Patent Description:
Elevator systems may be configured with an electronic safety actuator as an alternative to the typical, centrifugal governor. In such electronic safety actuators, a bi-stable magnetic actuator is used to engage the safeties, and thus enable stopping of an elevator car. The safety actuators include magnet assemblies that are configured to provide a friction interface to generate a braking force when activated and engaged with a guide rail of an elevator system. It may be advantageous to provide improved magnet assemblies that may have increased life, lower costs, and/or high braking force. <CIT> discloses an electronic safety brake actuator for actuating an electronic brake, using a magnet assembly according to the preamble of claims <NUM> and <NUM>.

In accordance with an aspect of the present invention, magnet assemblies of electromechanical assemblies for elevator systems are provided. The magnet assemblies include a magnet, a first block assembly arranged on a first side of the magnet, and a second block assembly arranged on a second side of the magnet opposite the first block assembly. Each of the first block assembly and the second block assembly each include a respective friction engagement surface and each of the first block assembly and the second block assembly are formed of layers of sheet metal, and a portion of the layers of sheet metal include blade teeth that form the friction engagement surface for engagement with a guide rail.

Some embodiments of the magnet assemblies may include that the layers of sheet metal include a first group of sheet metal layers that are generally rectangular and a second group of sheet metal layers that include teeth that form the blade teeth.

Some embodiments of the magnet assemblies may include that the layers of sheet metal and the magnet include at least one aperture for receiving at least one respective fastener to join the layers of sheet metal and the magnet together.

Some embodiments of the magnet assemblies may include that the layers of sheet metal are saw blade sheet metal stock.

Some embodiments of the magnet assemblies may include an encapsulating body that houses the magnet, the first block assembly, and the second block assembly.

Some embodiments of the magnet assemblies may include that the encapsulating body is formed of a non-magnetic material.

Some embodiments of the magnet assemblies may include that the layers of sheet metal include alternating angled teeth that form the blade teeth.

Some embodiments of the magnet assemblies may include that the magnet, the first block assembly, and the second block assembly are configured to engage with the guide rail and act upon a connecting rod to actuate a safety brake.

Some embodiments of the magnet assemblies may include that the magnet, the first block assembly, and the second block assembly are configured to travel within a track of the electromechanical assembly.

In accordance with another aspect of the present invention, magnet assemblies of electromechanical assemblies for elevator systems are provided. The magnet assemblies includes a magnet, and a first block assembly arranged on a first side of the magnet, and a second block assembly arranged on a second side of the magnet opposite the first block assembly. Each of the first block assembly and the second block assembly are formed from powder metal sintering and include a monolithic tooth configuration configured to form a friction engagement surface for engagement with a guide rail.

In accordance with another aspect of the present invention, magnet assemblies of electromechanical assemblies for elevator systems are provided. The magnet assemblies includes a magnet, and a first block assembly arranged on a first side of the magnet, and a second block assembly arranged on a second side of the magnet opposite the first block assembly. Each of the first block assembly and the second block assembly include an abrasive coating configured to form a friction engagement surface for engagement with a guide rail. The magnet assemblies further include an encapsulating body that houses the magnet, the first block assembly, and the second block assembly, wherein the encapsulating body is formed of a non-magnetic material.

Some embodiments of the magnet assemblies may include that the abrasive coating comprises at least one of Cubic Boron Nitride ("CBN") and industrial diamond.

The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:.

The position reference system <NUM> can be any device or mechanism for monitoring a position of an elevator car and/or counter-weight, as known in the art.

