Patent Publication Number: US-6712183-B2

Title: Traction elevator

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a traction elevator having a compensating rope guide, and more particularly to a traction elevator that can reduce the swing of the compensating rope so as to stop the emission of unpleasant noise and vibration of an elevator car, and thus increase the comfort of the ride in the car. 
     2. Description of the Related Art 
     FIG.  11 ( a ) is a side view of an ordinary type of widely used traction elevator. In the traction elevator, three ropes  3  (only one is shown) are attached at a first end thereof to a top of a the car  1 , and at a second end thereof to a top of a counterweight  2 . The ropes  3  are guided by a deflector sheave  6   a  and a sheave  6  driven by a motor in a machine room  5  located over an elevator shaft  4 . Friction between the ropes  3  and sheave  6  raises and lowers the car  1  in order to carry passengers and freight. 
     However, in a traction elevator operating in a very tall shaft, if there is an imbalance of weight between a portion of ropes  3  on the car  1  side of sheave  6  and a portion of the ropes  3  on the counterweight  2  side of sheave  6 , the ropes  3  might slip on the sheave  6 . Therefore, in the traction elevator operating in a tall shaft, as shown in FIG.  11 ( b ), a compensating rope  7  is usually attached at a first end thereof to the bottom of the car  1 , and at a second end thereof to the bottom of the counterweight  2 . 
     Then, this kind of the compensating rope  7  can be roughly classified into three types. 
     First, as shown in FIG.  12 ( b ), a wire rope  10  such as the rope  3  is used as the compensating rope  7 . Second, as shown in FIG.  12 ( c ), a chain  8  made of steel is in use as the compensating rope  7 . Third, as shown in FIG.  12 ( a ), a coated chain  13  composed of the chain  8  covered with coating  9  such as resin is also used as the compensating rope  7 . 
     In the following description, the wire rope  10 , the chain  8  and the coated chain  13  are referred to generically as the compensating rope  7 . 
     As shown in FIG.  12 ( b ), the wire rope  10  is generally used in a high-speed elevator, and a tension pulley  11  is usually attached at the curving portion of the wire rope  10  to tension the wire rope  10 . Accordingly, the tension pulley  11  lowers the vibration of the wire rope  10  and puts the wire rope  10  in orbit. 
     The chain  8  is usually used in a relatively low-speed elevator. As shown in FIG.  12 ( c ), this type of the chain  8  can omit the tension pulley  11  attached at the curving portion of the wire rope  10  in FIG.  12 ( b ), and thus reduce the cost of equipment, because the chain  8  does not swing as easily as the wire rope  10  when hanging with the tension of its own weight. 
     However, if the chain  8  is used in a high-speed elevator, the chain  8  makes noise and swings more than the wire rope  10  in a condition of hanging with the tension of the weight of the tension pulley  11  in FIG.  12 ( b ). Although the chain  8  does not swing as easily as the wire rope  10  when hanging with the tension of its own weight, the chain  8  is not available in the high-speed elevator. 
     In recent years, the coated chain  13  compromising the wire rope  10  and the chain  8  has been adopted. 
     As shown in FIG.  12 ( d ), the coated chain  13  includes the chain  8  covered with the coating  9  that reduces noise. Further, guides composed of small rollers  14  are arranged above the curving portion of the coated chain  13  in order to reduce the swing of the coated chain  13 . Therefore, the coated chain  13  can be adopted for a high-speed elevator. 
     However, as shown in FIG. 13, when a building with an elevator sways due to a sudden gust of wind or an earthquake, the coated chain  13  swings and then seems to shift over the rollers  14  at the downward side of the guides. On the other hand, at the upward side of the guides, the coated chain  13  is pulled by the car  1  or the counterweight  2  and goes up as it is. Accordingly, the coated chain  13  is strongly pressed against the rollers  14  and an angle bracket (not shown) supporting the rollers  14  at an acute angle, and then the coated chain  13  emits unpleasant noise due to resistance between the coated chain  13  and the rollers  14 . Further, since the coated chain  13  is caught in a corner of the rollers  14 , a rotation of the rollers  14  becomes difficult. As a result, the car  1  begins to vibrate, and the vibration may negatively influence the comfort of the ride in the car  1 . 
     SUMMARY OF THE INVENTION 
     Accordingly, one object of this invention is to provide a traction elevator having a compensating rope guide which can reduce the swing of a compensating rope so as to stop the emission of unpleasant noise and vibration of an elevator car, and thus avoid negatively influencing the comfort of the ride in the car. 
