JPH0110663Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a push button for returning a counter to zero.

A conventional counter zero return push button is rotatably mounted on a support shaft supported on a frame, and has a number wheel with an integral heart cam, a pinion interposed between these number wheels, and a pinion that can be rotated freely. a zero return bracket member which supports a pinion shaft mounted on the frame and is integrally provided with a heart cam pressing piece corresponding to the heart cam and is rotatably supported by the frame; A torsion spring that elastically maintains the engagement between the wheel and the pinion, and a cam that is slidably supported by the frame and that engages one end of the pinion shaft are integrally provided, and the initial It consists of a push button that has a habit of returning to its position. When the push button is pressed, the pinion shaft is pressed by the cam, and the zero return bracket member rotates together with the pinion shaft against the force of the torsion spring, causing the number wheel and pinion to mesh. is released, the heart cam pressing piece presses the heart cam, and the number wheel returns to zero. According to such a conventional pushbutton zero return counter, the torsion spring is located on one side of the zero return bracket member and is mounted on its support shaft, so assembly is extremely troublesome, and it is not suitable for right-handed pushbutton zero return counters. The operating force required to return to zero changes depending on whether the tool is left-handed, and twisting occurs in the entire member. Furthermore, due to space constraints, it is difficult to use a torsion spring with a sufficiently large number of turns, and as a result, the tension changes rapidly as the zero return bracket member rotates, and careless operation can cause Inconveniences may occur when the push button is not pushed all the way to its final position.

The present invention was devised in view of the above circumstances, and the terminal side of the cam groove that is engaged with one end of the pinion shaft provided in the guide portion of the push button is opened at the side edge, and the cam groove is separated by the cam groove. By configuring the lower part of the divided guide part to be elastically deformable, the operating force of the push button can be kept constant from the beginning to the end, and the counter assembly can be significantly rationalized, and it can also be used to prevent vibrations, etc. To provide a counter zero return push button which ensures the return to zero by preventing the push button from rattling and giving a click feeling to the operation.

Hereinafter, the configuration and the like will be explained in detail by referring to embodiments shown in the drawings.

The drawing shows a tape counter as an embodiment of the present invention, in which reference numeral 1 denotes a frame having an upwardly U-shaped cross section and consisting of a bottom plate 2 and side plates 3 and 4. A number axle 5 is supported between the side plates 3 and 4 with one end protruding outward from the side plate 3, and a stepped gear 6 and number wheels 7, 8, and 9 each having a heart cam integrally provided on the side thereof are supported. It is rotatably mounted on a shaft. A zero return bracket member 12 is supported by bearing plates 10 and 11 (only 11 is shown) which are provided upright from the frame bottom plate 2 in the vicinity of the side plates 3 and 4. Zero return bracket member 1
2, the dowels protruding from both sides of the bearing plate 1
It is rotatably supported by being fitted into the U-shaped shaft holes numbered 0 and 11, and a heart cam pressing piece is integrally protruded from its base corresponding to the heart cam of the number wheel. Pinion shaft 1 on both arms
3 is supported. On the pinion shaft 13 is a transmission pinion 14 interposed between the stepped gear 6 and the number wheel 7.
and the shift pinions 15 and 16 interposed between the number wheels.
is rotatably mounted on the shaft. A bearing sleeve 17 is integrally formed at one corner of the frame bottom plate 2, and a rotating shaft 18 is rotatably inserted into this bearing sleeve.
A worm 19 is fixed to the upper part of the rotating shaft 18, and a pulley 20 is fixed to the lower part. The worm 19 meshes with the small diameter gear of the stepped gear 6,
The pulley 20 is connected to a tape drive source by a belt. Therefore, as the tape travels, the pulley 20 rotates, and the worm 19 also rotates together with the worm 19 via the rotating shaft 18, thereby driving the stepped gear 6 to rotate. The rotation of the stepped gear 6 is transmitted to the number wheel 7 via the transmission pinion 14, and when the number wheel 7 rotates once, the number wheel 8 is advanced one step via the shift pinion 15, and this operation is performed sequentially thereafter. is repeated and the running distance of the tape is displayed on the number wheel.

