Hand guard arrangement for a pulley in an elevator

Abstract

Disclosed is a hand guard arrangement (122) for a pulley in an elevator (100), the pulley being in particular a backside pulley (116) of an elevator drive (108), the hand guard arrangement (122) comprising: a pulley cover (126) with a slit (124) for inserting a cleaning tool (120), the slit (124) being wider than the cleaning tool (120) but narrower than a finger of a service person, the slit (124) having in particular a width of 8mm or less, wherein the pulley cover (126) is configured to be mounted, in particular permanently mounted, in front of the pulley, with the slit (124) being aligned to the pulley (116), thereby limiting pulley access to the slit (124); and a traction member cover (128) being arranged at an angle to the pulley cover (126), the traction member cover (128) being configured to be arranged in front of an inlet area (130) between the pulley and at least traction member that is in contact with a circumference of the pulley, thereby inhibiting access to the inlet area (130).

Description

[0001] Hand guard arrangement for a pulley in an elevator

[0002] The present disclosure relates to elevators and, more particularly, to a hand guard arrangement for a pulley in an elevator, a pulley arrangement with a pulley and such a hand guard arrangement, an elevator drive with such a hand guard arrangement, an elevator with such an elevator drive, a method for mounting such a hand guard arrangement to an elevator drive and a method for cleaning a pulley in an elevator.

[0003] An elevator may have one or multiple, typically at least two, traction members such as belts or ropes connecting a car of the elevator to at least one drive pulley and further on to a counterweight of the elevator. The traction member(s) typically also suspend the car and the counterweight and are therefore suspension traction means (STMs). In the interest of conciseness, the expression “traction member” is generally used in this document.

[0004] If a traction member(s) runs only over the drive pulley that is driven by a hoisting machine, a wrap angle of 180° between two vertical sections of the traction member(s) results at the drive pulley. To enable an enlarged lateral distance between the car and the counterweight, a drive pulley with a diameter corresponding to the desired distance may be used. Alternatively, the traction member(s) may run from the drive pulley to a deflection pulley laterally spaced apart from the drive pulley by the desired lateral distance. By using a deflection pulley, a more compact drive unit is possible, but the wrap angle at the drive pulley is reduced. As friction and therefore traction between the drive pulley and the traction member(s) is proportional to the wrap angle, a further pulley may be arranged as backside pulley between and below the drive pulley and the deflection pulley.

[0005] As traction members, belts as generally known in the elevator filed are in the following assumed, without limiting to such traction members. Belts generally have a frontside that contacts the drive pulley and the deflection pulley as mentioned, and a thereto opposite and generally parallel backside. The frontside has a frontside traction surface that is designed to provide the required traction. Typically, the backside is generally flat, while the frontside may be flat or structured, e.g., with an arrangement of parallel ribs and grooves. The drive pulley, the deflection pulley, the backside pulley and the belt(s) are generally arranged such that the belt(s) are wound around a partial surface of the drive pulley with the frontside traction surface contacting the drive pulley, the belt(s) are wound around a partial surface of the backside pulley with a backside surface contacting the backside pulley and the belt(s) are wound around a partial surface of the deflection pulley with the frontside traction surface contacting the deflection pulley. With an overall pulley and belt arrangement including the backside pulley, the belt(s) runs over the drive pulley with a wrap angle of significantly more than 90° and even up to close to 180°, down to the backside pulley and back up to the deflection pulley. A pulley that is contacted by the backside of the traction member(s), in particular belt(s), is referred to as backside pulley.

[0006] The backside of the belt(s) faces upward between the drive pulley and the laterally offset deflection pulley. Dust and abrasions may settle on the backside and adhere to the backside pulley, particularly at its circumferential surface. Therefore, it is generally necessary to clean the backside pulley by removing the accumulated dust and abrasions from the backside pulley from time to time.

[0007] The cleaning may be done by a service person mechanically scraping off the accumulated dust and abrasions using a handheld cleaning tool. To reach the complete circumference of the backside pulley, it is necessary to move the belt(s) while scraping, to rotate the backside pulley. For this purpose, the elevator drive may be operated by powering a hoisting machine of the elevator drive. Such cleaning procedure, however, involves some risk of severe injure for the service person due to required manipulations in close proximity of moving components of the elevator drive. In particular, the cleaning tool, other objects and / or fingers respectively a hand of the service person may potentially be pulled in and pinched between the backside pulley and the belt(s).

[0008] CN102951510A discloses a protective cover for a traction system. The protective cover comprises a traction sheave protective cover body, a left protective cover body, a right protective cover body, a cover plate and a screen, bolt connecting holes for fixing the protective cover with a tractor are arranged at the top of the traction sheave protective cover body, bolt connecting holes for fixing the protective cover to a frame are arranged on the lower portion of the traction sheave protective cover body, bolt connecting holes are arranged on the left and on the right of the traction sheave protective cover body respectively, and the traction sheave protective cover body is in fastened connection with the left protective cover body and the right protective cover body through bolts. The protective cover for the traction system has the advantages of simple structure, safety, reliability, convenience in mounting.

