Storm window lock
BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     The present invention relates to locks for spring biased latches for storm windows. More particularly, the present invention relates to catches for spring biased latches associated with storm windows. 
     2. Brief Description of the Prior Art 
     Vertically hung storm windows having a fixed window and a coplanar screen facing the outside of a building or a home with inside positionable windows are well known. The positionable window utilizes spring biased latches mounted into a bottom side of a sash of the window to engage any one of a plurality of notches positioned along a casing, into which the entire storm window is mounted. The latch extends into a notch to position the window and retracts from the notch to allow repositioning of the window. By varying the position of the positionable window, the extent to which outside air is allowed to mix with inside air through the screen is controlled. 
     It is desirable in having such a positionable window, that the window be capable of being locked from the inside, so as to secure the window from unauthorized break-ins. This has previously been accomplished by a tab bent out of the casing near the bottommost or closed position of the positionable window. The tab then interferes with the latch mechanism when it is desired to raise the positionable window. To raise the positionable window, the latches must be retracted. 
     The use of a tab to lock the positionable window has certain drawbacks. Mainly, in locking the positionable window at the bottommost position, the spring biased latches must be retracted in order to pass over the tab and then released to provide the desired interference lock. If the latches were retracted automatically as the positionable window was dropped to its bottommost position the window would lock as it was closed. 
     The prior art procedure whereby a tab is punched out of the storm window casing to provide the interference lock with the latch of the positionable window does not require extra parts to provide a locking feature to the storm window, but does require an additional manufacturing step. The tab is also subject to being impacted by the positionable window as it is dropped to the bottommost or closed position. As a result, the tab, which is merely bent aluminum, can break off. 
     In manufacturing a storm window casing, corner pieces fit into the four channel structural members forming the casing to join side members to top and bottom members. The present invention is a corner piece which serves to join the members as well as the lock for the latches, thereby combining these features in an economic and advantageous manner. 
     OBJECTS AND SUMMARY OF THE INVENTION 
     It is therefore the principal object of the present invention to provide a latch for a storm window lock that automatically locks a positionable window of a storm window upon closing. 
     It is a related object of the present invention to provide a latch that serves to provide a structural connection for the members of the storm window casing. 
     It is a further object of the present invention to provide a latch that is highly serviceable in everyday use, requiring little or no maintenance and long life. 
     In accordance with the objects of the invention, a catch or keeper for a positionable window spring biased latch of a vertically hung storm window is provided. The keeper fits at the two lowermost corners of the storm window casing, joining parallel side structural members of the casing to a bottom structural member. It is further understood that conventional constructions might include a horizontal window or slider having two sliding windows and a fixed window, i.e., a 3-lite slider, or a single fixed and single sliding window, i.e., a 2-lite slider. For slider-type windows, no notches are necessary. 
     The keeper has a generally vertically oriented locking arm that fits within an inner track of the side members forming the casing of the storm window. An integrally connected horizontal arm makes a right angle with respect to the locking arm and fits within the inner track of the bottom member forming a horizontal portion of the storm window casing. 
     The locking arm portion of the keeper has a downwardly sloping ramp adapted to engage a lock prong of a spring biased latch located along a bottom side of a positionable window sash. The ramp of the locking arm biases the latch inward on downward movement of the positionable window. As the sash of the positionable window is lowered even further to a closed position within the storm window casing, the lock prong is urged into a recess formed in the locking arm. Once the lock prong of the latch is in the recess, the positionable window cannot be raised without biasing the latch. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an exploded perspective view of a storm window with a catch of the present invention positioned in the lowermost corners of a storm window casing. 
     FIG. 2 is a rear elevational view of the storm window as it would appear looking from the inside to the outside. 
     FIG. 3 is a side elevational view of the storm window. 
     FIG. 4 is a fragmentary enlarged sectional view taken in the plane of line 4--4 of FIG. 3. 
     FIG. 5 is a top plan view of a latch for the storm windows shown in FIG. 1. 
     FIG. 6 is a side elevational view of the latch for the storm windows shown in FIG. 1. 
     FIG. 7 is a bottom plan view of the latch of the storm window shown in FIG. 1. 
     FIG. 8 is an end elevational view of the latch for the storm windows shown in FIG. 1. 
     FIG. 9 is a top plan view of the catch shown in FIG. 1. 
