JPH0566835U - Key switch - Google Patents

Abstract

(57) [Abstract] [Purpose] To elastically deform the rubber spring 6 placed below the intersection of two links 4 and 5 that are cross-linked in a side view in an X shape to guide the key top 2 up and down. , It is possible to easily change the size of the stroke of the key top 2 and prevent breakage of the links 4 and 5. [Structure] Pin portions 13a, 13b, 12a, 12b at free upper and lower ends of both links located on one side of a perpendicular line of a midway intersection of the first link 4 and the second link 5 are used as a key top 2 and a holder member. 7 are locked to the rotary locking portions 15 and 27, and the pin portions 11a and 11 at the upper and lower free ends of the both links.
b, 14a and 14b are locked to the sliding lock parts 16 and 28 of the key top 2 and the holder member 7. The length of the sliding groove in the sliding engagement portion 28 is increased so that the pin portions 14a and 14b do not support even when the key top 2 reaches the lowest position.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a key switch used for a keyboard of an input device such as a word processor and a personal computer.

[0002]

[Prior Art]

 Conventionally, as a key switch in a keyboard of this type, as disclosed in Japanese Patent Laid-Open No. 60-89011, a stem projecting downward on the lower surface of a key top is attached to a key holder portion formed in a holder member. A rubber spring with a contact point on the bottom surface is placed under the stem to support the guide so that it can be moved up and down, and a membrane switch with electrical contacts formed on the flexible sheet at the lower end of the rubber spring. Key switches equipped with the above switching members are generally used.

However, in such a keyboard, when the stroke amount is increased, the key stem and the stem guide that guides the key stem so as to move only in the vertical direction are increased accordingly, and the keyboard is thinned. There was a problem that it became difficult. Therefore, the present applicant previously proposed, in Japanese Patent Application No. 3-330160, a keyboard structure which solves the above problems and achieves a large stroke amount and can be made thin. In this keyboard, the upper and lower guide means of the key top is composed of a first link and a second link which are arranged so as to cross each other in an X shape in a side view, and both links are rotatably connected at their midway crossing portions. , One of the free ends of the first link and the second link is rotatably locked to the lower surface of the key top and the holder member, and the other of the free ends of the first link and the second link is the key top. It is slidably locked to the lower surface of the holder and the holder member, and a cap-shaped elastically deformable rubber spring is placed below the midway intersection of both links. It was proposed that the rubber spring be pressed and deformed via the so that the switching part would switch.

[0004]

[Problems to be solved by the device]

 However, even in this device, if the lower ends of the first link and the second link come into contact with the stopper at the end of the sliding range when the keytop is pressed, each link is pressed each time the keytop is pressed. There was a problem that bending stress would be applied to and the durability would deteriorate.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a key switch having good durability.

[0006]

[Means for Solving the Problems]

 To achieve the above object, the present invention provides a guide means for connecting and locking the lower surface of the key top and a holder member below the key top to guide and support the vertical movement of the key top, and the vertical input by the key top. In a key switch comprising a cap-shaped rubber spring elastically deformable via the guide means by an operation and a switching portion that performs a switch operation by the elastic deformation of the rubber spring, the guide means has an X-shaped side view. Of the first link and the second link, the two links are rotatably connected to each other at the midway crossing portion thereof, and the midway crossing portion of the free ends of the first link and the second link is connected. The free end located on one side across the perpendicular line passing through is rotatably locked to the lower surface of the key top and the holder member, and the free end positioned on the other side of the first link and the second link is The lower end of the first link or the second link is locked to the lower surface of the key top and the holder member so as to be slidable in a substantially horizontal direction, and the free end of the first link or the second link is located at the lowest position. The sliding length of the sliding engagement portion is set so as not to contact the end of the sliding engagement portion of the member.

[0007]

【Example】

 Next, an embodiment embodying the present invention will be described with reference to FIGS. FIG. 1 shows a side sectional view of a key switch. The key switch 1 includes a key top 2, a guide means 3 in which a first link 4 and a second link 5 are arranged in an X shape in a side view, and the guide means 3 Cap-shaped rubber spring 6 which is pressed by, a holder member 7 made of synthetic resin for supporting the guide means 3, and mounting portions 7a of the holder member 7 with switching parts 29, 29 (see FIG. 7). A flexible printed board 9 stretched on the lower surface of the holder member 7 and a reinforcing plate 10 stretched on the lower surface side.

