Patent Description:
Due to their operational environment, underground mining machines are subjected to high potential hazard during operation. Particularly, underground mining machines are usually used in an environment with a potentially explosive atmosphere where methane is present. Therefore, such systems have to meet demanding regulatory requirements as regards explosion prevention to avoid that any source of ignition is exposed to the potentially explosive atmosphere surrounding the mining machine during its operation.

Large underground mining machines, such as longwall mining machines, are equipped with control cabinets having a human interface device for receiving input from an operator, based on which a function of the mining machine is controlled. These control cabinets are typically exposed to the potentially explosive atmosphere and, accordingly, have to meet the demanding regulatory requirements in view of explosion prevention.

Control cabinets of underground mining machines are known which are equipped with a human-machine interface formed by a plurality of individually provided control elements for controlling the function of the mining machine and its components. These control elements may be provided in the form of translationally actuatable buttons, i.e. which are actuated upon being pushed by an operator. Alternatively or additionally, control elements may be employed which are actuated upon being rotated or pivoted by an operator.

<CIT> refers to a single key setting and operating device for a flame-proof switch. <CIT> refers to a dual independent push button rotary knob assembly. <CIT> refers to an explosion-proof mushroom button head.

Starting from the prior art, it is an objective to provide an improved human interface operating device for use in an underground mining machine. It may also be an objective to provide a human interface operating device which in particular has an improved user operability and, at the same time, meets the regulatory requirements for such an application. Further, it is an objective to provide an underground mining machine which is equipped with such a human interface operating device.

These objectives are solved by means of a human interface operating device and an underground mining machine according to the independent claims. Preferred embodiments are set forth in the present specification, the Figures as well as the dependent claims.

In the following, the invention will be explained in more detail with reference to the accompanying Figures. In the Figures, like elements are denoted by identical reference numerals and repeated description thereof may be omitted in order to avoid redundancies.

<FIG> shows a human-machine interface (HMI) <NUM> installed in a control cabinet of an underground mining machine (not shown), such as a longwall mining machine, in the following referred to as "the mining machine". Specifically, the control cabinet may be provided in the mining machine such that the HMI <NUM> is arranged at an outer surface thereof so as to be easily accessible for an operator. In this way, the HMI <NUM> is exposed to an environment of the mining machine and thus, during operation, may be subjected to a potentially explosive atmosphere.

Generally, the HMI <NUM> refers to an interface of the mining machine, via which an operator interacts with the mining machine, i.e. a control cabinet (not shown) thereof , for controlling functions or for monitoring operating conditions thereof.

In the shown configuration, the HMI <NUM> comprises an input unit in the form of a human interface operating device <NUM> for receiving a user input from the operator, in response of which functions of the mining machine are to be controlled. Further, the HMI <NUM> comprises a display unit <NUM> for providing information, e.g. feedback information, to the operator about operating conditions or parameters of the mining machine. In other words, by means of the HMI <NUM>, operation of the mining machine can be controlled and supervised by an operator.

For receiving user input, the operating device <NUM> is provided with a physical component in the form of a control element <NUM> which is intended and configured for being actuated by an operator, i.e. by an operator's hand. In this way, the operating device <NUM> enables that the operator gives input to the control cabinet for controlling the mining machine. Specifically, by actuating the control element <NUM> of the operating device <NUM>, the operator can control functions of the mining machine, such as setting operating parameters, setting operating conditions, reading out operating parameters, reading status messages, performing test functions, etc. More specifically, for doing so, the operator may use the control element <NUM> so as to navigate, e.g. scroll, through a menu list displayed to the user by the display unit <NUM> and to select individual menu items from the menu list so as to cause the control cabinet or the mining machine to perform a function associated to the selected menu item.

To that end, the display unit <NUM> may be a touch-sensitive display unit, i.e. having a touchscreen, and may constitute a further input unit, i.e. in addition to the operating device <NUM>. In such a configuration, the HMI <NUM> is provided with redundancy to increase its reliability. In other words, an operator can control functions of the mining machine by using either the operating device <NUM> or the touchscreen of the display unit <NUM>.

In the following, the structural configuration of the operating device <NUM>, which constitutes a human interface operating device, is specified with reference to <FIG> and <FIG>.

