Patent Description:
Hoistway surveying prior to rail installation may be performed by a technician with a folding ruler. The technician is typically required to lean into the open hoistway to obtain the measurements, which could be dangerous and results in imprecise measurements.

<CIT> describes an in-hoistway measurement device and an in-hoistway measurement system.

<CIT> describes a measuring device for measuring an elevator shaft and a method using the measuring device to measure an elevator shaft.

According to a first aspect of the invention, a tool for surveying a multi-level elevator hoistway in preparation for installing hoistway rails is provided according to claim <NUM>.

In some embodiments, the sensor is a laser sensor.

In some embodiments, the sensor is pivotally connected to the platform.

In some embodiments, the sensor is spaced apart from the first coupling link, and the tool includes a counterbalance for countering rotation induced by the sensor relative to an axis of the rope.

In some embodiments, the first and second L-bracket segment each include outer segments that extend away from the platform and are parallel with each other; and the outer segments each define a slot for receiving the first guide wire, each slot defining an inner portion that extends toward the platform.

In some embodiments, each slot defines an outer slot portion that converges toward the inner portion, wherein the slot outer portion of the first L-bracket segment extends in first direction and the slot outer portion of the second L-bracket segment extends in a section direction that is opposite of the first direction.

In some embodiments, the second surface of the platform includes a second coupling link for connecting with the rope.

According to a second aspect of the invention, a method of surveying a multi-level elevator hoistway in preparation for installing hoistway rails is provided according to claim <NUM>.

In some embodiments, the sensor is laser sensor.

In some embodiments, the method includes coupling a rope to a first surface of the platform and the ceiling, the first level is an upper level nearest the ceiling and the second level is a lower level nearest the pit; and lowering the platform includes releasing the rope.

In some embodiments, the rope is coupled to the ceiling via a pulley located at a first rail installation position.

In some embodiments, upon the platform reaching the second level, the method includes: pivoting the sensor on the platform so that the sensor is oriented to measure a second distance to a second proximate wall, the second proximate wall being another of the front wall and the first sidewall; raising the platform, level by level from the second level to the first level and, at each level, instructing the controller, over the wireless network, to measure the second distance from the platform to the second proximate wall and store on non-transient memory or transmit second data representing the second distance; and determining, from the second data, a second clearance at each level between the first rail of the hoistway rails and the second proximate wall.

In some embodiments, the first surface of the platform includes a first coupling link for connecting with the rope; the sensor is offset from the first coupling link; and the tool includes a counterbalance for countering rotation induced by the sensor relative to an axis of the rope.

In some embodiments, the platform extends from a first side to a second side that are opposite each other, the first side of the platform includes a first bracket and the second side of the platform includes a second bracket; and coupling the platform to the first set of guide wires includes coupling the first bracket to a first guide wire and coupling the second bracket to a second guide wire.

In some embodiments, upon the platform reaching the first level, the method includes: recoupling the platform to the first set of wires so that the platform is inverted, the first bracket is coupled to the second wire, and the second bracket is coupled to the first wire; orienting the sensor to measure a third distance to a third proximate wall, the first proximate wall being one of the second sidewall; lowering the platform, level by level, toward the second level within the hoistway and, at each level between the first and second levels, instructing the sensor, over the wireless network, to measure the third distance and store on non-transient memory or transmit third data representing the third distance; and determining, from the third data, a third clearance at each level between the first rail of the hoistway rails and the third proximate wall.

In some embodiments, the first and second brackets are configured the same as each other; and the first bracket defines first and second L-bracket segments, wherein the first L-bracket segment extends perpendicularly away from the first surface of the platform and the second L-bracket segment extends perpendicularly away from the second surface of the platform.

Turning to <FIG>, as indicated, a building may include the multi-level elevator hoistway <NUM> in which first and second hoistway rails 109A, 109B will be installed. The rails 109A, 109B may be the same as each other. The hoistway <NUM> may define a ceiling <NUM> and a pit <NUM>, and walls <NUM>, including first and second sidewalls 170A, 170B, that are opposite each other, and front 170C and back walls 170D. The rails 109A, 109B are configured in the hoistway <NUM> such that, e.g., a first end 109A1 of the first rail 109A is near the front wall 170C and a second end 109A2 of the first rail 109A is near the back wall 170D. The hoistway <NUM> may have a first level 125A that is an uppermost level, near the ceiling <NUM>, and a second level 125B that is a lowermost level, near the pit <NUM>. The front wall 170C may define an entryway <NUM> at each level.

