JPH01264125A - Depressing key switch - Google Patents

Abstract

PURPOSE:To integrally mold a compact key switch with a simple structure, prevent the deviation of buckling, and obtain the stable switch characteristic by coupling a spring member with a key system restricted to parallely move in the vertical direction and providing a circular movable contact at the boundary section between the upper and lower sections. CONSTITUTION:The upper section 7 of a spring material 5 has a insertion hole 11 of the lower end of a key system 13, the inclination of the spring material 5 is restricted by a key system 13 restricted to parallely move in the vertical direction and transmitting a key action, the depressing force is uniformly applied to the spring member 5. Its movable contact 17 is circularly provided along the boundary between the upper and lower sections, thus the transmission of the force of the reverse cup-shaped spring material 5 and the deformation by the buckling of the lower section 9 of the spring member 5 are unified by the effect of the circular contact 17 as a reinforcing frame. A key switch is made simple in structure and compact, it can be integrally molded, the deviation of the buckling of the lower section 9 of the spring member 5 is prevented, and the stable switch characteristic is obtained.

Description

[Detailed description of the invention] Nine sharpening forces [Industrial application field] The present invention relates to a press-down switch for a keyboard, etc., and is particularly simple in structure, easy to manufacture and start, and This invention relates to a press switch with stable on/off characteristics.

[Prior Art] Conventionally, push switches for keyboards and the like have been provided using two springs as shown in FIG. That is, the first spring is a coil compression spring 105 that receives the pressing blade from the key top 101 via the key stem 103, and the second spring is a coil compression spring 105 that supports the pressing blade from the coil compression spring 105. A rubber spring 109 is received through the stem 107.

The rubber spring 109 has an inverted cup shape, of which g
A movable contact 111 is provided at l. Movable contact 111
faces a fixed contact 115 provided on the printed circuit board 113, and when the key top 101 is pressed, the movable contact 111 contacts the fixed contact 115 and closes, turning on the switch. .

The rubber spring 109 has a click characteristic, as shown in characteristic A in FIG. 7, in which its repulsive force (load) increases with the pressing stroke, but buckles midway and the repulsive force rapidly decreases.

As shown in characteristic B, the coil compression spring 105 increases monotonically with respect to the stroke. This coil compression spring 105
The relationship between the rubber spring 109 and the rubber spring 109 is as shown in characteristic C in FIG. It contracts rapidly (point C3), and the movable contact 111 comes into contact with the fixed contact 115 almost instantaneously, turning on the switch. When returning the key top 101, at the position returned from the stroke where buckling occurred when pressed (point C5), the buckling returns, the movable contact 111 instantly opens from the fixed contact 115, and the switch is turned off. (C6 points). Due to such hysteresis and the force relationship between the two springs 105 and 109, the strokes differ between on and off, and the on/off is instantaneous, so chattering can be prevented.

As another conventional example, a key switch as shown in FIG. 15 has been proposed (!JsP 4.378, 478).

In this case, the entire spring member 200 has an inverted cup shape, and consists of an upper spring 201 and a lower spring 203.

The lower spring 203 buckles when the key stem 205 is pressed and exhibits a click characteristic. Upper spring 20 inside spring material 200
A disk-shaped movable contact 207 is provided at the boundary between the lower spring 203 and the lower spring 203. When the lower spring 203 buckles, it contacts the fixed contact 209 and turns on.

[Problem to be solved by the invention] However, with such a configuration, various problems arose.

In the former case, due to the characteristics of the coil spring, unless it is compressed to some extent from the beginning, the key switch will have a large stroke and be difficult to use.

As a countermeasure against this problem, it is possible to use the key stem 103 or the like to apply a compressive force, that is, a preload, but due to its structure, each key switch becomes large and may not meet the specifications of the keyboard. Furthermore, it will require more man-hours to get up in the morning.

The coil compression spring 105 is usually made of steel wire, and since the material is different from that of the lower rubber spring 109 and it cannot be integrally molded, a push-down auxiliary stem 107 is placed between the two springs 105 and 100.
It is necessary to intervene and publish it separately. Accordingly, the number of parts increases, and the number of man-hours required for the erecting is also increased, and the erected structure also becomes long in the vertical direction, resulting in greater space constraints.