A guide groove 21 in the height direction is provided in the frame side plate 3, and a push button 22 is slidably assembled to the frame along the guide groove 21. The push button 22, the details of which are shown in FIG. 2, has a rectangular base 23.
, a guide section 25 connected by a connecting section 24 having a thick wall portion approximately equal to the groove width of the guide groove 21 and facing the base section 23, and an operating section 26 protruding from the connecting section 24. . The guide portion 25 is provided with a cam groove 27 that opens at the side edge of the substantially central portion in the height direction. It is slightly extended laterally. The lower piece portion 25b is
The lower edge 28 is formed as a sloped surface downward to the right in FIG.
It acts as a guide for the pinion shaft 13 when it is assembled into a. Further, the lower piece portion 25b is configured to be elastically deformable vertically and in the thickness direction due to its material properties, for example by making the entire portion slightly thinner. The cam groove 27 has a starting end 27a having substantially the same inclination as the guide lower edge 28,
The pinion shaft 13 has a generally horizontal terminal end portion 27b which is bent and communicates with the pinion shaft 13, and has a substantially F-shape.The starting end portion 27a and the terminal end portion 27b respectively position the starting point and ending point of the pinion shaft 13 during the zero return operation. That is, as shown in FIG. 4, the starting end 27a is located at a position that determines the distance between the number wheel 6 and each support shaft 5, 13 of each pinion, which are kept meshed in the normal state.
In other words, the pinion shaft 13 is positioned so that its center is located on the same vertical line as the center of the dowel of the zero return bracket member 12. Further, as shown in FIG. 5, the terminal end portion 27b is connected to the support shaft 1 of each pinion that is disengaged from the number wheel 6 during the zero return operation.
3 is located slightly inside the opening of the cam groove 27, that is, the lower end of the upper piece 25a and the lower piece 25b.
This is positioned so that it is located on the upper edge of the . The connecting portion 24 is provided with a groove that fits into the end of the frame side plate 3 and a boss portion 29 that is long vertically downward, and the coil spring 30 inserted into the boss portion 29 is connected between the frame bottom plate 2. It is configured to be placed in a compressed state and urge the push button 22 upward. An engagement surface 31 is formed on the operating portion 26 to engage with one end of the numerical axle 5 to regulate the position of the push button 22.
2 initial positions are determined.

Therefore, one end of the pinion shaft 13 is connected to the guide portion 2.
In order to assemble it into the cam groove 27 of No. 5, first press the push button 2.
2 from above the frame side plate 3, and move the pinion shaft 13 onto the guide surface 2 of the lower piece 25b.
8 to the tip, and then, by strongly pressing the push button 22, the lower piece 25b is elastically deformed, and one end of the pinion shaft 13 is guided from the tip of the lower piece 25b to the terminal end 27b of the cam groove 27. Implement it and do it.

Next, the operating procedure of the push button 22 will be explained.

As shown by the arrow X in FIG. 4, the push button 22 is pressed through the operating portion 26 against the force of the spring 30. As the push button 22 is lowered, the pinion shaft 13 moves in the cam groove 27 from the starting end 27a to the ending end 27b, as shown in FIG. This movement of the pinion shaft 13 causes the zero return bracket member 12 to rotate clockwise in FIG. to return the number wheels to zero all at once. When the operating force on the push button 22 is released, the push button returns to its initial position by the action of the coil spring 30, and the pinion shaft 13 also returns the cam groove 27 from the terminal end 27b to the starting end 27a. As a result, the stepped gear, number wheel, and each pinion mesh again. Here, since the cam groove 27 is formed from a starting end 27a and a terminal end 27b with different inclinations, the pinion shaft 13 passes from the starting end 27a through the bending communication section in accordance with the pressing operation of the push button 22. When reaching the terminal end 27b, the load changes,
This creates a click feeling and ensures a reliable return to zero. Further, since the coil spring 30 is configured to act directly on the push button 22, the push button 22 is always urged to the initial position and the push button is prevented from shaking. Also,
In the initial state, the pinion shaft 13 is stably located at the starting end 27a of the cam groove 27, so the tension of the coil spring should be large enough to elastically maintain the engagement between the number wheel and the pinion, as in the conventional case. It is not necessary, and it may be enough to return the push button to its initial position. Moreover, since the terminal end 27b of the cam groove 27 is provided substantially horizontally, the vertical movement stroke of the pinion shaft 13 is shortened.
Therefore, the tension of the spring should be weaker. In other words, the operating force required to return to zero can be reduced compared to conventional ones, and furthermore,
Since the coil spring 30 having a relatively large number of turns can be used instead of the torsion spring, the tension can be stabilized and so-called feather touch return to zero can be achieved.

As explained above, according to the present invention, a cam groove is provided in the counter zero return push button, the terminal end of this cam groove is opened, and the lower piece forming one cam surface can be elastically deformed. Since the pinion shaft is made of an elastic piece, it can be easily introduced into the cam groove by sliding one end of the pinion shaft along the guide surface when assembling the push button, and the work time for assembling the push button can be shortened. Furthermore, if the lower piece is elastically deformed and one end of the pinion shaft is introduced into the cam groove, the one end of the pinion shaft will not come off the cam groove during the push button operation, and the push button operation can be ensured. Furthermore, a coil spring can be attached to the push button side, so that the rotational movement of the bracket member is stabilized when the push button is operated, and the counter can be reliably returned to zero.

[Brief explanation of drawings]

Fig. 1 is an exploded perspective view showing the entire counter according to the present invention, Fig. 2 is a perspective view showing the external appearance of the push button, Fig. 3 is a side view of Fig. 2, and Figs. 4 and 5.
The figure shows the zero return operation state of essential parts, and is a sectional view at the beginning and end, respectively. 1...Frame, 3...Side plate, 13...Pinion shaft, 22...Push button, 25b...Lower piece, 2
7...Cam groove.

Claims (1)

[Scope of utility model registration request] In a counter zero return push button that is slidably supported on the side plate of the frame and has a cam groove in which one end of the pinion shaft engages in the guide part, the terminal end of the cam groove is opened at the side edge of the guide part. At the same time,
A push button for returning to zero for a counter, characterized in that a lower piece of a guide portion divided by a cam groove is configured to be elastically deformable.