1. Field
The present disclosure relates generally to systems and methods for winding and unwinding linear material and, in particular, to a motorized reel having a motor controller for controlling the same.
2. Description of the Related Art
Linear material, such as hoses, ropes, cables, and electrical cords, can be cumbersome and difficult to manage. Mechanical reels have been designed to help wind such linear material onto a spool member. As used herein, a spool member is an element on which a linear material can be wound and unwound, such as a cylindrical drum. Some conventional reels are manually operated, requiring the user to physically rotate the spool member to wind the linear material about the spool member. This can be tiresome and time-consuming for users, especially when the linear material is of a substantial length. Other reels are motor-controlled, and can automatically wind up the linear material. These automatic reels often have a gear assembly wherein multiple revolutions of the motor cause a single revolution of the spool member. For example, some conventional automatic reels have a 30:1 gear reduction, wherein 30 revolutions of the motor result in one revolution of the spool member.
However, when a user attempts to pull out the linear material from the automatic reel, the user must pull against the increased resistance caused by the gear reduction because the motor spins 30 times for every full revolution of the spool member. Not only does this place an extra physical burden on the user, but the linear material experiences additional strain as well. Some automatic reels include a clutch system, such as a neutral position clutch, that neutralizes (or de-clutches) the motor to enable the user to freely pull out the linear material. This often requires the user to be at the site of the reel to activate the clutch. In addition, clutch assemblies can be expensive and substantially increase the cost of automatic reels.
For these reasons, some motorized reels include a motor controller that provides a “powered-assist” (also known as “reverse-assist”) feature, in which the motor controller detects when a user pulls the linear material from the spool member, and responds by operating the motor to rotate the spool member in a direction that unwinds the linear material. Powered-assist thereby reduces the pulling burden that is otherwise placed on the user. In one known implementation, the motor controller detects when a tension in the linear material exceeds a predetermined threshold, and responds by signaling the motor to rotate the spool member in an unwind direction.
Conventional automatic reel motors also tend to rotate the spool member at a constant rate. As a result, when the end portion of the linear material is being wound upon the spool member, such rotation can cause the end of the linear material to swing uncontrollably or even hit forcefully against the reel unit. This erratic movement can result in property damage or serious injury to nearby persons who may be hit by the linear material. Oftentimes, the user must also push a button or activate a control to stop the spool member from rotating. To account for such problems, some automatic reels incorporate encoders that keep track of the amount of linear material left to be wound. By tracking the amount of unwound linear material, a reel's motor controller can reduce the wind-up speed of the spool member when winding in the terminal end portion of the linear material. This feature is known as “docking.”
When a linear material is released or expelled (such as by a powered-assist feature of a reel) from a source (such as a spool member), it is possible for slack to develop if the released linear material is not pulled away from the source. Slack may develop when the rate at which the linear material is released is greater than the rate at which it is pulled away. In different contexts, it may be desirable to maintain a certain amount of slack between one location, such as the source of the linear material, and another location. For example, in some contexts it may be desirable for the linear material to be as taut as possible. In other contexts it may be desirable that there be a certain range of slack. Too much slack can lead to, among other things, tangling and knotting.
In some embodiments, an apparatus for detecting and ameliorating high slack scenarios or high tangle-probability scenarios is provided. Some embodiments of the apparatus comprise a rotatable spool member from which a linear material may be unwound or around which it may be wound; a spool sensor system capable of detecting the length of linear material unwound from or wound around the spool member; a translation sensor system (referred to as a “transmission sensor system” in U.S. Provisional Application No. 61/477,108 filed Apr. 19, 2011) capable of detecting the length of linear material that has passed a monitored location; and a control system configured to receive input from both the spool sensor system and the translation sensor system, calculate an amount of slack in the linear material (e.g., the length of linear material between the spool member and the monitored location, minus the shortest possible linear material length between the spool member and the monitored location), and output a signal to cause the spool member to rotate in a way calculated to adjust the amount of slack in the linear material or the rate at which the amount of slack increases. For example, the control system can output a signal to cause the spool member to rotate in a way calculated to reduce the amount of slack or decrease the rate at which the amount of slack forms or increases.
In some embodiments, the rate of release of linear material (e.g., unwinding of the linear material from a spool member in a powered-assist operation) is controlled to be substantially equal to the rate at which the linear material is pulled away (“pull-out rate”), thereby minimizing any initial variance from the desired degree of slack. In some embodiments, sensors detect the rates at which the released linear material translates past two locations. By comparing the observations of these sensors, the amount of slack between the two locations can be determined. In certain embodiments, based on the results of the comparison or even based on the results of the observations of one of the sensors, corrective action is taken, such as adjusting the rate at which linear material is released from a source such as a spool member.
In another aspect, the present disclosure provides a reel comprising a linear material, a spool member rotatable about a winding axis, a motor configured to rotate the spool member about the winding axis, a housing surrounding the spool member and motor, a motor controller, a spool sensor system, and a translation sensor system. The spool member is configured to rotate in a wind direction about the winding axis to wind the linear material about the spool member. The spool member is also configured to rotate in an unwind direction about the winding axis to unwind the linear material from the spool member. The housing has a spooling port through which the linear material extends. The motor controller is configured to detect when the linear material is pulled from the spool member through the port, and to respond to the detected pulling of the linear material by conducting a powered-assist operation in which the motor controller operates the motor to rotate the spool member about the winding axis in the unwind direction. The spool sensor system is configured to be used by the motor controller to detect an unwind rate at which the linear material is unwound from the spool member during the powered-assist operation. The translation sensor system is configured to be used by the motor controller to detect a pull-out rate at which the linear material is pulled through the port in an unwind direction during the powered-assist operation. The motor controller is configured to adjust a rotation speed of the motor during the powered-assist operation based at least partly on the unwind rate and the pull-out rate, in order to limit a length of unwound linear material between the spool member and the port to less than a predetermined length.
