Abstract:
A sash window fastener includes lock and latch assemblies, and a fitting. The lock mounts upon the meeting rail, and includes a pivotable cam to engage a keeper on the master frame, and a pivotable arm acting as a follower. The arm interconnects with the latch within the meeting rail, so cam rotation controls arm positioning—causing translation of the latch. The cam can occupy three positions causing three corresponding latch positions: an extended position securing the cam to the keeper, with the latch engaging the master frame to prevent tilting, and also receiving a post of the fitting therein to further secure the window against impact loading; a first retracted position disengaging the cam from the keeper, and permitting sliding of the window into an open position that also elevates the latch member above the post; and a second retracted cam position causing latch member retraction that permits tilting.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation-in-part of U.S. patent application Ser. No. 14/566,908, filed on Dec. 11, 2014, having the title “Integrated Sash Lock and Tilt Latch Combination with Improved Wind-Force-Resistance Capability,” which is a continuation-in-part of U.S. patent application Ser. No. 14/278,226, filed on May 15, 2014, having the title “Integrated Sash Lock and Tilt Latch Combination with Improved Interconnection Capability Therebetween.” which is a continuation-in-part of U.S. patent application Ser. No. 14/198,986, filed on Mar. 6, 2014, having the title “Integrated Sash Lock and Tilt Latch with Screwless Installation and Removal from Meeting Rail,” with the disclosures of each being incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to improvements in locks and tilt latches for slidable sash windows (or doors), and more particularly to improvements to an integral sash lock/tilt latch combination that is capable of providing better resistance to wind loading for improved pressure ratings. 
       BACKGROUND OF THE INVENTION 
       [0003]    Single hung and double hung sliding sash windows are commonly used today in the construction of residential and commercial buildings. Sash locks are typically mounted to the meeting rail of the bottom sash window to lock the sash or sashes, by preventing the lower sash (or both the lower and upper sashes for a double hung window), from being opened through sliding movement relative to the master window frame. Also, in order to assist in the cleaning of the exterior of the glazing of the sash window, it may be constructed differently. Rather than the sash window frame itself being slidable within the master window frame, a lower pivotal member on the sash window may slide therein, and a pair of tilt latch devices mounted on an upper part of the window frame may also slide in the track of the master window frame. The tilt latches may be actuated to be withdrawn from the track to permit tilting of the sash window about the lower pivotal member into the room. 
         [0004]    However, this arrangement relies solely upon the tilt latch at the top of the sliding sash window and the pivotal attachment at the bottom of the sash member to provide the structural integrity needed to resist high wind loads, since the sash frame itself is not nested within the track of the master window frame. Because of the annual threat of extreme weather at the eastern coastal areas of the U.S., particularly from hurricanes but also from macro-scale storms (a Nor&#39;easter) that can generate hurricane force winds, these areas often mandate that the windows installed today be constructed according to very high standards. These standards may require the window to be able to structurally withstand, for a set period of time, a specified design pressure, which would permit the window to maintain its integrity throughout the sustained winds of a category five hurricane. Under such loading, it is not uncommon to see a window convex significantly, but when properly designed, the window will regain its original form. This significant deformation under such high wind loads creates a serious problem for the window hardware, particularly the tilt latch, as the latch member merely being biased into the master window frame track does not serve to resist bending. The deformation thus permitted from high wind loads may result in moisture and debris entering the interior of the dwelling through any gaps resulting from the deformation. 
         [0005]    Another issue with respect to the design of windows for extreme weather concerns impact loading. An impact resistant sash window may include an impact-resistant glazing housed in a frame that may be securely fastened to the master window frame. The impact resistant glazing may be made of two sheets of glass laminated together, with a shatter-proof membrane between the sheets. If the exterior of the glazing is impacted by debris carried by high speed winds, the outer sheet of glass may shatter, but the inner sheet of glass is protected by the membrane, which may also serve to retain the shattered outer glass fragments in the frame. The inner sheet of glass still prevents the wind and moisture from reaching the interior of the dwelling. However, the tilt latch being unable to resist deformation may nonetheless allows debris and moisture to enter the residence through gaps resulting from such deformation, irrespective of the integrity of the impact-resistant glazing being maintained. 
         [0006]    The present invention seeks to provide improvements to the window latch hardware in the form of an integrated sash lock and tilt latch fastener for single hung or double hung windows, which provides better resistance to wind loading and impact loading, for improved window pressure ratings. 
       OBJECTS OF THE INVENTION 
       [0007]    It is an object of the invention to provide a sash lock to prevent relative sliding movement of one or both sliding sash windows that are slidable within a master window frame. 
         [0008]    It is another object of the invention to provide a tilt latch to permit pivoting of a sliding sash window inwardly into the room in which the window is installed. 
         [0009]    It is a further object of the invention to provide a combination sash lock and tilt latch that act cooperatively through the use of a single handle member. 
         [0010]    It is also an object of the invention to provide a Hit latch device that may be blindly coupled to a sash lock for cooperative interaction and actuation therefrom. 
         [0011]    It is yet another object of the invention to provide a tilt latch that may better support the sash window frame to resist deformation. 
         [0012]    It is also an object of the invention to provide a tilt latch that may be permit the sash window to resist impact loading. 
         [0013]    Further objects and advantages of the invention will become apparent from the following description and claims, and from the accompanying drawing figures. 
       SUMMARY OF THE INVENTION 
       [0014]    An integral sash locking and tilt latching fastener for a sliding sash window may include a lock assembly that may be interconnected with a latch assembly. 
