Background of the Invention
1. Field of the Invention
The present invention relates generally to lockable receptacles, and more particularly, to a lockable receptacle for holding a key to a dwelling, or like structure, to which the lockable receptacle is attached.
2. Description of the Prior Art
Key boxes are frequently provided for holding the keys to a building, a motor vehicle, or a like structure to which the key box is attached. An authorized person, such as a fireman, realtor, car salesman, or mechanic is provided with a master key to open the key box so as to gain access to the keys to the structure.
Prior key boxes have exhibited a number of drawbacks. Firstly, these key boxes have typically taken the form of a box-like structure, which, for reasons of economy, is conventionally formed of cast "pot " metal, such as zinc alloy. Due to their relatively low strength and angular configuration, these pot metal key boxes are susceptible to penetration by a thief by means of hammering or prying. While it would be possible to strengthen such conventional box-like key boxes by forming the parts from steel, this Would be very expensive.
Another serious drawback of conventional key boxes is that they typically require the use of the master key to lock the box again. For example, in the key box disclosed in U.S. Pat. No. 4,296,617 (Campagna), a circular lock detent 74 is rotated between a locked and unlocked position by the master key to lock the key in this key box, it is necessary to replace the key within the box and then rotate the lock detent to the locked position using the master key. This is particularly disadvantageous if it is necessary to remove the key from Within the key box and give it to another person (e.g., a mechanic) for subsequent use: this key cannot be locked up again without either (a) calling the authorized holder of the master key to do this, which is a significant inconvenience, or (b) giving the master key to the other person (i.e., the mechanic), Which risks the possibility that the master key may be copied. Furthermore, it is simply inconvenient, even for the authorized holder of the master key, to retrieve the master key from his key ring or pocket to lock the key box again. Still further, these conventional key boxes typically contain an unattached key (e.g., see key 62 in Campaqna), and this is easily lost once it has been removed from the key box.
Another disadvantage of conventional key boxes is that they are frequently limited by their physical configuration to use with a single type of structure. For example, the cylindrical lock box of Campagna is configured to be installed in a bore formed through a door of a building, which arrangement is highly unsuitable for use with automobiles or the like. By way of another example, the key holder disclosed in U.S. Pat. No. 3,744,281 (Logue et al.) shows a key box mounted on What appears to be a sheet metal bracket which hooks over the top of a car window and extends downwardly between the window and the door, and this arrangement, in turn, would not be suitable for permanent attachment to the exterior of a building.
Accordingly, -here exists a need for a high strength, yet inexpensive, key box in Which the key may be replaced and locked Without requiring use of the master key. Furthermore, there is a need for such a key box which facilitates mounting on a wide variety o; structures, including buildings and motor vehicles.
Summary of the Invention
The present invention has solved the problems cited above, and comprises generally a receiver portion formed of an elongated tubular member having a longitudinally extending cavity which is open through only one axial end, and mounting means formed integrally with the exterior of the tubular member for attachment of the receptacle to a structure, and a closure plug which is receivable within the open axial end of the tubular member so as to enclose a key within the longitudinal cavity. Locking means are mounted to the closure plug for locking the plug in the open end of the tubular member, the locking means having an engagement portion which is selectively movable, in response to operation of a master key, from a locked position, in which the engagement portion engages the tubular member to prevent withdrawal of the closure plug from the cavity, to an unlocked position, in Which the engagement portion disengages from the tubular member so as to permit withdrawal of the closure plug from the cavity. The locking means is configured to permit the closure plug to be inserted in the open end of the tubular member, so that the engagement portion lockingly engages the tubular member, without requiring operation of the master key.
The tubular member may comprise an outer sleeve, and the closure plug an inner sleeve for containing the locking means, the inner sleeve being configured to be slidingly received in the outer sleeve. The outer sleeve forms a cylindrical lonqitudinal cavity, and the inner sleeve may be cylindrical to be received therein. The lock mechanism, in turn, may be cylindrical, and the inner sleeve may be provided with a cylindrical lonqitudinal bore for receiving this. The engagement portion of the lock mechanism may be a locking plunger Which extends outwardly from the sleeve through a transverse bore therein.