In another aspect, the present disclosure provides a method comprising the following. The method includes providing a linear material being connected to a rotatable spool member housed within a housing. The spool member is rotatable about a winding axis. The spool member is configured to rotate in a wind direction about the winding axis to wind the linear material about the spool member, and is also configured to rotate in an unwind direction about the winding axis to unwind the linear material from the spool member. The housing has a port through which the linear material extends. The method further includes detecting the linear material being pulled from the spool member through the port; responding to the detected pulling of the linear material by conducting a powered-assist operation in which a motor rotates the spool member about the winding axis in the unwind direction; detecting an unwind rate at which the linear material is unwound from the spool member during the powered-assist operation; detecting a pull-out rate at which the linear material is pulled through the port in the unwind direction during the powered-assist operation; and adjusting a rotation speed of the motor during the powered-assist operation based at least partly on the unwind rate and the pull-out rate, in order to limit a length of unwound linear material between the spool member and the port to less than a predetermined length.
In still another aspect, the present disclosure provides a reel comprising a linear material, a spool member rotatable about a winding axis, a motor configured to rotate the spool member about the winding axis, a housing surrounding the spool member and motor, a motor controller configured to control rotation of the motor, a spool sensor system, and a translation sensor system. The spool member is configured to rotate in a wind direction about the winding axis to wind the linear material about the spool member. The spool member is also configured to rotate in an unwind direction about the winding axis to unwind the linear material from the spool member. The housing has a spooling port through which the linear material extends. The spool sensor system is configured to be used by the motor controller to detect a first rate at which the linear material is wound upon or unwound from the spool member. The translation sensor system is configured to be used by the motor controller to detect a second rate at which the linear material translates through the port in a wind-up direction or an unwind direction. The motor controller is configured to control the motor based at least partly on the first and second rates, in order to limit a length of unwound linear material between the spool member and the port to less than a predetermined length.
For purposes of summarizing the disclosure, certain aspects, advantages and novel features of the invention have been described herein. It is to be understood that not necessarily all such advantages may be achieved in accordance with any particular embodiment of the invention. Thus, the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein.
The illustrated automatic reel 100 comprises a body or housing 102 supported by a base or leg structure, such as a plurality of legs 104 (e.g., four legs of which two legs are shown in
The illustrated legs 104 support the housing 102 above a surface such as ground (e.g., a lawn), a floor, or a table-top. The legs 104 may also advantageously include wheels, rollers, or other like devices 105 to enable movement of the automatic reel 100 on the ground or other supporting surface. In certain embodiments, the legs 104 are capable of locking or being affixed to a certain location to prevent lateral movement of the automatic reel 100.
The illustrated automatic reel 100 also comprises an interface panel 106, which can include a power button 108, a select button 110 and an indicator light 112. The power button 108 controls the operation of the motor, which controls the automatic reel 100. For example, pressing the power button 108 activates the motor when the motor is in an off or inactive state. In certain embodiments, in order to account for premature commands or electrical glitches, the power button 108 may be required to be pressed for a predetermined time or number of times, such as, for example, at least about 0.1 seconds before turning on the motor. In addition, if the power button 108 is pressed and held for longer than a predetermined time period (e.g., about 3 seconds), the automatic reel 100 may turn off the motor and generate an error signal (e.g., activate the indicator light 112).
In some embodiments, if the power button 108 is pressed while the motor is running, the motor is turned off. Preferably, commands issued through the power button 108 override any commands received from a remote control device (discussed below). In certain embodiments, the power button 108 may be required to be pressed for more than about 0.1 second to turn off the motor.
The illustrated interface panel 106 also includes the select button 110. The select button 110 may be used to select different options available to the user of the automatic reel 100. For example, a user may depress the select button 110 to indicate the type or size of linear material used with the automatic reel 100. In other embodiments, the select button 110 may be used to select a winding speed for the automatic reel 100.
The illustrated indicator light 112 can provide information to a user regarding the functioning of the automatic reel 100. In an embodiment, the indicator light 112 comprises a fiber-optic indicator that includes a translucent button. In certain embodiments, the indicator light 112 is advantageously structured to emit different colors or to emit different light patterns to signify different events or conditions. For example, the indicator light 112 may flash a blinking red signal to indicate an error condition.
In other embodiments of the invention, the automatic reel 100 may comprise indicator types other than the indicator light 112. For example, the automatic reel 100 may include an indicator that emits an audible sound or tone.
Although the interface panel 106 is described with reference to particular embodiments, the interface panel 106 may include more or less buttons (or other control elements) usable to control the operation of the automatic reel 100. For example, in certain embodiments, the automatic reel 100 advantageously comprises an “on” button and an “off” button. Also, the interface panel 106 can include devices for implementing an interface 208 (
Furthermore, the interface panel 106 may include other types of control elements, displays, or devices that allow for communication to or from a user. For example, the interface panel 106 may include a liquid crystal display (LCD), a touch screen, one or more knobs or dials, a keypad, combinations of the same or the like. The interface panel 106 may also advantageously include an RF receiver that receives signals from a remote control device, such as signals for operating the motor or a flow controller regulating fluid flow through the linear material (e.g., hose). Examples configurations of remote controls for controlling a flow controller and the reel motor 204 are disclosed in U.S. Pat. No. 7,503,338 to Harrington et al. and U.S. Patent Application Publication No. US2008/0223951A1 to Tracey et al. In some embodiments, an RF receiver can be located elsewhere within the reel 100, and not on the interface panel 106.
