The present disclosure relates to an improved line guide assembly for fishing rods.
Line guides are employed to control movement of fishing line along the length of a fishing rod during use. Over the lifetime of the fishing rod, fishing line is cast and retrieved through the guides thousands of times, bringing with it moisture and particles from the environment. This repeated movement of the fishing line through the guides commonly results in abrasive wear on the inside circumference of the guides. It is common to employ rings of very hard material such as ceramic to define the inside circumference of the guides to improve resistance to wear. The extreme hardness of the wear resistant ceramic rings complicates manufacture of the rings and assembly of the rings to a support that positions the guide above the surface of the rod. The ceramic rings also tend to be very brittle, so the use of lightweight or complex sectional shapes is not practical. It is common for the rings to be secured to the support by an adhesive, which fails upon repeated flexure and causes the rings to pop out. The frame that supported the wear resistant ring is typically left with exposed edges and remnants of the adhesive that tend to cut fishing line, making the rod unfit for use until the damaged guide is replaced,
Typically, each rod carries five to fifteen such guides as well as a tubular top member and hook keeper. These components vary in size and weight to accommodate the intended use of the fishing rod. Fishing enthusiasts generally prefer components of smaller size or gauge and of reduced weight. Unfortunately, lighter gauge material also is more susceptible to distortion, bending and breaking unless the rod is carefully handled. For example, when packing or transporting the rod it is possible to bend the fishing line guides inadvertently or accidentally, requiring that the guides be straightened, typically by cold working which tends to increase the brittleness of the material and therefore reduces the usable life of the guide component. In many cases the distortion of the conventional guides and tops is caused by the rod getting caught on branches and trees when walking through the woods and brush.
U.S. Pat. No. 6,612,065 describes line guides manufactured from super-elastic shape memory alloy material. Such line guides are extremely durable and resistant to deformation due to the superelastic properties of the Nickel Titanium (NiTi) alloy materials. These line guides have gained significant acceptance among fishermen.
The disclosed line guides combine a wear resistant ring with a superelastic, shape memory alloy frame and support to provide a lightweight and durable assembly. The wear resistant ring is constructed of hard material such as ceramic. Silicon Carbide (SiC), Zirconia (ZrO2), Silicon Nitride (Si3N4), and Alumina (3 Al2O3) are ceramic materials compatible with the disclosed line guides. Other hard and wear resistant materials may also be suitable. According to aspects of the disclosure, the wear resistant ring includes a groove or annular depression on the outside surface where the ring and frame meet. The groove provides an enhanced mechanical connection between the wear resistant ring and the superelastic frame. The groove also provides a location for the application of adhesive, where the enhanced surface area of contact between the ring and frame at the location of the groove improves the resulting adhesive bond between the wear resistant ring and the frame.
In the disclosed line guide assembly, the frame and support are constructed of shape memory alloy material that is heat treated and mechanically worked to have superelastic properties over a temperature range consistent with the environment for most fishing activities, e.g., approximately 0° C. (32° F.)-38° C. (100° F.). Chilling the superelastic material significantly below the bottom of this range will convert the material into a pliable martensitic phase that allows significant deformation without permanent change in shape. Superelasticity refers to the ability of properly prepared shape memory alloys to recover from strains of up to 8% that would permanently deform ordinary elastic metals such as stainless steel. Over the temperature range of normal use, the superelastic frame is in an austenitic state, which is relatively stiff. When exposed to high levels of stress, the superelastic material undergoes a temporary phase transformation into a stress induced martensitic condition that permits elastic deformation (strain) of the material without permanent deformation. When the stress is removed, the material reverts to its pre-stress austenitic condition. This property of the disclosed frame and support enhance the durability of the disclosed line guide assemblies when exposed to impact and bending stresses.
The superelastic properties of the shape memory alloy material used for the frame and support of the disclosed line guide assemblies enhance the mechanical connection between the frame and wear resistant ring by elastically gripping the ring. The superelastic shape memory alloy support and attachment portions of the line guide assembly recover their original shape after strains of up to 8% that would distort conventional elastic metals such as stainless steel. These alloys also have the so-called “shape memory” attribute, where chilling the material below its transformation temperature renders the material soft and pliable. In the soft, pliable martensitic phase, shape memory alloy material can be distorted, for example to replace a damaged wear resistant ring without the need to remove the frame from the rod blank. When the shape memory alloy warms through its transformation temperature, it recovers its programmed shape while reverting to a relatively stiff austenitic phase. NiTi alloys are also resistant to tarnish and do not rust or oxidize when exposed to saltwater, naturally have a low coefficient of friction and are less dense than conventional stainless steel.