Turning to <FIG>, a schematic illustration of a prior elevator car overspeed safety system <NUM> of an elevator system <NUM> is shown. The elevator system <NUM> includes an elevator car <NUM> that is movable within an elevator shaft along guide rails <NUM>. In this illustrative embodiment, the overspeed safety system <NUM> includes a pair of braking elements <NUM> that are engageable with the guide rails <NUM>. The braking elements <NUM> are actuated, in part, by operation of lift rods <NUM>. The triggering of the braking elements <NUM> is achieved through a governor <NUM>, typically located at the top of the elevator shaft, which includes a tension device <NUM> located within the pit of the elevator shaft with a cable <NUM> operably connecting the governor <NUM> and the tension device <NUM>. When an overspeed event is detected by the governor, the overspeed safety system <NUM> is triggered, and a linkage <NUM> is operated to actuate a combination of lift rods <NUM> simultaneously to cause actuation (e.g., self-engagement) of the braking elements <NUM> (e.g., safety wedges) that engage with the guide rail and cause a smooth and even stopping or braking force to stop the travel of the elevator car. As used herein the term "overspeed event" refers to an event during which a speed, velocity, or acceleration of an elevator car exceeds a predetermined threshold of the respective state of motion, and is not intended to be limited to constant speed, but rather also includes rates of change (e.g., acceleration) and also direction of travel of motion the elevator car (e.g., velocity). The linkage <NUM>, as shown, is located on the top of the elevator car <NUM> and ensures simultaneous operation of the braking elements <NUM>. However, in other configurations, the linkage may be located below a platform (or bottom) of the elevator car. As shown, various components are located above and/or below the elevator car <NUM>, and thus pit space and overhead space within the elevator shaft must be provided to permit operation of the elevator system <NUM>.

Turning now to <FIG>, schematic illustrations of an elevator car <NUM> having an overspeed safety system <NUM> in accordance with an embodiment of the present disclosure are shown. <FIG> is an isometric illustration of an elevator car frame <NUM> with the overspeed safety system <NUM> installed thereto. <FIG> is an enlarged illustration of a portion of the overspeed safety system <NUM> showing a relationship with a guide rail. <FIG> is a schematic similar to <FIG>, but with the guide rail removed for clarity of illustration.

The car frame <NUM> includes a platform <NUM>, a ceiling <NUM>, a first car structural member <NUM>, and a second car structural member <NUM>. The car frame <NUM> defines a frame for supporting various panels and other components that define the elevator car for passenger or other use (i.e., define a cab of the elevator), although such panels and other components are omitted for clarity of illustration. The elevator car <NUM> is moveable along guide rails <NUM> (shown in <FIG>), similar to that shown and described above. The overspeed safety system <NUM> provides a safety braking system that can stop the travel of the elevator car <NUM> during an overspeed event.

The overspeed safety system <NUM> includes a first safety brake <NUM>, a first electromechanical actuator <NUM>, and a controller or control system <NUM> operably connected to the first electromechanical actuator <NUM>. The first safety brake <NUM> and the first electromechanical actuator <NUM> are arranged along the first car structural member <NUM>. A second safety brake <NUM> and a second electromechanical actuator <NUM> are arranged along the second car structural member <NUM>. The control system <NUM> is also operably connected to the second electromechanical actuator <NUM>. The connection between the control system <NUM> and the electromechanical actuators <NUM>, <NUM> may be provided by a communication line <NUM>. The communication line <NUM> may be wired or wireless, or a combination thereof (e.g., for redundancy). The communication line <NUM> may be an electrical wire to supply electrical power from the control system <NUM> and an electromagnet of the first electromechanical actuator <NUM>. It will be appreciated that in alternative configurations, the communication may be a wireless communication system, both for data/information and/or wireless power transfer. It will be appreciated that the overspeed safety system <NUM>, in accordance with embodiments, can include any number of safety brakes, such as one, two, three, or more.

As shown, the control system <NUM> is located on the top or ceiling <NUM> of the car frame <NUM>. However, such position is not to be limiting, and the control system <NUM> may be located anywhere within the elevator system (e.g., on or in the elevator car, within a controller room, etc.). The control system <NUM> may comprise electronics and printed circuit boards for processing (e.g., processor, memory, communication elements, electrical buss, etc.). Thus, the control system <NUM> may have a very low profile and may be installed within ceiling panels, wall panels, or even within a car operating panel of the elevator car <NUM>. In other configurations, the control system <NUM> may be integrated into various of the components of the overspeed safety system <NUM> (e.g., within or part of the electromechanical actuator <NUM>).