The locking plunger of the lock mechanism may be a spring-loaded, outwardly biased plunger having an outer end Which is configured to react against the outer sleeve to depress the plunger so that the inner sleeve and lock mechanism can be inserted into the open end of the outer sleeve without use of the master key; the outer end of the locking plunger may have a beveled leading face Which reacts against the outer sleeve to depress the plunger. In the locked position, the plunger extends outwardly from the inner sleeve to engage the locking recess in the outer sleeve, and in the unlocked position the plunger is retracted to a position intermediate the diameters of the exterior and the longitudinal bore of the inner sleeve, so that the outer end of the plunger disengages from the locking recess, but so that a side of the plunger abuts the wall of the transverse bore In the inner sleeve so that the lock mechanism and inner sleeve can be withdrawn together from the cavity by exerting a longitudinal force on the lock mechanism alone, as by pulling on the master key.
The inner sleeve may have a plurality of transverse bores positioned at different selected longitudinal distances from the outer end of the sleeve so that a plurality of lock mechanisms having locking plungers at different longitudinal distances from their outer ends can be received in the inner sleeve, the locking plunger of each lock mechanism being positionable in a selected one of the transverse bores so that the outer end of the lock mechanism is flush with the outer end of the inner sleeve.
As noted above, the inner and outer sleeves may be cylindrical. The lock mechanism, in turn, may be responsive to manual rotation of a master key in engagement therewith, and engagement means may be provided for preventing rotation of the inner sleeve in the outer sleeve as the master key is rotated. The engagement means may comprise a first longitudinally extending flat formed in the wall of the longitudinal cavity, and a second longitudinally extending flat formed in the exterior of the inner sleeve and configured to slidingly abut the first longitudinally extending flat when the inner sleeve is received in the outer sleeve.
The integrally form.RTM.d mounting means may comprise a mounting flange which extends longitudinally along the exterior of the tubular member. The transverse cross section of the elongated tubular member and the integrally formed mounting flange may be generally continuous so that the tubular member and flange are formable of an extruded material, such as high strength extruded aluminum alloy.
Brief Description of the Drawings
FIG. 1 is an exploded perspective view of a tubular key box incorporating the present invention;
FIG. 2 is a perspective view of the key box of FIG. 1, showing the assembled locking plug to which the secondary key is attached, this assembly being positioned for reinstallation in the outer sleeve of the-key box;
FIG. 3 is a perspective view of the key box of FIGS. 1-2, showing the master key inserted within the cylindrical lock mechanism of the locking plug;.
FlG. 4 is a top view of a cross-section taken along line 4--4 of FIG. 3, showing the master key in a locked position in which the plunger of the cylinder lock mechanism is in engagement with an annular locking groove in the outer sleeve;
FIG. 5 is a top view of the cross-section of FIG. 4, showing the master key in an unlocked position in which the lock plunger has been withdrawn from the locking groove in the outer sleeve so that the locking plug and key can be withdrawn therefrom;
FIG. 6 shows an end view of a cross-section taken along line 6--6 of FIG. 5, showing the annular relationship of the outer sleeve, inner sleeve, and cylinder lock mechanism;
FIG. 7a is a perspective view of the inner sleeve which contains the cylinder lock mechanism
FIG. 7b is a perspective view of another inner sleeve, this being configured to hold and partially enclose the key so as to facilitate its replacement in the outer sleeve;
FIG. 8 is a perspective view of a portion of a building having the key box of FIGS. 1-7 mounted thereto by means of bolts directly attached to a mounting flange which is formed integrally with the tubular outer sleeve;
FIG. 9 is a perspective view similar to that of FIG. 8, showing the key box mounted thereto by means of a bracket which is bolted to the mounting flange of the, key box and fits over the top edge of the door of the building; and
FIG. 10 shows a perspective view of a portion of an automobile having the key box of FIGS. 1-7 mounted thereto by means of a bracket which fits over the top edge of the window of the automobile.
