Abstract:
An auto cam lock is disclosed here. The disclosed auto cam lock comprises a lock housing assembled with a cam and an actuator; a cam adapted to rotate between an extending position and a retracted position, the cam being adapted to be engaged with and retained by the lock housing when the cam is in the retracted position; a cam resilient means for giving the cam a resilient force adapted to drive the cam to rotate from the retracted position to the extending position; an actuator operatively coupled with the cam, said actuator being adapted to move between an extending position and a retracted position, and said the actuator being adapted to release the cam from the cam&#39;s retracted position retained by the lock housing when the actuator moves from the actuator&#39;s extending position to the actuator&#39;s retracted position; and an actuator resilient means for giving the actuator a resilient force adapted to drive the actuator to move from the retracted position to the extending position.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to windows, and more specifically, to cam latching mechanisms for windows. 
       BACKGROUND OF INVENTION 
       [0002]    Double hung and other sliding sash type windows are very common. Typically, a latch or locking mechanism is used to secure the sashes in place to inhibit unintentional opening of the sashes and unauthorized entry to the structure. 
         [0003]    One very common mechanism used to lock sashes together is the so-called check rail lock, which includes a sweep cam attached to a rotatable handle. The check rail lock is mounted on one of the sashes, usually the lower sash of a double-hung window proximate the center of the sash rail. A keeper structure is mounted on the other sash proximate the check rail lock. As the handle is rotated in either direction, the sweep cam is rotated into or out of engagement with the keeper in order to enable locking or opening of the window as desired. A drawback of these devices, however, is that the handle can be rotated so that the sweep cam is extended even when the sash is open. When the sash is closed with the sweep cam in such position, the extended position of the sweep cam prevents full closure of the sash. The operator of the window may not notice the window is not fully closed and latched. In addition, the sweep cam may strike and damage the other sash. 
         [0004]    Another prior mechanism includes a sliding latch bolt that may be mounted on one sash and that is selectively engageable with a keeper mounted on the other sash. A drawback with these mechanisms, however, is often that the bolt must be held in a retracted position as the window is operated. In other case, where a mechanism for holding the bolt in a retracted position is employed, the bolt either releases as soon as the window is raised, or must be manually released with a separate catch or button. In such cases, the window may fail to close fully and may not be noticed by the operator of the window. 
         [0005]    Some prior mechanisms have tried to solve the above problems, but the solutions focus on bolt latch. What is still needed is a simple and comfortable cam latch mechanism for a window that automatically latches when the window is returned to a closed position. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention addresses the need of the industry for a simple and comfortable cam lock that automatically latches a window when the window is returned to a closed position. According to an embodiment of the invention, a window is equipped with an auto cam lock having a cam and a spring driven actuating mechanism in the housing of the window lock. The auto cam lock is mounted on a sash of a window assembly opposite a keeper or similar cam latch receiving structure. With the window in a closed position, the cam latch is received in the keeper to latch the sashes together, and the actuating mechanism is confined in a retracted position by the keeper. To open the window, the cam latch is disengaged from the keeper by rotating a handle and pulling outwardly away from keeper. The cam latch slides out of the keeper and goes into the housing, and the actuating mechanism is released by the keeper and extends outwardly from the housing and reaches an extended position. The cam latch is held in a retracted position by a stopping mechanism in the housing of the lock. With the cam latch in this position, the sash may be moved to open the window. To close the window, the sash with the auto cam lock is moved toward the keeper. The outwardly extending portion of the actuating mechanism contacts the keeper that pushes the actuating mechanism inwardly into the housing. The actuating mechanism actuates the cam latch and disengages the cam latch from the stopping mechanism. A spring urges the cam latch forwardly so that it is once again engaged in the keeper and the sashes are latched together as before. 
         [0007]    According to one embodiment, a cam lock for a window includes a lock; a cam adapted to rotate between an extending position and a retracted position; a cam resilient means for giving the cam a resilient force adapted to drive the cam to rotate from the retracted position to the extending position; an actuator operatively coupled with the cam; and an actuator resilient means for giving the actuator a resilient force adapted to drive the actuator to move from the retracted position to the extending position. 