The automatic reel 100 is preferably powered by a battery source. For example, the battery source may comprise a rechargeable battery. In an embodiment, the indicator light 112 is configured to display to the user the battery voltage level. For example, the indicator light 112 may display a green light when the battery level is high, a yellow light when the battery life is running out, and a red light when the battery level is low. An example of a suitable battery is disclosed in U.S. Pat. No. 7,320,843 to Harrington.
In certain embodiments, the automatic reel 100 is configured to shut down the motor when the linear material is in a fully unwound state (or at least unwound as much as possible).
In addition to, or instead of, utilizing battery power, other sources of energy may be used to power the automatic reel 100. For example, the automatic reel 100 may comprise a cord that electrically couples to an AC outlet. In other embodiments, the automatic reel 100 may comprise solar cell technology or other types of powering technology.
As further illustrated in
A skilled artisan will recognize from the disclosure herein a variety of alternative embodiments, structures and/or devices usable with the automatic reel 100. For example, the reel 100 may comprises any support structure, any base, and/or any console usable with embodiments described herein.
As shown in the block diagram of
In certain embodiments, the spool member 202 comprises a substantially cylindrical drum capable of rotating about a winding axis 126 to wind and unwind linear material. In other embodiments, the spool member 202 may comprise other devices suitable for winding and unwinding a linear material.
Referring to
With reference to
In an embodiment, the motor 204 is coupled to the spool member 202 via a gear assembly. For example, the automatic reel 100 may advantageously comprise a gear assembly having an about 30:1 gear reduction, wherein about 30 revolutions of the motor 204 produce about one revolution of the spool member 202. In other embodiments, other gear reductions may be advantageously used to facilitate the winding of linear material. In yet other embodiments, the motor may comprise a brushless DC motor 204, a stepper motor, or the like.
In certain embodiments, the motor 204 operates within a voltage range between about 10 and about 15 volts and consumes up to approximately 250 watts. In one embodiment, under normal load conditions, the motor 204 may exert a torque of approximately 120 ounce-inches (or approximately 0.85 Newton-meters) and operate at approximately 2,500 RPM. In some embodiments, the motor 204 is capable of operating within an ambient temperature range of approximately about 0° C. to about 40° C., allowing for a widespread use of the reel 100 in various types of weather conditions.
In certain embodiments, the motor 204 advantageously operates at a rotational velocity selected to cause the spool member 202 to completely wind up a 100-foot garden hose within approximately 20-60 seconds. However, as a skilled artisan will recognize from the disclosure herein, the wind-up time may vary according to the type of motor used and the type and length of linear material wound by the automatic reel 100.
In certain embodiments, the motor 204 is configured to wind linear material at a maximum translational velocity of, for example, between approximately 3 and approximately 4 feet per second. As used herein, “translational velocity” refers to the speed at which an unwound portion of the linear material translates due to winding or unwinding. In certain embodiments, the motor 204 is configured to wind linear material at a maximum translational velocity of approximately 3.6 feet per second. To maintain the linear material translational velocity below a selected maximum velocity, the motor 204 may advantageously operate at different speeds during a complete wind-up of the linear material. For instance, the translational velocity of the linear material may depend upon the number of layers of linear material wound on the spool member 202. Thus, in order to achieve a relatively high translational velocity when winding of the linear material begins, yet stay below the maximum translational velocity as the number of layers of linear material wound onto the spool member 202 increases, the motor controller 206 can be configured to decrease the rotational velocity (e.g., the RPM) of the spool member 202 as more linear material becomes wound onto the spool member 202.
One skilled in the art will recognize from the disclosure herein that the automatic reel 100 need not wind the linear material at a constant velocity. For example, the reel motor 204 may operate at a constant RPM throughout the winding process. In such an embodiment, the translational velocity of the linear material may increase as more layers of linear material become wound upon the spool member 202.
In one particularly advantageous embodiment, the rotational velocity of the motor 204 decreases during winding to reduce the translational velocity of the linear material when a relatively short length of linear material remains to be wound onto the spool member 202. Such a motor velocity reduction may protect against injury and property damage by preventing the end of the linear material from being too forcefully wound into the automatic reel 100. As mentioned above, this feature is known as “docking.”
In certain embodiments, the automatic reel 100 preferably includes a powered-assist function (also referred to as “reverse-assist”) to reduce the effort required by a user to pull (i.e., unwind) linear material from the spool member 202 within the automatic reel 100. The powered-assist function can counteract at least a portion of the effect of pulling against a large gear reduction of the automatic reel 100. For example, when the user pulls on the linear material, the internal spool member 202 rotates and causes the motor 204 to rotate in the unwind direction.
The powered-assist process 300 begins at Block 302, wherein the motor 204 is in an inactive state. At Block 304, the motor controller 206 determines if the linear material is being pulled, such as by a user trying to unwind the linear material from the automatic reel 100. For example, in certain embodiments, the motor controller 206 detects a tension of the linear material above a predetermined amount, such as, for example, a tension that causes the motor 204 to spin in the reverse direction. If the motor controller 206 does not sense a pull or increased tension of the linear material, the process 300 returns to Block 302. If the motor controller 206 senses that the linear material is being pulled, the process 300 proceeds with Block 306.
