JPH0465483B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a non-contact type pushbutton with a so-called interlock system that prevents the switch from being operated even if two pushbuttons are pressed down at the same time in a switch that has two pushbuttons on one main body. Regarding the switch, its purpose is to be small in size for low voltage, and to operate smoothly and reliably.

Conventionally, push button switches for operating hoist cranes, etc., are commonly used with contacts, which generates sparks each time the switch is operated, which wears out the contacts and shortens the life of the switch, which often requires replacement with a new one. Moreover, poor contact occurs, making crane operation less reliable. Furthermore, since it is a contact type, the distance between the contacts must be maintained within a predetermined safety distance, so there is a limit to miniaturization. Hoist cranes and the like have a large number of push button switches housed in one pendant switch case so that each operation such as traveling, traversing, hoisting and lowering can be performed using each switch. Therefore, the switch case becomes large and may be difficult to operate with one hand.

Furthermore, one switch body is provided with two push buttons, and each push button is used to perform operations opposite to each other, such as an ON-OFF operation for forward rotation and an ON-OFF operation for reverse rotation of a three-phase motor. However, if both push buttons are pressed at the same time, the power supply may be shorted or the motor may be damaged. A so-called interlock mechanism is adopted that makes it impossible.

This mechanical method requires a large number of parts, takes time to assemble, and requires more force to press the push button.
There is a limit to the size and weight reduction, and it is inferior to nimble operability.

In view of this, the present invention provides a so-called switch body with two pushbuttons, optically operating the pushbuttons, and making it optically impossible to operate the switch even if both pushbuttons are pressed at the same time. It is equipped with an optical interlock mechanism to prevent damage to the motor, etc., and is designed to be compact, easy to assemble, and easy to operate.

The present invention will be explained in detail below based on the illustrated embodiments.

Fig. 1 is an exploded perspective view of the push-button switch of the present invention seen from the back side. In this figure, 1 is the main body block of the push-button switch, which is molded, lightweight, durable,
It is integrally formed of a material with excellent insulation properties, such as synthetic resin. This main body block 1 has a push button insertion groove 2 formed in its longitudinal center on the back side for inserting two opposing pushbuttons with a light shielding plate.
is formed continuously with the push button insertion groove 2. The size of the light shielding plate insertion groove 3 is determined so that the two push buttons face each other, and the two light shielding plates are inserted so as to overlap each other when inserted into the push button insertion grooves 3 respectively. In the center of this main body block, element insertion grooves 4 and 5 are provided in which a light receiving element PT (phototransistor, CDS cell, photodiode, etc.) and a light emitting element LED are inserted, respectively, facing each other so as to sandwich the light shielding plate insertion groove 3. . In the illustrated embodiment, two device insertion grooves 4 and 5 are arranged in parallel so that two pairs of light-receiving devices are used, but it is also possible to use only one pair of light-receiving devices. The element insertion grooves 4 and 5 are open only on the bottom side of the main body block 1, and one element can be inserted independently, and the inner wall of the groove has a light emitting element that emits light at all times. Light passing holes 4a and 5a are bored so that the light reaches the light receiving element side. Of course, the light passing holes 4a and 5a are positioned on the same straight line in the light traveling direction.

On the outer periphery of the lower bottom surface of the main body block 1, a short board guide 6 for supporting the board and back cover that is placed along the bottom surface of the main body block, and a lid guide 7 with a hole 7a for securing the back cover are provided on the peripheral wall. The lid guide is integrally formed with a step-shaped board holder 8 on the inside of the lid guide so as to be at the same horizontal position as the lower surface of the peripheral walls 4b, 5b of the element insertion groove.

