Patent Publication Number: US-11047157-B1

Title: Vent stop

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
     This application is a continuation-in-part of U.S. application Ser. No. 15/791,676, filed on Apr. 11, 2017, which is a continuation-in-part of U.S. application Ser. No. 15/484,295, filed on Apr. 11, 2017, which is a continuation of U.S. application Ser. No. 15/471,158, filed Mar. 28, 2017, which is a continuation of U.S. application Ser. No. 14/198,949, filed Mar. 6, 2014, now issued as U.S. Pat. No. 10,006,232, which is a continuation of U.S. application Ser. No. 12/658,642, filed Feb. 9, 2010, now issued as U.S. Pat. No. 8,833,809, which is a divisional of U.S. application Ser. No. 11/977,445, filed Oct. 24, 2007, now issued as U.S. Pat. No. 8,235,430, which is a continuation-in-part of U.S. application Ser. No. 11/390,467, filed Mar. 28, 2006, now issued as U.S. Pat. No. 7,530,611, all disclosures of which are incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to improved window vent stops particularly for double hung windows and the like and to improvements in their operation. These window vent stops are used to prevent a window or door from opening more than a desired amount. 
     BACKGROUND OF THE INVENTION 
     There are a number of different types of window vent stops available on the market. An example of a window vent stop mechanism is shown in U.S. application Ser. No. 11/390,467, filed Mar. 28, 2007, the disclosures of which are herein incorporated herein by reference. These window vent stops are used to restrict the opening of windows and doors. For example, a window may be opened only a portion due to security concerns or to increase comfort in the room. Window vent stops are primarily used on double hung windows and sliding doors where a sash or a door member slides from a first position to a second position. The window sash lock prevents the sash or the sliding door from moving past a selected point. These sash locks can permit the window to be opened a desired amount for ventilation or other purposes. 
     There are many different types of windows currently available. These windows include casement windows, transom windows, single hung windows, double hung windows, sliding windows, etc. Double hung windows are windows that have a pair of window sashes that may be raised and lowered. Each sash resides in a pair of tracks or recesses that are typically at each side edge of the window. This permits the lower sash to be raised and the upper sash to be lowered. Traditionally, most windows were made of wood. More recently, the windows including the window sashes have been made of extruded metal or plastic. 
     Single hung windows are similar in design to double hung windows except that there is only one sash that may be raised or lowered. Sliding windows are also not unlike double hung windows in design. While a double hung window has sashes that are raised and lowered, a sliding window has sashes that are movable along a track to the right or left. Similarly, sliding doors operate the same way as sliding windows. 
     Double hung windows, single hung windows, sliding windows and sliding doors have a variety of open positions in which they may be placed. While a fully opened position can be desirable for ventilation purposes there can be a downside to the fully opened position. One downside is security. A fully open window or door, however, can be a location for unauthorized ingress and egress from the premises. For example, a double hung window that is opened wide can be a source of danger to small children who may climb up to the window. As a result, many municipalities have enacted laws requiring window guards. Additionally, an opened window or door can provide an invitation to third parties to gain access to the building. As a result, there are a number of vent stops that are available to secure a window or door having sliding members in a partially opened position. 
     One particular problem encountered, however, by users of window vent stops is that the installation becomes a difficult process. In order to install the window vent stop properly, a recess must be cut into the sash stile of the window. This recess must be wide enough to allow the vent stop&#39;s initial insertion into the recess, but it must also be snug enough that the vent stop will remain securely installed and able to serve its purpose of preventing the window from being opened wider than a specified distance. Problems occur when a mold of the window vent stop to be installed is used to carve the recess. At times due to mistakes by the person installing or the inaccuracies of the mold used to carve the recess, the recess cut into the sash stile is often not exactly a perfect fit for the vent stop, whether it be too large or too small. Therefore, a new vent stop must be purchased in these situations. 
     Another problem with the prior art vent stops, is that if a user wants a particular vent stop, that user must purchase a vent stop that is specifically fit for the sash stile thickness of that user&#39;s windows. If a user purchases and attempts to install a window vent stop that is either too big or too small for the sash stile in the window, that user must purchase a new window vent stop. 
     Thus, there is a need in the art for window vent stops with the ability to be used with sash stiles of various thicknesses and with recesses of variable sizes. This would save a user time and money in the installation of the window vent stop. The present invention fulfills this need by using flexible side engagement pieces which allow a particular vent stop to be installed in virtually any sash stile. 
     OBJECTS OF THE INVENTION 
     It is an object of the present invention to provide a vent stop that can be installed more easily than the prior art vent stops. 
     It is another object of the present invention to provide an improved vent stop that is more dependable in its operation than the prior art vent stops. 
     It is a further object of the present invention to provide a vent stop that provides a mechanism that permits the vent stop to be installed in a variety of different window types and sizes. 
     It is still another object of the present invention to provide a vent stop that is more flexible in its ability to fit into a variety of recesses carved into a sash stile. 
     It is still another object of the present invention to provide a vent stop that is more flexible in its ability to fit into a variety of recesses routed into a sash stile. 
     It is a still further object of the present invention to provide a vent stop that has flexible side engagement pieces which permit the vent stop to be installed in a variety of window types. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to an improved vent stop or sash lock for use in a sliding sash window assembly or a sliding door assembly. The window may have one or more sashes usually upper and lower sash window frames installed for vertical sliding movement. 
     Alternatively, the window may have left and right horizontal sliding sashes. The door may also have one or more sliding doors. One sash frame or sliding door frame has a recess into the interior thereof. The vent stop has a housing adapted to be disposed in the recess. 
     This housing includes a cavity, usually with a bottom plate therein. Inside the cavity is a tumbler that may be in a retracted position and an extended position. When the tumbler is in an extended position the tumbler has a protruding apex at the top. The apex prevents a sash or door from moving when the apex contacts the sash or the door. The tumbler has at least one pivot means for pivotally securing said tumbler to said housing for movement between the extended position and the retracted position. In the extended position the bottom of the tumbler overlies a portion of the second sash to prevent movement of the lower sash past the tumbler. When in a retracted position within said cavity the sash or door can be raised and/or moved past the tumbler without interference. Also within the housing is a spring means for biasing said tumbler into the extended position. The tumbler has at least one means for retaining the tumbler within the housing. The retaining means may be one or more pins that extend laterally from the side of the tumbler and ride within an opening in the sidewall of the housing. Alternatively, the interior wall of the housing may have one or more pins extending toward the tumbler and riding within an opening in the tumbler&#39;s side wall. 
