Patent Description:
Conventional hand brake valves, in particular the ones that are used in applying and releasing the parking brake of the commercial vehicles are known. For instance, the European patent publication <CIT> is one such hand brake valve.

In some conventional hand brake valves, a feedback means is provided within the device to inform the drivers/users/operators of the commercial vehicles whether an intended movement in relation to a handle of the hand brake valves has been successful or not. One of the means for providing such a feedback to the drivers is an audible "click" noise. Another means for providing such a feedback or combined with the audible click to the drivers is through a tiny tactile force feedback experienced by the drivers after completing the intended movement of the handle of the hand brake valves.

In certain operation conditions such feedback means discussed above may not be enough for the drivers of the commercial vehicles to know or realize that the hand brake valve has been engaged or not. This is particularly relevant in situations, wherein due to external factors or the environment in which the conventional hand brake valves operate and/or due to faulty working of the hand brake valves, the hand brake valves may wrongly indicate to the user or the drivers of the commercial vehicle with the requisite feedback as mentioned in the previous paragraph, but in fact, are not actually engaged i.e., the intended movement of the handle is not successful.

It is one of the objectives of the present invention to provide further improvements in relation the feedback means of the hand brake valves, whereby the drivers or operators of the commercial vehicles can successfully identify whether the intended movement of the handle of the hand brake valves to engage or disengage the parking brake has been completed.

In accordance with an embodiment of the present invention, a hand brake valve is disclosed. The hand brake valve comprises a housing, a handle that is configured to pivot with respect to a geometric center point, wherein the handle pivots from a non-engaged position towards an engaged position and/or vice-versa, and indicating means for indicating that the hand brake valve is in the engaged position, wherein the indicating means is configured to physically draw an indicator element outside the housing so as to provide a user of the hand brake valve with a visual signal that the hand brake valve is in the engaged position. One of the technical advantages of providing the indicating means according to the present invention, is that, by drawing the indicator element out of the housing, a simple mechanism is created which combines a visual indication to the user of the hand brake valve while at the same time, optionally, providing an audible click. Such a simple mechanism can be provided as a standalone confirmation to the driver of the vehicle or the user of the hand brake valve or can be combined with an electronic switch activating a lamp in a vehicle dashboard.

The term "indicating means", in accordance with the present embodiment, may refer to a device or an apparatus or a group of components that facilitates indicating the engaged position of the hand brake valve.

In accordance with the above embodiment or in relation to a different embodiment, when the handle is at the non-engaged position, the indicator element is completely within the housing. Such a clear separation of the position of the indicator element within or outside the housing enables the user of hand brake valve to discern what the actual position of the hand brake valve is, with clarity.

Furthermore, in relation to one or more of the above-mentioned embodiments, the indicating means further includes a linear tube for receiving the indicator element such that the indicator element linearly reciprocates within the linear tube, wherein the linear tube is preferably integrally formed with respect to the housing. The linear tube, for instance, aligns the indicator element in a direction that is suitable for drawing the indicator element out of the housing without or with a least amount of resistance, which is caused e.g., due to friction between an internal surface of the linear tube and the indicator element.

In one or more of the above embodiments, wherein the hand brake valve further comprises a pivotable lever, which is connected to the indicator element at a first end of the pivotable lever is configured to pivot with respect to a pivot shaft. The technical purpose of the pivotable lever is to maintain the position of the indicator element at the disengaged position (of the hand brake valve) within the housing and nudge the same indicator element outside the housing at the engaged position of the hand brake valve, particularly when the handle pivots to the appropriate position in the direction as indicated in the accompanying figures.

In conjunction with the embodiment explained in the previous paragraph, wherein the hand brake valve further includes a counterweight which follows the movement of the handle, and wherein the pivotable lever is selectively pushed by the counterweight downwards at its second end when the handle reaches the engaged position. In this present context, the word "follows" may mean that the counterweight follows the motion or the moment of the handle. For instance, the arcuate motion of the handle is closely followed up to a point and then the counterweight drops at a slot to move the pin outside the housing. Furthermore, when the handle reaches the engaged position, the counterweight pushes the pivotable lever down at the second end such that the indicator element is drawn outside the housing. With the help of this counterweight pushing the pivotable lever, in addition to pushing the indicator element out of the housing, the user of the hand brake valve may additionally hear an audible signal such as a "click" noise to be assured of the function that the hand brake valve has indeed been moved to the engaged position. In a particular implementation, the counterweight is held under the tension exerted by a spring, and as soon as the handle of the hand brake valve reaches the engaged position, the tension of the spring may be released and the counterweight falls down to hit the second end of the pivotable lever.

