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continued from previous page                         23 may include an eye (not shown in FIG. 1) or other closed
         12 through the end of the support rod 31 to the cable 16 (and   guide such that tension on the lower stay cable 21 will be
         thus to the helicopter or other device). The mast 12 may thus   directly applied to the upper stay cable 20.
         be held in a near vertical orientation by the tension on the
         cable 16 during assembly of the mast system 10. After assem-  Dynamic tension control  apparatus  and method for
         bly of the mast system 10 is substantially completed so as to   aero-mechanical conveyor
         laterally support the mast 12, as will be explained further be-  Pat. 7,798,313  U.S. class 198/814  Int. class B65G 23/44
         low, the helicopter (not shown) or other device may extend the   Inventor: David Francis Hesketh, Fort Mill, SC.
         cable 16. When the mast 12 is supported laterally, extending   Assignee: Spiroflow Systems, Inc., Monroe, NC.
         the cable 16 will cause it to slide down the support rod 31 so   This patent presents a tensioning assembly for use in an
         as to enable its removal from the bottom of the support rod 31.   aero-mechanical conveyor for moving bulk materials. The
         The helicopter (not shown) or other device may then retract   conveyor includes  upper and lower housings  having head
         the cable 16 and leave the mast system 10 assembly location.  and tail pulley assemblies mounted therein. The tensioning
           Referring  to  figure  4,  the  upper  tensioning  arms  22  and   assembly includes first and second extendable tubes that de-
         lower tensioning arms 23 are shown in their retracted posi-  fine sections of inflow and outflow conveyor tubes that inter-
                                                              connect the upper and lower housings. An endless rope as-
                                                              sembly is disposed within the conveyor tubes and around the
                                                              head and tail pulleys. An adjustable actuator is positioned
                                                              in cooperative engagement with the first and second extend-
                                                              able tubes. When the actuator is in a first position, the ex-
                                                              tendable  tubes  have  a  first  length  and  when  the  actuator
                                                              is in a second position, the extendable tubes have a second
                                                              length. The actuator is configured to move between the first
                                                              position and the second position in response to changes in
                                                              tension within the endless rope assembly as indicated by a
                                                              signal from a tension measuring device.
                                                               Referring now specifically to the drawings, an aero-mechan-
                                                              ical conveyor according to the present invention is illustrated
                                                              in figure 6 and shown generally at reference numeral 10. The
                                                              conveyor 10 includes an upper housing 12 and an infeed hous-
         Figure 5: Detailed view of an example device to releasably couple a   ing 14 that are interconnected by inflow and outflow conveyor
         stay cable to an anchor and to apply tension to the stay cable.  tubes 16 and 18. A head pulley assembly 32 that includes a
                                                              sprocket is mounted on an upper shaft 34 that is positioned
         tions, that is, with the free ends moved laterally proximate   in the upper housing 12. Upper shaft 34 extends through one
         the mast 12. Each of the upper tensioning arms 22 can be   side of the upper housing 12 perpendicularly to the plane upon
         urged into its retracted position, as shown, by means of a tor-  which rope assembly 40 travels. The upper shaft 34 is carried
         sion spring 27 disposed around each pivot 24 and configured   by and extends through bearing housings (not shown). The
         to rotate the free end of each corresponding upper tension-  upper housing 12 includes a top portion 20 that is removably
         ing arm 22 toward the mast 12. Correspondingly, each lower
         tensioning arm 23 may be urged into its laterally retracted
         position by an associated torsion spring 29. As the lower ten-
         sioning arms 25 are pulled away from the mast 12 by the us-
         ers pulling on the lower stay cables 21 and engaging the quick
         connects, the torsion springs 27, 29 provide tension on both
         the lower stay cables and on the upper stay cables 20. Ten-
         sion thus maintained on the upper stay cables 20 provides the
         combined structure of mast 12 and upper stay cables 20 with
         substantial resistance to lateral deflection such as by wind
         or the weight of any equipment installed near the top of the
         mast 12, including the antenna element.
           Figure 5 shows a more detailed view of the quick connect
         35 coupled to the anchor eye 34. The quick connect 35 may
         include two, spring loaded levers 35A, 35B which are ordi-
         narily urged such  that the distal ends overlap,  forming a
         closed loop. When a user depresses the two open ends of the
         levers 35A, 35B together, the loop opens, enabling the loop
         to be removed from (or affixed to) the eye 34. The tensioner
         may be a wire “come-along” of any type known in the art.
           In  other  examples, the  tensioning  arms  22,  23  may be
         fixedly coupled to the mast so as to extend laterally perpen-
         dicularly outward from the longitudinal axis of the mast,
         substantially as shown in figure 1. In such implementations,
         the lower stay cable  21 and the upper stay cable  20 may
         each be formed from single length of wire rope or the like,
         and fixedly attached to the outer end of one of upper ten-  Figure 6: Cut-away side elevation of a tension control in use on an
         sioning arms. The outer end of each lower tensioning arm   aero-mechanical conveyor.

         58     Wire Rope News & Sling Technology   August 2017
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