Furthermore, the auxiliary stem 107 for pressing down the rubber spring is the rubber spring 1.
Rubber splashes 1 because it is only in contact with 09.
If the buckling of the rubber spring 109 is uneven, there is no ability to regulate or correct the inclination of the rubber spring 109. Therefore, movable contact 1
11 cannot be prevented from coming into contact with the fixed contact 115 at an angle relative to the horizontal position. When the contacts close or open due to tilting, the voltage signal used to detect on/off changes slowly, and in some cases the voltage goes up and down, leading to errors in judgments compared to the threshold value. . Furthermore, there is a risk of false detection due to different chattering patterns. As a result, the characteristics of the switch become unstable, causing discomfort and discomfort to the operator.

In the latter case, a key switch is realized by an integral flip-out. Therefore, the number of parts is reduced. However, since the key stem 205 is also merely in contact with the upper spring 201, there is a problem that, like the former, it is impossible to regulate or correct the deviation of buckling. The movable contact 207 also requires an upper air vent 211, and stress is concentrated on the lower spring 203 of the air vent 211 when pressed. For this reason,
Buckling was uneven between the air vent 211 portion and other portions, making the switch characteristics even more unstable.

Furthermore, since the movable contact 207 is disk-shaped, the push-down stroke after switch-on, that is, the overtravel, is shortened due to the presence of the movable contact 207, as shown in FIG. 15(C). Therefore, in order to increase the overtravel from the viewpoint of usability, the key switch had to be lengthened in the vertical direction, resulting in space constraints.

Moreover, the movable contact 207 cannot be molded integrally with the spring material 200, and a separate step of attaching it to the inside of the spring material 200 is required.

SUMMARY OF THE INVENTION Therefore, the present invention solves the above-mentioned problems and realizes a press key switch that has a simple structure, can be integrally molded, is compact, prevents uneven buckling, and has stable switch characteristics. For this purpose, we adopted the following configuration.

[Means for Solving the Problems] That is, the gist of the first invention is to provide a key stem that is regulated to move in parallel in the vertical direction and transmits key operations, and a key stem that is fixed to a base and has characteristics of an upper and a lower part. Different reverse directions
It is a spring material in the shape of a spring, and the upper part has an insertion hole for the lower end of the key stem and has a spring characteristic in which the repulsive force increases monotonically in response to a press stroke, and the lower part has a spring characteristic in which the repulsive force decreases midway through the press stroke. an annular movable contact located inside the inverted cup-shaped spring member and provided along the boundary between the upper and lower parts; A push-down key switch is provided with a fixed contact located inside and fixed to the base and capable of closing with the annular movable contact when the key stem is depressed.

The gist of the second invention is a spring material that is fixed to a base and has different characteristics between an upper part and a lower part, the upper part having a spring characteristic that a repulsion force increases monotonically with respect to a pressing stroke,
A spring material whose lower part has a click characteristic in which the repulsion force decreases in the middle of the pressing stroke, a movable contact provided at the boundary between the upper and lower parts of this spring material, and a movable contact fixed to the base and which engages with the said movable contact when pressed. a closeable fixed contact, an auxiliary member that contacts the boundary between the upper and lower parts of the spring material to provide an auxiliary pressing blade to the lower part, and whose contact surface is regulated to move in parallel in the vertical direction; It is a press-down key switch that is characterized by the ability to enjoy.

[Function] The inverted cup-shaped spring material achieves click characteristics due to its buckling phenomenon. Buckling reduces the repulsive force as a spring. Therefore, in the conventional configuration, if the pressing operation is even slightly unbalanced, part of the inverted cup-shaped spring material l'? (1: Buckling also starts from that part. Therefore, the repulsive force is the weakest in that part, and the push-down blade is further concentrated in that part. As a result, the buckling in that part becomes even more pronounced, and as mentioned above, Due to this phenomenon, the characteristics as an on/off switch become unstable.

