Trolley with a brake module for a gravity overhead conveyor

Abstract

Carriage (1) with a brake module (6) for a gravity overhead conveyor, characterized in that the brake module (14) comprises several fluid cylinders (15), one end of which is connected to a carriage (1) and the other end of which is eccentrically connected to an axis (4, 5) of the carriage (1), wherein the fluid cylinders (15) are indirectly eccentrically connected to the axis (4) at different mounting points (16, 17) and the mounting points (16, 17) are arranged on different running wheels (3) assigned to an axis (4, 5).

Description

[0001] The invention relates to a carriage with a brake module for a gravity-driven overhead conveyor. Gravity has long been used to transport unit loads. The advantage of this is that no additional drives are required if the appropriate incline of the conveying path can be achieved. In gravity conveyors, gravity alone acts as the driving force on the conveyed goods. The conveyed goods slide or roll, for example, on chutes or roller tracks, either downwards on an inclined conveying path or, as with drop pipes, fall freely. A problem with these gravity conveyors is that the conveying speed is significantly influenced by both the coefficient of friction or resistance between the conveyed goods and the supporting elements, as well as by the mass of the conveyed goods.The conveying speed is either so low that the material stops moving, or so high that there is a risk of collision with the previous material.

[0002] The frictional resistance encountered during downward sliding or rolling – the sliding or rolling friction resistance – must be overcome by the force of gravity acting on the conveyed material. Therefore, gravity conveyors are currently only suitable for applications where a precisely defined conveying speed is not required, as this speed – apart from free fall – always depends on the prevailing frictional conditions between the conveyed material and the sliding or roller track. These frictional conditions can change within certain limits during operation, for example, due to contamination, wear, or fluctuating material properties that influence the frictional conditions. Thus, gravity conveyors are currently used primarily as linking elements between driven continuous conveyors, as feeding conveyors, and for the downward, steep, or vertical conveying of bulk and unit loads.Existing gravity conveyors can be divided into three basic types: chutes, drop pipes and roller conveyors, which are always floor-mounted or elevated conveyors.

[0003] In a chute, the conveyed material slides downwards on an inclined open or closed channel (chute). The angle of inclination of the chute must be greater than the angle of friction at rest between the conveyed material and the chute so that the material starts sliding on its own at any point along the chute and cannot come to a standstill. Nevertheless, the material accelerates with increasing conveying length, assuming a constant coefficient of sliding friction. Chutes are manufactured as single-use, multi-use, and telescopic chutes in straight or curved designs. Straight chutes, usually made of wood or sheet steel, have an angle of inclination of 20 to 80°, depending on the conveyed material. The sliding surfaces of the chutes are often lined with plastics to reduce wear and friction. The movement of the material on the chute follows the principle of an inclined plane.

[0004] In contrast, downpipes are used for the vertical downward conveyance of non-sensitive bulk materials in storage areas, on ships, etc. Besides individually usable downpipes, which can also be operated at an angle (similar to a chute), complete downpipe systems are used.

[0005] Roller conveyors are similar to roller conveyors in terms of construction and material requirements, except that, unlike roller conveyors, they do not require driven rollers, as they are gravity conveyors, meaning they convey material exclusively downwards. Roller conveyors have carrying rollers whose axles are fixed in longitudinal beams. They are suitable for conveying unit loads with flat, stable, and sufficiently large contact surfaces. A variety of complex conveying tasks can be accomplished by using curves, switches, and other features. For longer conveying distances, brake rollers are installed to limit the conveying speed. The braking torque is generated by centrifugal friction brakes or hydraulic brakes integrated into the rollers. A braking device for a roller conveyor is known from DE 18 07 424 A.This shows a brake roller for a roller conveyor with an integrated double-acting piston cylinder.

[0006] Furthermore, German patent DE 20 2006 010 633 U1 describes a braking system for vehicles of all types, which specifically features a frame-mounted fluid cylinder. The fluid cylinder exerts a braking effect on a wheel and is eccentrically connected to an axle of the wheel.

