Abstract:
Modular conduit systems in which a plurality of tubular link components are interconnected to form a continuous conduit. Each adjacent pair of tubular link components has a ball-and-socket joint that enables the pair of tubular link components to be pivoted with respect to each other. The ball-and-socket joint consists of a ball attached to a first one of the pair of adjacent tubular link components and a socket attached to a second one of the pair of adjacent tubular link components, where the ball is positioned within the socket. The amount of friction between the ball and the socket is adjustable, so that the amount of force required to pivot the pair of tubular link components with respect to each other, which is dependent upon the amount of friction between the ball and the socket, is variable.

Description:
BACKGROUND 
     Field of the Invention 
     The invention relates to systems and methods for forming flexible conduits that utilize interlocking links that are individually adjustable to allow a user to modify the tension between the links and thereby fine-tune the ability of the conduit to flex to a desired position, but also provide enough rigidity for the conduit to support other system components to which the conduit is connected. 
     Related Art 
     Various modular conduit systems are known. These conduits are used for purposes such as protecting electrical, hydraulic or other lines that are positioned within the modular conduits. For instance, U.S. Pat. No. 394,695 to Shutz, U.S. Pat. No. 1,822,624 to Hoeftmann, and U.S. Pat. No. 5,986,215 to Watanabe disclose modular conduit systems for protecting cables in potentially harsh environments such as the sea floor. The modular conduits may also be used as structural components in a system, where the conduit provides a flexible means to position and support other components of the system. For example, U.S. Pat. No. 5,197,767 to Kimura discloses an articulable supporting sheath. Modular conduits may also be used to form or connect pipes, as in the examples of U.S. Pat. No. 1,284,099 to Harris and U.S. Pat. No. 4,856,822 to Parker. 
     One conventional modular conduit is marketed and sold under the name “Loc-Line”. This product has a series of components or links that are interconnected by ball-and-socket joints (a ball at the end of one component fits into a socket of an adjacent component. The ball pivots within the socket to allow the relative positions of the components to be adjusted. The links can be moved so that the entire conduit is flexed. The friction between the links normally holds the conduit in a desired position. The links can be male-female (ball on one end, socket on the other), male-male (ball on both ends), female-female (sockets on both ends), or male/female on one end and a non-ball-and-socket termination on the other end. The links can be straight, angled, curved, etc. and can be made in various sizes. 
     There are several problems with modular conduits such as this. For example, the links are typically connected by pushing the ball of one link into the socket of another link. This makes the links easy to assemble, but it also causes the links to easily become disconnected as well. Additionally, as the links wear, they become looser and move more freely with respect to each other. As a result, the conduit formed by the links is less likely to maintain a desired position. Still further, because the links are intended to be easily repositioned, the conduit formed by the links typically cannot hold much weight. 
     SUMMARY OF THE INVENTION 
     The various embodiments of the invention may solve one or more of these problems by providing means to adjust the tension of each link. In other words, each link can be tightened to increase the friction between links, thereby making the links hold their respective positions better. Alternatively, each link can be loosened to decrease the friction between links, thereby making the links move more freely with respect to each other. The individual links can be individually tightened or loosened so that portions of the conduit are more rigid and support more weight, while other portions are more easily repositioned. 
     One embodiment comprises a modular conduit system that includes a plurality of tubular link components which are interconnected to form a continuous conduit. Each adjacent pair of tubular link components has a ball-and-socket joint that enables the pair of tubular link components to be pivoted with respect to each other. The ball-and-socket joint consists of a ball attached to a first one of the pair of adjacent tubular link components and a socket attached to a second one of the pair of adjacent tubular link components, where the ball is positioned within the socket. The amount of friction between the ball and the socket is adjustable, so that the amount of force required to pivot the pair of tubular link components with respect to each other, which is dependent upon the amount of friction between the ball and the socket, is variable. 
