Patent Publication Number: US-8113968-B2

Title: Screen apparatus and method of use

Description:
FIELD OF THE INVENTION 
     The present invention relates to screen apparatus and particularly to a screen apparatus for use in sports training or sports skills development. 
     BACKGROUND ART 
     There are many devices available in the art which are adapted to provide training for particular sports. A selection of devices are described below. 
     Pitching practice, golf ball targets, tennis training, football kicking practice and other ball devices are in common use. The patents, U.S. Pat. No. 1,043,308, issued Nov. 5, 1912, to A. G. Everson, and U.S. Pat. No. 5,333,856, issued Aug. 2, 1994, to J. S. Gery, are examples of these devices having pockets provided in netting. Netting has been provided with indicia for indication of ball control and simulation of actual game conditions with U.S. Pat. No. 1,511,430, issued Oct. 14, 1924, and U.S. Pat. No. 2,254,986 issued Sep. 2, 1941, to M. Ziel, examples. Adjustable target sizes have been taught in U.S. Pat. No. 5,333,856 and by U.S. Pat. No. 5,351,948, issued Oct. 4, 1994, to R. J. Thomas. Various materials can be used for the netting. Portable frames have also been used, with U.S. Pat. No. 4,718,668, issued Jan. 12, 1988, to D. Schipske and U.S. Pat. No. 4,836,542, issued Jun. 6, 1989 to M. J. Crawley, examples. It has been taught that these frames can be made of plastic and permanently or removably assembled., U.S. Pat. No. 4,836,542 and U.S. Pat. No. 5,351,948. It is known that hollow frames can be filled with water or other material for stability, U.S. Pat. No. 4,718,668. 
     Other examples of prior art include U.S. Pat. No. 1,527,988 (McMurtrie) that discloses a net device comprising entirely of cells and used to play a game with a golf ball. U.S. Pat. No. 3,580,578 (McCarthy) discusses a goal for a bouncing ball game. U.S. Pat. No. 4,492,380 (Saytar) discloses a goal assembly for a modified basketball and hockey game. U.S. Pat. No. 3,822,883 (De Vos) discloses a target with compartments for playing a ball game where a ball is thrown into the compartments for points. U.S. Pat. No. 4,497,485 (Mascosko) discloses a baseball pitching target. U.S. Pat. No. 5,037,095 (Nedwick) discloses a quarterback trainer apparatus. U.S. Pat. No. 5,096,191 (Fang) discloses a basketball training apparatus with hoops. None of the references, however, contains the suggestion that the device may be modified for use to improve a player&#39;s reaction time in a simulated game situation. 
     As it stands however, there are remarkably few devices which are capable of assisting a sportsperson or player with improving reaction time to real game situations. 
     It will be clearly understood that, if a prior art publication is referred to herein, this reference does not constitute an admission that the publication forms part of the common general knowledge in the art in Australia or in any other country. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a screen apparatus and method of use, which may at least partially overcome at least one of the above-mentioned disadvantages or provide the consumer with a useful or commercial choice. 
     In one form, the invention resides in a screen apparatus for use in sports training or sports skills development, the screen apparatus including a plurality of screen members and a support means for supporting the screen members in a use condition, each of the screen members at least temporarily attached relative to the support means such that in use, the screen members define a screen until struck by an object at which time at least one of the screen members is at least partially dislodged to allow passage of the object in a substantially uninhibited manner. 
     In a second form, the invention resides in a method for using a screen apparatus for sports training or sports skills development including the step of locating a screen apparatus between a trainee and an object to decrease the visibility of the object by the trainee and then propelling the object through the screen apparatus to simulate a sports situation such that the trainee has less time to react to the object. 
     The apparatus of the present invention is particularly adapted to sports training or skills development for sports. The apparatus is designed to improve a player&#39;s co-ordination and/or reaction time as the device is preferably used to decrease the time that a player is given to intercept (or evade) the object. It can also be used to prevent the player having an early view of the object as it travels towards the player. 
     Reaction time is important in many sports and day to day activities, though it is not often measured nor do athletes or sportsmen specifically train to improve reaction time. As with all sports fitness training, specificity is very important, and if a trainee were to seriously want to improve reaction time in a certain sport, the trainee needs to train in a manner more specific to the visual cues and muscle reactions that are encountered during that sport. 
     The apparatus of the present invention is used to improve the overall capabilities of the player, both mentally and physically and can be used for all levels of players whether professional athletes or amateur sportsmen. It can also be used to train sportsmen from a variety of different sports. 