[0007] German patent DE 29 17 896 A1 also discloses a carriage with a brake module for a gravity overhead conveyor, wherein the brake module is implemented via a disk mounted in a sealed chamber filled with a viscous fluid. This disk is coupled to an axle of the carriage and is braked by the viscous fluid in a speed-dependent manner, thereby braking the carriage.

[0008] DE 12 18 954 A also describes a trolley for a gravity overhead conveyor with a braking module consisting of permanent magnets, a copper plate, and other plates. The braking module comprises several plates made of an electrically conductive material and permanent magnets for generating a magnetic field, wherein the permanent magnets and the plates are coupled to an axis of the trolley and the plate and the permanent magnets are arranged to be movable relative to each other.

[0009] Overhead conveyors are also regularly used as electric monorails or power-and-free conveyors. An electric monorail system (EMS) consists of a rail system on which individually driven EMS vehicles travel. Conductor wires are integrated into the rail, supplying the vehicles with power and control information. The bogies are driven by their own electric motor via a friction wheel. This frictional connection limits the bogie's climbing ability to gradients of up to 30° with a payload of 250 kg or 45° with a payload of 100 kg. Changes in elevation are otherwise bridged by a hoist or a lift with a track section. Switching points divide and merge material flows. This is achieved by shifting a section of track so that either the straight or the curved section is inserted into the conveyor path.

[0010] However, electric monorail systems have numerous disadvantages. For example, inclines and declines are only possible for smaller systems with a payload of up to approximately 0.2 tons, and changes in elevation require lifting and lowering stations. Furthermore, a motor and thus drive systems are necessary, making this system less energy-efficient than a gravity conveyor. In addition, parts wear out and may need to be replaced, resulting in high costs and maintenance.

[0011] Power-and-free conveyor systems consist of two superimposed rails. A (power) chain runs continuously in the upper rail, pulling (free) cars, which carry the load, via carriers in the lower rail. Because the cars can be uncoupled from and re-engaged from the running power chain as needed, buffer zones and switches can be implemented. However, power-and-free conveyor systems also have numerous disadvantages. Firstly, the chains used generate extremely high noise levels. Secondly, the closed circuits result in a complex design. Thirdly, motors are required for the system's operation.

[0012] Furthermore, system components wear out and may need to be replaced. This results in high costs and maintenance.

[0013] Slides, downpipes, and roller conveyors operate exclusively on a floor-level basis. While the electric monorail and the power-and-free conveyor system are elevated or floor-level, they are equipped with external drives and therefore require connections to electricity, hydraulics, etc.

[0014] However, braking systems for overhead conveyors do not yet exist. This is where the invention comes in. The invention aims to provide a wear-free, energy-efficient braking system for an overhead conveyor that automatically regulates its required braking torque depending on the load being conveyed and the speed.

[0015] This problem is solved by the features of claim 1. The dependent claims each relate to particularly preferred embodiments of the invention.

[0016] According to the invention, a carriage with a brake module for a gravity overhead conveyor is proposed.

[0017] To generate a smooth, constant movement, the brake module has several fluid cylinders, one end of which is connected to the carriage and the other end of which is eccentrically connected to an axis of the carriage.

[0018] For the purposes of the invention, a gravity overhead conveyor is understood to be any conveying device which transports a good by utilizing gravity, wherein the good is arranged below a carriage which is part of the conveying device.

[0019] By coupling the impeller to the carriage via a fluid cylinder, which is eccentrically connected to an axle of the carriage, it becomes possible to maintain the carriage speed at a near-constant level within certain tolerance limits, particularly regardless of the mass of the conveyed material and the incline of the conveying path. This also improves adherence to fixed conveying and cycle times in the material flow. Utilizing gravity as both a conveying force and a braking or damping force enables low-wear, self-sufficient, and load- or speed-dependent braking without the need for an external energy supply.

[0020] The braking module according to the invention decelerates the movement of the carriage in such a way that the carriage, and thus the conveyed material, maintains a constant speed until the end of the conveying path, depending on the setting of the braking module. The braking module transmits a braking torque, dependent on the speed of the carriage, indirectly via the axle or directly to the carriage's wheels. According to the invention, the braking module operates autonomously. The braking effect is applied without any externally supplied energy. The kinetic energy influenced by gravity is converted into braking energy by means of the braking module. Supply lines such as cables, hoses, or similar components are not required. Due to the small number of parts, the braking module is virtually wear-free.

