Activation keyboard, particularly for motor-vehicle climate controls

BACKGROUND OF THE INVENTION

This invention concerns an activation keyboard, especially for a motor-vehicle climate control device for being installed from a front side of a dashboard instrument panel, which keyboard includes a housing in which a circuit board having electric and electronic components thereon is arranged, with a plurality of keys, or buttons, of the keyboard acting on switches of the circuit board.

Such a keyboard is disclosed in German patent document DE 43 44 054 C2, but this keyboard has a large depth, which is troublesome in some applications. Moreover, there is a need for a keyboard having a structure that can be assembled from its individual parts without further connecting elements such as screws, rivets or the like.

Thus, it is an object of this invention to provide a keyboard of the type described in the opening paragraph above having a small depth and allowing an uncomplicated mounting without the use of connecting elements.

SUMMARY OF THE INVENTION

According to principles of this invention, a keyboard of the general type described above has keys, or buttons, having guide projections which, when the keys are pushed from an operating side, are shoved along guide plates, or stemples with motion of each key being restricted by a locator, the locator having two stops which restrict the motion of the key between the two stops and with a switch activated by the key being switched ON and OFF within this motion. Advantageous embellishments are also possible.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is described and explained in more detail below using embodiments shown in the drawings. The described and illustrated features, in other embodiments of the invention, can be used individually or in preferred combinations. The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of a preferred embodiment of the invention, as illustrated in the accompanying drawings in which reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating principles of the invention in a clear manner.

FIGS. 1 and 2

are respectively top plan and side-elevation views of a keyboard of this invention,

FIG. 3

is an enlarged view of a portion III circled by a dashed line in

FIG. 2

,

FIG. 4

is a top plan view of a front side (operating side) of a housing of the keyboard of

FIG. 1

,

FIGS. 5 and 6

are side views of keys, or buttons, of the keyboard of

FIG. 1

,

FIGS. 7 and 8

are respectively top plan and side views of a carrier plate of the keyboard of

FIG. 1

, with segmented portions of the circuit board being shown in FIG.

7

and segmented portions of the housing and circuit board being shown in

FIG. 8

,

FIGS. 9

to

11

are cutaway views of portions of the keyboard of

FIG. 1

,

FIG. 12

is an enlarged view of a portion XII of

FIG. 11

enclosed in a dashed line, and

FIG. 13

is a cross-sectional view of a dovetail guide used in this invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1

shows a plan view and

FIG. 2

a side view of a keyboard

1

, especially for use to control a motor-vehicle air conditioner, which is front mounted in a dashboard instrument panel

2

, the keyboard including a housing

3

, in which electrical and electronic components are arranged, with a plurality of keys, or buttons,

4

of the keyboard acting on switches

5

(

FIG. 9

) arranged on a circuit board

6

(FIG.

9

).

The keys

4

, shown in

FIGS. 5 and 6

, are pushed, from an operating side thereof so that their guide projections

7

slide along guide plates

10

and the keys are held by snap-in locators

11

which limit displacement, or motion, between two stops

12

,

13

, with each switch

5

, which is activated by a respective key

4

, being switched ON and OFF within this displacement.

It is advantageous for the guide plate

10

and guide projection

7

to form an interlocking dovetail guide

14

(FIG.

13

), which extends through the openings

15

,

16

of the circuit board

6

and a carrier plate

17

(

FIGS. 7

,

9

). This structure allows placement of the circuit board

6

quite close to the keys

4

, with a so-called “drawer-effect”, preventing a tilting, or cocking, of the keys

4

.

The locator

11

is formed as a locking tab

20

on the guide plate

10

and a cutout

21

in the guide projection

7

; which may be seen in

FIG. 9

, with the locking tab

20

, because of elastic deformation of the wall of the guide projection

7

, snapping into the cutout

21

. Thus, connecting and securing elements are not needed.

Because key surfaces

22

of the keys

4

which contact the switches

5

are made in key frames

23

, a flat structure also results, with the key frames

23

assuring no deformation of the keys

4

themselves (

FIGS. 5

,

6

).

Front, visible, key-surface walls

24

extend beyond the key frames

23

(

FIGS. 5

,

6

) and are guided in key-guide openings

25

of a housing front wall

26

(FIG.

4

). A pleasing appearance is achieved in this way and light escape from illumination elements (not shown) in an interior of the keyboard

1

is prevented.

It is advantageous for the circuit board

6

to be borne by a carrier plate

17

, having clip attachments

27

inserted in a housing wall

30

(

FIG. 12

) and held in clip-slots

31

of the housing wall

30

(FIG.

3

). With this arrangement, an economical assembly of the keyboard

1

is achieve (FIG.

9

).

To indicate desired, adjusted standard data, the keyboard has a conventional LCD display (FIG.

10

), with bent gripper strips

32

of the carrier plate

17

, securing an LCD-element

33

that is in electrical contact with leads of the circuit board

6

vie compressed conductive-rubber pieces

34

. A durable, elastic retention of the LCD element

33

is assured by the compressed conductive rubber pieces

34

.

For an uncomplicated mounting of the keyboard

1

in an opening in the instrument panel

2

, the carrier plate

17

is provided with a spring bracket

35

(

FIGS. 7

,

8

) for reaching around the housing-frame to be sprung inwardly by the instrument-panel wall of the instrument panel

2

when the keyboard

1

is mounted therein, and for clamping about this instrument-panel wall with a complementary hook structure

36

; an opposite other side of the housing wall

30

(

FIG. 2

) forming a receiving groove

38

for the instrument-panel wall with a receptacle part

37

and a housing front wall

26

. In this way, only the receiving groove

38

portion of the keyboard

1

need be placed, in the opening of the instrument panel

2

, that is, placed on the instrument panel wall, with the other side then being pressed into the opening, so that the spring bracket

35

flexes inwardly and clamps about the instrument panel wall with the hook structure

36

. In this way, an uncomplicated fastening of the keyboard

1

is achieved.

As presented in

FIGS. 8

to

11

, which show cross-sections of portions of the keyboard

1

, the bent gripper strips

32

, on both sides of the carrier plate

17

, are of bent angle brackets

40

, with cutouts

41

at a bending area

42

(

FIGS. 7

,

8

) being so arranged that legs

43

,

44

are created above and below the bending zone

42

, so that the legs

43

,

44

align the angle bracket

40

parallel relative to housing wall

45

.

In addition, the carrier plate

17

, can have bent affixing surfaces

46

in the cutouts

16

, through which the guide plates

10

extend on which the circuit board

6

can be supported for proper positioning.

FIG. 12

shows an enlarged section from

FIG. 11

, from which may be seen, how the clip elements

27

of the carrier plate

17

are snapped into the clip slots

31

, and likewise, how the legs

43

,

44

align the angle bracket

40

parallel relative to housing wall

45

.