As shown in FIGS. 1, 2 and 6, the rubber spring 6 is provided with a mounting hole for the holder member 7 so as to cover the switching parts (electrical contact parts) 29, 29 of the printed board 9 from above. It is inserted and arranged in 7a. The rubber spring 6 of the present invention is made of electrically insulating silicone rubber or EPDM (ethylene propylene diene methylene) or the like, and has a thick disk-shaped head in plan view, and a skirt extending downward from the periphery of the head. A downward-opening cap-shaped body is integrally formed of a dome-shaped dome portion and a thick-walled flange portion that extends radially outward substantially horizontally on the outer periphery of the dome portion. When the key top is pressed, the lower surface of the head of the rubber spring 6 which is pressed by the lower surface of the connecting and intersecting portion of the first link 4 and the second link 5 contacts the contact portions of the switching portions 29, 29. The movable contact portion 30 made of conductive rubber having conductivity for electrically turning on and off both switching portions is fixed. The entire rubber spring 6 may be formed to have conductivity by dispersing and filling conductive particles such as carbon black in silicone rubber.

The key top 2 formed of a synthetic resin such as ABS resin has an upper surface (front surface) on which letters such as numbers and letters are engraved or printed. On the lower surface of the key top 2, longitudinal longitudinal grooves for locking pin portions 11a, 11b on the upper free end side of the first link 4 which will be described later slidably in the longitudinal direction of the key top 2 in a substantially horizontal direction. -Shaped sliding locking portions 16 and 16 and hole-shaped rotation locking portions 15 and 15 for locking the pin portions 13a and 13b at the upper free end of the second link 5 so as to be rotatable only. A pair of left and right locking members 17 having a front-rear longitudinal direction, which are integrally provided with each other, are integrally formed or adhered by an adhesive or the like to project (see FIG. 3).

With reference to FIGS. 4A and 4B, the first link 4 and the second link 5 made of a synthetic resin such as glass fiber reinforced synthetic resin will be described in detail. FIG. 4A is a plan view of the first link 4, and FIG. 4B is a plan view of the second link 5. The first link 4 is formed integrally with the base portion 18 and the upper and lower free end portions 19 and 20 into a substantially H-shape in a plan view. The base portion 18 has a support hole 21 penetrating in a horizontal direction on its side surface. Prepare Pin portions 12a, 12b are laterally projected on the side surfaces of the arm portions 20a, 20b extending from both left and right ends of the lower free end portion 20, and pin portions 11a, 11b are laterally projected on the side surface of the upper free end portion 19. To project.

Further, the second link 5 is also integrally formed by the base 22 and the upper and lower free ends 23 and 24 into a substantially H shape in plan view. A pivot shaft 25 is laterally projected on one side surface of the base portion 22, and the pivot shaft 25 is fitted into the support hole 21 of the first link 4 to connect the first link 4 and the second link 5. The pivot shaft 25 is rotatably connected. On the side surfaces of the arm portions 24a and 24b extending from both left and right ends of the lower free end portion 24 of the second link 5, pin portions 14a and 14b are respectively provided to project laterally, and on the side surface of the upper free end portion 23, a pin is provided. The projections 13a and 13b are laterally projected.

In this embodiment, in a side view, the distance from the center line of the support hole 21 in the first link 4 to the center lines of the upper and lower pin portions 11 a, 12 a and the pivot shaft 25 of the second link 5 are shown. It is formed so that the distances from the center line to the pin portions 13a and 14a are equal to each other. According to this structure, as will be described later, the guide means 3 is rotationally displaced about the pin portions 12a and 12b on the lower free end side of the first link 4, so that the key top 2 is fixed to the holder member 7. It can be moved up and down in parallel with the top surface.

