MX2008006554A - Lift actuator - Google Patents

Abstract

An improved electric lift actuator for use on a variety of lift systems, includes various improvements that enable a universal design with interchangeable parts across several load ranges. The universal design further enables additional features and functionality (e.g., improved load cell location, improved operator sensing and electrical signal/air channel in operator pendant, improved reliability and reduced cost for operator force sensing, etc.) In addition the universal design is incorporated with a rotational drive assembly wherein the load sensing and wire rope slack sensing, as well as cable limits may be achieved using improved components and techniques - such as non-contact sensors, etc. Many of the improvements described are believed to reduce cost and improve the performance and expand the capacity and reliability of the actuator in addition to making the actuator a common design across several applications and load ranges.

Description

ELEVATION ACTUATOR Field of the Invention The present invention is directed to an improved lifting actuator, and more specifically to an electric lifting actuator for use in a variety of lifting systems, wherein the actuator includes several improvements that reduce the cost and improve the operation (eg, total maximum capacity increased) and the reliability of the actuator in addition to the manufacture of the actuator, the end effector and the components with common designs through various applications and / or loading intervals. BACKGROUND OF THE INVENTION The use of electric lifting actuators is well known in the material handling industry. Electric hoists are particularly useful, and have been applied in various ways to provide different lifting capabilities for personal lifting devices for lifting and transporting loads. Examples of such devices include Gorbel G-Force ™ and Easy Arm ™ systems. More specifically, the present invention is directed to a class of material handling devices called rockers or elevations, which include a motorized lifting pulley having a cable or line that, with a fixed end to the pulley, is wound around the pulley while rotating, and a final effector or operator control in the form of a hanging electromechanical device or the like that can be attached to another end of the cable (free or not fixed). The end effector has components that connect with the load that is elevated, and the rotation of the pulley rolls up or unrolls the line and causes the end effector to raise or lower the load connected to it. In one mode of operation, the actuator applies the torque to the pulley and generates an ascending line force that exactly equals the gravity force of the object that is raised so that the tension in the line essentially balances the weight of the object. Therefore, the only force that the operator must impose to maneuver the object is the acceleration force of the object. In a class of systems, these devices measure human force or movement and, based on this measurement, vary the speed or force applied by the actuator (pneumatic drive or electric drive). An example of such a device is U.S. Patent No. 4,917,360 to Yasuhiro Kojima, U.S. Patent No. 6,622,990 to Kazerooni, and U.S. Patent No. 6,386,513 to Kazerooni. U.S. Patent No. 6,622,990 entitled "HUMAN POWER AMPLIFIER FOR LIFTING LOAD WITH SLACK PREVENTION APPARATUS ", by Kazerooni., Published on September 23, 2003. With this and similar devices, when the human pushes up on the end effector the pulley rotates and raises the load; The human pushes down on the end effector, the pulley rotates in the opposite direction and lowers the load.A similar operation can be observed in the systems that have what is frequently referred to as a "floating mode" where the application of an operator of the upward or downward force to the load by itself results in the movement of load assisted by the system. Description of the Invention The embodiments described herein are designed to provide various improvements to the electric actuator and to the lifting systems In a general sense, the improved design facilitates the standardization of the actuator design to network the number of required components to manufacture and to serve a wide range of lifting systems, whereby few components are switched between several actuators having different lift load ranges. The redesign also modifies several components in the actuator and in the associated user controls (for example, hanging operator control) to improve the reliability, usability and expandability of the controls. It is described in the embodiments of the present lifting actuator, which comprises: a controller; an electric motor to impute the actuator, the motor operates in response to the control signals of the controller, to make a drum on which a wire rope is located, with a fixed end to the drum, is rolled and unrolled; and an operator interface, located near the free end of the wire rope, the operator interface includes a detachable lifting tool, wherein the operator interface provides signals from the operator to the controller to control the operation of the actuator. Also described are: a structure for rotatingly suspending the motor, a mechanical reducer and a drum thereof; a load sensor attached to the structure to detect the load as a result of the rotation of the motor / net assembly / drum / net when a load is applied to the unwound end of the wire rope; a low voltage sensor to detect the orientation angle of the motor / reducer / drum assembly and to determine when a low voltage condition is present in response to a low voltage sensor signal, mounted on the rotary assembly in a; a universal motor and network assembly that can be adjusted to one of a plurality of additional network drivers to alter the capacity range of the actuator; a planetary network, wherein the mechanical configuration of the uctor network is substantially included within the wire rope pulley drum; a cable guide to control the position and maintain the wound integrity (tightness) of the cable while it is wound on or unrolled from the drum; usable cable limit sensors, actuated in response to the extreme axial movement of the cable guide while the cable is wound and unwound; and the cable guide includes a plurality of cords for coupling to the grooves in the drum to provide the lateral force to move the guide as well as the cable. The grooves also serve as a location for the wire rope in the drum, thus providing an exact placement of a single layer of wire rope in the drum.

