US3888073A

US3888073A - Construction to facilitate assembly of a timepiece

Info

Publication number: US3888073A
Application number: US212611A
Authority: US
Inventors: Masahiro Kurita
Original assignee: Suwa Seikosha KK
Current assignee: Suwa Seikosha KK
Priority date: 1970-12-28
Filing date: 1971-12-27
Publication date: 1975-06-10
Anticipated expiration: 1992-06-10
Also published as: CH1898171A4; FR2120058B1; GB1342148A; DE2165082B2; DE2165082C3; DE2165082A1; CH571243B5; JPS5045316Y1; FR2120058A1

Abstract

In a timepiece, a pair of support plates are mounted in fixed spaced relationship on pillars and a plurality of gear wheels with pivot shafts are disposed between said plates and rotatably mounted in bearing means on the plates. One longitudinal end of each of the gear wheel shafts is initially disposed in the bearing means on one of the plates. To facilitate assembly of the other plate, the other longitudinal ends of the gear wheel shafts are temporarily supported in predetermined alignment by holes in a relatively thin guide sheet, thereby making it a relatively simple matter to place the other plate in position to complete the assembly in which the gear wheels are rotatably supported between the two plates.

Description

United States Patent Kurita 1 June 10,1975

CONSTRUCTION TO FACILITATE ASSEMBLY OF A TIMEPIECE Primary E.raminer-Edith Simmons Jackmon Attorney. Agent, or Firm-Robert E. Burns; Emmanuel J. Lobato; Bruce L. Adams [57] ABSTRACT In a timepiece. a pair of support plates are mounted in fixed spaced relationship on pillars and a plurality of gear wheels with pivot shafts are disposed between said plates and rotatably mounted in bearing means on the plates. One longitudinal end of each of the gear wheel shafts is initially disposed in the bearing means on one of the plates. To facilitate assembly of the other plate. the other longitudinal ends of the gear wheel shafts are temporarily supported in predetermined alignment by holes in a relatively thin guide sheet, thereby making it a relatively simple matter to place the other plate in position to complete the assembly in which the gear wheels are rotatably supported between the two plates.

8 Claims, 1 Drawing Figure of s 1 CONSTRUCTION TO FACILITATE ASSEMBLY OF A TIMEPIECE The present invention relates to timepieces and more particularly to facilitating assembly of gear wheels between two support plates of a timepiece.

ln known timepieces. a base plate and a bridge plate are supported in fixed spaced relationship by pillars and a plurality of gear wheels and an anchor each having pivot shafts are disposed and rotatably supported between said plates. in assemblying the aforesaid elements. the lower ends of the shafts of the gear wheels and anchor are initially placed in the respective bearing means in the base plate so that the gear wheel and anchor shafts are generally vertically disposed. During as sembly. and particularly when the aforesaid elements are used in an electric watch. a drawing force is applied to the anchor as the shafts of the gear wheel and anchor are disposed in the aforesaid upright dispositions and before the bride plate is assembled. Accordingly, the magnetic force tends to cause the unsupported upper ends of the gear wheel and anchor shafts to lean over or to become otherwise misaligned or displaced from their generally upright disposition. When this occurs. the misaligned and displaced shafts make it extremely difficult to insert the upper ends of the gear wheel and anchor shafts into the bearing support openings on the bridge plate.

Accordingly. it is an object of the present invention to avoid and overcome the foregoing and other difficulties of and objections to prior art practices by the provision of a guide plate which temporarily supports the upper longitudinal ends of the gear wheel and anchor shafts in predetermined desired alignment to thereby facilitate assembly of the bridge plate thereon.

Another object of the invention is to provide for easy assembly and disassembly of a timepiece without requiring any special tools and which overcomes disadvantages in known methods of assembly, thereby resulting in reducing manufacturing and repair costs.

The aforesaid objects of the present invention and other objects will become apparent as the description proceeds.

For a better understanding of the present invention reference should be had to the accompanying drawing which is a cross-sectional view of one embodiment of the present invention.

Referring to the drawing. there is shown a base plate 1 and a bridge plate 2 made of relatively thin material. The two plates are held in fixed spaced relationship by means of pillars 3 and 4. Rotatably supported between the two plates 1, 2 are a plurality of rotatable elements which are shown in the drawing to include gear wheels 5, 6, and 7 and an anchor 8.