[0009] US20080000725A1 discloses a safety guard apparatus for an elevator machine having a brake and a sheave for engaging one or more hoist ropes rotatably driven by the elevator machine, the safety guard apparatus consisting of a sheave guard including a front sheave wall, a back sheave wall and a pair of oppositely disposed side sheave walls defining a generally rectangular structure adapted for substantially enclosing the sheave of the elevator machine, and a cover guard releasably secured to the sheave guard and including a front cover wall, a back cover wall and a top cover wall through which the one or more hoist ropes and the sheave can be viewed. The safety guard apparatus further including a hoist rope guard releaseably secured to at least one of the pair of oppositely disposed side sheave walls of the sheave guard, wherein the hoist rope guard including a lower portion pivotally coupled to a upper portion for substantially enclosing the one or more hoist ropes extending from the sheave.

[0010] CN107082346A discloses a protective cover used for a tractor. According to the tractor protective cover, protective segmental plates capable of being bent in various manners are manufactured into protective covers of various types for achieving different purposes of traction wheel side face protection, incliner lateral traction steel wire rope protection, guide pulley side face protection and protection of spaces in a rack. Wing plates of the protective covers of various types are provided with long-kidney holes or circular holes, and the long-kidney holes and the circular holes are used for installing the protective covers of various types on the tractor and or the rack, or enabling the protective covers of various types to be installed in a mutually connected mode. The circular holes in the wing plates on the protective covers of various types can also be used for fixedly installing riveting pressure nuts or enabling the riveting pressure nuts to be installed in the mutually connected mode or installing front protective plates. Circular holes in the middle plate surfaces of the protective segmental plates can also be used for fixedly installing the riveting pressure nuts, and every two independent protective segmental plates are connected through connecting plates. The tractor protective cover is single in specification, convenient to manufacture and capable of being applicable to the tractors of various types, the tractor protective cover can be cut and used as needed according to the matched size length and can be used in a lap joint mode during undersize, material waste is reduced, and universality is high.

[0011] W02001087759A1 discloses a protection against the accidental contact with rope drives. The inventive protection is provided with a protective element for the ropes that are guided at an angle, said protective element being linked with one lateral element on each side. Said lateral elements are provided with respective tabs and angles, said angles linking the protective element with the control panel. The lateral elements are stabilized by means of a connection piece. A protective element for the ropes that are guided vertically is provided with a horizontal extension that serves as a protective element for the driving disk. A panel is provided on the front face of the protective element for the driving disk. Said panel is linked with a panel of the protective element for the ropes that are guided at an angle.

[0012] US2728552A disclses a locking means for a traveling block having spaced side members with a plurality of sheaves rotatably supported therebetween and having pivotable guard plates covering the sheaves and extending adjacent the edges of said side members, said locking means securing the guard plates to the side members comprising a recess provided in the side members, a pair of apertured plates rigidly secured in spaced relation in said recess, said apertures in said plates being in alignment, an internally threaded member having oppositely opposed pins rotatably disposed in the aligned apertures of the plates to provide pivotable movement of the threaded member, a threaded stud engaged in the threaded member and adapted to be pivotable therewith, said guard plates having a slot conterminous with one edge thereof for receiving the stud in an upstanding position thereof, and means on the stud cooperating with the guard plate for maintaining the guard plate in locked position against the side plates.

[0013] Therefore, there may be a need to provide an improved cleaning solution, reducing or eliminating the abovementioned associated shortcomings. Particularly, there may be a need for a hand guard arrangement serving as a simple and / or inexpensive means for reducing dangers upon cleaning portions or components of an elevator drive, in particular a pulley. Furthermore, there may be a need for a pulley arrangement that comprises such hand guard arrangement, and for an elevator with such pulley arrangement. Additionally, there may be a need for a method for mounting a hand guard arrangement and a method for cleaning a pulley in an elevator, each being adapted for overcoming the abovementioned shortcomings.

[0014] Regarding the pully, the following description is largely focused on a backside pulley of an elevator drive, as discussed above and further below. However, other applications in an elevator are well possible, such as for various pulleys for traction and / or compensation members that may be present in an elevator of various generally known designs. The expression “backside pulley” refers to a pulley the circumference of which is in contact with a backside surface of one or more traction members, especially a belts as mentioned before.

[0015] Such needs may be met with the subject-matter of the independent claims. Advantageous embodiments are defined in the dependent claims, described throughout the specification and / or visualized in the figures.

[0016] According to an aspect, a hand guard arrangement for a pulley in an elevator is disclosed. The pulley may in particular be a backside pulley of an elevator drive. The hand guard arrangement comprises: a pulley cover with a slit for inserting a cleaning tool, the slit being wider than the cleaning tool, but narrower than a finger of a service person, wherein the pulley cover is configured to be amounted, in particular permanently mounted, in front of the pulley, with the slit being aligned to the pulley, thereby limiting pulley access to the slit; and a traction member cover being arranged at an angle to the pulley cover, the traction member cover being configured to be arranged in front of an inlet area between the pulley and at least one traction member that is in contact with a circumference of the pulley, thereby inhibiting access to the inlet area. Pulley access is according limited to objects that can pass through the slit. Pulley access through the slit is limited. The slit is in particular wider than the cleaning tool, but narrower than a finger of a service person.

[0017] According to a further aspect, a pulley arrangement for use in an elevator, in particular an elevator drive, is disclosed, the pulley arrangement comprising: a pulley and a hand guard arrangement according to any embodiment as discussed above and / or further below, wherein the pulley cover is arranged in front of the pulley with the slit extending parallel to the pulley, thereby limiting pulley access to the slit, wherein the traction member cover is arranged in front of the inlet area between the pulley and at least one traction member that is in contact with a circumference of the pulley, thereby inhibiting access to the inlet area, the at least one traction member being in particular at least one belt.

