This invention relates to devices for cleaning swimming pools and similar things, and more specifically is directed to apparatus and methods involving a cleaning tool utilizing a frame with a net retained thereon by a retaining member, and the retaining member is formed from at least two different materials.
The disclosures of my previously-issued U.S. Pat. Nos. 5,473,786, 6,302,277, and 6,368,502 are incorporated by reference as if expressly stated herein.
A wide variety of tools and processes have been developed to clean swimming pools and similar things (fountains, spas—both above and below ground, fish ponds, etc.), including and in addition to those described in my previously-issued U.S. Pat. Nos. 5,473,786 and 6,302,277. Among those devices and methods are devices that are commonly referred to as “leaf rakes”. Commonly, leaf rakes utilize a modular approach in order to permit replacement of parts of the leaf rake that tend to wear out. Among such prior art modular devices are some of mine (the Piranha Net PA-500 and Stingray Net SR-400), and others such as Purity Red Baron. Devices such as these typically include a replaceable net sized and configured to fit a frame, a replaceable elongated clip that serves as a retaining means to hold the net to the frame and a contact edge or lip (or cleaning surface) that makes contact with the interior surfaces of a pool. Also commonly and also modularly, an attachment means is provided to attach the frame to a handle or pole.
The Leslie's Pro Rake is another type of leaf rake that utilizes a modular approach. Its retaining means is not an elongated clip, but a very rigid, collar-like element with a net means permanently attached thereto. The collar and net means are snapped over the mouth portion of the frame during assembly. The Leslie's Pro Rake has an additional component that snaps over the front portion of the collar and on which a cleaning surface makes contact with an interior pool surface. In addition, some models of the Leslie's Pro Rake have a flexible tip on the contact portion of the additional snapping portion.
Prior art attempts to permit modular assembly and/or disassembly have many shortcomings. Among other things, the elongated clip must be stiff enough to retain the net on the frame while at the same time being flexible enough to permit ease of assembly and disassembly. Since securely retaining the net on the frame is more often a greater concern, the resulting rigidity of the elongated clip/retaining means tends to compromise the ease of assembly, disassembly, and/or replacement of parts.
Further compromise associated with rigidity occurs in the performance of the leaf rake as it is used on various surfaces found in swimming pools, spas, fountains, and other water features. In pools that have hard surfaces such as plaster, Pebble Tec, and rock, the portions of the elongated clip that make contact with such surfaces tend to last longer and perform better when they are rigid. However, in pools that have soft and smooth surfaces such as vinyl, fiberglass, acrylic, and tile, the benefits of having rigid contact portions of the elongated clip are limited. Fiberglass, acrylic and tile surfaces are generally very smooth and even slippery; sometimes these surfaces are made with varying textures that reduce slippage by giving grip to a swimmer's feet. When cleaning very smooth and slippery surfaces, the rigid contact portions of a conventional elongated retaining clip tend to glide over such surfaces almost too easily and, as a result, some debris may escape cleaning by either sliding between the clip and the smooth surface or sliding around the leaf net itself. Said another way, such rigid contact edges can prevent those contact edges from conforming very well to the surface being cleaned—the edges may not be sufficiently flexible. When cleaning surfaces that have slip reducing textures, this problem may be compounded; very small debris such as sand may easily slide between the textured surface and the contact points of a rigid elongated clip because the rigidity does not allow the contact points to conform to the variations of the textured surfaces.
Furthermore, the liners of vinyl pools, both in-ground and above ground, often lay directly upon firm surfaces such as concrete, wood, or dirt. It is not uncommon for tiny objects such as very small rocks, granules of sand, or other debris to be caught between the vinyl liner and the firm surface upon which it lays, resulting in small bumps in the liner. Though often very small, such bumps are usually detectable when struck by the contact points of a rigid elongated retaining clip during cleaning. As a result, the smoothness of motion that contributes to ease of cleaning is reduced or compromised as the rigid contact points of the cleaning tool grind against the liner. Furthermore, the small rocks and debris beneath the vinyl liner are potential hazards to the integrity of the vinyl liner, especially if the liner above those rocks and debris is subject to repeated abrasion. In extreme cases, the integrity of the liner of a vinyl pool may ultimately be compromised to the point where a leak forms in the areas where heavy abrasion occurs (such as from repeated cleanings from a leaf rake).