The external shape and size of the push button body are determined so that the push button 10 slides smoothly into the push button insertion groove 2 without rattling. A push piece 11 is provided so as to protrude from the side to allow a switch operation, a spring locking projection 12 is provided on the opposite side of the push piece 11, and a light shielding plate 13 is provided on the side surface. This light-shielding plate 13 has a light-transmitting window 14 formed on the upper end side of the light-shielding plate so that when a push button is pressed down, the light from the light-emitting element on the push-button side among the two parallel elements reaches the light-receiving element facing the push-button. A push-down light-shielding piece 15 is provided on the outer end side of the light-transmitting window so as to block light between the elements of the other push button when the push button is pressed. 1
0 and 10 so that their light-shielding plates overlap each other, and the light-shielding piece pressed by the other push button is located at the position of the light-transmitting window of one. Also, one push button is the 4th button.
As shown in the figure, a press-down light-shielding piece cut out may also be used.

The board 20 is sized to fit into a board guide/lid guide protruding around the bottom surface of the main body block, and printed wiring is applied to this board, and a protrusion 21 is provided at one end of the board. To ensure that attachment to a block can be performed reliably. This is done by inserting the protrusion 21 into the notch 7b provided in the lid guide. The board 20 further includes screw holes 22, 23, 2 for attaching terminals for supplying power to the light emitting element LED and for extracting electric signals from the light receiving element.
4 and 25 respectively and facing light emitting elements.
A pair of LED and a light receiving element PT are provided, and one or two sets are provided, and these are provided in a protruding manner so as to be inserted into the element insertion grooves 4 and 5 of the main body block. Further, R is a resistor, and 26 and 27 are spring insertion holes for inserting a spring 40 used for returning the push button.

The back cover 30 is for pressing and fixing the substrate 20 to prevent dust from entering the element section, etc., and is made of an insulating material and shaped as shown in FIG. 1, like the main body block. The back cover 30 has spring support parts 31 and 32 on the inner surface that support the spring 40 for returning the push button, and cutouts 33, 34, and 3 for terminal insertion on both sides.
5 and 36, respectively, and these four notches are provided at positions facing the upper end of the board guide and the terminal mounting screw holes on the board when the back plate is attached to the main body block, and are located outside both sides of these notches. A hook-shaped locking piece 30a is provided protruding from the end face and is connected to the locking hole 7a of the main body block. A protrusion 37 is provided at one outer end of the back cover to fit into the notch 7b of the main body block, so that the directionality of the back cover can be ensured when it is attached to the main body block.

To assemble the parts configured as described above, as shown in FIG. 1, two push buttons 10, 10 are inserted into the push button insertion grooves 2, 2 of the main body block 1 with the light shielding plates overlapping each other. A push piece 11 is made to protrude from the top surface of the main body block. Next, a substrate 20 on which a light emitting element, a light receiving element, etc. are printed is placed on the back side of this main body block. At this time, the light receiving element is placed in the element insertion groove 4, and the light emitting element is placed in the element insertion groove 5.
Insert each part accurately. This is provided so that each element is accurately inserted into the element insertion groove when each element is provided on the board, and the directionality of the board is determined by the protrusion 21.
and a notch 7b provided on the main body block side. Next, the spring 40 is inserted through the spring insertion hole 27 of the board so that it is engaged with the spring locking protrusion 12 of each push button. In FIG. 1, the substrate 20 is seen from its back side, so when it is attached to the main body block, it is inverted as shown by the arrow.

Next, attach the back cover 30. First, insert the spring 40 into the spring supports 31 and 32.
Further, when the protrusion 37 is inserted into the notch 7b and strongly pressed against the back side of the main body block, the locking piece 30a is inserted into the lid guide and utilizes the elasticity of the lid guide to open the locking hole 7a formed in the guide. are respectively fitted and locked. The substrate 20 is also held at the same time by this engagement of the back cover.

The main body 1 includes a mounting piece 9 with a mounting screw hole 9a drilled therein for easy attachment to a switch case, etc.
shall be installed protrudingly.

