baber/WOPTO huggingface dataset:
Patent KR-20000049861-A (KR)
Inventor: HAN SANG YEOL
IPC: E02B7/20
Filed: 2000-05-03
Abstract: PURPOSE: A door type automatic water gate device is provided to regulate a water level by discharging at a lower end normal times, to avoid water contamination by easily discharging deposited foreign matters and to maximize the section of passing water by perfectly opening the water gate on a flood. CONSTITUTION: A water level is checked by a sensor for measuring the water level of a dam. When it is over a certain water level, a sluice gate(10) is raised by sending an electric signal to a hydraulic cylinder(30). A supporting plate(22) is pushed up by operating the hydraulic cylinder so that the water gate is vertically raised and is opened from the lower end of the water gate. When the water level is continuously increased, not being regulated with the manipulation, the water gate is pushed up and a guide pin(40) passes around a curved line of a guide groove. Then the water gate starts a rotary-rising movement.
Patent KR-20000053932-A (KR)
Inventor: PARK BYUNG WOOK
IPC: G06F3/0354
Filed: 2000-05-09
Abstract: PURPOSE: An apparatus for manufacturing a ball mouse is provided, so that a user can utilize the ball mouse without forcibly folding a wrist of the user by vertically setting the ball mouse, to make the user utilize a line fixed body by mounting the line fixed body and to manufacture the ball mouse with various designs. CONSTITUTION: An apparatus for manufacturing a ball mouse with various designs comprises a substrate(14) and rotating balls(1,2). The substrate is vertically set on a bottom surface. The rotating balls are set according to the substrate. The rotating ball is far away from the substrate to mount a sense(4) as a far-away distance of the rotating ball from the substrate. A substrate fixed body(8) fixes the substrate. A click part(6) is vertically set aside.
Patent KR-20010034975-A (KR)
Title: Advertisement System And Method Using Card Bill
Inventor: YUN MOON HEE
Filed: 2000-05-10
Abstract: PURPOSE: An advertising system using a card selling slip and a method thereof are provided to enhance an advertising effects by printing an advertisement on a selling slip being issued from each card member store. CONSTITUTION: An advertisement host manager receives a request for an advertisement from an advertiser and stores the request in an advertisement database(S20). If a card being requested a generation of transaction is interpreted, a card inquiring device transmits the interpreted card information and a transaction details inputted by a user to the advertisement host(S10). The advertisement host requests transaction details of the card to a card inquiring system of a card company based on a transaction details inquiring information transmitted from the card inquiring device(S22). The card inquiring device detects whether the card can be transacted normally based on card information of the card transmitted from the advertisement host and the transaction details information(S30). The detecting result is transmitted to the advertisement host(S32). If the card can be transacted normally(S24), an advertisement is searched and extracted from the advertisement database(S26). The extracted advertisement information and the searching result are transmitted to the card inquiring device(S28). If the card inquiring device receives the advertisement information and the searching result from the advertisement host(S12), the transaction inquiring details and advertisement information are outputted on a selling slip(S14,S16).
Patent KR-20010077822-A (KR)
Inventor: HARAGUCHI MANABU
IPC: B65B37/08
Filed: 2000-05-19
Abstract: PURPOSE: A solid preparation filling apparatus is provided to improve assembling workability while keeping miniaturization in a solid preparation filling apparatus for filling a predetermined container with a solid preparation such as a tablet. CONSTITUTION: A solid preparation filling apparatus consists of plural tablet cases(7) keeping various kinds of solid preparation; plural hoppers(51-52) receiving the solid preparation discharged from the tablet cases; discharge ports(51A-52A) formed at the end of each hopper; plural holding cells(21) arranged at the lower part of the hoppers and rotationally moved on the circumference having the discharge ports; a shutter opening/closing an inlet/outlet of the holding cells; and a guide unit(61) for guiding the solid preparation to a specific container from the holding cells. When the solid preparation is discharged from the tablet cases, the holding cells are moved to adjust the position. Thereby, the solid preparation is dropped into the holding cells from the tablet cases by meeting the inlet/outlet of the holding cells with the discharge ports of the hoppers. When the solid preparation fills the container, the inlet/outlet of the holding cells is met with the guide unit. Finally, the shutter is opened.