They are further described in relation to several alternative embodiments of the operator interface: a handle; a rotary coupler to join the interface to the wire rope, but allows it to rotate 360 degrees in relation to the rope by means of a slip ring similar to thin layers suitable for providing electrical contacts and a channel or air duct at the same; a winding sensor for detecting a vertical component of a displacement applied to the handle, wherein the handle engages a core that passes inside the coil by a flexible filament; a liquid crystal display on the interface to display the status information to an operator; a non-contact optical proximity sensor to detect the presence of an operator's hand on the handle during operation; and a bayonet or bolt type quick disconnect attachment so that the tools are attached to the bottom of the interface.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic illustration of an exemplary embodiment of the present invention; Figures 2-4 are illustrative representations of various alternative embodiments (eg, different load capacities) of an actuator drive assembly according to several common design aspects of the embodiments described; Figures 5 and 6 are exemplary representations of a planetary gear assembly illustrating convenient alternative modes for different load capacities; Figures 7A-C and 8-11 are illustrative representations of an improved load sensing system used as an aspect of the embodiments described, wherein a load cell is used to detect the load applied via the rotation of the drive assembly in relation to the load. to the suspended structure; Figures 12A and 12B are alternative embodiments of the operator interface devices used in accordance with the disclosed invention; Figures 13A-13C are illustrative examples of the components and operation (Figures 13A, 13B) of the operator interface device shown in Figure 12A; Figure 14 is an illustration of a slip ring assembly convenient for conducting electrical signals as well as air (fluid) to the operator interface device of Figure 12A; Figures 15A-B and 16 are detailed representations of alternative embodiments of the operator interface devices of Figures 12A-B; Figures 1 7-1 9 are detailed illustrations representing a mode of the present invention directed to the detection of the potential of a low voltage condition of the wire rope according to an aspect of the present invention; Figures 20-21 represent an alternative mode of low voltage detection that can be used according to the described invention; Figures 22-24 are detailed representations of the improved characteristics of cable management and drum coverage, including low voltage prevention, in accordance with one aspect of the present invention; Figures 25 and 26 illustrate one embodiment wherein the cable entry components of Figures 22-23 are used to detect the limits of cable travel; and Figures 27-29 illustrate an alternate modality to detect the limits of travel of the cable using the inputs of Figures 22 and 23. Best Way to Realize the Invention The following is a description intended to provide information related to each one of several improvements even electric lift actuator and has been described with respect to its modalities. However, it will be appreciated that several of the improvements can be used or implemented in other types of actuators or load handling equipment in general and are not limited specifically to an electric actuator or lifting system as described herein. The drawings are not presented to scale and some characteristics of them can be shown at an enlarged ratio for better clarity. Referring to figure 1, a schematic representation of one embodiment of the invention is shown, showing a winding or driving pulley and associated mechanical assemblies in an exemplary human power amplifier 110. In the upper part of the device, a winding pulley 111, driven by a actuator 112, is attached directly to a roof, wall, or tall crane, arm or similar structure (not shown). The surrounding pulley 111 is a line or cable 113 having one end attached to the pulley and the free opposite end for attachment to a load. The cable 113, also referred to as a wire rope, is capable of raising or lowering a load 125 when the pulley 111 rotates. Line 113 can be any type of line, wire, cable, belt, rope, wire line, cord, cord, chain or other member that can be wound around a pulley or drum and can provide a lifting force to a load . It is attached to line 113 of an end effector 114, which includes a human interface subsystem (e.g., a handle or pendant 116) and a load interface subsystem 117, which in this embodiment includes a removable J-shaped hook. , but may also include a pair of suction cups or similar cargo securing means. Not shown, but included in one embodiment of the suction cup, is an air hose to supply vacuum to the suction cups. In one embodiment, the actuator 112 is an electric motor with a transmission, but alternatively it can be an electrically driven motor without a transmission. In addition, the actuator 112 can also be driven using other types of energy including pneumatic, hydraulic and other alternatives. As used herein, the transmissions are mechanical devices such as gears, pulleys and the like that increase or decrease the tension force in the line. The pulley 111 can be replaced by a drum or crank or any mechanism that can convert the rotary or angular movement provided by the actuator 112 to a vertical movement that raises and lowers the line 113. Although in this mode the actuator 112 directly drives the pulley of winding 111, the actuator 112 can be mounted in another location and transfer the energy to the winding pulley 111 via another transmission system such as a chain and pinion assembly. The actuator 112 preferably operates in response to an electronic controller 150 that receives signals from the end effector 114 on a signal cable (not shown), wiring harness or similar signal transmission means. It will be appreciated that there are several ways to transmit the electrical signals, and the transmission means can be an alternative signal transmission means including wireless transmission (eg, RF, optical, etc.). One embodiment of the present invention contemplates a common winding rope 148 in which the winding control wiring and / or air duct is molded as necessary to allow such a rope to retain its shape (eg, circularly wound rope 113). ). One or more sensors can be used, in addition to operator controls to provide functional and / or safety features to the system. For example, the controller 150 may receive information from the sensors (e.g., switches) such as a low voltage sensor 160, a cable travel limit sensor 170, a load cell 1170 (e.g., FIGS. , 11) or an operator presence sensor 1710 (FIG. 17). In one embodiment, the controller 150 contains three primary components: 1. A control circuit that includes an analog circuit, a digital circuit, and / or a computer with input-output capability and a standard peripheral. The function of the control circuit is to process the information received from several inputs and generate the command signals for the control of the actuator (via the power amplifier). 2. A power amplifier that sends power to the actuator in response to a command from the control circuit (e.g., a load cell that indicates the force caused by the load). In general, the power amplifier receives electrical power from a power source and supplies the appropriate amount of power to the actuator. The amount of electrical energy (current and / or voltage) supplied by the power amplifier to the actuator 112 is determined by the command signal generated within the computer and / or control circuit. It will be appreciated that various motor-impulse-amplifier configurations can be used, based on the lifting requirements. In one embodiment, the preferred motor-drive system is ACOPOS Servo Drive produced by B &; R Automation under manufacturer's part number 8V1016.50-2. One embodiment also contemplates the addition of other modules used in combination with this drive, such as a CPU (for example, ACOPOS 8AC140 or 8AC141), module I / O (for example, 8AC130.60-1) and similar components to finalize the controls. 