Patent Publication Number: US-9890569-B2

Title: Door latch assembly with convertible cam drive

Description:
BACKGROUND 
     The present invention relates generally to door latch assemblies that include a door bolt assembly operable by a door handle assembly preferably having a paddle style handle. More specifically, the present disclosure relates to a door latch assembly configured to operate with selectively positionable door handles in either in up, down, horizontal left or horizontal right configurations. 
     Examples of existing door latch, door bolt, and door handle assemblies are described in U.S. Pat. Nos. 6,293,598; 7,258,374; 7,481,607; 6,196,599 and U.S. Pat. No. 5,730,478, and US Patent Publication No. 2013/0076046A1, all commonly assigned to Architectural Builders Hardware Manufacturing, Inc., as well as U.S. Pat. Nos. 4,986,583 and 5,403,047 all of which are hereby incorporated by reference. Such door latch assemblies include, generally, a door bolt assembly with a latch mechanism, and at least one door handle mechanism. 
     In some cases, institutions such as hospitals occasionally update their door latch configurations. This process involves providing new handles while retaining the existing latch/bolt assembly. In many cases, the new handles are mechanically incompatible with the existing latch/bolt, requiring that the latch/bolt be replaced as well. Such replacement adds additional material and labor costs to the institution. 
     A common problem of conventional door latch and door handle assemblies is that they can only be positioned in one orientation, up, down, horizontal left or horizontal right configurations due to the size of the hole of the door through which they are mounted. However, in some instances, the orientation of the door handle may need to be changed from up or down to horizontal left or horizontal right without resizing the hole in the door. For example, an installer may make a mistake in sizing of a hole through the door to install a door latch assembly such that the door handles cannot be oriented in a vertical position (parallel to the length of the door). However, by orienting the door handles in a horizontal position (perpendicular to the length of the door), an installer may still be able to use the hole in the door without resizing it. In another example, a horizontal orientation of a door handle may be preferred by a door latch assembly user because of the circumstances in which the room with the door is used. For instance, the door may be an entrance to a hospital room or assisted living room such that the patient in the room is more comfortable in gripping a paddle style door handle when oriented horizontally rather than vertically. 
     Conventional door latch and door handle assemblies do not allow for such a change in orientation in an easy straightforward manner using the same door latch/handle assemblies. In addition, there is a need for a latch/bolt mechanism which facilitates exchange of handle types without requiring latch/bolt replacement. 
     SUMMARY 
     The above-listed needs are addressed by the present door latch assembly, which features a convertible cam drive assembly that allows the same door latch/handle assemblies to be used when orienting the door handle into different configurations (e.g. up, down, horizontal left or horizontal right). Another feature of the present cam drive assembly is that it accommodates a variety of handle operational mechanisms. 
     More specifically, an embodiment of a door latch assembly is described with a convertible cam drive having a door bolt assembly including a sliding bolt configured for reciprocal sliding action between a latch position and a release position. Such an embodiment includes a door handle assembly having a base plate, a pivot pin and a cam receiving aperture of the base plate, and configured for being fastened to a door in one of a plurality of orientations with respect to a length of the door. Further, the present door handle assembly includes a door handle configured for pivoting relative to the pivot pin from a rest position to an actuating position and having a cam engaging portion. A cam drive assembly has a bolt actuator as well as a cam holder configured for placement within the cam receiving aperture of the base plate for accommodating the base plate being mounted in one of the plurality of orientations with respect to the door. The cam drive assembly is constructed and arranged for receiving the cam engaging portion of the door handle when pivoted from the rest position to the actuating position, thereby causing the sliding bolt to move from a latch position to a release position using the bolt actuator. 