Patent KR-20000077329-A (KR)
Title: 핸드 오버 동작의 회수에 기초하여 생성된 기지국 기술인접 리스트로부터 기지국에 접속될 관련 기지국을 선택할수 있는 이동 통신 시스템
IPC: H04W36/08
Filed: 2000-05-19
Abstract: 이동 통신 시스템은 제1 및 제2 접속 기지국과 상기 제1 접속 기지국에 접속된 이동국을 포함한다.  이동 단말이 제1 접속 기지국으로부터 복수의 기지국 중 하나로 핸드오버 동작한 회수를 나타내는 핸드오버 카운트에 기초하여, 복수의 기지국 중 관련 기지국들이 선택된다.  관련 기지국들로부터의 전계 강도에 기초하여, 관련 기지국들 중에서 제2 접속 기지국이 선택되며, 이동 단말은 제2 접속 기지국과 접속 링크를 개설한다.
Patent KR-20010109585-A (KR)
Inventor: PARK CHEOL U
Filed: 2000-05-31
Abstract: 본 발명은 자동차의 일측에 취부되는 연료탱크에 관한 것으로, 특히 연료가 출렁거리는 소리를 방지하기 위하여 내부공간에 수직격판과 수평격판으로 다수의 층을 구획하고, 각 층마다 연료의 양을 측정하는 부구를 형성한 연료탱크에 관한 것으로, 
     상기한 연료탱크의 내부에 수직상으로 형성되며 연료가 유통되도록 벽면에 유통공이 형성된 수직격판과; 상기한 연료탱크의 내부를 복수개의 수평영역으로 구획하도록 다단계로 설치되는 수평격판과; 상기한 수평격판의 중앙부에 형성되어 상층의 연료가 하층으로 이동되도록 하는 안내공과; 상기한 수평격판에 의해 이루어지는 각층의 일측에는 연료량을 검출하기 위하여 형성한 각각의 부구와; 상기한 각층에 형성된 각각의 부구에 연결되어 부구의 상하이동 방향에 따라 그 저항값이 가변되는 다수의 가변저항과, 상기 가변저항들로부터 얻어지는 저항값으로 유량을 측정 표시하는 유량계; 로 구성되는 것을 특징으로 하며, 상기한 수평격판에 형성되어 상층의 연료를 하층으로 안내하는 안내공의 하부에는 연료가 위에서 아래로만 이동되도록 체크밸브를 형성한 것을 특징으로 한다.
Patent KR-20010109762-A (KR)
Inventor: KWON YEONG GWAN
IPC: H04B5/04
Filed: 2000-06-02
Abstract: 본 발명은 호출기의 화면상에 표시되는 내용을 사용자의 요구에 따라 다양한 음성으로 선택 출력하는 무선 호출기의 멀티 음성출력 장치에 관한 것이다. 
     개시한 본 발명의 멀티 음성출력 장치는, 수신 고주파 신호를 고주파수신부에서 주파수 변환하여 복조하고 디코더부에서 복조된 신호를 원래의 데이터로 변환하여 화면상에 표시하고 스피커를 통해 음성 출력하는 호출기에 있어서, 이 화면상의 표시데이터 및 호출기의 옵션기능, 시간 정보에 대한 서로 다른 음성 데이터를 저장하고 있는 메모리수단; 화면상의 정보에 대응한 서로 다른 종류의 음성데이터를 선택·출력하기 위해 화면상에서 원하는 음성출력모드를 선택하는 음성선택키를 갖는 키입력수단; 및 액정표시수단의 화면상에 음성출력모드를 표시하며 음성선택키에 의해 선택된 음성출력모드에 따라 메모리수단에 저장된 음성데이터들 중에서 한 종류의 음성데이터를 읽어들여 스피커를 통해 음성 출력하는 중앙처리장치를 포함하며; 
     이에 따라 수신 메시지, 시간정보 및 호출기의 옵션 등의 정보를 음성으로 출력하는 과정에서, 여러 사람의 음성을 화면상에서 선택하여 원하는 음성으로 출력할 수 있어 한 가지의 음성으로 출력하는 단조로움이 해소되는 이점이 있다.
Patent KR-20010110027-A (KR)
Inventor: MUN SANG WON
Filed: 2000-06-05
Abstract: 본 발명은 컴퓨터의 글자판을 이용하여 전화기로 사용할 수 있게 전화기 회로를 컴퓨터 글자판 내부에 설치하여 컴퓨터 글자판으로 사용하면서 겸하여 전화기로 사용할 수 있어 매우 편리한 것이다. 