If the wear resistant ring becomes separated from the frame, or is worn, damaged or cracked, the frame and support can be chilled to a martensitic (pliable) state and the ring can be reinserted. When the frame and support warm to ambient temperatures, they will return to an austenitic state and again grip and support the retained wear resistant ring. If the wear resistant ring is lost or broken, the smooth, round shape of the wire frame allows the line guide to be used without the ring, with little risk of abrasion or damage to the fishing line.
Aspects of the frame and ring relationship combine to form a robust mechanical connection between the frame and the wear resistant ring. One is the relationship between the groove in the wear resistant ring and the diameter of the wire from which the frame is constructed. The outside diameter of the ring defines an upper edge of the annular groove and is larger than the inside diameter of the frame, resulting in an overlap that retains the ring relative to the frame. The depth of the groove may be as little as 25% of the diameter of the wire or as great as 95% of the diameter of the wire. Generally speaking, a deeper groove provides greater mechanical connection between the ring and the frame. The other is the relationship between the frame and the circumference of the wear resistant ring. The frame may be configured to surround as little as 50% (180°) of the circumference of the ring, or up to approximately 90% (325°) or more of the circumference of the wear resistant ring. Generally speaking, a greater percentage of the circumference of the ring surrounded by the frame, the greater the mechanical engagement between the frame and the ring. The frame is configured to grip the ring at the frame/groove interface. In combination, the groove partially surrounding the frame, along with the frame tightly surrounding a majority of the ring provide a robust mechanical connection between the frame and the ring, even in the absence of adhesive. Adhesive may be added to enhance the security of the engagement between the frame and the ring.
Line guide assemblies according to the disclosure are illustrated in
It is typical for the diameter of each line guide in a series to increase as the series progresses from the tip of a fishing rod toward the butt and reel. Therefore, generally each line guide assembly in a series has a slightly different configuration, with line guide assemblies near the reel having a larger diameter and typically being spaced further from the rod blank (not shown). The proportions of the line guide assemblies change accordingly, so the diameter of the wire used for a line guide assembly near the reel is larger and supports a larger diameter wear resistant ring further from the rod blank than a line guide near the rod tip. Changes in proportion and wire diameter may necessitate adjustments to the length of the legs of the support portion 16, the angular position of the support portion 16 and frame 12 relative to the foot of the attachment portion 18 of the wireform, as well as changes in the length of the attachment portion along the rod blank. The length of the attachment portion 18 along the rod blank is also typically greater in the larger diameter line guides closer to the reel end of the fishing rod.
In the disclosed embodiments, the wireform used to construct the frame 12, support portion 16 and attachment portion 18 is a single, continuous length of Nickel Titanium (NiTi) shape memory alloy wire with a round cross-section. Other superelastic, shape memory materials may be compatible with the disclosed embodiments, and wire having cross sectional shapes other than round may also function in the context of the disclosed embodiments. The wire is placed on a form and heat treated so that at least the frame 12 and support portion 16 have superelastic properties over a range of temperatures encountered in most fishing environments, e.g., a range of about 32° F. (0° C.)-100° F. (38° C.). This process also imparts the finished shape of the frame 12, support portion 16, and attachment portion 18, to which the part will return when distorted in the chilled, martensitic state. The superelastic properties of shape memory alloy wire makes the disclosed assemblies extremely durable and resistant to bending forces and impacts on the assemblies. The superelastic wireframes will rebound to their original shape from strains that would permanently deform other materials, such as stainless steel. The NiTi alloy is highly resistant to corrosion from salt and materials commonly encountered in fishing environments. The highly flexible superelastic NiTi wireforms move with the rod blank during casting and use, resulting in livelier rod action and less damping of rod flexure than occurs with less flexible line guide assemblies.
A shape-memory alloy (SMA) is an alloy that “remembers” its original shape and that when deformed in its cold martensitic state returns to its original shape when heated through its transformation temperature. The two main types of shape-memory alloys are copper-aluminium-nickel, and nickel-titanium (NiTi) but SMAS can also be created by alloying zinc, copper, gold and iron. Iron-based and copper-based SMAS, such as Fe—Mn—Si, Cu—Zn—Al and Cu—Al—Ni, are commercially available and cheaper than NiTi. However, NiTi based SMAs are more preferable for most applications due to their stability, practicability and superior thermo-mechanic performance.
SMAs under certain conditions display the property of superelasticity, which allows the material to recover from unusually large strains. Instead of transforming between the martensite and austenite phases in response to temperature, this phase transformation can be induced in response to mechanical stress. When SMAs are loaded in the austenite phase, the material will transform to the martensite phase above a critical stress, proportional to the transformation temperatures. Upon continued loading, the twinned martensite will begin to de-twin, allowing the material to undergo large deformations. Once the stress is released, the martensite transforms back to austenite, and the material recovers its original shape. As a result, these materials can reversibly deform from very high strains of up to 8 percent.