     In another embodiment, door handle assembly is provided for use with a door latch assembly with a cam assembly further having a separate cam actuator configured for attachment to the cam engaging portion of the door handle and engaging a bolt actuator such that cam actuator is mountable upon the door handle in a selected one of a plurality of orientations. Such a door latch assembly includes a door bolt assembly having a sliding bolt configured for reciprocal sliding action between a latch position and a release position, and having a bolt opening and a rear surface. Further, the door latch assembly includes a door handle assembly having a pivot pin as well as a door handle configured for pivoting relative to the pivot pin from a rest position to an actuating position and having a cam engaging portion. In addition, the door handle assembly includes a base plate coupled to the door handle, having a cam receiving aperture, and configured for attaching to a door in one of a plurality of orientations with respect to the length of the door. Moreover, the door latch assembly includes a cam drive assembly having a cam with a finger as well as a cam holder configured for placement within the cam receiving aperture of the base plate in one of a plurality of orientations with respect to the door. The cam actuator is secured to the cam engaging portion of the door handle and configured for moving the finger laterally along the axis of the sliding bolt within the bolt opening and making contact with the rear surface of the sliding bolt thereby moving the sliding bolt from the latch position to the release position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is top exploded perspective view of the present door latch assembly shown mounted on a door; 
         FIG. 2  is a side perspective view of a cam with finger used in conjunction with a sliding bolt in the present door latch assembly; 
         FIG. 3  is a side perspective view of a cam holder used in the present door latch assembly; 
         FIG. 4  is a side perspective view of the cam in the cam holder used in the present door latch assembly; 
         FIG. 5  is a side perspective view of the cam and cam holder fastened to the base plate used in the present door latch assembly; 
         FIG. 6  is a side perspective view of a universal handle used in the present door latch assembly; 
         FIG. 7  is a side perspective view of an embodiment of a push/pull cam actuator (mortise backset) used in the present door latch assembly; 
         FIG. 8  is a side perspective view of an embodiment of a push/pull cam actuator (low profile backset) used in the present door latch assembly; 
         FIG. 9  is a side perspective view of an embodiment of a push door handle assembly with a cam actuator (mortise backset) used in the present door latch assembly; 
         FIG. 10  is a side perspective view of an embodiment of a pull door handle assembly with a cam actuator (mortise backset) used in the present door latch assembly; 
         FIG. 11  is a side perspective view of an embodiment of a push door handle assembly with a cam actuator (low profile backset) used in the present door latch assembly; 
         FIG. 12  is a side perspective view of an embodiment of a pull door handle assembly with a cam actuator (low profile backset) used in the present door latch assembly; 
         FIG. 13  is top exploded perspective view of a present door latch assembly shown mounted on a door; 
         FIG. 14  is a side perspective view of an embodiment of a push/pull cam actuator (low profile backset) used in the present door latch assembly; 
         FIG. 15  is a top perspective view of an embodiment of the door latch assembly with the push door handle assembly in the latch position; and 
         FIG. 16  is a top perspective view of the door latch assembly of  FIG. 15  with the push door handle assembly in the release position. 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to  FIG. 1 , the present door latch assembly is shown and generally designated  10 . The door latch assembly  10  includes door handle assemblies  12  and  14  as well as a door bolt assembly  15 . Each door handle assembly  12 ,  14  is similar except one is optionally configured as a push door handle assembly and another is optionally configured as a complimentary pull door handle assembly. As such, only one will be described in detail. Included in the door handle assembly  12 ,  14  is a faceplate or cover plate  16 , a door handle  18 , and at least one faceplate fastener  20  such as a screw used for securing the faceplate to a mounting plate or base plate  22 . Further, each faceplate  16  has a faceplate opening  24  that is configured for allowing the door handle  18  to pass through for actuation by a user.  FIG. 1  shows each faceplate opening  24  being rectangular in shape, however, persons of ordinary skill in the art would understand that other shapes are contemplated. 
     In addition, each faceplate  16  is secured to sidewalls  26  of the mounting/base plate  22  using the faceplate fasteners  20 . Moreover, each door handle  18  is configured to be pivotably secured to a corresponding mounting/base plate  22 . Further, each door handle  18  is configured for movement between a rest position and an actuating position to open the door by actuating (lifting or pressing) the door handle about a pivot point described below. 
