Abstract:
A lock assembly comprises a housing and a latchbolt including an attachment member. A retractor element is disposed within the housing for linear reciprocating movement. The retractor element includes a first attachment location at a first position relative to the axis of reciprocation of the retractor element and a second attachment location at a second position relative to the axis of reciprocation of the retractor element. The second attachment location is spaced from the first attachment location by a distance along the axis of reciprocation of the retractor element. The attachment member of the latchbolt is selectively engageable with the retractor element at either the first attachment location or the second attachment location for movement together with the retractor element. An operator is operatively connected to the retractor element for facilitating selective reciprocation of the retractor element for moving the latchbolt between a latched position and an unlatched position.

Description:
BACKGROUND  
       [0001]    This invention relates generally to a lockset for use with a door, and more particularly to a lockset with an adjustable backset distance for use with doors having different backset distances. 
         [0002]    “Backset” is the distance between the edge of a door and the relatively transverse axis of rotation about which the latch operator moves for extending and retracting a latch bolt of a latch mechanism. Backset has been standardized by the industry. Standard backsets for commercial door openings are 2⅜ inches and 2¾ inches. 
         [0003]    Manufacturers of latch constructions have satisfied the demand for latchsets having standard backset measurements by producing and marketing two different models of latch constructions. However, maintaining an inventory of assemblies and components for locksets having two different backsets is inefficient. 
         [0004]    An alternative is providing adjustable latch mechanisms, which have become an accepted feature of tubular locksets. Unfortunately, adjustable latch mechanism solutions for this application have typically been of insufficient strength for a Grade 2 commercial lockset capable of meeting ANSI standards. 
         [0005]    For the foregoing reasons, there is a need for a new lockset which is easily adjusted for mounting on doors of differing backset distances. Such adjustment should be effected in a way that provides the assembly with inherent strength. Ideally, the new lockset construction would allow for relatively quick and easy selective adjustment between the two standard backset measurements. 
       SUMMARY  
       [0006]    According to the present invention, a lock assembly is provided comprising a housing and a latchbolt including an attachment member. A retractor element is disposed within the housing for linear reciprocating movement. The retractor element includes a first attachment location formed in the retractor element in a first position relative to the axis of reciprocation of the retractor element and a second attachment location formed in the retractor element in a second position relative to the axis of reciprocation of the retractor element. The second attachment location is spaced from the first attachment location by a distance along the axis of reciprocation of the retractor element. The attachment member of the latchbolt is selectively engageable with the retractor element at either the first attachment location or the second attachment location for movement together with the retractor element. An operator is operatively connected to the retractor element for facilitating selective reciprocation of the retractor element for moving the latchbolt between a latched position and an unlatched position. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0007]    For a more complete understanding of the present invention, reference should now be had to the embodiments shown in the accompanying drawings and described below. In the drawings: 
           [0008]      FIG. 1  is an exploded perspective view of a lockset assembly according to an embodiment of the present invention. 
           [0009]      FIG. 2  is a close-up perspective view of a lock body as shown in  FIG. 1 . 
           [0010]      FIG. 3  is an exploded perspective view of the lock body shown in  FIG. 2 . 
           [0011]      FIG. 4  is an elevated plan view of a latch retractor as shown in  FIG. 3  and a latch assembly according to an embodiment of the present invention. 
           [0012]      FIG. 5  is a perspective view of a latchbolt assembly according to an embodiment of the present invention. 
           [0013]      FIG. 6  is an exploded perspective view of the latchbolt assembly shown in  FIG. 5 . 
           [0014]      FIG. 7  is an exploded perspective view of a latch retractor as shown in  FIG. 4  and a latch assembly according to an embodiment of the present invention. 
           [0015]      FIG. 8  is an elevated plan view of the latch retractor and the latch assembly as shown in  FIG. 7 . 
       
    
    
     DESCRIPTION  
       [0016]    The adjustable backset arrangement according to the present invention is for use in a conventional lockset such as, for example, the locksets described by U.S. Pat. No. 4,920,773 and U.S. Pat. No. 6,131,970, the contents of both of which are incorporated herein by reference. Moreover, it is understood that the overall construction of the lockset assembly is not critical to the present invention and, for purposes of illustration, may be as described herein or in the above-referenced U.S. patents. Accordingly, although the present invention will be described in detail herein with reference to an exemplary embodiment of an adjustable backset function, detailed explanations of the functioning of all of the lockset components are deemed unnecessary for understanding of the present invention by one of ordinary skill in the art. 
