Abstract:
A device to limit an opening of a window having a hinged sash coupled to a window frame including a window opening limiting structure having a first member and a second member. One of them is securable to the sash and the other of the first member and the second member being securable to the frame. A selectively releasable coupler by which the first member and the second member are couplable is shiftable between a coupled status and a released status. The first member and the second member bridge a preselected distance such that the sash is inhibited from opening beyond a predetermined distance. The coupler is releasable so that the sash can be opened beyond the predetermined distance and re-engages automatically when the sash is closed.

Description:
RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Application No. 61/307,705 filed Feb. 24, 2010, which is incorporated herein in its entirety by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to casement and awning windows and, more specifically, to devices for limiting the opening of casement and awning windows. 
     BACKGROUND OF THE INVENTION 
     A casement or an awning window generally refers to a sash that is attached to its frame by one or more hinges. The hinges can be located on any side of the sash and the frame though generally not on the lower edge of the sash and frame. In general, a casement window rotates along a horizontal plane (the hinges of a casement window defining a vertical rotation axis), while an awning window rotates along a vertical plane (the hinges of an awning window defining a horizontal rotation axis). Most casement and awning windows which employ the use of a crank lever or cam handle operator open outwardly so as not to interfere with the operator of the window. 
     An advantage of many casement and awning windows is that substantially the full window opening can be exposed without requiring the removal of the window from the frame. In contrast, for example only half of the opening of a double-hung window can be exposed by raising the lower sash or lowering the upper sash. The sashes of double hung or horizontally sliding windows must be completely removed from the frame to expose the entire window opening. 
     The ability of casement windows to be opened so as to fully expose the window opening also can be disadvantageous, however. In certain instances, some casement and awning windows can be opened wide enough that individuals or large objects can fit through the opening. 
     Recent modifications to building codes and window safety standards have been implemented in an effort to prevent or deter injuries to individuals, particularly children, from falling out of open windows. For example, proposed changes to the International Building Code (“IBC”) and the International Residential Code (“IRC”) aimed at child window safety require that certain windows be fitted with window opening control devices. Such window opening control devices may limit the ability of casement windows to be opened beyond a certain point. This limited opening is typically defined by the maximum diameter of a hypothetical sphere that is allowed to pass through the window opening when the sash of the window is opened to the limited position. For example, current CTC safety standards stipulate that a 4-inch diameter sphere shall not pass the opening of a casement or awning window when the opening is in its largest opened position. 
     At times, there may be a need to override the window opening limit device so that the casement window can be opened beyond the limited position. In particular, it may be necessary to fully open the window. During an emergency, for example, an egress casement window opening may provide an escape route for individuals or an access route for emergency personnel. Accordingly, building and residential codes may require window opening limit devices to be equipped with a release mechanism. The need may also exist that such window opening limit devices be operable without keys, tools, or special knowledge and deter or prevent operation by young children. 
     Unless the window opening limit device is reengaged once released, casement windows could potentially be operated so as to allow the window opening to be fully exposed. Subsequent users, for example, may not realize that the window is equipped with such a device or that the device has been released. Therefore, there exists a need for window opening limit devices to possess the capability to be self re-engaging even if a user does not intend to reengage the device through the user&#39;s actions. 
     The cost of replacing windows is often significant. Therefore, there also exists a need for a window opening limit device that can be installed onto existing casement windows. 
     In addition, existing casement and awning windows are not uniform in size. In fact, the size of casement and awning windows can vary substantially. Therefore, there exists a further need for a window opening limit device that can be installed onto existing casement or awning windows regardless of the dimensions of the window frame. 
     SUMMARY OF THE INVENTION 
     The present invention substantially addresses the aforementioned needs of the industry. Throughout this application structures may referred to as being associated with a window sash or frame for convenience of description. It is to be understood that the embodiments of the invention described herein can generally be reversed so that the sash component can be attached to the frame and/or the frame component can be secured to the sash. Accordingly, the fact that this specification refers to a sash component or a frame component should not be considered limiting to the inventions disclosed herein. 
     According to one embodiment of the invention, a window opening limiting device includes a sash bracket, a limiting arm, and a track with a release mechanism. The sash bracket may be coupled to a side of the casement window sash and the track may be coupled to a corresponding side of the casement window frame. The arrangement may be reversed as well. The sash bracket is generally coupled to the side of the window sash opposite the side of the sash that is hinged to the window frame. The limiting arm is coupled to the sash bracket and the track. The length of the limiting arm controls how far the sash can be opened from the closed position before reaching the limited position. The end of the limiting arm that is distal from the bracket includes a pin or wheel that engages in the track and which when the window is opened travels from a first end of the track to a second end of the track. 
     At the second end of the track is located the release mechanism. When the pin or wheel abuts the release mechanism, opening of the sash is limited by the abutment. When is it desired to open the sash further than the limited opening permitted, the release mechanism is activated thus permitting the pin or wheel to exit the second end of the track and the sash to open completely. In an embodiment, the release mechanism requires two independent actions to effect release: a sliding motion of one element and a pivoting motion of another element. The limiting arm is biased, for example by a spring, to a desired position so that when the window is closed the pin or wheel is forced against the bias of the spring to the first end of the track where the pin or wheel reenters the first end of the track and is thus placed in a position to limit the opening of the window without further action of the individual operating the window. The window opening limiting device is thus self-resetting upon closing the window. 
     Another embodiment of the invention includes a sash arm coupled to the sash by a sash bracket and a frame arm coupled to the frame by a frame bracket. The sash arm is biased to a desired position by a positioning spring or other biasing structure. The sash arm further includes a slider lock and a receiving hook. The frame arm also includes a positioning spring or other biasing member to bias the frame arm to a desired position. The frame arm also includes a pin at its distal end that is sized and configured to engage the receiving hook of the sash arm. The pin is pivotable within the receiver hook so that the sash arm and the frame arm may pivot relative to each other as well as relative to their respective sash bracket and frame bracket. When the casement sash has reached the window opening limited position, the sash arm engaged to the frame arm at the pin and receiver hook reach the limit of their length having pivoted relative to each other and stop further opening movement of the sash. 
