JPS603733B2 - push button digital switch - Google Patents

Description

[Detailed description of the invention] The present invention relates to a push-button digital switch.

Conventionally, a push-button type digital switch operates a feed pawl 3a or 3b by pressing a push nail la or lb against a return spring 2a or 2b to move a ratchet wheel 4 by one pitch, as shown in FIG. The character wheel 5, which has numbers or characters printed at equal pitch intervals on its outer circumferential surface, is rotated integrally with the ratchet wheel 4, and the numbers or characters are displayed through the display window 7 of the case 6. At the same time, by sliding the slider 8 attached to the character wheel 5 on a fixed contact (not shown), an output signal corresponding to the number or character displayed on the display window 7 is output. It looks like this. However, in the above-mentioned conventional push-button type digital switch, the components such as push-down and release la, lb, return springs 2a, 2b, feed claws 3a, 3b, etc. are each made of separate members, so the number of parts is extremely large, and the internal mechanism itself is It has the drawbacks of being complicated and requiring complicated assembly work.

In particular, in the case of small push-button type digital switches, the increase in the number of parts and the complexity of assembly work are major causes of cost increases. Therefore, the feed claws 3a, 3
It may be possible to reduce the number of parts and assembly man-hours by integrating push buttons la and lb with synthetic resin.
There is a problem in that it cannot be reliably rotated pitch by pitch, which may cause malfunction.

The present invention has been made in view of the above-mentioned conventional drawbacks and problems, and an object of the present invention is to provide an inexpensive push spade type digital switch that has a small number of parts, is easy to assemble, and is free from malfunctions. Next, the present invention will be explained with reference to the accompanying drawings, which are one embodiment of the present invention.

2 to 6, it is a box-shaped case body made of synthetic resin, with a display window 11 and rectangular holes 12, 12 perforated on the top surface, and a cylindrical support shaft 13 inside. ，
14, an elastic reversal prevention pawl 15, and approximately triangular grooves 16a and 16b are integrally provided.

17 is a push button made of synthetic resin and integrally molded into a substantially U-shape.
The heads 18a, 18b are inserted into the rectangular holes 12, 12 provided on the upper surface of the case body 10, respectively, and the large flanges 19, 19 are latched to the inner surface of the case body 10, and the thin plate-shaped A semi-circular recess 21 provided at the center of the bottom of the chest 20 engages with a support shaft 14 protruding from the case body 10.

Feed pawls 22a and 22b are integrally provided on the inner side of the body portion 20, and a rod-shaped protrusion 23 is provided on one side of the tip thereof, and a protrusion 24 is provided near the tip. 23, 23 are grooves 1 provided in the case body 10'
6a and 16b, respectively. Since the vicinity of the central part 20a of the bottom side of the ear portion 20 and the bent portions 20b, 20b are narrow in the middle, the body portion 20 has flexibility, and the case body can be inserted with the chest portion 20 slightly curved. 10, the L push button 17 is always given an upward return force. 25 is a disc-shaped character wheel with an integral ratchet wheel 26,
The center hole 27 is connected to the support shaft 13 provided in the case body 10.
The head 15a of the anti-reverse pawl 15 is elastically engaged with the pawl wheel 26 to be intermittently positioned one pitch at a time.

On the outer peripheral surface of the character wheel 25, consecutive numbers from 0 to 9 are printed at equal pitch intervals according to the number of teeth of the ratchet wheel 26,
This number is the display window 11 provided on the top of the case body 10.
is now displayed. On the front side of the character wheel 25, that is, on the side opposite to the ratchet wheel 26, there are two protrusions 28, 2.
8 is provided, and a slider 29 made of conductive metal is inserted into the protrusion 28 with braze and is integrally attached by force-sealing. Reference numeral 30 denotes a synthetic resin cover that closes the closing part of the case body 10, and a fixed contact of a predetermined shape (
(not shown) is printed, and the slider 29 slides into contact with this fixed contact to sequentially switch the contacts.

Note that the terminals of the fixed contacts are exposed to the outside of the case body 10 along the inner surface of the extension portion 31 of the cover 30. Next, the operation of the push-button digital switch having the above configuration will be explained. Now, when the head 18a of the pusher nail 17 is pressed downward, the pusher rod 17 uses the support shaft 14 of the case body 10 as a fulcrum, resists its own return force, and collapses, so that the pusher nail 17 is pushed back against the restoring force, and the pusher nail 17 is pushed back against its own return force. By sliding the protrusion 23 along the groove 16a of the case body 10 in the direction of the arrow 32 in FIG. The character wheels 25 are rotated together in the counterclockwise direction in FIG. 3 by more than half a pitch.

