Abstract:
A magnetically assisted coupling comprises at least two shaft segments. Each shaft segment has opposed ends and a hollow core. Adjacent segment ends are configured in a probe/socket configuration such that one segment end is configured to receive the adjacent segment end. Magnets of opposite polarity are mounted within said hollow core of adjacent segment ends, such that the magnet in the socket is positioned at a bottom of the socket, while the magnet in the probe defines a probe end. When adjacent segment ends are brought into close proximity the magnets attract each other and draw the probe end into the socket until the magnets are in contact.

Description:
BACKGROUND OF THE DISCLOSURE 
     The present disclosure relates to segmented shafts, and more particularly to a form of coupling for connecting segments of a shaft for use as a staff, probe, support or the like. 
     Segmented shafts are used for many purposes, including but not limited to, hiking poles, tent poles, avalanche probes and wading staffs. In each of these applications, the shaft is broken into segments for ease of storage and transportation. The segments are assembled together to form a longitudinally extended shaft. The segments are typically retained in the connected configuration, which allows the full length of the shaft to be employed for the desired purpose. 
     The prior art includes for example, segmented hollow tent poles connected by an elastic cord, where the elastic cord exerts tension on the assembled pole to retain the segments in a connected, extended configuration during use. This type of segmented shaft is designed for use in compression and the segments easily separate when exposed to tension or pulling forces. Wading staffs and avalanche probes also may employ a cord extending through hollow shaft segments, where the segments are assembled and the cord is secured in tension to retain the segments in a connected, extended configuration even when the staff or probe are exposed to tension or pulling forces during use. This type of segmented shaft typically requires two hands to assemble and secure the shaft in its connected, extended configuration. 
     Fishermen wade into streams and other bodies of water to fish. Traditionally, fishermen have used felt soled shoes to grip the stones of riverbeds and shores underfoot. Despite their grip in slippery conditions, felt soled shoes have been shown to harbor spores and larvae of non-native plants and animals, thus transmitting invasive species as anglers travel between different bodies of water. In an attempt to prevent transmission of invasive species, many fishing areas have banned the use of felt soled wading shoes. As a result, many anglers have changed to rubber soled shoes, which provide less sure footing. 
     Many anglers use wading staffs to improve their stability in the water and reduce the risk of injury, drowning, or loss of expensive fishing gear. Traditional wading staffs are collapsible, and may consist of telescoping segments that are secured by bayonet or threaded connections similar to hiking poles. Other wading staffs employ hollow, tubular shaft segments secured by an inextensible cord that is secured in tension to prevent disconnection of the segments when expose to a pulling motion during use, such as when the tip of the staff is wedged between material in a river or stream bed. Though traditional wading staffs are sturdy and provide an additional measure of stability, traditional wading staffs can be unwieldy and require two hands to deploy and secure. A fisherman is typically already carrying a fishing rod and may not have both hands available to deploy and assemble a wading staff. Thus, there is a significant risk an angler may drop the most expensive piece of equipment, the fishing rod, while assembling a traditional wading staff. 
     Additionally, traditional wading staffs also take a considerable time to assemble. An angler needing to quickly brace himself upon entering an unexpectedly stronger current or slippery area may not have sufficient time to assemble his wading staff. Furthermore, an angler seeking to move quickly to an area where a fish is rising would need to take considerable time to assemble his wading staff, and risk missing a trophy. 
     There is a need in the art for a sturdy segmented shaft that provides strong connective forces between each segment, yet may be quickly deployed and assembled with one hand. 
     SUMMARY 
     Briefly stated, a magnetically assisted coupling according to the disclosure employs magnets positioned to secure adjacent shaft segments against disconnection under tension. The disclosed magnetically assisted coupling will be discussed in the context of a self-deploying wading staff, but the disclosed coupling is not limited to this use and may be employed in many applications which require a segmented shaft. 
     Generally speaking, the disclosed magnetically assisted coupling includes magnets of opposite polarity mounted within adjacent hollow shaft segments. One shaft segment end is configured to receive the other shaft segment end in a probe/socket configuration. One of the magnets is positioned at the bottom of the socket, while the other magnet is secured to define the end of the probe. When brought into close proximity, the magnets attract each other, and draw the probe end into the socket until the magnets are in contact or nearly so. Unlike prior art probe/socket type shaft couplings, the disclosed magnetically assisted coupling is essentially self-assembling and retention against pulling or tension forces is achieved without manual intervention because of the strong attraction between the magnets within the coupling. 