     The slider lock may be slid back by an individual operating the sash to release the pin from the receiver hook so that the casement sash may be opened to its fully open position. The biasing springs hold the sash arm and frame arm in position so that as the sash is closed the pin engages the receiver hook and presses back the slider lock which is biased toward the distal end of the sash arm and permits the pin to reengage with the receiver hook, thus reactivating the opening limited device for the next opening of the window. 
     In another embodiment of the invention, the window opening limiting device includes a sash arm assembly and a track assembly. The sash arm assembly includes a hinged mounting bracket, a pivotable arm and a pin at a distal end of the pivotable arm. The slider assembly includes a track with a slider. The slider includes a toggle latch that is biased toward an open position and a release button that secures the toggle latch in the closed position when the toggle latch is closed. The release button also can be pressed to release the toggle latch from the closed position so that the spring bias can direct it toward the open position. When the window is open, the pivotable arm pivots relative to the hinged mounting bracket and the pin which is engaged in the toggle latch causes the slider to slide along the track. When the pivotable arm reaches its most direct extension and the slider reaches the second end of the track, the window opening is limited. 
     When it is desired to open the window to a further extent, an individual operating the window can press the release button and release the toggle latch which then allows the pin at the distal end of the pivotable arm to be separated from the toggle latch. The window then can be opened to its full extent. The pivotable arm is spring biased or otherwise biased to a desired position so that when the window is closed, the pin at the distal end of the pivotable arm engages the toggle latch and overcomes the bias of the toggle latch to cause the toggle latch to assume a closed position at which the toggle latch is secured close by the release button. The slider is then pushed along the track to the first end of the track as the window is closed, thus, the window opening limiting device is reset to limit the opening of the window upon the next opening of the window. This and other embodiments of the invention may also include a hinge in the mounting bracket of the sash arm assembly which permits the pivotable arm to pivot along an axis 90° to its first pivoting axis about which the arm pivots. 
     In another exemplary embodiment of the invention, the window opening limiting device includes a frame bracket supporting a fixed pin, and a biased sash arm that is biased toward the window frame and frame bracket. The sash arm includes a slide hook assembly at a distal end thereof. The slide hook assembly includes a moveable slide including a hook near the end and a ramp structure at the end of the sash arm. 
     In this embodiment, when the casement sash is opened, the bias of the sash arm biases it toward the frame bracket with pin. As the sash arm slides along the pin, the pin eventually reaches the slide hook assembly at the end of the sash arm. The hook assembly engages the pin on the frame bracket and prevents further opening movement of the casement window sash. When it is desire to open the casement window sash to a larger degree, the individual operating the sash grasps the slide of the slide hook assembly and can slide it distally against spring tension or other biasing force to release the pin from the slide hook assembly. It is then possible to open the casement window sash further and to its full opening capacity. When the casement window sash is closed, the sash arm, which is biased toward the sash frame, contacts the sash frame at its distal end and slides against the sash frame until the distal end which has a ramp shaped structure thereon contacts the fixed pin of the frame bracket. The ramp structure then rides up over the fixed pin so that the fixed pin passes proximally beyond the slide hook assembly relative to the sash arm. The sash arm then can lie against the pin and rest in this position, reset, awaiting the next opening of the window. 
     Another embodiment of the invention includes a sash arm biased toward the frame and a slide track receiver on the frame. A keeper on the slide track receiver is slidably or pivotally coupled to the receiver and when in a closed position forms a close ended slide track within the slide track receiver. The biased sash arm includes a pin at its distal end that can be received in the slide track. As the window is opened, the pin at the end of the biased sash arm travels within the slide track until it reaches and abuts the keeper at the end of the slide track and thus stops the window from opening farther. When it is desired to open the window further, an individual operating the window can press a push tab on the keeper to either slide or pivot the keeper to open it and to release the pin at the end of the biased sash arm from the slide track. It is then possible to open the window to its fully opening capacity. 
     The spring bias of the sash arm keeps it in a position extended outwardly toward the frame so that as the window is closed the pin contacts the slide track receiver assembly and working against the closing bias of the keeper either slides or pivots the keeper to permit the pin to enter the slide track. The pin then travels down the slide track as the sash arm is pivoted toward the sash until the window is in a closed position. Thus, the window opening limiting device is prepared for another operation when next the window opens. 
     Another embodiment of the invention includes dual sash arms that share a common pivot on a frame bracket. The dual sash arms include a catch thereon that engages when the two sash arms approach each other on the common pivot and prevents the dual sash arms from moving beyond a certain point. The distal ends of the sash arms engage each into an individual dual track via pins on the distal ends thereof. 
     The tracks are arranged so that the dual arms travel in opposite directions as the window is open and closed. As the casement window sash is open, the pins of the distal ends of the dual sash arms move toward each other and the sash arms themselves move toward each other until a catch at a juncture of the two sash arms stops further movement of the sash arms while the pins at the distal ends of the sash arms are still engaged in the tracks. This stops the window from opening beyond its opening limited position. 
     When it is desired to open the window further beyond the opening limited position, an individual operating the window releases the catch that prevents further movement of the dual sash arms relative to each other, the two sash arms are then permitted to pass each other and the catch engages again but this time holding the two sash arms in an extended position biased toward the window frame and so that he distal pins are close enough together to pass through the gap between the dual tracks. The window can then be opened to its full capacity. As the window is again closed, the pins at the end of the duals sash arms are each received through the gap between the two tracks and into their respective track and begin to be forced away from each other by movement of the casement window sash. The force applied to the dual sash arms overcomes the releasable catch at the Y juncture of the sash arms and the sash arms gradually are spread and moved toward the frame until the window is closed. Because the pins at the end of the sash arms have reentered the dual tracks and the catch at the juncture of the sash arms has been reset by the closing of the window. The window opening limiting device is now prepared for the next operation. 
     Another embodiment of the invention also includes dual sash arms and tracks. The two sash arms are forced toward each other as the window opens and eventually reach a point where they are fully extended outwardly and because they are still engaged in the dual sash tracks prevent the window from opening further. When it is desired to open the window beyond the opening limited position, an individual operating the window can grasp the dual sash arms and squeeze them together to overcome a bias thus removing them from between the dual tracks. It is then possible to open the window to its full capacity. 
