A wear-indicating roller assembly

Abstract

A wear-indicating roller assembly (101) for an elevator installation is disclosed. The roller assembly (101) includes a pair rolling members (102-1, 102-2), that is consisting of a first rolling member (102-1) and a second rolling member (102-2), adapted to be coupled to each other. At least one of the first rolling members (102-1) or the second rolling member (102-2) includes a body (104) having an inner portion (106) with a coloured indicator substance. The body (104) includes an outer portion (108) and a rolling surface (108-1) defined on the outer portion (108). The rolling surface includes at least one wear-indicating segment (112). The body (104) includes at least one cavity (110) formed in the inner portion (106) and adapted to be covered by the wear- indicating segment (112) of the rolling surface (108-1). The coloured indicator substance leaks through the at least one cavity (110) and becomes visible at the body and / or in proximity of the pair of rolling members (102-1, 102-2). The visibility of the leaked coloured indicator substance is indicative of an alert to replace the worn roller assembly (101).

Description

[0001] A WEAR-INDICATING ROLLER ASSEMBLY

[0002] The present invention relates to an elevator door system of an elevator installation and to a wear-indicating roller assembly for an elevator door system of an elevator installation.

[0003] Nowadays, elevators are an essential part of multi-story buildings, such as commercial buildings or residential buildings, fortransporting persons / goods between different floors. Such elevators usually require periodic maintenance and inspection to ensure optimal operation of the elevators without any breakdowns. For instance, roller components, such as elevator door rollers, are subjected to wear over a period of time during the operation of the elevator unit. Therefore, the technician is required to periodically monitor the condition of such components and replace such components based on the amount of wear. If the roller components are not monitored or replaced periodically, then wear endured by such components may result in degradation of the overall performance of the elevator. For instance, if the elevator door rollers are not monitored periodically for wear / tear, then worn-out rollers might result in vibration, noise, and misalignment in the elevator doors. Therefore, the technician is required to periodically monitor and replace the roller components based on the amount of wear / tear sustained by such components.

[0004] EP0703338B1 shows a roller for a sliding door, in particular for an elevator sliding door consisting of a ball bearing, and an inner ring in a working position of the roller with a sliding door load-bearing suspension bracket.

[0005] Currently, rollers are inspected by field technician during their maintenance visit. The technician is required to dismantle multiple components to properly diagnose the service condition of the rollers. In particular, the technician is required to dismantle multiple components so that the rollers are visually accessible to determine the service condition of such rollers. Therefore, such a process for determination of the service condition of the rollers is cumbersome and time-consuming. Further, the technician can visualize the wear on the rollers only when the roller is in the last stages of its service life. In this case, there are chances of system breakdown of the bearing capability of the rollers. Service calls with high urgence can be the effect of a breakdown. After a breakdown, the technician replaces the roller and reinstates the operational status of the elevator unit. This is a reactive approach, which causes nonavailability of elevator service and user dissatisfaction. Therefore, there is an immense desire to develop a roller that can eliminate one or more shortcomings associated with the abovementioned elevators.

[0006] According to a first aspect of the invention, a wear-indicating roller assembly for an elevator installation is disclosed. The roller assembly includes at least a pair of rolling members. The pair consisting of a first roller member and a second roller member. The first rolling member and the second rolling member are adapted to be coupled to each other, and at least one of the pair of rolling members includes a body. The body includes an inner portion holding a coloured indicator substance, and an outer portion formed opposite to the inner portion. The body includes a rolling surface defined on the outer portion and comprising at least one wearindicating segment. Further, the body includes at least one cavity formed in the inner portion and adapted to be covered by the wear-indicating segment of the rolling surface. The coloured indicator substance leaks through the at least one cavity upon wearing of the wear-indicating segment such that the coloured indicator substance is visible at least on the body and in proximity of the pair of rolling members. The visibility of the leaked coloured indicator substance is indicative of an alert to replace the worn roller assembly.

[0007] According to a second aspect of the invention, an elevator door system for an elevator installation is disclosed. The elevator door system includes a door rail and a wear-indicating roller assembly as described in the above paragraphs. A pair of rolling members of the wearindicating roller assembly, when assembled, engages with the door rail such that at least a rolling surface of at least one of the pair of rolling members forms a surface contact with the door rail.

[0008] Possible features and advantages of embodiments / aspects of the invention can be considered, among other things, and without limiting the invention, to be dependent upon the concepts and findings described below.

[0009] As explained earlier, the wear-indicating roller assembly comprises the pair of rolling members, where at least one rolling member includes the body having the coloured indicator substance. In one embodiment, the body of only one rolling member may be provided with the coloured indicator substance. In another embodiment, the body of each rolling member may be provided with the coloured indicator substance. The coloured indicator substance is provided in the inner portion of the body such that the coloured indicator substance is only visible when the wear-indicating roller assembly is worn out. This has the advantage that the technician can determine whether to replace the wearindicating roller assembly based on the visibility of the coloured indicator substance.

