Abstract:
An improved energy tube-cable-router for securing flat cables and fluid carrying tubes and adapted to eliminate an undesirable pumping action of the fluid within the tubes by maintaining the longitudinal axis of tubes in a plane containing the central radius of curvature of tube-cable-router.

Description:
FIELD OF THE INVENTION 
     This present invention relates to a flexible router for simultaneously securing a number of liquid carrying tubes and electrical ribbon cables. 
     BACKGROUND OF THE INVENTION 
     Various types of analytical tests related to patient diagnosis and therapy can be performed by analysis of a liquid sample taken from a patient&#39;s infections, bodily fluids or abscesses. These assays are typically conducted with automated clinical analyzers onto which liquid patient samples have been loaded. The analyzer extracts liquid sample from a container and combines the sample with various reagents in special reaction cuvettes. Usually the sample-reagent solution is incubated or otherwise processed before being analyzed. Analytical measurements are performed using a beam of interrogating radiation interacting with the sample-reagent combination to generate absorption readings or the like. The readings allow determination of end-point or rate values from which an amount of analyte related to the health of the patient may be determined using well-known calibration techniques. 
     Within such analyzers, a large number of liquid sample and reagent aspiration/dispensing probes are usually employed in order to extract incoming sample from a container, dispense aliquot portions of said sample into an aliquot array, to aspirate aliquot samples from the array and dispense aliquot samples into a reaction cuvette, and/or to extract reaction reagents from a container and directly dispense aspirated reagents into a reaction cuvette. In addition, within such analyzers, a very large number of electrical cables are interconnected between the various electromechanical controlling and controlled devices. For space-saving reasons, a popular electrical cable is shaped like a flat ribbon and is formed of a number of electrical conductors covered by an insulator and placed side-by-side. Ribbon electrical cables are frequently utilized to direct electrical signals between stationary printed circuit boards and electromechanical devices that are translated horizontally and vertically for millions of cycles. In a typical static application a latch may be sufficient to retain the cable securely. However, in applications in which substantial and/or sustained movement is encountered like described, latches are usually found to be inadequate over periods of sustained use. Thus, a need exists for a retaining device which secures the cable firmly irrespective of substantial sustained movement. 
     In order to minimize impact upon patients as well as to decrease the costs of clinical assays, the volumes of liquid sample aliquots and reagents are increasingly made smaller, in the range of about 1 microliter to five microliters; therefore, the pumping systems associated with sample and reagent aspiration and dispensing probes must be capable of handling precise precisely known and controlled liquid volumes. Almost all sample and reagent aspiration/dispensing probes are mounted on translatable arms having both horizontal and vertical motion in order to translate probes between locations as well as to raise and lower probes into and out of containers. Consequently, a popular practice is to attach a probe to a pumping system using flexible tubing within a guide chain; furthermore, to reduce pumping volume uncertainties, the tubing is filled with an inert liquid, as opposed to air, between the pumping system and the probe. The tube is also generally secured on and between stationary and/or moving parts using a guide with circular dimensions. To run such tubes, in particular from a stationary junction point to a movable device like a dispensing probe, it is common to use so-called line guide elements which are interconnected to form an energy conducting guide chain, like those available from Igus GMBH (KoIn, Germany). 
     For example, U.S. Pat. No. 6,745,555 discloses an energy guiding chain, in which the articulated joints include joint elements that are elastically deformable in the bending direction of the chain links and designed as separate components, where the joint elements extend partially between the inside and outside lateral surfaces of the straps. 
     U.S. Pat. No. 6,550,233 discloses an energy guiding chain having a plurality of plastic chain links that are connected to one another, each of which includes two side straps and two cross-members, where the cross-members are connected to the side straps in detachable fashion. A snap mechanism is provided which interacts with a snap ridge provided on each end of the cross-members. 