[0021] By arranging at least one fluid cylinder in the brake module of the carriage, a carriage is advantageously created which automatically regulates its speed by utilizing dynamic pressure. The fluid cylinder is preferably designed as a single-acting or double-acting cylinder, but this is not limited to these configurations. Preferably, the fluid cylinder has at least one throttle valve for reducing and / or limiting its travel speed. The fluid can be a compressible or incompressible substance. Gases, particularly compressed air, or liquids such as water or oil are preferably used. With compressible media, the start of the braking process is smooth.

[0022] The carriage has at least one axle. Each axle of the carriage has at least one, and usually two, wheels. The reciprocating motion of the fluid cylinder creates a braking module that can automatically regulate the speed.

[0023] The fluid cylinder according to the invention consists of a cylinder and a piston movable translationally within it. The cylinder chambers located on both sides of the piston are sealed pressure-tight from the environment. The fluid cylinder, i.e., the piston or the cylinder, is suitable for the arrangement of a throttling section.

[0024] In the described stroke movement of the fluid cylinder, the piston and cylinder are moved relative to each other.

[0025] In an embodiment of the carriage not belonging to the invention, the brake module for generating a uniform, constant movement can have at least one plate made of at least one electrically conductive material and at least one magnet for generating a magnetic field.

[0026] The magnet and / or the plate are coupled to an axis of the carriage according to the non-inventional invention, and the plate and magnet are arranged to be movable relative to each other. By arranging an eddy current brake in the braking module of the carriage according to the non-inventional invention, consisting of the plate and at least one magnet, a carriage according to the non-inventional invention is created which automatically regulates its speed by utilizing the induced eddy currents. The relative movement of the magnet and plate in the braking module according to the non-inventional invention is preferably configured such that the magnet moves along a circular path; however, the braking module according to the non-inventional invention is not limited to this embodiment. It proves particularly advantageous that the circular path lies in a plane that is oriented parallel to the plane of the plate.

[0027] In a non-inventive embodiment of the carriage, the plate can also be a ring or a disc. It is advantageous for the length of the circular path's radius to correspond to half the plate's radius. This design, particularly of the plate, promotes the generation of large-scale eddy currents, thus leading to improved braking. The plate, especially its outer contour, is circular for this purpose. Furthermore, to promote eddy currents, the plate has smooth, non-frayed edges. It is advantageous for the plate to be made of an electrically conductive material. With regard to its own weight, conductivity, and manufacturing costs, the plate is made of metal, in a preferred embodiment of aluminum. The higher the conductivity, the stronger the braking effect. The latter is, for example, greater with a copper plate than with an otherwise identical steel plate.

[0028] Furthermore, in the non-inventive embodiment of the braking module, a magnetic north pole and a magnetic south pole are assigned to a cross-sectional section of the plate. The north and south poles are positioned on opposite sides of the plate. In this non-inventive embodiment, the braking module can only have one magnet, whose poles are positioned on opposite sides of the plate. In an alternative embodiment, at least one magnet is positioned on each of the opposite sides of the plate, with the north pole of one magnet and the south pole of another magnet being assigned to a cross-sectional section of the plate. This embodiment makes it possible to increase the braking performance, since the size of the plate area under the excitation pole influences the braking performance.

[0029] For the non-inventive braking module, permanent or electromagnets are used. The magnets are arranged on a circular path with the axis of rotation of the plate at its center. A highly functional embodiment of the non-inventive braking module is that several magnets are arranged on a carrier oriented parallel to the plate. This makes it particularly easy to orient the magnetic field of the magnet perpendicular to the plane of the plate, which also contributes to an improvement in braking performance compared to the prior art. The carrier is fixedly connected to the carriage relative to it. The plate, on the other hand, is rotationally movable, in particular arranged coaxially on the axis of the carriage. The magnetic field passes through the movable plate. At the same time, the distance between the magnet and the plate is selected or set to be as small as possible.

