baber/WOPTO huggingface dataset:
Patent KR-20000024108-A (KR)
Inventor: LEE KYUNG HEE
IPC: G01L5/00
Filed: 2000-01-15
Abstract: PURPOSE: An apparatus having an oval bob for measuring buoyancy is provided to accurately measure a buoyancy by visually discriminating the buoyancy force when measuring the buoyancy. CONSTITUTION: A weight(18) is attached to a lower portion of a buoyancy body(10). An oval bob(30) is inserted into the lower portion of the buoyancy portion(10). A water tank(20) which is filled with water is a transparent material for observing an inner portion. An oval bob inserting portion(14) is installed at a lower portion of the buoyancy portion(10) and is inserted into a center hold(32) of the oval bob(30). An upper side of a wire(16) is fixed to an upper portion of the medium barrel bob inserting portion(14) with a thread(17). The weight(18) is attached to a lower portion of the wire(16)
Patent KR-20000049380-A (KR)
Inventor: YEOM CHEON GWON
IPC: A47L17/08
Filed: 2000-01-29
Abstract: PURPOSE: A washing device capable of supplying detergent, suitable for removing oily substances and food leftovers from kitchen utensils including food containers and dishes, which makes dishwashing convenient is provided as the structure of the washing device having a detergent supplying part installed thereof and a bar having lots of bumps where a scrubber can be inserted. CONSTITUTION: A washing device for a scrubber that can supply detergent is comprised of a tube type container(2) that can be used as a hand lever where detergent is added. The container(2) is sealed with an open-and-shut type plug(3) where a multitude of bumps is formed on its surface and a scrubber(100) is inserted at the bottom of the container(2). Between the container(2) and the open-and-shut type plug(3), a pressing bar(7) is installed that operates up and down elastically. When pressure is applied onto the pressing bar(7), the detergent in the container is supplied to the scrubber at the bottom through discharging holes(8) formed at the open-and-shut type plug(3), and when pressure is removed from the pressing bar(7), the discharging holes(8) of the plug are closed, thus the supply of the detergent is interrupted.
Patent KR-20000050629-A (KR)
Inventor: LEE WON CHULL
IPC: H04N7/14
Filed: 2000-01-31
Abstract: PURPOSE: A bidirectional television distributor of physical incorporating terminal resistor. is provided not to use a distributor for satellite broadcasting receiver television. CONSTITUTION: A bidirectional television distributor of physical incorporating terminal resistor according to the present invention includes a case(20), and a lower cover(40). The case is divided into a radio television zone and a complex wired television zone. The outward side of the case is combined with the body and the body is grounded. The case(20) includes a plurality of F connection sphere. The television repeater is composed of one F type In connector. The cover(40) is formed with a lower cover made of aluminum. The television repeater further includes one IN-connection hole. The short term loss of the case is over 20dB, a printed circuit board is implemented for the one In connection hole and a plurality of OUT connection holes.
Patent KR-20010083629-A (KR)
Title: premix compositions including avermectin derivatives for eradicating parasites and a process for their manufacture
Inventor: CHOI MI SUK
IPC: A23K1/16
Filed: 2000-02-17
Abstract: PURPOSE: Provided is a method for preparing an insecticidal feed premix composition containing ivermectine derivatives as an activated compound, hydrogenated castor oil and corn cob. The premix has high thermal stability, and the chemicals do not be decomposed in the preparation process. CONSTITUTION: The method includes the following steps of: (i) dissolving ivermectine derivatives being one or more compounds selected from formula 1 and formula 2 in ethanol; (ii) mixing 0.6-0.8wt% of the ivermectine-melted solution with about 90wt% of corn cob and dehydrating the mixture; and (iii) adding 6-10wt% of solution of castor oil hydrogenated in ethanol as an auxiliary agent to the dried corn cob and dehydrating the resulting mixture.
Patent KR-20010081796-A (KR)
Title: Toy using speech recognition
Inventor: JOO YOUNG HO
IPC: A63H30/04
Filed: 2000-02-18
Abstract: PURPOSE: Manufacture of a toy having a speech recognition function is provided to achieve the interactive simple conversation between a person and the toy, and to reduce the cost of manufacturing by using a speech recognition microprocessor. CONSTITUTION: After converting the voice of a person into an electrical signal via a mike, the electrical signal is again converted into a digital signal by using an analog to digital converter to increase the convenience of calculation. The digital information is processed by using a speech recognition and synthesis microprocessor to output a corresponding response. There are various kinds of responses including a physical action such as the up and down motion of an arm as well as a voice of the person. In the case of the output of the voice, the voice previously saved in a main memory is output by using a digital to analog converter, and in the case of the output of the physical action, a visual response is performed by using a small DC motor and a small gear box.
