Security Door Locking Mechanism

The present invention relates to locks for security doors and, more particularly, to locking mechanisms of the type used to secure safe doors.

In the prior art, the building of a combination and/or key-operated safe door has required persons with specialized training. The door itself has been no problem, it is merely welded together by anyone skilled in the art. The mounting and integration of the locking mechanism, however, is another story. The lock mechanism is first mounted to the inner portion of the door and then the operating mechanism is specially constructed for each particular door. Each shape, of the door takes individual consideration. Therefore, each safe door is a custom product. As with most custom products made on an individual basis, the cost thereof is very high.

Therefore, it is the object of the present invention to provide a locking mechanism of a general nature which can be attached to the inside of any door to operate retractable pins disposed about the edge thereof to turn the door into a security door.

The foregoing objective has been met by the lock mechanism of the present invention for a security door having a plurality of movable bolts adjacent the inner edge comprising an activating member attached to the inner surface of the door for rotation about an axis normal to the inner surface; linkage means operably connected between the activating member and bolts for moving the bolts into position to lock the door when the activating member is rotated in one direction and for moving the bolts out of their locking position when the activating member is rotated in the opposite direction; first locking means operably connected for releasably engaging the activating member to prevent rotation thereof; second locking means operably connected for releasably engaging the first locking means to prevent movement thereof whereby the second locking means must be released before the first locking means can release the activating member; means operably connected for rotating the activating member from outside the door; means operably connected for operating the first locking means; and means operably connected for operating the second locking means.

In the preferred embodiment, the activating member has a slot at the periphery thereof; the first locking means comprises a first sliding member adapted to slide into and out of the slot; and, the second means comprises a second sliding member adapted to slide into and out of engagement with an abutting surface of the first sliding member.

Additionally, in the preferred embodiment, the means for operating the first locking means is a removable means and the second locking means includes means for preventing the means for operating the first locking means from being operably connected to the first locking means when the second locking means is engaged with the abutting surface.

FIG. 1 is a perspective view of the locking mechanism of the present invention attached to a security door.

FIG. 2 is a perspective view of the outside portion of the door showing the opening handle, combination dial, and key slot and key used in conjunction with the present invention.

FIG. 3 is a perspective view showing the activating member and two locking members of the present invention.

FIG. 4 is a cutaway plan view of FIG. 3 in the plane IV--IV.

FIG. 5 is a partially-cutaway elevation of the locking mechanism of FIG. 4 in the plane V--V.

FIG. 6 is a cutaway drawing of the mechanism of FIG. 5 in the plane VI--VI.

FIG. 7 is a cutaway view through the mechanism of FIG. 5 in the plane VII--VII.

FIG. 8 is a cutaway view through the mechanism of FIG. 5 in the plane VIII--VIII.

FIG. 9 is a cutaway view through the mechanism of FIG. 5 in the plane IX--IX.

FIG. 10 is a detailed drawing of the mechanism whereby the handle is used to rotate the operating mechanism.

FIG. 11 is a cutaway view of the mechanism of FIG. 10 in the plane XI--XI.

FIG. 12 is an elevation view of the locking mechanism showing the first mechanism open and the second mechanism closed.

FIG. 13 is a cutaway through the mechanism of FIG. 12 in the plane XIII--XIII.

FIG. 14 is a cutaway view through the key of FIG. 13 in the plane XIV--XIV.

FIG. 15 is an elevation view of the locking mechanism in its completely open position to allow the activating member to rotate.

FIG. 16 is a view of the key of FIG. 13 in the plane XIV--XIV being rotated.

FIG. 17 is an exploded view of the locking mechanism of the present invention.

FIG. 18 is a front elevation of a slide bolt in its extended position.

FIG. 19 is a front elevation of a slide bolt in its retracted position.

Referring first to FIGS. 1, 18 and 19, the locking mechanism of the present invention is shown incorporated on a safe or security door. The door is generally indicated as 10 and has an outside surface 12 and inside surface 14. A number of slide bolts 16 of the type shown in FIGS. 18 and 19 are attached as by welding along the inner edge of the door 10. As can be seen in the more detailed drawings of FIGS. 18 and 19, the slide bolts 16 comprise a housing 18 having a longitudinal bore 20 therethrough. A cylindrical bolt 22 is disposed within the bore 20. A slot 24 is cut through the outer surface of the housing 18 to communicate with the bore 20. Operating pin 26 passes through the slot 24 and is affixed to the bolt 22. By sliding the operating pin 26 to one extreme of the slot as shown in FIG. 18, the bolt 22 can be extended to lock the door 10. By sliding the operating pin 26 to the opposite end of slot 24, the bolt 22 can be withdrawn to unlock the door 10.