In certain embodiments wherein the motor 204 comprises a brush DC motor, the motor controller 206 can be configured to sense a reverse electromotive force (EMF) associated with the motor 204, to determine when the linear material is being pulled. When the motor 204 is inactive, the motor controller 206 does not provide power to the motor 204. As the user pulls on the linear material, the turning of the brush DC motor generates a detectable reverse EMF, which is sensed by the motor controller 206. The motor controller 206 can be configured to respond to the detection of such reverse EMF (e.g., if it exceeds a certain magnitude) by initiating a powered-assist operation and possibly also by “waking up” (e.g., electrically activating) rotation sensors associated with a slack control system, such as rotation sensors used in a spool sensor system 402 and/or a translation sensor system 404 (described below with respect to
Once the motor controller 206 senses the pulling of the linear material, the motor controller 206 causes the motor 204 to rotate in an unwind direction, which causes the spool member 202 to unwind portions of the linear material wound thereon, which is illustrated by Block 306.
In certain embodiments, the motor controller 206 causes the spool member 202 to rotate in the unwind direction by operating a relay or other suitable switching device to reverse the direction of the current applied to the motor 204. The reverse current causes the motor 204 to rotate the spool member 202 of the automatic reel 100 such that the linear material is unwound from the spooling member 202.
At Block 308, the motor controller 206 determines if the user has stopped pulling the linear material or if the linear material has been fully unwound (or unwound as much as possible), and if so, the motor controller 206 causes the motor 204 to stop rotating in the unwind direction. If the user has not stopped pulling the linear material and ii the linear material is not fully unwound, the process 300 returns to Block 306 wherein the spool member 202 continues to rotate to unwind the linear material.
In certain alternative embodiments, rather than causing the motor 204 to rotate in the unwind direction until such time that the user stops pulling the linear material or until the linear material is fully unwound (as in Block 308), the motor controller 206 causes unwinding rotation of the motor 204 and the spool member 202 (in Block 306) for only a predetermined period of time. For example, when the motor controller 206 senses a pulling of the linear material (Block 304), the motor controller 206 may cause the spool member 202 to rotate to unwind linear material for five seconds. In other embodiments, the motor controller 206 may cause the spool member 202 to unwind a predetermined length of the linear material (e.g., approximately 10 feet) or may cause the spool member 202 to perform a certain number of revolutions (e.g., 10 revolutions).
Although described with reference to particular embodiments, the skilled artisan will recognize from the disclosure herein a wide variety of alternatives to the powered-assist process 300. For example, in certain embodiments, a remote control advantageously includes an “unwind” (or equivalent) button (not shown) to activate the automatic reel 100 to operate the motor 204 in the unwind direction to unwind the linear material from the spool member 202 within the automatic reel 100.
The skilled artisan will also readily appreciate from the disclosure herein that numerous modifications can be made to the electronics to operate the reel device 100. For example, the above process 300 may be implemented in software, in hardware, in firmware, or in a combination thereof. In addition, functions of individual components, such as the motor controller 206, may be performed by multiple components in other embodiments of the invention.
Skilled artisans will understand from the present disclosure how to construct a motor controller that implements a powered-assist process such as the process 300 of
In preferred embodiments, a reel includes a slack control system that monitors and/or reports on the amount or an approximation of “slack”: the amount of linear material between a source of linear material (such as the spool member 202) and another location. A slack control system can help to reduce problems caused by excessive slack, such as knotting, tangling, and inefficient winding and unwinding.
As shown in the block diagram of
The spool sensor system 402 can enable the motor controller 206 to detect winding or unwinding translational movement and/or velocity of the linear material relative to the spool member 202, by monitoring revolutions and/or rotational velocity of the spool member 202, the motor output shaft 704 (
The translation sensor system 404 can enable the motor controller 206 to detect winding or unwinding translational movement and/or velocity of the linear material at another location, typically a location near (e.g., within six inches) the spooling port 114. For example, during a powered-assist operation, the translation sensor system 404 can be configured to be used by the motor controller 206 to detect a rate at which the linear material is pulled (typically by a user) through the spooling port 114 in the unwind direction. This rate is referred to herein as a “pull-out rate.”
In the illustrated embodiment, the slack control system 400 includes one spool sensor system 402 and one translation sensor system 404. In some alternative embodiments, a slack control system includes a plurality (e.g., a pair) of translation sensor systems 404, without a spool sensor system 402. For example, one translation sensor system 404 can be positioned near (e.g., within 2-6 inches) the spool member 202 to detect translational movement and/or velocity of linear material that is winding onto or unwinding from the spool member 202, and another translation sensor system 404 can be positioned at another location to detect those same properties at that location. This can enable the detection of slack between the two translation sensor systems 404. In still other embodiments, a slack control system includes a spool sensor system 402 and a plurality of translation sensor systems 404.
