This invention relates generally to improvements in door latch and related latch bolt operators for releasibly latching and/or locking a door, such as a residential or commercial entry door, with multiple latch bolts. More specifically, this invention relates to an extension for use with a multipoint latch bolt system of the type disclosed in U.S. Pat. No. 5,290,077, wherein the extension accommodates secure closure of a door having a curved or irregular top shape, such as a round top door.
Door latch and lock assemblies for use with hinged swinging doors are generally known in the art, and typically include at least one movable lock member mounted at a selected vertical position along a free side edge of the door in proximity with an actuator positioned for convenient manual access and operation. For example, in a hinged or swinging door, a spring-loaded latch bolt is normally mounted on the door at a mid-height position to engage a strike or keeper plate mounted on the adjacent door jamb, to retain the door in a normal closed position. A rotary handle or lever is commonly included as part of the latch and lock assembly, and is adapted for manual rotation to retract the latch bolt from the strike plate and thereby permit the door to be opened. These lock assemblies further include at least one lock device which may be designed to preclude latch bolt retraction in the locked condition, and/or may comprise a separate dead bolt for use in selectively locking the door.
Although such conventional door latch and lock assemblies as described above have generally performed their latching and/or locking functions in a satisfactory manner, there has been an on-going desire and need for further improvements in entry door security for residences and business establishments, particularly with respect to withstanding high winds loads such as gale-force or hurricane-force winds. Toward this end, so-called multipoint lock assemblies have been developed wherein multiple lock members such as multiple retractable latch bolts are provided at vertically spaced positions along the free side edge of a traditional or generally rectangular-shaped door for engaging a corresponding number of strike plates mounted at corresponding positions on the adjacent door jamb. In some designs, the multiple lock members are adapted for independent actuation, with the unfortunate result that frequently only one of the lock members is engaged due to human forgetfulness and/or neglect. In other designs, the multiple lock members are adapted for concurrent actuation by means of a single operator handle or lever.
U.S. Pat. No. 5,290,077 discloses an exemplary multipoint door lock assembly including multiple retractable latch bolts mounted at vertically spaced positions along the free side edge of an entry door or the like. A primary latch bolt is positioned generally at a mid-height location in close proximity with an actuator mechanism. A pair of secondary latch bolts are respectively positioned vertically above and below the primary latch bolt, and are linked by slide-mounted extension rods with the actuator mechanism. A lever handle or the like at an outboard side of the door is manually grasped and rotated to operate the actuator mechanism to retract all three latch bolts in a concurrent manner. When the rotary lever handle is released, one or more springs incorporated into the actuator mechanism causes the latch bolts (and lever handle) to return automatically to a normal extended position. As is known in the art, each latch bolt normally includes one tapered face to accommodate automatic retraction as the latch bolt engages the associated strike plate during door closure movement, followed by automatic re-extension of the latch bolt into a strike plate keeper recess as the door reaches the closed position.
However, a multipoint latch system of the type shown in U.S. Pat. No. 5,290,077 has not been designed for use with modern entry doors of a non-standard type or shape having a curved or irregular-shaped top, such as a round top door. Such curved or round top doors can undesirably flex at the curved upper ends thereof to result in undesired door opening in response to a high wind load, despite the presence of a multipoint latch system mounted along a free side edge of the door.
There exists, therefore, a need for further improvements in and to multipoint door latch mechanisms particularly of the type adapted for concurrently retracting multiple latch bolts in a multipoint system of the shown and described in U.S. Pat. No. 5,290,077, wherein the door latch mechanism includes an extension fitted into a curved or round top door to provide at least one addition latch bolt positioned generally at the top of the door, but wherein this additional latch bolt is retracted in unison with other system latch bolts to permit easy door opening, when desired. The present invention fulfills these needs and provides further related advantages.
In accordance with the invention, a latch and lock extension is provided for a round top door, for use in combination with a multipoint latch and lock mechanism of the type disclosed in U.S. Pat. No. 5,290,077. The extension includes at least one auxiliary latch cartridge having an associated auxiliary latch bolt disposed generally at the curved top of the door for operation in unison with multiple latch cartridges mounted along a vertically extending free side edge of the door, in accordance with the multipoint latch mechanism disclosed in U.S. Pat. No. 5,290,077, which is incorporated by reference herein. In an extended position, the auxiliary latch bolt engages a keeper in the top of an associated door frame for securely retaining the door in a closed position.
