Disclosed is a privacy slat for insertion into the channels of a chain link fence that engages the knuckles of the fence wire by providing an elongated body member having a pair of longitudinal fins along the outside edges thereof in which at least one notch is provided in at least one of the fins for engagement with a knuckle of the fence. The fence slats of the present invention also utilize a pair of longitudinal fins having a unique angled configuration that substantially fills the fence channel.

BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to privacy slats for chain link fences, and in particular to a unique notched slat for locking engagement with a chain link fence to provide superior privacy and durability. 
     2. Description of the Prior Art 
     Traditional chain link fences are made of interwoven wires which link together to form diamond-shaped openings surrounded by the knuckles of the linking wires. Vertical and angled channels are also formed by the wires. Several different varieties of slats have been developed for insertion into the channels formed by chain link fences to obscure the view through the fence and provide a level of privacy. The most significant problem with privacy slats for chain link fences is holding them securely in place in the vertical or angled channels of the fence. Another significant problem is providing the best possible coverage of the vertical channels to maximize privacy and avoid unnecessarily large gaps between slats. 
     A number of existing chain link fence slats provide an elongated hollow body member having longitudinal fins (or wings or legs) along both outside edges, such as those disclosed in U.S. Pat. Nos. 5,007,619 and 5,184,801. The body member fills the vertical channel and the edge fins engage the knuckles of the wire fence. The '619 patent describes an additional bottom member having a channel into which each of the fence slats may be locked. To further facilitate engagement with the knuckles, many existing fence slats include strands (or fringes or cuts) along the outside edges of the fins, such as those disclosed in U.S. Pat. Nos. 4,687,957; 4,860,998; and 5,775,676. While these inventions provide improved engagement with the fence, they can be difficult to thread into the vertical fence channels, and may still suffer from slippage and movement in the channels. The addition of the bottom locking member is costly, cumbersome and may be prone to failure. 
     It is therefore desirable to provide a simple easily inserted chain link fence privacy slat that securely engages the fence without the need for additional locking members. 
     SUMMARY OF THE INVENTION 
     The present invention provides a chain link privacy slat that is easily inserted into the vertical or angled channels of the fence and which securely engages the knuckles of the fence wire by providing an elongated body member having a pair of longitudinal fins along the outside edges thereof wherein at least one notch is provided in at least one of said fins for engaging a knuckle of the fence. The body member may be solid or hollow, and the fins are provided on opposite sides thereof such that they come into contact with the knuckles of the fence along the vertical channel. A plurality of slats may be provided in parallel positions, each having one or more notches in the same location for engagement with the same corresponding knuckle(s) of each fence channel. Up to three notches may be provided on the fin on one side of the body member near the trailing end. In an alternative embodiment, another notch may be provided on the opposite fin for engagement with a knuckle on the opposite side of the vertical channel. In other alternative embodiments, a plurality of notches may be provided on the fins on one or both sides of the body member; however, too many notches will make it difficult to thread the fence slat into the channel. Fringes or strands may also be provided on the longitudinal fins along with the notch(es). 
     It is desirable that each of the oppositely positioned fins of each slat provide maximum privacy protection. In the present invention, the hollow or solid body member has a roughly rectangular cross sectional area including a width and depth that fills a large central portion of the elongated chain link fence channel, the two oppositely positioned longitudinal edge fins extending out from the body member to the edges of the channel. The edge fins of the present invention are straight and originate from each of the shorter parallel sides of the body member. These fins may originate at (a) opposite corners of the body member where the shorter parallel sides meet the longer parallel front or back surfaces of the body member, or (b) at opposite positions near the center of each of the shorter parallel sides. Each fin extends outwardly at an acute angle relative to the adjacent shorter side of the body member and each fin is wide enough to reach the center of the wire fence knuckles along the sides of the channel. Each fin extends at the same angle until it reaches the plane of either the front or back surface of the body member, the fin on one side extending until it reaches the plane of the front surface of the body member, the fin on the opposite side extending at the same angle in the opposite direction until it reaches the plane of the back surface of the body member. This configuration provides maximum coverage between slats in the fence when each slat is inserted with its fins extending in the same direction as the fins of all other slats. 
