Patent Abstract:
A lockable sash assembly for installation on a window assembly is provided. The window assembly includes sashes movable relative to each other to open and close the window assembly when the lockable sash assembly is in a window-openable condition and substantially unmovable relative to each other when the lockable sash assembly is in a window-unopenable condition. The sash assembly includes a sashlock having a rotating device (such as a lever-controlled cam) which is movable between a window-openable position and a window-unopenable position. The sash assembly also includes a locking device which is convertible between a locked state whereat the rotating device is blocked from moving from the window-unopenable position to the window-openable position and an unlocked state whereat the rotating device is unblocked from moving from the window-unopenable position to the window-openable position.

Full Description:
FIELD OF THE INVENTION  
         [0001]    The invention relates generally to a sashlock assembly and more particularly to a sashlock assembly which includes a key lock to retain the sashlock in a latched position.  
         BACKGROUND OF THE INVENTION  
         [0002]    In a double hung window assembly a pair of sashes are mounted in a frame and movable vertically to open or close the window. When the window is closed, usually there is only a small gap, if any, between the top rail of the lower sash and the bottom rail of the top sash.  
           [0003]    A sashlock assembly is commonly used with double hung windows. When the window assembly is closed, the sashlock assembly is shifted from an unlatched position to a latched position to keep the window closed. A sashlock assembly usually includes a sashlock mounted on the top rail of the bottom sash and a keeper mounted on the bottom rail of the top sash. The rails may provide horizontal mounting surfaces on the respective sashes that are flush when the window is closed. In some applications, especially with extruded vinyl or aluminum sash rails, the keeper or the sashlock or both may be secured to vertical surfaces or to specially formed slots or recesses in the rails.  
           [0004]    A sashlock typically comprises a housing and a rotating assembly which includes a rotating member and a lever. The rotating member, usually a cam, is mounted to the housing for rotation between an unlatched position and a latched position. The lever is operably connected to the cam and extends outside of the housing so that the cam may be conveniently moved between the latched and unlatched positions. When the sashlock is in the unlatched position, the cam is retracted and thus disengaged from the keeper, and the sashes may be moved relative to each other. When the sashlock is in the latched position, a portion of the cam engages the keeper to prevent movement of the sashes.  
           [0005]    Unfortunately, sashlocks are sometimes vulnerable to unauthorized tampering from the outside of the building which shifts the sashlock from the latched to the unlatched position. For example, with some prior art sashlocks, it is possible from the outside of the building to insert a blade into the gap between the two sashes, engage the cam with the blade, and force the cam back to its unlatched position. The window may then be opened from the outside of the building to provide access into the building.  
         SUMMARY OF THE INVENTION  
         [0006]    The present invention provides a lockable sashlock assembly which eliminates, or at least reduces the chances of, successful unlatching of the sashlock from outside the building. Particularly, the invention provides a lockable sashlock assembly which may be locked in the latched condition. In this specification the terms “latched” and “unlatched” are used with reference to the engagement between the cam of the sashlock and the keeper. The terms “locked” and “unlocked” are used with reference to a safety lock device used to hold the cam in its latched position.  
           [0007]    The lockable sashlock assembly according to the present invention includes a sashlock having a rotating device and a safety lock mechanism. The rotating device (usually a cam) is movable between an unlatched position in which the window assembly is openable and a latched position in which the window assembly is unopenable. The safety lock mechanism has a locked state in which the rotating device is retained in its latched position, thus securing the window assembly against forced entry. The safety lock mechanism may be switched to an unlocked state in which the rotating device is free to turn between its latched and unlatched states. The locking mechanism includes a key slot and is convertible from the locked state to the unlocked state upon insertion of an appropriately shaped key in the key slot.  
           [0008]    Accordingly, the sashlock assembly may be locked so that even if a blade is inserted into the gap between the two sashes to engage the rotating member, it will still not be possible to force the cam back to its unlatched position. Additionally, since in the preferred embodiment a key is necessary to turn the safety lock mechanism to the unlocked state, the lockable sashlock assembly according to the present invention can also be used to control window openings inside the building. For example, if a facility&#39;s regulations forbid the opening of windows in certain designated areas, the relevant sashlocks can be placed in the locked state and only authorized personnel provided with the key.  
           [0009]    The invention comprises these and other features hereinafter fully described in the specification and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principles of the invention may be suitably employed.  
       
    
    
     DRAWINGS  
       [0010]    [0010]FIG. 1 is a perspective illustration, partially cut away, of a sashlock assembly according to the present invention, the sashlock assembly being shown installed on a double hung window assembly.  
