JPS639005Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a counter zero return mechanism that improves operability, prevents wear and damage of the pinion shaft and zero return push button, and improves durability.

Conventionally, counters that count the number of rotations of various devices, especially zero-return type counters, have been used to reset a group of number wheels to zero all at once by pushing down a pinion shaft and rotating a zero-return lever by pressing a push button. It is equipped with a zero return mechanism. However, in such a zero return mechanism, when the zero return lever rotates in response to the zero return operation, sliding friction occurs on the contact surface between the push button and the pinion shaft.
A smooth and nimble return-to-zero operation could not be obtained, and there were problems with operability. Further, there were also disadvantages in that the push button and pinion shaft were worn out, and in the case of a zero return mechanism that was used for a long period of time or was used frequently, the pinion shaft could become flattened or damaged.

The present invention was developed in view of the above-mentioned points, and has an extremely simple structure in which a rotatable sleeve is fitted to the part of the pinion shaft that the push button contacts, thereby eliminating rolling friction between the push button and the sleeve. The purpose of the present invention is to provide a zero return mechanism for a counter, which solves the above-mentioned conventional drawbacks at once.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

Fig. 1 is a partially cutaway plan view showing an embodiment of a counter equipped with a zero return mechanism according to the present invention, Fig. 2 is a partially omitted exploded perspective view of the counter, and Fig. 3 is a side view of the zero return mechanism. FIG. In these figures,
Reference numeral 1 denotes a counter frame formed of synthetic resin or metal plate into a substantially U-shape, and is composed of a pair of opposing left and right side wall plates 1A and 1B, and a bottom plate 1C. Between the pair of side wall plates 1A and 1B, a total of three shafts, namely a drive shaft 2, a numerical axle 3, and a lever shaft 4, are rotatably supported in parallel with each other at a predetermined distance.

A drive gear 5 is fitted and fixed to one end of the drive shaft 2 in close proximity to the inner surface of the right side wall surface 1B.

A transmission gear 6 and four number wheels 7 are each rotatably supported on the number axle 3. The transmission gear 6 is composed of first and second gears 6A, 6B, and a cylindrical portion 6C connecting these gears 6A, 6B, and the first gear 6A is always meshed with the drive gear 5. On the circumferential surface of each number wheel 7, numbers from "0" to "9" are displayed at equal intervals in the circumferential direction. Further, a pin gear 8 and a heart cam 9 are formed concentrically on one side of each number wheel 7, and a segment gear 10 is integrally formed on the other side.

A zero return lever 11 formed in a substantially U-shape is rotatably supported on the lever shaft 4 . At the base of the zero return lever 11, four pressing pieces 12 are provided, corresponding to the heart cams 9 of each number wheel 7, in a state where they are supported by the lever shaft 4, respectively. These pressing pieces 12 are constantly urged to the right by springs 13. A pinion shaft 14 is rotatably supported between opposing arm portions 11A and 11B of the zero return lever 11. Four pinions 15 are rotatably supported on this pinion shaft 14, and are interposed between the number wheels 7 of each digit and between the lowest digit number wheel 7a and the second gear 6B. These pinions 15 are pressed against each number wheel 7 and the second gear 6B by the return force of the zero return lever 11 in the direction of the arrow in FIG. It is normally meshed with the second gear 6B.

Three pinion alignment springs 17 are erected on the bottom plate 1C of the counter frame 1. These springs 17 are used to press the pinions 15 that separate from each number wheel 7 to align them when returning to zero, and their upper ends meet square boss portions 15a protruding from the side surfaces of each pinion 15. is facing closely from behind.

A push button mounting portion 19 is bent approximately horizontally at the rear end of the upper end surface of the left side wall plate 1A of the counter frame 1 and extends above the left end of the pinion shaft 14.
are integrally provided, and a through hole 20 is formed approximately in the center thereof. The upper end of a cylindrical body 21 is fitted and fixed into this through hole 20, and this cylindrical body 2
A shaft portion 22A of the push button 22 is slidably inserted into the inner hole of the push button 22. At the lower end of the shaft portion 22A is a pusher 2 that presses the pinion shaft 14 during zero return operation.
2B is fixed. A sleeve 2 is provided at the left end of the pinion shaft 14 corresponding to the presser 22B.
3 is rotatably fitted. This sleeve 2
3 is made of the same metal as the presser 22B, and has the same hardness as the presser 22B. Note that the presser 22B is normally placed on the upper surface of the sleeve 23.

