encountered. However, the joints are designed to resist yielding unless an excessive force greater than the force required to open the mailbox door is applied to the actuating rod. 
     It is a further object of this invention to provide an actuating rod which is telescopic from an extended to a shortened length in order to place the rod in a non-use condition. 
     It is a further object of this invention to provide an actuating rod which may be quickly disconnected from its mounting means and to provide mounting means with quickly separable components and which may be quickly removed in its entirety from the postal service vehicle. 
     It is a further object of this invention to provide a spring bias means for closing the mailbox door which may be latched in an inactive condition to remove the bias from the door. 
     It is a further object of this invention to provide a pawl connection between a signal flag and the mailbox door which is enclosed within the mailbox out of the weather. 
     It is a further object of this invention to provide the signal flag with a yieldable spring pawl which permits the signal flag to be raised and lowered manually even when the mailbox door is closed, but which when the flag is raised normally holds the flag in raised position until the door is opened, whereupon the flag falls by gravity to its lowered position, or until an operator grasps the flag and manually manipulates the flag to its lowered position. 
    
    
     With the foregoing more important objects and features in view and such other objects and features which may become apparent as this specification proceeds, the invention will be understood from the following description taken in conjunction with the accompanying drawings, in which like characters of reference are used to designate like parts, and in which: 
     FIG. 1 is a perspective view of a mailbox in accordance with the invention, also showing a cooperating actuating rod mounted on a vehicle shown by dotted lines, the box being in its closed position; 
     FIG. 2 is a front elevational view of the mailbox and actuating rod shown in FIG. 1; 
     FIG. 3 is a perspective view similar to that in FIG. 1, but showing the mailbox open; 
     FIG. 4 is an enlarged sectional detail of the actuating rod, taken substantially in the plane of the line 4--4 in FIG. 2; 
     FIG. 5 is an enlarged perspective view of the mailbox door biasing spring and a portion of the door hinge pin; 
     FIG. 6 is a fragmentary vertical sectional view of a portion of the mailbox door in its closed position showing the spring linkage attached to the mailbox signal flag pivot pin engaged with a detent in the door surface for holding the signal flag upright when the door is closed; 
     FIG. 7 is an exploded perspective view of the open mailbox and the signal flag with its associated parts; 
     FIG. 8 is an enlarged sectional detail of the flexible lever arm for opening the mailbox door taken on line 8--8 of FIG. 1. 
    
    
     Referring now to the accompanying drawings, the reference character B generally designates a rural mailbox mounted on a supporting post 10 at one side of a road. For the most part, the box is of a conventional construction, including a body 12 of an inverted U-shaped cross-section, with a floor or bottom 13 and a closed end 14. The end of the box body facing the road is open and provided with a door 15, the latter being mounted by a horizontal hinge pin 16 for movement between a closed position shown in FIGS. 1-2 and an open position shown in FIG. 3. A signal flag 17 is pivotally mounted as at 18 at one side of the body 12, the flag being movable between a raised position shown in FIG. 1 and a lowered position shown in FIG. 3. In the latter position, the flag rests against a stop bracket 19 secured to the side of the box. 
     In accordance with the invention, a torsion spring 20 is positioned on the hinge pin 16, the spring having end portions 20a which bear against the underside of the box bottom 13 as shown in FIG. 1, while an intermediate portion 20b of the spring bears against the door 15 at a point below the hinge pin. The spring thus biases the door to its closed position. While this spring arrangement is preferred, any other suitable spring may of course be used for the same purpose. As shown in FIG. 5, the end portions 20a,20a of the torsion spring 20 are each provided with a latching hook 20a&#39; which is adapted to be hooked over one of the legs 20b&#39; of the intermediate portion 20b when it is desired to remove the the spring bias from the door 15. Until such time as a decision is made to equip a mail delivery vehicle with automatic mailbox door opening means as will be subsequently described, the mailbox will be served manually without spring bias applied to close the door as is presently conventional. The spring 20 may be activated to bias the door into closed position by unlatching the hooks 20a&#39; from the legs 20b&#39;. 
     In accordance with this invention, a lever arm 21 is mounted on the outside of the door 15 so as to project outwardly and downwardly with respect to the door in the closed position thereof. As hereinafter described, the arm 21 cooperates with an actuating rod 23 which is mounted on a mail service vehicle 24 so as to automatically open the mailbox door as the vehicle approaches the box. 
