Description:DESCRIPTION

TECHNICAL FIELD
[001] The present disclosure generally relates to the field of elevators. Particularly but not exclusively the present disclosure relates to safety braking systems for elevator cars and counterweights.
BACKGROUND
[002] Typically, in an elevator a car is moved by means of a drive and guided along guide rails to different access levels of a building or site. Traction drives or hydraulic drives serve as the drive to operate the elevators. A traction drive is composed of at least of a motor, a drive pulley and traction mean such as, for example, a cable or belt. Eleva-tors include a safety system to stop the car from traveling at excessive speeds in re-sponse to an elevator component breaking or otherwise becoming inoperative. Tradi-tionally, elevator safety systems include a speed sensing device referred to as a gov-ernor, a governor rope, safeties or clamping mechanisms that are mounted to the elevator car frame for selectively gripping elevator guide rails, and a tension sheave located in an elevator pit. The governor includes a governor sheave located in a machine room which is positioned above the elevator or within an elevator shaft. The governor rope is attached to travel with the elevator car and makes a complete loop around the governor sheave and the tension sheave.
[003] The governor rope is connected to the safeties through mechanical linkages and lift rods. The safeties include brake pads that are mounted for movement with the gov-ernor rope and brake housings that are mounted for movement with the elevator car. If the hoist ropes break or other elevator operational components fail, causing the elevator car to travel at an excessive speed, the governor releases a clutch that grips the governor rope. Thus, the rope is stopped from moving while the elevator car continues to move downwardly. The brake pads, which are connected to the rope, remains in a position while the brake housings move downwardly with the elevator car. The brake housings are wedge shaped, such that as the brake pads are moved in a direction opposite from the brake housings, the brake pads are forced into frictional contact with the guide rails. Eventually the brake pads become wedged between the guide rails and the brake housing such that there is no relative movement between the elevator car and the guide rails. The governor rope holds the brake pads so that the frictional force between the brake pads and the guide rails remain over a predetermined threshold until the system resets. To reset the safety system, the brake housing (i.e., the elevator car) must be moved upward while the governor rope is simultaneously released from the clutch. This returns the brake pads to their original positions. One disadvantage with this traditional safety system is that the installation of the sheaves, rope, multiple links, and governor is very time consuming. Another disadvantage is the significant number of components that are required to effectively operate the system. The governor sheave assembly, governor rope, and tension sheave assembly are costly and take up a significant amount of space within the hoist way, pit, and machine room. Also, the operation of the gover-nor rope and sheave assemblies generates a significant amount of noise, which is un-desirable. Further, high number of components and moving parts increases mainte-nance costs. These disadvantages have an even greater impact in modern high-speed elevators.
[004] The present disclosure is directed to overcome one or more limitations stated above or any other limitations associated with the prior art. The information disclosed in this background of the disclosure section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowl-edgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.
SUMMARY OF THE INVENTION
[005] One or more shortcomings of existing braking system or device have been overcome, and additional advantages are provided through the system as claimed in the present disclosure. Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are de-scribed in detail herein and are considered a part of the claimed disclosure.
[006] The limitations of the prior arts are addressed to a great extent by a safety braking system for a hoisted structure which can be guided along a guide rail, as disclosed in the present disclosure. The safety braking system includes a brake unit mounted to a hoisted structure and is configured to move along a guide rail to guide the hoisted structure. The system also includes one or more brake shoes accommodated in a space defined between a brake liner of the brake unit and the guide rail. Further, an actuation mechanism is provided in the system which is configured to operate the one or more brake shoes from first position and a second position. The actuation mechanism includes a trigger assembly secured to the hoisted structure. The trigger assembly being configured to be electrically activated based on pre-defined parame-ters. The actuation mechanism includes a linkage mechanism connecting the trigger assembly and each of the one or more brake shoes. The trigger assembly when elec-trically activated actuates the linkage assembly to displace the one or more brake shoes to the second position from the first position. In the second position, the one or more brake shoes adapted to frictionally engage the guide rail and the brake unit to exert braking force on the hoisted structure.
[007] In an embodiment of the present disclosure, the trigger assembly includes a housing, an actuating rod movably disposed in the housing. One end of the actuating rod is coupled to the linkage assembly and a support plate is defined on the actuating rod. Further, a resilient member is disposed within the housing between the support plate defined on the actuating rod and the housing. A restraining mechanism is configured to hold the resilient member in compressed state and release the resilient member to a relaxed state when electrically activated. The restraining mechanism being config-ured to hold the actuation rod in the extended position in the compressed state and operate the actuation rod to the retracted position in the relaxed state of the resilient member, relative to the housing. The safety system includes a roller arrangement movably mounted on the brake liner of the brake unit. The roller arrangement is pro-vided in a side of the brake liner which is adapted to come in contact with the one or more shoes. Further, the brake liner is defined with a guide arrangement to guide the roller arrangement to traverse along the brake liner when the corresponding brake shoe of the one or more brake shoes is operated to the second position. The restrain-ing mechanism includes a fuse wire cartridge, wherein the fuse wire cartridge com-prising a first section secured to the housing and a second section releasably coupled to the first section through a fuse wire. A restraining lever coupled to the second sec-tion of the fuse wire cartridge at one end and other end opposite to the one end is configured to abut the support plate of the trigger assembly. The restraining lever abuts the support plate (S) defined on the actuating rod when the resilient member is in compressed state.
