Patent Description:
Bulk materials consist of particles of different densities and sizes, and it is impossible to perceive bulk materials present in a batch as a set of separate objects. To evaluate these materials, sampling devices are used to take a sample from the batch of material that is intended to be representative of the entire batch being analysed. In the activity related to the trading of bulk materials of agricultural origin, bulk material is transported in large quantities in tanks and containers by means of mass transport, such as trucks, railway wagons or barges. In such activity, it is necessary to comply with the established standards of quality control of agricultural products, because the quality of the product affects its intended use and price. Samples to determine the quality of the transported bulk material are collected using sampling devices that often operate in an automated manner.

In the solutions known in the state of the art, sampling devices for bulk materials have a vertical column permanently anchored in the ground, on which a driving module is mounted. The driving module has a base connected to the column and an arm connected thereto, at the free end of which a sampling probe is attached. The arm in many cases has a telescopic structure and is rotatably attached to the base, which allows the arm to move up and down. The task of the driving module is to insert the sampling probe into the material being collected. In the case of a telescopic arm, its length is set before driving the probe and remains constant during the driving process. Rotary mounting of the arm to the base results in guiding the probe in an arc while driving it into the bulk material. This causes the mechanical system to be loaded with forces resulting from the displacement of the probe immersed into the bulk material, not only in the direction along the axis of the probe, but also in the direction transverse to the axis of the probe. It also makes it difficult to operate the probe precisely. Furthermore, these difficulties are also caused by unpredictable, variable forces of interaction between the probe and the bulk material. In the case of operating close to the walls of containers with bulk material, the inability to precisely predict the trajectory of the movement of the probe may lead to a collision with elements of the environment and, consequently, to damage.

In the state of the art, there are also solutions with a gantry on which a sampling mechanism is seated. In such solutions, guides are used to allow the probe to move vertically while driving into the bulk material. However, these are solutions characterized by large dimensions, and thus also a high price.

The document <CIT> discloses a typical pneumatic device for sampling bulk products comprising a mast in the form of a stationary vertical column seated in the ground, on the upper part of which an arm in the form of a parallelogram is mounted. The arm has a kinematic structure of a parallelogram and consists of two longer connectors and two shorter connectors. At the end of the arm, a probe is attached to the shorter connector. The upward and downward movement of the arm is provided by a pneumatic cylinder mounted under the arm in the upper part of the vertical column.

While the patent document <CIT> discloses a device for collecting soil samples comprising a structure with a pair of arms forming a parallelogram system connected to a support structure. The pair of arms is movably connected to vertical arms of the support structure. At the free end of the pair of arms, a probe in the form of a drill is mounted for collecting soil samples. The pair of arms forming a parallelogram is raised and lowered by hydraulic cylinders that are pivotally attached to the top of the vertical arm of the support structure frame.

Sampling devices are also used outside of agriculture. The patent document <CIT> discloses a device for automatically sampling material during casting processes. The sampling device comprises a crawler chassis on which a sampling mechanism is mounted, comprising a rigid base pivotally connected with two connectors, and the upper ends of which are pivotally connected by a short connector. In the upper part, an arm with a sampling probe is attached to the shorter connector. The arm is moved up and down by means of a mechanical lift with two vertical guides. A rigid base is seated in the vertical guides, which moves up and down together with the connectors connected thereto and the arm with the probe.

Besides, <CIT> discloses a device for sampling particulate material. This device contains a support pole that is attached to a moveable dolly or alternatively may be rigidly connected to a permanent support. The support pole has an arm with a sampling probe. The sampling probe is attached to the arm by a plate which is pivotally connected to said arm. The arm may be rotated about the support pole in order to be position over a bed of said particulate material from which position the probe may be lowered into said material. The support pole is connected to a sleeve by means of a hinge, and said sleeve is connected to the arm with the sampling probe. An actuator in form of a hydraulic piston is pivotally connected to sleeve at the bottom of the sleeve by hinge. Piston rod is pivotally connected at its upper end extending from piston to arm by hinge. As the piston rod is raised the arm is raised and as the piston rod is lowered the arm is lowered.

