This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2017-043763, filed Mar. 8, 2017, the entire contents of which are incorporated herein by reference.
The present invention relates to a pointer which is used for timepieces such as wristwatches and a timepiece including the same.
For example, a pointer for a wristwatch is known which has a structure where a pointer body made of synthetic resin and a metal pointer attachment section that is provided in a rotation center portion of the pointer body have been integrally formed by insert molding, as described in Japanese Patent Application Laid-Open (Kokai) Publication No. 2015-114295.
The pointer attachment section of this pointer for a wristwatch is formed to have a cylindrical shape where a pointer shaft is inserted and attached, and to have an inner diameter larger than the thickness of the pointer body so as to be fixed in a mold for molding by a positioning pin of the mold being inserted thereinto at the time of insert molding.
That is, when the cylindrical pointer attachment section of this pointer is placed in the mold for molding so as to perform insert molding, this cylindrical pointer attachment section is required to be fixed in the mold by the positioning pin being inserted thereinto so that it does not move within the mold when an injection pressure is applied by synthetic resin being injected into the mold.
Accordingly, in the case of this pointer, the inner diameter of the pointer attachment section cannot be made smaller. In addition, by being required to have the same size as the inner diameter of the pointer attachment section, the outer diameter of the pointer shaft to be inserted into the pointer attachment section is large, and therefore the pointer shaft cannot be formed to be thin.
An object of the present invention is to provide a pointer for which the outer diameter of a pointer shaft can be made small and a pointer body can be favorably molded, and a timepiece including the same.
In accordance with one aspect of the present invention, there is provided a pointer comprising: a pointer body formed of synthetic resin; and a pointer attachment section formed of a material harder than the synthetic resin and provided in a rotation center portion of the pointer body, wherein the pointer attachment section comprises a large-diameter section to which the pointer body is fixed and which includes a positioning section, and a small-diameter section which is provided coaxially with the large-diameter section and to which a pointer shaft is attached.
The above and further objects and novel features of the present invention will more fully appear from the following detailed description when the same is read in conjunction with the accompanying drawings. It is to be expressly understood, however, that the drawings are for the purpose of illustration only and are not intended as a definition of the limits of the invention.
An embodiment where the present invention has been applied in a wristwatch will hereinafter be described with reference to
This wristwatch includes a wristwatch case 1, as shown in
In this wristwatch case 1, a timepiece module 5 is provided, as shown in
The main display section 8 is structured such that the upper end of a pointer shaft 11 provided in a center portion of the dial 8 protrudes upward from the dial 6, and pointers 12 such as a second hand 12a, a minute hand 12b, and an hour hand 12c are attached to the upper end of this protruding pointer shaft 11, as shown in
The sub-display section 9 is structured such that a sub-pointer shaft 14 is provided in a center portion of a sub-display area 13 which is a circular hole provided between the center of the dial 6 and an outer peripheral portion of the dial 6 on the 12 o'clock side, and a sub-pointer 15 is attached to the upper end 14a (see
The display device 10 includes a flat display panel such as a liquid crystal display panel or an electroluminescence (EL) display panel and electrooptically displays information such as a date, as shown in
The sub-pointer 15 in the sub-display section 9 includes a pointer body 16 made of synthetic resin and a metal pointer attachment section 17 provided in a rotation center portion of this pointer body 16 and referred to as “hakama”, and the pointer body 16 and the pointer attachment section 17 are integrally formed by insert molding, as shown in
This pointer body 16 is provided with an indication section 16a that indicates a day of the week in a disk-shaped area, as shown in
The pointer attachment section 17 is formed of a metal such as phosphor bronze, brass, or aluminum, as shown in
That is, the large-diameter section 18 is formed to have a substantially cylindrical shape in its entirety, as shown in
That is, this mold fixing section 20 includes a circular hole 20a provided inside the large-diameter section 18 and a bottom section 20b provided on the lower surface of this circular hole 20a, and is formed to have a concave shape in its entirety, as shown in
Also, the large-diameter section 18 is formed such that its length in the vertical direction (height) is equal to the thickness T of the pointer body 16, as shown in
These pointer fixing sections 21 are a pair of disk-shaped flange sections provided on an upper end portion and a lower end portion of the outer periphery of the large-diameter section 18 so as to project outwardly, as shown in
On the other hand, the small-diameter section 19 is formed to have a substantially cylindrical shape in its entirety, and is provided coaxially with the large-diameter section 18, on the undersurface of the bottom section 20b of the mold fixing section 20 in the large-diameter section 18, as shown in
Also, this small-diameter section 19 is formed such that its outer diameter is smaller than the thickness T of the pointer body 16 and is smaller than the inner diameter of the circular hole 20a of the mold fixing section 20 in the large-diameter section 18. For example, it is formed to be substantially one-third of the inner diameter of the circular hole 20a, as shown in
Next, a case where this sub-pointer 15 is molded by insert molding is described.
