Watch having a sensor

Abstract: A sensor housing pipe is secured to a back of a watch at a recess formed on an underside of the back. A sensor is housed in the sensor housing pipe. A sensor lid is provided for securing the sensor in the sensor housing pipe. The sensor lid has openings for communicating the sensor with the outside of the watch.

Description: BACKGROUND OF THE INVENTION The present invention relates to a watch having a sensor for sensing an environmental condition such as hydraulic pressure and atmospheric temperature. In a conventional watch having a sensor, the sensor is mounted on a watch case or on a shield for shielding a dial, so that the sensor is projected from the surface of the shield or the watch case. There is a case that the projected sensor deteriorates the appearance of the watch. Japanese Patent Application Laid-Open 56-19480 discloses a watch having a sensor wherein the sensor is mounted on a back of the watch, so that the sensor is not exposed when worn on a wrist. In such a watch, there may occur a problem that a detecting portion of the sensor is blocked by a surface of a wet suit or skin of the wrist to prevent water from flowing to the sensor, rendering the detection of hydraulic pressure impossible. JP-A-03-195919 discloses a portable apparatus with a water depth meter comprising a pressure sensor unit fitted within a case from the inside thereof. SUMMARY OF THE INVENTION An object of the present invention is to provide a watch having a sensor having simple construction wherein flow of water or air is not blocked, thereby ensuring the detection of hydraulic pressure, atmospheric pressure, and others. According to the present invention, there is provided a watch having a watch case and a back, and in accordance with Claim 1 or Claim 2. In embodiments of the invention, the sensor housing pipe may be integral with the back. Positioning means may be provided for positioning the sensor with respect to a component member of the watch. The back may be secured to the watch case by a screw ring. Sealing means may be provided for keeping a screw thread of the screw ring watertight. These and other objects and features of the present invention will become more apparent from the following detailed description with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS Fig. 1 is a sectional side view of an electronic wrist watch having a pressure sensor as a first embodiment of the present invention; Fig. 2 is a plan view of a back of the watch of Fig. 1 as viewed from the outside thereof; Fig. 3 is a sectional side view of a sensor mounting portion in a second embodiment of the present invention; Fig. 4 is a plan view of a back of the watch of Fig. 3 as viewed from the outside thereof; Fig. 5 is a sectional side view showing a third embodiment of the present invention; Fig. 6 is a sectional side view showing a fourth embodiment of the present invention; Fig. 5 is a sectional side view showing a fifth embodiment of the present invention; Fig. 8 is an enlarged sectional view of a part of Fig. 7; Fig. 9 is a perspective view showing a housing pipe of Fig. 7; Fig. 10 is a perspective view showing a sensor lid thereof; Fig. 11 is a sectional side view showing a sixth embodiment of the present invention; Fig. 12 is a sectional side view showing a seventh embodiment of the present invention; Fig. 13 is a sectional side view showing an eighth embodiment of the present invention; Fig. 14 is a plan view showing a holding plate of Fig. 13; Fig. 15 is a sectional side view showing a ninth embodiment of the present invention; and Fig. 16 is a plan view showing a sensor lid of Fig. 15 as viewed from the outside thereof. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to Fig. 1 showing the first embodiment of the present invention, an electronic wrist watch 1 has a watch case 2, a shield 3 secured to an upper edge of the watch case 2 and a crown 4 extending from a side of the watch case 2. In the watch case, a movement 7 having a dial 5 and a circuit board 8 are mounted. A back 10 is detachably secured to the watch case 2 at a flange 10a by a screw ring 2b, interposing an O-ring 2a. As shown in Fig. 2, the back 10 has a recess 10c for mounting a pressure sensor 12. From the recess 10c, a plurality of grooves 10e extend redially, thereby forming lands 10b between the grooves. Formed in the recess 10c is a hole 10d in which a sensor housing pipe 13 is inserted and secured to the back by brazing. The pressure sensor 12 is inserted in the sensor housing pipe 13, interposing an O-ring 14. The detecting portion of the sensor 12 is outwardly