[0010] The coloured indicator substance can be embodied as one of a coloured liquid substance and a coloured powder substance.

[0011] In one or more embodiments, the rolling surface may be subjected to a maximum wear effect during the operation of the wear-indicating roller assembly. The rolling surface of the body includes at least one wear-indicating segment and at least one cavity formed in the inner portion. Advantageously, the at least one wear-indicating segment is provided as an integral part of the rolling surface such that the at least one wear-indicating segment undergoes a wear effect similar to the rolling surface during the rolling movement of the wear-indicating roller assembly. In particular, this has the advantage that at least one wear-indicating segment is provided as an integral part of a surface, i.e., the rolling surface, which is subjected to a maximum wear effect and therefore, if the at least one wear-indicating segment worn out then it indicates an accurate wear condition of the wear-indicating roller assembly.

[0012] In one embodiment, the body of each rolling member may include one cavity and one wearindicating segment covering such a cavity. In another embodiment, the body of each rolling member may include multiple cavities equally distant apart from each other and multiple wearindicating segments corresponding to such cavities.

[0013] The at least one wear-indicating segment covers the at least one cavity such that the coloured indicator substance may not spill out through the at least one cavity until the at least one wearindicating segment is worn out. In particular, when the at least one wear-indicating segment is worn out, then the coloured indicator substance leaks through the at least one cavity to indicate that the wear-indicating roller assembly needs to be replaced.

[0014] Advantageously, when the wear-indicating segment is worn out, the coloured indicator substance visibly leaks on at least the body and in the proximity of the pair of rolling members. This has the advantage that the technician is not required to dismantle multiple components to properly diagnose the service condition of the rollers. Rather, based on the visibility of the coloured indicator substance, the technician can determine, with ease, that the wear-indicating roller assembly is required to be replaced. This substantially reduces the overall timeconsumption and the overall complexity associated with a process for determination the service condition of the rollers. Therefore, the wear-indicating roller assembly of the present invention is compact, more reliable, easy to replace, and easy to implement.

[0015] In the following, further embodiments of the present invention are described.

[0016] In one or more embodiments, a thickness of the wear-indicating segment is less than a thickness of remaining segments of the rolling surface. The thickness of the wear-indicating segment is selected to achieve at least one of a threshold usage cycles and a threshold service life of the roller assembly.

[0017] This has the advantage that the overall amount of material required for manufacturing the roller assembly is substantially reduced. In particular, owing to the lesser thickness of the at least one wear-indicating segment, the material required for forming the rolling surface is reduced and therefore, the overall material cost is also substantially reduced. Further, this has the advantage that the remaining segments have a higher thickness compared to the at least one wearindicating segment, and therefore, the overall strength of the wear-indicating roller assembly is un-compromised.

[0018] Furthermore, advantageously, the wear-indicating segment provides flexibility in regulating usage cycles and / or service life of the roller assembly. In particular, by varying the thickness of the wear-indicating segment, the usage cycles and / or service life of the roller assembly can be varied. This also ensures that the thickness of the remaining segments need not be varied for regulating the usage cycles and / or service life and thereby the overall strength of the wearindicating roller assembly is un-compromised.

[0019] In one or more embodiments, the thickness of the wear-indicating segment is in a range of 0.2 mm to 1mm.

[0020] In one or more embodiments, the pair of rolling members, when assembled, is attached to an elevator door system, and engages with a door rail such that at least the rolling surface of at least one of the pair of rolling members forms a surface contact with the door rail.

[0021] As mentioned earlier, the rolling surface of at least one of the pair of rolling members may include the at least one wear-indicating segment. Advantageously, when the pair of rolling members, in an assembled condition, attached to the elevator door system, the rolling surface forms the surface contact with the door rail such that the wear-indicting segment may also form the surface contact with the door rail and undergo wear to allow spillage of the coloured indicator substance through the cavity of the rolling member.

[0022] In one or more embodiments, the body includes a chamber defined in the inner portion and adapted to be filled with the coloured indicator substance such that the coloured indicator substance leaks through the at least one cavity upon wearing of the wear-indicating segment.

[0023] This has the advantage that the coloured indicator substance can be filled within a confined space, such as the chamber, to ensure that the coloured indicator substance is not visible until the at least one wear-indicating segment is worn out. In particular, the coloured indicator may remain confined within the chamber and leak through the at least one cavity only when the at least one wear-indicating segment covering such cavity is worn out. Advantageously, the chamber securely holds the coloured indicator substance within the body of at least one rolling member.

[0024] In one or more embodiments, the body includes an engaging member concentrically formed with respect to the rolling surface. The engaging member of the first rolling member is adapted to be fastened to the second rolling member to form the roller assembly.

[0025] This has the advantage that the pair of rolling members can be removably coupled to each other through the engaging member using fasteners, and therefore the overall modularity of the wearindicating roller assembly is increased. Further, such removable fastening of the rolling members substantially simplifies the repair process for the wear-indicating roller assembly.