     The housing also has at least one side engagement piece, preferably two, which is preferably made from the same type of material as the housing and is flexible and bendable with the shape of the recess cut into the sash stile into which the window vent stop is placed. These side engagement pieces are intended to aid in the installation of the window vent stop into the sash stile and are flexible so as to enable the installation of the window vent stop in a wide variety of sash stiles of different sizes. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view of a preferred embodiment of the vent stop of the present invention with the tumbler in the extended position. 
         FIG. 2  is a side view of the tumbler of the vent stop of the present invention. 
         FIG. 3  is a side top perspective view of the vent stop of  FIG. 1  with the tumbler in the retracted position. 
         FIG. 4  is a side bottom perspective view of the vent stop of  FIG. 1  with the tumbler in the retracted position. 
         FIG. 5  is a top perspective view of the vent stop of  FIG. 1  positioned over a slot in a window or door sash. 
         FIG. 6  is a top perspective view of the vent stop of  FIG. 1  partially installed in a slot in a window or door sash. 
         FIG. 7  is a side view of the vent stop of  FIG. 1  showing the side opposite the one shown in  FIG. 1 . 
         FIG. 8  is a top perspective view of the vent stop of  FIG. 1  fully installed in a window or door sash. 
         FIG. 9  is a top side perspective view of the vent stop of  FIG. 1 . 
         FIG. 10  is a top perspective view of the vent stop of  FIG. 1  with the tumbler in the extended position. 
         FIG. 11  is a side view of a preferred embodiment of the vent stop of the present invention different from the embodiment in  FIGS. 1-10 . 
         FIG. 12  is a cross-sectional view of the vent stop of  FIG. 11 . 
         FIG. 12A  is a cross-sectional view of the vent stop of  FIG. 12 , but with the tumbler shown in the retracted position. 
         FIG. 13  is a side cross-sectional view of the vent stop of  FIG. 11  as it is being installed into a window sash stile. 
         FIG. 14  is a side cross-sectional view of the vent stop of  FIG. 13  after it has been installed in the sash stile. 
         FIG. 15  is a side cross-sectional view of the vent stop of  FIG. 14  installed in a sash stile of a greater thickness. 
         FIG. 16  is a side view of another vent top embodiment in accordance with the present invention, with the tumbler shown in the extended position. 
         FIG. 17  is a bottom view of the vent stop of  FIG. 16 . 
         FIG. 18  is a top view of the vent stop of  FIG. 16 . 
         FIG. 19  is a second side view of the vent stop of  FIG. 16 . 
         FIG. 20  is a first end view of the vent stop of  FIG. 16 . 
         FIG. 21  is a second end view of the vent stop of  FIG. 16 . 
         FIG. 22  is a first perspective view of the vent stop of  FIG. 16 . 
         FIG. 23  is a second perspective view of the vent stop of  FIG. 16 . 
         FIG. 24  is an exploded perspective view of the component parts that may be assembled to produce the vent stop of  FIG. 16 . 
         FIG. 25  is a cross-sectional view of the component parts that may be assembled to produce the vent stop of  FIG. 16 . 
         FIGS. 26-29  show a sequence of cross-sectional views in which the tumbler of the vent stop of  FIG. 16  is actuated from the extended position into the retracted position. 
         FIGS. 30-33  show a sequence of cross-sectional views in which the tumbler of the vent stop of  FIG. 16  is actuated from the retracted position into the extended position. 
         FIG. 34  is a side cross-sectional view showing the vent stop of  FIG. 16  being initially positioned within a slotted opening in a window or door sash. 
         FIG. 35  is the side cross-sectional view of  FIG. 34 , but is shown after the vent stop is fully inserted and retained within the slotted opening. 
         FIG. 36  is an end view of the vent stop after being fully inserted and retained within the slotted opening, as shown in  FIG. 35 . 
         FIG. 37  is a perspective view of yet another vent stop embodiment. 
         FIG. 38  is a side view of the vent stop of  FIG. 37 . 
         FIG. 39  is a top view of the vent stop of  FIG. 37 . 
         FIG. 40  is an end view of the vent stop of  FIG. 37 . 
         FIG. 41  is an exploded perspective view of the housing and tumbler of the vent stop of  FIG. 37 . 
         FIG. 42  is a side view of the housing of the vent stop of  FIG. 37 . 
         FIG. 43  is a top view of the housing of  FIG. 42 . 
         FIG. 44  is a bottom view of the housing of  FIG. 42 . 
         FIG. 45  is a first end view of the housing of  FIG. 42 . 
         FIG. 46  is a second end view of the housing of  FIG. 42 . 
         FIG. 47  is a cross-sectional view through the housing of  FIG. 42 . 
         FIG. 48  is a side view of the tumbler of the vent stop of  FIG. 37 . 
         FIG. 49  is a top view of the tumbler of  FIG. 48 . 
         FIG. 50  is a bottom view of the tumbler of  FIG. 48 . 
         FIG. 51  is a first end view of the tumbler of  FIG. 48 . 
         FIG. 52  is a second end view of the tumbler of  FIG. 48 . 
         FIG. 53  is a side cross-sectional view through the vent stop of  FIG. 37  when installed in a sliding sash window or door, shown with the tumbler in the second tumbler position, and with a sliding sash member positioned distally, but being moved towards the tumbler of the vent stop. 
         FIG. 54  is the side cross-sectional view of  FIG. 53 , but is shown after the sliding sash member has contacted, and had its sliding travel restricted/limited by, the tumbler positioned in the second tumbler position. 
         FIG. 55  is the side cross-sectional view of  FIG. 53 , but is shown after a user has applied a force to the tumbler to pivot it into a first tumbler position, where it no longer restricts movement of the sash member, and where it is releasably maintained by a surface of the integral spring member of the tumbler being engaged with a surface of a contoured feature on the bottom wall of the housing. 
         FIG. 55A  is an enlarged detail view of a portion of the cross-sectional view of the housing and tumbler, as shown in  FIG. 55 . 
         FIG. 56  is the side cross-sectional view of  FIG. 55 , but is shown after the sliding sash member has been moved further towards a fully opened position to contact the angled protruding surface of the tumbler, and trigger the release of the tumbler from its first position. 
         FIG. 57  is the side cross-sectional view of  FIG. 56 , but is shown with the sliding sash member being moved back towards a closed position, and with the second end of the tumbler biased into contact with the sash member. 
         FIG. 58  is the side cross-sectional view of  FIG. 57 , but is shown after the sliding sash member has moved back into the open position, with the tumbler being biased back into the second tumbler position. 
     
    
    
     DETAILED DESCRIPTION OF THE PRESENT INVENTION 
     As used throughout this specification, the word “may” is used in a permissive sense (i.e., meaning having the potential to), rather than the mandatory sense (i.e., meaning must). Similarly, the words “include”, “including”, and “includes” mean including but not limited to. 
