JPS6224911Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a key switch suitable for use in electronic devices such as cash registers, which prevents the discharge of static electricity charged on the operator's body.

Conventionally, the key lock mechanism of a key switch was made of metal, so if the operator was charged with electricity when the key was inserted, static electricity would be generated through the key, the key lock mechanism, and the key switch mounting case. The electric discharge will cause the operator to receive an electric shock, which will cause discomfort to the operator.
Static electricity could generate induced voltage in electrical circuits, causing electronic components to malfunction. Charging of the human body may result in an unexpectedly high voltage, which may cause extreme discomfort.Also, although the lock mechanism and the electric circuit are separated by an insulating material, the lock mechanism is made of metal. Therefore, especially in key switches, the outer cylinder also serves as a mounting part for the electric circuit, so it is often relatively close to the electric circuit, and there is a drawback that there is a high possibility of trouble occurring due to induced voltage.

The purpose of the present invention is to eliminate these drawbacks, allow the operator to insert the key and operate the electronic device with peace of mind, and reduce the possibility of failure by alleviating the generation of induced voltage in the electric circuit. Another object of the present invention is to provide a key switch that is easy to manufacture and inexpensive. That is, the key switch according to the present invention is characterized in that it is equipped with a key lock mechanism using an insulating material for the outer cylinder and the inner cylinder.

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is an exploded perspective view of the key switch, and FIG. 2 shows a further exploded perspective view of the inner cylinder 1. A hole 10 having a rectangular cross section for accommodating a tumbler 11 made of an insulating material passes through the inner cylinder 1 vertically. A spring hole 101 with a bottom parallel to the hole 10 is provided on one side of the hole 10 in communication with the hole 10 so as to expand the hole 10, and a spring 14 is housed in the spring hole 101 to support the spring holder 13 of the tumbler 11 and move the tumbler 11 inside. It is biased so as to be pushed out of the cylinder 1. In the case of the figure, there are holes 10 with three spring holes 101 on the right side and two spring holes 101 on the left side when viewed from the keyhole 12 side. When the inner tube 1 with the tumbler 11 attached is inserted into the outer tube 2
The AA cross section is as shown in Figure 3. That is, the upper end of the tumbler 11 is fitted into a corresponding groove 21 provided in the outer cylinder 2 under the force of a spring 14, so that the inner cylinder 1 cannot rotate within the outer cylinder 2. This state is a locked state. When the key 19 is inserted into the keyhole 12 provided through the inner cylinder 1 and the tumbler 11, the key thread 20 provided on the key 19 is inserted.
moves the tumbler 11 downward. tumblr 1
The length of the top and bottom of 1 is approximately equal to the diameter of the inner cylinder 1, and if the height of the key thread 20 is selected appropriately, it will match the inner cylinder 1 in some cases and the tumbler will not protrude either above or below. The inner cylinder 1 can freely rotate within the outer cylinder 2. In some cases, the freedom of rotation of the inner cylinder 1 can be restricted to a certain angular range by making the tumbler 11 project below the inner cylinder 1 and fitting into the rotation angle limiting groove 22 of the outer cylinder 2. Tumbler 11 with 5 pieces like this
It can be unlocked with different keys 19 on the lock 20 and rotated within an appropriate angular range. The key lock mechanism is configured as described above. Furthermore, the inner cylinder 1 has teeth 15 provided by dividing the outer circumference of the inner cylinder into equal integer parts.
As shown in the figure, a ball (or a roller may be used) 17 is pressed against the toothed portion 15 by a spring 18, and a plurality of rotations are performed in the appropriate angular range according to the division of the toothed portion 15. It is designed so that it can be stopped.
At this stop position, a key switch is constructed that can appropriately operate a micro switch 4 and a rotary switch, which will be described later. As shown in FIG. 1, there is a protrusion 16 at one end of the inner cylinder 1, and when the cam component 5 consisting of a rotor 51 made of an insulating material and a camshaft 52 is inserted into the cam component accommodation hole 23 of the outer cylinder 2. Since the protrusion fits into a recess (not shown) provided on the lower end surface of the camshaft 52 and the cam component 5 is connected to the inner cylinder 1, the substrate 6 is inserted from the opening side of the accommodation hole 23.
By mounting and fixing to the outer cylinder 2 with screws 9, the cam part 5 rotates together with the inner cylinder 1, with one end held by the base plate 6. A sliding contact 53 is fixed to the upper end surface of the rotor 51, while fixed contacts (not shown) are provided in a predetermined pattern on the surface of the substrate 6 on the rotor side. A rotary switch is constituted by the rotary switch and the fixed contact, and when the cam part 5 rotates together with the inner cylinder 1, the circuit is disconnected between the contact 53 and the fixed contact.

When the micro switch 4 is secured with the screw 8 while holding the spacer 3 made of insulating material, the actuator 41 just contacts the cam portion 54 of the cam shaft 52, and as the cam shaft 52 rotates, the cam portion 54 closes the micro switch 4. 4 is switched. In a key switch having the above structure, a charged operator inserts the key 19 into the keyhole 12.
If the inner tube 1, tumbler 11, and outer tube 2 are made of insulating material, there will be no electrical conduction with the electronic device to which the outer tube 2 is attached, so there is no risk of electrical discharge. In addition, the micro switch 4 is installed on the outer cylinder 2,
The actuator 41 is a cam portion 54 of a camshaft 52 made of an insulating material.
The rotary switch sliding contact 53 is located on the upper end side of the camshaft 52 made of insulating material and is indirectly rotated by the inner cylinder 1, so that both of them are kept at a sufficient distance from the charged part. Since they are separated by an insulating material, malfunction of the electric circuit can be prevented. Further, since the outer cylinder 2 has a complicated shape, it can be made extremely inexpensively by making it from an insulating material such as plastic. It goes without saying that the key 19 may be made of an insulating material.

As is clear from the above explanation, the key switch according to the present invention can prevent discharge even when the operator is charged with electricity when used in electronic equipment, so the operator will not feel uncomfortable due to electric shock, and will not be induced by static electricity. The effect and advantage of being able to reduce the cost of an outer cylinder with a complicated structure without causing malfunction of electronic components due to the generation of voltage are extremely large in practical terms.

[Brief explanation of the drawing]

1 to 3 are explanatory diagrams showing one embodiment of the present invention, in which FIG. 1 is an exploded perspective view, FIG. 2 is an exploded perspective view of an inner cylinder and a perspective view of a key used therein, and FIG. FIG. 3 is a sectional view taken along line AA in FIG. 2. 1: Inner cylinder, 2: Outer cylinder, 11: Tumbler.

Claims (1)

[Scope of utility model registration request] An inner cylinder is rotatably provided in an outer cylinder attached to a housing of an electronic device, a keyhole into which a key is inserted and a tumbler for regulating rotation of the inner cylinder are provided in the inner cylinder, and 1. A key switch having a switch at one end that is driven to open and close as the inner cylinder rotates, characterized in that the outer cylinder, the inner cylinder, and the tumbler are made of an insulating material.