Patent Publication Number: US-11377323-B2

Title: Retrofitting an elevator machine with primary and secondary braking

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 15/355,834 filed Nov. 18, 2016, the disclosure of which is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND 
     Exemplary embodiments pertain to the art of retrofitting elevator machines with braking functionality. 
     Elevator systems are useful for carrying passengers between various levels in a building. There are various types of elevator systems. Some are referred to as traction-based systems because of reliance upon traction between a drive sheave and hoisting ropes to move and position the elevator car. Elevator machines in traction-based systems include a motor and a brake. There are a variety of known brake configurations. 
     Supplemental brakes for conventional elevator machines are known. Some elevator codes require braking functions that are not provided by older machines. Supplemental brakes can be added to meet such code requirements. One type of supplemental brake is referred to as a rope grabber because it provides a mechanism for clamping onto the roping arrangement. A rope grabber prevents the roping arrangement from moving, which maintains a position of an elevator car within a hoistway. 
     Rope grabber braking has drawbacks. One drawback is that the rope grabber system needs to be positioned below the elevator machine drive sheave. This requires taking up space within the hoistway or raising the elevator machine within a machine room for providing adequate spacing for the rope grabber system. Raising elevator machines is very costly, requires adequate clearance in the machine room, and may require new ropes. Such installation is cramped, resulting in limited accessibility for future service. Additionally, some elevator applications exceed the capability of existing rope grabbing devices, or have other space limitations. Rope grabbers, by applying braking forces directly onto the ropes, increase rope wear. 
     Other options to meet new braking requirements include replacing the existing elevator machine with a completely new machine, which includes the necessary braking capabilities. Such action, however, can be costly and time consuming, and results in wasting otherwise serviceable elevator machinery. 
     There is a need to enhance braking of installed elevators while eliminating the requirements of: (1) directly applying braking forces to elevator ropes; (2) mounting an additional braking device in the hoistway; (3) raising the elevator machine to accommodate proper braking; and (3) completely replacing elevator machinery, which results in unnecessary waste. On the other hand, there is a need for elevator machinery to include both a primary braking system and a secondary emergency braking system, per safety code requirements. 
     BRIEF DESCRIPTION 
     Disclosed is a method of retrofitting an elevator machine with primary and secondary braking, the machine being disposed on a machine support frame in an elevator machine room, and engaging one or more ropes for providing selective movement of an elevator car disposed in an elevator shaft, the machine having a drive sheave including a cylindrical brake drum, and brake components including dual brake arms; the method including: removing the brake components; affixing flanged disc segments about the drum and interlocking the flanged disc segments to form a brake rotor; and mounting respective brake calipers to frame mounts for providing primary and secondary braking to the elevator machine. 
     In addition to one or more of the features described above, or as an alternative, further embodiments may include that each flanged disc segment is formed from a rolled angle. 
     In addition to one or more of the features described above, or as an alternative, further embodiments may include that each flanged disc segment is formed by affixing together an annular band segment and an annular flange segment and providing therebetween a keyed connection. 
     In addition to one or more of the features described above, or as an alternative, further embodiments may include that the annular band segments and annular flange segments are welded and/or bolted together. 
     In addition to one or more of the features described above, or as an alternative, further embodiments may include that affixing each flanged disc segment to the drum includes connecting, to circumferentially adjacent ends of each flange, fastening members, and thereafter fastening together the fastening members. 
     In addition to one or more of the features described above, or as an alternative, further embodiments may include that the fastening members are circumferentially adjacent tubes, secured together via a bolt, at least one washer and a nut. 
     In addition to one or more of the features described above, or as an alternative, further embodiments may include that affixing each flanged disc to the drum includes wrapping a continuous rod around an outer diameter of the drum, clamping together the rod ends, and providing hoop compression with a parallel rod clamp. 
     In addition to one or more of the features described above, or as an alternative, further embodiments may include that the rod ends are threaded and the clamp includes tubes and tightening nuts. 
     In addition to one or more of the features described above, or as an alternative, further embodiments may include that each flanged disc segment includes disc guide holes, the drum includes matching drum guide holes, and affixing the flanged disc segments to the drum includes positioning guide members therethrough, for orienting each flanged disc segment against the drum. 
     In addition to one or more of the features described above, or as an alternative, further embodiments may include that the guide members are bolts or dowels. 