The operating device <NUM> is configured and designed such that, in a mounted state of the operating device <NUM> in which it is secured to a housing <NUM> of the control cabinet as depicted in <FIG>, it forms a flameproof enclosure according to the IEC <NUM>-<NUM> standard, in particular the IEC <NUM>-<NUM>:<NUM> standard, for sealing an inside from an outside of the control cabinet. In other words, the shown operating device <NUM> forms a flameproof enclosure of the control cabinet which meets the requirements set forth in the IEC <NUM>-<NUM> standard, in particular the IEC <NUM>-<NUM>:<NUM> standard. By doing so, the operating device <NUM> is configured and designed such that, in the mounted state, it has a pressure resistance of more than <NUM> bar, for example, <NUM> bar. In other words, the operating device <NUM> is designed so as to withstand a pressure difference, e.g. of <NUM> bar or more than <NUM> bar, between the inside and the outside of the housing <NUM> of the control cabinet. Such a pressure difference may occur due to a malfunction, particularly an unintended explosion within the control cabinet.

With such a configuration, the inside of the control cabinet may be sufficiently sealed from its outside when being used for the intended application. In other words, even if an unintended explosion occurs within the housing <NUM> of the control cabinet during operation of the mining machine, it may be prevented that a potentially explosive atmosphere present around the control cabinet becomes inflamed thereby, particularly by a flame propagating through the housing <NUM>, the operating device <NUM> or a junction therebetween.

As regards its structural configuration, the operating device <NUM> comprises a base body <NUM> which is secured to the housing <NUM> of the control cabinet. The base body <NUM> supports the control element <NUM> which is partly accommodated therein. Specifically, the base body <NUM> includes a through bore <NUM> extending along a longitudinal axis L of the operating device <NUM>, within which the control element <NUM> is received. The through bore <NUM> extends from an inner end <NUM> towards an outer end <NUM> of the operating device <NUM> and opens into a recess <NUM> provide at the outer end <NUM>. In the context of the present disclosure, the term "inner end" refers to an end section of the operating device <NUM> which, in the mounted state in which the operating device <NUM> is secured to the housing <NUM> of the control cabinet, is accommodated in the inside of the control cabinet. Accordingly, the term "outer end" refers to an end section of the operating device <NUM> which is arranged opposed to the inner end <NUM> and which, in the mounted state, is exposed to the outside of the control cabinet, i.e. the environmental atmosphere of the mining machine.

A circumferential outer surface of the base body <NUM> comprises three adjacent and cylindrically shaped portions being provided with differing diameters. Particularly, at the outer end <NUM>, the base body <NUM> includes a threaded portion <NUM> that is releasably secured to the housing <NUM> by means of a threaded connection. Specifically, the housing <NUM> is provided with a bore, an inner surface of which is provided with a further threaded portion <NUM> that is designed complementary to and engaged with the threaded portion <NUM> of the base body <NUM>.

Adjacent to the further portion <NUM>, the base body <NUM> includes a protruding portion <NUM> which, in a radial direction of the base body, i.e. perpendicular to the longitudinal axis L, extends beyond the threaded portion <NUM>. Specifically, the protruding portion <NUM> is designed and configured such that, in the mounted state, a lateral outer surface, i.e. which faces the outside end <NUM>, abuts on a lateral inner surface of the housing <NUM>, i.e. which faces the inside of the control cabinet.

Further, at the inner end <NUM>, the base body <NUM> further includes a lowered portion <NUM> having a diameter that is lower compared to the threaded portion <NUM>. As can be gathered from <FIG> and <FIG>, three spacer screws <NUM> are secured to an end surface of the lower portion <NUM>, by means of which a circuit board <NUM> of the operating device <NUM> is hold in a predefined position relative to the base body <NUM>. Specifically, the circuit board <NUM> is fastened to the spacer screws <NUM> by means of further screws as indicated in <FIG>, in which, for overview reasons, the circuit board <NUM> is not shown.

As set forth above, the base body <NUM> is secured to the housing <NUM> by means of a threaded connection. In this configuration, the coupling between the base body <NUM> and the housing <NUM> is provided such that it forms a flameproof enclosure according to the IEC <NUM>-<NUM> standard, in particular the IEC <NUM>-<NUM>:<NUM> standard. For doing so, the threaded connection between the base body <NUM> and the housing <NUM> is designed so as to fulfill the corresponding requirements set forth in the IEC <NUM>-<NUM> standard, in particular the IEC <NUM>-<NUM>:<NUM> standard. Particularly, to form a flameproof enclosure, a gap formed between the engaged threaded portions <NUM>, <NUM> of the based body <NUM> and the housing <NUM> is provided with a certain gap width and a certain gap length. In the shown configuration, the threaded connection between the base body <NUM> and the housing <NUM> is provided with a size of M95, a pitch of <NUM> and a fit of <NUM>/<NUM>. Further, the threaded connection extends along the longitudinal axis L over <NUM>. In other words, the threaded connection is provided with a length l<NUM> of <NUM>.