[0018] According to a further aspect, an elevator drive is disclosed, the elevator drive comprising a pulley arrangement according to any embodiment as discussed above and / or further below, the pulley being a backside pulley, the elevator drive further comprising a drive pulley coupled to a hoisting machine and a deflection pulley, wherein in an operational configuration at least belt is wound around a partial surface of the drive pulley with a frontside traction surface of the at least one belt contacting the drive pulley, the at least one belt is further wound around a partial surface of the backside pulley with a backside surface of the at least one belt contacting the backside pulley and the at least one belt is further wound around a partial surface of the deflection pulley with the frontside traction surface of the at least one belt contacting the deflection pulley.

[0019] According to a further aspect, an elevator is disclosed, the elevator comprising a pulley arrangement according to any embodiment as discussed above and / or further below, the pulley arrangement being in particular part of an elevator drive of the elevator.

[0020] According to a further aspect, a method for mounting a hand guard arrangement according to any embodiment as discussed above and / or further below in relation to a pulley of an elevator, the pulley being in particular a backside pulley of an elevator drive, the method comprising: positioning the hand guard arrangement so that the pulley cover is arranged in front of the pulley and the slit in the pulley cover is aligned to the pulley, thereby limiting pulley access to the slit, and that the traction member cover is arranged at an angle to the pulley cover and in front of the inlet area between the backside pulley and at least one traction member that is in in contact with a circumference of the pulley, thereby inhibiting access to the inlet area; and mounting the hand guard arrangement in that position. According to a further aspect, a method for cleaning a pulley in an elevator is disclosed, the pulley being in particular a backside pulley of an elevator drive in accordance with any embodiment as discussed above and / or further below, the method comprising: inserting a cleaning tool into the slit of the pulley cover, scraping built-up deposits from the pulley using the cleaning tool, while the hosting machine is operating.

[0021] In the following, basic ideas underlying embodiments in accordance with the present disclosure and associated possible advantages will be roughly summarized, however without limiting the scope of the invention. Subsequently, possible features of embodiments of the invention and associated possible advantages will be described in more detail.

[0022] As a general idea underlying embodiments in accordance with the present disclosure, accidents may be prevented by arranging a mechanical barrier between, e.g., a hand of a service person and potentially hazardous moving parts of an elevator drive. The moving parts of the elevator drive may be pulleys, a hoisting machine with or without a gear and one or traction members, such as belts, running over the pulleys. Particularly, a pulley may be a backside pulley as mentioned before.

[0023] The barrier may consist of individual covers. By way of example, one cover may shield a backside pulley and be referred to as pulley cover. Another cover may shield an area between the backside pulley and the traction member, e.g. one or more belts. This cover may be referred to as traction member cover.

[0024] To make it possible to access the pulley, for example backside pulley, for the purpose of cleaning, the pulley cover may have an opening wide enough for a cleaning tool but small enough not to get body parts, such as fingers or a hand, through. The opening may be elongated with a length being larger than a width, the opening may have a rectangular shape with or without rounded comers. The opening may have a width of e.g. more than 1 mm, preferably more than 2 mm, more than 3 mm or more than 5 mm but generally less than 10 mm, preferably less than 8 mm or less than 6 mm. In other words, the opening may be a linear slit, as the cleaning tool used to clean the backside pulley may be, e.g., a blade-shaped spatula or scraper. The cleaning tool may be supported by an edge of the slit, so that forces on the cleaning tool may be absorbed at least partially by the pulley cover. The pulley cover and the traction member cover may be arranged between an area where a service person must put at least one hand to use the cleaning tool, and the pulley or the traction member(s) respectively. In other words, the handguard arrangement may be arranged with its pulley cover and its traction member cover in an access area at which a technician may introduce the cleaning tool into for cleaning the pulley. The width of the slit may be chosen in accordance with applicable codes or standards. By way of example, EN ISO 13857:2019 requires a maximum width of 8mm for a distance in a range of 20mm to 80mm to the moving part, i.e. pulley. Such distance may be given in atypical case. The pulley cover is favorably aligned with respect to the pulley such that the length of the slit extends parallel to a pulley axis.

[0025] The pulley cover and the traction member cover may be angled to each other, i.e., arranged and oriented at a non-zero angle with respect to each other, so that the service person may reach between the pulley cover and the traction member cover with the cleaning tool in hand. The angle may be, e.g., larger than 50°, larger than 70°, larger than 90°, larger than 110° or even larger than 130°. The pulley cover and / or the traction member cover may be planar, i.e., plate-like. The pulley cover and / or the traction member cover may be made of a sheet material such as sheet metal. The pulley cover and / or the traction member cover may be made of a continuous material. Alternatively, the pulley cover and / or the traction member cover may be made of a discontinuous material such as a grid or lattice with small openings, the openings being generally smaller than the width of the slit, i.e. for example smaller than 5 mm or smaller than 2 mm, thereby providing a partial transparency for the pulley cover and / or the traction member cover. The pulley cover and / or the traction member cover may alternatively be made of a transparent material, such as polycarbonate, for example. The pulley cover and the traction member cover may be stamped and / or bent parts. A tool holder for the cleaning tool may be arranged on the pulley cover or the traction member cover, keeping the cleaning tool readily available when not used.

