Method and apparatus for adjusting steering angle for elevator sheave

Information

  • Patent Grant
  • 6591944
  • Patent Number
    6,591,944
  • Date Filed
    Tuesday, December 12, 2000
    23 years ago
  • Date Issued
    Tuesday, July 15, 2003
    21 years ago
Abstract
A steering angle of an elevator sheave on a shaft is adjusted at installation and subsequently during maintenance by one of several embodiments. In one embodiment, a bolt with a jam nut is adjusted to position the shaft precisely. In another embodiment, a tee bracket is anchored to a hoistway wall, and a jack bolt with shims is used to adjust the vertical placement of the long beams that support the elevator car frame and therefore the shaft.
Description




FIELD OF THE INVENTION




This invention pertains to the field of elevators, and in particular, to adjusting the steering angle of an elevator sheave during or after installation.




BACKGROUND OF THE INVENTION




When flat ropes or belts pass over a sheave or shaft, they tend to move (“track”) across the sheave or shaft under certain conditions: (1) if the belt is not almost perfectly perpendicular to the shaft, or (2) if the belt has non-uniform properties across its cross-section. For example, the sanding belt of a belt sander moves across the shaft during use, necessitating an adjustment of the shaft to ensure perpendicularity between the sanding belt and the shaft. Another example is a VCR, which has a tracking control for the same purpose. If the lateral movement of the belt across the shaft is too great, the belt can track off the shaft and become damaged, tangled, or cut in two.




With the advent of belt-powered machinery during the early industrial age, it was discovered that making the belt with a slightly curved cross-section and imparting a slight curve (crown) to the shaft reduced tracking and limited horizontal belt movement to a small area. Thus, a region of stability exists as long as the angle between the belt and the shaft are close to 90 degrees, even if exact perpendicularity is not maintained.




In the case of an elevator using coated steel belts (CSB) instead of wire ropes, the shaft must be installed within the region of stability, and must be capable of being adjusted as needed throughout the life of the elevator.




SUMMARY OF THE INVENTION




Briefly stated, a steering angle of an elevator sheave on a shaft is adjusted at installation and subsequently during maintenance by one of several embodiments. In one embodiment, a bolt with a jam nut is adjusted to position the shaft precisely. In another embodiment, a tee bracket is anchored to a hoistway wall, and a jack bolt with shims is used to adjust the vertical placement of the long beams that support the elevator car frame and therefore the shaft.




According to an embodiment of the invention, an apparatus for adjusting a steering angle of an elevator sheave on a shaft includes retaining means for retaining the shaft in an elevator car frame; vertical positioning means for adjusting a vertical position of the shaft; and horizontal positioning means for adjusting a horizontal position of the shaft; whereby an axial direction of the shaft is adjusted to be substantially perpendicular to a gravitational force acting on the elevator car frame.




According to an embodiment of the invention, an apparatus for adjusting a steering angle of an elevator sheave on a shaft includes a retainer retaining the shaft in a first frame; a flat rope reeved over the sheave, the flat rope having an entry direction with respect to the sheave and an exit direction with respect to the sheave; and a first positioning device for adjusting a position of the shaft with respect to the entry direction of the flat rope, whereby an axial direction of the shaft is adjusted to be substantially orthogonal to the entry direction.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

shows a first embodiment of the present invention.





FIG. 2

shows a second embodiment of the present invention.





FIG. 3

shows a modification of the second embodiment of the invention.





FIG. 4

shows a third embodiment of the present invention.





FIG. 5

shows a fourth embodiment of the present invention.





FIG. 6

shows a side view of a tee bracket and associated shims according to the fourth embodiment of the present invention.





FIG. 7

shows a top view of the tee bracket used in the fourth embodiment of the present invention.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT




Referring to

FIG. 1

, a plurality of CSB's (coated steel belts)


10


are reeved around a shaft


12


, or around a sheave (not shown) on shaft


12


. Either the sheave is conventionally supported on bearings on shaft


12


, or shaft


12


is conventionally supported via bearings in at least one non-rotating end cap


14


. Other means of support are known in the art. The direction of the force imposed on shaft


12


depends on the directions that CSB


10


runs with respect to shaft


12


. In the simplest case, the entering and leaving directions of CSB


10


are parallel and opposite to the force of gravity, i.e., the force is vertical. In other cases, CSB


10


has an entering direction and a leaving direction angled with respect to the force of gravity. Whatever the direction of the forces imposed on shaft


12


by CSB


10


, the steering angle of shaft


12


needs to be adjustable.




