Car brake and load measurment device

Abstract

Disclosed is a car brake and load measurement device (3) for use in an elevator system (1), the elevator system (1) including an elevator car (1.1) that is vertically movable in a hoistway (1.5), the car brake and load measurement device (3) including: a car brake (3.1), the car brake (3.1) being switchable by an elevator controller (1.7) between an activated state and an alternative non-activated state, wherein the car brake (3.1) is configured to brake and hold the elevator car (1.1) by frictionally engaging an associated stationary braking member (1.6.1) arranged in the hoistway (1.5) in the activated state, a coupling structure (3.2), wherein the coupling structure (3.2) is configured to be in an operational configuration rigidly connected to a car structure (1.1.2) of the elevator car (1.1) and rigidly connected to the car brake (3.1) such that a holding force that acts between the elevator car and the car brake (3.1) in the activated state of the car brake (3.1) is transferred between the car structure (1.1.2) and the car brake (3.1) via the coupling structure, a load sensor (3.3), the load sensor (3.3) being configured to be arranged in a force flow between the car structure and the coupling structure such that a measurement force, the measurement force being at least part of the holding force, is transferred via the load sensor (3.3), wherein a measurement axis of the load sensor (3.3) is vertical.

Description

[0001] CAR BRAKE AND LOAD MEASURMENT DEVICE

[0002] The present disclosure is related to the field of elevator technology, in particular car brakes and load measurement devices, elevator cars, elevator systems and methods for determining a load of an elevator car.

[0003] In the field of elevators, it is generally required to determine the load respectively payload of an elevator car. Such load measurement is required to ensure that the permissible maximum payload is not exceeded, respectively that the elevator system is operated within its rated operational limits. Further, information regarding the payload is generally used to control the elevator drive for efficient and smooth operation. For determining the load situation, a number of solutions are known in the art. One typical approach is based on a floating elevator floor that is supported by a car structure, such as a car sling, via load cells. While technically advantageous, such design is complex and costly. Another solution relies on measuring a load-induced deformation at a structural part of the elevator car, using, e.g. strain gauge sensors. Such design, however, is susceptible to a number of distortions and measurement errors. Other designs for specific architectures of an elevator system are known as well.

[0004] Another key aspect of elevator systems is related to the braking of the elevator car and safely maintaining its position in a situation where the elevator drive is non-active respectively does not generate torque, for example if the elevator car is at a landing. Typically, a machine brake arrangement with one or more machine brakes is foreseen for this purpose at the elevator drive. In some alternative architectures, a car brake arrangement with one or mor car brakes is foreseen at the elevator car, with the car brakes being controllable to frictionally engage a stationary braking member that is arranged in the hoistway.

[0005] WO2023117773 Al discloses a brake device for braking a movable elevator car of an elevator system and for measuring load changes produced in the elevator car. The brake device has: at least one brake, preferably two brakes, for braking the elevator car relative to a stationary component of the elevator system; a brake holding arrangement for holding the brake on the elevator car; a load measuring device having a force transmission element for measuring a force acting on the force transmission element; and a load measuring device holding arrangement for holding the load measuring device on the elevator car. Force measurement is based on measuring a displacement of the brake. US20220363515 A 1 discloses a braking apparatus that brakes and measures load changes in an elevator car, includes a brake, a brake holding arrangement holding the brake on the car, a load measuring device measuring a force acting on a force transmission element and a load measuring device holding arrangement holding the load measuring device on the car. The brake can be displaced relative to the car in a force direction generated by the brake and the load measuring device is held on the car fixed relative to the car in the force direction. The force transmission element is operatively connected to the brake to measure a force acting between the brake and the load measuring device due to a relative displacement of the brake relative to the load measuring device. A connecting piece arrangement connects the load measuring device holding arrangement and the brake holding arrangement in an elastically deformable manner.

[0006] It is an overall objective of the present disclosure to improve the state of the art regarding the load measurement in elevator systems, in particular elevator systems where one or more car brakes are arranged at the elevator car. Favorably, disadvantages of the prior art are reduced and favorably avoided. Preferably, the solution is of low design complexity and is cost-efficient.

[0007] In an aspect, the present disclosure concerns a car brake and load measurement device for use in an elevator system, the elevator system including an elevator car that is vertically movable in a hoistway.

[0008] The car brake and load measurement device includes a car brake. The car brake is switchable by an elevator controller between an activated state and an alternative non-activated state, wherein the car brake is configured to brake and hold the elevator car by frictionally engaging an associated stationary braking member arranged in the hoistway in the activated state. The stationary braking member may in particular be clamped by the car brake in the activated state. The car brake may in particular be an electromagnetic or hydraulic car brake. It is noted that the car brake is a brake that is configured and operated to brake and hold the elevator car in position during regular operation of the elevator system. Optionally, the car brake may additionally serve as safety brake.

[0009] The car brake and load measurement device further includes a coupling structure. The coupling structure is configured to be in an operational configuration rigidly connected to a car structure of the elevator car and rigidly connected to the car brake such that a holding force that acts between the elevator car and the car brake in the activated state is transferred between the car structure and the car brake via the coupling structure. The holding force may in particular be a vertically oriented force that is exerted by the elevator car onto the car brake at standstill of the car, i.e., a force that must be compensated by the car brake to hold the elevator car at standstill in position. Typically, also, one or more traction members such as at least one first and / or second traction member as discussed further below may be connected to the car structure. The car structure is a structural part of the elevator car that is suited for the transferring the holding force, such as a car sling and / or frame structure of the elevator car. The expression rigidly refers to connecting respectively coupling that allows now or substantially no relative movement.

[0010] The car brake and load measurement device further includes a load sensor, the load sensor being configured to be arranged in a force flow between the car structure and the coupling structure A measurement axis of the load sensor is vertical. In such arrangement a measurement force, the measurement force being at least part of the holding force, is transferred via the load sensor. The load sensor is typically a force sensor and / or pressure sensor. The load sensor is typically a onedimensional sensor, i.e., is configured to measure a load respectively force along the measurement axis only.

[0011] Above and in the following, the expression “operational configuration” refers to a configuration where the car brake and load measurement device respectively a car brake and load measurement assembly as discussed further below is connected respectively mounted to an elevator car that is arranged vertically movable in a hoistway.

[0012] In an aspect, the present disclosure concerns a car brake and load measurement assembly. The car brake and load measurement assembly includes a first car brake and load measurement device and a second car brake and load measurement device according to any embodiment as discussed above and / or further below.

[0013] The first and second car brake and load measurement device may in particular be designed in an identical or substantially identical manner. Any general respectively unspecific reference to a car brake and load measurement device or its sub-units and components as well as associated expressions, such as measurement force, may therefore refer to the first and / or second car brake and load measurement device.

[0014] In an aspect, the present disclosure concerns an elevator car, the elevator car including a car brake and load measurement assembly according to any embodiment as discussed above and / or further below. The first car brake and load measurement device is arranged at a first edge of the elevator car and the second car brake and load measurement device is arranged at a second edge of the elevator car. The first and second edge of the elevator car extend parallel to each other and extend in a common horizontal plane. The car brake and load measurement assembly may in particular be arranged at a top or a bottom of the elevator car.

