Abstract:
A multi-point sash lock assembly being shiftable between a locked and an unlocked disposition includes a tie bar assembly including a tie bar guide, the tie bar guide having at least one guide end, the guide end being integrally, unitarily formed. A multi-point sash lock assembly for securing a rounded side of a window to a rounded window frame and a method of forming a multi-point sash lock assembly are further included.

Description:
RELATED APPLICATION  
       [0001]     The present application claims the benefit of U.S. Provisional Application No. 60/677,429 filed May 2, 2005, which is incorporated herein in its entirety by reference. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates to lock systems and more specifically to sash lock systems for casement windows.  
       BACKGROUND OF THE INVENTION  
       [0003]     Multi-point sash lock systems for casement windows are known. Such known systems are disclosed in U.S. Pat. Nos. 4,803,808; 5,087,087; and 5,118,145, hereby fully incorporated herein by reference. These systems typically have a single operating control, usually a lever. The lever is typically linked to a tie-bar that has multiple engaging structures disposed at intervals along its length. Operation of the lever causes the tie-bar to move longitudinally. Keepers are attached to the window sash proximate the locations of each of the engaging structures so that as the tie-bar moves, the engaging structures are moved in and out of engagement with the keepers. The entire sash lock assembly is usually concealed in the frame construction of the window, with the exception of the lever, which projects from a slot on the interior side of the window.  
         [0004]     These known mechanisms, while being generally adequate for locking a window sash have not provided entirely satisfactory performance in some respects. Installation of the lock assembly on the window frame and sash is difficult with some prior systems because it is necessary to carefully measure and accurately position the tie-bar at the correct distance from the locked position of the window sash. If the tie-bar is located too far away from the sash location, the engaging structures will not engage the keepers. If the tie bar is too close, the engaging structures may interfere with the window sash itself. Although some prior art systems have addressed this problem by providing a locating lip on the tie-bar guide that engages in a pre-located groove in the window frame, these systems have not been entirely satisfactory in that the locating lip of the guide must fit snugly into the groove so as to avoid misalignment of the guide when it is secured to the window frame. Such misalignment may cause binding of the tie bar in the guides. Moreover, this operation consumes valuable time and effort in a mass production environment.  
         [0005]     Further, it is necessary to locate tie bar guide structures along the length of the tie bar at optimal positions for operation of the mechanism. In some prior systems, this process must be done manually for each individual window, adding time and cost to assembly of the window. Again, although some prior systems have addressed this problem by securing the tie bar guide to the tie bar before installation with a structure that is then destroyed upon first operation of the window in order to release the guide from the tie bar, these systems have not been entirely satisfactory. In some cases, the prior systems are prone to come loose before the tie bar assembly is secured to the window frame. In addition, prior systems generally require an aperture to be formed in the tie bar that engages a structure on the guide. These systems require additional steps in manufacturing in order to form the aperture and engaging structure.  
         [0006]     The keeper structure of prior mechanisms has not been entirely satisfactory in prior systems. Many prior systems have a keeper in which the keeper hook extends outwardly at 90 degrees from a flange portion which is secured to the window with fasteners. Such a system, which loads the fasteners axially in part, is prone to the keeper being pulled from the sash in high winds. Other systems, using a flat keeper secured to the sash are also known. These prior systems, however, generally have multiple fastener holes, which must be secured with precisely positioned fasteners, adding time and cost to window fabrication.  
         [0007]     Also, the lever handle arrangement of some prior systems has presented particular problems during construction. It is desirable to ship the window to a construction site with the finish hardware not attached so as to prevent scratching or other damage during window shipping and installation. It is also desirable and sometimes essential, however, to operate the window prior to installation being complete. In prior systems, the window lock system cannot be operated without the finish hardware being attached.  
         [0008]     Further, round top architectural windows having an operable sash are becoming increasingly popular. Prior art multi-point sash lock systems do not generally provide the capability of locking such a round top window sash with the same system as for the remainder of the window. The locking system should conform to the rounded side of the window and should function in a manner similar to that for a straight side.  