The locking mechanism of the present invention is generally indicated as 28. Mechanism 28 comprises a back plate 30 attached to the inner surface 14 of the door 10 as by welding. A pair of locks 32, 34 are mounted to the back plate 30. Back plate 30 has a pin 36 extending normal thereto on which is mounted a cylindrical activating member 38. Activating member 38 can be rotated clockwise and counter-clockwise about the pin 36 by a handle (not shown at this point) on the outside of the door 10. The locks 32, 34 operate in tandem from outside the door in a manner to be described in detail hereinafter so as to lock the activating member 38 from rotation.

As can easily be seen in the drawings, the activating member 38 is adapted for ready connection to a variety of operating linkages for the slide bolts 16. For example, along the vertical edge of the door 10, the four slide bolts 16 are mounted in vertical alignment. A slide bar 40 is mounted between the guide tabs 42 of the respective housings 18. The slide bar 40 contains an angled slot 44 operably disposed over each operating pin 26. As will be readily recognized by those skilled in the art, this is a standard approach which will cause the four bolts 22 to be extended in the same manner shown when the bar 40 is in its lower position and to be retracted simultaneously when the slide bar 40 is raised. Activating member 38 is provided with an operating roller post 46 disposed within slot 48 provided in the slide bar 40 therefor. Consequently, as the activating member 38 is rotated in a clockwise direction, post 46 will force slide bar 40 in the downward direction extending the bolts 22. When the activating member 38 is rotated in a counter-clockwise direction, the post 46 will raise the slide bar 40, thus retracting the bolts 22.

Activating member 38 is also provided with posts 50 to which individual linkages 52 can be attached on one end and connected to the operating pin 26 of a slide bolt 16 on the opposite end as shown in FIG. 1 with respect to the single top and bottom bolts. Activating member 38 also contains auxillary drive tabs 54 for use in conjunction with other devices such as the timer 56.

The unique locking mechanism of the present invention will now be described in greater detail. The basic manner of operation is shown in FIGS. 2 and 3. The outside surface 12 of door 10 is provided with a combination dial 58, a key-slot or hole 60 into which key 62 can be inserted, and an operating handle 64. The locks 32, 34 operate in tandem to secure the activating member 38. Lock 32 is operated by the key 62 and lock 34 is operated by the combination dial 58. With the door 10 in a fully locked condition, the key 62 cannot be inserted into the keyslot 60. Upon successful manipulation of the combination dial 58, the bolt 66 of lock 34 is retracted which opens the keyslot 60 for the insertion of key 62. Upon the insertion of key 62 and the turning thereof to activate lock 32, the bolt 68 thereof is retracted which, in turn, releases the activating member 38 for rotation. The handle 64 can then be turned to rotate the activating member 38 to open the lock mechanism. As will be seen and recognized in the description which follows hereinafter, the locks 32, 34 are of a generally available standard commercial variety with only minor modification to the bolts 66, 68 thereof being required for them to be incorporated within the locking mechanism 28 of the present invention. For that reason, both locks 32 and 34 could comprise combination locks or, conversely, both locks 32, 34 could comprise key-operated locks. One or both of locks 32, 34 could also employ other types of locks such as magnetically-operated locks. All that is required is that the lock 32 and 34 have some form of extending and retracting bolts 68, 66, or the like, respectively.

Attention is now directed to FIGS. 4-9 wherein the locking mechanism 28 is shown in greater detail in its completely locked state. The back plate 30 has a pair of guide bars 70, 72 welded thereto in parallel spaced relationship. The locks 32, 34 are attached to the guide bars 70, 72 by the bolts 74. A pair of sliders 76, 78 are disposed between the guide bars 70, 72. Slider 76 is an outer slider having a slot 80 therein with parallel sides. Slider 78 is an inner slider disposed within slot 80. While the guide bars 70, 72 and sliders 76, 78 being described herein with respect to a tested embodiment of the present invention have straight sides, those skilled in the art will easily recognize that the novel features of the present invention could also be accomplished by making the guide bars 70, 72 and sliders 76, 78 in the form of circular segments for arcuate rather than linear motion. It should be further recognized that whereas two locks 32, 34 are employed with two sliders 76, 78, additional locks could be added in tandem. In that case, outer slider 76 would be an inner slider of yet another slider with a third lock disposed to operate that slider.