In the first invention, since the upper part of the spring material has the insertion hole for the lower end of the key stem, the tilt of the spring material is restricted by the key stem which is regulated to move in parallel in the vertical direction and transmits key operations, and the push-down blade will be applied uniformly to the spring material. Moreover, because the movable contact is located inside the inverted cup-shaped spring material and is provided in an annular shape along the boundary between the upper and lower parts, even if the inverted cup-shaped spring material has uneven strength. Even if the spring material is unevenly fatigued over time, the annular contact acts as a reinforcing frame to equalize the force transmission of the inverted cup-shaped spring material and the deformation caused by buckling of the upper part of the spring material.

The reason why it is possible to make deformation uniform with the reinforcing frame is because (when shoulder buckling occurs, the boundary between the upper and lower parts also deforms greatly. The annular contact point as a reinforcing frame can prevent this deformation over the entire circumference. This is because the deformation is not concentrated in one part but is evenly distributed over the entire circumference.

Therefore, the buckling of the upper part of the spring material always occurs uniformly around the entire circumference, so that the annular contact does not tilt, and the entire surface lands on the fixed contact side almost instantaneously during a click operation. Therefore, extremely stable switching characteristics can be realized constantly.

Furthermore, because the movable contact is annular, in the case of a large push-down stroke, the upper part of the spring material deforms greatly, passing through the center hole of the movable contact and coming into direct contact with the base, ensuring sufficient overtravel. No excessive load is applied to the movable or fixed contacts.

In the second invention, the auxiliary member contacts the boundary between the upper and lower parts of the spring material and provides an auxiliary pressing blade to the lower part.

Moreover, the contact surface of the auxiliary member is restricted to move in parallel in the vertical direction. Therefore, if the movable contact is about to tilt, that is, if buckling is about to start unevenly, the buckled part will start to fall toward the fixed contact, and the part where buckling is not about to start or The part that is insufficiently buckled tries to maintain its position, but the auxiliary push-down blade from the auxiliary member is transmitted through the contact surface that moves in parallel, so the auxiliary push-down blade has not begun to buckle. It will be concentrated in a portion or an insufficient portion, forcing buckling to start or accelerate.

Therefore, even if the movable contact is tilted, it is corrected to its original position, and as in the first invention, stable switching characteristics can be obtained.

[Example] Next, each invention will be explained in detail. Each invention is not limited to these, but includes various embodiments without departing from the gist thereof.

FIG. 1 shows a longitudinal sectional view of an embodiment of the push key switch of the first invention. This figure shows one key switch part of the keyboard.

Fixed contacts 3 are formed in a pattern on the printed circuit board 1. An inverted cup-shaped spring material 5 made of rubber 11 is provided on the printed circuit board 1 so as to cover the fixed contact 3. This inverted cup-shaped spring material 5 has spring characteristics divided into two parts, an upper part 7 and a lower part 9. The upper giPJ 7 has a spring characteristic of characteristic B shown in FIG. 7, and the lower part 9 has a spring characteristic of characteristic A. When struck, the upper part 7 has a click characteristic in which the repulsive force increases monotonically with respect to the pressing stroke, and the lower part 9 has a click characteristic in which the repulsive force decreases due to buckling halfway.

The upper part 7 has a substantially cylindrical shape, and an insertion hole 11 is provided in a thick part 7a provided inside the upper part 7. This thick portion 7a is further provided with a notch 7b for venting air.

The lower part 9 has a truncated conical shape, and is mounted on the printed circuit board 1 at its lower thick peripheral edge 9a. Furthermore, a movable contact 17 is provided inside the boundary 15 between the upper part 7 and the lower part 9. This movable contact 17 is formed in a cylindrical shape coaxial with the upper part 7. In addition, four locations (90
The cutout portions 9b at each angle (°) are provided for adjusting the air pressure inside the inverted cup-shaped spring material 5, and communicate between the inside of the inverted cup-shaped spring sheath 5 and the outside.