         [0009]     What is needed in the industry is a multi-point sash lock system that addresses these needs.  
       SUMMARY OF THE INVENTION  
       [0010]     The present invention is an improved sash lock system for casement windows that addresses the needs of the industry. In an embodiment, the invention includes a tie bar assembly having a tie bar longitudinally slidable with a lock drive operable with a lever. The tie bar has a plurality of rollers for engaging keepers (known as biscuit keepers) spaced apart on the window sash. The tie bar is guided with a plurality of guides secured to the window frame. Each guide has a pair of spaced apart guide portions, each with a separate locating lip for engaging a pre located groove in the window frame. The spaced apart position of the locating lip and overall greater length of the guide enable more accurate alignment of the guide to prevent binding of the tie bar. Further, the guide has a locating tab which may be molded as part of the central structure of the guide connecting the guide portions. The locating tab is riveted directly to the tie bar using the same rivet as is used for the roller. Upon first operation of the mechanism, the locating tab is ripped from the guide and remains attached to the tie bar thereafter. This locating method uses fewer parts and saves time in assembly as compared to the prior systems.  
         [0011]     In an embodiment, the lever is equipped with finish hardware, including a detachable finish sleeve and removable escutcheon. The lever itself is of sufficient length so as to project from the slot and be grasped to effect unlocking operation even without the finish sleeve in place. Hence, the sash lock system is operable during construction, while enabling the finish hardware to be installed at the last minute so as to minimize the risk of damage.  
         [0012]     In an embodiment, the mechanism has a plurality of flat biscuit keepers. These keepers are installed in the sash in grooves cut with a plunge saw. The portion of the keeper that is inserted in the slot has a single slot that receives multiple fasteners to secure the keeper in place. This keeper saves assembly time as compared to prior art systems due to the slot, which eliminates the need to precisely locate the fasteners in apertures.  
         [0013]     In an embodiment the present invention provides the capability of locking a round top window sash with the same system as for the remainder of the window wherein a generally linear configuration is used.  
         [0014]     The present invention is a multi-point sash lock assembly being shiftable between a locked and an unlocked disposition, including a tie bar assembly including a tie bar guide, the tie bar guide having at least one guide end, the guide end being integrally, unitarily formed. The present invention is further a multi-point sash lock assembly for securing a rounded side of a window to a rounded window frame and a method of forming a multi-point sash lock assembly. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]      FIG. 1  is a perspective view of a first or linear embodiment of a multi-point sash lock system for casement window according to an embodiment of the invention;  
         [0016]      FIG. 1   a  is an elevation of a multi-point sash lock system for casement window according to an embodiment of the invention, depicted attached to a window sash and window frame;  
         [0017]      FIG. 1   b  is a cross-sectional view taken through section C-C of  FIG. 1   a;    
         [0018]      FIG. 1   c  is a cross-sectional view taken through section B-B of  FIG. 1   a;    
         [0019]      FIG. 1   d  is a cross-sectional view taken through section A-A of  FIG. 1   a;    
         [0020]      FIG. 2  is a partial perspective view of the drive mechanism of a multi-point sash lock system for casement window according to an embodiment of the invention, depicting the lever, base plate and slide portions of the mechanism;  
         [0021]      FIG. 3  is a perspective view of the lever portion of the drive mechanism of a multi-point sash lock system for casement window according to an embodiment of the invention;  
         [0022]      FIG. 4  is a partial perspective view of the drive mechanism of a multi-point sash lock system for casement window according to an embodiment of the invention, depicting the lever, escutcheon, handle cover, and slide portions of the mechanism;  
         [0023]      FIG. 4   a  is a partial perspective view of a portion of the slide of the drive mechanism of a multi-point sash lock system for casement window according to an embodiment of the invention;  
         [0024]      FIG. 5  is a partial perspective view of the drive mechanism of a multi-point sash lock system for casement window according to an embodiment of the invention, depicting the lever, handle cover, and base plate portions of the mechanism;  
         [0025]      FIG. 6  is a partial perspective view of the drive mechanism of a multi-point sash lock system for casement window according to an embodiment of the invention, depicting the lever and base plate portions of the mechanism;  
         [0026]      FIG. 7  is a partial perspective view of the drive mechanism of a multi-point sash lock system for casement window according to an embodiment of the invention, depicting the lever, slide, and base plate portions of the mechanism;  
