Abstract:
A door latch assembly configured to maintain an openable door in a closed position using a nose portion interacting with a striker plate, the latch assembly configured for opening the door through either moving the nose portion in response to a force in a plane substantially parallel to the door surface or by retracting the nose portion in response to a force substantially normal to the door surface. Such a dual function latching assembly provides a user with the option to either open the door by exerting a force on the latch assembly substantially normal to the door surface or by turning the latch assembly by exerting a rotating force against the matching assembly in a plane substantially parallel to the door surface.

Description:
FIELD OF THE INVENTION  
         [0001]    The invention relates generally to door latches. More specifically, the invention relates to a dual functioning latching apparatus that can maintain a door in a closed position through the interaction between a nose on the latch with a striker plate. The latch of the invention provides a user with options for disengaging the latch with the door frame permitting the user to operate the latch and door in a variety of ways. More specifically, the invention relates to a door latch for a all season door such as a storm or screen door used in conjunction with a main entry door installation. Such a latch can be installed on the surface of the door and can maintain the screen door in a closed position. Such all season doors, storm doors or screen doors are typically manufactured of thinner material than common entry doors and can comprise windows, insulating systems, gaskets, closure systems and other elements common to screen doors or storm doors in conjunction with the dual function latch of the invention.  
         BACKGROUND OF THE INVENTION  
         [0002]    Door latching apparatus has been a rapidly evolving technology for use in primary entry doors and secondary doors such as all season doors doors. The primary function of the door latch, or catch, is to maintain a door in a closed position when not in use by engaging a strike plate. The door latch however, should respond to the application of a force that moves the latch in such a way to disengage the strike to open the door easily. Once the force is released, the latch should maintain a secure and safe closure, even when the latch is not locked.  
           [0003]    Although door latches are known and generally function adequately for their intended purposes, some problems remain. One problem stems from the fact that door latches typically operate in a limited and specific manner. For example, some prior art latches operate in response to rotational forces applied to a handle. Others operate when a user pushes on a handle. Naturally, a user can become accustomed to a certain type of latch mechanism after repeated use. A broad array of closure systems have been used in configuring all season doors, storm doors or screen doors over the years. Simple closures have been used such as simple hook and eye closure systems, spring loaded compression systems and with simple hardware systems. Many screen doors are not latched at all and simply are maintained in a closed position with a spring loaded device that closes the door after its operation. Certain all season doors have been manufactured using either a latch that has an opening by pressing on a lever arm that disengages the latch nose from the strike. Still other doors have latch mechanisms that rotate to withdraw the latch nose from the strike thus permitting the operation of the door. Many users become familiar with one or the other mode of operating of the door and can often be confused when confronted with a door having an unfamiliar operating mode. Such problems can be minor annoyances, however, they can also provide safety concerns if rapid exiting of a location in the presence of some hazard is required.  
           [0004]    Further, encounters with non-familiar types of latches can be awkward, especially for elderly users. In situations where a user has a limited range of motion in their wrists or hands, it may become necessary to install a new latch that is better suited to the user&#39;s physical capabilities. In nursing home environments, it would not be feasible to replace each latch to accommodate a specific user. Accordingly, a latch system capable of accommodating a broader range of user preferences and physical capabilities is desirable.  
           [0005]    Miller U.S. Pat. No. 4,632,439 shows an adjustable latch system that is operated by either compressing a button in a door handle or by compressing a lever arm on the interior of the door to operate the latch nose. This system is representative of conventional systems typically using a force normal to the surface of the door operating either a lever arm or a compression button. Certain handle mechanisms in the prior art are configured such that the handle can move in both a rotation mode and in a normal mode with respect to the surface of the mounting surface. However, in all of these systems, such handles do not operate to open or close a door system when operated in both a rotational and a normal force mode. Examples of these types of handles are shown in Nehls U.S. Pat. No. 2,141,659; Dickason U.S. Pat. No. 2,278,534; Sanderlin et al. U.S. Pat. No. 2,605,648; and Mayer U.S. Pat. No. 1,684,499. Fujiya U.S. Pat. No.  4 , 480 , 451  shows a rotational latch having an interior lock operable using a handle that can move in more than one direction. Lastly Butterfield et al. U.S. Pat. No. 4,072,331 shows a “three-way” actuation means. This actuation means provides a variety of operating levers that can be used to operate the door. No one lever has the capability of permitting operation of the door with the operation of the handle in both a rotational and axial mode.  