Document <CIT> discloses mechanism of the overload of a crane or the like and an over alarm device. When a hook exceeds a predetermined ascent height in a crane operation, and a load applied to a suspended article is reduced.

What is more, <CIT> discloses a device for taking a samples from a mass of grains. The grain sampling device has a vertical tubular probe, which is connected to a support. Support is connected to a mast by two arms forming an articulated parallelogram. An actuator connects said mast with one of the arms, thus moving probe along a substantially vertical trajectory in order to be raised or lowered. The probe itself is connected by a flexible conduit to a grain receptacle.

A old type of grain sampling probe in known from document <CIT>. In the document the grain sampling probe, comprised of a base, an elongated support pole, a support arm pivotally connected at one end to the top portion of the support pole, an elongated hollow probe pivotally connected to the other end of said support arm, a power output means and a mechanical drive means associated with the power output means to move the probe at a uniform rate of speed downwardly and upwardly so that the probe will obtain a truly representative core sample of the grain or other material within a grain hauling vehicle.

The aim of the invention is to solve the technical problem of the non-linear movement of the probe during the process of driving the probe into the bulk material, which is difficult to precisely control. The aim is also to limit uncontrolled transverse forces acting on the probe during driving into the bulk material.

The invention relates to a mechanism for sampling, especially of bulk materials, having a rigid base connected by at least two rockers to an arm, at the free end of which the probe is pivotally mounted. Rockers are pivotally connected to the base and the arm. The arm is in the form of a rigid beam of constant length, with the first rocker mounted at the end of the arm, and the second rocker attached to the arm. The essence of the invention is in that the length of the boom part of the arm, corresponding to the section between attachment point of the second rocker and the attachment point of the probe is at least <NUM> times greater than the distance between the points of attachment of the first and second rocker to the arm. Furthermore, the quotient of the distance of the point attachment of the probe from the line defined by the points of attachment of the first and second rocker to the arm and the length of the section defined by the points of attachment of the first and second rocker to the base ranges between <NUM> and <NUM>.

It is expedient for the mechanism to have a driving mechanism attached thereto.

It is reasonable when the driving mechanism is pivotally mounted on the base and is connected to the arm.

It is especially good when the driving mechanism is attached to the arm behind the attachment point of the second rocker, i.e. the length of the section defined by the point of attachment of the driving mechanism to the arm and the attachment point of the probe to the arm is shorter than the length of the section defined by the point of attachment of the second the rocker to the arm and the attachment point of the probe to the arm.

It is equally good if the base of the mechanism has a bracket on which the driving mechanism is pivotally mounted.

Preferably, the base has a mounting plate.

It is equally appropriate that the arm has a slant arranged between the attachment point of the second rocker and the free end of the arm with the probe so that the free end of the arm with the probe is arranged at an angle relative to the part of the arm that is connected to the first and second rockers.

It is also reasonable for the angle between the part of the arm with the attachment points of both rockers and the part of the arm with the probe to be between <NUM>° and <NUM>°.