These upper parts 7. The lower part 9 and the movable contact 17 can be integrally molded by two-color molding. The upper part 7 and the lower part 9 are made of an insulating rubber material, but the movable contact 17 is made of an electrically conductive rubber material.

The key stem 13 has a cylindrical shape, and has a guide arm 13a extending obliquely downward at its lower part and a small diameter cylindrical protrusion 13b at its center. This protrusion 13b is a spring material 5
is inserted into the insertion hole 11 of. Insertion hole 1 of protrusion 13b
1 may be completely fitted so that the two are integrated, or may be loosely fitted as shown in the figure.

Further, a cylindrical fitting protrusion 19a of the key top 19 is fitted into the upper part of the key stem 13. The fitting protrusion 19a is provided with a notch similar to that shown in FIG. 9, and by fitting into the protrusion 13c provided on the inner peripheral surface of the key stem 13, the rotational position of the key top 19 is fixed.

The key stem 13 is slidably inserted into a cylinder 21a provided at the top of a holder 21 having a convex cross section. The tip end 13d of the guide arm 13a is in contact with the inner circumferential surface of a semi-cylindrical sliding cupboard 21b which is provided on the inner circumferential surface of the holder 21 in the same manner as in FIG. 9 and extends in the vertical direction. Therefore, the key stem 13 can only be moved in parallel in the vertical direction while maintaining its posture.

Further, the holder 21 has a screw hole 21d in its peripheral wall 21c, and is screwed onto the substrate 1 by a bolt (not shown) inserted through the hole 1a on the substrate 1 side. In this embodiment, a holder 21 is provided for each key, but a normal method using a holder integrally formed with a plurality of keys may also be used.

The operation of the press key switch having the above configuration will be explained with reference to FIGS. 1 to 8. First, Keed Shiv 19 top surface 1
When 9b is not pressed, as shown in FIG. 1, the biasing force of the spring member 5 moves the key stem 13 and the keyed pump 19 to a position where the guide arm 13a abuts the upper end surface 21e of the sliding groove 21b inside the holder 21. exists in

When the operator starts a pressing operation, the upper surface 19b of the key top 19 is first pressed. Then, the relationship between the load on the key top 19 (=repulsive force of the spring material) and the pressing stroke becomes as shown in characteristic C shown in FIG. 8, which is a combination of the above characteristics A and B.

First, when a load starts to be applied, the upper part 7 of the spring material does not start to contract unless the load increases sufficiently, so mainly the lower part 9 contracts slightly according to characteristic A according to the stroke (point C1). ■Next, as the load increases, the upper part of the spring material 7. Both lower parts 9 shrink so as to maintain the same repulsive force (C
2 points). In this case, as shown in FIG. 2, the lower part 9 has a larger spring constant, so the upper part 7 mainly contracts.

■If you try to push it down further, from this stroke position, the repulsive force of the upper part 9 of the spring material will suddenly decrease due to buckling, so the lower part 9 will suddenly contract, and the upper part 7 will suddenly shrink in order to balance the repulsive force. It grows to. In this way, the load suddenly decreases even though the stroke hardly changes (point C3). The state during this time is shown in FIGS. 3 and 4. FIG. 3 shows the moment when the lower part 9 buckles and the movable contact 17 is rapidly moving downward. Due to this phenomenon, the movable contact 17 comes into contact with the fixed contact 3 almost instantaneously, and the switch is turned on as shown in FIG. 4.

Here, since the spring material upper part 7 is inserted through the protrusion 13b of the key stem 13 which is slidable only in the vertical direction, the spring material 5
The entire spring material 5 is prevented from inclining due to the uneven expansion and contraction of the spring material. Therefore, the pressing blade from the key top 19 is evenly applied to the entire spring member upper part 9 from directly above. In addition to this, the annular movable contact 17 acts as a strain prevention frame for the non-uniform spring material 5 and prevents buckling from starting unevenly. Since buckling is doubly prevented from occurring in this way, the buckling of the lower part 9 does not start from a part but occurs simultaneously all around the circumference. Therefore, since the entire lower surface 17a of the movable contact 17 instantly turns on to the fixed contact 3, the turning point does not become unstable, resulting in stable switch-on characteristics.