         [0008]    Embodiments of the housing of the latch mechanism may include a top cover and a bottom cover. A hook mechanism and a post-hole mechanism are coupled with the top cover and the bottom cover. The top and the bottom covers can be held together in two steps. The first step is that the post-hole mechanism holds the top cover and the bottom cover together when the hook mechanism does not hold the top cover and the bottom cover. The second step is that the hook mechanism holds the top cover and the bottom cover together with the post-hole mechanism. 
         [0009]    The advantage of this invention is a simple and comfortable solution for manufacturers and consumers to manufacture, assemble, install, and use an automatic cam latch for a window. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  depicts one exemplary embodiment of the disclosed art. 
           [0011]      FIG. 2  is a top exploded view of the exemplary embodiment in  FIG. 1 . 
           [0012]      FIG. 3  is a bottom exploded view of the exemplary embodiment in  FIG. 1 . 
           [0013]      FIG. 4  is a bottom detailed view of the handle in exemplary embodiment in  FIG. 1 . 
           [0014]      FIG. 5  is a top detailed view of the cam in exemplary embodiment in  FIG. 1 . 
           [0015]      FIG. 6  is a top detailed view of the top cover in exemplary embodiment in  FIG. 1 . 
           [0016]      FIG. 7  is a detailed view of the mechanism on the base over of exemplary embodiment in  FIG. 1 . 
           [0017]      FIG. 8  is a bottom detailed view of the actuator of exemplary embodiment in  FIG. 1 . 
           [0018]      FIG. 9  is a top detailed view of the actuator of exemplary embodiment in  FIG. 1 . 
           [0019]      FIG. 10  shows an exemplary assembly process of the disclosed auto cam lock. 
           [0020]      FIG. 11  shows an exemplary assembly process and moving process of the assembly cover of the auto cam lock. 
           [0021]      FIG. 12  shows the semi-assembled state and the final-assembled state of the lock. 
           [0022]      FIG. 13  A-D show the action process of the lock. 
           [0023]      FIG. 14  A-E show the detailed action process of the lock. 
           [0024]      FIG. 15  shows the work process of the indicator. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0025]      FIG. 1  is one exemplary embodiment of the disclosed art.  FIG. 2  is a top exploded view of the exemplary embodiment in  FIG. 1 .  FIG. 3  is a bottom exploded view of the exemplary embodiment in  FIG. 1 . Auto cam lock  100  in  FIG. 1  includes lock housing  102 , cam receiver  104 , and handle  106  (shown in  FIG. 1 ). Lock housing  102  includes top cover  108  and base cover  110 . In lock housing  102 , there are further cam  112 , actuator  114 , cam spring  118 , and actuator spring  120 . Between handle  106  and top cover  108 , there is handle spring  116 . Those skilled in the art will realize and understand, upon reading this description, that resilient elements other or different than springs may be used to fulfill the same function. 
         [0026]    Top cover  108  further includes top cover shaft hole  122 , top cover shaft hole breach  123 , top cover spring hole  124 , and an one-way pass element that can be resilient lobe  126 . Top cover  108  further includes four top cover hooks  190 , a pair of top cover post  192 , top cover front wall  194 , housing indicator window  187 , and actuator fixing beam  196 . 
         [0027]    Base cover  110  includes rear wall  128 , bottom wall  130 , and a pair of side walls  132 . Base cover  110  further includes base projection  140 , a cam stop element that can be base stop post  134 , base stop post stair  136 , base actuator post  138 , base cam stop pin  142 , base cam hole  144 , base cam spring hole  149 , a pair of base cam hole breaches  146 , and a pair of base cover holes  148 . Base cover  110  further includes four base cover screw holes  184 , base indicator window  186 , cam hole edge  183 , and four base cover hooks  188  (shown in  FIG. 3 ). 