     U.S. Pat. No. 6,170,249 discloses an energy guiding chain for accommodating cables and hoses. The chain has laterally spaced parallel side-plates with upper and lower cross-members. A cross-sectional space for cables and hoses is defined by the side-plates and the upper and lower edges of the side-plates. The cross-sectional space is expanded since at least one of the cross-members is detachably mounted on the side-plates. 
     U.S. Pat. No. 5,980,409 discloses an energy transmission chain with high lateral stability, particularly when installed in a lateral position. 
     While these energy guiding chains are quite useful in handling cables and hoses, it t has been discovered, however, that the tubing must be precisely placed and maintained along the central radius of curvature of such a guide in order to prevent a “peristaltic-type” pumping action of the fluid within the tube as the curved section of tubing moves. If the tubing falls to the inside of the guide, the tubing is slightly compressed; likewise, if the tubing falls to the outside of the guide, the tubing is slightly stretched. Both actions cause a change of volume of fluid inside the curved portion and a pumping action is created as the probe is translated between aspirate and dispense locations and the tubing is moved in opposite directions along a circular guide. This false pumping is in addition to the controlled pumping, thereby adversely affecting the accuracy of the aspirated or dispensed sample/reagent liquid. 
     SUMMARY OF THE INVENTION 
     The present invention meets the combined needs for securing flat cables and fluid carrying tubes and adapted to eliminate an undesirable pumping action of the fluid within the tubes by providing a number of multiple tube-cable links adapted to simultaneously secure a flat ribbon electrical cable and a number of fluid tubes, the fluid tubes being constrained to be translated in a linear plane, the tube-cable links flexibly joined to one another forming a flexible energy tube-cable-router, in combination with a pair of mounting brackets at both ends of a said tube-cable-router, one mounting bracket suitable for mounting proximate a stable electrical power and control source, the other mounting bracket located proximate a moveable liquid aspiration/dispensing probe. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be more fully understood from the following detailed description thereof taken in connection with the accompanying drawings which form a part of this application and in which: 
         FIG. 1  is a perspective view of a flexible tube-cable-router exemplary of the present invention; 
         FIG. 2  is an exploded view of the tube-cable-router of  FIG. 1 ; 
         FIG. 3  is a perspective view of a first mounting bracket adapted to retain a first end of the tube-cable-router of  FIG. 1 ; 
         FIG. 3A  is a front elevation view of the mounting bracket of  FIG. 3 ; 
         FIG. 3B  is a top plan view of the mounting bracket of  FIG. 3 ; 
         FIG. 3C  is a side elevation view of the mounting bracket of  FIG. 3 ; 
         FIG. 4  is a perspective view of a link adapted to simultaneously retain a number of tubes as well as a flat electrical cable and adapted to mate with the mounting bracket of  FIG. 3 ; 
         FIG. 4A  is a front elevation view of the link of  FIG. 3 ; 
         FIG. 4B  is a bottom plan view of the link of  FIG. 3 ; 
         FIG. 4C  is a side elevation view of the link of  FIG. 3 ; 
         FIG. 5  is a perspective view of a second mounting bracket adapted to retain a second end of the tube-cable-router of  FIG. 1 ; 
         FIG. 5A  is a front elevation view of the mounting bracket of  FIG. 4 ; 
         FIG. 5B  is a top plan view of the mounting bracket of  FIG. 4 ; 
         FIG. 5C  is a side elevation view of the mounting bracket of  FIG. 4 ; and, 
         FIG. 6  is an illustration of tubes carried with their longitudinal axes maintained in a plane containing the central radius of curvature of the tube-cable-router of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  is a perspective assembly view of the flexible tube-cable-router  10  of the present invention constructed by assembling together an articulated number of individual dual-end link members  12  to form a two-ended chain of link members  12 . A first end mounting bracket terminator  14  is attached to one end of the chain of link members  12  and a second end mounting bracket terminator  16  is attached to the remaining end of the chain of link members  12 . 