In such a configuration, when the drive shaft 2 rotates, the number of rotations is displayed by the number on the number wheel 7. That is, when the drive gear 5 rotates together with the rotation of the drive shaft 2, the drive gear 5 rotates.
The rotation is from the first gear 6A to the second gear 6 of the transmission gear 6.
The rotation of the number wheel 7a is transmitted to the lowest digit number wheel 7a through the pinion 15 for the lowest digit, which is pivotally supported on the right end of the B-pinion shaft 14.
The rotational speed of the drive shaft 2 is sequentially transmitted to the higher-order digit wheels 7b, 7c, and 7d through the numerals 7b, 7c, and 7d.

Next, when the push button 22 is pressed down, the pusher 22B
presses the pinion shaft 14 through the sleeve 23, so the zero return lever 11 is rotated counterclockwise in FIG. 3 about the lever shaft 4 against the spring 16. As a result, the pinion 15 temporarily separates from each number wheel 7 and the second gear 6B, and at the same time, the pressing piece 12 presses and rotates the heart cam 9 of each number wheel 7, causing each number wheel 7 to return to zero all at once. .

As the push button 22 is pressed, the pusher 22B
When the sleeve 23 is pressed, the sleeve 23 rotates, and rolling friction is generated between the sleeve 23 and the presser 22B. This rolling friction is sufficiently smaller than the sliding friction that occurs when the pinion shaft 14 is directly pressed by the pusher 22B, so the zero return lever 11
can rotate smoothly and provide good operability. Further, since the zero return lever 11 can be rotated without difficulty, there is no risk of excessive pressing force being applied to the pinion shaft 14, and the pinion shaft 14 will not be bent.
Furthermore, since it is rolling friction, the presser 22B
This reduces wear on the sleeve 23 and improves durability. In addition, by appropriately selecting sleeves 23 having different outer diameters, the sleeves 23 can be used for adjusting the stroke of the push button 22.

In the above embodiment, the pusher 22B of the push button 22 and the sleeve 23 are made of the same metal, but the present invention is not limited to this, and may be made of different metals or hard synthetic materials. Of course, it may be formed of resin.

As explained above, the counter zero return mechanism according to the present invention has a rotatable sleeve mounted on the pinion shaft at the part corresponding to the push button, and prevents rolling wear between the push button and the sleeve during the zero return operation. Therefore, the zero return lever can be rotated smoothly and operability can be improved. In addition, since there is little wear and it can be returned to zero with a small operating force, the pinion shaft can be prevented from becoming worn out or damaged, and the durability of the counter can be improved, which has great practical effects.

[Brief description of the drawings]

Fig. 1 is a partially cutaway plan view showing an embodiment of a counter equipped with a zero return mechanism according to the present invention, Fig. 2 is an exploded perspective view of the counter, and Fig. 3 is a side sectional view of the zero return mechanism. be. 1...Counter frame, 3...Number axle, 4
... Lever shaft, 7 ... Number wheel, 9 ... Heart cam, 11 ... Zero return lever, 12 ... Pressing piece, 1
4...Pinion shaft, 15...Pinion, 22...
Push button, 23...sleeve.

Claims (1)

[Scope of utility model registration request] A plurality of number wheels rotatably supported on a number axle, each with a heart cam on one side;
A zero return lever is rotatably supported on a shaft and has a return habit, and the zero return lever is provided in correspondence with the heart cam of each number wheel, and when the zero return operation is performed, the heart cams are pressed to move the number wheels all at once. A plurality of pressing pieces for returning to zero and a pinion shaft supported by the zero return lever are rotatably supported and are interposed between the number wheels, and usually performs a digit feeding operation by meshing with these number wheels. , a plurality of pinions that are separated from the number wheel during the zero return operation, a push button that performs the zero return operation by pressing the pinion shaft and rotating the zero return lever, and the push button of the pinion shaft. A zero return mechanism for a counter, comprising a rotatable sleeve disposed at a contacting portion.