         SUMMARY OF THE INVENTION  
         [0006]    The present invention is directed to a dual functioning latching apparatus that can maintain a door, preferably an all season door, in a closed position through the interaction of a latch nose with a striker plate. A user can apply a number of different forces to the latch handle to disengage the nose from the striker plate. In a rotational function of the latching apparatus, the user may apply a force to move the handle in a rotational fashion in a plane that is substantially parallel to the door surface to retract the latch nose. The latching apparatus is also configured such that the user at his option can apply an axial force to the handle that is substantially normal to the door surface so that one end of the handle moves toward the door to retract the latch nose. This dual function latching assembly provides a user with the option of either opening the door by exerting a force on the latch assembly substantially normal to the door surface or by exerting a rotational force against the matching assembly in a plane substantially parallel to the door surface.  
           [0007]    With regard to the rotational function of the latching apparatus, the rotational movement of the handle corresponds to the rotational movement of the latch nose about the access of the spindle. In the first position, the latch nose can contact a strike on the door frame. The rotation of the handle in either a clockwise or counterclockwise motion rotates the latch nose to a position that is away from the strike so a user can open the door. When the user is not applying a force to the handle, a turning axis spring can return the handle and latch nose to the first position.  
           [0008]    The retractional function of the latching apparatus functions independently of the rotational function. For example, the user can open the door by applying a force in a direction substantially normal to the door surface. In one embodiment, a first spring biases the handle in an extended position. The user can depress the handle on the latching apparatus. This action displaces the handle so that it no longer contacts the latch nose. The displacement of the handle enables the latch nose to pivot toward the spindle and away from the strike on the doorframe. This pivoting action is caused by a second spring that is fastened to the latch nose and the spindle assembly. The second spring biases the latch nose away from the strike on the doorframe. When the user is not applying a force to the handle, the first spring can return the handle to the extended position and overcome the force of the second spring to displace the latch nose to its extended position.  
           [0009]    In an alternative embodiment, the latch assembly includes a locking lever. The locking lever has a locked position and an unlocked position operatively connected to the spindle/handle assembly. The lock lever is configured for contacting a corresponding feature on the spindle to substantially prevent axial or rotational movement of the spindle. Similarly, the lock lever is also configured to contact the latch nose when the lock lever is in the locked position. The contact between the lock lever and the latch nose prevents the latch nose from moving toward the spindle and clearing the strike on the doorframe. For the purpose of this patent application, the term “strike” refers to a mechanical element installed on a door frame that can interact with the latch nose of the latch of the invention to maintain the door in a closed position. Strikes are commonly simple planar metal elements having a curved surface to facilitate the engagement and disengagement of the latch nose with the strike surface. For the purpose of this patent application the term “to detract the latch nose from the strike” typically implies that the latch nose is removed from an engaging position with respect to the strike either through a rotational force placed on the handle or through a axial force placed on the handle in a direction normal to the surface of the door. In this application, the term “axial force” relates to a force directed in parallel to the axis of rotation of the latch and acts unlatch in a direction towards the surface of the door. The term “all season door” refers to a door used in conjunction with a main entry door and can be a storm door a screen door or other door that provides added insulation, insect resistance, ease of use, air circulation or other feature in an opening having a entry door.  