         [0015]    The lock assembly may be mounted to the top of the meeting rail of the sash window. The lock assembly may include a housing and a cam pivotally mounted within the housing. The cam may be configured to pivot for a portion thereof to protrude out from a cavity in the housing to releasably engage a keeper secured to the master window frame (or secured to a second sliding sash window) in a “locking” position, to lock the sash window (or windows) and prevent both sliding and tilting. The cam may have a graspable hub portion that may protrude upwardly, out from an orifice in the sash lock housing, to permit actuation of the device through rotation of the cam by a user. Alternatively, the device may have a separate handle member secured to the cam, where the handle may provide greater leverage to facilitate easy rotation and counter-rotation of the cam. The lock assembly may also include a lever arm that may be pivotally mounted within the lock housing, and which may be configured for a portion thereof to extend beyond the surface of the housing that is used for mounting of the lock, and into the hollow of the meeting rail of the sash window, when mounted thereon. 
         [0016]    The latch assembly may be received through an opening on a side of the sash member. The latch assembly may include a housing, biasing means, and a latch member slidably disposed within the housing. An opening in the latch member is configured to receive the lever arm of the lock assembly, when positioned within the hollow meeting rail, for coupling of motion therebetween. The latch housing, latch member, and biasing means are configured for the biasing means to normally bias the latch member, so that a portion of one end (i.e., a portion of its “tongue”) may protrude out from the housing, and out of the side of the sash window frame, when mounted therein. 
         [0017]    With the cam rotated into the “locking” position, to prevent sliding of the sash window through engagement of the cam with the keeper, the latch member may also then be in its fully extended position, in which it may be engaged within a track of the master window frame, which engagement may normally serve to prevent tilting of the sash window. 
         [0018]    When the cam is actuated to rotate (e.g., 135 degrees), it may move from the extended locking position into a first retracted unlock position—a position where the cam is disengaged from the keeper on the master window frame, and would no longer prevent the sash window from sliding. Rotation of the cam into the first retracted unlock position may cause a portion thereof to be move into proximity to a follower portion of the lever arm, without actuating it, so that the latch member may remain engaged within the track of the master window frame to prevent tilting of the sash window. 
         [0019]    When actuation of the shaft/handle member causes the cam to rotate further (e.g., another 45 degrees), it may move the cam from the first retracted unlock position into a second retracted unlock position. Rotation of the cam into the second retracted unlock position may cause the portion thereof being in proximity to the follower portion of the lever arm to contact and actuate the arm, and thereby drive the lever arm to also rotate. The rotational motion of the lever arm may act to oppose the biasing of the latch member, through the interconnection therebetween, to drive the tongue of the latch member to translate and retract into the latch housing, and become disengaged from the track of the master window frame. With the tongue of the latch member withdrawn from the track of the master window frame, the sash window may be tilted into the room. 
         [0020]    The cam may be releasably secured in the extended locking position using a detent mechanism. The detent mechanism may also releasably secure the cam at the first retracted cam position, thereby also releasably securing the latch member at the first retracted unlock position, due to the interconnection therebetween. The detent mechanism may also releasably secure the cam at the second retracted unlock position. However, although the detent mechanism may be configured so that it provides a tactile indication to the user as to when the shaft/handle member reaches those positions, the spring of the latch assembly may nonetheless provide a biasing force large enough to overcome the anti-rotation-resisting force provided by the detent mechanism, when the cam is in the second retracted unlock position. Therefore, after the user moves the handle for the cam to reach the second retracted unlock position and thereafter releases the handle, the latch spring may bias the latch member into its extended position, to protrude into the track of the master window frame to again prevent tilting, which may drive the lever arm because of the interconnection therebetween. The lever arm and cam may thus be driven to return to the first retracted unlock position. 
         [0021]    Both a left-hand and right-hand version of the above described integral sash locking and tilt latching fastener may be mounted on a sliding sash window, to provide improved impact resistance. Alternatively, only the left-hand or the right hand arrangement may be used to secure the window. The following discussion proceeds with a discussion of one version of the fastener (e.g., the left-hand fastener), with the understanding that a mirror image version may also be formed and used on the window. Also note that the left-hand and right-hand latch arrangements disclosed herein may alternatively be driven by a single sash lock, which may be configured as disclosed in concurrently filed application Ser. No. 14/______,_______, filed on ______-_______-2015, having the title, “Integrated Sash Lock and Tilt Latch Combination Using One Lock for Two Tilt Latches,” the disclosures of which are incorporated herein by reference. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]      FIG. 1  is a perspective view of a sliding sash window slidably disposed in a master window frame, and which utilizes a left-hand and a right-hand version of the integrated sash lock/tilt latch fastener of the present invention 
           [0023]      FIG. 2  is an exploded view of the components that are used for the left-handed version of the integrated sash lock/tilt latch fastener of the present invention, and may include a sash lock assembly, a latch assembly, and a fitting. 
           [0024]      FIG. 3  is a bottom perspective view of the housing used for the sash lock assembly of the integrated sash lock/tilt latch fastener of  FIG. 2 . 
           [0025]      FIG. 4  is a top perspective view showing the exterior of the housing of  FIG. 3 . 
           [0026]      FIG. 5  is a perspective view of a leaf spring that may be used as part of a detent mechanism for the sash lock of  FIG. 2 . 
           [0027]      FIG. 6  is a bottom perspective view of the shaft/handle member used for the sash lock assembly of  FIG. 2 . 
           [0028]      FIG. 7  is a top perspective view of the shaft/handle member of  FIG. 6 . 
           [0029]      FIG. 8  is a front perspective view of the cam used for the sash lock assembly of  FIG. 2 . 
           [0030]      FIG. 9  is a top perspective view of the cam of  FIG. 8 . 
           [0031]      FIG. 10  is a bottom perspective view of the cam of  FIG. 8 . 
           [0032]      FIG. 11  is a bottom perspective view of the lever arm used for the sash lock assembly of  FIG. 2 . 
           [0033]      FIG. 12  is a top perspective view of the lever arm of  FIG. 11 . 