[008] In an embodiment, the system includes a control unit communicatively coupled to the actuation mechanism. The control unit is configured to trigger the actuation mechanism based on the pre-defined parameter. Triggering the actuation module transmits an electrical pulse to the fuse wire cartridge to melt the fuse wire to release the restraining lever in turn releasing the actuating rod to the retracted position.
[009] It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined to form a further embodiment of the disclosure. The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects and features described above, further aspects and features will become apparent by reference to the drawings and the following detailed description.
BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
[0010] The novel features and characteristic of the disclosure are set forth in the appended claims. The disclosure itself, however, as well as a mode of use, further objectives, and advantages thereof, will best be understood by reference to the following de-tailed description of an embodiment when read in conjunction with reference to the accompanying drawings wherein like reference numerals represent like elements and in which:
FIG.1 illustrates a schematic perspective view of a hoisted structure with a safety braking system, in accordance with an embodiment of the present disclosure.
FIG.2 illustrates a side view of a safety braking system for a hoisted structure of FIG. 1.
FIG.3 illustrates a front view of the safety braking system of FIG.1.
FIGS.4a to 4c illustrates a trigger assembly for the safety braking system of FIG.1, in different positions, in accordance with embodiments of the present disclosure.
FIG.5 illustrates a schematic view of fuse wire cartridge used in the trigger assembly, in accordance with an embodiment of the present disclosure.
FIG.6 illustrate a block diagram of the safety braking system, in accordance with an embodiment of the present disclosure.
[0011] The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alter-native embodiments of the system and methods illustrated herein may be employed without departing from the objective of the disclosure described herein. It should be appreciated by those skilled in the art that any block diagrams herein represent con-ceptual views of illustrative systems embodying the principles of the present subject matter.

DETAILED DESCRIPTION OF THE DRAWINGS
[0012] The foregoing has broadly outlined the features and technical advantages of the pre-sent disclosure in order that the detailed description of the disclosure that follows may be better understood. Additional features and advantages of the disclosure will be described hereinafter which forms the subject of the claims of the disclosure. It should be appreciated by those skilled in the art that, the conception and specific embodiments disclosed may be readily utilized as a basis for modifying other devic-es, systems, assemblies, and mechanisms for carrying out the same purposes of the present disclosure. It should also be realized by those skilled in the art that, such equivalent constructions do not depart from the scope of the disclosure as set forth in the appended claims. The novel features which are believed to be characteristics of the disclosure, to its system, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present disclosure.
[0013] In accordance with various embodiments of the present disclosure relates to a safety braking system for a hoisted structure guided along a guide rail. The safety braking system includes a brake unit mounted to a hoisted structure and configured to move along a guide rail to guide the hoisted structure. The system further includes one or more brake shoes accommodated in a space defined between a brake liner of the brake unit and the guide rail. The system also includes an actuation mechanism con-figured to operate the one or more brake shoes from a first position and a second po-sition. The actuation mechanism includes a trigger assembly and a linkage mechanism working in tandem with each other to displace the one or more brake shoes from the first position to the second position. The trigger assembly may be electrically activat-ed based on pre-defined parameters to actuate the linkage assembly to displace the one or more brake shoes to the second position. In the second position, the one or more brake shoes is adapted to frictionally engage the guide rail and the brake unit to exert braking force on the hoisted structure. The forthcoming paragraphs will eluci-date the configuration of the braking system. Forthcoming embodiments elucidate the braking system and method of braking in detail in conjunction to FIGs 1 to 6.
[0014] In an embodiment, the safety braking system of the configuration described above requires lesser number of mechanical components as compared to the conventional systems. Also, the system eliminates need of installation of the sheaves, rope, and multiple links. Also, the safety braking system of the present disclosure eliminates the need of governor. Eliminating the governor and use of lesser mechanical compo-nents reduces cost of installation and system significantly.
[0015] While the embodiments in the disclosure are subject to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the figures and will be described below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative fall-ing within the scope of the disclosure.
[0016] It is to be noted that a person skilled in the art would be motivated from the present disclosure and modify construction of a safety braking system for a hoisted structure guided along a guide rail. However, such modifications should be construed within the scope of the disclosure. Accordingly, the drawings show only those specific de-tails that are pertinent to understand the embodiments of the present disclosure, so as not to obscure the disclosure with details that will be readily apparent to those of or-dinary skill in the art having benefit of the description herein.