Turning to <FIG>, prior to installation of the rails 109A, 109B, the hoistway <NUM> may be surveyed to determine a clearance between the rails 109A, 109B and the walls <NUM>. According to an embodiment, first and second sets of guide wires 200A, 200B are temporarily located adjacent to the sidewalls 170A, 170B and extend between the ceiling <NUM> and the pit <NUM>. Specifically, the first set of guide wires 200A is located adjacent to the first sidewall 170A and the second set of guide wires 200B is located adj acent to the second sidewall 170B. The first set of guide wires 200A includes a first wire 200A1 that is near, or primate, the front wall 170C and a second wire 200A2 that is near the back wall 170D. The second set of guide wires 200B includes a first wire 200B1 that is near, or primate, the front wall 170C and a second wire 200B2 that is near the back wall 170D. The guide wires in each set may be spaced apart from each other by a distance corresponding to a width of the guide rails <NUM>, e.g., in the front-to-back direction for the hoistway <NUM>.

At the start of the survey, a rope <NUM> is hung from the ceiling <NUM> at a location corresponding to a center of the first rail 109A. A first pulley 220A may be connected to the ceiling <NUM> above the location of the center of the first rail 190A to enable letting-out or drawing-in the rope <NUM>. A second pulley 220B may be connected to the ceiling <NUM> above the location of the center of the second rail 190B for the same purpose.

As shown in <FIG> and <FIG>, a tool or assembly is disclosed for surveying the hoistway <NUM>. The tool includes a platform <NUM> or sled that supports a spatial range sensor <NUM>. The sensor <NUM> includes an electronic controller <NUM> configured to receive instructions from a mobile device <NUM> of a technician <NUM> over a wireless network <NUM> to measure a first distance D1 between the platform <NUM> and a first proximate wall 170P1 and store on non-transient memory, e.g., on the controller <NUM>, or transmit to the mobile device <NUM> first data representing the first distance D1. The first proximate wall 170P1 may be the first sidewall 170A or the front wall 170C, depending on the orientation of the sensor <NUM> and platform <NUM>. As shown in <FIG>, the first proximate wall 170P1 is the first sidewall 170A. The sensor <NUM> may be a laser sensor. The wireless network <NUM> may be a Bluetooth network or other wireless network identified below.

The platform <NUM> includes a first surface <NUM> that is a top surface and a second surface <NUM> that is a bottom surface. The platform <NUM> extends from a first end <NUM> to a second end <NUM> that are opposite each other and define a front end and a back end. The platform <NUM> also extends from a first side <NUM> to a second side <NUM> that are opposite each other. A first coupling link <NUM> that is a top coupling link is connected to the first surface <NUM> for connecting with the rope <NUM>.

The first coupling link <NUM> is located adjacent to the first end <NUM> so that a reaction force R from the rope <NUM> engaging the first coupling link <NUM>, e.g., along the axis of the rope <NUM>, is midway between the first and second sides <NUM>, <NUM>. The first coupling link <NUM> includes first and second legs 370A, 370B connected to the platform <NUM> at their bottom ends by first and second eyelet fasteners 372A, 372B or ring fasteners. The first eyelet fastener 372A is near the first side <NUM> of the platform <NUM> and the second eyelet fastener 372B is near the second side <NUM> of the platform <NUM>. A third fastener 372C or coupling ring connects the first and second legs 370A, 370B at their top ends and the rope <NUM>. This configuration provides a more stable connection between the rope <NUM> and the platform <NUM> than a single point of contact.

The platform <NUM> has a first corner <NUM> (<FIG>) at the junction of the second end <NUM> and the first side <NUM>, and the sensor <NUM> is located there. That is, the sensor <NUM> is offset from the first coupling link <NUM>. The offset distance is for example a distance between a center of the first rail 109A and the first end 109A1 of the first rail 109A. With this configuration, the first distance D1 is indicative of clearance between the first end 109A1 of the first rail 109A and the first sidewall 170A of the hoistway <NUM>.

The platform includes a counterbalance <NUM>. The counterbalance <NUM> counters rotation inducing forces from the positioning of the sensor <NUM> relative to the axis of the rope <NUM>.