Patent KR-20010081805-A (KR)
Title: Advertisement Motion Video Production and Display System Using The Internet
Inventor: CHANG WHIE
Filed: 2000-02-18
Abstract: PURPOSE: A system for manufacturing and expressing a moving picture advertisement using the Internet is provided to enable a moving picture advertisement section to easily manufacture a moving picture advertisement using all sorts of data mounted in an advertisement server computer, and to display the advertisement on an advertisement electric sign. CONSTITUTION: A user connected to the Internet(20) can connect through an Internet web browser. An advertisement server computer(10) is equipped with an electric sign schedule reference unit which enables the user to refer to advertisement schedules of useful electric signs and to set up the time for displaying the sign, and an advertisement server computer(10) which transmits an advertisement manufactured to the relevant electric sign. An electric sign management computer(30) is connected to an electric sign. In addition, the electric sign management computer(30) displays the advertisement transmitted from the Internet server at the set time.
Patent KR-20010091343-A (KR)
Title: Potentially hydrophilic resins and compositions comprising the same
Inventor: NAGANUMA HITOSHI
IPC: C08F120/00
Filed: 2000-03-14
Abstract: PURPOSE: A potential hydrophilic resin, a potential hydrophilic resin composition and a method for recycling product using the resin composition are provided, to allow the printing or sheet formed on a plastic product to be released by alkali treatment and the released one to be removed from the treatment solution readily. CONSTITUTION: The potential hydrophilic resin comprises 20-90 wt% of a monomer unit which generates a carboxylic group in alkali condition; 0.5-35 wt% of a monomer unit having a carboxylic group; 0.5-35 wt% of a monomer unit having a hydroxyl group; and 5-75 wt% of other monomer unit. Preferably the monomer unit which generates a carboxylic group in alkali condition is methyl acrylate; the monomer unit having a carboxylic group is (meth)acrylic acid; and the monomer unit having a hydroxyl group is hydroxyalkyl (meth)acrylate. Optionally the potential hydrophilic resin comprises further 0.5-35 wt% of a macro monomer unit; and/or 0.1-10 wt% of a polyfunctional monomer unit.
Patent KR-20010091424-A (KR)
Inventor: HOUHWUNG TE
IPC: A44B11/06
Filed: 2000-03-15
Abstract: PURPOSE: A buckle is provided to reduce a working time and a manufacturing cost by using a compact cover which is not need any spring. CONSTITUTION: The buckle comprises a male element(3) having a projection(32), a latching recess(321), and a belt receiving hole; a female element(2) having a hole(22) for receiving the projection(32) and a vertically movable groove(231); and a cover having an axis fitted with the groove(231) and a protrusion fitted with the latching recess(321); wherein, an elastic member(11) is formed at the side of the cover and a guide recess(111) is formed at the bottom of the cover to guide the cover to be returned to an original position.
Patent KR-20000053747-A (KR)
Inventor: KO JUNG SEOK
IPC: A61L2/14
Filed: 2000-03-23
Abstract: PURPOSE: A small fixed quantity liquid automatic supplying device having carburetor attached thereon is provided to provide predetermined quantity of liquid for producing metal vapor to chemical reacting room. CONSTITUTION: A fixed quantity liquid supplying device has a chemical reacting room(21) providing liquid for plasma emitting through a spouting providing pipe(23). A small fixed quantity liquid automatic supplying device having carburetor attached thereon comprises a fixed quantity liquid automatic supplier(20), a carburetor(24), a temperature controller and a heater(22). The fixed quantity liquid automatic supplier(20) automatically supplies a small quantity of liquid for plasma emitting through the spouting providing pipe(23) according to a rotating speed control of a motor. The carburetor(24) has a heater(22) for evaporating the spouted liquid by being connected to the spouting pipe of the fixed quantity liquid automatic supplier(20). The temperature controller controls the temperature of a heater(22) mounted in the carburetor(24). The heater(22) encircles all of the spouting providing pipe(23) to prevent the condensation of the liquid transferred through the spouting providing pipe(23). Therefore, the manufacturing cost of the fixed quantity liquid supplying device is diminished.