     The door handle assemblies  12 ,  14  are secured to a door  30  by a plurality of mounting fasteners  32 , such as bolts and associated mounting nuts  34 . Further, each mounting/base plate  22  has a plurality of mounting openings  36  configured for being in registry with associated mounting openings  38  on the door  30 . The mounting bolts  32  are passed through the mounting plate openings  36  then through the door mounting openings  38  and the mounting openings of the other mounting/base plate  22 . As is known in the art, the mounting bolts  32  are then secured using the mounting nuts  34 . 
     A pivot pin  42  is configured to pass through a selected pair of corresponding aligned openings in the sidewalls  26 . The pivot pin  42  also passes through a complementary bore  44  ( FIG. 6 ) in the door handle  18  and maintains pivoting action and alignment of the door handle  18  relative to the mounting plate  22 . A torsion spring (not shown) is located on the pivot pin  42  and is configured for returning the door handle  18  to the rest position when released. As is known in the art, the torsion spring is preferably U-shaped with coiled spring-shaped side portions, a horizontal bottom portions and a pair of legs. Each of the spring-shaped side portions is configured for wrapping around the pivot pin  42 , on opposite sides of the door handle  18 . 
     While other configurations are contemplated, the door latch assembly  10  is preferably a so-called “low profile” design as is well known in the art. Included in the assembly  10  is the door bolt assembly  15  including a sliding bolt  46  made up of an outside barrel  47  and an inside barrel  48  reciprocating within the outside barrel between a latched and a released or retracted position. Also included on the outside barrel is a dress plate  50  at one end of the sliding bolt  46 . At least one dress plate fastener  52  passes through the dress plate  50  and an underlying back plate for attaching the door bolt assembly  15  to the door  30 . If desired, spacers are located between the back plate and the dress plate  50 . 
     Referring now to  FIG. 2 , included within the sliding bolt  46  is a sliding bolt opening  56  in the outside barrel  47  configured for receiving a finger  58  of the door handle assembly  12 ,  14 . The finger  58  is attached to a pivoting cam  60 . While in the preferred embodiment, the finger  58  and the cam  60  are integrally formed, as by casting, other fabrication techniques, including separate finger and cam attached during assembly, are contemplated. On the inside barrel  48 , a corresponding inside barrel opening  62  is in registry with the sliding bolt opening  56  when the door bolt assembly  15  is in the latched or rest position. A spring (not shown) contained within the rear of the sliding bolt  46 , biases the rear surface  65  of the sliding bolt  65  to maintain the sliding bolt in a latched position. The finger  58  makes contact with a rear surface  65  of the sliding bolt  46 , causing the inside barrel  48  to laterally slide relative to the outside barrel  47 , overcoming the default biased force of the spring and opening the latch to a released or retracted position by retracting a strike  64  relative to the dress plate  50 . 
     Further, the cam  60  includes a cam body  66  configured for engaging a cam actuator  67 ,  68  ( FIGS. 7, 8 ) secured to the door handle  18 . The cam body  66  includes a plurality of surfaces such as a cam body rear surface  69  and a cam body curved surface  70  which are configured with certain angles, radii, and finishes to engage the cam actuator  67 ,  68  secured to the door handle  18  and operate the door latch when the door handle  18  is selectively oriented horizontally (perpendicular to the length of the door  30 , or vertically, parallel to the length of the door). In addition, the cam  60  includes pivot pin hole  76  configured for receiving a cam pivot pin  85  ( FIG. 4 ). When the cam actuator  67 ,  68  engages the cam body  66 , the cam  60  is rotated about the pivot pin  85  thereby engaging the finger  58  with the rear surface  65  of sliding bolt  46  of the door bolt assembly  15  and overcoming the default biased condition of the sliding bolt to move it from a latch position to a release position. 