3. A logic circuit composed of electromechanical or solid state regulators, switches and sensors, to start and stop the system in response to a sequence of possible events. For example, regulators are used to start and stop the operation of the entire system using two buttons installed in the controller or in the end effector. Regulators also attach a friction brake (not shown) in the event of a power failure or when the operator leaves the system. Generally depending on the application, several architectures and detailed designs are possible for the logic circuit. In one embodiment, the logic circuit may be similar to that used in the gravity force lift and is sold by Gorbel, Inc. As described in detail in US Patent No. 6,622,990, the human interface subsystem 114 can be designed to be held by a human hand and measure applied human force, that is, the force applied by the human operator against the human interface subsystem 114. In one embodiment, applied human force is detected by a load cell 1170 (eg, figures 10, 11) or by the similar output generation sensor as described in more detail below, wherein the level of signal output generated by the load sensor is a function of the load applied to the effector end by the human and is added to or removed from the load that is supported. The load interface subsystem 117, which will also be described below, is a detachable or adaptive mechanism designed to interact with a load, and contains several adaptable fastening, fastening or other load-grabbing devices. The design of the load interface subsystem depends on the geometry of the load and other factors related to the lifting operation. In addition to the hook 117, other loading interfaces could include suction cups as well as various hooks, clamps and grippers and similar means that connect to the load interface subsystems. For lifting heavy objects, the load interface subsystem may comprise multiple loading interfaces (i.e., hooks, clamps, grippers, suction cups, and / or multiple combinations thereof). With the description of the components of a lifting system, attention will now be put again to various aspects of the present invention. One aspect is referred to as a "structural block design" for the actuator system. The structural block design is generally presented in Figures 2 to 6, where several aspects of the design are established. In creating the structural block design, various components of a lifting system (eg, actuator, handle, gear reducers, etc.) are designed such that the components can be used in a plurality of models or types of elevators ( Easy Arm ™, G-Force ™, etc.). Recognizing that in some characteristic situations such as the lifting capacity that must be configured as necessary, the designs were also analyzed to determine that, if any, the components can be used commonly or universally and that they should be selected as necessary. An example is presented in Figures 2-4. In Fig. 2, for example, the motor 210 and an associated reducer 212 are used, and either or both of these components can be used through various actuators having a range of lifting capacities - for example as presented in Figs. and 4. In a lower capacity unit, an integral drum pulley adapter 216a is attached to the motor / reducer assembly. No additional reduction is used. Referring also to Figures 3 and 4, joining instead of the integral drum pulley adapter 216a is an alternative (Figure 3) or an additional speed reduction means (Figure 4) in the form of reducers 216b and 216c, respectively. The additional reducer 216b is designed / dimensioned (for example, internal assembly of planetary gear 218; Fig. 5) to allow the motor 210 to raise an increased load weight. Referring also to Figure 4, a reducer 216c is attached, wherein the additional reducer used is designed / dimensioned to allow the engine 210 to lift loads within another range. In this way, the universal motor can be used through a plurality of actuator loading intervals, whereby the primary component that is added / changed is the additional reducer. As will be appreciated, the embodiments shown utilize a configuration of the stacked structural block gear reduction, wherein the reducer assemblies 216a, 216b and 216c are different in load carrying capacity because the internal planetary gear 218 has ratios that They vary between different models. For a lower lifting capacity, a simple adapter is used instead of an additional reduction. For a heavier capacity, a second reducer or "stacked" reducer is added, and the design of the second reducer is selected according to the desired capacity for the lifting actuator. Also, while using different or alternative reducer (and planetary) mounts, the controller is similarly altered or reprogrammed to appropriately adjust the motor drive characteristics to adapt the alternative capabilities of reduction of mounts and direction of motor rotation . It will be appreciated that the drive designs of the actuator shown in Figures 2-6 allow mass production, even on demand, of the drive unit for a specific application, and that they further facilitate efficient service as well as a more cost-effective design at volumes Lower. As also presented in Figures 5 and 6, various embodiments include the reduction gear inside the drum pulley. 111. The planetary gear reducers 218 are located within the wire rope drum pulley 111, which saves space, weight and cost in contrast to conventional systems that place the reducer in line with the drum. They also improve the balance of the actuator while it is suspended from an external structure such as a girder beam. With the uctor network inside the drum, the unit is compact, and the weight of the unit is slightly reduced due to less drum material. The cost of the reducer can also be reduced by producing the drum from a conventional pipeline against a solid block of material that is mechanically treated. For example, in one embodiment, the drum can be manufactured from an aluminum alloy, or alternatively from a nylon composite or similar polymer composite that provides convenient mechanical characteristics. As will be appreciated by those skilled in the art of lifting systems, an important aspect of various embodiments described herein is the reduction of the weight of such systems. In order to practically increase the lifting capacity of an elevation, the impact of the increased capacity of the lifting support structure (eg supports, cantilever arms, trolleys, etc.) must also be considered. Thus, while it may be possible to provide the increased lifting capacity, it may be necessary to decrease the weight of the lifting equipment by itself to obtain an advantage of the increased capacity. For example, if the lifting capacity can be increased to 25 kg, to use the improved lift, it is necessary to ensure that the supporting structure can handle the increased capacity, or the total weight supported by the structure should be decreased. It is the last point that is treated by several aspects of the modalities described in the present. The reduction of the weight of the actuator allows the greater use of the capacity of the support structure for the load weight. On the other hand, the decreased weight of the actuator makes it easier to move the lift around (less effort from the operator (manual) or smaller