GB2290125A - Dual function manual control device, eg for vehicle ventilation systems - Google Patents

Abstract

The control device (10) has a control element (12, 14, 20) such as a knob or slider which can be moved in a predetermined direction or path of movement between a number of first control positions to control a first function and can also be temporarily moved to a second control position (22 - 26) to control a second function by moving the control element (12, 14, 20) in the same direction as for the first control function. Thus, the control device (10) can control a plurality of functions with a simple control element (12, 14, 20). When used for vehicle ventilation systems, the control elements (12, 14, 20) may control the blower fan, air temperature and air distribution as respective first functions and air recirculation, air conditioner actuation and rear screen heater actuation as respective second functions. <IMAGE>

Description

CONTROL DEVICE The present invention relates to a control device, for example a dual function control switch for a vehicle ventilation system.

Control devices for use in controlling vehicle ventilation systems and the like are well known. These may include rotary knobs which can rotate either between discrete settings, for choosing for example between various options, or have infinite movement, for controlling for example air temperature.

It is also known to have in systems such as vehicle ventilation systems some electrically controllable components, such as a rear windscreen demister or an air conditioning unit. These components may be controlled by a switch of the momentary contact type to enable the component to switch off automatically, for example after a predetermined operating period. The control switches may either be separate dedicated switches or may be combined with a mechanical control device, for example a temperature control knob. When combined with another device, this has always been by adding to the device an additional direction of movement unconnected to the main direction of movement of the device. For example, in a known vehicle, a rotary temperature control knob can be pulled out from its normal position by a predetermined amount to activate the rear windscreen heater.

A problem with such a type of dual function control device is that it is expensive.

The present invention seeks to provide an improved control device and vehicle ventilation system.

According to an aspect of the present invention, there is provided a control device comprising a control element movable in a predetermined direction or path of movement between at least two first control positions to control a first function associated with the control device; the control device including a second control position associated with a second function, the control element being movable in said predetermined direction or path of movement to reach the second control position and thereby to actuate the second function.

Considerable cost saving can be achieved with a control device of the above type since it is not necessary to provide different directions or paths of movement to the control element. Moreover, the control device can be easier to use since the control element need only be moved in a single direction or path of movement.

Preferably, the control device comprises biasing means for biasing the control element out of the second control position towards one of the first control positions. In this manner, the first function can still be controlled following actuation of the second function.

The control device may comprise an electrical switch associated with the second function and actuable when the control element is moved to the second control position. The electrical switch is preferably a momentary contact switch.

In a preferred embodiment, the control device comprises two or more second control positions associated with a plurality of second functions, the control element being movable in said predetermined direction or path of movement to reach each second control position. It may not be possible with some prior art control devices to control three or more different functions with the same control element, as can be the case with the present control device.

Preferably, the control element is rotatable around an axis of rotation, the at least two first control positions being disposed along an arc of rotation of the control element, the or each second control position being disposed adjacent an or a respective end of said arc. Such a control element may be a rotary control knob.

Alternatively, the control element may be a linearly slidable element, the at least two first control positions being disposed within a predetermined length of travel of the control element, the or each second control position being disposed adjacent an or a respective end of said predetermined length of travel.

According to another aspect of the present invention, there is provided a vehicle ventilation system including at least one control device as herein specified.

An embodiment of the present invention is described below, by way of example only, with reference to the accompanying drawing, in which: Figure 1 is a front elevational view of embodiments or rotary control knobs incorporating temporary control positions for actuating momentary electrical switches; and Figure 2 is a front elevational view of embodiments of control sliders incorporating temporary control positions for actuating momentary electrical switches.

Referring to Figure 1, the embodiment of multi-function control unit 10 shown provides complete control for a vehicle ventilation system. The control unit 10 includes a fan blower control knob 12 rotatable between five discrete positions designated 0 to 4 for controlling a ventilation blower motor between zero speed and full speed. A temperature control knob 14 is, in this example, infinitely variable between a maximum temperature position 16 and a minimum temperature position 18 and controls a heating element or valve for providing heated incoming air. An air direction control knob 20 is rotatable between four positions for directing air (i) to the vehicle windscreen only, (ii) to both the windscreen and the feet of the front passenger footwells, (iii) to the passenger footwells only and (iv) to the dashboard vents only.

The functions performed by the rotary control knobs 12,14,20 are of conventional type so will not be described further herein. These functions can be thought of in this example as being mechanically operated by the rotary knobs 12,14,20 in that rotation of each knob 12,14,20 causes movement of an element (not shown) associated with the particular function assigned to that control knob. In each of the above-described positions, the rotary control knobs 12,14,20 remain in the position selected, such that the ventilation system continues to operate at the selected settings until a change is manually made.

In addition to the above-mentioned functions, each of the control knobs 12,14,20 can be rotated on application of pressure thereto to close temporarily an electrical switch (not shown). For example, the blower motor control knob 12 can be rotated temporarily beyond the 0 position to a temporary position 22 to close an on/off switch for activating an air re-circulation function. The temperature control knob 14 can be rotated temporarily beyond the minimum temperature position 18 to a temporary position 24 to close an on/off switch for activating an air conditioning system. Similarly, the air direction control knob 20 can be rotated temporarily beyond the windscreen demist position to a temporary position 26 to close an on/off switch for activating a rear windscreen heater unit.