■When pressed further, the load increases monotonically (point C4). Eventually, the upper portion 7 contracts until the thick portion 7a comes into contact with the upper surface of the substrate 1, as shown in FIG. Even if you press more than this,
Since pressure is applied to the substrate 1 through the thick portion 7a, damage to the contacts 3.17 due to excessive pressing can be prevented.

Also, at this time, the notch 7b is connected to the upper part 7. Since the annular movable contact 17 and the thick wall portion 7a play the role of letting air escape from the space surrounded by it or introducing it into the space, the splash characteristics of the upper part 7 do not change, and the layer is stabilized. The switch characteristics are as follows. In this case, air flows out through the gap between the key stem 13 and the key top 19.

■Next, as the stroke position is returned, the load monotonically decreases. However, even if the stroke is returned from the state shown in FIG. 3, the buckled state of the upper part 9 of the spring material remains as shown in FIG. 6. That is, hysteresis occurs. This is because the repulsive force of the lower part 9 is reduced due to the buckling of the lower part 9, and in order to sufficiently increase the repulsive force to counter the repulsive force of the upper part 70 and eliminate the buckling, it is necessary to return the stroke further. It becomes necessary.

■Therefore, the buckling of the lower part 9 returns only after returning to point 05 (point C6). That is, the load increases rapidly. At this time, the switch turns off instantly.

That is, the state shown in FIG. 2 is reached. When the key stem 13 is turned off, the buckling recovery is biased, as in the case when the key stem 13 is turned on.
Since this is doubly prevented by the annular movable contact 17 and the annular movable contact 17, the OFF point does not become unstable, resulting in stable switching characteristics.

Furthermore, due to the shift in strokes between switch-on and switch-off associated with this hysteresis, chattering is reduced compared to when the on/off strokes are the same.

(2) After this, the load decreases monotonically as the I-reduction decreases (point C7), and then it contracts relatively rapidly, returning to the initial state, that is, the state shown in FIG.

Next, an embodiment of the push key switch according to the second invention will be described. FIG. 9 shows its developed view. This figure also shows one key switch part of the keyboard.

Fixed contacts 33 are formed in a pattern on the disk-shaped substrate 31. On this disc-shaped substrate 31 is mounted an inverted, pump-shaped spring member 35 made of rubber and having the same shape as in the previous embodiment.

An annular floating stem 37 as an auxiliary member is arranged on the spring material 35. The inner diameter of this floating stem 37 is designed to be slightly larger than the outer diameter of the upper part 39 of the spring material 35 in an unloaded state, and when the spring material 35 is inserted into the floating stem 37, the floating stem 37 lower surface 37a
The spring member 35 can come into contact with the upper surface 43a of the boundary portion 43 between the upper portion 39 and the lower portion 41. This lower surface 37a and upper surface 4
3a is a flat surface, and in the raised state, the entire upper surface 43a is in contact with the lower surface 37a, and the upper surface 43a receives the load of the floating stem 37 uniformly. On the instep, two rod-shaped guides 37b are erected on the outer peripheral surface of the floating stem 37 at opposing positions.

The key stem 45 has a cylindrical shape, and a contact plate 4 is provided at the bottom of the key stem 45.
5a, and a small diameter cylindrical protrusion 45b is provided at the center thereof. This protrusion 45b is inserted into the insertion hole 39a of the spring member 35. The degree of fitting of the protrusion 45b into the insertion hole 39a is the same as in the previous embodiment. The abutting plate 45a is basically disc-shaped, and has an oval shape with a notch in the opposing part across the center, and two bar-shaped guides 45d are vertically disposed at 90 degrees from the notch surface 45c. has been done.

Further, a cylindrical fitting protrusion 47a of the key top 47 is fitted into the upper part of the key stem 45.

The function of the notch 47b of the fitting protrusion g847a is the same as in the previous embodiment.