     Amongst other qualities, the apparatus is directed toward two specific purposes, namely;
         1. to allow a mobile object to pass through the screen at various speeds, in a virtually unimpeded manner; and/or   2. to be useable in situations where a player on a first side of the apparatus can see through the screen reasonably well but the trainee on the opposite side of the screen has difficulty seeing the person or object on the first side, in effect having a substantially “one-way” vision quality.       

     Each of the screen members are preferably manufactured from a light material so as not to disrupt or only minimally disrupt the passage of the object through the screen. As the object will preferably strike at least one of the screen members in order to pass the screen, the object will be affected in some manner, but the amount of disruption will preferably be minimised. According to the most preferred form, the screen member will preferably include a mesh member. The screen member may alternatively be opaque or partially opaque and partially see through to allow for user&#39;s of different standards and abilities and to allow for development of skills by increasing the difficulty level. 
     The mesh member will preferably be tightly meshed with openings approximately 1 mm on a side. The openings are preferably defined by members extending in a first direction and other members extending in a second direction, normally substantially perpendicularly. 
     The mesh member will typically be formed of plastic or fabric or similar A particularly preferred embodiment of the mesh member is one manufactured of what is conventionally termed “shade cloth”. The screen members used in a screen may be of different sizes. For example, upper screen members may be smaller than lower screen members or centrally located screen members may be smaller than outlying screen members. 
     The mesh member will preferably make up the major surface area of each of the screen members. The mesh member will preferably be flexible but it may be rigid or semi-rigid. It is preferred that the mesh member will be stretched across a frame. The frame will generally be a surround frame. The frame may be rigid or semi-rigid. The frame, as with the screen member itself, may be of any shape but is preferably rectangular as this will allow a more geometrical arrangement with a large number of configurations. The frame will typically include a pair of side members and a top and a bottom member, each of which are preferably elongate members. The frame members may be of any cross-sectional shape and will preferably be extruded from a die. The mesh member will typically be tightly stretched across the support frame. 
     Alternatively, the screen members may not include a frame but simply be screen material. In this configuration, the screen members may preferably be configured as ribbons or similar suspended from an upper portion of a support frame and hanging under the influence of gravity. Suspending a plurality of ribbons across a support frame in a substantially coplanar orientation thereby forms a screen. A swivel assembly may be used to attach each of the ribbon screen members to the support member and preferably the swivel assembly biases the ribbon screens into a position whereby the full width of the ribbon screen member is presented to the users. 
     The mesh member due to its configuration, will generally provide the limited visibility intended from the apparatus. The limited visibility may be increased through the provision of a backing screen located behind the trainer so that the trainee player has to peer through the screen apparatus of the invention and the view is then of the backing screen. 
     The screen members may be of any shape. According to a particularly preferred embodiment, each screen member may be elongate and ribbon-like. Each ribbon may be at least partially rectangular or have at least one less wide portion (scalloped portion) over its length in order to provide a small amount of visibility through the screen. The scalloped portions will preferably be provided in lower difficulty level screens and become smaller as the proficiency of the users increases. 
     Each screen member will preferably be between approximately 0.8 m by 2.0 m but will be of any size depending on the size of the object being used to train the player. A 0.5 m×0.64 m embodiment is particularly useful as it can be used for such sports as soccer, hockey, and rugby because it suits the size of the ball used in those sports. In the ribbon screen embodiment of the present invention, each ribbon screen member may be approximately 0.1 m in width and of any height suitable for the particular sport or training drill. 
     The support means of the invention preferably include means to temporarily fix the screen members in a use condition such that a screen can be formed. The support means preferably include one or more ground bearing members with one or more uprights and laterally extending members. There will typically be a plurality of laterally extending members so that many screen members can be used to form the screen. 
     The support means may include flexible members such as ropes, strings, webbing straps or the like. Alternatively, one or more of the support members may be rigid or semi-rigid, manufactured from light but strong materials such as plastic for example. The support means used according to the invention is preferably modular so it can be packed into a small bag or similar for transport and quickly erected to form a size adjustable screen. The modularity of the support means also preferably results in the screen being adjustable in both size and configuration. 