     종래에는 컴퓨터와 전화기를 한 테이블에 놓고 사용하기에는 장소가 좁아서 전화기는 별도의 장소에 두고 사용하여야 하기 때문에 전화를 걸 때에나 받을 때에 매우 불편한 경우가 허다하다. 
     이러한 문제를 해결하기 위하여 컴퓨터 글자판을 전화기로 사용하기 위하여서는 컴퓨터 글자판이 주글쇠(Main Key)와 보조글쇠(Help Key)로 구성된 것을 따로 분리하여 보조글쇠를 전화기 숫자판으로 활용할 수 있게 내부 글자판 회로도 분리되어야 한다. 
     따라서 글자판은 주글쇠와 보조글쇠로 분리되어 있지만, 글쇠회로판은 주글쇠회로와 보조글쇠회로가 서로 연결되어 있기 때문에 이것을 분리하여 주글쇠회로는 컴퓨터에 고정되게 연결하고. 보조글쇠회로가 전화 전환스위치에 의하여 주글쇠회로와 접속된 때에는 컴퓨터 글자판이 되고, 주글쇠회로와 보조글쇠회로가 분리되었을 때에는 전화기 회로와 접속되어 전화기 숫자판이 되는 것이다. 
     따라서 전화전환스위치에는 주글쇠회로와 보조글쇠회로, 그리고 전화기회로가 연계되어서 컴퓨터 글자판과 전화기 숫자판으로 이용할 수 있게 구성된 것이다. 
     이와 같이 본 발명은 컴퓨터 글자판이 전화전환스위치에 의하여 컴퓨터를 사용하면서도 전화기로도 사용할 수 있어서 매우 편리한 효과가 있는 것이다.
Patent KR-20010066827-A (KR)
Inventor: GUANTER JEAN-CHARLES
IPC: H02J7/10
Filed: 2000-06-09
Abstract: PURPOSE: A method for controlling an accumulator charge and a device for implementing the method are provided to allow the accumulator charge to be stopped prior to the occurrence of overheating, and thus prior to overcharging, without requiring a complex and costly device. CONSTITUTION: When an apparatus such as a clock, a telephone, or the like in which a battery(4) is stored is set on a charger(2), a counter is made to operate and increases step count signals. When the increased value reaches a predetermined value, the charging operation is stopped. After that, the step count signals are decreased in accordance with the operation load of the apparatus. When the apparatus is removed from the charger(2) during the charging operation, the step count signals are decreased in accordance with the operation load in the same way and, when the apparatus is set on the charger(2) again, the step count signals are increased.
Patent KR-20010020984-A (KR)
Title: Semiconductor device and process for manufacturing semiconductor device
Inventor: OGAWA TAKAHIRO
IPC: H01L27/115
Filed: 2000-06-13
Abstract: PURPOSE: To make the sidewall of a transistor at a memory cell thin by forming a dual sidewall spacer at the transistor of a peripheral circuit and a single side wall spacer at the transistor of a memory cell. CONSTITUTION: By forming an SiN film on the entire surface of a silicon substrate 1 and performing etchback by anisotropic etching, a single sidewall spacer 15 is formed at the side of a floating gate 6 and a control gate 7 in a memory cell M. Also, a duel side wall consisting of a sidewall spacer 10 formed by an HTD film and a sidewall spacer 15 by the SiN film is formed at the sidewall of a gate electrode 7b in a peripheral circuit A, thus making thin the sidewall of the transistor at the memory cell.
Patent KR-20000054601-A (KR)
Inventor: SONG MOO YOUNG
IPC: B41M5/00
Filed: 2000-06-13
Abstract: PURPOSE: A printing method utilizing design-printed paper is provided to obtain products with high distinction while simplifying work process. CONSTITUTION: A method comprises the steps of forming an adhesive layer by spraying a polyethylene liquid onto a selected base material, cutting by a cutter a paper printed with a design by water or oiliness colorant and attaching the paper to the adhesive layer, and performing a thermal printing to the paper and drying the paper and the adhesive layer. The printed paper formed integrally with the adhesive layer is not easily separated from the base material and is not easily decolored. The printed portion can be utilized as a decorative design.