     The entrance to the space between the dual tracks has a ramped slope so as the window closes the ramps engage the pins on the two sides of the access opening to the dual tracks. The ramped tracks then overcome the bias of the dual sash arms and direct the pins inwardly until the dual sash arm pins are within the dual tracks. At this point, the pins abut the back wall of the dual tracks and as the window continues to close the dual sash arms are forced apart and slide along the dual tracks until the dual sash arms are generally parallel to the sash. Thus, this embodiment of the invention is prepared again to limit the opening of the casement sash at the next operation. 
     Another embodiment of the invention includes a U-shaped sash arm defining a longitudinal slot therein. The U-shaped sash arm is secured to a sash bracket and includes a pivoting catch at the distal end thereof that closes off the longitudinal slot when in a closed orientation. This embodiment also includes a fixed pin on a bracket secured to one of the sash or the frame. The catch at the end of the longitudinal slot is structured so that when the fixed pin is received in the longitudinal slot the catch prevents the fixed pin from departing from the distal open end of the longitudinal slot. The catch is further arranged so that it can be released and so that when the fixed pin enters the longitudinal slot it resets the catch in the latched orientation. 
     In this embodiment of the invention, when the casement sash is opened the fixed pin travels along the longitudinal slot from proximal to distal until it abuts the catch at the distal end the slot. At this point, the abutment of the fixed pin with the catch at the distal end of the slot prevents the casement sash from opening beyond the window opening limited position. 
     When it is desired to open the window beyond its window opening limited position, an individual operating the window releases a lever or other actuator to release the catch at the distal end of the longitudinal slot. The pin is thus enabled to exit the longitudinal slot and enables that casement sash to be opened to its full extent. The bracket at the proximal end of the U-shaped arm includes a biasing member, such as a spring, to hold the U-shaped arm in a desired position so that when the window sash is closed the pin enters the distal end of the longitudinal slot and overcomes the bias of the catch to transition the catch from the open position to a closed position. As the casement sash continues to close the pin travels down the longitudinal slot toward the proximal end of the U-shaped arm. When the U-shaped arm is generally parallel to the window frame and sash and the window is closed the window opening limiting device of this embodiment is then prepared to stop the window at the limiting position when the window is next opened. 
     The window opening limit devices can be installed on existing casement windows of different dimensions to uniformly limit the maximum open position of the window. The limiting arm can be actively released by a user so that the sash can be opened from a closed position to a fully opened position. The limiting devices are adapted to passively reengage when the window is closed so that the sash can only be opened from the closed position to the limited position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention may be more completely understood in consideration of the following detailed description of various embodiments of the invention in connection with the following drawings, in which: 
         FIG. 1  is a perspective view of a window opening limit device according to an example embodiment of the invention with some parts removed for clarity; 
         FIG. 2  is a perspective view of the window opening limit device of  FIG. 1  from an opposing direction; 
         FIG. 3  is a perspective view of a casement window; 
         FIG. 4  is a perspective view of a window opening limit device of  FIGS. 1 and 2  installed in a window; 
         FIG. 5  is another perspective view of a window opening limit device of  FIG. 4  installed in a window; 
         FIG. 6  is a detailed perspective view of a track and a limiting arm of a window opening limit device according to an embodiment of the present invention, when the sash is positioned in the opening limited position; 
         FIG. 7  is an exploded perspective view and a side view of a window opening limit device according to an embodiment of the present invention; 
         FIG. 8  is an elevational view of the window opening limit device 
         FIG. 9  is a perspective view of the window opening limit device of  FIG. 7  installed in a window in an uncoupled state; 
         FIG. 10  is a perspective view of the window opening limit device of  FIG. 7  installed in a window in a coupled state; 
         FIG. 11  is a perspective view of a window opening limit device according to another embodiment of the present invention in an uncoupled state; 
         FIG. 12  is a perspective view of a window opening limit device of  FIG. 11  in a coupled state; 
         FIG. 13  is a perspective view of a window opening limit device of  FIG. 11  in another orientation; 
         FIG. 14  is perspective view of a window opening limit device according to another embodiment of the invention, installed in a window; 
         FIG. 15  is perspective view of the window opening limit device of  FIG. 14  in a released configuration, installed in a window; 
         FIG. 16  is perspective view of the window opening limit device of  FIG. 14  in phantom when the sash is positioned in the closed position; 
         FIG. 17  is a schematic plan view of a window opening limit device according to another embodiment of the invention; 
         FIG. 18  is a schematic plan view of a window opening limit device according to another embodiment of the present invention; 
         FIG. 19  is a schematic plan view of a window opening limit device according to another embodiment of the present invention; 
         FIG. 20  is a schematic plan view of a window opening limit device according to another embodiment of the present invention; 
         FIG. 21  is a schematic plan view of a window opening limit device according to another embodiment of the present invention in an engaged orientation; 
         FIG. 22  is a schematic plan view of the window opening limit device of  FIG. 21  in a released orientation; 
         FIG. 23  is a perspective view of a window opening limit device according to an embodiment of the invention installed in a casement window; 
         FIG. 24  is a perspective, exploded view of the window opening limit device of  FIG. 23 ; 
         FIG. 25  is a side elevation view of the window opening limit device of  FIG. 23  depicted in a window-closed position; 
         FIG. 26  is a side elevation view of the window opening limit device of  FIG. 23  depicted in a window-open, travel-limited position; 
         FIG. 27  is a side elevation view of the window opening limit device of  FIG. 23  depicted in a window-open, travel-limited position, and with the release mechanism depicted after completion of a first release action; 
         FIG. 28  is a side elevation view of the window opening limit device of  FIG. 23  depicted in a window-open position, and with the release mechanism depicted after completion of a second release action; 
         FIG. 29  is a side elevation view of the window opening limit device of  FIG. 23  depicted in a window-open position, and with the limiting arm exiting from engagement with the track; 
         FIG. 30  is a side elevation view of the window opening limit device of  FIG. 23  depicted in a window-open position, and with the limiting arm fully clear of the track; and 
         FIG. 31  is a side elevation view of the window opening limit device of  FIG. 23  depicted in a window-open position but with the sash closing toward the frame, and with the limiting arm approaching engagement with the track. 
     
    
    
     While the present invention is amenable to various modification and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. In particular, although the invention is primarily described in the context of a casement window, the invention is equally applicable in the context of an awning window. 