     Either the support means or the screen members (or both) may be provided with attachment means (or parts thereof) to at least temporarily attach the screen members relative to the support means to form the screen. According to one preferred embodiment, the attachment means will use hook and eye fasteners such as Velcro® with a portion on the support means and the corresponding portion of the fastener on the screen member, preferably on one or more of the frame members. In order to form a more complete screen, the screen members may have attachment means to attach to one another. Other attachment means may be used such as magnetic attachment, slide guides for example. The screen members may be at least partially dislodged from the support means during use, but preferably, the screen members are simply dislodged from the screen by the object moving the screen members and the screen members settling into the screen position once the object has passed. 
     It is preferred that either the upper or the lower end of each of the screen members is held more securely to the support means than the opposite end of the screen members. This preferably forms a flap member of the screen member so that the object can dislodge the screen&#39;s less secured end from the screen or support means. When the upper end is more securely attached than the lower end, the flap will be dislodged and then usually realign itself with the screen for continued use, whereas when the lower end of the screen member is more securely attached than the upper end, the upper end with be disengaged and fall under the influence of gravity to let the object pass through an opening so formed. For example, the less securely attached end of each screen member may be provided with a number of spaced apart Velcro® fastening portions and a more or less continuous strip at the more securely attached end. Magnetic fastening means may be used at a lower end to assist with the realignment of the screen once the object has passed. 
     It is also preferred that the attachment means of the invention is located on the side of the screen which faces the trainee when the screen is erected as this will provide a substantially one-way screen. However, screen members may be erected with the attachment means located on either side of the screen and in some embodiments there may be combinations of first and second side attachment means. In a third embodiment, the attachment members may be located toward the midline of the support members as this may provide two-directional capability without requiring the attachment means to be located on either side of the screen. 
     There may be primary attachment means located at the upper and/or lower ends of the screen members and secondary attachment means at the sides, if required. In fact, attachment means may be provided only at the upper end if required. Alternatively, the attachment means may be provided on at least one of the sides of the screen member. 
     The screen formed by collocation of a number of screen members may be associated with the support means through the use of a pivoting mounting frame, adapted to be substantially vertical in use and be mounted for pivoting about a central axis. This may allow the pivoting screen and the screen members to swing back and forth as used and self-locate themselves once dislodged from their set position by the passing of an object. The pivoting screen may be provided with biasing means such as springs for example to assist with the self location of the screen. The screen members may abut one another, partially overlap each other, or for development screens, be spaced from one another. 
     The erection of the screen may form a screen which has the appearance of a continuous screen but is in fact, formed of a number of cells of each of the screen members. 
     The screen can be erected having any configuration to assist the sport in relation to which the apparatus is being used. For example, for soccer training or hockey training, the screen may be erected in front of a goal mouth and spaced from the goal mouth for the training of the goal keeper. Balls can them be propelled toward the goal through the screen at the goal, and the goal keeper can attempt to stop them. For rugby training, a pair of parallel screens may be used to define a channel through which a player can run and pass to either side of themselves to support players running on the opposite side of the channel. For tennis, the screen can be used above the net of a conventional court and the ball served or hit through the screen. 
     The object used to propel through the screen will generally be a ball or similar piece of sports equipment. However, it is to be appreciated that the object may be a person, to simulate a tackling drill for example. Different sports will have different objects that can be used and it is to be noted that the object des not have to be a ball or similar. 
     The inventor of the present invention is aware that the object will typically deviate in path after striking the screen but this may be used to further complicate the training drill for the trainee. The deviation of the object when passing the screen will preferably be minimised. Further, the difficulty level may be adjusted by placing the screen closer to the trainee so that the time for reaction is decreased as the trainee becomes more adept at using the apparatus. 
     The apparatus of the present invention is designed to avoid “folding” about the object as this may impede the progress of the object. The screen is not to be limited to any size or dimension. It is preferably lightweight to provide portability and will preferably be substantially unaffected by weather conditions. 
     The apparatus can be used from a single screen or a plurality of screens can be used to construct a “wall”. In this instance, individual apparatus may be butted together or marginally overlapped with each other to provide the wall. Alternatively, a series of screens can be staggered or separated to provide partial visibility to allow progressive development of a player by closing the openings. 
     Where the initial development of a player is concerned, the screens will generally not be butted against each other, adjoining each other or overlapping to produce the low visibility situation. In these situations, the screens will generally be separated to allow for the gradual development of the player&#39;s reaction time. The separation of the screens will be gradually closed as they progress. 
     The screen members are also ideally suited to have advertising or sponsorship details located thereon. Other printing may be used such as targets or similar to increase accuracy. 
     Typically, the screen will be used in a fixed location but it is anticipated that moving drills can be developed using a screen mounted for movement. The screen apparatus may be retro-fit to existing apparatus such as goal posts or similar and appropriate mounting means will be used in these circumstances. 