           [0010]    The above summary of the present invention is not intended to describe each disclosed embodiment or every implementation of the present invention. The figures and the detailed description that follows exemplify these embodiments more particularly. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    The invention may be more completely understood in consideration of the following detailed description of various embodiments of the invention in connection with the accompanying drawings, wherein like numerals represent like parts throughout several views, in which:  
         [0012]    [0012]FIG. 1 is a partially exploded front view of a latch assembly of the present invention;  
         [0013]    [0013]FIG. 2 is an exploded front view of the head and spindle assembly of the present invention;  
         [0014]    [0014]FIG. 3 is an exploded front view of the base assembly of the present invention;  
         [0015]    [0015]FIG. 4 is a front view of the turning axis hub of the present invention;  
         [0016]    [0016]FIG. 5 is a side view of the turning axis hub of the present invention;  
         [0017]    [0017]FIG. 6 is a side view of the latch nose of the present invention;  
         [0018]    [0018]FIG. 7 is a front view of the latch nose of the present invention;  
         [0019]    [0019]FIG. 8 is a top view of the latch base of the present invention;  
         [0020]    [0020]FIG. 9 is a side view of the latch base of the present invention;  
         [0021]    [0021]FIG. 10 is a bottom view of the latch base of the present invention;  
         [0022]    [0022]FIG. 11 is a front view of the stator of the present invention;  
         [0023]    [0023]FIG. 12 is a top view of the spindle head of the present invention;  
         [0024]    [0024]FIG. 13 is a side view of the spindle head of the present invention;  
         [0025]    [0025]FIG. 14 is a front view of the spindle head of the present invention;  
         [0026]    [0026]FIG. 15 is a front view illustrating handle positions when a push force is applied to the latch assembly of the present invention;  
         [0027]    [0027]FIG. 16 is a side view illustrating the handle positions when a twist force is applied to the latch assembly of the present invention; 
     
    
       [0028]    While the invention is amenable to various modifications in alternative forms, the specifics thereof have been shown by way of example in the drawings and will be described in detail. The intention is not limited to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.  
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0029]    The door latch apparatus of the invention is configured to maintain a hinged door in a closed position by engaging a strike. The latching apparatus is capable of being mounted on the surface of the door comprising a latch nose and a handle. The latching apparatus is configured such that the user can disengage the latch in either of two different operating modes. First the latch can be disengaged from the strike by the application of rotational force in a plane parallel to the surface of the door. As the handle is moved in that rotational direction, the latch nose is moved away from the strike to disengage the strike permitting the user to operate the door to an open position. The latch also has the capability of being operated in a substantially different mode for a user that expects to be able to operate the door in a different mode. In this mode, the user compresses the handle by placing an axial force on the handle directed towards the surface of the door in a direction normal to the door. As the handle is compressed by this axial force, the handle is coupled with the latch nose through a lever and spring mechanism in a way such that the nose is retracted from the strike. As the operator continues to press the handle in this mode, the door can be operated to an open position. In this way, the latch mechanism of the invention provides a dual operating function in which the dual operating mode can permit a user to operate the door in both common operating modes. The nose, handle, strike, spindle, mounting materials, fasteners and other component parts can be made of conventional structural materials. Commercially available metals, thermoplastics, composites and coatings can be used in the manufacture of the functional unit of the claims.  
         [0030]    Referring to the drawings, wherein like reference numerals refer to like parts throughout the several views, FIG. 1 shows a partially exploded view of a latch assembly  100  of the present invention. The handle  101  is shown as a substantially elongated member with a first end that is not in contact with the spindle head  109  and a second end that contacts the spindle head  109  at pivot  106 . The portion of handle  101  contacting the pivot  106  may have an aperture. The aperture on the handle  101  can be a variety of dimensions. In a preferred embodiment, the diameter of the aperture is at least 0.1 inches (2.5 mm). This dimension permits a fastener to pass through the aperture and the pivot that is a sufficient size and strength to withstand the force of a user opening the door  122 .  
         [0031]    The handle  101 , latch nose  102 , spindle head  109 , and spindle  110  can be manufactured from a variety of materials including wood, metal, or thermoplastics. In any case, the material should be rigid enough to resist deformation and strong enough to withstand repeated forces from several directions under a variety of operating conditions. Handle  101  can comprise a variety of shapes based on the user&#39;s physical capabilities and aesthetic preferences. However, it is desirable to select a handle  101  that is long enough to move the latch nose  102  with relatively little effort. In most cases, handle  101  will be at least 2.5 inches (6.4 cm.) long, although in some embodiments, handle  101  can be up to 5 inches (12.7 cm.) long. Handle  101  can be straight or curved, and have a variety of cross sectional profiles based on the aesthetic preferences of the user. The cross-sectional area of handle  101  should preferably be rigid enough to withstand a variety of forces from several directions. In a preferred embodiment, the cross sectional area of handle  101  should be at least 0.04 in 2  (0.26 cm 2 ).  