Description of the Preferred Embodiments
FIG. 1 shows an exploded view of a tubular key box 10 according to the present invention. Key box 10 comprises generally a tubular receiver portion 12, and a cylindrical locking plug portion 14 which is received within receiver portion 12 so as to enclose a secondary key 16 therein. Tubular receiver portion 12 comprises generally a cylindrical outer sleeve 18 and a substantially planar mounting flange 20 which is formed integrally with cylindrical outer sleeve 18 so as to extend along a longitudinal edge thereof.
Outer sleeve 18 forms a generally cylindrical chamber 22 which is sized to receive secondary key 16. A 360.degree. annular locking groove 24 is formed in the inner Wall of outer sleeve 18, and this serves as an engagement area for the locking mechanism of locking plug portion 14. The open mouth end 26 of the outer sleeve defines a circular opening 27, while the closed end 28 is sealed by a blank plug 30 (see FIG. 5}. A raised flat 32 (see FIG. 1) forms a planar, longitudinally extending abutment surface within sleeve 18, the purpose of which will become apparent from the following description, and the end of this is recessed from the mouth end of the sleeve to form the circular opening 27.
It Will be appreciated -rom the foregoing that, with the exception of the machined circular mouth opening 27 and locking groove 24, the tubular receiver portion has a continuous cross section throughout its length. This is important in that it permits the tubular receiver portion to be formed by means of a continuous extrusion through a die. Tubular receiver portion 12 can consequently be fabricated of inexpensive, but very high strength extruded aluminum alloy, which is much tougher than the zinc alloy castings which are typically employed by conventional key boxes. For example, key boxes in accordance with the present invention can be formed of extruded 6061-T6 high strength aluminum alloy. Furthermore, this permits mounting flange 20 to be formed integrally with the tubular outer sleeve 18, and the radiused joint 34 between these portions is strong and does not afford any purchase for a prying instrument. Still further, this facilitates the fabrication of a range of key boxes having internal chambers of various lengths, since the extruded aluminum can be cut at whatever length is desired.
Circular opening 27 at the mouth end of tubular receiver portion -2 is sized to receive a generally cylindrical) inner sleeve 40, this having secondary key 16 mounted at its inner end 42. An internal bore 44 extends from the outer end 46 of inner sleeve 40, and is sized to receive a cylinder lock mechanism 50. An example of cylindrical lock mechanism which is suitable for use in the key box of the present invention is a Gem Fop-out.TM. Model YPT-1010, available from Fort Lock Corporation, 3000 N. River Road, River Grove, Illinois 60171. It is conventional within the lock industry that such cylindrical lock mechanisms (which are commonly used on vending machines) have a standard external diameter of 3/4 inch. Accordingly, the internal bore 44 of inner sleeve 40 is sized to have a diameter just slightly greater than 3/4 inch so as to slidingly receive cylinder lock mechanism 50. An outwardly biased spring-loaded locking plunger 52 extends from lock mechanism 50 and is provided with a beveled leading face 54 at its outer end. A cylindrical transverse bore 56 in inner sleeve 40 accommodates the passage of spring-loaded locking plunger 52 therethrough; preferably, the inner sleeve is provided With a plurality of radially spaced-apart transverse bores 56 at various selected positions along its length. This arrangement of multiple transverse bores is highly advantageous in that, although conventional cylindrical lock mechanisms 50 have a standardized external diameter, the lonqitudinal distance between their outer ends 58 and their locking plungers 52 vary from model to model and manufacturer to manufacturer. Accordingly, the plurality of transverse bores 56 at various selected lengths along inner sleeve 40 permit these various models and makes of cylindrical lock mechanisms to be accommodated a single configuration of inner sleeve 40 with their locking plungers received in selected transverse bores 56, while in each case their outer faces 58 remain flush with the outer end 46 of sleeve 40. The annular configuration of locking groove 24 permits the locking plungers to engage it at the various radial positions of bores 56. Thus, a standard tubular key box 10 having a standard receiver Portion and standard inner sleeve 40 can be provided to locksmiths, who can, in turn, select a cylindrical lock mechanism 50 of their choice and install it therein. Cylindrical lock mechanism 50 is operated by a master key 60; as the master key is rotated from a locked position to an unlocked position, the spring-loaded plunger 52 is Withdrawn from locking groove 24 and so as to permit plug portion 14 to be withdrawn from tubular receiver portion 12.