Additionally, the contact points of elongated clips have many possible configurations, with each configuration having unique features that contribute to the effectiveness of the cleaning tool. The profiles of some elongated retaining clips are designed to actually scoop under targeted debris during cleaning by providing a smooth, ramping transition surface that urges targeted debris into the net. Such configurations are described in my U.S. Pat. No. 5,473,786. Other profiles (such as that found on the Purity Red Baron device) are limited in their ability to lift targeted debris. Whatever the configuration, the rigidity of the elongated clip remains a factor that limits effectiveness in cleaning on some surfaces, especially vinyl liners, fiberglass, acrylic, and tile for the reasons mentioned above.
On the other hand, however, these clip elements typically cannot be made from a material that is too flexible or soft, because such material may be too easily damaged and/or it may not provide the degree of stiffness and structural integrity that is sometimes needed and desired during the cleaning process (for example, to scrape accumulated debris from the bottom of a pool, or to effectively clean a large smooth area of the pool surface).
Moreover, the elongated retaining clips currently used on leaf rakes typically are made from a single plastic substance which is extruded from a single die. Plastic extrusion is a well-known manufacturing process by which molten plastic is forced through a die, the die being a steel plate with an opening shaped so that the plastic forced through that opening has a given desired profile. As the molten plastic passes through the die, it takes on the general yet enlarged shape of the opening's profile. The newly formed molten plastic is then pulled for a distance of several yards, being stretched, formed and cooled until it takes its intended shape.
These single-material retaining clips used on leaf rakes have the dilemma discussed above; they must be both rigid enough to retain a net on a frame while also being flexible enough to permit assembly, disassembly, and reassembly with replacement parts, and their contacting edges must similarly strike a balance between sufficient stiffness and sufficient flexibility. Those compromises result in similar compromises in the pool leaf rake's performance.
It is, therefore, one of the many objects of my invention to provide an improved tool for cleaning debris from swimming pools, including the combination of a frame means forming a mouth portion and a net means covering the mouth portion, with an elongated clip that serves as a retaining means for retaining the net means in operative relationship with the frame means. In the preferred embodiment, the retaining means is a single elongated clip comprised of two different material substances, each substance having its own rigidity characteristics, in order that the assembled device can provide both the desired rigidity for retaining the net on the frame along with a flexible/soft contact portion for improved cleaning of pool surfaces. Accordingly, for apparatus and methods that are focused on this objective, the portion of the retaining means that grips the frame means is rigid enough to hold the net means on the frame means, and the contact portion of the retaining means is relatively softer, soft enough to desirably conform to variations in pool surfaces and provide reduced abrasion to vinyl liners or similar surfaces during cleaning.
One of the many methods of creating such an improved tool (having a single elongated clip comprised of two different material substances) is by a process called coextrusion. Coextrusion is very similar to ordinary plastic extrusion. However, whereas ordinary extrusion involves forcing a single molten plastic substance through a die, coextrusion actually involves forcing two different molten plastic substances that are heated separately to pass together and adjacently through a single die. As the two substances meet in the die, they bond to each other and are subsequently pulled, stretched, formed and cooled as one single elongated piece. Coextrusion is accomplished with a variety of plastics such as ABS, Polypropylene or Polyethylene, and coextruded parts generally are a single piece of plastic comprised of two different material characteristics (such as rigidity and/or colors, etc.). Although coextrusion is apparently used in many other industries, it does not appear to have been used in connection with pool leaf rakes or similar devices.
Another object of my invention is to provide a tool similar to the aforementioned cleaning tool, in which the profile of the retaining means is generally U-shaped and comprised of two different materials, with each material having its own unique rigidity. Among other things, the less rigid portions of the retaining means are preferably located in distinct areas of the profile to allow additional flexibility in key areas of the retaining means in order to increase ease of assembly, disassembly, and reassembly of the cleaning tool.
