• Title/Summary/Keyword: Screw joint

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Repair of Closed Bilateral Mandibular Fractures Using Bone Plate and Screw in Dogs (개에서 골판을 이용한 비개방성 양측성 하악골절의 수복)

  • 정순욱;한현정;김지선;김준영;정만복
    • Journal of Veterinary Clinics
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    • v.20 no.1
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    • pp.138-141
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    • 2003
  • First case, a one-year-old female Shih Tzu weighing 3 kg with closed transverse fractures of bilateral mandibular body between 2nd and 3rd premolar teeth were treated surgically with bone plates and screws, and cranial luxation of temporomandibular joints were reduced to closed method. Second case, a 8.4 years old male Yorkshire terrier weighing 2.6 kg with closed transverse/oblique fractures of bilateral mandibular body between premolar and molar teeth were treated surgically with bone plates and screws. Radiographic examination revealed that the fractures in two cases fixed well and temporomandibular joint was stabilized. One month after operation, jaw activity was excellent and malocclusion wasn't observed.

Development of a Biped Walking Robot Actuated by a Closed-Chain Mechanism

  • Choi, Hyeung-Sik;Oh, Jung-Min;Baek, Chang-Yul;Chung, Kyung-Sik
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.209-214
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    • 2003
  • We developed a new type of human-sized BWR (biped walking robot), named KUBIR1 which is driven by the closed-chain type of actuator. A new type of the closed-chain actuator for the robot is developed, which is composed of the four-bar-link mechanism driven by the ball screw which has high strength and high gear ratio. Each leg of the robot is composed of 6 D.O.F joints. For front walking, three pitch joints and one roll joint at the ankle. In addition to this, one yaw joint for direction change, and another roll joint for balancing the body are attached. Also, the robot has two D.O.F joints of each hand and three D.O.F. for eye motion. There are three actuating motors for stereo cameras for eyes. In all, a 18 degree-of-freedom robot was developed. KUBIR1 was designed to walk autonomously by adapting small 90W DC motors as the robot actuators and batteries and controllers are on-boarded. The whole weight for Kubir1 is over 90Kg, and height is 167Cm. In the paper, the performance test of KUBIR1 will be shown.

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Simplified model to study the dynamic behaviour of a bolted joint and its self loosening

  • Ksentini, Olfa;Combes, Bertrand;Abbes, Mohamed Slim;Daidie, Alain;Haddar, Mohamed
    • Structural Engineering and Mechanics
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    • v.55 no.3
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    • pp.639-654
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    • 2015
  • Bolted joints are essential elements of mechanical structures and metal constructions. Although their static behaviour is fairly well known, their dynamic behaviour due to shocks and vibrations has been less studied, because of the large size of the finite element models needed for a detailed simulation. This work presents four different simplified models suitable for studying the dynamic behaviour of an elementary bolted joint. Three of them include contact elements to allow sliding of the screw head and the nut on the assembled parts, and the last one allows rotation between screw and nut. A penalty approach based on the Coulomb friction model is used to model contact. The results show that these models effectively represent the dynamic behaviour, with different accuracy depending on the model details. The last model simulates the self loosening of a bolt subjected to transversal vibrations.

Management of open bite that developed during treatment for internal derangement and osteoarthritis of the temporomandibular joint

  • Arai, Chihiro;Choi, Jae Won;Nakaoka, Kazutoshi;Hamada, Yoshiki;Nakamura, Yoshiki
    • The korean journal of orthodontics
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    • v.45 no.3
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    • pp.136-145
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    • 2015
  • This case report describes the orthodontic treatment performed for open bite caused by internal derangement (ID) and osteoarthritis (OA) of the temporomandibular joint (TMJ). A Japanese woman, aged 31 years and 11 months, referred to our department by an oral surgeon had an open bite with clockwise rotation of the mandible and degeneration of the condyle. The overbite was corrected through intrusion of the maxillary and mandibular molars using mini-screw implants to induce counterclockwise rotation of the mandible. Then, the mandibular second premolars were extracted and comprehensive orthodontic treatment was performed to establish a Class I molar relationship with distalization of the maxillary arch and to eliminate anterior crowding. Following treatment, her facial profile improved and a functional and stable occlusion was achieved without recurrence of the TMJ symptoms. These results suggest that orthodontic intrusion of the molars is one of the safer and less stressful alternatives for the management of open bite due to degeneration of the condyles caused by ID and OA of TMJ.