In assemblying the above described elements. particularly when used in an electric clock. a drawing force is applied to the anchor 8. This drawing force is applied at the stage of assembly when the gear wheels 5, 6 and 7 and the anchor 8 are each in a generally upright positions. that is. with the lower ends of the gear wheel and anchor shafts disposed in suitable pivot supports in the base plate l, but before the bridge plate 2 is placed in position. Accordingly. with the upper ends of the gear wheel and anchor shafts unsupported. there is a tendency for the magnet which is used to apply the drawing force to the anchor 8 to apply its magnetic force to the gear wheels 5, 6, 7, thereby tending to cause the latter to lean over or otherwise be displaced from their 2 generally upright disposition. When this occurs it is extremely difficult to insert the upper ends of the shafts of the gear wheels 5, 6, 7 and anchor 8 into the hearing support openings on the bridge plate 2.

Accordingly, the aforesaid known prior art method of assembly results in alignment problems when attempting to place the bridge plate 2 in position to complete the assembly.

According to the present invention. the aforesaid difficulty is overcome by the use of a guide plate 9 which maintains the upper ends of the shafts of the gear wheels 5, 6, 7 and anchor 8 in alignment at all times even when the drawing force of a magent is applied to the anchor. The guide plate 9 is a thin plate adapted to rest on a shoulder on the pillars 3, 4 so that the guide plate 9 is supported by the pillars 2, 3 in fixed spaced relationship relative to the base plate 1.

The guide plate 9 has a plurality of openings adapted to receive the upper end portions of the shafts of the gear wheels 5,6,7 and anchor 8 to temporarily support the upper ends of said shafts before the bridge plate 2 is placed in assembled position. The diameters of the openings in the guide plate 9 in which the shafts of the gear wheels and anchor are received are slightly greater than the diameter of the respective shafts accommo dated therein. Accordingly, it is a relatively easy task to place the guide plate 9 in position on the pillars 3., 4 as the upper ends of the shafts of the gear wheel and anchor are received in their respective opening in the guide plate 9. Once the guide plate 9 is placed in position as aforesaid. it serves as a temporary support for the upper portions of the shafts of the gear wheels and anchor until the bridge plate 2 is placed in assembled position.

In assemblying the elements shown in the drawing, the base plate 1 is generally horizontally disposed and the lower ends of the shafts of the gear wheel and anchor are placed in their respective bearing or pivot supports in the base plate 1 so that said shafts are generally vertically disposed as shown in the drawing. The guide plate 9 is then lowered into position wherein the openings therein receive the upper portion of the pillars 3, 4 and the upper portion of the shafts of the gear wheels and anchor. As previously indicated, the diameters of the openings in the guide plate 9 are slightly greater than the respective diameters of the shafts so that it is a relatively simple task to lower the guide plate 9 into position where it rests on the shoulders of the pillars 3,4.

The upper sections of the gear wheel and anchor shafts are now temporarily supported and they will be prevented from leaning over or otherwise being displaced when a magnetic force is applied to the anchor 8.

Subsequently, with the guide plate 9 still in position as aforesaid, the bridge plate 2 is lowered into positon on the upper portion of the pillars 3, 4 while the bearing means on the bridge plate 2 receive the upper ends of the shafts of the gear wheels and anchor,

It will be apparent that it is a relatively simple task to lower the bridge plate 2 into assembled position inasmuch as the shafts of the gear wheels and anchor are maintained in alignment by the guide plate 9. Although the diameters of the openings of the guide plate 9 are slightly larger than the diameters of the respective shafts accommodated therein, such difference in diameter is not significally large and any slightly misaligned shaft would be guided into its respective bearing support on the bridge plate 2 as the latter is lowered into position.

Once the bridge plate 2 is in position on the pillars 3, 4 it is suitably secured by fastening means to complete the assembly. In the assembled condition, the gear wheels 5, 6, 7 are rotatably and pivotally supported by the base plate l and bridge plate 2 with the guide plate 9 no longer serving as a support. The guide plate 9 is retained in position on the pillars 3, 4 adjacent the bridge plate 2 and thereafter facilitates disassembly and assembly for repairs without requiring any special as sembly tools.

The guide plate 9 may be easily and inexpensively manufactured from a sheet of metal, plastic or other material in which the various openings may be readily punched out. The plate 9 may be transparent and sufficiently flexible to permit bending of the plate so that the shafts can be registered with the openings in the plate sequentially rather than simultaneously.

It will be seen that in accordance with the present invention there is provided a timepiece of the pillar type which may be readily assembled and disassembled without requiring any special tools and a method of assembly which overcomes disadvantages of known prior art methods of assembly, thereby resulting in reducing manufacturing and repair costs.