The illustrated slack control system 400 can be configured to be used by the motor controller 206 to monitor and/or report on the amount or an approximation of slack: the amount or length of linear material 122 (
In some contexts it is desirable that slack is minimized, while in others there is a desired range of slack. Some embodiments generate and send an alert or signal when the amount of slack exceeds (or falls below) a threshold. Some embodiments control the amount of slack, for example, by causing the motor controller 206 to send an appropriate signal to the motor 204 or to modify a signal already being sent. Such corrective action may be taken when appropriate, as determined by the configuration of that embodiment. Some embodiments take corrective action when the slack exceeds a threshold or is more than a relative or absolute amount above a threshold; when the rate of slack formation exceeds a threshold; or when the embodiment otherwise detects that a risk of excess slack is imminent. For example, during a powered-assist operation, the motor controller 206 can be configured to adjust a rotation speed of the motor 204 to limit a length of unwound linear material between the spool member 202 and the spooling port 114 to less than a predetermined or dynamically computed length, and/or to substantially equalize the “unwind rate” (the translational rate of the linear material unwinding from the spool member 202) with the “pull-out rate” (the translational rate at which the linear material passes through the spooling port 114). In some embodiments, the sensor systems 402 and 404 can be used to maintain the amount of slack above (as opposed to below) a desired minimum (as opposed to maximum) threshold.
In the illustrated embodiment, the motor controller 206 can be configured to determine the appropriate corrective action for an excess (or insufficient) slack condition based on the current status of the motor 204 and the information received from the spool sensor system 402 (e.g., about the spool member 202) and the translation sensor system 404. For example, if there is too much slack and the spool member 202 is already winding in the linear material 122, the motor controller 206 may be configured to cause the motor 204 to rotate the spool member 202 at a faster rate. On the other hand, if the spool member 202 is unwinding, then the motor controller 206 can signal the motor 204 to cause the spool member 202 to unwind at a slower rate, to cease unwinding, or to reverse direction and wind in.
Some embodiments may allow the user to input, adjust, and/or control various slack-management parameters, by using the motor controller interface 208. For example, the interface 208 can allow a user to specify the maximum amount of permissible slack in the linear material between the spool member 202 and the spooling port 114 of the housing 102. Information entered by the user through the interface 208 is transmitted to the motor controller 206 for use in the monitor and control calculations. In other embodiments, the slack control system 400 does not allow a user to input, adjust, or control slack-management parameters. In such embodiments, the interface 208 plays no role in the slack control system 400.
In one embodiment, schematically illustrated in
Preferably, the translational movement of the linear material 122 (caused by winding or unwinding) between the monitored location 504 and the spooling port 114 is constrained to create a high degree of probability that any portion of linear material 122 that passes the location 504 passes unimpeded through the spooling port 114. One possible constraint is a tube (not shown) through which the linear material extends, the tube extending from the spooling port 114 and the monitored location 504 and having inner dimensions and configuration such that the linear material 122 is unlikely to snag or loop on itself within the tube.
The slack control system 400 is not limited to a system that is contained in a housing 102. Further, a slack control system can be used in systems that lack a rotatable spool member 202. Slack can form both from the winding or unwinding of linear material 122 with respect to the spool member 202, as well as from any other type of extension or return of linear material 122 with respect to a non-spooled linear material source. Embodiments of the invention are configured to monitor, report, and/or control linear material slack between any type of linear material source and a monitored location. In embodiments in which the source of linear material is not a spool, this can be achieved by the use of two or more translation sensor systems 404 at different locations, wherein the slack is formed between those locations. It will be understood that one of the translation sensor systems 404 can, but need not, be provided near the linear material source.
In embodiments in which the spool member 202 is located within a housing 102, the translation sensor system 404 of
The translation sensor system 404, regardless of where it is located relative to the housing 102, may be configured to monitor a location inside the housing 102, outside the housing 102, or a point within the spooling port 114 where the linear material 122 passes from inside the housing 102 to outside the housing 102.
In Block 604, the motor controller 206 compares the information about the spool member 202 (received from the spool sensor system 402) with the information from the translation sensor system 404. In Block 606, the motor controller 206 evaluates any difference in measured or calculated linear material translation (due to winding or unwinding) or rates of such translation between the two sets of information. If the difference is not greater than a particular threshold, the method returns to Block 602 for receipt of more information. If the difference is greater than the particular threshold, then the method proceeds to Block 608. The threshold value used in Block 606 may be set by a user using, for example, the motor controller interface 208; it may be dynamically set by the motor controller 206 based on algorithms and systems which, for example, account for the past behavior of the overall apparatus and the current state of the components of the apparatus (e.g., the size or number of spooled linear material layers on the spool member 202); it may be predetermined in the configuration of the slack control system 400; and/or it may be set by other systems and methods.
In Block 608, the motor controller 206 determines and implements an appropriate corrective action to counter excess linear material slack or rate of slack formation as determined in Block 604. For example, if the spool member 202 is unwinding, then the motor controller 206 can signal the motor 204 to cause the spool member 202 to unwind at a slower rate, to cease unwinding, or to reverse direction and wind in the linear material 122. On the other hand, if there is too much slack and the spool member 202 is already winding in the linear material 122, the motor controller 206 may be configured to cause the motor 204 to rotate the spool member 202 at a faster rate.
In other embodiments of methods of controlling slack, one or more of the steps shown in the slack management flow chart 600 are not performed. In some embodiments, additional processes are performed. It will be understood by one of skill in the art that various mechanisms, including those disclosed, can be used to compare information about the amount of linear material 122 released from or gathered into a source with the amount of linear material 122 that has passed a monitored location. Similarly, a variety of mechanisms, including those disclosed herein, can be used to decrease the rate at which slack develops and/or to reduce the amount of slack in the linear material 122.