An additional object of my invention is to provide tools similar to the aforementioned characters that are comprised of a frame means that forms a mouth portion, a net means covering the mouth portion of the frame means, a single retaining means made with two different material substances, each substance having its own unique rigidity, and the retaining means being available in a variety of configurations that have unique features which contribute to the effectiveness of the cleaning tool.
Yet another object of my invention is the provision of an improved tool for cleaning debris from swimming pools, including the combination of a frame means forming a mouth portion, a net means covering the mouth portion, and a retaining means that both holds the net on the frame and provides contact areas that contribute to the effectiveness of the cleaning tool. The component of the frame that forms the frame's mouth portion has a cross-sectional profile that may include angles, notches and/or corners. Preferably, interior surfaces of the elongated retaining clip interlockingly fit with the frame's angles, notches and corners to increase the clip's effectiveness in retaining the net on the frame. While some of the features that comprise the clip's interlocking surfaces may be made from a rigid material, other parts of the interlocking surfaces may be made from a second, more flexible material so that assembly, disassembly, and reassembly of interlocking components is easier. Such flexible material can provide other benefits, such as improving the effective “grip” of the retaining means holding the net in position on the frame member.
Still another object of my invention is to provide an improved tool for cleaning debris from swimming pools, including the combination of a frame means forming a mouth portion and a net means covering the mouth portion, with an elongated clip that serves as a retaining means for retaining the net means in operative relationship with the frame means. The retaining means is a single elongated clip comprised of at least two distinct portions made from different material substances, each substance having its own unique rigidity. There is a gripping portion that retains the net on the frame, and a contact portion that makes contact with a pool's surface and has features that contribute to the effectiveness of the cleaning tool. In an alternative embodiment, the two or more portions are formed separately and then interlocked with each other, or snapped together, glued, bonded, or otherwise affixed to one another to form a single, elongated clip. Still other embodiments can include one material layer covering all or most of another layer (for example, a stiff inner clip can be “coated” with a softer exterior layer, or a softer cover element snapped over or onto a supporting/gripping clip). In certain applications, it can even be desirable to reverse the relatively hard/soft materials (soft inside, hard outside) and/or to have discrete and differently performing sections or portions of a “single” contiguous layer enwrapping the tool's frame.
A further object of my invention is to provide tools similar to the aforementioned characters that are comprised of a frame means that forms a mouth portion, a net means covering that mouth portion, a single retaining means made with two different material substances, each substance having its own unique rigidity and corresponding gripping or cleaning function, and one or more additional portions formed separately and attached to the single retaining means. In an alternative embodiment, the one or more additional portions are glued, bonded, interlocked, snapped together or otherwise affixed to the single, elongated clip.
An additional object of my invention is to provide tools similar to the aforementioned characters that are comprised of a frame means that forms a mouth portion, a net means covering the mouth portion of the frame means, a single retaining means made with two different material substances, each substance having its own unique rigidity. Preferably, the retaining means is available in a variety of configurations that have unique features which help retain the net on the frame and contribute to the effectiveness of the cleaning tool. For aesthetic or other purposes, each different material substance of the clip element or retaining means can have its own distinct color. In instances where the material substances also have different rigidity and flexibility, the different colors can serve to identify those areas of rigidity and flexibility.
Still another object of my invention is the provision of a retaining means to be used on a cleaning tool that is coextruded or otherwise formed from more than two different materials simultaneously. Among other things, such assemblies may provide an even more precise control of the materials within the tool, such as having three or more material stiffnesses, weights, colors, etc.
Other objects and advantages of the invention will be apparent from the following specification and the accompanying drawings, which are for the purpose of illustration only.
