MAILBOX POST PROTECTOR
A mailbox or wooden post protector made of a unitary, resistantly-flexible plastic material, having four walls and an opening within one of the walls for installation around the base of the wooden post. The plastic sheet material is typically polycarbonate, which can better withstand deterioration, cracking and fracture even at low temperatures over several years, compared to conventional plastics, and has a thickness of about 5 mil to about 40 mil, and more typically from about 15 mil to about 30 mil, and can be formed by folding adjacent walls along a transverse crease lines. The polycarbonate sheets can be transparent, translucent or opaque, and can be made clear or in a variety of colors.
This application claims the benefit of co-pending U.S. Provisional Patent Application No. 60/481,072, filed Jul. 8, 2003, and is a continuation-in-part of co-pending U.S. patent application Ser. No. 10/866,300, filed Jun. 12, 2004.
BACKGROUND OF INVENTIONThe United States government has operated a postal service since 1775 when the Continental Congress named Benjamin Franklin the first Postmaster General. Rural free delivery service to individual residences in the rural America first began in 1896, and by 1908, much of America received its main daily by postal delivery.
Presently, a significant proportion of the population receives the U.S. mail in residential mail boxes positioned on or near the resident's property and along the side of the road. There are a variety of mail boxes in use, but the majority of them are shoebox-sized or larger containers that are affixed to the top end of an upright support, such as a wooden post. The bottom end of the support is buried into the ground to secure the mailbox from swaying and falling over.
Many residents position the mailbox in the lawn along side the road. In the course of cutting the grass, the resident or a lawn care professional will use a trimming device to trim grass growing close to the base of the mailbox post that can not cut with a lawn mower. A typical grass trimming device has an electric or gasoline-operated motor that drives a spool hub at an opposite end via an elongated shaft. The hub carries a length of flexible trimming string, a portion of which projecting outwardly from hub 20. As the motor is operated, the hub rotates at great speed. The outwardly-projecting section of line is swung in a circle about the axis of the shaft, whereby it will contact and cut off grass or other material in its path. Examples of such devices are shown in U.S. Pat. Nos. 2,708,335; 3,006,421; 3,608,291; 4,200,978; and 4,584,771.
The flexible plastic string used in the grass trimmers is designed and selected for durability. The string typically is made of a flexible plastic with a high hardness that resists wear and breaking when striking the earth, asphalt, concrete, stones and other hard or sharp articles. Some grass trimming strings are designed with star-shaped profiles that provide the outer surface with edges that improve the cutting function.
The strength, durability and design of the flexible plastic string also causes damage and wear along the base of wooden mailbox posts when trimming grass close to the base. After repeated grass cutting and trimmings, the periphery of the base of the wooden post can experience significant wear. As many mailbox wooden posts are made of pressure-treated wood, the wearing away of the outer wood surface along the base exposes the wood in toward the interior which tends to have less of the water-resistant chemicals. With time, the wood along the worn base of the wooden post begins to deteriorate rapidly with additional wear and water.
At the same time, lawn mowers housings often strike and gouge the base of the wooden post in the operator's effort to cut the grass as close as possible to the post.
Therefore, a need exists for a means for preventing the wear of the base of wooden posts by grass trimmers and lawn mowers.
SUMMARY OF THE INVENTIONThe present invention relates to a post protector comprising a resistant unitary structure having a periphery defined by a plurality of walls configured to surround a complementary periphery of a wooden post, and having an opening along the periphery of the unitary structure that defines first and second wall edges.
The present invention further relates to a post protector for a wooden post, the post protector comprising a single, resilient, rectilinear sheet of material consisting essentially of polycarbonate, having a width, a length, and a thickness from about 5 mil (a mil is 1/1,000 of an inch) up to 40 mil, more typically 15 mil to 30 mil, and having four spaced apart pivotable joints, defined by fold lines formed transverse to the length to form five consecutive, adjacent walls including a first wall and a fifth wall, wherein adjacent walls are foldable to a right angle wherein a portion of the first wall overlaps a portion of the fifth wall. Each fold line thereby defines a corner of the wooden post, when the post protector is positioned around the base portion of the wooden post.
The invention also relates to a post protector wherein each corner is defined by at least two, closely-spaced fold lines.
The present invention also relates to a method of forming a post protector, comprising the steps of: 1) providing a sheet of rectilinear polycarbonate material having a length, a width and a thickness of between about 5 mil and about 40 mil; 2) forming a plurality of spaced-apart crease lines on a first surface of the sheet transverse to the length and across the entire width of the sheet; and 3) folding the sheet along the plurality of formed creases to form a plurality of joints that separate a plurality of distinct walls.