Patent KR-20010111919-A (KR)
Inventor: HAN TAK DON
Filed: 2000-06-14
Abstract: 본 발명은 물리적으로 또는 전자적으로 표현된 코드이미지를 이용한 인증 서비스 방법 및 그 장치에 관한 것으로, 인증서버에서 정당한 사용자인지의 여부를 확인하는 인증과정을 거친 후 사용자가 요구하는 서비스를 제공하는 방법에 있어서, 상기 인증과정은 인증매체에 물리적 또는 전자적으로 표현된 코드이미지를 입력하는 단계; 상기 인증매체에 표현된 코드이미지를 소정의 디코딩 알고리즘에 의하여 사용자의 인증정보를 추출하는 단계; 상기 인증정보를 상기 인증서버로 전송하는 단계; 상기 인증서버는 상기 인증정보로부터 상기 사용자가 정당한 사용자인지의 여부를 판단하는 단계; 및 상기 판단단계에서 정당한 사용자로 판단되면 사용자에게 상기 서비스를 제공하는 단계를 포함하여, 종래의 ID나 암호만으로 인증절차를 수행하는 것에 비하여 보다 안전하게 사용자 인증을 보증할 수 있다.  즉, 종래에는 타인의 ID 및 암호만 알고 있으면 이를 도용하여 인터넷과 같은 통신망을 통한 온라인 서비스를 마음대로 이용할 수 있는 문제점이 있지만, 본발명에 의하면 추가로 그 사용자에게 발급된 카드에 표시된 코드이미지까지 입력하여야 하므로 그 만큼 보안성이 향상된다.
Patent KR-20020001199-A (KR)
Title: Function Trace and Surveillance Mehtod in Communication System
Inventor: BAE CHEOL MIN
IPC: H04Q1/20
Filed: 2000-06-27
Abstract: PURPOSE: A method for tracking and monitoring a function operation in a communication system is provided to facilitate monitoring of an operation according to a function development and a function operation in operation of a system by classifying a function operation performing state into an operation standard, a function standard and a priority standard, extracting only a matter to be monitored, and tracking and monitoring its function operation. CONSTITUTION: In a method for tracking and monitoring a function operation in a communication system, there are three steps classifying the function operation based on an operational standard, a function standard, and a priority standard. One of those steps is selected(S51). Tracking data are inputted according to the classification standard(S52). The function operation is tracked by a tracking and monitoring data of the function operation(S53). A program for tracking the function operation outputs a log message to a monitor on the basis of the inputted data or stores the log message in a disk of a system(S54). The outputted or stored log message is analyzed(S55).
Patent KR-20020002049-A (KR)
Title: Half tone mask employing in tft-lcd manufacture process
Inventor: IN TAE HYEONG
IPC: H01L29/786
Filed: 2000-06-29
Abstract: PURPOSE: A halftone mask used in manufacturing a thin-film-transistor liquid-crystal-display(TFT-LCD) is provided to easily form a halftone mask region by using a half-transmission layer capable of changing the permeability of ultraviolet(UV) rays, and to decrease the number of mask processes for manufacturing the TFT-LCD by using the halftone mask. CONSTITUTION: The halftone mask(20) is used to reduce the number of mask processes, composed of a quartz substrate(11) and a chrome pattern(12) formed on the quartz substrate. The half-transmission layer(13) regarding UV rays is formed in a predetermined region of regions not blocked by the chrome pattern.
Patent KR-20020002821-A (KR)
Title: Wafer level package and method of fabricating the same
Inventor: HUH GI ROK
IPC: H01L23/28
Filed: 2000-06-30
Abstract: PURPOSE: A wafer level package and a method for manufacturing the package are provided to eliminate the use of a separate substrate, to realize a chip-sized package, and to strengthen a joint force of a solder ball. CONSTITUTION: The package includes a metal wire(31) bonded to a bond pad of a semiconductor chip(10) and bent in loop shape. An encapsulant(40) is coated around the bond pad to expose a loop-shaped part only of the metal wire(31). The loop-shaped part of the metal wire(31) is contained in the solder ball(50) mounted on the encapsulant(40), thereby increasing the joint strength of the solder ball(50) to a board(60). The package is manufactured from a wafer having a plurality of the chips(10). A dummy pad is formed on a scribe lane of the wafer, and then connected to the second end of the metal wire(31) bonded to the bond pad at the first end. The encapsulant(40) is locally formed on the wafer to cover the dummy pad and the bond pad. The wafer is then cut along the scribe lane to separate the chips(10), and the solder ball(50) is mounted on the encapsulant(40).