faced, and projected from a large diameter portion 13a of the housing pipe 13. A sensor lid 15 is secured to the large diameter portion 13a by press fitting, so that the pressure sensor 12 is secured in the housing pipe 13. The sensor 12 is electrically connected to the circuit board 8 by connecting springs 16 each of which passes through a hole formed in a circuit supporting plate 18. The sensor lid 15 has four openings 15c as shown in Fig. 2 so as to apply an outside pressure to the pressure sensor 12. Furthermore, a sensor cover 17 is secured to a projected portion 15d of the sensor lid 15 by welding. The sensor cover 17 has a shape for covering the whole of the sensor lid 15. However, a gap 17a is formed between the sensor cover 17 and the sensor lid 15 except for the projected portion 15d. A gap 17b is formed between the end of the sensor cover 17 and the back 10. The sensor cover 17 is provided such that the underside of the cover 17 becomes coplanar with the surface of the land 10b of the back. Thus, the underside of the watch contacts with a wrist 11 of the wearer without rough feeling when worn. In use in water, the water enters the sensor cover 17 passing through the grooves 10e, recess 10c of the back 10 and the gap 17b between the cover 17 and the back 10. The water flows in the sensor lid 15 passing through the gaps 17b and 17a, and the openings 15c. Thus, the water pressure is applied to the pressure sensor 12. Therefore, the water pressure can be reliably measured without blocking of the wet suit or the skin of the wrist. In use in atmosphere, the atmospheric pressure is exactly applied to the pressure sensor 12 in the same manner as the detection of the water pressure. Referring to Figs. 3 and 4 showing the second embodiment of the present invention, the same parts as Figs. 1 and 2 are identified with the same reference numerals as those of the figures. In the second embodiment, the sensor cover 17 of the first embodiment is not provided, and hence a sensor lid 20 is directly contacted with the wrist 11. The sensor lid 20 is secured to the housing pipe 13 by the press fit. The sensor lid 20 has radially arranged grooves 20a on the peripheral wall and grooves 20b on the underside wall, each communicated with the groove 20a. An opening 20c is formed in an inner end of each groove 20a. Outside pressure is applied to the pressure sensor 12 through the grooves 20a and 20b and openings 20c. Since the grooves 20a are radially arranged and communicated with the peripheral grooves 20b, the grooves are not blocked by the skin of the wrist. Referring to Fig. 5 showing the third embodiment, a pressure sensor 25 has two sensor pins 26 on the underside thereof. The pins 26 extend from holes of a housing pipe 27. A movement 28 comprises an electronic circuit block 30 and a circuit supporting plate 31. The pressure sensor 25 is inserted in the housing pipe 27 secured to the back 10 and fixed by the sensor lid 20. The movement 28 is mounted in the watch case 2, and connecting springs 33 are inserted in holes 32 of the circuit supporting plate 31. Each of the sensor pins 26 is engaged with the hole 32, and the back 10 is secured to the watch case 2 by the screw ring 2b. Fig. 6 shows the fourth embodiment of the present invention. In the watch, an intermediate member 34 is disposed between the circuit supporting plate 31 and the back 10. The intermediate member 34 has two pins 36 to be engaged with positioning holes 35 of the circuit supporting plate 31, respectively. A hole 37 is formed in the intermediate member 34 for receiving the housing pipe 27. The movement 28 is inserted in the watch case 2, connecting springs 33 are inserted in the holes 32 of the circuit supporting plate 31, and the pins 36 are engaged with the positioning holes 35, respectively. The housing pipe 27 secured to the back 10 is engaged in the hole 37 of the intermediate member 34, and the back 10 is fixed to the watch case 2 by the screw ring 2b. Thus, the back 10 engages with semispheric projections 34a, thereby holding the intermediate member 34. In accordance with the third and fourth embodiments, positioning means is provided for positioning the pressure sensor and the electronic circuit block. Therefore, both the members can be easily and exactly connected with each other. Referring to Figs. 7 and 8 showing the fifth embodiment, the watch is characterized by a housing pipe 40 and a sensor lid 41, the other structure is the same as the second embodiment. As shown in Fig. 9, the housing pipe 40 comprises a large diameter portion 40a and a small diameter portion 40b. Three grooves 