The present invention further relates to a method of protecting the base of a wooden mailbox post from damage from lawn care equipment, comprising the steps of: 1) providing a post protector formed as a resistant rectilinear sheet of polycarbonate material having a width, a length, and a thickness from about 5 mil up to about 40 mil, and having four spaced apart fold lines formed transverse to the length to form five consecutive walls including a first wall and a fifth wall; 2) placing the post protector around the base portion of the wooden post having a rectilinear cross section, so that the plurality of fold lines align with corresponding corners of the wooden post, wherein the first wall overlaps a portion of the fifth wall; and 3) securing the first wall to the fifth wall.
The invention also relates to a method of protecting the base of a mailbox or wooden post from wear and abrasion, comprising the steps of: providing a resistant unitary structure having a periphery defined by four walls configured to surround a complementary periphery of a wooden post, and having an opening along the periphery of the unitary structure defined by a first wall edge and a second wall edge; separating the first wall edge from the second wall edge; passing the separated wall edges around the base of the post; and bringing together the first and second wall edges, to position the unitary structure around the base of the post.
BRIEF DESCRIPTION OF THE DRAWINGS
A typical post protector 10 is shown in
In the embodiment shown in
The unitary protector typically has a wall height sufficient to protect the base of the post when grass is trimmed by a string trimmer. Typically the height of the unitary protector is between about 8 cm and about 20 cm.
The opening 16, and the corresponding wall edges 30 and 32, can be linear, or can be non-linear or curvilinear.
Further, an adhesive, such as a pressure sensitive adhesive, can be affixed to either or both wall edges to adhesively join the wall edges after the post protector is positioned around the base of the wooden post. Prior to positioning of the post protector around the base of a wooden post, a release film can be adhered to the pressure-sensitive adhesive to prevent premature adhesion to other surfaces or to the opposed confronting wall edge. A suitable release film can use a silicon release coating well known in the art. The release film can be manufactured from films, paper, or other materials as is well known in the art. Preferably, the release film is a polyethylene film having a thickness of from about 0.012 mm (0.5 mil) to about 0.12 mm (5.0 mil).
In another embodiment shown in
The post protector can also be configured for securement around the base of a wooden post that is oriented in the ground at an angle, such as an angled post on an A-frame shaped swing set. In such an embodiment of the post protector, shown in
The unitary structure 12 typically comprises a thermoplastic material, which can be a transparent, translucent or opaque, and either clear or non-colored, or colored. Typically the thermoplastic is resilient to retain its shape and to resist wear and impact, though is sufficiently flexible permit the first and second edges to be separate by hand and positioning around the base of the wooden post, as shown in
Colored post protectors can be provided by blending a colorant such as a pigment or dye into the stock plastic resin, prior to forming the sheet. Alternatively, certain plastic colorants can be applied to the inside surface of an otherwise clear or translucent post protector. Conventional paints applied to the outside surface of the post protector are typically easily blasted away by the direct impact of the nylon string, rotating at high speed, or rotations per minute (rpm), on the outer painted surface. The same conventional paints applied to the inside surface of the post protector are likewise typically easily blasted away by the indirect impact of the nylon string on the outer surface of the post protector, which impact is communicated to the inside surface and results in the adhered paint being literally thrusted off the inside surface at the point of impact of the nylon string. Permanent dyes and inks can be used that are insensitive to the impact of the nylon string.
The thermoplastic material typical has a thickness from about 5 mil ( 5/1000 of an inch, or about 0.12 mm) to about 0.25 inch (about 6 mm). The post protector shown in
The thicker material has good rigidity and structure, and can retain its form and shape after being applied around the base of the wooden post. The thickness of the thicker, more rigid material is typically about 50 mil to about 0.25 inch.
The post protector can be made from a strip of plastic sheet of the desired width and thickness, and cut to a length. The corners formed between adjacent walls can be made by bending the plastic strip at about a right angle. The thicker sheet material that is rigid typically requires that the plastic strip material be heated to a temperature (for example, proximate to the softening point of the plastic) that sufficiently softens the sheet material and facilitates bending or folding of the sheet. The sheet material can be bent around a heated wire, or contacted with a stream of heated air, to melt or soften the plastic material sufficiently for bending, while avoiding excessive deterioration of the plastic material. Typically the strip of plastic sheet is formed around a model or form of substantially the same size as a typical wooden post. Typically the 90 degree bend has a rounded inner surface, preferably having an internal radius of at least about 2 mm.
