Embodiments described herein relate to manually operated counterweight hoists.
Theaters or performance spaces include hoists that are motorized and controlled by a digital rigging control system. However, due to budgetary limitations, many theaters include only a few motorized hoists and many more manually operated counter-weight hoists. These manually operated counterweight hoists do not include some modern safety features. Furthermore, these existing manually operated counterweight hoists are not integrated with a digital rigging control system.
In some aspects, manually operated counterweight hoists described herein include a batten operable to support a load, an arbor operable to support one or more counterweights, a hand line operable to move the batten or the arbor, a brake operable to prevent movement of the arbor and the batten by constricting movement of the hand line, a brake actuator operable to activate the brake, a sensor that measures a speed of the arbor, and a controller including an electronic processor. The controller is operatively coupled to the sensor and the brake actuator. The controller is configured to receive a measurement signal from the sensor, determine whether the speed of the arbor exceeds a threshold based on the measurement signal, and activate the brake actuator when the speed of the arbor exceeds the threshold.
In some aspects, methods described herein provide for a method of operating a manually operated counterweight hoist that includes an arbor, a hand line operable to move the arbor, a brake operable to prevent movement of the arbor, a brake actuator operable to activate the brake, a sensor that measures a speed of the arbor, and a controller that includes an electronic processor and is operatively coupled to the brake actuator and sensor. The method includes moving, by the hand line, the arbor, receiving, by the controller, a measurement signal from the sensor, determining, by the controller, whether a speed of the arbor exceeds a threshold based on the measurement signal, activating, by the controller, the brake actuator when the speed of the arbor exceeds the threshold, and constricting, by the brake, the hand line in response to activating the brake actuator.
In some aspects, systems described herein include a motorized hoist, a manually operated counterweight hoist, and a system control device that is operatively coupled to the motorized hoist and the manually operated counterweight hoist. The manually operated counterweight hoist includes a batten operable to support a load, an arbor operable to support one or more counterweights, a hand line operable to move the batten or the arbor, a brake operable to prevent movement of the arbor and the batten by constricting movement of the hand line, a brake actuator operable to activate the brake, a sensor that measures a speed of the arbor, and a controller including an electronic processor. The controller is operatively coupled to the sensor and the brake actuator, and the controller is configured to receive a measurement signal from the sensor. The system control device includes a second electronic processor and is configured to control operation of the motorized hoist, receive the measurement signal from the controller, determine whether the speed of the arbor exceeds a threshold based on the measurement signal, and instruct the controller to activate the brake actuator when the speed of the arbor exceeds the threshold.
Before any embodiments are explained in detail, it is to be understood that the embodiments are not limited in its application to the details of the configuration and arrangement of components set forth in the following description or illustrated in the accompanying drawings. The embodiments are capable of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof are meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings.
In addition, it should be understood that embodiments may include hardware, software, and electronic components or modules that, for purposes of discussion, may be illustrated and described as if the majority of the components were implemented solely in hardware. However, one of ordinary skill in the art, and based on a reading of this detailed description, would recognize that, in at least one embodiment, the electronic-based aspects may be implemented in software (e.g., stored on non-transitory computer-readable medium) executable by one or more processing units, such as a microprocessor and/or application specific integrated circuits (“ASICs”). As such, it should be noted that a plurality of hardware and software based devices, as well as a plurality of different structural components, may be utilized to implement the embodiments. For example, “servers,” “computing devices,” “controllers,” “processors,” etc., described in the specification can include one or more processing units, one or more computer-readable medium modules, one or more input/output interfaces, and various connections (e.g., a system bus) connecting the components.
Relative terminology, such as, for example, “about,” “approximately,” “substantially,” etc., used in connection with a quantity or condition would be understood by those of ordinary skill to be inclusive of the stated value and has the meaning dictated by the context (e.g., the term includes at least the degree of error associated with the measurement accuracy, tolerances [e.g., manufacturing, assembly, use, etc.] associated with the particular value, etc.). Such terminology should also be considered as disclosing the range defined by the absolute values of the two endpoints. For example, the expression “from about 2 to about 4” also discloses the range “from 2 to 4”. The relative terminology may refer to plus or minus a percentage (e.g., 1%, 5%, 10%, or more) of an indicated value.