40c are formed on the large diameter portion 40a. The small diameter portion 40b is engaged with the hole 10d of the back 10 and secured thereto by brazing. As shown in Fig. 10, the sensor lid 41 comprises a base portion 41a and an annular peripheral portion 41b. A plurality of grooves 41c are formed on the peripheral portion 41b, corresponding to grooves 40c of the housing pipe 40. The sensor lid 41 is secured to the housing pipe 40 by press fit at a position where the grooves 41c correspond to the groves 40c. In use, water enters the space between the pressure detecting portion of the pressure sensor 12 and the sensor lid 41 passing through grooves 41c and 40c, so that water pressure can be accurately measured. Fig. 11 shows the sixth embodiment of the present invention. A housing pipe 42 has a screw thread 42e formed on a large diameter portion 42a and grooves 42c. A sensor lid 43 has a plurality of openings 43d at a base portion 43a and an annular portion 43b. a plurality of radial grooves 43c formed on the peripheral end thereof, and a screw thread 43e formed on the inside wall. Each of the openings 43d is opened facing outwardly. The sensor lid 43 is secured to the housing pipe 42 by engagement of screw threads 42e and 43e. In accordance with the embodiment, the openings 43d are provided in addition to grooves 42c and 43c. Thus, pressure can be more accurately measured. Referring to Fig. 12 showing the seventh embodiment, a housing pipe 45 has an annular portion 45b, a plurality of openings 45c at a base portion 45a and the annular portion 45b, an annular shoulder portion 45d and a screw thread 45e formed on an upper peripheral wall. A screw ring 46 is provided for securing the pressure sensor 12 in the housing pipe 45. The screw ring 46 comprises an annular portion 46a, a screw thread 46b to be engaged with the screw thread 45e of the housing pipe 45, and a flange 46c. The screw thread 45e of the housing pipe 45 projects from the inside wall of the back 10. The O-ring 14 is disposed between the pressure sensor 12 and the flange 46c. The screw thread 46b is engaged with the screw thread 45e, thereby securing the pressure sensor 12 in the housing pipe 45. Fig. 13 shows the eighth embodiment. A housing pipe 47 comprises a base portion 47a having a plurality of openings 47c, and an annular portion 47b secured to the back 10 by brazing. A flange 47d is formed on the annular portion 47b, abutted on the underside of the back 10. The pressure sensor 12 is inserted in the housing pipe 47. The inner end of the housing pipe 47 is projected from the inside wall of the back. The O-ring 14 is disposed on the inside wall of the housing pipe 47, and a holding plate 48 is mounted on the O-ring 14. The holding plate 48 has a pair of lugs 48a each having a hole for a screw 50, as shown in Fig. 14. holding plate 48 is secured to the back 10 by the screws 50. Thus, the pressure sensor 12 is held in the housing pipe 47. Referring to Fig. 15 showing the ninth embodiment of the present invention, the embodiment is characterized in that a housing pipe is integral with the back and the screw thread of the screw ring for securing the back is kept watertight. Namely, a housing pipe 55 having the same shape as the housing pipe 40 of Fig. 8 is integral with the back 10. As shown in Fig. 16, a sensor lid 51 has three lugs, each having a hole for a screw 56. The pressure sensor 12 is inserted in the housing pipe 55 interposing the O-ring 14. The sensor lid 51 is secured to the back 10 by the screws 56. Thus, the sensor is held in the housing pipe 55. On the other hand, a screw ring 52 has an outwardly extending flange 52b at a position below a screw thread 52a. An annular groove 53 is formed on the underside of the watch case 2 below the screw thread 52a. In the groove 53, an O-ring 54 is engaged. Thus, by engaging the screw ring 52 with the watch case 2, screw threads of the watch case 2 and the screw ring 52 are kept watertight. Therefore, the screw threads 52a are prevented from rusting. In accordance with the embodiment, since the housing pipe is integral with the back, the construction of the watch is simplified. Screw threads of the watch case and the screw ring for securing the back to the watch case is kept watertight. Consequently, the rusting of the screw threads which renders the screw ring undetachable can be prevented. While the invention has been described in conjunction with preferred specific embodiment thereof, it will be understood that this description is intended to illustrate and not limit the scope of the invention, which is defined by the following claims.