     DETAILED DESCRIPTION 
     An exemplary embodiment of window opening limit device  100  in accordance with the invention is depicted in  FIGS. 1-2  and  4 - 6 . Window opening limiting device  100  generally includes sash bracket  102 , limiting arm  104 , and track  106 . 
     For reference purposes, an example of casement window  110  is depicted in  FIG. 3 . Casement window  110  generally includes frame  112 , sash  114 , and operator mechanism  116 . Frame  112  includes head jamb  118 , sill  120 , and sides  122  and defines window opening  124 . Sash  114  includes top rail  126 , bottom  128 , side rails  130 , and window pane  132 . Sash  114  may also include screen  134 . Sash  114  is typically coupled with hinges (not shown) to frame  112  and can be opened and closed through operation of operator mechanism  116 . 
     Referring to  FIGS. 1-2  and  4 - 16 , sash bracket  102  generally includes mounting bracket  140 , biasing member  142 , and stabilizer head  144 . Sash bracket  102  may also define mounting apertures  146 . Generally, sash bracket  102  is structured to have a low-profile such that pivot head  144  does not extend beyond the outermost edge of side rail  130 . 
     Limiting arm  104  presents proximal end  150 , distal end  152 , and main section  154  extending between distal and proximal ends  150 ,  152 . Proximal end  150  is pivotably coupled to sash bracket  102 . Distal end  152  may be slightly offset from main section  154 , as depicted in  FIGS. 1-2 . Distal end  152  generally includes engagement structure  156  adapted to releasably engage track  106 . In an example embodiment, engagement structure  156  may be slide wheel  158  that is rotatable on axle  160 . 
     Track  106  generally includes main plate  170 , primary flange  172 , and secondary flange  174 . Track  106  may also include stop  176 . A biasing member (not shown) may be positioned intermediate main plate  170  and stop  176 . Main plate  170  defines apertures  178  adapted to receive fastening members (not shown) for coupling track  106  to frame  112 . In an embodiment, track  106  is adapted for mounting on the inside surface of sides  122 . Primary and secondary flanges  170 ,  172  may have beveled edges  178  and lips  180  to retain and guide slide wheel  158  proximal main plate  170 . Primary flange  172  generally extends the length of main plate  170 . Secondary flange  174  generally extends for only a portion of the length of main plate  170 . Primary flange  172  and secondary flange  174  thereby define engagement region  182  and disengagement region  184  on main plate  170 . In an embodiment, stop  176  is positioned in or proximal to disengagement region  184 . Main plate  170 , primary flange  172 , secondary flange  174  define channel  185  adapted to receive slide wheel  158 . 
     Another embodiment of window opening limiting device  100  is depicted in  FIGS. 7-10 . Referring particularly to  FIGS. 7 and 8 , sash arm  186  generally includes position biasing member  194 , arm  196  and coupling pin  198 . Sash arm  186  is coupled to sash bracket  188  at pivot axle  200 . Position biasing member  194  is located between sash arm  186  and sash bracket  188 . Position biasing member  194 , biases sash arm  186  to a desired position. Coupling pin  198  is secured to a distal end of arm  196  relative to sash bracket  188 . 
     Frame arm  190  generally includes arm  202 , position biasing member  204  and slider lock  206 . In this example embodiment, arm  202  presents receiving hook  208  at a distal end thereof, spring indentations  210  and slider lock stop  212 . Arm  202  is coupled to frame bracket  192  by pivot axle  214 . 
     In this example embodiment, slider lock  206  is configured to slide over arm  202 . Slider lock  206  presents spring members  216 , slider channel  218 , coupling pin receiving slot  220  and tapered entrance  222 . When moved distally relative to arm  202 , slider lock  206  abuts slider lock stop  212 . Receiving hook  208  is configured to accept coupling pin  198  therein. Coupling pin receiving slot  220  is sized to receive coupling pin  198  therein and to slidably secure coupling pin within receiving hook  208  when slider lock  206  is advanced toward an over receiving hook  208 . Position biasing member  204  is operably coupled to frame bracket  192  and arm  202  and positioned to bias frame arm  190  to a desired position. Window opening limiting device  100 , according to this embodiment of the invention, is depicted in an uncoupled state in  FIG. 9  wherein coupling pin  198  is not received in receiving hook  208 .  FIG. 10  depicts window opening limiting device  100  according to this embodiment of the invention in a coupled state wherein coupling pin  198  is received in receiving hook  208  and secured therein by slider lock stop  212 . 
     Referring to  FIGS. 11-13  another example embodiment of window opening limiting device  100  is depicted. This example embodiment generally includes sash arm assembly  224  and track assembly  226 . Sash arm assembly  224  generally includes sash bracket  228  and arm  230 . As can be seen in  FIGS. 11-13 , sash bracket  228  generally includes mounting plate  232 , hinge barrel  234 , moving plate  236  and pivoting arm support  238 . Mounting plate  232  is adapted to be secured to a window sash by screws or other fasteners. Mounting plate  232  is joined to moving plate  236  by hinge barrel  234 . Moving plate  236  supports pivoting arm support  238 . Pivoting arm support  238  is coupled to arm  230 . Arm  230  generally includes distal coupling pin  240  and proximal pivot coupling  242 . 
     Track assembly  226  generally includes track  244  and slider  246 . Slider  246  is adapted to be coupled to track  244  in a slidable relationship. Track  244  is configured to be secured to a window frame by screws or other fasteners (not shown). 
     Slider  246  generally includes slider body  248 , toggle latch  250  and release actuator  252 . Toggle latch  250  is biased by a spring or other biasing member toward an open position in which receiving throat  254  is open outwardly and capable of receiving distal coupling pin  240  therein. Release actuator  252  is configured to secure toggle latch  250  in a closed orientation. Actuation of release actuator  252  releases toggle latch  250  so that it may travel toward its biased open position. Distal coupling pin  240  is receivable into receiving throat  254  so that when toggle latch  250  is in a closed orientation, distal coupling pin  240  is secured therein. 
     Another example embodiment of the invention is depicted in  FIGS. 14-16 . In this embodiment, the invention generally includes frame bracket  256  and biased sash arm  258 . 
     Frame bracket  256  generally includes mounting plate  260  and fixed pin  262 . Mounting plate  260  is adapted to be secured to a surface, for example, via screws or other fasteners. Fixed pin  262  extends outwardly from mounting plate  260 . 