[0026] In one or more embodiments, the engaging member includes a first circular element protrudes from the outer portion. The first circular element includes a first peripheral wall defining a half portion of a supporting surface of the first rolling member. Further, the engaging member includes a second circular element protruding from the inner portion. The second circular element includes a second peripheral wall defining an inner boundary of the chamber. Each of the first circular element and the second circular element includes a plurality of fastening holes circumferentially formed thereon to receive fasteners for fastening the first rolling member with the second rolling member, such that the half portions of the first and the second rolling members laterally align with each other to form the supporting surface.

[0027] The advantage of providing the second peripheral wall is that the inner boundary of the chamber is defined such that the coloured indicator substance filled within the chamber remains therein. In particular, the second peripheral wall ensures that the coloured indicator substance restricts the spilling of the coloured indicator substance from the chamber during a rolling movement of the wear-indicating roller assembly.

[0028] In one or more embodiments, the at least one first or the second rolling member includes a cover element coupled to the body and is adapted to hold the coloured indicator substance within the chamber and restrict spillage of the coloured indicator substance from the chamber. This also include that both, the first and the second rolling member include a cover element coupled to the body and are adapted to hold the coloured indicator substance within the chamber and restrict spillage of the coloured indicator substance from the chamber.

[0029] In one or more embodiments, the body includes a flange extending orthogonally from the rolling surface and defining an outer perimeter of the chamber. The flange includes a step portion adapted to engage with the cover element to form a hermetically sealed connection therebetween.

[0030] The advantage of providing the flange is that the outer perimeter is defined for the chamber and therefore, the outer perimeter ensures that the coloured indicator substance remains within the chamber and restricts spillage of the coloured indicator substance from the chamber. Further, advantageously, the step portion of the flange is formed such that the cover element forms the hermetically sealed connection and thereby, ensuring that the coloured indicator substance is not leaked from the chamber through the outer perimeter of the chamber. In particular, such a hermetically sealed connection eliminates any gaps between the outer perimeter of the chamber and the cover element when the cover member is attached to the body. This ensures that the coloured indicator substance remains within the chamber and does not leak from the chamber when the cover member is attached to the body. In one or more embodiments, the cover element includes a peripheral region adapted to be seated on the step portion and forms the hermetically sealed connection to restrict spillage of the coloured indicator substance through the outer perimeter of the chamber. The cover element includes an inner surface adapted to orthogonally abut the second peripheral wall when the cover member coupled to the body and forms a sealed connection therebetween to restrict spillage of the coloured indicator substance through a central opening of the body.

[0031] Advantageously, the peripheral region of the cover element is formed such that the peripheral region forms the hermetically sealed connection with the step portion of the flange of the body to restrict the spillage of the coloured indicator substance through the outer perimeter of the chamber. Further, advantageously, the cover element is provided with the inner surface which forms a surface contact with the second peripheral wall defining the inner periphery of the chamber, and thereby ensuring that the sealed connection is formed between the cover element and the second peripheral wall. Such sealed connection ensures that the coloured indicator substance filled within the chamber may not spill through the central opening of the body. Therefore, the advantage of attaching the cover member with the body is that the chamber is sealed from the outer periphery and the inner periphery such that the coloured indicator substance may not spill or leak from the chamber at least during the operation of the wearindicating roller assembly.

[0032] In one or more embodiments, the wear-indicating roller assembly comprises at least one dampening ring disposed on the supporting surface defined when the half portions of the rolling members laterally align with each other. A top surface of the at least one dampening ring flushes with the rolling surface of each rolling member.

[0033] In one or more embodiments, the at least one dampening ring may be formed of a soft elastic polymeric material including, but not limited to, natural hard rubber, synthetic rubber, Polyurethane, Polyvinyl Chloride (PVC), and an elastomeric material. This has the advantage that the at least one dampening ring can inhibit vibrations transmitted to the wear-indicating roller assembly from the guide rail and thereby, ensuring a smooth rolling movement of the wear-indicating roller assembly on the guide rail. In particular, to ensure that the door rail of the elevator door system maintains constant surface contact with the rolling surface so that the rolling motion of the wear-indicating roller assembly is smooth, the contact should be free from vibrations. To dampen the vibrations, the dampening ring may be arranged in such a way that the dampening ring may absorb vibrations in the wear-indicating roller assembly. For instance, the dampening ring may absorb vibrations in the door rail and prevent the transmission of vibrations to a door header of the elevator door system. In another instance, the dampening ring may absorb vibrations in the door header and prevent transmission thereof to the door rail.

[0034] Further, advantageously, the at least one dampening ring substantially reduces noise levels during the operation of the wear-indicating roller assembly. The at least one dampening ring may be formed of a flexible material.

[0035] In one or more embodiments, the at least one dampening ring is fixedly integrated, using a moulding process, to the half portion of each rolling member.