     FIG. 10 is a front elevational view of the catch shown in FIG. 1. 
     FIG. 11 is a side elevational view of the catch shown in FIG. 1. 
     FIG. 12 is a side elevational view of a spring and lock mechanism associated with the latch of the storm window shown in FIG. 1. 
     FIG. 13 is a bottom plan view of a spring and lock mechanism associated with the latch of the storm window shown in FIG. 1. 
     FIG. 14 is an enlarged sectional view taken in the plane of line 14--14 of FIG. 2. 
     FIG 15 is an enlarged sectional view taken in the plane of line 15--15 of FIG. 2. 
     FIG. 16 is an enlarged sectional view taken in the plane of line 16--16 of FIG. 2. 
     FIG. 17 is an enlarged sectional view taken in the plane of line 17--17 of FIG. 4. 
     FIG. 18 is an enlarged sectional view taken in the plane of line 18--18 of FIG. 2. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A storm window 20, seen in FIG. 1, of basically conventional vertically hung construction allows selective admission of outside air to the inside of a home or building through a screen 22 mounted within a screen frame 23. The screen covers approximately one half of the area defined by a storm window casing 24. The storm window casing 24 includes four generally linear extruded members 24a, 24b, 24c and 24d joined together at mitered corners 25a, 25b, 25c and 25d. The remaining area of the storm window casing 24 has a fixed window 26 mounted within a fixed window frame 27. The screen frame 23 and fixed window frame 27 are in contact with outside air and are aligned in an outer track 28 formed around the inner perimeter of the storm window casing 24. A sash 30 holds a positionable or sliding window 32, which window 32 is slideable along an inner track 29 formed around the inner perimeter of the storm window frame 24, adjacent to the outer track 28. 
     In the assembled configuration, the conventional storm window 20 therefore presents the fixed window 26 and screen 22 to the outside or exterior of a home or building. The sliding window 32 is positionable at various levels along the members 24a and 24c of the storm window casing 24, intermediate the inside of a home or building and the coplanar fixed window 26 and screen 22 exteriorly mounted with respect to the home or building. 
     A catch or keeper 31 of generally L-shaped configuration fits within the inner track 29 at mitered corners 25b and 25c to assist in interconnecting members 24a, 24b and 24c of the storm window casing 24 (FIGS. 1, 9, 10 and 11). A pair of latches 34 are slideably mounted on a bottom side 80a of sash 30, adjacent to member 24b when the sliding window 32 is closed, which latches retract along a line perpendicular to the direction of movement of the sliding window 32. As the sliding window 32 is dropped to its bottommost or closed position, the keeper 31 automatically locks both latches 34 of the sliding window 32 to prevent the sliding window 32 from being raised along its sliding path in inner track 29. 
     As is the case with conventional vertically hung storm windows, the sliding window 32 utilizes the pair of latches 34 mounted onto the sash 30 to set the window position. Thus, more or less of the screen 22 is open between inside and outside air. Wedge-shaped notches 36 are formed in the storm window casing 24 at preset positions along members 24a and 24c (FIG. 1) on the inside of and along the inner tracks 29. Each latch 34 has at a projected end 38 a support edge 40 (FIG. 5) of wedge-shaped top plan view that has a corresponding shape to the notches 36, providing mating receipt between the edge 40 and the notches 36. 
     In operation, to change the position of the sliding window 32 from the position covering the entire screen 22 (FIG. 2), at which position the latches 34 are locked against sliding by the catch or keeper 31, the latches must be retracted relative to the keeper, and the sliding window raised. As the sliding window 32 is raised, the support edge 40 sequentially engages the notches 36. The wedge shape of the notch 36 and corresponding edge 40 are both directed downward, so that as the sliding window is raised, the notches automatically bias the latch 34 inward by the sliding engagement with similarly shaped edge 40. At an uppermost or fully open position, the sliding window 32 exposes the entire surface area of the screen 22 to mix outside and inside air. To lower the sliding window 32, both latches 34 are retracted, removing support edge 40 from the associated pair of notches 36 in members 24a and 24c, and the window is dropped under the force of gravity until the proper notch is located, or the locked position at the keeper 31 is reached. 
