Abstract:
An independent dual deadbolt locking mechanism for securing doors, windows or the like. The dual locking mechanism has a single pivot key that acts to place two deadbolt locks in either a locked or unlocked position simultaneously. The deadbolts may be oriented at various angles to one another. Typically, the deadbolts are oriented at a 90 degree angle from one another, with one deadbolt locking into the side frame of a door, and the other locking into the upper door frame or floor. The mechanical arrangements of the locking mechanism allows one deadbolt to be broken or forced into an unlocked position without affecting or unlocking the other independent deadbolt.

Description:
RELATED APPLICATION 
     This application is a continuation-in-part of U.S. patent application Ser. No. 08/248,438, filed May 24, 1994, now U.S. Pat. No. 5,472,246. 
    
    
     FIELD OF THE INVENTION 
     This invention relates generally to a locking mechanism for locking and unlocking doors or similar structures, and particularly to a locking mechanism having dual deadbolt locks which are protected from being simultaneously forcibly opened. 
     BACKGROUND OF THE INVENTION 
     Standard deadbolt door locks are designed to project a single sliding bolt into a socket of a casing of a door. This single sliding bolt construction provides only limited security for doors and windows since there is locking only at one location. 
     Locking mechanisms have been proposed which have multiple deadbolt locking capabilities for added security. U.S. Pat. No. 1,513,835 discloses a locking device for windows that has a pair of locking bolts movable at fight angles to each other. The mechanism of this patent, however, transmits motion from one locking bolt to the other. 
     U.S. Pat. No. 2,125,227 discloses a locking device for a door which projects a sliding bolt into the side casing of a door and also projects a pair of pins upwardly and downwardly into the lintel and sill of a door. The pins are not independently held in place once being locked. 
     Although prior multiple locking mechanisms exist, such mechanisms have many of the same failings that single locking mechanisms have. Single deadbolt locks may be forcibly unlocked by forcing the deadbolt back into its chamber with a crow bar or similar object. Prior multiple deadbolt locking devices are constructed where each deadbolt is always in an interlocking engagement with another deadbolt so whenever there is motion by one deadbolt, an equivalent motion is transferred to the other deadbolt. This transferring of motion is present even when one deadbolt is forced back into its chamber or unlocked position. By forcibly unlocking one deadbolt, the other interlocking deadbolt becomes unlocked as well. 
     To fully take advantage of a multiple deadbolt locking device, there is a need for a dual locking device that has deadbolts which may be maintained in a locked position independently, regardless of whether one of the deadbolts becomes forcibly unlocked. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention, an independent dual locking mechanism is provided that is ideally suited for securing doors, windows and the like. The locking mechanism, according to the present invention, has all the advantages of dual locking deadbolt locks over single deadbolt locking mechanisms, and more importantly, the present invention has two deadbolts, that when locked, act independently of each other. Therefore, if one lock is forcibly broken or unlocked, the other remains in a locked position. 
     The dual locking mechanism also has the capability of being adjustable. While preferably the dual deadbolts may be at right angles to each other for interlocking engagement with a socket in the casing of a door and an upper door sash or floor, they also may be oriented with one deadbolt in an upper door sash and the other in the floor. The deadbolts of the locking mechanism may also be adjusted to all other angles between 180 and 0 degrees. 
     Accordingly, the invention relates to an independent dual locking mechanism comprising two deadbolts, separate means for linking each deadbolt to a single location, actuating means at the single location which is connected to the separate means and used for locking and unlocking the two deadbolts simultaneously while only using a single method of activation, and a means for preventing one deadbolt from becoming unlocked when the other deadbolt is forcibly unlocked or broken. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention is described in greater detail in the following description of examples embodying the best mode of the invention, taken in conjunction with the drawing figures, in which: 
     FIG. 1 is a perspective view of the first embodiment showing the dual locking mechanism according to the invention with dual deadbolts disposed at right angles to one another, and with both deadbolts extended in the locked position. 
     FIG. 2 is an elevational view of the first embodiment of the dual locking mechanism, partially is section to show detail, and shown mounted in a door with the deadbolts extended into the locked position. 
     FIG. 3 is an elevational view of the first embodiment similar to FIG. 2, but with the deadbolts retracted to an unlocked position. 
     FIG. 4 is a plan view of the first embodiment showing one of the deadbolts in an extended locked position and illustrating its attached locking mechanism. 
