The discussion below is merely provided for general background information and is not intended to be used as an aid in determining the claimed subject matter.
Moveable platform systems suspended by cables are known. In one embodiment, an upper platform mounted to, for example, a bridge supports a lower platform using six wire ropes. Both the upper platform and the lower platform each have three spaced apart locations where two wire ropes are joined or come together such that the wire ropes at each location come from two different locations on the other platform. A stable lower platform is obtained because the wire ropes are kinematically constrained and where the stiffness of the platform is determined, at least in part, by the tensile elasticity of the wire ropes. The lower platform can be moved in a work envelope as determined by the length of each of the wire ropes suspending the lower platform from the upper platform as well as the linear position of the upper platform on the bridge, if the upper platform is moveable on the bridge in one degree of linear motion, and/or the bridge is movable on gantry rails in another degree of linear motion.
This Summary and the Abstract herein are provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary and the Abstract are not intended to identify key features or essential features of the claimed subject matter, nor are they intended to be used as an aid in determining the scope of the claimed subject matter. The claimed subject matter is not limited to implementations that solve any or all disadvantages noted in the background.
Aspects of the disclosure relate to hoist systems. In one embodiment, a hoist system includes an upper platform that has a plurality of rotatable support arms. The plurality of rotatable support arms are connected to a lower platform utilizing a plurality of flexible members. A plurality of hoists extends and retracts the plurality of flexible members.
In another embodiment, a hoist system includes an upper platform that has a plurality of adjustable length support arms. The plurality of adjustable length support arms are connected to a lower platform utilizing a plurality of flexible members. A plurality of hoists extends and retracts the plurality of flexible members.
In yet another embodiment, a hoist system includes a lower platform, an upper platform, and a plurality of extendable and retractable flexible members. The lower platform has a first set of pulleys and a second set of pulleys, and the upper platform has a plurality of support arms. Each flexible member is guided by one of the first set of pulleys and one of the second set of pulleys so as to form a couple when the corresponding flexible member is in tension. A plurality of hoists extends and retracts the plurality of flexible members.
Furthermore, any of the embodiments described herein may include a plurality of sensors to configured to measure position, stress, strain, tension or other parameters of the system such as described below, and/or a controller to receive signals from such sensors.
Additionally, any of the embodiments described above may include one or more of the following features. The support arms may be rotatable about a vertical axis. The support arms can be extendable and retractable with respect to a vertical axis. The hoists may be disposed at an end of the support arms. Each of the support arms may include a sheave or pulley that guides one of the flexible members to the lower platform, and each of the hoists may be disposed remote from the ends of the support arms. A trolley can be included that supports the upper platform for rotation thereon, and a plurality of actuators can be included that are configured to extend and retract the plurality of support arms together or individually to position the lower platform where desired.
Besides extending and retracting the support arms so as to position the lower platform where desired, it should also be noted that extension and retraction of the support arms can be controlled for other purposes. For instance, stiffness of the upper platform with the support arms retracted is typically greater than when the support arms are extended, for example, when lifting loads vertically. Relative stiffness of the upper platform, or of the system as a whole, can be determined or calculated and stored, for example, in computer memory. When it is desired to lift a load, or otherwise move a load within the work envelope with a desired amount of stiffness, such inputs can be provided to the system, for example, through a computer interface or the like wherein the system then extends or retracts the support arms in order to obtain the desired stiffness.
Another example of automatic extension or retraction of the support arms occurs when it is desired to move the lower platform to the uppermost reaches of the work envelope, (i.e. as close to the upper platform as possible). In order to achieve this position, it is advantageous to retract the support arms in order to control the angles of the wire ropes, for example, relative to the rotational axis of the upper platform.
