Nissin Kogyo Co., Ltd.

Mitsuhiro Hanaoka

Takayoshi Shinohara

Atsushi Shimizu

Tsutomu Amano

Kazuhiro Ohta

Toshiaki Mitani

Genichi Hatakoshi

Osamu Ueno

Junpei Ishiguro

Norihiro Kobayashi

A cup seal includes a base portion disposed on a cylinder bore opening portion side of a seal groove, an inner circumferential lip portion extended from an inner circumferential side of the base portion toward a cylinder bore bottom portion and having an inner circumferential surface slidably abutting against an outer circumferential surface of a piston (plunger), and an outer circumferential lip portion extended from an outer circumferential side of the base portion toward the cylinder bore bottom portion and having an outer circumferential surface abutting against a seal groove bottom surface. The cup seal also includes an abutment surface and contact pressure adjustment surface.

Cylinder apparatus

A cup sealincludes a base portiondisposed on a cylinder bore opening portion side of a seal groove, and an inner lip portionextended from an inner circumferential side of the base portion toward a cylinder bore bottom portion and having an inner circumferential surface slidably abutting against an outer circumferential surface of a piston. In a state where the cup sealis fitted into the seal groove and a plungeris inserted into a cylinder bore, an abutting force maximum portionwhere an abutting force against the plungerbecomes maximum within an inner circumferential surface of the cup sealis provided on an end portion on the cylinder bore opening portion side of an inner circumferential surface part of the base portion

A cup sealincludes a base portiondisposed on a cylinder bore opening portion side of a seal groove, an inner circumferential lip portionextended from an inner circumferential side of the base portion toward a cylinder bore bottom portion and having an inner circumferential surface slidably abutting against an outer circumferential surface of a piston (plunger), and an outer circumferential lip portionextended from an outer circumferential side of the base portion toward the cylinder bore bottom portion and having an outer circumferential surface abutting against a seal groove bottom surface. An abutment surfacehaving a protruded end protruded toward the cylinder bore opening portion and abutting against a surface on the cylinder bore opening portion side is provided on a base end surfaceof the base portion, and a contact pressure adjustment surfacewhich is brought into non-contact with an inner circumferential side of the opening-side-surface in a non-operational state is provided at a position closer to the inner circumference than the abutment surface.

A cup sealincludes a base portion, an inner circumferential lipslidingly contactable with a plungerand an outer circumferential lipcontactable with the bottom surfaceof the seal groove. Further, on the cup seal, there are provided elastic projectionsprojecting from the outer circumferential side leading end of the inner circumferential liptoward the cylinder hole bottom portion. The length of the cup sealfrom the base end faceto the leading end portionsis set longer than axial length of the seal groove. When the cup sealis fitted into the seal groove, force is imparted on the inner circumferential liptoward the cylinder hole inner circumferential direction to energize the inner circumferential liptoward the piston all the time.

Cylinder device

A reed switch unit,for detecting a liquid level in a reservoir,of a master cylinder which comprises a reed switch,including a contact part,which is sealingly contained in a glass tube,, and lead portions,which axially extend from opposite ends of the glass tube,, and a unit body,provided with terminals,for respectively supporting the lead portions,so as to be electrically connectable thereby to fix the reed switch,. The lead portions,and the terminals,are connected with each other by means of a resistance welding. Accordingly, it is possible to provide a reed switch unit which is improved in quality as well as enhanced in productivity, by mounting a reed switch on a unit body without conducing soldering.

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Nagano, Japan

Mitsuhiro Hanaoka