[0030] The braking module, which is not according to the invention, can also include a generator for producing electrical voltage for controlling and supplying the magnet, in particular an electromagnet. When using an electromagnet, the braking force depends on the magnitude of the coil current of the electromagnet.

[0031] In a preferred embodiment of the invention, the fluid cylinder has at least one adjustment element for setting the travel speed. The travel speeds for the retraction stroke and / or the extension stroke of the fluid cylinder are adjustable, in particular independently of each other. This makes it possible to set and adjust the desired conveying speed, for example, to the mass of the conveyed material, the local geometry of the conveying path, or the desired transport time. Preferably, the fluid cylinder has two adjustment elements for independently setting the travel speed during the retraction stroke and / or extension stroke. In a preferred embodiment, the adjustment elements are rotatable, in particular for manual and / or mechanical actuation. This measure ensures that the braking effect can also be changed while the carriage is in motion.The adjustment element, designed for example as a rotary knob or swivel lever, can be adjusted both passively, such as when passing a protrusion, and actively, namely through handling, by means of external influence.

[0032] It is advantageous that the fluid cylinder is attached to a wheel of the carriage. In a further preferred embodiment, the brake module comprises two fluid cylinders, which are connected to the axle and / or at least one wheel, particularly at different mounting points. The use of more than two fluid cylinders is also possible. The fluid cylinders are preferably assigned to the same axle.

[0033] A further development of the invention relates to a carriage in which the mounting points are arranged at the same radial distance from the axis. For this purpose, the radial distance between the axis and the mounting point is as large as possible. This enables the achievement of a high braking torque. To facilitate overcoming a dead center of a fluid cylinder in the fully retracted or extended state, the mounting points of the fluid cylinders, which act as dampers, are offset from each other by a quarter turn of the axis(s). A quarter turn corresponds to 90° in a full circle of 360°.

[0034] In a preferred embodiment of the invention, the mounting points are arranged on different wheels assigned to the same axle. It has proven advantageous to arrange the mounting points on opposite sides of the wheels. Such a design of the brake module is easy to implement and simultaneously enables high braking performance.

[0035] Preferably, the brake module is enclosed by a housing that accommodates all the aforementioned components and protects them from external, especially physical, influences.

[0036] The invention allows for numerous embodiments. To further illustrate its basic principle, one of these is shown in the drawing and described below. The drawing shows in Fig. 1 a schematic representation of a carriage not according to the invention with an embodiment of a brake module not according to the invention; Fig. 2 a schematic representation of a first variant not according to the invention of the in Fig. 1 brake module shown; Fig. 3 a schematic representation of a second variant not according to the invention of the in Fig. 1 brake module shown; Fig. 4 a schematic representation of a carriage with an embodiment of the brake module according to the invention; Fig. 5 a schematic representation of the in Fig. 4 brake modules shown.

[0037] The Fig. 1 and Fig. Figure 4 shows a carriage 1 on a guide rail 2 for a gravity-fed overhead conveyor. The carriage 1 has four wheels 3, arranged in pairs on axles 4 and 5. A brake module 6, 14 of the carriage 1 is coupled to one axle 4.

[0038] Fig. Figure 1 shows a non-inventive embodiment of the brake module 6 with a housing 7, Fig. Figure 4 shows the second embodiment of the brake module 14.

[0039] The Fig. 2 and Fig. Figure 3 shows two different variants of the non-inventive embodiment of the braking module 6. This braking module 6 has a disc-shaped plate 8 made of an electrically conductive material. The plate 8 is coupled to the axis 4, so that when the axis 4 rotates, the plate 8 is also set into rotation. When the plate 8 rotates, the magnets 10, or rather their magnetic field 11, generate an eddy current in the plate 8. This eddy current slows the movement of the plate 8 and thus the rotation of the axis 4. The strength of the eddy current depends on the rotational speed of the plate 8. The faster the plate 8 rotates, the stronger the eddy current and the more the movement of the plate 8 is slowed. To illustrate the mode of operation, Figure 3 shows two different variants of the non-inventive embodiment of the braking module 6. Fig. 3 The movement 12 of the plate 8 and the braking force 13 of the eddy current opposing the movement 12 are indicated by arrows.