     In addition to one or more of the features described above, or as an alternative, further embodiments may include that mounting calipers includes mounting caliper mounting arms to the respective frame mounts, and mounting the calipers to the respective mounting arms. 
     In addition to one or more of the features described above, or as an alternative, further embodiments may include that the mounting arms each include a same number of calipers, circumferentially spaced about each arm by a mutually constant angle. 
     In addition to one or more of the features described above, or as an alternative, further embodiments may include that the machine includes a brake magnet housing with a spring guide rod, supported by via a brake magnet mount, and mounting calipers includes mounting an end of the mounting arms to respective opposing ends of the brake magnet housing or spring guide rod. 
     Further disclosed is an elevator machine, retrofitted with primary and secondary braking, the machine being disposed on a machine support frame in an elevator machine room, and engaging one or more ropes for providing selective movement of an elevator car disposed in an elevator shaft, the machine having a drive sheave including a cylindrical brake drum, and brake components including dual brake arms; the machine comprising: flanged disc segments, affixed about the drum and interlocked to form a brake rotor; and mounted, to frame mounts, respective brake calipers, for providing primary and secondary braking to the elevator machine. 
     In addition to one or more of the features described above, or as an alternative, further embodiments may include that each flanged disc segment is affixed to the drum by connecting, to circumferentially adjacent ends of each flange, fastening members, and thereafter fastening together the fastening members. 
     In addition to one or more of the features described above, or as an alternative, further embodiments may include that each flanged disc is affixed to the drum by wrapping a continuous rod around an outer diameter of the drum, clamping the rod ends, and providing hoop compression with a parallel rod clamp. 
     In addition to one or more of the features described above, or as an alternative, further embodiments may include that each flanged disc segment includes disc guide holes, the drum includes matching drum guide holes, and guide members are positioned therethrough, for orienting each flanged disc segment against the drum. 
     In addition to one or more of the features described above, or as an alternative, further embodiments may include caliper mounting arms, mounted to the respective frame mounts, and the calipers are mounted to the respective mounting arms. 
     In addition to one or more of the features described above, or as an alternative, further embodiments may include that the machine includes a brake magnet housing, with a spring guide rod, supported by a brake magnet mount, and an end of the mounting arms is mounted to respective opposing ends of the brake magnet housing or spring guide rod. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike: 
         FIG. 1  illustrates an exemplary elevator system; 
         FIGS. 2A-2D  illustrate a method of retrofitting an elevator machine with primary and secondary braking capabilities, according to a disclosed embodiment; 
         FIG. 3A-3C  illustrate a retrofitted elevator machine according to a disclosed embodiment; 
         FIG. 4A-4C  illustrate a rotor component of a retrofitted elevator machine according to a disclosed embodiment; 
         FIGS. 5A-5B  illustrate a rotor component of a retrofitted elevator machine according to another disclosed embodiment; 
         FIG. 6A-6B  illustrate a component for connecting a rotor to a drum according to a disclosed embodiment; 
         FIG. 7A-7C  illustrate a component for connecting a rotor to a drum according to another disclosed embodiment; 
         FIGS. 8A-8D  illustrate an embodiment for mounting calipers to a frame; 
         FIGS. 9A-9F  illustrate another embodiment for mounting calipers to a frame; 
         FIGS. 10A-10C  illustrate another embodiment for mounting calipers to a frame; 
         FIGS. 11A-11B  illustrate an embodiment for attaching the disk to the drum of the elevator machine; 
         FIGS. 12A-12D  illustrate another embodiment for attaching the disk to the drum of the elevator machine; and 
         FIGS. 13A-13D  illustrate another embodiment for attaching the disk to the drum of the elevator machine. 
     
    
    
     DETAILED DESCRIPTION 
     A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures. 
     The disclosed embodiments involve the removal, from the existing elevator machine, the singular machine brake. Thereafter, the application of a new split disc, or split ring (collectively referred to as the “split disc”), is provided to the outside face surface of the existing machine drive sheave, i.e., on the existing brake drum surface. Brake calipers are then mounted onto the existing machine bedplate structure or to caliper mounting arms. Brake pads are positioned to straddle the split disc. 
     The new split disc and brake calipers are sized to meet regulatory primary machine braking requirements. The same are sized, moreover, to meet regulatory secondary emergency braking requirements. 