In some embodiments, hoist systems may include a system for ascertaining elongation of the wire rope(s) due to the load on the lower platform. In this manner, compensation can be provided so as to position the lower platform in a selected position, compensating for elongation in the wire rope(s), compensating for slack in the wire rope(s) and/or other external forces applied to the lower platform and/or wire ropes(s) in one, some or all degrees of freedom. In one embodiment, elongation or slack of a wire rope is measured directly with a sensor or sensors, for example, where the sensors are operably coupled between the upper platform and the lower platform along one, some or all of the wire ropes. Referring to
Alternatively, or in addition, elongation of the wire rope can be ascertained by the amount of tension in the wire rope(s). Tension in the wire rope(s) can be measured using a load cell operably coupled to the wire rope to sense tension therein. For instance, the load cell can couple an end of the wire rope to the lower platform. In another embodiment, a load cell can be incorporated in the mount for each hoist. In yet another embodiment, tension can be inferred through the work performed by the hoist(s) for example by sensing characteristics of the power needed to operate the hoist such as the current for an electrical motor used to rotate a drum of the hoist, or fluid flow characteristics for a hydraulic or pneumatically powered hoist.
The system can null out the effects of elongation of the wire rope(s) in order to accurately position the lower platform as desired. However, in addition, the system can also null out any other forms of deflection that may occur due to deflections or the like in other components such as but not limited to support arms, upper platform, lower platform, bridges, rails or components thereof to name just a few. Sensor(s) can be configured to provide signal(s) corresponding to deflections of one or more of these components. For instance, such deflections can be measured by displacement sensors, strain gauges to name just a few.
Movement of the lower platform to desired locations can be performed manually where the operator is given independent control of all hoist motors and/or drive motors to rotate the upper platform. Typically, the operator is provided with a user interface having one or more joysticks or other control mechanism where movements thereof are translated so as to operate the hoist motors and/or drive motors to cause movement of the upper platform or carriage either directly through rotation thereof, movement of its trolley, and/or movement of a bridge supporting the carriage, if one is provided. Depending upon the location of the lower platform relative to any obstacles in structure such as the enclosure walls, the system can be programmed so as to automatically extend or retract one or more of the support arms/or rotate the upper platform in order to avoid contact of the wire ropes and/or the lower platform with the enclosure or other obstacles. The work envelope and any potential obstacles can be defined in computer memory wherein the position of the lower platform, wire ropes and/or upper platform/carriage can be tracked virtually in order to avoid contact with obstacles such as the enclosure walls. If desired, sensors can also be mounted to any of the components in the system such as the upper platform, lower platform, support arms and/or mechanisms coupled to the lower platform. Such sensors can be proximity sensors so as to sense contact or possible contact of components of the system with obstacles and/or otherwise control the system to avoid such obstacles. In one embodiment, a system controller receives inputs from some or all of the sensors described above, command signals from the user interface and provides control signals to hoists, actuators, drive(s) to rotate the upper platform, drive(s) to move the trolley on a bridge or truss, and/or drive(s) to move the bridge on rails.
As indicated above, in addition or in the alternative to monitoring elongation of wire rope(s), the sensors to directly or indirectly sense tension in the wire rope(s) can be configured so as to detect slack such as but not limited to if the lower platform were to encounter an obstacle. If slack is detected in one or more wire ropes via the sensor(s), the system controller can be configured to provide an alarm and/or automatically operate the appropriate hoist(s) until proper tension is obtained. If desired, the system controller can be further configured to prevent other motions of the lower platform, which can include preventing further operation of the hoists, drive(s), the drive mechanisms for the support arms (e.g. actuators), drive(s) for the trolley and/or drive(s) for a bridge on rails, the bridge supporting the trolley.
Some other features that may be present in any of the embodiments include the following. Each of the flexible members can utilize at least one pulley on the lower platform and have an attachment point on one of the plurality of support arms. Each of the flexible members can extend from one of the plurality of support arms and have an attachment point that is either on the same one of the plurality of support arms or on a different one of the plurality of support arms. Each of the flexible members may utilize two or more pulleys on the lower platform. A portion of each flexible member of each couple between the corresponding pulleys of the couple may extend along a line that is parallel to or in the plane of the lower platform. Alternatively or in addition, a portion of each flexible member of each couple between the corresponding pulleys of the couple may intersect with the plane of the lower platform.
If desired, a weighted collar can be included that is suspended from the upper platform and that supports a spine extending from the lower platform. A spine extending from the lower platform may have a shape that is keyed to a shape of an aperture in the weighted collar.