Still furthermore, the pivotable lever of the one or more embodiments of the present invention includes a slot for receiving the indicator element to establish a mechanical connection between the pivotable lever and the indicator element. It may however be necessary to provide a feature such that the indicator element is not released from the pivotable lever once it is moved or drawn outside the housing of the hand brake valve. This ensures that the pulling the indicator element within the housing and drawing it outside can be done repeatedly in cycles of operation of the hand brake valve.

In relation to one or more of the above embodiments, the handle pivots with respect to the geometric center point (C) with the help of a pivoting element, wherein the pivoting element is received at an arcuate receiver.

Furthermore, the hand brake valve, in accordance with the one or more embodiments discussed above, further comprises an inclined slot for selectively receiving the counterweight and for sliding the counterweight towards the pivotable lever. Such a slot naturally conforms to the dimensional requirements of the counterweight as well as makes the counterweight move in a direction aligned to hit the pivotable lever at its second end, e.g., at an appropriate location. Thus, the inclined slot not only provides the required direction for the counterweight to move down, but also facilitates ensuring that the counterweight pushes e.g., the right part of the pivotable lever. This ensures that the indicator element is drawn out of the housing with necessary reliability.

On a different, the hand brake valve of the above embodiments may additionally include an electric switch actuated by the indicating means, wherein the electric switch activates directly or indirectly (e.g. via a vehicle electronic control unit) either a light signal or the auditory signal to confirm that the hand brake valve is (indeed) in the engaged position, and wherein, preferably, the light signal indicating that the hand brake valve is in the engaged position is provided at a vehicle dashboard.

<FIG> illustrates a non-engaged position of a hand brake valve <NUM> in accordance with an embodiment of the present invention.

In the present embodiment, hand brake valve <NUM> comprises a housing <NUM>, a handle <NUM> that is configured to pivot with respect to a geometric center point (C), wherein handle <NUM> pivots from a non-engaged position towards an engaged position and/or vice-versa and indicating means <NUM> for indicating that the hand brake valve <NUM> is in the engaged position. The term "indicating means", in accordance with the present embodiment, may refer to a device or an apparatus or a group of components that facilitates indicating the engaged position of hand brake valve <NUM>. For instance, as mentioned above, handle <NUM> while pivoting with respect to the geometric center point C, it can move along a pivoting movement as marked e.g., with the reference sign "P" in <FIG>. This movement is facilitated by having handle <NUM> connected with a pivoting element <NUM> which has a circular surface <NUM>. This circular surface <NUM> of pivoting element <NUM> coordinates with an arcuate receiver <NUM> to facilitate the pivoting movement of handle <NUM>. For the sake of completeness, it is noted that the physical connection between handle <NUM> and pivoting element <NUM> is not directly shown in <FIG>, but such a physical connection does exist.

Furthermore, in accordance with the present embodiment, indicating means <NUM> is specifically configured to physically draw an indicator element <NUM> outside housing <NUM> so as to provide a user of hand brake valve <NUM> with a visual signal that hand brake valve <NUM> is in the engaged position. In particular, according to the illustration of the present embodiment, indicator element <NUM> is pushed out of housing <NUM> as will be shown in the explanation below. One of the technical advantages of providing indicating means <NUM> according to the present invention, is that, by drawing indicator element <NUM> out of housing <NUM>, a simple mechanism is created which combines a visual indication to the user of hand brake valve <NUM> while at the same time, providing an audible click (more on this below). Such a simple mechanism can be provided as a standalone confirmation to the driver of the vehicle or the user of hand brake valve <NUM> or can be combined with an electronic switch (not shown) activating a lamp (not shown) in a vehicle dashboard (not shown).

In accordance with the same or different embodiment, when handle <NUM> is at the non-engaged position, indicator element <NUM> is completely within housing <NUM>. Such a clear separation of the position of indicator element <NUM> within or outside housing <NUM> enables the user of hand brake valve <NUM> to discern what the actual position of hand brake valve <NUM> is, with clarity. As will be shown during the explanation of other features of hand brake valve <NUM> of the present invention, the errors or inadvertent wrong signals regarding the position of handle <NUM> of hand brake valve <NUM> is substantially reduced to the simplified mechanism.