     The phrases “at least one”, “one or more”, and “and/or” are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions “at least one of A, B and C”, “one or more of A, B, and C”, and “A, B and/or C” mean all of the following possible combinations: A alone; or B alone; or C alone; or A and B together; or A and C together; or B and C together; or A. B and C together. 
     Also, the disclosures of all patents, published patent applications, and non-patent literature cited within this document are incorporated herein in their entirety by reference. However, it is noted that citing herein of any patents, published patent applications, and non-patent literature is not an admission as to any of those references constituting prior art with respect to the present invention 
     Furthermore, the described features, advantages, and characteristics of any particular embodiment disclosed herein, may be combined in any suitable manner with any of the other embodiments disclosed herein. 
     Additionally, any approximating language, as used herein throughout the specification and claims, may be applied to modify any quantitative or qualitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term such as “about” is not to be limited to the precise value specified, and may include values that differ from the specified value in accordance with applicable case law. Also, in at least some instances, a numerical difference provided by the approximating language may correspond to the precision of an instrument that may be used for measuring the value. A numerical difference provided by the approximating language may also correspond to a manufacturing tolerance associated with production of the aspect/feature being quantified. Furthermore, a numerical difference provided by the approximating language may also correspond to an overall tolerance for the aspect/feature that may be derived from variations resulting from a stack up (i.e., the sum) of multiple individual tolerances. 
     It is further noted that any use herein of relative terms such as “top,” “bottom,” “upper,” “lower.” “vertical.” “horizontal,” etc. are merely intended to be descriptive for the reader, based on the depiction of those features within the figures for one particular position of the device, and such terms are not intended to limit the orientation with which the device of the present invention may be utilized. 
     As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure. 
     In  FIG. 1  the window vent stop of the present invention is shown generally at  10 . The vent stop  10  is shown positioned over slot  11  in sliding member, such as a window or door sash  12  as seen in  FIG. 5 . The slot  11  is shown as having an oval shape, but any other suitable shape and size slots including but not limited to a square, rectangle, oval, etc. can be used depending on the shape of the latch. Preferably, however, the vent stop  10  of the present invention will have a portion similarly shaped to the slot  11  as to present a clean appearance when placed in the window sash  12 , as seen in  FIG. 8 . In the present embodiment an oval shape for illustration purposes was used. The window sash can be a sash, doorframe, or any other member that has another piece sliding over it, where restriction of the window sash is desired. The tumbler  80  can be either in a raised or lowered position. When raised it prevents movement of the door or sash, as seen in  FIG. 1 . 
     A housing  13  is generally defined by a first sidewall  14 , a second sidewall  15 , a front wall  16 , a rear wall  17 , and a bottom wall  18 , as shown in  FIG. 4 . Bottom wall  18  can also serve as a cover. In the present embodiment however bottom wall  18  is sealed, and no cover is present. It is noted that the terms “front” and “rear” are used only for descriptive purposes and do not read on orientation of the device. Sidewalls  14 , as seen in  FIGS. 1 and 15 , are preferably the same length, as are front and rear walls  16  and  17 , respectively, providing for a generally rectangular shape to housing  13 . Preferably, when in place within slot  11 , sidewalls  14  and  15  contact the edges of slot  11  to provide for a tight fit, and prevent a lateral movement of the vent stop  10  within slot  11 . There is also a top plate  21  has a top surface  98  and an underside  99 , and extends outwardly past the edge of the front and rear walls  16  and  17 , creating a lip  33 , as seen in  FIG. 1 . Front wall  16  and rear wall  17  can each have a flexible clip  19  and  20 . In one embodiment of the present invention, there is only one flexible clip, first flexible clip  19 . However, in the preferred embodiments, there are two clips, first flexible clip  19  and second flexible clip  20 . The flexible clips  19  and  20  are preferably not identical, although, in alternate embodiments, they can be identical. 
     Either flexible clip  19  or  20  can be attached to either front wall  16  or rear wall  17  depending upon a user&#39;s preference. As such it should be appreciated, that the embodiments illustrated in  FIGS. 1-16  could easily be reversed and the first and second flexible clips  19  and  20  could be on the opposite wall  16  or  17 . In one embodiment, illustrated in  FIGS. 1-10 , first flexible clip  19  can extend generally in an upward fashion, originating at or near the bottom surface  18  of housing  13  and ending typically just below top plate  21 , as seen in  FIG. 1 . In addition, flexible clip  19  may be solid or hollow. In one preferred embodiment, flexible clip  19  may split and be comprised of two generally rectangular protrusions, so as to resemble two teeth, a first “tooth”  22  and a second “tooth”  23 , as seen in  FIG. 3 , located on sidewalls  14  and  15 . The first tooth  22  may have inner and outer surfaces, including inner surface  24 , as seen in  FIG. 3 , and outer surface  25 , as seen in  FIG. 4 , located adjacent to sidewall  14 . The second tooth  23  may also have inner and outer surfaces, including inner surface  26 , as seen in  FIG. 4 , and outer surface  27 , as seen in  FIG. 3 , located adjacent to sidewall  15 . Flexible clip  19  may be affixed to front wall  16  or flexible clip  19  may be an integral part of housing  13 , in the present embodiment flexible clip  19  is an integral part of housing  13 . In addition, flexible clip  19  has top surfaces  28  and  29 , located on teeth  22  and  23  respectively. 
     The second clip  20  ideally has more flexibility than the first clip  19 , as seen in  FIG. 1 , and is adapted to grip the window sash  12  when a user attempts to install the vent stop, as shown in  FIGS. 6 and 13 . It may be located at the end of the housing  13 . In this embodiment, the vent stop of the present invention can be more compatible with different style doorframes. For greater ease of installation, there is a tab  30  protruding from rear wall  17  of housing  13  as seen in  FIG. 1 , which ensures enough space between the clip and the housing  13 . When the vent stop  10  is depressed into slot  11  on a window sash  12 , the second flexible clip  20  should be inserted sideling into slot  11  as seen in  FIGS. 6 and 13 . Flexible clips  19  and  20  can engage a portion of the window sash  12 , as seen in  FIG. 6 . This engagement can prevent vertical (front and back) movement of the vent stop  10  within the window sash  12 , as well as preventing the vent stop  10  from being easily dislodged from slot  11 . 