         [0028]    Cam  112  includes cam latch  150 , cam groove  152 , cam stop wall  154 , cam actuate pin  156 , can stop pin  157 , cam stop pin arm  158 , cam indicator arm  160 , cam indicator  162 , cam spring slot  164 , and cam handle hole  166 . Cam  112  further includes cam shaft  180  and a pair of cam shaft projections  182  (shown in  FIG. 3 ). 
         [0029]    Cam receiver  104  includes receiver bevel wall  168  and a pair of receiver screw hole  170 . Cam receiver  104  further includes receiver keeper  210  and receiver guide slot  212  (shown in  FIG. 3 ). 
         [0030]    Cam spring  118  includes cam spring cam hook  172  and cam spring base hook  174 . Actuator spring  120  includes actuator spring actuator hook  176  and actuator spring extension  178 . Handle spring  116  includes handle spring handle hook  198  and handle spring cover hook  200  (shown in  FIG. 3 ).  FIG. 5  is a top detailed view of the cam in exemplary embodiment in  FIG. 1 . Cam  112  further includes handle guide slot  214  and cam spring hole  216 . 
         [0031]      FIG. 4  is a bottom detailed view of the handle in exemplary embodiment in  FIG. 1 . Handle  106  includes handle shaft  202 , handle shaft projection  204 , handle stop  206 , hand stop bevel side  207 , handle stop wall  205 , and handle spring tab  208 . 
         [0032]      FIG. 7  is a detailed view of the mechanism on the base over of exemplary embodiment in  FIG. 1 . Base cam stop pin  142  on base cover  110  further includes base cam stop point  218 . Base projection  140  on base cover  110  further includes base slide chamfer  220 , block wall  222 , and arc side  224 . Base cover  110  further includes actuator spring stop wall  219 , actuator stop wall  221 , and an actuator stop element that can be actuator stop slot  217 . 
         [0033]      FIG. 8  is a bottom detailed view of the actuator of exemplary embodiment in  FIG. 1 . Actuator  114  further includes actuator arm  226 , actuator block point  228 , actuator slide chamfer  230 , and actuate point  232 . These elements can also be seen from  FIG. 9  from a different perspective. Actuator  114  further includes actuator spring hole  234 , actuator spring slot  236 , actuator tongue  238 , actuator stop point  240 , actuator post hole  242 , and actuator bottom slot  244 . Those skilled in the art will realize and understand, upon reading this description, that other and or different elements may be included to fulfill the same function. 
         [0034]    One exemplary assembly process is shown in  FIG. 10 . The exemplary assembly process generally includes the flowing steps. Cam spring  118  is mounted in cam spring slot  164 , wherein cam spring cam hook  172  grips cam  112  through cam spring hole  216  and wherein cam spring base hook  174  is inserted into base cam spring hole  149 . Cam  112  is mounted on base cover  110 , wherein cam shaft  180  goes through base cam hole  144  and wherein cam shaft projections  182  go through base cam hole breaches  146 . The mounted cam spring  118  is in a pre-tight state that gives cam  112  a counterclockwise torque (from the top view). This counterclockwise torque rotates cam  112  until cam stop wall  154  pushes against base stop post  134 . This rotation also makes cam shaft projections  182  move away from base cam hole breaches  146  after cam shaft projections  182  go through base cam hole breaches  146 . Thus, cam shaft projections  182  hold cam  112  on cam hole edge  183 . Actuator spring  120  is mounted into actuator spring slot  236 , wherein actuator spring actuator hook  176  grips actuator  114  through actuator spring hole  234 . Actuator spring extension  178  pushes against actuator spring stop wall  219 . Actuator  114  is mounted on base cover  110 , wherein base actuator post  138  goes through actuator post hole  242  and wherein actuator stop point  240  goes through actuator stop slot  217 . Actuator spring  120  is in a pre-tight state that gives actuator  114  a counterclockwise torque (from the top view). This counterclockwise torque rotates actuator  114  until actuator stop point  240  pushes against actuator stop wall  221 . These steps lead to an assembled base shown in  FIG. 10 . 