The overspeed safety system <NUM> is an electromechanical system that eliminates the need for a linkage or linking element installed at the top or bottom of the elevator car. The control system <NUM> may include, for example, a printed circuit board with multiple inputs and outputs. In some embodiments, the control system <NUM> may include circuitry for a system for control, protection, and/or monitoring based on one or more programmable electronic devices (e.g., power supplies, sensors, and other input devices, data highways and other communication paths, and actuators and other output devices, etc.). The control system <NUM> may further include various components to enable control in the event of a power outage (e.g., capacitor/battery, etc.). The control system <NUM> may also include an accelerometer or other component/device to determine a speed of an elevator car (e.g., optical sensors, laser range finders, etc.). In such embodiments, the control system <NUM> is mounted to the elevator car, as shown in the illustrative embodiments herein.

The control system <NUM>, in some embodiments, may be connected to and/or in communication with a car positioning system, an accelerometer mounted to the car (i.e., a second or separate accelerometer), and/or to the elevator controller. Accordingly, the control system <NUM> may obtain movement information (e.g., speed, direction, acceleration) related to movement of the elevator car along an elevator shaft. The control system <NUM> may operate independently of other systems, other than potentially receiving movement information, to provide a safety feature to prevent overspeed events.

The control system <NUM> may process the movement information provided by a car positioning system to determine if an elevator car is traveling at a speed in excess of a threshold speed. If the threshold is exceeded, the control system <NUM> will trigger the electromechanical actuators and the safety brakes. The control system <NUM> will also provide feedback to the elevator control system about the status of the overspeed safety system <NUM> (e.g., normal operational position/triggered position). It will be appreciated that although referred to as an "overspeed" system, the systems may be configured to determine if an elevator car is accelerating at a rate in excess of a threshold acceleration, and the term "overspeed" is not to be limiting to merely a constant rate of motion.

Thus, the overspeed safety system <NUM> of the present disclosure enables electrical and electromechanical safety braking in the event of overspeed events. The electrical aspects of the present disclosure enable the elimination of the physical/mechanical linkages that have traditionally been employed in overspeed safety systems. That is, the electrical connections allow for simultaneous triggering of two separate safety brakes through electrical signals, rather than relying upon mechanical connections and other components such as wheels, ropes, etc..

With reference to <FIG>, details of parts of the overspeed safety system <NUM> are shown. The first electromechanical actuator <NUM> is mounted to the first car structural member <NUM> using one or more fasteners. The first electromechanical actuator <NUM> includes a magnet assembly <NUM> that is configured to magnetically engage with the guide rail <NUM>. The first electromechanical actuator <NUM> is operably connected to the control system <NUM> by the communication line <NUM>. The control system <NUM> can transmit an actuation signal to the first electromechanical actuator <NUM> (and the second electromechanical actuator <NUM>) to perform an actuation operation when an overspeed event is detected. As used herein the term "overspeed event" refers to an event during which a speed, velocity, or acceleration of an elevator car exceeds a predetermined threshold of the respective state of motion, and is not intended to be limited to constant speed, but rather also includes rates of change (e.g., acceleration) and also direction of travel of motion the elevator car (e.g., velocity). The first electromechanical actuator <NUM> will actuate a connecting rod <NUM>, by means of the magnet assembly <NUM> that is operably connected to the first safety brake <NUM>. When the connecting rod <NUM> is actuated, the first safety brake <NUM> will actuate to engage with the guide rail <NUM>, e.g., using a safety brake element <NUM>, such as a safety roller or wedge. In some embodiments, the two-part illustrated configuration may be integrated into a single unit, thus potentially eliminating the connecting rod.

In accordance with embodiments of the present disclosure, portions of the overspeed safety system are bolted or other attachment means are used to fix the components to the upright. That is, the overspeed safety system in accordance with some embodiments of the present disclosure does not float within the upright, and it is not guided by the rail. For example, in normal operation, the overspeed safety system has no contact with the guide rail. Therefore, as the elevator car floats in the front-to-back direction, the components of the overspeed safety system (e.g., a housing) move with the elevator car and the magnet assembly is sometimes closer to the blade of the guide rail and sometimes farther from the guide rail. One advantage of such approach, in accordance with embodiments of the present disclosure, is that guiding elements are not needed, and therefore, the risk of noise from the guiding elements rubbing along the rail is eliminated. Similarly, for example, there is no risk of these guiding elements wearing because they are not included in the design. However, because the magnet assembly floats with the elevator car, and thus may be relatively far from the guide rail, triggering of the system (e.g., moving the magnet assembly from an electromagnet assembly of the system to engage with the guide rail) may be more difficult. Further, such configuration may increase the difficulty of resetting the system after activation (e.g., removing the magnet assembly from the guide rail and returning it to the electromagnet assembly).