FIG. 2 shows locking plug portion 14 fully assembled, with spring-loaded locking plunger 52 protruding outwardly through transverse bore 56. The thickness of sleeve 40 is such that the outer end of locking plunger 52 extends sufficiently far beyond the outer wall of the sleeve to engage annular locking groove 24 when in the locked position. When key 60 is rotated to the unlocked position, the outer end of plunger 52 is withdrawn within the outside diameter of inner sleeve 40 so as to permit the locking plug portion 14 to be withdrawn from receiver portion 12; however, the plunger is not withdrawn inwardly sufficiently far to permit the lock mechanism to be pulled out of the inner sleeve; to disengage lock mechanism 50 from sleeve 40, it is necessary to press inwardly on the outer end of plunger 52 with a suitable instrument, such as a pen, to depress plunger 52 within the diameter of internal bore 44 so that the lock mechanism can be withdrawn, this generally requiring use of the master key so as to provide a safeguard against copying of the lock cylinder.
As noted above, outwardly-biased, spring-loaded plunger 52 is provided with a beveled leading face 54 at its outer end. This permits locking plug portion 14 to be inserted into receiver Portion 12 and locked therein without use of master key 60. Key 16 is first placed within chamber 22 and then inner sleeve 40 is inserted into the open mouth end 26 of outer sleeve 18. As this is done, the beveled leading face 54 of the plunger reacts against the lip of the mouth end of sleeve 18 to drive spring-loaded plunger 52 inwardly so that locking plug portion 14 can be pressed fully into the tubular outer sleeve until plunger 52 reaches annular locking groove 24 and moves outwardly into locking engagement therewith (as shown in FIG. 4), the non-beveled trailing face of the plunger preventing it from being subsequently withdrawn from the groove. When it is then desired to remove locking plug 14 so as to gain access to secondary key 16, the master key is inserted in the lock mechanism and rotated to withdraw locking plunger 52 inwardly out of engagement with locking groove 24, as shown in FIG. 5. After the locking plug and secondary key have been removed from the fixed receiver portion of the key box, the master key can be removed from the lock mechanism, and the secondary key -6 can be carried about and utilized as needed, locking plug portion 14 remaining attached thereto so as to serve as a convenient sized fob which helps to prevent misplacement or loss of the secondary key. When the operator has finished with secondary key 16, the secondary key and locking plug portion are simply pressed back into the tubular outer sleeve 18 without having to use the master key 60 again, thus avoiding the drawbacks of the conventional key boxes which have been described above.
FIG. 3 shows that locking plug portion 14 is configured to be installed in tubular receiver portion 12 so that the outer end of the locking plug is flush with the mouth end of the receiver, thus eliminating any point on the locking plug portion Where a thief might be able to achieve a grip with Which to pull or pry the plug outwardly from the receiver. When removing the locking plug, the master key is rotated from a locked position to an unlocked position in the direction indicated by arrow 62. FIG. 4 shows key 60 is in the locked position, in which the locking plunger is biased into engagement with the annular locking groove 24. When key 60 is rotated to the unlocked position shown in FIG. 5, locking Plunger 52 is withdrawn from annular locking groove 24, but, as previously noted, does not withdraw fully within the internal bore 44 of inner sleeve 40, and locking plunger 52 consequently abuts the wall of transverse bore 56 so as to permit the operator to withdraw the lock mechanism and inner sleeve together by simply pulling on master key 60. As this is done, secondary key 16 is simultaneously withdrawn from cylindrical chamber 22, inasmuch as it is connected by a conventional split ring 64 to an attachment pin 66 which is mounted transversely across a portion of inner sleeve 40 Which extends beyond the inner end 68 of cylinder lock mechanism 50.
