Abstract:
A casement sash locking system including locking assembly, drive assembly and lock strike that can be mounted on either side allowing the window to open from the left side or right side. The locking assembly includes a lock catch that functions to first lift the outer free end of the sash and then pull the sash to a closed position, thereby preventing drag of the sash on the window frame sill.

Description:
BACKGROUND OF THE INVENTION 
     Casement windows are hinged on one vertical edge to the jamb of a window frame allowing the opposite vertical edge to swing outwardly from the window frame. These kinds of windows, while having many attractive features, do present certain problems. The outer free vertical edge of the sash may drop over a period of time since it is cantilevered from the hinged window jamb, thereby causing drag when the sash is closed against the window frame sill. 
     Typically the casement type window will involve a locking assembly on the jamb adjacent the free edge of the sash, but the locking assembly will oftentimes be too high to be readily reached when windows are over sinks, counters, etc. 
     A related problem is that ideally the window should be capable of being deactivated for security reasons. 
     The locking systems typically used are limited in application due to the substantial space required for the locking mechanism. 
     Thus, it is seen that a locking system for casement windows is needed that will obviate any sash drag that might otherwise occur, occupy a minimum of space, be readily accessible and include security protection. 
     SUMMARY OF THE INVENTION 
     The window locking system of this invention includes a catch engageable with a lock strike on the sash which functions to move between first and second positions. In the first position the catch extends outwardly and downwardly from the window jamb, and in moving to the second position pivots upwardly into engagement with the lock strike on the sash, thereby lifting the outer free edge of the sash such that it will clear the windowsill when the sash is moved to its closed position. The catch, after having lifted the sash, then continues towards the second position by pulling the sash toward the window frame to the fully-closed position. 
     The preferred embodiment includes upper and lower locking assemblies and a drive assembly, including a handle located on the jamb below both locking assemblies, thereby making it readily accessible at the level of the windowsill. 
     The lock strike is recessed into the outer free vertical edge of the sash and includes a housing having interior lock or strike shoulders on opposite sides of an access opening. The lock strike housing can be mounted on either vertical edge of the sash with one strike shoulder being utilized on one side and the other being used on the other side. The locking assembly and the drive assembly can be mounted on either jamb as most of the component parts of each are compatible to operation in either location. 
     The drive assembly includes a rotatable cam which is removably connected to a handle whereby for security purposes the handle may be removed rendering the locking assembly inoperative. In U.S. Pat. No. 5,080,407, REMOVABLE LOCKING LEVER FOR A CASEMENT WINDOW, a handle is shown removably attached to a different kind of cam. 
     The design of the components of the drive assembly and locking assembly are such that they can be mounted in the window jamb where space available is at a minimum. Drive and locking assemblies are hidden under a very thin frame stop. The frame stop is a 4/4(0.688 inch) as compared to previous frame stops which are 5/4(1.093 inch). 
     The lock strike has an edge that seals against the primary weatherstrip to provide an air and water seal. The lock strike edge is coincident with the sash edge to form a continuous seal. The lock strike design in cooperation with the lock catch enables the lock catch to have a minimum clearance with the weatherstrip. The lock catch width is unique for casement windows in that it is only 0.090 inch thick. 
     The locking assembly may be used in any orientation (such as on its side for awning windows) because the lock catch action is not dependent on gravity. The lock mechanism will force the lock catch to drop to its lowered and extended position. 
     Additional advantages of this invention include a locking system not requiring a special window frame configuration, but instead only requires special cuts in the frame and frame stop. The locking system requires relatively few parts, and most of the parts are universal such that they can be used for left-hand or right-hand locking systems. Any number of locking assemblies can be operated on a single jamb by only one handle. The locking assembly housing has projections that engage the frame and frame stop, thereby transferring the load required to hold the sash closed to the frame and frame stop and thereby avoid the installation screws carrying the full load. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a fragmentary perspective view of a casement window including the locking system of this invention mounted over a kitchen sink. 
     FIG. 2 is an enlarged elevational view of the window only. 