As can be gathered from <FIG>, the longitudinal axis L of the operating device <NUM> coincides with the longitudinal or rotational axis of the control element <NUM>. The control element <NUM> is built up from a plurality of separated components which are releasably secured to one another for facilitating assembly and disassembly of the operating device <NUM>. As to substance, the control element <NUM> comprises a shaft <NUM> which extends through the through bore <NUM> of the base body <NUM> such that an outer end section <NUM> thereof protrudes into the recess <NUM>. As can be gathered from <FIG>, the shaft <NUM> comprises two adjacent and cylindrically shaped portions of different diameters. Specifically, the shaft <NUM> includes an engagement portion <NUM> which is received within and complementary designed to the through bore <NUM> of the base body <NUM>. At the inner end <NUM>, the shaft <NUM> includes a widened portion <NUM> having a diameter that is greater compared to the engagement portion <NUM> of the shaft <NUM>. In other words, the widened portion <NUM> protrudes beyond the engagement portion <NUM> in a radial direction of the control element <NUM>. The control element <NUM> further comprises a knob <NUM> which is releasably and force-fittingly mounted to the outer end section <NUM> of the shaft <NUM> by means of a connecting screw <NUM>. The knob <NUM> has a diameter which is greater than the diameter of the engagement portion <NUM> of the shaft <NUM>. Further, the knob <NUM> is received within the recess <NUM>. In this way, the control element <NUM> is protected from being exerted to unintended high forces. For example, by such an arrangement, when being used in a mine, the control element <NUM> is shielded from rocks falling down from a ceiling of the mine. Further, for improving its operability, the knob is provided with a knurled surface, particularly at its circumferential outer surface.

The control element <NUM> further comprises a helical spring element <NUM> arranged around the outer surface of the shaft <NUM>, particularly around its outer end section <NUM>. Specifically, the spring element <NUM> is interposed between the knob <NUM> and an outer surface of the operating device <NUM>, particularly an inner bottom of the base body's recess <NUM>.

In the shown configuration, the control element <NUM> is provided in the form of a rotatably and axially actuatable control element for controlling functions of the underground mining machine. In other words, the control element <NUM> is configured and designed such that it can be actuated by an operator upon rotating the control element <NUM>. Further, the control element <NUM> is configured and designed such that it can be actuated by an operator upon translationally moving the control element <NUM>. Thus, upon rotationally or axially actuating the control element <NUM>, an operator can navigate through the menu list displayed onto the display unit <NUM> and select individual menu items to perform an associated function of the mining machine. For example, upon rotating the control element <NUM>, an operator may navigate through the menu list so as to highlight a desired menu item. Then, upon pushing i.e. translationally actuating, the control element <NUM>, the operator may select the highlighted menu item so as to perform a function associated thereto.

More specifically, the control element <NUM> is designed and configured such that it is rotationally actuatable around and axially actuatable along its longitudinal axis L. For doing so, the control element <NUM> is rotatably and translationally supported in the base body <NUM> of the operating device <NUM> by means of a plain bearing <NUM>. By this configuration, the control element <NUM> may be rotated relative to the base body <NUM> around its longitudinal axis L upon being rotationally actuated by an operator. Further, the control element <NUM> may be translationally or axially moved relative to the base body <NUM> along its longitudinal axis L upon being translationally actuated, i.e. pushed, by an operator. The axial movement of the control element <NUM> is limited. This means that the control element <NUM> may be translationally moved in the base body <NUM> within a predefined area. Specifically, as can be gathered from <FIG>, a relative translational movement between the control element <NUM> and the base body <NUM> is delimited, on the one side, by the widened portion <NUM> of the shaft <NUM> and, on the other side, by the knob <NUM>. This structural configuration may contribute to the pressure resistance of the operating device <NUM>.