[0026] Operating the hoisting machine when cleaning a pulley may be done using a recall controller respectively operating the elevator in a recall mode in which the hoisting machine is operated and the car moved without a person being present directly in respectively at the car and at a reduced speed. A recall is generally initiated by a service person by way of a corresponding switch that is typically latching. Operating the hoisting machine, however, requires a dead man’s switch, typically a pushbutton, to be permanently actuated, e.g., pressed, by the service person. As the dead man’s switch is released, a safety chain is interrupted and the hoisting machine is stopped immediately. For the pulley cleaning, the service person generally holds the cleaning tool in one hand and actuates the dead man’s switch with the other hand.

[0027] The traction member cover may have a bent-up chamfer facing away from the at least one traction member. A chamfer creates a slope instead of a sharp edge. In case the traction member cover should make contact to the traction member(s), for example belt(s), the chamfer will avoid abrasion or even cutting into the traction member(s). The chamfer may also avoid a sharp edge of the traction member cover biting into the traction member(s) and / or be carried along by the traction member(s) and thus avoid damaging such as bending the traction member cover by the resulting forces.

[0028] The pulley cover may have a pull-in prevention member, the pull-in prevention member being in particular realized as bent-up rib of the pulley cover, the pull-in prevention member being arranged parallel to the slit and facing away from the traction member cover. The pull-in prevention member, for example rib, may increase a bending resistance of the pulley cover. The pull-in prevention member may also serve as a distancing element to keep a desired distance between the pulley cover and the pulley. The pull-in prevention member may have a width of more than 2 mm, preferably more than 5 mm or more than 10 mm, however typically less than 80 mm, preferably less than 40 mm. A head of the pull-in prevention member, for example rib, may be arranged between ten millimeters and one millimeter from a surface of the pulley. In this way, the pull-in prevention member may create a barrier for the cleaning tool and keep the cleaning tool from being pulled in between the traction member(s) and the pulley in case of slipping off while cleaning the pulley.

[0029] The hand guard arrangement may have a pulley cover extension extending a surface of the pulley cover. The pulley cover extension may have a number of inspection openings narrower than the finger. For example, the inspection openings may have lateral dimensions or a diameter being smaller than 10 mm, preferably smaller than 5 mm. In principle, a single inspection opening may be foreseen, but typically a set of more than one inspection opening is present. Inspection openings may be small slits or through- holes arranged in a pattern. Inspection openings allow visual access to the pulley in spite of the typically non-transparent hand guard arrangement and especially pulley cover extension. The pulley cover extension may close off a gap between an edge of the pulley cover and a structure in which the pulley is arranged and / or by which the pulley is carried, for example an elevator drive housing or elevator drive frame. Such structure is generally referred to as housing. The pulley cover extension may prevent the service person from reaching around the pulley cover. The pulley cover extension may be arranged essentially in the same plane or in a parallel plane as the pulley cover. The pulley cover extension may alternatively be arranged at an angle to the pulley cover.

[0030] The hand guard arrangement, in particular the pulley cover, may have mounting equipment for mounting the hand guard arrangement in relation to the pulley. The mounting equipment may have bent up flanges creating lateral contact surfaces to the housing. The mounting equipment may have stop surfaces transverse to the contact surfaces. The stop surfaces may be arranged at the predefined angle to a plane of the pulley cover. The mounting equipment may have mounting holes and screws may be arranged in the mounting holes and in threaded holes of the housing. Other mounting arrangements may be used as well.

[0031] The traction member cover may have angle adjustment equipment connected to the mounting equipment, the angle adjustment equipment being configured to adjust an angle between the pulley cover and the traction member cover. Angle adjustment equipment may also have bent up flanges creating contact surfaces to the mounting equipment. The angle adjustment equipment may have mounting holes to mount the traction member cover to the pulley cover. The mounting holes may create a hinge for the traction member cover to swivel around. The pulley cover may have threaded bolts for the mounting holes. Nuts may be tightened on the bolts to fix the set angle of the hinge.

[0032] The mounting equipment may comprise at least one mounting bracket mechanically interconnecting the pulley cover and the traction member cover. The mounting bracket may be configured to be mounted to a mounting interface of a structure in which the pulley is arranged and / or by which the pulley is carried, such as an elevator drive housing. The complete hand guard arrangement may be mounted to the housing by connecting at least one mounting bracket to a mounting interface of the housing. The slit in the pulley cover may be aligned to the backside pulley by aligning of the mounting bracket to the mounting interface. The mounting bracket may be arranged around a junction between the pulley cover and the traction member cover. The pulley cover and the traction member cover may be connected to the mounting bracket. In particular, two mounting brackets may be used to hold the hand guard arrangement together and mount the hand guard arrangement to the housing. The two mounting brackets may be arranged on opposing sides of the pulley cover and the traction member cover. The housing may have an existing threaded hole in an area designated as the mounting interface. The mounting bracket may be fixed to the mounting interface by screwing in a screw into that hole and tightening it down. The mounting bracket may also have multiple contact surfaces to the mounting interface. The contact surfaces may be angled to each other to make stop surfaces. The stop surfaces may contact the housing on different faces of a comer of the housing. Together, the screw and the stop surfaces may align the mounting bracket and the pulley cover in three dimensions.