FIGS. 6 and 7 are views showing a part of a holder member 7 made of synthetic resin such as glass fiber reinforced synthetic resin. The holder member 7 is provided with a flange portion at the lower end of the cap-shaped rubber spring 6 A substantially rectangular mounting hole 7a that can be fitted so as not to be displaced is formed, and a pair of left and right rotation locking portions 27 and a front and rear longitudinal groove-shaped sliding locking are formed on both left and right edges of the mounting hole 7a. The part 28 is integrally formed by injection so that the respective locking parts 27, 28 open downward. Then, the pin portions 12a, 12b on the lower end side of the first link 4 are rotatably fitted and inserted into the rotation locking portions 27, 27, and the sliding locking portions 28, 28 After the pin portions 14a, 14b on the lower end side of the second link 5 are fitted so as to slide back and forth, the printed board 9 is fixed to the lower surface side of the holder member 7, and the pin portions 12a, 12b, 14a, It is configured so that 14b does not fall off.

At this time, the geometrical dimensions of the pin portions 11a, 11b and 14a, 14b and the sliding engagement portions 16, 28 are such that the first link 4 and the second link 5 are substantially immovable in the left-right direction in FIG. Moreover, it is determined so as not to interfere with the sliding of the pin portions 11a and 14a in the left-right direction in FIG. Specifically, in the present embodiment, the tip of each pin portion slides in contact with the outer side surface of the corresponding slide locking portion. Further, for this reason, the pivot shaft 25 is prevented from coming out of the support hole 21.

With this configuration, when the key top 2 is pressed down, the first link 4 rotates downward around the position of the rotation locking portion 27 of the holder member 7, so that the first link 4 and the second link 4 are rotated. The midway crossing portion that is pivotally connected to the X-shaped member 5 in a side view presses the head of the rubber spring 6 obliquely downward. Then, the front and rear lengths of the sliding grooves of the respective slide locking portions 28 of the holder member 7 (the length from the front stopper portion 31 to the rear end portion 32 is set to (L1) so that the key top 2 faces downwards. In the unpressed state (free state), the elastic force of the rubber spring 6 causes the pin portions 14a, 14b on the lower end side of the second link 5 to be slidably locked when the key top 2 is at the highest position. The front stopper portion 31 of each of the portions 28, 28 is configured to abut on the side surface on the side closer to the rotation locking portion 27).

Moreover, the ascending / descending distance of the key top 2 from the uppermost position of the key top 2 until the rubber spring 6 is pushed downward by the guide means 3 to the maximum extent (called a push-down state) is called a stroke. Even in the fully pushed state, the pin portions 14a, 14b on the lower end side of the second link 5 are attached to the rear end portion 32 of the side surface of the sliding engaging portions 28, 28 farther from the rotation engaging portion 27. The length (L1) of the sliding groove is set so as not to abut.

In this case, by changing the horizontal distance (L2) from the rotation locking portion 27 to the front stopper portion 31, the height from the upper surface of the holder member 7 when the key top 2 is at the maximum raised position. The size (H1) can be regulated. As a result, even if the length (L1) of the sliding groove is the same, only by changing the position of the front stopper portion 31, it is possible to change the maximum rising position of the keytop 2 and the actual stroke at the same time. For example, it is possible to provide a keyboard having a short stroke and a low maximum raised position of the key top.

Moreover, if the length (L1) of the sliding groove is made long, it is possible to prevent securing the key stroke even when arranging various key strokes as described above. Absent. That is, when the key switches having different keystrokes are installed in a single keyboard, or when the keyboards having different keystrokes are manufactured, the first and second links having a single shape can be used. Furthermore, since the pins 14a and 14b of the second link do not come into contact with the rear end portion 32 even when the rubber spring 6 is fully pushed, an unreasonable force acts on the pin portion of the second link 5 and the like. Instead, it is possible to prevent accidents such as breakage.

In order to change the distances (L1) and (L2), the position of the sliding engagement portion 28 and / or the groove length of the sliding groove portion in one of the injection molding dies of the holder member 7 is changed. May be changed, or after the slide lock portion 28 is formed by injection molding with a large thickness, the slide groove of the slide lock portion 28 where the stroke is to be changed is cut. By doing so, the front stopper portion 31 and / or the rear end portion 32 may be adjusted so as to be determined.

