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BACKGROUND OF THE INVENTION 
     The invention relates to a barrier which is easily opened and closed to close off access across a doorway, hallway or other throughway in a house or other domicile. More specifically, the invention is concerned with a portable barrier for a child or dog, in the form of a roll-up sheet or curtain on a vertical axis, of sufficient height to prevent a child or dog from crossing the barrier. 
     Infant barriers, or baby gates, have been known in several forms. The most common conventional configuration was a device assembled of a series of wooden slats pivotally connected in scissors fashion, so that the slats would stack together relatively compactly with the device retracted against a wall, but would extend across and close the opening when the outer end was pulled, causing all the slats to pivot to oblique, parallelogram-forming orientations. Problems with such baby gates included latches that were not totally secure, bulkiness when the barrier was retracted, and a tempting open web of rigid members which could be climbed by some young children. 
     U.S. Pat. No. 5,690,317, Sandsborg, shows a form of child barrier or baby gate of the general type with which this invention is concerned. That barrier included a curtain of material which extended from and retracted to a housing adjacent to one jamb of the device on a vertical roll-up axis. The barrier device had a mechanism which locked the curtain against further extension once the barrier was pulled beyond the other jamb and then was allowed to retract somewhat. This was a type of ratchet device that had to be manually released before the barrier could be retracted. The release device was not reliably childproof, and the barrier device did not seem to have adequate means for applying tension to the curtain-like barrier, in order to present a relatively solid wall to the child. 
     SUMMARY OF THE INVENTION 
     The invention described here provides an efficient, portable and reliable moveable gate for infants or dogs, for use in doorways, hallways, stair landings and other household positions and throughways to establish a safe barrier. The gate, formed of a flexible material which pulls out from a vertical-axis housing or frame in the spring-loaded manner of a window shade, has a jamb mounting at the housing end and a latch at the extended end of the curtain-like barrier. Both are releasable from a respective fixture which attaches to the door jamb, wall or stair rail post, so that the infant gate can be quickly released and moved to another location in the house where additional such jamb mountings are attached. 
     Important features of the barrier device are the manner in which the gate latches, a convenient handle for latching, a mechanism for tightening the curtain-like barrier into a nearly solid gate after it has been latched, and a childproof device for releasing tension in the gate when it is to be retracted. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view showing a portable, retractable barrier device of the invention as installed in a doorway of a living space and with the barrier extended. 
     FIG. 2 is a perspective view showing the device in the extended position but without showing the doorway or walls between which the device is secured. 
     FIG. 3 is a view showing the barrier device retracted. 
     FIG. 4 is a frontal elevation view, partially broken away, showing the barrier device in the extended position in a doorway. 
     FIG. 5 is an exploded view in perspective showing a spring-loaded roller for retraction and storage of a flexible barrier sheet of the device. 
     FIG. 6 is an exploded view in perspective showing components of a clutch, clutch housing, a portion of a ratchet assembly, and upper mounting assembly for the barrier. 
     FIG. 7 is a perspective view showing a portion of the top end of the assembled roller, gear wheel, and clutch mechanism. 
     FIG. 8 is a sectional view showing the childproof release knob and clutch and clutch housing, and a ratchet pin of the ratcheting mechanism for the barrier storage roll. 
     FIG. 9 is a side view of the apparatus shown in FIG.  8 . 
     FIG. 10 is a perspective view showing the clutch housing which also acts as the upper mounting bracket positioned above the roller. 
     FIG. 11 is a plan view showing a portion of the apparatus at a retracted side. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     In the drawings, FIG. 1 shows a barrier device  10  as secured between two walls or door jambs  12  and  13  which form a throughway between. The barrier device  10  has a sheet of flexible barrier material  14  which is extended from a roller  16  at one side of the device, the side shown on the right in FIG.  1 . The flexible barrier sheet  14  may be of woven nylon fabric, woven vinyl, vinyl-coated fiberglass, other vinyl-coated woven fibers or other similar materials providing a strong barrier sheet flexible enough to roll up. The sheet thus extends from and retracts onto the roll  16  in the manner of a roll-up window shade, with a spring inside for urging the barrier sheet toward the retracted position. 