a is a profile view of
a, 2b, 2c, 2d, 2e, 2f, 2g, 2h, 2i, and 2k are profile views similar to
j is a profile view similar to
a and 3b are cross-sectional profile views similar to
c is a profile view similar to
a and 5b are profile views similar to
a, 8b, and 8c are profile views of still further alternative embodiments of the invention;
d is a profile view of yet another alternative embodiment of my invention, illustrating the contact portion or edge of the retaining means as being formed from relatively more rigid material and the generally U-shaped or gripping portion of the retaining means as being formed from relatively more flexible material;
a is a profile view of a retaining means having a rigid U-shaped gripping portion within a flexible outer portion;
b is a profile view showing the two rigid legs of a retaining means' U-shaped gripping portion joined by a flexible contact portion;
c is a profile view of an alternative embodiment of a retaining means, wherein the U-shaped gripping portion has adjacent contact portions partially surrounding said gripping portion;
d is a profile view of a retaining means made up of an outer, contact portion formed from rigid plastic, and an inner, gripping portion made from plastic that is more flexible than the outer portion;
e is a profile view of retaining means that has a rigid U-shaped gripping portion to grip a net on a frame, and an adjacent flexible contact portion with teeth-like ridges that enhance scrubbing or cleaning;
Referring now to the drawings, and particularly to
A flexible contact portion provides many advantages when compared to a rigid contact portion. Among the many benefits, a flexible contact portion 15 provides a smoother cleaning action over surfaces that may benefit from reduced abrasion. This is accomplished by way of the flexible contact portion bending, flexing and conforming to the shape/surface/texture of the surface to be cleaned. Therefore, when a flexible contact portion encounters an irregularity in the surface, it is able to conform to the shape of the irregularity without damaging the surface to be cleaned or the contact portion. For example, as shown in
As mentioned above, a variety of shapes of elongated retaining means can be useful on pool leaf rakes and may depend upon, among other things, consumer preferences. Whereas some are designed to actually scoop under targeted debris during cleaning and have a smooth, ramping transition surface that urges the targeted debris into the net in a manner consistent with my U.S. Pat. No. 5,473,786, others have more blunt contact portions and do relatively little lifting of debris. As also mentioned above, the coextruded features of my current invention can easily be adapted and used on all such designs.
Some manufacturers and consumers prefer modular designs that use retaining means that require the least amount of effort during assembly, disassembly, or reassembly on a frame element. Although the invention can be practiced in many other embodiments that do not focus on this element or feature,
Other manufacturers and consumers prefer modular retaining means that are somewhat more complicated (but arguably provide a more secure assembly or some other perceived benefit). Among other approaches, these can have cooperating/interlocking elements on the retaining means and/or the frame, such as one or more angles, notches, and/or corners. Examples of some of the many such profiles are shown in
Persons of ordinary skill in the art will understand that the size, shape, location, orientation, and/or number of such cooperating elements can be modified depending on the application and a number of factors. For example, one or more additional shapes (such as notch 23 at the corner of the frame (see
While interlocking features may help prevent the net portion from slipping off the frame, they correspondingly make assembly, disassembly and reassembly of the swimming pool cleaning tool more difficult. In certain embodiments of the present invention, however, various portions of the retaining means can be formed from different materials, each having its own material properties (such as flexibility, etc.). For example, by using a coextruding process or other suitable method of manufacture, some or all of those interlocking features of the retaining means can be formed from a relatively more flexible material, which can make assembly, disassembly, and reassembly of parts easier while still providing a sufficient or desirable level of increased “gripping” and retention of the net. Thus, in the example of
Persons of ordinary skill in the art will understand that, although many of the drawings illustrate the use of two different materials within the retaining means element and show those materials as being in single contiguous portions of the retaining means, the invention can be practiced in a wide variety of other ways, including for example using more than two such different materials, and/or using the same material at two or more different, non-contiguous locations within the cross-section of the retaining member. As previously discussed, such embodiments can provide benefits such as easing the assembly, disassembly, and reassembly of the retaining member onto a frame element. For example,
Some manufacturers and consumers use pool leaf rake frames that employ a frame with some cross section other than a rectangle (for example, a rod).
There are further instances where multiple coextruded features may be useful and/or desired. For example,
Persons of ordinary skill in the art will understand that while coextrusion is the preferred method of creating a single retaining means from more than two different materials simultaneously, it is possible to provide a retaining means which is formed from separate parts that are keyed to each other or otherwise fitted together. For example, in
Persons of ordinary skill in the art will appreciate that the invention can be practiced using any suitable materials and methods of manufacture and assembly. For example, there are many possible variations in which a single retaining means can be made from two or more parts of different materials.