     The primary benefits of the disclosed embodiments, for retrofitting an elevator machine with primary and secondary braking components, include: (1) the ability to perform a complete installation of the braking system in the machine room; (2) avoiding the need to raise, or re-rope the machine; (3) avoiding the direct application of braking/clamping forces to the ropes in order to achieve desired braking; (4) accessibility to the system for service remains the same as that for the machine; (5) avoiding the need to replace the entire elevator machine to provide the disclosed braking features; and (6) associated cost savings. 
       FIG. 1  schematically shows selected portions of an exemplary elevator system  20 . An elevator car  22  is situated for movement within a shaft or hoistway  24 . The elevator car  22  is supported by a roping arrangement  26 . 
     An elevator machine  30  causes desired movement of the elevator car  22  to provide desired elevator service. The elevator machine  30 , which could be a traction elevator machine, includes two brake arms  32  and related braking machinery (not shown). In the example of  FIG. 1 , the machine  30  is supported on a machine frame  36  within a machine room  38 . 
     An example procedure for retrofitting the machine with a braking arrangement according to disclosed embodiments is described below. 
     As illustrated in  FIGS. 1, 2A-2D and 3 , a method is disclosed of retrofitting an elevator machine  30  with primary and secondary braking. The machine  30  has a drive sheave  44 . The sheave  44  includes a cylindrical brake drum  46 . The machine  30  also has brake components, including dual brake arms  32 . 
     The machine  30  is installed on a machine support frame  36  in an elevator machine room  38 . The frame  36  has a pair of frame connection mounts  40 , illustrated schematically in  FIG. 3A  and illustrated structurally in  FIG. 8A , disposed on opposing circumferential sides of the drum  46 . The mounts  40  are designed to transfer brake loads to the frame  36 . The machine  30  engages one or more ropes  26  for providing selective movement of an elevator car  22  disposed in an elevator shaft  24 . 
     As illustrated in  FIGS. 2C, 2D and 3 , the method includes removing the brake components and affixing flanged disc segments  50  about the drum  46 . In addition, the method includes interlocking the flanged disc segments  50  to form a brake rotor. 
     The method further includes mounting, to the frame connection mounts  40 , respective brake calipers  52  ( FIG. 2D ). The calipers  52 , mounted to both frame mounts  40 , are capable of providing primary and secondary braking to the elevator machine  30 . 
     As illustrated in  FIGS. 4A-4C, and 5B , in one embodiment, each flanged disc segment  50  is formed from a rolled angle. One part of the rolled angle forms a band  54  of the flanged disc segment  50 , which is positioned against the drum  46 . The other part of the rolled angle is a flange  56 , which forms the disc rotor. The rolled angle may be equal legged, or the flange  56  may be longer to provide a greater braking surface. In addition, the flange  56  may form a mounting surface for an additional, extension flange  59  ( FIG. 5B ), to form a larger rotor braking surface. For example, in  FIG. 5B , the flange  56  has keyed portions  58 B for receiving an additional toothed extension flange  59 , extending radially outward from the flange  56 . The extension flange  59  may be multiple times, e.g., three times, the radial length of the lower flange  56 , so as to provide a suitable braking surface. The keyed portion  58 B and toothed extensions  59 B are connected via half-lap joints, formed with laps in the radial direction, with half-lap joints illustrated more clearly in  FIGS. 12D and 13D , with embodiments (disclosed below) that form the laps in the circumferential direction, and the laps are structurally reinforced via bolting, welding or the like. 
     As illustrated in  FIG. 5A , in one embodiment, each flanged disc segment  50  is formed by affixing together an annular band  54  and an annular flange  56 . The annular band  54  is positioned against the drum  46  and the flange  56  forms the disc rotor. Provided therebetween is another half-lap, keyed connection  58 , where the toothed sections are in the band  54  and the keyed sections are in the flange  56 . 
     As illustrated in  FIGS. 6A-6B , in one embodiment, the step of affixing each flanged disc segment  50  to the drum  46  includes connecting, to circumferentially adjacent ends of each flange  56  ( FIG. 6A ) or each band  54  ( FIG. 6B ), fastening members  60 , which are then fastened together. In one embodiment, the fastening members  60  are tubes  62 , secured via a bolt  64 , at least one washer  66  and a nut  68 . The effect of this embodiment is to bias the flanged disc segments  50  against the drum  46 . 
