JPH0638497A - Needle stopper mechanism for instrument - Google Patents

Abstract

PURPOSE:To construct a low-cost needle stopper mechanism for an instrument which is not externally seen desirably in a designing manner in the mechanism in which a needle for indicating a scale of a character board is stopped, for example, at a zero position. CONSTITUTION:The instrument transmits the power of a stepping motor 2 to an output gear 5 contained in a case 1 for rotating a shaft 5x to rotate a needle, and comprises a protrusion 1p provided on a surface of the case 1 oppositely to the gear 5, and a rib 5r provided at the gear 5 to be engaged with the protrusion 1p.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pointer stopper mechanism of an instrument for stopping a pointer indicating a scale on a dial, for example, at a zero position.

[0002]

2. Description of the Related Art FIG. 4 is a sectional view showing an example of a conventional pointer stopper mechanism of the above-mentioned measuring instrument, and FIG. 5 is a reduced plan view of the dial shown in FIG. In FIG. 4, 1 indicates a case,
It is composed of a lower case portion 1d, an intermediate plate portion 1m attached on the lower case portion 1d, and an upper case portion 1u attached on the intermediate plate portion 1m.

Reference numeral 2 denotes a stepping motor as a movement housed in the lower case portion 1d, which includes a rotor 2r as a rotating shaft and a stator 2s made up of a two-phase coil 2c arranged around the rotor 2r. It is composed of. A permanent magnet 2p magnetized in multiple poles is fixed on the circumference of the rotor 2r, and one end portion of the rotor 2r penetrating the middle plate portion 1m penetrates the middle plate portion 1m. Reference numeral 3 denotes a drive gear attached to one end portion of the rotor 2r, and 4 denotes a reduction gear as a transmission gear in which a shaft 4x is supported by the middle plate portion 1m and the upper case portion 1u. The reduction gear 4 is the drive gear 3 It is composed of a large gear portion 4a that meshes with the small gear portion 4s.

A shaft 5 is provided on the middle plate 1m and the upper case 1u.
x indicates a supported output gear, and a shaft 5x that meshes with the small gear portion 4s and serves as a pointer shaft passes through the upper case portion 1u. 6 is a dial through which the shaft 5x passes, 6g is a dial 6
, 7 is a pointer attached to the shaft 5x, 8 is a stopper pin attached to the front surface of the dial 6, and this stopper pin 8 is for positioning the pointer 7 at the zero position of the scale 6g. belongs to.

Next, the operation will be described. First, when the pointer 7 is in contact with the stopper pin 8 to indicate the zero position of the scale 6g, the pointer 7 separates from the stopper pin 8 from the control unit (not shown). Is supplied to the coil 2c of the stepping motor 2, the rotor 2r and the drive gear 3 rotate due to attraction and repulsion of magnetic poles generated between the stator 2s and the permanent magnet 2p.

When the rotor 2r and the drive gear 3 rotate in this manner, the reduction gear 4 meshed with the drive gear 3 at the large gear portion 4l also rotates, so that the output gear meshed with the small gear portion 4s. 5 also rotates. Therefore, the pointer 7 attached to the shaft 5x of the output gear 5 also rotates and points to the scale 6g provided on the dial plate 6. By reading the scale 6g pointed to by the pointer 7, for example, the traveling speed information can be visually recognized. can do. When the instruction control signal for causing the pointer 7 to contact the stopper pin 8 is supplied to the coil 2c while the traveling speed is instructed by the pointer 7 as described above, the pointer 7 contacts the stopper pin 8 and stops.

[0007]

Since the pointer stopper mechanism of the conventional instrument is composed of the stopper pin 8 attached to the dial plate 6, since the stopper pin 8 is required, the number of parts is large and the cost is high. Become. Further, since the stopper pin 8 can be seen from the outside on the front surface of the dial plate 6, it is not preferable in terms of design.

The present invention has been made in order to eliminate the above-mentioned inconvenience, and is a pointer stopper mechanism for an instrument which can be constructed at a low cost and can be made preferable from the outside in view of the design. Is provided.

[0009]

A pointer stopper mechanism for a measuring instrument according to the present invention is a measuring instrument for rotating a pointer by transmitting power of a movement to an output gear housed in a case for rotating a pointer shaft. An engaged portion is provided on a surface facing the output gear, and an engaging portion that engages with the engaged portion is provided on the output gear. Further, a pointer stopper mechanism for a meter according to another invention transmits the power of the movement to the output gear in the meter for rotating the pointer by transmitting the power of the movement to the output gear housed in the case for rotating the pointer shaft. In order to prevent the transmission gears from meshing with each other, the output gear is provided with incomplete tooth portions that do not form teeth.

