JPH0550639U - Keyboard switch with cantilevered key top - Google Patents

Abstract

(57) [Summary] [Purpose] To reduce the number of assembly processes and the number of parts. A housing 50 is provided with a recess 52 opening to the display surface side, an engagement protrusion 56 protruding into the recess 52, and a through hole 58 penetrating the pressing portion 36 of the hinge-type key top 32. To do. Through hole 6 that engages the mounting portion 40 with the engagement protrusion 56 and allows the operation portion 34 of the key top 32 to penetrate therethrough.
The concave plate 52 is formed by heat-sealing the name plate 60 on which the No.
The mounting portion 40 is fixed to the housing 50 by heat welding corresponding portions of the name plate 60 to at least one of the engaging projection 56 and the mounting portion 40. The heat welding and the mounting portion 40 for covering the recess 52 are provided in the housing 50.
It is possible to simultaneously perform the heat welding for fixing to the sheet in one step. Since the concave plate 52 is covered with the name plate 60, the cover sheet which has been necessary in the past is not necessary.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an improvement of a keyboard switch that turns on and off a switch portion mounted on a substrate depending on whether or not a key top supported by a housing is cantilevered.

[0002]

[Prior Art]

 Conventionally, this type of keyboard switch has been constructed as shown in FIG. That is, a lower FPC (flexible printed circuit board, the same applies hereinafter) 12, a spacer 16 having through holes 14, ... Thus, the membrane switch parts 20, ... Are formed. The membrane switch unit 20 includes a fixed contact 22 formed on the upper surface of the lower FPC 12 and a movable contact 24 formed on the lower surface of the upper FPC 18, and the fixed contact 22 and the movable contact 24 have through holes. They are facing each other through 14.

Reference numeral 26 denotes a housing (including a case, a cover, a door, etc. for mounting the key top) provided on the upper portion of the substrate 10. The housing 26 has a recess 28 opened downward. An engaging projection 30 formed integrally with the housing 26 is formed in the recess 28. Reference numeral 32 denotes a key top that is supported by the housing 26 in a cantilevered manner. The key top 32 includes an operating portion 34, a pressing portion 36, a hinge portion 38, and a mounting portion 40. The pressing portion 36 is located above the membrane switch portion 20, penetrates the through hole 42 of the housing 26, and protrudes to the outside. The mounting portion 40 engages with the engagement protrusion 30 and the tip portion 31 of the engagement protrusion 30. Are crushed by heat welding and fixed to the mounting portion 40.

Reference numeral 44 is a cover sheet that covers the recess 28 of the housing 26. The cover sheet 44 is formed by an adhesive 45 on the lower opening end surface of the housing 26 and the tip portion 31 of the engaging projection 30. It is fixed to the end face. Further, the cover sheet 44 is provided with a through hole 46 penetrating the pressing portion 36 of the hinge type key top 32. A display plate 48 is fixed to the upper side (display surface side) of the housing 26 with an adhesive 47.

[0005]

[Problems to be solved by the device]

 However, in the above-mentioned conventional example, the tip portion 31 of the engaging projection 30 of the housing 26 is fixed to the mounting portion 40 by heat welding, and the cover sheet 44 is fixed to the lower side of the housing 26. Since the display plate 48 is fixed to the upper side of the housing 26 by covering the recess 28, there are problems that the number of assembling steps is increased and the number of parts is increased. The present invention has been made in view of the above problems, and an object of the present invention is to provide a key board switch that cantileverly supports a key top that can reduce the number of assembly steps and the number of parts. It is intended.

[0006]

[Means for Solving the Problems]

 The present invention is a keyboard switch in which a switch mounted on a substrate is turned on and off by a key top that is cantilevered in a housing. And an engaging protrusion protruding into the recess, and a through hole through which the pressing portion of the key top penetrates, and the mounting portion of the key top is engaged with the engaging protrusion of the housing, A display plate having a through hole for penetrating the operation portion of the key top is fixed to an opening end portion of the housing on the display surface side to cover the recess of the housing, and the engagement protrusion of the housing and the key. -The key top is cantilever-supported to the housing by fixing corresponding portions of the display plate to at least one of the mounting portions of the top.