[0017] The terms “comprises”, “comprising”, or any other variations thereof used in the dis-closure, are intended to cover a non-exclusive inclusion, such that a system and method that comprises a list of components does not include only those components but may include other components not expressly listed or inherent to such system, method, or assembly, or device. In other words, one or more elements in a system or device proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or device.
[0018] The following paragraphs describe the present disclosure with reference to FIG(s) 1 to 6. In the figures, the same element or elements which have similar functions are indicated by the same reference signs. With general reference to the drawings, a safety braking system for a hoisted structure (4) [partially indicated by the dashed lines in FIG.1] in accordance with the teachings of a preferred embodiment of the present disclosure is illustrated and generally identified at reference numeral 10. The safety braking system (10) may be employed in the hoisted structures (4) such as an elevator car or counterweights used in the elevator assembly. It will be understood that the teachings of the present disclosure are not limited to any particular hoisted structure. Further, in the corresponding drawings neither the complete elevator sys-tem nor the elevator is depicted to promote better understanding of the instant in-vention.
[0019] The following detailed description is merely exemplary in nature and is not intended to limit application and uses. Furthermore, there is no intention to be bound by any theory presented in the preceding background or summary or the following detailed description. It is to be understood that the disclosure may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices or components illustrated in the at-tached drawings and described in the following specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, spe-cific dimensions or other physical characteristics relating to the embodiments that may be disclosed are not to be considered as limiting, unless the claims expressly state otherwise. Hereinafter, preferred embodiments of the present disclosure will be descried referring to the accompanying drawings. While some specific terms of “up-per,” “lower,” “below”, “above”, “right”, “left”, “rear” or “front” and other terms containing these specific terms and directed to a specific direction will be used, the purpose of usage of these terms or words is merely to facilitate understanding of the present invention referring to the drawings. Accordingly, it should be noted that the meanings of these terms or words should not improperly limit the technical scope of the present invention.
[0020] Also, it is to be understood that the phraseology and terminology used herein is for description and should not be regarded as limiting. Unless specified or limited oth-erwise, the terms “mounted,” “connected,” “supported,” and “coupled” and varia-tions thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not re-stricted to physical or mechanical connections or couplings. It is to be understood that this disclosure is not limited to the specific devices, methods, applications, con-ditions, or parameters described and/or shown herein and that the terminology used herein is to describe particular embodiments by way of example and is not intended to be limiting of the claimed invention. Hereinafter in the following description, var-ious embodiments will be described. For purposes of explanation, specific configura-tions and details are outlined to provide a thorough understanding of the embodi-ments. However, it will also be apparent to one skilled in the art that the embodi-ments may be practiced without the specific details. Furthermore, well-known fea-tures may be omitted or simplified in order not to obscure the embodiment being de-scribed.
[0021] Referring to FIGs 1 to 6 in conjunction, which illustrate the safety braking system (10) [hereinafter referred to as system (10)] and various components associated with the system (10). The system (10) of the present disclosure may be designed to be employed in the hoisted structures (4) such as but not limiting to elevator cars, coun-terweights, and the like. The hoisted structure (4) is apparent from FIG.1 in the cor-responding figures. Also, application of the system (10) elucidated going forward should not be construed as a limitation of the present disclosure. The system (10) may be supported for movement with the hoisted structure (4) for selectively engag-ing a blade portion of guide rail (1) guiding the hoisted structure (4) to prevent unde-sired movement of the hoisted structure (4) in a variety of situations. In an embodi-ment, the variety of situations [also referred to as pre-defined parameters in the pre-sent disclosure] include at least one of freefall condition or overspeed condition of the hoisted structure. The safety braking system (10) of the present disclosure en-sures effective braking for the hoisted structures (4) relative to the guide rails (1) when the hoisted structure (4) is encountering undesirable movements. FIG.1 and FIG.2 schematically illustrates an embodiment of the system (10) which may be mountable at an appropriate portion of the hoisted structure (4) to function effective-ly during undesired movement. The appropriate position on the hoisted structure (4) may include a car outer frame member but not limiting to the same. Hereinafter, fea-tures of the braking system (10) along with working may be elucidated.
