Abstract:
A low-cost combination tilt-lock-latch mechanism for a sliding window that combines ease of installation and adjustment with simplicity of use. The mechanism includes at least one tilt-latch mechanism adapted for mounting in the window sash. The tilt-latch mechanism includes a housing and a plunger having a latch bolt portion retractable within the housing. A plunger latch member automatically latches the plunger in a retracted position to enable tilting of the sash. Further, the mechanism may include an actuator mechanism and a flexible linking member. The tilt-latch may include a locking member adjustable from outside the housing of the tilt latch, to lock the flexible linking member to the plunger, thereby operably coupling the actuator mechanism with the tilt-latch.

Description:
RELATED APPLICATIONS  
       [0001]     This application claims the benefit of U.S. Provisional Application No. 60/647,112, entitled WINDOW LOCK SUITABLE FOR DOUBLE AND SINGLE HUNG WINDOWS, filed Jan. 26, 2005, and U.S. Provisional Application No. 60/716,455, entitled LOCK AND LATCH SYSTEM FOR VINYL WINDOWS, filed Sep. 13, 2005, hereby fully incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION  
       [0002]     This invention relates to window locks, and more particularly to window locks for sliding windows.  
       BACKGROUND OF THE INVENTION  
       [0003]     Double-hung windows include two window sashes typically mounted for vertical movement along adjacent parallel tracks in a window frame. Traditional double-hung window designs provide poor washability, because it is difficult for a person located inside a structure in which the window is installed to wash the outside of the window pane. To fully wash the outer surface of such windows (which outer surface is the one which is most often in need of cleaning), the person cleaning the window must typically go outside the dwelling. This is not only extremely inconvenient, as the person has to walk significant distances merely to wash both sides of a single window, but it can also force a window washer, when trying to wash double and single-hung windows located at significant heights, to face the undesirable choice of either risking injury by climbing to that height or doing a relatively poor job of washing by merely reaching from a distance with a hose or a special long pole apparatus of some type. Such cleaning is still further complicated where there are screens or storm windows that must be removed prior to washing.  
         [0004]     To overcome this problem, windows of this type have developed that enable one of the sashes to be tilted inwardly to gain access to the outside surface of the window pane from within the structure. Various types of latching mechanisms have been developed to enable the sash to secure the sash in place in the frame, but to also enable tilting the sash by operating the latches. A common arrangement has such latches positioned in opposite ends of a top horizontal rail of the upper and/or lower sash, with each latch typically including a tongue or plunger which during normal operation extends out from the side of the sash into the sash track in the window frame to guide the sash for typical vertical movement. The tongue or plunger of each latch is retracted when washing is desired to free the top rail of the sash from the track so that the sash may be suitably pivoted inwardly about pivots guiding the bottom rail of the sash in the track and thereby allow the washer to easily reach the outside surface of the window pane of that sash.  
         [0005]     The tongue or plunger in many of the prior art latches is usually biased outwardly into the track by a spring structure or the like, with the tongue retracted inwardly by the washer manually pulling the tongues in toward the center of the top rail against the force of the spring as, for example, in the mechanism disclosed in U.S. Pat. No. 5,139,291. A drawback of such mechanisms, however, is that both latches must be operated simultaneously, requiring that the operator use both hands. Moreover, simultaneous operation of latch controls spaced at the far edges of the sash can be awkward, especially for wide windows. Another mechanism, disclosed in U.S. Pat. No. 5,992,907, commonly owned by the owners of the present invention and hereby fully incorporated herein by reference, has a lever operably coupled with a check rail lock assembly that simultaneously operates remotely located tilt latch assemblies.  
         [0006]     Other mechanisms linking tilt latches with a single control that also locks the sashes together are well known. For example, U.S. Pat. No. 5,398,447 (the &#39;447 patent) discloses a tilt lock latch mechanism wherein a lever positioned proximate the center of the top rail of a lower sash may be rotated in one direction to engage a keeper positioned on the upper sash proximate the lever or in the opposite direction to operate remotely located tilt latches to enable tilting of the lower sash for cleaning. U.S. Pat. No. 5,791,700 (the &#39;700 patent) discloses a tilt lock latch mechanism wherein a single control lever operates both sash locks and remote tilt latches. To accomplish this, the control lever is selectively rotatably positionable in three discrete positions: (1) a first position wherein the sash locks and the tilt latches are engaged; (2) a second position wherein the sash locks are disengaged to enable sliding of the sashes but the tilt latches are still engaged; and (3) a third position wherein the sash locks and the tilt latches are disengaged to enable sliding of the window. Similarly, U.S. Pat. No. 6,817,142 (the &#39;142 patent) and its continuation U.S. application Ser. No. 10/959,696 also disclose a tilt lock latch mechanism having such a three position control lever.  