         [0011]    [0011]FIG. 2 is a top view of the sashlock assembly of FIG. 1 and which includes a sashlock and a keeper.  
         [0012]    [0012]FIGS. 3A and 3B are bottom views of the sashlock assembly of FIG. 2, the sashlock being shown with its safety lock mechanism unlocked and its cam unlatched from the keeper (FIG. 3A) and with its safety lock mechanism locked and its cam latched with the keeper (FIG. 3B).  
         [0013]    [0013]FIGS. 4A, 4B,  4 C,  4 D and  4 E are top, bottom, inner side, outer side and end views, respectively, of the housing of the sashlock.  
         [0014]    [0014]FIG. 4F is a sectional view taken along line  4 F- 4 F in FIG. 4C.  
         [0015]    [0015]FIG. 4G is a sectional view taken along line  4 G- 4 G in FIG. 4C.  
         [0016]    [0016]FIGS. 5A, 5B,  5 C, and  5 D are top, bottom, inner side and end views, respectively, of the cam of the sashlock.  
         [0017]    [0017]FIGS. 6A, 6B, and  6 C are top, bottom, and side views, respectively, of the lever of the sashlock.  
         [0018]    [0018]FIG. 7 is a perspective illustration of the safety locking mechanism of the sashlock.  
         [0019]    [0019]FIGS. 8A, 8B,  8 C, and  8 D are top, bottom, inner side and outer side views, respectively, of the keeper of the lockable sash assembly.  
         [0020]    [0020]FIG. 8E is a sectional view as seen along line  8 E- 8 E in FIG. 8A.  
     
    
     DETAILED DESCRIPTION  
       [0021]    [0021]FIG. 1 shows a lockable sashlock assembly  20  according to the present invention mounted on a window assembly  22 . As is explained in more detail below, the lockable sashlock assembly  20  eliminates, or at least reduces the chances of, successful unauthorized opening of the window assembly  22  from outside or inside a building.  
         [0022]    The window assembly  22  includes a lower sash  24  and an upper sash  26  which hold glass panes  28  and  30 , respectively. The lower sash  24  is positioned parallel to the upper sash  26  and adjacent thereto, with only a small gap  32  separating the sashes. The sashes  24  and  26  are mounted for relative linear movement to open and close the window assembly  22 . When the window assembly  22  is closed as shown in FIG. 1, a horizontal surface  34  on a rail of the lower sash  24  is aligned or flush with a horizontal surface  36  on a rail of the upper sash  26 .  
         [0023]    The lockable sashlock assembly  20  according to the present invention includes a sashlock  40  and a keeper  42 . The sashlock  40  and the keeper  42  are permanently mounted on the surfaces  34  and  36  with suitable fasteners such as screws  43 . Specifically, the sashlock  40  is mounted on the lower sash  24  and the keeper  42  is mounted on the upper sash  26 . The sashlock  40  and the keeper  42  are substantially flush with the corresponding faces of the sash rails which define the gap  32  (see FIG. 2). When the window assembly  22  is closed, the lockable sashlock assembly  20  can be moved between latched and unlatched positions to lock the window shut or allow it to be opened, respectively.  
         [0024]    The sashlock  40  comprises a housing  44  (FIGS. 3A and 3B), a rotating device including a cam  46  and a lever  48 , and a locking device  50 . As is explained in more detail below, the cam  46  is a rotating member. It is mounted for rotational movement within the housing  44  between a position corresponding to the openable condition of the sashlock  40  (i.e., unlatched) and a position corresponding to the unopenable condition of the sashlock (i.e., latched). The lever  48  is operably connected to the cam  46  to move it between these positions. The locking device  50  may be locked while the sash assembly  20  is in the closed condition. (See FIGS. 3A and 3B.) In this manner, unintended and/or unwanted tampering with the sashlock  40  which forces it back to the unlatched condition to open the window assembly  22  is impossible or at least more difficult.  
         [0025]    FIGS.  4 A- 4 G show the housing  44  of the sashlock  40  in various views. The housing  44  includes an inner wall  52 , an outer wall  54 , and a top wall  56 . The inner wall  52  is approximately perpendicular to the horizontal surface  34  of the lower sash  24 . The outer wall  54  is roughly C-shaped in plan view and connects opposite ends of the inner wall  52  and the top wall  56  which has a complimentary shape.  