To overcome these considerations, as described herein and in accordance with some embodiments of the present disclosure, biasing element (e.g., springs) are included in the overspeed safety system. One end of the biasing element is fixed against a housing of the overspeed safety system and the other end acts to push the electromagnet assembly into the housing. During resetting, the electromagnet assembly overcomes the force of the biasing elements, moves toward the guide rail and the magnet assembly that is magnetically engaged to the guide rail. When the electromagnet assembly contacts the back surface of the magnet assembly or becomes imminently close to it, the magnet assembly releases from the guide rail and magnetically engages with the electromagnet assembly (e.g., the magnetic force applied by the electromagnetic assembly overcomes the magnetic attraction between the magnet assembly and the guide rail). The biasing elements then act to move the electromagnet assembly and the magnet assembly back into the housing. The magnet assemblies are subject to repeated engagement with a guide rail to generate a friction braking force. Embodiments of the present disclosure are directed to robust, low cost, and/or high reliability magnet assemblies for use in electromagnet actuators of elevator systems.

Turning now to <FIG>, schematic illustrations of an electromagnet actuator <NUM> that may incorporate embodiments of the present disclosure is shown. The electromagnet actuator <NUM> may be a part of an electromechanical actuator, as shown and described above. The electromagnet actuator <NUM>, as illustratively shown in this example embodiment, includes a magnet assembly <NUM> that is operably (and magnetically) connectable to an electromagnet assembly <NUM>. The magnet assembly <NUM> includes an optional toothed block <NUM> and a magnet <NUM> (e.g., permanent magnet), and may be connected to a connecting rod (not shown), as will be appreciated by those of skill in the art, or directly connected to a safety brake in a single unit. The toothed block <NUM> provides for a contact structure or surface for engaging with a guide rail of an elevator system when the electromagnet actuator <NUM> is activated to provide a stopping or braking force. The teeth of the toothed block <NUM> are configured to grip into and frictionally engage with the guide rail such that a braking force is generated.

In this illustrative non-limiting configuration, the electromagnet assembly <NUM> includes a coil <NUM> arranged around a core <NUM> (e.g., formed from steel or steel plates). One or more lead wires <NUM> are electrically connected to the coil <NUM> to supply electricity thereto and thus generate a magnetic field by means of the coil <NUM> and the core <NUM>. The coil <NUM> and the core <NUM> are located within a housing or other part of an elevator car (e.g., a frame) and movably mounted thereto (e.g., along springs or other biasing elements). The magnet <NUM> of the magnet assembly <NUM> is releasable from the electromagnet assembly <NUM> during a braking operation and thus cause a connecting rod to engage a safety brake of an elevator car. It will be appreciated that other configurations of electromagnetic assemblies may be employed without departing from the scope of the present disclosure. As shown, the coil <NUM> and the core <NUM> are mounted to a flange support <NUM> by one or more fasteners <NUM> (e.g., bolts). The biasing elements are configured to apply a biasing force against the flange support <NUM>, as will be appreciated by those of skill in the art.

<FIG> illustrates a front elevation view, illustrating details of the magnet assembly <NUM>. In particular, <FIG> illustrates the arrangement of teeth <NUM> of the toothed blocks <NUM>. As shown, the teeth <NUM> are arranged in columns, and in particular, three columns of teeth <NUM> are provided on each toothed block <NUM>. The teeth <NUM> are formed through a machining process which requires hardening of the material of the toothed blocks <NUM> after the machining and formation of the teeth <NUM>. The teeth <NUM> are configured to provide a gripping or friction engagement with a guide rail during a braking operation. The teeth <NUM> will contact the material of the guide rail to generate a frictional braking force.