Finally, for illustration purposes only and not by limitation, any of the embodiments described above may include one or more of the following features. A remote end of each flexible member may be secured so as to form two spaced apart portions that are in tension. Both the upper platform and the lower platform can have at least three spaced apart locations where at least two flexible members are disposed such that the flexible members at each location come from at least two different locations on the other platform. Both the upper platform and the lower platform can have three spaced apart locations where two flexible members are disposed such that the flexible members at each location come from two different locations on the other platform. The plurality of hoists and the plurality of flexible members can each comprise three. The plurality of hoists and the plurality of flexible members can each comprise six. A plurality of pulleys can be included and mounted to one of the platforms, and each flexible member can be guided by at least one of the pulleys so as to form two spaced apart portions of each flexible member in tension extending between the upper and lower platforms. A reel system can be included that is configured to extend and retract lines between the upper and lower platforms.
Other aspects of the invention include methods of operating a hoist system as herein described with one or more of the features herein described.
These and various other features and advantages that characterize the claimed embodiments will become apparent upon reading the following detailed description and upon reviewing the associated drawings.
The embodiments described below and illustrated in the accompanying figures describe various inventive aspects for hoist systems. Although these aspects may be described and illustrated with respect to certain embodiments, it should be understood that these aspects can be combined in any manner or used alone in such hoist systems as desired and should not be limited to the specific embodiments herein provided.
The upper platform 104 supports the lower platform 102 (shown and labeled in
The carriage 106 of the upper platform 104 optionally has trolleys 105 that slide linearly in the support structure 101. This allows the upper platform 104 to be able to move relative to the support structure 101. Additionally, the support platform 108 of the carriage 106 can be rotatable relative to portion 107 of the carriage 106 using rollers, bearings, guide surfaces or the like. Bearings can include fluid films (e.g. air or liquid) if desired. Likewise, magnetic bearings may also be employed. In the embodiment illustrated, rollers or wheel assemblies 131 are provided and fixed relative to one portion of the carriage, herein portion 107, while the rollers or wheels of assemblies 131 engage a surface(s) of the support platform 108. One or more drive motors 133 are illustratively provided for the wheel assemblies 131. Again, this embodiment is merely exemplary.
The foregoing features taken alone or in combination may advantageously increase a work envelope of the lower platform 102. For instance, referring back to
Besides extending and retracting the support arms 112 so as to position the lower platform 102 where desired, it should also be noted that extension and retraction of the support arms 112 can be controlled for other purposes. For instance, stiffness of the upper platform 104 with the support arms 112 retracted is typically greater than when the support arms 112 are extended, for example, when lifting loads vertically. Relative stiffness of the upper platform 104, or of the system as a whole, can be determined or calculated and stored, for example, in computer memory. When it is desired to lift a load, or otherwise move a load within the work envelope with a desired amount of stiffness, such inputs can be provided to the system, for example, through a computer interface or the like wherein the system then extends or retracts the support arms 112 in order to obtain the desired stiffness.
Another example of automatic extension or retraction of the support arms 112 occurs when it is desired to move the lower platform 102 (shown and labeled in
In some embodiments, hoist systems may include a system for ascertaining elongation of the wire rope(s) 115 due to the load on the lower platform 102. In this manner, compensation can be provided so as to position the lower platform 102 in a selected position, compensating for elongation in the wire rope(s) 115, compensating for slack in the wire rope(s) 115 and/or other external forces applied to the lower platform 102 and/or wire ropes(s) 115 in one, some or all degrees of freedom. In one embodiment, elongation or slack of a wire rope is measured directly with a sensor or sensors, for example, where the sensors are operably coupled between the upper platform 104 and the lower platform 102 along one, some or all of the wire ropes 115. Referring to
Alternatively, or in addition, elongation of the wire rope can be ascertained by the amount of tension in the wire rope(s) 115. Tension in the wire rope(s) 115 can be measured using a load cell operably coupled to the wire rope 115 to sense tension therein. For instance, the load cell can couple an end of the wire rope 115 to the lower platform 102 again at 152. In another embodiment, a load cell can be incorporated in the mount for each hoist 113. In yet another embodiment, tension can be inferred through the work performed by the hoist(s) 113 for example by sensing characteristics of the power needed to operate the hoist such as the current for an electrical motor used to rotate a drum of the hoist, or fluid flow characteristics for a hydraulic or pneumatically powered hoist.