     Referring now to  FIGS. 3-5 , the cam holder  78  includes a cam receiving aperture  84 . Preferably, the aperture  84  is dimensioned for accommodating significant lateral sliding action of the finger  58  as the cam  60  pivots in the aperture. Further, the cam holder  78  includes a cam pivot pin bore  80  configured for receiving the cam pivot pin  85 . The cam receiving aperture  84  receives the cam body  66 , and the cam pivot pin  85  of the cam holder  78  holds the cam in place, allowing the cam  60  to pivot around the pivot pin. In addition, the cam holder  78  is mounted on the base plate  22  by cam mounting fasteners through a plurality of mounting holes  82  on the cam holder. The assembled cam holder  78  with the cam  60  (having cam body  66  and surfaces  69 ,  70 ) is mounted on the base plate  22  such that the door handle  18  is selectively oriented in one of a horizontal (perpendicular to the length of the door) and vertical position relative to the door  30 . Further, the embodiment of the cam  60  includes a cam body notch  74  configured for accommodating a cam block  75  ( FIG. 5 ). 
     Referring now to  FIG. 5 , a cam block  75  is optionally secured to the cam  60 . Such a cam block may be engaged by an embodiment of a cam actuator  67 ,  68  secured to a door handle. As mentioned herein, the cam  60  includes a cam body  66  with cam body rear surface  69  and cam body curved surface  70  to be used with other embodiments of a cam actuator  67 ,  68 . In addition, the cam holder  78  with the cam  60  are mounted to the base plate  22  to be positioned within the cam receiving aperture  87  of the base plate. The mounting plate openings  36  are used to mount the base plate  22  to the door  30 . Further, the pivot bore handle sliding bolt  44  is used to attach the door handle  18  to the base plate  22 . 
     Referring now to  FIG. 6 , an embodiment of a universal door handle  89  is shown and is configured to be mounted onto base plate  22  as shown in  FIG. 5  such that the orientation of the door handle is horizontal (perpendicular to the length of the door) or vertical (parallel to the length of the door). The universal door handle  89  includes and cam engaging portion  90  of the door handle used to engage a cam actuator  67 ,  68  and a door handle aperture  92  for accommodating the cam actuator. In addition, the universal door handle  89  includes a plurality of mounting holes  94  to secure the cam actuator  67 ,  68  to the universal door handle. 
     Referring now to  FIG. 7 , an embodiment of the cam actuator  67  is configured to be attached or coupled to a cam engaging portion  90  of the door handle  89 . The embodiment of the cam actuator  67  may be called a cam actuator with a mortise backset. Such a cam engaging portion  90  is one or more front surfaces of the door handle  89 . Further, the cam actuator  67  is configured to engage the cam  60  thereby overcoming the default biased force of the spring of the sliding bolt mechanism of the door bolt assembly  15  from a latched position to a release position. The cam actuator  67  includes a lip  98 , a flat cam engaging surface  100 , and a curved cam engaging surface  102 . Further, the flat cam engaging surface  100  and the curved cam engaging surface  102  are configured in certain angles, radii, and finishes to engage the cam  60  and cam body  66  having complimentary surfaces  69 ,  70  configured in certain angles, radii, and finishes. The cam actuator  67  may be paired with a push or pull door handle  18  and then oriented either horizontally (perpendicular to the length of the door) or vertically (parallel to the length of the door) depending on need. Further, the cam actuator  67  includes a plurality of cam actuator mounting holes  104  that are used to mount the cam actuator to the universal door handle  89 . 