     Another important feature of the present invention is in the minimisation of disruption of the screen under the influence of wind or similar A wind screen may be provided to be placed in between the screen assembly and the direction of the prevailing wind or more complex devices can be provided. One example of a more complex device is the provision of a catch system to hold the screen members in place and release them as the object approaches. This can be accomplished using an optic or light trigger such that as an object approaches the screen it is detected by disruption of a light beams of sheet which triggers the release of the catch holding the screen members. 
     Another additional feature which may be included in the invention is the provision of a return means to minimise the displacement of the screen members. If the object impacts the screen members with sufficient force, the screen members may be moved to a position such as over the top of the support means, such that it cannot fall back into place. A return means may be provided to minimise this occurrence. The return means may be a moving mechanism to return the screen members to their use position or it may be as simple as a bar or net preventing the screen members from moving into a problematic position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various embodiments of the invention will be described with reference to the following drawings, in which: 
         FIGS. 1A to 1E  is a series of sectional side views illustrating the steps involved in the use of a screen apparatus according to an embodiment of the present invention. 
         FIG. 2  is a front elevation view of a panel in the screen apparatus according to a preferred embodiment of the invention. 
         FIG. 3  is a schematic sectional side view of a preferred embodiment of the invention showing its function. 
         FIG. 4  is a front view of a screen formed according to a preferred embodiment of the present invention. 
         FIG. 5  is a schematic sectional side elevation illustrating the function of the screen illustrated in  FIG. 4  with a secure lower attachment means when an object strikes it. 
         FIG. 6  is a schematic view of one possible use of a screen apparatus according to the present invention. 
         FIG. 7  is a front elevation view of another preferred embodiment of the screen member according to the present invention. 
         FIG. 8  is a sectional side view showing the use of the screen member illustrated in  FIG. 7 . 
         FIG. 9  is a front elevation view of an embodiment of the screen with attachment means at the sides of the screen member. 
         FIG. 10  is a front elevation view of a screen formed from screen members as illustrated in  FIG. 7 , and will a pivoting screen arrangement. 
         FIGS. 10A to 10D  show the screen of  FIG. 10  in operation. 
         FIG. 11  is a front elevation view of a further embodiment of the present invention in the ribbon screen member configuration. 
         FIG. 12  is a sectional side view of the embodiment illustrated in  FIG. 11  in operation. 
         FIGS. 13A to 13D  are front elevation views of the operation of swivel action attachments for the ribbon screen members. 
         FIG. 14  is a perspective view of the embodiment illustrated in  FIG. 11  with the return means in use. 
         FIGS. 15A to 15E  are front elevation views of a blank, scalloped ribbon, a low vision ribbon, a fringed ribbon, a blank ribbon and weighted ribbons respectively. 
         FIGS. 16A to 16E  illustrate the methodology of the incremental difficulty of the screens. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     According to the preferred embodiment of the present invention, a screen apparatus for use in sports training or sports skills development is provided. 
     The screen apparatus as illustrated in  FIGS. 2 and 3  particularly, includes a plurality of screen members  10 , one of which is illustrated in  FIG. 2 , and support members  11  for supporting the screen members  10  in a use condition. Each of the screen members  10  is at least temporarily attached relative to the support members such that in use, the screen members  10  define a screen, as illustrated in  FIG. 3 , until struck by an object  12  at which time at least one of the screen members  10  is at least partially dislodged from the screen to allow passage of the object  12  in a substantially uninhibited manner. 
     Each of the screen members  10  are manufactured from a light material so as not to disrupt or only minimally disrupt the passage of the object  12  through the screen as seen in  FIG. 1 . 
     According to the preferred form, the screen member  10  is a mesh member stretched across a frame. The frame of the preferred embodiment is rectangular as illustrated in  FIG. 2 , as this will allow a more geometrical arrangement with a large number of configurations for the screen. The frame includes a pair of side members  13 , a top member  14  and a bottom member  15 , each of which are elongate members and the mesh is tightly stretched across the support frame. 
     The mesh will preferably be tightly meshed with openings approximately 1 mm on a side. The openings are defined by members extending in a first direction and other members extending in a second direction, normally substantially perpendicularly. 
     The mesh member of the preferred embodiment is formed of plastic and is what is conventionally termed “shade cloth”. 