Furthermore, in one embodiment, a method of cleaning an object such as the surface of a pool or the like is provided. The method may include some or all of the steps of: 1) identifying objects to be cleaned from the pool (i.e. leaves, twigs, or other debris) since debris may be floating on the pool's surface, suspended in the water, or laying on the bottom surfaces (pool bottom, steps, seats, etc.); 2) cleaning surface debris by a) trapping it against the pool's surface with the mouth portion of the tool, b) skimming the surface with the tool in such a way that part of the frame's mouth is submerged in the water while a remaining portion of the frame's mouth is above the surface, or c) approaching the debris with the tool below the water's surface and scooping the debris while lifting the tool out of the water; 3) cleaning suspended debris by moving the tool towards in such a way that the debris gets caught in the tool's mouth portion and is forced into the net; and 4) cleaning debris from the pool's bottom surfaces by a) laying the tool on the bottom surface in such a way that the contact portion of the retaining means is pointed at targeted debris, b) pushing the tool along the bottom until the contact portion of the retaining means raises the debris from the bottom, and c) continue pushing the tool until the debris is caught in the net portion of the tool.
In an alternative embodiment, a method of cleaning may include providing a cleaning tool such as the one described herein. Preferably, the contact portion of the cleaning tool makes sufficient contact with the surface of the object to be cleaned, such that the tool can easily slide along the surface and catch debris which is removed from the surface by the contact portion. Persons of ordinary skill in the art will understand that a wide range of methods associated with the present invention are possible, including but not limited to methods of manufacturing and methods of assembling a cleaning tool such as the one described herein.
In another embodiment, a method of assembling the device described herein is provided. This method may include some or all of the steps of: 1) providing a frame, a net and a retaining means; 2) holding the frame in such a way that the net can be placed over the frame's mouth portion; 3) holding the net in place with the frame to prepare it for assembly with the frame; 4) folding the edges of the nets mouth over the frame's mouth; 5) affixing the net's anti-slip means (i.e. Velcro) into proper position, with the edges of the net positioned to wrap around the mouth portion of the frame; 6) while holding the net on the frame, snap the retaining means over the frame so that the edges of the net will wrap around the frame as the frame passes into the gripping portion of the retaining means; 7) continue this process around the frame until the entire retaining means is snapped onto the frame and is holding the entire mouth portion of the net around the entire mouth portion of the frame (save the small areas adjacent to the tubular attachment means that ultimately lay between the ends of the mounted retaining means); and 8) ensure that the retaining means is completely snapped onto the frame and any interlocking portions of the retaining means and the frame are seated properly.
In yet another embodiment, a method of disassembling the device described herein is provided in order to allow for replacement of parts. The method may include some or all of the steps of: 1) gripping the rear ends of the U-shaped portion of the retaining means in a way that spreads the legs of the U-shaped portion apart; 2) releasing anti-slip means on the net (if any, and if net removal is desired); 3) pulling the retaining means away from the frame and, where necessary, continue to spread areas of the U-shaped portion of the retaining means that do not readily disengage from the frame; and 4) removing and replacing the net if desired.
In still another embodiment, a method of manufacturing the device described herein is provided. The method may include some or all of the steps of: 1) determining which materials of differing properties are compatible with each other for coextrusion and suitable for a retaining means that must grip a net on a frame and make contact with a pool's surface during cleaning; and 2) mixing, loading, heating, and extruding the designated differing materials together through a die in a manner consistent with coextrusion so that the designated differing materials form a retaining means having a profile composed of a) a U-shaped portion for gripping a net on the frame of a tool for cleaning swimming pools, and b) a contact portion for making contact with a pool's surface when mounted on a tool used to clean swimming pools.
A preferred method of manufacturing the retaining means with a U-shaped portion and contact portion of different material substances includes coextrusion. Persons of ordinary skill in the art will appreciate, however, that the U-shaped portion and contact portion may be joined together by some other process such as bonding with glue or a similar adhesive substance, or the formation of two extrusions (such as tabs) that snap/lock together.
