Abstract:
A protective winter turf cover is formed with a layered polyethylene laminated sheet with each layer having force striations running at an angle to the edge of the sheet and with the force striations of one layer at an angle to the force striations of the adjacent layer, the resulting turf cover being lightweight, compactly foldable, and substantially impermeable to water. The protective winter turf cover is efficiently held down with a dual apertured washer and x-position of nails therethrough.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation in part of U.S. patent application Ser. No. 10/032,652, filed Nov. 13, 2001, now U.S. Pat. No. 6,739,088 by the same inventor, incorporated herein by reference. 
    
    
     This invention relates to a cover for turf, and more particularly, to a temporary protective winter turf cover for use on golf course greens, tee areas of a golf course and similar areas. 
     BACKGROUND OF THE INVENTION 
     The increased popularity of golf throughout the world has led to a substantial increase in the need for more golf courses. Additionally, every day, on which a golf course stays open if it would normally be closed, increases the effectiveness and profitability of the course. In the Northern climates, competitiveness to stay open as late in the fall and open as early as possible in the spring is the challenge faced by today&#39;s golf course superintendents. 
     One problem with existing green covers is that neither rapid cooling nor rapid warming can be prevented. Yet without this ability, the most undesired crown hydration occurs, usually in a very rapid fashion. 
     A protective turf cover must have at least five desirable qualities. Firstly, it must protect the turf from excessive moisture gain in the crown area. Secondly, it must protect the turf without over stimulating the turf to make it come out of the dormancy too early in the spring. 
     Thirdly, a cover must be easily removable if weather warms sufficiently in order to allow play to resume, at a time when the course is not otherwise playable. Large amounts of revenue can be lost in some climates if greens are covered, the weather warms enough to allow play, but too much time and money is needed to remove the green covers to allow play to be resumed. 
     Fourthly, any cover must last as long as possible. A life expectancy of at least three to more than seven years is a must to cut costs on reorders and old cover disposal. 
     Fifth, the covers must be fabricated from a material, which can be folded and stored into as small as space as possible. 
     SUMMARY OF THE INVENTION 
     Among the many objectives of this invention is the provision of a golf green cover, which permits a golf green to be used in efficient fashion. 
     A further objective of this invention is the provision of a golf green cover, which prevents crown hydration. 
     Yet a further objective of this invention is the provision of a golf green cover, which greatly reduces crown hydration. 
     A still further objective of this invention is the provision of a golf green cover, which is easily installed. 
     Another objective of this invention is the provision of a golf green cover, which is easily stored. 
     Yet another objective of this invention is the provision of a golf green cover, which is easily folded. 
     Still, another objective of this invention is the provision of a golf green cover, which is easily unfolded. 
     Also, an objective of this invention is the provision of a protective winter turf cover, which may be easily disposed of at the end of its useful life. 
     A further objective of this invention is the provision of a protective winter turf cover, which has repeated uses. 
     A still further objective would be to provide a cover, which will delay rapid cooling. 
     Yet a further objective would be to provide a cover, which will delay rapid warming. 
     Another objective of this invention is the provision of a golf green cover, which may held down more easily. 
     These and other objectives of the invention (which other objectives become clear by consideration of the specification, claims and drawings as a whole) are met by providing a protective winter turf cover from a layered polyethylene-laminated sheet with each layer having force striations running at an angle to the edge of the sheet and with the force striations of one layer at an angle to the force striations of the adjacent layer, thereby forming a turf cover, which is lightweight, compactly foldable, and substantially impermeable to water. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  depicts a perspective view of a winter turf cover  100  of this invention being installed on a golf green  110 . 
         FIG. 2  depicts a perspective view of a ground holding device  120  for the winter turf cover  100  of this invention being installed on a golf green  110 . 
         FIG. 3  depicts an exploded view of reinforced tab  124  for the winter turf cover  100 . 
     