FIG. 6 shows the annular relationship between outer sleeve 18, inner sleeve 40, and cylindrical lock mechanism 50. FIG. 6 also particularly illustrates the continuous cross section of tubular receiver portion -2 which permits it to be formed of inexpensive high-strength extruded aluminum alloy. This cross-section includes the internal raised flat 32, which slidingly abuts a corresponding recessed flat 70 which extends longitudinally along the generally cylindrical outer wall of inner sleeve 40. The abutment of the flats 32 and 70 prevents the inner sleeve from rotating relative to the outer sleeve, so that the operator can turn the master key to operate lock mechanism 50. As is shown in FIG. 7A, recessed flat 70 extends most of the length of inner sleeve 40 from its inner end 42 towards its outer end 46, but stops short of outer end 46 so that a stopper lip 72 is formed Proximate the outer end of the sleeve. This stopper lip 72 Provides an inner shoulder 74 which abuts an outer shoulder 76 at the end of the raised flat in the outer sleeve, so as to prevent inner sleeve 40 and locking plug portion 14 from being pushed into outer sleeve 18 for forced entry.
In an exemplary key box incorporating the present invention, in which a conventional 3/4 inch outside diameter cylindrical lock mechanism is employed, it has been found suitable to form an inner sleeve 40 of aluminum tubing having an approximately 3/4 inch internal bore to accommodate the lock mechanism and an external diameter of approximately 1 1/16 inch, with the overall length of the inner sleeve being about 13/4 inch. The recessed flat 70 is cut approximately 1/16 inch into the wall of the inner sleeve, and terminates approximately 1/4 inch from the outer end 46 of the sleeve to form stopper lip 72. According]y, the circular opening at open mouth end 26 extends approximately 1/4 inch into sleeve 18 to accommodate the stopper lip. Outer sleeve 18 has an external diameter of approximately 13/8 inch and a bore of approximately 1 1/16 inch, with the raised flat extending about 1/16 inch into the bore, the other end of sleeve 18 being closed by a simple 1/4 inch thick pressed-in plug, this being formed with an external diameter a few thousands of an inch greater than the bore of the outer sleeve and of a slightly softer aluminum alloy. The annular locking groove is formed by a 360.degree. cut, approximately 1/4 inch Wide and 3/32 inch deep, in the inner wall of sleeve 18. This arrangement facilitates inexpensive manufacture of these components, inasmuch as the recessed flat on the inner sleeve can be formed by simply milling this piece over the required length, and the circular opening in the extruded outer sleeve can be formed by machining the mouth end round for a length corresponding to that of the stopper lip. Furthermore, the transverse bores 56, 56' are formed as round holes having a sufficient diameter to accommodate the square locking plunger 52, so that these can be formed by a simple drilling operation, and the annular locking groove can be formed by another simple machining operation. Accordingly, it Will be appreciated that this arrangement dispenses with the need for lugs or other structures Which might necessitate formation by casting, and permits assembly using a minimum of parts and only simple machining and milling operations. The outer sleeve and mounting flange can be cut to any suitable length; however, a mounting flange having a width of approximately 21/4 inches and a thickness of 1/4 inch, combined with an overall length of 43/4 inches has been found to provide a particularly sturdy and conveniently sized arrangement having sufficient storage space for most keys.