It should be understood that although certain drawings illustrate hardware and software located within particular devices, these depictions are for illustrative purposes only. Functionality described herein as being performed by one component may be performed by multiple components in a distributed manner. Likewise, functionality performed by multiple components may be consolidated and performed by a single component. In some embodiments, the illustrated components may be combined or divided into separate software, firmware and/or hardware. For example, instead of being located within and performed by a single electronic processor, logic and processing may be distributed among multiple electronic processors. Regardless of how they are combined or divided, hardware and software components may be located on the same computing device or may be distributed among different computing devices connected by one or more networks or other suitable communication links. Similarly, a component described as performing particular functionality may also perform additional functionality not described herein. For example, a device or structure that is “configured” in a certain way is configured in at least that way but may also be configured in ways that are not explicitly listed.
Other aspects of the embodiments will become apparent by consideration of the detailed description and accompanying drawings.
The plurality of lines 105 includes hand lines 105A that are manipulated by operators to adjust one or more components of the manual hoist 100. As shown, the hand lines 105A run from the bottom of an arbor 110 to a tension block 115. The manual hoist 100 further includes a rope lock, or brake, 120 through which the hand line 105A passes. The brake 120 is a device used to brake, or constrict, and release the hand line 105A when an operator raises and lowers a locking lever 125. An operator may raise the lock lever 125 of the brake 120 to prevent movement of the hand line 105A when loads connected to the manual hoist 100 are unbalanced. For example, an unbalanced load condition may occur while counterweights 130 are being added to or removed from the arbor 110. When loads connected to manual hoist 100 are balanced, a crew member may lower the lock lever 125 to release brake 120 and enable movement of hand line 105A. In some instances, a crew member activates brake 120, via lock lever 125, to prevent a runaway condition from causing damage to the arbor 110 and/or other components of manual hoist 100.
The plurality of lines 105 also includes lift lines 105B, which are used to support the loads, such as the loads supported by a batten 135, connected to manual hoist 100. As shown, the lift lines 105B run from the batten 135 up to loft blocks 140 of manual hoist 100. The lift lines 105B further extend across the stage 145 from the loft blocks 140 to a head block 150, and from the head block 150 down to arbor 110. The batten 135 supports a load, such as a backdrop or other stage props, and is raised and/or lowered by an operator using handlines 105A. In some embodiments, the plurality of lines 105 interconnect one or more additional components to manual hoist 100, such as locking rails, a loading bridge, drums, and other known components of a manually operated counterweight hoist.
The manual hoist 100 further includes additional components that provide the manual hoist 100 with improved features and capabilities to integrate the manual hoist 100 with a digital rigging control system. For example, the manual hoist 100 further includes a digital controller 200, one or more weight sensors, such as load cell 205, a position and/or speed sensor 210, an electronic actuator 215 for brake 120, and one or more cue lights 220. In some embodiments, the digital controller 200, the load cell 205, the position and/or speed sensor 210, the electronic actuator 215 for brake 120, and the cue lights 220 are installed during installation of the other above-described components of manual hoist 100. In other embodiments, the digital controller 200, the load cell 205, the speed sensor 210, the electronic actuator 215 for brake 120, and the cue lights 220 are installed after the above-described components of manual hoist 100 are installed. For example, a manual hoist installed in an existing theater that does not include adequate safety or digital control features may be retrofitted with one or more of the digital controller 200, the load cell 205, the speed sensor 210, the electronic actuator 215 for brake 120, and the cue lights 220.
As will be described below, the digital controller 200 includes combinations of hardware and software that are operable to, among other things, control operation of components included in the manual hoist 100 and integrate the manual hoist 100 with a digital rigging control system 500 (see
The memory 245 is a non-transitory computer readable medium and includes, for example, a program storage area and a data storage area. The program storage area and the data storage area can include combinations of different types of memory, such as a ROM, a RAM (e.g., DRAM, SDRAM, etc.), EEPROM, flash memory, a hard disk, an SD card, or other suitable magnetic, optical, physical, or electronic memory devices. The processing unit 240 is connected to the memory 245 and executes software instructions that are capable of being stored in a RAM of the memory 245 (e.g., during execution), a ROM of the memory 245 (e.g., on a generally permanent basis), or another non-transitory computer readable medium such as another memory or a disc. Software included in the implementation of the digital rigging control system 500 (
The user interface 230 is included to provide user control of one or more components of the manual hoist 100. The user interface 230 is operably coupled to the digital controller 200 to control, for example, drive signals provided to the electronic brake actuator 215. The user interface 230 can include any combination of digital and analog input devices required to achieve a desired level of control for the system 100. For example, the user interface 230 can include a display and input devices, a touch-screen display, a plurality of knobs, dials, switches, buttons, faders, or the like. In the embodiment illustrated in
With reference to
As also shown in
As described above, in some instances, the one or more load cells 205 are installed when the other components of the manual hoist 100 are installed in a theater or performance space. However, in other instances, the one or more load cells 205 are installed on preexisting manual hoists 100 that did not previously include any digital control features.