       FIG. 2  is a exploded perspective view of the flexible tube-cable-router  10  of  FIG. 1  and illustrates how the two-ended chain of link members  12  is assembled by successively placing link hinge pins  18  into link hinge openings  20  and also placing terminator hinge pins  22  of first end mounting bracket terminator  14  into link hinge openings  20  as well as placing link hinge pins  18  into terminator hinge openings  24  of second end mounting bracket terminator  16 . Tube-cable-router  10  is provided with a number of unique features described hereinafter in order to facilitate assembly and secure clamping of a number of fluid tubes  78  (seen in  FIG. 6 ) and a flat ribbon electrical cable  80  (seen in  FIG. 6 ). 
       FIG. 3  is a left front perspective view of the second end mounting bracket terminator  16  of  FIG. 1  and illustrates a first pair of parallel open side tube grooves  26  formed in a second groove plane ( 26 P) in a base member  28  and having axis  26 A essentially parallel to the longitudinal direction of travel of flexible tube-cable-router  10  in order to carry a pair of liquid tubes  78  (in broken lines) therein. Similarly, a second pair of parallel open side tube grooves  30  (best seen in  FIG. 3A ) is also formed in the second groove plane ( 26 P) in a shoulder member  32  and having axis  30 A essentially parallel to the longitudinal direction of travel of flexible tube-cable-router  10  in order to carry another pair of liquid tubes  78  therein, shoulder member  32  flaring outwardly from base member  28  to simultaneously secure a flat ribbon electrical cable and a number of fluid tubes. 
     A cable platform  34  is integrally superposed over base member  28  and comprises a transverse opening  36  defined by the upper surface  29  of base member  28  and the lower surface  37  of a flexible clasp  38  attached only at one end  39  to base member upper surface  29 .  FIG. 3A  shows how the transverse opening  36  is dimensioned to accept a flat ribbon cable  80  (shown in dashed lines) between base member upper surface  29  and flexible clasp  38 . For purposes of convenience in placing a flat ribbon cable within transverse opening  36 , the unattached end  41  of flexible clasp  38  is formed as a obliquely angled upwards step  42 . Best seen in  FIG. 3C , a terminator tab member  44  extends laterally from each shoulder member  32  a distance beyond base member  28  and terminator hinge openings  24  of second end mounting bracket terminator  16  are formed therein. Upper surface  29  of base member  28  is seen in  FIG. 3B  as openly exposed between shoulder members  32  with a pair of mounting holes  45  formed therein and inline with the longitudinal direction of travel of flexible tube-cable-router  10  in order to allow securing flexible tube-cable-router  10  to an appropriate surface. 
       FIG. 4  is a left perspective view of the link member  12  of  FIG. 1 , each link member  12  having two parallel tab elements  46  extending in one direction from a rectangular shaped link base cross-member  47  (best seen in  FIG. 4B ) having two parallel tongue elements  48  extending in an opposite direction from the cross-member. As illustrated, link hinge openings  24  are formed in recessed portions  46 R of tab elements  46  and transverse, cylindrical link hinge pins  18  are outwardly formed on tongue elements  48 . The side elements of assembled next adjacent link members  12  have overlapping sections and are joined by engaging the cylindrical hinge pins  18  of one link member  12  into the hinge openings  24  of a next adjacent link member  12  to pivot or rotate within a pivoting plane formed perpendicular to the central axis  18 A of hinge pins  18  and the central axis  24 A of hinge openings  24  ( FIGS. 4B and 4C ). The diametrical dimensions of hinge pins  18  and hinge openings  24  are chosen to have as little clearance as possible therebetween so that an assembly of interconnected link members  12  has high lateral stability. 