         [0026]    The housing walls  52 ,  54  and  56  define an internal chamber  58  (FIGS. 4B, C, F, and G) to receive the cam  46 . See FIGS. 3A and 3B. The inner wall  52  includes an opening  60  from the chamber  58 . (See FIG. 4C.) The top wall  56  includes openings  63  (FIGS. 4A and 4B) which receive fasteners  43  to mount the housing  44  (and thus the sashlock  40 ) to the top surface  34  of the lower sash  24  as shown in FIGS. 1 and 2.  
         [0027]    The sashlock&#39;s housing  44  (FIGS. 4B and C) also includes an internal wall  64  within the chamber  58  which defines a central cylindrical passage  68  through an opening in the top wall  56 . (See FIG. 4F.) The cylindrical wall of the passage  68  is generally vertically oriented and forms a vertical bearing surface to support the shaft  102  (FIG. 6C) of the lever  48  which is operably coupled to the cam  46 . Radial lever-set grooves  69  (see FIG. 4A) are formed in the top of the wall  64 . As described below they cooperate with corresponding ridges  108  (FIG. 6B) on the handle to provide a positive feel when the lever is in either of its two extreme positions. The bottom of the wall  64  of the housing  44  also includes radial position-set tabs  70  and  71  (see FIGS. 4B and 4C). The tabs  70  and  71  cooperate with a stop pin  82  (FIG. 5A) on the cam  46  to limit rotation of the cam to about 180°.  
         [0028]    The cam  46  shown in FIGS.  5 A-D is shaped to fit within the chamber  58  of the housing  44  (see FIG. 3A) and to engage the keeper (see FIG. 3B). The cam  46  (FIGS.  5 A-D) includes a central hub  86  which is generally cylindrical. The hub  86  includes a central opening  95  in the shape of a four-pointed star or a four-toothed gear. (See FIG. 5B.) In the assembled sashlock  40 , the opening  95  cooperates with a similarly shaped end portion  114  (see FIG. 6C) of the lever  48 . During assembly of the sashlock  40 , the portion  114  of the lever  48  is deformed or swagged into the opening  95  of the cam  46  so that the cam  46  and the lever  48  will rotate together about the vertical axis defined by the lever shaft passage.  
         [0029]    [0029]FIGS. 6A through 6D show the handle  48  in orthographic views. The handle  48  includes a lever  100  connected to a shaft  102 . The shaft  102  is generally perpendicular to the lever. The shaft  102  is proportioned to fit and rotate within the cylindrical passage  68  through the top of the housing  44 .  
         [0030]    The lever  100  meets the shaft  102  at a hub  104 . The hub  104  includes an annular bottom surface  106  which is the same size as the top of the wall  64  in the housing  44 . The annular bottom surface  106  is interrupted by a pair of raised detents  108  which fit in the lever set grooves  69  in the wall  64  of the housing.  
         [0031]    The detents  108  and grooves  69  provide a positive feel when the lever is in the fully open position (FIG. 3A) or the fully closed position (FIG. 3B). This is accomplished by means of a conventional wave washer (sometimes called a “Belleville” washer) (not shown) which surrounds the shaft  102  between the cam  46  and the inside of the housing  48 . The washer provides a spring bias that forces pushes the detents  108  into the similarly shaped grooves  69  in the housing. Accordingly, once the handle and hub are connected, rotation of the handle  48  causes the cam  46  to rotate similarly and to snap into.  
         [0032]    A web  76  (FIGS.  5 A-D) extends radially outward from the hub  86  of the cam  46 . The web  76  serves to connect the various other components of the cam  46  to the hub  86 . Specifically, a peripheral rim  78  extends around approximately 180° of the hub  86 . The rim  78  is arcuate in plan view, and it has a generally rectangular cross section. The rim  78  extends both above and below the plane of the web  76 . For approximately 90° around web  86  (from about 10:30 o&#39;clock to about 1:30 o&#39;clock in FIG. 5A), the rim  78  has a full rectangular cross section. For the succeeding 90° (proceeding clockwise as viewed in FIG. 5A) the rim  78  tapers downwardly along inclined face  79  to a rounded tip  96 . The bottom surface of the rim  78  tapers upward to the rounded tip  96 , but does so over an extent of only about  100 . The inclined face  79  of the rim  78  serves to engage the keeper  42  and to draw the two sashes into proper alignment as the cam  46  is rotated.  
         [0033]    The cam  46  also includes a stop pin  82 . The stop pin  82  extends upward (as viewed in FIGS. 5C and 5D) from the web  76 . The stop pin  82  cooperates with the tabs  70  and  71  in the housing  44  to limit the rotation of the cam to approximately 180°. In each of the limit positions, one side of stop pin  82  engages one or the other of the tabs  70  and  71 .  