     The device  10  includes, at the opposite jamb  13 , a handle  18  which has a vertical rod  20  that is secured to the free end  22  of the barrier sheet, as by a series of brackets or ties  24 . This handle with its vertical rod  20  is used to latch the barrier in the extended position shown. Preferably this is done by inserting the bottom end  26  of the rod, when the barrier sheet is being extended, down into a lower bracket  28  secured to the wall or jamb  13 . The bottom end of the rod  20  goes into a recess of the bottom bracket  28 , as shown. When the rod has been so seated, the top of the handle  18  is pushed into an upper bracket  30 , between generally parallel flanges  32  as shown, until a pair of spring pins  34  spring outwardly and latch into a pair of opposed openings  36  in the bracket flanges (see FIG.  2 ). The barrier sheet  14  is then retained in a firmly latched position across the throughway, by the latch means which in this pictured embodiment includes the rod  20 , the lower bracket  28  and the upper bracket  30 . Once this has been done, a carrier tensioning means can be utilized. A tensioning handle  38  on the roller side of the device, adjacent to the jamb or wall  12 , can be rotated in the tightening position (anticlockwise as seen in FIG. 1) to add more tension in the barrier sheet  14 , via a ratchet mechanism to be described below. 
     FIG. 2 is similar to FIG. 1, showing the barrier device  10  in the extended position, but showing the device without any door jambs or walls. Thus, FIG. 2 reveals more clearly the base side  40  of the mechanism, as well as the free side or opposite jamb side  42 . 
     As FIG. 2 illustrates, the barrier system  10  preferably includes four wall brackets or jamb brackets: the bottom bracket  28  at the barrier extension end  42 , the upper bracket  30  at the extension end, and a lower bracket  44  and upper bracket  46  at the base or roller end  40  of the device. Each of these four brackets preferably has screw holes, some of which are visible at  48  in FIG. 2, for attaching the bracket to a wall, door jamb or other limit position of a throughway to be controlled. The roller-end brackets  44  and  46  advantageously are of the type which has a generally keystone-shaped recess, tapered to a narrower dimension from top to bottom, as can be seen for the bracket  46  in FIG.  11 . This type of drop-in, slide-in connection is conveniently used and provides a rigid and secure retention for the device on the wall. Thus, the brackets  44  and  46  act as a first jamb connector means for connection to a door jamb or wall at one side of a throughway. If desired, a connecting structure (not shown) can be secured to or integral between the two roller-end brackets  44  and  46 , so as to provide a single unified implement to be secured to the wall or jamb, even if the connecting structure is not particularly rigid. This will define precisely the spacing between the two wall brackets  44  and  46 , thus preventing faulty installation and poor function in connection of the device to the wall or jamb. 
     At the other side  42 , the extended side of the system, the brackets  28  and  30  are again screwed to the wall or jamb and provide simple and easy to use securement for the handle  18  and rod  20  at the stretched or extended end of the barrier screen  14 . Again, these two brackets  28  and  30  can be connected to or integral with a vertical connecting structure between them, for purposes of assuring proper spacing on installation. The brackets  28  and  30  act as a second jamb connector means for this opposite side of the throughway. 