     The mesh makes up the major surface area of each of the screen members  10  and due to its configuration, will provide the limited visibility intended from the apparatus. The limited visibility can be increased through the provision of a backing screen located behind the trainer. 
     Each screen member  10  is approximately 0.3 m by 0.3 m but may be of any size depending on the size of the object being used to train the player. 
     The support means of the preferred embodiment illustrated in the Figures, includes a pair laterally extending members  11 . The support members of the preferred embodiment are rigid and manufactured from light but strong materials such as plastic. The support members  11  used according to the preferred embodiment are modular so it can be packed into a small bag or similar for transport and quickly erected to form a size-adjustable screen. 
     Both the support members  11  and the screen members  10  are provided with a portion of an attachment means to temporarily attach the screen members  10  relative to the support members  11  to form the screen. According to the preferred embodiment, the attachment means  19  is a hook and eye fastener such as Velcro® with a portion on the support means  11  and the corresponding portion of the fastener on each screen member  10 , or on one or more of the frame members. 
     According to the preferred embodiment, the lower end of each of the screen members  10  is held more securely to the lower support member  16  than the upper end of the screen member  10 . This forms a flap member out of the screen member  10  so that the object  12  can dislodge the screen member&#39;s  10  upper end from the upper support member and can fall under the influence of gravity to let the object  12  pass through the opening so formed. For example, the upper end of each screen member  10  is provided with a number of spaced apart Velcro fastening portions and a more or less continuous strip of Velcro® is used at the lower end. 
     It is also preferred that the attachment means  19  of the invention are located on the side of the screen which faces the trainee when the screen is erected, as illustrated in the Figures. 
     The screen can be erected having any configuration to assist the sport in relation to which the apparatus is being used. For example, for soccer training or hockey training, the screen may be erected in front of a goal mouth and spaced from the goal mouth for the training of the goal keeper. Balls can then be propelled toward the goal through the screen at the goal, and the goal keeper can attempt to stop them. For rugby training, a pair of parallel screens may be used to define a channel through which a player can run and pass to either side of themselves to support players running on the opposite side of the channel. For tennis, the screen can be used above the net of a conventional court and the ball served or hit through the screen. 
     The method of use and the operation of the apparatus of the preferred embodiment is illustrated in  FIGS. 1A to 1E . 
     In  FIG. 1A , the object  12  is seen approaching the screen of the preferred embodiment by being kicked or struck towards the screen. At this stage, the trainee either cannot see the object or has only limited vision of the object  12 . In  FIG. 1B , the object  12  has struck the screen member  10 . The apparatus of the present invention is designed to avoid “folding” about the object. The upper end of the screen member has been dislodged from the upper support member  17  and the screen begins to fall. The screen is also pushed out of the way by the momentum of the object  12  and continues to move creating an opening as seen in  FIGS. 1C and 1D  to allow the object  12  to pass through the screen. Note the small size of the object  12  when compared to the size of the screen, meaning that it is likely that only a single screen member  10  has been dislodged. In  FIG. 1E , the screen member which is flexible, has fallen being retained attached to the lower support member  16  and the object has passed the screen and continues on its path. 
     The screen illustrated in  FIG. 4  has functional features that may be less apparent from  FIGS. 1 to 3 , such as the upper screen members  20  being larger than the lower screen members  21 . The screen in  FIG. 4  also has the lower screen members  21  more securely attached to the support members  11  at the lower end with an attachment strip  22  with the upper end of this row being attached using spaced apart Velcro tabs  23 . The upper and middle rows of screen members are more securely attached to the support members  11  at the upper end with an attachment strip  22  with the upper end of this row being attached using spaced apart Velcro® tabs  23 . The screen members are also overlapped  24  in the screen illustrated in  FIG. 4  to minimise the visibility offered to the trainee. 
       FIG. 5  illustrates the object  12  as it travels through the screen illustrated in  FIG. 4 , as seen from the side. The object  12  strikes the central screen member  10  which is more securely attached at the lower end than the top. The object dislodges the screen member  10  from its attachment at the upper end and the screen member  10  falls, creating an opening through which the object  12  passes and continues on its path. The adjacent screen members  10  are not dislodged. 
       FIG. 6  illustrates one example of use of the screen  50  of the present invention. The trainees  51  run in lines substantially parallel to the screen in the direction of the arrows, and pass the object  12 , in this case a ball, back and forth through the screen. 