The illustration of <FIG> may be considered representative of a configuration of a toothed block. This configuration illustrates the inclusion of the three columns of teeth <NUM> which may be intentionally designed in view of operational, functional, and manufacturing considerations. The two primary considerations for formation and arrangement of the teeth are (i) maximizing the amount of tooth material (e.g., steel) in proximity to a guide rail so that a magnetic attraction of the magnetic to the guide rail can be maximized and (ii) minimizing the amount of tooth material that is actually in contact with the guide rail so that the pressures applied by the tips of the teeth can be high and the teeth can "cut into" the guide rail. That is, there is a balance between material frictional contact and magnetic contact between the magnet assembly and the guide rail to ensure a desired braking or stopping force to be generated. It was determined that when employing a machined magnet assembly, having three columns of teeth provided a preferred configuration and balance between the magnetic attraction and the frictional contract forces, which are inversely related.

Turning now to <FIG>, schematic illustrations of an electromechanical actuator <NUM> that may incorporate embodiments of the present disclosure are shown. <FIG> illustrates an isometric illustration of the electromechanical actuator <NUM> and <FIG> is a partial cross-sectional view of the electromechanical actuator <NUM>.

The electromechanical actuator <NUM> includes a first housing <NUM> and a second housing <NUM> that are fixedly connected together. Although shown, two separate housing components <NUM>, <NUM> are configured to form a housing assembly <NUM>. In alternative embodiments, the housing assembly <NUM> may be a single body, structure, or component that has substantially the same shape, structure, and configuration as the illustrative first and second housings <NUM>, <NUM>. The electromechanical actuator <NUM> further includes an electromagnet assembly <NUM> and a magnet assembly <NUM>. As shown in <FIG>, the electromagnet assembly <NUM> may be housed between the first housing <NUM> and the second housing <NUM> and the magnet assembly <NUM> is housed within a track <NUM> defined by the second housing <NUM>. In operation, the magnet assembly <NUM> may move along and within the track <NUM>.

The electromagnet assembly <NUM> is a preformed structure that includes a coil and a core (e.g., laminated core, machined piece(s), etc.). Although shown and described as a laminated core, other core structures are possible without departing from the scope of the present disclosure. For example, in some embodiments, the core may be steel cores (e.g., formed from machined pieces) or ferrite cores. Advantageously, because the preformed structure is a unitary structure, the electromagnet assembly <NUM> does not include flanges and/or fasteners. The electromagnet assembly <NUM> may be moveably mounted within the housing <NUM>, <NUM> along one or more guides <NUM> and be biased to a rest position by one or more biasing elements <NUM> along the guides <NUM>. Additionally, lead wires electrically connected to the coil of the electromagnet assembly <NUM> may be securely retained or installed within the unitary structure. The electromagnet assembly <NUM> includes an encapsulating body <NUM> which contains the components of the electromagnet assembly <NUM>. The encapsulating body <NUM> may be, for example, a preformed body, a cast body, a molded structure, or a potted structure that has the components of the electromagnet assembly <NUM> embedded therein (e.g., coil, laminated core, lead wire, etc.). In some embodiments, the encapsulating body <NUM> may be preformed and the components installed therein and in other embodiments, the encapsulating body <NUM> may be formed around the components. The lead wire may electrically connect to an electrical connector <NUM>. The electrical connector <NUM> may be fixedly attached to or mounted to the first housing <NUM> and can provide for electrical connection between the electromagnet assembly <NUM> and an electrical source of the control system (e.g., as shown and described above).

The first housing <NUM> is configured to be mounted to or affixed to a portion of an elevator car, such as a frame. The second housing <NUM> is configured to be a portion of the structure that is moveable along (e.g., adjacent or relative to) a guide rail of an elevator system. That is, the second housing <NUM> defines a portion of the electromechanical actuator <NUM> that is adjacent to or proximate the guide rail. This results in the magnet assembly <NUM> being arranged and retained within the track <NUM> of the second housing <NUM> between material of the first and/or second housing <NUM>, <NUM> and the guide rail. It will be appreciated that the second housing <NUM> preferably does not contact the guide rail. That is, although the elevator car and electromechanical actuator <NUM> may float away from the guide rail (e.g., relative movement/motion), the dimensions of the magnet assembly <NUM> are such that the magnet assembly <NUM> never leaves the track <NUM>.

As shown in <FIG>, the electromagnet assembly <NUM> is an encapsulated component of the electromechanical actuator <NUM>. However, as described herein, other components, such as the magnet assembly <NUM> may be alternatively or additionally encapsulated.

