• Title/Summary/Keyword: Jaw-wedge

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A Study on Clamping Characteristics of Jaw-wedge for Automatic Jig Vise (자동 지그 바이스용 조오-웨지의 클램핑 특성 연구)

  • Jung, Si-Kyo;Maeng, Hee-Young
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.20 no.6
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    • pp.745-750
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    • 2011
  • A jig vise is a device to clamp workpiece precisely, which is widely used for various machine tools and manufacturing purpose. A new elastic structured jaw-wedge of jig vise is developed, in this paper, so as to satisfy the clamping requirement and the suppression effect of upright movement of workpiece. The advanced design parameters of jaw-wedge are derived step by step considering the stress distribution and the displacement profiles of ANSYS analysis, and it could find the optimum model which shows the uniform displacement profiles and exhibits the non-concentrated stress distribution of jaw neck. As a result, it is ascertained that an jaw-wedge developed in this study is the simple elastic structure which is effective for automatic multiple clamping purpose without the danger of shear crack or bucking of jaw.

The Effect of Clamping Angle of a Locker on the Clamping Force of the Wedge Type Rail Clamp (Locker 의 물림각이 쐐기형 레일클램프의 압착력에 미치는 영향 평가)

  • Han D.S.;Lee S.W.;Han G.J.;Ahn C.W.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.10a
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    • pp.1042-1045
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    • 2005
  • The wedge type rail clamp has the operating mechanism: First, the jaw pad clamps a rail with small clamping force. Next as the wind speed increases, the clamping force of the Jaw pad Is Increased by the wedge. The initial clamping force of a jaw pad was determined by the clamping angle of a locker. In this study, we carried out the finite element analysis to evaluate the relationship between the clamping angle of a locker and the clamping force of a jaw pad with respect to the design wind speed, such as 2, 4, 6, 8, and 10m/s, we adopted the wedge type rail clamp fur 50tons class container crane with the wedge angle of $10^{\circ}$.

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Study on the Wedge Angle of Wedge Type Rail Clamp for Container Crane (컨테이너 크레인용 쐐기형 레일 클램프의 쐐기각에 대한연구)

  • Han, Geun-Jo;Lee, Ho;Sim, Jae-Jun;Han, Dong-Sub;An, Chan-Woo;Jeon, Young-Hwan
    • Journal of the Korean Society for Precision Engineering
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    • v.21 no.9
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    • pp.119-126
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    • 2004
  • In this paper, we design a wedge type rail clamp which can protect container crane from a sudden strong blast with constant clamping force regardless of the operating period. When we design wedge type rail clamp, it is important to determine the angle of wedge and analyze a contact condition of roller and wedge so that we might develop a wedge type rail clamp for parking devices of port cargo working system with variable capacity. Therefore, this paper suggests a process to decide wedge angles within feasible range which could be obtained using load analysis and FEA of wedge type rail clamp

A Study on Wedge Angles of Wedge-type Rail Clamp for Preventing Jaw from Rotating (쐐기형 레일 클램프에서 조(jaw)의 회전을 방지하기 위한 적정 쐐기각에 대한 연구)

  • Shim J. J.;Lee S. W.;Han D. S.;Park J. S.;Jeon Y. H.;Lee H.;Han G. J.;Ahn C. W.
    • Journal of Navigation and Port Research
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    • v.29 no.8 s.104
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    • pp.735-740
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    • 2005
  • In this paper, we designed a wedge type rail-clamp which can protect container crane from sudden wind blast with constant clamping force regardless of the operating period. When we design wedge type rail clamp, it is important to determine an angle of wedge which prevent rotating of jaw and for smooth operation when wind blows. Therefore, this paper suggest a process to decide an angle of wedge within proper range obtained by experimental analysis as well as FEA of the wedge type rail clamp. A model with $6^{\circ}$ wedge angle is the most proper model to use in rail clamp bemuse it generated satisfactory clamping force and rotating angle underdesign specification.