         [0007]     Each of the above described mechanisms, however, has certain drawbacks. The &#39;447 patent mechanism, while generally simple, requires rotation of the control lever in opposite directions from a center position for unlocking and tilting. This is inconvenient and may result in unintended tilting operation of the window if an inexperienced user seeking merely to unlock the window rotates the lever in the wrong direction. Also, the &#39;447 patent mechanism requires that a separate control be manipulated by the operator to maintain the control lever in a desired position. The &#39;700 patent mechanism, while enabling same-direction rotation of the control lever, is relatively complex, and may be expensive to manufacture and difficult to install and adjust. The &#39;142 patent mechanism may be difficult to adjust, requiring partial disassembly and manipulation of a screw on the tilt latches for tensioning the strap connecting the control lever with the tilt latches. Moreover, the &#39;142 patent describes a separate button that must be manipulated for engaging or releasing the tilt latches. This may be confusing for a user and result in frustration when attempting to tilt the window for cleaning, or in failure to properly reengage the tilt latches when cleaning is complete.  
         [0008]     Another mechanism, described in U.S. Pat. No. 6,877,784, includes a rotary lever with sash lock that actuates remote tilt latches through an extensible member. A drawback of this mechanism, however, is that it is relatively complex, including a spring-loaded control lever and a pivoting trigger release mechanism in each of the tilt latches, making it relatively more expensive to produce and reducing reliability. Further, there are no simple means provided for attaching the extensible member to the tilt latches, nor is any means for adjusting length and tension of the extensible member provided.  
         [0009]     U.S. patent application Ser. No. 10/289,803 discloses a similar tilt lock latch mechanism including a three-position control lever that actuates a sash lock as well as remotely located tilt latches. One drawback of this mechanism, however, is that a relatively complicated fastener arrangement is used for connecting the actuator spool to the tilt latch connector, affecting cost of manufacture and usability of the mechanism. Also, the tilt latches are not equipped with any mechanism for holding the latches in the retracted position. When the window is tilted into position after cleaning, the protruding latch bolts may mar the window frame if the operator forgets to manually retract them. Moreover, a separate button is described that must be manipulated for engaging or releasing the tilt latches, thus complicating operation.  
         [0010]     What is still needed is a low-cost combination tilt-lock-latch mechanism for a double hung window that is easy to install and adjust, and simple to use.  
       SUMMARY OF THE INVENTION  
       [0011]     The present invention addresses the need for a low-cost combination tilt-lock-latch mechanism for a sliding window that combines ease of installation and adjustment with simplicity of use. In embodiments of the invention, an integrated lock and tilt-latch mechanism for a sliding window includes at least one tilt-latch mechanism adapted for mounting in the window sash. The tilt-latch mechanism includes a housing presenting a longitudinal axis and having an aperture defined in a first end thereof, a plunger having a latch bolt portion, a plunger latch member, and first and second biasing members. The plunger is disposed in the housing and is selectively slidably shiftable along the longitudinal axis of the housing between an extended position in which the latch bolt portion of the plunger projects through the aperture in the housing to engage the window frame so as to prevent tilting of the sash, and a retracted position in which the latch bolt portion of the plunger is substantially within the housing to enable tilting of the sash. The first biasing member is arranged so as to bias the plunger toward the extended position. The plunger latch member is operably coupled with the tilt-latch housing and is arranged so as to be selectively slidably shiftable in a direction transverse to the longitudinal axis when the plunger is in the retracted position. The plunger latch member is shiftable between a first position in which the plunger latch member engages and prevents shifting of the plunger and a second position in which the plunger latch member enables shifting of the plunger. The second biasing member arranged so as to bias the plunger latch member toward the first position so that when the plunger is retracted, the plunger latch automatically shifts to retain the plunger in the retracted position. The plunger latch may include a trigger portion arranged so that when the sash is tilted into position in the frame, the trigger portion contacts the window frame or second sash, shifting the plunger latch so as to release the plunger. The mechanism further includes an actuator mechanism adapted for mounting on the sash. The actuator mechanism includes a housing, a control on the housing, a lock member, and a tilt-latch actuator member. The lock member and the tilt-latch actuator member are operably coupled with the control. A linking member operably couples the tilt-latch actuator member and the plunger of the tilt-latch mechanism. The control is selectively positionable among at least three positions including a locked position in which the lock member is positioned so that a portion of the lock member extends from the housing of the actuator mechanism, an unlocked position in which the lock member is positioned substantially within the housing of the actuator mechanism, and a tilt position in which the lock member is positioned substantially within the housing of the actuator mechanism and the plunger of the tilt-latch mechanism is positioned in the retracted position.  
         [0012]     In another embodiment of the invention, an integrated lock and tilt-latch mechanism for a sliding window having a frame with at least one sliding sash therein, the sash also tiltably positionable relative to the frame, includes an actuator mechanism and at least one tilt-latch adapted for mounting on the sash, and a flexible linking member. The actuator mechanism includes a housing, a control, a lock member, and a tilt-latch actuator member. The lock member and the tilt-latch actuator member are operably coupled with the control, and the tilt-latch actuator has structure for receiving and applying tension to the flexible linking member. The at least one tilt-latch includes a tilt-latch housing presenting a longitudinal axis and having an aperture defined in a first end thereof. A plunger is disposed in the tilt-latch housing, the plunger having a latch bolt portion and being selectively slidably shiftable along the longitudinal axis between an extended position in which the latch bolt portion of the plunger projects through the aperture and a retracted position in which the latch bolt portion of the plunger is substantially within the tilt-latch housing. The plunger defines a channel for receiving the flexible linking member and has a locking member positioned proximate the channel. The locking member is selectively shiftably adjustable from a location outside the tilt-latch housing between a first position in which the flexible linking member is freely slidable in the channel to enable insertion and removal of the flexible linking member, and a second position in which the locking member is engaged with the flexible linking member to fixedly secure the flexible linking member in the channel, thereby operably coupling the tilt-latch actuator with the plunger of the tilt-latch. The control is selectively positionable between at least three positions including a locked position in which the lock member is positioned so that a portion of the lock member extends from the housing of the actuator mechanism, an unlocked position in which the lock member is positioned substantially within the housing of the actuator mechanism, and a tilt position in which the lock member is positioned substantially within the housing of the actuator mechanism and the plunger of the tilt-latch mechanism is positioned in the retracted position.  