     FIG. 5 is an enlarged schematic view the first embodiment of a portion of the invention showing the main pivot element of the dual locking mechanism. 
     FIG. 6 is an enlarged side elevational view of the first embodiment of the pivotal connection between the main pivot element and the first actuator when the first deadbolt is in a locked position. 
     FIG. 7 is a plan view of a door having the second embodiment of the dual locking mechanism with the first deadbolt in an extended locked position in the upper sash of the door and the second deadbolt in an extended locked position in the side casing of the door. 
     FIG. 8 is a plan view of the second embodiment of the dual locking mechanism with the covers removed from the main housing and first deadbolt housing, and showing the first and second deadbolts extended to locked positions. 
     FIG. 9 is a plan view of the housing cover for the main housing of the second embodiment. 
     FIG. 10 is a plan view of the housing cover for one of the deadbolts of the second embodiment. 
     FIG. 11 is an enlarged plan view of the second embodiment of the dual locking mechanism with the cover removed from the main housing showing the second deadbolt in an extended locked position. 
     FIG. 12 is an enlarged plan view similar to FIG. 11, but showing the second deadbolt in a retracted unlocked position. 
     FIG. 13 is an enlarged plan view of the second embodiment of the dual locking mechanism with the cover removed from the first deadbolt housing and showing the first deadbolt in an extended locked position. 
     FIG. 14 is a plan view of the second embodiment of the dual locking mechanism showing a separable two-piece actuator for the first deadbolt. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings in more detail, reference numeral 10 generally designates an independent dual deadbolt locking mechanism constructed in accordance with a preferred first and second embodiment of the present invention. In the first embodiment, the mechanism 10 includes a first and second deadbolt 12 and 14, first and second actuators 16 and 18, a housing 20, a main pivot element 22, and a dual pivot link 24. 
     The main pivot element 22 pivots about a central pivot 25 located at a first end 20a of the housing 20. The main pivot element 22 has first extending arms 22a and second extending arms 22b. The arms 22a include slots 26, and arms 22b include slots 28. The first actuator 16 has a first end 16a and a second end 16b. A series of holes 16c are located in the first end 16a. The first end 16a fits between the arms 22a of the main pivot element 22 so that one of the holes 16c of the first actuator 16 is positioned between slots 26. A pin 30 is secured in the one hole 16c and through the slots 26 to allow the first actuator 16 to pivot about the pin 30 between the arms 22a. 
     The first deadbolt 12, as best shown in FIG. 2, has a first end 12a and a second end 12b. The first end 12a has a hollowed opening 12c. The second end 16b of the first actuator 16 extends into the hollow opening 12c of the first deadbolt 12. The second end 16b has a hole 32 therethrough. A rod 34 is mounted in first deadbolt 12 in opening 12c and extends through hole 32 allowing the second end 16b of the first actuator 16 to pivot about rod 34. A spring 35 extends around rod 34 and bears against the end 16b, biasing the first end 16a of the first actuator 16 in a direction toward the second deadbolt 14, for purposes that will become apparent below. 
     As seen in FIG. 1, the first deadbolt 12 is slidable within a hollow first deadbolt housing 36. The first deadbolt housing 36 includes a stop 38 which protrudes inwardly to limit travel as the first deadbolt 12 moves longitudinally through the first deadbolt housing 36. The stop 38 also acts as a stop for the mechanism 10 when the deadbolts 12 and 14 are retracted, as described below. 
     The dual pivot link 24 has opposite ends 24a and 24b. The end 24a has hole 24c therethrough and is located between the arms 22b of the main pivot element 22. A pin 42 is mounted in the hole 24c of the pivot link 24 to the second set of arms 22d of the main pivot element 22. The pin 42 also extends axially beyond the arms 22b sufficiently to contact the housing 20. As seen on FIGS. 1 and 2, a pair of notches 56 are located on both sides of the housing 20 to receive the extended pin 42 when the locking mechanism 10 is in a locked position. 
     The second actuator 18 has a first end 18a and a second end 18b. The first end 18a has a hole therethrough. The end 24b of the dual pivot link 24 consists of two arms 24d. A hole extends through each arm 24d. The first end 18a of the second actuator 18 is positioned between the arms 24d of the dual pivot link 24 to the end 18a of the second actuator 18. 