         [0035]    Handle spring  116  is mounted on top cover  108 , wherein handle spring cover hook grips top cover  108  by going through top cover spring hole  124 . Handle spring handle hook  198  grips handle spring tab  208 . Handle  106  is pushed toward top cover  108  wherein handle shaft  202  goes through top cover shaft hole  122  and wherein handle shaft projection  204  goes through top cover shaft hole breach  123 . After handle shaft projection  204  goes through top cover shaft hole breach  123 , handle  106  is rotated in clockwise, wherein handle shaft projection  204  moves away from top cover shaft hole breach  123 , and wherein handle stop  206  passes resilient lobe  126 . Handle shaft projection  204  moves away from top cover shaft hole breach  123  so that handle shaft projection  204  can hole handle  106  on top cover  108 . Handle stop  206  can pass resilient lobe  126  because resilient lobe  126  is pushed centripetally by handle stop  206  and slides on handle stop  206  along handle stop bevel side  207 . Once handle stop  206  passes resilient lobe  126 , it cannot pass back since resilient lobe  126  resumes to its original position and blocks handle stop wall  205 . Handle spring  116  is in a pre-tight state that gives handle  106  a counterclockwise torque, and handle  106  is rotated until handle stop  206  pushes against resilient lobe  126 . These steps are shown in  FIG. 11 , and these steps lead to assembled cover shown in  FIG. 10 . 
         [0036]    The assembled cover is further mounted on the assembled base. Handle shaft  202  goes through cam handle hole  166 . Handle shaft projection  204  goes into handle guide slot  214 . Handle guide slot  214  is fan-shaped with two straight sides. Handle shaft projection  204  is adapted to move from one straight side to the other straight side when handle  106  rotates relatively to cam  112 . Top cover posts are pushed into base cover holes  148 . The lock body has two assembled states: semi-assembled state and final assemble state. In semi-assembled state, top cover hooks  190  rest on base cover hooks  188 . In final assembled state, top cover hooks  190  are further pushed downward and top cover hooks  190  and base cover hooks  188  hold together. The assembled cover is relatively easy to be moved from the assembled base in semi-assembled state. Semi-assembled state is delivered from lock manufactures to window manufacturers for the purpose of mounting locks on windows. The assembled cover needs to be removed since screw holes  184  are on base cover  110 . When the lock is mounted on the window, window manufacturers can further push the assembled cover down to the final assembled state. In final assembled state, the assembled cover is relatively difficult to be moved from the assembled base. The semi-assembled state and the final assembled state are shown in  FIG. 12 . The assembled body of auto cam lock  100  is shown in  FIG. 10 . In the final assembled state, actuator fixing beam  196  pushes against actuator  114 , and thus keeps actuator  114  in a proper position during its action process. Those skilled in the art will realize and understand, upon reading this description, that other and or different assemble processes may be used to fulfill the same function. 
         [0037]      FIG. 13  A-D show the action process of the lock.  FIG. 13-A  depicts the lock state of auto cam lock  100 . The following elements can be found in  FIG. 2  and  FIG. 3 . Cam latch  150  rotates out of lock housing  102  into cam receiver  104 . Receiver keeper  210  goes into cam groove  152 . Thus, cam  112  is held by cam receiver  104 . Actuator  114  is in a retracted position in lock housing  102 , wherein receiver bevel wall  168  pushes against actuator tongue  238 . 
         [0038]      FIG. 13-B  depicts the unlock process of auto cam lock  100 . Handle  106  rotates clockwise (from the top view). Handle shaft projection  204  pushes one side of handle guide slot  214  (shown in  FIG. 5 ), which rotates cam  112  clockwise (from the top view). Cam latch  150  rotates out of cam receiver  104  and into lock housing  102 . Before the assembled body (shown in  FIG. 10 ) clears cam receiver  104 , actuator  114  is in a retracted position in lock housing  102  and receiver bevel wall  168  pushes against actuator tongue  238 . Handle  106  rotates back counterclockwise to its initial position under the torque given by handle spring  116 . 
         [0039]      FIG. 13-C  depicts the open state of auto cam lock  100 . Cam stop pin  157  is held by base cam stop point  218 . Thus cam  112  is kept in the retracted position. The assembled body clears cam receiver  104 . Without being pushed by receiver bevel wall  168 , actuator  114  extends out of lock housing  102  under the torque given by actuator spring  120 . 