In this embodiment, the mold 23 includes a lower mold 24, an upper mold 25, and a slide core 26, as shown in
That is, the hollow section 27 formed between the lower mold 24 and the upper mold 25 has the same shape as the shape of the sub-pointer 15 when it is vertically reversed, as shown in
That is, the guide cylinder section 26a is formed such that its outer diameter is slightly larger than the outer diameter of the large-diameter section 18 of the pointer attachment section 17 and its inner diameter is equal to the outer diameter of the positioning pin 26b, as shown in
As a result, the positioning pin 26b is structured such that it fixes the pointer attachment section 17 in the hollow section 27 in the mold 23 when its leading end is inserted into the circular hole 20a of the mold fixing section 20, as shown in
Also, in the upper mold 25, an insertion hole 25a into which the small-diameter section 19 of the pointer attachment section 17 is inserted is provided, as shown in
When the sub-pointer 15 is to be molded by this mold 23, first, the lower mold 24 and the upper mold 25 are first opened, the small-diameter section 19 of the pointer attachment section 17 is inserted into the insertion hole 25a of the upper mold 25, and then the lower mold 24 and the upper mold 25 are overlapped with each other in this state. As a result, the pointer attachment section 17 is arranged in the hollow section 27 in the mold 23. Here, the large-diameter section 18 of the pointer attachment section 17 is arranged between the slide core 26 in the lower mold 24 and the upper mold 25.
In this state, the positioning pin 26b of the slide core 26 is inserted into the circular hole 20a of the mold fixing section 20 in the large-diameter section 18 of the pointer attachment section 17. Here, the positioning pin 26b slides toward the large-diameter section 18 of the pointer attachment section 17 while being guided by the guide cylinder section 26a of the slide core 26, and the leading end of this positioning pin 26b is inserted into the circular hole 20a of the mold fixing section 20 in the large-diameter section 18 of the pointer attachment section 17.
Here, since the outer diameter of the positioning pin 26b is equal to the inner diameter of the circular hole 20a of the mold fixing section 20 in the large-diameter section 18 of the pointer attachment section 17, or in other words, since it is larger than the outer diameter of the small-diameter section 19 of the pointer attachment section 17, the strength of the positioning pin 26b has been ensured. Accordingly, when the leading end of the positioning pin 26b is inserted into the circular hole 20a of the mold fixing section 20 in the large-diameter section 18 of the pointer attachment section 17, the large-diameter section 18 of the pointer attachment section 17 is pressed against the upper mold 25 by the leading end of the positioning pin 26b.
As a result, the bottom section 20b of the mold fixing section 20 in the large-diameter section 18 of the pointer attachment section 17 is pressed against the upper mold 25 by the positioning pin 26b with the small-diameter section 19 of the pointer attachment section 17 being inserted into the insertion hole 25a of the upper mold 25. Accordingly, the pointer attachment section 17 is firmly fixed with its position being accurately regulated inside the hollow section 27 in the mold 23 by the positioning pin 26b.
Then, resin is injected from the gate 25b of the upper mold 25 and fed into the hollow section 27 in the mold 23. Here, since the pointer attachment section 17 has been fixed in the hollow section 27 in the mold 23 by the positioning pin 26b, the pointer attachment section 17 in the hollow section 27 in the mold 23 is not moved or shifted by the injection pressure of the resin fed into the hollow section 27.