     The second deadbolt 14 is slidable mounted inside a hollow second deadbolt housing 54. The housing 20, as best shown in FIG. 1, is secured to the second deadbolt housing 54. The second end 18b of the second actuator 18 extends inside an open end 14a of the second deadbolt 14. The second end 18b has a hole therethrough. A rod 42 is mounted through the deadbolt 14 inside the open end 14a and extends through the hole in end 18b, thereby pivotally connecting the second end 18b of the second actuator 18 in the second deadbolt 14. 
     As seen in FIG. 2, the second end 18b of the second actuator 18 has a bore 44 that holds a spring 46. The spring 46 biases against and inside the open end 14a of the second deadbolt 14 and the bottom of the bore 44, thereby biasing the second actuator 18 outwardly (to the left as seen in FIGS. 2 and 3). 
     A fixed pivot pin 48 extends through the center pivot 25 of the housing 20. The pivot pin 48 also extends through the center of the main pivot element 22 and thereby acts to pivotally mount the main pivot element inside the housing 20. 
     FIGS. 2 and 3 show a rod 50 mounted in the housing 20. A spring 52 is wrapped around rod 50. The spring 52 has a first arm 52a extending beneath a stop 55 located in the housing 20. A second spring arm 52b extends against and beneath an angled elbow 22c of the main pivot element 22 when the locking mechanism is in the unlocked position or the locked position. 
     Both first and second deadbolt housings 36 and 54 include a pair of mounting plates 58. The mounting plates 58 am shaped to orient and guide the deadbolts 12 and 14, and have holes 60 to accommodate mounting of the dual deadbolt locking mechanism to the top, bottom or sides of a door with screws or bolts. As seen in FIGS. 2 and 3, when the dual locking mechanism 10 is mounted in a door 64, them are lateral bores 62 in the door 64 to accommodate the positioning of the dual locking mechanism 10 inside the door 64. Also, there is a through bore 66 located where the lateral bores 62 intersect to accommodate rotation of the main pivot element 22 and for insertion of a key or attachment of a handle or knob to the pivot pin 48 for use in locking and unlocking the dual locking mechanism 10. 
     In operation, to place the dual deadbolt locking mechanism 10 in a locked position from an unlocked position, the pivot pin 48 is turned counter-clockwise (as seen in FIG. 1 and 2). When the pivot pin 48 is turned in the counter-clockwise direction, the attached main pivot element 22 turns in conjunction with the pivot pin 48. The first extending arms 22a rotate with the main pivot element 22 forcing the attached first end 16a of the first actuator 16 to move inside the first deadbolt housing 36, which causes the first deadbolt 12 to slide through and partially out of the first deadbolt housing 36 to a locked position. The spring 35 biases the actuator end 16a in the direction of the second deadbolt 14. This biasing of actuator end 16a forces the pin 30 to a position adjacent the first end of the housing 20a when the pivot pin 48 is completely turned in a counterclockwise direction as seen in FIGS. 2 and 3. Once the pin 30 is in a position adjacent the first end 20a, the first end 20a prevents the pin 30 from moving past the first end 20a, thereby preventing the deadbolt 12 from sliding back through the first deadbolt housing 36 and unlocking the first deadbolt 12. Only when the pivot pin 48 is turned back in the clockwise direction will the pin 48 rotate from the first end 20a and allow unlocking of the first deadbolt 12. 
     When the dual locking mechanism 10 is in a locked position, the slots 26, which hold the pin 30, are positioned to guide the pin 30 against the edges of the side housing 20 when force is exerted axially on the first deadbolt 12, thereby preventing movement and unlocking of the first deadbolt 12 (as better seen in FIG. 6). 
     Turning the pivot pin 48 in a counter-clockwise direction also forces the second extending arms 22b of the main pivot dement 22 to cause the end 24b of the dual pivot link 24 to slide along the edges of the housing 20 over and past both notches 56. The pin 42 abuts against the edges of the housing 20 adjacent to the notches 56. As the main pivot element 22 continues to rotate in the counter-clock wise direction, the pin 42 slides in the slots 28, thereby moving past the point where the pin 42 initially abuts against the edges of the housing, and moves into the notches 56, thereby locking the interconnected second deadbolt 14 in the locked position (as better seen in FIG. 5). 