[0007]

[Action]

 The display plate is fixed (for example, heat-welded) to the opening end of the housing on the display surface side and to one or both of the engaging projection of the housing and the mounting portion of the key top to cover the concave portion of the housing. Since the key top mounting part is fixed to the housing, the fixing for covering the recessed part of the housing and the fixing for mounting the key top mounting part to the housing must be performed simultaneously in one step. You can Further, since the display plate covers the recess of the housing, the cover sheet conventionally used to cover the recess of the housing becomes unnecessary.

[0008]

【Example】

 FIG. 1 shows an embodiment of a keyboard board according to the present invention that cantileverly supports a key top. In FIG. 1, reference numeral 10 denotes a substrate. On the substrate 10, a lower FPC 12 having fixed contacts 22, ... Formed on the upper surface thereof and a spacer having through holes 14 ,. -16 and the upper FPC 18 having the movable contacts 24, ... Formed on the lower surface thereof are sequentially laminated and fixed, thereby forming the membrane switch section 20, ... As an example of the switch section.

Reference numeral 50 denotes a housing (including a case, a cover, a door, etc. for attaching the key top) provided at a predetermined position on the upper side of the substrate 10. The housing 50 has a display surface side. A concave portion 52 that is open to a certain upper side is formed. The bottom plate 54 of the housing 50 is integrally formed with an engaging protrusion 56 that protrudes into the recess 52, and also has a through hole 58 located above the membrane switch unit 20.

Reference numeral 32 denotes a keytop that is supported by the housing 50 in a cantilever manner. The keytop 32 includes an operating portion 34, a pressing portion 36, a hinge portion 38, and a mounting portion 40 that are integrally formed. .. The tip of the pressing portion 36 of the key top 32 penetrates the through hole 58 of the housing 50 and is in contact with the upper surface of the upper FPC 18 of the membrane switch portion 20. The mounting portion 40 of the key top 32 is formed in a substantially cylindrical shape, and is inserted and engaged with the engaging protrusion 56 of the housing 50.

Reference numeral 60 is a display plate formed of a metal plate such as aluminum, and a heat-welding film 62 formed of a thermosetting resin is applied to the lower surface of the display plate 60. The outer periphery of the lower surface of the display plate 60 is fixed to the engagement step portion 64 formed at the open end of the housing 50 by heat welding, and the tip 57 of the engagement protrusion 56 of the housing 50 is fixed to the display plate. It is crushed by heat welding and fixed to the corresponding portion of the lower surface of 60, and the attachment portion 40 of the key top 32 is fixed to the housing 50 by this adhesion. The display plate 60 is provided with a through hole 66 for penetrating the operating portion 34 of the key top 32.

The fixing of the display plate 60 by heat welding is performed as follows. First, the display plate 60 is placed on the opening side of the recess 52 of the housing 50. At this time, the tip of the engaging projection 56 is in contact with the lower surface of the display plate 60 at a position higher than the cross section of the engaging step portion 64, and the outer periphery of the lower surface of the display plate 60 is engaged with the engaging step portion 64. Positioning is performed so that the operating portion 34 of the key top 32 penetrates the through hole 66. Then, a predetermined pressure (for example, 5 kg / cm ² ) is applied to the display plate 60 for a predetermined time (for example, 10 seconds) to pressurize it and heat it at a predetermined temperature (for example, 110 ° C.).

Then, the outer circumference of the lower surface of the display plate 60 is fixed to the engaging step portion 64 of the housing 50 by heat welding, and the tip 57 of the engaging protrusion 56 of the housing 50 is crushed to correspond to the lower surface of the display plate 60. The spot and the heat welding for fixing are simultaneously performed. That is, in one heat welding step, the welding for covering the recess 52 of the housing 50 and the welding for mounting the mounting portion 40 of the key top 32 to the housing 50 are simultaneously performed.

Next, the operation of the above embodiment will be described. (A) When the operating portion 34 of the key top 32 is pushed downward in the state shown in FIG. 1, the hinge portion 38 is elastically deformed around the fulcrum, and the pressing portion 36 fixes the movable contact 24 of the membrane switch portion 20 to the fixed contact. It is brought into contact with 22 and is switched on. (B) When the pressing of the key top 32 to the operating portion 34 is released, the state returns to the state of FIG. 1 due to elasticity, so that the movable contact 24 of the membrane switch section 20 comes out of contact with the fixed contact 22 and the switch Turns off.