     The shapes that second clip  20  could have are virtually endless, so long as the clip  20  maintains its flexibility while still possessing the ability to grip the window sash  12 , to provide a clean installation of the vent stop  10 . However, in one embodiment, the second clip  20  preferably is “S”-shaped, characterized by curved upper and lower portions  66  and  67 , each connected by a generally flat center portion  68 , as shown in  FIG. 7 . In this embodiment, the lower portion  67  of the second clip  20  preferably is connected to the rear wall  17  of the housing  13 ; nevertheless, the clip  20  could be secured to the housing  13  at any feasible point along the rear wall  17 . The lower portion  67  of the second clip  20  is arcuate, curving upward toward the flat center portion  68 , creating an S-shaped clip, that strongly resembles the appearance of the “integral” sign in calculus. However, the bottom portion  67  could be curved in an opposite manner, or could even be flat, at an angle to the center portion  68  of the clip  20  in alternate embodiments. In another alternate embodiment, the second clip  20  does not even have a lower portion and the center portion  68  extends diagonally outwardly from the rear wall  17  of the housing  13 . The center portion  68  of the second clip  20  extends diagonally outwardly from the lower portion  67 , creating a gap  69  between it and the rear wall  17 . This gap  69  allows the clip  20  to bend inwardly upon the installation of the vent stop  10 . In alternate embodiments, however, the center portion  68  may extend straight in an upward direction from the lower portion  67  rather than outwardly. In other embodiments, the center portion  68  may be more S-shaped, with a portion that extends outwardly from the lower portion  67  and then inwardly toward the rear wall  17 . Alternatively the distance the clip  20  maintains between it and the rear wall  17  may be adjustable based on the desired flexibility. The upper portion  66  of the second clip  20  is a generally curved piece, arced in the opposite direction of the lower portion  68 . But, in alternate embodiments it may be curved in a different direction, such as upward. The upper portion has top and bottom surfaces  96  and  97 . The top surface  96  of the upper portion  66  is where the window sash or other window sash  12  may rest when the vent stop is secured. The top surface  96  of the upper portion  66  of the second clip  20 , along with the underside of the lip  33  of the top plate  21 , act as a gripping mechanism holding the window sash in place. Although the upper portion  66  is generally short, equal in length to the lower portion  67 , it may be longer or shorter as desired. 
     In another preferred embodiment, shown in  FIGS. 11-15 , the first clip  19  has only one protrusion  86 , which extends outwardly from the rear wall  17  of the housing  13 . This embodiment of the first clip, is characterized by a protruding arm  86  and a base portion  87  connected to a recessed wall  88  situated between the rear wall  17  and the bottom wall  18  of the housing  13 , as shown in  FIG. 11 . The base portion has top and bottom surfaces  89  and  90  respectively, as well as a rear surface  91 , which are all generally flat. Extending from the base portion  87  of the first clip  19  is a single protruding arm  86 , which is flexible and is at an angle with the rear wall  17 . The arm  86  is generally rectangular, with an inner surface  92 , an outer surface  93 , a pointed upper surface  94  and a flat side surface  95 , as shown in  FIG. 13 . When the vent stop is slid into the slot  11  in the window sash  12 , this embodiment of the first clip will bend inwardly toward the rear wall  17 , until the vent stop fits inside the slot. Once the vent stop  10  has been inserted, the protruding arm  86  will release back to its old position further away from the rear wall  17 , with the window sash  12  being secured between the pointed upper surface  94  of the first clip  19  and the lip  33  of the top plate  21 , as shown in  FIG. 14 . In alternate embodiments, the shape of the first clip may be changed. For instance, the upper surface  94  does not have to be pointed, and the arm  86  can attach to the housing  13  at a different point along the rear wall  17 . Additionally, a raised member, or tab could extend outwardly from the rear wall  17  so as to limit the amount of room the arm  86  has to move inward toward the rear wall  17 . Essentially, any embodiment practicable to one in the art that would achieve the flexible support described above is possible. 
     Another preferred embodiment of the second clip  20  of the vent stop  10  of the present invention can also be seen in  FIGS. 11-15 . In this embodiment, the second clip  20  comprises an arm  71  and a gripping mechanism  72 , as shown in  FIG. 11 . The arm  71  generally has a base portion  73  that extends outwardly from the front wall  16 , so that the arm  71  is diagonal to the surface of the front wall  16 . In the present embodiment, this base portion  73  is generally characterized by a flat upper surface  74 , and a bottom surface which is indistinguishable from the rest of the arm  71 , as shown in  FIG. 11 . In alternate embodiments, the base portion  73  may be longer or curved, much like the lower portion  67  of the S-shaped clip  20  shown in  FIGS. 1-10 . The arm  71  is generally fat, although, in alternate embodiments, it may be curved as so desired. Extending from the top of the side opposite the base portion  73  of the arm  71  is the gripping mechanism  72  of the second clip. 
     The gripping mechanism  72  comprises a protruding hook  75 , a flat support surface  76  and a vertical retaining block  77 . The protruding hook  75  extends outwardly from the top of the arm  71  of the second clip  20 , so that the hook may catch the window sash  12  and secure the vent stop  10  to the sash. The hook  75  is generally curved upward and has top and bottom surfaces  78  and  79  as well as a front surface  81 , as shown in  FIG. 13 . The window sash generally comes into contact with the top surface  78 , where it comes to rest securely upon installation, as shown in  FIG. 14 . Although the hook  75  is generally curved, it could be flat in another embodiment, as the user desires. It may be curved in the opposite direction in another embodiment. The hook  75  is connected directly to a flat support surface  76 , as shown in  FIG. 11 , the purpose of which is to further secure the window sash  12  to the vent stop  10 . The support surface  76  comes into contact with a vertical retaining block  77 , which has a front end  82  and a rear end  83 , as shown in  FIG. 13 . This retaining block  77  extends upwardly to the lip  33  of the top plate  21  on the rear end  83 , and upwardly toward the underside  85  of an inner flange  84  running parallel to the top plate  21 . The retaining block  77  further locks the window sash  12  in place in the clip  20 . In various alternate embodiments, each of the various pieces  75 ,  76 , and  77  of the gripping mechanism  72  may be removed. For instance, one embodiment might utilize the hook  75  and the support surface  76 , but not the retaining block  77 . Any arrangement that would safely secure the window sash  12  within the grip of the clip  20  that is practicable to one knowledgeable in the art is possible. 
     In alternate embodiments not yet illustrated a variety of configurations of clips  19  and  20  can be utilized. For instance, since the second clip  20  requires only a gripping mechanism for holding the window sash  12  in place while the vent stop  10  is installed, any practicable gripping mechanism may be utilized. One example would be to utilize two protrusions extending outward from the wall of the housing, with no clip extending upward. One protrusion will fit underneath the window sash  12  and, the other, above it. For the first clip  19 , in order to facilitate installation, the clip  19 , as seen in  FIGS. 11-15  could be concaved on both sides, creating an easier installation into the slot  11  and more flexibility. A final example of an alternate embodiment is if the clips  19  and  20  were on the sidewalls  14  and  15  of the housing  11  rather than the front wall  16  and rear wall  17 . In this way, the vent stop  10  could be secured to the window sash  12  in a different manner. 