While in accordance with the patent statutes a preferred embodiment of the present invention has been illustrated and described in detail, it is to be understood that the invention is not lmited thereto or thereby.

What is claimed is:

1. In as assembly of a timepiece comprising a base plate and a bridge plate, pillars supporting said plates in fixed spaced relationship, a plurality of gear wheels having support shafts disposed between said plates, bearing means carried by said plates rotatably support ing said gear wheel shafts, the improvement which comprises a guide plate mounted on said pillars adjacent said bridge plate, said guide plate being of thin flexible sheet material having a thickness less than that of the bridge plate and having a plurality of openings through which end portions of the shafts of said gear wheels pass, said openings being large enough to receive the end portions of said shafts freely while small enough to guide and position said end portions of the gear wheel shafts to maintain the latter in alignment with the corresponding bearing means on the bridge plate as the latter is assembled into position on the pillars.

2. An assembly according to claim 1 wherein said pillars are provided with shoulders, said guide plate having openings in which longitudinal end portion of the pillars are received, said guide plate being retained against said shoulder by said bridge plate.

3. An assembly according to claim 1 wherein said guide plate is disposed generally parallel to said base plate and bridge plate and substantially contiguous with said bridge plate.

4. An assembly according to claim I, wherein said material is metal.

5. An assembly according to claim 1, wherein said material is plastic.

6. An assembly according to claim 1, wherein said guide plate is transparent.

7. In an assembly of a timepiece comprising a base plate and a bridge plate, pillars supporting said plates in fixed spaced relationship, a plurality of gear wheels having support shafts disposed between said plates, bearing means carried by said plates rotatably supporting said gear wheel shafts, the improvement which comprises a guide plate mounted on said pillars adjacent said bridge plate, said guide plate having a thickness less than that of the bridge plate and having a plurality of openings through which end portions of the shafts of said gear wheels pass. said openings being large enough to receive the end portions of said shafts freely while small enough to guide and position said end portions of the gear wheel shafts to maintain the latter in alignment with the corresponding bearing means on the bridge plate as the latter is assembled into position on the pillars, and an anchor means having a support shaft rotatably supported by said bearing means on said base plate and bridge plate.

8. In an assembly of a timepiece comprising a base plate and a bridge plate, pillars supporting said plates in fixed spaced relationship, a plurality of gear wheels having support shafts disposed between said plates, bearing means carried by said plates rotatably supporting said gear wheel shafts, the improvement which comprises a guide plate mounted on said pillars adjacent said bridge plate, said guide plate having a thickness less than that of the bridge plate and having a plurality of openings through which end portions of the shafts of said gear wheels pass, said openings being large enough to receive the end portions of said shafts freely while small enough to guide and position said end portions of the gear wheel shafts to maintain the latter in alignment with the corresponding bearing means on the bridge plate as the latter is assembled into position on the pillars, each of said pillars having one end secured to said base plate and the other end provided with two shoulders of which one positions said guide plate and the other positions said bridge plate.

Claims

1. In as assembly of a timepiece comprising a base plate and a bridge plate, pillars supporting said plates in fixed spaced relationship, a plurality of gear wheels having support shafts disposed between said plates, bearing means carried by said plates rotatably supporting said gear wheel shafts, the improvement which comprises a guide plate mounted on said pillars adjacent said bridge plate, said guide plate being of thin flexible sheet material having a thickness less than that of the bridge plate and having a plurality of openings through which end portions of the shafts of said gear wheels pass, said openings being large enough to receive the end portions of said shafts freely while small enough to guide and position said end portions of the gear wheel shafts to maintain the latter in alignment with the corresponding bearing means on the bridge plate as the latter is assembled into position on the pillars.

4. An assembly according to claim 1, wherein said material is metal.

5. An assembly according to claim 1, wherein said material is plastic.

6. An assembly according to claim 1, wherein said guide plate is transparent.

7. In an assembly of a timepiece comprising a base plate and a bridge plate, pillars supporting said plates in fixed spaced relationship, a plurality of gear wheels having support shafts disposed between said plates, bearing means carried by said plates rotatably supporting said gear wheel shafts, the improvement which comprises a guide plate mounted on said pillars adjacent said bridge plate, said guide plate having a thickness less than that of the bridge plate and having a plurality of openings through which end portions of the shafts of said gear wheels pass, said openings being large enough to receive the end portions of said shafts freely while small enough to guide and position said end portions of the gear wheel shafts to maintain the latter In alignment with the corresponding bearing means on the bridge plate as the latter is assembled into position on the pillars, and an anchor means having a support shaft rotatably supported by said bearing means on said base plate and bridge plate.