Motorised column

Abstract

An electric column for a lift truck includes one or more electric actuators located at the outermost edges of a vertically elongated frame of the column and selectively moving a carriage along the vertically elongated frame.

Description

Cross-references to related applications

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 5 67,796, filed March 20, 2024, the contents of which are incorporated herein by reference in their entirety. Background Technology

[0002] The subject matter of this application generally relates to columns used for lifting vehicles.

[0003] A crane truck is typically a battery-powered vehicle with controls in its operator's cab that allow the operator to lift and move materials while driving the crane through factories, warehouses, and other locations. A telescopic upright column, usually attached to the front of the crane truck, includes a sliding carriage to which forks or other crane truck attachments (such as clamping arms) can be attached. The telescopic column has a "free-lift" phase and a "main-lift" phase; the "free-lift" phase refers to the carriage's translational movement along the column, while the "main-lift" phase allows the column to extend and retract further vertically. Many different types of attachments exist that can be engaged with the crane truck, each with different operations. For example, some attachments have only one pair of forks, while others have multiple pairs to allow the crane truck to handle multiple pallets of goods at once. Some crane trucks have clamping arms instead of forks, intended for gripping cylindrical loads, and these clamping attachments themselves encompass many types, which may or may not include rotation, tilting, etc.

[0004] Therefore, as is readily understood, the lifting platform and its attachments have separate control systems. This means the lifting platform is equipped with its own actuator for raising and lowering the column, while the lifting attachment is similarly equipped with its own actuator tailored to the specific operation of that attachment. However, these different operations must be coordinated during use. As an example, when the lifting platform moves a pallet of goods in a warehouse, the platform must lower the carriage so that the attachment's forks are flush with the lateral opening in the pallet resting on the ground, and the platform's forks must also be positioned horizontally to align with the pallet's opening. As another example, when a lifting platform with a clamping attachment moves a roll of paper in a warehouse, the platform must vertically position the carriage and horizontally position the clamping arm so that it is vertically centered relative to the roll and surrounds it. The clamping arm must then be moved inward to grip the roll with sufficient force to allow it to be raised and lowered, but not so forcefully as to damage it. Then, the slide of the column must be raised to transport the paper roll to its destination, where it is lowered and released.

[0005] While the operation of the column and the attachments are implemented separately, both are controlled by the operator of the lift truck. This essentially means that regardless of the independent design of the attachment operation, its control must ultimately be traced back to the lift truck. Historically, control of both the lift truck and the attachments has been provided hydraulically via pumps and reservoirs located on the lift truck. Therefore, although both the lift truck and the attachments have independent hydraulic actuators (i.e., one or more actuators for raising the column, and one or more actuators for operating the attachments), the fluid source and control signals for the attachments originate from the lift truck. This necessitates the use of hoses extending across the column to supply fluid to the attachments. Furthermore, some attachments are electrically controlled using, for example, solenoid valves, which is typically achieved using wires that also extend across the column to provide power and signals to the electrical components of the attachment.

[0006] These hoses and cables present several drawbacks. First, these components often obstruct the operator's view, who typically must see the load approaching or positioned during release. Second, because many columns are telescopic, the movement of the column causes wear and tear on the hoses and cables. Regarding the cables, many newer attachments offer independent batteries to power certain electrical components on the attachment, but these batteries require charging. Other newer attachments utilize radio frequency or other electromagnetic control signals transmitted from the rig to the attachment. Therefore, while some hydraulic attachments have eliminated the need for cables extending across the column, hydraulic hoses must still be used to supply fluid to the cylinders operating the hydraulic attachment's forks, clamping arms, etc.

[0007] Therefore, what is desired is improved equipment and systems that enable the lift truck to operate various attachments without the need for hoses or potentially overhead wiring and without obstructing the operator's view. Attached Figure Description

[0008] To better understand the present invention and demonstrate how to implement it, examples will now be provided with reference to the accompanying drawings, in which:

[0009] Figure 1 An exemplary speed characteristic of a typical existing hydraulic column is shown.

[0010] Figure 2 An exemplary motorized column of the prior art is shown.

[0011] Figure 3A An improved electric column as described in this patent specification is shown.

[0012] Figure 3B It shows Figure 3A An enlarged view of the column with a pulley system.

[0013] Figure 3CIt shows along Figure 3B The view of column 3A with line AA in the middle.

[0014] Figure 4 An exemplary electric actuator for the electric column of Figure 3 is shown. Detailed Implementation

[0015] As mentioned earlier, existing aerial work platforms typically utilize hydraulic power and control circuits to raise and lower the platform's column carriage, as well as to provide power and control for various attachments. The use of hydraulic power and control systems is advantageous due to their power density. For example, refer to... Figure 1 The hydraulically powered lift truck is capable of lifting loads up to 4,000 pounds at speeds exceeding 120 feet per minute during both the free-lift and main-lift phases, while requiring only 15 gallons or less of fluid per minute. This power efficiency enables the lift truck to operate productively by grabbing, lifting, maneuvering, lowering, and releasing loads within relatively short timeframes.