     FIG. 3 is a fragmentary cross-sectional perspective view of the drive assembly, locking assembly mounted on a window frame jamb and lock strike on the sash. 
     FIG. 4 is a view similar to FIG. 3, but with the component parts of the drive assembly and locking assembly being exploded. 
     FIG. 5 is a cross-sectional view taken along line 5--5 in FIG. 3 showing the lock catch in its first position extending downwardly and outwardly. 
     FIG. 5A is a view similar to FIG. 5, but showing the locking assembly removed from the jamb. 
     FIG. 6 is a cross-sectional view taken along line 6--6 in FIG. 5. 
     FIG. 7 is a cross-sectional view taken along line 7--7 in FIG. 5. 
     FIG. 8 is a view similar to FIG. 5, but showing the lock catch having been pivoted from its first position towards its second position in engagement with the lock strike on the sash for lifting it before pulling it to a closed position. 
     FIG. 9 is a view similar to FIG. 8, but showing the lock catch having completed its upward travel and ready to be moved horizontally for closing the sash. 
     FIG. 9A is a view similar to FIG. 9, but showing the locking assembly removed from the frame jamb. 
     FIG. 10 is a view similar to FIG. 9, but showing the lock catch having moved horizontally inwardly for pulling the sash to a fully-closed position. 
     FIG. 10A is a view of the locking assembly of FIG. 10 removed from the window frame jamb. 
     FIG. 11 is a cross-sectional view taken along line 11--11 in FIG. 10. 
     FIG. 12 is a cross-sectional view taken along line 12--12 in FIG. 10. 
     FIG. 13 is a view similar to FIG. 10, but showing the drive assembly and locking assembly mounted on the opposite window frame jamb in engagement with a lock strike mounted on the opposite vertical end edge of the sash. 
     FIG. 14 is a fragmentary elevational view of the window of FIG. 13 and also shows in dash lines the window before being raised by the locking assembly. 
     FIG. 15 illustrates an alternative drive assembly for operating the lock assembly. 
     FIG. 16 is a cross-sectional view taken along line 16--16 in FIG. 15. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The locking system of this invention as seen in FIG. 3 includes a locking assembly 10 and a drive assembly 12 mounted on a jamb 14 in a window frame 16. As seen in FIGS. 1 and 2, a window assembly 18 is mounted over a kitchen counter 20 and includes sash 22. The sash 22 includes a lock strike 24. 
     The lock assembly 10 is seen in FIG. 4 to include a housing 26 which holds a lock cam 28 for operating a lock catch 30. The housing 26 is symmetrical in appearance and has a pair of lock catch 30 channels 32 as defined by oppositely disposed side walls 34 and a guide block 36. The housing 26 has ears 38 to receive screws 40 engageable with the jamb 14. A cap 42 may be snapped over the housing 26. A positioning tab 44 extends from the housing 26. 
     The lock cam 28 is circular in shape and includes a gear 46 on its bottom side for engagement with a rack 48 on a link 50. The top face of the lock cam 28 includes oppositely disposed pins 52 for engagement with the lock catch 30 in a vertical slot 54. The lock catch 30 includes an outer end 56 having a hook opposite the inner end having the elongated vertical slot 54. A longitudinally extending flange 58 extends along the bottom side of the lock catch 30 and is received in one or the other of the channels 32 of the housing 26. Flange 58 is also received in the right side slot of a pair of oppositely disposed slots 60 extending from the periphery of the lock cam 28 inwardly. 
     The sequential operation of the lock assembly 10 is seen in FIGS. 5, 8 and 10. In FIG. 5 the lock catch 30 extends downwardly and outwardly in a first position. As the lock cam 28 is rotated clockwise as seen in FIG. 8, the upper wall 62 of the right-hand cam slot 60 presses down on the flange 58 below the vertical slot 54 causing the lock catch 30 to pivot upwardly at its hook end 56. The fulcrum for the pivoting of the lock latch 30 is the point of contact of the flange 58 with the housing channel 32 bottom wall 34. As the lock cam 28 continues to rotate clockwise as seen in FIG. 10, the pin 52 operating in the slot 54 pulls the lock latch 30 horizontally inwardly to the left. The maximum inward travel is reached when the pin 52 reaches the nine o&#39;clock position. 