         [0013]     In a further embodiment of the invention, a window includes a frame, a first sash and a second sash, each slidable in the frame. The first sash is also tiltably positionable relative to the frame. An integrated lock and tilt-latch mechanism is positioned on the first sash, including an actuator mechanism and at least one tilt-latch adapted for mounting on the sash, and a flexible linking member. The actuator mechanism inlcudes a housing, a control, a lock member, and a tilt-latch actuator member. The lock member and the tilt-latch actuator member are operably coupled with the control and the tilt-latch actuator has structure for receiving and applying tension to the flexible linking member. The at least one tilt-latch includes a tilt-latch housing presenting a longitudinal axis and having an aperture defined in a first end thereof, and a plunger disposed in the tilt-latch housing. The plunger has a latch bolt portion and is selectively slidably shiftable along the longitudinal axis between an extended position in which the latch bolt portion of the plunger projects through the aperture and a retracted position in which the latch bolt portion of the plunger is substantially within the tilt-latch housing. The plunger defines a channel for receiving the flexible linking member and has a locking member positioned proximate the channel. The locking member is selectively shiftably adjustable, from a location outside the tilt-latch housing, between a first position in which the flexible linking member is freely slidable in the channel to enable insertion and removal of the flexible linking member, and a second position in which the locking member is engaged with the flexible linking member to fixedly secure the flexible linking member in the channel, thereby operably coupling the tilt-latch actuator with the plunger of the tilt-latch. The control is selectively positionable between at least three positions including a locked position in which the lock member is positioned so that a portion of the lock member extends from the housing of the actuator mechanism, an unlocked position in which the lock member is positioned substantially within the housing of the actuator mechanism, and a tilt position in which the lock member is positioned substantially within the housing of the actuator mechanism and the plunger of the tilt-latch mechanism is positioned in the retracted position.  
         [0014]     In yet another embodiment of the invention, a window includes a frame, a first sash and a second sash, each slidable in the frame, wherein the first sash is also tiltably positionable relative to the frame. An integrated lock and tilt-latch mechanism is positioned on the first sash, the mechanism including at least one tilt-latch mechanism having a housing presenting a longitudinal axis, a plunger having a latch bolt portion, a plunger latch member, and first and second biasing members. The plunger is disposed in the housing and is selectively slidably shiftable along the longitudinal axis between an extended position in which the latch bolt portion of the plunger engages the frame of the window to prevent tilting of the first sash and a retracted position in which the latch bolt portion of the plunger is substantially within the housing to enable tilting of the first sash. The first biasing member is arranged so as to bias the plunger toward the extended position. The plunger latch member is operably coupled with the housing and arranged so as to be selectively slidably shiftable in a direction transverse to the longitudinal axis when the plunger is in the retracted position. The plunger latch member is shiftable between a first position in which the plunger latch member engages and prevents shifting of the plunger and a second position in which the plunger latch member enables shifting of the plunger. The second biasing member is arranged so as to bias the plunger latch member toward the first position. The mechanism further includes an actuator mechanism including a housing, a control on the housing, a lock member, and a tilt-latch actuator member. The lock member and the tilt-latch actuator member are operably coupled with the control with a linking member operably coupling the tilt-latch actuator member and the plunger of the at least one tilt-latch mechanism. The control is selectively positionable among at least three positions including a locked position in which the lock member is engaged with the second sash to prevent relative sliding movement of the first and second sashes, an unlocked position in which the lock member is free from contact with the second sash, and a tilt position in which the lock member is free from contact with the second sash and the plunger of the tilt-latch mechanism is positioned in the retracted position to enable tilting of the first sash. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]      FIG. 1  is a perspective view of a double-hung window with integrated lock and tilt-latch assembly according to an embodiment of the present invention;  
         [0016]      FIG. 2  is a fragmentary perspective view of an inner and outer sash of a double-hung window with integrated lock and tilt-latch assembly according to an embodiment of the present invention;  
         [0017]      FIG. 3  is a fragmentary perspective view of the top sash rail of a window with integrated lock and tilt-latch assembly according to an embodiment of the present invention;  
         [0018]      FIG. 4  is an exploded view of the assembly depicted in  FIG. 3 ;  
         [0019]      FIG. 5  is an exploded view of a tilt-latch assembly according to an embodiment of the invention;  
         [0020]      FIG. 6  is an exploded view of a tilt-latch assembly according to another embodiment of the invention;  
         [0021]      FIG. 7  is a cross-sectional view of the plunger portion of the tilt-latch assembly of  FIG. 6  taken at Section  7 - 7  of  FIG. 6 ;  
         [0022]      FIG. 8  is a perspective view of a first portion of the housing of the tilt latch assembly of  FIG. 6 ;  
         [0023]      FIG. 9  is a side elevation view of the housing portion depicted in  FIG. 8 ;  
         [0024]      FIG. 10  is a perspective view of a second portion of the housing of the tilt latch assembly of  FIG. 6 ;  