The positions 22,24,26 of the control knobs 12,14,20 are in this embodiment temporary positions, such that as soon as rotational pressure applied to each control knob is released, a suitable spring (not shown) causes the control knob to return to the adjacent "permanent" setting, such as the 0 position in the case of blower control knob 12, minimum temperature position 18 in the case of temperature control knob 14 and windscreen demist position in the case of air direction control knob 20. Each of these functions can be de-activated if desired by rotating the relevant control knob 12,14,20 to the temporary position 22,24,26 to close the on/off switch a second time and thereby to toggle the function to the off state. This provides full driver control of each function.

By use of momentary contact switches and of the temporary positions of the control knobs 12,14,20, it is possible for the air re-circulation, air conditioning and rear heater functions to be switched off by other means, for example by a timer after expiry of a predetermined operating time, by a temperature control device when a predetermined temperature is reached, or by the vehicle ignition circuit when the ignition is first switched on. The functions can be switched on again by rotating the relevant control knob 12,14,20 to its associated temporary position.

The functions activated by rotation of the control knobs 12,14,20 to their temporary positions 22-26 can be thought of in this example as electrical functions since they are activated by an electrical switch.

It will be apparent that even when the relevant function has been activated, the primary "mechanical" function associated with each control knob 12,14,20 can still be controlled by rotating the control knob 12,14,20 to any of its other positions without affecting the operating state of the electrical function.

In an alternative embodiment, each of the positions 22,24,26 is a permanent position, such that the relevant knob 12,14,20 remains in that position until moved therefrom by the driver or a passenger.

It will be apparent that the electrical function controllable by each knob 12,14,20 is controlled by rotating the knob 12,14,20 in the same manner as it is normally rotated to control its primary "mechanical" function.

There is no need to have a second direction of movement of the control knobs 12,14,20.

A second embodiment of multi-function control unit 30 is shown in Figure 2. This control unit 30 includes three sliders 32,34,36 which are reciprocably slidable within respective slots along a single line of movement. The slider 32 controls the direction of air into the passenger compartment in a similar manner to the air direction control knob 20.

The slider 34 controls air temperature in a similar manner to the temperature control knob 14, while the slider 36 controls the blower motor in a similar manner to the blower control knob 12.

Each of the sliders 32-36 is movable from one of its extreme positions 38 (in Figure 2 the left-hand-most position) to a temporary position 40,42,44, respectively. In its position 40 the air direction control slider 32 switches on or off a rear windscreen heater, while in its position 42 the temperature control slider 34 switches on or off an air conditioning unit, and in its position 44 the blower control slider 36 activates or deactivates an air re-circulation function.

Each of the sliders 32,34,36 moves out of its temporary position 40,42,44 when pressure applied to the slider is removed by a biasing force produced by a spring (not shown) to cause the slider to move to the adjacent extreme position, in a similar manner to the equivalent control knob of Figure 1.

In a similar manner to the rotary control knobs 12,14,20 of the embodiment of Figure 1, the sliders 32,34,36 move along the same path in order to activate their electrical function. It will also be apparent that the positions 40,42,44 shown could be permanent positions, although this is less desirable.

The operation of the sliders 32,34,36 is basically the same at that of the rotary knobs 12,14,20 of the embodiment of Figure 1, so will not be described further herein.

Maintaining a common direction of movement of the control devices 12-20 and 32-36, in the examples shown rotation or linear movement, considerably reduces the cost of each control device and simplifies its construction compared to control devices which have two separate directions of movement for the separate functions.

The temporary nature of the positions 22-26 and 40-44 ensures that each control knob 12,14,20 or slider 32-36 can still be used to control its other function whilst the electrical component associated therewith has been activated.

It will also be apparent that each control device 12,14,20 and 32-36 could include more than one temporary control position. For example, each control device could include a temporary position beyond the end of both of its normal extremities of travel. This would enable each of the control devices described above to control three different functions. With other types of control device, it may be possible to control even more separate functions.

Although the above embodiments show only rotary and sliding control devices, other types of control device could be adapted to incorporate the principles described above.

Claims (9)

Claims:

1. A control device comprising a control element movable in a predetermined direction or path of movement between at least two first control positions to control a first function associated with the control device; the control device including a second control position associated with a second function, the control element being movable in said predetermined direction or path of movement to reach the second control position and thereby to actuate the second function.

2. A control device according to claim 1, comprising biasing means for biasing the control element out of the second control position towards one of the first control positions.

3. A control device according to claim 1 or 2, comprising an electrical switch associated with the second function and actuable when the control element is moved to the second control position.

4. A control device according to claim 3, wherein the electrical switch is a momentary contact switch.

5. A control device according to any preceding claim, comprising two or more second control positions associated with a plurality of second functions, the control element being movable in said predetermined direction or path of movement to reach each second control position.

6. A control device according to any preceding claim, wherein the control element is rotatable around an axis of rotation, the at least two first control positions being disposed along an arc of rotation of the control element, the or each second control position being disposed adjacent an or a respective end of said arc.

7. A control device according to any one of claims 1 to 5, wherein the control element is a linearly slidable element, the at least two first control positions being disposed within a predetermined length of travel of the control element, the or each second control position being disposed adjacent an or a respective end of said predetermined length of travel.

8. A vehicle ventilation system including at least one control device according to any preceding claim.

9. A control device substantially as hereinbefore described with reference to and as illustrated in Figure 1 or Figure 2 of the accompanying drawing.