Weight measurements taken by the load cell 205 are periodically, or continuously, transmitted to the digital controller 200 for processing. The digital controller 200 is configured to determine a load on the manual hoist 100 based on the measurement signals received from load cell 205. For example, the digital controller 200 may be configured to determine a total weight of the counterweights 130 added to arbor 110, a weight of the load supported by batten 135, and/or a total load on the manual hoist 100 based on the measurements taken by the one or more load cells 205. In some embodiments, the digital controller 200 is further configured to display the determined load on manual hoist 100 using the cue lights 220, the indicators 225, and/or user-interface 230. In some embodiments, the digital controller 200 activates the indicators 225 when the determined load on manual hoist 100 exceeds an overload threshold. In some embodiments, the digital controller 200 logs, or stores, the determined load on manual hoist 100 in memory 245. In embodiments in which a first load cell 205 measures the load weight of arbor 110 and a second load cell 205 measures the weight of the load supported by batten 135, the digital controller 200 is configured to determine whether the two loads are balanced based on weight measurements received from the first and second load cells 205. In such embodiments, the digital controller 200 is further configured to display an unbalanced load condition using the cue lights 220, the indicators 225, and/or user-interface 230 when the digital controller 200 determines that the difference between the arbor 110 load weight and the load weight supported by batten 135 exceeds a balance threshold (e.g., a 1% difference).
The manual hoist 100 further includes the position and/or speed sensor 210. The position and/or speed sensor 210 is configured to measure the position and movement, or speed, of one or more lines 105 of the manual hoist 100. In some embodiments, the position and/or speed sensor 210 is implemented as a quadrature encoder on a friction wheel through which line 105 passes. In some embodiments, other types of position and/or speed sensors are used.
As shown in
In operation, the position and/or speed sensor 210 periodically, or continuously, transmits the position and/or speed measurements to digital controller 200. In some embodiments, the position and/or speed sensor 210 transmits a measured position of the arbor 110 to the digital controller 200, which may be configured to determine and display the position of arbor 110 to an operator using one or more of the cue lights 220, the indicators 225, and/or the user-interface 230. For example, the digital controller 200 may be configured to determine that arbor 110 is in a raised position based on a measurement signal received from the position and/or speed sensor 210. Accordingly, the digital controller 200 may be further configured to display the raised position of arbor 110 to an operator. As another example, the digital controller 200 may be configured to determine that arbor 110 is in a lowered position based on a measurement signal received from the position and/or speed sensor 210. Accordingly, the digital controller 200 may be further configured to display the lowered position of arbor 110 to an operator.
In operation, the position and/or speed sensor 210 is further configured to periodically, or continuously, transmit a measured speed of the arbor 110 to the digital controller 200. In other embodiments, the position and/or speed sensor 210 is additionally configured to transmit a measured speed of the load supported by batten 135 to the digital controller 210. The digital controller 200 is configured to determine the speed of the arbor 110 and/or the load supported by batten 135 based on the speed measurements received from the position and/or speed sensor 210. In some embodiments, the digital controller 200 is further configured to perform one or more actions based on the determined speed of arbor 110 and/or the load supported by batten 135. For example, the digital controller 200 is configured to activate the electronic brake actuator 215 when the determined speed of the arbor 110 and/or the load exceeds an overspeed threshold. That is, during a runaway condition in which components of the manual hoist 100 move at unsafe speeds, the digital controller 200 is configured to detect the unsafe condition and automatically activate the electronic brake actuator 215 without intervention from an operator. In some embodiments, the digital controller 200 is further configured to activate one or more of the cue lights 220, the indicators 225, and/or components of user-interface 230 to alert an operator of the runaway condition when the determined speed exceeds the overspeed threshold. In some embodiments, the digital controller 200 is configured to display the determined speed of arbor 110 and/or the load to an operator using one or more of cue lights 220, the indicators 225, and/or the user-interface 230 even when the determine speed does not exceed the overspeed threshold.