         [0025]      FIG. 11  is a side elevation view of the housing portion depicted in  FIG. 10 ;  
         [0026]      FIG. 12  is a bottom perspective view of a housing cover and control lever according to an embodiment of the present invention;  
         [0027]      FIG. 13  is an exploded view of a tilt-latch assembly according to yet another embodiment of the invention;  
         [0028]      FIG. 14  is an exploded view of the base portion of an actuator assembly according to an embodiment of the invention;  
         [0029]      FIG. 15  an assembled view of the base portion of an actuator assembly depicted in  FIG. 14 ;  
         [0030]      FIG. 16  is an exploded view of an actuator assembly according to an embodiment of the invention;  
         [0031]      FIG. 17  is an assembled view of the actuator assembly depicted in  FIG. 16 ;  
         [0032]      FIG. 18  is an exploded view of the housing cover and control lever of an actuator assembly according to an embodiment of the present invention;  
         [0033]      FIG. 19  is an assembled view of the housing cover and control lever depicted in  FIG. 18 ;  
         [0034]      FIG. 20  is a perspective view of the spool of an actuator assembly according to an embodiment of the invention;  
         [0035]      FIG. 21  is a cross-sectional view of the spool depicted in  FIG. 20  taken at Section  21 - 21  of  FIG. 22 ;  
         [0036]      FIG. 22  is a bottom plan view of the spool depicted in  FIG. 20 ;  
         [0037]      FIG. 23  is a side view of the spool depicted in  FIG. 20 ;  
         [0038]      FIG. 24  is a top plan view of the spool depicted in  FIG. 20 ;  
         [0039]      FIG. 25  is a top perspective view of the sweep cam of an actuator assembly according to an embodiment of the invention;  
         [0040]      FIG. 26  is a bottom plan view of the sweep cam depicted in  FIG. 25 ;  
         [0041]      FIG. 27  is a cross-sectional view of sweep cam depicted in  FIG. 20  taken at Section  27 - 27  of  FIG. 28 ;  
         [0042]      FIG. 28  is a top plan view of the sweep cam depicted in  FIG. 25 ;  
         [0043]      FIG. 29  is a top plan view of the pick plate of an actuator assembly according to an embodiment of the invention;  
         [0044]      FIG. 30  is a bottom plan view of the pick plate depicted in  FIG. 29 ;  
         [0045]      FIG. 31  is a fragmentary perspective view of the top sash rail of a window with integrated lock and tilt-latch assembly according to an alternative embodiment of the present invention;  
         [0046]      FIG. 32  is an exploded view of the top sash rail of a window with integrated lock and tilt-latch assembly depicted in  FIG. 31 ;  
         [0047]      FIG. 33  is an exploded view of the tilt-latch portion of the integrated lock and tilt-latch assembly depicted in  FIGS. 31 and 32 ;  
         [0048]      FIG. 34  is a perspective view of a tilt-latch assembly according to an embodiment of the invention with the housing depicted in phantom to reveal structures enabling locking of a linking member from outside the housing with an Allen wrench;  
         [0049]      FIG. 35  depicts the tilt-latch assembly of  FIG. 34  with the Allen wrench engaged with the locking cam member;  
         [0050]      FIG. 36  is a perspective view of an integrated lock and tilt-latch assembly according to the present invention in a “locked” position;  
         [0051]      FIG. 37  is a perspective view of an integrated lock and tilt-latch assembly according to the present invention in an “unlocked” position;  
         [0052]      FIG. 38  is a perspective view of an integrated lock and tilt-latch assembly according to the present invention in a “tilt” position;  
         [0053]      FIG. 39  is a bottom perspective view of the actuator assembly of an integrated lock and tilt-latch assembly according to the present invention in a “locked” position;  
         [0054]      FIG. 40  is a bottom perspective view of the actuator assembly of an integrated lock and tilt-latch assembly according to the present invention in an “unlocked” position;  
         [0055]      FIG. 41  is a bottom perspective view of the actuator assembly of an integrated lock and tilt-latch assembly according to the present invention in a “tilt” position;  
         [0056]      FIG. 42  is a perspective view of a tilt-latch assembly according to an embodiment of the invention with the housing depicted in phantom revealing the linking member passage and locking member prior to locking of the linking member;  
         [0057]      FIG. 43  depicts the tilt-latch assembly of  FIG. 42  with the locking cam member positioned to lock the linking member to the plunger;  
         [0058]      FIG. 44  is a top perspective view of the body of the base assembly of an actuator assembly according to an embodiment of the present invention;  
         [0059]      FIG. 45  is a bottom plan view of the body depicted in  FIG. 44 ;  
         [0060]      FIG. 46  is a top plan view of the body depicted in  FIG. 44 ;  
         [0061]      FIG. 47  is a perspective view of a keeper according to an embodiment of the present invention;  
         [0062]      FIG. 48  is a rear elevation view of the keeper depicted in  FIG. 47 ; and  
         [0063]      FIG. 49  is a front elevator view the keeper depicted in  FIG. 47 . 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0064]     As depicted in  FIG. 4 , tilt lock latch assembly  30  generally includes actuator assembly  32 , tilt latch assemblies  34 , and linking member  36 . Actuator assembly  32  generally includes a housing  38  defined by base assembly  40  and housing cover  42 . Control lever  44  is coupled with housing cover  42  through aperture  46 , which receives shank  48  of lever  44  therethrough. Shank  48  has upper portion  50  which is generally cylindrical in shape and lower portion  52  which defines flats  54 ,  54 A. Full height protuberance  55  extends outwardly from flat  54 A, while half height protuberance  55 A extends outwardly from flat  54 . Retainer  56  is received on upper portion  50  of shank  48  and retains lever  44  on housing cover  42  so that lever  44  is rotatable about axis A-A relative to housing cover  42  as annotated in  FIG. 12 .  