Patent KR-20010092999-A (KR)
Title: A gas spring
Inventor: PARK GYEONG BAE
IPC: F16F9/06
Filed: 2000-03-28
Abstract: PURPOSE: A gas spring is provided to prevent a shock generated from the maximum elongated point of a piston rod by forming a T-shaped oil path at the end of the piston rod and installing an O-ring at a stopper. CONSTITUTION: A T-shaped oil path(113) is formed at the lower portion of a piston rod(111) to penetrate the shaft center and the circumference at the lower surface. A stopper(120) is inserted into the piston rod and fixed to a sill(31) of a cylinder(30). An O-ring(121) is connected to the bore of the stopper. The O-ring controls the oil path to prevent a shock generated from the maximum elongated point of the piston rod. When a trunk lid is opened by a gas spring, the cylinder increases the inclination angle and elongates the piston rod upward. The pressure of a first working chamber(40) rises up, and a piston ring(102) is moved downward from an annular groove(106). Thereby, a first oil slit(107) is opened. Oil and gas in the first working chamber flows into a second working chamber(50) through the T-shaped oil path, the first and a second oil slit(107,108). Herein, the gas spring has relatively large oil and gas flow sectional area. Therefore, a relatively small damping force is increased to a piston(100) and the trunk lid is opened easily. The O-ring of the stopper closes the oil path of the piston rod when the piston rod reaches the maximum elongated point.
Patent KR-20000036889-A (KR)
Inventor: CHO HYUN JOON
IPC: C02F9/14
Filed: 2000-03-31
Abstract: PURPOSE: Method and apparatus are provided, which is characterized in that pH of animal husbandry wastewater is decreased gradually. So, biological treatment is efficient. CONSTITUTION: First pH control tank(110) is installed between screen(100) and water collection tank(120). First biological membrane tank(150) is installed between anaerobic tank(140) and flowrate control tank(160). Second pH control tank(170) and centrifuging tank(180) are installed between flowrate control tank(160) and aeration tank(190). Second biological membrane tank(150) is installed next to aeration tank(190). Continuously, first sedimentation tank, third pH control tank(220), internal return tank(230), coagulation tank(240) are installed. So that, pH of animal husbandry wastewater is decreased by three pH control tanks.
Patent KR-20010020710-A (KR)
Title: Disk drive
Inventor: SAKAI MASAKATSU
IPC: G11B21/08
Filed: 2000-04-04
Abstract: PURPOSE: To obtain a disk device which suppresses a maximum value of the input current of the entire disk device while securing a display function with a display means, in consideration of the fact that it is conventionally difficult that a maximum current of an FDD connected to a computer through a USB interface is made equal to or lower than 500 mA. CONSTITUTION: An LED 12 to indicate the operation state of the FDD is not continuously lit for seek but is lit in a section including no peaks of the current of a stepping motor 16 for transportation of heads 4 and 5. Thus, a sum Im+Id of a current Im of the stepping motor 16 and a current Id of the LED 12 is suppressed to a low value.
Patent KR-20010094903-A (KR)
Title: Producing method for nano-size ultra fine Titanium Dioxide by the chemical reaction using flame
Inventor: JANG HUI DONG
IPC: C01G23/07
Filed: 2000-04-07
Abstract: PURPOSE: A preparation method of nano-sized TiO2 powders by vapor phase oxidation using flame which is characterized by using a five-tube flame reactor for inflow of large quantity of reactant, TiCl4 and gases. Thereby, the method raises the productivity of ultrafine TiO2 powers. CONSTITUTION: Nano-sized(less than 50nm) TiO2 powders are prepared by flowing TiCl4 vapor, Ar, H2, O2 and air into a flame reactor with five tubes, burner(20), at the same time, and flaming over 1000deg.C. The initial concentration of vaporized TiCl4 is 1.13x10¬-5 - 4.54x10¬-5(mol/l), and TiCl4 vapor, Ar, O2, H2 and air are flowed into a first(14), second(15), third(16), forth(17) and fifth(18) tube, respectively, where the gas flow rate of each tube is 2, 6, 7, 17 and 68(v/v ppm) in a volume fraction. The TiO2 powders are used for photocatalyst, pigment, cosmetics and coater.