     The arm 21 is formed from flexible spring wire and includes a mounting portion 21a at one end, an elongated intermediate portion 21b extending linearly from the mounting portion and a hooked end portion 20c remote from the mounting portion. The mounting portion 21a is a tightly wound helical coil spring. The end portion 22 of the mounting portion 21a remote from the intermediate portion 21b extends through an opening 26 in a latch member 25 which is secured to the door 15 by screws 27. The end portion 22 is formed with an S-shaped end which is adapted to fit around the screws 27 and be clamped between the latch member 25 and the outer surface of the door 15 as shown by dotted lines in FIG. 3. Other means for securing the coiled spring mounting portion 21a to the latch member 25, such as by welding the end of the mounting portion to the latch member, may be utilized. At least the elongated intermediate portion 21b of the arm 21 has an oval cross section, as seen in FIG. 8, with its major axis in a vertical plane and its minor axis in a horizontal plane so that the arm 21 is more flexible to bend horizontally toward and away from the mailbox than it is to bend vertically. The arm 21 has substantial resistance to bending in a vertical plane so that when the arm is engaged by the actuating rod 23 it will be forced down without substantial bending to open the door 15. The force necessary to bend the arm 21 vertically is therefore substantially greater than the force required to be exerted upon the arm 21 by the rod 23 for opening the door 15. The hooked end portion 21c curves upwardly from the intermediate portion 21b and is terminated in a spiral. The flexibility of the arm 21 and the spiral ended hook portion 21c prevent injury to a person or to an object traveling into the path of the arm 21. The present invention therefore provides safety features which are highly desirable, even if they are not required. 
     The latch member 25 has a first planar end portion 25a by which it is secured to the outside of the door 15, a second planar portion 25b inclined upwardly and outwardly from end portion 25a, and a third planar portion 25c inclined upwardly and inwardly from the second portion 25b over the top of the door 15. The free end 25c&#39; of the third portion 25c of latch member 25 is bent under in a rounded reverse bend to provide a hook for latching engagement with another latch member, or keeper 28, mounted on top of the mailbox B adjacent the open end 11 of the body 12. The keeper 28 is secured to the top of the mailbox by suitable fastening means 29, such as rivets, screws, or spot welds, and it includes a hooked end portion 28a which yieldably engages with the free end portion 25c&#39; of the latch member 25 to hold the door 15 in closed position. The latch including latch member 25 and keeper 28 will release the door 15 when a predetermined outward force is applied to the door arm 21. The third portion 25c of latch member 25 is substantially perpendicular to the second portion 25b from which the arm 21 projects outwardly and downwardly. The arm 21 is normally substantially parallel to the third portion 25c. 
     The actuating rod 23 includes an elongated downwardly slanted portion 30 having an upper end 31 and a free end 32 at its lower extremity, and mounting means 33 secured to the upper end 31 for positioning the downwardly slanted portion 30 outwardly from the side of the vehicle 24. 
     The mounting means 33 for the actuating rod 23 includes a substantially flat mounting plate 34 positioned horizontally on the upper ledge 35 of a front fender of a modern postal service vehicle to one side of the vehicle hood 37. The mounting plate 34 is secured on top of the fender by hooks 38 which depend from the inner side edge of the mounting plate and which have pins which engage in holes provided in the down-turned flange 36 of the fender 35. A strap 39 is secured to the opposite side edge of the mounting plate 34 and is buckled to the bottom edge of the vehicle fender with a J-shaped hook (not shown). A cylindrical standard 40 is welded to the mounting plate 34 and extends upwardly therefrom substantially perpendicularly to the mounting plate. The upper end of the standard 40 provides a socket 41 for detachably supporting therein a cylindrical rod 42 which provides an upward extension of the standard 40. A pair of vertically aligned holes 43 are provided in the standard 40 for engaging spring pressed detents 44 secured on the rod 42. The detents 44 when pressed into the holes 43 lock the rod 42 in the socket 41, and when the detents are pushed inwardly out of the holes, the rod 42 may be quickly removed from the socket 41. A flat plate 45 is welded to the upper end of the rod 42 and extends laterally from the side of the vehicle substantially perpendicular thereto. The end of rod 42 is cut so that when the plate 45 is welded thereto the plate is inclined at an angle, as indicated at 46, which is approximately 45° from a horizontal plane. A pivot pin 47 extends through a hole in the plate 45 and an aligned hole in one end 49 of a link 48 to provide a first pivoted friction joint connecting the link 48 to the upward extension 42. A second pivot pin 51 extends through the end 50 of the link 48 opposite the end 49 and connects the link 48 with a flattened end 52 of a ferrule 53 to provide a second pivoted friction joint. The mating faces of the flat ends of link 48 and of the plate 45 and flat end 52 of ferrule 53 respectively are suitably roughened so that the first and second pivoted friction joints are designed to remain in a fixed position until an excessive force is applied to overcome the friction forces and permit the joints to yield. The upper portion 31 of the downwardly slanted rod 30 is removably held in the open end of the quick disconnect ferrule 53. This permits the rod 30 to be removed from the mounting means 33. If it is desired to remove both the rod 30 and link 48 from the vehicle, the upper extension 42 may be removed from the standard 40 by depressing the detent pins 44. Finally, if the whole system including the actuating rod 23 and mounting means 33 is to be removed, the mounting plate 34 is removed from the vehicle by opening the hood 37, loosening the strap 39 and disengaging the plate pins 38 from fender holes. The rod 30 is designed to telescope in order to shorten same while not in use in the manner of an automobile radio antenna. 