In general, there are two cases for adjusting the steering angle of shaft


12


. Either the adjustment support is on the same side of shaft


12


as the entering or leaving direction of CSB


10


or on the opposite side. When the adjustment support is on the same side of shaft


12


as the entering or leaving direction of CSB


10


, shims or a jack bolt can be used. When the adjustment support is on the opposite side of shaft


12


as the entering or leaving direction of CSB


10


, a through-bolt, U-bolt, or any structure that goes around shaft


12


and secures to a permanent support can be used. The following embodiments are therefore examples of these two cases.




End cap


14


fits through a hole (not shown) in a shaft mounting member


16


and through a hole


18


in a lever


20


. A first bolt


22


connecting lever


20


and shaft mounting member


16


provides a pivot point for lever


20


. A second bolt


26


connects lever


20


and shaft mounting member


16


via a slot


24


. A jack bolt


28


threads into a flange


30


off shaft mounting member


16


, with an end of jack bolt


28


pushing against lever


20


. Flange


30


is optionally integral with shaft mounting member


16


. Jack bolt


28


is preferably locked with a jam nut


32


. Lever


20


provides several specific advantages.




(a) It reduces friction during the adjustment where the belt wrap of CSB


10


is not 180 degrees.




(b) It provides mechanical advantage of force or displacement to permit fine tuning.




(c) It provides protection to the shaft end once in place since jack bolt


28


acts on lever


20


instead of shaft


12


.




(d) It provides flexibility in positioning jack bolt


28


with respect to shaft


12


, since one can put jack bolt


28


against shaft


12


, or move it closer to the pivot point, or make lever


20


longer and place jack bolt


28


further from the pivot point, which increases the leverage and allows for more fine tuning of the placement of shaft


12


.




(e) It permits adjustment when jack bolt


28


cannot act directly on shaft


12


since jack bolt


28


can operate directly on lever


20


instead.




To adjust the orientation of shaft


12


, jack bolt


28


is turned, thereby changing the vertical orientation of shaft


12


. Once the proper orientation is achieved, shaft


12


is secured by tightening bolts


22


and


26


and locked by jam nut


32


. An optional bolt


34


is used to secure shaft


12


against thrust loads. Instead of end cap


14


, bearings (not shown) could be mounted in hole


18


of lever


20


for shaft


12


. If adjustment is required in two directions, the adjustment apparatus for each direction can be located at the same end of shaft


12


or at opposite ends of shaft


12


.




Referring to

FIG. 2

, a bracket


36


is attached to shaft mounting member


16


. A bolt


38


passes through bracket


36


and end cap


14


. Two nuts


40


, one on each side of end cap


14


, are rotated to adjust the position of shaft


12


. Once properly positioned, a jam nut


42


secures shaft


12


with respect to bracket


36


.




Referring to

FIG. 3

, a bracket


48


is attached to a flange


50


of shaft mounting member


16


. Bolt


38


can thus be assembled through end cap


14


and then through bracket


48


, unlike the embodiment of

FIG. 2

where bolt


38


is assembled through bracket


36


and then through end cap


14


. Bolt


38


is secured to bracket


48


by nuts


44


,


45


. Nuts


40


are rotated to adjust the precise position of shaft


12


, after which shaft


12


is secured in place by a jam nut


46


.




Referring to

FIG. 4

, end cap


14


is held in place by a U-bolt


52


. An optional groove (not shown) can be cut in end cap


14


to fit U-bolt


52


. U-bolt


52


fits through a plate


54


which is attached to shaft mounting member


16


, where it is adjusted by a plurality of nuts


56


and secured in the loaded direction by a plurality of nuts


58


.




Referring to

FIG. 5

, at least one coated steel belt (not shown) reeves around a corresponding drive sheave


60


. Drive sheave


60


is part of a machine


62


, which is known to those skilled in the art as the motor and sheave assembly for an elevator. Machine


62


is mounted in a machine frame


64


, which in turn is supported within the elevator hoistway by at least one long beam


66


as shown in FIG.