         [0017]    Certain terminology is used herein for convenience only and is not to be taken as a limitation on the invention. For example, words such as “upper,” “lower,” “left,” “right,” “horizontal,” “vertical,” “upward,” and “downward” merely describe the configuration shown in the FIGs. Indeed, the components may be oriented in any direction and the terminology, therefore, should be understood as encompassing such variations unless specified otherwise. 
         [0018]    Referring now to the drawings, wherein like reference numerals designate corresponding or similar elements throughout the several views, a cylindrical lockset assembly for use with a conventional opening in a door (not shown) is shown in  FIG. 1  and generally designated at  20 . The cylindrical lockset assembly  20  comprises an inside subassembly  22  and an outside subassembly  24 . The inside subassembly  22  includes a rose plate  26 , a rose  28 , and a lever  30 . The outside subassembly  24  includes a rose plate  32 , a rose  34 , and a lever  36 . A chassis  40  is located between the inside subassembly  22  and the outside subassembly  24 . A latch assembly  42  is positioned for operable attachment to the chassis  40  and includes a latchbolt  44  which extends outwardly from a face plate  46  in an extended, or latched, position. 
         [0019]    The rose plates  26 ,  32  are each formed in a generally circular configuration and having an axial central opening  48 ,  50 . Two pair of holes  52 ,  54  are formed on the periphery of each rose plate  26 ,  32 . One pair of holes  52  are adapted to pass bolts  56  which extend through the door. The other pair of holes is provided for receiving screws (not shown) for fastening the rose plates  26 ,  32  to their respective roses  28 ,  34 . A pair of inwardly extending tabs  58  are formed in the outside rose plate  32  by punching holes through the outside rose plate  32 . 
         [0020]    The roses  28 ,  34  are each formed in a generally circular configuration and include a side wall  60 ,  62  defining an inner dish-like cavity in the inside surface of the rose  28 ,  34 . An axial opening  64 ,  66  is formed through each rose  28 ,  34  and extends through rotating spindles  68 ,  70  which extend outwardly from the roses. A return spring  72  is positioned in the cavity of each rose  28 ,  34 . As described above, the rose plates  26 ,  32  are fastened to the roses  28 ,  34  using screws for retaining the springs  72  within the cavity. 
         [0021]    The levers  30 ,  36  each include a handle  74 ,  76  which is formed integrally with a hub  78 ,  80 . Each hub  78 ,  80  has an axial opening  81  which, in a locking lockset, may communicate with an axial opening formed through the handle for receiving a turn button or lock cylinder for locking of the latchbolt in the extended, or latched, position. Further, although levers are shown, it is understood that other latch operating means are suitable, such as a doorknob or the like. 
         [0022]    Referring now to  FIGS. 2 and 3 , the chassis  40  comprises a housing  90  for accommodating a U-shaped retractor  95  and opposed rollback sleeves  92 ,  94 . The housing  90  includes a case  96  and opposed end caps  98 . The case  96  is formed in a U-shaped configuration having a base  100  and a pair of legs  102  formed integrally with the base  100 . The legs  102  have inwardly bent ends  101 . Two pairs of opposed tabs  103  extend transversely from each leg  102 . 
         [0023]    The end caps  98  are generally circular and have a central axial opening  104 . Four spaced notches  106  are formed in the end caps  98  for receiving the tabs  103  on the case  96 . 
         [0024]    The retractor  95  is formed with a base  108  having a cam surface  110  on each side and a pair of spaced, parallel arms  112 . The ends of the arms  112  are formed with a pair of opposed outer lips  114  and a pair of opposed inner lips  116 . The lips  114 ,  116  are preferably spaced apart by about ⅜ inches, which is the difference between the standard door backset distances of 2⅜ inches and 2¾ inches. As will be described below, when the outer set of lips have been engaged, the lockset will be maintained at the backset distance of 2¾ inches. When the inner set of lips is used, the backset distance will have been adjusted by the full difference in standard door backset distance to 2⅜ inches. However, it is understood that the present invention is not so limited and that more or differently spaced lips could be utilized to accommodate other backset distances. 
         [0025]    The sleeves  92 ,  94  are each formed with a pair of cramming elements  93  at one end. The camming element  93  are formed by rolling back portions of the sleeves  92 ,  94  which extend from the end of the cylindrical portions. The sleeves are rotatably received in the openings  104  in the end caps  98 . 