    
    
     Throughout the figures of the drawings, where the same part appears in more than one figure of the drawings, the same number is applied thereto. 
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In accordance with the present invention, a temporary protective winter turf cover, as a protective cover, is provided for a grass surface, especially a golf green. Any polymer capable of being formed into a light weight, flexible sheet is suitable for forming winter turf cover. In a preferred form, the protective winter turf cover is formed from at least one polyethylene sheet. The preferred polyethylene will be discussed below. Further discussion of the protective cover is found in the parent application incorporated herein by reference and need not be repeated herein. 
     Due to the particular structure of the cover, rapid cooling or rapid warming of the covered golf green is avoided. While it is not desired to bound by any particular theory, the following postulate is offered for this success. The impermeability of the cover combined with the ultra white color provides a cover which will substantially delay either rapid cooling or rapid warming. The ultra white reflects sunlight and delays heating. The impermeability prevents undesired water contact. 
     The turf cover of the present invention provides a protective turf cover that has many advantages. There are at least four outstanding advantages of this turf cover. First, the turf cover protects the turf from excessive moisture gain in the crown area. Second, the turf cover protects the turf without over stimulating the turf to make it come out of the dormancy too early in the spring. Third, a cover must be able to be easily removed if weather, typically winter weather, warms and allows play to resume. Fourth, a cover must be able to be easily replaced, when, again typically winter weather, if the weather cools and requires play to cease. 
     Fifth, covers must last as long as possible. A life expectancy of three to seven years is a must to amortize costs on reorders and old cover disposal. Fifth, the covers must be fabricated from a material, which can be folded and stored into as small as space as possible. 
     In this manner, even with the thin foam layer, such sheets can be easily stored and carry out the other desired functions. 
     Referring now to  FIG. 1  and  FIG. 2 , a winter turf cover  100  is placed over a golf green  110 . The laminated structure of the winter turf cover  100  provides for a lightweight, substantially durable and water-impermeable material. By keeping water or snow from contacting or penetrating golf green  110 , crown hydration during winter months of colder climates is avoided. 
     One part of ground holding device  120  includes at various positions in the fabric  122  of the winter turf cover  100  are reinforced tabs  124 . Each reinforced tab  124  serves to receive a nail  132  or have nail  132  removed therefrom a plurality of times for panels  142  to form the winter turf cover  100  of this invention. 
     Through each reinforced tab  124  may have a nail  132  with a slide washer  126  between the nail head  134  and the reinforced tab  124  in order to hold turf cover  100  in place. Such reinforced tabs  124  are on one, two, three or four sides of a preferably rectangular fabric  122 . Thus, each reinforced tab  124  and each nail  132  provide part of ground holding device  120 . 
     With  FIG. 2 , the preferred form, double ground holding device  200  cooperates with reinforced tab  124  to provide an improved hold to keep winter turf cover  100  in position on golf green  110  and more efficiently resist the effect of wind thereon. Dual aperture washer  202  is placed over reinforced tab  124  after the winter turf cover  100  is placed on the green  110 . 
     A nail  132  of any suitable length is driven through each member of the pair of nail apertures  206  into reinforced tab  124  and then into the green  110 . Each nail  132  is angled so that nails  132  form a shape having basically an underground x-position  208 . This structure greatly increases the hold down capability of the winter turf cover  100 . 
     Reinforced tab  124  as shown in  FIG. 3  may be positioned anywhere on the fabric  122  by glue, friction or another suitable manner. Additionally, slide washer  126  may be positioned between dual aperture washer  202  and nail head  134  if desired. As many as desired of reinforced tab  124  are placed in various positions on the fabric  122 . Reinforced tab  124  receives nail  132  as desired. 
     Dual aperture washer  202  may be made of rubber, plastic, metal or other suitable material. Preferably, the shape is rectangular, although any shape is suitable, so long as it sufficient for two apertures  206 . Dual aperture washer  202  preferably has a circumference of 25 centimeters. More preferably, the circumference is 5 to 25 centimeters. Most preferably, the circumference is 10 to 25 centimeters. 
     This application—taken as a whole with the abstract, specification, claims, and drawings being combined—provides sufficient information for a person having ordinary skill in the art to practice the invention as disclosed and claimed herein. Any measures necessary to practice this invention are well within the skill of a person having ordinary skill in this art after that person has made a careful study of this disclosure. 
     Because of this disclosure and solely because of this disclosure, modification of this method and device can become clear to a person having ordinary skill in this particular art. Such modifications are clearly covered by this disclosure.