[0036] This has the advantage that the at least one dampening ring is formed as an integral part of each rolling member without multiple removable components and therefore, the overall manufacturing cost of the wear-indicating roller assembly is substantially reduced, and the overall strength of each roller member is substantially increased. Further, the overall design of each rolling member is simpler to manufacture.

[0037] In one or more embodiments, the at least one dampening ring is removably disposed on the supporting surface formed when the rolling members are coupled to each other.

[0038] In one or more embodiments, the body is formed of a lightweight material compared to the cover element.

[0039] Comparatively, a size of the body is substantially larger than a size of the cover element and therefore, the body is formed of the lightweight material compared to the cover element in order to maintain the overall weight of the wear-indicating roller assembly substantially low. In an embodiment, the body may be formed of a polymeric material. Further, the cover element may be formed of a metallic material.

[0040] In one or more embodiments, the rolling surface has an arcuate profde and is subjected to a higher wear rate relative to the half portion. Advantageously, the arcuate profile is formed complementary to a profile of the door rail such that the rolling surface effectively forms the surface contact with the guide rail during the rolling movement of the wear-indicating roller assembly. Further, the rolling surface is subjected to the higher wear rate and therefore, the at least one wear-indicating segment is provided on the rolling surface. This ensures that if the at least one wear-indicating segment is worn out then it indicates an accurate wear condition of the wear-indicating roller assembly. In particular, this has the advantage that once the at least wear-indicating segment is worn out, then the wear-indicating roller assembly needs to be replaced and thereby, reducing the risk of prolonged operation of such wear-indicating roller in a worn-out condition. Owing to the implementation of the at least one wear-indicating segment, the wear-indicating roller can be replaced well before a breakdown / service call associated with the elevator door system might happen due to an extensively worn-out roller. Therefore, this further eliminates the chances of sudden breakdown / service call associated with the elevator door system during the prolonged operation of worn-out rollers.

[0041] The term “threshold usage cycle” may be defined as a threshold number of operational cycles of the elevator door system in which the wear-indicting rolling assembly is deployed. The operational cycles may be referred to opening and closing cycle of the elevator door.

[0042] The term “threshold service life” may be defined as a threshold operational time period, such as a number of operational years, of the wear-indicating roller assembly.

[0043] Further advantages, features and details of the invention will become apparent from the following description of embodiments and from the drawings, in which identical or functionally identical elements are denoted with identical reference signs. The drawings are merely schematic and not to scale.

[0044] Figure 1 illustrates an isometric view of an elevator door system for an elevator installation, according to an embodiment of the present invention;

[0045] Figure 2 illustrates an isometric view of a wear-indicating roller assembly for the elevator door system, according to an embodiment of the present invention;

[0046] Figure 3 illustrates an exploded view of the wear-indicating roller assembly, according to an embodiment of the present invention;

[0047] Figures 4a and 4b illustrate different isometric views of a body of one rolling member of the wear-indicating roller assembly, according to an embodiment of the present invention;

[0048] Figures 5a and 5b illustrate an isometric view of the body and an enlarged view of a portion of the body, respectively, according to an embodiment of the present invention;

[0049] Figure 6a illustrates a sectional view of a portion A of the elevator door system as shown in Figure 1, according to an embodiment of the present invention;

[0050] Figure 6b illustrates a sectional view of an enlarged portion of the elevator door system as shown in Figure 6a, according to an embodiment of the present invention;

[0051] Figure 7 illustrates a partial exploded view of the wear-indicating roller assembly, according to an embodiment of the present invention;

[0052] Figure 8a illustrates a planar view of the wear-indicating roller assembly, according to an embodiment of the present invention; and

[0053] Figure 8b illustrates an isometric sectional view of an enlarged portion of the wear-indicating roller assembly as shown in Figure 8a, according to an embodiment of the present invention.

[0054] Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

[0055] Figure 1 illustrates an isometric view of an elevator door system 100 for an elevator installation, according to an embodiment of the present invention. The elevator door system 100 may be employed to either open or close an elevator door (not shown). The elevator door system 100 may include a door header 105 that may support the elevator door thereon. The elevator door system 100 may include a door panel 107 having various components that allow the movement of the door header 105 to operate the elevator door. For instance, the door panel 107 may include a door rail 103 mounted thereon along the length of the door panel 107. In addition, the elevator door system 100 may include at least one wear-indicating roller assembly 101 (also indicated by the dotted line A) mounted on the door rail 103 and may adapted to slide the door header 105 relative to the door panel 107. In the illustrated embodiment, only one wearindicating roller assembly 101 may be depicted in the elevator door system 100. However, it should not be construed as limiting and the elevator door system 100 may include multiple wear-indicating roller assemblies, without departing from the scope of the present invention.

[0056] In the illustrated embodiment, the wear-indicating roller assembly 101 may be coupled to the door header 105, such that a rolling motion of the wear-indicating roller assembly 101 over the door rail 103 causes the door header 105 to slide relative to the door panel 107.