Embodiments of a slack control system 400 are particularly useful when linear material 122 is being unwound from the spool member 202 and something, typically a user, is pulling the unwound linear material 122 away from the reel 100. At some point, the user may stop pulling the linear material 122 away from the spool member 202, and rotational momentum may cause the spool member 202 to continue unwinding linear material 122 even after the user stops pulling the linear material 122 away from the spool member 202. Or the linear material 122 may unwind at a rate faster than the user pulls it away from the spool member 202. For example, the motor 204 may cause the spool member 202 to unwind at a rate that is greater than the rate at which the linear material 122 is pulled away by the user. Also, a slack control system 400 can be implemented in linear material 122 dispensing systems that do not have the powered-assist functionality described above.
In embodiments that have powered-assist functionality, a slack control system can be used to improve the responsiveness and user experience. For example, the slack control system 400 may detect that slack is accumulating or increasing during a powered-assist operation. If the slack control system 400 detects that at least some linear material 122 is being pulled away from the spool member 202 through the translation sensor system 404, the motor controller 206 may be configured to respond to the increased slack by causing the powered-assist operation to at least temporarily stop (i.e., causing the motor 204 to stop rotating in the unwind direction) or by causing the motor 204 to rotate in the unwind direction at a slower rate more commensurate with the detected rate at which linear material 122 is being pulled through the translation sensor system 404. The motor controller's determination of whether to stop power-assisting (at least temporarily) versus simply power-assisting at a reduced rotational rate may depend on the total amount of slack that has accumulated within the linear material 122, with greater accumulated slack more likely to lead to an at least temporary cessation of the powered-assist operation. Similarly, if the slack control system 400 detects a cessation in the outward pull of the linear material 122 from the reel 100 (e.g., by detecting that no linear material is translating through the translation sensor system 404), the motor controller 206 can be configured to respond by stopping the powered-assist operation, and possibly even by causing the motor 204 to rotate in the wind-up direction to eliminate some or all of any slack that has formed.
As shown in
Embodiments may use multiple sources 702 and/or multiple sensors 706 to enable the motor controller 206 to detect rotational velocity of the shaft 704 and/or spool member 202. Generally, the more sources 702 or sensors 706 are used, the more precise a measurement of rotational velocity or displacement the sensor 706 can detect, up until the point at which the sources 702 are so close to one another that they interfere with each other and cannot be distinguished by the sensor 706. Embodiments may have two, three, four, or more sensors 706. The sensors 706 may be arranged regularly (e.g., at equal circumferential intervals) around the monitored rotating component containing the sources 702, or may alternatively be grouped closer to each other, as shown in
Similarly, embodiments may also have two, three, four, or more sources 702. The sources 702 may be arranged regularly (e.g., at equal circumferential intervals) about the monitored rotating component containing the sources 702, or may alternatively be grouped closer to each other. Multiple sources 702 may also provide redundancy of measurement, mitigating the risk of failure of one or more of the sources. For example, circuitry associated with the sensor/source mechanism may detect failure of one or more sources 702 and rely upon input from remaining non-failed sources 702, may weight data depending on how many sources 702 report it, or use any of a variety of approaches known to those of skill in the art for achieving redundancy and failure support from multiple inputs.
Embodiments may use multiple sensors 706 or multiple sources 702 to determine changes in direction of rotation of a monitored rotating component. For example, suppose a shaft/sensor assembly has first and second sensors 706. If rotation of the shaft 704 is detected (e.g., proximity detection of an identifiable source 702) twice consecutively by the first sensor 706 without an intervening detection by the second sensor 706, the motor controller 206 may conclude that the direction of rotation of the shaft 704 has changed. In another example, suppose a shaft/sensor assembly has first and second sources 702 and at least one sensor 706. If the sensor 706 detects the first source 702 twice consecutively without an intervening detection of the second source 702, the motor controller 206 may conclude that the direction of rotation of the shaft 704 has changed. It will further be appreciated that such methods for detecting changes in direction of rotation can be used in embodiments in which the sources 702 are mounted on the spool member 202 or another element that rotates when the spool member 202 rotates about its winding axis.
Control logic and heuristics for a sensor/source mechanism may be contained in software or control circuitry associated with the mechanism. For example, sensor 706 can be interfaced with a microprocessor. In other embodiments, some or all of that logic and heuristics may be provided in a different controller (which may also use software, hardware, or a combination thereof), such as motor controller 206. A portion of the control logic may be configured to convert observations or data from the one or more sensors 706 to data indicative of the rate and/or direction of rotation of the output shaft 704 of the motor 204. The control logic may do so based on the number and relative positioning of sources 702 and sensors 706. In some embodiments, the control logic may also factor in a predefined relationship between the rate of rotation of the shaft 704 and the motor 204. For example, consider an embodiment with two sensors 706 circumferentially spaced apart by 180° about the shaft 704, and two sources 702 also circumferentially spaced apart by 180° about the shaft 704. In this example, a portion of the control logic might determine that when, over a period of one second, the sensors 706 collectively detected sources 702 four times, then the shaft 704 is rotating at approximately 0.5 to 1.0 revolutions per second (with more information about the initial relative positions of the sensors 706 and sources 702, more precision may be possible). In another example involving the same embodiment, the control logic may observe that it took approximately one second after the first source 702 detection by a sensor 706 for a fourth source 702 detection to be made, and may conclude that the shaft 704 is rotating at approximately 0.5 revolutions per second. A rate and/or direction of rotation of the motor 204 can be determined based on a known or assumed relationship between the rotation of the motor 204 and the rotation of the shaft 704 (which may or may not be one-to-one). In some embodiments, the motor controller 206 receives the output of the sensor(s) 706 and determines, from the sensor output, the rate and/or direction of rotation. In some embodiments, separate control logic (e.g., electronic circuitry and/or a logic chip) provided in conjunction with the sensor(s) 706 and/or source(s) 702 is configured to use the sensor output to determine the rate and/or direction of rotation and to communicate that information to the motor controller 206.