     The unlocking of the lock assembly is accomplished by rotating the lock cam 28 in a counter clockwise direction whereupon the bottom wall 64 of the slot 60 on the right-hand side of the lock cam 28 as seen in FIG. 5 presses upwardly on the bottom side of the flange 58 while the adjacent sidewall of the guideblock 36 in the housing 26 forming the channel 32 presses downwardly on the top side of the flange 58 insuring that the catch 30 returns to its original position shown in FIG. 5. Thus it is seen that in moving from a fully open position of FIG. 5 to a fully closed position of FIG. 10 the lock cam 28 rotates 180° with the pin 52 moving from a three o&#39;clock position to a nine o&#39;clock position. The oppositely disposed cam slot 60 and pin 52, along with the opposite housing channel 32 are used when the locking assembly 10 is mounted on the opposite jamb 14A as seen in FIGS. 13 and 14. 
     The lock strike 24 includes a housing 66 having an access opening 68 to an interior chamber 70. A pair of shoulders 72 are disposed on opposite sides of the access opening 68 for engagement by the hook end 56 of the lock catch 30. As seen in FIGS. 1-12, the hook 56 engages the upper shoulder 72. When the lock strike housing 66 is mounted on the opposite edge of the sash 22 as seen in FIGS. 13 and 14, the lower shoulder 72 becomes the upper shoulder. The lock strike housing 66 is recessed into the outer vertical end edge of the sash 22 giving a flush appearance to the end edge and the interior surface of the sash. 
     The drive assembly 12 includes a housing 74 having a vertical channel 76 in which a plate element 78 is received. The plate 78 includes a transversely extending slot 80 which receives a pin 82 on the bottom side of a drive handle cam 84. A handle 86 is detachably connected to the cam 84 for rotating the cam and in turn causing upward and downward travel of the plate element 78 which in turn is connected through a notch 88 to a notch 90 in the lower end of the link 50 having the rack 48. A screw 92 extends through the cam 84 and the housing 74 to secure the drive assembly 12 to the frame jamb 14. An arcuate slot 94 in the housing 74 receives the free end of the pin 82 on the drive handle cam 84. A pair of strengthening and positioning tabs 96 are provided on the housing 74 to support the side 97 of the channel 76 in the housing 74. 
     As seen in FIG. 2, a pair of lock assemblies 10 are operated by a single drive assembly 12 located adjacent a windowsill 98, thus placing the handle 86 in a position convenient for being reached over the counter 20. 
     The locking system of this invention allows for the window jamb 14 to be manufactured in quantity without special routing being required to accommodate the lock assembly 10 or the drive assembly 12. The shoulders and slots in these component pieces are such that they will accommodate these assemblies at any point along their length and thus will be mounted to the jamb 14 with the lock assemblies being in alignment with the lock strikes 24. 
     The lock assembly 10 and drive assembly 12 are hidden under a very thin frame stop 100 as seen in FIG. 12. The frame stop 100 is routed out to provide recesses for receiving the lock assembly 10 and drive assembly 12. It is further seen in FIG. 12 that a primary weather seal 102 is provided on the jamb 14 which engages the outer end edge 104 of the sash 22, and since the outer wall of the lock strike housing 66 is coincident with the sash outer end edge 104, a continuous seal is provided. A secondary rain strip seal 106 is also provided on the frame jamb 14 for engagement with the outer end edge 104 of the sash 22. 
     It is understood that alternate drive assembly arrangements can be utilized wherein the drive handle cam 84 is connected directly to the link 50 for operating the lock cam 28. 
     In FIGS. 15 and 16 an alternate drive assembly is shown. The drive cam 84A includes a pin 110 which connects it directly to a rack plate link 112 through an end 114 which is twisted 90 degrees to allow flexing as it is operated. The rack teeth on the plate link 112 are in the form of spaced apart holes 114 along the longitudinal center of the plate link. Locating the rack teeth 114 along the center allows for a thinner or weaker material to be used.