     Link base cross-member  47  comprises a cut-away central portion  47 C (best seen in  FIG. 4B ) with two open top parallel tube grooves  50  formed essentially parallel to the longitudinal direction of travel of flexible tube-cable-router  10  in order to carry a pair of liquid tubes therein. Similarly, base cross-member  47  comprises outwardly opposed flange portions  47 F with two open side parallel tube grooves  52  formed essentially parallel to the longitudinal direction of travel of flexible tube-cable-router  10  in order to carry a pair of liquid tubes therein.  FIG. 4A  shows parallel tube grooves  50  and  52  as having their longitudinal axis  50 A and  52 A, respectively in a groove plane  52 P perpendicular to the pivoting plane PP ( FIG. 4B ). Because the flexible tube-cable-router  10  of the present invention is formed by assembling together an articulated number of individual dual-end links  12  with high lateral stability, the longitudinal axis of tubes carried by flexible tube-cable-router  10  are constantly maintained in a plane perpendicular to the groove plane and containing the central radius of curvature of tube-cable-router  10 . Because the longitudinal axis of tubes  78  carried by flexible tube-cable-router  10  are maintained in a plane containing the central radius of curvature of tube-cable-router  10 , “peristaltic-type” pumping action of fluid carried within such tubes is minimized as the curved section of tubes is moved in the direction of travel of tube-cable-router  10 . The elimination of peristaltic pumping, in combination with carrying flat ribbon cable  80  next described, is a key feature of the present invention. 
     A link cable platform  54  is integrally superposed over link base cross-member  47  and comprising a transverse opening  56  defined by the upper surface  55  of link base cross-member  47  and the lower surface  59  of a flexible clasp  60  attached only at one end  61  to link base cross-member upper surface  55 .  FIG. 4A  shows how the transverse opening  56  is formed as a cross-sectional opening to accommodate a flat ribbon cable  80  (shown in dashed lines) between link base cross-member  47  and flexible clasp  58 . For purposes of convenience in placing a flat ribbon cable  80  within transverse opening  56 , the unattached end  63  of flexible clasp  58  is formed as a obliquely angled upwards step  62 . Best seen in  FIG. 4C , tab elements  46 , having link hinge openings  24  formed in recessed portions  46 R thereof, extend laterally in one direction from rectangular shaped link base cross-member  47  and tongue elements  48 , having link hinge pins  18  are outwardly formed thereon, extend in an opposite direction from the cross-member. The lower surface  47 L of link base cross-member  47  is seen in  FIG. 4B  as openly exposed between flange portions  47 F with a pair of open bottom parallel tube grooves  50  formed essentially parallel to the longitudinal direction of travel of flexible tube-cable-router  10  in order to carry a pair of liquid tubes  78  therein. 
       FIG. 5  is a left front perspective view of the first end mounting bracket terminator  14  of  FIG. 1  and illustrates a first pair of parallel open side tube grooves  66  formed in a central region  68 C of a tube tower  68  and essentially parallel to the longitudinal direction of travel of flexible tube-cable-router  10  in order to carry a pair of liquid tubes therein. Similarly, a second pair of parallel open side tube grooves  70  (also seen in  FIG. 5A ) is formed in end regions  68 E of tube tower  68  and essentially parallel to the longitudinal direction of travel of flexible tube-cable-router  10  in order to carry a pair of liquid tubes  78  therein. The tube tower  68  is flexibly hinged at only one side to a vertical side wall  71  extending upwards from a mounting bracket terminator base  72 , being superposed thereover. An upwardly extending opposing sidewall  73  of mounting bracket terminator base  72  has an inclined upper surface  73 S (seen in  FIG. 5A ) so that a transverse cross-sectional opening  77  is created between upper surface  73 S and tube tower  68 , enabling accommodation of a flat ribbon cable  80  (shown as dashed lines in  FIG. 5A ) between tube tower  68  and mounting bracket terminator base  72 . As seen in  FIG. 5B , first end mounting bracket terminator  14  comprises a frontward extending flare portion  72 F and tab elements  74  extending in an opposite direction from the frontward extending flare portion  72 F, tab elements  74  having link hinge pins  76  formed outwardly thereon. A mounting hole  72 H is formed in flare portion  72 F to allow securing assembled flexible tube-cable-router  10  to an appropriate surface. 