As indicated above, the shape and size and materials used for the various components of the invention can vary widely, depending on the specific application for which the invention may be intended and other factors (costs, weight, etc.). For example,
Persons of ordinary skill in the art will understand that various method steps to assemble these and other alternative embodiments, and the method steps by which the invention may be used in such applications, may vary somewhat but still be within the scope of the invention. Among other things, once the cleaning apparatus has been assembled (or if it is already assembled and/or non-modular), the tool preferably can be used in a number of ways, including many that are useful for cleaning pools, spas, or other things. Various parts of the apparatus (such as the roughened/serrated surface(s) of the tool, etc.) can be manipulated by a user to scrape or loosen debris. The contact edge can function, among other things, as a “squeegee” when cleaning a surface (although the surface may in fact be underwater).
Many of the embodiments discussed above are directed to a retaining means that incorporates at least two elements having different material properties (i.e. one soft, the other firm; different colors, etc.). Among the benefits of such embodiments is that they can provide a soft contact portion that is gentle on vinyl or fiberglass or other pool surfaces, while also having structural or supporting properties in the other material that aid in the use and functionality of those embodiments. More broadly, many embodiments of the invention can be additionally modular in design, with the frame portion being aluminum, the retaining means being its own separate part, and the net means being replaceable and retained on the frame by the retaining means.
Other embodiments of the present invention, however, are not limited to tools made from multiple components. Such other embodiments include those that are not modular in design (and/or are of a lesser or different degree of modularity). For example, the tool's frame, scooping/contact surface, net made from fabric, and even the tubular attachment means for attaching the tool to a pole all can be fabricated as one single part. In other words, the manufacturing process can fabricate or mold all and/or at least some of the various elements together as part of the same process, reducing and/or eliminating the modularity aspect of those embodiments. Depending on the application to which the invention is to be put, as well as other factors (economics, etc.), certain embodiments may be more desirable than others.
Such non-modular (and/or less modular) embodiments can include a soft contact surface such a described herein. That contact surface can be included in such embodiments in any suitable manner, including by way of example by being incorporated into, attached/molded onto, and/or affixed to other elements of the apparatus. Persons of ordinary skill in the art will understand that such non/less modular embodiments can provide some or even all the same advantages of material properties (softness, hardness, color differences, etc.) as with the embodiments that use extruded, modular designs.
Just a few examples of such non-modular and/or less modular embodiments that can have contact portions made from two or more plastics of different material properties are shown in
Another issue with prior art devices is that typically the frames have profiles or cross-sections that correspond to two primary shapes: (1) rectangles (most prior art); and (2) circles (these include, for example, frames fabricated by bending a round metal rod).
While such rectangular cross-sections have some benefits (e.g., good strength-to-weight ratios, preventing the corresponding retaining element from undesirably twisting or rotating about the longitudinal axis of the frame), they also have shortcomings. These include, by way of example, a) assembly/disassembly are difficult, and b) successfully scooping targeted debris from a swimming pool depends upon getting that debris “up and over” the leading edge of the rectangular frame bar, and then into the bag element of the apparatus. This is illustrated in
As mentioned above, such “rectangular cross section” frames also can be difficult to work with during assembly/disassembly. In many devices, and as illustrated in
Thus, additional objects of my invention are to a) to modify and/or remove point C from the frame/tool's cross-sectional profile, and/or b) make a tool that is easier to assemble/disassemble due to its retaining clip's ability to more easily receive/release the frame element (while still maintaining a desired degree of secure grip during use of the assembled tool/apparatus). One way to do this is to use a cross-section or profile for the frame that is NOT generally configured as a rectangle or circle. Some of the many examples of such modified frames are illustrated in
Shapes such as triangles offer a virtually unlimited range of specific shapes and sizes of cross-sections, any of which can provide relatively easier assembly and disassembly of the clip with the frame. Among other things, such shapes do not have a “blunt” side that can be difficult to press into a retaining clip during assembly, and/or can get caught on the retaining clip during disassembly (the “blunt” surface that typically may be most relevant to difficult disassembly is the right side of the “rectangle” shape shown in the drawings). Depending on the configuration, they can modify and/or effectively eliminate point C, and can also provide a relatively straight and/or smooth line of travel for debris as it moves towards the net along the paths A to B.