The sensor <NUM> is attached to a sensor platform <NUM>, which may be a sensor support bracket. As shown in <FIG>, the sensor platform <NUM> is pivotally connected to the platform <NUM> by a fastener <NUM> extending between the sensor platform and the platform <NUM>. A guide pin <NUM> extends from the sensor platform <NUM> through an arcuate slot <NUM> in the platform <NUM>. With this configuration, the sensor <NUM> is configured to pivot within a predetermined range, such as ninety degrees against the platform <NUM>. One of the fastener <NUM> and the guide pin <NUM> may be configured for engaging the platform <NUM> and rotationally locking the sensor <NUM> against the platform <NUM>. For example the fastener <NUM> or guide pin <NUM> may be threaded and secured with a wing nut (not shown). This may prevent the sensor <NUM> from unintended rotational movement during use.

As shown in <FIG>, the pivoting enables the sensor <NUM> to measure a second distance D2 between the sensor <NUM> and a second proximate wall 170P2, which is the front wall 170C. The second distance D2 may be processed similarly to the first distance D1 when surveying the hoistway <NUM>.

The first side <NUM> of the platform <NUM> includes a first bracket <NUM> configured to engage the first wire 200A1 and the second side <NUM> of the platform <NUM> includes a second bracket <NUM> configured to engage the second wire 200A2. The first and second brackets <NUM>, <NUM> are essentially the same as each other.

Turning to <FIG>, the first bracket <NUM> has first and second L-bracket segments 430A, 430B, which are top and bottom L-bracket segments. The first L-bracket segment 430A extends perpendicularly away from the first surface <NUM> of the platform <NUM> and the second L-bracket segment 430B extends perpendicularly away from the second surface <NUM> of the platform <NUM>. The first and second L-bracket segments 430A, 430B include first and second outer segments 430C, 430D that extend away from the platform <NUM> and are parallel with each other and the platform surfaces.

Turning to <FIG>, the first outer segment 430C of the first L-bracket segment 430A defines a first slot 440A for receiving the first guide wire 200A1. The second outer segment 430D of the second L-bracket segment 430B defines a second slot 440B for receiving the first guide wire 200A1. The first slot 440A defines a first slot outer portion 440A1 that opens toward the first end <NUM> of the platform <NUM> and the second slot 440B defines a second slot outer portion 440B1 that opens toward the second end <NUM> of the platform <NUM>. That is, the first and second slot outer portions extend in opposite directions relative to each other.

The first slot outer portion 440A1 extends partially through the first outer segment 430C to a first slot inner portion 440A2 that extends toward the first side of the platform <NUM>. The first slot inner portion 440A2 is configured to receive the first wire 200A1 with a clearance fit. The second slot outer portion 440B1 extends partially through the second outer segment 430D to a second slot inner portion 440B2 that extends toward the first side <NUM> of the platform <NUM>. The second slot inner portion 440B2 is aligned with the first slot inner portion 440A2 and has a same size and shape as the first slot inner portion 440A2. In operation, tension in the wire 200A1 prevents it from slipping out of the slots. With this configuration in both the first and second brackets <NUM>, <NUM>, the platform <NUM> is slidable against the set of guide wires <NUM>.

Turning to <FIG>, the second surface <NUM> of the platform <NUM> includes a second coupling link <NUM> for connecting with the rope <NUM>. The first and second coupling links <NUM>, <NUM> are configured the same as each other. With this configuration, the counterbalance <NUM> provides the same effect whether the rope <NUM> is connected to the first or second coupling link <NUM>, <NUM>. The platform <NUM> may be flipped around its center, i.e., inverted, so that the second surface <NUM> faces the hoistway ceiling <NUM>. In the flipped configuration, the first bracket <NUM> engages the second wire 200A2, the second bracket <NUM> engages the first wire 200A1, and the rope <NUM> is connected to the second coupling link <NUM>. A third distance D3 may be measured by the sensor <NUM> that is indicative of clearance between the second end 109A2 (<FIG>) of the first rail <NUM> and a third proximate wall 170P3, for example, the back wall 170D of the hoistway <NUM>.