         [0065]     As depicted in  FIGS. 14-17  and  44 - 46 , base assembly  40  generally includes body  58 , sweep cam  60 , spool  62 , detent spring  64 , housing retainer  66 , and pick plate  68 . Underside  70  of body  58  defines semicircular recess  72  which receives sweep cam  60 , and shallow recess  74  which receives pick plate  68 . Aperture  76  extends through from recess  72  to top surface  78  of body  58 . Boss  80  surrounds aperture  76  in recess  72 , and defines inner recess  81  around aperture  76 . Spring receiver  82  intersects with inner recess  81  at inner edge  84  of aperture  76 . Detent spring  64  is received in spring receiver  82  with point  86  of bend  88  facing away from aperture  76 . Stop  89  projects from boss  80  adjacent back edge  89 A of body  58 . Spool housing  90  projects downwardly from underside  70  and generally includes inner wall  92 , outer wall  94  and spool detent  96 . Inner wall  92  and outer wall  94  define slots  98 ,  100 , which are aligned in the longitudinal direction of body  58 . Chamfers  101  may be provided at the edges of slots  98 ,  100 . Aperture  102  extending through body  58  to top surface  78  is defined in top wall  104  of spool housing  90 . Spool detent  96  is positioned adjacent inner wall  92  and has projection  106  at bottom end  108  extending inwardly toward spool housing  90 .  
         [0066]     Shallow recess  74  is shaped conformingly with and receives pick plate  68 . Pivot post  109  is positioned at end  109 A of recess  74  and has a pair of branches  109 B,  109 C, each with an outwardly extending projection  109 D at the bottom end thereof. Tab  109 E extends inwardly toward  72  from opposite edge  109 F of recess  74 .  
         [0067]     Sweep cam  60  has shaft portion  110  defining opening  112  and cam portion  114  extending radially from shaft portion  110 , as depicted in  FIGS. 25-28 . Opening  112  has generally flat sides  116 ,  118 , but with full height notch  120  formed in side  118 , and half-height notch  121  formed in side  116  and extending half the length of opening  112  from end  121 A of shaft portion  110 . Cam portion  114  has outer wall  122  spaced apart and connected with shaft portion  110  by web  124 . Circumferential recess  125  is defined in web  124 . Leading edge  126  of outer wall  122  is tapered upwardly from tip  128  to shoulder  130 , at which point the full height of outer wall  122  is reached. Gear segment  132  is formed in outer wall  122  at bottom edge  134  opposite leading edge  126  and shoulder  130 , and is positioned slightly radially outward from the remainder of outer wall  122 . Projections  136 ,  137 , extend outwardly from outer surface  138  of shaft portion  110  proximate web  124 . Post  140  projects downwardly from bottom surface  142  of sweep cam  60  proximate opening  112 .  
         [0068]     Sweep cam  60  is rotatably received in recess  72  of body  58  with bottom surface  142  facing downward and shaft portion  110  extending through aperture  76 . Projections  136 ,  137 , travel within inner recess  81 , but engage in bend  88  of detent spring  64  to provide detents at two positions in the rotational travel of sweep cam  60 . Stop  89  slides within circumferential recess  125 . Pick plate  68  defines aperture  144  at narrow end  146 , and curved slot  148 . Pick plate  68  is received in shallow recess  74  covering sweep cam  60  and retaining it in recess  72 . Pivot post  109  is received through aperture  144  so that pick plate  68  is pivotable about pivot post  109  in a narrow path of travel corresponding with shallow recess  74 . Curved edge  150  is received under tab  109 E while projections  109 D extend outwardly on either side of aperture  144  to retain pick plate  68  in position. Post  140  extends through curved slot  148  to enable actuation of pick plate  68  with rotation of sweep cam  60  as described further hereinbelow.  
         [0069]     Spool  62  generally includes barrel portion  152  and shaft portion  154  as depicted in  FIGS. 20-24 . Barrel portion  152  defines slot  156  extending upwardly from bottom edge  158 . Mouth  160  of slot  156  may have chamfered edges  162 . Gear sector  164  is formed in a portion of top edge  166  of barrel portion  152 . Notch  168  is defined in barrel portion  152  near bottom edge  158 . Shaft portion  154  extends from barrel portion  152  and includes a pair of branches  170 ,  172 , each with an outward projection  174  proximate end  176 .  