     As illustrated  FIGS. 7A-7C , in another embodiment, the biasing effect occurs, e.g., via a hose clamp configuration ( FIG. 7B ). This is implanted by wrapping a continuous rod  70  around an outer diameter of the drum  46 , clamping the rod ends  72 , and providing hoop compression, via a parallel rod clamp  74 . In one embodiment, the rod ends  72  are threaded and the clamp includes tubes  76  and tightening nuts  78 . In one embodiment, as illustrated in  FIG. 7A , the connector tubes  76  are separate structures, bolted to the rod  70  at tube ends  76 A, and bearings  76 B can be utilized to assist in the compression of the rod  70 . Alternatively, as illustrated in  FIG. 7C , the connector  76 C can be a single, integrated, double tubed structure. 
     Turing back to  FIG. 2C , in one embodiment, each flanged disc segment  50  includes band guide holes  80 , and the drum  46  includes matching drum guide holes (not shown), for orienting each flanged disc segment  50  against the drum  46 . In this embodiment, the step of affixing the flanged disc segments  50  to the drum  46  includes positioning guide members, which could be bolts, dowels or the like, through the band  54  and drum guide holes. 
     Turning back to  FIGS. 3A-3C , in one embodiment, the step of mounting calipers  52  includes mounting arcuate mounting arms  82 , illustrated schematically, to the respective frame mounts  40 . In this embodiment, the mounting step includes mounting the calipers  52  to the respective mounting arms  82 . In addition, the mounting arms  82  each include a same number of calipers  52 . The calipers  52  are separated on each mounting arm  82  by an angle  83  about the disc circumference to provide an even brake force distribution. To achieve proper angling, the arms  82  may be arcuate. 
     As illustrated, on each vertical half of the rotor  46 , e.g., left and right halves, circumferentially adjacent calipers may be separated by a substantially constant angle. Also as illustrated, pairs of calipers on opposing vertical halves of the rotor  46  may be disposed on a common axis. This is illustrated with e.g., calipers C 1  and C 4  in the four caliper configuration ( FIG. 3B ) and C 1  and C 6  in the six caliper configuration ( FIG. 3C ). Further, in the six calipers configuration, a center or middle caliper C 2 , C 5  on each vertical half of the rotor  46  may be disposed on the rotor  46  center horizontal axis. With two calipers on each side ( FIG. 3B ), the rotor  46  center horizontal axis bisects the angle between circumferentially adjacent calipers, e.g., C 1 , C 2 . Additional configurations are within the scope of the disclosure. 
     As illustrated in  FIGS. 3A-3C , the machine includes a legacy brake magnet housing  84 , with a horizontally extending spring guide rod  88 . The housing  84  is supported by the machine structure via a brake magnet mount  85  ( FIG. 2A ), which essentially is a cast iron box. In one embodiment, the step of mounting calipers  52  includes mounting an end  86  of the mounting arms  82  to opposing sides of the magnet housing  84  or spring guide rod  88 . 
     In addition to the above method for retrofitting a machine, an elevator machine  30  retrofitted by the above method is considered part of the disclosure. Turning to  FIGS. 8A-8D , an embodiment is illustrated for mounting calipers  52  to the frame  36 , with a pair of caliper mounting arms  82 , i.e., each including a pair of calipers  52 . The absence, or removal, of brake magnet housing  84 , illustrated in the above disclosed embodiments, leaves the mounting arms  82  without a central support. Thus the mounting arms  82  are built stiffly enough to carry the loads using, e.g., I-beam supports. With this embodiment, the mounting arms  82  must be removed in order to change brake pads. 
     Turning to  FIGS. 9A-9F , another embodiment is illustrated for mounting calipers  52  to a frame  36 , with a pair of caliper mounting arms  82 , i.e., each including a pair of calipers  52 . In this embodiment, with the absence, or removal, of the brake magnet housing  84 , an additional frame mounted central support  84 A is provided connected to ends  86  ( FIG. 9C ) of the mounting arms  82 . The mounting arms  82 , may therefore be slender compared with the arms  82  in the embodiment illustrated in  FIGS. 8A-8D . This configuration is preferred, e.g., where space is limited. For example, where the frame  36  has additional vertical supports  36 A ( FIG. 9A ), the forward space for mounting stiffer mounting arms  82  may be unavailable. Here too, the mounting arms  82  must be removed in order to change brake pads. As illustrated in  FIG. 9C , the frame mount  40  extends slightly past envelope of the elevator machine  30 , e.g., spaced from a frame notch  36 B, in order to not interfere with rope drop in ropes  26 . 