[0015] In an aspect, the present disclosure concerns an elevator system. The elevator system includes an elevator car according to any embodiment as discussed above and / or further below. The elevator system further includes a hoistway, a first elevator drive, a first counterweight, a first traction member and an elevator controller. Optionally the elevator system further includes a second elevator drive, a second counterweight a second traction member. The elevator car and the first counterweight are coupled by way of the first traction member with the first traction member suspending the elevator car and the first counterweight. If applicable, the elevator car and the second counterweight are coupled by way of the second traction member, with the second traction member suspending the elevator car and the second counterweight. The first traction member is coupled to the first elevator drive. If applicable, the second traction member is coupled to the second elevator drive. By operating the first elevator drive and, if applicable, the second elevator drive, the elevator car and the first counterweight, or, if applicable, the first and second counterweight are vertically movable in opposite directions.

[0016] The elevator system further includes a first and a second stationary braking member arranged in the hoistway, such that the first stationary braking member can frictionally engage with the car brake of the first car brake and load measurement device and the second stationary braking member can frictionally engage with second car brake of the second car brake and load measurement device. The first respectively second stationary braking member are in particularly formed integrally, e.g. in one piece, with a first respectively second guide rail for the elevator car.

[0017] The elevator controller is operationally connected to the car brake of the first car brake and load measurement device and of the second car brake and load measurement device and configured to switch the car brakes between their respective activated state and non-activated state. Favorably, the load sensor of the first car brake and load measurement device and the second car brake and load measurement device is also operationally connected to the elevator controller. In an aspect, the present disclosure concerns a method for determining a load of an elevator car, in particular an elevator car according to any embodiment as discussed above and / or further below. The method is carried out using a car brake and load measurement assembly according to any embodiment as discussed above and / or further below.

[0018] The method includes holding the elevator car in position by the car brake of the first car brake and load measurement device frictionally engaging with an associated first stationary braking member and the car brake of the second car brake and load measurement device frictionally engaging with an associated second stationary braking member. The car brake of the first car brake and load measurement device is rigidly connected with the coupling structure of the first car brake and load measurement device and the car brake of the second car brake and load measurement device is rigidly connected with the coupling structure of the second car brake and load measurement device. The coupling structure are rigidly connected with a car structure of the elevator car. For holding the elevator car in position, the car brake of the first and second car brake and load measurement device are controlled by the elevator controller to assume their respective activated state.

[0019] The method further includes measuring a first measurement force in a force flow between the coupling structure of the first car brake and load measurement device and the car structure, and measuring a second measurement force in a force flow between the coupling structure of the second car brake and load measurement device and the car structure. The first measurement force is at least part of a first holding force that acts between the elevator car and the car brake of the first car brake and load measurement device, and the second measurement force is at least part of a second holding force that acts between the elevator car and the car brake of the second car brake and load measurement device. The first measurement force is measured with the load sensor of the first car brake and load measurement device and the second measurement force is measured with the load sensor of the second car brake and load measurement device.

[0020] Load measurement in accordance with the present disclosure is advantageous in that it eliminates a number of error sources that tend to compromise the measurement in some designs. Thereby, the measurement precision and reliability is increased. Further, a car brake and load measurement device respectively a car brake and load measurement assembly in accordance with the present disclosure are comparatively simple in design and can be realized in a cost-efficient manner. A particular advantage is that the coupling between the elevator car respectively car structure and the elevator brakes can be generally rigid and that the load sensor is arranged in the force flow in a manner that allows force measurement with little distortions. Further, a car brake and load measurement device is flexible regarding different payloads and car weights as well as the mounting to the elevator car. Therefore, it can be uses in a variety of application scenarios with little, if any, application specific design modification. Further favorable advantages and characteristics of particular embodiments are discussed below in the context of such embodiments.

[0021] The expression “load” refers to the payload that is transported by the elevator system and is generally arranged inside the elevator car, respectively to the mass of such load. Typically, the payload are passengers and / or goods.

[0022] It is noted that car brake and load measurement devices respectively car brake and load measurement assemblies in accordance with the present disclosure do not directly measure the payload respectively its gravitational force. However, the weight of the payload can be determined as explained in the following: Generally, the elevator car of an elevator system in accordance with the present disclosure includes one or more counterweights, in particular a first and optional second counterweight as discussed above and further below. With Few COMBINED being the absolute value of the gravitational force of the counterweight or, as applicable, of the combined gravitational forces of all counterweights, and FCAR GROSS being the absolute value of the gravitational force resulting from the gross weight of the car including the payload, the combined holding force that needs to be hold and compensated at standstill is

[0023] FHOLD COMBINED = FcAR_GROSS - FCW_COMBINED.

[0024] Since the weight of the empty car and of the counterweights are known, the weight of the payload can accordingly be calculated in a straight-forward manner. It is noted that the measurement is performed in the activated state of the car brake respectively car brakes, in particular first and second car brake. No further brakes, such as additional machine brakes, are present, or, if present, activated. Further, the elevator drive or elevator drives are switched off respectively deactivated.

[0025] It is noted that the combined holding force FHOLD COMBINED can be downwards directed respec- tively aligned with the direction of gravity, or upwards directed respectively opposed to the direction of gravity, in dependence of the load situation. Typically, the counterweight or counterweights are dimensioned such that they are heavier than the empty car. Typically, the weight of the counterweight(s) is in a range of the weight of the empty car plus 30% to 70%, e.g. 50%, of the rated payload. For the elevator car being empty or lightly loaded, the combined holding force HOLD COMBINED will be directed upwards respectively the value of FHOLD COMBINED is negative. Only for a heavier loaded elevator car, the combined holding force will be directed downwards respectively the value of FHOLD COMBINED is positive. The bar brake and load measurement devices need accordingly be configured and arranged for bidirectional force measurement.

[0026] Preferably, the weight of the traction member or traction members is further taken into consideration for the load determination. The weight of a portion of the first and, if applicable second traction member that connects the first and, if applicable second counterweight with the first, and, if applicable second elevator drive acts can be added to the weight of the counterweight. The weight of a portion of the first and, if applicable second traction member that connects the elevator car with the first, and, if applicable second elevator drive can be added to the gross weight of the elevator car. The corresponding gravitational forces can accordingly be considered as part of the gross weight of the elevator car FCAR GROSS, and combined gravitational force of the counterweights, Few COMBINED, respectively. It is noted that the wights of the portions of the traction media depends on the position of the car and counterweigh(s) in the hoistway. These positions are generally available in the elevator controller.

[0027] For a car brake and load measurement assembly with a first and second car brake and load measurement device, the combined holding force FHOLD COMBINED is the sum of the first holding FHOLD i for the first car brake and load measurement device and the second holding FHOLD 2 for the second car brake and load measurement device. Under ideally symmetric conditions, FHOLD 1 equals FHOLD 2. As discussed further below, the measurement forces may for each load sensor correspond to the respective holding force FHOLD 1 respectively FHOLD 2, or a portion thereof.