     In the preferred embodiment, between one and three notches are provided on the same fin on one side of the body member, relatively close to the trailing end of the slat. In this way, most of the slat may be smoothly threaded into the channel of the fence ahead of the notch(es). Each of the notches (or notch) then engages one of the first knuckles (the first knuckle) that it comes into contact with. 
     In the embodiment having notches on oppositely positioned fins, it is preferable that they be staggered from each other such that the notch on one side engages a knuckle on a different level (row) than the notch on the opposite side. This prevents the formation of large gaps around the knuckles of a single given row. 
     It is therefore a primary object of the present invention to provide a privacy slat for a chain link fence that securely engages the fence. 
     It is also a primary object of the present invention to maximize the coverage provided by privacy slats for chain link fences. 
     It is also an important object of the present invention to provide a privacy slat for a chain link fence having an elongated central body member and a pair of oppositely positioned outwardly extending fins with one of said fins having at least one notch therein for engaging a knuckle of the chain link fence. 
     It is also an important object of the present invention to provide a privacy slat for a chain link fence having an elongated central body member and a pair of oppositely positioned outwardly extending fins which extend outwardly at acute angles from opposite sides or corners of the body member. 
     Additional objects of the invention will be apparent from the detailed descriptions and the claims herein. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side view of the present invention showing a single notch in a fin. 
     FIG. 2 is an enlarged view of the notch of FIG.  1 . 
     FIG. 3 is a side view of another embodiment of the present invention showing three notches on one fin. 
     FIG. 4 is a cross-sectional top view of a fence slat of the present invention. 
     FIG. 5 is a side view of another embodiment of the present invention showing the location of notches on opposite fins relative to the main body of the slat. 
     FIG. 6 is a side view of the fence slat of the present invention installed in a chain link fence. 
     FIG. 7 is a side view of another embodiment of the present invention installed in a chain link fence. 
     FIG. 8 is a cross-sectional top view of another embodiment of the fence slat of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings wherein like reference characters designate like or corresponding parts throughout the several views, and referring particularly to FIGS. 1 and 4 it is seen that the invention includes a slat generally  15  having an elongated hollow body member  19  having a leading end  25  and a trailing end  26 . A pair of longitudinal fins  21  and  22  are provided on opposite sides of body member  19  extending along the length thereof. Body member  19  is designed to fill the open central area of a vertical or angled channel of a chain link fence, with fins  21  and  22  extending out from body member  19  to the centers of the knuckles  45  formed by the wires  42  of the fence. Angular cuts  23  and  24  are provided in fins  21  and  22 , respectively, at the leading end  25  of body member  19  to facilitate insertion of member  19  into the channels of the chain link fence. 
     Body member  19  has a generally rectangular cross section as shown in FIG. 4, and may be solid or hollow. In the hollow embodiment shown in FIG. 4, or in a solid embodiment, body member  19  has a front surface  28 , a parallel rear surface  30 , and two shorter connecting parallel opposite sides  27  and  29 . Fins  21  and  22  extend out from the sides  27  and  29  of body member  19 , originating at opposite positions thereon Fins  21  and  22  may originate near the centers of sides  27  and  29  as shown in FIG. 4, or from the comers as shown in FIG.  8 . Each of fins  21  and  22  extends out at an acute angle relative to its respective side ( 27  or  29 ) a sufficient distance to reach the plane of the opposite surface of body member  19 . Each of fins  21  and  22  is also wide enough to fill the fence channel (i.e. to reach the centers of the wire fence knuckles  45 ). 