     Biased sash arm  258  generally includes arm  264 , slide hook  266  and sash bracket  268 . Arm  264  is pivotably secured to sash bracket  268  and biased toward frame bracket  256  by a spring (not shown) or other biasing member. Arm  264 , in this example embodiment, generally presents straight body  272 , and at distal end  270 , ramp  274  and retainer  276 . 
     Slide hook  266  generally presents ramped portion  278 , hook  280  and arm channel  282 . Straight body  272  of arm  264  is received in arm channel  282  of slide hook  266  in slidable relation. Slide hook  266  is biased proximally from distal end  270  of arm  264 . Biasing may be accomplished by springs or other biasing members (not shown). Ramped portion  278  is shaped to essentially conform to the outside of ramp  274 . Retainer  276  is shaped so that when slide hook  266  is moved distally, retainer  276  occupies the space in hook  280 . Hook  280  is sized and shaped to engage fixed pin  262  when hook  280  is under tension relative to fixed pin  262 . Ramp  274  and ramped portion  278  are shaped to permit biased sash arm  258  to ride up and over fixed pin  262  when bias sash arm  258  is moved toward fixed pin  262 . 
     Two similar embodiments of the invention are depicted in  FIGS. 17 and 18 . Because of their structural similaries, these two embodiments will be described together. The embodiments depicted in  FIGS. 17 and 18 , generally include a biased sash arm  284  and slide track  286 . Biased sash arm  284  generally includes sash mounting plate  288 , arm  290  and distal pin  292 . Sash mounting plate  288  is adapted to be secured to a sash or other structure by screws or other fasteners (not shown). Arm  290  is pivotively mounted to sash mounting plate  288  and biased toward a particular desired position. Distal pin  292  is located at the distal end of arm  290 . Distal pin  292  may also include a bushing or wheel or other friction reducing device thereon (not shown). 
     Slide track  286  generally includes track  294  and keeper  296 . In this embodiment of the invention, track  294  is generally oriented parallel to the long axis of sash  114  or frame  112  when installed. Track  294  defines track entrance/exit  298  at one end thereof. Keeper  296  is secured to track  294  so that track entrance/exit  298  can be opened or closed by manipulation of keeper  296 . Keeper  296  is also spring loaded so that keeper  296  can be displaced by distal pin  292  to open track entrance/exit  298  and permit entrance of distal pin  292 . Further, keeper  26  is structured so that when distal pin  292  is in track  294 , distal pin abuts keeper  296  and is retained within track  294 . 
     The bias of bias sash arm  284  is such that distal pin  292  is aligned with track entrance/exit  298  when sash  114  is moved toward frame  112 . Keeper  296  further includes push tab  300 . Push tab  300  is positioned so that force is applied to push tab  300  will move keeper  296  to open track entrance/exit  298 . 
     Referring to  FIG. 19 , another embodiment of the invention is depicted. This embodiment includes dual arms  302  and dual slide tracks  304 . 
     Dual arms  302  generally include first arm  306  and second arm  308 . First arm  306  and second arm  308  are secured to frame bracket  310  by common pivot  312 . First arm  306  and second arm  308  also include arm catch  314 . As depicted in the present embodiment, first arm  306  and second arm  308  may have a bent or dog leg shape. Arm catch  314  may be located approximate bend  316  of first arm  306  and second arm  308 . Arm catch  314  is structured to prevent first arm  306  and second arm  308  from passing each other when they are approximately in the orientation depicted in  FIG. 19 . Arm catch  314  may be released to permit first arm  306  to pass second arm  308 . Arm catch  314  may also be structured to permit passage of first arm  306  pass second arm  308  in the reversed direction but with some resistance. First arm  306  and second arm  308  also include first distal pin  318  and second distal pin  320 . 
     Dual slide tracks  304 , each generally present ramp entrance/exit  322 . In the depicted embodiment, dual slide tracks  304  are generally mirror images of each other. Dual slide tracks  304  are positioned so that when dual arms  302  are secured by arm catch  314 , ramped entrance/exit  322  of dual slide tracks  304  are closer together than are first distal pin  318  and second distal pin  320 . When arm catch  314  is released, first arm  306  and second arm  308  can be move closer together so that first distal pin  318  and second distal pin  320  are as narrow or narrower than ramped entrance/exit  322  of dual slide tracks  304 . 
     Referring to  FIG. 20  another embodiment of the invention is depicted. This embodiment includes dual arms  324  and dual slide tracks  326 . 
     Dual arms  324  include first curved arm  328 , second curved arm  330 , first distal pin  332  and second distal pin  334 . First distal pin  332  is at the distal end of first curved arm  328 . Second distal pin  334  is at the distal end of second curved arm  330 . First curved arm  328  and second curved arm  330  are biased to maintain a position similar to that depicted in  FIG. 20  with first distal pin  332  and second distal pin  334  a desired distance apart. 
     Dual slide tracks  326  generally include first track  336 , second track  338  and common entrance  340 . Common entrance  340  may take the form of funnel  342 . This embodiment of the invention may also optionally include keeper  344 . First track  336  and second track  338  share a common long axis and meet at common entrance  340 . Common entrance  340  is slightly narrower than the spacing between first distal pin  332  and second distal pin  334  when they are biased to a desired position. Funnel  342  defines ramped edges  346 . Ramped edges  346  slope inwardly toward common entrance  340 . 
     Another embodiment of the invention is depicted in  FIGS. 21 and 22 . This embodiment of the invention generally includes U-shaped arm  348  and sash bracket  350 . U-shaped arm  348  generally includes mounting plate  352 , arm  354 , pivoting catch  356  and catch release  358 . Arm  354  is pivotally coupled to mounting plate  352  which is adapted to be secured to a surface by screws or other fasteners (not shown). Arm  354  defines longitudinal slot  360  along the length thereof. Pivoting catch  356  is located generally at a distal end of arm  354 . Pivoting catch  356  is structured to close off the end of longitudinal slot  360  and to be released to open the end of longitudinal slot  360 . Sash bracket  350  generally includes mounting plate  362  supporting fixed pin  364 . Mounting plate  362  is adapted to be secured by screws or other fasteners to a surface. Fixed pin  364  is appropriately sized to be received in longitudinal slot  360 . Pivoting catch  356  is structured so that when fixed pin  364  abuts pivoting catch  356  from outside of longitudinal slot  360 , fixed pin  364  forces pivoting catch  356  to permit fixed pin to enter longitudinal slot  360  and to move pivoting catch  356  to a closed position. Pivoting catch  356  is secured in the closed position by catch release  358 . Arm  354  is biased at mounting plate  352  to assume a desired position so that fixed pin  364  is aligned with pivoting catch  356  at entrance  366  of longitudinal slot  360 . 