Turning to <FIG>, a method is disclosed of surveying a multi-level elevator hoistway in preparation for installing hoistway rails using the tool. As shown in block <NUM>, the method includes coupling, at the first level 125A within the hoistway, the platform <NUM> to the first set of guide wires <NUM>, such that the platform <NUM> is slidable against the first set of guide wires <NUM>. As shown in block 1110A, block <NUM> is further defined by coupling the first bracket <NUM> to the first wire 200A1 and the second bracket <NUM> to the second wire 200A2 so that the first surface <NUM> faces the ceiling <NUM> and the sensor <NUM> is proximate the front wall 170C and the first sidewall 170A.

As shown in block <NUM>, the method includes coupling the rope <NUM> to the first surface <NUM> of the platform <NUM> and the ceiling <NUM>. As shown in block <NUM>, the method includes orienting the sensor to face a first proximate wall 170P1 which is one of the front wall 170C and the first sidewall 170A and, as discussed above, is the first sidewall 170A. As shown in block <NUM>, the method includes releasing the rope <NUM> to lower the platform <NUM>, level by level, toward the second level 125B within the hoistway <NUM>. At each level between the first and second levels 125A, 125B, the method includes block <NUM> of instructing the sensor <NUM>, via the mobile device <NUM> over the wireless network <NUM>, to measure the first distance D1 and store on non-transient memory or transmit to the mobile device <NUM> first data representing the first distance D1. As shown in block <NUM> the method includes determining, from the first data, a first clearance at each level between the first rail 109A and the first proximate wall 170P1.

As shown in block <NUM>, upon the platform <NUM> reaching the second level 125B, the method includes pivoting the sensor <NUM> on the platform <NUM> so that the sensor <NUM> is oriented to measure a second distance D2 to the second proximate wall 170P2, which is another one of the front wall 170C and the first sidewall 170A and, as discussed above, is the front wall 170C. As shown in block <NUM>, the method includes drawing-in the rope to raise the platform <NUM>, level by level from the second level 125B to the first level 125A. As shown in block <NUM>, at each level, the method includes instructing the controller <NUM>, via the mobile device <NUM> over the wireless network <NUM>, to measure the second distance D2 from the platform <NUM> to the second proximate wall 170P2 and store on non-transient memory or transmit to the mobile device <NUM> second data representing the second distance D2. As shown in block <NUM>, the method includes determining, from the second data, a second clearance at each level between the first rail 109A and the second proximate wall 170P2.

As shown in block <NUM>, the method includes recoupling the platform <NUM> to the first set of wires <NUM>, at the first level 125A, so that the platform is inverted, the first bracket <NUM> is coupled to the second wire 200A2, and the second bracket is coupled to the first wire 200A1. That is, the first surface <NUM> faces the pit <NUM> and the sensor <NUM> is proximate the back wall 170D and the first sidewall 170A. As shown in block <NUM>, the method includes orienting the sensor <NUM> to face a third proximate wall 170P3, which, as discussed above, is the back wall 170D. As shown in block <NUM>, the method includes releasing the rope <NUM> to lower the platform <NUM>, level by level, toward the second level 125B within the hoistway <NUM>. As shown in block <NUM>, at each level <NUM> between the first and second levels 125A, <NUM>, the method includes instructing the sensor <NUM>, via the mobile device <NUM> over the wireless network <NUM>, to measure the third distance D3 and store on non-transient memory or transmit to the mobile device <NUM> third data representing the third distance D3. As shown in block <NUM> the method includes determining, from the third data, a third clearance at each level between the first rail 109A and the third proximate wall 170P3.

The above method can be repeated by coupling the platform <NUM> to the second set of guide wires 200B to determine a clearance between the second rail 109B and the front wall 170C, the back wall 170D and the second sidewall 170B. Thus, a system and method are provided that enables surveying the hoistway <NUM> without requiring a mechanic to take measurements at each level <NUM> in the hoistway <NUM>.

Turning to <FIG>, another flow chart shows a more general method of surveying the hoistway with the tool. As shown in block <NUM>, the method includes coupling, at the first level 125A within the hoistway <NUM>, the platform <NUM> to the first set of guide wires 200A, such that the platform <NUM> is slidable against the first set of guide wires 200A. As shown in block <NUM> the method includes lowering the platform <NUM>, level by level, toward the second level 125B within the hoistway <NUM>. As shown in block <NUM>, at each level between the first and second levels 125A, 125B, the method includes instructing the sensor <NUM>, over the wireless network <NUM>, to measure the first distance D1 and store on non-transient memory or transmit to first data representing the first distance D1. As shown in block <NUM>, the method includes determining, from the first data, a first clearance at each level <NUM> between a first rail 109A and the first proximate wall 170P1.