[0033] The mounting equipment may comprise a fixed angle bracket mounted to or formed in one piece with the pulley cover, and an angle adjustable bracket mounted to or formed in one piece with the traction member cover. The angle between the pulley cover and the traction member cover may be fixed by screwing down the angle adjustable bracket. An angle of the pulley cover relative to the housing, may be defined by the fixed angle bracket of the mounting equipment. This angle might be identical for all embodiments of the elevator drive. The fixed angle bracket makes adjustment of this angle unnecessary. The fixed angle may be, e.g., between 20 degrees and 40 degrees out of the vertical. An angle of the traction member cover relative to the housing may be adjusted by the adjustable angle bracket. The adjustable angle bracket and the fixed angle bracket may form a hinge around which the traction member cover may be rotated relative to the pulley cover. Identical adjustable angle brackets may be used across a whole family of elevator drives. The traction member cover angle may be adjustable, e.g., by 90 degrees. The angle may be adjusted by moving an arched slit of the adjustable angle bracket relative to a screw on the fixed angle bracket and tightening the screw when the traction member cover has the desired angle. At the desired angle, an edge of the traction member cover may be arranged at a small distance to the traction member(s). The distance may be e.g. between one millimeter and 10 millimeters. While cleaning the pulley, in particular a hosting machine, of the elevator drive may be operated in a backwards operation. In backwards operation, the car is raised, and the counterweight is lowered. Accordingly, in an area between the backside pulley and the deflection pulley, the traction member(s), specifically belt(s), are moved in a direction away from the backside pulley. Debris scraped of the backside pulley and falling off the cleaning tool onto the belt(s) is then carried away from the backside pulley and will not lodge on the backside pulley again. As mentioned before, the elevator is favorably operated in recall mode.

[0034] It shall be noted that possible features and advantages of embodiments are described herein partly with respect to a hand guard arrangement, partly with respect to a pulley arrangement, partly with respect to an elevator drive an elevator drive and partly with respect to an elevator as well as partly with respect to a method for mounting a hand guard arrangement or a method for cleaning a pulley in an elevator. One skilled in the art will recognize that the features may be suitably transferred from one embodiment to another and features may be modified, adapted, combined and / or replaced, etc. in order to come to further embodiments in accordance with the present disclosure.

[0035] In the following, exemplary embodiments will be described with reference to the enclosed figures. However, neither the drawing nor the description shall be interpreted as limiting.

[0036] Figure 1 illustrates a schematic view of an elevator according to an embodiment of the present disclosure;

[0037] Figure 2 illustrates a perspective view of a hand guard arrangement according to an embodiment of the present disclosure;

[0038] Figure 3 illustrates a partial sectional view of an elevator drive according to an embodiment of the present disclosure; and

[0039] Figure 4 illustrates a partial sectional view of an elevator drive according to another embodiment of the present disclosure. The figures are only schematic and not to scale. Same reference signs refer to same or similar features.

[0040] Figure 1 illustrates a schematic view of an elevator 100 according to an embodiment of the present disclosure. The elevator 100 comprises a car 102, a counterweight 104, a number of two or more belts 106 serving as traction members respectively suspension traction means (STM) and connecting the car 102 and the counterweight 104.

[0041] Furthermore, the elevator 100 comprises an elevator drive 108 according to an embodiment of the present disclosure. The belts 106 runs over multiple pulleys of the elevator drive 108.

[0042] Specifically, from the car 102 the belts 106 run vertically up to a drive pulley 110 of the elevator drive 108. The drive pulley 110 is mechanically coupled to a hoisting machine 112 of the elevator drive 108. From the counterweight 104 the belts 106 run vertically up to a deflection pulley 114 of the elevator drive 108. The drive pulley 110 and the deflection pulley 114 may be arranged at a same level, i.e. in a same horizontal plane.

[0043] The deflection pulley 114 is laterally offset from the drive pulley 110. A distance between the drive pulley 110 and the deflection pulley 114 defines how far apart the vertical runs of the belts 106 are.

[0044] The elevator drive 108 further has a backside pulley 116 arranged between and below the drive pulley 112 and the deflection pulley 114. The backside pulley 116 runs over a backside of the belts 106. In other words, while the belts 106 contact the circumferential surface of the drive pulley 112 and the circumferential surface of the deflection pulley 114, respectively, with a generally textured frontside traction surface comprising, e.g., V- shaped grooves, the belts 106 contact the circumferential surface of the backside pulley 116 with a generally non-textured backside surface. The backside pulley 116 is arranged close to the drive pulley 110, so that the belts 106 run almost straight down from the drive pulley 110 to the backside pulley 116. This creates a large wrap angle of, e.g., more than 140° or even more than 160° around the drive pulley 110. From the backside pulley 116 to the deflection pulley 114 the belts 106 run upwards at an angle. Since the backside pulley 116 runs over the backside of the belts 106 and the backside is facing upward between the drive pulley 110 and the deflection pulley 114, abraded material and dust settling on the backside may adhere to the backside pulley 116 and rough up a surface of the backside pulley 116. When the resulting deposits run over the backside during operation of the elevator, vibrations and noise may be caused.

[0045] Therefore, the backside pulley 116 needs cleaning from time to time. Cleaning is generally done manually by a service person 118 using a cleaning tool 120.

[0046] The presented elevator drive 108 has a dedicated hand guard arrangement 122 to protect the service person 118 from injury during a cleaning procedure. The hand guard arrangement 122 restricts access to the backside pulley 116 to a slit 124 in a pulley cover 126. The slit 124 is smaller than a finger of the service person 118 respectively does not permit to insert a finger through it, so that the service person 118 can only reach the backside pulley 116 with the cleaning tool 120. The cleaning tool 120 may have a blade with a distal tip or edge. The slit 124 is wide enough to pass the cleaning tool 120 and long enough to preferably reach the complete length of the backside pulley 116 along its axis. In other words, the slit 124 in the pulley cover 126 has a width being larger than the width of the cleaning tool 120 at least in a portion of the cleaning tool which is to be inserted through the slit 124 such that, e.g., the distal tip or distal edge of the blade of the cleaning tool 120 reaches a circumferential surface of the backside pulley 116. Furthermore, the slit 124 in the pulley cover 126 preferably has a length being at least as long as a portion of the circumferential surface of the backside pulley 116 along which the belts 106 contacts the circumferential surface of the backside pulley 116 and along which deposition may therefore typically accumulate.