           [0034]      FIG. 13  is a front view of the lever arm of  FIG. 11 . 
           [0035]      FIG. 14  is a first end view of the lever arm of  FIG. 11 . 
           [0036]      FIG. 15  is a second end view of the lever arm of  FIG. 11 . 
           [0037]      FIG. 16  is a first side view of the lever arm of  FIG. 11 . 
           [0038]      FIG. 17  is a second side view of the lever arm of  FIG. 11 . 
           [0039]      FIG. 18  is a rear view of the lever arm of  FIG. 11 . 
           [0040]      FIG. 19  is an exploded view of the component parts of the sash lock assembly of  FIG. 2 , shown just prior to being assembled together. 
           [0041]      FIG. 20  is a top perspective view of the assembled sash lock assembly of  FIG. 2 . 
           [0042]      FIG. 21  is a bottom perspective view of the assembled sash lock assembly of  FIG. 20 , shown with the cam rotated into the extended locking position. 
           [0043]      FIG. 22  is a bottom perspective view of the assembly sash lock of  FIG. 21 , shown with the cam rotated into the first retracted position. 
           [0044]      FIG. 23  is the top perspective view of the cam shown in  FIG. 9 . 
           [0045]      FIG. 24  is a front perspective view of a keeper that may be engaged by the cam of  FIG. 23 . 
           [0046]      FIG. 25  is a rear perspective view of the keeper of  FIG. 24 . 
           [0047]      FIG. 26  is a perspective view illustrating the sash lock assembly of  FIG. 22  positioned adjacent to the keeper of  FIG. 24 , and with the cam in the extended locking position to engage and be secured to a tooth of the keeper. 
           [0048]      FIG. 27  illustrates a cutaway of the perspective view of  FIG. 26 , being cut on one side of the cam axis. 
           [0049]      FIG. 28  illustrates a cutaway of the perspective view of  FIG. 26 , being cut on the other side of the cam axis. 
           [0050]      FIG. 29  is a first perspective view of the housing used for the latch assembly of  FIG. 2 . 
           [0051]      FIG. 30  is a second perspective view of the latch housing of  FIG. 29 . 
           [0052]      FIG. 31  is a third perspective view of the latch housing of  FIG. 29 . 
           [0053]      FIG. 32  is a first perspective view of the latch member used for the latch assembly of  FIG. 2 . 
           [0054]      FIG. 33  is a second perspective view of the latch member of  FIG. 32 . 
           [0055]      FIG. 34  is a front view of the latch member of  FIG. 32 . 
           [0056]      FIG. 35  is a top view of the latch member of  FIG. 32 . 
           [0057]      FIG. 36  is a bottom view of the latch member of  FIG. 32 . 
           [0058]      FIG. 37  is a first end view of the latch member of  FIG. 32 . 
           [0059]      FIG. 38  is a second end view of the latch member of  FIG. 32 . 
           [0060]      FIG. 39  is a perspective view of a spring that may be used to bias the latch member of the latch assembly of  FIG. 2 . 
           [0061]      FIG. 40  is a first perspective view of the latch assembly used for the integrated sash lock/tilt latch fastener of  FIG. 2 . 
           [0062]      FIG. 41  is a second perspective view of the latch assembly of  FIG. 40 . 
           [0063]      FIG. 42  is a front perspective view of the fitting assembly used with the integrated sash lock/tilt latch fastener of  FIG. 2 . 
           [0064]      FIG. 43  is a front perspective view of a housing used for the fitting assembly of  FIG. 42 . 
           [0065]      FIG. 44  is a rear perspective view of the housing of  FIG. 43 . 
           [0066]      FIG. 45  is a perspective view of a post used for the fitting assembly of  FIG. 42 . 
           [0067]      FIG. 46  is a side view of the post of  FIG. 45 . 
           [0068]      FIG. 47  is an end view of the post of  FIG. 45 . 
           [0069]      FIG. 48  is a cutaway view of the sliding sash window of  FIG. 1 , showing the fitting assembly of  FIG. 42  installed into the track of the master window frame, and with the sash lock assembly and latch assembly of  FIG. 2  installed upon and interconnected, within the sliding sash window. 
           [0070]      FIG. 49  is a perspective view illustrating the the sash lock assembly and latch assembly and the interconnection therebetween, when installed upon the sliding sash window, with the cam shown in the extended locking position, to engage the keeper (but not driving the lever arm), and also illustrating the latch member of the latch assembly engaged with the post of the fitting assembly. 
           [0071]      FIG. 50  is the perspective view of  FIG. 49 , but is shown with the cam in the first retracted position, to be moved proximate to the lever arm, but not yet driving the lever arm to correspondingly rotate. 
           [0072]      FIG. 51  is the perspective view of  FIG. 50 , but is shown with the interconnected sash lock assembly and latch assembly moved away from the fitting assembly, as would similarly be accomplished by opening the sliding sash window to disengage the latch member from the post of the fitting assembly, and with the cam having been rotated into the second retracted position, during which rotation the cam drives the lever arm, which actuates the latch member, causing it to also move into a retracted position. 
           [0073]      FIG. 52  is an enlarged detail view showing the interconnection between the lever arm of the sash lock assembly and the latch member of the latch assembly. 
           [0074]      FIG. 53  is a top view of the sash lock assembly, with the handle shown positioned for the cam to be in the extended locking position. 
           [0075]      FIG. 54  is the top view of  FIG. 53 , but is shown with the handle rotated for the cam to be in the first retracted position, which rotation may be 135 degrees. 
           [0076]      FIG. 55  is the top view of  FIG. 54 , but is shown with the handle rotated an additional amount for the cam to be in the second retracted position, which additional rotation may be 45 degrees. 