In the above embodiments, sensor data may be obtained and processed separately, or simultaneously and stitched together, or a combination thereof, and may be processed in a raw or complied form. The sensor data may be processed on the sensor (e.g. via edge computing), by controllers identified or implicated herein, on a cloud service, or by a combination of one or more of these computing systems. The sensor may communicate the data via wired or wireless transmission lines, applying one or more protocols as indicated below.

Wireless connections may apply protocols that include local area network (LAN, or WLAN for wireless LAN) protocols. LAN protocols include WiFi technology, based on the Section <NUM> standards from the Institute of Electrical and Electronics Engineers (IEEE). Other applicable protocols include Low Power WAN (LPWAN), which is a wireless wide area network (WAN) designed to allow long-range communications at a low bit rates, to enable end devices to operate for extended periods of time (years) using battery power. Long Range WAN (LoRaWAN) is one type of LPWAN maintained by the LoRa Alliance, and is a media access control (MAC) layer protocol for transferring management and application messages between a network server and application server, respectively. LAN and WAN protocols may be generally considered TCP/IP protocols (transmission control protocol/Internet protocol), used to govern the connection of computer systems to the Internet. Wireless connections may also apply protocols that include private area network (PAN) protocols. PAN protocols include, for example, Bluetooth Low Energy (BTLE), which is a wireless technology standard designed and marketed by the Bluetooth Special Interest Group (SIG) for exchanging data over short distances using short-wavelength radio waves. PAN protocols also include Zigbee, a technology based on Section <NUM>. <NUM> protocols from the IEEE, representing a suite of high-level communication protocols used to create personal area networks with small, low-power digital radios for low-power low-bandwidth needs. Such protocols also include Z-Wave, which is a wireless communications protocol supported by the Z-Wave Alliance that uses a mesh network, applying low-energy radio waves to communicate between devices such as appliances, allowing for wireless control of the same.

Wireless connections may also include radio-frequency identification (RFID) technology, used for communicating with an integrated chip (IC), e.g., on an RFID smartcard. In addition, Sub-<NUM> RF equipment operates in the ISM (industrial, scientific and medical) spectrum bands below Sub <NUM> - typically in the <NUM> - <NUM>, <NUM> and the <NUM> frequency range. This spectrum band below <NUM> is particularly useful for RF IOT (internet of things) applications. The Internet of things (IoT) describes the network of physical objects-"things"-that are embedded with sensors, software, and other technologies for the purpose of connecting and exchanging data with other devices and systems over the Internet. Other LPWAN-IOT technologies include narrowband internet of things (NB-IOT) and Category M1 internet of things (Cat M1-IOT). Wireless communications for the disclosed systems may include cellular, e.g. <NUM>/<NUM>/<NUM> (etc.). Other wireless platforms based on RFID technologies include Near-Field-Communication (NFC), which is a set of communication protocols for low-speed communications, e.g., to exchange date between electronic devices over a short distance. NFC standards are defined by the ISO/IEC (defined below), the NFC Forum and the GSMA (Global System for Mobile Communications) group. The above is not intended on limiting the scope of applicable wireless technologies.

Wired connections may include connections (cables/interfaces) under RS (recommended standard)-<NUM>, also known as the TIA/EIA-<NUM>, which is a technical standard supported by the Telecommunications Industry Association (TIA) and which originated by the Electronic Industries Alliance (EIA) that specifies electrical characteristics of a digital signaling circuit. Wired connections may also include (cables/interfaces) under the RS-<NUM> standard for serial communication transmission of data, which formally defines signals connecting between a DTE (data terminal equipment) such as a computer terminal, and a DCE (data circuit-terminating equipment or data communication equipment), such as a modem. Wired connections may also include connections (cables/interfaces) under the Modbus serial communications protocol, managed by the Modbus Organization. Modbus is a master/slave protocol designed for use with its programmable logic controllers (PLCs) and which is a commonly available means of connecting industrial electronic devices. Wireless connections may also include connectors (cables/interfaces) under the PROFibus (Process Field Bus) standard managed by PROFIBUS & PROFINET International (PI). PROFibus which is a standard for fieldbus communication in automation technology, openly published as part of IEC (International Electrotechnical Commission) <NUM>. Wired communications may also be over a Controller Area Network (CAN) bus. A CAN is a vehicle bus standard that allow microcontrollers and devices to communicate with each other in applications without a host computer. CAN is a message-based protocol released by the International Organization for Standards (ISO). The above is not intended on limiting the scope of applicable wired technologies.

