TWO:For disadvantages there is, on the other hand, a want of uniformity in fittings that prevents their interchange from one part of a line shaft to the othera matter of great importance, as such exchanges are frequently required. A line shaft, when constructed with pieces of varying diameter, is special machinery, adapted to some particular place or duty, and not a standard product that can be regularly manufactured as a staple article by machinists, and thus afforded at a low price. Pulleys, wheels, bearings, and couplings have all to be specially prepared; and in case of a change, or the extension of lines of shafting, cause annoyance, and frequently no little expense, which may all be avoided by having shafts of uniform diameter. The bearings, besides being of varied strength and proportions, are generally in such cases placed at irregular intervals, and the lengths of the different sections of the shaft are sometimes varied to suit their diameter. With line shafts of uniform diameter, everything pertaining to the shaftsuch as hangers, couplings, pulleys, and bearingsis interchangeable; the pulleys, wheels, bearings, or hangers can be placed at pleasure, or changed from one part of the shaft to another, or from [47] one part of the works to another, as occasion may require. The first cost of a line of shafting of uniform diameter, strong enough for a particular duty, is generally less than that of a shaft consisting of sections varying in size. This may at first seem strange, but a computation of the number of supports required, with the expense of special fitting, will in nearly all cases show a saving.
日本化学機械製造は、国内外に豊富な実績を持つプラントエンジニアリングとものづくりのプロフェッショナル集団です。
設計?製造?建設?メンテナンスまで自社一貫で担い、
顧客企業様の課題を解決するベストパートナーであるために日々前進し続けています。
オンリーワンの技術を武器に、私たちと一緒にあらゆる分野のプラントエンジニアリングに挑戦してみませんか。
- THREE:Presuming an engineering establishment to consist of one-storey buildings, and the main operations to be conducted on the ground level, the only vertical lifting to be performed will be in the erecting room, where the parts of machines are assembled. This room should be reached in every part by over-head travelling cranes, that cannot only be used in turning, moving, and placing the work, but in loading it upon cars or waggons. One result of the employment of over-head travelling cranes, often overlooked, is a saving of floor-room; in ordinary fitting, from one-third more to twice the number of workmen will find room in an erecting shop if a travelling-crane is employed, the difference being that, in moving pieces they may pass over the top of other pieces instead of requiring long open passages on the floor. So marked is this saving of room effected by over-head cranes, that in England, where they are generally employed, handling is not only less expensive and quicker, but the area of erecting floors is usually one-half as much as in America, where travelling-cranes are not employed.
- THREE:III.CHAPTER VI. ON THE NATURE AND OBJECTS OF MACHINERY.
TWO:In constructing patterns where it is optional whether to employ cores or not, and in preparing drawings for castings which may have either a ribbed or a cored section, it is nearly always best to employ cores. The usual estimate of the difference between the cost of moulding rib and cored sections, as well as of skeleton and cored patterns, is wrong. The expense of cores is often balanced by the advantage of having an 'open mould,' that is accessible for repairs or facing, and by the greater durability and convenience of the solid patterns. Taking, for example, a column, or box frame for machinery, that might be made either with a rib or a cored section, it would at first thought seem that patterns for a cored casting would cost much more by reason of the core-boxes; but it must be remembered that in most patterns labour is the principal expense, and what is lost in the extra lumber required for a core-box or in making a solid pattern is in many cases more than represented in the greater amount of labour required to construct a rib pattern.
TWO:With a white oblong sheet of paper in his pocket with the signature of the chief magistrate at Bow Street, Prout went down jauntily to call upon Lawrence. The latter looked at him smilingly.
担当者：総務課 西田佳司
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TWO:That something had been cast overboard, tied to the float, was obvious to Larry, Dick and Sandy."After this infernal rumble, deadly silence followed, interrupted only by the groans of the wounded. The German artillery ceased to fire, and from all sides their infantry came rushing on, their faces expressing the terror caused by such great calamities. They were no longer soldiers longing to destroy, but human beings hurrying to go to the assistance of other human beings.