[0016] As mentioned earlier, a disadvantage of hydraulically operated lifts is that hoses often obstruct the operator's view of the load during operation, and the extension and retraction of the column causes wear on the hoses and any electrical connections between the lift and its attachments. Some attachments provide electrical actuation and control over the attachment's functions, and these attachments improve upon these disadvantages because they eliminate the need for wiring for the attachment, and sometimes even eliminate the need for hydraulic hoses.

[0017] Similarly, there is already an electric, rather than hydraulically driven, propulsion force for the lift column. Therefore, instead of using one or more hydraulic actuators to provide the actuation force for the vertical movement of the lift column, an electric motor is used instead. Figure 2 A conventional motorized column 10 is shown, comprising a mounting plate 12 fixed to a vertically elongated frame 14, on which a carriage 16 performs vertical translational movement. The plate 12 may be fixed to a lift carriage that supplies power to a motor 18 located at the top of the frame 14. The motor 18, in turn, drives or rotates a ball screw 22 via a gear assembly 20. The ball screw 22 includes a threaded outer surface with which the carriage 16 engages. The carriage 16 may also slidably engage with opposing lateral guide rails 24a and 24b of the frame. This arrangement prevents the carriage 16 from rotating as the ball screw 22 rotates; the threaded engagement of the carriage 16 causes it to translate upwards or downwards along the frame 14, depending on the direction of rotation of the ball screw 22. The column 10 may also include wire guides 25 for cable management.

[0018] However, electric columns (such as column 10) have several significant disadvantages compared to hydraulic columns. First, the central position of the ball screw 22 obstructs the operator's view. Thus, even when the lift is engaged with electric attachments that do not require hydraulic hoses or lines, the electric column itself will still obstruct the operator's view when the attachments are operating a load. Second, to drive the central shaft, the motor 18 must be positioned above the top horizontal guide rail 24c of the frame 14, offset from the centerline of the frame 14, to drive the frame 14 via the gear assembly 20. Motors are typically heavy, and this off-center positioning above the column reduces the lift's stability due to the rotational inertia generated by the motor 18. This, in turn, limits the ability of the column to be attached to various attachments (tilting, lateral movement). Furthermore, the motor 18 limits the lifting height of any other stage of the column and also limits the clearance of the load, as the motor may strike, for example, the top of a trailer to which the load is to be inserted.

[0019] Third, the single-rail design of column 10 limits the lifting height. While additional stages of the electric column could theoretically be added to this design, these stages would require a separate motor and drive shaft, exacerbating the drawbacks described in the previous paragraph. Furthermore, motor 18 is less efficient in power delivery than a hydraulically driven column. Even Figure 2 The large, heavy-duty motor 18 shown can only achieve a travel speed of approximately 150 mm / s for the carriage 16, which is about a quarter of the travel speed of a hydraulically driven column. Similarly, in principle, this problem could be overcome by using a larger and heavier motor, but this would exacerbate the disadvantages described in the previous paragraph. Finally, the environmental exposure of the components of the column 10, particularly the ball screw 22, is a concern, as substances such as grease can attract dust because the ball screw may not be properly sealed. Alternatively, a bellows could be included to cover the ball screw assembly, but this would limit the column's travel.

[0020] This patent specification discloses an improved electric column assembly that addresses the aforementioned drawbacks of existing electric columns. First, this patent specification discloses an electric column in which the electric actuator is positioned within the frame of a vertically elongated column, rather than above (or below) the column as in existing electric columns. This allows the novel electric column disclosed in this patent specification to better balance the weight of the attached lift vehicle. Second, instead of utilizing a centrally positioned ball screw driven by an electric motor, embodiments of the disclosed electric column may include one or more electric actuators driven by a motor located within a compact housing of the actuator. This design effectively avoids the use of a centrally positioned ball screw that would obstruct the driver's view. Because the disclosed actuators are compact, they can also be arranged laterally within the column frame so that they themselves do not obstruct the driver's view. Furthermore, the compact design of the disclosed actuators allows the column to be driven by multiple actuators (each equipped with an independent motor) rather than by a single large motor. Therefore, the performance characteristics of the disclosed electric column driven by the electric actuator are superior to those of existing electric columns, as will be disclosed in further detail below.