[0010]

The pointer stopper mechanism of the instrument according to the present invention is
The rotation of the output gear is stopped by the abutment of the engaged portion with the engaged portion or the engagement of the transmission gear with the imperfect tooth portion of the output gear.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a cross-sectional view showing a pointer stopper mechanism of an instrument according to a first embodiment of the present invention, and FIG. 2 is a plan view of a main part in which a part of the pointer stopper mechanism of the instrument shown in FIG.
The same or corresponding parts as those in FIGS. 4 and 5 are designated by the same reference numerals and the description thereof will be omitted. In the first embodiment, illustration of the dial and pointer is omitted.

Reference numeral 1p indicates a protrusion as an engaged portion provided on the surface of the upper case portion 1u facing the upper surface of the output gear 5. Reference numeral 5l denotes a rib as an engaging portion provided in the radial direction on the upper surface facing the inner side of the upper case portion 1u of the output gear 5, which abuts the protrusion 1p.

Next, an operation different from the conventional example will be described. When the rib 5r abuts the projection 1p of the upper case 1u while the output gear 5 is being rotated by the power of the stepping motor 2, the output gear 5 is stopped from rotating.

As described above, according to the first embodiment of the present invention, since the protrusion 1p is integrally provided on the upper case 1u and the rib 5r is integrally provided on the output gear 5, the number of parts is reduced. Therefore, the pointer stopper mechanism of the instrument can be constructed at low cost. Also, the protrusion 1p and the rib 5
Since r is provided in a portion that cannot be seen from the outside, the instrument can be made preferable in terms of design.

FIG. 3 is a plan view showing an output gear used in a pointer stopper mechanism of an instrument according to a second embodiment of the present invention, which is the same as or corresponds to the parts shown in FIGS. 1, 2, 4 and 5. The same reference numerals are given and the description is omitted. In FIG.
Reference numeral 5n indicates an incomplete tooth portion of the output gear 5, which is a portion in which teeth are not formed so that the small gear portion 4s of the transmission gear 4 cannot mesh.

Next, the operation different from that of the first embodiment will be described. In the state where the output gear 5 is rotated by the power of the stepping motor 2, the output gear 5 is provided with the incomplete tooth portion 5n that the small gear portion 4s of the transmission gear 4 cannot mesh with. Even if the small gear portion 4s tries to engage with each other, it cannot engage with each other, so that the output gear 5 can be stopped by the incomplete tooth portion 5n.

As described above, according to the second embodiment of the present invention, the same effect as the first embodiment can be obtained.

In the above embodiment, the upper case 1u
Although the projection 1p is provided on the output gear 5 and the rib 5r is provided on the output gear 5, the upper case 1u may be provided with the rib and the output gear 5 may be provided with the projection.

[0019]

As described above, according to the present invention, the engaged portion is provided on the surface of the case facing the output gear, and the engaging portion for engaging the engaged portion is provided on the output gear. , Or because the output gear has an incomplete tooth portion that does not form teeth so that the transmission gear that transmits power to the output gear cannot mesh, the engagement portion abuts against the engaged portion, or the transmission gear By engaging with the incomplete tooth portion of the output gear, the rotation of the output gear can be stopped.

Therefore, since the engaged portion is provided integrally with the case and the engaging portion is provided integrally with the output gear, the number of parts can be reduced, and the pointer stopper mechanism of the instrument is inexpensively constructed. be able to. Further, since the engaged portion and the engaging portion are provided in the portion which cannot be seen from the outside, it can be made preferable in terms of design.

[Brief description of drawings]

FIG. 1 is a sectional view showing a pointer stopper mechanism of an instrument according to a first embodiment of the present invention.

FIG. 2 is a plan view of a partially broken main portion of a pointer stopper mechanism of the instrument shown in FIG.

FIG. 3 is a plan view showing an output gear used in a pointer stopper mechanism of an instrument according to a second embodiment of the present invention.

FIG. 4 is a cross-sectional view showing an example of a pointer stopper mechanism of a conventional instrument.

5 is a reduced plan view of the dial shown in FIG. 4. FIG.

[Explanation of symbols]

 1 case 1u upper case 1p protrusion 2 stepping motor 3 drive gear 4 reduction gear 5 output gear 5x shaft 5r rib 5n imperfect tooth portion 6 dial 7 pointer

Claims (2)

[Claims] 1. An instrument for rotating a pointer by transmitting motive power of a movement to an output gear housed in a case for rotating a pointer shaft, wherein an engaged portion is provided on a surface of the case facing the output gear. An indicator stopper mechanism for an instrument, wherein the output gear is provided with an engaging portion that engages with the engaged portion. 2. An instrument for rotating the pointer by transmitting the power of the movement to an output gear housed in a case for rotating the pointer shaft, wherein the transmission gear for transmitting the power of the movement cannot mesh with the output gear. A pointer stopper mechanism for a measuring instrument, wherein the output gear is provided with an incomplete tooth portion that does not form teeth.