BACKGROUND OF THE INVENTION

This invention relates generally to a locking mechanism for locking and unlocking doors or similar structures, and more particularly to a locking mechanism having dual deadbolt locks which are protected from being simultaneously forceably opened.

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 onelocation.

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 right 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 notindependently 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 orsimilar object. 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 forciblyunlocked.

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 the advantage of duallocking deadbolt locks over single deadbolt locking mechanisms. 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 alocked 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 to 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 meansand 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.

BRIEFDESCRIPTION OF THE DRAWINGS

The invention is described in greater detail in the following description of an example embodying the best mode of the invention, taken in conjunction with the drawing figures, in which:

FIG. 1 is a perspective view showing the dual locking mechanism according to the invention with the 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 dual locking mechanism, partially in section to show detail, and shown mounted in a door with the deadbolts extended into the locked position.

FIG. 3 is an elevational view similar to FIG. 2, but with the deadbolts retracted to an unlocked position.

FIG. 4 is a plan view of the only one of the deadbolts, showing the deadbolt in an extended locked position and illustrating its attached locking mechanism.

FIG. 5 is an enlarged schematic view 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 pivotal connection between the main pivot element and the first actuator when the first deadbolt is in a locked position.

DESCRIPTION OF AN EXAMPLE EMBODYING THE BEST MODE OF THEINVENTION

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 embodiment of the present invention. The mechanism 10 includes afirst and second deadbolts 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 includeslots 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 firstactuator 16 is positioned between and the slots 26. A pin 30 is secured in the one hole 16c and the 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 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. Thesecond 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 bearsagainst the end 16b, biasing the first end 16a of the first actuator 16 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 slidably mounted inside 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 longitudinallythrough 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 and extends through the slots 28 to pivotallyconnect the end 24a 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 in FIG. 1 and 2, a pair of notches 56 are locatedon 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 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 secondactuator 18 is positioned between the arms 24d of the dual pivot link 24. A pin 58 extends through the holes in the arm 24d and the end 18a to pivotally connect the end 24d of the dual pivot link 24 to the end 18a of the second actuator 18.

The second deadbolt 14 is slidably mounted inside a hollow second deadbolt housing 54. The housing 20, as best shown in FIG. 1, is secured to the housing 54. The second end 18b of the second actuator 18 extends inside an open end 14a of thesecond 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 hole in the end 18b, thereby pivotally connecting the second end 18b of the second actuator 18 inthe 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 secondactuator 18 outwardly (to the left in FIGS. 2 and 3).

A fixed pivot pin 48 extends through the central 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 22 inside the housing 20.

FIG. 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 angledelbow 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 mounting plates 58. The mounting plates 58 are shaped to orient and guide the deadbolts 12 and 14, and have holes 60 to accommodate mounting of the dual deadbolt locking mechanism to thetop, bottom or sides of a door with screws or bolts. As seen in FIG. 2 and 3, when the dual locking mechanism 10 is mounted in a door 64, there are lateral bores 62 in the door 64 to accommodate the positioning of the dual locking mechanism 10 insidethe 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 andunlocking 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-clockwisedirection, 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 deadbolthousing 36, which causes the first deadbolt 12 to slide through and partially out of the first deadbolt housing 36 to a locked position. Spring 35 biases the actuator end 16a in the direction of the second deadbolt 14. This biasing of actuator end 16aforces pin 30 to a position adjacent the first end of the housing 20a when pivot pin 48 is completely turned in a counterclockwise direction as seen in FIGS. 2 and 3. Once pin 30 is position adjacent the first end 20a, the first end 20a prevents pin 30from moving past the first end 20a thereby, preventing deadbolt 12 from sliding back through the first deadbolt housing 36 and unlocking of the first deadbolt 12. Only when pivot pin 48 is turned back in the clockwise direction will pin 48 rotate fromthe first end 20a and allow unlocking of the first deadbolt 12.

When the dual locking mechanism 10 is in a locked position, slots 26 holding pin 30 are positioned to guide pin 30 against the edges of the side housing 20 when force is exerted axially on the first deadbolt 12, thereby preventing movement andunlocking 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 element 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 notches56. Pin 42 abuts against the edges of the housing 20 adjacent to notches 56. As the main pivot element 22 continues to rotate in the counter-clock wise direction, pin 42 slides in slots 28, thereby moving past the point where pin 42 initially abutsagainst the edges of the housing, and moves into 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 rod 34, first actuator 16, or pin 30 to break, the locking of the second deadbolt 14 would be unaffected since pin 42 would still be in notches 56, therebykeeping 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 pin 42 or pin 58 to break, the locking of the first deadbolt 12 would be unaffected since pin 30 would still abut against edge 20a, preventingaxial movement of the first deadbolt 12 and thereby preventing the first deadbolt 12 from moving into an unlocked position.

Various changes can be made to the invention without departing from the spirit thereof or scope of the claims.

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