The key stem 45 itself is slidably inserted into a cylinder 49a provided at the top of a holder 49 having a convex cross section. 2 guys F' 45 2 holes each on the outside of d.
The hinges 45e are in contact with the inner circumferential surface of two opposing sliding grooves 49b among four semi-cylindrical sliding grooves 49b that are provided at equal intervals on the inner circumferential surface of the holder 49 and extend in the vertical direction. Therefore, the key stem 45 can only be moved in parallel in the vertical direction while maintaining its posture.

Furthermore, the two outer edges 37c of the two rod-shaped guides l" 37b of the floating stem 37 are in contact with the inner peripheral surfaces of the remaining two sliding grooves 49b. Therefore, the floating stem 37
It is also possible to simply move in parallel in the vertical direction while maintaining the same posture.

Further, the holder 49 has a threaded hole 49d in its peripheral wall 49c, and is screwed and fixed to the substrate 31 by a bolt (not shown) inserted through the hole 31a on the substrate 31 side. As in the previous embodiment, the usual method of using a holder integrally formed with a plurality of keys can be adopted.

The positional relationship between the floating stem 37 and the key stem 45 and the function of the floating stem 37 will be explained.

Figures 10 to 12 show spring material 35. floating stem 37,
The key stem 45 and holder 49 are shown in a state in which key money has been paid. Incidentally, FIG. 11 shows a sectional view taken along line A-A in FIG. 13.

As can be seen from the figure, the guide 37b of the floating stem 37 is connected to the cutout surface 45 of the abutment plate 45a provided on the key stem 45.
Located a little distance from c. Therefore, both stems 37.4
5 is the lower surface of the contact plate 45a and the upper surface 37 of the floating stem 37.
If they do not come into contact with each other, their vertical positions are not restricted to each other.

FIG. 12 shows the operation of the press key switch with the above configuration.

This will be explained with reference to FIG. First, key top 47
- When the surface A is not pressed, as shown in FIG. 49e.

On the other hand, the floating stem 37 is placed on the upper surface 43a of the protruding ring-shaped boundary part 43 of the spring member 35, and the floating stem 37
The entire load is uniformly applied to the entire boundary portion 43.

The relationship between the load (repulsion force of the spring material) accompanying the pressing operation of the operator and the pressing stroke is almost the same as the characteristic C shown in FIG. 8 shown in the case of the previous embodiment.

First, as the load increases, the upper part of the spring material is 39° and the lower part is 4°.
1 both shrink so as to maintain the same repulsive force. In this case, as shown in FIG. 13, the lower part 41 has a larger spring constant, so the upper part 39 mainly contracts.

■If you try to push it down further, the repulsive force of the upper part 41 of the spring material decreases rapidly from this stroke position due to buckling, so the lower part 41 contracts rapidly, and the upper part 39 suddenly expands to balance the repulsive force. . In this way, the load suddenly decreases even though the stroke hardly changes. FIG. 13 shows the state immediately before buckling.

Since the key stem 45 can slide only in the vertical direction during buckling, the effect of regulating the posture of the spring member 5 by the protrusion 45b is the same as in the previous embodiment.

Further, the effect of the annular movable contact 51 is also similar.

Furthermore, in this embodiment, the floating stem 37, which is movable only in the vertical direction, applies its load only to the lower part 41 of the spring member 35. The lower surface 37a of the floating stem 37 only moves in parallel in the vertical direction. Therefore, when the lower part 41 of the spring member 35 begins to buckle unevenly, the upper surface 43a of the boundary portion 43 tends to tilt. However, since the lower surface 37a of the floating stem 37 is not tilted due to the restriction of the guide 37b, the entire load of the floating stem 37 is concentrated on the upper surface 43a of the portion that is not yet significantly buckled. This promotes buckling on the less buckled side, thereby correcting the buckling bias.

In this way, buckling is triple-prevented, so the buckling of the lower part 41 does not start from a part but occurs simultaneously all around the circumference. Therefore, the entire lower surface 51a of the movable contact 51 instantly turns on to the fixed contact 33, resulting in stable switching characteristics.