         [0026]    In assembling the components of the chassis  40 , the rollback sleeves  92 ,  94  are positioned so that the cramming elements  93  are located adjacent the cam surfaces  110  on each side of the retractor  95 . The sleeves  92 ,  94  and retractor  95  are then located in the case  96  between the legs  102  and close to the inner surface of the base  100 . The ends of two springs  120  are positioned over a pair of spaced posts  122  extending outwardly from the base  100  of the case  96 . The other ends of the springs  120  engage a retainer  124 , which fits in a corresponding opening in the rear of the retractor  95  thereby placing the springs  120  in a contained position for subsequent compression. To complete the housing  90 , the end caps  98  are then slipped over the sleeves  92 ,  94  with the tabs  103  on the case  96  being inserted in the notches  106  in the end caps  98  and twisted. The retractor  95 , the inward ends of the sleeves  92 ,  94 , the springs  120  and the retainer  124  are contained within the housing  90 . The sleeves  92 ,  94  extend outwardly from the openings  104  in the end caps  98 . In this arrangement, the lips  114 ,  116  of the retractor  95  are exposed through the housing  90 . 
         [0027]    Referring now to  FIG. 4 , the latch assembly  42  includes a latch case  130  which is secured at one end to the face plate  46 . The latchbolt  44  is contained partially within the latch case  130  and extends outwardly of the latch case to the extended position and through an opening in the face plate  46 . The latchbolt  44  is retractable into the latch case  130  to a retracted, or unlatched, position. Thus, the latchbolt  44  is movable between the extended or latched position and the retracted or unlatched position. The latch bolt  44  includes a bolt tail  132  which extends from the rear of the latch case  130 . The end of the bolt tail  132  is T-shaped and has arms  134 ,  135 . The bolt tail  132  is designed to be positioned through opening of the retractor housing  90  with the arms  134 ,  135  located behind the lips  114 ,  116  of the retractor  95 . As shown in  FIG. 4 , the bolt tail  132  is adapted to be of a length to allow the arms  134 ,  135  to engage behind the inner lips  116  of the retractor  95 . In this arrangement, upon rotation of one of the sleeves  92 ,  94 , the cramming elements  93  will engage the cam surfaces  110  on the retractor  95  to urge the retractor  95  inwardly against the biasing of the springs  120 . As the retractor  95  is moved inwardly, the bolt tail  132  is pulled with the retractor  95  to withdraw the latchbolt  44  to the retracted position. 
         [0028]    Another embodiment of the latch bolt  44  according to the present invention is shown in  FIGS. 5 and 6 . This embodiment includes a deadlocking function. The latchbolt  44  comprises a bolt tail  132 , a deadlatch  136 , a deadlatch tail  137 , and a deadlocking release lever  138 . The bolt tail  132  is secured within a slot  140  formed in the rear of the head  142  of the latchbolt  44 . The deadlatch  136  is connected to the deadlatch tail  137 . The deadlatch  136  and deadlatch tail  137  and deadlocking release lever  138  reciprocate relative to each other and with respect to the bolt tail  132 . In use, this embodiment of the lath bolt  44  functions in a conventional manner with the deadlatch  136  being held in the retracted position when the door is closed and preventing latchbolt  44  from being pushed to the retracted position. 
         [0029]    In assembling the components of the cylindrical lockset assembly  20  of  FIG. 1 , the latch assembly  42  is first positioned within an opening in the edge of a door. The edge opening communicates with a larger transverse opening in the door. The chassis  40  is inserted through the larger opening. As the chassis  40  is moved into the larger opening, the chassis  40  engages and becomes attached to ears  144  extending from the rear of the latch case  130 , which fit behind the bent ends  101  of the legs  102  of the case  96 . In this position, the housing  90  is located within the door opening and the sleeves  92 ,  94  extend from opposite sides of the door. The bolt tail  132  is then attached to the inner lips  116  of the retractor  95  in the manner previously described and the face plate  46  is secured to the edge of door. 
         [0030]    According to the present invention, mounting of the latch assembly  42  to the chassis  40  may also involve the step of selectively modifying the latch case according to a larger backset of the door. Referring to  FIGS. 7 and 8 , this is accomplished by first slipping an auxiliary latch case  160 , or sleeve, over the original latch case  130 . The auxiliary latch case  160  is longer, but the bolt tail  132  is dimensioned so that the bolt tail extends from the rear of the auxiliary latch case  160 . It is understood that, according to the present invention, when using a latch assembly with a deadlocking function as described above, the deadlatch tail  137  and the deadlocking release lever  138  are also longer. The modified latch assembly may then be connected to the chassis  40  by engaging the ears  162  extending from the rear of the auxiliary latch case  160  behind the bent ends  101  of the legs  102  of the case  96 . The bolt tail  132  is then attached to the outer lips  114  of the retractor  95  in the manner previously described, and the face plate  46  is secured to the edge of the door. 