     In particular, in FIG. 4, fin  21  extends at an acute angle relative to side  27  beginning at a position on side  27  and ending to a location on the plane  30 ′ of rear surface  30 . Similarly, fin  22  extends at an acute angle relative to side  29  beginning at an opposite position on side  29  and ending to a location on the plane  28 ′ of front surface  28 . In FIG. 8, fin  21  originates at the corner of surface  28  and side  27  of body member  19  and extends at an acute angle relative to side  27  beginning at the corner and ending when it reaches plane  30 ′ of rear surface  30 . Similarly,  22  originates at the corner of surface  30  and side  29  of body member  19  and extends at an acute angle relative to side  29  beginning at said corner and ending when it reaches plane  28 ′ of front surface  28 . Maximum privacy is provided by installation of identical adjacent fence slats  15  having fins  21  and  22  with the same configuration, the fins of each adjacent slat having the same position as the fins of all other slats. 
     At least one notch  31  is provided on one of fins  21  or  22 , as shown in the preferred embodiments of FIG.  1 . In this embodiment, a single notch  31  is cut into fin  22  near the trailing edge  26  of slat  15  in order to facilitate easy insertion of slat  15  into the chain link fence channel in the direction of arrow C. Notch  31  has a length A and a depth B, and includes an angular cut  33  on its trailing edge  32 . Cut  33  on the trailing edge  32  of notch  31  makes it easier (although still somewhat difficult) to pull slat  15  past a knuckle  45  in fence wires  42  while traveling in direction C; it is much more difficult to pull slat  15  in the opposite direction as no cut is provided on the leading edge  34  of notch  31 . Length A and depth B of notch  31  may be of any suitable dimension. In the preferred embodiment, the length dimension A should be approximately twice the depth dimension B. 
     Another preferred embodiment is illustrated in FIG. 3 having three notches  31  on one fin. These notches could be on either fin  21  or  22 . Cuts  33  on the uppermost two notches facilitate pulling them past at least two knuckles  45  as slat  15  is inserted into a fence channel  40  with leading edge  25  going first. An alternative embodiment is shown in FIG. 5 having at least one notch  31  on each of opposite fins  21  and  22 . The positions of notches  31  in FIG. 5 are staggered because of the staggered positions of knuckles  45  on opposite sides of a chain link fence channel  40  (as illustrated in FIGS.  6  and  7 ). 
     Fence slats  15  of the present invention are installed by first locating a vertical or angled channel  40  in a chain link fence. Then, leading edge  25  is inserted into the channel, aided by cuts  23  and  24 . The smooth edges of fins  21  and  22  slide past knuckles  45  of the fence channel  40  until the first notch  31  is encountered. Notch  31  locks over the first knuckle  45  that it comes into contact with. Notch  31  may be the only one provided in which case it should be very close to the trailing edge  26  of slat  15  so that once this first knuckle is encountered, the position of slat  15  is fixed. In such a case, no cut  33  is required, and it may be eliminated. However, where additional or multiple notches  31  are provided, slat  15  must be inserted further. Cuts  33  on each of notches  31  facilitates such further movement, allowing slat  15  to be inserted more easily (although with great difficulty) than it can be removed. However, the more notches provided, the more difficult it is to continue insertion of slat  15 . It is therefore preferred that no more than three notches  31  be used. It is also very difficult to continue such insertion when notches are provided on both of opposite fins  21  and  22 . It is therefore preferred that all notches be located on one or the other of fins  21  or  22 , but not on both fins. 
     In one embodiment, a set of fringes, fingers or strands  20  may be provided along the lengths of fins  21  and  22  in order to allow the fins to more closely conform to the shape of the fence channels, and to slide between knuckles  45  during insertion. 
     It is to be appreciated that any number of notches  31  may be provided on one or both of fins  21  and  22 . When more than one notch  31  is used, the leading notches may have a lesser depth dimension B, and may have a larger or more acutely angled cut  33  in order to facilitate pulling such leading notches through the fence channel  40 . Cut  33  may be eliminated from the lowermost of notches  31  to prevent movement in either direction once such notch locks over a fence knuckle  45 . 
     It is to be understood that variations and modifications of the present invention may be made without departing from the scope thereof. It is also to be understood that the present invention is not to be limited by the specific embodiments disclosed herein, but only in accordance with the appended claims when read in light of the foregoing specification.