[0022] The safety braking system (10) among other components may include a brake unit (2). The brake unit (2) [refer FIG.3] of the present disclosure may be connected to the hoisted structure (4) at appropriate portions. In an embodiment, the system (10) may be mounted on either ends of the hoisted structure (4) on at least one of bottom portion, top portion, and the like. In another embodiment, the system (10) may be mounted to a structural member such as a cross beam (4a) provided under the hoist-ed structure (4). The cross member (4a) may be provided at the bottom portion of the hoisted structure (4a). The system (10) may be Further, the brake unit (2) may be configured to move along the guide rail (1) respective to the movement of the hoist-ed structure (4) to guide the hoisted structure (4). In some embodiments, the brake unit (2) may be structured to partially encompass the guide rail (1) [as shown in FIG.1]. In an embodiment, the brake unit (2) may include a housing (2H) [refer FIG.3] defining an opening. The opening of the housing (2H) may be configured to accommodate a brake liner (2a) [best shown in FIG.3]. In an embodiment, the brake liner (2a) may be adjustably connectable within the housing (2H) of the brake unit (2). The brake liner (2a) may be connected to the housing (2H) by mechanical joining members but not limiting to the same. In some embodiments, the brake liner (2a) may be defined with a key on at least one of a top major surface and a bottom major sur-face. The key defined on the brake liner (2a) may be accommodated within a corre-sponding keyway defined in the housing (2H), thereby arresting the movement of the brake liner (2a) within the housing (2H). In an embodiment, shape of the brake liner (2a) may resemble a wedge-shaped profile and may be positioned inverted con-figuration within the housing (2H). In an embodiment, the brake liner (2a) may be defined with an elongated slot. The elongated slot may be defined along an inclined surface of brake liner (2a) having the wedge-shaped profile.
[0023] The system (10) further includes one or more brake shoes (3) [refer FIGs 3] configure to work in tandem with the brake unit (2) and the guide rail (1) when the hoisted structure (4) encounters undesirable movement. The one or more brake shoes (3) may be positioned in a space defined between the guide rail (1) and the brake unit (2), in particular between the brake liner (2a) and the guide rail (1) [as shown in FIG.1 and 4]. An exemplary representation of one of the one or more brake shoes (3) is depict-ed in FIG.3 in the corresponding figures. The one or more brake shoes (3) may be structured to engage with the blade portion of the guide rails (1). In embodiment, a surface of the one or more braking shoes (3) engaging with the guide rail (1) may be provided with a frictional material or defined with frictional surface. In an embodi-ment, shape of each of the one or more brake shoes (3) may correspond to shape of the brake liner (2a). The brake liner (2a) and the one or more brake shoes (3) is de-fined with complementing wedge-shaped profile.
[0024] In an embodiment, the system (10) includes a roller arrangement (6) movably mount-ed on the brake liner (2a) of the brake unit (2) and configured to come in contact with the one or more brake shoes (3). The roller arrangement (6) may include housing configured to accommodate a plurality of rollers. The housing may include side plates spaced apart from each other and a plurality of rollers provided between the side plates along the length of the housing. A guide arrangement may be defined on the brake liner (2a) and may be configured to guide the roller arrangement (6) to traverse along the brake liner (2a) when the corresponding brake shoe of the one or more brake shoes (3) is operated to the second position. In an embodiment, the guide arrangement may be a slot defined in the brake liner (2a) and a corresponding protru-sion on the housing [i.e., either side plates] of the roller arrangement (6). In another embodiment, the guide arrangement may be a protrusion defined on the brake liner (2a) and a slot defined on the housing [i.e., either side plates] on the roller arrange-ment (6).
[0025] Further, the system (10) includes an actuation mechanism (AM) configured to dis-place/operate the one or more brake shoes (3) to the second position from the first position. The actuation mechanism (AM) may be mounted on the cross beam (4a) relative to the one or brake unit (2). The actuation mechanism (AM) may include trigger assembly (5). The trigger assembly (5) is depicted in FIGs 1 and 2 and specif-ic components/features of the trigger assembly (5) is illustrated in subsequent figures i.e., FIGs 4a and 4b. The trigger assembly (5) will be elucidated in detail in the forthcoming paragraphs. Further, the actuation mechanism (AM) may include a link-age assembly (5f). The relative movement between the one or more brake shoes (3), the linkage assembly (5f) and the trigger assembly (5) along with the functioning of the same will be elucidated in detail in the forthcoming embodiments.