     First sidewall  14  has an inner surface, not shown, and outer surface  31 , as seen in  FIG. 1 . Second sidewall  15  has inner surface, not shown, and outer surface  32 , as seen in  FIG. 3 . On sidewalls  14  and  15  there can be four apertures, apertures  34  and  35  on sidewall  14 , as seen in  FIG. 1 , and apertures  36  and  37  on sidewall  15 , as seen in  FIG. 3 . Apertures  34  and  36  of sidewalls  14  and  15 , respectively, are aligned along the same central axis and are positioned towards rear wall  17 , and are used to prevent tumbler  80  from rotating passed a predetermined area and to support a substantial upward force associated with the lifting of the lower sash against the stopping surface of the latch. Apertures  35  and  37  of sidewalls  14  and  15 , respectively, are also aligned along the same central axis; these apertures are designed so as to allow tumbler  80  to rotate in an outwardly fashion. In another embodiment one could implement bored cavities, aligned in a similar fashion, instead of apertures. 
     In yet another embodiment, sidewalls  14  or  15  may have at least one rotation member extending there from. In this type of embodiment tumbler  80  would have apertures or bored cavities aligned along the same central axis so as to allow tumbler  80  to rotate in an outwardly fashion. 
     A lip  33  is attached to top plate  21  is preferably at least the same size or larger and the same general shape as slot  11 . Thus, when vent stop  10  is placed into slot  11 , lip  33  will contact at least the edges of slot  11  or over spread the upper surface of the window sash  12 . These dimensional attributes will allow for a tight fit that will exhibit a finished smooth exterior, which can be aesthetically pleasing. Although top plate  21  is referred to as a “plate”, it is understood that housing  13 , clip  19 , lip  33  and top plate  21  can be, integral pieces, without any need for adhesives or assemblage. 
     In the preferred embodiment second clip  20 , attached to the rear of the housing, is preferably almost as high as the lower portion of the housing under the slot  11 . Thus, when vent stop  10  is placed into slot  11 , clip  20  will contact at least the edges of slot  11  or over spread, the upper surface of the window sash  12 . These dimensional attributes will allow for a tight fit that will exhibit a finished smooth exterior, which can be aesthetically pleasing. Although top plate  21  is referred to as a “plate”, it is understood that housing  13 , clip  19 , clip  20  and top plate  21  can be integral pieces, without any need for adhesives or assemblage. 
     A tumbler  80  is preferably designed to fit within cavity  38  of housing  13 , as seen in  FIG. 11 . Tumbler  80  may have an upper surface  39 , which is preferably smooth and/or flat on the front portion, as seen in  FIG. 2 . Where upper surface  39  is flat, it will exhibit a more finished look for the vent stop  10  when it is placed in window sash  12 . Tumbler  80  may have an indent  40  located toward the rear top surface. In addition tumbler  80  may have a grooved top portion  41  located right above indent  40 , as in the present invention, which may act as a button  42 , so as to allow the user to activate tumbler  80 . The rear edge  43  of tumbler  80  slopes downward and comes to a point  44 , where rear edge  43  meets arcuate bottom portion  45 . Tumbler  80  can have a front end  46  and a rear end  49 , along with side surfaces  52 . Tumbler  80  can have rotation members  53 , which can fit in apertures  35  and  37 , of sidewalls  14  and  15  respectively, of housing  13 . The rotation members  53  can be located on side surfaces  52 , respectively, close to rear end  49 . Preferably, rotation members  53  are cylindrical pegs, which protrude from side surfaces  52  of tumbler  80 , respectively. The rotation members  53  can allow tumbler  80  to extend outwardly, thus exposing front end face  54  of tumbler  80 , which would prevent movement of window sash  12 . The tumbler  80  will be allowed to rotate until arcuate surface  45  of tumbler  80  comes into contact with a surface  50  of peg  51 , as seen in  FIG. 12 , and discussed hereinafter. The window vent stop may be constructed of any type of material known in the art, including, but not limited to plastic, metal, wood, etc., to be capable of withstanding the downward force imposed on the tumbler by the sash window. The peg may be any shape known in the art, including, but not limited to, a cylindrical peg, a rectangular block, or a square peg. In the present embodiment a plastic cylindrical peg was implemented. In addition, cylindrical peg  51  may be separate part or it may be an integral part of housing  13 , however, in the present embodiment the cylindrical peg  51  is a separate member. 
     Tumbler  80  has a cavity  55  that houses the plate spring  56 , as seen in  FIGS. 2 and 12 . However, this is not the only possible method of attaching a spring to tumbler  80 . For example, tumbler  80  can have a protruding peg on either of the side surfaces  52  that could hold the plate spring  56  in place. If this type of spring configuration is implemented, then housing  13  would have to be of such dimensions so as to allow for the additional needed space. Tumbler cavity  55  has a top and bottom surface equal in width to plate spring  56  it houses. Plate spring  56  also has a rounded bottom portion that contacts the left arcuate nest  47  and the right recession  48  in the inner bottom surface  57  of the housing  13  such that the tumbler is forced to a retracted position in the housing or an extended position out of the housing. In another embodiment rounded bottom portion  58  may be replaced by any angled shaped portion known in the art, which is capable of sliding. Inner bottom surface  57  of housing  13  has an arcuate nest  47  for cradling rounded bottom portion  58  of plate spring  56 , as seen in  FIG. 12 . A divide point  59 , where the left arcuate nest  47  meets the right recession  48 , confines the bottom rounded portion  58  of plate spring  56  to be forced in different directions when the vent stop is activated or deactivated. In normal operation when the user wishes to activate tumbler  80 , the user will apply a downward, or inward force to button  42 , this will cause rounded bottom portion  58  of plate spring  56  to move out of arcuate nest  47  and pass the divide point  59  and move into the right recession  48  of bottom surface  57  of housing  13 . One must point out that arcuate nesting portion  47 , divide point  59 , right recession  48  of the bottom surface  57  and bottom rounded portion  58  of the plate spring  56  are of great consequence in the operation of this invention. 