     In operation, window opening limiting device  100  can be used in any number of ways. In the embodiment depicted in  FIGS. 1-6 , device  100  can be mounted in window such as casement window  110  depicted in  FIG. 3 . In general, sash  114  of casement window  110  is shiftable between a closed and fully opened position. In the closed position, sash  114  is positioned within frame  112  such that sash  114  substantially fully occupies window opening  124 . In the fully opened position, the angle formed by bottom  128  of sash  114  and sill  120  of frame  112  is maximized, such as, for example, by the configuration of operator mechanism  116  or interference between side rail  130  of sash  114  and side  122  of frame  112  (which may occur, for example, when sash  114  is released from the sash arm of operator assembly  116 ). In an example embodiment of the invention, device  100  defines a limited position intermediate the closed and fully opened positions wherein the sash is partially open with respect to frame  112 . As used herein, the limited position can be numerically described by the minimum distance between the corresponding side rail  130  and side  122 . In an example embodiment, when device  100  is engaged, sash  114  is shiftable between the closed position and the limited position but cannot be shifted between the limited position and fully opened position during normal operation. When device  100  is disengaged, sash  114  is shiftable between the closed position beyond the opening limited position and to the fully opened position. 
     Referring to  FIGS. 1-2  and  4 - 6 , sash bracket  102  is generally mounted to sash  114  and track  106  is generally static-mounted to frame  112 . In this example, sash bracket  102  is coupled to side rail  130  of sash  114  and track is coupled to side  122  of frame  112 . According to this embodiment, sash bracket  102  is positioned higher than track jamb  106  with respect to sill  120  and bottom  128 . In an alternative embodiment, sash bracket  102  is coupled to bottom  128  of sash  114  and track  106  is coupled to sill  120  of frame  112 . A possible disadvantage of this mounting arrangement can be interference between device  100  and existing window hardware. In another example embodiment, device  100  can be retrofitted onto casement window  110  that has already been installed in a structure. In an alternative embodiment, device  100  can be installed onto casement window  100  before casement window  100  is installed in the structure. 
     A feature and advantage of installing device  100  on side rail  130  and side  122  is that sash bracket  102  and track  106  are variably positionable with respect to sash  114  and frame  112  on casement windows of different dimensions while maintaining a substantially uniform opening limited position. In contrast, if device  100  is installed on sill  120  and bottom  128 , device must be positioned distal to the hinges and proximal the corners formed by sill  120  and side  122 , and bottom  128  and side rail, respectively. 
     When sash  114  is in the closed position, biasing member  142  exerts a force upon distal end  150  of limiting arm  104 . This causes slide wheel  158  to occupy engagement region  182  of track  106 . In particular, the force exerted by biasing member  142  urges slide wheel  158  toward the inner portion of beveled edge  178  or primary flange  170  and away from beveled edge  178  of secondary flange  172 . 
     As sash  114  is opened, sash bracket  102  shifts away from track  106 . Since limiting arm  104  is coupled to sash bracket  102 , this causes distal end  150  of limiting arm  104  to follow sash bracket  102 . Slide wheel  158  travels along channel  186  from engagement region  182  toward disengagement region  184 . As slide wheel  158  approaches disengagement region  184 , distal end  150  of limiting arm  104  is pulled away from biasing member  142 . In an example embodiment, distal end  150  of limiting arm  104  is not pulled away from biasing member at least until slide wheel has cleared engagement region  182  and occupies channel  186 . At this point, lips  184  of primary and secondary flanges  172 ,  174  retain slide wheel  158  within channel  186 . This process can be reversed by returning sash  114  to the closed position. 
     When sash  114  reaches the opening limited position, slide wheel  158  is positioned within channel  186  proximate stop  176 . Limiting arm  104  is prevented from disengaging from track  106  by abutment of slide wheel  158  to stop  176 . In this orientation stop  176  blocks slide wheel  158  from exiting channel  186  through disengagement region. In this manner, sash  114  cannot be opened any further because slide wheel  158  of limiting arm  104  cannot move through channel  186  in a direction away from sill  120  toward head jamb  118 . The limited position can be varied by utilizing limiting arms  104  of different lengths. For example, increasing the length of limiting arm  104  will cause the limited position to be closer to the fully opened position, and vice versa. 
     In the example embodiment, limiting arm  104  can be disengaged from track  106  so that sash  114  is shiftable from the opening limited position to the fully opened position. When it is desired to open the window beyond the opening limited position, a user can apply pressure to stop  176  so that stop  176  is shifted toward main plate  170  of track  106 . This creates a gap between stop  176  and primary and secondary flanges  170 ,  172  through which slide wheel  158  can pass. As sash  114  is opened further, slide wheel  158  enters disengagement region  184  of track  106  and then exits track  106  entirely. Since secondary flange  172  is not present in disengagement region  184 , limiting arm  104  can disengage from track  104 . 
     A feature and advantage of the above mechanism for releasing limiting arm  104  from track  106  is that it requires two points of activation. In particular, a user must exert a force upon stop  176  while simultaneously guiding slide wheel  158  through channel or pushing sash  114 . Such a releasing procedure, that requires multiple simultaneous actions, reduces the likelihood of inadvertent operation, such as, for example, by a child. In an alternative embodiment, device  100  includes a biased triggering mechanism (not shown) that allows limiting arm  104  to be released from inside frame  112 . Device  100  may include any number of mechanisms that allow limiting arm  104  to be released from track  106 . 