For example, turning now to <FIG>, a schematic illustration of an electromechanical actuator <NUM> that may incorporate embodiments of the present disclosure is shown. The electromechanical actuator <NUM>, as shown, includes a unitary formed housing <NUM> similar to that shown and described above (but in single-body form). The electromechanical actuator <NUM> includes an encapsulated electromagnet assembly <NUM> and an encapsulated magnet assembly <NUM>. The encapsulated electromagnet assembly <NUM> is housed in a portion of the housing <NUM> and translatable or moveable along guides <NUM>, similar to that described above. The encapsulated magnet assembly <NUM> is housed within a track <NUM> defined by a portion of the housing <NUM>. In operation, the encapsulated magnet assembly <NUM> may move along and within the track <NUM>.

Similar to the described encapsulated electromagnet assemblies described above, the components of the magnet assembly of the electromechanical actuator <NUM> are encased within a material to protect such components and improve part life. As shown, the encapsulated magnet assembly <NUM> includes an encapsulating body <NUM> that houses a magnet <NUM>, which may include a toothed block. The encapsulating body <NUM> also houses a connector pin <NUM> that is configured to engage with a connecting rod to enable actuation of a safety brake when the encapsulated magnet assembly <NUM> moves upward along the track <NUM>. The formation and structure of the encapsulated magnet assembly <NUM> may be substantially similar to that of the encapsulated electromagnet assemblies described above. That is, similar materials and/or manufacturing processes may be employed to form the encapsulated magnet assembly <NUM>.

The connector pin <NUM> may be part of a component integrator <NUM> that allows for different locations/arrangements of connection to a connecting rod. Depending on a specific application and arrangement of parts (e.g., of the safety brake) some safeties lend themselves to lifting from the top of a wedge (e.g., most symmetric safeties) and others lend themselves to lifting from a face of a wedge (e.g., most asymmetric safeties). The preformed structure of the component integrator <NUM> permits different connection points to the connector pin <NUM>, and thus enables greater versatility as compared to prior configurations.

Conventionally, the magnet assemblies included toothed blocks with machined teeth. Machining of such magnet blocks can be costly and require highly skilled or specialized tools. Further, such toothed blocks are subject to repeated operation and engagement with a guide rail, and thus wear can occur. Improved magnet blocks for electromechanical actuators may be desirable.

Embodiments of the present disclosure are directed to improved magnet blocks that may be used with electromechanical actuators of elevator systems. In accordance with embodiments of the present disclosure, alternative means for manufacturing and/or forming magnet blocks are provided that do not require intricate machining or costs associated therewith.

For example, turning to <FIG>, schematic illustrations of a magnet assembly <NUM> in accordance with an embodiment of the present disclosure are shown. The magnet assembly <NUM> may be used in encapsulated or non-encapsulated configurations, as shown and described above. The magnet assembly <NUM> includes two block assemblies <NUM>, <NUM> arranged on opposite sides of a magnet <NUM>. The magnet <NUM> may be a permanent magnet. The block assemblies <NUM>, <NUM> are not machined assemblies, but rather are formed from a stack or group of joined sheet metal layers <NUM>. That is, the block assemblies <NUM>, <NUM> are laminated blocks or blocks formed of laminations, sheets, or layers of sheet metal.

A first group <NUM> of sheet metal layers <NUM> are generally rectangular and a second group <NUM> of sheet metal layers <NUM> include a friction engagement surface <NUM> in the form of blade teeth. In some embodiments, the block assembly <NUM>, <NUM> may be formed from saw blade sheet metal stock (e.g., band saw stock). As such, the geometric profile of the first and second groups <NUM>, <NUM> of sheet metal layers <NUM> may be formed through die cuts or punch-outs. The sheet metal layers <NUM> and the magnet <NUM> include apertures <NUM> that are aligned to receive fasteners, such as bolts, screws, rivets, etc. used to join the sheet metal layers <NUM> and the magnet <NUM> together to form the magnet assembly <NUM>.