         [0027]      FIG. 8  is a front perspective view of an escutcheon and handle cover portion of a multi-point sash lock system for casement window according to an embodiment of the invention;  
         [0028]      FIG. 9  is a rear perspective view of an escutcheon and handle cover portion of a multi-point sash lock system for casement window according to an embodiment of the invention;  
         [0029]      FIG. 10  is a perspective view of a handle cover portion of a multi-point sash lock system for casement window according to an embodiment of the invention;  
         [0030]      FIG. 11  is a front elevation view of an escutcheon and handle cover portion of a multi-point sash lock system for casement window according to an embodiment of the invention;  
         [0031]      FIG. 12  is a partial perspective view of a multi-point sash lock system for casement window according to an embodiment of the invention, depicting the lock drive, tie-bar assembly and biscuit keeper portions of the mechanism;  
         [0032]      FIG. 13  is a partial perspective view of the connection between the slide portion of the lock drive assembly and the tie bar assembly of a multi-point sash lock system for casement window according to an embodiment of the invention;  
         [0033]      FIG. 14  is a partial perspective view of the roller portion of the roller assembly and a portion of the tie bar of a multi-point sash lock system for casement window according to an embodiment of the invention;  
         [0034]      FIG. 15  is a partial perspective view of the rivet portion of the roller assembly and a portion of the tie bar of a multi-point sash lock system for casement window according to an embodiment of the invention;  
         [0035]      FIG. 16  is a partial perspective view of the tie-bar guide assembly of a multi-point sash lock system for casement window according to an embodiment of the invention, depicting the tie-bar guide and tie-bar together;  
         [0036]      FIG. 17  is a partial perspective view of the tie-bar guide assembly of a multi-point sash lock system for casement window according to an embodiment of the invention, depicting the tie-bar guide;  
         [0037]      FIG. 18  is another partial perspective view of the tie-bar guide assembly of a multi-point sash lock system for casement window according to an embodiment of the invention, depicting the tie-bar guide;  
         [0038]      FIG. 18   a  is a partial perspective view of a further embodiment of a guide end of the tie-bar guide assembly;  
         [0039]      FIG. 19  is a partial perspective view of the connection between the slide portion of the lock drive assembly and the tie bar assembly of a multi-point sash lock system for casement window according to an embodiment of the invention;  
         [0040]      FIG. 20  is a side elevation view of a biscuit keeper of the present invention, depicting the keeper received in a slot in a window sash;  
         [0041]      FIG. 21  is a perspective view of the biscuit keeper of  FIG. 20  with a roller assembly received between the base and hook portions of the keeper;  
         [0042]      FIG. 22  is a side elevation view of a second or curved embodiment of the present invention, including the curved tie-bar assembly of a multi-point sash lock system for a round top casement window;  
         [0043]      FIG. 23  is a top perspective view of the curved tie-bar assembly of a multi-point sash lock system for casement window according to an embodiment of the invention;  
         [0044]      FIG. 24  is a bottom perspective view of the curved tie-bar assembly of a multi-point sash lock system for casement window according to an embodiment of the invention;  
         [0045]      FIG. 25  is a perspective view of the keeper portion of a curved tie-bar assembly of a multi-point sash lock system for casement window according to an embodiment of the invention;  
         [0046]      FIG. 26  is a perspective view of the tie-bar guide portion of a curved tie-bar assembly of a multi-point sash lock system for casement window according to an embodiment of the invention;  
         [0047]      FIG. 27  is a perspective view of the adjustable link linking the curved tie-bar to the straight tie-bar of a multi-point sash lock system for casement window according to an embodiment of the invention;  
         [0048]      FIG. 28  is a photograph of a portion of the curved tie-bar assembly with the tie-bar and guides attached to a window frame and the keeper attached to a window sash and with the roller assembly received in the keeper;  
         [0049]      FIG. 29  is a photograph of a casement window equipped with the multi-point sash lock of the first embodiment of the present invention; and  
         [0050]      FIG. 29   a  is another photograph of a casement window equipped with the multi-point sash lock of the first embodiment of the present invention.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0051]     Referring now to  FIGS. 1-1   d ,  29 , and  29   a , multi-point sash lock assembly  30  generally includes drive assembly  32 , tie-bar assembly  34 , and biscuit keepers  36 . Multi-point lock assembly  30  is used to latch and lock an operable window sash  36   a  with a window frame  36   b . Optional round top window tie bar assembly  38  (see  FIGS. 22-28 ) may be coupled to tie-bar assembly  34  if desired for latching an operable sash round-top window (depicted in part in  FIG. 28 ).  