motors (truck)). After returning to FIGS. 7A-C and 8 to 10, other components of a mode of the actuator 112 are shown in which the load supported by the actuator can be detected directly using a compressive load cell. The actuator 112 further includes an arm 710 or similar structure and a sleeve 712 which are operatively connected to each other and to the drum pulley 111. In one embodiment the arm 710 is attached to the sleeve to provide surfaces for operating the load sensing characteristics and low voltage sensing described herein, and to provide for stopping the positive turn during a low voltage condition. As illustrated, for example in Figure 9, the sleeve 712 further supports the further reduction and the drum pulley 111 having a wire rope or cable 930 wound thereto, with one end attached to the drum pulley 111. In In one embodiment, the actuator 112 also utilizes a very high molecular weight polymer wear (UHMW) ring 999 (the ring-shaped opening in the bottom of the actuator through which the wire rope 930 passes). The use of the wear ring results in a higher durability when compared to conventional actuators. In another embodiment, it will be appreciated that alternative designs of the actuator may alter the manner in which the supports (e.g. arm 710) are connected to drive components of the actuator and / or to the covers and housings as depicted in Figure 8. For example, the design shown in Figure 10 uses a slightly different arm and a related support structure in the actuator. The actuator 112 further includes the centerpiece 840, whereby the drum or further reduction of the drive assembly of the actuator is supported thereon by supports 844, but where the drive assembly, which includes a drum pulley 111, the sleeve 712, the winding rope support and the arm 710, is capable of rotating movement, in spite of the contraction, in relation to the central part as it will be appreciated as required to use the load cell to detect the load on the actuator (rotation of drive components of the actuator). The actuator 112 further includes, as depicted in FIG. 8, a support member 850 connected to the center piece 840, for suspending the actuator from its support structure - such as a cart or arm (not shown) - as well as a housing 860 (shown as a cut in Figure 8) to include the operational components of the actuator. One mode of a convenient housing for the actuator shown is found, for example, in the US Patent Application of American Design 29 / 256,812. It will be appreciated that in addition to the molded covers, it may be possible to further reduce the cost of the actuator 112 using the less expensive covers. For example, coverings or cover components made of sheet metal formed or shapes of raw material or plastics, can result in significant reductions. On the other hand, the current sheet forming techniques allow the formation of shapes of some complex shapes similar to those represented partially in Figure 8 and in the design application identified above. In a modality that uses the formed metal covers, the entrances or openings remain the same, but the rest of the cover can be altered in design to adapt the alternative materials and training techniques. In addition to the improved universal drive design, electronic drive and control devices, for example ACOPOS Servo Driver, produced by B &; R Automation under manufacturer part number 8V1016.50-2, further provides the improved input-output capability and also enables design improvements characterized as ready-to-use components. The ready-to-use features of various components - actuators, handles, etc. they allow the lift controller (not shown) to recognize which type of handle has been attached to the lift, and adjust any control or programmatic I / O so that the detected component works correctly with the handle. The ready-to-use design overcomes the difficulties observed in conventional lifting systems when mechanical and electrical alterations must be made when changing from one type of handle or type of actuator to another, thereby avoiding slow and costly modifications, and allowing the possibility of alterations and technical updates. Another feature allowed by an improved controller associated with the actuator 112 is the remote diagnostic capability. In a remote diagnostic mode, the controller includes a communication circuit such that the information can be exchanged between the driver controller and another computing device (e.g., work station, crane controller, etc.) via a network connection (LAN / WAN / Internet). According to one aspect of the present invention, the remote diagnostic capability allows remote configuration as well as the location of faults of a lifting device such as an actuator. For example, when a customer in Detroit has a problem with a particular driver, it would be possible to access the driver of that driver (with some IP network address or a similar identifier) from a remote location, or at least receive data from the driver at the remote location, via Ethernet, a modem and / or the Internet, and verify and change the settings as well as address any operating problems. Remote diagnosis and serviceability are believed to significantly reduce the cost of maintaining and servicing the systems since it is currently not possible to achieve lift service or address operational problems without commonly having a technical trip to the job site or have to send the actuator again for the service. This will greatly reduce the lost time of the unit. It is anticipated that the controller will use a standard communication protocol such as CANbus as well as other well known digital communication technologies and protocols, and at least will be able to execute and register the rudimentary diagnostic functionality including the transmission of registration information and operation registration. , among others. As described above, the design of the actuator 112 is such that the impeller assembly can rotate relative to the center piece 840. Such a design facilitates the use of a compressive load cell 1170 as more fully depicted in FIGS. 10 and 11. In a conventional load-balancing elevation, the load cell is commonly included within or associated with the final control pendant or effector, where the load is applied or attached. Such systems, however, require the use of more complex load sensors (strain and compression detection), and in addition require the signals to be returned to the driver controller in a timely and accurate manner to control the load. They also require a more complex and costly union load cell design to provide reasonable safety if the load cell based on the pendant fails. Mounting the compressive load cell 1170 on the drum centerpiece 840 allows the detection of a rotational force applied to the arm 710, the rotational force being created by a load suspended at the free end of the cable 930. Place the load cell on the actuator housing, adjacent to the control systems, also provides a shorter transmission path and improved signal quality received by the controller 150 (FIG. 1). Carrying the load cell out of the load path also improves the safety of the lifting devices because if the load cell fails, the load will not necessarily fall. Therefore, the design shown in FIGS. 10 and 11 allows detection of the load in a location adjacent to the drive assembly, and without the load cell attaching to the lift system. In the impeller assembly (eg, drum pulley 111, reduction gearbox 212, additional adapter / reduction (216a, boc) and motor 210) the components of the assembly rotate axially in the rolling supports 844. A drive surface 1174 is associated with the arm 710, and the arm 710 in turn is mounted to the sleeve 712 which is fixed to one face of the gear reducer assembly 