The subsequent operations are the same as in the previous embodiment. In the OFF state, the entire load of the floating stem 37 is concentrated on the upper surface 43a of the boundary portion 43, which tries to quickly return from buckling, by the operation opposite to the above, so that uneven recovery from buckling is prevented. Therefore, the movable contact 51
Since the entire lower surface 51a of the switch is instantly turned off by the fixed contact 33, stable switching characteristics are obtained.

The effect of hysteresis is similar to the previous embodiment.

In this embodiment, in order to prevent uneven buckling, the key stem 45. Although there are three effects of the floating stem 37 and the annular movable contact 51, the effect of the floating stem 37 alone has a sufficient effect.

[lambda] cross-section effect] In the push-down key switch of the first invention, a spring member is fitted into a key stem that is regulated to move in parallel in the vertical direction, and an annular movable contact is provided at the upper and lower boundaries. Therefore, by regulating the inclination of the entire spring material, uneven buckling of the upper part of the spring material is prevented, resulting in stable switch characteristics. Further, since the movable contact is annular, a large overdrive can be obtained, and no stress is placed on the contact, and since the movable contact can be cut out, it is possible to integrally mold the spring material and the movable contact.

The push-down key switch of the second invention includes an auxiliary member that contacts the boundary between the upper and lower parts of the spring material to provide an auxiliary push-down blade to the lower part, and whose contact surface is regulated to move in parallel in the vertical direction. have. Therefore, the load-bearing position of the auxiliary member moves so as to correct the buckling of the spring material, so that the uneven buckling of the upper part of the spring material is corrected and prevented, resulting in stable switching characteristics.

Furthermore, both inventions have a simple structure and require no man-hours to set up in the morning, and do not require preloading of the spring material, making them compact, free from space constraints, and easy to use.

[Brief explanation of the drawing]

Figures 1 to 6 are longitudinal sectional views of an embodiment of the first invention, Figure 7 is a graph of stroke versus load showing each characteristic A and B of the upper and lower parts of the spring material, and Figure 8 is the combined characteristic. Graph C, FIG. 9 is a developed view of an embodiment of the second invention, FIG. 1O is a partially assembled view thereof, FIG. 11 is a sectional view thereof, and FIGS. 12 and 13 are explanatory diagrams of its operation. , Fig. 14 (A), (B)
and FIGS. 15(A) to 15(C) show the conventional press key switch.
Represents a cross-sectional view of Sochi. 1.31... Board 3,33... Fixed contact 5.35... Spring material 7.39... Upper part of spring material 9.41... Upper part of spring material 11.39a...
Insertion hole 13.45...Key stem 13a...Guide arm 15.43...Boundary portion 17.51...Annular movable contact 21b, 49b...Sliding groove 37...Annular floating stem 37b, 45d...rod-shaped guide

Claims (1)

[Claims] 1. A key stem that is regulated to move in parallel in the vertical direction and transmits key operations, and an inverted cup-shaped spring member fixed to a base and having different characteristics at the upper and lower parts, the upper part of which is the key stem. An inverted cup-shaped spring material having an insertion hole at the lower end and a spring characteristic in which the repulsion force increases monotonically in response to the push-down stroke, and a click characteristic in which the repulsion force decreases midway through the push-down stroke in the lower part. , an annular movable contact provided inside the inverted cup-shaped spring member along the boundary between the upper and lower parts;
A press-down key switch comprising: a fixed contact located inside the spring material and fixed to the base, and capable of closing with the annular movable contact when the key stem is pressed. 2 A spring material that is fixed to the base and has different characteristics at the upper and lower parts, the upper part has spring characteristics in which the repulsion force increases monotonically in response to the push-down stroke, and the lower part has the spring property in which the repulsion force increases in the middle of the push-down stroke. a spring material having a decreasing click characteristic; a movable contact provided at the boundary between the upper and lower parts of the spring material; a fixed contact fixed to the base and capable of closing with the movable contact when pressed; A push-down key switch comprising: an auxiliary member that contacts the boundary between the upper and lower parts to provide an auxiliary push-down blade to the lower part, and whose contact surface is regulated to move in parallel in the vertical direction.