         [0040]      FIG. 13-D  depicts the lock process of auto cam lock  100 . When the assembled body contacts cam receiver  104 , receiver bevel wall  168  pushes against actuator tongue  238 . Actuator  114  is back to the retracted position in lock housing  102 . In this process, actuate point  232  pushes cam actuate pin  156 . Cam stop pin  157  is released from base cam stop point  218 . Cam  112 , under the resilient torque given by cam spring  118 , rotates counterclockwise (from the top view) from lock housing  102 . Cam latch  150  rotates out of lock housing  102  into cam receiver  104 . Receiver keeper  210  goes into cam groove  152 . Auto cam lock  100  is locked as before. 
         [0041]      FIG. 14  A-E show the detailed action process of auto cam lock  100 .  FIG. 14-A  shows elements used in  FIG. 14  C-E. These elements also exist in  FIG. 2 ,  FIG. 3 , and  FIG. 7-9 .  FIG. 14-B  depicts the locked and unlocked states of auto cam lock  100 .  FIG. 14-C  depicts the lock position of auto cam lock  100 . Cam stop pin  157  is held by base cam stop point  218 . Actuator slide chamfer  230  rests on base side chamfer  220 . 
         [0042]      FIG. 14-D  depicts the unlock process of auto cam lock  100 . Actuator  114  extends out of lock housing  102  under the torque given by actuator spring  120 . During this process, actuator slide chamfer  230  slides counterclockwise (from a top view) along base slide chamfer  220 . Since both actuator slide chamfer  230  and base slide chamfer  220  are bevel-shaped, actuator arm  226  is lifted upwardly in this process, and actuate point  232  does not touch cam actuate pin  156 . After actuator  114  extends out of lock housing  102 , actuator slide chamfer  230  clears base slide chamfer  220  and actuator arm  226  resumes its horizontal position. 
         [0043]      FIG. 14-E  depicts the lock process of auto cam lock  100 . Receiver bevel wall  168  pushes against actuator tongue  238 . When actuator  114  goes back to the retracted position in lock housing  102 , actuator block point  228  contacts block wall  222  so that actuator slide chamfer  230  cannot slide onto base slide chamfer  220 . Actuator block point  228  slides along arc slide  224 . During this process, actuate point  232  is pushes centrifugally by base projection  140 . Thus, actuate point  232  touches cam actuate pin  156  and release cam stop pin  157  from base cam stop pin  142 . Cam  112  is actuated and, under the resilient torque given by cam spring  118 , rotates counterclockwise (from the top view) from lock housing  102 . Auto cam lock  100  is locked as before. Those skilled in the art will realize and understand, upon reading this description, that other and or different actuating processes may be used to fulfill the same function. 
         [0044]      FIG. 15  shows the work process of cam indicator  162 . When top cover  108  is mounted on base cover  110 , base indicator window  186  overlaps with housing indicator window  187 . At one end of cam indicator arm  160 , there is a cam indicator  162  that has a different color than other part of cam indicator arm  160 . One exemplary color for cam indicator  162  is red, and the rest part of cam indicator arm  160  is white. When cam  112  extends out of lock housing  102 , cam indicator  162  overlaps with housing indicator window  187 , so cam indicator  162  cam be seen from outside. When cam  112  is in the retracted position, the other part of cam indicator arm  160  overlaps with housing indicator window  187 . Therefore, the locked position and the unlocked position can be told from the color in housing indicator window  187  from outside. Those skilled in the art will realize and understand, upon reading this description, that other and or different indicating mechanisms may be used to fulfill the same function. 
         [0045]    The disclosed art can have different embodiments with various screw holes. Multiple screw locations increase the adaptability of this latch mechanism to many window systems, including but not limited to, sliding window systems and double-hung window systems. Those skilled in the art will also realize and understand, upon reading this description, that other and or different screw locations may be used to adapt this latch mechanism to various window systems.