[0047] The hand guard arrangement 122 further comprises a traction member cover 128. The traction member cover 128 is angled from a lower end of the pulley cover 126 to the belts 106, effectively blocking access to an inlet area 130 between the backside pulley 116 and the belts 106. The traction member cover 128 hinders the service person 118 from reaching the inlet area 130 with his fingers or hand, thereby effectively preventing potentially serious accidents like crushing the fingers or even amputating them. When the service person 118 starts servicing the elevator drive 108 and in particular cleaning the backside pulley 116, the elevator 100 is set in a service mode, taking the elevator 100 out of normal operation. The service mode may be a recall mode as discussed before. In the service mode, the elevator drive 108 is generally blocked from automated and / or passenger-controlled operation. A recall mode may be initiated by a latching switch (not separately shown) and a dead man’s switch 132 needs to be continuously actuated for the hoisting machine 112 to operate. The dead man’s switch 132 may in particular be a pushbutton.

[0048] When the elevator 100 is set in the service mode, for example recall mode, for the cleaning, the service person 118 takes the cleaning tool 120 from a tool holder arranged on the hand guard arrangement 122 and passes the cleaning tool 120 through the slit 124 until it touches the surface of the backside pulley 116. Of course, it is also possible that the cleaning tool 120 is not taken from a holder where it is stored when not used, but is instead carried by the service person 118 as part of the maintenance equipment.

[0049] Then the service person 118 presses the dead man’s switch 132 and due to the rotation of the backside pulley 116 the circumferential surface of the backside pulley 116 moves relative to the cleaning tool 120. Thereby, the cleaning tool 120 then scrapes any deposits off the surface. Tangential forces acting onto the cleaning tool 120 due to the scraping are at least partially transferred to a rim of the slit 124 and on to the pulley cover 126 where they are absorbed. To remove deposits accumulated on the cleaning tool 120, the service person 118 may periodically take the cleaning tool 120 out of the slit 124 and clean of the deposits. The service person 118 will reinsert the cleaning tool 120 into the slit 124 and continue scraping until the surface meets requirements respectively until substantially all deposits are removed. To scrape the entire length of the backside pulley 116, the service person 118 may move the cleaning tool 120 sideways in the slit 124. After finishing the cleaining, the service person 118 may return the cleaning tool 120 to the tool holder. Typically, cleaning the backside pulley 116 is a step of a larger maintenance procedure.

[0050] During the cleaning, the hoisting machine 112 will preferably move the car 102 up and the counterweight 104 down, so that deposits falling onto the belts 106 are moved out of the inlet area 130 towards the deflection pulley 114. Figure 2 illustrates a perspective view of a hand guard arrangement 122, according to an embodiment of the present disclosure. The hand guard arrangement 122 essentially corresponds to the hand guard arrangement in Figure 1. The pulley cover 126 and the traction member cover 128 are two essentially flat pieces of a sheet material, like sheet metal, arranged at an angle to each other. The slit 124 runs across a main surface of the pulley cover 126. The slit 104 is wide enough to pass the blade of the cleaning tool 120 through. The cleaning tool 120 may be a spatula or scraper. The slit 124 is too narrow to pass a finger or a handle of the cleaning tool 120 through and favorably meets applicable safety standards respectively codes. The slit 124 is many times longer or broader than it is wide. Favorably, the traction member cover 128 has no openings. A gap between the pulley cover 126 and the traction member cover 128 is minimal and arranged parallel to the slit 124.

[0051] The pulley cover 126 is configured to keep a service person from touching the backside pulley 116 of the elevator drive 108. When installed, the pulley cover 126 is arranged in front and / or on top of the backside pulley 116. The pulley cover 126 is then aligned in a plane being essentially parallel to a tangential to the backside pulley 116.

[0052] The traction member cover 128 is configured to keep the service person from touching the belts running under the backside pulley 116 and in a direction to or from the deflection pulley 114. When installed, the traction member cover 128 is arranged in front of an inlet area 130 between the belts 106 and the backside pulley 116. At least a leading edge of the traction member cover 128 is then arranged very close to the belts 106 to maximize a working space in front of the slit 124.

[0053] In an embodiment, the hand guard arrangement 122 has two mounting brackets 200. The mounting brackets 200 interconnect the pulley cover 126 and the traction member cover 128 close to where the pulley cover 126 and traction member cover 128 adjoin to each other. The mounting brackets 200 are configured to fix the pulley cover 126 and traction member cover 128 to the elevator drive 108, specifically a housing thereof (not separately referenced). Here, the mounting brackets 200 have one screw point each to be screwed to mounting interfaces of the housing. The mounting brackets 200 also have additional screw points connected to the pulley cover 126 and traction member cover 128. In an embodiment, the mounting brackets 200 are multipart and have a fixed angle bracket 202 and a variable angle bracket 204 each. The fixed angle brackets 202 are connected to the pulley cover 126. The variable angle brackets 204 are connected to the fixed angle brackets 202 and the traction member cover 128. When installed, the fixed angle brackets 202 are connected directly to the mounting interfaces.