[0057] The wear-indicating roller assembly 101 of the present invention is designed in such a way that the wear-indicating roller assembly 101 may provide a visual indication indicative of the operational service life undergone by the wear-indicating roller assembly 101. In the illustrated embodiment, the wear-indicating roller assembly 101 may be designed to spill or release a coloured indicator substance upon the lapse of a predetermined threshold usage or a threshold service life. The coloured indicator substance, in one example, may either be a coloured powder substance, or a coloured liquid substance.

[0058] The term threshold usage cycle may be defined as a threshold number of operational cycles of the elevator door system 100 in which the wear-indicting rolling assembly 101 is deployed. The operational cycles may be referred to opening and closing cycle of the elevator door. The term threshold service life may be defined as a threshold operational time period, such as a number of operational years, of the wear-indicating roller assembly. The release of the coloured indicator substance may indicate that the wear-indicating roller assembly 101 is worn and nearing operational service life. Therefore, the wear-indicating roller assembly 101 may indicate to the technician to replace the worn-out roller assembly 101. The construction and operational details of the wear-indicating roller assembly 101 are explained in detail in subsequent paragraphs.

[0059] Figure 2 illustrates an isometric view of the wear-indicating roller assembly 101 for the elevator door system 100, according to an embodiment of the present invention. Figure 3 illustrates an exploded view of the wear-indicating roller assembly 101, according to the same embodiment of the present invention. Such a wear-indicating roller assembly 101 is suitable to be used in of an elevator door system as shown in Fig. 1. The wear-indicating roller assembly 101 may include various components, including, but not limited to, at least a pair of rolling members 102-1, 102-2, a dampening ring 118 positioned between the pair of rolling members 102-1, 102- 2, and a bearing 119 adapted to rotatably mount the wear-indicating roller assembly 101 to the door header. The pair of rolling members 102-1, 102-2 may interchangeably be referred to as the rolling member 102-1, 102-2, without departing from the scope of the present invention.

[0060] Further, the first rolling member 102-1 and the second rolling member 102-2 may include a rolling surface 108-1. The rolling members 102-1, 102-2, when assembled, may engage with the door rail 103 such that the rolling surface 108-1 of at least one rolling member 102-1, 102-2 forms a surface contact with the door rail 103. Such an arrangement results in the rolling of the wear-indicating roller assembly 101 relative to the door rail 103. Moreover, the rolling motion also causes the wearing of the rolling of the rolling member 102-1, 102-2 and the rolling surface 108-1 may experience wear and tear. Further, upon the lapse of the threshold usage cycle or the threshold service life, a portion of the rolling surface 108-1 may wear out thereby releasing the coloured indicator substance indicating a visual indication for the replacement of worn wearindicating roller assembly 101.

[0061] In the illustrated embodiment, each rolling member 102-1, 102-2 may include a cover element 116 that covers an outer side of the rolling member 102-1, 102-2. In addition, the wearindicating roller assembly 101 may include a plurality of fasteners 202 that couples the rolling members 102-1, 102-2 together. Further, each rolling member 102-1, 102-2 may include the body 104 that may be coupled together by the fasteners 202, such that the dampening ring 118 is positioned therebetween.

[0062] In the illustrated embodiment, the body 104 may be formed of a lightweight material compared to the cover element 116. The body 104 of each rolling member 102-1, 102-2 may include an engagement member 114 that may be concentrically formed with respect to the rolling surface 108-1. The engagement member 114 of one rolling member 102-1 may be fastened using the fasteners 202 to the engagement member of another rolling member 102-2 to form the wearindicating roller assembly 101. The constructional details of the body 104 are explained in the subsequent paragraphs.

[0063] Figures 4a and 4b illustrate different isometric views of a body 104 of a first rolling member or a second rolling member of a wear-indicating roller assembly, according to an embodiment of the present invention. Such a body could also be part of the wear-indicating roller assembly of Figures 1, 2 or 3. Specifically, Figure 4a illustrates a front side of the body 104 whereas Figure 4b illustrates a rear side of the body 104. For the following description, the structure of the body 104 will be explained with respect to the rolling member and the same explanation is applicable for the rolling member. The rolling member, as mentioned before, may include the body 104. Further, the body 104 may include an inner portion 106 and an outer portion 108 that may be formed opposite to the inner portion 106. The inner portion 106 may be configured to hold the coloured indicator substance.

[0064] In the illustrated embodiment, referring to Figures 3 and 4a-4b, the engagement member 114 may extend through the outer portion 108 and the inner portion 106. Further, the engagement member 114 may include a first circular element 302 protruding from the outer portion 108. The first circular element 302 may include a first peripheral wall 302-1. The engagement member 114 may also include a second circular element 304 protruding from the inner portion 106. The second circular element 304 may include a second peripheral wall 304-1. The engagement member 114 may include a central opening 310 that may receive a bearing 119 (shown in Figure 3).