As a result, the resin is favorably injected into the hollow section 27, so that the pointer body 16 is molded. Here, the resin projects into an area between the pair of flange sections that are the pointer fixing sections 21 respectively provided on the upper end portion and the lower end portion of the outer periphery of the large-diameter section 18 of the pointer attachment section 17. Therefore, the pointer body 16 is reliably and firmly fixed to the large-diameter section 18 of the pointer attachment section 17. As a result, the sub-pointer 15 where the pointer body 16 and the pointer attachment section 17 have been integrally formed is formed.
Then, the sub-pointer 15 is taken out of the mold 23. Here, the positioning pin 26b of the slide core 26 provided in the lower mold 24 is pulled out, and the leading end of the positioning pin 26b is extracted from the circular hole 20a of the mold fixing section 20 in the large-diameter section 18 in the pointer attachment section 17. In this state, the lower mold 24 and the upper mold 25 are separated from each other so as to extract the small-diameter section 19 in the pointer attachment section 17 inserted into the insertion hole 25a of the upper mold 25. As a result, the sub-pointer 15 can be taken out of the mold for molding 23.
Next, a case is described in which the sub-pointer 15 formed as described above is attached to the sub-pointer shaft 14 in the sub-display section 9 so as to be used.
In this case, the small-diameter section 19 of the pointer attachment section 17 of the sub-pointer 15 is mounted on the upper end 14a of the sub-pointer shaft 14 incorporated into the timepiece module 5 and positioned at the center of the sub-display area 13 of the sub-display section 9. That is, when the upper end 14a of the sub-pointer shaft 14 is inserted by press fitting into the small-diameter section 19 of the pointer attachment section 17, the small-diameter section 19 of the pointer attachment section 17 is attached to the upper end 14a of the sub-pointer shaft 14.
Here, the inner diameter of the small-diameter section 19 of the pointer attachment section 17 in the sub-pointer 15 is significantly smaller than the inner diameter of the circular hole 20a of the mold fixing section 20 in the large-diameter section 18 of the pointer attachment section 17. For example, the inner diameter of the small-diameter section 19 is as small as substantially 0.2 mm, whereas the inner diameter of the circular hole 20a of the mold fixing section 20 is substantially 0.7 mm. As a result, the outer diameter of the upper end 14a of the sub-pointer shaft 14 is formed to be small, so that the entire sub-pointer shaft 14 can be formed to be thin.
Accordingly, when the sub-pointer shaft 15 is being moved with it being attached to the sub-pointer shaft 14, the rotational moment of a wheel (not shown) of the sub-pointer shaft 14 rotated by a train wheel mechanism (not shown) is small since the sub-pointer shaft 14 is thin. Therefore, the power consumption of a step motor (not shown) for driving the train wheel mechanism is small, so that power saving can be achieved.
As described above, the sub-pointer 15 in this wristwatch includes the pointer body 16 formed of synthetic resin and the pointer attachment section 17 formed of metal and provided in the rotation center portion of the pointer body 16, and the pointer attachment section 17 includes the large-diameter section 18 to which the pointer body 16 is fixed and the small-diameter section 19 which is provided coaxially with this large-diameter section 18 and to which the sub-pointer 14 is attached. As a result of this structure, the outer diameter of the sub-pointer shaft 14 can be formed small and the pointer body 16 can be favorably molded.
That is, in the sub-pointer 15 in this wristwatch, the outer diameter of the small-diameter section 19 in the pointer attachment section 17 to which the sub-pointer shaft 14 is attached can be formed significantly smaller than the outer diameter of the large-diameter section 18 to which the pointer body 16 is fixed. Therefore, the outer diameter of the sub-pointer shaft 14 which is attached to the small-diameter section 19 of the pointer attachment section 17 can be formed to be minimally small. As a result, the sub-pointer shaft 14 can be formed to be significantly thin.
Also, in the sub-pointer 15 in this wristwatch, the outer diameter of the large-diameter section 18 of the pointer attachment section 17 can be formed significantly larger than the outer diameter of the small-diameter section 19 of the pointer attachment section 17. Therefore, the pointer body 16 can be reliably and favorably fixed to the outer periphery of the large-diameter section 18 and the pointer attachment section 17 can be reliably fixed in the mold 23 by the large-diameter section 18. As a result, the pointer body 16 can be favorably formed on the pointer attachment section 17 by insert molding.