         [0052]     Drive assembly  32  (see  FIGS. 1-12 ) generally includes base plate  40 , slide  42 , and lever  44 . Lever  44  is pivotally attached to base plate  40  with rivet  46 , which extends through aperture  48  in lever  44  and aperture  49  in base plate  40 . As depicted in  FIGS. 2 and 3 , lever  44  has handle portion  50 , hub portion  52 , and inner actuating portion  54 . When multi-point lock assembly  30  is mounted in a window sash ( FIGS. 29 and 29   a ), handle portion  50  extends through a slot in the window frame to enable multi-point lock assembly  30  to be actuated without the attachment of any finish hardware. Base plate  40  is secured to the window frame with fasteners extending through apertures  55 .  
         [0053]     Finish hardware is depicted in  FIGS. 4, 5 , and  8 - 11 . To lend a finished appearance to the slot, removable escutcheon  56  may be fitted in the slot with handle cover  57  over handle portion  50  of lever  44 . Escutcheon  56  generally includes body portion  58  with perimeter flange  60 , well portion  62  defining recess  64 , and flexible securing tabs  66  for engaging the ends of the slot to hold escutcheon  56  in place in the slot. Handle portion  50  extends through aperture  67  in well portion  62 . Bottom walls  67   a  are advantageously sloped downwardly so that handle cover  57  engages them when lever  44  is at either a fully locked or fully unlocked position. Handle cover  57  effectively extends toe reach of handle portion  50 , thereby making it easier to grasp the combination of the handle portion  50 , handle cover  57 .  
         [0054]     Handle cover  57  has finger grip portion  68  and shank portion  70 . Shank portion  70  has bifurcated end  72  with a pair of legs  74 , each of which has an inwardly directed tab  76 . Shank portion  70  is partially hollow so as to receive handle portion  50  of lever  44 . Hub portion  52  of lever  44  has rounded edges  78  and opposing notched portions  80 . When shank portion  70  is disposed over handle portion  50 , legs  74  fit around rounded edges  78 , and tabs  76  engage notched portions  80  to secure handle cover  57  on lever  44 .  
         [0055]     In an embodiment of the invention, handle portion  50  is sufficiently long so as to extend from the slot in the window sash even when handle cover  57  is not in place. Such arrangement facilitates construction, where it may be desirable or necessary to lock or unlock the window before installation and before the installation of the finish hardware, escutcheon  56  and handle cover  57 . Escutcheon  56  and handle cover  57  may then be installed after all window installation is complete, thus alleviating the problem of damage to the finishes of these components during installation.  
         [0056]     Base plate  40  is depicted in  FIG. 6  and has channel  82  at bottom edge  84 . Channel  82  has bottom wall  86 , outward sidewall  88 , and inwardly turned portion  90 . Upper edge  92  has a pair of tabs  94  for engaging and supporting the bottom surface  96  of escutcheon  56 .  