212. The compression style load cell 1170 is rigidly attached to the center piece 840 of the elevator, and is located to detect the force applied by the drive surface 1174. While the operator manually applies the force to a suspended load, the drive mechanism rotates in the direction of the arrow 1178 and changes the force applied to the cell of cargo. The heavier the force, the greater the compression detected by the load cell, and vise versa. As depicted in Figure 11, the force sensor may include a small bias spring 1150 at the shaft end of the load cell 1145 that "balances" the dead weight of the cable and / or pendant away from the load cell, and as described below it is also important for low voltage detection. In an alternative embodiment, the present invention contemplates the derivation of the load applied to the cable, or to the suspended suspension thereof, monitoring the current of the motor through the controller and the associated software. A further improvement of the lifting actuator may include the signal conditioning of the load cell. In addition to processing the signal of the load cell to make the signal useful for the present application, it is further contemplated that a single conditioning circuit can be used for the signal of the load cell, where up to three or more load cells they can be used (for example, three different charging intervals) and a common or universal conditioning circuit can be used. Again, the alternative to the universal method of signal conditioning would again have separate circuits to handle the different load cells and the output signals they generate in response to the load suspended from or applied to the cable. After referring to FIGS. 12A-B and 13A-C and 14, an improved electromechanical mechanism for determining the operator's intent on the control pendant 116 is presented in FIG. 12A. As an alternative, a pendant such as that shown in FIG. Figure 12B can be used to control the present invention. The aspects of such a pendant are described in the North American Application Published 2005 / 0207872A1, filed on March 21, 2005 by M. Taylor et al. (USSN 11 / 085,764). Both devices may use various signaling devices (visual, audible, vibratory), and may include a liquid crystal display or similar means 3610 to indicate the current operating status or other information for the operator. In the embodiment of Fig. 12A, as illustrated further in Figs. 13A-C, the detection mechanism uses a coil arrangement 131 Ó, as compared to the traditional linear variable displacement transducer (LVDT). ). In mode, the coil is used to detect a base, consisting of a metal bar or a similar component, therein and to detect the operator's intent (raising or lowering). A further modification of the embodiment shown is the use of the flexible filament 1320 to attach the center to the displacement portion of the handle, operator handle 1716. The use of an adaptive coil array is believed to be a less expensive alternative to commercially available LVDT. On the other hand, the use of a flexible filament (for example, nylon or similar plastic or flexible material) to connect the center with the handle prevents cutting the center under use situations where the handle is subjected to excessive torsional force or turns under load, as well as preventing friction in the system if it is not perfectly aligned. It is also possible to use LVDT or magnetic detection devices to determine the descending or ascending operator inputs illustrated by Figures 13A and 13B, respectively. The embodiments shown in Figures 13A and B illustrate the respective movement of the handle (a large lower arrow), in relation to the coil. Alternative means for detecting the entry of the operator via the handle are described, for example, in the US Patent No. 6,386,513 of Kazerooni entitled "HUMAN POWER AMPLIFIER FOR LIFTING LOAD INCLUDING APPARATUS FOR PREVENTING SLACK IN LIFTING CABLE", published on May 14 of 2002, and WO2005092054, entitled "ELECTRONIC LIFT INTERFACE USING LINEAR VARIABLE DIFFERENTIAL TRANSDUCERS", published on October 16, 2005. In one embodiment, the control pendant may be similar to that presented, for example, in the American Design Application Co -pending 29 / 256,811. Another aspect of the improved control pendant is presented in Figure 14, where a slip ring has been designed to allow accurate and reliable transmission of the coil sensor output 1320 as well as 1610 power switch signals or related electrical signals present in the electrical connector 1624, up to the actuator 112 via the control coil winding wire which can be connected to the connector 1628. The design uses a slidable ring assembly of thin layers type 1620, in the control handle, to allow the 360 degree continuous rotation, regardless of the wire rope and the control coil cord cable. The adaptive slide ring passes the electrical signals from the swivel handle to the control coil cord wire. The adaptive sliding ring assembly is also specifically designed to allow air (pneumatic and / or vacuum) or other pressurized fluid to pass through its center via a rotary inlet 1640. This allows the operator to apply air power to the tools endings, and they still rotate 360 degrees continuously. It will be appreciated that the contacts of the slip ring are known, but it is believed that the design of an integrated electric and air pipe that facilitates unrestricted turning is an improved aspect of the pending design not previously used in hoisting technology. The air conduit preferably allows the transmission of a presumed fluid (eg, pneumatic, vacuum, hydraulic) to a tool associated with the pendant. The improved design also controls or reduces the "main space" in the pendant at a reasonable cost. Referring to Figs. 1 3A-C 1, a further aspect of the pendulum design is illustrated, wherein the presence of the operator (hand on the grip) is detected using an inductive, or preferably a reflective photoelectric sensor 1710. In an embodiment , sensor 1 710 is a tubular photoelectric sensor (metal, 12mm, PN P) and a light indicator on the sensor switches when it detects reflected light that indicates that an operator's hand is present. It will be appreciated that several alternative types of switches of the operator's state are known, however, many of these require a firm fastener or prolonged fastening of the operator fastener 1 716, which can lead to operator fatigue as well as confusion. . The design presented in Figures 13A-C illustrates a photoelectric sensor as a means for detecting the hand of the elevator operator when coupled with the control handle, without requiring any interpretation by the user, avoiding the tendency for users to use the switch as a means to turn the unit on and off. When coupled, the sensor sends a signal back to the controller which then allows the forklift to be operated in an up and down direction. Alternative sensors or switches for detecting the operator's hand include a mechanical style roller switch similar to known designs, a tactile sensor, an inductive optical sensor, and a membrane sensor. As will be appreciated, the location of the sensor within the body of the pendant is preferable to avoid damage or forcing, however, the pendant handle must then include an opening 1730 through which the presence of the operator's hand can be detected. In several applications of an actuator and a control pendant, it is sometimes necessary to change or alter the loading interface in the field. For example, instead of a hook, the load may need to be raised using a threaded connector or the like. Referring to FIGS. 15A-B, the design depicted therein contemplates a quick disconnect adapter on the underside of the end pendant 116, where an operator can quickly change the end tool by sliding a collar 1810 that contracts the securing bolts. 