The main advantage of the invention is that thanks to the connection of the arm with the base through two rockers and maintaining the size ratios of the individual elements of the mechanism, in the required range of work, during the movement of the arm - and thus the probe - up and down, the probe moves along the path strongly similar in shape to a straight line section. Deviations from straightness may occur, but are not greater than the cross-sectional diameter of the probe. This minimizes the value of the transverse forces acting on the probe during its driving and facilitates the operation of the probe, making the path of the probe's trajectory with high accuracy coincide with the constant vertical axis in the entire working range. Thanks to this design, the up and down movement of the probe and the position of the probe in the bulk material are fully predictable for the operator. This directly translates into the certainty and precision of controlling the probe both when driving it into the bulk material and when operating it over the material and above containers or storage boxes. An additional advantage of the invention is the reduction of the production costs of the device by eliminating the need to use progressive kinematic pairs in the form of telescopic guides enabling linear movement, because the technical implementation of progressive pairs with high transverse load capacity is expensive. Furthermore, the sampling mechanism can cooperate with the driving mechanism, which allows the high functionality of the sampling mechanism to be maintained. Furthermore, the arm with a slant allows for a particularly good adaptation of the sampling mechanism for bulk materials of agricultural origin, where often the probe must be driven into a grain container with high walls. This arm design is particularly useful when taking samples from various types of trailers having sides of different heights.

The invention is presented in an embodiment and in the drawing, in which <FIG> shows a kinematic diagram of the mechanism, <FIG> - a kinematic diagram of the mechanism in various positions of the arm, and <FIG> - the mechanism design in a side view.

A sampling mechanism <NUM> is designed to collect samples of bulk materials, especially of agricultural origin. It comprises a rigid base <NUM>. The base <NUM> is formed by a rigid bracket 2A fixedly attached to a horizontal mounting plate <NUM> by means of posts of different heights. The mounting plate <NUM> is adapted to be mounted on a mechanical system enabling the plate to be maneuvered in such a way that it is possible to move the sampling mechanism <NUM> together with the mounting plate <NUM> along the horizontal axis or to rotate the sampling mechanism <NUM> together with the mounting plate <NUM> around the vertical axis.

The rigid bracket 2A of the base <NUM> is connected by a first rocker <NUM> and a second rocker <NUM> to an arm <NUM> in the form of a rigid beam of constant length. The first and second rockers <NUM>, <NUM> have a constant length. The first and second rockers <NUM>, <NUM> are connected to the base <NUM>, i.e. to the rigid bracket 2A, and to the arm <NUM> in a pivotal manner. The length of the rigid bracket 2A corresponds to the length a of the section defined by the points of attachment of the rockers <NUM>, <NUM> to the rigid bracket 2A, and thus to the base <NUM>. Additionally, the rigid bracket 2A is attached at an angle α to the mounting plate <NUM>, and thus is inclined relative to the horizontal plane. The angle α between the section defined by the points of attachment of the first and second rockers <NUM>, <NUM> to the base <NUM> and the horizontal plane is <NUM>°.

In an embodiment, the first and second rockers <NUM>, <NUM> and the arm <NUM> have been implemented as single parts of the mechanism, but in other embodiments it is possible to multiply them, for example doubling the single parts.

In other embodiments, it is possible to make the rockers as double elements mounted on both sides of the arm, which in the kinematic diagrams will be presented as a single functional part, such as a single rocker.

At the free end of the arm <NUM>, a probe <NUM> is pivotally mounted. The probe <NUM> mount is a non-driven pivot that enables it to achieve a vertical position due to the force of gravity.

The arm <NUM> itself, has a slant <NUM> arranged between the attachment point of the second rocker <NUM> and the free end of the arm <NUM> with the probe <NUM> and two inseparably and immovably connected parts can be distinguished therein. The free end of the arm <NUM> with the probe <NUM> is arranged at an angle β with respect to the part of the arm <NUM> that is connected to the first and second rockers <NUM>, <NUM>, and is inclined towards the base <NUM>. In an embodiment, the angle β between the part of the arm <NUM> with the attachment points of the first and second rockers <NUM>, <NUM> and the part of the arm with the probe <NUM> is obtuse and equals to <NUM>°. In order to maintain the straightness of the movement of the probe <NUM>, the point of attachment of the probe <NUM> to the free end of the arm <NUM> is not collinear with the straight line k determined by the points of attachment of the first rocker <NUM> and the second rocker <NUM> to the arm <NUM>. Additionally, the quotient of the distance h of the probe <NUM> attachment point and line K defined by the points of attachment of the first and second rockers <NUM>, <NUM> to the arm <NUM> and the length a of the section defined by the points of attachment of the first and second rockers <NUM>, <NUM> to the base <NUM> ranges between <NUM> and <NUM>, and in an embodiment it is <NUM>. In other embodiments, however, when using a straight arm, to attach the first rocker <NUM> or the second rocker <NUM> to the arm, a spacer should be used, moving the attachment point of this connector away from the axis of the arm <NUM>. The second rocker <NUM> is connected to the arm <NUM> in such a way in such a way that the length e of the section between the point of attachment of the second connector <NUM> to the arm <NUM> and the point of attachment of the probe <NUM> to the arm <NUM> is at least <NUM> times greater than the length c of the section between the points of attachment of the first and second rockers <NUM>, <NUM> to the arm <NUM>. So, the following inequality is valid: <MAT> where:.