[0028] In an embodiment of the car brake and load measurement device, the load sensor includes a load cell. Load cells are commercially available as readily assembled and typically calibrated devices. Further, load cells can use a variety of sensing elements, such as piezo-electric elements or one or multiple strain gauges. In an embodiment of the car brake and load measurement device, the load sensor is in an operational configuration configured for both the measurement force being upwards-directed or downwards-directed. This may be achieved by using a load sensor that is by design configured to measure forces in opposite directions respectively is a bidirectional load sensor. In alternative designs as discussed further below in more detail, the load sensor is as such designed for force measurement in a single direction, e.g., a compression force. In such design, bidirectional measurement may be enabled by biasing the load sensor with a biasing force.

[0029] In an embodiment of the car brake and load measurement device, the load sensor is configured not to undergo substantive deformation under permissible load conditions. With other words, the load sensor can be considered as a rigid body. The permissible load conditions in particular include any permissible payload, including zero as minimum payload, the rated payload as well as a maximum overload for which the elevator system is designed.

[0030] In an embodiment of the car brake and load measurement device, the load sensor is configured to be mounted by way of axial clamping.

[0031] In an embodiment of the car brake and load measurement device, the load sensor includes a throughgoing sensor channel, wherein the car brake and load measurement device further includes a sensor-sided fastening device, wherein in an operational configuration the coupling structure is connected to the car structure by way of the sensor-sided fastening device, the sensor sensor-sided fastening device being in particular a sensor-sided fastening bolt, wherein the sensor-sided fastening device extends through the sensor channel.

[0032] In an embodiment of the car brake and load measurement device, the load sensor is biased by a biasing force in an operational configuration, the biasing force being in particular a compression force. By way of a biasing force, it can be ensured that a total measurement force that acts on the load sensor always acts in the same direction, independent of whether the measurement force as discussed before is directed upwards or downwards. The total measurement force is the force that is effectively measured by the load sensor and includes the measurement force and the biasing force. The total measurement force results from the superimposition of the measurement force and the biasing force. In particular, the load sensor may be designed for the total measurement force being in each case a compression force, i.e., a force tending to compress the load sensor. In dependence of the direction of the acting holding force and accordingly the measurement force, the holding force may in particular also be a compression force and act in the same direction as the biasing force, or may, alternatively, be a relieving force and act in the opposite direction as the biasing force. The biasing force is favorably selected such that the total measurement force does in any case not change sign under all operational conditions. The arrangement may in particular be such that in one of the directions of the measurement force, in particular in the downwards direction, the total measurement force corresponds to the sum of the absolute values of the measurement force and the biasing force, while in the opposite direction of the measurement force, in particular in the upwards direction, the total measurement force corresponds to the absolute value of the biasing force minus the absolute value of the measurement force. In such design, the biasing force should at least correspond to the maximum upwards-directed measurement force or be somewhat larger. In a particular embodiment, the biasing force is exerted by a sensor-sided fastening device, such as a sensor-sided fastening bolt, as discussed above and further below.

[0033] In an embodiment of the car brake and load measurement device, the coupling structure includes a brake-sided coupling structure part and a car-sided coupling structure part, wherein the brake-sided coupling structure part is connected to the car brake and / or is formed integrally with the car brake, wherein the car-sided coupling structure part is configured to be connected to the car structure in an operational configuration, wherein the brake-sided coupling structure part and the car-sided coupling structure part are connected by way of interlocking. The coupling of the brake-sided coupling structure part to the care brake and of the car-sided coupling structure park to the car structure may in each case in particular be a rigid coupling. Such two-parted design of the coupling structure is in particular favorable regarding the assembly as well as maintenance and repair. The holding force is transferred by way of the interlocking connection of the brake-sided coupling structure part and the car-sided coupling structure part.

[0034] In a particular embodiment with a brake-sided coupling structure part and a car-sided coupling structure part, the brake-sided coupling structure part includes a protruding member and the carsided coupling structure part includes a recess, wherein protruding member protrudes into or through the recess. In an exemplary design, the protruding member and the recess have in each case a rectangular or square cross section. Generally, a cross section respectively a circumferential contour of the brake-sided coupling structure part and the car-sided coupling structure part, in particular a protruding member and a recess as mentioned, may be complementary or substantially complementary.

[0035] In a particular embodiment of the before-discussed type, the car-sided coupling structure part includes a generally plate-shaped body, wherein the recess includes a throughgoing cutout in the plate-shaped body. Such embodiment allows a particularly compact and simple design. As discussed further below in more detail, the plate-shaped body may in an operational configuration especially extend parallel to an edge the elevator car.

[0036] In an embodiment of the car brake and load measurement device, the brake-sided coupling structure part and the car-sided coupling structure part are connected in a compliant manner. The compliance may be or include a vertical compliance respectively act in vertical direction. It is noted that the relative movement, in particular vertical movement, between the brake-sided coupling structure part and car-sided coupling structure part that is enabled by the compliance is not evaluated for the load measurement. However, the compliance allows to minimize and favorably eliminate measurement errors that could otherwise result from tolerances and misalignment especially of the stationary braking members and / or guide rails. Without particular measures, such tolerances can cause undesired additional forces that would distort the measurement. A travel range respectively displacement that is allowed due to the compliance may be in a range of few millimeters, such as ±lmm to ±3mm relative to a neutral position, or even below. The compliance may be realized, e.g., by way of compliant respectively deformable members, such as elastomer members, for example elastomer disks, and / or springs.

[0037] In an embodiment of the car brake and load measurement device, the coupling structure, in particular the car-sided coupling structure part, is configured to couple to the car structure at a sensor-sided car coupling position and at least one further car coupling position, wherein the sensor-sided car coupling position and the at least one further car coupling position are spaced apart with respect to each other. In such arrangement, the measurement force is transferred between the car structure and the coupling structure at the sensor-sided car coupling position and a further holding force portion, the further holding force portion corresponding in particular to a difference of the holding force and the measurement force, is transferred between the car structure and the coupling structure at the at least one further car coupling position. The load sensor is for such embodiment arranged in the force flow at the sensor-sided car coupling position. In an embodiment as generally assumed in a following, a single further car coupling position is present. In further alternative embodiments, a plurality of two or more further car coupling positions are present and the further holding force is transferred between the car structure and the coupling structure in combinate at the plurality of further car coupling positions.

[0038] This kind of embodiment allows not to transfer the complete holding force via the load sensor, but only a fraction respectively portion thereof. In this way, a load sensor having a smaller measurement range may be used. By way of example, the portion of the holding force that is transferred as measurement force may be 80%, 70%, 50%, 30%, 20% or generally any desired portion of the holding force. In an embodiment, the measurement force is generally equal to the further holding force respectively half of the holding force. In further embodiments, the measurement force is smaller than the further holding force respectively less than half of the holding force, or is larger than the further holding force, respectively more than half of the holding force.

[0039] The portion of the holding force that is transferred via the load sensor and accordingly serves as measurement force is generally determined by the design of the coupling structure, in particular the car-sided coupling structure part. A further advantage of this type of embodiment is an increased flexibility for connecting the coupling structure, particularly the car-sided coupling structure part, to the car structure. The coupling structure may be designed to couple to the car structure, e.g., at two car coupling positions that are chosen in accordance with overall design requirements and / or constraints. Either of such car coupling positions may be the sensor-sided car coupling position and a load sensor of a suited measurement range may be used, while the other car coupling position is the further car coupling position.