     The unique construction of the catch or keeper 31 locks the sliding window 32 from movement along the inner track 29 once the sliding window 32 is closed. The keeper 31 fits into the inner track 29 at both mitered corners 25b and 25c of the overall storm window casing 24 (FIG. 1). The keeper is an integral body of generally L-shaped configuration (FIGS. 9, 10 and 11) having a locking arm 42, disposed generally vertically and aligned along the direction of movement of the sliding window 32, and an anchor or horizontal arm 44 (FIG. 11), which arm 44 combines with arm 42 to fit the keeper in the corners 25b and 25c of the inner track 29. 
     Locking arm 42 of the keeper 31 is engaged by a latch 34 as the sliding window 32 descends along inner track 29. The edge 40 of the latch 34 is initially met by a downwardly and inwardly sloping ramp portion 46 of the keeper 31. As sliding window 32 moves downward, the latch 34 is biased inwardly by the sliding relationship between the edge 40 of the latch 34 and the ramp portion 46. Once the latch is biased away from the inner track 29, a generally rectangular locking prong 48 is met by the ramp portion 46, in a relationship that is maintained until the ramp portion ends. 
     At the position where the sliding window 32 nears its bottommost position, the ramp portion 46 ends in a relatively short, compared to the length of the locking arm 42, land portion 50. The land portion 50 is generally vertically oriented, lying in a plane parallel to the longitudinal axes of members 24a and 24c. The land portion receives the locking prong 48 from the ramp portion 46 and terminates in a latch recess 52. The latch recess 52 is an outwardly opening recess formed in locking arm 42 which opens perpendicularly to the direction of movement of the sliding window 32. The latch recess 52 receives the locking prong 48 of the latch 34 to thereby lock the sliding window 32 at that position. 
     From the foregoing, it is seen that the keeper 31 automatically locks the latches 34 to prevent movement of the sliding window 32 in the sliding direction. As the sliding window 32 is lowered to the closed position, each latch 34 is automatically biased by the engagement between the latch and the ramp portion 46 of the catch 31. Once the locking prong 48 is fitted within a recess 52, the sliding window 32 cannot be raised along the sliding direction. The horizontal arm 44 of the catch, which is locked into the inner track 29 of the member 24b, resists any movement of the sliding window 32 by being mounted in member 24b, unless the latch 34 is retracted. 
     The keeper 31 also assists in connecting and aligning frame members 24a, 24b and 24c (FIG. 1). Conventional construction would utilize a separate corner piece connected by a screw to the members for this purpose. The configuration of the keeper 31, having a horizontal arm 44 and a generally vertically oriented locking arm 42, means that the locking arm extends into the inner track 29 of frame members 24a and 24c, which inner track tightly grips the locking arm 42 along the length thereof by engagement with a pair of parallel grooves 54 (FIGS. 9, 10 and 11), while the horizontal arm is frictionally held within the inner track 29 of frame member 24b (FIG. 4). The frame members are then connected by a single screw at each mitered corner 25a through 25d. 
     The inner track 29 and outer track 28 of frame members 24a, 24b, 24c and 24d of the storm window casing 24 are constructed from a single conventionally available aluminum extrusion. The transverse section of tracks 28 and 29 is seen in FIGS. 15, 16, 17 and 18 to include a flat planar inner surface 56 forming the inside of inner track 29. The inner surface 56 is integrally connected by a first flange portion 58 to a middle surface 60, lying in a plane parallel to the inner surface 56 and extending a relatively short distance further into the opening defined by the storm window casing 24 than does inner surface 56. A second flange portion 62 integrally connects middle surface 60 to outer surface 64, which outer surface 64 is in contact with the outside air and lies in a plane parallel to the inner and middle surfaces respectively. The outer surface 64 extends a relatively short distance further into the opening defined by the storm window casing 24 than does the middle surface 60. The inner track 29 and outer track 28 are therefore seen to staircase inward from the inside to the outside of the casing 24. An innermost end 66 of the inner, middle and outer surfaces is inturned to perpendicularly intersect the frames 23 and 27 and the sash 30, thereby assisting in sealing the window. A pair of lips 68, disposed on the inside of both the outer 64 and inner surfaces 56 near the inturned end 66 receive therebetween a sealing element 70 mounted about the entire perimeter of the storm window casing 24 and against which sealing element frame members 23 and 27 and sash 30 rest. 