In order to regulate the uppermost position of the key top 2 and adjust the size of the stroke, the shape of the pair of locking members 17, 17 provided on the lower surface of the key top 2 is changed instead of the holder member 7. Is also good. That is, the front stopper portion 31 (rotation) of the slide locking portions 16 and 16 for locking the upper free end side pin portions 11a and 11b of the first link 4 slidably in the front-back direction in a substantially horizontal direction. The position on the side closer to the locking portion 15 and / or the length of the sliding groove of the sliding stopper 16 may be changed. Further, the rotation locking portion 15 and the sliding locking portion 16 may be separately provided on the lower surface of the key top 2.

In addition, in order to increase the length of the sliding groove in the sliding engaging portion 28, the rear end portion 32 may be formed as a rear open type engaging groove that is virtually absent. Further, a substrate such as a membrane switch circuit board may be used instead of the flexible printed board 9 forming the switching part 29, and the present invention can be applied to a variable capacitance type keyboard.

[0022]

[Operation and effect of the device]

 In short, according to the present invention, one free end of the first link or the second link cross-connected in an X shape in a side view is rotatably locked to the lower surface of the key top and the rotation locking portion of the holder member. On the other hand, the other free end is slidably locked in a substantially horizontal direction with respect to the lower surface of the key top and the sliding locking part of the holder member. With this configuration, the key top is vertically guided and supported with respect to the holder member. The rubber spring located below the cross-linking portion of the pair of links can be pressed by the downward rotational movement of the pair of links to perform the switching operation, so that the structure is extremely simple.

Furthermore, even when the key top is in the lowest position where the rubber spring has been pushed down, the free end of the link does not abut against one of the sliding engagement parts, so it is impossible for the link to rise and fall. It is possible to provide a key switch with excellent durability because no force acts and accidents such as broken links can be prevented.

[Brief description of drawings]

FIG. 1 is a side sectional view of a key switch.

FIG. 2 is a side cross-sectional view when a key switch is in a fully-depressed state.

FIG. 3 is a bottom view of the key top.

FIG. 4A is a plan view of a first link, and FIG. 4B is a plan view of a second link.

5 is a cross-sectional view taken along the line VV of FIG.

FIG. 6 is a plan view of a rubber spring and a mounting hole.

FIG. 7 is a perspective view of a mounting hole portion of a holder member.

[Explanation of symbols]

 1 Key Switch 2 Key Top 3 Guide Means 4 First Link 5 Second Link 6 Rubber Spring 7 Holder Member 7a Mounting Hole 9 Printed Circuit Board 10 Reinforcing Plate 11a, 11b, 12a, 12b Pins 15, 27 Rotation Locking Part 16 , 28 Sliding locking part 25 Pivot shaft 29 Switching part 30 Moving contact part 31 Front stopper part 32 Rear end part

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Isao Mochizuki 15-1 Naeshiro-cho, Mizuho-ku, Nagoya City Brother Industries, Ltd.

Claims (1)

[Scope of utility model registration request] 1. A guide means for connecting and locking a lower surface of a key top and a holder member below the key top to guide and support the vertical movement of the key top, and the guide means by vertical input operation by the key top. In a key switch including a cap-shaped rubber spring elastically deformable via a switch, and a switching unit that performs a switch operation by elastic deformation of the rubber spring, the guide means includes a first link cross-arranged in an X shape in a side view. A second link, the two links are rotatably connected at the midway intersection, and one side of the free ends of the first link and the second link is sandwiched by a perpendicular line passing through the midway intersection. The free end located on the lower side of the key top and the holder member is rotatably locked, and the free end located on the other side of the first link and the second link is connected to the lower surface of the key top and the holder member. And slidably locked to each other in a substantially horizontal direction, and the free end of the first link or the second link is slidably locked on the keytop or the holder member in a state where the keytop is located at the lowest position. A key switch characterized in that the sliding length of the sliding engaging portion is set so as not to come into contact with the end of the portion.