[0040] The coupling structure, in particular the car-sided coupling structure part, may include a sensorsided car coupling device at respectively associated with the sensor-sided car coupling position and a further car coupling device at respectively associated with the further car coupling position. The sensor-sided car coupling device and the further car coupling device may in an embodiment include tubular members that extend in each case parallel to each other and vertically in an operational configuration.

[0041] A sensor-sided fastening device, such as a sensor-sided fastening bolt as mentioned before, may in an embodiment extend through the tubular member of the sensor-sided car coupling device and may further extend through the sensor channel of the load sensor as mentioned before. The load sensor and the tubular member of the of the sensor-sided car coupling device may be arranged in a coaxial manner and axially adjacent to each other. Similarly, a further fastening device, such as further fastening bolt, may extend through the tubular member of the further car coupling device.

[0042] In a further embodiment of the car brake and load measurement device, the coupling structure, in particular the car-sided coupling structure part, is configured and arranged such that the complete holding force is transferred between the car structure and the coupling structure via the load sensor. In such design, the load sensor is configured for measuring the complete holding force in both vertical directions, i.e., in upwards direction and downwards direction.

[0043] In a further embodiment of the car brake and load measurement device, the coupling structure, in particular the car-sided coupling structure part, is configured to couple to the car structure at a plurality of two or more car coupling positions, wherein the car coupling positions are spaced apart with respect to each. The respective portion, in particular a generally identical respective portion, of the measurement force is transferred between the car structure and the coupling structure at each of the car coupling positions. The car brake and load measurement device includes for such design a plurality of load sensors corresponding to the plurality of car coupling positions, wherein each load sensor is associated with a respective car coupling position. Each load sensor is configured to be arranged in an operational configuration in a force flow between the car structure and the coupling structure such that a partial measurement force, the partial measurement force being part of the holding force, is transferred via the respective load sensors. The measurement axes of the load sensor are vertical. The partial measurement forces sum up to the holding force. For such arrangement, the complete holding force is measured by an arrangement of two or more load sensors, wherein each of the load sensors transmits a respective portion of the holding force. Such arrangement is favorable in that each load sensor only measures a portion of the measurement force and can accordingly be dimensioned for a comparatively small load, while at the same time the complete holding force can be measured. Preferably, the arrangement is such that the holding force is equally or substantially equally distributed between the car coupling positions and the partial measurement forces are identical or substantially identical. Some differences, however, may occur in particular due to load asymmetries. An arrangement with a plurality of load sensors, however, is more complex and costly.

[0044] In an embodiment of the car brake and load measurement assembly, the car brake and load measurement assembly includes a linkage device. The linkage device extends between and connects the first and second car brake and load measurement device. The linkage device may extend between the car brake and load measurement devices. The linkage device serves the purpose of increasing the mechanical stability of the setup. The linkage device does generally not transfer substantial forces between the first and second car brake and load measurement device. The linkage device may in an embodiment with the car-sided coupling structure part and the brake-sided coupling structure part of the car brake and load measurement devices. The connection between the car brake and load measurement devices and the linkage device is favorably dismountable, e.g. for the purpose of maintenance.

[0045] In a particular embodiment, the linkage device is or includes a generally tubular member, with an inner cross section corresponding to a cross section of the protruding members of the brakesided coupling structure parts of the first and second car brake and load measurement assembly. In this way, the protruding members may be inserted into the linkage device at its respective opposite ends. By way of example, the inner cross section of the linkage device may be square or rectangular.

[0046] In the following, exemplary embodiments are described in more detail with additional reference to the figures. The figures show:

[0047] Fig. 1 an elevator system according to an embodiment of the present disclosure in a side view;

[0048] Fig. 2 an elevator car according to an embodiment of the present disclosure in a top view; Fig. 3 a car brake and load measurement assembly according to an embodiment of the present disclosure in a perspective view;

[0049] Fig. 4 a car brake and load measurement device according to an embodiment of the present disclosure in a perspective view;

[0050] Fig. 5 a car brake and load measurement device according to an embodiment of the present disclosure in a perspective sectional view;

[0051] Fig 6 a schematic view of acting forces at a load sensor.

[0052] In the following, reference is first made to Figure 1, showing an elevator system 1 according to an embodiment in accordance with the present disclosure in a highly schematic side view. Apart from particular aspects as discussed in the following, the elevator system 1 may generally be designed as known in the art.

[0053] The elevator system 1 includes an elevator car 1.1 that is vertically movable in a hoistway 1.5, with g indicating the vertically-downwards pointing vector of gravity acceleration. The elevator car 1.1. is designed to receive a payload PL, such as passengers and / or freight. The total gravitational force of the elevator car 1.1 and the payload PL is CAR GROSS. In the shown design, the elevator car 1.1 is vertically guided by a first guide rail 1.6a and a second guide rail 1.6b that extend vertically on opposite sides of the elevator car 1.1. In the shown design, the guide rails 1.6a, 1.6b further include integrally formed stationary braking members 1.6.1a, 1.6.1b as discusses further below. Other arrangements are possible.

[0054] In the shown exemplary design, the elevator system 1 is a so-called dual drive elevator system and includes a first elevator drive 1.3a and a second elevator drive 1.3b, with the elevator drives 1.3a, 1.3b being of generally identical design. The elevator car 1.1 is coupled with a first counterweight 1.2a by way of a first traction member 1.4a. Similarly, the elevator car 1.1 is coupled with a second counterweight 1.2b by way of a second traction member 1.4b. The traction members 1.4a, 1.4b may each include one or more ropes or belts as generally known in the art.

[0055] The first traction member 1 ,4a is further coupled with the first elevator drive 1.3a and the second traction member 1.4b is coupled with the second elevator drive 1.3b. The coupling with the elevator drives 1.3a, 1.3b is made for each of the first traction member 1 ,4a respectively second traction member 1 ,4b by guiding a section thereof over a traction sheave (not individually referenced) of the respective elevator drives 1.3a, 1.3b. By operating the elevator drives 1.3a, 1.3b, the elevator car 1.1 and the counterweights 1.2a, 1.2b move vertically in opposite directions, i.e., the elevator car 1.1 may move upwards while the counterweights 1.2a, 1.2b move downwards, or vice versa, in dependence of the rotational direction of the traction sheaves. The elevator drives 1.3a, 1.3b are generally controlled to operate in a synchronous manner but with opposite rotational directions.

[0056] The counterweights 1.2a, 1.2b are typically identically designed and have associated gravitational forces Few i and Few 2, respectively.

[0057] The resulting combined gravitational force of both counterweights 1.2a, 1.2b is accordingly FCW_COMBINED = Fcwj + Fcw_2- The counterweights 1.2a, 1.2b are typically dimensioned such that their total weight corresponds to the weight of the empty car 1.1 plus about 30% to 70%, e.g. 50%, of the rated payload.

[0058] It is noted that the shown dual -drive design is not essential. In alternative embodiments of the elevator system 1, a single elevator drive is present. Especially in such arrangement, only one counterweight may be present in an embodiment, but also two or more counterweights are possible.

[0059] In accordance with the present disclosure, a car brake and load measurement assembly 2 as discussed in the following is present. The car brake and load measurement assembly 2 includes a first car brake and load measurement device 3a and a second car brake and load measurement device 3b.