FIG. 7B shows another inner sleeve 40', having a configuration generally similar to inner sleeve 40 shown in FIG. 7A, with the exception that the inner end 42' of the sleeve has been extended longitudinally so as to form a cylindrical chamber 76 which receives and partially encloses the secondary key 16'. A pair of diametrically opposite internal grooves 77 and 78 extend longitudinally along the inside wall of chamber 76, these being formed by a simple longitudinal saw cut. Grooves 77 and 78 are sized to receive and hold the edges of the handle portion 79 of key 16', and chamber 76 preferably has sufficient length that at least a substantial portion of the handle portion of the key is received therein. In use, the inner sleeve is withdrawn from the outer sleeve as previously described, and then the operator removes key 16' from grooves 77, 78 by pulling it outwardly in the direction indicated by arrow 80. Key 16' can then be used, and is retained to inner sleeve 40' by a chain 82 Which accommodates the movement of key 16' into and out of chamber 76. The arrangement shown in FIG. 7B assists the operator in replacing the secondary key in the tubular key box, since the key is held by the inner sleeve so that it will fit into the outer sleeve without having to first manually position the key within the key box before pressing the locking plug in behind it. This arrangement is particularly advantageous where the key box 10 is positioned in a relatively high location (as at the top of a door, where it may be difficult for a short person to reach it, or in a position selected to minimize access thereto by a thief), since the tubular receiver can be aligned in a vertical direction and the inner sleeve 40' and the key 16' held therein can be replaced in the outer sleeve as a unit by pressing them upwardly into the receiver portion with one hand. As a simpler alternative to the arrangement shown in FIG. 7B, chamber 76 may extend a sufficient distance to form a cylindrical cup for holding the shank portion of the key (vice the handle portion), the key 16' being in an inverted position relative to that shown in FIG. 7B.
The versatility of the key box 10 incorporating the present invention is significantly enhanced by the arrangement of the integral mounting flange 20. This mounting flange provides a convenient yet secure attachment fitting, not only for direct mounting of the key box to a structure, such as a building, but also for mounting to a suitably formed mounting bracket or other fitting Which is in turn attachable to a selected portion of a structure. For example, FIG. 8 shows tubular key box 10 mounted to the exterior of a building 90 adjacent to the entrance door 92 thereof. In this arrangement, the mounting flange 20 directly abuts the external surface of the wall 94 of the building, and is securely fixed thereto by means of bolts (not shown) which extend through wall 94 from the interior of the building and into threaded bores (not shown) which are provided in the back side of the mounting flange 20. The arrangement shown in FIG. 8 is particularly suitable for use in a permanent installation, such as might be required by a fire department for commercial buildings in a business park or the like, where the key box contains the keys to the particular building 90 and the fire department holds the master key to the key box. A similar mounting arrangement may be suitable for use with utility vehicles, such as earth moving equipment, utility trucks, and the like, where the flange 20 of the key box may be permanently bolted to some suitable portion of the vehicle, such as a bumper and the master key may be held by a foreman or a security officer.
FIG. 9 shows an arrangement in Which the tubular key box 10 is detachably mounted to buildinq 90 by means of a U-shaped mounting bracket 96 Which extends over the top edge of door 92 so as to be held firmly in place when the door is closed and locked by locking door knob 97. This arrangement is eminently suitable for use by realtors, where the key box is temporarily mounted to a house which is to be shown, the realtors gaining access to the key to door knob 97 by means of the master key to key box 10. The broad, flat rear face 98 (see FIG. 6) of mounting flange 20 provides a convenient yet secure attachment point for the mounting bracket, the heads of the bolts, rivets, or the like at rear face 98 being inaccessible when the key box is attached to the locked door as shown. Mounting bracket 96 is configured to position key box 10 sufficiently far below the top of door 92 that a gap 99 is formed which accommodates the molding of the door when in the closed position.
FIG. 10 shows a mounting arrangement somewhat similar to that shown in FIG. 9, in which the key box 10 is temporarily mounted to an automobile 100 by means of another U-shaped mounting bracket 102 which is attached to the rear face of flange 20, bracket 102 being configured in this case to fit over the edge of the door window 104 of the automobile When the window is rolled up and the door 106 is closed and locked. This arrangement is particularly suitable for use by automobile dealers, rental companies, and the like, where a salesman or the like may use the master key to gain access to keys of the automobile which are contained in the key box. Accordingly, it will be appreciated that integral mounting flange 20 provides a single configuration of tubular key box 10 With the adaptability to be mounted to a wide variety of structures.
A key box having cylindrical outer and inner sleeves as previously described has been found to be a particularly effective and economical arrangement; however, it should be recognized that it may be found desirable in some circumstances to form these tubular components with corresponding oval, square, or polygonal cross-sections
Having described my invention, many modifications thereto will become obvious to those skilled in the art to Which it pertains without deviation from the spirit of the invention as defined by the scope of the appended claims.