         [0032]    Spindle  110  can be slidably inserted into spindle head  109  at housing  104 . Spindle  110  can comprise a variety of shapes and dimensional configurations depending upon the thickness of the door  122  and the housing  104 . Spindle  110  can have a substantially elongated shape, with a substantially square cross-sectional profile. Spindle  110  should be able to withstand the repeated torque applied by a user against torsion spring  132 . In a preferred embodiment, spindle  110  should be at least 2 inches (5 cm) long and have a cross sectional area of at least 0.097 in 2  (0.62 cm 2 ). Spindle  110  is preferably fabricated from a metallic or thermoplastic material.  
         [0033]    Spindle  110  can then be secured to housing  104  using a variety of methods. In a preferred embodiment, a pin  107  extends through slot  113  in the side of housing  104  and into spindle recess  112 . The interaction of pin  107  and slot  113  secures spindle  110  into housing  104  so that spindle  110  cannot exit housing  104 , or rotate relative to housing  104 . In an alternative embodiment, spindle  110  can be secured into housing  104  with a press fit between the spindle head  109  and housing  104 .  
         [0034]    Latch nose  102  may be rotatably fastened to spindle head  109  at rivet aperture  105   b  on spindle head  109  and rivet aperture  105   a  on latch nose  102 . Once rivet apertures  105   a  and  105   b  are properly aligned, a rivet or other suitable fastener may be inserted through rivet apertures  105   a  and  105   b  to rotatably secure the latch nose  102  to the spindle head  109 . Rivet aperture  105  may be located in multiple locations, with a variety of dimensions. It is desirable for rivet aperture  105   a  to be large enough to permit a fastener of suitable strength to pass therethrough. In a preferred embodiment, rivet aperture  105   a  can have a diameter of 0.125 inches (3.2 mm). The diameter of rivet aperture  105   b  should be large enough to correspond to the dimension of rivet aperture  105   a . In the preferred embodiment, rivet aperture  105   b  can have a diameter as small as 0.1 inches (2.5 mm).  
         [0035]    Latch nose  102  has surface  111  suitably arranged for contacting a corresponding strike  124  extending from a doorframe  123 . Surface  111  is preferably at least 45° relative to the surface of the door frame. Surface  111  and strike  124  should be manufactured from a material that is wear resistant. In a preferred embodiment, the surface  111  on the latch nose  102  is biased toward the spindle  110  by a spring  103 . The spring  103  may be secured to the latch nose  102  by a stud  108  located on the interior surface of latch nose  102 . Stud  108  can be molded from the same material as latch nose  102 . The size of stud  108  can vary depending on the size of spring  103 . For example, stud  108  may be 0.126 inches (3.2 mm) in diameter.  
         [0036]    Spring  103  may be secured to the spindle head  109  or housing  104  by attaching the spring  103  to the end of the pin  107  that is protruding from the housing  104 . When a user is not applying a force to the handle  101  the handle  101  is in an extended position (shown in FIG. 1). When a user is applying a force to the handle  101  that is normal to the surface of the door, the handle  101  is in a retracted position (shown with dashed lines in FIG. 15). A pivot spring may be located at pivot  106  that biases the handle  101  in an extended position. Handle  101  and latch nose  102  are rigidly in contact with one another when handle  101  is in an extended position. When a user applies a force normal to handle  101  such that handle  101  moves to a retracted position, latch nose  102  is permitted to rotate towards spindle  110  due to the force of spring  103 . When the force normal to handle  101  is no longer applied, the pivot spring should be strong enough to overcome the force of spring  103  acting on latch nose  102  and return the handle  101  to the extended position.  