         [0057]     Referring to  FIG. 4 , slide  42  generally includes base portion  98  and riser  100 . Opposing ends  102 ,  104  of base portion  98  have lateral notches  106 ,  108 , respectively. Main body  110  of base portion  98  has lateral facing recess  112 . Riser  100  has vertical notch  114  with shouldered region  116 .  
         [0058]     As depicted in  FIGS. 2 and 7 , slide  42  engages and slides along inside channel  82  of base plate  40  with inwardly turned portion  90  received in lateral facing recess  112  to retain slide  42  in engagement with base plate  40 . Rivet  118  having head  120  is secured to inner actuating portion  54  of lever  44  through aperture  122 . Rivet  118  is engaged in vertical notch  114  of slide  42  with head  120  riding in shouldered region  116 .  
         [0059]     In operation, as lever  44  is rotated in the direction of the arrow about rivet  46  ( FIG. 7 ), rivet  118  moves downwardly in vertical notch  114 , causing slide  42  to slide within channel  82  in a direction opposite the direction of movement of lever  44 . The length of inner actuating portion  54  is selected so that rivet  118  does not bottom in vertical notch  114  when lever  44  is at the midpoint of travel. Those of skill in the art will appreciate that slide  42  and lever  44  function as a classic “lost-motion” mechanism.  
         [0060]     It is desirable that top portion  114   a  of vertical notch  114  be slightly narrower than bottom portion  114   b , and that top portion  114   a  be slightly smaller than the diameter of the shank portion of rivet  118  so as to offer additional frictional resistance to sliding of rivet  118 . This combination of features provides a positive detent-like function at both ends of travel of lever  44 , tending to retain lever  44  in the fully locked and unlocked positions through friction between rivet  118  and the edges of vertical notch  114 , and to provide positive tactile feedback to an operator to indicate the fully locked and fully unlocked positions have been reached.  
         [0061]     As depicted in FIGS.  1 ,  12 - 16  and  19 , tie bar assembly  34  generally includes tie bar  124  with roller assemblies  126  and tie bar guides  128 . Link  130  is riveted to end  132  of tie bar  124  with square rivet  134  through square aperture  136 . Lip portion  138  engages in one of lateral notches  106 ,  108 , in slide  42  to link tie bar  124  to drive assembly  32 .  
         [0062]     Each roller assembly  126  as depicted in  FIGS. 14-16  includes a rivet  140  having a head  142  and a shank  144 . Shank  144  extends through bore  146  of roller  148  so that roller  148  rotates on shank  144 . Although in the depicted embodiment, rivet  140  and bore  146  are axially aligned with roller  148  being symmetrical about the common axis, it will be appreciated that bore  146  may be asymmetrical in roller  148  so that roller assembly  126  is eccentric as taught in U.S. Pat. No. 4,803,808 to Greisner, hereby fully incorporated herein by reference.  
         [0063]     As depicted in  FIGS. 17 and 18 , tie bar guide  128  generally includes central body portion  150 , guide ends  152 ,  154 , and locating tab  156 . At least the central body portion  150  and the guide ends  152 ,  154  are preferably integrally, unitarily formed. Locating tab  156  preferably is formed with a frangible coupling to the tie bar guide  128 . Locating lip  158  is provided to engage in a groove in the window frame to locate tie bar assembly  34  at a predetermined distance from the window sash. In the embodiment of  FIG. 18   a , the locating lip  158  and the portion of the backwall  157  that in part defines the locating lip  158  do not diminish in thickness. Accordingly, the locating lip  158  has a rectangular cross section. Guide ends  152 ,  154 , each have an aperture  160  for slidably receiving tie bar  124  therethrough. Each aperture  160  is formed by a back wall  161   a , a spaced apart front wall  161   b  and two connecting ends  161   c . The front wall  161   b  is ribless. One or more apertures  162  may be provided on tie bar guide  128  for receiving fasteners to attach the guide to a window frame.  