     Referring now to  FIG. 8 , an alternate embodiment of the door handle cam actuator is generally designated  68 . The cam actuator  68  is particularly configured for use with the push/pull low profile door latch assemblies and is configured to be attached or coupled to a cam engaging portion of the door handle  89 . Such a cam engaging portion is one or more front surfaces  90  of the door handle  89 . Further, the door handle cam actuator  68  is configured to engage the cam  60  thereby, overcoming the default biased force of the spring of the sliding bolt mechanism of the door bolt assembly  15  from a latched position to a release position. The cam actuator  68  includes a lip  108 , a flat cam engaging surface  110 , and a curved cam engaging surface  112 . Further, the flat cam engaging surface  110  and the curved cam engaging surface  112  are configured in certain angles, radii, and finishes to engage the cam  60  and cam body  66  having complimentary surfaces  69 ,  70  configured in certain angles, radii, and finishes. The cam actuator  68  may be paired with a push or pull door handle  18  and then oriented either horizontally (perpendicular to the length of the door) or vertically (parallel to the length of the door) depending on need. Further, the cam actuator  68  includes a plurality of cam actuator mounting holes  114  that are used to mount the cam actuator to the universal door handle  89 . 
     Referring now to  FIGS. 9-10 , an embodiment of a cam actuator  67  is attached, fastened, or otherwise coupled to the cam engaging portion  90  of an embodiment of a push/pull door handle  89  (e.g. front surface(s) of the door handle  89 ). Further, an embodiment of a push/pull door handle  89  is configured to be actuated relative to a pivot pin  42  between a rest (latched) position and an actuated (release) position. In the rest position, the cam actuator  67  touches the cam  60 , but does not engage the cam  60  to move the sliding bolt mechanism of the door bolt assembly  15  thereby remaining in a latch position. In the actuated position, the cam actuator  67  does engage the cam  60  with its lip  98  and surfaces  100 ,  102  to move the sliding bolt mechanism of the door bolt assembly  15 , thereby positioning the sliding bolt mechanism in the release position. The cam actuator  67  is secured to the universal door handle  89  using a plurality of cam actuator mounting fasteners  116  against the cam engaging portion  90  and door handle aperture  92  for accommodating the cam actuator.  FIG. 9  shows the cam actuator  67  with mortise backset secured to a push door handle  89 .  FIG. 10  shows the cam actuator  67  with mortise backset secured to a pull door handle. 
     Referring now to  FIGS. 11-12 , an embodiment of the cam actuator  68  is attached, fastened, or otherwise coupled to the cam engaging portion  90  of the push/pull door handle  89  (e.g. front surface(s) of the door handle  89 ). Further, an embodiment of a push/pull door handle  89  is configured to be actuated relative to a pivot pin  42  between a rest position and an actuated position. In the rest position, the cam actuator  68  does not engage the cam  60  to move the sliding bolt mechanism of the door bolt assembly  15  thereby remaining in a latch position. In the actuated position, the cam actuator  68  engages the cam  60  with its lip  108  and surfaces  110 ,  112  to move the sliding bolt mechanism of the door bolt assembly  15  thereby positioning the sliding bolt mechanism in the release position. The cam actuator  68  is secured to the universal door handle  89  using a plurality of cam actuator mounting fasteners  118  against the cam engaging portion  90  and the door handle aperture  92  for accommodating the cam actuator.  FIG. 11  shows the cam actuator  68  with low profile backset secured to a push door handle  89 .  FIG. 10  shows the cam actuator  68  with profile backset secured to a pull door handle. 
     Embodiments of the present door latch assembly  10  include cam actuators  67 ,  68  coupled to either a push or pull door handle  18  that engages a cam  60  having a cam block  75  attached to the cam body notch  74 . Other embodiments include cam actuators  67 ,  68  coupled to either a push or pull door handle  18  that engages a cam  60  without cam block  75  attached. 
     Referring now to  FIG. 13 , an alternate embodiment of the latch assembly  10  is generally designated  120 . Components shared with the assembly  10  are designated with identical reference numbers. A main distinguishing feature of the assembly  120  is the cam actuator  122 , which shares function with the actuators  67 ,  68 , but includes distinctive structure. Further, the latch assembly  120  includes an adjustable adapter plate  124  that is coupled door handle  18  and provides a mounting point for the cam actuator  122 . The functioning of latch assembly in general and the adjustable adapter plate  124  in particular can be found in US Pub. No. 20130076046 which is incorporated by reference. In one embodiment, it is contemplated that the cam actuator  122  is attachable at more than one place, either right, left or center, to the adjustable adapter plate  124 . Referring to  FIG. 14 , the cam actuator  122  is particularly configured for use with the push/pull low profile door latch assemblies such as latch assembly  120  and is configured to be attached or coupled to the cam engaging portion  90  of the door handle  18 . Further, the door handle cam actuator  122  is configured to engage the cam  60  thereby overcoming the default biased force of the spring of the sliding bolt mechanism of the door bolt assembly  15  from a latched position to a release position. 