As shown also in <FIG>, indicating means <NUM> further includes a linear tube <NUM> for receiving indicator element <NUM> such that indicator element <NUM> linearly reciprocates within linear tube <NUM>, wherein linear tube <NUM> is preferably integrally formed with respect to housing <NUM>. Linear tube <NUM>, for instance, aligns indicator element <NUM> in a direction that is suitable for drawing indicator element <NUM> out of housing <NUM> without resistance.

Further, in an embodiment of the present invention, hand brake valve <NUM> further comprises a pivotable lever <NUM>, which is connected to indicator element <NUM> at a first end <NUM> of pivotable lever <NUM> is configured to pivot with respect to a pivot shaft <NUM>. This region where pivotable lever <NUM> and indicator element <NUM> are connected to each other is marked with reference sign "<NUM>" in <FIG>. The technical purpose of pivotable lever <NUM> is to maintain the position of indicator element <NUM> at the disengaged position (of hand brake valve <NUM>) within housing <NUM> and nudge same indicator element <NUM> outside housing <NUM> at the engaged position, particularly when handle <NUM> pivots to the appropriate position in the direction as indicated with reference sign "P" in <FIG> and <FIG>.

It follows from the above, the pivotable lever <NUM> includes a slot (not shown in <FIG> and <FIG>) for receiving indicator element <NUM> to establish a mechanical connection between pivotable lever <NUM> and indicator element <NUM>. Further, handle <NUM> pivots with respect to the geometric center point (C) with the help of a pivoting element <NUM>, wherein pivoting element <NUM> is received at an arcuate receiver <NUM>.

In accordance with one or more above embodiments discussed in relation to <FIG>, hand brake valve <NUM> further comprises an electric switch (not shown in figures) actuated by indicating means <NUM>. In accordance with this implementation, the electric switch provides the possibility of indicating that hand brake valve <NUM> is in an engaged position with the help of e.g., a lamp.

Furthermore, the electric switch may also activate either a light signal or the auditory signal to confirm that hand brake valve <NUM> is in the engaged position, and wherein, preferably, the light signal indicating that hand brake valve <NUM> is in the engaged position is provided at a vehicle dashboard (not shown in the figures).

<FIG> illustrates an engaged position of hand brake valve <NUM> in accordance with an embodiment of the present invention.

In the same or different embodiment as discussed in the previous paragraphs, hand brake valve <NUM> further includes a counterweight <NUM> which follows the (pivoting) movement (P) of handle <NUM>, and wherein pivotable lever <NUM> is selectively pushed by counterweight <NUM> downwards at its second end <NUM> when handle <NUM> reaches the engaged position. In this way, when the user of hand brake valve <NUM> moves handle <NUM> via knob <NUM> from a disengaged position, counterweight <NUM> may move along with handle <NUM> or may stay in a stationary position with or without the help of a spring to retain counterweight <NUM> under tension, but as soon as handle <NUM> reaches the engaged position, counterweight <NUM> drops down.

It follows from the above, wherein, when handle <NUM> reaches the engaged position, counterweight <NUM> pushes (as it drops down) pivotable lever <NUM> down at second end <NUM> such that indicator element <NUM> is drawn outside housing <NUM> (c. With the help of this counterweight <NUM> pushing pivotable lever <NUM>, in addition to pushing indicator element <NUM> out of housing <NUM>, the user of hand brake valve <NUM> may additionally hear an audible signal such as a "click" noise to be assured of the function that hand brake valve <NUM> has indeed been moved to the engaged position.

Claim 1:
A hand brake valve (<NUM>), comprising
a housing (<NUM>),
a handle (<NUM>) that is configured to pivot with respect to a geometric center point (C), wherein the handle (<NUM>) pivots from a non-engaged position towards an engaged position and/or vice-versa, and
indicating means (<NUM>) for indicating that the hand brake valve (<NUM>) is in the engaged position,
characterized in that,
the indicating means (<NUM>) is configured to physically draw an indicator element (<NUM>) outside the housing (<NUM>) so as to provide a user of the hand brake valve (<NUM>) with a visual signal that the hand brake valve (<NUM>) is in the engaged position.