         [0034]    The web  76  is bounded in part by a straight edge  88  which extends approximately tangent to the hub  86  from a 6 o&#39;clock position as viewed in FIG. 5A. The edge  88  is positioned so that when the sashlock  40  is in the open position (FIG. 3A) the edge  88  is even with the inner wall  52  of the housing, as is the tip  96  of the rim  78 .  
         [0035]    The final component of the cam  46  is the lock tab  84 . The lock tab  84  extends radially outwardly from the web  76 , its edge forming a continuation of the straight edge  88 . (See FIGS. 5A and 5B.) The lock tab  82  is thinner than the rim  78  and forms a co-planar surface with the lower edges of the rim  78 . (See FIG. 5C.) The lock tab  84  cooperates with the safety lock  50  to hold the cam  46  in its latched position (see FIG. 3B) as is discussed more fully below.  
         [0036]    The housing  44  (FIGS. 4A, 4B, and  4 G) is configured to support the locking device  50 . To this end an internal wall  66  extends down from the top wall  56  of the housing to form an insert well  72  which is sized and shaped to receive the safety lock mechanism  50 . The insert well  72  is in the form of a cylindrical bore  73 , and two slots  74  extend diametrically from the bore  73  along its entire length.  
         [0037]    [0037]FIG. 7 shows the lock mechanism  50 . The lock mechanism  50  is of a conventional design and includes an outer casing  118  and a tumbler assembly  120 . The outer casing  118  is cylindrical and includes a pair of side wings  124  extending diametrically therefrom. In the assembled sashlock  40 , the casing  118  is positioned within the housing&#39;s insert well  72  (defined by the internal wall  66 ). Specifically, the casing  118  is positioned within the bore  73  and the side wings  124  are positioned within the diametric slots  74 . The bore  73  fits closely around the casing  118  and the wings  124  fit closely in the slots  74 . Accordingly, the lock mechanism  50  cannot rotate with respect to the housing  44 .  
         [0038]    The tumbler assembly  120  includes a disk  126  at its upper end. This disk is proportioned to fit at least partially within an annular recess  128  formed in the top of the insert well  72 . See FIGS. 4A and 4G. When the lock assembly  50  is inserted in the insert well  72 , contact between the disk  126  and the recess  128  positions the lock, limiting its movement in one axial direction (to the right as viewed in FIG. 4G).  
         [0039]    The lock casing  118  is also provided with an annular groove  130  which surrounds the lower end of the casing. The groove  130  is proportioned to receive a conventional snap ring (not shown). The groove  130  is positioned so that when the lock mechanism  50  is in the insert well  72  and the disk  126  is seated in the recess  128 , the groove  130  is just clear of the lowermost end of the insert well. The snap ring  131  when installed in the groove  130 , prevents movement of the lock mechanism in the opposite axial direction (to the left as viewed in FIG. 4G). Together the disk  126  and snap ring  131  prevent removal of the lock mechanism  50 .  
         [0040]    The lock mechanism  50  includes a block pin  132  which is rotatable with the tumbler assembly  120 . The block pin  132  extends downward from the tumbler assembly  120  and is eccentric. Therefore, when the tumbler assembly is rotated 180° within its casing  118 , the block pin  132  moves between the positions shown in FIGS. 3A and 3B. (One of these is shown in phantom in FIG. 7.)  
         [0041]    As with most conventional lock mechanisms, the tumbler assembly  120  includes a slot  144  which receives a key  146 . The key allows the tumbler assembly  120  to rotate, but when it is removed the tumbler assembly is locked against rotation. However, the particular type of lock mechanism is not significant. A device which uses a hexagonal (Allen) key could be used, or virtually any other that will fit in the space requirements.  
         [0042]    In the assembled sashlock  40 , the lock mechanism device  50  is positioned radially outward from all portions of the cam  46  except for its lock tab  84 . Additionally, all portions of the lock mechanism  50 , except for its block pin  132 , are positioned above the cam&#39;s lock tab  84 . When the locking device  50  is in the unlocked state, the block pin  132  is positioned outside the path  62  of the cam  46  in the housing  44 . (See FIG. 3A). When the locking device  50  is in the locked state, the block pin  132  is positioned within the cam path  62 . (See FIG. 3B).  
