【正文】 981 patent discloses a conveyor construction including a frame and a tensioning section including spaced side members mounted for longitudinal movement relative to the frame. The tensioning section includes a spindle about which a conveyor belt is trained, and movement of the tensioning section functions to control the tension of the belt. A drive and locking arrangement for imparting movement to the tensioning section and for selectively locking the tensioning section in position includes a pair of pinion carriers or retainer blocks mounted one to each side of the frame, with a drive pinion being rotatably supported by the retainer blocks. Each side member includes integrally formed gear teeth engageable with opposite ends of the drive pinion, and a drive pinion actuator is engaged with one side of the frame for imparting rotation to the drive pinion to extend and retract the tensioning section. A locking arrangement is interconnected with the opposite end of the drive pinion, and functions to selectively frictionally engage the drive pinion with one of the retainer blocks to prevent rotation of the drive pinion and to thereby maintain the tensioning section in a desired position relative to the frame.This construction is generally satisfactory, but can present problems upon the imposition of a sudden or random force applied to the spindle once the tensioning section has been locked into a particular position so as to set a desired tension for the moving belt. Such a force may be caused by a collision or impact of the spindle with another piece of equipment or with a structural member, such as a wall. If this impact force has enough intensity, it can overe the frictional locking force of the locking arrangement, such as by shearing or stripping the locking ponents, resulting in undesirable, retractable movement of the tensioning section which will alter the belt tension and negatively affect the performance of the conveyor. In some designs, the impact force may act to drive the gear teeth on the moving side members against the drive pinion as its locked position is overe causing damage or destruction to the gear teeth on the drive pinion.It is desirable to provide a conveyor construction which rectifies the problems described above, and offers enhancements in the ponents, assembly, operation and maintenance of the tensioning section of the conveyor.SUMMARY OF THE INVENTIONIt is one object of the present invention to provide a conveyor construction in which involuntary, retractable movement of the tensioning section is limited so as to maintain a desired tension on the conveyor belt and preserve the integrity of the drive pinion structure.It is also an object of the present invention to provide a conveyor construction which relies upon wedging action between the ponents of the tensioning unit to prevent damage to the drive pinion structure when an undesirable force is inflicted upon the spindle.It is a further object of the present invention to provide a conveyor construction having an improved structure for engaging the drive pinion structure with the tensioning section.In accordance with one aspect of the invention, a conveyor construction includes a frame having a pair of side members, a belt and a tensioning section mounted for longitudinal extendable and retractable movement relative to the frame for establishing a desired tension on the belt. The tensioning section includes a spindle engaged with the belt and a pair of side plate structures connected to the spindle and located one adjacent each frame side member. A drive member is rotatably mounted relative to the frame and is drivingly engaged with the tensioning section for imparting longitudinal extendable and retractable movement relative to the frame upon rotation of the drive member. A locking device exerts a frictional locking force on the side plate structures relative to the frame side members for selectively fixing the position of the tensioning section relative to the frame. This aspect of the invention contemplates an improvement in the form of a restraining arrangement incorporated in the side plate structures for limiting the retractable movement of the tensioning section upon the imposition of a random force applied to the spindle and overing the frictional locking force of the locking device so as to substantially retain the desired tension on the belt and preserve operability of the drive member.Each of the side plate structures includes a first member which is selectively moveable or lockable relative to a fixed second member. The first member preferably includes a head plate extending longitudinally along an inside surface of one of the frame side members. The second member preferably includes a clamp plate extending longitudinally along an inside surface of the head plate. The head plate is integrally constructed of a forward portion, a mid portion and a rear portion. The spindle has opposed ends, each end being rotatably mounted to the head plate. The forward portion of the head plate includes a circular socket member connected to the mid portion by an angularly and inwardly offset segment. The socket member receives a spherical ball bearing assembly for enabling rotation of the spindle. The mid portion is formed with a first throughslot and includes a first pair of upper and lower angled surfaces. The rear portion is formed with a second throughslot and includes a set of teeth extending axially along a wall forming the second throughslot. The drive member has opposed ends provided with drive pinion ends rotatably mounted t。 ScottM. Hall, Sussex, WI(US)。這次畢業(yè)設(shè)計(jì)中要求的手工繪圖，也鍛煉了手工繪圖能力，為以后的繪圖工作奠定了良好的基礎(chǔ)。為以后成為一名合格的機(jī)械相關(guān)工作人員打下了良好的基礎(chǔ)。也明白了想象中的方案與實(shí)際情況有時(shí)會(huì)有很大差別的，各種機(jī)構(gòu)是否合理需要通過使用科學(xué)的方法來進(jìn)行計(jì)算驗(yàn)證。在這次設(shè)計(jì)中，我查閱了大量資料，使用了手頭各種資源，如網(wǎng)絡(luò)資源、圖書館系統(tǒng)、圖書館館藏書目、相關(guān)課本及筆記。但是，這種制動(dòng)器也有一些缺點(diǎn)，缺點(diǎn)有：制動(dòng)器摩擦材料面積較小，所受壓力較大，磨損嚴(yán)重，需經(jīng)常調(diào)整；由于礦井下粉塵的影響，對(duì)制動(dòng)效果有一定的影響。方案四級(jí)為本設(shè)計(jì)中所采用的盤閘式制動(dòng)系統(tǒng)。因此，這種方案也由于校核不合格而放棄。外殼通過防塵密封圈將裝有制動(dòng)蹄的環(huán)形空間密封起來，可以