     In addition to the tumbler cavity  55  of tumbler  80 , there exists an arcuate surface  45  that interacts with an arcuate surface  50  of cylindrical peg  51 . Arcuate surface  45  is preferably located on the rear bottom portion of tumbler  80 . Tumbler  80  may have a protruding portion  60  located at the bottom front end wall of tumbler  80 , as seen in  FIG. 2 . The protruding portion  60  has a top surface  61  that extends perpendicularly from the front end face  54  of the tumbler  80 . The protruding portion  60  also has a first side  62 , as seen in  FIG. 2 , and a second side, not shown, a front face  64 , and a bottom  65 , as shown in  FIG. 12 . Bottom  65  of the protruding portion  60  extends outwardly in the same direction as top surface  61  so as to meet with the outside edge of front end face  64  and is parallel to the upper surface  39  so as to come into contact with the bottom surface  57  of the housing  13  and limit further rotation of the tumbler  80  in the housing  13  when the tumbler  80  is in the retracted position. The protruding portion  60  may be designed as to allow a meshing between the protruding portion  60  and the bottom surface of top plate  21 , which would cause tumbler  80  from further rotating outwardly; thus if needed, protrusion  60  could be used as a limiting device. 
     The release of the tumbler  80  from housing  13  can be controlled by an interaction between button  42  and plate spring  56  in tumbler  80  and bottom surface  57  of the housing  13 . Button  42 , as mentioned previously, is located on the rear end portion of tumbler  80 , can have a grooved top surface  41 , which can be in the same plane as the upper surface  39  of the tumbler  80 , where the user can engage button  42  easily with any suitable instrument known in the art, including but not limited to a finger, fingernail, pen, pencil etc., as seen in  FIG. 2 . When the user engages grooves  41 , it will move rounded bottom portion  58  of plate spring  56  from a cradled position to a freed position within cavity  38  of housing  13 . In the present embodiment the user applies a downward or inward force to groove  41  of tumbler  80 . 
     When the user wishes to activate tumbler  80 , so as to prevent movement of a sliding window member, the user will exert a downward, or upward force, greater than the force being exerted by the rounded bottom portion  58  of plate spring  56  against the top surface of the arcuate nesting area  47  of the bottom surface  57  of housing  13 , on groove  41 , of button  42 . This force will cause plate spring  56  to move in a direction opposite that of the force applied by the user. When the force applied by the user has reached the critical point, it will cause the rounded bottom portion  58  of plate spring  56  to move out of equilibrium with nesting area  47  of bottom surface  57  of housing  13  and slide across divide point  59  of bottom surface  57  of housing  13  and comes in the next equilibrium with right recession  48  of bottom surface  57  of housing  13 . The critical point is reached when the force applied by the user overcomes the static frictional force, at which time bottom round portion  58  of plate spring  56  will begin to slide and the frictional force will drop back to a nearly constant value equal to that of the kinetic frictional force. When tumbler  80  is free to pivot on rotation members  53 , the upward force of spring  56  will cause tumbler  80  to rotate in an outwardly direction until the rounded bottom portion  58  of plate spring  56  comes into contact with right recession  48  of bottom surface  57  of housing  13 . In the same instance arcuate surface  45  of tumbler  80  will come in contact with arcuate surface  50  of cylindrical peg  51 . In addition, a protruding portion  60  can also be implemented, so as to further limit movement of tumbler  80  by coming into contact with bottom surface of top plate  21 . Once rounded bottom portion  58  of plate spring  56  has stopped sliding tumbler  80  will be exposed, thus preventing sliding window member from opening any further. 
     Another embodiment is shown in  FIGS. 16-25 , which illustrate a vent stop  100 . As seen in  FIGS. 24-25 , vent stop  100  may be formed to include a housing  110 , and a tumbler  180 . Housing  110  may be formed to be substantially similar to the housing  13  that is described hereinabove. Tumbler  180  may be formed to be different than tumbler  80 . 
     Tumbler  180  may be designed to fit within the cavity of housing  110 , as shown in  FIGS. 26-29 , and may extend from a first end  181  to a second end  182 . The tumbler may include hinge pins  185  that may be pivotally received within apertures formed in the sidewalls of housing  110 . The hinge pins  185  may protrude from the side surfaces  180 A and  180 B of the tumbler (see  FIG. 21 ). The tumbler  180  may thus pivot with respect to the housing  110 , using hinge pins  185 , between a retracted tumbler position (e.g.,  FIG. 29 ), and an extended tumbler position (e.g.,  FIG. 26 ). 
     The tumbler  180  may have an upper surface  183 , which may be smooth and/or substantially flat for at least a portion thereof, as seen in  FIG. 25 . Tumbler  180  may have an indentation  184  that may be formed to divide the upper surface  183  of the tumbler into two portions, with the indent being positioned in proximity to a minimum distance point with respect to the hinge pins  185 . The indent  184  may thus provide an indication of the hinge pin location, and also therefore which side of the upper surface  183  should be pushed for it to pivot in a particular direction. The rear side  186  of tumbler  180  may slope downward, as shown in  FIG. 25 , and may form a point  187  where the rear side  186  meets the arcuate bottom surface portion  189 . Outward pivoting of the tumbler  180  may occur until the bottom surface portion  145  contacts, and has its movement stopped by, a surface  114  of the housing  110 , as seen in  FIG. 26 . Inward pivoting of the tumbler  180  may be limited to the retracted position shown in  FIGS. 29 and 30  by the lowermost surface of a protruding stop feature  187  contacting a bottom interior surface  117  of a bottom wall  116  of the housing  110 . As discussed hereinafter, the protruding stop feature  187  may protrude away from a bottom portion of the tumbler  180  in proximity to the second end  182 . 
     Tumbler  180  may be formed with a front end surface  146 . When the tumbler  180  is in the extended tumbler position, a substantial portion of the front end surface  54  is exposed outside of the housing  110 , which exposed portion may prevent movement of a sliding window/door sash member. In one embodiment, the positioning/angle of the front end surface  54  with respect to the positioning of the arcuate bottom surface portion  145  and the hinge pins  185  may be such that when it is exposed in the extended tumbler position, it may be substantially perpendicular to the outermost surface of the top plate of the housing  110 . 
     Tumbler  180  may also be formed with a selectively shaped elongated protrusion  188  ( FIG. 24 ). The elongated protrusion  188  may extend from a bottom surface, in proximity to the protruding stop feature  187 , which may preferably be positioned in proximity to the second end  182 , so that the selectively shaped elongated protrusion  188  may similarly protrude down from the bottom surface of the tumbler to also be in relatively close proximity to the second end  182 . The elongated protrusion  188  may have a first portion  188 A ( FIG. 25 ) that may extend away from the bottom surface, and which may transition into a second portion  188 B that may extend generally towards the first end  181  and also generally back towards the bottom surface of the tumbler. The second portion  188 B may transition into a third portion  188 C that may be curved, and which may generally curve away from the bottom surface, as seen in  FIG. 25 . A bulbous feature  188 D may be formed at the end of the third portion  188 C. The bulbous feature  188 D may be formed to have a radiused surface that may protrude radially away from the bottom surface, as seen in  FIG. 25 . The positioning and the sizing of the radius of the bulbous feature  188 D is configured to correspond to the positioning and size of an apex  120  that may be formed in the cavity of the housing  110  on the interior surface of the bottom wall  116 , adjacent to correspondingly curved surfaces  120 A and  120 B also formed in the bottom wall  116 . The bulbous feature  188 D may thus operate similar to the rounded bottom portion of the plate spring  56  that is used in conjunction with tumbler  80 , as discussed hereinabove. 