     Turning to  FIGS. 10A-10C , another embodiment is illustrated for mounting calipers  52  to a frame  36 , with a caliper unitary mounting structure  82 , illustrated with four calipers  52 . In this embodiment, again with the absence, or removal, of a brake magnet housing  84 , an additional frame mounted central support  84 A is provided. The support  84 A is connected to a rearward extending bracket  82 A attached to a joining apex  82 B of the caliper mounting structure  82 . The mounting structure  82  may therefore be slender, similar to arms  82  illustrated above in  FIGS. 9A-9F . In this embodiment, the mounting structure  82  need not be removed to change brake pads. 
     Turning to  FIGS. 11A-11B , an alternative flanged disc segment  50  is illustrated. Each flanged disc segment  50  in this embodiment is a disc without a band  54 . The resulting flanges  56  have radially outer and inner portions  56 A,  56 B. The outer portion  56 A forms the braking rotor. The inner portion  56 B is axially thicker than the outer portion  56 A, providing structural stability. In addition, circumferentially opposing ends  56 C,  56 D of the flanges  56  include axially extending flange connectors  56 E, with through holes  56 F, for connecting with circumferentially adjacent flanges  56  via bolts  56 G. 
     Turning to  FIGS. 12A-12D , another embodiment is illustrated for connecting each flanged disc segment  50  to the drum  46 . Each flanged disc segment  50  in this embodiment is a two piece structure, including a band  54  for connecting a flange  56  to a drum  46 . The flange  56  forms the braking rotor. The flange  56  and band  54  are welded together prior to being installed against the drum  46 . 
     Circumferentially opposing ends  56 AA,  56 BB of the flange  56  are half-lapped in the circumferential direction, to connect with circumferentially adjacent flanges  56  as illustrated in  FIGS. 12B-12D . One of the ends  56 AA,  56 BB is provided with a pair of tapered through holes  56 CC, and the other of the ends includes threaded holes  56 DD to flush mount a screw  56 EE ( FIG. 12D ). 
     One of the circumferentially opposing ends  54 A of the band  54  is provided with a pair of circumferentially extending countersunk impressions  54 C and through-holes  54 D ( FIG. 12A ). The other end  54 B is provided with circumferentially extending threaded holes  54 E ( FIG. 12D ). With this configuration, bolts  54 F are used to connect circumferentially aligned flanged disc segments  50 , as illustrated in  FIGS. 12B-12D . 
     The band  54  is provided with four pairs of radially extending through-holes  54 G ( FIG. 12A ). The drum  46  is machined to include matching holes  46 A ( FIG. 13D ) and eight spring pins  54 H ( FIG. 12D ) are applied to secure the band  54  to the drum  46 . 
     Turning to  FIGS. 13A-13D , another embodiment is illustrated for connecting flanged disc segments  50  to the drum  46 . Each flanged disc segment  50  in this embodiment is a unitary structure, including a band  54  for connecting a flange  56  to a drum  46 , the flange  56  forming the braking rotor. The flange  56  and band  54  are cast formed, with a radial corner joint  50 A. Dimensionally, the embodiment  13 A- 13 D is essentially the same as the structure illustrated in  FIGS. 12A-12D , connecting to the drum  46  in similar fashion. 
     Those skilled in the art who have the benefit of this description will realize that a variety of brake configurations and a variety of machine configurations could be used that are different than the illustrated example. The techniques associated with the example retrofitting procedure may be used in a variety of elevator system configurations to retrofit a previously installed elevator machine with a supplementary brake. 
     The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this invention. The scope of legal protection given to this invention can only be determined by studying the following claims. 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, element components, and/or groups thereof. 
     While the present disclosure has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the present disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the present disclosure without departing from the essential scope thereof. Therefore, it is intended that the present disclosure not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this present disclosure, but that the present disclosure will include all embodiments falling within the scope of the claims.