           [0077]      FIG. 56  is a top cross-sectional view through the window of  FIG. 1 , showing the sash lock handle positioned for the cam to be in the extended locking positon, with the latch member in the corresponding extended position, and with the sliding window in a closed position for the latch member to have the post of the fitting assembly nested in an orifice therein, to secure the window against impact loading. 
           [0078]      FIG. 57  is a front cross-sectional view of the window shown in  FIG. 56 . 
           [0079]      FIG. 58  is an enlarged detail view showing the post of the fitting assembly nested within the orifice of the latch member, as shown in  FIG. 57 , to secure the window against impact loading. 
           [0080]      FIG. 59  is the top cross-sectional view of  FIG. 56 , but shown with the handle rotated to move the cam into the first retracted position to unlock the sliding sash window. 
           [0081]      FIG. 60  is a front cross-sectional view of the window shown in  FIG. 59 . 
           [0082]      FIG. 61  is the top cross-sectional view of  FIG. 59 , but shown with the handle rotated further to move the cam into the second retracted position. 
           [0083]      FIG. 62  is a front cross-sectional view of the window shown in  FIG. 61 . 
           [0084]      FIG. 63  is an enlarged detail view showing the interconnection between the lever arm of the sash lock assembly and the latch member of the latch assembly, with the cam in the first retracted position. 
           [0085]      FIG. 64  is the enlarged detail view of  FIG. 63 , but shown with the cam having been rotated into the second retracted position, and having actuated the lever arm to drive the latch member into a retracted positon, to withdraw from the track in the master window frame. 
           [0086]      FIG. 65  is an enlarged detail view showing the tongue of the latch member in the extended position, but elevated away from the post of the fitting assembly in the track of the master window frame, which corresponds to the cam positioning shown in the enlarged detail view of  FIG. 63 . 
           [0087]      FIG. 66  is the enlarged detail view of  FIG. 65 , but showing the tongue of the latch member in the retracted position, which corresponds to the cam and lever arm positioning shown in the enlarged detail view of  FIG. 64 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0088]      FIG. 1  shows a left-hand and a right-hand integrated sash lock/tilt latch fastener of the present invention installed with respect to a sliding sash window  400  that is slidably disposed in a master window frame  500 . To simplify the presentation herein, the following disclosure is directed only to the left-hand fastener shown in  FIG. 1 , since the right-hand fastener is a mirrored version of the left-hand fastener, being principally made up of mirror image parts. 
         [0089]    The left-hand integrated sash lock/tilt latch fastener, as seen in  FIG. 2 , may include a lock assembly  100 , a latch assembly  200 , and a fitting assembly  300 . The latch assembly  200  may be blindly mated to the lock assembly  100  during installation of each with respect to the sash window  400 . 
         [0090]    As seen in the exploded view of  FIG. 19 , the sash lock assembly  100  may include a housing  10 , a shaft/handle member  40 , a cam  50 , a lever arm  70 , and a pair of identical leaf springs  90 / 90 ′. 
         [0091]    Perspective views of the housing  10  used for the sash lock assembly  100  are shown in  FIGS. 3-4 . The housing  10  is not limited to the shape illustrated within  FIGS. 3-4 , and could take on many different appropriate shapes, including a rectangular shape, an irregular shape, etc. However, the housing  10  may be shaped to have a wall  12  formed to have a curved outer surface  13  that may span from a first end  21  of the housing to second end  22 . The wall  12  defined by the curved surface  13  may transition to form a first side surface  13 Si and a second side surface  13 Sii, where the transition thereto may be curved and gradual, or may instead be abrupt to form a sharp edge, as shown in  FIG. 4 . The wall  12  defined by the curved outer surface  13  may also transition to form a rear surface  13 R, which transition may similarly be smooth and gradual, or may instead be abrupt. The wall  12  defined by the curved outer surface  13  may also transition to form a generally flat front surface  13 F. The side surfaces  13 Si and  13 Sii, the rear surface  13 R, and the front surface  13 F, may each define respective wall portions  12 Si,  12 Sii,  12 R, and  12 F, which may transition into each adjacent wall portion, and each of which may terminate on a generally flat bottom surface, for mounting of the sash lock onto the top of the meeting rail of a sash window. 
         [0092]    The housing  10  may be generally hollow with the interior surface  14  of wall  12  and the respective interior surfaces of wall portions  12 Si,  12 Sii,  12 R, and  12 F forming a cavity. Certain features may protrude into the interior cavity of the housing, including a wall  34  that may be generally parallel to, but offset a distance D away from wall portion  12 F. The distance D between wall portion  12 F and wall  34  may be sufficient for the housing  10  to overhang a keeper on the master window frame, and receive a portion of the keeper between those walls and beneath the bottom surface  14 . The wall portion  12 F and the wall  34  may have a respective opening  12 FP and  34 P formed therein. The opening  12 FP in the wall portion  12 F may permit a portion of cam  50  to protrude out from the housing in the extending locking position, to engage the keeper therein, and which may be shrouded by the top wall  12 . 
         [0093]    Extending outwardly from the interior surface  14  of the housing  10  may be at least one hollow cylindrical protrusion that may be used to secure the sash lock assembly  100  to the sash window  400 . In one embodiment of the housing  10 , two hollow cylindrical protrusions  15  and  16  may be used, and each may be configured to respectively receive a screw for mounting of the sash lock assembly  100  to the sash window  400 . 
         [0094]    Extending from the interior surface  14  of the housing  10  into the cavity may be a shaft  25 , which may be used for pivotal mounting of the lever arm  70  within the housing cavity. 
         [0095]    The housing  10  may have a cylindrical boss  18  extending upwardly from the outer surface  13 , and may also have a cylindrical boss  19  extending downwardly from the interior surface  14 , into the housing cavity. Cylindrical boss  18  and boss  19  may have a through-hole  20 . The hole  20  may be used for pivotal mounting of a shaft that may extend from a locking cam  50 , or alternatively, the hole  20  may be used for pivotal mounting of a separate shaft/handle member  40 , to which the locking cam may instead be fixedly secured. 