In one preferred embodiment of the invention, the extension comprises a curved channel for guiding an elongated auxiliary actuator drive bar along a curved path from the free side edge of the door to the at least one auxiliary latch cartridge disposed generally at the top of the curved or round top door. The auxiliary actuator drive bar is constructed from an assembled plurality of articulating links and a plurality of relatively rigid bridge links to accommodate the specific size and curved shape of the curved channel. A lower end of the auxiliary actuator drive bar is adapted for quick and easy connection to an upper end of a main drive bar forming a portion of the multipoint latch mechanism as disclosed in U.S. Pat. No. 5,290,077.
In operation, manipulation of the multipoint latch mechanism of U.S. Pat. No. 5,290,077 is effective to manually withdraw all of the latch bolts, including the auxiliary latch bolt, in unison from their respective keepers to permit door opening. Upon release, each latch bolt including the auxiliary latch bolt is desirably spring-loaded for automatic return to an advanced position. Thus, when the door is closed, each latch bolt is automatically extended into latching engagement with the associated keeper mounted on or in the associated door frame for securely retaining the door in the closed position.
Other features and advantages of the invention will become more apparent from the following detailed description, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.
The accompanying drawings illustrate the invention. In such drawings:
As shown in the exemplary drawings, a curved extension referred to generally by the reference numeral 10 in
As shown best in
The extension 10 of the present invention accommodates secure door retention in the closed position for modern door configurations including a non-linear, irregular or curved top, such as the round top door shape shown in
More specifically, the upper end of the first bridge link 44 is coupled as by means of a small screw 54 to a lower end of a flexible adjustment link 56 constructed from a low friction material such as a molded plastic material, and preferably such as an acetyl polymer. This adjustment link 56 has a relatively short but nevertheless elongated slot 58 formed therein for passage of the screw 54 into threaded engagement with and attachment to the upper end of the first bridge link 44. This slot 58 accommodates minor or fine-tuned length adjustment of the entire auxiliary actuator drive bar 40.
The adjustment link 56 extends upwardly from the slotted coupling with the first bridge link 44, and includes a central region 60 which has a reduced thickness to permit curved flexing in a manner to accommodate the specific curved shape of the channel 36, while continuing to exhibit substantial longitudinal stiffness. This reduced thickness central region 60 merges at an upper end of the adjustment link 56 with a laterally extending rounded groove 62.
The rounded groove 62 at the upper end of the adjustment link 56 rotatably receives a matingly shaped rounded tongue 64 formed in a lower end of an adjacent articulating link 46, which in turn has another rounded groove 62 formed at an upper end thereof. This upper rounded groove 62 in turn receives, as viewed in the illustrative embodiment depicted in
The second articulating link 46 (
The final bridge link 44 is connected by a pair of screws 76 or the like to a tab-shaped connector 78. The thus-assembled auxiliary actuator drive bar 40 can be slidably installed into the curved channel 36 and exhibits sufficient longitudinal stiffness for movement reciprocally back and forth within the curved channel 36, in response to longitudinal displacement of the main drive bar 42 (
The tab-shaped connector 78 at the uppermost end of the auxiliary actuator drive bar 40 extends radially inwardly from the drive bar 40 for connection in turn with an actuator link 82 of the auxiliary latch cartridge 16. Such connection is achieved, as shown in
As shown in
The entire channel 36 and associated channel adapter 86 are conveniently concealed within the door recess 38 by a faceplate strip 100. This faceplate strip 100 extends from a lowermost end aligned with and/or joined to an upper end of a similar faceplate strip (
A variety of further modifications and improvements in and to the door latch extension 10 of the present invention will be apparent to those persons skilled in the art. Accordingly, no limitation on the invention is intended by way of the foregoing description and accompanying drawings, except at set forth in the appended claims.
Number | Date | Country | |
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61291982 | Jan 2010 | US |