A Experimental Analysis on the Relationship between the Angle of a Locker and the Clamping Force of Wedge Type Rail Clamp (Locker의 물림각과 쐐기형 레일클램프의 압착력에 관한 실험적 고찰)

  • Han Dong-Seop;Shim Jae- Joon;Han Geun- Jo;Lee Kwon-Hee
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2005.10a
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    • pp.247-252
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    • 2005
  • The wedge type rail clamp has the operating mechanism: First, the jaw pad clamps a rail with small clamping force Next as the wind speed increases, the clamping force of the jaw pad is increased by the wedge. In order to design the wedge type rail clamp, we need to determine the proper wedge angle to minimize the sliding distance of a roller and the proper clamping angle of a locker to generate the initial clamping force of a jaw pad. The researches for the proper wedge angle have conducted, and in this study we conducted the investigation to determine the proper clamping angle of a locker in the rail clamp with wedge angle of $10^{\circ}$. Because the initial damping force of the jaw pad was determined by the clamping angle of the locker, in order to carry out the clamping force of a jaw pad, we measured the locking force applied to a locker with respect to the clamping angle of a locker, such as $3^{\circ},\;4^{\circ},\;5^{\circ},\;6^{\circ},\;$ using a pressure gauge, and compared the results with the FEA results.

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Comparison of Enhanced Dynamic Wedge with Physical Metal Wedge based on the Basic Dosimetric Parameters (선량계측인자에 따른 기능강화동적쐐기와 금속쐐기의 비교)

  • Lee Jeong-Woo;Hong Semie;Choi Kyoung-Sik;Chung Jin-Beom;Choe Bo-Young;Jang Hong Seok;Suh Tae-Suk
    • Progress in Medical Physics
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    • v.16 no.2
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    • pp.70-76
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    • 2005
  • For clinical implementation of Enhanced Dynamic Wedge (EDW), it is necessary to adequately analyze and commission its dosimetric properties in comparison to common physical metal wedge (MTW). This study was implemented with the essential measurements of parameters for clinical application, such as percentage depth dose, peripheral dose, surface dose, effective wedge factor, and wedge profile. In addition, through the comparison study of EDW with open and MTW, the analysis was performed to characterize the EDW. We also compared EDW dose profiles of measured values using chamber array 24 (CA24) with calculated values using radiation treatment planning system. PDDs of EDW showed good agreements between $0.2\~0.5\%$ of open beam, but $2\%$ differences with MTW. In the result of the measurements of peripheral dose, it was shown that MTW was about $1\%$ higher than open field and EDW. The surface doses of $60^{\circ}$ MTW showed 10% lower than the others. We found that effective wedge factor of EDW had linear relationships according to Y jaw sizes and was independent of X jaw sizes and was independent of X jaw sizes and asymmetric Y jaw opening. In comparison with measured values and calculate values from Golden-STT based radiation treatment planning system (RTP system), it showed very good agreement within difference of $1\%$. It could be concluded that EDW is a very reliable and useful tool as a beam modification substitute for conventional MTW.

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Dosimetric Characteristics of Dynamic Wedge Technique (Dynamic Wedge의 조직내 방사선량 분포의 특성)