Turning now to <FIG>, schematic illustrations of a single layer of a sheet metal layer <NUM> for use in a magnet assembly in accordance with an embodiment of the present disclosure are shown. The sheet metal layer <NUM> includes a plurality of teeth <NUM>, <NUM> which may be arranged in an alternating angled orientation or configuration, as illustrated, to form a friction engagement surface of a block assembly. That is, when assembled, a stack of sheet metal layers <NUM> may form a structure that include teeth that are alternating with respect to a body <NUM> of the sheet metal layer <NUM>. The body <NUM> further includes apertures <NUM> configured to receive a fastener to enable joining of multiple sheet metal layers <NUM>.

Advantageously, the material used to form such block assemblies may be significantly more cost effective than machining a toothed block from a single material block. In some embodiments, the saw blade sheet metal stock may be punched to form laminations that are then stacked together. After combining laminated blocks with a magnet, the assembly is riveted and then, may optionally be encapsulated. Advantageously, because the block assemblies are made from laminations of saw blade sheet metal stock, machining is no longer necessary. Further, heat treatment of the machined blocks can be eliminated because the saw blade sheet metal stock may already be hardened. In some embodiments, the addition of a coating for corrosion protection may not be necessary because of the saw blade sheet metal stock. That is, saw blade sheet metal stock with corrosion protection already applied may be employed.

Furthermore, because the magnet assembly is formed from laminated material in the form of sheet metal layers, eddy currents - which are created during actuation due to a changing magnetic field - will be dramatically reduced. The reduction of eddy currents ensures greater efficiency of the actuator that incorporates the magnets assemblies described above. Greater efficiency permits a reduction in the size of a trigger and/or reset capacitor or capacitors. Such reduced capacitors may enable further reductions in cost because the capacitors of such electromechanical actuators constitute a significant portion of the material cost of the system.

Turning now to <FIG>, schematic illustrations of a magnet assembly <NUM> in accordance with an embodiment of the present disclosure are shown. <FIG> illustrates magnet assembly <NUM> in isolation and <FIG> illustrates the magnet assembly <NUM> as installed within an encapsulating body <NUM>. In this embodiment, the magnet assembly includes blocks that are formed using a powdered metal sintering process. The magnet assembly <NUM> includes a first block assembly <NUM>, a second block assembly <NUM>, and a magnet <NUM> secured between the first and second block assemblies <NUM>, <NUM>.

Each block assembly <NUM>, <NUM> is formed from a powdered metal sintering process. In this process, powdered metal is used to fill a cavity (e.g., die) that is shaped like the formed magnet assembly block (i.e., the illustrated block assemblies <NUM>, <NUM>). The powdered metal is then compacted. The compacted powered metal is then ejected from the die and sintered in an oven. Sintering not only increases the material density but also hardens the material by causing the metal particles to fuse together. After sintering, a small amount of material on the teeth may be removed via a grinding process to sharpen the tips. Optionally, a corrosion protection layer is added (e.g., black oxide, nickel, etc.).

Due to the use of a die or preconfigured cavities used to preform the entire block assembly, each block assembly <NUM>, <NUM> includes friction engagement surface <NUM>. In this embodiment, the friction engagement surface <NUM> comprises a number of monolithic teeth arranged in a single column. Because of the use of a die to manufacture the block assemblies <NUM>, <NUM>, no machining is necessary to form the friction engagement surface <NUM>. However, as noted above, in some embodiments, the friction engagement surface <NUM> may be sharpened after formation. In some embodiments, and as shown, the friction engagement surface <NUM> may each be monolithic in nature, rather than multi-toothed configurations. For example, in some conventional configurations, the teeth of a toothed block may be formed of columns of teeth on each side of the magnet (e.g., three columns on each side as shown in <FIG>). However, due to the manufacturing process of powdered metal sintering, the teeth of the magnet assembly <NUM> are monolithic with only a single column of teeth on each side of the magnet <NUM>. As shown in <FIG>, the teeth of the friction engagement surface <NUM> are arranged as single column, with individual monolithic elements or teeth <NUM>, with each monolithic element <NUM> having a tooth edge <NUM>.