When the thinner, flexible sheet material is used, another means of forming the sheet material into the post protector is by forming a crease line in the material and then folding the material at the crease line, either by hand or with a tool or machine. When forming the crease line, cutting or etching of the surface of the sheet material should be avoided, since the etched sheet can more easily tear or break along the crease line.
In a typical embodiment, a polycarbonate or acrylic sheet material is used. Polycarbonate sheets have high shatter and breakage strength, in a wide variety of temperatures, and can withstand deterioration, cracking and fracture even at low temperatures over several years. Polycarbonate is also sufficiently malleable to permit for nails or screws to be driven through the sheet material without splitting or shattering the material. They also better withstand breakdown by ultraviolet light than do other plastic materials.
Polycarbonate sheet material having a thickness of between about 10 mil and 30 mil, more typically of between 20 mil and 30 mil, are cut to the desired pattern or footprint, and then are creased (scored) and folded, typically by hand or an apparatus. The crease can be formed by any means well known in the art, such as with a rounded implement along a straight edge, by pressing the sheet material into a groove formed in work surface, or by other folding and creasing means. After the crease is formed, the sheet material can be folded along the crease by hand, or with a hand tool, or with an apparatus.
The resulting post protector structure can be folded at the joints so that the plurality of walls lie substantially flat, so that the substantially flat, folded post protector 210 shown in
The present invention also relates to a kit 201 as shown in
In a specific method, the post protector is made by 1) providing a sheet of polycarbonate material having a thickness of between 5 mil and 50 mil, in a dimension sufficient to be formed to surround the periphery of a wooden post; 2) forming a plurality of crease lines on an inner surface of the sheet material; and 3) folding the material along the plurality of creases so as to form distinct sidewalls defined by the crease lines. For the typical wooden mailbox post, for example, at least three (and more typically four) parallel creases are formed laterally to the length dimension of the sheet, spaced apart sufficiently to have the folds conform to the outer periphery of the wooden post. Typical wooden posts have square cross sections of about 3-⅜ inch by 3-⅜ inch (8.6 cm by 8.6 cm), also called a “4×4”, or of about 5-⅜ inch by 5-⅜ inch (13.7 cm by 13.7 cm), also called a “6×6”. For a typical 4×4 wooden post, a sheet of about 15 inches (38 cm) in length is sufficient. For a typical 6×6 wooden post, a sheet of about 23 inches (58 cm) in length is sufficient.
The outer surface of the post protector can improve the appearance of the post protector after installation onto a wooden post. A surface that is very smooth and shiny can prevent build-up of bits of nylon from the string trimmer from accumulating on the post protector. One embodiment of the post protector device has a roughened or irregular outer surface, such as a matte finish, which diminishes reflectance and glare from off the device, although the outer matte surface can allow bits of the nylon string trimmer to embed into the finish, leaving a streaked appearance. Other embodiments provide placing the matte finish on the inside surface of the post protector. The inside matte finish can cover blemishes, scars and wearing of the base of the wooden post, yet in some cases, still show through color and overall grain and texture of the wooden post.
A typical width of the plastic strip, representing the height of the post protector, is between about 5 cm to about 20 cm, more typically about 10 cm to about 15 cm. The length of the plastic strip is sufficient to surround the periphery of the base of the wooden post.
The post protector can have a plurality of apertures formed therein that can be disposed across the entire width and height. Typically elongated apertures are oriented vertically, and preferably are of a width of about the thickness of the material, or not more than about 5 mm. This prevents a trimming string from striking the wooden post through the apertures.
The post protector shown in
Another embodiment of the post protector is shown in
The invention also relates to a method of protecting the base of a mailbox or wooden post from wear and abrasion, comprising the step of attaching around the base of the post a post protector as described herein.
In another embodiment, the invention relates to a method of protecting the base of a mailbox or wooden post from wear and abrasion, comprising the steps of: providing a resistant unitary structure having a periphery defined by four walls configured to surround a complementary periphery of a wooden post, and having an opening along the periphery of the unitary structure defined by a first wall edge and a second wall edge; separating the first wall edge from the second wall edge; passing the separated wall edges around the base of the post; bringing together the first and second wall edges, to position the unitary structure around the base of the post. The resistant unitary structure is attached by separating by hand the opening along the periphery and positioning the structure around the base. Typically, the thermoplastic structure will have structural memory that returns to its original structure once the manual separation of the wall edges has been released. The method can further include the step of securing the structure in place around the base. Once means of securing the structure to the wooden post is a fastener, such as a nail or screw that secures the structure to the wooden post itself. Another means of securing the structure is an adhesive affixed to one or both confronting surfaces of first and second wall edges, which preferably overlap one another.