     If a large enough force is exerted axially against the first deadbolt 12 to cause either the rod 34, the first actuator 16, or the pin 30 to break, the locking of the second deadbolt 14 would be unaffected since the pin 42 would still be in the notches 56, thereby keeping the second deadbolt 14 in a locked position. Likewise, if a large enough force is exerted axially against, the second deadbolt 14 to cause either the pin 42 or the pin 58 to break, the locking of the first deadbolt 12 would be unaffected since the pin 30 would still abut against the edge 20a, preventing axial movement of the first deadbolt 12 and thereby preventing the first deadbolt 12 from moving into an unlocked position. 
     In a second embodiment, as seen in FIGS. 7 through 14, the mechanism 70 includes first and second deadbolts 72 and 74, first and second actuators 76 and 78, a main housing 80, a housing 82 for the first deadbolt 72, and a main pivot element 84. 
     The main pivot element 84 pivots about a central pivot point 86 within the housing 80. The main pivot element 84 includes a pivot pin 134, first extending and spaced apart arms 84a, second extending and spaced apart arms 84b, and an extending section 84c. The arms 84a include slots 90, and arms 84b include slots 92. The housing 80 has an L-shaped slot 80a therein having grooves 80b and 80c. Groove 80c includes an end notch 80d therein. The first actuator 76 may include a first link 76a and a second link 76b (FIG. 14). A hole 94 is located in the first link 76a. The first link 76a fits between the arms 84a of the main pivot element 84 so that hole 94 of the first actuator 76 is positioned between slots 90. A pin 92 extends through hole 94 and slots 90 to create a sliding pivotal connection between arms 84a and link 76a of the first actuator. The pin 90 also extends sufficiently to slide within the grooves 80b and 80c of the L-shaped slot 80a. 
     As seen in FIGS. 8 and 11-13, the first deadbolt 72 has a cavity 72a therein with holes 102 extending through the first deadbolt 72 to the cavity 72a. A connecting pin 100 extends through a hole in the second link 76b of the first actuator 76 and through the holes 102 to make a pivotal connection between the first deadbolt 72 and the first actuator 76. 
     The first deadbolt housing 82 has an internal cavity 104 therein. The first deadbolt 72 is positioned within the cavity 104 and is longitudinally slidably movable within the cavity 104. A cover 106 fits over cavity 104 to enclose the first deadbolt 72 within the first deadbolt housing 82. The cover 106 includes a groove 108 therein for accommodating and guiding the pin 100 when pin 100 moves longitudinally within the first deadbolt housing 82. The first deadbolt housing 82 also includes mounting holes 110 for mounting the housing 82 to the surface of a door 112 as seen in FIG. 7. The first actuator 76 is enclosed by a protective sleeve 113 that is connected between the main housing 80 and the first deadbolt housing 82. 
     The second actuator 78 has a first end 78a and a second end 78b. A hole 96 is located in the first end 78a. The first end 78a fits between the arms 84b of the main pivot element 84. A pin 98 extends through hole 96 and slots 92 to create a sliding pivotal connection between arms 84b and end 78a of the second actuator. The pin 98 is extended into and slides within the groove 84b of L-shaped slot 80a. 
     As seen in FIG. 8, the second deadbolt 74 has a cavity 74a therein with holes 114 extending through the second deadbolt 74 to the cavity 74a. A pin 116 extends through a hole in the second end 78b of the second actuator 78 and through holes 114 to make a pivotal connection between the second deadbolt 74 and the second actuator 78. 
     As seen in FIGS. 8, 11 and 12, the housing 80 has a cavity 118 therein. The cavity 118 has a section 118a to accommodate the rotation of main pivot element 84 about central pivot 86, a section 118b to accommodate the first actuator 76, and a section 118c to accommodate the second actuator 78 and slidable movement of the second deadbolt 74 within. The second deadbolt 74 is positioned within the cavity 118 and is slidably movable within the cavity 118c. A cover 120 fits over the cavity 118 to enclose the main pivot element 84, second actuator 78 and second deadbolt 74 within the housing 80. The cover 120 includes an L-shaped slot 122 therein, directly corresponding to the slot 80a, for accommodating pins 92 and 96 when the pins 92 and 96 move within the grooves 80b and 80c of the housing. The housing 80 also includes mounting the holes 124 for mounting the housing 80 to the door 112 as seen in FIG. 7. 