     The sections of the downwardly slanted rod 30 are oval in cross section with a major axis in a vertical plane and a minor axis in a horizontal plane so that the rod is more flexible to bend horizontally toward and away from the mailbox B than it is to bend vertically. Both the rod 23 and the lever arm 21 are preferably coated with a low friction material T such as Teflon. 
     The signal flag 17 and the door 15 of the mailbox B may be operated independently of each other. Only in the case that the flag 17 is in the up position and the door is being opened will both door and flag operate simultaneously. The pivot pin 18 is a rivet by which the flag 17 is pivotally supported on the side of the mailbox B. The rivet 18 has a square sectioned shank 18&#39; which extends first, through a square hole 54 in the lower end of the flag support standard 17&#39;; second, through a square hole 55a in a round spacer 55 which fits in the round hole 56 in the side of the mailbox; thirdly, through a spring pawl 57; fourthly, through a pawl keeper washer 58; and finally, through a square hole in a rivet head washer 60. The end of the rivet 18 is upset beyond the rivet head washer to hold the flag and pawl assembly together. The square hole washer-spacer 55 has a thickness which is greater than the thickness of the mailbox wall 12 so as to allow a free rotational fit between the flag assembly and the box. The pawl keeper 58 is symetrically fabricated with four tangs 58a and a square-center hole. The tangs of the pawl keeper 58 fit over the split end portions of the spring pawl 57 and hold the ends firmly against the square shank 18&#39;. A cover plate 61 having an inwardly offset portion 61&#39; is secured inside the mailbox to prevent mail from coming in contact with the flag pawl 57 which would cause restricted movement of the pawl. 
     The spring pawl 57 is preferably formed from spring wire having a coiled intermediate portion 57a, a pair of legs 57b,57b extending from opposite ends of the coil 57a toward the rivet 18 and right angled end portions 57c on each of the legs 57b. The right angled end portions 57c of the legs 57b face in opposite directions and together form a split square adapted to fit the square rivet shank 18&#39;. The end portions 57c are held securely against the square shank 18&#39; by the four tangs of the pawl keeper 58. A loop 57d of one or more coils is provided in each of the legs 57b. 
     In accordance with the usual custom of rural mailbox owners, when a letter to be mailed is placed in the mailbox B to be picked up by the postal service, the person placing the letter in the box raises the flag 17 to an upstanding position as shown in FIG. 1 where it comes against the up position stop 62. When the flag 17 is raised, the pawl 57 is swung down to a position where it extends outwardly toward the open end 11, and the coiled intermediate portions 57a projects slightly beyond the open end so that when the door 15 is raised to a closed position the coil 57a fits in the outwardly deformed dimple 15a. With the door closed, the dimple 15a holds the pawl 57 therein and the flag is held in the raised position. When the door 15 is opened, the pawl 57 is released and the flag 17 falls by gravity to a lowered position against the stop 19. The center of gravity of the flag 17 in the raised position is offset clockwise from a vertical position so that the flag will fall under its own weight when the pawl 57 is released from engagement with the dimple 15a. 
     The pawl 57 is made of spring material and is designed for the purpose of permitting manual operation of the flag 17 to raised or lowered position with the door 15 closed. When the flag 17 is being raised and the door 15 is closed, the pawl 57 swings down in a counterclockwise direction until it hits the inside of the door 15. The pawl will then yield, shortening in length sufficiently to enter the dimple 15a, whereupon the elasticity of the pawl extends the pawl fully into the dimple 15a where it is securely held. When an operator wishes to lower the flag 17 from its raised position, without opening the door 15, it is merely necessary to grasp the flag and rotate it clockwise to the lowered position. In rotating the flag 17 clockwise, sufficient force is required to cause the pawl to yield and to shorten lengthwise until it escapes from the dimple 15a in the door whereupon the flag is free to fall under its own weight to the lowered position against the stop 19. The loops or coils 57d in the legs 57b permit the pawl 57 to contract lengthwise without any deformation of the arms 57b between the coils 57d and the shaft 18&#39;. The ease in yielding is thereby a function of the number of turns in the coils 57d, their diameter, and the size of the spring wire. The coiled intermediate portion 57a of the pawl spring wire forms the free end of the pawl which contacts the door 15. The diameter of the coiled end 57a determines how well the flag 17 seeks the same orientation each time it is raised to the upright position. The number of turns of the coil 57a determine the surface contact area of the pawl 57 with the door 15 for wear purposes. The flag 17 and its associated parts as shown in FIG. 7 permit the flag to be operated easily even in freezing weather and ice condition. For weather purposes, the mechanical contact of the pawl 57 with the door 15 is inside the mailbox B. If the flag becomes iced, it can be pushed manually to the down position. 
     A weather weep hole with a downwardly open cover 63 is provided in the side of the mailbox below the pivot 18 of the signal flag to permit drainage of any rain water which might enter the box. 
     While the invention has been described in detail for the purpose of illustration, it will be obvious that numerous modifications and variations may be resorted to within the spirit and scope of the invention without departing from the claims.