The actuating member 38 contains a slot 82 in its outer periphery. The outer slider 76 is sized to slide into the slot 82. The inner slider 78 is not as long as the slot 80 of outer slider 76. As a consequence, inner slider 78 can be slid to either end of the slot 80. In its position as shown in FIG. 5, the inner slider 78 is in abutment with the inner end of the slot 80 of outer slider 78 to, thereby, prevent retraction of the outer slider 76 from within the slot 82 of the activating member 38. It should be noted at this point that the back plate 30 comprises a vertical member 84 and horizontal members 86 which are welded as at 88 to the inner surface 14 of door 10. Thus, a space 90 is created between the inner surface 14 of the door 10 and the vertical member 84 into which a hard plate (not shown) can be placed. The vertical member 84 has a hole 92 in alignment with the keyhole 60. Both are in alignment with the entry hole 94 of lock 32. As can be seen, however, the inner slider 78 has a hole 96 therein which is out of alignment with hole 92 when slider 78 is in its locked position extended as shown in FIG. 5. As a consequence, the key 62 cannot be inserted into the lock 32 but, rather, abuts against inner slider 76 in the manner shown in FIG. 9. The outer slider 78 is provided with a hole 98 which is best seen in FIG. 17 and is connected to the bolt 68 of lock 32 by a rollpin 100 positioned partially in the hole as seen in FIGS. 4 and 5. As a consequence, when bolt 68 is extended from lock 32, the outer slider 76 is extended into slot 82 of the actuating member 38 as shown in FIG. 5. In like manner, the inner slider 78 contains a hole 103 which is best seen in FIG. 17 and is connected to bolt 66 of lock 34 by a rollpin 102. Inner slider 78 also contains a slot 104 through which the operating shaft 106 between the combination dial 58 and the lock 34 can pass and allow the inner slider 78 to move between its extended and retracted positions. A stop 108 is welded to the lower guide bar 72 to support lock 34 adjacent the slot 82 such that if an attempt is made to force the lock, the force will be transmitted to the case of the lock 34 and from thence to the stop 108 rather than being born by the bolts 74 entirely.

Turning now to FIG. 12, the first stage of opening the lock 28 of the present invention is shown. Upon successful manipulation of the combination dial 58, the bolt 66 of lock 34 is withdrawn into the lock 34. In so doing, rollpin 102 moves the inner slider 78 to the left as FIG. 12 is viewed. This places hole 96 in alignment with hole 92 and keyhole 60. The key 62 can now be inserted into operable engagement with the lock 32. This is shown in FIG. 13. As can be seen in FIG. 14, a typical key contains a plurality of arcuate sections 110 which are placed into operable engagement with the mechanism of the lock 32 when the key 62 is inserted therein. As the key is rotated, the arcuate sections rotate as shown in FIG. 16. This causes the final stage of unlocking of the lock mechanism 28 to occur. As shown in FIG. 15, as the key 62 is rotated in the manner of FIG. 16, its bolt 68 is retracted into lock 32. Its rollpin 100 thereupon slides the outer slider 76 to the left as FIG. 15 is viewed which, in turn, retracts it out of the slot 82 of the activating member 38. Activating member 38 can then be rotated to open the various locking mechanisms operably connected thereto. One principal advantage of the present locking mechanism is that the key can be used for convenience to open and close the locking mechanism 28 throughout the working day but complete security can be accomplished by a quick rotation of the combination dial to effect the double locking.

Turning now to FIGS. 4, 5, 10, 11, and 17 with particularity, the components for rotating the activating member 38 will be discussed in detail. A shaft 112 extends from the handle 64 and passes through a sleeve bearing 114 in door 10 provided to allow the handle 64 and shaft 112 to be rotated without binding. Shaft 112 passes through a hole 116 in the back plate 30 adjacent pin 36. A drive gear assembly 118 is connected on the inner end of shaft 112. The inner hub 120 of activating member 38 has a bearing 122 which surrounds the pin 36, again to allow non-binding movement. Inner hub 120 has a spur gear segment 124 which meshes with a corresponding spur gear segment 126 on the drive gear assembly 118. Drive gear assembly 118 is also provided with an arcuate stop ring 128 which abuts against the inner hub 120 at either end of the desired arc of travel of the activating member 38 to prevent further movement thereof.