1820, and allow the tool mounting rod 1830 to be released. Then another tool can be quickly and easily joined by sliding its mounting rod up into the mounting hole, contracting the securing bolts as it passes and then securely securing it. in place when the bolts engage the 1834 shank grooves. No attachments are required to change the tools. It will be appreciated by experts in lifting systems that the known threaded coupling technique can be used, or that alternatives requiring the operator to physically remove a 1910 bolt (FIG. 16) to release the tools can be included within the scope of various modalities described herein. After referring to Figs. 17-21, aspects of one embodiment of the present invention are presented which incorporate an improved low-voltage detection capability of the cable. Particularly, as referred to above in relation to improved load detection, the mode of the actuator shown in Figures 17-21, detects the low tension of the cable using the rotation of the drum, as well as the reduction of the gear and the motor (assembly impeller) (however in the opposite rotating direction). In this design, the main drive assembly (drum pulley 111, gearbox (not shown) and motor 210) rotates axially on the rolling brackets 844. A drive plate or arm 710 is mounted to a sleeve that was fixed to the side of the assembly of the primary gearbox, and also rotates together with the drive assembly. When the operator removes all the weight, except the control handle and any applicable tool of the 930 wire rope, low tension is induced. When the low voltage is indicated, the impeller assembly rotates to the left (arrow 2020), aided by the use of a compression spring 150 (fig. 1 1). The supply of the spring force adjustment will be required to facilitate variations of the adaptive applied tools. The compression spring 1 1 50 is mounted between the load cell 1 1 70 and the surface 1 1 74 of the impu tion plate and is coaxial in a bolt or load shaft installed in the load cell. When the drive assembly rotates under no-load or low-voltage conditions, a microswitch 2030 mounted to the main support structure of the forklift detects the presence of the drive plate (Figure 24) by contacting the drive plate. in 2034. When the micro-switch is activated, sends a signal to the controller (not shown) whereby the software only allows the forklift to move in the upward direction. For the safety of the user, once the low voltage is detected, the controller will not allow the forklift to supply any additional wire rope in the downward direction. As will be appreciated, the use of the rotary impeller assembly for low-voltage load and detection purposes allows the load sensing device to "consider" any torsional force load and thereby be able to detect all the load that the wire rope, and the air hose of the coil rope would consider. That is, the load sensor will have a compressive load applied to it, which is the direct result of the weight of the load. Also, while the load is raised or lowered, the cumulative load remains equal, even the relative portions of the load carried by the coil cord, air hose, and wire rope may be several. Since all the wire rope and the coil rope assembly are supported by the rotary impeller assembly, the load cell always detects its full weight, so variations in the loading height do not affect the load sensing or the operation in floating mode. Any potentially damaging affection, for example in floating mode, of the tributary force and the weight of the coil rope is denied by this assembly configuration. In the alternative mode, it may be possible to detect low voltage using the software to monitor the motor current to determine a low voltage condition. Although it is possible, there remains a concern that such a method may prove unreliable. It is also contemplated that instead of the mechanical contact switch (roller switch or the like), a non-contact proximity sensor 2040 can be used to detect the rotation of the plate 710. Such a mode is presented, for example, in the Figures 20 and 21, wherein the sensor 2040 is used to detect the rotation of the plate 710 to determine the low voltage condition. The attention is now again directed to several additional aspects of the improved actuator 112, which includes a wire rope guide arrangement and drum pulley (cable). Referring to Figures 22-29, the improved design uses a two-piece assembly 2610 (2610a, 2610b, etc.) whose clamps or mounts around the wire rope or other lifting means, and slides from back to front in the rails are provided by the drum cover 998 (FIG. 25). The sliding movement of the assembly 2610 is induced by the threads 2620 contained in a mounting half, 2610a which operate in the open grooves 2622 of the wire rope drum pulley 111. The assembly 2610, when mounted on the rope 930 , provides a displacement inlet or an opening through which the wire rope 930 exits the drum as presented in Figure 24. Such a device, in addition to the function of protecting the cable and the drum, also prevents any lateral wear of the cable. The drum grooves and keeps the wire rope firmly contracted in the drum pulley, thus avoiding the creation of unwanted low tension. That is, the lateral forces of the wire rope are taken by the inlet and the wire is not prone to wear of the drum surface because the alignment at the entrance of the drum grooves is almost perfect in all cases. The large support section of the threads on door 2610a provides great lateral force, and distributes this force over many grooves in the drum, since any lateral force is only likely to occur when the wire rope is almost completely outward, and the coupling of the entrance and of the drum grooves is in its maximum number of threads at the entrance. Having this half of the entrance permanently attached to the drum allows to maintain the record when replacing the wire rope. Another characteristic of this modality is presented specifically in figures 24-29, where the slip input 2610 allows the input itself to be used as an indicator of the upper and lower travel limits of the cable. As presented by the broken arrows in Figures 25 to 28, the back-and-forth slides of the inlet driven by the spin of the drum pulley while the wire rope is rolled and unwound from it. The addition of limit switches 2510 presented in FIGS. 25 and 26, for example, allows input movement 2610, transmitted through a bar 2520, or similar member, to be used to identify travel limits. As described below, the design allows adjustment of the limit switches not to be affected by changes to the system, replacement of the wire rope, etc. In fact, only the inlet side closest to the secured end of the wire rope, 2610b, has to be removed to change the rope, although the limit switch for the maximum of outside wire rope has to be diverted for the operation of recharge. It will be appreciated that a conventional additional ball screw drive mechanism can be used to move the wire rope drum pulley back and forth, or that a mechanism can be used that operatively couples or drives an idle pulley via a only groove in the drum pulley as is the case in many current Gorbel actuators. Referring specifically to FIGS. 25 and 26, a limit detection system using the micro-switches 2510 is presented as briefly noted above. A mode is represented consisting of a bar 2520 moving forward and backward as a result of the movement of the threaded inlet (inlet 2610a). Two adjustable cylinders 2530 which can be moved to the desired location and then fixed in place, for example, with a fixing nut or similar means, are contained in the bar. These cylinders come into contact with the micro-switches 2510 when the input is at its upper and lower limit location.