     The object of this invention can be achieved by providing an elevator having a rope connected at the first end thereof to the top of a car and at the second end thereof to the top of a counterweight, and guided and driven by a sheave which is rotated by a motor, composed of a compensating rope suspended from the car to the counterweight, the compensating rope having a curving portion, a first linear portion on the car side of the curving portion and a second linear portion on the counterweight side of the curving portion for compensating an imbalance of weight between a portion of the rope on the car side of the sheave and a portion of the rope on the counterweight side of the sheave. A first guide is arranged to guide the first linear portion and the second linear portion. A second guide is arranged below the first guide and positioned between the extended lines of the first linear portion of the compensating rope and the second linear portion of the compensating rope for guiding the curving portion of the compensating rope. A frame is arranged in the pit of an elevator shaft for supporting the first guide and the second guide. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein: 
     FIG.  1 ( a ) is a side view showing a shaft of a traction elevator having a compensating rope guide of a first embodiment of the present invention; 
     FIG.  1 ( b ) is a top view taken along line A—A in FIG.  1 ( a ); 
     FIG. 2 is a side view of first guide and second guide of the first embodiment; 
     FIG. 3 is a plan view of rotatable member of the first embodiment; 
     FIG. 4 is a side view of a compensating rope guide of a second embodiment of the present invention; 
     FIG. 5 is an illustrative diagram showing an example of the operation of compensating rope in FIG. 4; 
     FIG. 6 is a side view of a rotatable member of compensating rope guide of a second embodiment of the present invention; 
     FIG. 7 is a side view of a compensating rope guide of a third embodiment of the present invention; 
     FIG. 8 is a side view of a compensating rope guide of a fourth embodiment of the present invention; 
     FIG. 9 is a side view of a rotatable member of compensating rope guide of a fifth embodiment of the present invention; 
     FIG.  10 ( a ) is a plan view of a rotatable member of a compensating rope guide of a sixth embodiment of the present invention; 
     FIG.  10 ( b ) is a cross-sectional view of the rotatable member in FIG.  10 ( a ); 
     FIGS.  11 ( a ) and  11 ( b ) are side views of ordinary types of traction elevators which have been widely used; 
     FIGS.  12 ( a ),  12 ( b ),  12 ( c ) and  12 ( d ) show various compensating rope designs; and 
     FIG. 13 is an illustrative diagram showing an example of the operation of compensating rope. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, the embodiments of the present invention are described below. 
     FIG.  1 ( a ) is a side view showing the construction of a shaft of a traction elevator having a compensating rope guide of a first embodiment of the present invention. FIG.  1 ( b ) is a view in the direction of an arrow A—A in FIG.  1 ( a ). 
     As shown in FIGS.  1 ( a ) and  1 ( b ), in this embodiment, three ropes  3  (only one is shown) are attached at a first end thereof to a top of a the car  1  and at a second end thereof to a top of a counterweight  2 . The ropes  3  are guided by a deflector sheave  6   a  and a sheave  6  driven by a motor in a machine room  5  located over an elevator shaft  4 . Two compensating ropes  35  are suspended from the car  1  to the counterweight  2 . Each of the compensating ropes  35  has a curving portion  30 , a first linear portion  31  on the car  1  side of the curving portion  30  and a second linear portion  32  on the counterweight  2  side of the curving portion  30  for compensating an imbalance of weight between the portion of the ropes  3  on the car  1  side of the sheave  6  and the portion of the ropes  3  on the counterweight side of the sheave  6 . A first guide  33  is arranged in a pit  12  located below the lowest floor for guiding the first linear portions  31  and the second linear portions  32  in the pit  12 . A second guide  34  is arranged below the first guide  33  and positioned between the extended lines of the first linear portions  31  of the compensating ropes  35  and the second linear portions  32  of the compensating ropes  35  for guiding the curving portions  30  of the compensating ropes  35 . The compensating ropes  35  such as the coated chain  13  in FIG.  12 ( d ) are guided by the first guide  33  and the second guide  34 . 
     The first guide  33  and the second guide  34  are supported by a frame  19  fixed to a pair of car guide rails  17  for guiding the car  1  and a pair of counterweight guide rails  18  for guiding the counterweight  2 . The frame  19  is composed of brackets  19   a ,  19   b ,  19   c  and  19   d . Further, the first guide  33  is composed of four rotatable members  15  so that the compensating ropes  35  are directed in the moving directions of the compensating ropes  35 . Furthermore, the second guide  34  is composed of two bars  16 . 