     Limiting arm  104  reengages with track  106  as sash  114  is returned to the closed position. As sash  114  is shifted to the closed position, side rail  130  of sash  114  and/or track  106  cause limiting arm  104  to move toward a generally vertical orientation (with respect to embodiments in which track jamb  106  is mounted onto side rail  130  and sash bracket  102  is mounted onto side  122 ). Stabilizer head  144  generally limits transverse movement of limiting arm  104  as sash  114  is shifted toward the closed position. When sash  114  reaches the closed position, biasing member  142  and stabilizer head  144  guide and urge slide wheel  158  into engagement region  150  of limiting arm  106 . Limiting arm  106  is thereby positioned to engage channel  186  when sash  114  is once again opened. A feature and advantage of the present invention is limiting arm  104  automatically reengages track  106  upon closing. Therefore, if the user forgets that the limiting arm  104  was disengaged from track  106 , and a new user was not aware of this action, device will return to the function of limiting opening of sash  114  once sash is returned to the closed position. 
     Referring to  FIGS. 7-10 , in operation of the depicted embodiment of the invention, sash arm  186  and frame arm  190  are biased by position biasing members  194  and  204  so that coupling pin  198  is generally aligned with receiving hook  208 . When sash  114  is moved toward frame  112 , coupling pin  198  contacts slider lock  206  and causes slider lock  206  to retract and coupling pin  198  to enter receiving hook  208 . Slider lock  206  then returns to its former position because of biasing spring members  216 . Coupling pin  198  is then secured within receiving hook  208  by slider lock  206  and sash  114  is prevented from opening beyond a preselected opening limited position. 
     When it is desire to open the window farther, an individual operating the window can grasp slider lock  206  and slide it away from receiving hook  208  to release coupling pin  198  from receiving hook  208 . Sash  114  is then released by window opening limiting device  100  and can be opened to its full extent. 
     Referring now to  FIGS. 11-13 , in this embodiment of the invention, as sash  114  is opened relative to frame  112 , arm  230  pulls on slider  246  to which it is secured. Slider  246  moves along track  244  until arm  230  reaches its most direct extension. Sash  114  has then reached its window opening limited position. When it is desired to open the window farther, an individual operating the window may actuate release actuator  252  which permits toggle latch  250  to open because of its biased arrangement. When toggle latch  250  opens, distal coupling pin  240  is released from toggle latch  250  and sash  114  may now be extended to its fully open position. In this embodiment of the invention, hinge barrel  234  allows movement between mounting plate  232  and moving plate  236  to accommodate movement of arm  230  relative to sash  114 . Pivoting arm support  238  permits pivoting of arm  230  relative to mounting plate  232  and moving plate  236 . When sash  114  is closed from its fully open position, arm  230  is positioned so that distal coupling pin  240  is aligned with receiving throat  254  of toggle latch  250 . As the window is closed and toggle latch  250  is pushed inwardly, release actuator  252  activates to secure toggle latch  250  in the closed position. As sash  114  is closed farther, slider  246  slides along track  244  until window sash  114  is fully closed and window opening limiting device  100  of this embodiment is prepared for a next opening of the window. 
     Referring to  FIGS. 14-16 , in the depicted embodiment of the invention, as sash  114  is opened, biased sash arm  258  bears against fixed pin  262  until hook  280  of slide hook  266  engages fixed pin  262 . At this point, sash  114  is limited from opening farther. 
     When it is desired to open sash  114  beyond this position, an individual operating the window can grasp slide hook  266  and pull it away from fixed pin  262 . Arm  264  is now released from fixed pin  262  and sash  114  can be opened to its full extent. When sash  114  is closed, biased sash arm  258  is positioned so that ramped portion  278  contacts frame  112 . Bias sash arm  258  slides along frame  112  until ramped portion  278  of slide hook  266  contacts fixed pin  262 . Ramped portion  278  then slides over fixed pin  262  and sash  114  is permitted to close farther until the position depicted in  FIG. 16  is achieved. At this point, this embodiment of the invention is ready to be open again and provide only limited opening of the window. 
     Referring to  FIGS. 17 and 18 , in the embodiments depicted herein as the window is opened and arm  290  is extended, distal pin  292  slides up track  294  until it abuts keeper  296  at track entrance/exit  298 . Sash  114  has now reached its window opening limited position. When it is desired to open the window farther, an individual operating the window may press on pushtab  300  to slidably or pivotably move keeper  296  to open track entrance/exit  298 . Sash  114  may then be opened to its fully open position. 
     As sash  114  is closed, arm  290  is held by bias in a position so that distal pin  292  is aligned with track entrance/exit  298 . As sash  114  is closed, distal pin  292  contacts keeper  296  and displaces keeper  296  so that distal pin  292  enters track  294 . As sash  114  is further closed, distal pin  292  travels down track  294  and window opening limiting device  100 , according to these embodiments of the invention, is prepared for another opening of the window to limit its opening extent. 
     Referring to  FIG. 19 , in operation of in this embodiment of the invention, as sash  114  is opened, first distal pin  318  and second distal pin  320  each travel along dual tracks  304  toward each other. When first arm  306  and second arm  308  reach approximately the position depicted in  FIG. 19 , arm catch  314  prevents further movement of first arm  306  relative to second arm  308 . First distal pin  318  and second distal pin  320  are each engaged in dual slide tracks  304  and sash  114  has reached it window opening limited position. 
     When it is desired to open the window farther, an individual operating this embodiment of the invention, releases arm catch  314  which permits first arm  306  and second arm  308  to move past each other which permits first distal pin  318  and second distal pin  320  to exit ramped entrance/exit  322  of dual slide tracks  304 . Sash  114  may now be open to its full extent. As sash  114  is closed, first distal pin  318  and second distal  320  are held in a position aligned with ramped entrance/exit  322 . As sash  114  continues to close, dual slide tracks  304  contact first distal pin  318  and second distal  320  and overcome the bias of arm catch  314  causing first distal pin  318  and second distal  320  to slide down dual slide tracks  304 . Arm catch  314  is now reset to a position where it will stop movement of first arm  306  relative to second arm  308 . First distal pin  318  and second distal pin  320  move down dual slide tracks  304  as sash  114  continues to close. Window opening limiting device  100  of this embodiment of the invention is then prepared for another operation of the window. 
     Referring to the embodiment depicted in  FIG. 20 , as sash  114  is opened, first curved arm  328  and second curved arm  330  move toward each other as first distal pin  332  and second distal pin  334  move down first track  336  and second track  338  respectively. First curved arm  328  and second curved arm  330  reach their greatest axial extent while first distal pin  332  and second distal pin  334  are still within first track  336  and second track  338  respectively. Sash  114  is then limited at its window opening limiting position. 