[0021] Figure 3A An exemplary motorized column 100 incorporating the features just described is shown. Specifically, the motorized column 100 may have a vertically elongated frame 102 to which a carriage 104 is slidably connected, allowing the carriage 104 to selectively translate vertically. The frame 102 may be composed of outermost lateral supports 106a, 106b, an outermost bottom support 106c, and an outermost top support 106d, which are laterally spaced apart to define the width of the frame. The outermost bottom support 106c and the outermost top support 106d are vertically spaced apart to define the height of the frame. The supports 106a, 106b, 106c, and 106d collectively define the outermost edge 109 of the frame 102 on which the carriage 104 translates.

[0022] The electric column 100 also includes two electric actuators 108, the structure of which will be described in more detail later in this patent specification. The electric actuators preferably have the same structure and are preferably positioned within the outermost edge 109 of the frame 102, and more preferably, each electric actuator is positioned close to one of the lateral supports 106c and 106d. In this way, the actuators do not obstruct the view through the central opening 110 of the electric column 110, while balancing the weight of the electric column 100 to provide greater stability for lift vehicles / attachments connected to the column 100, thereby facilitating a wide range of tilting, lateral movement, and lateral acceleration operations for any attachments connected to the column. The electric actuators 108 raise and lower the carriage 104, as described in more detail below.

[0023] The electric column 100 shown in Figure 3 has significantly better performance than existing electric columns, for example... Figure 2 The motorized column shown is described. Specifically, in some embodiments, the motorized column 100 can preferably lift a total weight (including load, attachments, and chain) of up to 2000 kg while achieving a maximum speed for lifting and hoisting the load, which is significantly higher than [previous speed]. Figure 2 The electric column can reach speeds. Preferably, for example, the electric column of Figure 3 can reach speeds of at least 200 mm / s when lifting heavy loads (e.g., up to 2000 kg). More preferably, the electric column of Figure 3 can reach speeds of at least 400 mm / s when lifting such heavy loads, and in other embodiments, speeds in the range of 575-650 mm / s can be achieved, which is comparable to the speed of a hydraulic column, i.e., 118 feet / minute (600 mm / s), as can be seen in... Figure 1 As seen in the image. The lifting height of carriage 104 is approximately 3 feet (1000 mm).

[0024] As described later in this patent specification, the motorized column 100 of Figure 3 is a standard column with a limited free-lift height. The actuators and embodiments disclosed in this patent specification can be used with motorized columns having two or more stages. For example, a three-stage column using the embodiments of this disclosure can lift a total weight (load, attachments, chain) of up to 2000 kg while maintaining the maximum speed as previously described, for example, 600 mm / s, but with a total lifting height exceeding 15 feet (4775 mm), of which the free-lift height is approximately 5 feet (1484 mm to 1568 mm).

[0025] As previously stated, the disclosed electric column 100 achieves speeds previously unattainable for electric columns. This is achieved through several features of the column 100. First, as previously mentioned, the column 100 is designed to include two actuators, and thus two motors, thereby providing higher power and speed. Second, see, for example, [link to previous section]. Figure 3B and Figure 3C The electric column 100 may include a standard column with a limited free lifting height, wherein the column 100 includes a longitudinally extendable frame segment 124 slidably mounted to a guide rail member 126. The electric actuator 108 includes a rod (e.g., Figure 4 The rod 204 is fixed to the frame segment 124 to alternately raise and lower the frame segment 104 along the guide rail member 126. Each of the two chains 125 extends around a corresponding pulley system 130, which is rigidly fixed to the frame segment 124. Each chain 125 is fixed at one end to the carriage 104 and at the other end to the outer frame of the column 100. Thus, as can be seen in these figures, when the electric actuator 108 raises (or lowers) the frame segment 124, the carriage 104 must rise (or fall) at twice the rate of the frame segment 124 because the length of the chain 125 is fixed. In other words, the carriage 104 obtains twice the linear displacement provided by the corresponding motor of the electric actuator 108 to those actuators. Furthermore, by combining the electric motor with a motor having a high power density ( Right now Using a motor that can achieve extremely high torque with a relatively small but powerful magnet / coil can increase the speed of the column 100.

[0026] Because the movement of the carriage 104 along the column 100 is not independent of the longitudinally extendable frame of the column 100, the column 100 is referred to as a standard column with a “limited” free lift height. However, as previously stated, alternative embodiments of the motorized column according to the disclosure of this application may include multi-stage columns, such as two- or three-stage columns with independent free lift capabilities, for example, by including more motorized actuators 108, enabling the carriage to move along the column in a manner independent of the column’s own extendability.

[0027] Figure 4 An actuator 200 including a motor is shown, which drives a rod 204 via a gear assembly. Specifically, the actuator 200 may include a housing 202, from which the shaft 204 extends slidably via the operation of the motor, which is enclosed within a chamber 206 of the actuator 200. Also enclosed within the chamber 206 is a gear assembly that transmits force from the motor to the rod 204.