When data is transmitted over a network between end processors as identified herein, the data may be transmitted in raw form or may be processed in whole or part at any one of the end processors or an intermediate processor, e.g., at a cloud service (e.g. where at least a portion of the transmission path is wireless) or other processor. The data may be parsed at any one of the processors, partially or completely processed or complied, and may then be stitched together or maintained as separate packets of information. Each processor or controller identified herein may be, but is not limited to, a single-processor or multi-processor system of any of a wide array of possible architectures, including field programmable gate array (FPGA), central processing unit (CPU), application specific integrated circuits (ASIC), digital signal processor (DSP) or graphics processing unit (GPU) hardware arranged homogenously or heterogeneously. The memory identified herein may be but is not limited to a random access memory (RAM), read only memory (ROM), or other electronic, optical, magnetic or any other computer readable medium.

The controller may further include, in addition to a processor and nonvolatile memory, one or more input and/or output (I/O) device interface(s) that are communicatively coupled via an onboard (local) interface to communicate among other devices. The onboard interface may include, for example but not limited to, an onboard system bus, including a control bus (for inter-device communications), an address bus (for physical addressing) and a data bus (for transferring data). That is, the system bus may enable the electronic communications between the processor, memory and I/O connections. The I/O connections may also include wired connections and/or wireless connections identified herein. The onboard interface may have additional elements, which are omitted for simplicity, such as controllers, buffers (caches), drivers, repeaters, and receivers to enable electronic communications. The memory may execute programs, access data, or lookup charts, or a combination of each, in furtherance of its processing, all of which may be stored in advance or received during execution of its processes by other computing devices, e.g., via a cloud service or other network connection identified herein with other processors.

Embodiments can be in the form of processor-implemented processes and devices for practicing those processes, such as processor. Embodiments can also be in the form of computer code based modules, e.g., computer program code (e.g., computer program product) containing instructions embodied in tangible media (e.g., non-transitory computer readable medium), such as floppy diskettes, CD ROMs, hard drives, on processor registers as firmware, or any other non-transitory computer readable medium, wherein, when the computer program code is loaded into and executed by a computer, the computer becomes a device for practicing the embodiments. Embodiments can also be in the form of computer program code, for example, whether stored in a storage medium, loaded into and/or executed by a computer, or transmitted over some transmission medium, such as over electrical wiring or cabling, through fiber optics, or via electromagnetic radiation, wherein, when the computer program code is loaded into and executed by a computer, the computer becomes a device for practicing the exemplary embodiments.

Claim 1:
A tool for surveying a multi-level elevator hoistway (<NUM>) in preparation for installing hoistway rails (109A, 109B), the tool comprising:
a platform (<NUM>) that supports a spatial range sensor (<NUM>) that includes an electronic controller (<NUM>),
wherein the controller (<NUM>) is configured to receive instructions over a wireless network (<NUM>) to measure a first distance between the platform (<NUM>) and a first proximate wall (170P1) and store on non-transient memory or transmit first data representing the first distance;
the platform (<NUM>) extends from a first side (<NUM>) to a second side (<NUM>) that are opposite each other, the first side (<NUM>) of the platform (<NUM>) includes a first bracket (<NUM>) configured to engage a first guide wire (200A1) and the second side (<NUM>) of the platform (<NUM>) includes a second bracket (<NUM>) configured to engage a second guide wire (200A2); and
the platform (<NUM>) defines a first surface (<NUM>) and a second surface (<NUM>), and a first coupling link (<NUM>) is connected to the first surface (<NUM>) for connecting with a rope (<NUM>) to raise or lower the platform (<NUM>) against the first and second guide wires (200A1, 200A2);
wherein:
the first and second brackets (<NUM>, <NUM>) are configured the same as each other; and characterized in that:
the first bracket (<NUM>) defines first and second L-bracket segments, wherein the first L-bracket segment (430A) extends perpendicularly away from the first surface (<NUM>) of the platform (<NUM>) and the second L-bracket segment (430B) extends perpendicularly away from the second surface (<NUM>) of the platform (<NUM>).