[0065] As shown in Figures 4a and 4b, each of the first peripheral wall 302-1 and the second peripheral wall 304-1 may include a plurality of fastening holes 306 that may be formed circumferentially thereon. During the assembly of the first or second rolling members 102-1, 102-2, the plurality of fastening holes 306 may receive the fasteners 202 for fastening the rolling members 102-1, 102-2 together. Further, the top surfaces of the first circular element 302 may abut each other when the roller members 102-1, 102-2 are assembled.

[0066] As shown in Figure 4a, the rolling surface 108-1 may be defined on the outer portion 108. In addition, the outer portion 108 may also include a half portion 108-2 that may extend from an edge of the rolling surface 108-1. In the illustrated embodiment, the half portion 108-2 may have a flat surface. In one or more embodiments, the half portion 108-2 may have a curved profile similar to the rolling surface 108-1. In the illustrated embodiment, the half portions 108- 2 of the outer portions 108 of the roller members 102-1, 102-2 laterally align with each other to form a supporting surface that may support the dampening ring 118 thereon. A manner in which the half portion 108-2 is arranged is explained in the subsequent paragraphs. As shown in Figure 4a, the half portion 108-2 may include four bulge sections formed by the fastening holes 306. Further, the combined width of the half portions 108-2 may be equal to the width of the supporting surface for supporting the dampening ring 118 thereon.

[0067] Details of the inner portion will be explained in conjunction with Figures 5a and 5b which illustrate an isometric view of the body 104 and an enlarged view of a portion of the body 104, respectively, according to an embodiment of the present invention.

[0068] Referring to Figures 4b and 5a-5b, the inner portion 106 may be formed behind the outer portion 108. Accordingly, the rear side of the rolling surface 108-1 and the half portion 108-2 may define a base of the inner portion 106. The inner portion 106 may include a flange 308 that may extend from the periphery of the inner portion 106. Further, the flange 308 may extend orthogonally from the rolling surface 108-1 (see Fig. 4a). The flange 308 may engage with the cover element 116 (shown in Figures 2 and 3). In the illustrated embodiment, the flange 308 (see Fig. 4b) may include a step portion 308-1 that may receive a circumferential edge of the cover element.

[0069] Referring to Figure 4b and Figures 5a-5b, a chamber 106-1 may be defined in the inner portion 106. The chamber 106-1 may be filled with the coloured indicator substance. Further, the second peripheral wall 304-1 of the second circular element may define an inner boundary of the chamber 106-1. The flange 308 may define an outer perimeter of the chamber 106-1. The body 104 may also include at least one cavity 110 formed in the inner portion 106. In particular, the at least one cavity 110 may be provided in the chamber 106-1 defined in the inner portion 106. In the illustrated embodiment, the body 104 may include four cavities 110 formed equally distant apart from each other. The at least one cavity 110 may interchangeably be referred to as the cavity 110, without departing from the scope of the present invention.

[0070] The cavity 110 may be adapted to allow the release of the coloured indicator substance upon wearing of the rolling surface 108-1. The cavity 110 may be formed as a depression in the chamber 106-1. Referring to Figure 5b, the cavity 110 may include a pair of walls 110-1 that forms a longitudinal channel. The arrangement of walls 110-1 and the longitudinal channel portions allows for easy discharge of the coloured indicator substance from the chamber 106-1.

[0071] According to the present invention, the coloured indicator substance may be hermetically sealed in the chamber 106-1 such that the coloured indicator substance does not leak during the normal operation of the wear-indicating roller assembly 101. Referring to Figures 6a and 6b which illustrate various views of a portion of the wear-indicating roller assembly 101, according to an embodiment of the present invention. Such wear-indicating roller assembly 101, can be the same as presented in Figures 1 to 5b. Specifically, Figure 6a illustrates a sectional view of a portion A of the elevator door system as shown in Figure 1 whereas Figure 6b illustrates a sectional view of an enlarged portion of the elevator door system as shown in Figure 6a.

[0072] As shown, the door rail 103 may be engaged to the rolling surface 108-1 of assembled rolling members 102-1, 102-2 such that the rolling surface 108-1 or at least one of the first rolling member 102-1 or the second rolling member 102-2 forms a surface contact with the door rail 103. Further, the first rolling member 102-1 and the second rolling member 102-2 are designed in such a way that the rolling surface 108-1 may have different thicknesses at different segments thereof. For instance, the rolling surface 108-1 may include a wear-indicating segment 112 formed over the cavity 110. In the illustrated embodiment, the rolling surface 108-1 may include four wear-indicating segments formed over four respective cavities 110.

[0073] Further, a thickness of the wear-indicating segment 112 may be less than the thickness of the rolling surface 108-1 at remaining segments thereof. In an embodiment, the thickness of the wear-indicating segment 112 is in a range of 0.2 mm to 1mm. The thickness T may be selected based on at least one of the threshold usage cycles and the threshold service life of the wearindicating roller assembly 101. In addition, the rolling surface 108-1 may have an arcuate profile, such that the rolling surface 108-1 is subjected to a higher wear rate relative to the half portion 108-2.