         [0070]     Spool  62  is rotatably received in spool housing  90  with shaft portion  154  extending through aperture  102 . On top surface  78  of body  58 , projections  174  extend on either side of aperture  102  to retain spool  62  in spool housing  90 . Projection  106  of spool detent  96  engages in notch  168  to form a detent in the rotational travel of spool  62 . With projection  106  engaged in notch  168 , slot  156  is aligned with slots  98 ,  100 , in spool housing  90 .  
         [0071]     Top surface  78  of body  58  defines raised portion  178  corresponding with recess  72 . Projections  180 ,  182 , extend from raised portion  178  on either side of aperture  76 . Posts  184 ,  186 , extend from top surface  78  on either side of raised portion  178 . Posts  184 ,  186 , define semicylindrical recesses  188 ,  190 , facing toward raised portion  178 . Apertures  192 ,  194 ,  196 , extend through body  58 .  
         [0072]     As depicted in  FIGS. 14 and 15 , housing retainer  66  has planar central portion  198  defining aperture  200 , and square apertures  202 ,  204 . Each square aperture  202 ,  204 , has a pair of upwardly bent tabs  206  on opposing sides thereof. Ears  208 ,  210 , extend outwardly and angle downwardly from the plane defined by central portion  198 . Housing retainer  66  is received on raised portion  178  with projections  180 ,  182 , extending through square apertures  202 ,  204 . Tabs  206  engage on the sides of projections  180 ,  182  to retain housing retainer  66  is place. Outer edges  212  of ears  208 ,  210 , are positioned at the inner side of semicylindrical recesses  188 ,  190 .  
         [0073]     Housing cover  42  is received on top surface  78  of body  58  with posts  214 ,  216 , received in semicylindrical recesses  188 ,  190 , respectively as depicted in  FIGS. 16-17 . Outer edges  212  of ears  208 ,  210 , frictionally engage posts  214 ,  216  to securely retain housing cover  42  on base assembly  40 . Guide post  218  is received in aperture  196  to assist with accurate alignment of housing assembly  38  with base assembly  40 . Shank  48  extends into opening  112  of sweep cam  60  so that full height protuberance  55  mates with notch  120  and half-height protuberance mates with half-height notch  121 , thereby coding lever  44  with sweep cam  60 .  
         [0074]     Body  58  and spool  62  are desirably made from easily moldable, durable polymer material such as acetal or nylon. Lever  44 , housing cover  42 , and sweep cam  60 , are preferably cast from suitable metallic material such as zinc alloy. Pick plate  68  and housing retainer  66  are preferably die cut from metallic sheet material. Any of the above components, however, may be made from any other suitable material such as polymer or metal. In the depicted embodiments, actuator assembly  32  is easily assembled by mating sweep cam  60  and spool  62  with body  58 . Pick plate  68  may then be positioned under tab  109 E and aperture  144  pressed down on pivot post  109  to retain sweep cam  60  in place. Lever  44  may likewise be assembled on housing cover  42  by pressing retainer  56  on shank  48  with an arbor press. Housing retainer  66  may be pressed or pushed onto projections  180 ,  182 , and the assembly completed by mating housing cover  42  on body  58  as described above.  
         [0075]     As depicted in  FIGS. 5-11 , each tilt latch assembly  34  generally includes housing  220 , plunger  222 , primary spring  224 , plunger latch  226 , latch spring  228 , and locking cam  230 . Housing  220 , generally includes barrel portion  232  and face plate  234 . In embodiments of the invention as depicted, for example, in  FIGS. 5, 6 ,  8 - 11 , and  13 , housing  220  may be formed in two sections  236 ,  238 , which mate along the longitudinal axis of housing  220 . In these embodiments first housing section  236  has projecting hooks  240 , which engage shoulder structures  242  of second housing section  238  to secure the two sections  236 ,  238 , together. Second housing section  238  may also have locating pins  244 , which are received in recesses  246  to inhibit relative movement between the sections  236 ,  238 .  
         [0076]     Plunger  222  generally includes latch bolt portion  248 , central body portion  250 , and tail portion  252 . End  253  of latch bolt portion  248  is tapered from leading edge  253 A to shoulder  253 B. Channel  254  extends axially from end  256  through tail portion  252 . Central body portion  250  defines lock cavity  258  which includes a first portion  260  extending longitudinally within plunger  222 , and a second portion  262  extending transversely to first portion  260 . Channel  254  continues axially from tail portion  252  through second portion  262  of lock cavity  258 , and emerges at outer surface  264  of central body portion  250  proximate shoulder  253 B of latch bolt portion  248 .  
         [0077]     Plunger  222  is received in barrel portion  232  of housing  220  with latch bolt portion  248  extending through conformingly shaped aperture  266  defined by face plate  234 . Primary spring  224  is received over tail portion  252  and bears against back wall  268  of housing  220  and central body portion  250  to bias plunger  222  toward face plate  234 .  
         [0078]     Locking cam  230  generally includes axle portion  270  and radial protrusion  272 . End  274  of axle portion  270  has hex socket  276  adapted to receive an Allen wrench of standard dimension. Locking cam  230  is received in lock cavity  258  with axle portion  270  extending axially and rotatable within first portion  260  and radial protrusion  272  within second portion  262 . Bore  278  is axially aligned with axle portion  270  and extends from first portion  260  of lock cavity  258  through to front end  280  of central body portion  250  proximate face  282  of latch bolt portion  248 . Adjustment latch arm  284  extends rearwardly from front wall  286  of central body portion  250 , and includes angled portion  288  which intersects bore  278  and laterally projecting tab  290  at end  292 .  