     FIG. 2 is a side view of the first guide  33  and the second guide  34  of the first embodiment shown in FIG.  1 . FIG. 3 is a plan view of one of the rotatable members  15  of the first embodiment. 
     As shown in FIG.  2  and FIG. 3, each of the rotatable members  15  is composed of four cylindrical rollers  20  supported by an angle bracket  21  and fixed to the bracket  19   b . The bars  16  are fixed to the bracket  19   d  with U-shaped bolts  24  and nuts  22 . 
     Each surface of cylindrical rollers  20  is composed of a low friction member having low frictional property against a surface of the compensating ropes  35 . Urethane rubber, Bakelite, Aluminum alloy and Nylon are appropriate for the low friction member, and Polyethylene is also available. 
     According to this traction elevator, the first guide  33  guides the first linear portions  31  and the second linear portions  32  of the compensating ropes  35  and the second guide  34  guides the curving portions  30  of the compensating ropes  35 . Accordingly, even if the compensating ropes  35  swing and seem to shift over the first guide  33 , the second guide  34  prevents the compensating ropes  35  from moving over the first guide  33 . As a result, there is no possibility of the compensating ropes  35  swaying seriously, and the comfort of the ride in the car  1  is not influenced. Further, this traction elevator stops the emission of unpleasant noise and vibration of the car  1  and provides a pleasant environment for residents and passengers. 
     Furthermore, since the surfaces of the cylindrical rollers  20  are composed of low friction member having low frictional properties against the surfaces of the compensating ropes  35 , the compensating ropes  35  are not caught in any of the corners  36  of the cylindrical rollers  20 . 
     FIG. 4 is a side view of the compensating rope guide of a second embodiment of the present invention. In the following description, only components different from components explained in the first embodiment are described. In this embodiment, the first guide  33  and the second guide  34  in the first embodiment are modified. The rotatable member  15  in FIG. 2 is substituted by a rotatable member  40 . The first guide is composed of four rotatable members  40  shown in FIG.  6 . Each of rotatable member  40  is composed of four cylindrical rollers  20  supported by the angle bracket  21  like the rotatable member  15  in FIG.  3 . Each cylindrical roller  20  forms one side of a quadrilateral, and the two facing pairs of the cylindrical rollers  20  mutually intersect. One facing pair of the cylindrical rollers  20  is located above the other. The second guide  34  is composed of two second rotatable members  37  fixed to the bracket  19   d  so that the compensating ropes  35  are directed in the direction in which they are moving. Each of the second rotatable members  37  consists of the bar  16  and a cylindrical cover  38  rotatably covering a surface of the bar  16 . 
     The second rotatable members  37  are arranged to contact and guide the compensating ropes  35  when the compensating ropes  35  swing by a predetermined distance from their stationary position. 
     According to this embodiment, since the two pair of cylindrical rollers  20  which mutually intersect are placed one above the other, if the compensating ropes  35  hit a corner of the cylindrical rollers  20 , the compensating ropes  35  are not caught in the corner. As a result, the rotation of the cylindrical rollers  20  does not become difficult and the compensating ropes  35  do not negatively influence the comfort of the ride in the car  1 . 
     Further, since the second guide  34  is composed of the second rotatable members  37  so that the compensating ropes  35  are directed in the direction in which they are moving, when a building sways due to a sudden gust of wind or an earthquake and the compensating ropes  35  contact the second rotatable members  37 , the second rotatable members  37  rotate so as to attenuate the friction between the second guide  34  and the compensating ropes  35  and to prevent the compensating ropes  35  from being damaged. Further, since the second rotatable members  37  are arranged to contact and guide the compensating ropes  35  when the compensating ropes  35  swing by a predetermined distance, the compensating ropes  35  do not contact the second rotatable members  37  in normal operation, except that the compensating ropes  35  swing a large distance due to a sudden gust of wind or an earthquake. Consequently, in normal operation, no unpleasant noise is caused by interference between the compensating ropes  35  and the second rotatable members  37 . Further, as shown in FIG. 5, even if the compensating ropes  35  seem to get over the first guide  33  due to a big swing, the second guide  34  restricts that motion of the compensating ropes  35  and prevent the compensating ropes  35  from being pressed against the angle bracket  21  of the first guide  33  at acute angle and from being damaged. 
     FIG. 7 is a side view of a compensating rope guide of a third embodiment. In the following description, only components different from the components explained in the first embodiment are described. 