[0060] By way of the car brake of the first car brake and load measurement device 3a frictionally engaging the first stationary braking member 1.6.1a and the car brake of the second car brake and load measurement device 3b frictionally engaging the second stationary braking member 1.6.1b in the hoistway 1.5 (car brakes not individually referenced in Figure 1), the elevator car 1.1 with the payload PL can be hold in position with the elevator drives 1.3a, 1.3b being switched off respectively not applying a torque. As discussed before in the general description, the total respectively combined holding force FHOLD COMBINED that needs to be exerted respectively compensated by the car brakes to maintain the elevator car 1.1. with the payload PL in position is given by the difference of the gravitational force FCAR GROSS resulting from the gross weight of the car, and the combined gravitational force Few COMBINED., taking further into consideration the gravitational forces of the traction members 1.41, 1.4b on both sides of the traction sheaves respectively elevator drives l-3a, 1.3b. The combined holding force FHOLD COMBINED can be downwards directed (if the gross weight of the elevator car 1.1 including payload PL is higher than the combines weight of the counterweights 1.2a, 1.2b) or upwards directed otherwise. The combined holding force FHOLD COMBINED includes a first folding force FHOLD i for the car brake of the first car brake and load measurement device 3 a and a second folding force FHOLD 2 for the car brake of the second car brake and load measurement device 3b, with

[0061] FHOLD COMBINED = FHOLDJ + FH0LD_2. It is noted that in the elevator system 1 the elevator drives 1.3a, 1.3b do generally not have additional machine brakes, but the elevator car 1.1 is braked exclusively by the brakes of the car brake and load measurement devices 3a, 3b. In variants where additional machine brakes are present, such machine brakes are assumed to be released respectively non-activated for the load measurement.

[0062] The elevator system 1 further includes an elevator controller 1.7. The elevator controller includes the circuitry and software respectively firmware for controlling operation of the elevator system 1. The elevator controller 1.7 is especially operatively connected to and controls operation of the elevator drives 1.3a, 1.3b and the car brakes of the car brake and load measurement device 3a, 3b. The load sensors (not individually shown in Figure 1) of the car brake and load measurement devices 3a, 3b may also be operatively connected to the elevator controller 1.7 and the elevator controller 1.7 may be configured to evaluate measurement data respectively measurement signals as provided by the load sensors. The elevator controller 1.7 may be configured to control operation of the elevator drives 1.3a, 1.3b and / or the car brakes in dependence of load measurement data provided by the load sensors.

[0063] In the following, reference is additionally made to Figure 2, showing the elevator car 1.1 in a schematic top view, respectively a view on the top 1.1.1 of the elevator car 1.1, together with a cartesian coordinate system x, y, z for reference. The negative z-axis corresponds to the direction of gravity, while the x-axis and v-axis extend horizontally and are aligned with the sides of the elevator car 1.1 as indicated. Exemplarily, the v-axis is parallel to a first edge 1.1a and a second edge 1. lb of the elevator car 1.1, with the edges 1.1a, 1.1b delimiting the elevator car 1.1 in the top view. It is noted that not all elements of the elevator car 1.1 are shown in Figure 1. In particular, the side walls, including door(s) of the elevator car are omitted.

[0064] The car brake and load measurement assembly 2 is in the shown design arranged at a top side of the elevator car 1.1, such that the elevator car 1.1 is generally arranged under the car brake and load measurement assembly 2. The first car brake and load measurement device 3a of the car brake and load measurement assembly 2 is arranged at the first edge 1.1a and the second car brake and load measurement device 3b is arranged at the second edge 1. lb of the elevator car 1.1, i.e. on opposite sides along the x-axis. Along the y-axis. the car brake and load measurement devices 3a, 3b are aligned. The car brake and load measurement devices 3a, 3b are con- nected by a linkage device 2.1 as discussed further below. The linkage device 2.1 extends parallel to the x-axis. In the shown design, the linkage device 2.1 includes a horizontal hollow profile, e.g. a steel profile, that extends between the car brake and load measurement devices 3a, 3b. The car brake and load measurement devices 3a, 3b are connected to a car structure 1.1.2 of the elevator car 1.1. In the shown design, the car brake and load measurement devices 3a, 3b are connected to horizontally extending beams at the first edge 1.1a and second edge 1. lb and form part of the car structure 1.1.2. At the side of the first edge 1. la, a first car-sided traction member connector 1.1.3a for coupling with the first traction member 1 ,4a is foreseen. Similarly at the side of the second edge 1. lb, a second car-sided traction member connector 1.1 ,3b for coupling with the second traction member 1 ,4b is foreseen. It is noted that instead of the top 1.1.1 , the car brake and load measurement assembly 2 could also be arranged different, in particular at a bottom side of the elevator car 1.1, such that the elevator car 1.1 is arranged generally over the car brake and load measurement assembly 2. Further in the shown design, the traction member connectors 1.1.3a, 1.1.3b are mounted to the car structure for directed connecting with the traction members 1.4a, 1.4b. In the shown design, the traction member connectors 1.1.3a, 1.1.3b are in vertical direction arranged in a lower part of the elevator car 1.1 respectively at the bottom side of the elevator car 1.1. Other arrangements are possible. In other designs, suspension pulleys are foreseen at the top side or bottom side of the elevator car 1.1 and the traction members 1.4a, 1.4a are guided via such suspension pulleys.

[0065] In the following, the design and operation of the car brake and load measurement assembly 2 is further discussed with additional reference to Figures 3, 4, 5. It is noted that while Figures 1, 2 shows a car brake and load measurement assembly 2 with first car brake and load measurement device 3a and second car brake and load measurement device 3b, Figures 4, 5 show elements of one car brake and load measurement device 3. Further, individual features of the first car brake and load measurement device 3a and the second car brake and load measurement device 3b are generally not separately referenced, since the car brake and load measurement devices 3a, 3b are of identical design.

[0066] The car brake and load measurement devices 3a, 3b include in each case a car brake 3.1. In the shown design, the car brakes 3.1 are hydraulic brakes. Each car brake 3.1 includes a brake body 3.1.1 (referenced in Figure 5) of in this design generally U-shaped cross section. The brake body 3.1.1 carries two stationary brake pads 3.1.3 and for each stationary brake pad 3.1.3 a corresponding movable brake pad 3.1.2 that faces the stationary brake pad 3.1.3. Each movable brake pad 3.1.2 is movable away from the corresponding stationary brake pad 3.1.3 by way associated hydraulic cylinders 3.1.4. By way of a brake closing spring 3.1.5, the movable brake pad 3.1.2 is biased respectively forced in the direction of the stationary brake pad 3.1.3. Between the stationary brake pads 3.1.3 and the movable brake pads 3.1.2, a gap (not references is present). The design with two hydraulic cylinders 3.1.4 and pairs of in each case a stationary brake pad 3.1.3 and movable brake pad 3.1.2 provides redundancy.