     As better seen in FIG. 11 and 12, the housing 80 includes a peg 126 extending within the cavity 118. A spring element 128 is looped around a peg 126 and biases against the extending portion 84c whereby the main pivot dement is biased in a clockwise direction as seen in FIG. 12. 
     A screw 130 is fastened in the second deadbolt 74. A spring element 132 is secured to the deadbolt 74 by the screw 130. A spring element 132 biases against second actuator 78. 
     As seen in FIG. 14, the first actuator 76 may be provided exist as separable parts 76a and 76b for easy disassembly of the mechanism 70. This construction allows for attaching or detaching of either the housing 80 or the first deadbolt housing 82 to or from a door 112 without having to attach or detach the other at the same time. 
     In operation, to place the dual deadbolt locking mechanism 70 in a locked position from an unlocked position, the pivot pin 134 is turned counter-clockwise (as seen in FIG. 8). When the pivot pin 134 is turned in the counter-clockwise direction, the main pivot element 84 rotates about and in conjunction with pivot pin 134. The first extending arms 84a rotate with the main pivot element 84 causing the pin 92 to slide upwardly within the groove 80b (and similarly within the slot 122) to a position in the groove 80c (as seen in FIGS. 8, 11, and 12). The movement of the pin 92 within the slot 90 as the pivot element 84 rotates allows the pin 92 to operably slide in the L-shaped slot 80. As the pin 92 moves upwardly along the groove 80b, the first actuator 76 is forced upwardly, thereby forcing the first deadbolt 72 out of the first deadbolt housing 82. Also, as the pin 92 slides upwardly along the groove 80b, the pin 98 slides to the left (as seen in FIGS. 8, 11, and 12), to the end notch 80d. When the pivot 134 is fully turned, the pin 98 is lodged in the end notch 80d. At the same time, the pin 92 moves from groove 80b to 80c, orienting the first deadbolt 72 to a locked position. The first deadbolt 72 cannot be moved back into the first deadbolt housing 82 without turning the main pivot element 84 since the pin 92 is now out of the groove 80b and in the groove 80c, thereby preventing lateral movement downward. The spring element 132 is biased against the second actuator 78 when the deadbolts 72 and 74 are in a locked position to bias the pin 96 in the end notch 80d. It also cannot be moved laterally to the right in FIGS. 8, 10, and 11 without first turning the pivot 134. 
     Similarly, when the main pivot element 84 is turned counter clockwise, the second deadbolt moves into an extended locked position out of the housing 80. The pin 98 moves along the groove 80c as main pivot element is turned counter clockwise, and the attached second actuator 78 pushes the second deadbolt 74 out of the housing 80 to a locked position. The second deadbolt 74 becomes fully locked in position when the pin 96 moves into the end notch 80d. It will be evident that the pin 96 cannot move out of the end notch 80d and along the groove 80c without turning main pivot element 84. The spring element 128 is biased against the extending element 84c when the deadbolts 72 and 74 are in the locked position to prevent the main pivot element 84 from rotating if one of the deadbolts 72 and 74 is forced to attempt to move the first and second deadbolts out of their locked positions. The deadbolts 72 and 74 can only be moved out of their locked positions by applying a counter-clockwise rotational force about the pivot 134 against the force of spring element 128 bearing on the main pivot element 84. 
     To move both deadbolts 72 and 74 from a locked position to an unlocked position, the main pivot element 84 must be turned clockwise to the position shown in FIG. 12. In a fully unlocked position, the pin 92 abuts against the end of the groove 80b. The spring element 128 is biased against the extending section 84c thereby keeping the main pivot element 84 from rotating counter-clockwise. In this fully unlocked position, the main pivot element 84 can only rotate in a clockwise direction if a rotational force to overcome the force of the spring element 128 is applied to the main pivot element 84 through the pivot pin 134. Of course, the pin 134 can be connected to a lock set hole cylinder or a door knob, in a conventional fashion. 
     A seen in FIG. 7, the second embodiment of the dual locking mechanism 70 is advantageous in that the main housing 80 and the first deadbolt housing 82 have apertures 124 and 110 therein for mounting to the surface of the outside surface of the door 112, thereby not requiring any bores within the door for accommodating placement of the mechanism 70 within the door. 
     Various changes can be made to the invention without departing from the spirit thereof or scope of the following claims.