         [0043]    [0043]FIGS. 8A through 8E show the keeper  42  in various views. The keeper  42  is shaped to be fastened to a rail of a sash and to capture the cam  46 . To this end the keeper has a top wall  144  which forms an arch or bridge. Holes  150  are formed in each end of the bridge to receive fasteners such as the screws  43  shown in FIG. 2. The screws  43  hold the keeper to the sash rail  36 . Between the two openings  150 , the top wall  144  rises upward to form an opening  146 . The opening  146  is proportioned to receive the cam  46 . A dog or tooth  148  projects downward from the top of the arch of the wall  144 . The dog  148  is captured by the inclined portion  79  of the cam  46  as the cam moves from the open to the closed position, eventually being positioned behind the rim  78  when the sashlock is in the locked position shown in FIG. 3B.  
         [0044]    The operation of the lockable sash assembly  20  may be explained in detail by referring back to FIGS. 3A and 3B. When the sash assembly  20  is in its unlatched condition, the cam  46  is positioned entirely within the internal chamber  58  of the sashlock housing  44  and so is clear of the space  32  between the lower and upper sashes  24  and  26 , respectively, as shown in FIG. 2. The cam hub&#39;s flat edge  88 , the rim&#39;s rounded point  96 , and the lock tab  84  are positioned flush with the inner wall  52 . See FIG. 3A. When the cam  46  is in this window-openable position, the cam&#39;s stop pin  82  abuts the corresponding position-set tab  70  of the housing  44 . (See FIG. 4C and FIGS. 5A and 5D.) The lever  48  is positioned in a position corresponding to the window-openable position of the cam  46 .  
         [0045]    In FIG. 3A, the locking device  50  is shown in the unlocked state in which the block pin  132  is clear of the path of the cam  46 . As was explained above, the locking device  50  is positioned radially outward from all portions of the cam  46  when in the unlocked state. Accordingly, when the locking device  50  is in the unlocked state, the cam  46  may freely rotate by and past the locking device  50 .  
         [0046]    To convert the lockable sash assembly from the unlatched position to the latched position, the lever  48  is turned in the appropriate direction (counterclockwise as viewed in FIG. 3A) toward a position corresponding to the latched position of the cam  46 . In the illustrated embodiment, the lever  48  will be moved approximately 180° in this process and the lock tab  84 , will pass under the locking device  50 . Once the lever  48  reaches the window-latched position, the lever&#39;s set grooves  116  will coordinate with the housing&#39;s set grooves  69  to “click” the lever  48 , and thus the cam  46 , into position. (See FIG. 4A and FIG. 6C.) The cam&#39;s position set pin  82  then abuts the position-set tab  71  of the housing  44 . (See FIGS. 4B, 5A, and  5 D.)  
         [0047]    When the sashlock  40  is in the latched position, the flat edge  88  of the cam  46  is within the housing  44  and a portion of the cam  46  extends from within the housing across the space  32  between the sashes  24  and  26 , through the keeper&#39;s opening  146  and behind the dog  148 . (See FIGS. 3B, 4D, and  8 C.) In this manner, the cam  46  forms a barrier preventing relative movement between the sashes  24  and  26 .  
         [0048]    When the sash assembly  20  is in the latched position, it may be placed in the locked state by changing the locking device  50  from the unlocked state to the locked state. Specifically, the key  146  may be inserted into the key slot  144  (FIG. 2), and the tumbler assembly  120  then may be rotated approximately 180°. As was explained above, when the locking device  50  is in its locked state, the block pin  132  is positioned within the path of the cam  46 , as shown in FIG. 3B. The pin  132  thus prevents movement of the cam  46  back toward the unlatched position because of the engagement between the pin and the lock tab  84  of the cam. Accordingly, until the key  130  is used to turn the locking device  50  back the unlocked state, the sashlock assembly  20  cannot be converted back to the unlatched position and thus the window assembly  22  cannot be opened.  
         [0049]    One may now appreciate that a lockable sash assembly according to the present invention may be locked so that even if a blade is inserted into the gap between the two sashes to engage the rotating member, it will still not be possible to move the member back to its unlatched, window-openable position. Additionally, since in the preferred embodiment a key is necessary to turn the locking device to the unlocked state, the lockable sash assembly according to the present invention can also be used to control window openings inside the building.  
         [0050]    Although the invention has been shown and described with respect to certain preferred embodiments, it is obvious that equivalent alternations and modifications will occur to others skilled in the art upon the reading and understanding of this specification. The present invention includes all such equivalent alterations and modifications and is limited only by the scope of the following claims.

Technology Classification (CPC): 8