[0067] For each car brake and load measurement device 3a, 3b, an associated stationary braking member 1.6.1a, 1.6. lb is arranged vertically in the hoistway 1.5 and extends over at least the travel range of the elevator car 1.1. The stationary braking members 1.6.1a, 1.6.1b may, e.g., be vertically extending rail elements. As mentioned before, the stationary braking members 1.6.1a, 1.6.1b may be formed integrally with the guide rails 1.6a, 1.6b. Note that Figure 5 only schematically shows a section of a stationary braking member 1.6.1 (in dashed lines) for clarity reasons. The stationary braking member 1.6.1 in particular extends in the gap that is present between the stationary brake pads 3.1.3 and the movable brake pads 3.1.2. By way of the hydraulic cylinders 3.1.4, the movable brake pads 3.1.2 can be retracted respectively moved away from the stationary brake pads 3.1.3. At the same time, the brake closing springs 3.1.5 are compressed. In this configuration, the clearance between the movable brake pads 3.1.2 and the stationary brake pads 3.1.3 is such that little or favorably no friction is present between the brake pads 3.1.2, 1.3.3 and the stationary braking member 1.6.1, corresponding to the non-activated state of the car brake 3.1. As the hydraulic pressure of the hydraulic cylinders 3.1.4 is removed, the brake closing springs 3.1.5 expand, thereby forcing the movable brake pads 3.1.2 towards the stationary brake pads, 3.1.3, such that the stationary braking member 1.6.1 is frictionally clamped between the movable brake pads 3.1.2 and the stationary brake pads 3.1.3, corresponding to an activated state of the car brake 3.1. It is noted that the design and operation of the car brakes 3.1 is generally known in the art. Other types of hydraulic brakes as well as differently actuated brakes, such as electromagnetic brakes, can be used as well.

[0068] The car brake and load measurement devices 3a, 3b further include in each case a coupling structure 3.2 (referenced as such in Figure 3). By way of the coupling structures 3.2, the car brakes 3.1 are coupled to the car structure 1.1.2 as explained in the following.

[0069] Each coupling structure 3.2 includes a brake-sided coupling structure part 3.2.1 and a car-sided coupling structure part 3.2.2. The brake-sided coupling structure part 3.2.1 is connected to the car brake 3.1. Specifically in the shown design, the brake-sided coupling structure part 3.2.1 is mounted to the brake body 3.1.1. As best visible in Figure 5, the brake-sided coupling structure part 3.2.1 includes in this design a plate-shaped brake abutment member 3.2.1.2 that abuts the brake body 3.1.1 and an integrally formed protruding member 3.2.1.1 that projects from the brake abutment member 3.2.1.2 in a direction away from the car brake 3.1. The protruding member 3.2.1.1 has an exemplarily square cross section along its extension direction. The brake-sided coupling structure part 3.2.1 is removably mounted to the car brake 3.1 in the interest of assembly as well as maintenance and repair. In the shown design, the brake-sided coupling structure part 3.2.1 is removably connected to the brake body 3.1.1 by way of a brake fastening device 3.2.1.3, such as a cylindric bolt. In the shown design, a mounting flange 3.2.1.4 is arranged at an axial end of the brake fastening device 3.2.1.3, for example by screwing or welding, or is formed in one piece with the brake fastening device 3.2.1.3. The mounting flange 3.2.1.4, in turn, is mounted, e.g. screw-mounted, to the brake-sided coupling structure part 3.2.1, for example the protruding member 3.2.1.1. Other arrangements are possible.

[0070] The protruding members 3.2.1.1 belonging to the two car brake and load measurement devices 3a, 3b extend in this design along the x-axis and are arranged to face each other in an aligned manner.

[0071] Each car-sided coupling structure part 3.2.2 includes in the shown design a plate-shaped body 3.2.2.1. The plate-shaped body 3.2.2.1 may be aligned with respectively extend along thc i axis. Specifically, the plate-shaped body 3.2.2.1 is arranged such that it extends transverse to the protruding member 3.2.1.1. At the opposite ends of the plate-shaped body 3.2.2.1, car coupling devices 3.2.2.2, 3.2.2.3 are arranged. The car coupling devices 3.2.2.2, 3.2.2.3 are in the shown design formed integrally with the plate-shaped body 3.2.2.1 and are further tubular respectively have in each case a through-going axial channel that is oriented vertically respectively along the z-axis in an assembled state. The car coupling device 3.2.2.2 is a sensor-sided car coupling device and the car coupling device 3.2.2.3 is a further car coupling device. The sensor-sided car coupling device 3.2.2.2 defines a sensor-sided car coupling position SC and the further car coupling device 3.2.2.3 defines a further car coupling position FC (referenced in Figure 5).

[0072] As best visible in Figures 4, 5, the car-sided coupling structure part 3.2.2 of the car brake and load measurement devices 3a, 3b is in the shown design mounted to the car structure 1.1.2 by way of fastening bolts, namely a sensor-sided fastening bolt 3.2.4 and a further fastening bolt 3.2.5. The sensor sided fastening bolt 2.3.4 extends through the channel of the sensor-sided car coupling device 3.2.2.2 and the further fastening bolt 3.2.5 extends through the channel of the further car coupling device 3.2.2.3. The fastening bolts 3.2.4, 3.2.5 are connected to the car structure 1.1.2 by way of screwing. Other arrangements are possible as well.

[0073] The load sensor 3.3 of the car brake and load measurement devices 3a, 3b is in the shown design a tubular load cell with a through-going axial sensor channel 3.3.1 (referenced in Figures 3, 6) that is configured to measure compression forces. The load cell 3.3 is arranged coaxially with the sensor-sided car-coupling device 3.2.2.2, with the sensor-sided fastening bolt 3.2.4 extending through the sensor channel 3.3.1 and the channel of the sensor-sided car-coupling device. The load sensor 3.3 is clamped between the sensor-sided car coupling device 3.2.2.2 and the head of the sensor-sided fastening bolt 3.2.4 with a biasing force BIAS that acts as compression force.

[0074] As best visible in Figure 5, the car-sided coupling structure part 3.2.2 of the car brake and load measurement devices 3a, 3b, specifically the plate-shaped body 3.2.2.1, has a recess 3.2.2.5 that is realized as through-going cut-out in the plate-shaped body 3.2.2.1. The protruding member 3.2.1.1 extends through the recess 3.2.2.5. Thereby, the brake-sided coupling structure part 3.2.1 and the car-sided coupling structure part 3.2.2 are connected in an interlocking manner and a force can be transferred between them.

[0075] As also visible in Figure 5, the recess 3.2.2.5 is in particular in the vertical direction slightly larger than the protruding member 3.2.1.1 that extends therethrough. Accordingly, some vertical play is present, allowing some relative movement between the brake-sided coupling structure part 3.2.1 and the car-sided coupling structure part 3.2.2. The coupling between the brake-sided coupling structure part 3.2.1 and the car-sided coupling structure part 3.2.2 is further realized in a compliant manner. For this purpose, compliant members 3.2.6 that are exemplarily realized as elastomeric disks are foreseen in vertical directions at the interface of the brake-sided coupling structure part 3.2.1 and the car-sided coupling structure part 3.2.2. In the shown design, the carsided coupling structure part 3.2.2 includes spaced apart support devices 3.2.2.4 that project parallel to each other from the plat-shaped body 3.2.2.1. The support devices 3.2.2.4 overlap respectively cover the protruding member 3.2.1.1 along its extension direction fully or at least in part. One of the compliant members 3.2.6 is vertically arranged on each side in a gap between protruding member 3.2.1.1 and the corresponding support device 3.2.2.4. The above-described compliant arrangement serves the purpose of compensating for general tolerances and in particular misalignments of the guide rails 1.6a, 1.6b and their respective stationary braking members 1.6.1a, 1.6.1b, which may otherwise compromise the load measurement. The possible vertical movement range between the brake-sided coupling structure part 3.2.1 and the car-sided coupling structure part 3.2.2 may be in a typical range of, e.g. ±lmm to ±3mm relative to a neutral position.