Patent KR-20010097059-A (KR)
Inventor: KIM GONG SU
IPC: F24C7/08
Filed: 2000-04-19
Abstract: 본 발명은, 판상의 지지부와; 상기 지지부 상에 소정의 이격간격을 두고 배치되는 한 쌍의 누름스위치와; 상기 지지부의 판면방향 일측에 배치되는 누름판과, 상기 누름판으로부터 상기 각 누름스위치를 향해 돌출되는 한 쌍의 작용돌기와, 상기 각 작용돌기의 축선방향에 가로로 배치되며 상기 누름판으로부터 상기 지지부를 향해 연장된 시소다리를 갖는 시소노브를 구비한 시소형 스위치장치에 관한 것으로서, 상기 시소다리와 상기 지지부 사이에는 소정의 탄성체가 개재되는 것을 특징으로 한다.  이에 의하여, 내구적 기능을 유지하여 누름판의 오작동을 효과적으로 방지할 수 있을 뿐만 아니라 접점의 거리가 짧은 경우에도 시소 스위칭 동작을 민감하게 감지할 수 있도록 한 시소형 스위치장치가 제공된다.
Patent KR-20010097173-A (KR)
Inventor: CHA YONG CHUL
IPC: G01M3/00
Filed: 2000-04-20
Abstract: 본 발명에 의한 누수 및 누유 센서는 레이켐 케이블의 단선에 따른 인가전압의 변화와 누수나 누유가 발생시 변화된 레이켐 케이블의 저항값에 따라 센서전압을 변화시키는 센서부; 누수나 누유가 발생하여 상기 센서부의 센서전압이 소정의 제1기준전압보다 클 때 제1레벨을 출력하는 제1비교부; 상기 센서부의 상기 레이켐 케이블이 단선되어 센서전압이 소정의 제2기준전압보다 작을 때 제1레벨을 출력하는 제2비교부; 상기 센서부의 단선이나 누수, 누유가 감지되면 구동하는 무전위 접점을 갖는 릴레이; 및 상기 제1비교부와 제2비교부의 출력중 어느 한쪽이 제1레벨일 때 상기 릴레이를 구동시키는 릴레이 구동부를 포함함을 특징으로 한다. 
     본 발명에 의한 누수 및 누유 센서는 감지하고자 하는 위치에 설치된 레이켐 케이블과 상기 케이블과 직렬로 접속된 저항에 걸리는 전압을 기준전압과 비교하여 산출된 누수 및 누유 여부의 센서 신호를 릴레이의 무전위 접점을 통하여 출력함으로써 자동제어기와의 집적 접속이 가능하며 각 레이켐 케이블이 설치된 해당 위치에 대한 감지결과를 알 수 있다.
Patent KR-20010007010-A (KR)
Inventor: THOMAS ALAN GOHL
IPC: G06F12/00
Filed: 2000-04-21
Abstract: PURPOSE: The performance of a computer is improved in the case of accessing an object heap by a garbage collection technique by organizing a data object in the object heap on the basis of access relations between data objects. CONSTITUTION: A compiler (42) receives a source code (46) and outputs a class file (48). The file (48) loaded in a virtual machine (44) is transferred to an object access profiling block (56). The machine (44) includes an object heap (58) including a From section (work storage area) (60) and a To section (62). Object references in the file (48) are ordered by garbage collection logic (70) by using access information according to an access ordered tree, and references to objects accessed with temporal proximity accompanied are ordered close to each other to form a group and ordered by a relative access frequency.
Patent KR-20000071778-A (KR)
Title: 연마제 재생방법 및 연마제 재생장치
IPC: H01L21/304
Filed: 2000-04-22
Abstract: 본 발명은 사용후의 연마제로부터 신액(新液)과 동등한 연마성능을 갖는 연마입자를 포함하는 연마제를 용이하게 재생할 수 있도록 하기 위한 것으로, 연마제 재생장치는 CMP공정으로 생긴 슬러리 폐액을 회수하기 위한 폐액회수부(A), 연마입자를 재분산하기 위한 재분산부(J), 재생된 연마용 슬러리를 공급하기 위한 재생슬러리 공급부(L) 등이 설치된다. 재분산부(J)에서 전자기 혹은 초음파의 인가 또는 분산제의 투입에 의한 재분산을 행하여, 연마입자 등이 응집되어 이루어지는 조대입자를 재분산시킴으로써, 사용된 연마제로부터 연마제 중의 연마입자를 거의 잃지 않고 연마율의 저하나 연마손상의 발생이 없는 신액과 동등한 연마성능을 갖는 연마입자를 포함하는 연마제를 용이하게 재생할 수 있다.