  • Oh Young Taek;Keum Ki Chang;Chu Seong Sil;Kim Gwi Eon
    • Radiation Oncology Journal
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    • v.14 no.4
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    • pp.323-332
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    • 1996
  • Purpose : The wedge filter is the most commonly used beam modifying device during radiation therapy Recently dynamic wedge technique is available through the computer controlled asymmetric collimator, independent jaw. But dosimetric characteristics of dynamic wedge technique is not well known. Therefore we evaluate dosimetric characteristics of dynamic wedge compared to conventional fixed wedge. Materials and Methods : We evaluated dosimetric characteristics of dynamic wedge and fixed wedge by ion chamber, film dosimetry and TLD in phantoms such as water, polystyrene and average breast phantom. Six MV x-ray was used in $15{\times}15cm$ field with 15,30 and 45 degree wedge of dynamic/liked wedge system, Dosimeric characteristics are interpreted by Wellhofer Dosimetrie system WP700/WP700i and contralateral breast dose (CBD) with tangential technique was confirmed by TLD. Results : 1) Percent depth dose through the dynamic wedge technique in tissue equivalent phantom was similar to open field irradiation and there was no beam hardening effect compared to fixed wedge technique. 2) Isodose line composing wedge angle of dynamic wedge is more straight than hard wedge. And dynamic wedge technique was able to make any wedge angle on any depth and field size. 3) The contralateral breast dose in primary breast irradiation was reduced by dynamic wedge technique compared to fixed wedge. When the dynamic wedge technique was applied, the scatter dose was similar to that of open field irradiation. Conclusion : The dynamic wedge technique was superior to fixed wedge technique in dosimetric characteristics and may be more useful in the future.

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Load analysis of Wedge type Rail Clamp (쐐기형 Rail Clamp의 하중분석)

  • Han, Geun-Jo;Ahn, Chan-Woo;Kim, Tae-Hyong;Shim, Jae-Joon;Han, Dong-Seop;Lee, Ho
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.1-6
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    • 2003
  • In this paper, we design a wedge type rail clamp which can protect container crane from wind with constant clamping force regardless of the operating period. When we design wedge type rail clamp. it is important to determine the angle of wedge and analyze a contact condition of roller and wedge so that we might develop a rail clamp with variable capacity. Therefore, this paper suggest a process to decide wedge angles within feasible range which could be obtained using load analysis and FEA of wedge type rail clamp.

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Numerical study of mono-strand anchorage mechanism under service load

  • Marceau, D.;Fafard, M.;Bastien, J.
    • Structural Engineering and Mechanics
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    • v.18 no.4
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    • pp.475-491
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    • 2004
  • Anchorage devices play an important role in post-tensioned bridge structures since they must sustain heavy loads in order to permit the transfer of the prestressing force to the structure. In external prestressing, the situation is even more critical since the anchorage mechanisms, with the deviators, are the only links between the structure and the tendons throughout the service life of the structure. The behaviour of anchorage devise may be studied by using the finite element method. To do so, each component of the anchorage must be adequately represented in order to approximate the anchor mechanism as accurately as possible. In particular, the modelling of the jaw/tendon device may be carried out using the real geometry of these two components with an appropriate constitutive contact law or by replacing these components by a single equivalent. This paper presents the numerical study of a mono-strand anchorage device. The results of a comparison between two different representations of the jaw/tendon device, either as two distinct components or as a single equivalent, will be examined. In the double-component setup, the influence of the wedge configuration composing the jaw, and the influence of lubrication of the anchor, will be assessed.

The Head Scatter Factor For Quasi - small Field Sizes (준소조사면에서의 산란인자)

  • 이상공;김진기;김정홍;김부길;권형철;김정수
    • Progress in Medical Physics
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    • v.6 no.2
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    • pp.13-19
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    • 1995
  • The behavior of the correction factor associated with the collimator opening(head-scatter factor) were investigated for the 6MV x-ray beams of medical linear accelerator. The primary photon fluence was measured in air quasi-small fied size. Consideration in this study was given to the effect of head scatter factor with quasi-small fied size, the upper and lower collimator jaw scatter collection factors of quasi-small field (4-10cm) were measured with ion chamber. In general, the wedge factors which are used clinical practics are ignored of dependency on field sizes and depth. In wedge factors for each wedge filter were measured at various depth by using 6MV X-ray. In this present we inverstigated systematically the depth and field sizes dependency to determine the absorbed dose more accurately. Head scatter(upper-lower collimator jaw)appears to be (1) a small effect, less than 5% over the range of clinical field sizes (2) generated primarily at the flattening filter and therefored influenced most by the upper collimator setting.

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