[0040] Fig. Figure 2 shows a first variant of the non-inventive embodiment of the brake module 6. A portion of the housing 7 surrounding the brake module 6 is shown. Within the housing 7, the plate 8 is arranged between a housing wall and an intermediate wall, perpendicular to the axis 4 and parallel to the housing wall and the intermediate wall. The housing wall and the intermediate wall serve as supports 9 for receiving several magnets 10. The magnets 10 are arranged at equal radial distances around the axis 4. All magnets 10 have the same orientation perpendicular to the plane of the plate 8. This means that the north pole of the magnets 10 on one support 9 faces the plate 8. For the magnets 10 arranged on the other support 9, the south pole faces the plate 8. The axis 4 is rotatably mounted in the supports 9. The plate 8 and the magnets 10 are movable relative to each other.The magnets 10 used in this non-inventive variant of the brake module 6 are preferably permanent magnets.

[0041] Fig. Figure 3 shows a second variant of the non-inventive embodiment of the brake module 6. In this brake module 8, a magnet 10 is provided which surrounds the plate 8, such that both the north and south poles of the magnet 10 face the plate 8. In this variant of the brake module 6, the magnet 10 is an electromagnet. It is possible for several such magnets 10 to be arranged on the plate 8. The magnet 10 is powered by a generator (not shown). The generator is coupled to one of the axes 4, 5 of the carriage 1 and converts a portion of the kinetic energy into electrical energy when the axes 4, 5 rotate.

[0042] The Fig. 4 and Fig. Figure 5 shows an embodiment of the brake module 14 according to the invention. The brake module 14 comprises two fluid cylinders 15. One end of each fluid cylinder 15 is connected to the carriage 1. Both fluid cylinders 15 are indirectly connected eccentrically at their other end to the same axis 4 of the carriage 1. The indirect eccentric connection to the axis 4 is made via the wheels 3 of the axis 4, with each fluid cylinder 15 being attached to a different wheel 3. The mounting points 16, 17 of the fluid cylinders 15 on the wheels 3 are arranged on a circular path concentric with the axis 4 and offset from each other by a quarter turn of the axis 4. The fluid cylinders 15 have two adjustment elements 18 which throttle the fluid flow in the fluid cylinder 15. By adjusting the intensity of the throttling, the travel speed of the fluid cylinder 15 and thus the travel speed of the carriage 1 is determined.The travel speeds for the retraction stroke 19 and the extension stroke 20 of the fluid cylinder 15 are independently adjustable. Retraction stroke 19 and extension stroke 20 are in . Fig. 5 indicated by arrows. Reference symbol list 1 trolley 2 running rail 3 wheel 4-axis 5-axis 6 Brake module (first embodiment) 7 cases 8 plate 9 carriers 10 Magnet 11 Magnetic field 12. Movement of the plate 13 Braking force 14 Brake module (second embodiment) 15 fluid cylinders 16 Attachment point 17 Attachment point 18 Adjustment element 19 Entry stroke 20 Extension stroke

Claims

[1] Trolley (1) with a brake module (6) for a gravity overhead conveyor, characterized by , that the brake module (14) comprises several fluid cylinders (15), one end of which is connected to a carriage (1) and the other end of which is eccentrically connected to an axis (4, 5) of the carriage (1), wherein the fluid cylinders (15) are indirectly eccentrically connected to the axis (4) at different mounting points (16, 17) and the mounting points (16, 17) are arranged on different running wheels (3) associated with an axis (4, 5). [2] Trolley (1) according to claim 1, characterized by , that the fluid cylinder (15) has at least one adjusting element (18) for setting the travel speed, wherein the travel speed for the retraction stroke (19) and / or the extension stroke (20) of the fluid cylinder (15) is in particular independently adjustable. [3] Trolley (1) according to claim 1 or 2, characterized by, that the fluid cylinder (15) is attached to a wheel (3) of the carriage (1). [4] Trolley (1) according to at least one of the preceding claims, characterized by , that the fastening points (16, 17) are arranged on a circular path concentric to the axis (4, 5). [5] Trolley (1) according to at least one of the preceding claims, characterized by , that the fastening points (16, 17) are arranged offset from each other by a quarter turn of the axes (4, 5).

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