     In one embodiment, each tubular link component is split into two halves. The opposing halves are secured to each other by means such as screws that can provide an adjustable securing force. The halves of each of the tubular link components may be substantially identical to facilitate manufacturing and to reduce costs. The tubular link components may be designed to leave a gap between the halves to allow them to be drawn toward each other, thereby increasing the amount of friction in the ball-and-socket joint. 
     The modular conduit system may include a base component which is connected to a first end of the conduit, as well as a head component which is connected to a second end of the conduit. The conduit is supported by the base component, and the head component is supported by the conduit. The base component may include, for example, a rechargeable battery, while the head component may include a light that is powered by the battery. Electrical and control lines may be coupled between the base component and the head component. These lines may be positioned within the conduit formed by the plurality of tubular link components. 
     Another embodiment may comprise a first tubular link for use in a modular conduit. The tubular link has a tubular member with a first, male end and a second, female end. The male end has a spherical outer surface has the same radius of curvature a spherical inner surface of the female end so that a series of the tubular links can be joined together (each having its male end inserted into the female end of an adjacent link) to form a flexible modular conduit. The tubular member is divided longitudinally into two separable halves that are adjustably secured together. The amount of force that is applied by the halves at the female end to a male end of an adjacent tubular link is adjustable to modify the amount of friction between the tubular links and thereby control the flexibility or rigidity of the joint between the tubular links. The separable halves of the tubular link may be substantially identical, and may be secured to each other with screws. When the two halves are secured to each other, a gap may be left between the halves, so that the two halves can be drawn toward each other, to increase the amount of friction between the female end of the tubular link and the male end of the adjacent tubular link. 
     Numerous other embodiments are also possible. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other objects and advantages of the invention may become apparent upon reading the following detailed description and upon reference to the accompanying drawings. 
         FIGS. 1A-1D  are a set of diagrams illustrating an exemplary modular conduit link in accordance with one embodiment. 
         FIG. 2  is a diagram illustrating a link that has two female ends in accordance with one embodiment. 
         FIG. 3  is a diagram illustrating a link that has a first end that is male and a second end that has a threaded connection in accordance with one embodiment. 
         FIG. 4  is a diagram illustrating a link that forms an elbow in accordance with one embodiment. 
         FIG. 5  is a diagram illustrating an assembled modular conduit having multiple links in accordance with one embodiment. 
         FIG. 6  is a diagram illustrating an exemplary tool utilizing a modular conduit in accordance with one embodiment. 
     
    
    
     While the invention is subject to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and the accompanying detailed description. It should be understood, however, that the drawings and detailed description are not intended to limit the invention to the particular embodiment which is described. This disclosure is instead intended to cover all modifications, equivalents and alternatives falling within the scope of the present invention as defined by the appended claims. Further, the drawings may not be to scale, and may exaggerate one or more components in order to facilitate an understanding of the various features described herein. 
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     One or more embodiments of the invention are described below. It should be noted that these and any other embodiments described below are exemplary and are intended to be illustrative of the invention rather than limiting. 
     In one embodiment, interlocking links are used to form a flexible conduit. Each link has a male end and a female end, where the male end of one link is sized to fit within the female end of another link. The links are individually adjustable to control the friction between them, thereby controlling the amount of force that is required to move the links with respect to each other. A greater amount of friction makes the links more difficult to move, while less friction allows the links to move more freely. 
     In one embodiment, the modular conduit can be used as a flexible support for a tool such as a portable lighting unit. In this embodiment, the conduit extends from a base that houses a rechargeable battery to a lighting head that is powered by the battery. Electrical lines from the battery to the lighting head are enclosed within the conduit to protect them. The links that form the conduit may be tightened as needed to ensure that the conduit is sufficiently rigid to support the lighting head on the base, while maintaining a desired amount of flexibility to enable the lighting head to be properly positioned with respect to the base. As the individual links wear and become looser, they can be re-tightened to ensure that the conduit provides the desired support and flexibility. 