Claims: A watch having a watch case (2), a back (10), a sensor housing pipe (13) provided in a recess (10c) formed on an underside of the back, a sensor (12) housed in the sensor housing pipe (13), securing means (15, 20, 41, 43) for securing the sensor in the sensor housing pipe, wherein the back has a plurality of grooves (10e) formed on the underside thereof and communicating the recess of the back with outside of the watch, a sensor cover (17) or sensor lid (20, 41, 43, 51) is mounted on said back and has an underside, an engaging surface is formed on the underside of the sensor cover or sensor lid and is flush with the underside of the back to engage with a wrist of a wearer, the sensor cover or sensor lid has an opening (17b, 20a, 20b, 20c, 41c, 43c, 43d), at a position inward of the engaging surface, when the watch is being worn on a wrist, opening to an outside of the watch, and communicating with said grooves, and a fluid passage (17a, 15c, 40c) is provided within the sensor cover or sensor lid and communicating the sensor with the opening to sense an environmental condition of the watch. A watch having a watch case (2), a back (10), a sensor housing pipe (45, 47) provided in a recess (10c) formed on an underside of the back, a sensor (12) housed in the sensor housing pipe, securing means (46, 50) for securing the sensor in the sensor housing pipe, wherein the back has a plurality of grooves (10e) formed on the underside thereof and communicating the recess of the back with outside of the watch, the sensor housing pipe (45, 47) is formed with a sensor cover portion (45a, 47a) which has an underside, an engaging surface is formed on the underside of the sensor cover portion and is flush with the underside of the back to engage with a wrist of a wearer, the sensor cover portion has an opening (45c, 47c) at a position inward of the engaging surface, when the watch is being worn on a wrist, opening to an outside of the watch, and communicating with said grooves, and a fluid passage is provided within the sensor cover portion and communicating the sensor with the opening to sense an environmental condition of the watch. A watch according to Claim 1 wherein the sensor housing pipe (55) is integral with the back. A watch according to Claim 2 wherein the securing means is a holding plate (46, 48) secured to an inside wall of the back. A watch according to Claim 1 wherein a sensor cover (17) is provided and the securing means is a sensor lid (15) secured to the sensor housing pipe (13). A watch according to Claim 1 further comprising positioning means (26) for positioning the sensor with respect to a component member of the watch. A watch according to Claim 1 or Claim 2 further comprising a screw ring (2b) securing the back to the watch case. A watch according to Claim 1 wherein the sensor housing pipe (13) has a base portion having openings and an annular portion secured to the back. A watch according to Claim 6 wherein the positioning means comprises pins (26) provided from the sensor, and holes formed in the component member. A watch according to Claim 7 further comprising sealing means (54) for keeping a screw thread of the screw ring watertight. A watch according to Claim 10 wherein the sealing means is an O-ring (54) disposed between the watch case and the screw ring.

Inventors: MURAKAMI TOMOMI, NISHIKAWA JUNICHI, UEHARA NOBUYUKI, MURAKAMI, TOMOMI, NISHIKAWA, JUNICHI, UEHARA, NOBUYUKI, MURAKAMI, TOMOMI, C/O TANASHISEIZOSHO, NISHIKAWA, JUNICHI, C/O TANASHISEIZOSHO, UEHARA, NOBUYUKI, C/O TANASHISEIZOSHO
Applicants: CITIZEN WATCH CO LTD, CITIZEN WATCH CO., LTD.
Application year: 1995
Main classification: G04G1
IPC codes: G04G1