[0074] The low thickness ensures that as the rolling surface 108-1 wear during the operation of the wear-indicating roller assembly 101, the wear-indicating segment 112 wears off to expose the cavity 110. As a result, the coloured indicator substance leaks through the cavity 110 upon wearing of the wear-indicating segment 112. The leaked coloured indicator substance spills at various locations. For instance, the coloured indicator substance may be visible on the body 104 or in proximity to the pair of rolling members 102-1, 102-2 or both. The proximity of the pair of rolling members 102-1, 102-2 may include, but is not limited to, a door rail 103, the door header 105, and the frame 204. The visible coloured indicator substance at the aforementioned locations may be indicative of an alert to replace the worn wear-indicating roller assembly 101.

[0075] Further to ensure that the door rail 103 maintains constant surface contact with the rolling surface 108-1 so that the rolling motion of the wear-indicating roller assembly 101 is smooth, the contact should be free from vibrations. To dampen the vibrations, the dampening ring 118 may be arranged in such a way that the dampening ring 118 may absorb vibrations in the wearindicating roller assembly 101. For instance, the dampening ring 118 may absorb vibrations in the door rail 103 and prevent the transmission of vibrations to the door header 105. In another instance, the dampening ring 118 may absorb vibrations in the door header 105 and prevent transmission thereof to the door rail 103.

[0076] As shown in Figure 6b, the dampening ring 118 may be installed in a seat formed by the two half portions 108-2 that are laterally aligned to form the supporting surface. The dampening ring 118 is installed in the seat in such that a top surface of the at least one dampening ring 118 flushes with the rolling surface 108-1 of each rolling member 102-1, 102-2. The dampening ring 118 may be installed to the half portions 108-2 in different ways. For instance, the dampening ring 118 may be fixedly integrated into the half portion 108-2 of each rolling member 102-1, 102-2 using a moulding process. In another instance, the dampening ring 118 is removably disposed on the supporting surface formed when the rolling members 102-1 and 102-2 are coupled to each other.

[0077] In one embodiment, the cover element 116 not only defines an outer surface of the rolling member 102-1, 102-2 but also seals the chamber 106-1. A manner by which the cover element 116 seals the chamber 106-1 is explained with respect to Figures 7, 8a, and 8b, according to an embodiment of the present invention. Specifically, Figure 7 illustrates a partially exploded view of the wear-indicating roller assembly 101 exposing the chamber 106-1 whereas Figure 8a illustrates a planar view of the wear-indicating roller assembly 101. Further, Figure 8b illustrates an isometric sectional view of an enlarged portion of the wear-indicating roller assembly 101 as shown in Figure 8a.

[0078] The cover element 116 may restrict spillage of the coloured indicator substance from the chamber 106-1. In the illustrated embodiment, the cover element 116 may encapsulate the chamber 106-1. Further, the cover element 116 may include a peripheral region 116-1 adapted to be seated on the step portion 308-1. The peripheral region 116-1 along with the step portion 308-1 may form a hermetically sealed connection to restrict spillage of the coloured indicator substance through the outer perimeter of the chamber 106-1. Further, in one or more embodiments, a chemical adhesive may be applied between the peripheral region 116-1 and the step portion 308-1 to further seal the chamber. The chemical adhesive may include, but is not limited to, an epoxy adhesive, a polyurethane adhesive, and a polyimide adhesive, without departing from the scope of the present invention.

[0079] In addition, the cover element 116 may include an inner surface 116-2 that faces the inner portion 106. The inner surface 116-2 may abut the second peripheral wall 304-1 orthogonally when the cover element 116 is coupled to the body 104. The orthogonal abutting may also provide a sealed connection between the second peripheral wall 304-1 and the inner surface 116-2 that may restrict spillage into the central opening 310. As a result, the cover element 116 seals the chamber 106-1 both at the second peripheral wall 304-1 and at the step portion 308-1. Further, in one or more embodiments, the chemical adhesive may be applied between the second peripheral wall 304-1 and the inner surface 116-2 to further seal the chamber 106-1.

[0080] Finally, it should be noted that the term “comprising” does not exclude other elements or steps and the pronouns “a” or “an” do not exclude a plurality. Also, elements described in association with different embodiments may be combined. It should also be noted that reference signs in the claims should not be construed as limiting the scope of the claims.

Claims

Claims:

1. A wear-indicating roller assembly (101) for an elevator installation, the roller assembly (101) comprising: at least a pair rolling members (102-1, 102-2), that is consisting of a first rolling member (102-1) and a second rolling member (102-2), the first rolling member and the second rolling member are adapted to be coupled to each other, and at least one of the pair of rolling members (102-1, 102- 2) comprising: a body (104) comprising: an inner portion (106) holds a coloured indicator substance. an outer portion (108) formed opposite to the inner portion (106); a rolling surface (108-1) defined on the outer portion (108) and comprising at least one wearindicating segment (112); and at least one cavity (110) formed in the inner portion (106) and adapted to be covered by the wearindicating segment (112) of the rolling surface (108-1), wherein the coloured indicator substance leaks through the at least one cavity (110) upon wearing of the wear-indicating segment (112) such that the coloured indicator substance is visible at least on the body (104) and in proximity of the pair of rolling members (102-1, 102-2), wherein the visibility of the leaked coloured indicator substance is indicative of an alert to replace the worn roller assembly (101).