As described above, the digital controller 200 is configured to activate the electronic brake actuator 215 when the digital controller 200 determines that the speed of the arbor 110 and/or the load supported by batten 135 exceeds an overspeed threshold. Activation of the electronic brake actuator 215 causes the brake 120 to stop line 105 without intervention from an operator. That is, when activated, the electronic brake actuator 215 automatically closes the brake 120 to brake, or constrict, movement of the line 105 without an operator having to operate lock lever 125. Thus, the digital controller 200 is configured to automatically stop movement of the arbor 110 during a runaway condition by activating the electronic brake actuator 215.
In some embodiments, the electronic brake actuator 215 is a cam-actuated device that is controlled by digital controller 200. In other embodiments, the electronic brake actuator 215 is implemented using other types of automatic actuators or motors. In some embodiments, the electronic brake actuator 215 is connected directly to the brake 120. In other embodiments, the electronic brake actuator 215 is connected to the lock lever 125, and thus, is configured to operate the lock lever 125 in response to an activation signal received from the digital controller 200. In such embodiments, the digital controller 200 controls electronic brake actuator 215 to raise lock lever 125 to prevent movement of the line 105, and thus, movement of the arbor 110 during a runaway condition. Furthermore, in such embodiments, the digital controller 200 controls electronic brake actuator 215 to lower lock lever 125 to enable movement of the line 105, and thus, movement of the arbor 110 when the runaway away condition is resolved.
The manual hoist 100 further includes one or more cue lights 220. In some embodiments, the one or more cue lights 220 are implemented as one or more light emitting diodes (LEDs). In other embodiments, other types of lights are used to implement the cue lights 220. In some embodiments, as described above, the cue lights 220 are integrated with the indicators 225 and/or the user-interface 230 of digital controller 200. For example, as shown in
The digital controller 200 is configured to illuminate one or more of the cue lights 220 when it is time for an operator to move the manual hoist 100. For example, when the manual hoist 100 is included in a digital rigging system including many other hoists, the digital cue lights 220 of the manual hoist 100 are illuminated to indicate to an operator that the manual hoist 100 should be moved. In some embodiments, the cue lights 220 are illuminated in a first color (e.g., green) when the manual hoist 100 should be moved by an operator. That is, when it is time for an operator to raise and/or lower the manual hoist 100, the digital controller 200 may be configured to illuminate a green LED included in cue lights 220. Similarly, in some embodiments, the cue lights 220 are illuminated in a different color (e.g., red) when the manual hoist 100 should not be moved and/or is in a runaway condition. For example, if a runaway condition occurred and the electronic brake actuator 215 was activated, the digital controller 200 may be configured to illuminate a red LED included in the cue lights 220. In some embodiments, the cue lights 220 are illuminated in a third color (e.g., yellow) when no action is to be taken with the manual hoist. For example, when the manual hoist 100 is in a standby mode, the digital controller 200 may be configured to illuminate a yellow LED included in the cue lights 220.
In some embodiments, the digital controller 200 is configured to illuminate the cue lights 220 in accordance with a first illumination pattern when the manual hoist 100 should be moved by an operator. For example, the digital controller 200 may be configured to blink one or more of the cue lights 220 at a first rate and/or for a first amount of time when the manual hoist 100 should be moved by an operator. Similarly, in some embodiments, the cue lights 220 are illuminated in accordance with a second illumination pattern when the manual hoist 100 should not be moved and/or is in a runaway condition. For example, if a runaway condition occurred and the electronic brake actuator 215 was activated, the digital controller 200 may be configured to blink one or more of the cue lights 220 at a second rate and/or for a second amount of time. In some embodiments, the cue lights 220 are illuminated in accordance with a third illumination pattern when no action is to be taken with the manual hoist. For example, when the manual hoist 100 is in a standby mode, the digital controller 200 may be configured to illuminate one or more cue lights 220 in a steady pattern.
The method 400 includes receiving a position and/or speed measurement of the arbor 110 from the position and/or speed sensor 210 (block 405). As described above, the digital controller 200 is configured to continuously, or periodically, receive position and/or speed measurements from the position and/or speed sensor 210. The method further includes determining, by the digital controller 200, whether a current speed and/or position of the arbor 110 exceeds a threshold (e.g., an overspeed threshold) (block 410).