Then, when the pressing force of the push anchor 17 is released, the push button 17 rises due to its own return force, and the projection 23 moves into the groove 16.
a in the direction of arrow 33 in FIG. 4, the protruding piece 24 of the feed pawl 22a is displaced outward from the ratchet wheel 26 and rises to a position where it does not come into contact with the tips of the teeth of the ratchet wheel 26. The flange portion 19 comes into contact with the case body and returns to its original position. In this case, the bottom of the groove 16a is
As shown in the figure, the steps 34 and 34 are also
4, and when the projection 23 of the feed claw 22a moves in the direction of arrow 32 or 33, the projection 23 is pushed up by pressing the end face with the slope 35, When it moves to a position above or below the neutral line 36 in the figure, it falls from the top surface of the step 34 to the bottom surface. Since this fall is restricted by the step 34, the protrusion 23 does not move in the opposite direction to the directions of the arrows 32 and 33. On the other hand, the ratchet wheel 26 is connected to the head 1 of the reverse prevention pawl 15.
5a and the pressing force, the head 15a of the anti-reverse claw 15 is further rotated counterclockwise in FIG.
One feed is completed by engaging and positioning the next tooth of the ratchet wheel 26.

At this time, the number of the character wheel 25 is displayed for one pitch on the display window 11 of the case body 10, and the slider 29 corresponds to this.
switches the mirror point of the fixed contact and outputs an output signal corresponding to the above displayed number. Note that when operating the head 18a of the pusher 17, the bottom center recess 21 of the body 20 is aligned with the case body 1.
Since it is supported by the support shaft 14 of 0, the sagging caused by the above operation does not spread to the other side of the 8 part 20, so there is no problem with the above operation. Next, when the other head 18b of the push nail 17 is pressed downward, the push rod 17 performs the same operation as described above, and moves the ratchet wheel 26 and character wheel 25 together in the opposite direction, that is, clockwise. Rotate it.

This rotation completes one feed in the opposite direction, and a display and an output signal corresponding to this feed are issued. In the above embodiment, everything other than the display element 29 and the fixed contact that constitute the support mechanism is made of synthetic resin;
There are almost no problems caused by rust, etc., and the insulation is extremely good. In addition, the feed claws 22a, 22b
The return spring is integrated with the push button 17, the anti-reverse claw 15 and grooves 16a and 16b are integrated with the case body 10, and the ratchet wheel 26 is integrated with the character wheel 25, so the number of parts is reduced. It is half the size of a pot and is extremely easy to assemble. Z In the above embodiment, the projections 24, 24 are provided near the tips of the feed claws 22a, 22b, but the invention is not limited to this. Part is ratchet wheel 26
It may also be configured to engage with. Z As is clear from the above explanation, according to the present invention, the feed pawl is integrally formed with the push button using synthetic resin, and is formed into a substantially U-shape, and the center of the bottom is supported by the case to impart coagulability. By doing so, it is possible to reduce the number of parts and assembly man-hours, thereby reducing costs. In addition, the tip of the feed pawl is guided by the annular groove of the case, allowing the feed pawl to move in one direction only, in the direction of engagement with the ratchet wheel and release, so even if the resin deteriorates over time, This has the advantage that the feed claw can be operated reliably and malfunctions can be prevented.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of a conventional push-button digital switch.
The figure is a plan view of a push-button digital switch according to the present invention.
3 is a cross-sectional view taken along the line mm in FIG.
The figures show the groove in FIG. 3, where A is an enlarged front view, the front view is a sectional view taken along the line V-V of A, and FIG. 6 is an exploded perspective view of FIG. 3. 10...Case body, 11...Display window, 1
3, 14... Support shaft, 15... Reversal prevention claw,
16a, 16b... Concave groove, 17... Push nail, 20... Both moon parts, 21... Concave part (
bottom center), 22a, 22b... feed claw, 23
...Protrusion, 24...Protrusion, 25...
...Character wheel, 26...Claw wheel, 29...
Slider, 34... step. Figure 1 Figure 3 Figure 2 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] 1. A character wheel that is rotatably mounted inside a case and has numbers or letters printed at equal pitches on its outer circumferential surface, and a contact that is attached to the character wheel and sequentially opens and closes while slidingly contacting a fixed contact provided on the case. a slider that rotates coaxially with the character wheel, a ratchet wheel that rotates coaxially with the character wheel, and a flexible approximately U-shaped body whose bottom center is supported by the case, with both ends protruding outside the case; A push button integrally made of synthetic resin with a feed pawl that intermittently rotates the ratchet wheel forward or backward one pitch at a time by pressing either of its ends; an annular recessed groove that slidably engages with the ratchet wheel and guides the feed pawl in the direction of engagement and disengagement with the ratchet wheel in response to the operation of the push button, and only in one direction; A push-button digital switch consisting of a reversal prevention pawl that is constantly engaged and positions the ratchet wheel intermittently.