[0026] The trigger assembly (5) of the actuation mechanism (5) may be secured to a portion of the crossbeam (4a) [as shown in FIG.2]. The trigger assembly (5) may be mounted onto the crossbeam (4a) by at least one of mechanical joining method or thermal join-ing method. The trigger assembly (5) may include a housing (5a) [refer FIGs 2 and 4a] which may be connectable to the crossbeam (4a). In an embodiment, the housing may be provided on a bottom portion of the hoisted structure (4) or any other posi-tion suitable for the functioning of the trigger assembly (5) without deviating from the scope of the present disclosure. The housing (5a) may include a base and a side-wall structure projecting vertically upward from the base. The base of the housing (5a) may be secured to the crossbeam (4a) as depicted in FIG.2. At least one of the mechanical joining method or thermal joining methods such as riveting, or welding may be used to secure the housing (5a) to the crossbeam (5). The sidewall structure of the housing (5a) may be defined with one or more provisions to receive compo-nents such as an actuating rod (5e), a resilient member (5d) and restraining mecha-nism (5b) among other operative components. The actuating rod (5e) may be mova-bly disposed in the housing (5a) and a part of the actuating rod (5e) may extend out-side the housing (5a) through a provision defined in the sidewall structure of the housing (5a). In an embodiment, the provision defined in the sidewall may be an ap-erture or a hole which is adapted to movably receive the actuating rod (5e). In an embodiment, one or more support bushes (5g) [refer FIG.4a/4b] may be secured to the sidewall structure of the housing (5a) corresponding to the one or more provi-sions that are adapted to movably support the actuating rod (5e). The aperture de-fined in the each of the support bushes (5g) may be aligned with the aperture de-fined in sidewall structure in the housing. In an embodiment, the actuating rod (5e) is configured to move between an extended position [as shown in FIG.4a] and re-tracted position [as shown in FIG.4b] relative to the housing (5a). In another embod-iment, the actuating rod (5e) may be defined with a holder at a first end (5e1). Fur-ther, a support plate (S) may be defined on the actuating rod (5e). The support plate (S) may be provided on a portion of the actuating rod (5e) which is inside the hous-ing (5a). The support plate (S) may be positioned at a substantially central portion of the actuating rod (5e). In an embodiment, the support plate (S) may be defined with an arm extending radially outwardly. The arm is received by a slot defined in the sidewall structure of the housing (5a). The movement of the arm relative to the slot in the housing (5a) ensures linear movement of the actuating rod (5e) when displaced between extended position and the retracted position. In another embodiment, the arm of the support plate (S) may be used to reset the actuating rod (5e) to the ex-tended position which will be elucidate in later embodiments of the present disclo-sure.
[0027] A resilient member (5d) [refer FIGs 2/4a/4b] may be disposed within in the housing between the support plate (S) defined on the actuating rod (5e) and the housing (5a). In an embodiment, the resilient member (5d) may be disposed along the actuating rod (5e) between the support plate (S) and the support bush (5g). The resilient mem-ber (5d) may be at least one of but not limiting to a torsional spring, coil spring and the like. In some embodiments, the resilient member (5d) may be a bellow spring. The resilient member (5d) may be adapted to displace from a compressed state [as shown in FIG.4a/4c] to a relaxed state [as shown in FIG.4b]. Initially, the resilient member (5d) may be held in a compressed state [as shown in FIG.4a]. The resilient member (5d) may be biased towards the relaxed position and may be adapted to dis-place the actuating rod (5e) from the extended position to the retracted position once released from the compressed state.
[0028] The resilient member (5d) as described above is held in the compressed state by a restraining mechanism (5b). The restraining mechanism (5b) may be configured to hold the resilient member (5d) in the compressed state and release the resilient mem-ber (5d) to a relaxed state based on pre-determined parameters. The restraining mechanism (5b) includes a fuse wire cartridge (5b2) [refer FIG.5] securely connecta-ble to the housing (5a) proximal to the actuating rod (5e). In an embodiment, the fuse wire cartridge (5b2) may be provided below the actuating rod (5e) within the housing (5a). The fuse wire cartridge (5b2) may be secured to the sidewall structure of the housing (5a) via a tensioner (5b1). The tensioner (5b1) may be configured to move the fuse wire cartridge (5b2) to position the fuse wire cartridge (5b2) relative to the position of the support plate (S) on the actuating rod (5e). The fuse wire car-tridge (5b2) may include a first section (5b21) and a second section (5b2) [refer FIG.5]. In an embodiment, the first section (5b21) may comprise a plurality of elec-trical contacts (7a) and the second section (5b22) may include a fuse wire (7b). In another embodiment, the second section (5b22) may comprise the plurality of electri-cal contacts (7a) [refer FIG.5] and the first section (5b21) may include the fuse wire (7b) [refer FIG.5]. The fuse wire (7b) in the fuse wire cartridge (5b2) may be a one-loop fuse wire, a two-loop fuse wire or a multi-loop fuse wire. The first section (5b21) and the second section (5b22) may be connected to each other such that the second section (5b22) may be held under compressive force relative to the first sec-tion (5b21).