EXAMPLES OF THE INVENTION Example 1A piece of 20 mil-thick clear polycarbonate sheet was provided having a width of 5 inches and a length of about 15 inches. A wooden platform was provided into which is formed four parallel spaced-apart grooves, each groove being of about 0.25 inches wide, 0.0125 inches deep, and 6 inches long. The grooves were spaced apart 3.5 inch (at centerlines), and the edges were smoothed to prevent a sharp edge. The left and bottom sides of the sheet were placed against stops so that the sheet extended about 2 inches left of the left-most groove and spanned the remaining three grooves. Using the convex roller on the spline-installation tool, the convex roller is pressed down onto the sheet over the right-most groove, which helps to maintain alignment. Care was taken not to press too firmly. The process was repeated with the remaining grooves. The resulting scored sheet was then folded by hand, and placed around the base of a 4×4 wooden mailbox post.
Example 2This example is the same as Example 1, except that the polycarbonate sheet is 30 mil thick, 6 inches in width, and about 23 inches in length, and the grooves were spaced apart about 5.5 inches.
Example 3 The post protector according to Example 1 is folded at its corners substantially as shown in
Claims
1. A post protector for placement about the base portion of a wooden post positioned in the ground, the post protector comprising a single, resilient, rectilinear sheet of material consisting essentially of polycarbonate, having a width, a length, and a thickness from about 0.005 inches to about 0.040 inches, and having four spaced-apart pivot joints, defined by fold lines formed transverse to the length, to form five consecutive, adjacent walls including a first wall and a fifth wall, wherein adjacent walls are foldable to a right angle wherein a portion of the first wall overlaps a portion of the fifth wall
2. The post protector according to claim 1 wherein the second, third and fourth walls have the same length.
3. The post protector according to claim 1 wherein having a thickness of about 0.015 inches to about 0.030 inches.
4. The post protector according to claim 1 further comprising a pressure-sensitive adhesive material affixed to at least one of the first and second walls.
5. The post protector according to claim 3 wherein the polycarbonate sheet is clear.
6. The post protector according to claim 5 wherein the polycarbonate sheet is colorless.
7. The post protector according to claim 5 wherein the polycarbonate sheet has a color selected from the group consisting of brown, black white and green.
8. The post protector according to claim 3 wherein the polycarbonate sheet is opaque.
9. The post protector according to claim 9 wherein the polycarbonate sheet has a color from the group consisting of brown, black white and green.
10. The post protector according to claim 1 wherein at least one of the inner surface or the outer surface of the polycarbonate sheet has a matte finish.
11. The post protector according to claim 10 wherein the inner surface of the polycarbonate sheet has a matte finish.
12. The post protector according to claim 1 wherein each corner is defined by at least two, closely-spaced fold lines.
13. A method of forming a post protector, comprising the steps of:
- 1) providing a sheet of rectilinear polycarbonate material having a length, a width and a thickness of between about 0.005 inches and about 0.040 inches;
- 2) forming a plurality of spaced-apart crease lines on a first surface of the sheet transverse to the length and across the entire width of the sheet; and
- 3) folding the sheet along the plurality of formed creases to form a plurality of joints that separate a plurality of distinct walls.
14. The method according to claim 13 wherein the at least four creases are formed without cutting or etching of the surface of the sheet material.
15. The method according to claim 13 wherein the folded post protector is folded at the joints so that the plurality of walls lie substantially flat, to permit securing the post protector in the substantially flat orientation for packaging and shipment.
16. The method according to claim 13 wherein the thickness is between about 0.015 inches and about 0.030 inches.
17. A method of protecting the base of a wooden mailbox post from damage from lawn care equipment, comprising the steps of:
- 1) providing a post protector formed as a resistant rectilinear sheet of polycarbonate material having a width, a length, and a thickness from about 5 mil up to about 40 mil, and having four spaced apart fold lines formed transverse to the length to form five consecutive walls including a first wall and a fifth wall;
- 2) placing the post protector around the base of the wooden mailbox post having a rectilinear cross section, so that the plurality of fold lines align with corresponding edges of the wooden post, wherein the first wall overlaps a portion of the fifth wall; and
- 3) securing the first wall to the fifth wall.
18. The method according to claim 16, further comprising securing the first wall to the wooden post.
Type: Application
Filed: Jun 14, 2007
Publication Date: Oct 25, 2007
Inventor: Daniel NESBITT (Cincinnati, OH)
Application Number: 11/763,071
International Classification: E04H 12/22 (20060101);