         [0037]    In an alternative embodiment, the spring  103  may be secured to the latch nose  102  by inserting the first end of spring  103  over a stud  108  located on the interior surface of latch nose  102 . The interior diameter of the first end of spring  103  and stud  108  can be configured to create a tight fit. Similarly, the spring  103  may be secured to the spindle head  109  or housing  104  by inserting the second end of spring  103  over the end of the pin  107  that is protruding from the housing  104 .  
         [0038]    With reference to FIG. 2, the spindle  110  to spindle head  109  assembly is shown with dashed lines representing hidden features in the corresponding parts. For example, spindle recess  112  is shown on spindle  110 . Spindle  110  can be inserted into housing recess  114  on spindle head  109 . Housing recess  114  is configured so that when spindle  110  is inserted into the housing recess  114 , spindle recess  112  aligns with slot  113  on the spindle head  109 . Spring pin  107  can then be inserted into slot  113  and spindle recess  112 , which locks spindle  110  into housing recess  114 . It should be appreciated that the spindle  110  to spindle head  109  assemblies can comprise many different embodiments while falling within the scope of this invention. For example, the spindle recess  112  can consist of a drilled hole in the side of the spindle  110 , or it could consist of a milled groove running the entire circumference of spindle  110 . In an alternative embodiment, spindle  110  would not contain a spindle recess  112 . In that situation, spindle  110  could be press fit into housing recess  114  or secured in place with the friction of spring pin  107  inserted into slot  113 . In a preferred embodiment, spindle recess  112  is at least 0.15 inches (3.8 mm) deep and at least 0.12 inches (3.0 mm) in diameter. The center of spindle recess  112  can preferably be located at least 0.12 inches 3.0 mm from one end of the spindle  110 .  
         [0039]    An exploded side view of the base assembly  130  is shown in FIG. 3. Base assembly  130  includes a turning axis hub  136  extending outward from the base assembly  130  and a snap ring groove  134  recessed in the base assembly  130 . Base assembly  130  can be inserted into latch base  131  so that the turning axis hub  136  contacts the surface of latch base  131 . Then, torsion spring  132  can be inserted over base assembly  130  past snap ring groove  134 . Torsion spring  132  biases the rotation of the base assembly  130  in its inserted position relative to the latch base  131 . Moreover, torsion spring  132  biases handle  101  in the relaxed position, shown as the solid line handle  101  in FIG. 16.  
         [0040]    In a preferred embodiment, snap ring groove  134  is at least 0.05 inches (1.3 mm) in length. Turning axis hub  136  can preferably extend outward from the base assembly, to a diameter of at least 1.2 inches (30 mm). The base assembly  130  is most preferably at least 1 inch (25 mm) long when measured in its axial dimension. The portion of the base assembly  130 , on the side of the turning axis hub  136  toward the snap ring groove  134  can preferably measure at least 0.5 inches (13 mm) along the axial dimension. Similarly, the portion of the base assembly  130 , on the side of the turning axis hub  136  away from the snap ring groove  134  can preferably measure at least 0.3 inches (7.6 mm) along the axial dimension. The turning axis hub  136  can measure at least 0.05 inches (1.2 mm) along the axial dimension. The turning axis hub  136  should preferably be located at least 0.4 inches (10 mm) from the snap ring groove  134 . The base assembly can preferably be manufactured from a wear resistant metal or thermoplastic material.  
         [0041]    When a user exerts a rotational force against the handle  101  in a plane substantially parallel to the door surface, handle  101  moves to either the counterclockwise position  101 ′ or the clockwise position  101 ″. In a preferred embodiment, the counterclockwise position  101 ′ of the handle and the clock-wise position  101 ″ of the handle are less than 50° from the relaxed position of the handle  101 , shown as a solid line on FIG. 16. The position of the latch nose  102  moves relative to the handle  101 . When the handle  101  is in the counterclockwise position  101 ′ or clockwise position  101 ″, the latch nose is able to clear the strike  124  on the surface of the door frame  123 , and the user is able to open the door  122 . In a preferred embodiment, the latch nose  102  can clear the strike  124  when the latch nose is rotated less than 50° in response to a rotation of the handle  101 .  