     The cam actuator  122  includes block-shaped door handle engaging portions  126 , a cam actuator surface  130 , and a flat cam engaging surface  132  configured to engage the cam  60  and the cam body  66  having complimentary surfaces  69 ,  70  configured in certain angles, radii, and finishes. Further, the door handle engaging portions  126  are spaced apart from one another. In addition, while other configurations are contemplated, in the preferred embodiment the cam actuator surface  130  is substantially perpendicular to the door handle engaging portions  126  as well as being substantially perpendicular to the flat cam engaging surface  132 . Thus, the cam actuator surface  132  is offset in space between the door handle engaging portions  126  and the flat cam engaging surface  132  such that the door handle engaging portions are in a different but parallel vertical plane with respect to the flat cam engaging surface  132 . 
     Embodiments of the door latch assembly  120  include cam actuators  122  coupled to either a push or pull door handle  18  that engages a cam  60  having a cam block  75  attached to the cam body notch  74 . Other embodiments include cam actuators  122  coupled to either a push or pull door handle  18  that engages a cam  60  without cam block  75  attached. 
     The cam actuator  122  is optionally paired with a push or pull door handle  18  and then oriented either horizontally (perpendicular to the length of the door) or vertically (parallel to the length of the door) depending on need. Further, the cam actuator  122  includes a plurality of cam actuator mounting holes  128  that are used to mount the cam actuator to the door handle  18 . 
     Referring to  FIG. 15 , the door latch assembly  120  is shown in the latch position. Further, in the latch position, the cam actuator  122  touches the cam  60  but is not engaging the cam to cause latch action. Also, the strike of door bolt assembly  15  is in an extended position. However, referring to  FIG. 16 , the door latch assembly is shown in release position, whereby a downward pushing force on the handle  18 , represented by the arrow ‘A’ causes the cam actuator  122 , and specifically the surface  132  to engage the cam  60 , causing pivoting action of the cam in the cam holder  78  ( FIG. 4 ), and corresponding lateral movement of the finger  58  due to pivoting action of the cam  60  about the pivot pin  85 . Movement of the finger  58  causes the strike  64  to retract within the door (not shown). 
     Referring again to  FIGS. 15-16 , it will be seen that the present door latch assembly  120  includes the door bolt assembly  15  having the sliding bolt  46  configured for reciprocal sliding action between a latch position and a release position. Further, the door latch assembly  120  includes a door handle assembly  12 ,  14  configured for being fastened to the door in one of a plurality of orientations with respect to a length of the door  30 . 
     In the embodiments shown in  FIGS. 15-16 , in the door latch assembly  120 , the door handle assembly  12 ,  14  is positionable vertically or parallel with respect to the length of the door  30 . That is, the longitudinal axis of the door handle  18  is parallel to the length of door  30 . However, in other embodiments, the door latch assembly  120  is mounted to orient and position the door handle assembly  12 ,  14  horizontally or perpendicular to the length of the door  30 . That is, the longitudinal axis of the door handle  18  is perpendicular to the length of door. The convertible cam drive allows flexibility for an installer of the door latch assembly  120  to orient or position the door handle assembly  12 ,  14  in different ways depending to the different circumstances and uses for the space using the door without the need for reconfiguring or boring a new hole in the door or installing a new door latch/bolt assembly. 
     While particular embodiments of the present door latch assembly with a convertible cam drive assembly has been described herein, it will be appreciated by those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects and as set forth in the following claims.