     FIG. 3 shows the barrier apparatus  10  in the fully retracted position, with the barrier sheet  14  rolled up on the roller or drum  16 , under the influence of an internal spring  50  which is shown in FIG.  5  and also in dashed lines in FIG.  4 . As shown in the drawings, the spring  50  is positioned around a central rod  52  within the roller, the rod extending beyond the top and bottom of the roller to be journalled in a clutch housing  54  at the upper end and a lower end mounting  56  at the lower end, best seen in the views of FIGS. 2,  4  and  5 . The housing  54  and lower mounting  56  serve as a frame means retaining the roller for rotation at top and bottom, and these slip into the wall brackets  46  and  44  as described above, providing a quick release connection means. Since the roller or drum  16  rotates relative to the mounting apparatus at the jamb, to allow extension and retraction of the sheet of barrier material  14 , the rod  52  preferably is fixed in position in the lower end mounting  56  and/or in the clutch housing  54 , against rotation. The spring  50  is fixed to the rod  52  at one end, and to a hub  58  at the other end, so as to wind up and store energy acting between the stationary rod  52  and the rotatable drum or roller  16 . A machine bolt  59  may be employed to retain the spring to the hub  58 , via an eyelet (not shown) formed in the lower end of the spring. The lower hub  58  is fixed to the roller  16 , and thus to the tensioning wheel or handle  38 , which acts as an upper-end hub, at the upper end. As best seen in FIG. 5, a ratchet wheel  60  is fixed to the tensioning wheel  38 , for interaction with a ratchet pawl  62  shown in FIG.  6  and also in FIG.  9 . In the assembled device, the ratchet wheel  60  is covered by a cover plate  64 , with the pawl passing through a slot  66  in the plate, as detailed in the exploded view of FIG.  6 . FIG. 7 shows this portion of the device in the assembled configuration. 
     FIGS. 6-10, along with FIG. 5, show the structure and indicate the manner of operation of the ratchet assembly and of a release clutch having a childproof safety feature to prevent the child from releasing tension in the stretched and tensioned barrier sheet  14 , i.e., a childproof tension release means. A release knob  68  is shown in FIG. 6, configured to fit down over a clutch spool  70  which itself is journalled for rotation within the clutch housing  54 . FIGS. 8 and 9 show these components assembled. The inside of the childproof release knob  68  has teeth (not clearly shown in the drawings) which engage downwardly against upper teeth  72  on the spool  70 , as shown in FIG.  6 . Such a safety clutch means is well known in childproof devices, including pharmaceutical bottles and jars. Typically the teeth  72  have a ramp slope at one edge, and a steep abutment (e.g. 90°) at the opposite edge, so that the release knob  68  tends to slip when it is rotated in the releasing direction, unless it is pushed down with a fair amount of force to engage against the ramps and rotate the spool. In the apparatus shown in FIG. 6, this would be the counterclockwise direction. On other hand, when the knob  68  is turned in the opposite, clockwise direction, it easily engages the sharp abutments of the teeth  72  and rotates the spool with it in the clockwise direction. The knob or outer cap  68  is held to the spool  70  by a depending annular flange  69 , the bottom edge of which snaps under a ledge  71  of the spool on assembly. 
     A compression spring  74  engages downwardly against a clip  76  which on assembly is fixed into a groove  78  on the pawl  62 , thus urging the pawl  62  downwardly against the ratchet wheel  60 , shown in FIG.  5 . The top of the spring  74  engages against a closure disc  79  which is fixed to the top of the spool  70  or within the top of the center aperture  81  of the spool, closing that aperture. 
     The spool  70  has a nub or boss  80  to engage with a coarse thread groove  82  which follows a helical path as shown in FIG.  9 . When the spool is unscrewed, i.e. rotated in the counterclockwise direction, the nub  80  will follow the thread groove  82  to raise the spool upwardly within the clutch housing  54 . This is effective to raise the lower end of the pawl  62 , as can be seen from FIGS. 6,  8  and  9 , thus removing the pawl from contact with the ratchet wheel  60  and releasing tension in the barrier sheet. The thread groove  82  of the clutch housing  54  is best seen in FIG.  10 . 
     FIG. 9 also shows a bore  84  (dashed lines) in the clutch housing  54 , to receive the upper end of the roller rod  52 . 
     In use of the movable barrier  10 , the brackets  44 ,  46 ,  28  and  30  are mounted within a throughway such as a doorway, hall, stair area, etc. Multiple sets of these four brackets are provided, so that the barrier assembly  10  can be used at several different locations within the living space, office, etc. The roller side  40  of the apparatus is assembled into the throughway by slipping the back edge of the clutch housing into the bracket  46  and the back end of the lower mount  56  into the bracket  44 . Before assembling the device into the mounting brackets, the user should be sure that there is some degree of tension within the spring  50 , so that the roller  16  tends to be pulling the sheet  14  toward retraction, even though it is fully retracted as in FIG.  3 . This can be done by making several rotations of the bracket  46  in the winding-up direction (counterclockwise as seen in FIGS.  2  and  3 ), just before mounting the unit. The unit is now ready for operation. 
