Page 49 - Wire Rope News & Sling Technology
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the second end of the ropes 3 is immovably fixed. Anchor-
         age 13 in the upper part of the shaft, the traction sheave   Join The  RevoluT ion
         7 and the diverting pulley 9 suspending the counterweight
         on the ropes are preferably so disposed in relation to each
         other that both the rope portion going from the anchorage 13
         to the counterweight 2 and the rope portion going from the
         counterweight 2 to the traction sheave 7 are substantially
         parallel to the path of the counterweight 2.
           Similarly, a solution is preferred in which anchorage 14 in
         the upper part of the shaft, the traction sheave 7, diverting
         pulley 15 and the diverting pulleys 4 suspending the eleva-
         tor car on the ropes are so disposed in relation to each other
         that the rope portion going from the anchorage  14 to the
         elevator car 1 and the rope portion going from the elevator
         car 1 via diverting pulley 15 to the traction sheave 7 are sub-
         stantially parallel to the path of the elevator car 1. With this
         arrangement, no additional diverting pulleys are needed to
         define the passage of the ropes in the shaft. The roping ar-
         rangement between the traction sheave 7 and the diverting
         pulley 15 is referred to as Double Wrap roping, wherein the
         hoisting ropes are wrapped around the traction sheave two
         and/or more times. In this way, the contact angle can be in-
         creased in two and/or more stages.
           For example, in the embodiment presented in figure 1, a
         contact angle of 180°+180°, i.e. 360° between the traction
                                                                 Do you want a
         sheave 7 and the hoisting ropes 3 is achieved. Double Wrap
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         Figure 2: Diagram representing a second traction sheave elevator.
         roping can be arranged in other ways, too, e.g. by placing the
         diverting pulley on the side of the traction sheave, in which
         case, as the hoisting ropes are passed twice around the trac-
         tion sheave, a contact angle of 180°+90°=270° is obtained,
         or by placing the diverting pulley at some other appropriate
         position. The rope suspension acts in a substantially centric      Manheim, PA/800•233•3010
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