Advantageously, the powdered metal sintering magnet assemblies described herein can provide various improvements over conventional machining processes. For example, quality and quantity of manufactured components may be increased. The teeth are brought to final dimensions after heat treatment, rather than before heat treatment. After heat treatment, the teeth are resistant to damage by impacts. By contrast, machined blocks (e.g., under prior configurations) are brought to final dimensions before heat treatment. Given this, powdered metal sintered blocks present an advantage with respect to quality control (e.g., ensuring the final shape of the teeth).

Turning now to <FIG>, a schematic illustration of a magnet assembly <NUM> in accordance with an embodiment of the present disclosure is shown. In this embodiment, the magnet assembly includes blocks that are formed without teeth. The magnet assembly <NUM> includes a first block assembly <NUM>, a second block assembly <NUM>, and a magnet <NUM> secured between the first and second block assemblies <NUM>, <NUM>. The block assemblies <NUM>, <NUM> may be manufactured by machining, molds, powder metal sintering, or by other processes. In this embodiment, the block assemblies merely have the form of the blocks but no formed teeth.

In contrast, in this embodiment, the block assemblies <NUM>, <NUM> include a friction engagement surface <NUM> in the form of an abrasive coating applied to the block assemblies <NUM>, <NUM>. In some embodiments, the blocks may be fabricated from low carbon steel to maximize magnetic permeability of the blocks. Subsequently, the blocks and the magnet <NUM> may be assembled as shown, and then encapsulated within a housing (e.g., as shown in <FIG>). A super abrasive coating is then applied only to the exposed steel surfaces of the blocks. The super abrasive could be one of many types, including, without limitation, Cubic Boron Nitride ("CBN") or industrial diamond.

The friction engagement surface <NUM> provides for a contact surface between the block assemblies <NUM>, <NUM> and a guide rail. The friction engagement surface <NUM> provides for gripping engagement to generate braking force and thus stop the movement of an elevator car.

Because the blocks of the present embodiment no longer have teeth, a greater number of types of steels are available for the formation of the blocks. That is, the material of the block is no longer the material that provides the contact and engagement surface with a guide rail, but rather it is the friction engagement surface <NUM> that provides such contact. Because of this, heat treatment of the blocks can be eliminated. Moreover, the addition of a coating for corrosion protection may no longer be necessary because the friction engagement surface <NUM> fulfills this function.

In some embodiments, by encapsulating the magnet assembly prior to the addition of the friction engagement surface <NUM> (e.g., as shown in <FIG>), the cost of the manufacturing process may be reduced. By coating the blocks with the abrasive coating <NUM> after encapsulation, no masking is needed. As such, the entire exposed friction interface - which is small in surface area - can be coated economically.

Accordingly, in accordance with embodiments of the present disclosure, electromechanical systems may incorporate one or more improved magnet assemblies, as shown and described above. Advantageously, embodiments of the present disclosure enable increased electromechanical actuator component product life as compared to prior configurations, and specifically improved magnet assemblies thereof. The magnet assemblies of the present disclosure provided for reduced costs while improving component life. The blocks that support a magnet and are configured to engage with a guide rail of an elevator system are improved, as described above. Variations on the contact configurations is improved, such as through improved tooth configurations and/or through the use of an abrasive coating.

The terms "about" and "substantially" are intended to include the degree of error associated with measurement of the particular quantity and/or manufacturing tolerances based upon the equipment available at the time of filing the application.

Claim 1:
A magnet assembly (<NUM>) of an electromechanical assembly (<NUM>; <NUM>; <NUM>) for an elevator system (<NUM>), the magnet assembly (<NUM>) comprising:
a magnet (<NUM>);
a first block assembly (<NUM>) arranged on a first side of the magnet (<NUM>); and
a second block assembly (<NUM>) arranged on a second side of the magnet (<NUM>) opposite the first block assembly (<NUM>),
wherein each of the first block assembly (<NUM>) and the second block assembly (<NUM>) each include a respective friction engagement surface (<NUM>) for engagement with a guide rail (<NUM>); characterized in that each of the first block assembly (<NUM>) and the second block assembly (<NUM>) are formed of layers of sheet metal (<NUM>; <NUM>), and
wherein a portion of the layers of sheet metal (<NUM>; <NUM>) include blade teeth (<NUM>, <NUM>) that form the friction engagement surface (<NUM>) for engagement with a guide rail (<NUM>).