In this embodiment, the large-diameter section 18 of the pointer attachment section 17 is formed such that its outer diameter is substantially equal to or larger than the thickness T of the pointer body 16. Accordingly, by this large-diameter section 18, the pointer attachment section 17 can be reliably fixed in the mold 23. Also, the small-diameter section 19 in the pointer attachment section 17 is formed such that its outer diameter is smaller than the thickness T of the pointer body 16. Therefore, the outer diameter of the small-diameter section 19 can be formed to be minimally smaller than the outer diameter of the outer diameter section 18. As a result, the sub-pointer shaft 14 can be formed to be significantly thin.
Also, in the sub-pointer 15 in this wristwatch, the pointer fixing sections 21 for fixing the pointer body 16 to the outer periphery of the large-diameter section 18 of the pointer attachment section 17 are provided. Accordingly, by these pointer fixing sections 21, the pointer body 16 can be reliably fixed to the pointer attachment section 17. More specifically, these pointer fixing sections 21 are a pair of disk-shaped flange sections provided on the upper end portion and the lower end portion of the outer periphery of the large-diameter section 18 so as to project outwardly. Therefore, the pointer body 16 can be formed to project into the area between the pair of flanged sections. As a result, the pointer body 16 can be reliably and firmly fixed to the outer periphery of the large-diameter section 18.
In this embodiment, the large-diameter section 18 of the pointer attachment section 17 is formed such that its outer periphery has a square shape. Therefore, when the pointer body 16 is fixed to the outer periphery of the large-diameter section 18, the pointer body 16 can be reliably and favorably fixed to the large-diameter section 18 in a manner not to be rotated. By this structure as well, the pointer body 16 can be reliably and firmly fixed to the outer periphery of the large-diameter section 18.
Also, for this sub-pointer 15 in the wristwatch, the pointer body 16 and the pointer attachment section 17 are integrally formed by insert molding. Accordingly, this wristwatch is high in productivity, and can be mass-produced so as to be produced at low cost. That is, when the sub-pointer 5 is to be molded, the pointer attachment section 17 made of metal is arranged inside the hollow section 27 in the mold 23, and resin is injected into the hollow section 27 in the mold 23 in this state, whereby the pointer body 16 and the pointer attachment section 17 are integrally formed.
In this embodiment, in the large-diameter section 18 of the pointer attachment section 17, the mold fixing section 20 for fixing the pointer attachment section 17 to the mold 23 is formed, of which the outer diameter is larger than the outer diameter of the small-diameter section 19. Therefore, when resin is injected into the mold 23, the pointer attachment section 17 can be reliably and favorably fixed in the mold 23 without being moved or shifted within the mold 23 by the injection pressure of the resin.
That is, this mold fixing section 20 is formed to have a concave shape into which the positioning pin 26b of the slide core 26 in the mold 23 is inserted, and the inner diameter of this concave shape is larger than the outer diameter of the small-diameter section 19. As a result of this structure, the outer diameter of the positioning pin 26b can be formed larger than the outer diameter of the small-diameter section 19, whereby the strength of the positioning pin 26b can be ensured.
Accordingly, in the sub-pointer 15, when the pointer attachment section 17 made of metal is to be arranged within the mold 23, the positioning pin 26b can be inserted into the concave-shaped mold fixing section 20 in the large-diameter section 18 of the pointer attachment section 17, which can reliably and firmly fix the pointer attachment section 17 in the mold 23.
In this embodiment, the concave-shaped mold fixing section 20 includes the circular hole 20a which is larger than the outer diameter of the small-diameter section 19 and formed in the large-diameter section 18, and the bottom section 20b provided on the lower surface of this circular hole 20a. Therefore, the positioning pin 26b can be reliably and favorably inserted into the circular hole 20a of the concave-shaped mold fixing section 20 formed in the large-diameter section 18 of the pointer attachment section 17, which can reliably and firmly fix the pointer attachment section 17 in the mold for molding 23.
Also, this concave-shaped mold fixing section 20 can press the leading end of the positioning pin 26b against the bottom section 20b of the concave-shaped mold fixing section 20 when this leading end of the positioning pin 26b is inserted into the circular hole 20a of the concave-shaped mold fixing section 20. As a result, the bottom section 20b of the mold fixing section 20 can be pressed against the inner surface of the upper mold 25. Therefore, the pointer attachment section 17 can be reliably and firmly fixed in the mold for molding 23.