A Study on Structural Safety Analysis of Hub Space (허브스페이스의 구조적 안전성 해석에 대한 연구)

  • Han, Moonsik;Cho, Jaeung
    • Transactions of the Korean Society of Automotive Engineers
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    • v.23 no.3
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    • pp.352-359
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    • 2015
  • This study investigates the analysis result of structure and fatigue due to the models of the hub space with bolt joint at wheel and the existence or nonexistence of hub ring as the part of suspension system of vehicle. As the static analysis result, the structural vulnerability can be found at hub bolt and the center of wheel at three models. Model 2 and 3 have nearly same deformation and model 1 can be endured at the least load among three models. As the fatigue analysis result, fatigue lives of three models are same at the severest load of SAE bracket history. As many screw threads of weak bolts are jointed in case of model 1, model 1 is shown to be the weakest at fatigue damage among three models. By the result of this study, model 1 with bolt joint becomes most weakest among three models. As model 2 with no hub ring and model 3 with hub ring have the nearly same states of analysis results, hub ring is shown to have no influence on the safety of automotive driving.

Shear Performance Evaluation at the Interface Between CLT and Concrete (구조용 집성판(CLT)-콘크리트 경계면의 전단성능 평가)

  • Park, Keum-Sung
    • Journal of Korean Association for Spatial Structures
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    • v.21 no.3
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    • pp.35-42
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    • 2021
  • An experimental study was carried out to evaluate the shear performance at the interface composed of structural laminates and concrete. The main variables are the number of CLT layers and the shape of the shear connector. The number of CLT layers consisted of 3 and 5 layers. A total of 6 test specimens for shear performance evaluation were prepared in the form of a shear connector, a direct screw type and a vertically embedded type. As a result of the experiment, similar behavior was shown in all specimens, regardless of the number of layers, including direct screw type (SC series) and vertically embedded type (VE series). The behavior at the joint surface was damaged due to the occurrence of initial shear cracks, expansion of shear groove cracks, and splaying at the interface after the maximum load.After the maximum load, the shear strength decreased gradually due to the effect of the shear connector. It can be seen that the shear strength of all specimens is determined by shear and compression stress failure of concrete at the interface of the notch joint.

Open Reduction of Proximal Interphalangeal Fracture-Dislocation through a Midlateral Incision Using Absorbable Suture Materials

  • Lee, Jae Jun;Park, Hyoung Joon;Choi, Hyun Gon;Shin, Dong Hyeok;Uhm, Ki Il
    • Archives of Plastic Surgery
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    • v.40 no.4
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    • pp.397-402
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    • 2013
  • Background Fracture-dislocation of the proximal interphalangeal (PIP) joint is a relatively common injury. Various treatments for fracture-dislocation of the PIP joint have been reported. In the present study, we performed open reduction through a midlateral incision using absorbable sutures to reduce the small bone fragments and performed volar plate repair. Methods We treated nine patients with fracture-dislocation of the PIP joint with small fractured bone fragments too small for pinning or screw fixation. Patients with volar plate injury were treated with open reduction and volar plate repair at the periosteum of the middle phalangeal bone base by the modified Kessler method using absorbable sutures. All patients were placed in a dorsal aluminum extension block splint, which maintained the PIP joint in approximately 30 degrees of flexion to avoid excessive tension on the sutured volar plate. Results At a mean final follow-up of postoperative 9 months, all patients were evaluated radiographically and had adequate alignment of the PIP joint and reduction of the displaced bone fragments. Range of motion was improved and there were no complications. Conclusions This technique is an excellent alternative to the current method of treating patients with fracture-dislocations that include small fragments that are too small for pinning or screw fixation. It is a less invasive surgical method and enables stable reduction and early exercise without noticeable complications.