2. The wear-indicating roller assembly (101) according to claim 1, wherein a thickness (T) of the wear-indicating segment (112) is less than a thickness of remaining segments of the rolling surface (108-1), wherein the thickness (T) of the wear-indicating segment (112) is selected to achieve at least one of a threshold usage cycles and a threshold service life of the roller assembly (101).

3. The wear-indicating roller assembly (101) according to claim 2, wherein the thickness (T) of the wear-indicating segment (112) is in a range of 0.2 mm to 1mm.

4. The wear-indicating roller assembly (101) according to any of the preceding claims, wherein the body (104) comprises: a chamber (106-1) defined in the inner portion (106) and adapted to be filled with the coloured indicator substance such that the coloured indicator substance leaks through the at least one cavity (110) upon wearing of the wear-indicating segment (112).

5. The wear-indicating roller assembly (101) according to any of the preceding claims, wherein the body (104) comprises: an engaging member (114) concentrically formed with respect to the rolling surface (108-1), wherein the engaging member (114) of the first rolling member (102-1) is adapted to be fastened to the second rolling member (102-2) to form the roller assembly (101).

6. The wear-indicating roller assembly (101) according to claim 5, wherein the engaging member (114) comprises: a first circular element (302) protrudes from the outer portion (108), and comprises a first peripheral wall (302-1) defining a half portion (108-2) of a supporting surface of the first or the second rolling member (102-1, 102-2); and a second circular element (304) protrudes from the inner portion (106), and comprises a second peripheral wall (304-1) defining an inner boundary of the chamber (106-1), wherein each of the first circular element (302) and the second circular element (304) comprises a plurality of fastening holes (306) circumferentially formed thereon to receive fasteners (202) for fastening the first rolling member (102-1) with the second rolling member (102-2), such that the half portions (108-2) of the first and the second rolling members (102-1, 102-2) laterally align with each other to form the supporting surface.

7. The wear-indicating roller assembly (101) according to any of the preceding claims, wherein the first or the second rolling member (102-1, 102-2) comprises: a cover element (116) coupled to the body (104) and adapted to hold the coloured indicator substance within the chamber (106-1) and restrict spillage of the coloured indicator substance from the chamber (106-1).

8. The wear-indicating roller assembly (101) according to any of the preceding claims, wherein the body (104) comprises: a flange (308) extending orthogonally from the rolling surface (108-1) and defining an outer perimeter of the chamber (106-1), and the flange (308) comprises a step portion (308-1) adapted to engage with the cover element (116) to form a hermetically sealed connection therebetween.

9. The wear-indicating roller assembly (101) according to any of the preceding claims, wherein the cover element (116) comprises:a peripheral region (116-1) adapted to be seated on the step portion (308-1) and forms the hermetically sealed connection to restrict spillage of the coloured indicator substance through the outer perimeter of the chamber (106-1), and an inner surface (116-2) adapted to orthogonally abut the second peripheral wall (304-1) when the cover member (116) coupled to the body (104) and forms a sealed connection therebetween to restrict spillage of the coloured indicator substance through a central opening (310) of the body (104).

10. The wear-indicating roller assembly (101) according to any of the preceding claims further comprising: at least one dampening ring (118) disposed on the supporting surface defined when the half portions (108-2) of the rolling members (102-1, 102-2) laterally align with each other, wherein a top surface of the at least one dampening ring (118) flushes with the rolling surface (108-1) of each rolling member (102-1, 102-2).

11. The wear-indicating roller assembly (101) according to claim 10, wherein the at least one dampening ring (118) is fixedly integrated, using a moulding process, to the half portion (108-2) of each rolling member (102-1, 102-2).

12. The wear-indicating roller assembly (101) according to claim 10, wherein the at least one dampening ring (118) is removably disposed on the supporting surface formed when the rolling members (102-1, 102-2) are coupled to each other.

13. The wear-indicating roller assembly (101) according to any of the preceding claims, wherein the body (104) is formed of a lightweight material compared to the cover element (116).

14. The wear-indicating roller assembly (101) according to any of the preceding claims, wherein the rolling surface (108-1) has an arcuate profile and is subjected to a higher wear rate relative to the half portion (108-2).

15. An elevator door system ( 100) for an elevator installation, the elevator door system (100) comprising: a door rail (103); anda wear-indicating roller assembly (101), according to any of the claims 1-16, wherein a pair of rolling members (102-1, 102-2) of the wear-indicating roller assembly (101), when assembled, engages with the door rail (103) such that at least a rolling surface (108-1) of at least one of the pair of rolling members (102-1, 102-2) forms a surface contact with the door rail (103).

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