         [0096]    The housing  10  may also have curved walls  17 A and  17 B that may protrude from the boss  19  further into the cavity, and which may provide support for the cam  50 . Also, additional walls  33 A,  33 B,  33 C, and  33 D may protrude into the housing cavity, which may permit fixedly supporting of a first and second leaf spring  90 / 90 ′ ( FIG. 5 ) therein, in conjunction with flat end surfaces  17 Ai,  17 Bi,  17 Aii, and  17 Bii of the curved walls  17 A and  17 B. 
         [0097]    As seen in  FIGS. 6-7 , the shaft/handle member  40  may have a cylindrical shaft  43 , one end of which may have a keyed protrusion  44  extending therefrom, which may have an orifice therein. At the other end of the shaft  43 , a graspable handle portion  46  may extend generally orthogonally with respect to the axis of shaft  43 . The shaft  43  of the shaft/handle member  40  may be configured to be pivotally received within the hole  20  in the housing  10 . The keyed protrusion  44  may be any suitable cross-sectional shape, and in this exemplary embodiment, the keyed protrusion is formed using a rectangular shape. 
         [0098]    The locking cam  50  is illustrated in  FIGS. 8-10  and may have a cylindrical hub  53 , with a keyed opening  54  that is shaped to match the keyed protrusion  44  of the shaft member  40 . Extending laterally away from the hub  53  may be a wall  55 , and extending laterally away from the wall  55  may be a curved cam wall  56 , which may be used to engage the tooth of the corresponding keeper, and may also be used to draw the sliding sash window in closer proximity to the master window frame (or to the other sash window for a double-hung arrangement). 
         [0099]    The curved cam wall  56  may have a protrusion  56 P protruding laterally therefrom, which may be a cylindrically shaped protrusion or a part-cylinder. The axis of the cylindrically shaped protrusion  56 P may be substantially parallel to the axis of the keyed opening  54 . 
         [0100]    Protruding away from the hub  53  may be a cylindrical member  57 , which may be generally concentric with the hub, and through which the keyed opening  54  may also extend. The cylindrical member  57  may have a first flat  58 A formed thereon, and a second flat  58 B formed thereon to be clocked 180 degrees away from the first flat  58 A. The flats  58 A and  58 B may co-act with a pair of identical leaf springs  90  and  90 ′ ( FIG. 5 ) to operate as a detent mechanism to releasably inhibit pivotal movement of the cam  50 , when the cam is at an extended (lock) position, and when at another positioned termed herein as a second retracted (unlock) position. 
         [0101]    The cylindrical member  57 A may also have a third flat  59 A formed thereon, as seen in  FIG. 19 , being located at a position that is clocked roughly 135 degrees from the first flat  58 A. A fourth flat  59 B may also be formed on the cylindrical member  57  at a position that is clocked roughly 180 degrees from the third flat  59 A. The flats  59 A and  59 B may also co-act with respect to the leaf springs  90 / 90 ′ at another sash unlocked position, which is termed herein as a first retracted unlock position. Although the detent mechanism could be formed using other component parts, and may also be formed using only one leaf spring  90 , to provide greater stability of the cam in being releasably retained at those positions, the pair of leaf springs  90 / 90 ′ may preferably be used. Note that the flats could be formed on the cylindrical hub  53 , instead of on the protruding cylindrical member  57 . 
         [0102]    Interaction between the sash lock assembly  100  and the latch assembly  200 , once installed with respect to the sliding sash window  400 , may be through the use of the lever arm  70 , which may be pivotally mounted within the housing  10 . 
         [0103]    The lever arm  70  is shown in detail within  FIGS. 11-18 . Lever arm  70  may include a hub  73 , with a mounting hole  74  therein that may be generally concentric with the hub. Extending laterally away from the axis of the hub  73  may be an arm member  75 , a portion  75 C of which may be particularly contoured to act as a follower with respect to the cam  50 . The arm member  75  may transition into a post  76  that may be generally orthogonal to the arm member  75 , and may also be generally parallel to the axis of the hub  73 . 
         [0104]    As noted above, the component parts used for sash lock assembly  100  are shown in the exploded view of  FIG. 19 . As seen therein, initial assembly of sash lock assembly  100  may proceed with leaf springs  90 / 90 ′ being installed into the housing cavity, to be positioned between the inwardly protruding walls (e.g.,  33 A,  33 B) and the flat end surfaces (e.g.,  17 Ai, and  17 Bi) of the curved walls  17 A and  17 B. The leaf springs may be secured thereat using a friction fit, or adhesive, or mechanical fasteners, etc., or any combination of such securement methods. Those wall features protruding into the housing cavity may be positioned such that the leaf springs  90  and  90 ′, when secured therein, may be at a distance away from each other that is roughly the same as the distance used between the pair of flats  58 A and  58 B on the cam  50 , which may be roughly the same as the distance between the pair of flats  59 A and  59 B. 
         [0105]    The cylindrical shaft  43  of the shaft/handle member  40  may then be pivotally received in hole  20  of housing  10 . The locking cam  50  may be joined to the shaft/handle member  40 , with the keyed protrusion  44  of the shaft member  40  being received within the keyed opening  54  of locking cam  50 , and being secured thereat using a friction fit, adhesive, mechanical fasteners, or by being welded thereto, or by using any combination of such suitable means of securing two parts together. Note that additional pivotal support for the cam  50  may be provided by the curved housing walls  17 A and  17 B pivotally receiving the hub  53  (or cylindrical portion  57 ) of the cam therebetween. 