     A self-deploying staff incorporating the disclosed magnetically assisted coupling includes a top segment with a handle, a bottom segment terminating at a tip, and at least one intermediate segment. Each segment comprises a hollow tubular body that is configured at one or both ends to mate with an adjacent segment to define an extended tubular shaft. Intermediate segments have first and second mateable ends. The mateable ends each have magnets defining apertures, and adjacent segments have magnets of opposite polarity to facilitate coupling between adjacent segments. 
     Adjacent shaft segments are transformable between a coupled and an uncoupled configuration. When all of the segments are mated to form a unitary staff, the staff is in a deployed configuration. When each of the segments is uncoupled from its neighbor and the segments are folded into a compact bundle, the staff is in a storage configuration. The staff is typically placed in a storage pouch secured to the belt or person of the angler. It is intended that the handle of the stored staff be accessible to the angler for quick deployment. 
     A substantially inextensible cord is anchored at the handle end of the top segment and the second tip end of the bottom segment. The hollow cores and apertures of each segment allow the cord to extend from the handle to the tip. The cord retains each of the plurality of segments as part of the whole staff when adjacent segments are uncoupled. Additionally, the cord maintains the first and second connector ends in close proximity when the staff is in the storage configuration. 
     In one embodiment of the current disclosure, the cord is a static (inextensible) cord anchored at either the first end of the top segment or the second end of the bottom segment by a relatively stiff spring. The configuration of the static cord and spring urges each of the segments into a mated configuration without further manipulation. 
     To transform the staff between the storage configuration and the deployed configuration, an angler need only grasp the handle and withdraw the uncoupled staff from the storage pouch, which allows the bottom and intermediate segments to fall under the influence of gravity. As the bottom and intermediate segments fall, the spring loaded cord urges the segments in close proximity to one another, while the oppositely polarized magnets of adjacent segments urge the first and second ends into the mated configuration. The strong magnetic bond between magnets of coupled adjacent segments resists forces that pull on the segments during use. 
     To transform the staff between the deployed and the storage configuration, an angler must uncouple each individual segment from its neighbour, by applying a separating force sufficient to separate the magnets. As an angler decouples successive segments, he must fold each segment back on its neighbour to create a compact bundle. Once all the staff is in this uncoupled, bundled configuration, the angler can store the staff in a holster, pouch or pocket for easy access. 
     The staff of the present disclosure provides advantages over and relative to the prior art. Contrary to prior art staffs where segments require two hands to secure adjacent segments to each other, the staff of the present disclosure may be completely assembled with only one hand. Additionally, an angler may quickly assemble or disassemble the staff given the one-handed assembly capabilities and strong connective forces provided by the magnets. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Aspects of the preferred embodiment will be described in reference to the Drawings, where like numerals reflect like elements: 
         FIG. 1  shows a self-deploying staff incorporating the disclosed magnetically assisted couplings, the staff is depicted in a storage configuration, a holster and leash are also depicted; 
         FIG. 2  is an enlarged cross sectional view of one embodiment of a magnetically assisted coupling, showing first and second connector ends of adjacent segments of a self-deploying staff, with particular emphasis on the ferrule and magnet of the first connector end of one segment and the collar of the second connector end of the adjacent segment; 
         FIG. 3  is a cross-sectional view of the mateable ends of adjacent segments of the shaft of  FIG. 2 , the segments depicted in an uncoupled relationship and the static cord is not shown; 
         FIG. 4  is a cross-sectional view of the mateable ends of adjacent segments of the staff shown in  FIG. 3 , the segments depicted in a mated configuration and the static cord is not shown; 
         FIG. 5  shows the self-deploying staff of  FIG. 1  in a deployed configuration; and 
         FIG. 6  shows a cross-sectional view of one embodiment of the self-deploying staff, with particular emphasis on the spring anchored at the first end of the top segment. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference to the drawings, wherein like numerals represent like parts throughout the Figures, a self-deploying staff incorporating the disclosed magnetically assisted coupling is generally designated by the numeral  10 . 
     The self-deploying staff  10  is transformable between a storage configuration best seen in  FIG. 1  and a deployed configuration shown in  FIG. 5 . Referring specifically to  FIG. 6 , the self-deploying wading staff  10  generally comprises a top segment  12 , a bottom segment  14 , and a plurality of intermediate segments  16 . Each of the segments  12 ,  14 , and  16  comprises a shaft segment  18  defining a hollow core  20 . Though the shaft  18  in the Figures is depicted as having a generally circular cross-section, other cross-sectional shapes may be utilized for the shaft  18  without departing from the scope of the present disclosure. In one embodiment, the shaft segments are constructed from 7075 air craft grade aluminum tubing. 