Patent KR-20010097658-A (KR)
Inventor: HONG JONG HWA
IPC: B62D33/00
Filed: 2000-04-25
Abstract: 본 발명은 상용차의 리어아치커버에 관한 것으로, 리어아치멤버(100)에 체결되는 리어아치플레이트(210)와 ; 클립부재(230)를 매개로 리어아치플레이트(210)에 임시 고정되면서, 체결부재(240)를 매개로 리어아치플레이트(210)에 체결되는 방음재인 인슐레이터(220)로 이루어지되, 상기 체결부재(240)는, 리어아치플레이트(210)의 후면에 결합되는 용접보울트(241)와, 용접보울트(241)의 나사산부(241a)에 결합되는 본체(242a)에 지지플레이트부(242)가 일체로 형성되어진 너트부재(242)로 이루어진 구조로 되어, 부재수와 용접공수가 절감되도록 된 것이다.
Patent KR-20010103222-A (KR)
Inventor: CHO SEONG JUN
Filed: 2000-05-08
Abstract: 본 발명은 승압형 초퍼에 관한 것이다. 
     본 발명에서는, 
     (a). 스위칭 소자를 병렬로 구성하여 두 개의 스위칭 소자를 구성하도록 하여 스위칭 소자의 전류 부담을 줄이고, 구성된 두 개의 스위칭 소자에 대하여 동일한 전류 분담이 되도록 제어하므로써, 과다한 전류로 인한 발열 및 스트레스를 감소시킬 수 있도록 하여 시스템의 전반적인 신뢰성을 향상시킬 수 있도록 하는 스위칭 제어 방법을 제공하고자 하며, (b). 그리고, 승압형 초퍼로 입력되는 전류를 기준제한값 이내로 제한하여, 일시적인 전류증가를 억제하도록 스위칭 소자를 제어하므로써, 시스템의 안정성을 확보하고, 대전류측 소자를 보호할 수 있도록 하는 제어 장치를 제공하고자 하는 것이다.
Patent KR-20010113154-A (KR)
Inventor: CHOI WAN UK
IPC: C01B31/04
Filed: 2000-06-16
Abstract: 본 발명은 리튬 이차 전지용 음극 활물질 및 그의 제조 방법에 관한 것으로서, 상기 음극 활물질은 흑연화 촉매 원소가 내부에 분산되어 있는 결정질 탄소를 포함한다.  상기 음극 활물질은 탄소 전구체에 흑연화 촉매 원소를 첨가하고, 상기 혼합물을 300 내지 600℃로 열처리하여 코크스화하고, 상기 코크스를 탄화하고, 상기 탄화물을 2800 내지 3000℃에서 흑연화하는 공정으로 제조된다. 
     이 제조 방법은 흑연화 촉매를 사용함에 따라 활물질의 흑연화도를 증가시킬 수 있고, 따라서 활물질의 리튬 이온 삽입/탈리량을 증가시킬 수 있으므로 방전 용량이 우수한 활물질을 제조할 수 있다.  또한, 본 발명의 제조 방법은 전해액과의 반응성이 적으므로 초기 충방전 효율이 우수한 활물질을 제조할 수 있다.
Patent KR-20020005199-A (KR)
Title: Selective pointer forwarding method for tracking location of a mobile station in personal communication systems
Inventor: JANG SEON GYUN
IPC: H04B7/26
Filed: 2000-06-23
Abstract: PURPOSE: A selective pointer forwarding method for managing a location of a mobile station in a mobile communication system is provided to reduce the number of database accesses and a signal transmission load generated in a system by reducing a location registration expense and a call transmission cost generated for managing a location that is necessarily performed in a mobile communication system. CONSTITUTION: When a mobile station moves into a different location registration area, a controller of the mobile station selects a minimum expectation expense location registration point(200). The controller of the mobile station transmits a registration request message and an ID of the location registration point to a visitor location register(VLR), so as to be registered for the new location registration area(202). Then, the VLR registers a new location of the mobile station in the location registration point received from the mobile station(204).