Note that, although the present embodiment has been described using the case where the mold fixing section 20 in the large-diameter section 18 of the pointer attachment section 17 of the sub-pointer 15 is formed to have a concave shape, the present invention is not limited thereto and the mold fixing section 20 is not necessarily required to be formed in a concave shape. For example, the mold fixing section 20 may be a projection section projecting in the axial direction from the large-diameter section 18.
In this case as well, the mold fixing section 20, which is the projecting section, may be formed such that its outer diameter is equal to or slightly smaller than the outer diameter of the large-diameter section 18 and is sufficiently larger than the outer diameter of the small-diameter section 19 of the pointer attachment section 17. In this structure, the mold 23 is not required to have the slide core 26, and therefore can be simplified.
Also, in the above-described embodiment, the present invention has been applied in the sub-pointer 15 of the sub-display section 9. However, the present invention is not limited thereto. For example, the present invention may be applied in the second hand 12a of the main display section 8. That is, the second hand 12a may be constituted by a pointer body made of synthetic resin and a pointer attachment section made of metal, and this pointer attachment section may be formed in the same manner as that of the pointer attachment section 17 in the sub-pointer 15.
In this embodiment, the pointer body of the second hand 12a is formed to have a long narrow shape. Also, the pointer shaft 11 includes a cylindrical hour hand shaft to which the hour hand 12c is attached, a cylindrical minute hand shaft which is rotatably provided within this hour hand shaft and has an upper end to which the minute hand 12b is attached, and a second hand shaft which is rotatably provided within this minute hand shaft and has an upper end to which the second hand 12a is attached, and these pointer shafts are concentrically located.
In the case of this second hand 12a as well, the outer diameter of the second hand shaft in the pointer shaft 11 can be formed small and the pointer body can be favorably molded as with the sub-pointer 15. That is, in the case of this second hand 12a as well, the outer diameter of a small-diameter section of the pointer attachment section to which the second hand shaft in the pointer shaft 11 is attached can be made smaller than the outer diameter of a large-diameter section to which the pointer body is attached. Accordingly, the outer diameter of the second hand shaft in the pointer shaft 11 which is attached to the small-diameter section of the pointer attachment section can be made small.
Also, in this second hand 12a, the outer diameter of the large-diameter section of the pointer attachment section can be made significantly larger than the outer diameter of the small-diameter section of the pointer attachment section. Accordingly, by this large-diameter section, the pointer attachment section can be reliably fixed in the mold, whereby the pointer body and the pointer attachment section can be favorably formed by insert molding.
In the above-described embodiment and the modification examples, the present invention has been applied in a pointer-type wristwatch. However, the present invention is not necessarily required to be applied in a pointer-type wristwatch. For example, the present invention is widely applicable to various pointer-type timepieces such as a travel watch, an alarm clock, a table clock, and a wall clock.
While the present invention has been described with reference to the preferred embodiments, it is intended that the invention be not limited by any of the details of the description therein but includes all the embodiments which fall within the scope of the appended claims.
Number | Date | Country | Kind |
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2017-043763 | Mar 2017 | JP | national |
Number | Name | Date | Kind |
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4132188 | Gjertsen | Jan 1979 | A |
5553480 | Rose | Sep 1996 | A |
6180041 | Takizawa | Jan 2001 | B1 |
9804569 | Enta | Oct 2017 | B2 |
Number | Date | Country |
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204989766 | Jan 2016 | CN |
2015-114295 | Jun 2015 | JP |
2016-099182 | May 2016 | JP |
Entry |
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Awano, Yusuke, English Translation of JP2015114295, originally published Jun. 22, 2015, retrieved from Espacenet on Aug. 30, 2019, full document (Year: 2015). |
Notification of Reasons for Refusal dated Jan. 10, 2019 received in Japanese Patent Application No. JP 2017-043763 together with an English language translation. |
First Office Action dated Sep. 4, 2019 received in Chinese Patent Application No. CN 201810149646.4 together with an English language translation. |
Number | Date | Country | |
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20180259907 A1 | Sep 2018 | US |