While the wire rope guide or input mechanism slides back and forth, and the cylinders actuate the 2510 sensor, a signal is sent to the controls to activate the upper or lower travel limit of the unit. When a travel limit is triggered, the software will then only allow the forklift to operate in the opposite direction of the driven target (ie if the upper limit is operated, the forklift will only operate in a downward direction). The limits can be adjusted by moving the cylinders. Although the micro-switch mechanism is created to be the preferred one, by virtue of its simplicity, it should be appreciated that alternative detection systems can be used such as a sensor without magnetic contact can eliminate the contact force required to drive the sensor and thus eliminate component wear. For example, as presented in Figures 27-29, a magnetic sensor 3410 can be mounted immovably to the fixed wire rope drum cover 998. Together with two magnetic lenses 3420 and 3422, mounted to the wire guide mechanism 2610 wire rope, the sensor is operatively connected to the drum pulley. The objectives of sensor 3420, 3422 consist of a magnet facing north and south, and are convenient to similarly provide travel limit signals as discussed above. Other options for travel limit sensors include optical or other non-contact techniques, as well as conventional sensors and mechanical switches. Various features and functions described herein are preferably implemented using a controller or similar processing system convenient to operate under the control of the programmatic code. One embodiment contemplates controller 150 (Figure 1) having the pre-loaded functionality for a wide range of features and functions, wherein one or more features and functions are allowed only as a result of an instruction or a subsequent signal to the controller. In this way, the universal nature of the actuator 112 (including the controller 150) can be further expanded. The process or operation of pre-loading all the functionality of the software and then only enabling what the client wants or acquires, is believed to facilitate the anticipated exchange capacity of components according to an aspect of the present invention. Such a process would also allow the enhanced functionality to be enabled after an actuator has been implemented in the field - for example according to a customer's needs or to application changes, the actuator may have additional features or functions enabled. It is also possible that in the event that a ready-to-use component was subsequently attached to the actuator, the actuator would not only recognize the component as described above, but could alter its programmatic controls to facilitate the use of the newly installed component. It is believed that these improvements will allow quick adaptation of the actuators to the customer's requirements, while reducing or eliminating the need for on-demand software changes and continuous support. Returning to Figure 12A, a further improvement to the end effector or operator control pendant 116 is presented. In the presented embodiment, the pendant 116 fits a liquid crystal display 3610 or similar display technology to provide the ability to communicate. more easily available information to a user. The information displayed on the LCD may include basic information such as the status of the system (ie: ready-to-use system), advanced or optional information such as the weight of the load, system usage and service information (ie: number of completed cycles and system service indicators) as well as improved guidance and information when in programming mode such as what feature is currently programmed (ie: virtual limits). Using the LCD it is possible to provide more and different information to the installer, the user and even the maintenance personnel. Again, as an alternative to the LCD screen, conventional light emitting diodes and the like can be used to communicate the status information of the actuator to an operator.

In still an alternative additional embodiment, for example as presented in FIG. 25, the wire rope is firmly attached at all times between the drum pulley 111, the drum cover 998 and the displacement inlets 2610, so as not to space is available to allow a loop with little tension in the wire rope, anywhere in the actuator. Thus even a compression load applied to the wire rope will not allow little stress to form or accumulate inside the actuator 112, while the end is secured so that it does not slip. In practice, there is probably a small portion of wire rope that remains free as it enters the actuator and before leaving the entrance, while it is unwound from the pulley and before leaving the housing of the actuator or drum. It will be further appreciated that the use of a wire rope of a larger diameter (eg, a 0.25 inch diameter rope helps in this respect, since it has more column strength than a smaller diameter rope), reduce the ability of the rope to form a loop (low tension) when it is free at a short distance. Those skilled in the art will appreciate that the diameter of the rope is a function of the load capacity of the actuator and that it may be smaller or larger than 0.025 inches.

With the additional functionality provided in the current controls, the system can also perform one or more hardware identification processes during power up, and can compare the resulting information against the specified functionality. Using such information, the system can produce a warning message that can be displayed if problems such as inoperable or failing subsystems are encountered, for example, a failing handle or the detection of operator presence that is inoperable.

Again due to the universal design envisaged for several embodiments characterized herein, the present invention contemplates the use of a real-time port I / O assignment through the updating of a flexible configuration, instead of each time modifying the program of the source code. Such a system would allow the user to have access to the pre-programmed functionality within the controls to more quickly configure the unit's I / O for its specific application. It is contemplated that a software interface may be provided to further simplify the ease and flexibility of the application configuration.

It will be appreciated that various aspects of the features and functions described above and others, or alternatives thereof, may be desirably combined in many other and different systems or applications. Also that various alternatives, modifications, variations or improvements currently unforeseen or unexpected in the present may be carried out subsequently by those skilled in the art, which also have the purpose of being comprised by the following claims.

Claims (20)

1. A lifting system, comprising: a controller; an actuator that is responsive to the controller, the actuator includes a pulley with a cable attached thereto, the cable is wound on it in a single layer to support a load on a free end of the cable, where the pulley is driven by a motor and associated transmission, the motor is suitable for use with at least two load ranges, and the transmission has a structural block gear reduction configuration wherein the configuration determines the load lifting capacity of the actuator; and a charging interface, operatively connected to the end of the cable, the charging interface includes user controls and signals generated to be transmitted to the controller, wherein in response to the signals, the controller causes the operation of the actuator to raise and lower the load suspended from the actuator.