         [0079]     Plunger latch  226  has plate portion  294  defining aperture  296  which is conformingly shaped with the cross-section of latch bolt portion  248 . Trigger portion  298  extends from plate portion  294  and has bent end portion  300 . Plate portion  294  is slidingly received in transverse slot  302  in face plate  234 . Latch spring  228  is received in recess  304  and bears against edge  306  of plate portion  294  to bias plunger latch  226  in the direction of trigger portion  298 .  
         [0080]     In embodiments of the invention housing  220  and plunger  222  of tilt latch assembly  34  are made from low-cost, easily formable acetal polymer material. These components, however, may also be made from any material having sufficient strength and suitable durability characteristics. Primary spring  224 , plunger latch  226 , latch spring  228 , and locking cam  230  are desirably made from metallic material, but may also be made from any other suitable material. In the depicted embodiments, tilt-latch assembly  34  may be easily assembled by first assembling plunger latch  226  and latch spring  228  with separate housing sections  236 ,  238 , and locking cam  230  and primary spring  224  with plunger  222 . Plunger  222  may then be placed in one of housing sections  236 ,  238 , and the housing sections snapped together by mating projecting hooks  240  with shoulder structures  242  and locating pins  244  with recesses  246 .  
         [0081]     Tilt lock latch assembly  30  is received in top rail  308  of inside sash  310  of a double hung sash window  312 . Top rail  308  has cavity  314  defined in top surface  316  for receiving base assembly  40  with spool  62  disposed in lower cavity portion  318 . Lateral bore  320  extends between side faces  322 ,  324 , of top rail  308  and intersects lower cavity portion  318 .  
         [0082]     Tilt lock latch assembly  30  may be assembled by linking each of two tilt latch assemblies  34  disposed in lateral bore  320  of the window  312  with linking member  36 , and placing actuator assembly  32  in cavity  314  to engage linking member  36  with spool  62 . Linking member  36  is preferably formed from a suitable stretch-resistant flexible polymer material. Linking member  36  is engaged with the first tilt latch assembly by inserting an Allen wrench through bore  278  and engaging hex socket  276  of locking cam  230  as depicted in  FIGS. 34-35 . As the Allen wrench is inserted, it forces adjustment latch arm  284  outwardly toward barrel portion  232  of housing  220 , engaging tab  290  in aperture  326  to lock plunger  222  axially within housing  220  as the adjustment is made. Once engaged in hex socket  276 , the Allen wrench is rotated to rotate locking cam  230  so that radial protrusion  272  is clear of channel  254 . An end  328  of linking member  36  is then inserted in channel  254  at end  256  and threaded through channel  254  until it extends from housing  220  proximate latch bolt portion  248  as depicted in  FIG. 42 . The Allen wrench is then rotated in the opposite direction as depicted in  FIG. 43  to rotate locking cam  230  so that radial protrusion  272  forces linking member  36  into second portion  262  of lock cavity  258 . In this position, linking member  36  is frictionally locked within and secured to plunger  222 . The Allen wrench is then withdrawn from bore  278 , enabling tab  290  to recede from aperture  326 . Excess linking member  36  may then be trimmed off flush with face plate  234 .  
         [0083]     With the first tilt latch assembly  34  disposed in, and linking member  36  extending through, lateral bore  320  and trigger portion  298  facing outer sash  327 , linking member  36  may be engaged with the second tilt latch assembly  34  by the same process as described above. With the second tilt latch assembly  34  disposed in lateral bore  320  with trigger portion  298  facing outer sash  327 , and with the Allen wrench inserted in bore  278  of the first tilt latch assembly  34  to prevent its plunger  222  from being retracted, linking member  36  is drawn relatively taut before being locked in place and trimmed. Once linking member  36  is in place and taut, base assembly  40  of actuator assembly  32  may be dropped into cavity  314  so that spool  62  is received in lower cavity portion  318 . As spool  62  enters lower cavity portion  318 , chamfers  101  and  162  guide linking member  36  into slots  98 ,  100 , in spool housing  90  and slot  156  of spool  62  respectively. Fasteners  328  may then be driven through apertures  192 ,  194 , to secure actuator assembly  32  to top rail  308  and housing assembly  38  engaged with base assembly  40  to complete assembly.  
         [0084]     In operation, with inside sash  310  and outer sash  327  in a closed position as depicted in  FIG. 1 , lever  44  may be positioned in a first position as depicted in  FIG. 39 , wherein outer wall  122  of sweep cam  60  is received in optional keeper  330  or other structure on outer sash  327 , thereby locking inside sash  310  and outer sash  327  together. Projection  136  of sweep cam  60  is engaged in bend  88  of detent spring  64  to provide a detent at this “locked” position of lever  44 . In this first position, projection  106  of spool detent  96  is engaged in notch  168  of spool  62  and spool  62  remains aligned so that connecting member  36  is not under tension and latch bolt portions  248  of latch bolts  34  project outwardly into grooves  332  in window frame  334 , thereby preventing tilting of inside sash  310 . Pick plate  68  is positioned with leading edge  335  extending under sweep cam  60  to prevent tampering from outside the window.  