The wireframes are configured so the frame 12 defines an inside diameter smaller than the outside diameter of the wear resistant ring 14, so the frame 12 is at least partially received in the groove 20 defined by the ring 14. The inside diameter of the frame 12 is also slightly smaller than the smallest diameter defined inside the groove 20, so the frame 12 elastically grips the ring 14. The wireframe is placed around the ring 14 and may be secured in place using appropriate adhesive. The groove 20 is intentionally slightly larger in width than necessary to accommodate the diameter of the wire in the frame 12, leaving some room for adhesive. The groove/frame interface in the disclosed line guide assemblies 10 increases the surface area of contact between the frame 12 and ring 14, enhancing the adhesive bond.
As shown in
It will be noted that the frame 12 surrounds approximately 90% of the circumference of the wear resistant ring 14, and is configured to allow the frame 12 to flex radially relative to the ring 14. In the embodiment of
Table 1 below illustrates the relationship of wire diameter to groove depth 15 for a representative set of 6 line guides from size RC-6 (smallest diameter) to size RC-25 (largest diameter). The representative set of 6 line guides are selected from among approximately 10 sizes and are used to illustrate typical manufacturing variation and the resulting relationships between the frame 12 and the wear resistant ring 14. The groove depth 15 is sufficient to receive a majority of the wire diameter of the frame 12, leaving a small portion of the wire projecting beyond the groove 20. The portion of the frame 12 projecting radially outward of the groove 20 serves to protect the relatively fragile wear resistant ring 14 from damage by impact during transport, storage or use.
Table 2 below illustrates the relationship between the circumference of the wear resistant ring 14 and the frame 12 for the representative set of line guides shown in Table 1. The frames are configured to surround approximately 90% of the circumference of the wear resistant ring 14, or about 325°. The set of line guides shown in Tables 1 and 2 are designed together from consistent materials and methods of manufacture, so the variation between line guides in the set is relatively minor. Line guides employing alternative materials and manufacturing methods may exhibit a greater variation from the disclosed relationships.
The disclosed frame configurations can be described as “open” in contrast to frames that include a closed circle of material completely surrounding the wear resistant ring. The disclosed frame configurations allow the frame 12 to grip the wear resistant ring 14 and bend relative to the ring 14 during use. The disclosed line guide assemblies combine a lightweight, tough and highly flexible shape memory alloy frame 12, support 16 and attachment 18 with a grooved wear resistant ring 14.
After the frame 12 is secured around the ring 14, the legs of the support portion 16 may be secured together to form the foot of the attachment portion 18. The legs may be welded or adhesively bonded as shown in the disclosed embodiments (see
With reference to
A second embodiment of a line guide assembly 10a, according to aspects of the disclosure is illustrated in
The frame 12a of embodiment 10a surrounds approximately 270° of the circumference of the ring 14a, or about 75% of the circumference of the ring. In this embodiment, approximately 90° of the circumference of the wear resistant ring is not surrounded by the frame 12a. As shown in
A further alternative configuration for a line guide assembly 40 is shown in
In all embodiments, the width of the groove 20, 20a, 20b, is selected to accommodate variation in the diameter of the wire from which the frames 12, 12a, 12b, 32, 42 are constructed. It is intended for the frame 12, 12a, 12b, 32, 42 to be received in the groove with little or no resistance between the side walls of the groove 20, 20a, 20b and the frame.
Wear resistant rings compatible with the disclosed line guide assemblies 10, 10a may be constructed of any suitably hard and durable material. Representative examples include metal oxide ceramics, silicon nitride, and carbide materials. Alternatives may include metallic rings that may be coated with wear resistant coatings such as “diamond like” coating or the like. Metallic rings may also be used in their native (uncoated) finish state.
In both embodiments of the wear resistant ring 14a, 14b, the inward facing surface 19 of the ring 14a, 14b is a smooth, convex surface. This surface may be defined by a portion of a circle or a connected series of convex curves projected about the center of the ring 14a, 14b to form an annular structure. The surface 19 is free of corners or sharp curves and is configured to allow the fishing line to slide over the surface with low resistance and without damage to the fishing line. The surface 19 may be polished or in the case of a metal wear resistant ring, may be coated by physical vapor deposition “PVD” with a hard coating such as diamond like carbon “DLC” or Aluminum Titanium Carbo Nitride (AITiCN) to resist wear.
The illustrated line guide assemblies 10, 10a are of the single foot configuration, but the disclosed materials and methods are compatible with a two foot guide configuration as shown in
Number | Date | Country | |
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62139840 | Mar 2015 | US |