Seiko Instruments Inc

Tamotsu Ono

Kei Hirano

Mamoru Watanabe

Yuichi Shino

Shigeo Suzuki

Masayuki Kawata

Toshiyuki Fujiwara

A chronograph timepiece includes heart cams, a start-stop button, a reset-to-zero button, and a start-stop lever and a reset-to zero instruction lever operated by the start-stop button and the reset-to-zero button, respectively, for undergoing rotation around a common rotation center. A hammer operating lever rotates in a first direction when the start-stop lever rotates and rotates in a second direction when the reset-to-zero instruction lever rotates. When the hammer operating lever rotates in the second direction, a hammer lever causes the heart cams to be reset to zero by bringing hammer portions of the hammer lever into engagement with respective ones of the heart cams. When the hammer operating lever rotates in the first direction, the hammer lever causes the hammer portions to be disengaged from the heart cams.

Chronograph timepiece

Disclosed is a slip gear structure which is easy to handle at the time of dismantling/assembly and which does not easily suffer breakage even if dismantling/assembly is repeated, and a timepiece equipped with the same. A slip gear structure for a timepiece includes: a gear main body portion in the form of an annular plate having in the outer periphery thereof tooth portions, there being provided spring portions extending across an inner opening; and a positioning member equipped with a small diameter plate-like portion having a central hole with which a shaft is rotatably fit-engaged and a pair of support wall portions arranged on both sides of the central hole and protruding from one surface. When the slip gear structure is in a non-fit-engaged state with respect to the shaft, the spring portions of the gear main body are elastically pressed against side edge portions of the support wall portions, with central spring portions thereof situated between the side edge portions protruding into the central hole; and when the slip gear structure is in a fit-engaged state with respect to the shaft at the central hole, the central spring portions of the spring portions of the gear main body portion are elastically pressed against the shaft for slip engagement with the shaft.

Slip gear structure and timepiece equipped with the same

The present invention aims to provide a day display apparatus having less risk of occurrence of a day hopping even when an impact caused by a drop or the like is applied and a watch having the same. A day display apparatus of a watch includes a first day display wheel having a program tooth portion, a second day display wheel having a claw wheel portion and a gear portion, a jumper configured to perform a jump-and-stop operation with respect to the claw wheel portion, a day intermediate wheel engaging the gear portion, being rotated by the program tooth portion every time when the first day display wheel reaches a predetermined rotational position, and transmitting the rotation to the second day display wheel, and jump-and-stop control means configured to assume a rotation restrained position in which a jump-and-stop claw portion is restrained from coming apart from between the adjacent claw portions of the claw wheel portion when the jumper is at a rotation restrained state and assume a rotation allowing state in which the jump-and-stop claw portion is allowed to climb over the claw portion of the claw wheel portion every time when the first day display wheel reaches the predetermined rotational position and allows the second day display wheel to rotate.

Day display apparatus and watch having the same

An analog chronograph timepiece has a main plate and a setting stem for correcting time information. Defined at the main plate are a reference vertical axis line passing through the rotational center of the main plate and disposed parallel to a central axis line of the setting stem, and a reference horizontal axis line passing through the rotational center of the main plate and disposed orthogonal to the main plate reference vertical axis line. The main plate has regions disposed relative to the reference vertical and horizontal lines and in which a time coil block and first and second chronograph coil blocks are selectively arranged.

Analog chronograph timepiece having plural motors

To effectively prevent positional deviation of a battery. A hook-shaped member of a spring electrode terminal, and hook-shaped members of a spring electrode terminal are arranged in respective apices of a regular triangle to restrict movements of a battery in a direction along a cross section against the bias of a spring electrode terminal, which abuts against a negative surface of the battery. Battery abutments are arranged in respective apices of a substantially regular triangle to permit the bias of the respective spring electrode terminals to bias the battery toward the battery abutment, thus restricting positional deviation of the battery in a horizontal plane. When the battery is to be removed, a battery removal tool arranged near the hook-shaped member is inserted into a tool insertion portion to remove the battery.

Electronic timepiece

To provide a hand motion irregularity suppressed timepiece whose ability has been improved. As to a spring having a flat portion and a bent portion, the flat portion is disposed between a second chronograph wheel and a center wheel, and the bent portion is sandwiched and supported under a pressurized state by a train wheel bridge and a bottom plate. By this, the spring portion prevents a hand motion irregularity of the second chronograph wheel by the fact that the second chronograph wheel is pressure-contacted with the train wheel bridge. Further, by forming a gap between the second chronograph wheel and the center wheel, an accompanying rotation between the second center wheel and the center wheel is prevented.

Growing community of inventors

Chiba, Japan

Tamotsu Ono