The system can null out the effects of elongation of the wire rope(s) 115 in order to accurately position the lower platform 102 as desired. However, in addition, the system can also null out any other forms of deflection that may occur due to deflections or the like in other components such as but not limited to support arms 112, upper platform 104, lower platform 102, bridges, rails or components thereof to name just a few. Sensor(s) can be configured to provide signal(s) corresponding to deflections of one or more of these components. For instance, such deflections can be measured by displacement sensors, strain gauges to name just a few.
Movement of the lower platform 102 to desired locations can be performed manually where the operator is given independent control of all hoist motors and/or drive motors to rotate the upper platform. Typically, the operator is provided with a user interface having one or more joysticks or other control mechanism where movements thereof are translated so as to operate the hoist motors 113 and/or drive motors to cause movement of the upper platform 104 or carriage 106 either directly through rotation thereof, movement of its trolley, and/or movement of a bridge supporting the carriage 106, if one is provided. Depending upon the location of the lower platform 102 relative to any obstacles in structure 120 such as the enclosure walls, the system can be programmed so as to automatically extend or retract one or more of the support arms 112 and/or rotate the upper platform 104 in order to avoid contact of the wire ropes 115 and/or the lower platform 102 with the enclosure 120 or other obstacles. The work envelope and any potential obstacles can be defined in computer memory wherein the position of the lower platform 102, wire ropes 115 and/or upper platform 104/carriage 106 can be tracked virtually in order to avoid contact with obstacles such as the enclosure walls. If desired, sensors can also be mounted to any of the components in the system such as the upper platform 104, lower platform 102, support arms 112 and/or mechanisms coupled to the lower platform 102. Such sensors can be proximity sensors so as to sense contact or possible contact of components of the system with obstacles and/or otherwise control the system to avoid such obstacles. In one embodiment, a system controller 160 (shown and labeled in
As indicated above, in addition or in the alternative to monitoring elongation of wire rope(s) 115, the sensors to directly or indirectly sense tension in the wire rope(s) 115 can be configured so as to detect slack such as but not limited to if the lower platform 102 were to encounter an obstacle. If slack is detected in one or more wire ropes 115 via the sensor(s), the system controller 160 can be configured to provide an alarm and/or automatically operate the appropriate hoist(s) 113 until proper tension is obtained. If desired, the system controller 160 can be further configured to prevent other motions of the lower platform 102, which can include preventing further operation of the hoists 113, drive(s) 133, the drive mechanisms for the support arms 112 (e.g. actuators 144), drive(s) for the trolley 105 and/or drive(s) for a bridge on rails, the bridge supporting the trolley 105.
In the illustrated embodiment, the pulleys of the first set 312A-F are regularly closer together than the pulleys of the second set 310A-F. As indicated above, pulleys from the first set 312A-F and pulleys from the second set 310A-F are organized in pairs. Use of the spine assembly 304 so as to provide spaced-apart pulleys for each of the wire ropes 308A-308F in effect provides a couple using the wire ropes 308A-308F which can provide increased fidelity of control during movements of the lower platform 102, and in particular, angular movements (i.e., pitch, yaw and/or roll of the lower platform 102 with respect to a three orthogonal axes). In addition, the spine assembly 304 provides improved stiffness of the hoist system 300, particularly stiffness or rigidity to moments of angular movements (pitch, yaw and/or roll) of the lower platform 102. These benefits are realized due to the couple that is formed on the lower platform 102 by the set of two spaced apart pulleys 310A-310F and 312A-312F, respectively, provided for each wire rope 308A-308F.
It should be noted that each of the pulleys of the first set 312A-F, the second set 310A-F and pulleys 314A-F on the upper platform 104 (shown and labeled in
Generally, the benefits discussed above with respect to hoist system 400 are believed also realized in hoist system 500 illustrated in
In
Various parameters of the hoist systems 100, 200, 300, 400, 500, and 600 can be adjusted (or are monitored or sensed in order to provide accurate positioning of the lower platform 102) depending on the specific application to which it is intended. Using by way of example hoist system 300,
Collar system 700 illustratively includes a spine or partial spine 702, a collar 704, and spine cables 706A-C. In an embodiment, spine 702 is a rigid or flex resistant member such as, but not limited to, a rod. The collar 704 can have sufficient mass so as to have weight (i.e. “weighted collar”) to cause tension in the wire ropes 706A-C used to position the collar 704 on the spine and where the collar 704 slides freely on spine 702. The spine 702 is attached to lower platform 102 such that movement of either spine 702 or platform 102 is translated to the other member.