[0029] Further, a restraining lever (5b3) associated with the trigger assembly (5) may be coupled to the second section (5b22) of the fuse wire cartridge (5b2) at one end and other end opposite to the one end of the restraining lever (5b3) may abut the support plate (S) of the trigger assembly (5). The restraining lever (5b3) may abut the support plate (S) defined on the actuating rod (5e) when the resilient member (5e) is in com-pressed state. The restraining lever (5b3) may resemble a cocking lever. In an embod-iment, the restraining lever (5b3) may include a first portion and a second portion ex-tending from the first portion. The first portion is adapted to be secured to the sec-ond section (5b22) of the fuse wire cartridge (5b2) and the second portion is adapted to abut against the support plate (S). In an embodiment, the restraining lever (5b3) is designed such that the first portion may be longer than that of the second portion. Said design of the restraining lever (5b3) ensures that the force imparted on the first section (5b21) and the second section (5b22) of the fuse wire cartridge (5b2) is min-imum. In an embodiment, the fuse wire cartridge (5b2) may be electrically activated based on the pre-determined parameters. Electrically activating the fuse wire car-tridge (5b2) transmits electrical pulse to the electrical contacts (7a) to diffuse the fuse wire (7b) to release the restraining lever (5b3) in turn releasing the actuating rod (5e) to the retracted position. In an embodiment, the fuse wire cartridge (5b2) may be electrically activated by a control unit (CU) of the system (10) which will be elu-cidated in the forthcoming embodiments. Displacing the actuating rod (5e) to the re-tracted position in turn actuates the one or more brake shoes (3) to the second posi-tion via linkage assembly (5f) which is elucidated further.
[0030] The linkage assembly (5f) may be adapted to link the actuating rod (5e) of the trigger assembly (5) to the one or more brake shoes (3) [refer FIG.s 1/2/3]. The linkage as-sembly (5f) may include a plurality of links (5f1, 5f2, 5f3 and 5f4). The plurality of links (5f1, 5f2, 5f3 and 5f4) may include a first link member (5f1), a second link member (5f2), a third link member (5f3) and a fourth link member (5f4). The linkage assembly (5f) will be elucidated hereinafter in conjunction to FIG.2. Each of the plurality of links (5f1, 5f2, 5f3 and 5f4) may be operatively coupled to each other. In an embodiment, the actuating rod (5e) may be coupled to the first link member (5f1). The first link member (5f1) may be at least one of a wire or an elongated shaft made of metallic or composite materials but not limiting to the same. The first link member (5f1) may include two ends, one end of the two ends may be defined with a plurali-ty of threads. The one end may be received by the holder coupled to/provided in the first end (5e1) of the actuating rod (5e). The one end of the first link member (5f1) may be secured to the holder defined on the one end (5e1) of the actuating rod (5e) by fastening means such as a wingnut. The fastening means may be rotated along the threaded portion on the first link member (5f1) to adjust the length of the first link member (5f1) relative to the linkage assembly (5f). Further, the other end of the first link member (5f1) opposite to the one end connected to the actuating rod (5e) may be connected to the second link member (5f2). The second link member (5f2) may form a link between the third link member (5f3) and the first link member (5f1). In an embodiment, the second link member (5f2) may be secured to the third link mem-ber (5f3) on the end opposite the end connected to the first link member (5f1). The second link member (5f2) may be adapted to convert linear motion of the first link member (5f1) to pivotal motion of the third link member (5f3). The pivotal motion of the third link member (5f3) may be then converted to linear motion of the fourth link member (5f4) which is connected to the third link member (5f3) at one end and an other end of the fourth link member (5f4) may be connected to the one or more brake shoes (3). The fourth link member (5f4) may be coupled to the third link mem-ber (5f3) by mechanical joining methods. In a preferred embodiment, an auxiliary link (AL) [refer FIG.3] may be provided between the third link member (5f3) and the fourth link member (5f4). The auxiliary link (5f4) may be adapted to covert the pivotal motion of the third link member (5f3) to the liner motion of the fourth link member (5f4) which in turn is connected to the one or more brake shoes (3). Moving the fourth link member (5f4) in a liner motion [i.e., vertically upward direction] dis-places the one or more brake shoes (3) to the second position to frictionally engage the guide rail (1) and the brake line (2a) to exert braking force on the hoisted struc-ture (4).