In an embodiment, the length e of the section between the point of attachment of the second connector <NUM> to the arm <NUM> and the point of attachment of the probe <NUM> to the arm <NUM> is <NUM> times greater than the length c of the section between the points of attachment of the connectors <NUM>, <NUM> to the arm <NUM>.

In this description, it is assumed that the length of the section between the attachment point of the second rocker <NUM> and the attachment point of the probe <NUM> defines the boom part of the arm <NUM>.

Furthermore, the base <NUM> includes the bracket 2B of the driving mechanism <NUM>, to which a driving mechanism <NUM> in the form of an electric linear motor is pivotally connected. On the other side, the electric linear motor is pivotally connected to the arm <NUM>, behind the attachment point of the second rocker <NUM>. This means that the length of the section defined by the point of attachment of the electric linear motor to the arm <NUM> and by the point of attachment of the probe <NUM> to the arm <NUM> is smaller than the length the section defined by the point of attachment of the second rocker <NUM> to the arm <NUM> and the point of attachment of the probe <NUM> to the arm <NUM>.

In other embodiments, any type of actuator may be used as the driving mechanism. The drive can also be directly connected to the plate <NUM> and also implemented as a rotary drive of the second rocker <NUM>.

In an embodiment, the ratios between the lengths of the individual parts of the sampling mechanism <NUM> satisfy the following relationships:.

The following conditions have been met in the entire mechanism <NUM>: <MAT> <MAT> <MAT> <MAT> <MAT> <MAT> <MAT> where:.

The above-described ratios between the lengths of the individual parts of the sampling mechanism <NUM>, as well as the above-described angular values, have the following values: <MAT> <MAT> <MAT> <MAT> <MAT> <MAT> <MAT>.

Claim 1:
A sampling mechanism, especially for bulk materials, having a rigid base (<NUM>) connected by at least two rockers (<NUM>, <NUM>) to an arm (<NUM>), at the free end of which the probe (<NUM>) is pivotally connected; wherein the rockers (<NUM>, <NUM>) are pivotally connected to a base and the arm, wherein the arm (<NUM>) is in the form of a rigid beam of constant length and wherein the first rocker (<NUM>) is mounted at the end of the arm (<NUM>) and the second rocker (<NUM>) is attached to the arm (<NUM>), characterized in that the length (e) of a boom portion of the arm (<NUM>) corresponding to the section between the attachment point of the second rocker (<NUM>) and the attachment point of the probe (<NUM>) is at least <NUM> times greater than the distance (c) between the points of attachment of the first and second rockers (<NUM>, <NUM>) to the arm (<NUM>); and, furthermore, the quotient of the distance (h) of the point of attachment of the probe (<NUM>) from the line (K) defined by the points of attachment of the first and second rockers (<NUM>, <NUM>) to the arm (<NUM>) and the length (a) of the section determined by the points of attachment of the first and second rockers (<NUM>, <NUM>) to the base (<NUM>) ranges between <NUM> and <NUM>.