Comparative Analysis of Three Different Cervical Lateral Mass Screw Fixation Techniques by Complications and Bicortical Purchase : Cadaveric Study

  • Baek, Jin-Wook;Park, Dong-Mook;Kim, Dae-Hyun
    • Journal of Korean Neurosurgical Society
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    • v.48 no.3
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    • pp.193-198
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    • 2010
  • Objective : The purpose of this study is to compare the incidence of possible complications of cervical lateral screw fixation and the achievements of bicortical purchase using the Roy-Camille, Magerl and the modified methods. Methods : Six fresh-frozen cervical spine segments were harvested. The Roy-Camille technique was applied to C3 and C4, and the Magerl technique was applied to C5, C6, and C7 of one side of each cadaver. The modified technique was applied to the other side of each cadaver. The nerve root injury, violation of the facet joint, vertebral artery injury, and the bicortication were examined at each screwing level. Results : No vertebral artery injury was observed in any of the three methods. One nerve root injury was observed in each cervical spine segment using the Roy-Camille method (8.3%), the Magerl method (5.6%), and the modified method (3.3%). Facet joint injuries were observed in two cervical spinal segments using the Roy-Camille method (16.7%) and three with the Magerl method (16.7%), while five facet joint violations occurred when using the modified method (16.7%). Bicortical purchases were achieved on ten cervical spinal segments with the Roy-Camille method (83.3%) and Magerl method (55.6%), while twenty bicortical purchases were achieved in the modified method (66.7%). Conclusion : The advantages of the modified method are that it is performed by using given anatomical structures and that the complication rate is as low as those of other known methods. This modified method can be performed easily and safely without fluoroscopic assistance for the treatment of many cervical diseases.

Arthroscopic Pull-out Wire Fixation Using Cannulated Screw of Tibial Eminence Fractures (도관 나사못을 이용한 경골 과간 융기 골절의 관절경적 견인 봉합술)

  • Kim, Jong-Min;Kim, Hyung-Gyu;Park, Byeong-Mun;Song, Kyeong-Seop;Jung, Sung-Hoon;Noh, Haeng-Kee;Yoon, Jong-Joo
    • Journal of the Korean Arthroscopy Society
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    • v.13 no.3
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    • pp.254-258
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    • 2009
  • Tibial eminence fracture is caused by distortion, excessive flexion and extension, varus and valgus injury of the knee joint in the form of avulsion fracture. A failure over the exact anatomical reduction of fragment can lead to instability and limitation of joint motion. Recently, a variety of arthroscopic assisted reduction and fixation technique have been used. In the tibial eminence fracture, we created an arthroscopic pull-out wire fixation technique using a cannulated screw that is easy and more convenient than in the conventional technique. So we report this technique with a review of current literatures.

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Development of Humanoid Joint Module for Safe Human-Robot Interaction (인간과의 안전한 상호 작용을 고려한 휴머노이드 조인트 모듈 개발)

  • Oh, Yeon Taek
    • The Journal of Korea Robotics Society
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    • v.9 no.4
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    • pp.264-271
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    • 2014
  • In this study, we have developed the humanoid joint modules which provide a variety of service while living with people in the future home life. The most important requirement is ensuring the safety for humans of the robot system for collaboration with people and providing physical service in dynamic changing environment. Therefore we should construct the mechanism and control system that each joint of the robot should response sensitively and rapidly to fulfill that. In this study, we have analyzed the characteristic of the joint which based on the target constituting the humanoid motion, developed the optimal actuator system which can be controlled based on each joint characteristic, and developed the control system which can control an multi-joint system at a high speed. In particular, in the design of the joint, we have defined back-drivability at the safety perspective and developed an actuator unit to maximize. Therefore we establish a foundation element technology for future commercialization of intelligent service robots.