Weighted collar 704 is illustratively moved in a manner to track the motion of lower portion 102. For example, if the lower potion 102 is moved up a certain distance, weighted collar 704 is moved up approximately the same distance and at approximately the same rate. Embodiments are not limited to any particular method of moving weighted collar 704. In one embodiment, one or more hoists or reels are connected to collar 704 utilizing one or more spine cables. In the specific example shown in
In one embodiment, the weighted collar 704 has a cylindrical inner aperture that fits around the spine 702. The spine 702 is able to move freely up and down along the y-axis shown in coordinate system 710, and is able to rotate freely about the y-axis in the direction shown by arrow 711 in
In another embodiment, the spine 702 and the collar 704 are shaped such that they are keyed to each other. For instance, in one embodiment, the spine 702 has a rectangular shape, and the collar 704 has a rectangular aperture that the spine fits within. In such a case, in addition to reducing rotation about the x- and z-axes, 712 and 713, the system also helps to reduce rotation 711 about the y-axis.
As was previously mentioned, in an embodiment, collar 704 allows for spine 702 to move longitudinally (i.e. along the y-axis shown by coordinate system 710). This helps to ensure that an appropriate amount of tension is maintained in the spine cable or cables even if there is some discrepancy in the tracking of collar 704 to lower portion 102. Accordingly, the collar system 700 may help to reduce tilting even if there is less than perfect tracking of movement between collar 704 and lower portion 102.
The system controller 160 shown in
The computer 170 comprises a conventional computer having a central processing unit (CPU) 172, memory 174 and a system bus 176, which couples various system components, including memory 174 to the CPU 172. The system bus 176 may be any of several types of bus structures including a memory bus or a memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. The memory 174 includes read only memory (ROM) and random access memory (RAM). A basic input/output (BIOS) containing the basic routine that helps to transfer information between elements within the computer 170, such as during start-up, is stored in ROM. Storage devices 178, such as a hard disk, a floppy disk drive, an optical disk drive, etc., are coupled to the system bus 176 and are used for storage of programs and data. It should be appreciated by those skilled in the art that other types of computer readable media that are accessible by a computer, such as magnetic cassettes, flash memory cards, digital video disks, random access memories, read only memories, and the like, may also be used as storage devices. Commonly, programs are loaded into memory 174 from at least one of the storage devices 178 with or without accompanying data.
Input devices such as a keyboard 80 and/or pointing device (e.g. mouse, joystick(s)) 82, or the like, allow the user to provide commands to the computer 170. A monitor 184 or other type of output device can be further connected to the system bus 176 via a suitable interface and can provide feedback to the user. If the monitor 184 is a touch screen, the pointing device 182 can be incorporated therewith. The monitor 184 and input pointing device 182 such as mouse together with corresponding software drivers can form a graphical user interface (GUI) 186 for computer 170. Interfaces 88 on the system controller 60 allow communication to other computer systems if necessary. Interfaces 88 also represent circuitry used to send signals to or receive signals from the actuators and/or sensing devices mentioned above. Commonly, such circuitry comprises digital-to-analog (D/A) and analog-to-digital (A/D) converters as is well known in the art.
Although the subject matter has been described in language directed to specific environments, structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not limited to the environments, specific features or acts described above as has been held by the courts. Rather, the environments, specific features and acts described above are disclosed as example forms of implementing the claims.
The present application is based on and claims the benefit of U.S. provisional patent applications Ser. No. 61/320,094, filed Apr. 1, 2010, Ser. No. 61/356,254, filed Jun. 18, 2010, and Ser. No. 61/369,165, filed Jul. 30, 2010, the content of all of these documents being hereby incorporated by reference in its entirety.
Number | Date | Country | |
---|---|---|---|
61369165 | Jul 2010 | US | |
61356254 | Jun 2010 | US | |
61320094 | Apr 2010 | US |