The corresponding retaining clips can be fabricated from any suitable material and from any suitable method of fabrication. Among other things, they can be formed in standard, single-material extrusions or in a coextrusion or more complex form. To help the clip be more easily bent to match the longitudinal shape of the frame's mouth portion (so that those pieces can be more easily assembled together), one or more generally transverse slots can be cut at appropriate locations along the length of the retaining clip, as shown in
Persons of ordinary skill in the art will understand that the variety of cross-sectional shapes for the retaining clips is virtually unlimited. Preferably all such embodiments are configured with a cross section that securely engages with the particular frame member being used, but otherwise the precise shapes for both the interior portion of the cross-section (the part that at least generally contacts the frame member) and the exterior portion of the cross-section (those surfaces that remain visible after the clip and frame are assembled together) can be any of a broad range.
Thus, the precise shape of both the retaining means and the frame means can vary greatly.
In the embodiments of
Preferably, a generally triangular frame allows for a longer and/or more gradual transition surface (the scooping surface of the tool) than is possible with prior art frames that are generally rectangular. In other words, preferably point “C” (the uppermost “height” that debris must clear to then make it into the net/bag of the invention) is relatively much further to the right on the frame element.
In addition, in certain embodiments of the invention, the “high” point C is in fact generally a “point” (rather than the front edge of a generally horizontal upper surface of the frame, across which the debris must travel after it reaches that “high” point C). In such embodiments, the debris path can actually begin a relatively immediate “decline” (such as along a slope B-C in
Persons of ordinary skill in the art will understand that, among other benefits of the invention, certain embodiments can reduce the amount of frame material and resulting weight of the apparatus, therefore making the assembled tool easier to use than tools having conventional “rectangular cross-section” frames. Such person further will understand that other embodiments of the invention can use “conventional” or even prior art rectangular frames and still provide a similar or even identical outer contour (one having an effective high “point” rather than an extended somewhat horizontal upper surface), such as by forming the clip's outer shape to match that outer shape shown in the rightmost drawing in
In many embodiments, the ‘legs’ of the retaining means preferably are relatively stiff, to provide the retaining means with a desirably “tight” grip around the frame means, to maintain engagement between those parts. Frame embodiments that include a “sloping” (rather than blunt”) leading edge in cross-section (such as illustrated in many of the present drawings on the “left” side of the cross-section) preferably facilitate easier assembly of the frame into the retaining clip because that gradual wedge/slope spreads or forces the retaining clip legs apart as the two pieces are pressed toward each other.
In addition, the “downhill” side of the frame (in the attached drawings, the “right” side) preferably also can assist during assembly because it preferably enables the stiff ‘legs’ to pinch the frame in such a way that they urge the frame further or more strongly into the generally U-shaped web of the retaining means. The same preferably is true during disassembly: the stiff “legs” of the retaining means gradually open as the frame slides out of the retaining means and then pinch the frame so that it slides out of the retaining means (kind of like how pinching a watermelon seed forces it to shoot out from between your fingers). For embodiments having little or no constant horizontal thickness (instead having a “point” at which the frame thickness is at a maximum), the legs do not have to remain spread for such a long period of time—they only have to be at their maximum spread position for a relatively short time/distance during removal of the frame from the retaining means.
As illustrated in
Although much of the foregoing discussion of “non-circular” and “non-rectangular” cross sections is focused on generally triangular embodiments, persons of ordinary skill in the art will understand that a variety of such shapes that can be used to accomplish one or more of the invention's objectives. Just a few of the many examples of such embodiments are shown in
In certain embodiments of the invention (see examples in
Other embodiments of the invention can include varying the shape of the frame and/or the retaining clip along the longitudinal length or rim of the “mouth” of the assembled tool. The frame can be formed through any suitable process, such as aluminum extrusion and/or machined/ground to have a desired cross-section (such as a generally triangular cross-section) at one or more positions along the rim, and the retaining clip's cross section likewise can vary from position to position along the tool's rim. In
The apparatus and methods of my invention have been described with some particularity, but the specific designs, configurations, and steps disclosed are not to be taken as delimiting of the invention in that various modifications will at once make themselves apparent to those of ordinary skill in the art, all of which will not depart from the essence of the invention, and all such changes and modifications are intended to be encompassed within the appended claims.
This is a continuation-in-part of U.S. Ser. No. 13/193,188, filed on Jul. 28, 2011.