       FIG. 7  shows a further preferred embodiment of the screen member  10  with a strip of attachment Velcro®  30  at the upper end of the screen member  10  and a pair of magnetic attachment means  31  located one at either lower corner of the screen member  10 . Corresponding magnetic attachment means  32  are provided on the support members  11  to engage with the screen member magnetic attachment means. 
     The screen of  FIG. 7  is illustrated in use in  FIG. 8 . As can be seen, as the object  12  strikes the screen member, the pair of magnetic attachment means  31  located one at the lower end of the screen member  10  are dislodged from the corresponding magnetic attachment means  2  provided on the support members  11  and the screen member  10  is deflected upwardly about the fixed attachment Velcro®  30  at the upper end of the screen member  10 . As the screen member  10  falls back down, the magnetic attachments will self-locate the screen member  10  ready for next use. 
     The screen illustrated in  FIG. 9  has attachment means provided at the sides of the screen members, as illustrated by the “X”. The support means of this embodiment also has ground engaging members  33  which are sand filled to add to stability. 
     The screen of the embodiment illustrated in  FIG. 10  is formed by collocation of a number of screen members  10  and the screen is associated with a support frame  35  through the use of a pivoting screen mounting frame  36 , adapted to be substantially vertical in use and mounted for pivoting about a pair of opposed central pivot points  37 . The screen members  10  are fixed to the pivoting screen mounting frame  36  at the top of the screen members and set in the substantially vertical use condition as illustrated in  FIG. 10A . 
     As illustrated in  FIGS. 10A to 10D , this allows the pivoting screen mounting frame  36  to swing forwardly ( FIG. 10B ) and then backwardly ( FIG. 10C ) as used, deflected by the impetus of the object  12  as it passes through the screen and the screen members  10  self-locate themselves once dislodged from their set position by the passing of the object  12  as the pivoting screen mounting frame swings backwardly ( FIG. 10C ). The pivoting screen mounting frame  36  is provided with biasing means, in this embodiment springs  38 , to assist with the self location of the screen. Both the screen members  10  and the pivoting screen mounting frame  36  self-locate ready for next use, as illustrated in  FIG. 10D . 
     A further embodiment of the invention is illustrated in  FIGS. 11 and 12 , namely the ribbon screen. The screen includes a support frame holding a plurality of ribbon screen members  40  in a vertical orientation. The top rail  42  of the support frame is maintained in position by one or more leg members  41  and the ribbon members  40  hang from the top rail  42  under the influence of gravity. As seen in  FIG. 12 , as the object  12  passes the screen, one or more of the ribbon screen members  40  are pushed out of the way to allow the object  12  to pass after which the ribbon members  40  re-orient themselves due to gravity. The ribbon members  40  are attached to the top rail  42  using the preferred swivel attachments  43  illustrated in  FIG. 13 . 
     The operation of a return means in the form of a net member  44  to minimise the displacement of the ribbon members  40  is illustrated in  FIG. 14 . If the object  12  impacts the ribbon members  40  with sufficient force, the ribbon members  40  may be moved to a position such as over the top of the support means, such that it cannot fall back into place, as illustrated. A return means, such as the net  22  illustrated may be provided to minimise this occurrence. 
       FIGS. 15A to 15E  are front elevation views of a blank, scalloped ribbon, a low vision ribbon, a fringed ribbon, a blank ribbon and weighted ribbons respectively. The different ribbon members are used in different situations to allow the difficulty of the use of the screen to be adjusted for users of different levels. 
     For example, the scalloped edges  45  of the ribbon  40  illustrated in  FIG. 15A  allow partial clear vision through the screen through the gaps created. The ribbon illustrated in  FIG. 15B  has a nil-vision lower portion  46  and a low visibility upper portion  47 . The ribbon illustrated in  FIG. 15C  has a low visibility upper portion  48  provided on either lateral side of a central nil-vision portion  49  and the screen illustrated in  FIG. 15D  is completely nil-vision. Each ribbon illustrated in  FIG. 15E  has a weight  50  provided at a lower end to assist with minimising the effects of wind or to provide a small obstruction when moving the ribbon. 
     The graduation from the spaced screen illustrated in  FIG. 16A  to the blank screens of  FIG. 16E  increases the difficulty in using the screen by progressively restricting the view of objects on the far side of the screen. Normally, beginner users will start using screens of  FIG. 16A  or  16 B and increase difficulty as they become more proficient. The less difficult screens may also be used for children. 
     In the present specification and claims (if any), the word “comprising” and its derivatives including “comprises” and “comprise” include each of the stated integers but does not exclude the inclusion of one or more further integers. 
     Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more combinations.