[0054] In an embodiment, the hand guard arrangement 122 has a pulley cover extension 206. The pulley cover extension 206 is connected to the pulley cover 126 and extends a surface of the pulley cover 126. The pulley cover extension 206 is arranged opposite to the traction member cover 128 and extends away from the traction member cover 128. The pulley cover extension 206 is connected to the pulley cover 126 by mechanical connections such as screw points.

[0055] In an embodiment, the traction member cover 128 has a chamfer 208 on an edge facing away from the pulley cover 126. The chamfer 208 may be created by bending up the edge towards an upper side of the traction member cover 128. Additionally, the edge is folded over to make the edge rounded. Alternatively, the chamfer 208 may be realized from a dedicated separate piece of material.

[0056] In an embodiment, the pulley cover extension 206 has multiple inspection openings 210. The inspection openings 210 are smaller than a finger respectively do not allow a finger to pass therethrough. The inspection openings 210 are exemplarily arranged in a regular pattern. The inspection openings 201 provide visual access to the backside pulley 116 and for the service person and may be used for lighting the backside pulley 110 and the belts 106, e.g. with a hand-held torch or headlamp.

[0057] In an embodiment, a tool holder 212 is arranged on the pulley cover 126. The tool holder 212 stores the cleaning tool 120 when not in use. In the tool holder 212, the cleaning tool 120 is always ready to use. The tool holder 212 is two-part. The tool holder 212 has a clip for a blade of the cleaning tool 120 and a bolt for a hole in a handle of the cleaning tool 120. To remove the cleaning tool 120 from the tool holder 212, the cleaning tool 120 must be rotated around the bolt in the hole. The rotation frees the blade from the clip, so that the handle can be taken off the bolt. Here, the bolt is an extra-long bolt connecting the pulley cover 126 and the pulley cover extension 206. Figure 3 illustrates a partial sectional view of an elevator drive 108, according to an embodiment of the present disclosure. The elevator drive 108 essentially corresponds to the elevator drive in Figure 1. The hand guard arrangement 122 essentially corresponds to the hand guard arrangement in Figure 2. A part of the elevator drive 108 comprising the backside pulley 116 is shown.

[0058] The pulley cover 126 is arranged in front of the backside pulley 116, so that the slit 124 is arranged directly opposite the backside pulley 116. The pulley cover 126 is oriented tangentially to the backside pulley 116 such that it extends parallel to a rotational axis of the backside pulley 116. The fixed angle brackets 202 of the mounting brackets 200 predefine an angle of the pulley cover 126 relative to the elevator drive 108 respectively its frame or housing. The traction member cover 128 is arranged in front of and / or on top of the inlet area 130 where the belts 106 make contact to the backside pulley 116.

[0059] In this embodiment of the elevator drive 108, the deflection pulley 114 is a long distance away from the drive pulley 110, therefore the belts 106 have a low angle to the horizontal. This results in a big gap between the lower end of the pulley cover 126 and the belts 106. The edge of the traction member cover 128 facing away from the pulley cover 126 is lowered until it has a rather small distance of, e.g., five to seven millimeters from the backside of the belts 106. This way, the angle between the pulley cover 126 and the traction member cover 128 is around 135 to 140 degrees. At this angle, the chamfer 208 is almost parallel to the belts 106. This angle is set by adjusting and tightening the variable angle brackets 204 of the mounting brackets 200.

[0060] In an embodiment, the pulley cover 126 has a rib 300 facing away from the traction member cover 128. The rib 300 is in the shown design a bent-up part of the pulley cover 126 and serves as pull-in prevention member. The rib 300 is bent up by more than 90 degrees. A head of the rib 300 is arranged at around 2,5 millimeters distance to the surface of the backside pulley 116. This narrow gap effectively seals of the inlet area 130 between the rib 300 and the belts 106. Even when the cleaning tool 120 slips off the surface during a cleaning procedure, it cannot be pulled in between the backside pulley 116 and the belts 106, as the rib 300 effectively stops the cleaning tool 120. In an embodiment, the pulley cover extension 206 is long enough such that it effectively seals off an area behind the pulley cover 126, making it impossible for the service person to reach around an upper edge of the pulley cover 126.

[0061] Figure 4 illustrates a partial sectional view of an elevator drive 108, according to an embodiment of the present disclosure. The elevator drive 108 essentially corresponds to the elevator drive in Figure 3. However, in the embodiment of Figure 4, the deflection pulley 114 is arranged very much closer to the drive pulley 110 than in Figure 3. This results in a much steeper angle of the belts 106 between the backside pulley 116 and the deflection pulley 114.

[0062] As the parts of the hand guard arrangement 122 correspond essentially completely to the parts shown in Figure 3, the angle and orientation of the pulley cover 126 relative to the housing are essentially the same as in Figure 3. Therefore, the angle between the pulley cover 126 and traction member cover 128 is smaller than in Figure 3, to compensate for the steeper aligned belt(s) 106. Here, the traction member cover 128 is arranged essentially parallel to the belts 106.