     When it is desired to open sash  114  farther, an individual operating this embodiment of the invention grasps first curved arm  328  and second curved arm  330  and presses them together against spring bias thus positioning first distal pin  332  and second distal pin  334  within common entrance  340 . Sash  114  can then be opened to its full extent. 
     As sash  114  is closed, spring bias holds first curved arm  328  and second curved arm  330  so that first distal pin  332  and second distal pin  334  encounter funnel  342  and are pressed inward by ramped edges  346  against bias. When sash  114  has moved far enough, first distal pin  332  and second distal pin  334  are located within first track  336  and second track  338 . As sash  114  is closed further, first distal pin  332  travels down first track  336  and second distal pin  334  travels down second track  338  and window opening limiting device  100  of this embodiment of the invention is prepared to limit the opening of the window on its next actuation. 
     Referring to  FIGS. 21 and 22 , the embodiment depicted here is depicted in  FIG. 21  in an engaged position. As sash  114  is opened, fixed pin  364  travels down longitudinal slot  360  until fixed pin  364  encounters pivoting catch  356 . Upon abutting pivoting catch  356 , fixed pin  364  is prevented from traveling farther and sash  114  has reached its window opening limited position. 
     When it is desired to open sash  114  farther, an individual operating this embodiment of the invention activates catch release  358  which releases pivoting catch  356  and permits fixed pin  364  to exit longitudinal slot  360 . Sash  114  may then be open to its full extent. Biasing holds U-shaped arm  348  in a position so that when sash  114  is closed, fixed pin  364  encounters pivoting catch  356 . As fixed pin  364  forces pivoting catch  356  inwardly, catch release  358  secures pivoting catch  356  in the closed orientation so that fixed pin  364  is secured in longitudinal slot  360 . This embodiment of the invention is then reset to limit the opening of sash  114  again to the window opening limited position. 
     In the embodiment depicted in  FIGS. 23-31 , window opening limit device  400  is installed on casement window assembly  402 , which includes frame portion  404  and operable sash  406 . Window opening limit device  400  generally includes sash bracket  408 , limiting arm  410 , and track assembly  412 . 
     Referring to  FIGS. 23 and 24 , sash bracket  408  generally includes mounting bracket  414 , biasing member  416 , and pivot member  418 . Sash bracket  408  may also define mounting apertures  420 . Generally, sash bracket  408  is structured to have a low-profile such that pivot member  418  does not extend beyond the outermost edge of the side rail of the sash to which sash bracket  408  is mounted. 
     Limiting arm  410  presents proximal end  422 , distal end  424 , and main section  426  extending between distal and proximal ends  422 ,  424 . Proximal end  422  is pivotably coupled to sash bracket  408 , and may be slightly offset from main section  426 , as depicted in  FIGS. 23-24 . Distal end  424  generally includes engagement structure  428  adapted to releasably engage track assembly  412 . In an exemplary embodiment, engagement structure  428  may be slide wheel  430  that is rotatable on axle  432 . 
     Track assembly  412  generally includes track  434  and release assembly  436 . Track  434  generally includes main plate  438 , primary flange  440 , secondary flange  442 , and release mechanism housing portion  444 . Main plate  438  defines apertures  446  adapted to receive fastening members (not shown) for coupling track assembly  412  to frame portion  404 . Main plate  438 , primary flange  440 , and secondary flange  442  define channel  448  adapted to receive slide wheel  430 . 
     Release assembly  436  generally includes slide  450 , pivot stop  452 , and compression springs  454 . Pivot stop  452  is pivotally attached to track  434  with pivot  456 . Slide  450  is slidably received over release mechanism housing portion  444  of track  434 , and is secured with rivet  458  through slot  460 . Compression springs  454  are received in release mechanism housing portion  444 , and bear against end wall  462 , and a bulkhead (not depicted) defined within slide  450 , such that slide  450  is biased away from end wall  462 . 
     The operation of window opening limit device  400  is depicted in  FIGS. 25-31 . With casement window assembly  402  in the window closed position as depicted in  FIG. 25 , wherein operable sash  406  is received in frame portion  404 , limiting arm  410  is substantially aligned with track  434 . Slide wheel  430  is biased against primary flange  440  by biasing member  416 , and is registered with the bottom end of channel  448 . 
     As sash  406  is pivoted away from frame portion  404 , slide wheel  430  is urged against primary flange  440  through the bias of biasing member  416 , and as a result, slide wheel  430  rides upward in channel  448 . Slide wheel  430  eventually contacts pivot stop  452  as depicted in  FIG. 26 . In this position, slide wheel  430  is inhibited from moving further upward in channel  448  by pivot stop  452 , which is positioned such that slide wheel  430  cannot pass between pivot stop  452  and upper end  464  of secondary flange  442  when pivot stop  452  is positioned in the blocking position. 
     As depicted in  FIGS. 27-29 , limiting arm  410  can be released from track assembly  412  in order to enable sash  406  to be opened more fully by operation of release assembly  436 . First, as depicted in  FIG. 27 , slide  450  is slid upward against the bias of compression springs  454  to expose pivot stop  452 . Then, in a separate action, pivot stop  452  is pivoted clockwise from the blocking position to a non-blocking position as depicted in  FIG. 28 . In this position, the gap between pivot stop  452  and upper end  464  of secondary flange  442  is large enough to permit slide wheel  430  to pass through, thereby releasing limiting arm  410  from track assembly  412 . 
     As depicted in  FIG. 30 , once limiting arm  410  has been released, the bias of compression springs  454  can be permitted to urge slide  450  downward, simultaneously pivoting pivot stop  452  back to the blocking position. When sash  406  is closed, slide wheel  430  rides under bottom end  466  of secondary flange  442 , as depicted in  FIG. 31 , eventually returning to the position depicted in  FIG. 25  when sash  406  is fully closed. Hence, window opening limit device  400  is self-resetting each time sash  406  is closed. 
     The embodiments above are intended to be illustrative and not limiting. Additional embodiments are encompassed within the scope of the claims. Although the present invention has been described with reference to particular embodiments, those skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. For purposes of interpreting the claims for the present invention, it is expressly intended that the provisions of Section  112 , sixth paragraph of 35 U.S.C. are not to be invoked unless the specific terms “means for” or “step for” are recited in a claim.