[0031] The system (10) further includes a control unit (CU) [as shown in FIG.6] communi-catively coupled to the actuation mechanism (AM) [as shown in FIG.6] and a detec-tion module (DM) associated with the hoisted structure (4). The control unit (CU) may be configured to trigger the actuation mechanism (AM) based on signals re-ceived from the detection module (DM). The signal received from the detection module (DM) [as shown in FIG.6] may correspond to the pre-defined parameters. The pre-defined parameters are at least one of freefall condition and over speed con-dition of the hoisted structure (4). In an embodiment, the detection module (DM) may be a speed sensor configured to determine speed at which the hoisted structure (4) is traversing in the hoist way. The detection module (DM) sends the signal to the control unit (CU) which then triggers the actuation mechanism (AM) to operate the one or more brake shoes (3) between a first position and the second position. Trigger-ing the actuation mechanism (AM) electrically activates the trigger assembly (5) which in turn operates the linkage mechanism (5f) to operate/displace the one or more brake shoes (3) to the second position from the first position. Once the actua-tion mechanism (AM) is electrically activated, the actuation mechanism (AM) trans-mits an electrical pulse to the fuse wire cartridge (5b2) of the trigger assembly (5b). The electrical pulse transmitted to the electrical contacts (7a) of the fuse wire car-tridge (5b) to melt/diffuse/fuse the fuse wire (7b) which are in contact with the elec-trical contacts (7a). Upon diffusing the fuse wire (7b) to release the restraining lever (5b3) in turn releasing the actuating rod (5e) to the retracted position [as shown FIG.4b]. Once the fuse wire (7b) is diffused the second section (5b22) is released from the first section (5b21) of the fuse wire cartridge (5b2). Once the second sec-tion (5b22) is released from the first section (5b21), the restraining lever (5b3) cou-pled to the second section (5b22) abutting the support plate (S) collapses. Once the restraining lever (5b3) collapses, the resilient member (5d) moves to the relaxed state from the compressed state [refer FIG.4b]. When the resilient member (5d) is moved to the relaxed state it simultaneously moves the actuation rod (5e) to the retracted position. Upon moving the actuation rod (5e) to the retracted position, the linkage mechanism (5f) may be actuated. When the actuation rod (5e) is displacing to the re-tracted position, the linkage assembly (5f) simultaneously moves along with the ac-tuation rod (5e). The actuation rod (5e) draws the first link member (5f1) towards the housing (5a) during the retraction. Drawing the first link member (5f1) pivotally moves the third link member (5f3) through the second link member (5f2). The third link member (5f3) may then impart linear motion to the fourth link member (5f4). When the third link member (5f3) pivots relative to the movement of the first link member (5f1), the fourth link member (5f4) may displace upwardly along a vertical path. Vertical upward movement of the fourth link member (5f4) results in displac-ing of the one or more brake shoes (3) to the second position. Once the one or more brake shoes (3) is in second position, the inclined surface of the brake liner (2) may transverse along co-operating inclined surface of corresponding brake shoe of the one or more brake shoes (3) up to a pre-defined distance. Due to the complementing wedge-shaped profile of the brake liner (2) and corresponding brake shoe, the one or more brake shoes (3) frictionally engage both the guide rail (1) and the brake liner (2a) to progressively halt/slow down the hoisted structure (4). In the second position, the one or more brake shoes (3) is adapted to frictionally engage the guide rail (1) and the brake unit (2) to exert braking force on the hoisted structure (4). The hoisted structure (4) comes to halt once the one or more brake shoes (3) are engaged with the guide rail (1) and the brake liner (2a).
[0032] In an embodiment, a reset lever (5c) may be disposed at a pre-determined location in the housing (5a). For instance, a holder may be defined in the housing (5a) which is adapted to hold the reset lever (5c) [refer FIG.4c]. The reset lever (5c) may be used to reset the trigger assembly to initial stage as shown in FIG.4a and 4c after replacing the restraining lever and fuse wire cartridge. In an embodiment, the reset lever (5c) may be a reset bolt without deviating from the scope of the present disclosure.
[0033] In an embodiment of the disclosure, the control unit (CU) may be a centralized con-trol unit, or a dedicated control unit associated with the system (10). The control unit may be comprised of a processing unit. The processing unit may comprise at least one data processor for executing program components for executing user- or system-generated requests. The processing unit may be a specialized processing unit such as integrated system (bus) controllers, memory management control units, floating point units, graphics processing units, digital signal processing units, etc. The processing unit may include a microprocessor, such as AMD Athlon, Duron or Opteron, ARM’s application, embedded or secure processors, IBM PowerPC, Intel’s Core, Itanium, Xeon, Celeron, or other line of processors, etc. The processing unit may be imple-mented using a mainframe, distributed processor, multi-core, parallel, grid, or other architectures. Some embodiments may utilize embedded technologies like applica-tion-specific integrated circuits (ASICs), digital signal processors (DSPs), Field Pro-grammable Gate Arrays (FPGAs), etc. In some embodiments, the processing unit may be disposed in communication with one or more memory devices (e.g., RAM, ROM etc.) via a storage interface. The storage interface may connect to memory de-vices including, without limitation, memory drives, removable disc drives, etc., em-ploying connection protocols such as serial advanced technology attachment (SA-TA), integrated drive electronics (IDE), IEEE-1394, universal serial bus (USB), fibre channel, small computing system interface (SCSI), etc. The memory drives may fur-ther include a drum, magnetic disc drive, magneto-optical drive, optical drive, re-dundant array of independent discs (RAID), solid-state memory devices, solid-state drives, etc.
[0034] It is to be understood that a person of ordinary skill in the art may develop a system and a method of similar configuration without deviating from the scope of the pre-sent disclosure. Such modifications and variations may be made without departing from the scope of the present disclosure. Therefore, it is intended that the present disclosure covers such modifications and variations provided they come within the ambit of the appended claims and their equivalents.