         [0064]     When tie bar assembly  34  is originally assembled and before installation, locating tab  156  is riveted to tie bar  124  with rivet  140  in order to locate tie bar guide  128  at the proper position lengthwise along tie bar  124  for installation. The first time tie bar assembly  34  is operated from the locked disposition to the unlocked disposition, tie bar  124  forcibly slides longitudinally in tie bar guides  128 . The force of such translation causes the locating tab  156  frangible coupling to the tie bar guide  128  to be sheared. Locating tab  156  is thereby permanently separated from central body portion  150 . Locating tab  156  however remains attached to tie bar  124  with rivet  140  for the remainder of the life of the mechanism.  
         [0065]     Biscuit keeper  36  (see  FIGS. 20 and 21 ) generally includes main body portion  164  and hook portion  166 . Keeper  36  is installed in a window sash by first cutting a slot in the sash by suitable means such as a plunge saw. Once the slot is cut, main body portion  164  is inserted in the slot until shoulders  168  engage the surface of the window sash around the slot. One or more fasteners  169  can be inserted through slot  170  in main body portion  164  to secure the keeper  36  in place. When installed in this position, hook portion  166  projects outwardly from the window sash, and is positioned so as to align with roller assemblies  126 .  
         [0066]     In locking operation, as lock drive assembly  32  is operated as described above, slide  42  causes tie bar  124  to slide in tie bar guides  128 . Roller assemblies  126  engage keepers  36  between hook portion  166  and main body portion  164  to hold the sash in engagement with the window frame.  
         [0067]     Referring now to  FIGS. 22-28 , a round top window multi-point lock assembly  30   a  generally includes drive assembly  32 , round window tie-bar assembly  38 , and biscuit keepers  36 . Multi-point lock assembly  30   a  is used to latch and lock around top window operable window sash  36   a  with a window frame  36   b , as depicted in  FIG. 28 . Multi-point lock assembly  30   a  functions in substantially the same manner as multi-point lock assembly  30 , noted above, and includes substantially similar components as multi-point lock assembly  30 , thereby ensuring that similar functioning and similar appearing lock assemblies  30 ,  30   a  may be used in a unit window that includes both rectangular and round top windows. This enhances ease of use of the window unit and the appearance of the window unit.  
         [0068]     Optional round top window tie bar assembly  38  generally includes the same components as tie-bar assembly  34 , described above. Window tie bar assembly  38  generally includes curved tie bar  172 , tie bar guides  174 , roller assembly  176 , keeper  178 , and adjustable link  180 . Tie bar guides  174  have body portion  182  with an aperture  184  for slidably receiving curved tie bar  172  therethrough. Moreover, each tie bar guide  174  may have locating lip  184   a  for engaging in a groove in the window frame to locate the assembly  38  the proper distance from the window sash. Apertures  186  are provided to receive fasteners to secure the tie bar guide  174  to the window frame.  
         [0069]     Keeper  178  has lower flange portion  188  and hook portion  190 , as depicted in  FIG. 25 . Keeper  178  is secured to the window sash with one or more fasteners through apertures  192 .  
         [0070]     Referring to  FIG. 27 , curved tie bar  172  is linked to tie bar  124  with adjustable link  180 . Link  180  has a series of v-shaped notches  194  spaced apart along main body  196 , thereby defining segments  197  Bosses  198  are positioned in each respective segment  197  between each pair of notches  194 . Each boss  198  has an aperture  200  formed therethrough for receiving a screw  202  to attach opposing ends of link  180  to either tie bar  124  or curved tie bar  172 . Link  180  can be adjusted to a desired length by snapping off a segment(s)  197  of the link at any of notches  194 . Link  180  is desirably made from brittle zinc material to enable easy and clean breaks at notches  194 , but may also be made from any other suitably frangible material.  
         [0071]     In operation, longitudinal movement of tie bar  124  upon operation of lever  44  is transmitted to curved tie bar  172  though adjustable link  180 . Curved tie bar  172  slides through guides  174 , causing roller assembly  178  to move in and out of engagement with keepers  178 .