Another way in which an embodiment including sources 702 and sensors 706 can determine both the amount and the direction of rotation of the shaft 704 (or, as shown in
Sources 702 and sensors 706 may be similarly configured with respect to any rotating member or component of the reel 100 if, for example, there is a known relationship between the rotational displacement of the component and the amount of linear material wound or unwound while that component is rotating through the rotational displacement. Just as, in some embodiments, each revolution or portion of a revolution of a motor shaft 704 corresponds to a calculable length of linear material being wound or unwound from the spool member 202, in some embodiments the rotation of elements of a gearbox of the reel device 100 may have a similar relationship such that the sensor-source apparatus is configured to monitor the rotation of a gear operatively coupled with respect to the motor 204 and the spool member 202. Or, as illustrated in
In general, the number of sources 702 and the number of sensors 706 can vary independently. For example, an embodiment could be configured with multiple sensors 706 and one source 702, or with multiple sensors 706 and multiple sources 702. As stated above, it is typically the case that having more sources 702 and/or sensors 706 may result in a more precise or finer-grained measurement. Such embodiments may also be more tolerant of failure of one or more sources 702 or sensors 706. It will also be understood that in embodiments where the coupling or engagement between the motor 204 and the spool member 202 is geared, a sensor/source configuration associated with the motor (e.g., as in
As mentioned above, sensors 706 and sources 702, whether they are optical, magnetic, or otherwise, may have their own circuitry for calculating a net number of revolutions and/or rotational velocity in the winding or unwinding direction. The spool sensor system can be configured to send or make such information available to the motor controller 206. Alternatively, the spool sensor system can be configured to send pulses (each pulse being indicative of one passage of a source 702 in proximity to a sensor 706) to the motor controller 206, which can be configured to determine the number of revolutions and/or rotational velocity from the pulses. The motor controller 206 can be configured to use this information to manage slack in the linear material, as disclosed herein.
One of skill in the art will appreciate that while disc 1102 with embedded magnets may have certain advantages in terms of rotational stability or mechanics, for example, the one or more sources 702 need not be embedded in or otherwise provided on such a disc 1102 and may, for example, be directly attached to shaft 704.
A sensor/source apparatus such as those illustrated and described herein may be configured to have a particular accuracy and/or precision in measuring rotational displacement and/or velocity. For example, it may detect full or partial revolutions, depending in part on the associated control logic and the number of sensors 706 and sources 702. An apparatus with a single sensor 706 and a single source 702 may detect only single revolutions. The use and positioning of sensors 706 and sources 702, as well as the configuration of associated control logic, may allow measuring of ½, ⅓, ¼ as well as many other fractions of a revolution. Further, the measurement accuracy may also depend in part on the speed of rotation as well as the type and quality of the components. Also, some algorithms may yield precise measurements of the rate of rotation, while other algorithms may yield ranges. Embodiments may use one or both types of algorithms.
The translation sensor system 404 may comprise any apparatus that is capable of tracking the amount of linear material 122 that passes a location 504 that the translation sensor system 404 monitors. Alternatively or additionally, the apparatus can be capable of providing information from which the rate of linear material translation (due to winding or unwinding) at the location 504 can be tracked. As noted above, the motor controller 206 can compare the output of the translation sensor system 404 with information from the spool sensor system 402 (e.g., information about the number and direction of revolutions of the spool member 202) or with information from another translation sensor system 404 near the spool member 202 to determine if a critical amount of linear material 122 is slackened between the monitored location 504 and the spool member 202.
The illustrated translation sensor system 404 comprises a roller 1602 mounted with respect to the reel housing 102, preferably in proximity to (e.g., within four inches) the spooling port 114. The illustrated translation sensor system 404 further comprises a cradle 1604, a sensor 1606, and a nose cone attachment 1608. The linear material 122 can enter and leave the housing 102 through the spooling port 114. The attachment 1608 is mounted to an inner surface of the nose cone 120, and the cradle 1604 can be pivotably mounted to the attachment 1608, permitting a degree of pivoting or rotation of the cradle 1604 with respect to the attachment 1608 about a pivot axis 1618. The roller 1602 is rotatably mounted to the cradle 1604, such as by a center axle or axle pins, to permit the roller 1602 to rotate with respect to the cradle 1604 about a roller axis 1616. The roller 120 is preferably mounted such that the linear material 122 bears against an outer annular surface of the roller 1602 when the linear material 122 extends through the spooling port 114, and such that translation of the linear material 122 through the spooling port 114 (e.g., in conjunction with winding or unwinding of the spool member 202) causes the roller 1602 to rotate with respect to the housing 102 about the roller axis 1616.
The cradle 1604 and attachment 1608 can be mounted to position the roller 1602 above or below the linear material 122 when the linear material extends through the spooling port 114. While the illustrated embodiment shows the roller 1602 above the spooling port 114, it may be preferable to position the roller 1602 below the port 114, to promote better contact between the linear material 122 and the roller 1602 (due to gravity acting on the linear material).