2. The lift system according to claim 1, further comprising a planetary gear reducer used as the gear reduction of the transmission. The lifting system according to claim 1, further comprising a compression load sensor, operatively associated with the actuator, wherein the sensor detects a compression load of an actuator element in response to the load on the cable . 4. The lifting system according to claim 3, wherein the actuator element comprises an arm that is associated with the pulley and is associated with the motor and transmission, the arm is moved in a rotational direction in response to the load. 5. The elevation system according to claim 1, further comprising a communication circuit associated with the controller, the communication circuit allows the controller to communicate with a remote computer. The elevation system according to claim 5, wherein the communications with the remote computer include the transmission of remote diagnostic information. The lifting system according to claim 1, wherein the actuator additionally comprises a displacement inlet through which the free end of the cable leaves the pulley. 8. The lifting system according to the claim 7, wherein the displacement input is operatively associated with the pulley to maintain the register when the pulley rotates and the cable is rolled or unwound. The lift system according to claim 8, wherein the inlet traverses the pulley along a longitudinal direction in response to the rotation of the pulley, and further includes at least one convenient travel sensor for detecting the position of the inlet to determine the amount of cable unrolled from the pulley. 10. The lifting system according to the claim 9, wherein at least one travel sensor generates a signal when the lifting system has reached a travel limit. 11. A lifting system, comprising: a controller; an actuator that is responsive to the controller, the actuator includes a pulley with a cable wound thereto to support a load at a free end of the cable, where the pulley is driven by a motor and an associated transmission; a charging interface, operatively connected to the end of the cable, the charging interface includes user controls and generated signals that will be transmitted to the controller, where in response to the signals, the controller causes the operation of the actuator to raise and lower the load suspended from the actuator; and a convenient load cell for detecting only a compressive force in response to the load applied to the cable, the load cell produces a load signal that is transmitted to the controller, wherein the controller causes the operation of the actuator as a function of the charge signal. 12. A lifting system, comprising: a controller; an actuator that is responsive to the controller, the actuator includes a pulley with a cable wound thereto to support a load at a free end of the cable, where the pulley is driven by a motor and an associated transmission; a charging interface, operatively connected to the end of the cable, the charging interface includes user controls and generated signals that will be transmitted to the controller, where in response to the signals, the controller causes the operation of the actuator to raise and lower the load suspended from the actuator, wherein at least one user control generates a signal using a coil to detect the relative movement of a center and where the center is connected to a slidable handle using a flexible component; and a convenient load cell for detecting a compressive force, the load cell produces a load signal that is transmitted to the controller, wherein the controller causes the operation of the actuator as a function of the load signal. The lifting system according to claim 12, further comprising a rotatable slidable ring assembly that provides for the transmission of electrical signals, and a pressurized fluid therethrough. The lifting system according to claim 12, further comprising a convenient reflective photoelectric sensor for detecting the presence of an operator's hand on the handle. 15. The elevation system according to claim 12, further comprising a liquid crystal display in the charging interface, the display represents the information transmitted from the controller. 16. A lifting system, comprising: a controller; an actuator that is responsive to the controller, the actuator includes a pulley with a cable wound thereon to support a load at a free end of the cable, where the pulley is driven by a motor and an associated transmission, wherein the actuator further comprises a sliding guide operatively associated with the pulley to maintain the register when the pulley rotates and the cable is wound or unwound; and a charging interface, operatively connected to the end of the cable, the charging interface includes user controls and generated signals that will be transmitted to the controller, wherein in response to the signals, the controller causes the operation of the actuator to raise and lower the load suspended from the actuator. The lifting system according to claim 16, wherein the guide traverses the pulley along a longitudinal direction in response to the rotation of the pulley, and further includes at least one convenient travel sensor for detecting the position of the guide to indicate the amount of cable unrolled from the pulley. The lifting system according to claim 17, wherein at least one travel sensor generates a signal when the lifting system has reached a travel limit. 19. A lifting actuator, comprising: a controller; an electric motor for driving the actuator, the motor operates in response to the control signals of the controller, to drive a drum on which a wire rope is wound; an operator interface, attached closely to an unwound end of the wire rope, the operator interface includes a removable lifting tool, wherein the operator interface provides signals from the operator to the controller to control the operation of the actuator a structure for rotatingly suspending the entire drive assembly comprising the motor, the reduction and the drum; a load sensor attached to the structure, for sensing the load as a result of the rotation of the entire drive assembly when a load is applied to the unwound end of the wire rope; a low voltage sensor to detect the angle of orientation or rotation of the entire drive assembly, and determine when a low voltage condition is present in response to a low voltage sensor signal; a universal motor and reducer assembly that can be adjusted with one of a plurality of additional reducers to alter the capacity range of the actuator; a planetary reducer, wherein the planetary configuration of the uctor network is substantially included within the rope pulley drum; a cable guide to control the position of the cable that is rolled or unrolled from the drum; a cable limit sensor, operated in response to lateral movement of the cable guide while the cable is rolled or unwound; The cable assembly includes a plurality of threads to engage with the grooves in the drum to provide lateral force to move the cable while the cable is rolled or unwrapped. The lifting actuator of claim 1, wherein the operator interface further comprises: a handle; a rotating coupling to connect the interface to the rope, but allowing it to rotate 360 degrees in relation to the rope; a slidable pipe of thin layer type suitable for providing electrical contacts and a channel or air duct therewith; a coil sensor for detecting a vertical component of a displacement applied to the handle, wherein the handle engages a center passing inside the coil by means of a flexible filament; and a liquid crystal display in the interface to display the status information to an operator; a contactless proximity sensor to detect the presence of an operator's hand on the handle during the operation. SUMMARY An improved electric lift actuator is disclosed for use in a variety of lifting systems, including several improvements that allow a universal design with interchangeable parts through various loading intervals. The universal design also allows for additional features and functionality (eg, improved load cell location, improved operator detection and electrical signal / air channel in operator's pendant, improved reliability and reduced cost for detecting operator strength, etc.), in addition the universal design is incorporated into a gimbal drive assembly where load detection and low voltage detection of the wire rope, as well as cable boundaries can be achieved using the improved components and techniques. such as non-contact sensors, etc. It is believed that many of the improvements described reduce the cost and improve the operation and expand the capacity and reliability of the actuator in addition to making the actuator a common design through various applications and loading intervals.