The method 400 further includes activating, by the digital controller 200, the electronic brake actuator 215 when the determined position and/or speed of the arbor 110 exceeds the threshold (block 415). As described above, activation of the electronic brake actuator 215 causes the brake 120 to brake, or stop, movement of the hand line 105A to which the arbor 110 and/or the batten 135 is connected (block 420). Thus, in response to activation of the brake actuator 215, the brake 120 constricts movement of the line 105 connected to the arbor 110 and/or batten 135 when the position and/or speed of arbor 110 exceeds an overspeed threshold (e.g., during a runaway condition in which the load supported by batten 135 and the load on arbor 110 are unbalanced). When the position and/or speed of the arbor 110 does not exceed the overspeed threshold, the digital controller 200 does not activate electronic brake actuator 215 and the method returns to block 405 (block 425).
In some embodiments, the manual hoist 100 is included in a digital rigging control system that includes one or more motorized hoists. In such embodiments, the digital controller 200 is configured to interface, or electrically connect, the manual hoist 100 to one or more control devices included in the digital rigging control system. Moreover, in such embodiments, the digital controller 200 and/or other components of the manual hoist 100 are controlled by the digital rigging system.
As shown in
As shown, the motorized hoists 510A-510B are also electrically connected to and configured to communicate with the system control device 505. In particular, the motorized hoists 510A-510B include respective controllers having electronic processors and communication interfaces configured to communicate with the system control device 505. In some embodiments, the motorized hoists 510A-510B are further configured to communicate with each other and/or the manual hoists 100A-100D included in system 500. Operation of the motorized hoists 510A-510B is controlled by the system control device 505.
The system control device 505 may be implemented as a computing device that includes an electronic processor and a memory. In some embodiments, the system control device 505 may be, for example, a personal or desktop computer, a laptop computer, a tablet computer, a server, a control terminal, or a mobile phone (e.g., a smart phone). In some embodiments, the system control device 505 is implemented as a plurality, or combination, of the computing devices described above.
During operation of the digital rigging control system 500, the system control device 505 is configured to communicate with and control one or more of the manual hoists 100A-100D and the motorized hoists 510A-510B. In some embodiments, the system control device 505 is configured to perform one or more of the control actions described above with respect to the digital controller 200 of manual hoist 100. In such embodiments, the digital controller 200 may be configured to provide communication between the one or more above-described components of manual hoist 100 and the system control device 505. That is, the digital controller 200 may be configured to transmit, or forward, one or more measurement signals received from the components of manual hoist 100 to the system control device 505. Similarly, the digital controller may be further configured to transmit, or forward, one or more control signals from the system control device 505 to the one or more components of manual hoist 100.
For example, in some embodiments, the digital controller 200 is configured to transmit, or forward, load weight measurements received from load cell(s) 205 to the system control device 505. In such embodiments, the system control device 505 is configured to determine the load on the manual hoist 100 based on the measurement signals received from digital controller 200. For example, the system control device 505 may be configured to determine a total weight of the counterweights 130 added to arbor 110, a weight of the load supported by batten 135, and/or a total load on the manual hoist 100 based on the measurements taken by load cell(s) 205. After determining the load on manual hoist 100, the system control device 505 is configured to transmit a signal including the determined load to the digital controller 200. In some embodiments, the system control device 505 stores the determined load in a memory external to digital controller 200 (e.g., a memory of the system control device 505 or a server).
In some embodiments, the system control device 505 is further configured to instruct digital controller 200 to display the determined load on the cue lights 220, the indicators 225, and/or the user-interface 230, as described above. For example, the system control device 505 may be configured to instruct digital controller 200 to display the determine load and/or activate one or more indicators 225 when the determined load on manual hoist 100 exceeds an overload threshold. As another example, the system control device 505 may be further configured to instruct digital controller 200 to display an unbalanced load condition when the system control device 505 determines that the difference between the arbor 110 load weight and the load weight supported by batten 135 exceeds a balance threshold (e.g., a 1% difference). In other embodiments, the digital controller 200 determines whether to display any information associated with the load on manual hoist 100 based on the determined load that is received from the system control device 505.
Similarly, the digital controller 200 is configured to transmit, or forward, position and/or speed measurements received from the position and/or speed sensor 210 to the system control device 505. Furthermore, the system control device 505 is configured to determine the position and/or speed of arbor 110 based on the measurements received from digital controller 200. For example, the system control device 505 may be configured to determine whether the arbor 110 is in a raised or lowered position and transmit the determined position of the arbor 110 back to digital controller 200. In some embodiments, the system control device 505 is further configured to instruct the digital controller 200 to display, using the cue lights 220, indicators 225, and/or user-interface 230, the determined position of arbor 110.