         [0042]    Stator  133 , shown in FIG. 11, is inserted over base assembly  130  so that it secures torsion spring  132  in place. Stator  133  contains at least one extension  136  that protrudes outward from stator  135 . Extension  136  is useful for stabilizing stator  135  and torsion spring  132 . In one embodiment, the ends of torsion spring  132  can catch in notch  136 . Notch  136  provides a surface of resistance that is useful in biasing the torsion spring  132 . Then, snap ring  135  is secured to snap ring groove  134  and locks the torsion spring  132  and stator  133  in place.  
         [0043]    The latch base  131  is shown in FIGS. 8, 9, and  10 . Latch base  131  contains a cavity  182  with a supporting ring  183  surrounding the cavity  182 . The diameter of cavity  182  should be large enough so that base assembly  130  can pass there through, allowing turning axis hub  136  to contact supporting ring  183 . Preferably, cavity  182  can be at least 0.59 inches (15 mm) in diameter. The outer portion of supporting ring  183  can preferably be at least 1.2 inches (30 mm) in diameter.  
         [0044]    At least one mounting aperture  181  is located on the latch base  131  at a point adjacent to the supporting ring. Mounting aperture  181  should be large enough so that a fastener of suitable strength can pass there through. For example, mounting aperture  181  should preferably be at least 0.17 inches (4.3 mm) in diameter. The latch base  131  can be mounted to a door by inserting a fastener of suitable strength through the mounting aperture  181 . In a preferred embodiment, the latch base  131  is mounted to a door by inserting screws through mounting apertures  181  and  182  so that they are tightly affixed to the door. Alternatively, the latch base  131  can be mounted to the door with adhesive. The shape of the latch base can vary considerably based on aesthetic considerations. Latch base  131  can include notch  184  that can provide a surface that is useful in preventing rotation of latch base  131  relative to spindle  110 . In a preferred embodiment, notch  184  is at least 0.19 inches (4.8 mm) wide and 0.06 inches (1.5 mm) deep.  
         [0045]    Spindle  110  of the latch assembly  100  can be inserted into the cavity  182  and through a similarly aligned aperture in the door so that the supporting ring  183  contacts the housing  104  and an end of the spindle  110  is exposed on the side of the door opposite the handle. A second latch base and second handle can then be slid over the exposed end of spindle  110  so that the latch nose  102  can be moved from both sides of the door.  
         [0046]    [0046]FIG. 15 shows a first operable condition of the latch assembly  100  in which the latch nose  102  is moved by retracting the latch nose  102  in response to a force substantially normal to the door surface. The retracted position of the handle  101  and latch nose  102  are shown outlined in FIG. 15. The extended position of the handle  101  is substantially parallel to the surface of the door, and is shown with a solid outline on FIG. 15. In the extended position, the handle  101  makes contact with the latch nose  102  and biases the latch nose  102  toward the door. When the handle  101  is in the retracted position, the latch nose  102  is permitted to retract due to the force of the spring  103 . In a preferred embodiment, the retracted position of the handle is less than 50° from the extended position of the handle.  
         [0047]    A second operable condition of the latch assembly  100  is shown in FIG. 16. In the second operable condition, the latch nose  102  can be moved in response to a force in a plane substantially parallel to the door surface. The rotatable latch nose  102  and handle  101  position are shown outlined in FIG. 16. The user can rotate the handle  101  in either a clockwise or counterclockwise manner relative to the spindle  110 . The rotation of the latch nose  102  corresponds to the rotation of the handle  101 . When the user is not applying a force to the handle  101 , torsion spring  132  biases the handle  101  and the latch nose  102  so that the latch nose  102  is located toward the strike on a door frame (shown as a solid line latch nose  102  on FIG. 16). In a preferred embodiment, the counterclockwise position of the handle and the clockwise position of the handle are less then 50° degrees from the relaxed position of the handle  101 .  
         [0048]    The above specification provides a complete description of the manufacture and use of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.