The push-button switch assembled as described above can be used alone, but when used as a pendant switch for a crane, etc., two or more push-button switches are installed in the pendant switch case to control the crane's running, traversing, stopping, hoisting, and lowering. In each of these operations, electric wires are connected to the light-emitting element and the light-receiving element for sending and supplying electrical signals for controlling each operation.

When using pushbuttons of the same shape as shown in Figure 1, when you press the pushbutton you want to activate, the pushbutton is pushed down against the spring, and as a result, the light from the light emitting element on the pushbutton side, which is always on, is emitted. The light reaches the light-receiving element through the light-transmitting window of the pushed-down light-shielding plate, whereupon the light is converted into an electrical signal and the desired operation is performed. Light is blocked. Therefore, even if both push buttons are pressed at the same time, both buttons will be turned OFF and will not work. In addition, when using one of the push buttons as shown in Figure 4, if you press the push button without a light shielding piece, only that push button will be turned on, and if you press the push button with a light shielding piece, only the one side with the light shielding piece will be turned on. , and even if you accidentally press both buttons at the same time,
The operation on the non-shading single push button side remains OFF, and only the non-shading single push button side is preferentially operated.

Since the push-button switch constructed as described above uses a light-emitting and light-receiving element, the switch becomes contactless, and the life of the switch is extended, and its operation is ensured without contact failure. In addition, the light shielding plate with a push button protruding from it and the light transmitting window provided on the plate create an interlock between the overlapped light shielding plates by simply pressing the push button, so the operation is smoother and more reliable than conventional mechanical interlocks. In addition, even if you accidentally press two pushbuttons, the OFF state can be maintained, making it safe.The pushbutton switch is also smaller and lighter than before, making it easy to operate with one hand even when incorporated into a switch case. Because it is blocked, there are fewer failures, and the number of parts is small, making it easy to assemble.Furthermore, even in the unlikely event that the light emitting element fails, the light receiving element becomes dirty, or dirt gets in, all light will be blocked and the ON operation will not occur. Therefore, safety can be maintained even in the event of a failure, and since it can be operated with low voltage and small current, it has the advantage that even in the event of an electrical leakage, there is no danger to the human body and safety can be improved.

[Brief explanation of the drawing]

Figure 1 is an exploded perspective view seen from the back, Figure 2 is a sectional view taken along the line from Figure 1, and Figure 3 is from Figure 1.
FIG. 4, which is a sectional view taken along the line, is a diagram showing a modified embodiment of the push button. 1... Main body, 2... Push button insertion groove, 3... Light shielding plate insertion groove, 4, 5... Element insertion groove, 6... Board guide, 7... Lid guide, 8... Board holder, 10... Push button, 11... Push piece, 12... Spring stop projection, 13...
... Light shielding plate, 14 ... Light passing window, 15 ... Push light blocking piece, 20 ... Substrate, 30 ... Back plate, 40 ... Spring, LED ... Light emitting element, PT ... Light receiving element, R ...
…Resistor.

Claims (1)

[Claims] 1. Two pushbuttons each having a light-shielding plate with a light-transmitting window protruding thereon, the light-shielding plates stacked on top of each other, and a restoring spring interposed between each pushbutton so that it can freely slide in the vertical direction to form a single main body. Insert it into the block and
A light-shielding plate protruding from each pushbutton is provided with a light-shielding plate that passes through the upper end of the light-shielding plate so that when the pushbutton is pressed down, the light from the light-emitting element on the pushbutton side among the two sets of elements arranged in parallel reaches the light-receiving element facing the pushbutton. A light window is formed, and a push-down light-shielding piece is provided on the outer end side of the light-transmitting window to block light between the elements of the other push button when the push button is pressed, and a light shielding piece on both outside sides of the light shielding plate in the main body block is provided. On the other hand, an element insertion groove is formed in which a light emitting element and a light receiving element protruding from the printed circuit board so as to face each other are inserted independently, and light from the light emitting element reaches the light receiving element. , and a push button switch characterized in that the base plate and the back plate are fitted and fixed to the bottom of the main body block,