         [0031]    Next, the outside rose plate  32  is slid over the outside end cap  98 . As seen in  FIG. 2 , both end caps  98  have longitudinally-spaced lateral grooves  146  for receiving the rose plates  26 ,  32 . The rose plates  26 ,  32  are adapted to be engaged in either one of the two grooves  146  in the end caps  98  to accommodate different door thicknesses. The outside rose plate  32  has an oblong central opening  50 . The oblong opening  50  has a larger portion of sufficient dimension to allow the rose plate  32  to fit over the outside end cap  98  of the latch housing  90 . The oblong central opening  50  also has two opposed flats which define a narrower portion of the oblong central opening  50 . This shape of the opening  50  allows the outside rose plate  32  to be assembled eccentrically with respect to the housing  90  with the narrower portion of the oblong central opening  50  centered over the housing  90  and the flats seated in one set of grooves  146 . The outside rose plate  32  is thus aligned with the appropriate groove  146  in the end cap  98 , the outermost groove for a thick door or the innermost groove for a thin door, and moved laterally to a concentric position with respect to the housing  90 . Once the outside rose plate  32  is so engaged, the housing  90  is fixed rotationally and axially with respect to the outside rose plate  32 . The outside end cap  98  of the housing  90  also includes opposed longitudinal ribs  148  and the oblong central opening  50  in the outside rose plate  32  includes opposed notches. The notches are adapted to receive the corresponding longitudinal rib  148  when the outside rose plate  32  is engaged in either of the sets of grooves  146  as described above. This configuration further strengthens the assembly against rotation of the outside rose plate  32  with respect to the housing  90 . 
         [0032]    The outside rose  34  fits against the outside rose plate  32 . Openings in the outside rose plate  32  are aligned with threaded holes in the outside rose  34  for use with screws for securing the outside rose plate  32  to the outside rose  34 . 
         [0033]    The inside rose plate  26  is secured to the inside rose  28  and then moved over the inside end cap  98  and against the door surface. Bolt holes in the inside rose  28  are aligned with threaded bolt holes of the outside rose  34 . The threaded ends of the bolts  56  are then passed through the unthreaded holes in the inside rose  28  and into the threaded holes of the outside rose  34 . The bolts  56  are then tightened to draw the rose plates  26 ,  32  and roses  28 ,  34  to a secure assembled position on opposite sides of the door whereby the heads of the bolts  52  come to rest in countersunk holes in the outer face of the inside rose  28 . It is noted that in attaching the roses  28 ,  34  in the manner described above, protrusions on the sleeves  92 ,  94  are aligned with corresponding slots (not shown) in the spindles  68 ,  70  such that the sleeves  92 ,  94  and spindles  68 ,  70  rotate together within the lockset assembly  20 . 
         [0034]    To complete the assembly, an inside rose scalp  152  is slipped over the inside spindle  68  and the inside rose  28  and the inside lever  30  is secured onto the inside spindle  68 . Similarly, an outside rose scalp  154  is placed over the outside spindle  70  and the outside rose  34  and the outside lever  36  is secured onto the spindle  70 . In attaching the levers  30 ,  36 , the axial hub openings  79 ,  81  are positioned over the spindles  68 ,  70 , which include a pair of diametrically opposed longitudinal slots  156 . The slots  156  receive corresponding ribs formed in the levers  30 ,  36  to facilitate rotation of the spindles  68 ,  70  upon actuation of the levers  30 ,  36 . The hub openings  79 ,  81  are also formed with transverse depressions and are positioned for alignment with transverse slots formed in spindles  68 ,  70 . Spring-biased detents or catch plates (not shown) extend through the slots and into the depressions to retain the levers  30 ,  36  on the sleeves  92 ,  94 . 
         [0035]    Although the present invention has been shown and described in considerable detail with respect to only a few exemplary embodiments thereof, it should be understood by those skilled in the art that we do not intend to limit the invention to the embodiments since various modifications, omissions and additions may be made to the disclosed embodiments without materially departing from the novel teachings and advantages of the invention, particularly in light of the foregoing teachings. For example, although a cylindrical lock is shown, the novel retractor shown and described herein may be used with any type of latchset or lockset for accommodating two or more backset distances. Accordingly, we intend to cover all such modifications, omission, additions and equivalents as may be included within the spirit and scope of the invention as defined by the following claims. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Thus, although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface, in the environment of fastening wooden parts, a nail and a screw may be equivalent structures.