     The frame 27 of the fixed window 26 and the sash 30 of the sliding window 32 are of very similar construction (FIG. 1, 14, 15 and 16). Along top sides 72 and vertical sides 74 the fixed window frame 27 and the sash 30 of the sliding window 32 are both of generally H-shaped cross sectional view. All four ends 76 of the frame and sash are inturned to pinch therebetween seals 78 and the windows 26 and 32. A bottom side 80 of fixed window frame 27 and bottom side 80a of sash 30 are also of generally H-shaped cross section, but have an extension 82 (FIG. 14) disposed to the outside of the overall storm window 20, which extension leaves an opening 84 on the inside of the storm window 20 extending perpendicularly between the vertical sides 74 and adapted to receive the latches 34. As seen in FIG. 14, the fixed window frame bottom side 80 has parallel spaced apart sides 86 adapted to fit over and receive a top side 88 of the frame 23 of the screen 22. The bottom side 80a of the sliding window 32 is of similar construction to the bottom side 80 of the fixed window 26 but without the inclusion of the spaced apart sides 86 (FIG. 18). Bottom side 80a still provides space 84 to provide for mounting the pair of latches 34 to the bottom side 80a of the sash 30. 
     The frame 23 of the screen 32 (FIGS. 1, 14, 15, 17 and 18) has a similar cross section to top side 72 and vertical sides 74 of the sash 30. An edge 90 of screen frame 23 extends around the periphery of the frame and has two parallel sides 92 extending toward the outside of the window 20 and adapted to grasp therebetween an edge of the screen 22 (FIGS. 14 and 15). Bottom side 80c of the screen frame 27 is essentially the same as bottom side 80a of the slideable window sash 30 (FIG. 18). 
     The latches 34 are of generally flat rectangular elongated shape (FIGS. 5 through 8). Three ribs 94 are disposed along the length of the latch 34 and project laterally from each side of the latch in a plane parallel to the plane containing the fixed window 26 and screen 22. The bottom sides 80, 80c, and 80a of window frame 23, screen frame 27 and sash 30 respectively retain the ribs 94 of each latch in sliding engagement. One surface of the latch slides against the respective extensions 82 of the bottom sides, while the other side faces the inside of the window 20 for manual actuation. The inside surface has an indentation 96 at the end opposite projected end 38 that can be used to slide the latch against the bias of a spring 98 (FIGS. 12 and 13). Near the projected end 38 of the latch 34 is located an elongated hollow 100 (FIG. 7) adapted to receive along the length thereof the spring 98. The spring is therefore held in position in the hollow 100. One end of the spring is fixed to a block 102 while the other abuts against the latch near projected end 38. The block has a pin 104 that fits into a hole in the bottom sides 80, 80c and 80a of frames 23 and 27 and sash 30 respectively (FIG. 4). Pushing the pin 104 out of the hole permits the entire latch to be slid out of the respective frame or sash along the space 84. 
     The fixed window 26, the screen 22, and the sliding window 32 are all removable from the storm window casing 24 for cleaning, maintenance or storage. Removal of these three elements of the storm window 20 is largely accomplished by biasing the latches 34 toward the interior of the opening defined by the window casing 24 (FIGS. 1, 4, 5, 6 and 7). Each of the pair of latches 34 are biased to protrude in opposite direction into the respective tracks 28 for the fixed window 26 and screen 22, and track 29 for the slideable window 32. Retracting the pair of latches allows the bottom sides 80, 80c and 80a of the frames 23 and 27 and sash 30 to be removed from the storm window casing 24 by pulling the bottom side directly in from the casing 24. The top side 72 of fixed window frame 27 and window sash 30 are held in their respective tracks by a pair of opposed fingers 106 (FIG. 1), which fingers are rigidly mounted along the respective top sides 72 of the fixed frame 27 and the sash 30, respectively. The top side can be easily removed by skewing the window 26 or 32 relative to the casing 24. The screen frame 23 is held in position by the bottom side 80 of the fixed window frame 27 (FIG. 16), and can be easily removed once the bottom side 80c of the screen frame 23 has been removed. 
     The foregoing embodiment of the invention has been described with a certain degree of particularity. It should be understood, however, that this description has been made by way of example and that certain departures therefrom may be possible without departing from the spirit and scope of the invention defined in the appended claims.