5


. Additional support members, such as support member


67


shown in shadow, are optionally fastened between long beams


66


. One end


68


of long beam


66


sits in a pocket


70


of rear hoistway wall


72


on a sound isolation pad


74


, while another end


76


of long beam


66


sits in a pocket


78


of front hoistway wall


80


and a sound isolation pad


82


.




Referring also to

FIG. 6

, a tee bracket


84


sits in pocket


78


. Tee bracket


84


is anchored to front hoistway wall


80


by conventional means such as bolts


86


. A plurality of shims


88


are on top of tee bracket


84


and under sound isolation pad


82


. The system must be designed with a predetermined total shim height, thus allowing the system to be adjusted in both directions by removing or adding shims. When precisely positioning long beams


66


, shims


88


are removed or added as necessary. Shims


88


can be all the same thickness or of varying thicknesses preferably ranging from 1 mm to 8 mm thick. The range of the shim stack is preferably from no shims to 100 mm high.




Referring also to

FIG. 7

, a jack bolt


90


is threaded through a hole


92


in a top


94


of tee bracket


84


. Jack bolt


90


preferably abuts against support member, and turning jack bolt


90


raises end


76


of long beam


66


permitting a worker to insert or remove shims


88


as necessary. Horizontal positioning is accomplished by properly emplacing tee bracket


84


, while vertical positioning is accomplished via jack bolt


90


and shims


88


. Shims are preferably held in place by two shim retaining bolts


96


that are threaded through holes


98


in top


94


of tee bracket


84


. Two nuts


100


sized for jack bolt


90


are preferably welded over side holes in tee bracket


84


and are used to store jack bolt


90


after the adjustment of long beams


66


is made.




While the present invention has been described with reference to a particular preferred embodiment and the accompanying drawings, it will be understood by those skilled in the art that the invention is not limited to the preferred embodiment and that various modifications and the like could be made thereto without departing from the scope of the invention as defined in the following claims.



Claims
  • 1. Apparatus for adjusting a steering angle of an elevator sheave that is mounted upon a shaft, said apparatus including:means for retaining said shaft so that the shaft can be adjustably positioned in a first plane and in a second plane; a flat rope that is engaged by said sheave, said flat rope having a desired entry direction and a desired exit direction with respect to said sheave; a first positioning means for adjusting the position of said shaft in said first plane; and a second positioning means for adjusting the position of the said shaft in said second plane, whereby the flat rope is maintained in proper alignment as it passes over the sheave.
  • 2. The apparatus of claim 1 that further includes a frame that is connected to said means for retaining said shaft, said frame being mounted in a predetermined position within an elevator hoistway.
  • 3. The apparatus of claim 2 wherein said means for retaining said shaft includes at least one long beam that is connected to said frame;said first positioning means includes a tee bracket said tee bracket being adjustable mounted upon a wall of said hoistway for positioning the long beam in said first plane; and said second positioning means includes a jack bolt connected to the tee bracket for positioning said beam in said second plane.
  • 4. The apparatus of claim 3 wherein said second positioning means includes shim means that is insertable between the tee bracket and said long beam.
  • 5. The apparatus of claim 4 wherein said shim means further includes an isolation pad.
  • 6. The apparatus of claim 4 that further includes at least one shim retaining bolt for retaining a plurality of shims in assembly.
  • 7. The apparatus of claim 3 wherein said tee bracket further includes storage means for storing a jack bolt.
  • 8. The apparatus of claim 3 wherein a portion of said tee bracket is located within a pocket in said hoistway wall.
  • 9. The apparatus of claim 1 said first plane is substantially parallel to said second plane.
  • 10. The apparatus of claim 1 wherein said first and second positioning means are located at one end of said beam.
US Referenced Citations (3)
Number Name Date Kind
5358074 Ellsworth Oct 1994 A
5427581 McGrath et al. Jun 1995 A
5676613 Valcourt et al. Oct 1997 A
Foreign Referenced Citations (2)
Number Date Country
6255937 Sep 1994 JP
8702344 Apr 1987 WO