     Before the barrier  14  can be extended across the throughway, the childproof release knob  68  has to be rotated, to raise the clutch spool  70  (FIG.  6 ). This removes the ratchet pawl  62  from the ratchet wheel  60  and allows extending rotation of the roller, i.e. clockwise rotation as seen in the drawings. 
     When the user desires to extend the barrier to close a throughway, the handle  18  is gripped and used to pull the free end of the sheet of barrier material  14  to the left as seen in the drawings, until the opposite jamb or wall is encountered. The bottom of the rod  20  is manipulated into the recess of the lower mounting bracket  28 , which is easily accomplished using the horizontally extending handle, facilitating manipulation of the rod  20 . Once the rod is in place in the bracket  28 , the upper end of this device is pushed between the flanges  32  of the mounting bracket  30  using the handle  18 , until the spring pins  34  spring outwardly, popping into the flange holes  36 . 
     Once the barrier is in place across the throughway, with the handle  18  latched, the childproof release clutch knob  68  is rotated back down, to the locked position. This prevents further extension of the barrier sheet. 
     Normally it is desired to fix a strong tension within the barrier sheet  14 , to provide a relatively solid wall which is not yieldable to any appreciable extent. This is done by rotating the tensioning wheel  38  and thus, the roller in the tightening direction, counterclockwise in the drawings, to rotate the roller  16  in the retraction direction and increase tension. This causes a click-click-click of the ratchet assembly, as the pawl  62  ratchets against the ratchet wheel  60 . Each notch of tensioning is retained by a tooth of the ratchet wheel, and the pawl is permitted to rise and fall with each tooth, against the pressure of the compression spring  74  (FIG.  6 ). 
     The child or dog will now encounter a nearly solid wall due to the tension of the barrier  14  across the throughway. Since the release knob  68  and clutch have the childproof feature, any child young enough and small enough to be contained behind the barrier will be unable to manipulate the knob to the release position. 
     When the barrier is to be retracted, one could simply pinch in on the pins  34  of the handle  18 , thus releasing the device from the opposed end  42 . The spring would retract the barrier sheet even though the ratchet pawl engages the ratchet wheel. However, with high tension in the barrier this can be difficult and anything but smooth. Thus, the user will preferably push down on the childproof release knob  68 , rotate the knob in the counterclockwise direction and thus lift the spool  70  to release the pawl from the ratchet and thus to release the added tension in the barrier. This can be done while applying torque to the tensioning wheel  38 , if desired. Once so released, the only tension in the barrier would be that afforded by the spring  50  within the roller. The spring pins  34  are then pinched so as to allow release of the handle  18 , and the rod  20  is lifted out of the lower bracket  28 , whereby the coil spring  50  will retract the barrier around the roller, back to the position shown in FIG.  3 . 
     When the barrier is to be used at a different location, the user simply lifts the unit out of the roller-end mounting brackets  44  and  46 , and installs the unit in similar mounting brackets mounted at a different throughway location. 
     The above described preferred embodiments are intended to illustrate the principles of the invention, but not to limit its scope. Other embodiments and variations to this preferred embodiment will be apparent to those skilled in the art and may be made without departing from the spirit and scope of the invention as defined in the following claims.

Summary:
A moveable gate for infants or dogs is used in doorways, hallways, stair landings and other household positions to provide a safe barrier for the child or dog. The gate, formed of a flexible material which pulls out of a housing in the manner of a window shade, has a jamb mounting at the housing end and a latch at the extended end of the curtain-like barrier. Both are releasable from a fixture which attaches to the door jamb, wall or stair rail post, so that the infant gate can be quickly released and moved to another location in the house where additional such jamb mountings are attached or to another house which has similar door jamb pieces installed. Important features are the manner in which the gate latches, a mechanism for tightening the curtain-like barrier into a nearly solid gate after it has been latched, and childproof devices for releasing tension in the gate when it is to be retracted.