Patent KR-20020000429-A (KR)
Title: Improvement method for unbalance of green beam
Inventor: JU GWANG SIK
IPC: H01J29/70
Filed: 2000-06-26
Abstract: PURPOSE: A method for improving the unbalance control of a green beam is provided to be capable of removing floating capacitance resident in a coil part of a deflection yoke so that the causes of HCR distortion are not generated at the deflection yoke. CONSTITUTION: A pair of first and second horizontal coils are connected to each other in parallel so as to horizontally deflect a beam, thereby preventing HCR distortion phenomenon in a horizontal deflection coil. In this structure, a discharge path for capacitance being parasitic on the horizontal coils is formed or parasitic capacitances are offset. In addition, discharge means such as aluminum tabs(AL) may be attached to the decks of the horizontal coils so as to form the discharge path for the parasitic capacitance.
Patent KR-20010029878-A (KR)
Title: Self-latching solenoid valve assembly and control circuit
Inventor: JANSSEN ERIC P
IPC: F16K31/08
Filed: 2000-07-01
Abstract: PURPOSE: To provide a self-latch solenoid valve assembly capable of operating at a high speed and reducing power consumption. CONSTITUTION: An energizing member 46 for moving a valve element and a solenoid assembly 14 are used. The solenoid assembly has a housing 48 supporting a solenoid coil 56 inside it and a fixed ferromagnetic pole member 88 provided with a through passage and a pressing pin 84 supported so as to move in the passage. A ferromagnetic latch is supported by the housing, and a permanent magnet 90 is arranged between the latch and the pole member. The permanent magnet can move toward a pole member 74 by electromagnetic flux due to a pulse current flowing in the coil 56 and drives the valve element to a predetermined position against the pressing pin. The permanent magnet can move in the direction in which it leaves the pole member and moves toward the latch 88 by electromagnetic flux due to a pulse current flowing in the coil 56 in the opposite direction. The energizing member moves the valve element to the other predetermined position because of this movement.
Patent KR-20020006335-A (KR)
Title: Method for fabricating metallic reflection film by using transfer film in cathode ray tube
Inventor: RYU SANG CHEOL
IPC: H01J29/28
Filed: 2000-07-12
Abstract: PURPOSE: A method for forming a metallic reflection layer of a color cathode ray tube using a transcription metalizing film is provided to form easily a metallic reflection layer on an effective face by using a transcription metalizing film. CONSTITUTION: A transcription metalizing film is formed with a base layer(15), a release agent layer(16), a metallic reflection layer(17), an adhesive layer(18), and a protective cover layer(19). The base layer(15) is formed with material selected from a polyester styrene-butadiene rubber, a polybutadiene rubber, an ethylene butadiene rubber, a polyurethane rubber, a polyethylene, a polystyrene, a polymethylmethacrylate, a polyvinylchloride, a polypropylene, a urea resin, a phenolic resin, a polycaprolactam resin, and a polyvinylidene chloride resin. The release agent layer(16) is used for removing the base layer(15). The release agent layer(16) is formed with material selected from a polystyrene, a polymethylmethacrylate, a polyvinylchloride, a urea resin, a phenolic resin, a polycaprolactam resin, and a polyvinylidene chloride resin.
Patent KR-20020007503-A (KR)
Title: Structure of piston of clutch release cylinder for car
Inventor: JANG NAK TAEK
IPC: F16D25/08
Filed: 2000-07-14
Abstract: PURPOSE: Piston structure of a clutch release cylinder for a vehicle is provided to prevent oil leakage and lowering of hydraulic pressure in the release cylinder by restricting a parting line in a mold with making a piston of synthetic resin, and to improve strength against tension of a spring by modifying the structure. CONSTITUTION: A piston is supported elastically by a return spring(42) in a cylinder, and divided into a piston body(41a) and a return spring supporting part(43). The spring supporting part and the piston body are manufactured individually, and combined integrally by an assembling unit. The assembling unit consists of an assembling protrusion(44) formed in the inner periphery of the spring supporting part, and an assembling groove(45) formed in the outer periphery of the piston body. The piston body is combined with the spring supporting part by inserting the assembling protrusion to the assembling groove, and by pressing elastic grooves(41c) with the inner periphery of the spring supporting part. The parting line of a mold is eliminated, and burr is not formed in the cup installation surface of the piston body with manufacturing the spring supporting part and the piston body individually. Oil leakage, lowering of hydraulic pressure and the breakage of the piston are prevented with improving the strength against tension of the spring by modifying the structure.