In some embodiments, the system control device 505 is configured to determine the speed of arbor 110 and/or the load supported by batten 135 based on the measurements received from the digital controller 200. In such embodiments, the system control device 505 is further configured to determine whether the speed of the arbor 110 and/or the load supported by batten 135 exceeds an overspeed threshold. When the speed of the of the arbor 110 and/or load supported by batten 135 does exceed the overspeed threshold, the system control device 505 is configured to transmit a control signal that instructs digital controller 200 to activate the electronic brake actuator 215. That is, the system control device 505 is configured to determine whether the arbor 110 and/or load supported by batten 135 is in a runaway condition based on measurement signals received from the digital controller 200. When the system control device 505 determines a runaway condition is occurring, the system control device 505 activates, by the digital controller 200, the electronic brake actuator 215 to prevent movement of the arbor 110. In some embodiments, the system control device 505 is further configured to instruct the digital controller 200 to display the runaway condition using the cue lights 220, the one or more indicators 225, and/or the user-interface 230.
Furthermore, in some embodiments, the system control device 505 is configured to instruct the digital controller 200 to illuminate one or more of the cue lights 220. In some embodiments, the system control device 505 is configured to execute a cue program for controlling operation of the manual hoists 100A-100D and motorized hoists 510A-510B included in the digital rigging control system 500. In such embodiments, the system control device 505 is configured to transmit a signal that instructs digital controller 200 to illuminate the cue lights 220 in accordance with a first pattern when it is time for an operator to move the particular manual hoist 100. For example, as described above, the system control device 505 may be configured to instruct the digital controller 200 to illuminate the cue lights 220 in a particular color (e.g., green) and/or in a first blinking sequence to alert an operator that it is time to raise or lower the manual hoist 100. Similarly, in such embodiments, the system control device 505 is configured to instruct digital controller 200 to illuminate the cue lights 220 in accordance with a second color (e.g., red) and/or a second blinking sequence when the system control device 505 determines a runaway condition is present. In some embodiments, the system control device 505 is further configured to instruct digital controller 200 to illuminate the cue lights 220 in accordance with a third color (e.g., yellow) and/or a third blinking sequence when the manual hoist 100 is in a standby mode.
The method 600 includes receiving a position and/or speed measurement of the arbor 110 from the position and/or speed sensor 210 (block 605). As described above, the digital controller 200 is configured to continuously, or periodically, receive position and/or speed measurements from the position and/or speed sensor 210. At block 610, the method further includes transmitting the received position and/or speed measurements to the system control device 505 (block 610).
The method 600 further includes determining, by the system control device 505, whether a current speed and/or position of the arbor 110 exceeds a threshold (block 615) and instructing, by the system control device 505, the digital controller 200 to activate the electronic brake actuator 215 when the determined position and/or speed of the arbor 110 exceeds the threshold (block 620). As described above, activation of the electronic brake actuator 215 causes the brake 120 to brake, or stop, movement of the line 105 to which arbor 110 is connected. Thus, at block 620, the system control device 505 instructs the digital controller 200 to activate the electronic brake actuator 215 to stop movement of the arbor 110 when the position and/or speed of arbor 110 exceeds an overspeed threshold (e.g., during a runaway condition in which the load supported by batten 135 and the load on arbor 110 are unbalanced). The method 600 further includes activating, by the digital controller 200, the electronic brake actuator 215 in response to receiving an instruction from the system control device 505 (block 625). Accordingly, activating the electronic brake actuator 215 includes constricting, by the electronic brake actuator 215, movement of the hand line 105A, and thus, movement of the arbor 110 and/or batten 135. When the position and/or speed of the arbor 110 does not exceed the overspeed threshold, the system control device 505 does not instruct digital controller 200 to activate the electronic brake actuator 215 and the method returns to block 605 (block 630).
Thus, embodiments described herein provide, among other things, systems and methods for digital control of a manually operated counterweight hoist. Various features and advantages are set forth in the following claims.
This application claims the benefit of U.S. Provisional Patent Application No. 63/303,092, filed Jan. 26, 2022, the entire content of which is hereby incorporated by reference.
Number | Date | Country | |
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63303092 | Jan 2022 | US |