     The invention therefore provides several advantages. For instance, after the links are assembled to form a conduit, the links can be tightened to prevent the links from being disconnected from each other, which can be a problem in conventional modular conduits. Another advantage is that the links can be tightened to hold more weight, or loosened to make the conduit more easily flexible. Further, the links can be tightened to account for wear. In other words, as the conduit is used and the joints become looser and less capable of supporting a desired weight, the links can be tightened so they become stiffer, so the conduit remains useful for a longer period of time. Yet another advantage is that the links can be independently adjusted. It may be desirable for some portions of the modular conduit to be stiffer while others are more flexible. Individual links of the present modular conduit can be adjusted to achieve the desired characteristics in different parts of the conduit. 
     Referring to  FIGS. 1A-1D , a set of diagrams illustrating an exemplary modular conduit link is shown. The term “link” may be used herein to refer alternately to the link of the modular conduit and to the component that forms half of the link (specifically as depicted in  FIGS. 1A-1D .  FIG. 1A  shows a perspective view of one of the halves of the link.  FIG. 1B  shows a top view of the link.  FIG. 1C  shows an end view of the link.  FIG. 1D  shows a cross-section of the link. 
     The component  100  shown in  FIGS. 1A-1D  has a first, male end  110  and a second, female end  120 . Each of these ends has a generally spherical shape. The outer diameter of male end  110  has substantially the same radius (R) as the inner diameter of female end  120 , so that the male end will fit within the female and maintain contact over a substantial portion of the respective surfaces (male outer diameter and female inner diameter). Each half-link component  100  has a flat surface  140  that can be positioned against (or nearly against) the corresponding surface of another half-link. When two of half-links  100  are positioned in this manner, they form a link that is generally symmetric about axis  150 . 
     A pair of protrusions  130  and  131  extend outward from the female end  120  of component  100 . Each of protrusions  130  and  131  has a hole therethrough to accommodate a screw (or bolt). The screws secure the protrusions of one half-link to the protrusions of the other half-link. A tab  160  on each half-link is provided to fit within a corresponding recess in the other half-link to help align the two. It is noted that the use of two identical half-links to form the modular conduit link may reduce manufacturing costs (as compared to manufacturing two different halves that are not identical). 
     As noted above, two half-links  100  are secured to each other to form a link. Multiple links are then assembled to form a conduit. After several of the links are constructed from the half-links, the male end of a first link is inserted into the female end of a second link. It may be helpful to loosen the screws that secure the halves of the second link at its female end, allowing the halves to move apart slightly. After the male end of the first link is inserted into the female end of the second link, the screws may be tightened to draw the halves together, thereby retaining the male end of the first link in the female end of the second link. This process is repeated with as many links as desired to form a conduit. 
     Because the ends of each link are spherical, the links can pivot with respect to each other. The screws at the female end of each link can be tightened or loosened to provide the desired amount of friction at the joint between the links. As explained above, the more the screws are tightened, the more friction there is between the links, and the harder it is to move the links at the joint. While this makes the joint more difficult to flex, it enables the joint to support more weight. 
     Conventional modular conduits, on the other hand, are typically one-piece links that are snapped together and are not adjustable in this manner. If there is wear between the links of a conventional modular conduit, the joint becomes looser, and the weight that can be supported by the joint is reduced. At some point, the conventional modular conduit may not be able to support the weight for which it was originally designed, and it may simply have to be replaced. The adjustability of the present modular conduit allows it to be adjusted for wear, thereby extending the useful life of the conduit. 
     It should be noted that some conventional modular conduits use a two-piece design rather than a one piece design. These conventional two-piece designs, however, do not provide means to adjust the friction at each joint, and consequently do not allow the flexibility and support provided at each joint to be modified. 
     In one embodiment, the half-links may be sized so that the flat surfaces ( 140 ) of the two half-links may not quite touch each other when they are assembled into a conduit. This gap between the half-links may facilitate the adjustment of the friction at the joint by allowing the spacing between the halves of the female end to be changed. In other words, if the halves are already touching, the tightening of the screws may not bring the halves closer together and consequently may not increase the friction at the joint. The gap may allow the halves of the female end to better clamp down on the male end of the other link. It should be noted that the desirability of the gap between the half-links may not be necessary in all embodiments. 