[0076] A linkage device 2.1 that is exemplarily realized as hollow square profde extends between and connects the car brake and load measurement devices 3a, 3b of the car brake and load measurement assembly 2. As can be seen in Figure 5, the linkage device 2.1 extends between the respective opposing sides of the plate-shaped bodies 3.2.2.1. The linkage device 2.1 fits over the protruding members 3.2.1.1 in a substantially play-free manner. The linkage device 2.1 extends together with the protruding member 3.2.1.1 through the recess 3.2.2.5 for both car brake and load measurement devices 3a, 3b. The linkage device 2.1 serves the purpose of stability.

[0077] In the shown design, a bolt-receiving channel 3.2.7 extends for both car brake and load measurement devices 3a, 3b through the support devices 3.2.2.4 and the compliant members 3.2.6 as well as the linkage device 2.1. The bolt-receiving channels 3.2.7 are configured in each case to receive a bolt (not shown for clarity) for dismountable connecting the car brake and load measurement devices 3 with the linkage device 2.1. Other arrangements are possible.

[0078] In the following, the situation regarding the relevant acting forces and the load measurement is discussed with additional reference to Figure 6, schematically illustrating the situation for one of the car brake and load measurement devices 3a, 3b. It is assumed that the car brakes 3.1 of both car brake and load measurement devices 3a, 3b are in an activated state and the elevator car 1.1 with payload PL is accordingly maintained in position.

[0079] Along the v-axis. a holding force FHOLD that is exerted by the elevator car 1.1 onto the brake 3.1 of either of the car brake and load measurement devices 3a, 3b acts at a force application point P. The force application point P is generally given by the position of the protruding member 3.2.1.1 respectively a position where the holding force FHOLD is transferred between the brakesided coupling structure part 3.2.1 and the car-sided coupling structure part 3.2.2 (see also Figure 4). The holding force FHOLD as indicated may be the first holding force FHOLD i or the second holding force FHOLD 2. As discussed before, the first holding force FHOLD 1 and the second holding force HOLD 2 sum up to the combined holding force HOLD COMBINED and are generally equal or at least similar.

[0080] In the shown design, the holding force FHOLD is partly applied at the sensor-sided car coupling position SC via the sensor-sided car coupling device 3.2.2.2 and partly at the further coupling position FC via the further car coupling device 3.2.2.3, with the force distribution depending on the distance of the force application position P to the sensor-sided car coupling position SC and the further car-coupling position FC, as defined by the sensor-sided lever arm length Is and the further lever arm length F as referenced. It is noted that the force application position P is generally between the sensor-sided car coupling position SC and the further car coupling position FC. The larger force is applied at the side with the smaller lever arm length, and vice versa.

[0081] The part of the holding force FHOLD that is applied at the sensor sided car coupling position SC is referred to as measurement force F EASURE and is measured by the load sensor 3.3 as explained below. The further portion of the holding force FHOLD is referred to as further holding force portion FFURTHER and is not measured. In the example of Figure 6, the sensor-sided lever arm length Is is smaller than the further lever-arm length F. Consequently, the measurement force F EASURE is larger than the not-measured further holding force portion FFURTHER. For the sensor-sided lever arm length Is being equal to the further lever-arm length F, also the measurement force FMEASUERE and the further holding force portion FFURTHER would be generally equal.

[0082] In addition to the measurement force FMEASURE as portion of the holding force FHOLD, the load sensor 3.3 is subject to a biasing force FBIAS, resulting from the clamping of the load sensor 3.3 between the sensor-sided car coupling device 3.2.2.2 and the head of the sensor-sided fastening bolt 3.2.4. The biasing force FBIAS is a known compression force that is superimposed on the measurement force FMEASURE, resulting in the total measurement force FTOTAL. Consequently, the measurement force FMEASURE is determined as

[0083] FMEASURE = FTOTAL - FBIAS.

[0084] The force directions respectively algebraic signs are such that a downwards directed force respectively a force in direction of gravity is positive and an upwards directed force is negative.

[0085] While the biasing force FBIAS is in any case a compression force with a positive algebraic sign, the holding force FHOLD and accordingly also the measurement force FMEASURE may, in depend- ence of the load situation, be downwards-directed if the weight of the elevator car 1.1 with payload PL is larger than the combined weight of the counterweights 1.2a, 1.2b, taking additionally into account the weight of the traction members 1.4a, 1.4b as discussed or may alternatively be upwards-directed if the combined weight of the counterweights 1.2a, 1.2b is larger than the weight of the elevator car 1.1 with payload PL, taking additionally into account the wight of the traction members 1.4a, 1.4b. The latter is the case if the elevator car 1.1. is empty or lightly to moderately loaded. If the measurement force FMEASURE is downwards directed, it acts in the same direction as the biasing force FBIAS. Consequently, the measurement range respectively maximum force that can be measured by the load sensor 3.3 needs to be chosen in accordance with the maximum measurement force for a fully loaded elevator car 1.1 plus the biasing force FBIAS. If, on the other hand, the holding force FHOLD and accordingly the measurement force FMEASURE are upwards directed, the measurement force tends to relief the load sensor 3.3. respectively acts against the biasing force FBIAS. Consequently, the biasing force FBIAS must at least correspond to the upwards-directed measurement force for the elevator car 1.1 being empty, or chosen somewhat larger. It is again noted that that the holding force FHOLD as discussed is generally only half of the combined holding force FHOLD COMBINED that is exerted, by the elevator car 1.1. with payload PL due to the arrangement with two car brake and load measurement devices 3a, 3b.

Claims

- 24 -CLAIMS1. Car brake and load measurement device (3, 3a, 3b) for use in an elevator system (1), the elevator system (1) including an elevator car (1.1) that is vertically movable in a hoistway (1.5), the car brake and load measurement device (3) including:a car brake (3.1), the car brake (3.1) being switchable by an elevator controller (1.7) between an activated state and an alternative non-activated state, wherein the car brake (3.1 ) is configured to brake and hold the elevator car ( 1.1 ) by frictionally engaging an associated stationary braking member (1.6.1, 1.6.1a, 1.6.1b) arranged in the hoistway (1.5) in the activated state,a coupling structure (3.2), wherein the coupling structure (3.2) is configured to be in an operational configuration rigidly connected to a car structure (1.1.2) of the elevator car (1.1) and rigidly connected to the car brake (3.1) such that a holding force (FHOLD) that acts between the elevator car (1.1) and the car brake (3.1 ) in the activated state of the car brake (3.1) is transferred between the car structure (1.1.2) and the car brake (3.1) via the coupling structure (3.2),a load sensor (3.3), the load sensor (3.3) being configured to be arranged in an operational configuration in a force flow between the car structure (1.1.2) and the coupling structure (3.2), wherein a measurement axis of the load sensor (3.3) is vertical.