Patent KR-20020004074-A (KR)
Inventor: LIM CHEOL HUI
Filed: 2000-06-28
Abstract: PURPOSE: A settlement method is provided to process complicated procedures and documents in a bundle by constructing the network with an electric commerce service provider and a credit organization. CONSTITUTION: An EC service provider concludes various contracts necessary for a business concert in order to realize an electric settlement system. A user of the electric settlement system makes a circumstance for receiving a service of the electric settlement system. After drawing an electric document necessary for an electric certification, the electric document is submitted to the EC service provider and is recognized by the service provider. A fund is electronically transferred and is settled using electronic cash.
Patent KR-20010015225-A (KR)
Inventor: YAMAGUCHI AKIHIRO
IPC: H01J9/227
Filed: 2000-07-07
Abstract: PURPOSE: To form a screen with less color fog and coating unevenness and to improve the color purity and luminance by precoating a carbon film formed in a panel inside face with polyoxyethylene sorbitan fatty acid ester aqueous solution and by forming a phosphor screen on the panel inside face. CONSTITUTION: Preferably, the concentration of polyoxyethylene sorbitan fatty acid ester aqueous solution is 0.1-1.0 wt.%. The polyoxyethylene sorbitan fatty acid ester aqueous solution diluted and adjusted by pure water is sprayed on a panel inside face 2 having a carbon film 28 formed by a spray process and dried so as to precoat. Sequentially, coating liquid 7c, or a mixed liquid among first shade green phosphor particles, PVA, and ammonium dichromate is applied on the panel inside face 2 with a carbon film 28 formed thereon and dried. Then, the exposure and development processes are repeated so that green, blue, and red phosphor screens are formed respectively.
Patent KR-20020006125-A (KR)
Title: System for managing patients of dementia
Inventor: WOO JIN HO
Filed: 2000-07-11
Abstract: PURPOSE: A system for managing dementia patients is provided so that an amount of data transmitted on an Internet can be reduced and a speed and quality of service can be improved by recording a volume of data information in a user system. CONSTITUTION: A plurality of user systems(101) are systems which access an intermediate server(103) through an Internet network(102). When the user systems(101) attempt to access a common use database(105) through the Internet network(102), the intermediate server(103) collects such attempts, and directly access the database(105) through a database server(104). Since the intermediate server(103) collects access requests from the user systems(105) and directly accesses the database(105), a common use database fee can be reduced. On the other hand, the database(105) stores all information generated in the system, such as personal information of the patients, medical test results, treatment processes and results, and consultation reservation information. A doctor system(106) enables a doctor to directly access the database server(104) through the Internet network(102), so that the doctor can search the user information, decide scheduling and provide medical treatments.
Patent KR-20020010056-A (KR)
Inventor: LIM WI CHEOL
IPC: G06F12/00
Filed: 2000-07-28
Abstract: PURPOSE: A method for managing a flash memory is provided to upgrade data using one flash memory. CONSTITUTION: Compressed new image data are downloaded in a RAM(300). The currently used image data being stored in a flash memory(200) are compressed, and the data are stored in the first area of the flash memory(200). The downloaded new image data are copied in the second area of the flash memory(200). The compression of the image data copied in the second area is released, and the data are stored in the first area. When the currently used image data are compressed, the process is performed as the unit of segment, and the currently compressed segment data and progressed position information are stored in a non-volatile memory(100). When the currently used image data are extended, the process is performed as the unit of segment, and the currently extended segment data and progressed position information are stored in the non-volatile memory(100).