ADVANTAGES OF THE INVENTION
[0035] The safety braking system (10) for a hoisted structure (4) guided along a guide rail (1) in accordance with the present disclosure requires lesser number of mechanical components when compared to the conventional systems. The safety braking system (10) in accordance with the present disclosure significantly reduces activation time compared to conventional braking systems. Also, the cost of manufacturing is signif-icantly lesser as the number of components involve in manufacturing the safety brak-ing system is also less. The safety braking system (10) of the present disclosure elim-inates the need for a governor system, which in turn reduces space and cost con-straints.
, Claims:WE CLAIM:
1. A safety braking system (10) for a hoisted structure (4) guided along a guide rail (1), the system (10) comprising:
a brake unit (2) mounted to a hoisted structure (4) and being configured to move along a guide rail (1) to guide the hoisted structure (4);
one or more brake shoes (3) accommodated in a space defined between a brake liner (2a) of the brake unit (2) and the guide rail (1); and
an actuation mechanism (AM) configured to operate the one or more brake shoes (3) from a first position and a second position, the actuation mechanism (AM) comprises:
a trigger assembly (5) secured to the hoisted structure (4), wherein the trigger assembly (5) being configured to be electrically activated based on pre-defined parameters;
a linkage assembly (5f) connecting the trigger assembly (5) and each of the one or more brake shoes (3),
wherein the trigger assembly (5) when electrically activated actuates the link-age assembly (5f) to displace the one or more brake shoes (3) to the second po-sition from the first position,
and wherein, in the second position the one or more brake shoes (3) adapted to frictionally engage the guide rail (1) and the brake unit (2) to exert braking force on the hoisted structure (4).

2. The system (10) as claimed in claim 1, wherein the brake liner (2a) and the one or more brake shoes (3) is defined with complementing wedge-shaped profile.

3. The system (10) as claimed in claim 1 and 2, comprises a roller arrangement (6) mova-bly mounted on the brake liner (2a) of the brake unit (2), the roller arrangement (5) is provided in a side of the brake liner (2a) which is adapted to come in contact with the one or more brake shoes (3).

4. The system (10) as claimed in claim 1, wherein the trigger assembly (5) comprises:
a housing (5a);
an actuating rod (5e) movably disposed in the housing (5a), wherein one end (5e1) of the actuating rod (5e) is coupled the linkage assembly (5), and a support plate (S) is defined on the actuating rod (5e);
a resilient member (5d) disposed within the housing (5a) between the support plate (S) defined on the actuating rod (5e) and the housing (5a); and
a restraining mechanism (5b) being configured to hold the resilient member (5d) in compressed state and release the resilient member (5d) to a relaxed state when electrically activated,
wherein, the restraining mechanism (5b) being configured hold the actuation rod (5e) in the extended position in the compressed state of the resilient member (5d) and re-lease the actuation rod (5e) to the retracted position in the relaxed state of the resilient member (5d), relative to the housing (5a).

5. The system (10) as claimed in claim 4, wherein the restraining mechanism (5b) com-prises:
a fuse wire cartridge (5b2), wherein the fuse wire cartridge (5b2) comprising a first section secured to the housing (5a) and a second section releasably coupled to the first section through a fuse wire (7b); and
a restraining lever (5b3) coupled to the second section of the fuse wire car-tridge (5b2) at one end and other end opposite to the one end configured to abut the support plate (S) of the trigger assembly (5).

6. The system (10) as claimed in claim 4 and 5, wherein the restraining lever (5b) abuts the support plate (S) defined on the actuating rod (5e) when the resilient member (5d) is in compressed state.

7. The system (10) as claimed in claim 5, wherein the fuse wire (7b) is configured melt upon receiving electrical pulses and release the second section from the first section.

8. The system (10) as claimed in claim 1, wherein the linkage assembly (5f) comprises a first link member (5f1) one end of which is coupled to the actuating rod (5e), a second link member (5f2) coupled to an other end of the first link member (5f1) opposite to the one end, a third link member (5f3) is secured to the second link member (5f2) and a fourth link member (5f4) secured to the third link member (5f3) each movable rela-tive to each other based on the movement of the actuating rod (5e) from the extended position to the retracted position to displace the one or more brake shoes (3) to the second position.

9. The system (10) as claimed in claim 1 comprises a control unit (CU) communicatively coupled to the actuation mechanism (AM), wherein the control unit (CU) is config-ured to trigger the actuation mechanism (AM) based on the pre-defined parameters, wherein triggering the actuation module (AM) transmits an electrical pulse to the fuse wire cartridge (5b2) to melt the fuse wire (7b) to release the restraining lever (5b3) in turn releasing the actuating rod (5e) to the retracted position.

10. The system (10) as claimed in claim 8, wherein the control unit (CU) receives a signal corresponding to the predefined parameter from a detection module (DM) associated with the control unit (CU), wherein the pre-defined parameter is at least one of free-fall condition and over speed condition of the of the hoisted structure (4).