         [0085]     Window  312  may be unlocked by rotating lever  44  to a second position as depicted in  FIG. 40 . In this second position, sweep cam  60  is substantially within actuator assembly  32  and does not engage keeper structure  330  so that inside sash  310  and outer sash  327  are free to slide vertically in window frame  334 . Projection  137  of sweep cam  60  is engaged in bend  88  of detent spring  64  to provide a detent at this “unlocked” position of lever  44 . Once again, latch bolt  34  are not retracted and project outwardly into grooves  332  to prevent tilting of inside sash  310 . Projection  106  of spool detent  96  is still engaged in notch  168  of spool  62 . As sweep cam  60  rotates from the “locked” to the “unlocked” position, post  140  travels in curved slot  148  of pick plate  68 , rotating pick plate  68  inwardly about pivot post  109  so that leading edge  335  clears outer sash  327 .  
         [0086]     With window  312  unlocked, inside sash  310  may be tilted inward by rotating lever  44  to a third position as depicted in  FIG. 41 . As lever  44  rotates sweep cam  60 , gear segment  132  engages gear sector  164  of spool  62  causing spool  62  to rotate, thereby applying tension to connecting member  36 . The tension on connecting member  36  draws plunger  222  of each tilt latch assembly  34  inwardly toward actuator assembly  32 , sliding plunger  222  within housing  220  against the bias of primary spring  224  and drawing latch bolt portion  248  within housing  220 . As leading edge  253 A of latch bolt portion  248  clears plate portion  294  of plunger latch  226 , latch spring  228  urges plunger latch  226  in the direction of outer sash  327  so that plate portion  294  partially blocks aperture  266 . Leading edge  253 A of latch bolt portion  248  engages plate portion  294 , holding plunger  222  retracted within housing  220 . Trigger portion  298  projects slightly from the outer face  336  of top rail  308 . With lever  44  and tilt latches  34  in this “retracted” position, inside sash  310  may be tilted inwardly to gain access to the outside of the window. No detent or spring biasing of lever  44  is provided in the “retracted” position, and lever  44  may be freely rotated back to the “unlocked” position detent, or may remain at any angular position between the “unlocked” position detent and the “stop” position where sweep cam  60  contacts stop  89 .  
         [0087]     Once the window cleaning or other operation is completed and it is desired to return inside sash  310  to its operable position, inside sash  310  may be simply tilted back into position. Trigger portion  298  contacts outer sash  327 , urging plunger latch  226  against the bias of latch spring  228 . When plunger latch  226  clears leading edge  253 A of latch bolt portion  248 , primary spring  224  urges plunger  222  in the direction away from actuator assembly  32 , so that latch bolt portion  248  extends outwardly through aperture  266  and engages in grooves  332 .  
         [0088]     In an alternative embodiment of the invention depicted in  FIGS. 31-33 , top rail  308  is substantially hollow as is typically the case in vinyl window construction. Reinforcing insert  338  fits inside hollow top rail  308  to provide support for the tilt-latch assemblies  34 . Housing  220  of each tilt-latch assembly  34  has spring securing tabs  340  projecting on opposite sides proximate outer end  342 . Each tab  340  is resiliently attached to housing  220  at hinge line  344 . Outer end  346  is normally spaced apart from housing  220 , but is capable of being pressed inwardly into opening  348  in barrel portion  232  Lip  349  extends outwardly around perimeter  349 A of end wall  349 B. Housing  220  further has opposing flats  350 ,  352 . Flat  350  has longitudinal ridge  354  defined thereon.  
         [0089]     Tilt-latch assembly  34  is received through apertures  356  in top rail  308  and inside reinforcing insert  338 . Insert  338  is preferably made from metal, but may also be made from any other suitably rigid and durable material. Flats  350 ,  352 , mate with inside walls  358 ,  360 , of reinforcing insert  338  respectively to inhibit undesired rotation of tilt-latch assembly  34  about its longitudinal axis. Longitudinal ridge  354  mates with corresponding groove  362  in inside wall  358  so that tilt-latch assembly  34  is coded for proper orientation. As each tilt-latch assembly  34  is advanced into aperture  356 , tab  340  contacts edge  364 , forcing outer end  346  inwardly. Once outer end  346  clears edge  364  and lip  349  contacts outer surface  366  of top rail  308 , outer end  346  springs outwardly to engage inner surface (not depicted) of top rail  308  to retain tilt-latch assembly  34  in place.  
         [0090]     As depicted in  FIGS. 47-49 , optional keeper  330  generally includes flange portion  368  defining a finished outer surface  369  and skirt portion  370 . Skirt portion  370  defines recess  372  for receiving outer wall  122  of sweep cam  60 . Projection  374  engages in circumferential recess  125  of sweep cam  60  when sweep cam  60  is rotated to the “locked” position. Openings  376  may be defined in skirt portion  370  for receiving fasteners (not depicted) to secure keeper  330  to bottom rail  378  of outer sash  327  at a location adjacent actuator assembly  32  when bottom rail  378  is adjacent top rail  308  of inside sash  310 .