         [0106]    Next, the hole  74  of the hub  73  of the lever arm  70  may be pivotally received upon the shaft  25  of the housing. To pivotally secure the lever arm  70  thereto, the end of the shaft  25  may be bucked like a rivet, to form a manufactured head to prevent the lever arm from slipping off of the post. Alternatively, a screw or other mechanical fastener or component part may be used maintain the pivotal mounting of the hub  73  of the lever arm  70  upon the shaft  25  of the housing  10 . 
         [0107]    The assembled lock  100  is shown in  FIGS. 20-22 , the operation of which is discussed hereinafter, in conjunction with the latch assembly  200  and the corresponding installations with respect to the sash window  400 . 
         [0108]    The latch assembly  200  may include a latch housing  210 , shown in  FIGS. 29 to 31 , which may have a simple exterior surface (e.g., generally cylindrical), the complement of which may be easily formed (e.g., bored) in the frame of the sliding sash window  400 , to permit ease of its installation therein. The housing  210  is not limited to the shape illustrated within those figures, and could take on many different appropriate shapes, including an elongated rectangular shape. However, at least a portion of the housing  210  may be desirably shaped to have a cylindrical wall defined by a cylindrical outer surface  213 , and an inner surface  215 , each of which may have a portion that may span from a first end  211  to second end  212 . At the first end  211  of the housing  210 , an annular protrusion  213 A may protrude outwardly from the cylindrical outer surface  213 . An opening  213 P may be formed in a portion of the cylindrical outer surface  213  to create a flexible tab portion  213 T, upon which may be formed a series of spaced teeth (e.g.,  214 A,  214 B,  214 C,  214 D,), which may be used for securing the housing within the opening formed in the frame of the sash window  400 . To prevent the housing from rotating within the sash window, the housing may have a pair of triangular-shpaed tabs  217  protruding outward from the outer surface  213 . Protruding inward from the interior surface  215  may be one stop or a pair of stops  216 A and  216 B. A wall  218  may also protrude inward to obstruct a portion of the hollowed out interior between the first end  211  and the second end  212 . The housing  210  being so formed may slidably receive a latch member  250  therein. 
         [0109]    Perspective views of the latch member  250  are shown in  FIGS. 32-33 , while corresponding orthogonal views are shown in  FIGS. 35-38 . The latch member  250  may extend from a first end  251  to a second end  252 , and may include a tongue  253  that may begin at the first end of the latch member and may transition into a beam  255  that may extend to its second end. The tongue  253  may have an opening  253 P formed therein, which may be a cylindrical opening. The latch member  250  may also have one stop protruding therefrom, or may instead have a pair of stops  266 A and  266 B protruding therefrom ( FIG. 36 ). 
         [0110]    The beam  255  may transition and widen to form peripheral walls about an opening  275 A, the size of which may depend upon the cross-sectional shape of the post  76  of lever arm  70  of the lock assembly  100 , to provide for engagement of the post  76  with the latch member, to couple motion therebetween. The opening  275 A may be an elongated shape, which may, for example, be generally rectangular-shaped, as shown in  FIGS. 35 and 36 . The elongated opening may be oriented so that the longer direction of the opening is substantially perpendicular to the axis  255 X of the beam  255 . The rectangular opening  275 A may therefore have a length  275 L extending substantially normal to the axial direction  255 X of the beam, and a width  275 W extending substantially parallel to the axial direction of the beam. 
         [0111]    Extending away from the far end of the peripheral walls formed about opening  275 A may be a secondary beam  255 A that may be formed substantially the same as beam  255 , and the distal end of which may similarly widen to form peripheral walls about an opening  275 B that may be constructed the same as opening  275 A. Proximate to the connection of the beam  255 A with the peripheral walls about opening  275 A may be a first notch  255 N 1  on a first side of the beam and a second notch  255 N 1  on a second side of the beam, to produce an area that may be weakened with respect to a direction being normal to the axis  255 X of the beam. The weakened area may be used to sever most of the secondary beam  255 A from the peripheral walls associated with beam  255 , where it may be necessary to use the first opening  275 A for receiving the post  76  of the lever arm  70  of the sash lock  100 , for installation of the latch assembly within a sash window frame of a particular size. A third beam  255 B with peripheral walls about an opening  275 C may be similarly formed. An additional pair of notches  255 BN 1  and  255 BN 2  may be formed to permit severing of most of the beam  255 B. 
         [0112]    Biasing of the latch member  250  relative to the housing  210  may be through the use of a suitably arranged tension spring, or by using a compression spring. For the sake of brevity, the figures herein only depict an embodiment where a compression spring is utilized. The helical compression spring  291  ( FIG. 39 ) may be received within a recess  250 R formed in the latch member  250  ( FIG. 35 ), and then the latch member and spring combination may be slidably received within the interior surface  215  of housing  210 . One end of the spring  291  may act upon the wall  253 W of the tongue  253 , while the other end of the spring may act upon the wall  218  of the housing  210  ( FIG. 29 ), to bias at least a portion of the tongue  253  to protrude out from the latch housing, as seen in  FIGS. 40 and 41 . The extent that biasing by spring  291  may cause the tongue  253  to protrude out from the housing  210  may be limited by the stops  266 A and  266 B on the tongue contacting the stops  216 A and  216 B on the housing ( FIG. 41 ). Actuation of the latch member  250  relative to the latch housing  210  may cause at least a portion of the tongue  253  to retract within the hollow of the housing (see e.g.,  FIG. 51 ). 
         [0113]    The latch assembly  200  may thus be configured to interact with the fitting assembly  300  that is shown in  FIG. 2 , and is also shown in the perspective view of  FIG. 47 . The fitting assembly  300  may be assembled using the housing  310  shown in  FIGS. 43-44 , and the post  350  shown in  FIGS. 44-46 . 