It will be understood that the angle, lateral position, and/or relative altitude or height at which the linear material 122 approaches the roller 1602 may change depending on, among other things, the portion of the spool member 202 from which it is wound or unwound. Although the illustrated translation sensor system 404 is configured to monitor a particular location 504, in some embodiments additional structure is provided to ensure that the linear material 122 passes that location 504 and/or that the monitored location 504 is adjusted to where the linear material 122 passes. For example, the roller 1602 can be biased toward the linear material 122. In the illustrated embodiment in which the roller 1602 is positioned above the spooling port 114, the attachment 1608, cradle 1604, and roller 1602 are preferably configured so that the roller 1602 is downwardly biased to exert a downward force on the linear material 122 as the linear material translates through the spooling port 114. In some embodiments, one or more springs 1610 bias the cradle 1604 so as to pivot downwardly with respect to the attachment 1608 about the pivot axis 1618. In this manner, the springs 1610 help to account for the variability in the position of the linear material 122 and to ensure that the roller 1602 rotates as the linear material 122 translates through the spooling port 114. The combination of the biasing force of the roller 1602 against the linear material 122 and the friction between the linear material and the surface of the roller 1602 causes the roller 1602 to rotate as the linear material 122 translates due to winding or unwinding.
In addition to the aforementioned pivoting of the cradle 1604 with respect to the attachment 1608, the cradle 1604 and/or attachment 1608 can be configured to allow positional adjustment in other ways. For example, the cradle 1604 and/or attachment 1618 can be configured to rotate about an axis that is substantially perpendicular to the pivot axis 1618 and/or the roller axis 1616. Further the cradle 1604 and/or attachment 1608 can be configured to permit a degree of translation of the cradle 1604 relative to the nose cone 120 along such an axis.
The motor controller 206 can be configured to count the pulses to determine a length of linear material 122 that has passed through the monitored location 504 over a period of time, or a translational velocity of the linear material (based on pulses per unit time). The motor controller 206 can determine the length of linear material that has passed the monitored location 504 based on the number of detected revolutions of the roller 1602 and the circumference of the roller 1602. In other embodiments, the sensor 1606 includes a separate controller that itself counts the pulses and/or determines the translational velocity of the linear material and sends such information to the motor controller 206.
The illustrated roller 1602 has an outer annular surface with a somewhat concave longitudinal profile. Various factors, including the way in which the linear material 122 is wrapped around the spool member 202, can induce a certain amount of lateral variability in the lateral position of the linear material 122 with respect to the roller 1602. The range of lateral motion may depend on the size of the spool member 202 and the distance between the roller 1602 and the spool member 202. The illustrated concave profile of the roller 1602 helps to promote better contact between the linear material 122 and the roller 1602 during winding and unwinding. In some embodiments, the length of the roller 1602 can be as large as or larger than the expected range of lateral motion. In such embodiments, a roller 1602 that is generally cylindrical may be used without an unduly high risk of the linear material 122 sliding or jumping off of the roller 1602. In embodiments where the roller 1602 is not that long, and even in embodiments where it is, a roller 1602 having a concave, tapered, or saddle shape helps direct the linear material 122 back towards the center of the roller 1602 and reduces the likelihood of the linear material 122 jumping or sliding completely off of it. The degree of tapering can be chosen based on the properties of the overall automatic reel system 100, the size and nature of the linear material 122, and the materials and design of the particular embodiment. As can be seen in
One parameter involved in calculating the length of linear material 122 that translates past the roller 1602 is the circumference of the roller. In embodiments having a non-cylindrical roller 1602 as shown in
In the illustrated embodiment, springs 1906 and 1908 can be included to bias the rollers 1902 and 1904 toward one another. Using springs 1906 and 1908 tends to cause both rollers 1902 and 1904 to contact the linear material 122 to the same degree, which in turn promotes the likelihood that both rollers will rotate at the same speed as the linear material 122 translates through the spooling port 122.
In certain embodiments, the rollers 1902 and/or 1904 (as well as the roller 1602 shown in
While the illustrated rollers 1902 and 1904 are oriented horizontally, it will be understood that the rollers can have any suitable orientation, such as vertical or diagonal. Further, while the illustrated rollers 1902 and 1904 are oriented in parallel with each other, in some embodiments they can be non-parallel to each other, so long as they are capable of sandwiching the linear material 122 between their outer surfaces.
It will be understood that the linear material 122 is not a required element of the invention. Some embodiments comprise reels that do not include the linear material, but which are configured to be used with a user-provided linear material. More generally, no element described herein is necessarily required, unless specifically disclosed as such.
Having thus described certain embodiments of the present invention, those of skill in the art will readily appreciate from the disclosure herein that yet other embodiments may be made and used within the scope of the claims hereto attached. Numerous advantages of the invention covered by this disclosure have been set forth in the foregoing description. It will be understood, however, that this disclosure is, in many respects, only illustrative. Changes may be made in details without exceeding the scope of the disclosure.
The present application claims priority to U.S. Provisional Patent Application No. 61/477,108, filed Apr. 19, 2011. The present application incorporates by reference the entire disclosures of U.S. Pat. Nos. 6,279,848; 7,320,843; 7,350,736; 7,503,338; 7,533,843; and D632,548; and U.S. Patent Application Publication No. US2008/0223951 A1. The present application also incorporates by reference the entire disclosure of U.S. Provisional Patent Application No. 61/477,108, filed Apr. 19, 2011, with the exception of paragraphs [0020]-[0021], [0050], [0171]-[0177], the heading immediately preceding paragraph [0171], Claims 45-57 and 66, and FIG. 17.
Number | Date | Country | |
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61477108 | Apr 2011 | US |