[0028] In some preferred embodiments, the disclosed column 100 can regenerate energy when the carriage 104 is lowered. Specifically, the column 100 and its actuator / motor can be configured such that gravity causes the carriage 104 to move downward along the column 100, thereby driving the motor to operate as a generator.

[0029] Preferably, in some embodiments, a braking mechanism may be selectively applied to the motor 114, the braking power of which is twice the braking power output by the motor.

[0030] Optionally, the electric column may be equipped with a feedback sensor to measure the load weight. This sensor may be supported by a Bavarian (spring) washer assembly and can provide feedback to (potentially automatically) adjust the power based on the load weight. Furthermore, the electric column 100 can be optionally used on seated, walk-behind, and standing rider trucks. Optionally, the electric column will allow for a tilting function for the load, and in some embodiments, will allow for a switch from tilting the column to tilting the carriage. Optionally, the electric column can be used with various types of vehicles, column types (single-stage, double-stage, triple-stage, quadruple-stage, and quintuple-stage), and different load capacities.

[0031] Those skilled in the art will understand that the electric drive unit for the column described herein can also be used in high-power, compact motors for rotator applications, completely eliminating the need for traditional worm gearboxes. When used in rotators, its advantage lies in reducing rotator noise from hydraulic motors or gearboxes. It will be possible to configure rotators without worms or worm wheels; and the electric motor can be directly coupled to the rotating components.

[0032] Those skilled in the art should also understand that the embodiments of the electric column disclosed in this patent specification are suitable for use in unmanned automated guided vehicles (AGVs). Similarly, although Figure 3 depicts a single-stage column, the electric actuator disclosed in this patent specification can be used for multi-stage columns, such as two-stage or three-stage columns.

[0033] It should be understood that the present invention is not limited to the specific embodiments described, and modifications may be made thereto without departing from the scope of the invention as defined by the appended claims, but such modifications must be interpreted in accordance with the principles of applicable law, including the doctrine of equivalence or any other principle that extends the enforceability of the claims beyond their literal meaning. Unless the context otherwise requires, the number of instances of an element mentioned in a claim, whether referring to one instance or more than one instance, requires that at least the stated number of instances of that element be included, but is not intended to exclude structures or methods having more instances of that element than stated. When used in the claims, the word "comprising" or its derivatives are used in a non-exclusive sense and are not intended to exclude other elements or steps in the claimed structure or method.

Claims

1. A column, selectively attachable to a lifting vehicle and having a vertically elongated frame, the outermost edge of which is partially defined by opposing vertical members that are laterally spaced apart from each other and rigidly interconnected by an uppermost horizontal member, the column comprising: Carriage; as well as At least one electric actuator is located below the uppermost horizontal member and causes the carriage to alternately translate up and down along the opposite vertical member.

2. The column as described in claim 1, wherein, The frame includes a lowermost vertical member that rigidly interconnects the opposing vertical members, and the at least one electric actuator is located above the lowermost horizontal member.

3. The column as described in claim 2, wherein, The at least one electric actuator is at least partially positioned between the opposing vertical members.

4. The column as described in claim 1, wherein, The at least one electric actuator is configured to recover energy when the carriage is lowered.

5. The column as described in claim 1, wherein, The column includes a braking mechanism.

6. The column as described in claim 1, wherein, The at least one electric actuator includes a housing surrounding the motor.

7. The column as described in claim 1, wherein, The vertically elongated frame defines a central opening that provides unobstructed vision between the operator of the lift, to which the column is selectively attached, and the carriage.

8. The column as described in claim 1, wherein, The column does not have a ball screw for moving the carriage.

9. A column, the column being selectively attachable to a lifting vehicle and having a vertically elongated frame and a carriage selectively movable along the frame, the column comprising at least one electric actuator capable of causing the carriage to alternately move up and down along the frame at a speed of at least 200 mm / s when the carriage is carrying a load of 2000 kg.

10. The column as claimed in claim 9, wherein, The at least one electric actuator is capable of causing the carriage to alternately move up and down along the frame at a speed of at least 400 mm / s when the carriage is carrying a load of 2000 kg.

11. The column as claimed in claim 10, wherein, The at least one electric actuator is capable of causing the carriage to alternately move up and down along the frame at a speed of 575 mm / s to 650 mm / s when the carriage is carrying a load of 2000 kg.

12. The column as claimed in claim 9, wherein, The column has two of the electric actuators.

13. The column as described in claim 9, wherein, The vertically elongated frame defines a central opening that provides unobstructed vision between the operator of the lift, to which the column is selectively attached, and the carriage.

14. The column as claimed in claim 9, wherein, The column does not have a ball screw for moving the carriage.

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