         [0114]    The housing  310  of fitting assembly  300  may be formed to have a bottom wall  313 , and a rear wall  314 . The bottom wall  313  may have an opening  313 P formed therein that may accommodate the cross-sectional shape used for the post member  350 , so that the post may be mounted therein. The rear wall  314  may have a hole  314 H, which may include a countersunk opening  314 C to accommodate a flush-head mounting screw, which may be used for mounting of the fitting assembly  300  into the track of the master window frame  500 . Since the track of the master window frame may be fairly narrow, and for other design reasons, a mounting fastener for the fitting assembly  300  may desirably be only used through the rear wall  314 . Therefore, the housing  310  may be desirably formed as a bathtub fitting, with an extra thick bottom wall  313 , and thick side walls  315  and  316 . A flexible tab  317  protruding from the second side wall  316  may be used to optimally position the fitting assembly  300  within the track of the master window frame  50 . 
         [0115]    The post member  350  is shown in  FIGS. 45-47  as having a circular cross-section, but other cross-sectional shapes may alternatively be used. For example, the post member  350  may also be desirably formed with a rectangular cross-section. The cylindrical post  350  may extend from a first end  351  to a second end  352 , and may have a knurled surface  353  ( FIG. 46 ) that may be formed proximate to the second end  352 . The knurled surface  353  may be used for better securing of the post  350  within the orifice  313 P of the housing  310 , which securement may be enhanced using a friction fit, or adhesive, etc. 
         [0116]    The fitting assembly  300  may be installed into the track  501  of the master window frame  500 , as seen in  FIG. 48 . The latch assembly  200  may be installed through an opening in the side of the sash window frame  400 , which may be seen in  FIG. 57 , while the sash lock assembly  100  may be installed upon the top of the horizontal meeting rail  401 . 
         [0117]    The latch assembly may be size adjusted (i.e., removal of unnecessary beam section  255 B or beam portions  255 A and  255 B), based upon proper positioning of the sash lock on the meeting rail, and the appropriate opening that may be formed therein. The suitable opening (e.g.,  275 A,  275 B, or  275 C) on the latch member  250  may be coordinated with and properly positioned for horizontal alignment below the sash lock assembly  100  when mounted upon the meeting rail  401  of the window frame  400  (see  FIG. 57 ). For the window frame  300  shown in  FIG. 116 , the desired opening in the meeting rail  401  for the post  76  of the lever arm  70  of the sash lock assembly  100  may be positioned a particular distance away from the end of the window frame, which may accommodate alignment with opening  275 B of the latch assembly  200  shown therein. In this case, the beam  255 B could be removed using the notches  255 BN 1  and  255 BN 2 , (although it is shown still attached within  FIG. 57 ). For a larger window, the opening in the top of the meeting rail to accommodate mounting of the sash lock assembly  100  may be more appropriately positioned to be a greater distance away from the end of the window frame, and may thus be positioned for alignment with opening  275 C of the latch assembly  200 . Similarly, for a smaller window, the opening in the top of the meeting rail to accommodate mounting of the sash lock assembly  100  may be positioned a smaller distance away from the end of the window frame, and may be positioned for alignment with opening  275 A of the latch assembly  200 . In the latter example, the connection of the beam  255 A may be severed using notches  255 N 1  and  255 N 2 . 
         [0118]    For the installation of the sash lock assembly  100  upon the meeting rail  401  of the sash window frame  400 , after the post  76  of the lever arm  70  of the sash lock is passed through a suitable opening in the top of the meeting rail, the post must be received within the elongated opening  275 B of the latch member  250  of the latch assembly  200 . However, because of the elongated cross-sectional shape of the post  76  and the protrusion  77  protruding laterally therefrom (see  FIG. 11 ), in order for the post to also be received into the elongated opening  275 B of the latch member  250  of the latch assembly  200 , the lock assembly should initially be positioned substantially transverse to the axial direction  401 AX of the meeting rail  401 A. Such initial positioning may orient the long transverse direction of the post  76  and the protrusion  77  of lever arm  70  to be perpendicular to the axial direction  301 AX of the meeting rail  301 A, so that it may be generally in-line with the lengthwise side  275 L of the rectangular opening  275 B in the latch member  250 . 
         [0119]    After insertion of the post  76  through the opening  275 B of the latch member  250 , the latch assembly  100  may then be rotated roughly 90 degrees, and then be lowered for the flat bottom surface of the sash lock housing  10  to contact and be flush with the top of the meeting rail, and be fastened thereto to using fasteners through the hollow cylindrical protrusions  15  and  16  of the housing  10 . The 90 degree rotation of the sash lock assembly  100  after inserting the post  76  of the lever arm  70  through the opening  275 B of the latch member  250  may thus orient the long transverse direction of the cross-section of the post to be parallel to the axial direction  301 AX of the meeting rail  301 A, so that it may be generally in-line with the shorter width direction  275 W of the rectangular opening  275 A in the latch member  250 . 
         [0120]    The width  275 W of the rectangular opening  275 A in the latch member  250  may be just slightly larger than the long transverse direction of the cross-section of the post  76  of lever arm  70  positioned therein (i.e., a slight clearance fit, as shown in the enlarged view of  FIG. 52 ). With the interconnection being so configured, movement imparted to the lever arm  70  of the sash lock assembly  100  may cause corresponding movement of the latch member  250  of the latch assembly  200 , and similarly, the biased movement of the latch member may cause a corresponding movement in the lever arm. The protrusion  77  may serve to prevent disconnection of the post  76  of the lever arm from the opening  275 B in the latch member  250  (i.e., prevent the latch member from falling off of the post). For further information regarding this aspect of the installation, if required, a more detailed description and corresponding illustrations are provided within Applicant&#39;s co-pending application 14/278,226. 