The plain bearing <NUM> of the operating device <NUM> is formed by the shaft <NUM>, i.e. its engagement portion <NUM>, and the through bore <NUM> of the base body <NUM> which are engaged to one another. For allowing that the control element <NUM> can be actuated relative to the base body <NUM> in a convenient way for an operator, a defined gap is provided between the shaft <NUM>, i.e. its engagement portion <NUM>, and the through bore <NUM> of the base body <NUM>. In this way, a plain fit between the shaft <NUM>, i.e. its engagement portion <NUM>, and the through bore <NUM> of the base body <NUM> is provided. The plain bearing <NUM> forms a flameproof enclosure according to the IEC <NUM>-<NUM> standard, in particular the IEC <NUM>-<NUM>:<NUM> standard. In this way, it may be avoided that, in case of an unintended explosion in the inside of the control cabinet, a flame or any other medium capable of inflaming a potentially explosive atmosphere present at the outside of the control cabinet propagates through the gap between the shaft <NUM> and the trough bore <NUM>. For doing so, the gap between the shaft <NUM> and the base body <NUM> of the operating device <NUM> is designed so as to fulfill the corresponding requirements set forth in the IEC <NUM>-<NUM> standard, in particular the IEC <NUM>-<NUM>:<NUM> standard. Particularly, in the suggested plain bearing <NUM>, the gap between the shaft <NUM> and the base body <NUM> is provided with a certain gap width and a certain length. In the shown configuration, the plain fit between the shaft <NUM> and the through bore <NUM> is provided with a nominal size range of substantially <NUM> and a fit of H8/d9. In other words, between the shaft <NUM> and the through bore <NUM>, a clearance fit may be provided with a tolerance between <NUM> and +<NUM>. Further, the plain bearing <NUM> extends along the longitudinal axis over <NUM>. In other words, the plain bearing <NUM> is provided with a length l<NUM> of <NUM>.

For supporting the sealing effect of the gap provided between the shaft <NUM> and the through bore <NUM>, a sealing ring <NUM> is arranged between the shaft <NUM> and the through bore <NUM>. Specifically, the sealing ring <NUM> is disposed within a groove provided at the inner surface of the through bore <NUM> within the base body <NUM>, thereby forming a seal joint between the shaft <NUM> and the through bore <NUM> of the base body <NUM>.

Furthermore, at the inside end <NUM>, the control element <NUM>, particularly via the widened portion <NUM> of the shaft <NUM>, is force- or form-fittingly connected to a sensor unit <NUM> which is mounted onto the circuit board <NUM>. The sensor unit <NUM> is configured to sense or determine a rotational movement of the control element <NUM> relative to the base body <NUM> around its longitudinal axis L. Further, the sensor unit <NUM> is configured to sense or determine a translational movement of the control element <NUM> relative to the base body <NUM> along its longitudinal axis L. Based on the sensed or determined movements of the control element <NUM>, the sensor unit <NUM> generates an electric information signal which is transmitted to a data processor of the control cabinet which processes and interprets the received information signal so as to control the function of the mining machine.

As set forth above, the control element <NUM> comprises the spring element <NUM> which is interposed between the knob <NUM> and the base body <NUM>. In this way, the control element <NUM> is biased towards a neutral position as depicted in <FIG>, in which at least one of an axial position or orientation of the control element <NUM> is predefined relative to the base body <NUM> of the operating device <NUM>. In other words, when an operator actuates and thereafter releases the control element <NUM>, it is returned from its actuated position to its neutral position due to an elastic force exerted to the control element <NUM> by means of the spring element <NUM>.

It will be obvious for a person skilled in the art that these embodiments and items only depict examples of a plurality of possibilities. Hence, the embodiments shown here should not be understood to form a limitation of these features and configurations. Any possible combination and configuration of the described features can be chosen according to the scope of the invention.

This is in particular the case with respect to the following optional features which may be combined with some or all embodiments, items and/or features mentioned before in any technically feasible combination.

A human interface operating device, referred to as "the operating device" in the following, of an underground mining machine is provided. The operating device comprises a rotatably and axially actuatable control element for controlling functions of the underground mining machine, referred to as "the mining machine" in the following. The human interface operating device further comprises a base body configured to be secured to a housing of a control cabinet of the underground mining machine, wherein the control element is rotatably and translationally supported in the base body. The control element, at an inside-end section, is provided with a widened portion which, in a radial direction of the control element, protrudes beyond an engagement portion of the shaft, wherein the control element, at an outside-end section, is provided with a knob releasably mounted to the shaft, wherein a spring element is interposed between the knob and an outer surface of the base body. The knob <NUM> is received in its entirety within a recess provided at an outer end of the operating device (<NUM>).

By being provided with the control element, which can be actuated by an operator upon being rotationally as well as translationally moved, the suggested operating device of the mining machine can be operated in a more intuitive and more convenient way. Compared to known operating devices which are provided with control elements which are actuatable either rotationally or translationally, the suggested operating device enables an operator to provide his input to a single control element while allowing for a higher degree of freedom for interacting therewith. As a result, the suggested operating device is provided with an improved operability.