2. Car brake and load measurement device (3) according to the preceding claim, wherein the load sensor includes a load cell.

3. Car brake and load measurement device (3) according to anyone of the preceding claims, wherein the load sensor (3.3) is configured for both the measurement force being vertically upwards-directed or downwards-directed.

4. Car brake and load measurement device (3) according to anyone of the preceding claims, wherein the load sensor (3.3) is configured to be mounted by way of axial clamping.

5. Car brake and load measurement device (3) according to anyone of the preceding claims, wherein the load sensor (3.3) includes a throughgoing sensor channel (3.3.1), wherein the car brake and load measurement device (3) further includes a sensor-sided fastening device, wherein in an operational configuration the coupling structure (3.2) is connected to the carstructure (1.1.2) by way of the sensor-sided fastening device, the sensor sensor-sided fastening device being in particular a sensor-sided fastening bolt (3.2.4), wherein the sensorsided fastening device extends through the sensor channel (3.3.1).

6. Car brake and load measurement device (3) according to anyone of the preceding claims, wherein in an operational configuration the load sensor (3.3) is biased by a biasing force (FBIAS), the biasing force (FBIAS) being in particular a compression force.

7. Car brake and load measurement device (3) according to anyone of the preceding claims, wherein the coupling structure (3.2) includes a brake-sided coupling structure part (3.2.1) and a car-sided coupling structure part (3.2.2), wherein the brake-sided coupling structure part (3.2.1) is connected to the car brake (3.1) and / or is formed integrally with the car brake (3.1), wherein the car-sided coupling structure part (3.2.2) is configured to be connected to the car structure (1.1.2), wherein the brake-sided coupling structure part (3.2.1) and the carsided coupling structure part (3.2.2) are connected by way of interlocking.

8. Car brake and load measurement device (3) according to claim 7, wherein the brake-sided coupling structure part (3.2.1) includes a protruding member (3.2.1.1) and the car-sided coupling structure part (3.2.2) includes a recess (3.2.2.5), wherein protruding member (3.2.1.1) protrudes into or through the recess (3.2.2.5).

9. Car brake and load measurement device (3) according to claim 8, wherein the brake-sided coupling structure part (3.2.1) includes a generally plate-shaped body (3.2.2.1), wherein the recess (3.2.2.5) includes a throughgoing cutout in the plate-shaped body (3.2.2.1).

10. Car brake and load measurement device (3) according to anyone of claims 7 to 9, wherein the brake-sided coupling structure part (3.2.1) and the car-sided coupling structure part (3.2.2) are connected in a compliant manner.

11. Car brake and load measurement device (3) according to anyone of the preceding claims, wherein the coupling structure (3.2), in particular the brake-sided coupling structure part (3.2.2), is configured to couple to the car structure (1.1.2) at a sensor-sided car coupling position (SC) and at a further car coupling position (FC), wherein the sensor-sided car coupling position (SC) and the further car coupling position (FC) are spaced apart with respectto each other.

12. Car brake and load measurement assembly (2), the car brake and load measurement assembly (2) including a first (3a) and a second (3b) car brake and load measurement device according to anyone of the preceding claims.

13. Car brake and load measurement assembly (2) according to claim 12, the car brake and load measurement assembly (2) further including a linkage device (2.1), the linkage device (2.1) extending between and connecting the first (3a) and second (3b) car brake and load measurement device.

14. Elevator car (1.1), the elevator car (1.1) including a car brake and load measurement assembly (2) according to anyone of claims 12 to 13, wherein the first car brake and load measurement device (3a) is arranged at a first edge (1.1a) of the elevator car (1.1) and the second car brake and load measurement device (3b) is arranged at a second edge (1.1b) of the elevator car (1.1), wherein the first (1.1a) and second (1.1b) edge of the elevator car extend parallel to each other and extend in a common horizontal plane, wherein the car brake and load measurement assembly (2) is in particular arranged at a top or a bottom of the elevator car (1.1).

15. Elevator system (1), the elevator system (1) including an elevator car (1.1) according to claim 14, the elevator system (1) further including a hoistway (1.5), a first elevator drive (1.3a), a first counterweight (1.2a), a first traction member (1.4a), and an elevator controller (1-7),wherein the elevator car (1.1) and the first counterweight (1.2a) are coupled by way of the first traction member (1.4a) with the at least one first traction member (1.4a) suspending the elevator car (1.1) and the first counterweight (1.2a),wherein the first traction member (1.4a) is coupled to the first elevator drive (1.3a), such that by operating the first elevator drive (1.3a), the elevator car (1.1) and the first counterweight (1.2a) are vertically movable in opposite directions,the elevator system (1) further including a first (1.6.1a) and a second (1.

6. lb) stationary braking member arranged in the hoistway (1.5) such that the first stationary braking member (1.6.1a) can frictionally engage with the car brake (3.1) of the first car brake and load measurement device (3a) and the second stationary braking member (1.6.1b) can frictionally- 27 - engage with the car brake (3.1) of the second car brake and load measurement device (3b), wherein the first (1.

6. la) respectively second (1.

6. lb) stationary braking member are in particularly formed integrally with a first (1.6a) respectively second (1.6b) guide rail for the elevator car (1.1),wherein the elevator controller ( 1.7) is operationally connected to the car brake (3.1 ) of the first car brake and load measurement device (3a) and the second car brake and load measurement device (3b) and configured to control the car brakes (3.1) to assume their respective activated and non-activated state.

16. Method for determining a load of an elevator car (1.1), using a car brake and load measurement assembly (2) according to any of claims 12 or 13, wherein the elevator car (1.1) is in particular an elevator car (1.1) according to claim 14, the method including:holding the elevator car ( 1.1 ) in position by the car brake (3.1 ) of the first car brake and load measurement device (3a) frictionally engaging with an associated first stationary braking member (1.6.1a) and the car brake (3.1) of the second car brake and load measurement device (3b) frictionally engaging with an associated second stationary braking member (1.6.1b),wherein the car brake (3.1) of the first car brake and load measurement device (3) is rigidly connected with the coupling structure (3.2) of the first car brake and load measurement device (3) and the car brake (3.1) of the second car brake and load measurement device (3) is rigidly connected with the coupling structure (3.2) of the second car brake and load measurement device (3), wherein the coupling structures (3.2) are rigidly connected with a car structure (1.1.2) of the elevator car,measuring a first measurement force in a force flow between the coupling structure (3.2) of the first car brake and load measurement device (3) and the car structure (1.1.2), and measuring a second measurement force in a force flow between the coupling structure (3.2) of the second car brake and load measurement device (3) and the car structure (1.1.2), wherein the first measurement force is at least part of a first holding force ( HOLD i ) that acts between the elevator car (1.1) and the car brake (3.1 ) of the first car brake and load measurement device (3a) and the second measurement force is at least part of a second holding force ( HOLD I) that acts between the elevator car (1.1) and the car brake (3.1) of the second car brake and load measurement device (3b).

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