       FIGS. 26-29  show a sequence of cross-sectional views in which the tumbler of the vent stop of  FIG. 16  is actuated from the extended position into the retracted position.  FIGS. 30-33  show a sequence of cross-sectional views in which the tumbler of the vent stop of  FIG. 16  is actuated from the retracted position into the extended position. 
     As may be seen in those figures, the flexible elongated protrusion  188  is configured to bi-directionally bias the tumbler  180 , according to movement of the bulbous feature  188 D of the flexible elongated protrusion  188 , and its contact with respect to the apex  120 . 
     When the tumbler  180  is in the retracted tumbler position ( FIG. 30 ), actuation of its upper surface  183  by application of a force F OPEN  proximate to the first end  181  (i.e., to the “left” side of the indent  184  as shown therein) is configured to cause the bulbous feature  188 D of the flexible elongated protrusion  188  to cross the apex  120 . Subsequent contact between the bulbous feature  188 D and the apex  120  is configured to bias the tumbler to pivot out of the cavity toward the extended position shown in  FIG. 33 , until the bulbous feature is nested within the surface  120 B of the bottom wall  116  of the housing  110 . 
     When the tumbler  180  is in the extended position ( FIG. 26 ), actuation of its upper surface  183  by application of a force F CLOSE  proximate to the second end  182  (i.e., to the “right” side of the indent  184  as shown therein) is configured to cause the bulbous feature  188 D to cross the apex  120 . Subsequent contact between the bulbous feature  188 D and the apex  120  is configured to bias the tumbler toward the retracted position shown in  FIG. 29 , until the bulbous feature is nested within the surface  120 A on the bottom wall  116  of the housing  110 . 
     Another embodiment is shown in  FIGS. 37-58 , which illustrates a vent stop  200 . As seen in the perspective views of  FIGS. 37 and 41 , vent stop  200  may be formed to include a housing  210 , and a tumbler  280 . Housing  210  may be formed similar to the housing  110  described hereinabove, and tumbler  280  may be formed similar to tumbler  180 . 
     Tumbler  280  may be formed to fit within the cavity of housing  210 , as shown in  FIGS. 53-58 , and as seen in  FIG. 48  the tumbler may extend from a first end  281  to a second end  282 . The tumbler may include hinge pins  285  that may be pivotally received within apertures formed in the sidewalls of housing  210 . The hinge pins  285  may protrude from the side surfaces  289 A and  289 B of the tumbler (see  FIG. 52 ). The tumbler  280  may thus pivot with respect to the housing  210 , using hinge pins  285 , between a first tumbler position ( FIG. 55 ), and a second tumbler position ( FIG. 53  and  FIG. 54 ). 
     The tumbler  280  may have an upper surface  283 , which may be smooth and/or substantially flat for at least a portion or portions thereof, as seen in  FIG. 48 . The upper surface  283  of the tumbler  280  may have a plurality of ridges  284  formed thereon. The rear side  286 R of tumbler  280  may extend laterally away from the upper surface  283  at the first end  281 , and a rear stop side surface  287 R may extend away from the end of the rear side surface  286 R. The front side  286 F of tumbler  280  may extend laterally away from the upper surface  283  at the second end  282 , and a front stop surface  287 F may extend away from the end of the front side surface  286 F. 
     Pivoting of the tumbler  280  away from the first tumbler position shown in  FIG. 55  may occur until the rear stop side surface  287 R contacts, and has its movement stopped by, a surface  214  in the cavity of the housing  210 , as seen in  FIG. 53 , for the tumbler to occupy the second tumbler position. Pivoting of the tumbler  280  away from the second tumbler position shown in  FIG. 53  may occur until the front stop side surface  287 F contacts, and has its movement stopped by, a surface  215  in the cavity of the housing  210 , as seen in  FIG. 55 , for the tumbler to occupy the first tumbler position. 
     The front side  286 F of tumbler  280  may be formed at such an angle with respect to the rear stop side surface  287 R that when the tumbler  280  is in the second tumbler position, at least a substantial portion of the front side surface  286 F is exposed outside of the housing  210 , which exposed portion may prevent movement of a sliding window/door sash member ( FIG. 54 ). In one embodiment, the positioning/angle of the front side  286 F when the tumbler  280  is in the second tumbler position may be such that it may be substantially perpendicular to the bottom surface of the top plate of the housing  210 , and may thus have a substantial portion thereof be oriented to bear up against and stop the sliding movement of a sash member. 
     Tumbler  280  may also be formed with a selectively shaped and elongated protrusion  288  ( FIG. 41 ). As shown in  FIG. 48 , the elongated protrusion  288  may have a first portion  288 A that may extend laterally away from a bottom surface of the tumbler, in closer proximity to the front stop surface  287 F than the rear stop surface  287 R. The first portion  288 A of the elongated protrusion  288  may transition into a second portion  288 B that may extend generally towards the first end  281 . The second portion  288 B may extend far enough toward the first end  281  to have a suitable length and cross-section to provide a spring constant sufficient to appropriately bias the mass of the tumbler. The second portion  288 B may transition into a third portion  288 C that has a portion that may generally extend in a direction that is substantially perpendicular to the upper surface  283 . A particularly angled surface  288 D may be formed on the third portion  288 C. The positioning and the angle of the surface  288 D is configured to correspond to the positioning of a surface  220 A of a protrusion  220  formed on the bottom wall  216  in the cavity of the housing  210  (see  FIG. 47  and  FIG. 55A ). The surface  220 A of the housing protrusion  220  may transition into another surface  220 B to form an apex  220 P. The third portion  288 C is similar to the rounded bottom portion of the plate spring  56  that is used in conjunction with tumbler  80 , as discussed hereinabove, but is configured to operate somewhat differently. 
       FIG. 55  shows the tumbler  280  in the first tumbler position, in which at least a portion of the first end  281  of the tumbler protrudes out from the opening in the top plate of the housing  210 .  FIG. 54  and  FIG. 58  show tumbler  280  in the second tumbler position, in which at least a portion of the second end  282  of the tumbler protrudes out from the opening in the top plate of the housing  210  sufficiently to restrict/inhibit movement of a sliding sash member  299  from being opened past the location of the vent stop  200 . 