     Cable-router  10  is illustrated in  FIG. 6  as carrying one pair of liquid tubes  78  within the first pair of parallel open side tube grooves  26  formed in a base member  28  of mounting bracket terminator  16  and essentially parallel to the longitudinal direction of travel of flexible tube-cable-router  10  in addition to carrying another pair of tubes  78  within the second pair of parallel open side tube grooves  26  of mounting bracket terminator  16  of essentially parallel to the longitudinal direction of travel of flexible tube-cable-router  10 .  FIG. 6  also shows parallel tube grooves  50  and  52  of link member  12  as having their longitudinal axis  50 A and  52 A, respectively in a groove plane perpendicular to the pivoting plane so that the longitudinal axis of tubes  78  are constantly maintained in a plane perpendicular to the groove plane and containing the central radius of curvature of tube-cable-router  10 . In addition,  FIG. 6  illustrates bracket terminator  14  as carrying one pair of tubes  78  within the first pair of parallel open side tube grooves  66  and carrying another pair of tubes  78  within the second pair of parallel open side tube grooves  70 , both essentially parallel to the longitudinal direction of travel of flexible tube-cable-router  10 . As mentioned before, a key feature of the present invention is maintaining the longitudinal axis of tubes  78  in a plane containing the central radius of curvature of tube-cable-router  10  so that “peristaltic-type” pumping action of fluid carried within such tubes  78  is minimized as the curved section of tubes  78  is moved in the direction of travel of tube-cable-router  10 . 
     Cable-router  10  is further illustrated in  FIG. 6  as carrying a single flat ribbon cable  80  within the transverse opening  36  defined by the upper surface  29  of base member  28  and the lower surface  37  of the flexible clasp  38  of the second end mounting bracket terminator  16 . The illustration of a single cable  80  is not intended to be limiting, as is obvious to an artesian, more than one such ribbon cable  80  may be carried within the transverse opening  36  with simple adjustments of the dimensions of upper surface  29  and lower surface  37  of clasp  38 . In addition,  FIG. 6  illustrates bracket terminator  14  as carrying flat ribbon cable  80  within the transverse opening  77  defined by between tube tower  68  and mounting bracket terminator base  72  of bracket terminator  14 . Finally,  FIG. 6  illustrates cable-router  10  as carrying flat ribbon cable  80  within transverse opening  56  defined by the upper surface  55  of link base cross-member  47  and the lower surface  59  of clasp  60  attached only at one end  61  to link base cross-member upper surface  55  of link member  12 . 
     Cable-router  10  may be molded from any of a number of thermoplastic resin materials, including polyolefins, low density polyethylene, high impact polystyrene and polycarbonate. Clamp  10  can also be comprised of a combination of such resins. Preferably however, because of the necessity for precise dimensioning, an engineering plastic like acrylonitrile butadiene styrene, ABS, a copolymer of acrylonitrile, butadiene, and styrene may be advantageously employed. ABS plastics generally possess medium strength and performance and medium cost and are often used as the cost and performance dividing line between standard plastics (PVC, polyethylene, polystyrene, etc.) and engineering plastics (acrylic, nylon, acetal, etc.). 
     It should be readily appreciated by those persons skilled in the art that the present invention is susceptible of a broad utility and application. Many embodiments and adaptations of the present invention other than those herein described, as well as many variations, modifications and equivalent arrangements will be apparent from or reasonably suggested by the present invention and the foregoing description thereof, without departing from the substance or scope of the present invention. For example, the dimensions of transverse opening  36  can be adjusted to accommodate more than one ribbon cable  80 . Accordingly, while the present invention has been described herein in detail in relation to specific embodiments, it is to be understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for purposes of providing a full and enabling disclosure of the invention. The foregoing disclosure is not intended or to be construed to limit the present invention or otherwise to exclude any such other embodiments, adaptations, variations, modifications and equivalent arrangements, the present invention being limited only by the claims appended hereto and the equivalents thereof.