     In this embodiment, bars  23  are substituted for the rotatable members  15  in FIG.  2 . The bars  23  are respectively arranged at the wall  41  sides of the elevator shaft  4  on either side of the compensating ropes  35  and fixed to brackets  19   b  with U-shaped bolts  24  and nuts. 
     According to this embodiment, since the first guide  33  is composed of the bars  23  respectively arranged at the wall  41  sides of the elevator shaft  4  on either side of the compensating ropes  35  and the second guide  34  is composed of the bars  16 , the bars  23  restrict the swing of the compensating ropes  35  and the bars  16  prevent the compensating ropes  35  from getting over the bars  23  of the first guide  33 . As a result, the compensating ropes  35  do not swing by a large distance and have no influence on the comfort of the ride in the car  1 . Further, this embodiment reduces the cost of the compensating rope guide and provides an inexpensive elevator. 
     FIG. 8 is a side view of a compensating rope guide of a fifth embodiment of the present invention. In the following description, only components different from the components explained in the first embodiment are described. 
     The rotatable member  40  in the third embodiment shown in FIG. 6 is applied to the rotatable member  15  in FIG.  2 . In the fifth embodiment, the second guide  34  in FIG. 2 is omitted and two bell-shaped guides  25  are attached to both the upper and lower sides of the rotatable member  40  of the first guide  33  guiding linear portions of the compensating ropes  35 . The bell-shaped guides  25  are fixed to the rotatable member  40  with support member  26 . 
     According to this embodiment, the bell-shaped guides  25  keep the orbit of the compensating ropes  35  secure and prevent the compensating ropes  35  from being pushed against the angle bracket  21  at an acute angle, and from making unpleasant noise. 
     FIG. 9 is a side view of one of the rotatable members of the compensating rope guide of a sixth embodiment. In the following description, only components different from the components explained in the first embodiment are described. The rotatable member is applied to the rotatable member  15  in FIG.  2 . In this embodiment, rotatable member  42  is composed of four cylindrical rollers  20  supported by the angle bracket  21  like the rotatable member  15 . Each cylindrical roller  20  forms one side of a quadrilateral and the two facing pairs of cylindrical rollers  20  mutually intersect. One pair of cylindrical rollers  20  is placed above the other. Further, the edges of one pair of the cylindrical rollers  20  overlap inside a horizontally projected plane of the other pair of the cylindrical rollers  20 . 
     According to this embodiment, since the edges of one pair of the cylindrical rollers  20  overlap inside a horizontally projected plane of the other pair of the cylindrical rollers  20 , the compensating ropes  35  are not caught in a corner of the cylindrical rollers  20 . As a result, the rotation of the cylindrical rollers  20  does not become difficult and the compensating ropes  35  have no influence on the comfort of the ride in the car  1 . 
     FIG.  10 ( a ) is a plan view of a pair of rotatable members of a compensating rope guide of a seventh embodiment. FIG.  10 ( b ) is a side view of one of the rotatable members of the compensating rope guide of the seventh embodiment. In the following description, only components different from components explained in the first embodiment are described. The rotatable member is applied to the rotatable member  15  in FIG.  2 . In this embodiment, rotatable member  42  is composed of four cylindrical rollers  20  supported by the angle bracket  21  with a cut  43  corresponding to the path of the compensating ropes  35 . Each of the cylindrical rollers  20  forms one side of a quadrilateral and the two facing pairs of cylindrical rollers  20  mutually intersect. One pair of cylindrical rollers  20  is placed above the other. Further, the edges of one pair of the cylindrical rollers  20  overlap inside a horizontally projected plane of the other pair of the cylindrical rollers  20 . 
     According to this embodiment, since the cylindrical rollers  20  are supported by the angle bracket  21  with a cut  43  corresponding to the path of the compensating ropes  35 , if the compensating ropes  35  are pushed to the cylindrical rollers  20  due to a big swing, the compensating ropes  35  merely contact the angle bracket  21 . As a result, the compensating ropes  35  do not make unpleasant noise. 
     In the above embodiments, one second guide  34  is arranged in the pit  12 , but more than two second guides  34  placed one above the other may be arranged below the first guide  33 . 
     According to this invention, it is possible to provide a traction elevator having a compensating rope guide which can reduce the swing of a compensating rope so as to stop the emission of unpleasant noise and vibration of an elevator car, and thus not negatively influence the comfort of the ride in the car.