     Referring to  FIGS. 2 ,  3  and  4 , each shaft segment  18  has at least one of a probe (male) or socket (female) mateable connector end  22 ,  24 , respectively. Middle or intermediate shaft segments will have two mateable connector ends, each connector end being compatible with the connector end of an adjacent segment. In the disclosed staff  10 , each of the first and second connector ends  22 ,  24  includes a magnet  26  which defines an aperture  28 . As best seen in  FIG. 2 , the magnets  26  are cylindrical, with the middle of the magnet  26  defining an aperture  28 . The disclosed magnets are of the same material and have the same length, outside diameter and inside diameter, but this is not necessary and other configurations are possible. Magnets  26  located in adjacent mateable ends  22 ,  24  are selected and arranged to have opposite polarity. Attraction between opposite polarity magnets in adjacent first and second connector ends  22 ,  24  assists in conversion of the staff from the stored configuration shown in  FIG. 1  to a deployed configuration shown in  FIG. 5 . In one embodiment, the magnets  26  are rare earth magnets, preferably AlNiCo magnets, but other magnets may be compatible with the disclosed magnetically assisted couplings as will occur to those skilled in the art. 
     As best seen in  FIGS. 1 and 5 , a grip  23  is secured at the first end  22  of the top segment  12 , while a tip  25  is secured at the second end  24  of the bottom segment  14 . The grip  23  is constructed from a pliant yet buoyant material, such as closed cell foam or cork, while the tip  25  may be constructed from a carbide alloy (for durability) or soft material such as Delrin plastic (to reduce noise during use). 
     As best shown in  FIGS. 2 ,  3  and  4 , the magnets  26  of the disclosed shaft  10  are each received in a tubular ferrule  30 . The first and second connector ends  22  and  24  of adjacent shafts  18  define male and female portions of a mateable shaft coupling  27  and  29 , respectively. Since the magnets  26  are of the same outside diameter, the ferrules  30  may be constructed of substantially identical tubing. The shaft segments  18  are also constructed of aluminium tubing having the same dimensions. Using the same magnets  26  and tubular components reduces inventory, part count and tooling costs associated with manufacture of the disclosed staff  10 . The magnets  26  are secured in the ferrules  30  so that the correct polarity end (North or South) of each magnet  26  protrudes from the respective ferrule  30 . Magnets  26  may be secured to the ferrules  30  by swaging the ferrule around the magnet or by any form of adhesive. Other methods of joining these materials may also be compatible with the disclosed magnetically assisted couplings as will occur to those skilled in the art. 
     As shown in  FIG. 3 , the ferrule  30  is secured to one end  22  of a shaft segment  18  so that the ferrule  30  and magnet  26  project from the end of the shaft segment  18  to form the male part  27  of the mateable coupling. In the adjacent end  24  of the neighboring shaft segment  18 , the ferrule  30  is secured in a recessed position inside the shaft segment to form the female part  29  of the mateable coupling. The portion of the shaft segment  18  extending beyond the recessed position of the ferrule  30  and magnet  26  defines a collar  32 . The collar  32  is sized to receive the ferrule projecting from the first end  22  such that the ferrule of the male portion of the connector is secure within the hollow core, but may still be withdrawn without excessive force. The disclosed magnet/ferrule/shaft configuration employs straight tubing, which is easy to work with. Seating the magnets first in a ferrule allows the ferrule to be secured at alternative positions within the shaft segments to define male and female parts of the mateable coupling without the need to alter the segmented configuration of the tubular shaft segments  18  or ferrules  30 . 
     In the disclosed magnetically assisted couplings, the ferrule  30  of the coupling part  27  extends between adjacent shaft segments  18 , reinforcing the deployed shaft against side loads. As shown in  FIGS. 3 and 4 , greater than half of the length of the ferrule  30  is received in hollow core  20  of the male portion  27 , while less than half the length of the ferrule  30  projecting from the male portion  27  is received in the hollow core  20  of the female portion  29 . The magnets  26  provide a strong connective force between adjacent segments  12 ,  14  and  16 , and require that a minimal amount of the male portion  27  project into the female portion  29 . 
     The male and female coupling parts  27 ,  29  may be reversed, and a shaft can be constructed where an intermediate segment  16  may include two male coupler parts  27  or two female coupler parts  29 , so long as the adjacent ends of shaft segments include complimentary coupler parts. 
     A static cord  34 , is anchored at both extreme ends of the staff  10 . The cord  34  extends from the first end  22  of the top segment  12  (adjacent the grip) and the second end  24  of the bottom segment  14 . In the embodiment shown in  FIG. 6 , the cord  34  is formed from a static, non-stretchable material and held under tension by a coil spring  36  at the first end  22  of the top segment  12 . Other materials will occur to those skilled in the art and may include a fine metal cable or the like. In the embodiment depicted in  FIG. 6 , the spring is a compression spring  36 . First and second generally cylindrical stoppers  35  and  37 , respectively, act as seats for the compression spring  36 . The compression spring  36  and cord  34  cooperate to keep the cord  34  under tension at all times. 