Patent KR-20010049967-A (KR)
Inventor: BROECKER FRANZ JOSEF
IPC: C07C5/10
Filed: 2000-08-02
Abstract: PURPOSE: An apparatus for carrying out reactions in the gaseous, liquid and solid phases comprises a liquid stream-gas compressor for producing a reaction fluid, a reactor charged with metal braiding coated with catalyst, and a feed line. CONSTITUTION: The apparatus for carrying out reactions in the gaseous, liquid and solid phases comprises a liquid stream-gas compressor(6) for producing a reaction fluid by dispersing a gas phase in a liquid phase; a reactor(1) having an inlet and an outlet and a reaction chamber limited by heat-deviating walls, the reactor being charged with a metal braiding coated with catalyst; and a line(7) feeding the reaction fluid from the compressor to the reactor inlet and is short so that the degree of dispersibility of the fluid does not change during the passage through the line. Also, a process for carrying out reactions in the gaseous, liquid and solid phases comprising producing a reaction fluid by dispersion of a gaseous in a liquid phase; feeding the reaction fluid produced through the reactor; exchanging reaction heat on the walls of the reactor chamber; and separating the reaction fluid into a gas phase and a liquid phase.
Patent KR-20000063828-A (KR)
Inventor: PARK SEUNG CHANG
IPC: G06Q50/22
Filed: 2000-08-05
Abstract: PURPOSE: An electronic physical constitution diagnosis system and a signal processing method is provided to sense a pulse stroke of a patient by a plurality of piezoelectric sensors, send the sensed signals to a microprocessor, analyze the sensed signal and express the analysis result with a visual or an audio device. CONSTITUTION: An electronic physical constitution diagnosis system comprises a sensing band(1), an air pressing and control module(7), an analysis processor(3) and a power source(5). The sensing band(1) includes an air bag pressing a plurality of piezoelectric sensors closely on a patient wrist, the piezoelectric sensors sensing pulse strokes at an inner side of the wrist, and electric lines sending the signals sensed from the wrist. The air pressing and control module(7) supplies air for the air bag and controls an operation of an air pump. The analysis processor(3) includes an AD converter, an analysis database storing physical characteristics according to the pulse stroke pattern, and a built-in program analyzing the digital pulse stroke and determining the patient constitution.
Patent KR-20000063980-A (KR)
Inventor: SEO YEONG OK
IPC: B32B27/00
Filed: 2000-08-14
Abstract: PURPOSE: A heat-melted bonding sheet, making it possible to adhere without needing adhesives is provided. Especially, it can be used in the after-process of producing semiconductor or electronic parts effectively. CONSTITUTION: A heat-melted bonding sheet is characterized by being produced into more than 3 layers including: a layer comprised of a resin having high melting point of more than 200°C; a layer comprised of a resin having medium melting point of 140-200°C; and a layer comprised of a resin having low melting point of 70-130°C. The layers are piled up in the written order from the base film.
Patent KR-20010096462-A (KR)
Title: Process for producing oils with a high viscosity index
Inventor: BENAZZI ERIC
IPC: C10G45/04
Filed: 2000-08-21
Abstract: PURPOSE: A method for preparing oil having high viscosity index is provided to enable the recovery of oil fractions graded according to their viscosity indices by direct treatment of petroleum fractions. CONSTITUTION: The process for the production of oils of high viscosity index(VI) from a charge consisting of compounds of boiling points higher than 300deg.C., comprises reaction of the charge, or a mixture of charge with a re-cycled fraction, with hydrogen in the presence of a catalyst comprising an amorphous non-zeolitic matrix and a group VIII metal or metal compound and/or a group VIB metal; fractionation of the effluent to separate off a residue of oils mainly containing constituents of VI higher than that of the charge; and fractionation of the oil residues by thermal diffusion, the oils being separated according to their viscosity.
Patent KR-20020017545-A (KR)
Title: flowmetry for endoscopical fluid supply system
Inventor: KIM JEE HYOUNG
IPC: A61M5/14
Filed: 2000-08-31
Abstract: PURPOSE: Provided is a rate indicator of Ringer's solution supplier for endoscopy which can quantitatively and qualitatively show the flow rate of the solution so that an operator or assistant can easily note the supplying status of the solution. CONSTITUTION: The rate indicator visualizes the flow rate of Ringer's solution by measuring the force taken in pushing up an article which falls down by gravity or the force taken in pulling down an article which comes up by buoyancy upon supplying the Ringer's solution. This rate indicator is located so that an operator or assistant can readily note the supplying status of the Ringer's solution. In the conventional operation or treatment while supplying Ringer's solution, the operator or assistant can not note the flow rate or supplying status of the Ringer's solution. Since the conventional system using a forced circulation pump is bulky, the indicator is located at a down position where the operator or assistant cannot watch during their operation.