     While the body of the present modular conduit may be formed primarily be links as described above and shown in  FIGS. 1A-1D , it may be desirable to include other types of links in the conduit as well. Several examples of these alternative types of links are shown in  FIGS. 2-4 .  FIG. 2  shows a link that has two female ends (a female-female link). Each of the female ends is as described above. This link is designed to be coupled to the male end of an adjoining link so that the conduit terminates with a female end rather than a male end. A male-male link may alternatively be used to change the end of the conduit from female to male. A conduit could also be formed using alternating male-male and female-female links. 
       FIG. 3  shows a link that has a first end that is male (as described above) and a second end that has a threaded connection. This link may be used, for example, to convert the end of a conduit from a female termination to a threaded termination. The male-threaded link may be used to enable the conduit to be coupled to a system component that accepts the threaded connection. In one embodiment, the threaded end of the link is screwed into a base that supports the conduit, or a head component that is itself supported by the conduit. 
       FIG. 4  shows a link that forms an elbow. This link may be useful when it is necessary for the conduit to make a sharper bend than is possible with a joint between male and female ends. The link depicted in  FIG. 4  has a 90-degree bend, but alternative links could have angles that are greater than 90 degrees or less than 90 degrees. 
     Still other alternative types of links that are not shown in  FIGS. 2-4  may also be used. 
     Referring to  FIG. 5 , an assembled modular conduit having multiple links is shown. As depicted in this figure, conduit  500  has a threaded connector (male-threaded link) coupled to a series of male-female links (e.g.,  520 ). The male-female links are coupled to an elbow link  530 , and a female-female link  540  is coupled to the other end of the elbow link. A second threaded connector  550  is coupled to female-female link  540  to terminate the modular conduit. Conduit  500  provides a means to adjustably connect and support components that are coupled to the ends of the conduit. Modular conduit  500  also provides a means to protect electrical and control lines between the components by running these lines through the hollow conduit. 
     Referring to  FIG. 6 , a diagram illustrating an exemplary tool utilizing the present modular conduit is shown. In this example, the tool is a portable lighting system  600 . Lighting system  600  includes a base  610 , and modular conduit  620  and a light head  630 . Base  610  includes a rechargeable battery and has a flat bottom surface that allows the base to be placed on a work surface such as the floor. The base may also provide alternative means to position the system, such as a suction cup that may be used to mount the base on a workpiece. 
     Conduit  620  is coupled to base  610  by means of a threaded connector  623  similar to link  510  in  FIG. 5 . This connector is screwed into a corresponding set of female threads in the top of base  610 . Modular conduit  620  also includes a series of male-female links (e.g.,  621 ), a female-female elbow ( 622 ) and a second threaded connector  624 . Second threaded connector  624  screws into a corresponding threaded socket in the back of light head  630 , so that the light head is adjustably supported by conduit  620 , which is in turn supported by base  610 . Electrical lines (wires)  640  connected to the battery in base  610  are run through modular conduit  620  and are connected to light head  630  to provide power for the light. One or more control lines may also be run through the conduit to enable the functions of the light head to be controlled from switches on base  610 .) with the following new paragraph: 
     The benefits and advantages which may be provided by the present invention have been described above with regard to specific embodiments. These benefits and advantages, and any elements or limitations that may cause them to occur or to become more pronounced are not to be construed as critical, required, or essential features of any or all of the claims. As used herein, the terms “comprises,” “comprising,” or any other variations thereof, are intended to be interpreted as non-exclusively including the elements or limitations which follow those terms. Accordingly, a system, method, or other embodiment that comprises a set of elements is not limited to only those elements, and may include other elements not expressly listed or inherent to the claimed embodiment. 
     While the present invention has been described with reference to particular embodiments, it should be understood that the embodiments are illustrative and that the scope of the invention is not limited to these embodiments. Many variations, modifications, additions and improvements to the embodiments described above are possible. It is contemplated that these variations, modifications, additions and improvements fall within the scope of the invention as detailed within the following claims.