         [0121]    With the sash lock assembly  100  and latch assembly  200  installed with respect to the sash window  400  as described, the shaft/handle member  40  of the lock assembly may be actuated to three different positions, as seen in  FIGS. 53 ,  54 , and  55 , which may respectively correspond to the three different interrelated positions of the cam, lever arm, and latch member, as shown in  FIGS. 49. 50 , and  51 . A tactile indication may be provided to the person moving the shaft/handle member  40 , upon reaching each of those positions of the of the lock assembly  100 , as a result of the detent mechanism provided by the flats on the cam  50  and the leaf springs  90 / 90 ′. 
         [0122]    With the sash window  400  being in a closed position ( FIG. 57 ), and with the shaft/handle member  40  positioned as shown in  FIG. 53 , the cam  50  may be in the extended locking position shown in  FIG. 49  (i.e., a portion of wall  56  of the cam  50  protrudes out through the opening  12 FP of the wall  12 F of the housing  10  to engage the tooth  551  of the keeper  550 ). As seen in  FIG. 49  (and  FIG. 21 ), the cam  50  does not contact the follower portion  75 C of the arm member  75 , when in the extended locking position, and therefore, the post  76  is not actuated by the cam. As a result, the biasing of the latch member into its extended position by spring  291  also maintains the lever arm  70  in the position shown in  FIG. 49 , because of the interconnection therebetween. 
         [0123]    With the sash window  400  being in that closed position and with the latch member  250  also biased into its extended position ( FIG. 57 ), the post  350  of the fitting assembly  300  installed within the track of the master window frame  500  may be received within the opening  253 P of the tongue  253  of the latch assembly  200 . The size and positioning of post  350  may be such that it may be concentric with the opening  253 P of the tongue  253 , and with a very slight clearance fit therebetween. Therefore, with both a left-hand and right-hand sash fastener of the present invention installed on the sash window  400  ( FIG. 1 ) to engage fitting assemblies  300  installed on both side tracks of the master window frame  500 , both of the corners of the sliding sash window  400  may receive enhanced structural support in the closed and locked position. This structural support of the window may enhance its strength in the Z and X window directions shown in  FIG. 1 , beyond that which is provided by the typical tilt latch, and may prevent any significant deformation that would result in a breach in the seal between the exterior and the interior environment during extreme weather conditions (i.e., high wind loads). 
         [0124]    Alternatively, as shown in the enlarged view of  FIG. 58 , the cylindrical opening  253 P of the tongue  253  may be larger than the diameter of the post  350 , however, the relative positioning of parts may be such that there is only a slight clearance C between the side of the post most distal from the window center and the tongue  253 , with a larger clearance on the proximal side of the post. 
         [0125]    The shaft/handle member  40  may be rotated 135 degrees for the cam  50  to move from the extended locking position shown in  FIGS. 56-57 , into the first retracted unlock position shown in  FIGS. 59-60 , to permit the sash window  400  to slide in the master window frame  500 . As may be seen for the cam  50  and lever arm  70  positions within  FIG. 50 , the protrusion  56 P of the cam  50  may only then just come into proximity to (or make minimal contact with) the follower portion  75 C of the arm member  75 , so that the lever arm  70  may substantially remain unaffected by the 135 degrees of cam rotation. With the window elevated sufficiently (i.e., greater than the protruding height H of the top of post  350  above the top surface of the wall  313  of the fitting housing  310 ), the post may no longer be nested within the opening  253 P of the tongue  253  of the latch member  250 . 
         [0126]    If the user desires to tilt the sash window  400  into the room, the user may rotate the shaft/handle member  40  an additional 45 degrees for the cam  50  to move from the first retracted unlock position shown in  FIGS. 59-60 , into the second retracted unlock position shown in  FIGS. 61-62 . As may be seen for the cam  50  and lever arm  70  positions within  FIG. 51 , during the 45 degrees of rotation, the protrusion  56 P of the cam  50  may contact and drive the follower portion  75 C of the arm member  75 , so that the lever arm  70  may co-rotate. During the co-rotation, the post  76  of the lever arm  70  may oppose the biasing provided by spring  291  and drive the latch member  250  to retract from track of the master window frame into the latch housing  210 , as seen in  FIG. 62 . Once the user has tilted the sash window  400  out of the master window frame  500  and released the shaft/handle member  40 , the bias of spring  291  acting upon latch member  250  may overcome the resisting force provided by the detent mechanism, and move the tongue  253  of the latch member back into the extended position, with the follower portion  75 C of the lever arm  70  driving the cam to return to the first retracted unlock position. 
         [0127]    When the user desires to tilt the sash window  400  back into the master window frame  500 , the shaft/handle member  40  may again be rotated 45 degrees, so that the tongue may again be retracted into the latch housing  210 . When the sash window  400  is positioned back in the master window frame  500 , the shaft/handle  40  may be released, so that the tongue  253  may again be biased back into the track. The sash window  400  may then be closed, and the shaft/handle member  40  may be counter-rotated 135 degrees to lock the cam  50  with respect to the keeper  550  on the master window frame  500 . 
         [0128]    It should be noted that angular rotation amount other than 135 degrees is also possible, as long as the rotational movement from the extended locking position is sufficient to move the locking cam  50  far enough away from the keeper  550  to permit sliding movement of the sash window  400 , and although it may be desirable, the cam need not even be fully retracted within the housing  10  when in the first retracted unlock position. Therefore, the herein described 135 degree and 45 degree rotational amounts are merely exemplary, and the fastener may be constructed so that other rotational amounts may alternatively be used to reach those key positions. 
         [0129]    The examples and descriptions provided merely illustrate a preferred embodiment of the present invention. Those skilled in the art and having the benefit of the present disclosure will appreciate that further embodiments may be implemented with various changes within the scope of the present invention. Other modifications, substitutions, omissions and changes may be made in the design, size, materials used or proportions, operating conditions, assembly sequence, or arrangement or positioning of elements and members of the preferred embodiment without departing from the spirit of this invention.