In the above-described embodiment, the display plate is heat-welded to the engaging protrusion of the housing to fix the mounting portion of the keytop to the housing. However, the present invention is not limited to this, and at least the housing is not limited thereto. The key top mounting portion may be fixed to the housing by heat-welding the display plate to one of the engaging protrusion and the key top mounting portion.

For example, as shown in FIG. 2, the upper end surface of the mounting portion 40 a when the mounting portion 40 a of the key top 32 is engaged with the engaging protrusion 56 of the housing 50 is the engagement step portion 64 of the housing 50. It is formed on a surface having substantially the same height as the step surface of the key top 32, and the corresponding portion of the heat-welding film 62 of the display plate 60 is heat-welded to the upper end surface of the attachment portion 40a so that the attachment portion 40a of the key top 32 is formed. It may be fixed to the housing 50. At this time, the tip of the engaging protrusion 56 is not heat-welded to the display plate 60. Alternatively, the tip end surface of the engaging projection 56 is also formed at the same height as the upper end surface of the mounting portion 40a, and the front end surface of the engaging projection 56 and the upper end surface of the mounting portion 40a are attached to the heat welding film 62 of the display plate 60. The attachment portion 40a of the key top 32 may be fixed to the housing 50 by heat welding to the corresponding location.

In the above embodiment, the fixing of the opening end of the housing to the display plate and the fixing of the engaging protrusion of the housing or the mounting portion of the key top to the display plate are performed by heat welding. The present invention is not limited to this, and fixing other than heat welding (for example, fixing with an adhesive) may be used.

[0018]

[Effect of the device]

 As described above, the key board switch which cantileverly supports the key top according to the present invention has the opening end on the display surface side of the housing, the engaging projection of the housing and the mounting portion of the key top or By fixing (for example, heat-sealing) the display plate to both sides, the recess of the housing is covered and the mounting portion of the key top is fixed to the housing. It is possible to simultaneously fix the attachment portion of the key top to the housing. Therefore, compared to the conventional example in which fixing for covering the recess of the housing and fixing for mounting the key top mounting portion to the housing are performed separately, the number of fixing steps is reduced and assembly is simplified. Can be converted. Further, since the display plate covers the recess of the housing, the conventional cover sheet used to cover the recess of the housing is not required, and the number of parts can be reduced.

[Brief description of drawings]

FIG. 1 is a key which cantileverly supports a key top according to the present invention.
FIG. 3 is a front view showing an embodiment of a board switch and showing most of it in section.

FIG. 2 shows another embodiment of the present invention, and is a front view showing a major part in section.

FIG. 3 shows a conventional example, and is a front view showing most of the section.

[Explanation of symbols]

 10 ... Board 12 ... Lower FPC (flexible printed circuit board) 16 ... Spacer 18 ... Upper FPC (flexible printed circuit board) 20 ... Membrane switch part 32 ... Key top 34 ... Key top 32 operation part 36 ... Key -Pressing portion 38 of top 32 ... Hinge portion 40, 40a of key top 32 ... Mounting portion of key top 32 ... Housing 52 ... Recessed portion of housing 56 ... Engaging projections 58, 66 ... Through hole 60 ... Display plate 64 ... Engaging step

Claims (2)

[Scope of utility model registration request] 1. A keyboard switch in which a switch mounted on a substrate is turned on and off by a key top that is cantilevered in a housing, wherein the housing has a recessed portion that is open on the display surface side. And an engaging protrusion protruding into the recess and a through hole through which the pressing portion of the key top penetrates, and the mounting portion of the key top is engaged with the engaging protrusion of the housing, A display plate having a through hole for penetrating the operating portion of the key top is fixed to the opening end of the housing on the display surface side to cover the recess of the housing, and the engaging projection of the housing and the key. A cantilevered keytop, characterized in that the keytop is cantilevered by the housing by fixing corresponding portions of the display plate to at least one of the mounting portions of the top. Supported keyboard switch. 2. A keyboard board with cantilevered support of the key top according to claim 1, wherein the switch section attached to the substrate is a membrane switch section.