     The first and second generally cylindrical stoppers  35  and  37  are housed within the core  20  of the shaft  18 . The first generally cylindrical stopper  35  may comprise a washer, a cylindrical insert, or any structure which abuts the ferrule  30 , which acts as a fixed stop and prevents a spring first end  39  from projecting from the second end  24  of the top section  12 . The second generally cylindrical stopper  37  acts as an anchor point for the cord  34 , and abuts the second end  41  of the spring  36 . When the staff is in the storage configuration, the cord  34  and second stopper  37  compress the spring  36  against the fixed first stopper  35  and ferrule  30 . The disclosed configuration maintains tension on the cord  34 , which assists in one handed deployment and self-assembly of the wading staff. Other arrangements for maintaining tension on the cord  34  may occur to those skilled in the art and are intended to be encompassed by the appended claims. 
     The cord  34  and coil spring  36  facilitate one handed transformation of the staff  10  from the storage configuration to the deployed configuration by preserving alignment between adjacent shaft segments  18  and urging the segments together. When the magnets  26  embedded in the coupling portions  27 ,  29  come within close proximity to each other, the magnetic attraction completes the coupling and resists pulling forces that would otherwise separate the shaft segments  18  from each other. 
       FIGS. 1 and 5  show one embodiment of the present disclosure, where the wading staff  10  is included as part of a wading staff kit  100 . A holster  102  is configured to receive the wading staff  10  when in the storage configuration. The holster  102  may be constructed from any material that may get wet and dry out without significant warping or damage to the holster  102 . Appropriate materials include nylon fabric, leather, cotton, and expanded PTFE fabric. 
     In the embodiment of the kit depicted in  FIGS. 1 and 5 , a leash  104  connects the top segment  12  of the wading staff  10  with the holster  102 . The length of the leash  103  may be adjustable, while the holster  102  may have a loop of material (not shown), a resilient clip (not shown), or other structure for securing the holster  102  to an angler&#39;s waders, or vest. 
     The staff  10  of the present disclosure is self-deploying, insomuch that an angler need not physically manipulate each individual segment to transform the staff  10  between the storage and deployed configurations. An angler need only grasp the top segment  12 , and ensure that the bottom and intermediate segments  14  and  16  are free to fall under the influence of gravity. 
     As the bottom and intermediate segments  14  and  16  fall, the cord  34  ensures that the first and second connector ends  22  and  24  of each adjacent segment are maintained in close proximity to one another. In the embodiment where the cord  34  is formed from a static material and anchored via a coil spring, the cord urges the first and second ends  22  and  24  of adjacent shaft segments toward one another. 
     The magnetic field from each of the plurality of magnets  26  attracts and couples the first and second connector ends  22  and  24  of each adjacent segment. In the embodiment having male and female connector portions  27  and  29 , the magnets  26  urge the male portion  27  into the collar  32  of the female portion  29 . The magnets  26  are sufficiently strong to ensure that the ferrule  30  of the male portion  27  is secured within the female portion  29 . Once configured in the deployed configuration, the magnets  26  and cord  34  prevent the segments  12 ,  14  and  16  from uncoupling should the tip  25  get caught in mud, clay, or cracks between rocks. 
     To transform the staff  10  from the deployed configuration to the storage configuration, an angler must uncouple each individual segment  12 ,  14  or  16  from its neighbor. The segmented configuration of the staff  10  permits an angler to decouple as many or as few of the segments  12 ,  14  or  16  as is appropriate. The segments  12 ,  14  and  16  are folded back on one another, as each is successively decoupled from its neighbor, creating an increasingly larger diameter and shorter length bundle. To prevent the staff  10  from self-deploying in undesirable situations, the staff may be secured in the holster  102 , or the segments  12 ,  14  and  16  may be secured with a strap, a length of string, or other suitable material. 
     Though the magnetically assisted coupling for a segmented shaft of the current disclosure has been described in connection with an angler&#39;s wading staff, the coupling may be used in a number of other applications. For example, the magnetically assisted coupling may be used in hiking poles, tent poles, avalanche probes, and any of a multitude of other devices having segmented shafts that must be converted between and extended and compact configuration. 
     While a preferred embodiment has been set forth for purposes of illustration, the foregoing description should not be deemed a limitation of the invention herein. Accordingly, various modifications, adaptations and alternatives may occur to one skilled in the art without departing from the spirit of the invention and scope of the claimed coverage.