     In one embodiment, the second end  282  of the tumbler  280  that protrudes out from the opening in the housing top plate when in the second tumbler position may be finger actuated by a user to move it into the first tumbler position, and the first end  281  of the tumbler  280  that protrudes out from the opening in the housing top plate when in the first tumbler position may be finger actuated to move it into the second tumbler position. The elongated protrusion  288  may act as a leaf spring and may serve to bi-directionally bias the body of the tumbler  280 , as it moves with respect to the apex  220 P of the housing protrusion  220 . 
     When the tumbler  280  is in the first tumbler position ( FIG. 55 ), actuation proximate to the first end  281  of the tumbler causes the curved distal end  288 E of the flexible elongated member  288  to elevate from its positon in  FIG. 55A  and cross the apex  220 P, and subsequent contact between the distal end of the flexible elongated member and the surface  220 B on the bottom wall of the housing ( FIG. 56 ) generally biases the tumbler to pivot further toward, and into the second tumbler position. When the tumbler  280  is in the second tumbler position ( FIG. 58 ), actuation of the second end  282  of the tumbler causes the distal end  288 E of the flexible elongated member  288  to cross the apex  220 P, and subsequent contact between the distal end of the flexible elongated member and the surface  220 A on the bottom wall of the housing biases the tumbler to pivot further toward, and into the first tumbler position. 
     In another embodiment, the extent that the first end  281  of tumbler  280  protrudes out from the opening in the housing top plate when in the first tumbler position ( FIG. 55 ) may be coordinated with the positioning and travel of the sash member  299 , and with the angled surface  288 D of the elongated protrusion  288  and the surface  220 A of the housing protrusion  220 . They may be coordinated such that sliding of the sash member  299  contacts the tumbler  280  ( FIG. 55  and  FIG. 56 ), and the biasing by the elongated protrusion  288  may cause the tumbler to independently move into the second tumbler position without being directly actuated by a user, to place the vent stop into a safe position, preventing full opening of the window, when the window is moved back into a closed position ( FIG. 57  and  FIG. 58 ). 
     The full cycle of movement of tumbler  280  with respect to its interaction with a sliding sash member may be seen in  FIGS. 53-58 . 
     In  FIG. 53 , the tumbler  280  is shown in the second tumbler position, and with a sliding sash  299  member positioned distally, but being moved towards the tumbler, as indicated by the arrow in the sash member. In  FIG. 54  the sliding sash member  299  has contacted, and has had its sliding travel restricted/limited by the second end  282  of the tumbler  280  blocking the sliding movement of the sash member. 
       FIG. 55  is the side cross-sectional view of  FIG. 54 , but is shown after a user has applied a force to the second end  282  of the tumbler  280 , as indicated by the arrow directed towards the plurality of ridges  284 , which pivots the tumbler into the first tumbler position where it no longer restricts movement of the sash member  299 . As noted above, the tumbler  280  is releasably maintained in the first tumbler position by the angled surface  288 D of the elongated protrusion  288  being engaged with the surface  220 A of the housing protrusion  220  ( FIG. 47 ), which is shown enlarged within  FIG. 55A . The arrow pictured in the sash member  299  of  FIG. 55  indicates that the sash is being slid towards the vent stop  200 . 
       FIG. 56  is the side cross-sectional view of  FIG. 55 , but is shown after the sliding sash member  299  has been slid further towards a fully opened sash position and has not only contacted the protruding “upper” surface  283  of the tumbler  280 , but has pivoted the tumbler. This amount of pivotal movement of the tumbler is coordinated to trigger the release of the tumbler from its first tumbler position through pivotal movement of the tumbler causing the angled surface  288 D of the elongated protrusion  288  to disengage from the surface  220 A of the housing protrusion  220 , and move onto surface  220 B, which contact immediately biases the tumbler to pivot toward the second tumbler position, and it will occupy the position shown in  FIG. 57  (i.e., the second end  282  of the tumbler  280  is biased into contact with the side of the sash member  299 ). 
     In order that a relatively slight lateral displacement of the tumbler  280  resulting from contact by the sliding sash member  299  serves to trigger the disengagement of the elongated protrusion  288  from the housing protrusion  220 , the angled surface  288 D of the elongated protrusion  288  and the surface  220 A of the housing protrusion  220 , may be at a relatively steep angle, which may require a higher force to disengage, such as that provide by the relatively large mass of a sliding sash window or door. Also the engagement therebetween may be very small, as seen in  FIG. 5A . Moreover, as seen in  FIG. 55A , the angled surface  288 D of the elongated protrusion  288  may be oriented at the angle Θ 1  that may be slightly larger than the angle Θ 2  at which the surface  220 A of the housing protrusion  220  may oriented, so that the surface  288 D may engage the surface  220 A at a point very near the apex  220 P. In  FIG. 55A , the angle Θ 1  is show at about 16 degrees, and the angle Θ 2  is shown to be about 11 degrees, having about a five degree difference therebetween. The difference between the angles Θ 1  and Θ 2  may be in the range of zero degrees to three degrees in one embodiment, and may be in the range of three degrees to six degrees in another embodiment, and may be in the range of six degrees to ten degrees or more in another embodiment, and may also be a combination of such ranges in yet another embodiment. Also, as to the steepness of the surface  220 A, the angle Θ 1  may range in the range of zero degrees and seven degrees in one embodiment, between seven degrees and fourteen degrees in another embodiment, and between fourteen degrees and twenty degrees or more in another embodiment, and may also be a combination of such ranges in yet another embodiment. 
     After the sliding sash member  299  has triggered the release of the tumbler  280  from its second tumbler position, as shown in  FIG. 56 , to occupy the position shown in  FIG. 57 , subsequent movement of the sash member toward the closed sash position would move the sash member clear of the vent stop  200 , as shown by the arrow in the sash in  FIG. 57 . Once the sash member  299  is moved beyond the vent stop  200 , the tumbler  280  is no longer prevented from reaching the second tumbler position, and is biased thereto, as shown in  FIG. 58 . 
     After the sliding sash member  299  has triggered the release of the tumbler  280  from its first tumbler position, and has been biased from the position shown in  FIG. 56  into the position shown in  FIG. 57 , the sash member may be slid even further toward a fully open sash position, and may move clear of the vent stop  200 . Once clear of the vent stop  200 , the tumbler  280  is no longer prevented from reaching the second tumbler position, and is biased thereto, as seen in  FIG. 58 . As the sash member  299  is moved back towards the closed position, it may contact a portion of the top surface  283  proximate to the second end  282  of the tumbler and oppose the biasing for the tumbler to pivot until it again occupies the position shown in  FIG. 57 . From that position, as noted above, subsequent movement of the sash member  299  toward the closed sash position would move the sash member clear of the vent stop  200 , and the tumbler  280  would again be biased into the second tumbler position shown in  FIG. 58 . 
     As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.