[0063] Finally, it should be noted that the term “comprising” does not exclude other elements or steps and the “a” or “an” does 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

Claims1. A hand guard arrangement (122) for a pulley in an elevator (100), the pulley being in particular a backside pulley (116) of an elevator drive (108), the hand guard arrangement (122) comprising: a pulley cover (126) with a slit (124) for inserting a cleaning tool (120), the slit (124) being wider than the cleaning tool (120) but narrower than a finger of a service person, the slit (124) having in particular a width of 8mm or less, wherein the pulley cover (126) is configured to be mounted, in particular permanently mounted, in front of the pulley, with the slit (124) being aligned to the pulley (116), thereby limiting pulley access to the slit (124); and a traction member cover (128) being arranged at an angle to the pulley cover (126), the traction member cover (128) being configured to be arranged in front of an inlet area (130) between the pulley and at least traction member that is in contact with a circumference of the pulley, thereby inhibiting access to the inlet area (130), wherein the pulley cover (126) has a pull-in prevention member, the pull-in prevention member being in particular realized as bent-up rib (300) of the pulley cover (126), the pull-in prevention member being arranged parallel to the slit (124) and facing away from the traction member cover (128).

2. The hand guard arrangement (122) according to claim 1, wherein the traction member cover (128) has a bent-up chamfer (208) facing away from the at least one traction member.

3. The hand guard arrangement (122) according to any one of claims 1 to 2, with a pulley cover extension (206) extending a surface of the pulley cover (126), the pulley cover extension (206) having a number of inspection openings (210) narrower than the finger.

4. The hand guard arrangement (122) according to any one of claims 1 to 3, wherein the hand guard arrangement (122), in particular the pulley cover (126), has mounting equipment for mounting the hand guard arrangement (122) in relation to the pulley.

5. The hand guard arrangement (122) according to claim 4, wherein the traction member cover (128) has angle adjustment equipment connected to the mounting equipment, the angle adjustment equipment being configured to adjust an angle between the pulley cover (16) and the traction member cover (128).

6. The hand guard arrangement (122) according to any one of claims 4 to 5, wherein the mounting equipment comprises at least one mounting bracket (200), mechanically interconnecting the pulley cover (126) and the traction member cover (128), the mounting bracket (200) being configured to be mounted to a structure in which the pulley is arranged and / or by which the pulley is carried, in particular an elevator drive housing.

7. The hand guard arrangement (122) according to any one of claims 4 to 6, wherein the mounting equipment comprises a fixed angle bracket (202) mounted to or formed in one piece with the pulley cover (126) and an angle adjustable bracket (124) mounted to or formed in one piece with the traction member cover (128).

8. The hand guard arrangement (122) according to any one of claims 1 to 7, wherein the pulley cover (126) is configured to be aligned with respect to the pulley (116) such that a length of the slit (124) extends parallel to a pulley axis.

9. Pulley arrangement for use in an elevator (100), in particular an elevator drive (108), the pulley arrangement comprising a pulley and a hand guard arrangement (122) according to any one of claims 1 to 8, wherein the pulley cover (126) is arranged in front of the pulley with the slit (124) extending parallel to the pulley, thereby limiting pulley access to the slit (124), wherein the traction member cover (128) is arranged in front of the inlet area (130) between the pulley and at least one traction member that is in contact with a circumference of the pulley, thereby inhibiting access to the inlet area (130), the at least one traction member being in particular at least one belt (106).

10. Elevator drive (108), the elevator drive (108) comprising a pulley arrangement according to claim 9, the pulley being a backside pulley (116), the elevator drive (108) further comprising a drive pulley (110) coupled to a hoisting machine (112) and a deflection pulley (114), wherein in an operational configuration at least belt (106) is wound around a partial surface of the drive pulley (1100) with a frontside traction surfaceof the at least one belt (106) contacting the drive pulley (110) , the at least one belt (106) belt is further wound around a partial surface of the backside pulley (116) with a backside surface of the at least one belt (106) contacting the backside pulley (116) and the at least one belt (106) is further wound around a partial surface of the deflection pulley (114) with the frontside traction surface of the at least one belt (116) contacting the deflection pulley (114).

11. A method for mounting a hand guard arrangement (122) according to any one of the claims 1 to 8 in relation to a pulley in an elevator (100), the pulley being in particular a backside pulley (116) of an elevator drive (108), the method comprising: positioning the hand guard arrangement (122) so that the pulley cover (126) is arranged in front of the pulley and the slit (124) in the pulley cover (126) is aligned to the pulley, thereby limiting pulley access to the slit (124), and that the traction member cover (128) is arranged at an angle to the pulley cover (126) and in front of the inlet area (130) between the pulley and at least one traction member that is in contact with a circumference of the pulley, thereby inhibiting access to the inlet area (130); and mounting the hand guard arrangement (122) in that position.

12. The method according to claim 11, wherein in the process of positioning, least one mounting bracket (200) connected to the pulley cover (126) is mounted to a mounting interface of elevator (100), in particular elevator drive (108), wherein the pulley cover (126) is aligned to the pulley by a predefined alignment between the mounting bracket (200) and the mounting interface.

13. The method according to any one of claims 11 to 12, wherein in the process of positioning, the angle between the pulley cover (126) and the traction member cover (128) is adjusted.

14. A method for cleaning a pulley in an elevator (100), the pulley being a backside pulley (116) of an elevator drive (108) according to claim 10, the method comprising: inserting a cleaning tool (120) into the slit (124) of the pulley cover (126), scraping built-up deposits from the pulley using the cleaning tool (120) while the hoisting machine (112) is operating.

15. The method according to claim 14, wherein when the hoisting machine (112) is operated, a counterweight (104) of the elevator (100) is lowered, and a car (102) of the elevator (100) is raised.

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