The proposed operating device may be intended to be used in a control cabinet of an underground mining machine, such as a longwall mining machine, but is not limited to this application. Rather, it may be used in any application which is subjected to regulatory requirements in view of explosion prevention.

Specifically, the operating device may be configured and designed such that, in the mounted state of the operating device in which it is secured to the housing of a control cabinet, it forms a flameproof enclosure according to the IEC <NUM>-<NUM> standard, particularly the IEC <NUM>-<NUM>:<NUM> standard. Further, the operating device may be configured and designed such that, in the mounted state, it has a compressive strength or pressure resistance of <NUM> bar or more than <NUM> bar, e.g. of <NUM> bar.

In a further development, the control element may be rotationally actuatable around and axially actuatable along a longitudinal axis of at least one of the operating device and the control element. For doing so, the operating device may comprise a base body configured to be secured to the housing of a control cabinet of the underground mining machine. The control element is rotatably and translationally supported in the base body. More specifically, the control element may be rotatably and translationally supported in the base body by means of a plain bearing. The plain bearing may be formed by a shaft of the control element and a through bore provided at the base body. The shaft and the base body may be engaged to one another so as to form the plain bearing.

Further, the plain bearing may form a flameproof enclosure according to the IEC <NUM>-<NUM> standard, particularly the IEC <NUM>-<NUM>:<NUM> standard. In other words, the plain bearing may form a flameproof enclosure having a protective class "d" according to the IEC <NUM>-<NUM> standard.

Specifically, the plain bearing may be configured such that the shaft and the through bore are provided with a plain fit relative to one another. By being provided with a plain fit, a gap between the shaft and the through bore are provided with a sealing effect which may contribute to the flameproof enclosure. As an example, the plain fit provided between the shaft and the through bore may have a nominal size range of substantially <NUM> and a plain fit of H8/d9. Further, the plain bearing may extend along the longitudinal axis over at least <NUM>, e.g. over at least <NUM>. In one configuration, the plain bearing may extend along the longitudinal axis over substantially <NUM>. The suggested operating device is not limited to this configuration. Rather, the skilled person understands that any plain bearing fulfilling the requirements set forth in the IEC <NUM>-<NUM> standard may fall under the scope of the suggested operating device.

In a further development, e.g. in the range of an inside end of the plain bearing, a sealing ring may be provided between the shaft and the base body, i.e. its through bore. In the context of the present disclosure, the term "inside end of the plain bearing" may refer to an end section thereof which, in a mounted state of the operating device, faces an inside of the housing of the control cabinet.

The control element may be connected to a sensor unit. The sensor unit may be configured to sense or determine a rotational and axial movement of the control element. Specifically, the sensor unit may be configured to sense or determine a rotational movement of the control element around its longitudinal axis and an axial movement of the control element along its longitudinal axis.

In a further development, the control element may be biased towards a neutral or non-actuated position, in which at least one of an axial position or actual orientation of the control element relative to the base body predefined. For doing so, the operating device may be provided with a spring element which is interposed between the base body and the control element.

Further, the control element, at an inside-end section, may be provided with a widened portion which, in a radial direction of the control element, protrudes beyond an engagement portion of the shaft, i.e. which is engaged with the through bore of the base body. Further, the control element, at an outside end section being opposed to its inside end section, is provided with a knob releasably mounted to the shaft. The spring element is interposed between the knob and the outer surface of the base body.

Furthermore, an underground mining machine is provided which is equipped with an above-described human interface operating device. Since the proposed underground mining machine is equipped with the above-described human interface operating device, technical features which are described in connection with the operating device in the present disclosure may also relate and be applied to the underground mining machine.

Claim 1:
Human interface operating device (<NUM>) for an underground mining machine, comprising a rotatably and axially actuatable control element (<NUM>) for controlling functions of the underground mining machine,
further comprising a base body (<NUM>) configured to be secured to a housing (<NUM>) of a control cabinet of the underground mining machine, wherein the control element (<NUM>) is rotatably and translationally supported in the base body (<NUM>), wherein the control element (<NUM>), at an inside-end section, is provided with a widened portion (<NUM>) which, in a radial direction of the control element (<NUM>), protrudes beyond an engagement portion (<NUM>) of a shaft (<NUM>), wherein the control element (<NUM>), at an outside-end section, is provided with a knob (<NUM>) releasably mounted to the shaft (<NUM>), wherein a spring element (<NUM>) is interposed between the knob (<NUM>) and an outer surface of the base body (<NUM>),
characterized in that
the knob <NUM> is received in its entirety within a recess (<NUM>) provided at an outer end (<NUM>) of the operating device (<NUM>).